JP5636222B2 - Absorbent articles - Google Patents

Description

  The present invention relates to an absorbent article that uses a porous plastic film imparted with a fiber touch feeling as a top sheet, and hardly causes liquid residue on the surface.

  Conventionally, as absorbent articles such as panty liners, sanitary napkins, cage sheets, incontinence pads, toiletries, etc., liquid-impervious back sheets such as polyethylene sheets or polyethylene sheet-laminated nonwoven fabrics, nonwoven fabrics or liquid-permeable plastic sheets, etc. There is known one in which an absorbent body made of cotton-like pulp or the like is interposed between the liquid-permeable surface sheet.

  In the absorbent article, in order to satisfy the dry touch feeling on the skin and to increase the absorption rate of body fluid, the liquid-permeable surface sheet is also referred to as a heat-sealable hydrophobic porous plastic sheet (hereinafter also referred to as a mesh sheet). ), A hydrophilic fiber sheet called a second sheet is interposed between the liquid-permeable surface sheet and the absorbent body, and the mesh sheet and the second sheet are joined discontinuously by a predetermined emboss pattern. Has been proposed. As an absorbent article employing such a configuration, for example, the following Patent Document 1 can be cited.

  On the other hand, the sanitary napkin using the mesh sheet as a surface material has been unsatisfactory because it has no irregularities, is in close contact with the skin, has a vinyl feel, and is soft to the touch. For this reason, as the mesh sheet, there is known a structure in which a standing edge portion standing on the surface side is formed along the peripheral edge of the opening, and the surface of the mesh sheet is provided with a feeling of unevenness to give a fiber touch feeling like a nonwoven fabric. ing. As such a mesh sheet, for example, in Patent Document 2 below, as a microscopic aperture, the compression resistance and shear resistance of each of the surface deformation portions and the observer's skin so that the feel of the web is almost flexible and silky. Disclosed is a micro-opened polymer web having a crater-like aperture having a relatively thin irregularly shaped petal-like portion that reduces contact with the fluid. Further, Patent Document 3 below shows an expanded opening portion that can be seen with a large number of naked eyes, and has a central portion that has an opening portion that allows passage of bodily fluid discharged to the web, and a soft silky feel. An outer portion having a plurality of fine apertures, the fine aperture surface deformations forming the edges of the fine apertures being directed outwards, the fine apertures extending to the central portion; A web is disclosed that includes an outer portion that is not.

Japanese Patent No. 39998477 Japanese Patent No. 2543502 Japanese Patent No. 3880615

  However, in the web described in Patent Document 2, the minute aperture is formed in the shape of a crater that protrudes to the surface side, so menstrual blood collected around the minute aperture is transmitted to the absorber side. However, there was a problem that liquid residue was generated on the surface. On the other hand, in the above-mentioned Patent Document 3, it is expected that the liquid residue hardly occurs in the central portion because the fine hole portion is not formed in the central portion. However, since the fine hole portion is not formed in the central portion, there is a problem that the fiber touch feeling is not obtained and the skin is in close contact with the skin.

  On the other hand, in Patent Documents 2 and 3 described above, “a macroscopically expanded three-dimensional pattern” or “an expanded opening that can be seen with the naked eye” is formed in order to allow a body fluid to pass through to the absorber side. The expanded opening is formed with a protruding portion that protrudes substantially perpendicularly to the back surface at the periphery of the opening, and a substantially flat cross section is formed by forming the opening substantially flat between the openings. This is a three-dimensional sheet cross section (see FIG. 8). For this reason, in the above-mentioned expanded opening and its vicinity, menstrual blood collected around the micro-opening flows to the expanded opening and is absorbed by the lower absorber. In the flat part in the meantime, menstrual blood was liable to stay and a liquid residue was generated.

  Then, the main subject of this invention is providing the absorbent article which made it difficult to produce the liquid residue of a surface in the absorbent article which used the plastic film which provided the fiber touch feeling for the surface sheet, without impairing a fiber touch feeling. It is in.

In order to solve the above problems, as the present invention according to claim 1, an absorber is interposed between a top sheet made of a plastic film and a liquid-impermeable back sheet, and the top sheet and the absorber are In an absorbent article in which a second sheet is disposed between,
The top sheet has a large number of fine openings having standing edges that rise from the base surface of the plastic film along the periphery of the openings to the surface side, and the plastic film in which the fine openings are formed from the surface side. A plurality of pattern openings that do not have standing edges standing on the back side formed by applying heat embossing, and the fine openings are formed over the entire surface sheet, and the pattern openings Is formed with an opening area and an opening interval larger than the fine opening,
The second sheet has a hydrophilic property and a non-woven fabric having a fiber layer is used, and the pattern is obtained by applying the heating embossing in a state where the surface sheet on which the fine holes are provided and the second sheet are laminated. While the opening is formed, the top sheet and the second sheet are integrated,
The absorbent sheet is characterized in that the top sheet is formed by curving the base surface of the top sheet between adjacent pattern openings in a gentle curve.

