JP6116383B2 - Absorbent articles - Google Patents

Description

  The present invention relates to an absorbent article.

  As an absorbent for an absorbent article provided between a liquid permeable layer and a liquid impermeable layer, an absorption holding layer comprising fluff pulp, a superabsorbent polymer, and a heat-fusible synthetic resin fiber, and an absorption holding layer There is known an absorber having a non-woven fabric layer made of a heat-sealable synthetic resin fiber, which is disposed on the surface sheet side of (Patent Document 1). In the absorber described in Patent Document 1, in order to prevent the absorber from being deformed during use of the absorbent article, the heat-fusible synthetic resin fibers included in the absorption holding layer are entangled or heat-sealed. The heat-fusible synthetic resin fibers contained in the absorption holding layer and the heat-fusible synthetic resin fibers contained in the nonwoven fabric layer are heat-fused.

  On the other hand, as a heat-adhesive conjugate fiber for airlaid nonwoven fabric, a modified polyolefin graft-polymerized with a vinyl monomer containing an unsaturated carboxylic acid or unsaturated carboxylic acid anhydride is used as a sheath component, and a resin having a higher melting point than the modified polyolefin is used as a core. A core-sheath type composite fiber as a component is known (Patent Documents 2 and 3).

Japanese Patent No. 3916852 Japanese Patent No. 4221849 JP 2004-270041 A

  In the absorber described in Patent Document 1, in order to increase the interfacial peel strength between the absorption holding layer and the nonwoven fabric layer, increasing the amount of the heat-fusible synthetic resin fiber contained in the absorption holding layer or the nonwoven fabric layer, Due to the hydrophobicity of the heat-fusible synthetic resin fiber, the liquid absorbency of the absorber is lowered.

  On the other hand, the core-sheath type composite fibers described in Patent Documents 2 and 3 are known to have good adhesiveness with cellulosic fibers, but can be used as components of liquid-impermeable layers. It was not known.

  Therefore, the present invention provides an absorbent material layer by using a thermoplastic resin containing an unsaturated carboxylic acid, an unsaturated carboxylic acid anhydride or a mixture thereof as a monomer component as a component of the liquid-impermeable layer. An absorptive material layer and a liquid impermeable layer that may occur in a use environment (dry state and wet state) while preventing a decrease in liquid absorbency due to the hydrophobicity of the thermoplastic resin fiber contained It aims at providing the absorbent article which can prevent peeling.

  In order to solve the above problems, the present invention provides a liquid permeable layer, a liquid impermeable layer, an absorbent material layer provided between the liquid permeable layer and the liquid impermeable layer, An absorbent article comprising one joint, wherein the liquid-impermeable layer contains a thermoplastic resin containing an unsaturated carboxylic acid, an unsaturated carboxylic acid anhydride or a mixture thereof as a monomer component, and the absorption Provided is an absorbent article in which an absorbent material layer contains cellulosic water-absorbing fibers and the first joint joins the liquid-impermeable layer and the absorbent material layer.

  According to the present invention, as a component of the liquid-impermeable layer, a thermoplastic resin containing an unsaturated carboxylic acid, an unsaturated carboxylic acid anhydride, or a mixture thereof as a monomer component is used as an absorbent material layer. Peeling between the absorbent material layer and the liquid-impermeable layer that may occur in the environment of use (especially in a wet state) while preventing a decrease in liquid absorbency due to the hydrophobicity of the contained thermoplastic resin fibers An absorbent article that can be prevented is provided.

FIG. 1 is a partially broken plan view (front side) of a sanitary napkin according to a first embodiment of the present invention. FIG. 2 is a partially broken plan view (back side) of the sanitary napkin according to the first embodiment of the present invention. FIG. 3 is a cross-sectional view taken along line AA in FIGS. 1 and 2. FIG. 4 is a cross-sectional view of a sanitary napkin according to a second embodiment of the present invention. FIG. 5 is a diagram illustrating a manufacturing process of a sanitary napkin according to an embodiment of the present invention. FIGS. 6A and 6B are diagrams showing an SJ belt press used in the examples.

Hereinafter, the absorbent article of the present invention will be described.
The absorbent article of the present invention includes a liquid-permeable layer, a liquid-impermeable layer, the liquid-permeable layer, an absorbent material layer provided between the liquid-impermeable layer, and a first joint portion. The liquid-impermeable layer contains a thermoplastic resin containing an unsaturated carboxylic acid, an unsaturated carboxylic acid anhydride or a mixture thereof as a monomer component, and the absorbent material layer The absorbent article contains cellulosic water-absorbing fibers, and the first joint joins the liquid-impermeable layer and the absorbent material layer (Aspect 1).

  In aspect 1, as long as the 1st junction part joins a liquid impermeable layer and an absorptive material layer, you may join other 1 or 2 or more layers. A 1st junction part is formed by heat-processing a liquid-impermeable layer and an absorptive material layer. Examples of the heat treatment include a heat embossing process and a heating fluid injection process, and examples of the heating fluid injection process include a high-pressure steam injection process and a heated air injection process. When the liquid-impermeable layer and the absorbent material layer are heat-treated, the thermoplastic resin contained in the liquid-impermeable layer and the cellulosic water-absorbing fibers contained in the absorbent material layer are thermally fused, The impermeable layer and the absorbent material layer are integrated. At this time, other layers may be integrated together with the liquid-impermeable layer and the absorbent material layer. For example, when one or two or more intermediate layers exist between the liquid-impermeable layer and the absorbent material layer, the intermediate layer may be integrated together with the liquid-impermeable layer and the absorbent material layer.

  In the aspect 1, the first joint portion can prevent the liquid-impermeable layer and the absorbent material layer from being peeled off which may occur in the use environment (particularly in a wet state). In particular, a thermoplastic resin containing an unsaturated carboxylic acid, an unsaturated carboxylic acid anhydride, or a mixture thereof (preferably maleic acid or a derivative thereof, maleic anhydride or a derivative thereof, or a mixture thereof) as a monomer component, Bonding strength with cellulosic water-absorbing fibers by fusion is high, so the amount of thermoplastic resin fibers contained in the absorbent material layer can be reduced, even if the absorbent material layer does not contain thermoplastic resin fibers Even if it does, it can improve the joint strength of the 1st joined part. Therefore, according to the aspect 1, the liquid that may be generated in the use environment (particularly in a wet state) while preventing the liquid absorbency from being lowered due to the hydrophobicity of the thermoplastic resin fiber contained in the absorbent material layer. Peeling between the impermeable layer and the absorbent material layer can be prevented. Thereby, the twist and the shift | offset | difference at the time of use of an absorbent article can be prevented.

  In aspect 1, it is preferable that the said absorptive material layer contains the thermoplastic resin fiber which contains unsaturated carboxylic acid, unsaturated carboxylic acid anhydride, or mixtures thereof as a monomer component (aspect 2). In the aspect 2, the modified polyolefin in which the thermoplastic resin fiber contained in the absorbent material layer is graft-polymerized with a vinyl monomer containing an unsaturated carboxylic acid, an unsaturated carboxylic acid anhydride, or a mixture thereof, or the modified polyolefin A core-sheath type composite fiber having a sheath polymer as a mixed polymer of the resin and other resin and a core component having a higher melting point than the modified polyolefin is preferable (Aspect 3). According to the aspect 2 or 3, the bonding strength between the liquid impermeable layer and the absorbent material layer by the first bonding portion is improved, and the liquid impermeable layer that may occur in a use environment (particularly in a wet state) Separation from the absorbent material layer can be effectively prevented. In Embodiment 2 or 3, the unsaturated carboxylic acid, the unsaturated carboxylic acid anhydride, or a mixture thereof is preferably maleic acid or a derivative thereof, maleic anhydride or a derivative thereof, or a mixture thereof.

  In Aspect 2 or 3, it is preferable that the fibers contained in the absorbent material layer are bonded to each other (Aspect 4). In the aspect 4, since the advanced network is formed between the fibers by bonding the constituent fibers of the absorbent material layer, the strength of the absorbent material layer (particularly the strength when wet) is improved. Therefore, according to the aspect 4, peeling between the liquid-impermeable layer and the absorbent material layer that may be caused by a decrease in strength of the absorbent material layer can be prevented. Examples of the bonding mode include, for example, adhesion between thermoplastic resin fibers by thermal fusion of thermoplastic resin fibers or between thermoplastic resin fibers and cellulose water-absorbing fibers, between thermoplastic resin fibers by hydrogen bonding, and cellulose-based water absorption. Adhesion between fibers or between thermoplastic resin fibers and cellulose-based water-absorbing fibers can be mentioned. When the absorbent material layer includes other fibers, the thermoplastic resin fibers and / or cellulosic water-absorbing fibers may be bonded to the other fibers. Note that the hydrogen bond is cut by the liquid absorbed in the absorbent material layer.

  In any one of the aspects 2 to 4, the mass ratio of the thermoplastic resin fibers to the cellulosic water-absorbing fibers in the absorbent material layer is preferably 1/9 to 5/5 (aspect 5). . In the aspect 5, the lower limit of 1/9 is defined from the viewpoint of the degree of network formation between fibers, and when the mass ratio of the thermoplastic resin fiber to the cellulosic water absorbent fiber is 1/9 or more, Since a high-level network is formed between them, sufficient strength (particularly wet strength) can be imparted to the absorbent material layer, which may cause liquid damage that may occur due to a decrease in strength of the absorbent material layer. Peeling between the permeable layer and the absorbent material layer can be prevented. On the other hand, the upper limit of 5/5 is specified from the viewpoint of the liquid absorbability of the absorbent material layer, and when the mass ratio of the thermoplastic resin fiber to the cellulosic water-absorbing fiber is 5/5 or less, the absorption is performed. The liquid material layer can be provided with sufficient liquid absorbency.

In Aspect 5, the density of the absorbent material layer is preferably 0.06 to 0.14 g / cm ³ (Aspect 6). When the mass ratio of the thermoplastic resin fiber to the cellulosic water-absorbing fiber in the absorbent material layer is 1/9 to 5/5, the density of the absorbent material layer is 0.06 to 0.14 g / cm ^3. Sufficient liquid absorbency can be imparted to the absorbent material layer.

  In aspect 6, it is preferable that the absorbent material layer is obtained by injecting high-pressure steam into the mixed material containing the cellulose-based water-absorbing fiber and the thermoplastic resin fiber to increase the density. (Aspect 7). In the aspect 7, the density of the absorbent material layer is adjusted to a desired range by densification using high-pressure steam injection. When high-pressure water vapor is injected into the mixed material, the water vapor penetrates into the mixed material, and hydrogen bonds (for example, between the cellulose-based water absorbent fibers, between the thermoplastic resin fibers, between the cellulose-based water absorbent fibers and the thermoplastic resin fibers). Etc.), and the mixed material is softened. Therefore, the pressure required for densification decreases, and the density of the softened mixed material can be easily adjusted. When the density-adjusted mixed material is dried and hydrogen bonds are reformed, elastic recovery (increase in volume) of the fibers is suppressed, and the density of the absorbent material layer is maintained within a certain range. Aspect 7 is particularly suitable when an unsaturated carboxylic acid anhydride (for example, maleic anhydride or a derivative thereof) is contained as a monomer component in the thermoplastic resin fiber. When the unsaturated carboxylic acid anhydride group contained in the thermoplastic resin fiber reacts with water vapor to form an unsaturated carboxylic acid group, the number of oxygen atoms capable of forming hydrogen bonds increases. Elastic recovery (increase in bulk) is effectively suppressed.

In Aspect 6 or 7, it is preferable that the basis weight of the absorbent material layer is 40 to 900 g / m ² (Aspect 8). If the basis weight is less than 40 g / m ^2, the fibers of the thermoplastic resin fibers is insufficient, (strength, especially when wet) strength of the absorbent material layer while may be decreased, the 900 g / m ² If it exceeds, the fiber amount of the thermoplastic resin fiber becomes excessive, and the rigidity of the absorbent material layer may be too high.

  In any one of the aspects 1 to 8, it is preferable that the difference between the maximum tensile strength when dried and the maximum tensile strength when wet in the absorbent material layer is 1 to 5 N / 25 mm (embodiment 9). According to the ninth aspect, the absorbent material layer has sufficient strength to maintain an integrated structure with the liquid-permeable layer through before and after liquid absorption (that is, not only when dry but also when wet).

  In any one of the aspects 1 to 9, the liquid-permeable layer is a resin sheet, and the interfacial peel strength when the resin sheet and the absorbent material layer are dried is 0.76 to 10.91 N / 25 mm. It is preferable that the interfacial peel strength of the resin sheet and the absorbent material layer is 0.32 to 10.57 N / 25 mm (Aspect 10).

  In any one of the aspects 1 to 10, the absorbent article has a first coating layer that covers the liquid-impermeable layer side surface of the absorbent material layer, and the first coating layer includes: It is preferable that cellulosic water-absorbing fibers are contained, and the first joining portion joins the liquid-impermeable layer, the first coating layer, and the absorbent material layer (Aspect 11). In the aspect 11, the first joint portion is formed by heat-treating the liquid-impermeable layer, the first coating layer, and the absorbent material layer. Examples of the heat treatment include a heat embossing process and a heating fluid injection process, and examples of the heating fluid injection process include a high-pressure steam injection process and a heated air injection process. When the liquid-impermeable layer, the first coating layer, and the absorbent material layer are heat-treated, the thermoplastic resin contained in the liquid-impermeable layer and the cellulose-based water absorption contained in the first coating layer and the absorbent material layer The heat-fusible fibers are heat-sealed, and the liquid-impermeable layer, the first coating layer, and the absorbent material layer are integrated. Therefore, in the aspect 11, peeling between the liquid-impermeable layer and the absorbent material layer that may occur in a use environment (particularly in a wet state) can be prevented. In particular, a thermoplastic resin containing an unsaturated carboxylic acid, an unsaturated carboxylic acid anhydride, or a mixture thereof as a monomer component has a high bonding strength with a cellulosic water-absorbing fiber by heat fusion, so that bonding by the first bonding portion is performed. The strength is improved, and peeling between the liquid-impermeable layer and the absorbent material layer that may occur in a use environment (particularly in a wet state) can be effectively prevented.

  In aspect 11, the interfacial peel strength when dried of the absorbent material layer and the first coating layer is 1.75 to 4.23 N / 25 mm, and the interfacial peel when wet of the absorbent material layer and the first coating layer The strength is preferably 1.05 to 2.63 N / 25 mm (Aspect 12).

  In the aspect 11 or 12, the liquid permeable layer contains a thermoplastic resin containing an unsaturated carboxylic acid, an unsaturated carboxylic acid anhydride, or a mixture thereof as a monomer component, and the first joint portion is the liquid impermeable layer. It is preferable to join the permeable layer, the first coating layer, the absorbent material layer, and the liquid permeable layer (Aspect 13). In the aspect 13, the first joint portion is formed by heat-treating the liquid impermeable layer, the first coating layer, the absorbent material layer, and the liquid permeable layer. Examples of the heat treatment include a heat embossing process and a heating fluid injection process, and examples of the heating fluid injection process include a high-pressure steam injection process and a heated air injection process. When the liquid-impermeable layer, the first coating layer, the absorbent material layer, and the liquid-permeable layer are heat-treated, the thermoplastic resin contained in the liquid-impermeable layer and the liquid-permeable layer, the first coating layer, and the absorption The cellulosic water-absorbing fibers contained in the absorbent material layer are thermally fused, and the liquid impermeable layer, the first coating layer, the absorbent material layer, and the liquid permeable layer are integrated. Therefore, in the aspect 13, it is possible to prevent peeling between the liquid impermeable layer and the absorbent material layer and peeling between the absorbent material layer and the liquid permeable layer, which may occur in a use environment (particularly in a wet state). it can. In particular, a thermoplastic resin containing an unsaturated carboxylic acid, an unsaturated carboxylic acid anhydride, or a mixture thereof as a monomer component has a high bonding strength with a cellulosic water-absorbing fiber by heat fusion, so that bonding by the first bonding portion is performed. Effectively prevents the separation between the liquid-impermeable layer and the absorbent material layer and the separation between the absorbent material layer and the liquid-permeable layer, which may increase in strength and may occur in the use environment (particularly in a wet state). be able to. In Embodiment 13, the unsaturated carboxylic acid, the unsaturated carboxylic acid anhydride, or a mixture thereof is preferably maleic acid or a derivative thereof, maleic anhydride or a derivative thereof, or a mixture thereof.

  In any one of the aspects 1 to 13, the liquid-permeable layer contains a thermoplastic resin containing an unsaturated carboxylic acid, an unsaturated carboxylic acid anhydride, or a mixture thereof as a monomer component, and the absorbent article However, it is preferable that a second joint is further provided, and the second joint joins the liquid-permeable layer and the absorbent material layer (Aspect 14). In aspect 14, as long as the 2nd junction part joins a liquid permeability layer and an absorptive material layer, you may join other 1 or 2 or more layers. The second joint portion is formed by heat-treating the liquid permeable layer and the absorbent material layer. Examples of the heat treatment include a heat embossing process and a heating fluid injection process, and examples of the heating fluid injection process include a high-pressure steam injection process and a heated air injection process. When the liquid permeable layer and the absorbent material layer are heat-treated, the thermoplastic resin contained in the liquid permeable layer and the cellulosic water-absorbing fibers contained in the absorbent material layer are heat-sealed, resulting in liquid permeability. The layer and the absorbent material layer are integrated. At this time, other layers may be integrated together with the liquid-permeable layer and the absorbent material layer. For example, when one or two or more intermediate layers exist between the liquid permeable layer and the absorbent material layer, the intermediate layer may be integrated together with the liquid permeable layer and the absorbent material layer. In the aspect 14, it is possible to prevent the liquid permeable layer and the absorbent material layer from peeling off in the use environment (particularly in a wet state) by the second joint portion. In particular, a thermoplastic resin containing an unsaturated carboxylic acid, an unsaturated carboxylic acid anhydride, or a mixture thereof as a monomer component has a high bonding strength with a cellulosic water-absorbing fiber by heat fusion. The strength is improved, and peeling between the liquid-permeable layer and the absorbent material layer that may occur in a use environment (particularly in a wet state) can be effectively prevented. Thereby, the liquid transferability from a liquid-permeable layer to an absorptive material layer can be smoothed. In Embodiment 14, the unsaturated carboxylic acid, the unsaturated carboxylic acid anhydride, or a mixture thereof is preferably maleic acid or a derivative thereof, maleic anhydride or a derivative thereof, or a mixture thereof.

  In Aspect 14, the liquid permeable layer is a nonwoven fabric sheet containing fibers of the thermoplastic resin, and the interfacial peel strength at the time of drying of the nonwoven fabric sheet and the absorbent material layer is 0.97 to 4.07 N / 25 mm. Yes, it is preferable that the interfacial peel strength when wet of the nonwoven fabric sheet and the absorbent material layer is 0.75 to 4.10 N / 25 mm (aspect 15).

  In Aspect 14, the liquid permeable layer is a resin sheet, and the interfacial peel strength during drying of the resin sheet and the absorbent material layer is 0.76 to 10.91 N / 25 mm, and the resin sheet and the absorbent It is preferable that the interfacial peel strength when the material layer is wet is 0.32 to 10.57 N / 25 mm (Aspect 16).