In the invention of claim 1, a plastic film is used as the surface sheet, and the plastic film has a large number of fine apertures having standing edges standing from the base surface to the surface side along the periphery of the aperture; Two types of apertures are provided, including a large number of pattern apertures that do not have raised edges that stand on the back side formed by applying heat embossing from the front side to the plastic film in which the fine apertures are formed. ing. The fine openings are formed over the entire surface sheet, and the pattern openings are formed with an opening area and an opening interval larger than the fine openings. A fiber touch feeling is given to the plastic film by the fine openings, and liquid permeability is mainly given by the pattern openings.

The second sheet has a hydrophilic property and a non-woven fabric having a fiber layer is used, and the pattern is obtained by applying the heating embossing in a state where the surface sheet on which the fine holes are provided and the second sheet are laminated. An opening is formed, and the top sheet and the second sheet are integrated. Accordingly, since the plastic film in which the fine openings are formed has a large number of the pattern openings that do not have standing edges that stand on the back side by heating embossing from the front side, the pattern is formed by the heating embossing. The opening portion is slightly depressed, and the surface sheet is curved in a gentle curve at the base surface of the surface sheet between the adjacent pattern openings. As a result, menstrual blood collected between the fine openings in the top sheet is likely to flow toward the pattern openings, and liquid residue on the surface is less likely to occur.

Therefore, in the absorbent article according to the present invention, together with the fibers touch feeling is obtained over the entire surface of the topsheet, the liquid remaining surface is less likely to occur.

As the present invention according to claim 2, wherein the surface sheet has a front and back direction of the height of the absorbent article in a state where the formation of the fine apertures and H _1, the state of forming the pattern opening thereto when the front and back direction of the height of the absorbent article was referred to as H _2, the absorbent article according to claim 1, characterized in that formed in the following relationship (1) is provided.

(H ₂ −H ₁ ) / H ₁ × 100% <100% (1)
According to the second aspect of the present invention, the thickness of the surface sheet subjected to pattern opening is formed within a predetermined range with respect to the thickness of the surface sheet subjected to fine opening. Specifically, the front and back direction of the height of the front and back direction of the height of the absorbent article of the fine state opening was formed and H _1, the absorbent article in a state of forming the pattern opening thereto the when the H _2, are formed such that the relationship of the above equation (1). As a result, the base surface is not a three-dimensional surface sheet in which a protruding portion protruding to the back surface side and a flat portion between the pattern openings are formed on the periphery of the pattern opening as in the conventional case, but the base surface is curved in a gentle curved shape. Therefore, it becomes difficult to produce liquid residue on the surface.

As the present invention according to claim 3, wherein the pattern apertures, according to claim 1, 2 or which is more disposed longitudinally those formed with elongated shape in a zigzag pattern of the absorbent article An absorbent article is provided.

As the present invention according to claim 4 , there is provided the absorbent article according to any one of claims 1 and 2 , wherein a plurality of the pattern openings having two or more kinds of opening shapes are arranged.

In the third and fourth aspects of the invention, the aperture shape and the arrangement pattern of the pattern apertures are defined in consideration of liquid permeability and liquid inductivity.

  As described above in detail, according to the present invention, in an absorbent article using a plastic film imparted with a fiber touch feeling as a surface sheet, an absorbent article that does not easily cause liquid residue on the surface without impairing the fiber touch feeling is provided. become able to.

It is a partial fracture development view of sanitary napkin 1 concerning the present invention. It is the II-II arrow directional view. 3 is an enlarged plan view of a top sheet 3. FIG. It is sectional drawing of the surface sheet 3 and the second sheet | seat 6. FIG. It is process drawing which shows the manufacture point of the surface sheet. It is a formation procedure figure of the pattern opening 9. FIG. 3 is an enlarged plan view of a top sheet 3. FIG. It is sectional drawing which shows the conventional surface sheet.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  The sanitary napkin 1 is mainly used for panty liners, sanitary napkins, cage sheets, incontinence pads and the like. For example, as shown in FIG. 1 and FIG. 2 and a top sheet 3 made of a plastic film, an absorbent body 4 or an absorbent body 4 surrounded by crepe paper 5 in the illustrated example is interposed between the top sheet 3 and the top sheet 3 as shown in FIG. The second sheet 6 is arranged between the absorber 4 and the absorber 4. In addition, side nonwoven fabrics 7 and 7 formed along the longitudinal direction are provided on both side portions on the surface side, and a part of the side nonwoven fabrics 7 and 7 extend sideways and also extend sideways. Wing-like flaps W and W are formed by part of the existing liquid-impermeable back sheet 2. Around the absorber 4, the liquid-impermeable back sheet 2 and the top sheet 3 are joined by an adhesive means such as a hot melt adhesive.