  In aspect 16, it is preferable that the through-hole penetrating the resin sheet is formed with an opening ratio of 5 to 70% (aspect 17). According to the aspect 17, the liquid transferability from the liquid permeable layer to the absorbent material layer can be smoothed by forming the porosity in the resin sheet.

  In any one of the aspects 11 to 13, the absorbent article has a second coating layer that covers the liquid-permeable layer side surface of the absorbent material layer, and the second coating layer is a cellulosic material. It is preferable that the water-absorbent fiber is contained, and the first joint joins the liquid-impermeable layer, the first coating layer, the absorbent material layer, the second coating layer, and the liquid-permeable layer. (Aspect 18). In the aspect 18, the first joint portion is formed by heat-treating the liquid impermeable layer, the first coating layer, the absorbent material layer, the second coating layer, and the liquid permeable layer. Examples of the heat treatment include a heat embossing process and a heating fluid injection process, and examples of the heating fluid injection process include a high-pressure steam injection process and a heated air injection process. When the liquid impermeable layer, the first coating layer, the absorbent material layer, the second coating layer and the liquid permeable layer are heat-treated together, a thermoplastic resin contained in the liquid impermeable layer and the liquid permeable layer, and The cellulosic water-absorbing fibers contained in the first coating layer, the absorbent material layer, and the second coating layer are heat-sealed to form a liquid-impermeable layer, the first coating layer, the absorbent material layer, and the second coating layer. And the liquid-permeable layer is integrated. Therefore, in aspect 18, it is possible to prevent peeling between the liquid-impermeable layer and the absorbent material layer and peeling between the absorbent material layer and the liquid-permeable layer that may occur in a use environment (particularly in a wet state). it can. In particular, a thermoplastic resin containing an unsaturated carboxylic acid, an unsaturated carboxylic acid anhydride, or a mixture thereof as a monomer component has a high bonding strength with a cellulosic water-absorbing fiber by heat fusion, so that bonding by the first bonding portion is performed. Effectively prevents the separation between the liquid-impermeable layer and the absorbent material layer and the separation between the absorbent material layer and the liquid-permeable layer, which may increase in strength and may occur in the use environment (particularly in a wet state). be able to.

  In Aspect 14, the absorbent article has a second coating layer that covers the liquid-permeable layer side surface of the absorbent material layer, the second coating layer contains cellulosic water-absorbing fibers, and It is preferable that a 2nd junction part joins the said liquid-permeable layer, the said 2nd coating layer, and the said absorptive material layer (aspect 19). In Aspect 19, the second bonding portion is formed by heat-treating the liquid permeable layer, the second coating layer, and the absorbent material layer. Examples of the heat treatment include a heat embossing process and a heating fluid injection process, and examples of the heating fluid injection process include a high-pressure steam injection process and a heated air injection process. When the liquid permeable layer, the second coating layer, and the absorbent material layer are heat-treated, the thermoplastic resin contained in the liquid permeable layer and the cellulose-based water absorbent fiber contained in the second coating layer and the absorbent material layer And the liquid-permeable layer, the second coating layer, and the absorbent material layer are integrated. Therefore, in the aspect 19, it is possible to prevent the liquid permeable layer and the absorbent material layer from being peeled off, which may occur in the use environment (particularly in a wet state). In particular, a thermoplastic resin containing an unsaturated carboxylic acid, an unsaturated carboxylic acid anhydride, or a mixture thereof as a monomer component has a high bonding strength with a cellulosic water-absorbing fiber by heat fusion. The strength is improved, and peeling between the liquid-permeable layer and the absorbent material layer that may occur in a use environment (particularly in a wet state) can be effectively prevented.

  In Aspect 18 or 19, when the absorbent material layer and the second coating layer are dried, the interfacial peel strength is 1.75 to 4.23 N / 25 mm, and the absorbent material layer and the second coating layer are wet. The interfacial peel strength is preferably 1.05 to 2.63 N / 25 mm (Aspect 20).

Hereinafter, an embodiment of the absorbent article of the present invention will be described based on the drawings, taking a sanitary napkin as an example.
<First Embodiment>
A sanitary napkin 1A according to the first embodiment will be described with reference to FIGS.
As shown in FIGS. 1 to 3, the sanitary napkin 1 </ b> A according to the first embodiment includes a liquid permeable layer 2, a liquid impermeable layer 3, a liquid permeable layer 2, and a liquid impermeable layer 3. An absorbent material layer 41 provided therebetween, a first coating layer 43 covering the surface of the absorbent material layer 41 on the liquid impermeable layer 3 side, and an absorbent material layer 41 on the liquid permeable layer 2 side. A second coating layer 42 covering the surface, an embossed portion 5A integrating the liquid permeable layer 2, the second coating layer 42 and the absorbent material layer 41, the liquid impermeable layer 3, the first coating layer 43 and And an embossed portion 5B for integrating the absorbent material layer 41. 1 and 2, the X-axis direction is the width direction of the sanitary napkin 1A, the Y-axis direction is the longitudinal direction of the sanitary napkin 1A, and the plane direction extending in the X-axis and Y-axis directions is the sanitary napkin. It corresponds to the plane direction of 1A.

  The sanitary napkin 1A is worn for the purpose of absorbing liquid excretion (particularly menstrual blood) excreted from the wearer. At this time, the liquid-permeable layer 2 is worn on the wearer's skin side, and the liquid-impermeable layer 3 is worn on the wearer's clothes (underwear) side. The liquid excretion excreted from the wearer passes through the liquid permeable layer 2, reaches the absorbent material layer 41 through the coating layer 42, and is absorbed and held by the absorbent material layer 41. Leakage of liquid excretion absorbed and held by the absorbent material layer 41 is prevented by the liquid impermeable layer 3.

  As shown in FIGS. 1 and 2, the liquid-permeable layer 2 and the liquid-impermeable layer 3 are joined at their longitudinal ends with seal portions 11a and 11b to form a main body portion 6 and in the width direction. These end portions are joined together by seal portions 12a and 12b to form substantially rectangular wing portions 7a and 7b extending from the main body portion 6 in the width direction.

  The shape of the main body 6 can be appropriately changed within a range suitable for a female body, underwear, and the like, and may be, for example, a substantially rectangular shape, a substantially oval shape, a substantially saddle shape, or the like. The total length in the longitudinal direction of the main body 6 is usually 100 to 500 mm, preferably 150 to 350 mm, and the total length in the width direction of the main body 6 is usually 30 to 200 mm, preferably 40 to 180 mm.

  Examples of the bonding mode by the seal portions 11a, 11b, 12a, and 12b include embossing, ultrasonic waves, and a hot-melt adhesive. In order to increase the bonding strength, two or more bonding modes may be combined (for example, embossing is performed after bonding with a hot-melt adhesive).

  As embossing, for example, the liquid-permeable layer 2 and the liquid-impermeable layer 3 are combined and passed between an embossing roll having a convex portion corresponding to an embossing pattern to be formed and a flat roll, and embossing is performed. Examples thereof include a method (a method called a so-called round seal). In this method, since each sheet is softened by heating the embossing roll and / or the flat roll, the seal portion tends to be clear. Examples of the emboss pattern include a lattice pattern, a staggered pattern, and a wavy pattern. It is preferable that the embossed pattern is intermittently elongated so that the sanitary napkin 1A is not easily bent at the boundary of the seal portion.

  As the hot melt adhesive, for example, styrene-ethylene-butadiene-styrene (SEBS), styrene-butadiene-styrene (SBS), styrene-isoprene-styrene (SIS) and the like, or linear Pressure-sensitive adhesives or heat-sensitive adhesives mainly composed of olefins such as low density polyethylene; water-soluble polymers (for example, polyvinyl alcohol, carboxymethyl cellulose, gelatin, etc.) or water-swellable polymers (for example, polyvinyl acetate, poly And water sensitive adhesives such as sodium acrylate). Examples of the method for applying the adhesive include spiral coating, coater coating, curtain coater coating, and summit gun coating.

  As shown in FIG. 3, adhesive portions 13 a and 13 b are provided on the clothing side of the liquid-impermeable layer 3 that forms the wing portions 7 a and 7 b, and the liquid-impermeable layer 3 that forms the main body portion 6. An adhesive portion 13c is provided on the clothing side. The adhesive portion 13c is affixed to the crotch portion of the underwear, the wing portions 7a and 7b are bent to the outer surface side of the underwear, and the adhesive portions 13a and 13b are affixed to the crotch portion of the underwear, whereby the sanitary napkin 1A Stablely fixed to underwear.

Examples of the adhesive contained in the adhesive portions 13a, 13b, and 13c include, for example, styrene-ethylene-butylene-styrene block copolymer, styrene-butylene polymer, styrene-butylene-styrene block copolymer, styrene-isobutylene- Styrene polymers such as styrene copolymers; tackifiers such as C5 petroleum resins, C9 petroleum resins, dicyclopentadiene petroleum resins, rosin petroleum resins, polyterpene resins, terpene phenol resins; tricresyl phosphate , phthalic acid Examples include monomer plasticizers such as dibutyl and dioctyl phthalate; polymer plasticizers such as vinyl polymer and polyester.

  The liquid permeable layer 2 is a sheet through which liquid excretion excreted from the wearer can permeate, and one surface of the liquid permeable layer 2 is a surface on which the wearer's skin comes into contact.

  Although the material which comprises the liquid-permeable layer 2 is not specifically limited, It is preferable that the liquid-permeable layer 2 contains a thermoplastic resin from the point which improves the joining strength by the embossed part 5A.

  The thermoplastic resin contained in the liquid permeable layer 2 is not particularly limited, and examples thereof include polyolefin, polyester, polyamide, and the like.

  Examples of the polyolefin include, for example, linear low density polyethylene (LLDPE), low density polyethylene (LDPE), medium density polyethylene (MDPE), high density polyethylene (HDPE), polypropylene, polybutylene, and copolymers based on these (for example, Ethylene-vinyl acetate copolymer (EVA), ethylene-ethyl acrylate copolymer (EEA), ethylene-acrylic acid copolymer (EAA), ionomer resin), and the like. Polyethylene, particularly HDPE, is preferred from the viewpoint that the softening point is relatively low at around 100 ° C., so that it is excellent in heat workability, and the rigidity is low and the touch is supple.

  Examples of polyesters include, for example, linear or branched carbon numbers up to 20 including polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT), polybutylene terephthalate (PBT), polylactic acid, and polyglycolic acid. Examples thereof include polyesters such as polyhydroxyalkanoic acid, copolymers based on these, and copolymerized polyesters obtained by copolymerizing alkylene terephthalate as a main component with a small amount of other components. PET is preferable from the viewpoint of being able to constitute fibers and nonwoven fabrics having high cushioning properties because of its elastic resilience, and from the economical viewpoint that it can be obtained industrially at low cost.

  Examples of the polyamide include 6-nylon and 6,6-nylon.

  The thermoplastic resin contained in the liquid permeable layer 2 is preferably a thermoplastic resin containing an unsaturated carboxylic acid, an unsaturated carboxylic acid anhydride, or a mixture thereof as a monomer component. The type is not particularly limited as long as it contains an unsaturated carboxylic acid, an unsaturated carboxylic acid anhydride or a mixture thereof as a monomer component, and can be appropriately selected from the viewpoints of strength, heat-fusibility and the like. .

  Examples of the unsaturated carboxylic acid or unsaturated carboxylic acid anhydride contained as a monomer component in the thermoplastic resin include maleic acid or a derivative thereof, maleic anhydride or a derivative thereof, fumaric acid or a derivative thereof, and an unsaturated derivative of malonic acid. And vinyl monomers such as unsaturated derivatives of succinic acid, and other vinyl monomers include general-purpose monomers having radical polymerizability, for example, styrenes such as styrene and α-methylstyrene; methyl (meth) acrylate And (meth) acrylic acid esters such as ethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, and dimethylaminoethyl (meth) acrylate. Examples of maleic acid derivatives or maleic anhydride derivatives include citraconic acid, citraconic anhydride, pyrocynconic anhydride, and the like, and examples of fumaric acid derivatives or malonic acid unsaturated derivatives include 3-butene- Examples include 1,1-dicarboxylic acid, benzylidenemalonic acid, isopropylidenemalonic acid, and the like. Examples of unsaturated derivatives of succinic acid include itaconic acid and itaconic anhydride.

  The unsaturated carboxylic acid, unsaturated carboxylic anhydride or mixture thereof contained as a monomer component in the thermoplastic resin is preferably maleic acid or a derivative thereof, maleic anhydride or a derivative thereof, or a mixture thereof. Thereby, the joining strength by the embossed part 5A is improved, and peeling between the liquid permeable layer 2 and the absorbent material layer 41 that may occur in the use environment (particularly in a wet state) can be effectively prevented.

  One embodiment of the liquid-permeable layer 2 is a nonwoven fabric sheet containing thermoplastic resin fibers. The thermoplastic resin fiber contained in the nonwoven fabric sheet is preferably a thermoplastic resin fiber containing an unsaturated carboxylic acid, an unsaturated carboxylic acid anhydride, or a mixture thereof as a monomer component. The thermoplastic resin fiber containing an unsaturated carboxylic acid, an unsaturated carboxylic acid anhydride or a mixture thereof as a monomer component is not particularly limited, and may be appropriately selected from the viewpoints of strength, hydrogen bondability, heat fusibility, and the like. You can choose.

  The thermoplastic resin fiber containing an unsaturated carboxylic acid anhydride or a mixture thereof as a monomer component is preferably an unsaturated carboxylic acid, an unsaturated carboxylic acid anhydride or a mixture thereof contained in the monomer component as maleic acid or a mixture thereof. A thermoplastic resin fiber that is a derivative, maleic anhydride or derivative thereof, or a mixture thereof, more preferably graft polymerized with a vinyl monomer containing an unsaturated carboxylic acid, an unsaturated carboxylic anhydride, or a mixture thereof. A core-sheath type composite fiber having a modified polyolefin or a mixed polymer of the modified polyolefin and another resin as a sheath component and a resin having a melting point higher than that of the modified polyolefin as a core component. Thereby, the joining strength by the embossed part 5A is improved, and peeling between the liquid permeable layer 2 and the absorbent material layer 41 that may occur in the use environment (particularly in a wet state) can be effectively prevented.

  As the backbone polymer of modified polyolefin, linear low density polyethylene (LLDPE), low density polyethylene (LDPE), medium density polyethylene (MDPE), high density polyethylene (HDPE), polypropylene, polybutylene, and copolymers based on these (For example, ethylene-vinyl acetate copolymer (EVA), ethylene-ethyl acrylate copolymer (EEA), ethylene-acrylic acid copolymer (EAA), ionomer resin, etc.).

  For example, graft polymerization of vinyl monomer to the trunk polymer uses a radical initiator, mixes unsaturated carboxylic acid or unsaturated carboxylic acid anhydride and vinyl monomer into polyolefin, and introduces side chains made of random copolymer. And a conventional method such as a method of sequentially polymerizing different monomers and introducing a side chain comprising a block copolymer.

  The sheath component may be a modified polyolefin alone or a mixed polymer of the modified polyolefin and another resin. The other resin is preferably a polyolefin, and more preferably the same type of polyolefin as the backbone polymer of the modified polyolefin. For example, when the trunk polymer is polyethylene, the other resin is also preferably polyethylene.

  The resin used as the core component is not particularly limited as long as the resin has a higher melting point than the modified polyolefin. For example, polyamides such as 6-nylon and 6,6-nylon; polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT), polybutylene terephthalate (PBT), polylactic acid, polyglycolic acid and other linear or branched polyesters having up to 20 carbon atoms such as polyhydroxyalkanoic acid and copolymers mainly composed of these Or a copolymerized polyester obtained by copolymerizing a small amount of other components with alkylene terephthalate as a main component. PET is preferable from the viewpoint of having high resilience and high cushioning properties, and from the economical viewpoint of being industrially inexpensive.

  Spinning is possible if the composite ratio of the sheath component to the core component is in the range of 10/90 to 90/10, but is preferably 30/70 to 70/30. If the sheath component ratio decreases too much, the heat-fusibility decreases, and if it increases too much, the spinnability decreases.

  Addition of antioxidants, light stabilizers, UV absorbers, neutralizers, nucleating agents, epoxy stabilizers, lubricants, antibacterial agents, flame retardants, antistatic agents, pigments, plasticizers, etc. to thermoplastic resin fibers You may add an agent as needed. The thermoplastic resin fiber is preferably hydrophilized with a surfactant, a hydrophilic agent or the like.

  Although the fiber length of a thermoplastic resin fiber is not specifically limited, When mixing with a pulp by an airlaid system, Preferably it is 3-70 mm, More preferably, it is 5-20 mm. Below this range, the number of bonding points between the thermoplastic resin fibers or between the thermoplastic resin fibers and the other fibers decreases, so that sufficient bonding strength may not be imparted to the embossed portion 5. . On the other hand, if it exceeds this range, the defibrating property is remarkably lowered and a large number of defibrated materials are generated, so that formation unevenness occurs and the uniformity of the nonwoven fabric sheet is lowered. The fineness of the thermoplastic resin fiber is preferably 0.5 to 10 dtex, more preferably 1.5 to 5 dtex. When the fineness is less than 0.5 dtex, the defibration property is lowered, and when it exceeds 10 dtex, the number of fibers is reduced and the strength is lowered.

  A three-dimensional crimped shape may be imparted to the thermoplastic resin fiber. Thereby, even when the fiber orientation is in the plane direction, the buckling strength of the fiber works in the thickness direction, so that it is difficult to be crushed even if an external pressure is applied. Examples of the three-dimensional crimped shape include a zigzag shape, an Ω shape, and a spiral shape. Examples of the method for imparting the three-dimensional crimped shape include mechanical crimping and shape provision by heat shrinkage. Mechanical crimping can be controlled by the difference in peripheral speed of the line speed, heat, pressurization, etc. for continuous linear fibers after spinning, and the greater the number of crimps per unit length, the greater the resistance to external pressure. The buckling strength is increased. The number of crimps is usually 5 to 35 pieces / inch, preferably 15 to 30 pieces / inch. In shape imparting by heat shrinkage, for example, by applying heat to fibers made of two or more resins having different melting points, it is possible to perform three-dimensional crimping by utilizing the difference in heat shrinkage caused by the melting point difference. is there. Examples of the shape of the fiber cross section include an eccentric type and a side-by-side type of a core-sheath type composite fiber. The thermal contraction rate of such a fiber is preferably 5 to 90%, more preferably 10 to 80%.

  The nonwoven fabric sheet may contain other constituent fibers in addition to the thermoplastic resin fibers. Other constituent fibers include, for example, natural fibers (eg, wool, cotton, etc.), regenerated fibers (eg, rayon, acetate, etc.), inorganic fibers (eg, glass fibers, carbon fibers, etc.), synthetic resin fibers (eg, Polyolefins such as polyethylene, polypropylene, polybutylene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, ethylene-acrylic acid copolymer, ionomer resin; polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate And polyester such as polylactic acid; polyamide such as nylon). Non-woven fabric sheets include core-sheath fibers, side-by-side fibers, island / sea fibers, etc .; hollow fibers; flat fibers, Y-shaped fibers, C-shaped fibers, etc .; A three-dimensional crimped fiber of actual crimps; a split fiber that is split by a physical load such as water flow, heat, embossing, or the like may be mixed.

  Examples of the nonwoven fabric manufacturing method include a method of forming a web (fleece) and physically and chemically bonding fibers. Examples of the web forming method include a spunbond method and a dry method (card). Method, spunbond method, melt blown method, airlaid method, etc.), wet method, etc., and examples of the bonding method include thermal bond method, chemical bond method, needle punch method, stitch bond method, spunlace method, etc. It is done. In addition to the nonwoven fabric produced in this manner, a spunlace formed into a sheet shape by the hydroentanglement method may be used as the liquid permeable layer 2. Moreover, the nonwoven fabric which provided the unevenness | corrugation on the skin side surface (For example, the nonwoven fabric which formed the unevenness | corrugation in the upper layer side by shrink | contracting the lower layer side containing a heat shrink fiber etc., and unevenness | corrugation was formed by applying air at the time of web formation Nonwoven fabric or the like) may be used as the liquid permeable layer 2. By forming irregularities on the skin side surface in this way, the contact area between the liquid permeable layer 2 and the skin can be reduced.

The basis weight of the thermoplastic resin fiber containing an unsaturated carboxylic acid, an unsaturated carboxylic anhydride or a mixture thereof contained in the nonwoven fabric sheet as a monomer component is usually 5 to 50 g / m ² , preferably 10 to a 40 g / m ^2, more preferably from 20 to 30 g / m ^2. The mass ratio of the thermoplastic resin fiber containing unsaturated carboxylic acid, unsaturated carboxylic acid anhydride or a mixture thereof as a monomer component to other constituent fibers (thermoplastic resin fiber / other constituent fibers) is usually 1 / 9 to 9/1, preferably 2/8, and more preferably 8/2. The thickness of a nonwoven fabric sheet is 0.1-5 mm normally, Preferably it is 0.5-3 mm, More preferably, it is 0.8-2 mm.

  Another embodiment of the liquid permeable layer 2 is a resin sheet containing a thermoplastic resin. The thermoplastic resin contained in the resin sheet is preferably a thermoplastic resin containing an unsaturated carboxylic acid, an unsaturated carboxylic acid anhydride, or a mixture thereof as a monomer component. The unsaturated carboxylic acid, unsaturated carboxylic anhydride or mixture thereof contained as a monomer component in the thermoplastic resin is preferably maleic acid or a derivative thereof, maleic anhydride or a derivative thereof, or a mixture thereof. Thereby, the joining strength by the embossed part 5A is improved, and peeling between the liquid permeable layer 2 and the absorbent material layer 41 that may occur in the use environment (particularly in a wet state) can be effectively prevented.

  When the liquid permeable layer 2 is a resin sheet, it is preferable that a through hole (liquid permeable hole) penetrating the resin sheet is formed. The opening ratio of the resin sheet (the ratio of the total area of the through holes to the area of the resin sheet 2) is preferably 5 to 70%, more preferably 10 to 40%. When the aperture ratio is less than 5%, the liquid permeability of the liquid permeable layer 2 cannot be sufficiently improved. On the other hand, when the aperture ratio of the through holes exceeds 70%, the absorbent material layer 41 The return of the liquid to the liquid permeable layer 2 becomes remarkable. The diameter of the through hole is preferably 0.01 to 5 mm, more preferably 0.5 to 3 mm, and the interval between the through holes is preferably 0.02 to 20 mm, and more preferably 1 to 10 mm.

  Other embodiments of the liquid permeable layer 2 include, for example, a woven fabric, a net-like sheet having a mesh, and the like.

  From the viewpoint of enhancing the concealability of the liquid permeable layer 2, the nonwoven fabric used as the liquid permeable layer 2 may contain an inorganic filler such as titanium oxide, barium sulfate, calcium carbonate or the like. When the nonwoven fabric fiber is a core-sheath type composite fiber, an inorganic filler may be contained only in the core, or only in the sheath.

  The sanitary napkin 1 </ b> A may include other liquid permeable layers in addition to the liquid permeable layer 2. Examples of the other liquid permeable layer include a second sheet disposed between the liquid permeable layer 2 and the coating layer 42. As the second sheet, a sheet such as a nonwoven fabric exemplified in the liquid-permeable layer 2 can be appropriately selected and used.

  The liquid-impermeable layer 3 is a sheet through which liquid excretion excreted from the wearer cannot permeate, and one surface of the liquid-impermeable layer is a surface in contact with the wearer's clothes (underwear). ing. The liquid impervious layer 3 preferably has moisture permeability in addition to liquid impermeability in order to reduce stuffiness when worn.

  The liquid impermeable layer 3 contains a thermoplastic resin containing an unsaturated carboxylic acid, an unsaturated carboxylic acid anhydride, or a mixture thereof as a monomer component. The thermoplastic resin contained in the liquid permeable layer 3 is not particularly limited as long as it contains an unsaturated carboxylic acid, an unsaturated carboxylic acid anhydride or a mixture thereof as a monomer component, such as strength, heat-fusibility, etc. From this point of view, it can be appropriately selected.

  Examples of the unsaturated carboxylic acid or unsaturated carboxylic acid anhydride contained as a monomer component in the thermoplastic resin include maleic acid or a derivative thereof, maleic anhydride or a derivative thereof, fumaric acid or a derivative thereof, and an unsaturated derivative of malonic acid. And vinyl monomers such as unsaturated derivatives of succinic acid, and other vinyl monomers include general-purpose monomers having radical polymerizability, for example, styrenes such as styrene and α-methylstyrene; methyl (meth) acrylate And (meth) acrylic acid esters such as ethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, and dimethylaminoethyl (meth) acrylate. Examples of maleic acid derivatives or maleic anhydride derivatives include citraconic acid, citraconic anhydride, pyrocynconic anhydride, and the like, and examples of fumaric acid derivatives or malonic acid unsaturated derivatives include 3-butene- Examples include 1,1-dicarboxylic acid, benzylidenemalonic acid, isopropylidenemalonic acid, and the like. Examples of unsaturated derivatives of succinic acid include itaconic acid and itaconic anhydride.

  The unsaturated carboxylic acid, unsaturated carboxylic anhydride or mixture thereof contained as a monomer component in the thermoplastic resin is preferably maleic acid or a derivative thereof, maleic anhydride or a derivative thereof, or a mixture thereof. As a result, the bonding strength between the liquid impermeable layer 3 and the absorbent material layer 41 by the embossed portion 5B is improved, and the liquid impermeable layer 3 and the absorbent material that may be generated in a use environment (particularly in a wet state). Separation from the layer 41 can be effectively prevented.

  One embodiment of the liquid-impermeable layer 3 is a resin sheet containing a thermoplastic resin containing an unsaturated carboxylic acid, an unsaturated carboxylic acid anhydride, or a mixture thereof as a monomer component.

  The thermoplastic resin contained in the resin sheet is not particularly limited as long as it contains an unsaturated carboxylic acid, an unsaturated carboxylic acid anhydride or a mixture thereof as a monomer component, from the viewpoint of strength, heat-fusibility, etc. It can be selected appropriately.

  The thermoplastic resin containing an unsaturated carboxylic acid anhydride or a mixture thereof as a monomer component is preferably an unsaturated carboxylic acid, an unsaturated carboxylic acid anhydride or a mixture thereof contained as a monomer component, maleic acid or a derivative thereof. , A maleic anhydride or a derivative thereof, or a thermoplastic resin that is a mixture thereof. As a result, the bonding strength between the liquid impermeable layer 3 and the absorbent material layer 41 by the embossed portion 5B is improved, and the liquid impermeable layer 3 and the absorbent material that may be generated in a use environment (particularly in a wet state). Separation from the layer 41 can be effectively prevented.

  The covering layer 42 is absorbent for the purposes of preventing the absorbent material layer 41 from collapsing, improving the cushioning properties of the sanitary napkin 1A, improving the concealing property of the absorbent material layer 41, reducing rewet back from the absorbent material layer 41, and the like. The material layer 41 is provided on the surface of the liquid permeable layer 2 side. As shown in FIG. 3, the covering layer 42 is provided so as to cover substantially the entire surface of the absorbent material layer 41 on the liquid permeable layer 2 side, but provided so as to cover a part thereof. It may be done.

  The covering layer 42 has liquid permeability, and the liquid excrement that has passed through the liquid permeable layer 2 reaches the absorbent material layer 41 through the covering layer 42. Examples of the covering layer 42 include a nonwoven fabric, a woven fabric, a synthetic resin film in which liquid permeation holes are formed, and a net-like sheet having a mesh. Among these, a nonwoven fabric is preferable. In addition, the kind and form of the fiber which comprises a nonwoven fabric, and the manufacturing method of a nonwoven fabric are the same as the above.

The coating layer 42 preferably contains cellulosic water-absorbing fibers. Specific examples of the cellulosic water-absorbing fiber are the same as those of the absorbent material layer 41. The basis weight of the cellulosic water-absorbing fibers contained in the coating layer 42 is usually 5 to 50 g / m ² , preferably 10 to 40 g / m ² , and more preferably 10 to 25 g / m ² . . The mass ratio of the cellulosic water-absorbing fiber to other constituent fibers (cellulosic water-absorbing fiber / other component fibers) is usually 1/9 to 9/1, preferably 2/8, and more preferably. Is 8/2. The thickness of the coating layer 42 is usually 0.1 to 5 mm, preferably 0.3 to 3 mm, and more preferably 0.5 to 2 mm. The tissue, which is an example of a cellulosic absorbent fiber preferably contained in the coating layer 42, is composed of pulp and a paper strength enhancer. For example, NBKP (beating) (67.9%), NBKP (non-beating) (29.1%) And a paper strength enhancer (polyacrylamide compound) (2.14%) and a paper strength enhancer (polyamide epichlorohydrin) (0.86%).

  The covering layer 43 is provided on the surface of the absorbent material layer 41 on the liquid-impermeable layer 3 side for the purpose of preventing the absorbent material layer 41 from collapsing and improving the cushioning property of the sanitary napkin 1A. As shown in FIG. 3, the covering layer 43 is provided so as to cover substantially the entire surface of the absorbent material layer 41 on the liquid-impermeable layer 3 side. It may be provided.

  The coating layer 43 may have liquid permeability or may have liquid impermeability. When it has liquid permeability, examples of the coating layer 43 include nonwoven fabric, woven fabric, synthetic resin film having liquid permeation holes, and a net-like sheet having a mesh. As the coating layer 3, for example, a waterproof nonwoven fabric, a synthetic resin (eg, polyethylene, polypropylene, polyethylene terephthalate, etc.) film, a composite sheet of a nonwoven fabric and a synthetic resin film (eg, nonwoven fabric such as spunbond, spunlace, etc.) And a composite film in which a breathable synthetic resin film is bonded), an SMS nonwoven fabric in which a melt-blown nonwoven fabric having high water resistance is sandwiched between strong spunbond nonwoven fabrics, and the like.

When the coating layer 43 has liquid permeability, it is preferable to contain a cellulosic water-absorbing fiber. Specific examples of the cellulosic water-absorbing fiber are the same as those of the absorbent material layer 41. The basis weight of the cellulosic water-absorbing fibers contained in the coating layer 43 is usually 5 to 50 g / m ² , preferably 10 to 40 g / m ² , and more preferably 10 to 25 g / m ² . . The mass ratio of the cellulosic water-absorbing fiber to other constituent fibers (cellulosic water-absorbing fiber / other constituent fibers) is usually 1/9 to 9/1, preferably 2/8, Preferably it is 8/2. The thickness of the coating layer 43 is usually 0.1 to 5 mm, preferably 0.3 to 3 mm, and more preferably 0.5 to 2 mm. The tissue, which is an example of a cellulosic absorbent fiber preferably contained in the coating layer 42, is composed of pulp and a paper strength enhancer. For example, NBKP (beating) (67.9%), NBKP (non-beating) (29.1%) And a paper strength enhancer (polyacrylamide compound) (2.14%) and a paper strength enhancer (polyamide epichlorohydrin) (0.86%).

The interface between the liquid permeable layer 2 and the coating layer 42, the interface between the coating layer 42 and the absorbent material layer 41, the interface between the absorbent material layer 41 and the coating layer 43, and the coating layer 43 and the liquid impermeable layer 3 It is preferable that an adhesive (for example, a hot-melt adhesive) is applied to the interface with. In that case, the absorbent material layer 41 is bonded to one surface of the coating layer 42, the liquid permeable layer 2 is bonded to the other surface, and the absorbent material layer 41 is bonded to the other surface of the coating layer 43. The liquid-impermeable layer 3 is bonded to the surface. From the viewpoint of liquid permeability from the liquid permeable layer 2 to the absorbent material layer 41, the adhesive is not applied to the entire interface, and is applied in a pattern such as a dot, spiral, stripe, or the like. . As the adhesive, for example, styrene-ethylene-butadiene-styrene (SEBS), styrene-butadiene-styrene (SBS), styrene-isoprene-styrene (SIS) or the like mainly composed of rubber or linear low density Pressure-sensitive adhesive or heat-sensitive adhesive mainly composed of olefin such as polyethylene; water-soluble polymer (for example, polyvinyl alcohol, carboxymethyl cellulose, gelatin, etc.) or water-swellable polymer (for example, polyvinyl acetate, polyacrylic acid) And water-sensitive adhesives such as sodium). Examples of the method for applying the adhesive include spiral coating, coater coating, curtain coater coating, and summit gun coating. The coating amount (basis weight) of the adhesive is usually 0.5 to 20 g / m ² , preferably ² to 10 g / m ² .

  The absorbent material layer 41 contains cellulose-based water-absorbing fibers (hereinafter sometimes abbreviated as “water-absorbing fibers”) as its constituent fibers. Cellulose-based water-absorbing fibers are mainly involved in the liquid absorbency and retention of the absorbent material layer 41. Cellulosic water-absorbing fibers include, for example, wood pulp obtained from softwood or hardwood (for example, mechanical pulp such as groundwood pulp, refiner ground pulp, thermomechanical pulp, chemithermomechanical pulp; kraft pulp, sulfide pulp, alkali Chemical pulp such as pulp; semi-chemical pulp); mercerized pulp or crosslinked pulp obtained by chemically treating wood pulp; non-wood pulp such as bagasse, kenaf, bamboo, hemp, cotton (for example, cotton linter); rayon Examples thereof include recycled fibers such as fibers.

  The absorbent material layer 41 preferably contains a thermoplastic resin fiber in addition to the cellulosic water-absorbing fiber as its constituent fiber. The thermoplastic resin fiber is mainly involved in the strength of the absorbent material layer 41 (particularly, the wet strength after liquid absorption).

  When the absorbent material layer 41 contains cellulosic water-absorbing fibers and thermoplastic resin fibers, the cellulosic water-absorbing fibers and thermoplastic resin fibers are contained in the absorbent material layer 41 in a mixed state. Intersections (for example, intersections between thermoplastic resin fibers, intersections between thermoplastic resin fibers and cellulose water-absorbing fibers) are bonded by thermal fusion of thermoplastic resin fibers. Further, the fibers are mechanically entangled and bonded by hydrogen bonds formed between the thermoplastic resin fibers, between the cellulose-based water-absorbing fibers, or between the thermoplastic resin fibers and the cellulose-based water-absorbing fibers. In addition, when the absorptive material layer 41 contains another fiber, the thermoplastic resin fiber and / or the cellulosic water absorbing fiber may be bonded to the other fiber. Since an advanced network is formed between the fibers by adhering the constituent fibers of the absorbent material layer 41, the strength of the absorbent material layer 41 (particularly the strength when wet after liquid absorption) is improved. Therefore, the sanitary napkin 1 </ b> A peels off the liquid-permeable layer 2 and the absorbent material layer 41 that may be generated due to a decrease in the strength of the absorbent material layer 41 and the liquid-impermeable layer 3 and the absorbent material layer 41. Peeling can be prevented. As shown in FIGS. 1 to 3, when the coating layers 42 and 43 are present, the liquid permeable layer 2 and the coating layer 42 are peeled off, and the coating layer 42 and the absorbent material layer 41 are peeled off. Further, peeling between the absorbent material layer 41 and the coating layer 43 and peeling between the coating layer 43 and the liquid-impermeable layer 3 can be prevented.

  The heat fusion is performed, for example, by heating a mixed material containing cellulosic water-absorbing fibers and thermoplastic resin fibers at a temperature equal to or higher than the melting point of the thermoplastic resin fibers. The heating temperature can be appropriately adjusted according to the type of thermoplastic resin fiber. The temperature above the melting point of the thermoplastic resin fiber may be at or above the temperature at which a part of the thermoplastic resin fiber melts. For example, when the thermoplastic resin fiber is a core-sheath type composite fiber, the temperature at which the sheath component melts That is all you need.

  The thermoplastic resin fiber contained in the absorbent material layer 41 is not particularly limited as long as the intersection of the fibers can be heat-sealed. Examples of the thermoplastic resin constituting the thermoplastic resin fiber include polyolefin, polyester, polyamide, and the like.

  Examples of the polyolefin include, for example, linear low density polyethylene (LLDPE), low density polyethylene (LDPE), medium density polyethylene (MDPE), high density polyethylene (HDPE), polypropylene, polybutylene, and copolymers based on these (for example, Ethylene-vinyl acetate copolymer (EVA), ethylene-ethyl acrylate copolymer (EEA), ethylene-acrylic acid copolymer (EAA), ionomer resin), and the like. Polyethylene, particularly HDPE, is preferred from the viewpoint that the softening point is relatively low at around 100 ° C., so that it is excellent in heat workability, and the rigidity is low and the touch is supple.

  Examples of the polyester include linear or branched carbon atoms of up to 20 including polyethylene terephthalate (PET), polytrimethyl terephthalate (PTT), polybutylene terephthalate (PBT), polylactic acid, and polyglycolic acid. And polyesters such as polyhydroxyalkanoic acid, copolymers based on these, and copolymerized polyesters obtained by copolymerizing alkylene terephthalate as a main component with a small amount of other components. PET is preferable from the viewpoint of being able to constitute fibers and nonwoven fabrics having high cushioning properties because of its elastic resilience, and from the economical viewpoint that it can be obtained industrially at low cost.

  Examples of the polyamide include 6-nylon and 6,6-nylon.