Hereinafter, the structure of the sanitary napkin 1 will be described in detail.
The liquid-impervious back sheet 2 is made of a sheet material having at least water-impervious properties such as polyethylene and polypropylene, but in addition to this, a non-woven sheet after securing a substantially liquid-impervious property through a waterproof film. (In this case, a liquid-impervious back sheet is composed of the waterproof film and the nonwoven fabric). In recent years, those having moisture permeability tend to be suitably used from the viewpoint of preventing stuffiness. The water- and moisture-permeable sheet material is a microporous material obtained by melting and kneading an inorganic filler in an olefin-based resin such as polyethylene or polypropylene to form a sheet, and then stretching in a uniaxial or biaxial direction. A sheet is preferably used.

  As the top sheet 3, a plastic film is used. As this plastic film, for example, a thermoplastic resin film of an olefin resin such as polyethylene or polypropylene is preferably used, but a polyamide resin such as polyester or nylon, EVA, or the like can also be used.

  On the surface of the top sheet 3, a blood drainage port corresponding portion or the like is defined, and the surface of the surface sheet 3 is bulged tightly on the surface side, and in order to contain the absorbed body fluid, at least on both sides of the blood drainage port corresponding portion H. A pair of left and right blood discharge port corresponding embosses 11, 11 are formed along the longitudinal direction. In addition, when the embossed body 11 is formed with a middle high portion of the absorbent body, there is also an object of holding the middle high portion in a predetermined position. In the example shown in FIG. 1, decorative embosses are formed in appropriate shapes for decoration and the like before and after that.

  The absorbent body 4 interposed between the liquid-impervious back sheet 2 and the top sheet 3 is, for example, a pulp pile composed of fluffy pulp and a water-absorbing polymer, an airlaid absorbent body that can reduce the bulk, and the like. Can be used. Moreover, in the case of the said pulp pile, you may form the middle-high part of a high absorber on the use surface side. The water-absorbing polymer is mixed in the pulp constituting the absorber, for example, as granular powder. Examples of the pulp include chemical fibers obtained from wood, cellulose fibers such as dissolved pulp, and artificial cellulose fibers such as rayon and acetate. Softwood pulp having a longer fiber length than hardwood pulp functions and It is preferably used in terms of price.

  Further, synthetic fibers may be mixed in the absorbent body 4. As the synthetic fiber, for example, polyolefins such as polyethylene or polypropylene, polyesters such as polyethylene terephthalate and polybutylene terephthalate, polyamides such as nylon, and copolymers thereof can be used. It may be a mixture. In addition, a composite fiber such as a core-sheath fiber, a side-by-side fiber, or a split fiber having a fiber having a high melting point as a core and a fiber having a low melting point as a sheath can also be used. In the case of a hydrophobic fiber, it is desirable to use a synthetic fiber that has been surface-treated with a hydrophilizing agent so as to have an affinity for body fluids.

  The second sheet 6 disposed between the top sheet 3 and the absorbent body 4 only needs to be hydrophilic to body fluids. Specifically, by using recycled fibers such as rayon and cupra, natural fibers such as cotton, the material itself has hydrophilicity, or synthesis of olefins such as polyethylene or polypropylene, polyesters, polyamides, etc. The fiber which surface-treated with the hydrophilizing agent and provided the hydrophilic property can be used. The second sheet 6 is not limited as long as it has a fiber layer, but preferably a non-woven fabric can be used as it is. There are various nonwoven fabrics such as spunlace nonwoven fabric, spunbond nonwoven fabric, melt blown nonwoven fabric, needle punched nonwoven fabric, air-through nonwoven fabric, etc. depending on the production method. If importance is attached to the diffusibility of menstrual blood, a spunbond nonwoven fabric is desirable.