  The thermoplastic resin fiber contained in the absorbent material layer 41 is preferably a thermoplastic resin fiber containing an unsaturated carboxylic acid, an unsaturated carboxylic acid anhydride, or a mixture thereof as a monomer component. The thermoplastic resin fiber containing an unsaturated carboxylic acid, an unsaturated carboxylic acid anhydride or a mixture thereof as a monomer component is not particularly limited, and may be appropriately selected from the viewpoints of strength, hydrogen bondability, heat fusibility, and the like. You can choose. Specific examples of the thermoplastic resin fiber containing an unsaturated carboxylic acid, an unsaturated carboxylic acid anhydride, or a mixture thereof as a monomer component include the same specific examples as those contained in the liquid-permeable layer 2 (nonwoven fabric sheet), and preferably Is a thermoplastic resin fiber in which the unsaturated carboxylic acid, unsaturated carboxylic acid anhydride or mixture thereof contained as a monomer component is maleic acid or a derivative thereof, maleic anhydride or a derivative thereof, or a mixture thereof, More preferably, a modified polyolefin graft-polymerized with a vinyl monomer containing an unsaturated carboxylic acid, an unsaturated carboxylic acid anhydride or a mixture thereof or a mixed polymer of the modified polyolefin and another resin is used as a sheath component, and the modified polyolefin It is a core-sheath type composite fiber having a resin having a higher melting point as a core component. Thereby, the joining of the liquid-permeable layer 2, the coating layer 42, and the absorbent material layer 41 by the embossed portion 5A, and the joining of the liquid-impermeable layer 3, the coating layer 43, and the absorbent material layer by the embossing 5B are further performed. Separation between the liquid-permeable layer 2 and the coating layer 42, which may occur in the use environment (particularly in a wet state), separation between the coating layer 42 and the absorbent material layer 41, and the absorbent material layer 41 and the coating layer 43 and the coating layer 43 and the liquid-impermeable layer 3 can be effectively prevented.

  Examples of the thermoplastic resin fiber contained in the absorbent material layer 41 include a core / sheath type, a side-by-side type, and an island / sea type. From the viewpoint of thermal adhesiveness, a composite fiber composed of a core portion and a sheath portion is preferable. Examples of the shape of the core cross section in the core-sheath type composite fiber include a circle, a triangle, a square, and a star, and the core may be hollow or porous. The cross-sectional area ratio of the core / sheath structure is not particularly limited, but is preferably 80/20 to 20/80, and more preferably 60/40 to 40/60.

  The thermoplastic resin fibers contained in the absorbent material layer 41 include antioxidants, light stabilizers, UV absorbers, neutralizers, nucleating agents, epoxy stabilizers, lubricants, antibacterial agents, flame retardants, and antistatic agents. You may add additives, such as an agent, a pigment, a plasticizer, as needed. The thermoplastic resin fiber is preferably hydrophilized with a surfactant, a hydrophilic agent or the like.

  The fiber length of the thermoplastic resin fibers contained in the absorbent material layer 41 is not particularly limited, but is preferably 3 to 70 mm, more preferably 5 to 20 mm when mixed with pulp by the airlaid system. If it falls below this range, the number of fiber bonding points decreases, so that sufficient strength may not be imparted to the absorbent material layer 41. On the other hand, if it exceeds this range, the defibrating property is remarkably lowered and a large number of defibrated states are generated, so that uneven formation occurs and the uniformity of the absorbent material layer 41 may be lowered. The fineness of the thermoplastic resin fiber is preferably 0.5 to 10 dtex, more preferably 1.5 to 5 dtex. When the fineness is less than 0.5 dtex, the defibration property is lowered, and when it exceeds 10 dtex, the number of fibers is decreased and the strength may be lowered.

  The thermoplastic resin fiber contained in the absorbent material layer 41 may be given a three-dimensional crimped shape. Thereby, even when the fiber orientation is in the plane direction, the buckling strength of the fiber works in the thickness direction, so that it is difficult to be crushed even if an external pressure is applied. Examples of the three-dimensional crimped shape include a zigzag shape, an Ω shape, and a spiral shape. Examples of the method for imparting the three-dimensional crimped shape include mechanical crimping and shape provision by heat shrinkage. Mechanical crimping can be controlled by the difference in peripheral speed of the line speed, heat, pressurization, etc. for continuous linear fibers after spinning, and the greater the number of crimps per unit length, the greater the resistance to external pressure. The buckling strength is increased. The number of crimps is usually 5 to 35 pieces / inch, preferably 15 to 30 pieces / inch. In shape imparting by heat shrinkage, for example, by applying heat to fibers made of two or more resins having different melting points, it is possible to perform three-dimensional crimping by utilizing the difference in heat shrinkage caused by the melting point difference. is there. Examples of the shape of the fiber cross section include an eccentric type and a side-by-side type of a core-sheath type composite fiber. The thermal contraction rate of such a fiber is preferably 5 to 90%, more preferably 10 to 80%.

  The mass ratio (thermoplastic resin fiber / cellulosic water absorbent fiber) of the thermoplastic resin fiber to the cellulosic water absorbent fiber contained in the absorbent material layer 41 is preferably 1/9 or more. The lower limit of 1/9 is defined from the viewpoint of the strength of the absorbent material layer 41 (particularly the strength when wet after liquid absorption), and the mass ratio of the thermoplastic resin fiber to the cellulosic water-absorbing fiber is 1/9. When it is 9 or more, the absorbent material layer 41 maintains sufficient strength before and after liquid absorption (that is, not only when dry but also when wet). As a result, peeling between the liquid-permeable layer 2 and the absorbent material layer 41 that may occur due to a decrease in strength of the absorbent material layer 41 in a use environment (particularly in a wet state) and the liquid-impermeable layer 3 and the absorbent property. Separation from the material layer 41 can be prevented. 1 to 3, when the coating layers 42 and 43 are present, the liquid permeable layer 2 and the coating layer 42 are peeled off, and the coating layer 42 and the absorbent material layer 41 are peeled off. The peeling between the absorbent material layer 41 and the coating layer 43 and the peeling between the coating layer 43 and the liquid-impermeable layer 3 can be prevented.

  The strength of the absorbent material layer 41 increases as the mass ratio of the thermoplastic resin fibers to the cellulose water-absorbing fibers contained in the absorbent material layer 41 (thermoplastic resin fibers / cellulose-based water absorbent fibers) increases. For example, the mass ratio of the thermoplastic resin fiber to the cellulosic water absorbent fiber is 1/9, 1.5 / 8.5, 2/8, 2.5 / 7.5, 3/7, 3.5 / 6. As the thickness increases to .5, 4/6, and 4.5 / 5.5, the strength of the absorbent material layer 41 increases. Therefore, 1/9, 1.5 / 8.5, 2/8, 2.5 / 7.5, 3/7, 3.5 / 6.5, 4/6, 4.5 / 5.5 From the viewpoint of increasing the strength of the absorbent material layer 41, the mass ratio can have significance as the lower limit of the mass ratio of the thermoplastic resin fibers to the cellulosic water absorbent fibers.

  The upper limit of the mass ratio of the thermoplastic resin fibers to the cellulose-based water absorbent fibers (thermoplastic resin fibers / cellulose-based water absorbent fibers) in the absorbent material layer 41 is preferably 5/5. The upper limit of 5/5 is specified from the viewpoint of liquid absorbability of the absorbent material layer 41, and the mass ratio of the thermoplastic resin fibers to the cellulosic water absorbent fibers is 5/5 or less. Sufficient liquid absorbability can be imparted to the material layer 41.

  As the mass ratio of the thermoplastic resin fiber to the cellulose water-absorbing fiber in the absorbent material layer 41 (thermoplastic resin fiber / cellulosic water-absorbing fiber) becomes smaller, the influence of the hydrophobicity of the thermoplastic resin fiber becomes weaker, and the absorbent material. The liquid absorbency of the layer 41 is increased. For example, the mass ratio of the thermoplastic resin fiber to the cellulosic water-absorbing fiber is 5/5, 4.5 / 5.5, 4/6, 3.5 / 6.5, 3/7, 2.5 / 7. .5, 2/8, and 1.5 / 8.5, the liquid absorbency of the absorbent material layer 41 increases. Therefore, 5/5, 4.5 / 5.5, 4/6, 3.5 / 6.5, 3/7, 2.5 / 7.5, 2/8, 1.5 / 8.5 The mass ratio may have significance as the upper limit of the mass ratio of the thermoplastic resin fiber to the cellulosic water-absorbing fiber from the viewpoint of increasing the liquid absorbency of the absorbent material layer 41.

  The mass ratio of the thermoplastic resin fibers to the cellulose water-absorbing fibers in the absorbent material layer 41 (thermoplastic resin fibers / cellulosic water-absorbing fibers) is the degree of inter-fiber network formation and strength (particularly when wet) of the absorbent material layer 41. From the viewpoint of the strength and the liquid absorbability, it is preferably 1/9 to 5/5, more preferably 2/8 to 4/6.

  The desired strength (particularly the strength when wet) is adjusted by adjusting the mass ratio of the thermoplastic resin fibers to the cellulosic water-absorbing fibers in the absorbent material layer 41, and then the production conditions (for example, heat melting) It can be realized by adjusting the heating conditions during wearing. For example, hot air of 130 to 220 ° C., preferably 140 to 180 ° C. is applied to a fiber material having a mass mixing ratio of thermoplastic resin fibers to cellulose water-absorbing fibers of 1/9 or more, and an air volume of 2.5 to 30 m. The desired strength (particularly strength when wet) can be achieved by spraying at a rate of 0.5 to 60 seconds, preferably 5 to 30 seconds, at a rate of 5 to 20 m / sec. The blowing of hot air can be performed by, for example, an air-through method. Note that the blowing of hot air is an example of heat treatment. The heat treatment is not particularly limited as long as it can be heated to a temperature equal to or higher than the melting point of the thermoplastic resin fiber. The heat treatment can be performed using a heat medium such as microwaves, steam, infrared rays, etc. in addition to hot air.

The density of the absorbent material layer 41 is preferably 0.06 to 0.14 g / cm ³ , more preferably 0.07 to 0.12 g / cm ³ , and still more preferably 0.08 to 0.1 g / cm ^3. It is. When the mass ratio of the thermoplastic resin fibers to the cellulosic water-absorbing fibers contained in the absorbent material layer 41 is 1/9 to 5/5, the density of the absorbent material layer 41 is 0.06 to 0.14 g / If it is cm ^3, it is possible to impart sufficient liquid absorbent to the absorption material layer 41.

The density of the absorbent material layer 41 is calculated based on the following formula.
D (g / cm ³ ) = B (g / m ² ) / T (mm) × 10 ⁻³
[In formula, D, B, and T represent the density, basic weight, and thickness of the absorptive material layer 41, respectively. ]

The basis weight (g / m ² ) of the absorbent material layer 41 is measured as follows.
Three test pieces of 100 mm × 100 mm are cut out from the absorbent material layer 41, and the mass of each test piece in the standard state (temperature 23 ± 2 ° C., relative humidity 50 ± 5%) is shown as a direct balance (eg, Kensei Kogyo Co. The mass per unit area (g / m ² ) of the absorbent material layer 41 measured by an electronic balance HF-300 manufactured by the company and calculated from the average value of the three measured values was calculated as the basis weight of the absorbent material layer 41 and To do. In addition, regarding the measurement of the basic weight of the absorbent material layer 41, the measurement conditions described in ISO 9073-1 or JIS L 1913 6.2 are adopted as the measurement conditions not particularly specified above.

The thickness (mm) of the absorbent material layer 41 is measured as follows.
In a standard state (temperature 23 ± 2 ° C., relative humidity 50 ± 5%) by a thickness gauge (for example, FS-60DS, manufactured by Daiei Scientific Instruments Co., Ltd., measurement surface 44 mm (diameter), measurement pressure 3 g / cm ² ). Five different parts of the absorbent material layer 41 (when the thickness gauge FS-60DS is used, the diameter of each part is 44 mm) are pressed at a constant pressure of 3 g / cm ² , and the thickness of each part after 10 seconds is measured. And let the average value of five measured values be the thickness of the absorptive material layer 41.

  The density of the absorbent material layer 41 can be adjusted to a desired range by increasing the density of the mixed material containing cellulosic water-absorbing fibers and thermoplastic resin fibers. In order to maintain the density of the absorbent material layer 41 within a certain range, it is necessary to suppress the elastic recovery of the fibers and maintain the bulk of the absorbent material layer 41 within a certain range. In this respect, hydrogen bonds (for example, hydrogen bonds formed between cellulosic water-absorbing fibers, between thermoplastic resin fibers, between cellulosic water-absorbing fibers and thermoplastic resin fibers, etc.) are bulky in the absorbent material layer 41. Contribute to maintenance. The hydrogen bond is formed, for example, between an oxygen atom of a thermoplastic resin fiber (for example, an oxygen atom such as a carboxyl group, an acyl group, or an ether bond) and a hydrogen atom of cellulose (for example, a hydrogen atom of a hydroxyl group). . In addition, since a hydrogen bond is cut | disconnected by the liquid absorbed in the absorptive material layer 41, the absorptive material (cellulosic water absorbing fiber which is an essential component, an arbitrary component) contained in the absorptive material layer 41 is used. It does not inhibit the swelling of some superabsorbent material.

  The absorbent material layer 41 is preferably obtained by injecting high-pressure water vapor into a mixed material containing cellulosic water-absorbing fibers and thermoplastic resin fibers to increase the density. The density of the absorbent material layer 41 can be adjusted to a desired range by increasing the density using high-pressure steam injection. When high-pressure water vapor is injected into the mixed material, the water vapor penetrates into the mixed material, and hydrogen bonds (for example, between the cellulose-based water absorbent fibers, between the thermoplastic resin fibers, between the cellulose-based water absorbent fibers and the thermoplastic resin fibers). Etc.), and the mixed material is softened. Therefore, the pressure required for densification is reduced, and the softened mixed material can be easily adjusted in density. When the density-adjusted mixed material is dried and hydrogen bonds are re-formed, elastic recovery (increase in volume) of the fibers is suppressed, and the density of the absorbent material layer 41 is maintained within a certain range.

  Densification by jetting high-pressure steam is particularly suitable when an unsaturated carboxylic acid anhydride (for example, maleic anhydride or a derivative thereof) is contained as a monomer component in the thermoplastic resin fiber. When the unsaturated carboxylic acid anhydride group contained in the thermoplastic resin fiber reacts with water vapor to form an unsaturated carboxylic acid group, the number of oxygen atoms capable of forming hydrogen bonds increases, so the density-adjusted fiber elasticity Recovery (increase in bulk) is effectively suppressed.

Densification by injection of high-pressure steam is performed, for example, after bonding thermoplastic resin fibers to cellulosic water-absorbing fibers. The temperature, vapor pressure, etc. of the high-pressure steam are appropriately adjusted according to the required density range. The temperature of the high-pressure steam is preferably less than the melting point of the thermoplastic resin fiber (for example, when the thermoplastic resin fiber is a core-sheath type composite fiber, the melting point of the sheath component). High-pressure steam is preferably injected per unit surface area ^{0.03kg / m 2 ~1.23kg / m 2} . The vapor pressure of the high-pressure steam is usually from 0.1 to 2 Mpa, preferably from 0.3 to 0.8 Mpa.

When the densification is performed by jetting high-pressure steam, the basis weight of the absorbent material layer 41 is preferably 40 to 900 g / m ² , more preferably 100 to 400 g / m ² . If the basis weight is less than 40 g / m ² , the amount of fibers is too small, so that it is difficult to increase the density by jetting high-pressure steam. On the other hand, if the basis weight exceeds 900 g / m ² , the amount of fibers is too large. Internal penetration becomes difficult.

  By injecting the high-pressure steam, the collar portion and the groove portion can be formed on the surface of the absorbent material layer 41. The number, interval, and the like of the flange portion and the groove portion vary depending on the number, pitch, and the like of nozzles that inject high-pressure steam. In addition, the part into which high-pressure steam is injected becomes a groove part. The collar portion and the groove portion may be formed on the surface of the absorbent material layer 41 on the liquid permeable layer 2 side, or may be formed on the surface of the liquid impermeable layer 3 side.

  The ridge and the groove can be formed so as to extend in the longitudinal direction (Y-axis direction) of the sanitary napkin 1A and to be alternately arranged in the width direction (X-axis direction) of the sanitary napkin 1A. The ridge and the groove may extend continuously in the longitudinal direction (Y-axis direction) of the sanitary napkin 1A, or may extend intermittently with a part thereof omitted. For example, the collar part and the groove part may extend intermittently so that the part lacking the collar part and the groove part has a rectangular shape in plan view, a staggered shape in plan view, or the like.

  Further, the ridge and the groove can be formed so as to extend in the width direction (X-axis direction) of the sanitary napkin 1A and to be alternately arranged in the longitudinal direction (Y-axis direction) of the sanitary napkin 1A. The heel part and the groove part may extend continuously in the width direction (X-axis direction) of the sanitary napkin 1A, or may extend intermittently with a part thereof omitted. For example, the collar part or the groove part may extend intermittently so that the part lacking the collar part or the groove part has a rectangular shape in plan view, a staggered shape in plan view, or the like. A plurality of flanges and grooves extending in the width direction (X-axis direction) of the sanitary napkin 1A are formed on the surface of the absorbent material layer 41 on the liquid permeable layer 2 side or the surface on the liquid impermeable layer 3 side. When the force is applied in the width direction of the absorbent material layer 41, the absorbent material layer 41 is not easily twisted, and the absorbent material layer 41 is easily deformed into a curved shape along the shape of the wearer's body. Therefore, it is difficult for the wearer to feel uncomfortable.

  The shape of the buttocks is not particularly limited. For example, the top part and side surface of the collar part are curved surfaces, and the cross-sectional shape of the collar part is a substantially inverted U shape toward the liquid-permeable layer or the liquid-impermeable layer. The cross-sectional shape of the collar portion can be changed as appropriate, and may be, for example, a dome shape, a trapezoidal shape, a triangular shape, or an Ω-shaped square shape. Even if a force is applied to the absorbent material layer 41 and the collar is crushed, the width of the collar is preferably narrowed from the bottom to the top so that the space of the groove is maintained.

  From the viewpoint of liquid migration from the liquid permeable layer 2, the width of the collar portion is preferably 0.5 to 10 mm, and more preferably 2 to 5 mm. From the same viewpoint, the width of the groove is preferably 0.1 to 10 mm, and more preferably 1 to 5 mm.

  When a plurality of flanges are formed, the widths of the flanges may be substantially the same or different. For example, although the width of one collar is different from the width of another collar, a plurality of collars can be formed so as to be substantially the same as the width of another collar. The same applies when a plurality of grooves are formed.

  The high-pressure steam may be injected over the entire mixed material or may be injected over a part thereof. Moreover, you may change the temperature of high-pressure steam, vapor pressure, etc. which are injected for every part of mixed material. Changing the fiber density distribution of the absorbent material layer 41 by partially injecting high-pressure steam into the mixed material, or changing the temperature, vapor pressure, etc. of the injected high-pressure steam for each part of the mixed material. Can do.

  The high-pressure steam may be injected while pressing the mixed material, or may be injected without pressing. The fiber density distribution of the absorbent material layer 41 can be changed by spraying high-pressure steam while pressing a part of the mixed material and spraying high-pressure steam without pressing the other part. For example, when high-pressure steam is sprayed onto the mixed material while passing between mesh conveyor belts that are partially open, high-pressure steam is directly applied to the mesh conveyor belt without being pressed at the opening of the mesh conveyor belt, and the mesh conveyor belt is not open. Then, since high-pressure steam is applied while being pressed, the fiber density distribution can be changed.

In the case of increasing the density by jetting high-pressure steam, it is advantageous in the following points as compared with other methods. When the mixed material is densified by press roll molding, high compression is required to provide a bonding force between fibers that exceeds the repulsive force of the fibers. Moreover, even if compressed once by high compression, a fiber will elastically recover and a bulk will return. On the other hand, when the density of the mixed material is increased by combining a press roll and water spray, if the basis weight is 100 g / m ² or less, moisture can penetrate into the mixed material, but the basis weight is 100 g / m ^2. If it exceeds m ² , it becomes difficult to permeate moisture into the mixed material, and hydrogen bonds cannot be formed inside the mixed material. Moreover, if excessive moisture is given, it becomes possible to allow moisture to penetrate into the mixed material. In this case, however, an excessive amount of heat and time are required to evaporate the moisture, resulting in a decrease in productivity. On the other hand, when the density is increased by jetting high-pressure steam, the steam penetrates into the mixed material, and hydrogen bonds (for example, between the cellulose-based water-absorbing fibers, between the thermoplastic resin fibers, the cellulose-based water-absorbing fibers— The hydrogen bond formed between the thermoplastic resin fibers or the like is cut, and the mixed material is softened. Therefore, the pressure required for densification is reduced, and the density of the softened mixed material can be easily adjusted. Further, the water vapor easily evaporates and the time required for drying is short, so that productivity is improved.

The maximum tensile strength at drying (maximum tensile strength at a basis weight of 200 g / m ² ) of the absorbent material layer 41 is preferably 3 to 36 N / 25 mm, more preferably 8 to 20 N / 25 mm. The maximum tensile strength when wet (maximum tensile strength at a basis weight of 200 g / m ² ) is preferably 2 to 32 N / 25 mm, more preferably 5 to 15 N / 25 mm. “N / 25 mm” means the maximum tensile strength (N) per width of 25 mm in the planar direction of the absorbent material layer 41, and the planar direction of the absorbent material layer 41 is, for example, the absorbent material layer 41. Although the conveyance direction at the time of manufacture of (MD direction), the direction (CD direction) orthogonal to MD direction, etc. are mentioned, Preferably it is MD direction.

  The maximum tensile strength when drying the absorbent material layer 41 is a standard test piece (temperature 20 ° C., humidity 60%) with a sample piece (length 150 mm × width 25 mm) in a tensile tester (manufactured by Shimadzu Corporation, AG-1kNI). Measurement is performed by attaching a grip at an interval of 100 mm and applying a load (maximum point load) until the sample piece is cut at a tensile speed of 100 mm / min. In this case, “N / 25 mm” means the maximum tensile strength (N) per 25 mm width in the length direction of the sample piece.

  The maximum tensile strength when the absorbent material layer 41 is wet is determined by immersing the sample piece (length 150 mm x width 25 mm) in ion-exchanged water until it sinks under its own weight, or submerging the sample piece in water for 1 hour or more. And then measured in the same manner as the maximum tensile strength during drying. In this case, “N / 25 mm” means the maximum tensile strength (N) per 25 mm width in the length direction of the sample piece.

  Regarding the measurement of the maximum tensile strength at the time of dryness and wetness, the measurement conditions described in ISO 9073-3 or JIS L 1913: 2010 6.3 are adopted for the measurement conditions not particularly specified above.

  The difference between the maximum tensile strength when dry and the maximum tensile strength when wet of the absorbent material layer 41 (maximum tensile strength when dry-maximum tensile strength when wet) is preferably 1 to 5 N / 25 mm, more preferably 2 to 4 N / 25 mm. In this case, the absorbent material layer 41 has sufficient strength to maintain an integrated structure with the top sheet 2 or the covering layer 42. In addition, since the hydrogen bond formed at the time of drying is cut | disconnected at the time of wetness, the difference of the maximum tensile strength at the time of drying and the maximum tensile strength at the time of wetness becomes a parameter | index of the amount of hydrogen bonds.

  The absorbent material layer 41 preferably contains a highly water-absorbing material (for example, a highly water-absorbing resin, a highly water-absorbing fiber, etc.) in addition to the cellulosic water-absorbing fibers and the thermoplastic resin fibers. The content of the superabsorbent material is usually 5 to 80% by mass of the absorbent material layer 41, preferably 10 to 60% by mass, and more preferably 20 to 40% by mass. Examples of the superabsorbent material include starch-based, cellulose-based, and synthetic polymer-based superabsorbent materials. Examples of starch-based or cellulose-based superabsorbent materials include starch-acrylic acid (salt) graft copolymers, saponified starch-acrylonitrile copolymers, and crosslinked products of sodium carboxymethyl cellulose, and synthetic polymers. Examples of high water-absorbing materials include polyacrylates, polysulfonates, maleic anhydrides, polyacrylamides, polyvinyl alcohols, polyethylene oxides, polyaspartates, polyglutamates , Polyalginate-based, starch-based, and cellulose-based superabsorbent polymers (SAP), and the like. Among these, polyacrylate-based (particularly, sodium polyacrylate-based) superabsorbent Resins are preferred. Examples of the shape of the superabsorbent material include a particulate shape, a fibrous shape, and a scaly shape. In the case of the particulate shape, the particle size is preferably 50 to 1000 μm, more preferably 100 to 600 μm. . The particle size is measured according to the screening test method described in JIS R 6002: 1998.

  The absorbent material layer 41 may contain silver, copper, zinc, silica, activated carbon, an aluminosilicate compound, zeolite, or the like in order to impart a desired function. Thereby, functions, such as a deodorizing property, antibacterial property, and an endothermic effect, can be provided.

  The absorbent material layer 41 may be colored with a pigment or the like. Thereby, it is easy to visually check whether the cellulosic water-absorbing fibers and the thermoplastic resin fibers are uniformly dispersed. In addition, the color of the absorbed liquid can be masked. For example, when the liquid to be absorbed is urine, it is colored blue, and when it is menstrual blood, the user can feel cleanliness.

The thickness, basis weight, and the like of the absorbent material layer 41 can be appropriately adjusted according to characteristics (for example, absorbency, strength, lightness, etc.) that the sanitary napkin 1A should have. The thickness of the absorbent material layer 41 is usually 0.1 to 15 mm, preferably 1 to 10 mm, more preferably 2 to 5 mm, and the basis weight is usually 20 to 1000 g / m ² , preferably 40 to 900 g / m. ² and more preferably 100 to 400 g / m ² . When the basis weight is less than 40 g / m ² , the fiber amount of the thermoplastic resin fiber becomes insufficient, and the strength of the absorbent material layer 41 (particularly the strength when wet after liquid absorption) may not be maintained, while 900 g If it exceeds / m ² , the amount of the thermoplastic resin fiber becomes excessive, and the rigidity of the absorbent material layer 41 may be too high. In addition, the thickness of the absorptive material layer 41, basic weight, etc. may be constant over the absorptive material layer 41 whole, and may differ partially.

  The absorbent material layer 41 may be integrated with the liquid permeable layer 2 by a through-hole penetrating the liquid permeable layer 2 and the absorbent material layer 41. Thereby, the absorptivity / accommodability of a liquid (for example, menstrual blood) having a high viscosity is improved. The opening ratio of the through holes penetrating the liquid permeable layer 2 and the absorbent material layer 41 (the ratio of the total area of the through holes to the area of the liquid permeable layer 2) is preferably 0.1 to 20%, more preferably Is 1 to 10%, the diameter of the through hole is preferably 0.1 to 5 mm, more preferably 0.5 to 3 mm, and the interval between the through holes is preferably 0.2 to 30 mm, more preferably 5 to 20 mm.

  As shown in FIGS. 1 and 3, the embossed portion 5 </ b> A is intermittently formed on the periphery or the periphery of the excretory opening contact region 20 in the skin contact surface of the liquid permeable layer 2. The embossed part 5A is an example of a second joint part that joins the liquid-permeable layer and the absorbent material layer. In the present embodiment, the liquid-permeable layer 2 and the absorbent material layer 41 together with the liquid-permeable layer 2 and The covering layer 42 existing between the absorbent material layer 41 is bonded. In addition, in the 2nd junction part, like embossed part 5A concerning this embodiment, it is a crevice which has an opening in liquid permeable layer 2 (namely, crevice formed by being compressed from the liquid permeable layer 2 side). Alternatively, it may be a recess formed by being compressed from the absorbent material layer 41 side in a state where the liquid-impermeable layer 3 and the coating layer 43 are not laminated. The formation pattern of the embossed part 5A can be changed as appropriate. Examples of the formation pattern when the liquid-permeable layer 2 is viewed in plan include a straight line shape, a curved line shape, a ring shape, and a dot shape.

  The excretion opening contact area 20 is an area in which a wearer's excretion opening (for example, a small labia or a large labia) abuts when the sanitary napkin 1A is worn. The excretion opening | mouth contact | abutting area | region 20 is set to the approximate center of the absorptive material layer arrangement | positioning area | region. Note that the absorbent material layer arrangement region is a region where the absorbent material layer 41 overlaps the liquid permeable layer 2 when the absorbent material layer 41 is projected onto the liquid permeable layer 2. It is the substantially whole of the property layer 2 (refer FIG. 1). The position, area, and the like of the excretion opening contact region 20 can be adjusted as appropriate. The excretory opening contact area 20 may be set as an area substantially the same as the area where the excretion opening actually contacts, or may be set as a larger area, but liquid excrement such as menstrual blood From the viewpoint of preventing leakage to the outside, it is preferably set as a region larger than a region where the excretion port actually contacts. The excretion opening contact region 20 has a length of usually 50 to 200 mm, preferably 70 to 150 mm, and a width of usually 10 to 80 mm, preferably 20 to 50 mm.

  The embossed portion 5A is a recess formed by heat embossing. The embossed portion 5 </ b> A in the present embodiment is an example of a joint portion that joins the liquid permeable layer 2, the coating layer 42, and the absorbent material layer 41. The joining portion that joins the liquid permeable layer 2, the coating layer 42, and the absorbent material layer 41 is a joining method other than the heat embossing process, for example, ultrasonic embossing, heating fluid jetting process (for example, high-pressure steam jetting process, heating air) You may form by joining methods, such as injection processing.

  In the heat embossing process, a predetermined portion of the skin contact surface of the liquid permeable layer 2 is compressed in the thickness direction of the absorbent material layer 41 and heated. Thereby, embossed part 5A which unifies liquid permeable layer 2, covering layer 42, and absorptive material layer 41 in the thickness direction is formed as a crevice.

  The heat embossing process passes, for example, the liquid-permeable layer 2, the coating layer 42, and the absorbent material layer 41 between an embossing roll having convex portions provided on the outer peripheral surface and a flat roll having a smooth outer peripheral surface. And embossing. In this method, heating at the time of compression is possible by heating the embossing roll and / or the flat roll. The convex part of the embossing roll is provided so as to correspond to the shape, arrangement pattern, and the like of the pressing groove of the embossed part 5A. The heating temperature in the heat embossing treatment is usually 80 to 180 ° C., preferably 120 to 160 ° C., the pressure is 10 to 3000 N / mm, preferably 50 to 500 N / mm, and the treatment time is usually 0.0001 to 5 seconds. , Preferably 0.005 to 2 seconds.

  By the heat embossing treatment, the thermoplastic resin contained in the liquid-permeable layer 2 is converted into a material (preferably a cellulose-based water absorbent fiber) contained in the coating layer 42 and a cellulose-based water absorbent contained in the absorbent material layer 41. The liquid-permeable layer 2, the coating layer 42, and the absorbent material layer 41 are integrated by heat-sealing with fibers (preferably, a cellulose-based water-absorbing fiber and thermoplastic resin fiber). Thereby, the interfacial peel strength between the liquid-permeable layer 2 and the covering layer 42 and the interfacial peel strength between the covering layer 42 and the absorbent material layer 41 are increased. Therefore, in the sanitary napkin 1A, it is possible to prevent the liquid permeable layer 2 and the absorbent material layer 41 from being peeled off in a use environment (particularly in a wet state). In particular, the thermoplastic resin containing an unsaturated carboxylic acid, an unsaturated carboxylic acid anhydride or a mixture thereof contained in the liquid permeable layer 2 as a monomer component has a bonding strength with cellulosic water-absorbing fibers by heat fusion. Therefore, even if the absorbent material layer 41 does not contain the thermoplastic resin fiber or the amount of the thermoplastic resin fiber contained in the absorbent material layer 41 is reduced, the bonding strength by the embossed portion 5A Can be improved. Therefore, the sanitary napkin 1A may occur in a use environment (particularly in a wet state) while preventing a decrease in liquid absorbency due to the hydrophobicity of the thermoplastic resin fibers contained in the absorbent material layer 41. Separation of the liquid permeable layer 2 and the absorbent material layer 41 can be prevented. Thereby, the liquid transferability from the liquid permeable layer 2 to the absorbent material layer 41 can be smoothed. This effect is remarkable when the thermoplastic resin fiber contained in the absorbent material layer 41 is a thermoplastic resin fiber containing an unsaturated carboxylic acid, an unsaturated carboxylic acid anhydride, or a mixture thereof as a monomer component. Further, it becomes more prominent when the unsaturated carboxylic acid, unsaturated carboxylic acid anhydride, or a mixture thereof contained in the thermoplastic resin fiber is maleic acid or a derivative thereof, maleic anhydride or a derivative thereof, or a mixture thereof. .

  As shown in FIGS. 2 and 3, the embossed portion 5 </ b> B is formed in a substantially linear shape on the non-skin contact surface (clothing side) of the liquid impermeable layer 3. As shown in FIGS. 2 and 3, the two embossed portions 5 </ b> B extend in the longitudinal direction of the sanitary napkin 1 </ b> A at a constant interval. The embossed part 5B is an example of a first joint part that joins the liquid-impermeable layer and the absorbent material layer. In this embodiment, the liquid-impermeable layer 3 and the absorbent material layer 41 are liquid-impermeable. The covering layer 43 existing between the layer 3 and the absorbent material layer 41 is bonded. The formation pattern of the embossed part 5B can be changed as appropriate. Examples of the formation pattern when the liquid-impermeable layer 3 is viewed in plan include a curved shape, a ring shape, and a dot shape. Further, the end portions in the longitudinal direction of the two embossed portions 5B may be continuous to form an annular shape (for example, a circular shape, an elliptical shape, a heart shape, etc.).

  The embossed portion 5B is a recess formed by heat embossing. The embossed part 5 </ b> B in the present embodiment is an example of a joint part that joins the liquid-impermeable layer 3, the coating layer 43, and the absorbent material layer 41. The bonding part for bonding the liquid-impermeable layer 3, the coating layer 43, and the absorbent material layer 41 is a bonding method other than the heat embossing process, for example, ultrasonic embossing, heating fluid injection process (for example, high-pressure steam injection process, heating You may form by joining methods, such as an air injection process.

  In the heat embossing treatment, a predetermined portion of the non-skin contact surface of the liquid impermeable layer 3 is compressed in the thickness direction of the absorbent material layer 41 and heated. Thereby, embossed part 5B which unifies liquid impermeable layer 3, covering layer 43, and absorptive material layer 41 in the thickness direction is formed as a crevice.

  In the heat embossing process, for example, the liquid-impermeable layer 3, the coating layer 43, and the absorbent material layer 41 are placed between an embossing roll having convex portions provided on the outer peripheral surface and a flat roll having a smooth outer peripheral surface. It is performed by a method of embossing by passing. In this method, heating at the time of compression is possible by heating the embossing roll and / or the flat roll. The convex part of the embossing roll is provided so as to correspond to the shape and arrangement pattern of the pressing groove of the embossing part 5B. The heating temperature in the heat embossing treatment is usually 80 to 180 ° C., preferably 120 to 160 ° C., the pressure is 10 to 3000 N / mm, preferably 50 to 500 N / mm, and the treatment time is usually 0.0001 to 5 seconds. , Preferably 0.005 to 2 seconds.

  With the heat embossing treatment, the thermoplastic resin contained in the liquid-impermeable layer 3 becomes a cellulose-based water absorbent fiber (preferably, a cellulose-based water absorbent fiber and a thermoplastic resin fiber) contained in the absorbent material layer 41. The liquid-impermeable layer 3, the coating layer 43, and the absorbent material layer 41 are integrated by heat fusion. Thereby, the interfacial peel strength between the liquid-impermeable layer 3 and the covering layer 43 and the interfacial peel strength between the covering layer 43 and the absorbent material layer 41 are increased. Therefore, in the sanitary napkin 1A, peeling between the liquid-impermeable layer 3 and the absorbent material layer 41 that may occur in a use environment (particularly in a wet state) can be prevented. In particular, a thermoplastic resin containing an unsaturated carboxylic acid, an unsaturated carboxylic acid anhydride or a mixture thereof contained in the liquid-impermeable layer 3 as a monomer component is bonded to a cellulosic water-absorbing fiber by heat fusion. Even if the absorbent material layer 41 does not contain the thermoplastic resin fibers or the amount of the thermoplastic resin fibers contained in the absorbent material layer 41 is reduced, the embossed portion 5B is joined. Strength can be improved. Therefore, the sanitary napkin 1A may occur in a use environment (particularly in a wet state) while preventing a decrease in liquid absorbency due to the hydrophobicity of the thermoplastic resin fibers contained in the absorbent material layer 41. Separation of the liquid-impermeable layer 3 and the absorbent material layer 41 can be prevented. Thereby, the twist and deviation at the time of use of sanitary napkin 1A can be prevented. This effect is remarkable when the thermoplastic resin fiber contained in the absorbent material layer 41 is a thermoplastic resin fiber containing an unsaturated carboxylic acid, an unsaturated carboxylic acid anhydride, or a mixture thereof as a monomer component. Further, it becomes more prominent when the unsaturated carboxylic acid, unsaturated carboxylic acid anhydride, or a mixture thereof contained in the thermoplastic resin fiber is maleic acid or a derivative thereof, maleic anhydride or a derivative thereof, or a mixture thereof. .

  In the sanitary napkin 1A, the covering layer 42 and / or the covering layer 43 may be omitted. When the coating layer 42 is omitted, if the liquid-permeable layer 2 is a non-woven sheet, the interfacial peel strength during drying of the liquid-permeable layer 2 and the absorbent material layer 41 is preferably 0.97 to 4.07 N / 25 mm. The interfacial peel strength when wet of the liquid permeable layer 2 and the absorbent material layer 41 is preferably 0.75 to 4.10 N / 25 mm. If the liquid permeable layer 2 is a resin sheet, the liquid permeable layer 2 and the absorbent material layer 41 are preferably 0.76 to 10.91 N / 25 mm at the time of drying, and the wet interface peel strength of the liquid permeable layer 2 and the absorbent material layer 41 is preferably 0.00. 32 to 10.57 N / 25 mm. Moreover, when the coating layer 43 is omitted, if the liquid impermeable layer 3 is a resin sheet, the interfacial peel strength during drying of the liquid impermeable layer 3 and the absorbent material layer 41 is preferably 0.76 to 10. The interfacial peel strength when wet of the liquid impervious layer 3 and the absorbent material layer 41 is preferably 0.32 to 10.57 N / 25 mm. “N / 25 mm” means an interfacial peel strength (N) per width of 25 mm in the planar direction of the sanitary napkin 1A, and the planar direction of the sanitary napkin 1A is, for example, at the time of manufacturing the sanitary napkin 1A. The transport direction (MD direction), the direction orthogonal to the MD direction (CD direction), and the like are mentioned, and the MD direction is preferable.

The measurement of the interfacial peel strength at the time of drying is performed as follows.
A sample piece (length 40 mm × width 25 mm) at standard time (temperature 20 ° C., humidity 60%) is gripped by a tensile tester (Shimadzu Corporation, AG-1kNI) at a spacing of 20 mm, and the liquid permeable layer 2 or liquid is placed on the upper grip. The impermeable layer 3 is measured by attaching the absorbent material layer 41 to the lower grip and applying a load (maximum point load) until the sample piece completely peels off at a tensile speed of 100 mm / min. In this case, “N / 25 mm” means the interfacial peel strength (N) per 25 mm width in the length direction of the sample piece.

The measurement of the interfacial peel strength when wet is performed as follows.
After the sample piece (length 40 mm × width 25 mm) is immersed in ion-exchanged water until it sinks under its own weight, or after the sample piece has been submerged in water for 1 hour or longer, the measurement is performed in the same manner as in drying. In this case, “N / 25 mm” means the interfacial peel strength (N) per 25 mm width in the length direction of the sample piece.

  Regarding the measurement of the interfacial peel strength when dry and wet, the measurement conditions described in ISO 9073-3 or JIS L 1913 6.3 were adopted as the measurement conditions not particularly specified above.

  The sample piece used for the measurement of the interfacial peel strength between the liquid permeable layer 2 and the absorbent material layer 41 has the interfacial peel strength between the liquid impermeable layer 3 and the absorbent material layer 41 so as to include the embossed portion 5A. The sample piece used for the measurement is cut out from the sanitary napkin 1A so as to include the embossed portion 5B. For example, the sample piece is cut out from the sanitary napkin 1A so as to include a portion of the embossed portion 5A that extends in the longitudinal direction of the sanitary napkin 1A. In the sample piece thus cut out, it is preferable that the length direction thereof coincides with the extending direction of the embossed portion 5A. For example, by cutting the sanitary napkin 1A perpendicularly to the embossed portion 5A extending in the longitudinal direction, a sample piece whose length direction matches the extending direction of the embossed portion 5A can be produced.

  Desired dry and wet interfacial peel strength is the heat embossing treatment conditions, liquid permeable layer after the mass ratio of the thermoplastic resin fibers to the cellulosic water absorbent fibers in the absorbent material layer 41 is 1/9 or more. 2 or the liquid impermeable layer 3 can be realized by appropriately adjusting the type, amount, etc. of the thermoplastic resin. For example, when the liquid permeable layer 2 is a nonwoven fabric sheet, the interfacial peel strength when dried of 0.97 to 4.07 N / 25 mm and the interfacial peel strength when wet of 0.75 to 4.10 N / 25 mm are absorptive. This can be realized by setting the mass ratio of the thermoplastic resin fibers to the cellulose water-absorbing fibers contained in the material layer 41 (thermoplastic resin fibers / cellulosic water-absorbing fibers) to 1/9 to 5/5. When the liquid-permeable layer 2 or the liquid-impermeable layer 3 is a resin sheet, the interfacial peel strength when dried is 0.76 to 10.91 N / 25 mm, and the wet state is 0.32 to 10.57 N / 25 mm. The interfacial peel strength is such that the mass ratio (thermoplastic resin fiber / cellulosic water absorbent fiber) of the thermoplastic resin fiber to the cellulosic water absorbent fiber contained in the absorbent material layer 41 is 1/9 to 5/5. Can be realized.

A specific example of the manufacturing process of the sanitary napkin 1A will be described with reference to FIG.
[First step]
On the peripheral surface 151a of the suction drum 151 that rotates in the conveying direction MD, recesses 153 are formed at a required pitch in the circumferential direction as a mold for filling the absorbent material. When the suction drum 151 rotates and the recess 153 enters the material supply unit 152, the suction unit 156 acts on the recess 153, and the absorbent material supplied from the material supply unit 152 is vacuum sucked into the recess 153.

  The hooded material supply unit 152 is formed so as to cover the suction drum 151, and the material supply unit 152 supplies the mixed material 21 of the cellulosic water absorbent fiber and the thermoplastic resin fiber to the recess 153 by air conveyance. Supply. The material supply unit 152 includes a particle supply unit 158 that supplies the highly water-absorbing polymer particles 22, and supplies the highly water-absorbing polymer particles 22 to the recesses 153. Cellulose-based water-absorbing fibers, thermoplastic resin fibers, and highly water-absorbing polymer particles are supplied to the recesses 153 in a mixed state, and an absorbent material layer 224 is formed in the recesses 153. The absorbent material layer 224 formed in the recess 153 is transferred onto the carrier sheet 150 that proceeds in the transport direction MD.

[Second step]
The absorbent material layer 224 transferred onto the carrier sheet 150 travels away from the peripheral surface 151a of the suction drum 151 in the transport direction MD. In the carrier sheet 150, the absorbent material layer 224 in an uncompressed state is intermittently arranged in the transport direction MD. The heating unit 103 blows air heated to 135 ° C. at a wind speed of 5 m / sec against the upper surface of the absorbent material layer 224 and the heating unit 104 against the lower surface of the absorbent material layer 224. As a result, the thermoplastic resin fibers contained in the absorbent material layer 224 are melted, and the thermoplastic resin fibers, thermoplastic resin fibers-pulp, thermoplastic resin fibers-superabsorbent polymer particles are bonded (thermal fusion). The absorbent material layer 225 thus formed is formed. The conditions (temperature, wind speed, heating time) of the heated air blown against the absorbent material layer 224 are appropriately controlled according to the production rate and the like.

[Third step]
The breathable mesh conveyor belts 171 and 172 arranged vertically so as to form a pair run in the machine direction MD while compressing the absorbent material layer 225 on the carrier sheet 150. The dimension in the vertical direction d (the distance between the mesh conveyor belts 171 and 172) in the parallel traveling unit 175 is the gap between the upstream upper roll 176 and the upstream lower roll 177 rotating in the transport direction MD, and the downstream upper roll 178. The absorbent material layer 225 is compressed to a required thickness by the mesh conveyor bare belts 171 and 172. In FIG. 3, a steam jetting part 173 and a steam suction part 174 are arranged on the parallel running part 175 extending horizontally so as to face each other with the mesh conveyor belts 171 and 172 interposed therebetween. For example, a nozzle (not shown) having a diameter of 0.1 to 2 mm is absorbed in the steam injection unit 173 at a pitch of 0.5 to 10 mm, preferably 0.5 to 5 mm, and more preferably 0.5 to 3 mm. It is arranged in a cross direction CD (not shown) orthogonal to the machine direction MD and the vertical direction TD so as to cross the material layer 225, and each nozzle has a boiling point of water generated by the steam boiler 180 or more. The steam at the temperature is supplied through the pipe 182 as high-pressure steam adjusted to a steam pressure of, for example, 0.1 to 2.0 MPa by the pressure control valve 181. From each nozzle, high-pressure steam is jetted through the mesh conveyor belt 171 to the absorbent material layer 225 which is compressed by the mesh conveyor belts 171 and 172. The amount of high-pressure water vapor sprayed onto the absorbent material layer 225 is adjusted according to the traveling speed of the mesh conveyor belts 171 and 172, and when the mesh conveyor belts 171 and 172 are traveling at 5 to 500 m / min, are preferably injected at a range of 1.23kg / m ² ~0.03kg / m ² of the surface area of the absorbent material layer 225 faces the mesh conveyor belt 171. In the thickness direction of the absorbent material layer 225, the water vapor passes through the mesh conveyor belt 171, the absorbent material layer 225, and the mesh conveyor belt 172 in order, and is recovered by the suction action of the vacuum pressure by the steam suction unit 174. The The absorbent material layer 225 injected with the high-pressure steam proceeds in the transport direction MD, is separated from the mesh conveyor belts 171 and 172, and proceeds to the fourth step. A flange portion and a groove portion are formed on the surface of the absorbent material layer 225 to which the high-pressure steam is jetted. By adjusting the number, pitch, etc. of the nozzles of the steam injection unit 173, the number, interval, etc. of the flanges and grooves can be adjusted. Note that the portion where the high-pressure water vapor is injected becomes a groove.

  In the third process, in order to prevent the absorbent material layer 225 from being locally compressed by the mesh conveyor belts 171 and 172, at least one of the mesh conveyor belts 171 and 172 is easily deformed in the vertical direction TD. A material having sufficient flexibility is used. For the mesh conveyor belts 171 and 172, metal wire mesh belts made of stainless alloy, bronze, etc., plastic mesh belts made of polyester fiber, aramid fiber, etc. can be used. A metal belt formed of a plate may be used instead of the mesh belt. When the absorbent material layer 225 is extremely reluctant to mix metal powder, it is preferable to use a plastic mesh belt. Further, when a plastic mesh belt is required to have high heat resistance, it is preferable to use a mesh belt made of polyphenylene sulfide resin. A 10-75 mesh plain weave mesh belt using polyphenylene sulfide resin is an example of a particularly preferable mesh belt which has flexibility and can be used for both the mesh conveyor belt 171 and the mesh conveyor belt 172. It is preferable that the steam injection unit 173 and the pipe 182 are provided with appropriate heat retention measures or provided with a drain discharge mechanism. By doing so, it is possible to prevent drain generated in the steam injection unit 173 and the like from being ejected from the nozzle and excessively containing moisture in the absorbent material layer 225. The water vapor sprayed toward the absorbent material layer 225 may be dry steam that does not include a liquid component that is moisture, may be saturated steam, or may be wet steam that includes a liquid component. If the water vapor is wet or saturated steam, the pulp can be easily wetted and deformed. Dry steam can vaporize moisture contained in the pulp, and the vaporized moisture can facilitate the deformation of the pulp. Moreover, if the pulp is a thermoplastic synthetic fiber, the thermoplastic synthetic fiber can be easily deformed by the heat of the dry steam. The steam injection unit 173 may be provided with a heating mechanism to change the steam into superheated steam and spray it. It is preferable that the steam suction unit 174 has a pipe that allows the sucked high-pressure steam to go to an exhaust blower (not shown) after passing through the steam separator. In addition, the position of the steam injection part 173 and the steam suction part 174 may be switched, that is, the steam injection part 173 may be on the lower side and the steam suction part 174 may be on the upper side. Further, when it is not necessary to recover the high-pressure steam, the steam suction 174 can be performed without being arranged.

  Note that the third step may be omitted when it is not necessary to increase the density by jetting high-pressure steam.

[Fourth step]
The fourth step is an example of a step for producing a general sanitary napkin. The pair of rolls 300 and 301 cut out the absorbent material layer 226 obtained in the third step (the absorbent material layer 225 obtained in the second step when the third step is omitted) into a predetermined shape, Two coating layers are laminated on both sides of the absorbent material layer 226 to form an absorbent body. The liquid permeable layer is supplied from the roll 302 and sealed with heated embosses 303 and 304 having a high pressure portion and a low pressure portion, and the liquid permeable layer and the absorbent body are integrated. Thereafter, a liquid impervious layer is supplied from the roll 305, and the product is passed through steps 306 and 307 for sealing the peripheral edge of the product by heat embossing while the absorber is sandwiched between the liquid permeable layer and the liquid impermeable layer. Finally, it is cut into a product shape by steps 308 and 309.

Second Embodiment
A sanitary napkin 1B according to the second embodiment will be described with reference to FIG.
As shown in FIG. 4, the sanitary napkin 1 </ b> B according to the second embodiment is provided between the liquid-permeable layer 2, the liquid-impermeable layer 3, the liquid-permeable layer 2, and the liquid-impermeable layer 3. The absorbent material layer 41 thus formed, the coating layer 42 covering the surface of the absorbent material layer 41 on the liquid permeable layer 2 side, and the coating covering the surface of the absorbent material layer 41 on the liquid impermeable layer 3 side The layer 43, and the liquid impermeable layer 3, the coating layer 43, the absorbent material layer 41, the coating layer 42, and the embossed portion 5C that integrates the liquid permeable layer 2 are provided.

  As shown in FIG. 4, the sanitary napkin 1B has the same basic configuration as the sanitary napkin 1A except that an embossed part 5C is formed instead of the embossed parts 5A and 5B. In FIG. 4, the same members and portions as those of the sanitary napkin 1A are denoted by the same reference numerals, and description thereof is omitted unless necessary.

  Although illustration is omitted, the embossed portion 5C is intermittently formed on the periphery or the periphery of the excretory opening contact region 20 in the skin contact surface of the liquid permeable layer 2 in the same manner as the embossed portion 5A (see FIG. 1). Has been. The embossed portion 5C is an example of a first joint portion that joins the liquid-impermeable layer and the absorbent material layer. In the present embodiment, the liquid-permeable layer is used together with the liquid-impermeable layer 3 and the absorbent material layer 41. 2. The covering layer 42 and the covering layer 43 are joined. In addition, like the embossed part 5C according to the present embodiment, the first joint part is a concave part having an opening in the liquid permeable layer 2 (that is, a concave part formed by being compressed from the liquid permeable layer 2 side). As with the embossed part 5B according to the first embodiment, the liquid impervious layer 3 has an opening (that is, a recessed part formed by being compressed from the liquid impermeable layer 3 side). There may be. The formation pattern of the embossed portion 5C can be changed as appropriate. Examples of the formation pattern when the liquid permeable layer 2 is viewed in plan include a straight line shape, a curved line shape, a circular shape, and a dot shape.

  The embossed portion 5C is a recess formed by heat embossing. The embossed portion 5 </ b> C in the present embodiment is an example of a joint that joins the liquid permeable layer 2, the coating layer 42, the absorbent material layer 41, the coating layer 43, and the liquid impermeable layer 3. The bonding part for bonding the liquid permeable layer 2, the coating layer 42, the absorbent material layer 41, the coating layer 43, and the liquid impermeable layer 3 is a bonding method other than heat embossing, for example, ultrasonic embossing, heating fluid injection You may form by joining methods, such as processing (for example, high-pressure steam injection processing, heating air injection processing, etc.).

  In the heat embossing process, a predetermined portion of the skin contact surface of the liquid permeable layer 2 is compressed in the thickness direction of the absorbent material layer 41 and heated. Thus, an embossed portion 5C that integrates the liquid permeable layer 2, the coating layer 42, the absorbent material layer 41, the coating layer 43, and the liquid impermeable layer 3 in the thickness direction is formed as a concave portion. A heat embossing process can be implemented similarly to the case of the embossed parts 5A and 5B.

  By the heat embossing treatment, the thermoplastic resin contained in the liquid permeable layer 2 is converted into the material of the coating layer 42 (preferably, a cellulose-based water absorbent fiber) and the cellulose-based water absorbent fiber contained in the absorbent material layer 41. (Preferably, the cellulose-based water-absorbing fiber and the thermoplastic resin fiber) are heat-sealed, and the thermoplastic resin contained in the liquid-impermeable layer 3 is used as the material for the coating layer 43 (preferably, the cellulose-based water-absorbing fiber. ) And a cellulosic water-absorbing fiber (preferably a cellulosic water-absorbing fiber and a thermoplastic resin fiber) contained in the absorbent material layer 41, and the liquid-permeable layer 2, the coating layer 42, The absorbent material layer 41, the coating layer 43, and the liquid impermeable layer 3 are integrated. Thereby, the interfacial peel strength between the liquid permeable layer 2 and the covering layer 42, the interfacial peel strength between the covering layer 42 and the absorbent material layer 41, the interfacial peel strength between the covering layer 43 and the absorbent material layer 41, and the liquid The interfacial peel strength between the impermeable layer 3 and the coating layer 43 increases.

  The interfacial peel strength during drying of the absorbent material layer 41 and the coating layer 42 and the interfacial peel strength during drying of the absorbent material layer 41 and the coating layer 43 are preferably 1.75 to 4.23 N / 25 mm. The interfacial peel strength when wet of the material layer 41 and the coating layer 42 and the interfacial peel strength when dry of the absorbent material layer 41 and the cover layer 43 are preferably 1.05 to 2.63 N / 25 mm. Note that “N / 25 mm” means the interfacial peel strength (N) per width of 25 mm in the planar direction of the sanitary napkin 1B, and the planar direction of the sanitary napkin 1B is, for example, during the manufacture of the sanitary napkin 1A. The transport direction (MD direction), the direction orthogonal to the MD direction (CD direction), and the like are mentioned, and the MD direction is preferable.

  Desired dry and wet interfacial peel strengths are such that the mass ratio of the thermoplastic resin fibers to the cellulosic water-absorbing fibers contained in the absorbent material layer 41 is 1/9 or more, heat embossing treatment conditions, coating This can be realized by appropriately adjusting the type, amount, etc. of the cellulosic water-absorbing fibers contained in the layers 42 and 43. For example, the interfacial peel strength when dried of 1.75 to 4.23 N / 25 mm and the interfacial peel strength when wet of 1.05 to 2.63 N / 25 mm are the cellulose-based water absorbent fibers contained in the absorbent material layer 41. This can be realized by setting the mass ratio of the thermoplastic resin fibers to 1/9 to 5/5 (thermoplastic resin fibers / cellulosic water-absorbing fibers).

  In the sanitary napkin 1B, the covering layer 42 and / or the covering layer 43 may be omitted. When the coating layer 42 is omitted, if the liquid-permeable layer 2 is a non-woven sheet, the interfacial peel strength during drying of the liquid-permeable layer 2 and the absorbent material layer 41 is preferably 0.97 to 4.07 N / 25 mm. The interfacial peel strength when wet of the liquid permeable layer 2 and the absorbent material layer 41 is preferably 0.75 to 4.10 N / 25 mm. If the liquid permeable layer 2 is a resin sheet, the liquid permeable layer 2 and the absorbent material layer 41 are preferably 0.76 to 10.91 N / 25 mm at the time of drying, and the wet interface peel strength of the liquid permeable layer 2 and the absorbent material layer 41 is preferably 0.00. 32 to 10.57 N / 25 mm. Moreover, when the coating layer 43 is omitted, if the liquid impermeable layer 3 is a resin sheet, the interfacial peel strength during drying of the liquid impermeable layer 3 and the absorbent material layer 41 is preferably 0.76 to 10. The interfacial peel strength when wet of the liquid impervious layer 3 and the absorbent material layer 41 is preferably 0.32 to 10.57 N / 25 mm. Note that “N / 25 mm” means the interfacial peel strength (N) per width of 25 mm in the planar direction of the sanitary napkin 1B, and the planar direction of the sanitary napkin 1B is, for example, when the sanitary napkin 1B is manufactured. The transport direction (MD direction), the direction orthogonal to the MD direction (CD direction), and the like are mentioned, and the MD direction is preferable.

EXAMPLES Hereinafter, although this invention is demonstrated further in detail based on an Example, the scope of the present invention is not limited to an Example.
[Example 1]

(1) Preparation of Absorbent Material A (A1 to A7) Pulp (manufactured by Warehauser, NB416) and heat-fusible conjugate fiber A (hereinafter referred to as “composite fiber A”), 9: 1 (A1), 8: 2 (A2), 6.5: 3.5 (A3), 5: 5 (A4), 3.5: 6.5 (A5), 2: 8 (A6), 0:10 (A7) Absorbent materials A1 to A7 (basis weight 200 g / m ² ) were prepared by blending at a mass ratio.

  The composite fiber A is a core-sheath type composite fiber having polyethylene terephthalate (PET) as a core component and high-density polyethylene (HDPE) graft-polymerized with a vinyl polymer containing maleic anhydride as a sheath component. The core-sheath ratio of the composite fiber A is 50:50 (mass ratio), the amount of titanium oxide in the core component is 0.7% by weight, the fineness is 2.2 dtex, and the fiber length is 6 mm.

(2) Preparation of absorbent material B (B1 to B9) Pulp (manufactured by Warehauser, NB416) and heat-fusible conjugate fiber B (hereinafter referred to as “composite fiber B”), 9: 1 (B1), 8.5: 1.5 (B2), 8: 2 (B3), 6.5: 3.5 (B4), 5: 5 (B5), 3.5: 6.5 (B6), 2: 8 Absorbent materials B1 to B9 (basis weight 200 g / m ² ) were prepared by blending at a mass ratio of (B7), 0:10 (B8), and 10: 0 (B9).

  The composite fiber B is a core-sheath type composite fiber having polyethylene terephthalate (PET) as a core component and general high-density polyethylene (HDPE) as a sheath component. The core-sheath ratio of the composite fiber B is 50:50 (mass ratio), the amount of titanium oxide in the core component is 0.7% by weight, the fineness is 2.2 dtex, and the fiber length is 6 mm.

(3) Manufacture of absorber samples A (A1 to A7) and B (B1 to B9) The absorber materials A1 to A7 and B1 to B9 are bonded by a general through air method, and the composite fibers A and B are heated. The samples A1 to A7 and B1 to B9 were prepared by fusing. At this time, the heating temperature was set to 135 ° C., the air volume was set to 5 m / second, and the heating time was set to 20 seconds.

(4) Measurement of maximum tensile strength [maximum tensile strength during drying (N / 25 mm)]
Sample pieces (length 150 mm x width 25 mm, 5 pieces) at standard time (temperature 20 ° C, humidity 60%) are attached to a tensile tester (Shimadzu Corporation, AG-1kNI) at a grip interval of 100 mm, and a tensile speed of 100 mm / min. Then, a load (maximum point load) was applied until the sample piece was cut, and the maximum tensile strength per 25 mm width in the length direction (MD direction) of the sample piece was measured.

[Maximum tensile strength when wet (N / 25mm)]
After immersing a sample piece (length 150 mm x width 25 mm) in ion-exchanged water until it sinks under its own weight, or after submerging the sample piece in water for 1 hour or longer, the length direction of the sample piece is the same as above. The maximum tensile strength per 25 mm width in the (MD direction) was measured (ISO 9073-3, JIS L 1913 6.3). Regarding the measurement of the maximum tensile strength when dry and wet, the measurement conditions described in ISO 9073-3 or JIS L 1913 6.3 were adopted for the measurement conditions not particularly specified above. The measurement of the maximum tensile strength during drying and wetness in other examples was also performed in the same manner as described above.

(5) Measurement of basis weight, thickness and density of absorbent sample [basis weight]
Measurement of the basis weight (g / m ² ) of the absorber sample was performed as follows.
Three pieces of 100 mm × 100 mm sample pieces are cut out from the absorber sample, and the mass of each sample piece in the standard state (temperature 23 ± 2 ° C., relative humidity 50 ± 5%) is directly indicated (Electronic balance manufactured by Kensei Industry Co., Ltd.) HF-300) and the mass per unit area (g / m ² ) of the absorbent core calculated from the average value of the three measured values was taken as the basis weight of the absorbent sample.
In addition, regarding the measurement of the basis weight of the absorber sample, the measurement conditions described in ISO 9073-1 or JIS L 1913 6.2 were adopted for the measurement conditions not particularly specified above.

[Thickness]
The thickness (mm) of the absorber sample was measured as follows.
Thickness gauge by (Ltd. Daiei Kagaku Seiki Seisakusho FS-60DS, measurement surface 44 mm (diameter), measuring pressure 3 g / cm ^2), the absorber in the standard state (temperature 23 ± 2 ° C., a relative humidity of 50 ± 5%) Pressurize five different parts of the sample (the diameter of each part is 44 mm) with a constant pressure of 3 g / cm ² , measure the thickness of each part 10 seconds after pressurization, and calculate the average of the five measurements as the absorber sample It was set as the thickness.

[density]
The density of the absorber sample was calculated based on the following equation.
D (g / cm ³ ) = B (g / m ² ) / T (mm) × 10 ⁻³
[In formula, D, B, and T represent the density, basic weight, and thickness of an absorptive core, respectively. ]
In addition, the measurement of the basic weight of the absorber sample in another Example, thickness, and a density was implemented similarly to the above.

(5) Results and discussion Table 1 shows the measurement results.

The consideration based on Table 1 is as follows.
In the absorbent sample A, when the mixing ratio (mass ratio) of the composite fiber A to the pulp is less than 1/9, the maximum tensile strength when wet is expected to be less than 2 N / 25 mm, and the strength when wet cannot be secured. There is a fear. Therefore, in the absorber sample A, it is considered that the mixing ratio (mass ratio) of the composite fiber A with respect to the pulp is preferably 1/9 or more from the viewpoint of maintaining strength.

  In the absorbent sample B, when the mixing ratio (mass ratio) of the composite fiber B to the pulp is 1.5 / 8.5 or less, the maximum tensile strength when wet is less than 2 N / 25 mm, and the strength when wet is ensured. It may not be possible. Therefore, in the absorber sample B, it is thought that it is preferable that the mixing ratio (mass ratio) of the composite fiber B with respect to pulp exceeds 1.5 / 8.5 from the viewpoint of maintaining strength.

  When the absorber samples having the same mixing ratio (mass ratio) between the pulp and the composite fibers A and B (for example, the absorber sample A1 and the absorber sample B1) are compared, the maximum tensile strength (when dry and when wet) is In any mixing ratio (mass ratio), the absorber sample A is larger than the absorber sample B. Moreover, when the mixing ratio (mass ratio) of the pulp and the composite fibers A and B is in the range of 9: 1 to 3.5: 6.5 (absorber samples A1 to A5, B1 to B6), The difference between the maximum tensile strength and the maximum tensile strength when wet (the maximum tensile strength when dry-the maximum tensile strength when wet) is greater in the absorbent sample A than in the absorbent sample B.

  In the absorber sample A, such a difference in strength is caused by hydrogen bonds between the acyl groups of maleic anhydride and the oxygen atoms of ether bonds and the OH groups of cellulose. It is considered that such a hydrogen bond does not occur.

  This is also supported by the maximum tensile strength of the web sample. That is, when the maximum tensile strength of the sample in the web state was measured, all samples were less than 0.4 N / 25 mm (see Table 1), and the difference in strength was not caused by the difference in the degree of entanglement. This suggests that it is caused by the presence or absence of hydrogen bond formation. The sample in the web state is a sample which has not been subjected to any treatment after the absorber material is laminated on the base material, and is entangled with needle punch, heat treatment with hot air, embossing, energy wave, etc., adhesion No treatment such as treatment with an agent is performed.

  In addition, as shown in Table 2 below, because the composite fiber A has a higher heat of fusion than the composite fiber B, the composite fiber A has a higher crystallinity than the composite fiber B, and the difference in strength is as follows. , B is considered to be caused by a difference in crystallinity (bonding strength of the fiber itself).

  In JP-A-2004-270041, a modified polyolefin obtained by graft polymerization of maleic anhydride is bonded to a cellulose fiber because a carboxylic anhydride group of maleic anhydride is cleaved and covalently bonded to a hydroxyl group on the surface of the cellulose fiber. However, in this result, an increase in strength due to the formation of a covalent bond was not observed.

[Example 2]
(1) Production of absorber samples C (C1 to C7) and D (D1 to D9) Absorbent materials A1 to A7 (see Example 1) on a carrier sheet (manufactured by UCKN, tissue basis weight: 14 g / m ² ) And bonded by a general through-air method, and the composite fiber A is heated and fused (heating temperature: 135 ° C., air volume: 5 m / second, heating time: 20 seconds), and then a steam jet (SJ) belt. adjust with press machine to a density of about ^{0.08g / cm 3 (0.0793~0.0817g / cm} 3), was prepared absorber sample C1~C7 (120mm × 120mm, the three).
Absorber samples D1 to D9 (120 mm × 120 mm, 3 sheets each) were similarly manufactured using the absorber materials B1 to B9 (see Example 1).

The structure of the used SJ belt press is shown in FIG.
As shown in FIG. 6A, the SJ belt press machine 9 includes mesh conveyor belts 91a and 91b, a steam nozzle 92, and a suction box 93, and the steam nozzle 92 and the suction box 93 facing each other. In the meantime, the absorber sandwiched between the pair of mesh conveyor belts 91a and 91b is transported, and high-pressure steam is jetted from the steam nozzle 92 toward the absorber to compress the absorber. The water vapor that has passed through the absorber is sucked by the suction box 93 and exhausted. The thickness of the absorber can be adjusted by adjusting the distance between the pair of mesh conveyor belts 91a and 91b.

  The mesh conveyor belts 91a and 91b are polyphenylene sulfide plain weave mesh conveyors (manufactured by Nippon Filcon Co., Ltd.). The vertical and horizontal wire diameters are 0.37 mm, the vertical lines are 34 / inch, and the horizontal lines are 32 / inch. The distance between the mesh conveyor belts 91a and 91b is adjusted to 1 mm or 0.2 mm, and the line speed is 200 m / sec.

As shown in FIG. 6B, the steam nozzle 92 is formed with openings having a diameter of 0.5 mm with an opening pitch of 2 mm and 5 mm, and the steam pressure of water vapor ejected therefrom is 0.7 MPa. Yes, the steam throughput is 1.27 kg / m ² per unit area.

(2) Measurement of absorptivity (penetration time, liquid brushing time) A surface sheet (uses a surface sheet of Sophia Haodai) is placed on each absorber sample piece, and a perforated acrylic plate (in the center) 40 mm × 10 mm holes, 200 mm (length) × 100 mm (width)) were stacked. Using autoburet (Shibata Chemical Instruments Co., Ltd., Multidojimat E725-1 type), artificial menstrual blood (80 g of glycerin, 1 liter of ion-exchanged water, sodium carboxymethylcellulose) toward the hole in the acrylic plate 8 g, sodium chloride 10 g, sodium hydrogen carbonate 4 g, red No. 102 8 g, red No. 2 2 g and yellow No. 5 2 g were used, and 3 ml was injected at 90 ml / min. The time from the start of injection until the artificial menstrual blood staying in the hole in the acrylic plate disappeared was the permeation time (seconds), and the time from the start of injection until the artificial menstrual blood disappeared from the surface sheet was taken as the brush time (seconds) .

(3) Measurement of the maximum tensile strength at the time of drying and wet The maximum tensile strength at the time of drying and wet of each absorber sample piece was measured in the same manner as in Example 1.

(4) Results and discussion Table 3 shows the measurement results.

  As shown in Table 3, when the mixing ratio (mass ratio) of the pulp and the composite fiber A is in the range of 9: 1 to 5: 5 (absorber samples C1 to C4), the absorbability of the absorber sample is sufficient However, when the mixing ratio (mass ratio) of the pulp and the composite fiber A is in the range of 3.5: 6.5 to 0:10 (absorber samples C5 to C7), Absorbability was significantly reduced.

  As shown in Table 3, in the absorbent sample C, when the mixing ratio (mass ratio) of the composite fiber A to the pulp is less than 1/9, the maximum tensile strength when wet is expected to be less than 2 N / 25 mm, There is a possibility that strength when wet cannot be secured. Therefore, in the absorbent sample C, it is considered that the mixing ratio (mass ratio) of the composite fiber A to the pulp is preferably 1/9 or more from the viewpoint of maintaining strength.

  As shown in Table 3, in the absorbent sample D, when the mixing ratio (mass ratio) of the composite fiber B to the pulp is 1.5 / 8.5 or less, the maximum tensile strength when wet is less than 2 N / 25 mm. There is a possibility that strength when wet cannot be secured. Therefore, in the absorber sample D, it is thought that it is preferable that the mixing ratio (mass ratio) of the composite fiber B with respect to pulp exceeds 1.5 / 8.5 from the viewpoint of maintaining strength.

From the results shown in Table 3, when the density of the absorber is about 0.08 g / cm ³ (0.0793 to 0.0817 g / cm ³ ), the mixing ratio (mass ratio) of the pulp and the composite fiber A is 9 : In the range of 1 to 5: 5, it was revealed that the absorber has sufficient strength and absorbency. This is because the composite fiber A can secure the strength of the absorbent body in a smaller amount than the composite fiber B (thus, without inhibiting the absorbability).

Example 3
In Example 2, the fixed system a density of about ^{0.08g / cm 3 (0.0793~0.0817g / cm} 3), the mixing ratio of the intensity and from the standpoint of the absorbent, pulp and composite fibers A (mass Ratio) was examined.
In this example, the optimum range of density was examined from the viewpoint of absorbability.

In the same manner as in Example 2, using a pulp (basis weight: 200 g / m ² ) obtained by blending pulp (Warehauser, NB416) and composite fiber A at a mixing ratio (mass ratio) shown in Table 5, Absorber samples E1 to E9 of various densities (0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.12, 0.13, 0.14 g / cm ³ ) Was measured and absorbency (liquid brushing time) was measured.
Table 4 shows the measurement results.

From the measurement results shown in Table 4, the following became clear.
When the mixing ratio (mass ratio) of pulp and composite fiber A is in the range of 9: 1 to 5: 5, sufficient liquid brush performance (specifically, the liquid brush time after dropping 3 cc of artificial menstrual blood is 90. (Within seconds) is 0.06 to 0.14 g / cm ³ .

When the density is less than 0.06 g / cm ³ , the liquid brush time exceeds 90 seconds at any mixing ratio. If the density is less than 0.06 g / cm ³ , it is considered that the interfiber distance is large and the capillary force does not act.

When the density exceeds 0.12 g / cm ³ , the liquid brushing time is within 60 seconds when the mixing ratio (mass ratio) of the pulp and the composite fiber A is in the range of 9: 1 to 6.5: 3.5. However, in other ranges, it exceeds 60 seconds. When the density exceeds 0.12 g / cm ³ , the capillary action works, but the liquid movement gap becomes small and the liquid movement resistance increases, so the liquid brushing performance is considered to deteriorate.

From the results of Examples 1 to 3, the optimum range of the mixing ratio (mass ratio) of pulp and composite fiber A is 9: 1 to 5: 5, and the optimum density is 0.06 to 0.14 g / cm ³ . It became clear that there was.

Example 4
(1) Manufacture of Absorbent Material F (F1 to F5) Pulp (manufactured by Warehauser, NB416) and composite fiber A were mixed with 9: 1 (F1), 8: 2 (F2), and 6.5: 3. Absorbent materials F1 to F5 (basis weight 200 g / m 2) were produced by blending at a mass ratio of 5 (F3), 5: 5 (F4), and 10: 0 (F5).

(2) Production of absorber material G (G1 to G5) Pulp (manufactured by Werehauser, NB416) and composite fiber B are mixed with 9: 1 (G1), 8: 2 (G2), 6.5: 3. Absorbent materials G1 to G5 (basis weight 200 g / m 2) were produced by blending at a mass ratio of 5 (G3), 5: 5 (G4), and 10: 0 (G5).

(3) Manufacture of absorber samples F (F1 to F5) and G (G1 to G5) The absorber materials F1 to F5 and G1 to G5 are bonded by a general through-air method, and the composite fibers A and B are heated. The absorber samples F1 to F5 and G1 to G5 were manufactured by fusing. At this time, the heating temperature was set to 135 ° C., the air volume was set to 5 m / second, and the heating time was set to 20 seconds.

(4) Production of Resin Sheet A A resin sheet A of high density polyethylene (HDPE) grafted with a vinyl polymer containing maleic anhydride was produced.

(5) Manufacture of integrated samples F (F1 to F5) and G (G1 to G5) Absorber samples F (F1 to F5) and G (G1) cut to a size of 100 mm (MD direction) x 80 mm (CD direction) To G5) (Each basis weight is 200 g / m ² ), a resin sheet A cut out to a size of 100 mm (MD direction) × 80 mm (CD direction) is laminated, and embossing treatment (embossing pattern from the resin sheet side) -1 and embossed pattern-2) were performed to produce integrated samples F (F1 to F5) and G (G1 to G5).

(6) Embossing of embossing pattern-1 is a resin sheet side (upper side) embossing plate on which a large number of convex portions are formed (tip diameter of each convex portion: 3 mm, pitch between convex portions: vertical 11 mm) × 11 mm wide, height of each convex part: 6 mm, heating temperature: 135 ° C., using a flat plate (heating temperature: 135 ° C.) as an embossed plate on the integrated sample side (lower side), pressure It was performed at 100 N / mm 2 and an emboss time of 1 second.
(7) Embossed pattern-2
The embossing process of the embossing pattern-2 was performed by changing the pressure under conditions of a temperature of 110 ° C. and a time of 3 seconds using embossing continuous in the longitudinal direction. The embossing pressure was changed to 1 MPa (1.0 kPa) / mm ² , 3 Mpa (3.0 kPa / mm ² ) and 5 Mpa (5.0 kPa / mm ² ). When the integrated sample was viewed from the nonwoven fabric side by embossing, an embossed portion extending in the longitudinal direction was formed. The embossed portion includes a low-pressure squeezed portion and a high-pressure squeezed portion, and the embossed area (high-pressure squeezed portion + low-pressure squeezed portion) was 991.66 mm ² .

(8) Measurement of interfacial peel strength Interfacial peel at the time of drying and wetting of each of the integrated samples F (F1 to F5) and G (G1 to G5) subjected to the treatment of embossing pattern-1 and embossing pattern-2 The strength was measured.

[Interfacial peel strength during drying (N / 25mm)]
Standard sample (temperature 20 ° C, humidity 60%) sample piece (length 40mm x width 25mm, including 8 embossed parts) is gripped by a tensile tester (Shimadzu Corporation, AG-1kNI) at an interval of 20mm. And the resin sheet was attached to the lower grip. A load was applied at a tensile speed of 100 mm / min until the sample piece completely peeled, and the interfacial peel strength per 25 mm width in the length direction (MD direction) of the sample piece was measured.

[Interfacial peel strength when wet (N / 25 mm)]
After immersing a sample piece (length 40 mm x width 25 mm) in ion-exchanged water until it sinks under its own weight, or after submerging the sample piece in water for 1 hour or longer, the length direction of the sample piece is the same as above. The interfacial peel strength per 25 mm width in the (MD direction) was measured.

  Regarding the measurement of the interfacial peel strength when dry and wet, the measurement conditions described in ISO 9073-3 or JIS L 1913 6.3 were adopted as the measurement conditions not particularly specified above.

(9) Results and discussion Table 5 shows the measurement results.

The consideration based on Table 5 is as follows.
Interfacial peel strength between the absorber (the absorbent material layer in the present invention, the same applies hereinafter) and the resin sheet (the liquid impermeable layer or the liquid permeable layer in the present invention, the same applies hereinafter). Is 0.49 N / 25 mm or more, during use of the absorbent article, the interfacial peeling between the absorber and the resin sheet hardly occurs, the resin sheet and the absorber are integrated, and the resin sheet is liquid-impermeable. When used as a conductive layer, it leads to the prevention of twisting and displacement, and when the resin sheet is used as a liquid-permeable layer, it leads to good liquid migration from the resin sheet to the absorber. Therefore, assuming that the dry and wet interfacial peel strength is preferably 0.49 N / 25 mm or more, the integrated samples F2 to F4 satisfy this standard. Therefore, the mass mixing ratio of the composite fiber A to the pulp in the absorbent body is preferably 2/8 or more from the viewpoint of increasing the interfacial peel strength during drying and wetting, whereby 1.23 N / 25 mm or more. Interfacial peel strength during drying (embossing pattern-1), interfacial peel strength during drying (embossing pattern-2) of 3.58 N / 25 mm or more, and interfacial peeling strength during wetness of 0.98 N / 25 mm or more (embossing pattern-1) ) And 3.35 N / 25 mm or more of interfacial peel strength (embossed pattern-2). In addition, by setting the mass mixing ratio of the composite fiber A to the pulp in the absorber to 2/8 to 5/5, in the embossed pattern-1, the interfacial peel strength during drying of 1.23 to 2.95 N / 25 mm, And embossing pattern-2, the interfacial peel strength at drying of 3.58 to 10.91 N / 25 mm, and the embossing pattern-1 at wet interfacial peel strength of 0.98 to 2.78 N / 25 mm, and embossing In the pattern-2, it is possible to realize a wet interfacial peel strength of 3.35 to 10.57 N / 25 mm.

  Comparing the integrated samples (ie, F1 and G1, F2 and G2, F3 and G3, and F4 and G4) having the same mass mixing ratio of the composite fibers A and B to the pulp in the absorbent body are dry and wet. The interfacial peel strength is greater in the integrated sample F than in the integrated sample G at any mass mixing ratio. Therefore, when the mass mixing ratio of the composite fibers A and B to the pulp in the absorbent body is the same, when using the composite fiber A, the interfacial peel strength at the time of drying and wetting is higher than when using the composite fiber B. Can be increased. In addition, when it is desired to achieve a constant dry and wet interfacial peel strength, the composite fiber A is smaller in mass mixing ratio of the composite fiber to the pulp in the absorbent body than in the case of using the composite fiber B. (That is, the mass mixing ratio of the pulp in the absorbent body is increased correspondingly, and the absorbent performance of the absorbent body can be improved).

Example 5
(1) Production of Absorbent Material H (H1 to H5) Pulp (manufactured by Warehauser, NB416) and composite fiber A were mixed with 9: 1 (H1), 8: 2 (H2), and 6.5: 3. Absorbent materials H1 to H5 (basis weight ^{200 I} / m ² ) were manufactured by blending at a mass ratio of 5 (H3), 5: 5 (H4), and 10: 0 (H5).

(2) Manufacture of Absorbent Material I (I1 to I5) Pulp (manufactured by Warehauser, NB416) and composite fiber B were mixed with 9: 1 (I1), 8: 2 (I2), 6.5: 3. Absorbent materials I1 to I5 (basis weight 200 I / m ² ) were produced by blending at a mass ratio of 5 (I3), 5: 5 (I4), and 10: 0 (I5).

(3) Manufacture of absorber samples H (H1 to H5) and I (I1 to I5) The absorber materials H1 to H5 and I1 to I5 are bonded by a general through-air method, and the composite fibers A and B are heated. By fusing, absorber samples H1 to H5 and I1 to I5 were prepared. At this time, the heating temperature was set to 135 ° C., the air volume was set to 5 m / second, and the heating time was set to 20 seconds.

(4) Production of Non-woven Sheet A Core-sheath type composite fiber (1.7 dt ×) having polypropylene (PP) as a core component and high-density polyethylene (HDPE) graft-polymerized with a vinyl polymer containing maleic anhydride as a sheath component 38 mm, basis weight 25 I / m @ 2) was produced by a general through air method to produce a nonwoven sheet A. At this time, the heating temperature was set to 135 ° C., the air volume was set to 5 m / second, and the heating time was set to 20 seconds.

(5) Production of integrated samples H (H1 to H5) and I (I1 to I5) Absorber samples H (H1 to H5) and I (I1) cut into a size of 100 mm (MD direction) × 80 mm (CD direction) ~ I5) A nonwoven fabric sheet A cut out to a size of 100 mm (MD direction) × 80 mm (CD direction) is laminated on the upper surface of each (basis weight 200 g / m ² ), and embossing treatment (embossing pattern) from the nonwoven fabric sheet side -1 and embossing pattern-2) were performed to produce integrated samples H (H1 to H5) and I (I1 to I5). The embossing process (embossing pattern-1 and embossing pattern-2) was performed in the same manner as in Example 4.

(6) Measurement of interfacial peel strength Interfacial exfoliation during drying and wetting of each of the integrated samples H (H1 to H5) and I (I1 to I5) subjected to the treatment of emboss pattern-1 and emboss pattern-2 The strength was measured in the same manner as in Example 4.

(7) Results and discussion Table 6 shows the measurement results.

The consideration based on Table 6 is as follows.
When the interfacial peel strength between the absorbent body and the nonwoven fabric sheet (which is a liquid-permeable layer in the present invention; hereinafter the same) is 0.49 N / 25 mm or more, the absorbent body and the nonwoven fabric are used during use of the absorbent article. Interfacial peeling from the sheet is unlikely to occur, and liquid transfer from the nonwoven sheet to the absorbent body is good. Therefore, assuming that the dry and wet interfacial peel strength is preferably 0.49 N / 25 mm or more, the integrated samples H1 to H4 satisfy this standard. Therefore, the mass mixing ratio of the composite fiber A to the pulp in the absorber is 1/9 or more, which is advantageous in terms of increasing the interfacial peel strength during drying and wetting, and thereby 0.97 N / 25 mm or more. Interfacial peel strength during drying (embossing pattern-1) and interfacial peel strength during drying (embossing pattern-2) of 1.83 N / 25 mm or more, and interfacial peeling strength during emulsification (embossing pattern-1) of 0.68 N / 25 mm or more ) And 1.09 N / 25 mm or more of interfacial peel strength (embossing pattern-2). Further, by setting the mass mixing ratio of the composite fiber A to the pulp in the absorbent body to 1/9 to 5/5, in the embossed pattern-1, the interfacial peel strength during drying of 0.97 to 2.63 N / 25 mm, In the embossed pattern-2, the interfacial peel strength during drying of 1.83 to 4.07 N / 25 mm, and in the embossed pattern-1, the interfacial peel strength during wetness of 0.68 to 2.09 N / 25 mm, and the embossed pattern In the pattern-2, the interfacial peel strength at the time of 1.09 to 4.10 N / 25 mm can be realized.

  Comparing integrated samples (ie, H1 and I1, H2 and I2, H3 and I3, and H4 and I4) having the same mass mixing ratio of the composite fibers A and B to the pulp in the absorbent body, when dry and wet The interfacial peel strength is larger in the integrated sample H than in the integrated sample I at any mass mixing ratio. Therefore, when the mass mixing ratio of the composite fibers A and B to the pulp in the absorbent body is the same, when using the composite fiber A, the interfacial peel strength at the time of drying and wetting is higher than when using the composite fiber B. Can be increased. In addition, when it is desired to achieve a constant dry and wet interfacial peel strength, the composite fiber A is smaller in mass mixing ratio of the composite fiber to the pulp in the absorbent body than in the case of using the composite fiber B. (That is, the mass mixing ratio of the pulp in the absorbent body is increased accordingly, and the absorbent performance of the absorbent body can be improved).

Example 6
(1) Production of absorber material J (J1 to J4) Pulp (manufactured by Werehauser, NB416) and composite fiber A were mixed with 9: 1 (J1), 8.8: 2 (J2), 6.5: Absorbent materials J1 to J4 (basis weight 200 g / m ² ) were manufactured by blending at a mass ratio of 3.5 (J3) and 5: 5 (J4).

(2) Production of absorber material K (K1 to K5) Pulp (manufactured by Warehauser, NB416) and composite fiber B were mixed with 9: 1 (K1), 8: 2 (K2), 6.5: 3. Absorbent materials K1 to K5 (basis weight 200 g / m ² ) were produced by blending at a mass ratio of 5 (K3), 5: 5 (K4), and 10: 0 (K5).

(3) Manufacture of absorber samples J (J1 to J4) and K (K1 to K5) The absorber materials J1 to J4 and K1 to K5 are bonded by a general through air method, and the composite fibers A and B are heated. By fusing, absorber samples J1 to J4 and K1 to K5 were produced. At this time, the heating temperature was set to 135 ° C., the air volume was set to 5 m / second, and the heating time was set to 20 seconds.

(4) Manufacture of integrated samples J (J1 to J4) and K (K1 to K5) The bottom surface of the absorber samples J (J1 to J4) and K (K1 to K5) are manufactured by Unicharm Kokumi Non-Woven Co., Ltd. Tissue (composition: NBKP (beating) 67.9%, NBKP (non-beating) 29.1%, paper strength enhancer (polyacrylamide) 2.14%, paper strength enhancer (polyamide epichlorohydrin) 0.86%, basis weight: 20 g / m ² , MD direction strength (maximum point strength): 16.8 N / 25 mm, CD direction strength (maximum point strength): 2.9 N / 25 mm, thickness: 0.1 mm ) And heat embossing from the absorber sample side, and the absorber samples J (J1 to J4), K (K1 to K5) and the tissue are integrated at the embossed portion of the integrated sample J (J1 to J1). J4), K (K1-K 5) was produced.

  In the heat embossing process, an emboss plate on the absorber sample side (upper side) is a plate on which a large number of convex portions are formed (tip diameter of each convex portion: 3 mm, pitch between convex portions: 10 mm long × 10 mm wide, each convex Using a flat plate (heating temperature: 120 ° C.) as the embossing plate on the tissue side (lower side), using a pressure of 3 Mpa and an embossing time of 3 seconds. It was.

(5) Measurement of interfacial peel strength Interfacial peel strength at the time of drying and wetting of the integrated samples J (J1 to J4) and K (K1 to K5) was measured.

[Interfacial peel strength during drying (N / 25mm)]
Standard sample (temperature 20 ° C, humidity 60%) sample piece (length 40mm x width 25mm, including 8 embossed parts) is gripped by a tensile tester (Shimadzu Corporation, AG-1kNI) at an interval of 20mm. The absorbent sample was attached to the tissue, and a tissue was attached to the lower grip. A load was applied at a tensile speed of 100 mm / min until the sample piece completely peeled, and the interfacial peel strength per 25 mm width in the length direction (MD direction) of the sample piece was measured.

[Interfacial peel strength when wet (N / 25 mm)]
After immersing a sample piece (length 40 mm x width 25 mm) in ion-exchanged water until it sinks under its own weight, or after submerging the sample piece in water for 1 hour or longer, the length direction of the sample piece is the same as above. The interfacial peel strength per 25 mm width in the (MD direction) was measured (ISO 9073-3, JIS L 1913 6.3).

(6) Results and discussion Table 7 shows the measurement results.

Considerations based on Table 7 are as follows.
When the interfacial peel strength between the absorbent body and the tissue covering the absorbent body (the coating layer in the present invention; the same applies hereinafter) is less than 0.98 N / 25 mm, the absorbent article is absorbed during use. Separation of the interface between the body and the tissue covering the absorbent body may occur, and liquid transfer from the tissue to the absorbent body may be deteriorated. Therefore, based on the fact that both the dry and wet interfacial peel strengths are 0.98 N / 25 mm or more, the integrated samples J1 to J4 satisfy this standard. Therefore, the mass mixing ratio of the composite fiber A to the pulp in the absorber is 1/9 or more, which is advantageous in terms of increasing the interfacial peel strength during drying and wetting, whereby 1.75 N / 25 mm or more. The interfacial peel strength when dried and the interfacial peel strength when wet of 1.05 N / 25 mm or more can be realized. Moreover, by setting the mass mixing ratio of the composite fiber A to the pulp in the absorbent body to 1/9 to 5/5, the interfacial peel strength during drying of 1.75 to 4.23 N / 25 mm, and 1.05 to 2. An interfacial peel strength of 63 N / 25 mm can be achieved.

  Comparing the integrated samples (ie, J1 and K1, J2 and K2, J3 and K3, J4 and K4) having the same mass mixing ratio of the composite fibers A and B with respect to the pulp in the absorbent sample, when dry and wet The interfacial peel strength is larger in the integrated sample J than in the integrated sample K at any mass mixing ratio. Therefore, when the mass mixing ratio of the composite fibers A and B to the pulp in the absorbent body is the same, when using the composite fiber A, the interfacial peel strength at the time of drying and wetting is higher than when using the composite fiber B. Can be increased. In addition, when it is desired to achieve a constant dry and wet interfacial peel strength, the composite fiber A is smaller in mass mixing ratio of the composite fiber to the pulp in the absorbent body than in the case of using the composite fiber B. (That is, the mass mixing ratio of the pulp in the absorbent body is increased accordingly, and the absorbent performance of the absorbent body can be improved).

1A, 1B Sanitary napkin (absorbent article)
2 Liquid-permeable layer 3 Liquid-impermeable layer 5A, 5B, 5C Embossed part (joint part)
41 Absorbent material layer 42 First covering layer 43 Second covering layer

Claims (20)

An absorbent article comprising a liquid permeable layer, a liquid impermeable layer, an absorbent material layer provided between the liquid permeable layer and the liquid impermeable layer, and a first joint portion. ,
The liquid-impermeable layer contains a thermoplastic resin containing an unsaturated carboxylic acid, an unsaturated carboxylic acid anhydride or a mixture thereof as a monomer component,
The absorbent material layer contains cellulosic water-absorbing fibers,
In the first joint portion , the liquid impermeability is obtained by thermally fusing the thermoplastic resin contained in the liquid impermeable layer and the cellulose water-absorbing fiber contained in the absorbent material layer . a layer and the absorbent material layer is joined,
Absorbent article.   The absorptive article according to claim 1 in which said absorptive material layer contains the thermoplastic resin fiber which contains unsaturated carboxylic acid, unsaturated carboxylic anhydride, or mixtures thereof as a monomer ingredient.   The modified polyolefin in which the thermoplastic resin fiber contained in the absorbent material layer is graft-polymerized with a vinyl monomer containing an unsaturated carboxylic acid, an unsaturated carboxylic acid anhydride, or a mixture thereof, or the modified polyolefin and another resin The absorbent article of Claim 2 which is a core-sheath-type composite fiber which uses as a core component resin whose melting | fusing point is higher than said modified polyolefin.   The absorbent article according to claim 2 or 3, wherein fibers contained in the absorbent material layer are bonded to each other.   The absorptive article according to any one of claims 2 to 4 whose mass ratio of said thermoplastic resin fiber to said cellulosic water absorption fiber in said absorptive material layer is 1 / 9-5 / 5. The density of the absorbent material layer is 0.06~0.14g / cm ^3, the absorbent article according to claim 5.   The said absorptive material layer is a thing obtained by injecting high-pressure water vapor | steam to the mixed material containing the said cellulosic water absorbing fiber and the said thermoplastic resin fiber, and densifying it. Absorbent article. The basis weight of the absorbent material layer is 40~900g / m ^2, the absorbent article according to claim 6 or 7.   The absorbent article of any one of Claims 1-8 whose difference of the maximum tensile strength at the time of drying and the maximum tensile strength at the time of wet in the said absorbent material layer is 1-5 N / 25mm.   The liquid-impermeable layer is a resin sheet, and the interfacial peel strength at the time of drying of the resin sheet and the absorbent material layer is 0.76 to 10.91 N / 25 mm, and the resin sheet and the absorbent material layer The absorbent article according to any one of claims 1 to 9, wherein the interfacial peel strength when wet is 0.32 to 10.57 N / 25 mm.   The absorbent article has a first coating layer that covers a surface of the absorbent material layer on the liquid-impermeable layer side, the first coating layer contains cellulosic water-absorbing fibers, and The absorptive article according to any one of claims 1 to 10 with which a joined part joins said liquid impermeable layer, this 1st covering layer, and said absorptive material layer.   The interfacial peel strength upon drying of the absorbent material layer and the first coating layer is 1.75 to 4.23 N / 25 mm, and the interfacial peel strength when wet of the absorbent material layer and the first coating layer is 1. The absorptive article according to claim 11 which is 05-2.63 N / 25mm.   The liquid permeable layer contains a thermoplastic resin containing an unsaturated carboxylic acid, an unsaturated carboxylic acid anhydride or a mixture thereof as a monomer component, and the first joint portion includes the liquid impermeable layer, the first The absorbent article according to claim 11 or 12, wherein one covering layer, the absorbent material layer, and the liquid-permeable layer are joined.   The liquid permeable layer contains a thermoplastic resin containing an unsaturated carboxylic acid, an unsaturated carboxylic acid anhydride or a mixture thereof as a monomer component, and the absorbent article further includes a second joint portion, The absorptive article according to any one of claims 1 to 13 in which a 2nd joined part joins said liquid permeability layer and said absorptive material layer.   The liquid permeable layer is a nonwoven fabric sheet containing fibers of the thermoplastic resin, and the nonwoven fabric sheet and the absorbent material layer have an interfacial peel strength at drying of 0.97 to 4.07 N / 25 mm, and the nonwoven fabric The absorbent article according to claim 14, wherein the interfacial peel strength when wet of the sheet and the absorbent material layer is 0.75 to 4.10 N / 25 mm.   The liquid-permeable layer is a resin sheet, and the interfacial peel strength when dried of the resin sheet and the absorbent material layer is 0.76 to 10.91 N / 25 mm, and the resin sheet and the absorbent material layer are wet. The absorbent article according to claim 14, wherein the interfacial peel strength is 0.32 to 10.57 N / 25 mm.   The absorptive article according to claim 16 in which the penetration hole which penetrates said resin sheet is formed with the opening rate of 5-70%.   The absorbent article has a second coating layer that covers a surface of the absorbent material layer on the liquid permeable layer side, the second coating layer contains a cellulosic water-absorbing fiber, and the first joint portion. The absorption according to any one of claims 11 to 13, wherein the liquid impermeable layer, the first coating layer, the absorbent material layer, the second coating layer, and the liquid permeable layer are joined together. Sex goods.   The absorbent article has a second coating layer that covers a surface of the absorbent material layer on the liquid permeable layer side, the second coating layer contains a cellulosic water-absorbing fiber, and the second joint portion. The absorbent article according to claim 14, wherein the liquid permeable layer, the second coating layer, and the absorbent material layer are joined.   The interfacial peel strength upon drying of the absorbent material layer and the second coating layer is 1.75 to 4.23 N / 25 mm, and the interfacial peel strength when wet of the absorbent material layer and the second coating layer is 1. The absorptive article according to claim 18 or 19 which is 05-2.63N / 25mm.

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