  As the side nonwoven fabric 7, a water-repellent treated nonwoven fabric or a hydrophilic treated nonwoven fabric can be used from the viewpoint of an important function. For example, if importance is placed on functions such as preventing permeation of menstrual blood or vaginal discharge, or enhancing the touch feeling, water repellent treatment coated with silicon, paraffin or alkylchromic chloride water repellent It is desirable to use a nonwoven fabric. Further, if importance is attached to the absorption of menstrual blood and the like in the wing-shaped flaps W, W, a method of polymerizing a compound having a hydrophilic group, for example, an oxidation product of polyethylene glycol, in the process of producing a synthetic fiber, , By treating with a metal salt such as stannic chloride, partially dissolving the surface to make it porous, and depositing metal hydroxides to swell or make the synthetic fiber porous, applying capillary action to make it hydrophilic It is desirable to use a hydrophilic treated non-woven fabric provided with.

  In the sanitary napkin 1 according to the present invention, as shown in FIGS. 3 and 4, the top sheet 3 stands on the surface side of the sanitary napkin 1 from the base surface 3 a of the plastic film along the periphery of the opening. A large number of fine openings 8, 8... Having standing edges 8a and a plastic film in which the fine openings 8, 8. Two types of apertures including a large number of pattern apertures 9, 9... Having no standing edge are provided.

  The fine openings 8, 8... Are formed over substantially the entire surface sheet 3, and are mainly for giving a fiber touch feeling to the plastic film. The pattern openings 9, 9. It is formed with an opening area and an opening interval larger than those of the holes 8 and is mainly for imparting liquid permeability to the plastic film.

  In order to form openings in the top sheet 3, as shown in FIG. 5, after forming the fine openings 8, the pattern openings 9 are formed. The fine opening 8 is formed by a method in which a pin embossing roll and an anvil roll each provided with a number of protruding pins on the peripheral surface are arranged opposite to each other, and the plastic film is passed between the rolls, and the plastic film is softened at a temperature. A method of sucking from below the support or pressurizing with air pressure from the upper surface of the support while being softened in the vicinity and positioned on the upper surface of the support having a large number of apertures, a number of high-pressure liquid jets Examples thereof include a method of opening a hole by a high-pressure jet of liquid ejected from a nozzle, and the like can be formed by an appropriate method. The fine aperture 8 formed by such a method is formed with a protruding edge portion 8a (so-called “flash”) that protrudes to one side (the surface side of the sanitary napkin 1) along the periphery of the fine aperture 8. Become so.

  The pattern opening 9 is formed by a hole forming method that does not have an upstanding edge that rises from the base surface 3a of the plastic film to the back surface side. Specifically, as shown in FIG. 6, an embossing roll 20 having a large number of ridges 20a in the circumferential direction on the roll surface and heated to the softening point of the plastic film, and an anvil roll 21 having a flat surface Is used so that the plastic film is passed between the rolls 20 and 21. On the other hand, a pin roll provided with a needle pin and an anvil roll are arranged opposite to each other, and a method of passing a plastic film between these rolls or a state where the pin roll is positioned on the upper surface of a support body having a large number of openings The method of sucking from below the support, pressurizing with air pressure from the upper surface of the support, or the method of opening by the high-pressure jet of liquid ejected from the high-pressure liquid jet nozzle, etc. Therefore, it is excluded from the method of forming the pattern aperture 9.

  As described above, after forming the fine apertures 8 having the standing edges 8a standing on the front surface side, a large number of pattern apertures 9 having no standing edges standing on the back surface side by heating embossing from the front surface side are formed. By forming, as shown in FIG. 4, the portion of the pattern opening 9 subjected to pressure and the vicinity thereof are recessed on the back side, so that the base surface 3 a of the topsheet 3 between the pattern openings 9, 9 is It is formed with a gentle curve.

  Therefore, menstrual blood temporarily accumulated between the fine openings 8 and 8 of the surface sheet 3 is likely to flow toward the pattern openings 9 along the inclined surface of the base surface 3a that is curved in a gentle curve. Liquid residue on the surface is less likely to occur. Therefore, a fiber touch feeling can be obtained over almost the entire surface sheet 3, and liquid residue on the surface can be made difficult to occur.

As a means for defining the cross-sectional shape of the top sheet 3, a method of limiting the ratio of the height of the cross section of the sheet before and after the formation of the pattern aperture 9 to a predetermined range can be used. That is, as shown in FIG. 5, the top sheet 3 has a height H ₁ in the front and back direction of the sanitary napkin 1 in the state in which the fine apertures 8 are formed, and the pattern apertures 9 are formed in this. When the height in the front and back direction of the napkin 1 in the state is H ₂ , it is preferably formed by the relationship of the following formula (1). The ratio of the thickness is less than 100% in the following formula (1), but is preferably 50 to 100%, more preferably 50 to 80%.

(H ₂ −H ₁ ) / H ₁ × 100% <100% (1)
Thus, by forming the ratio of the height of the sheet cross-section before and after the formation of the pattern opening 9 within a predetermined range, a protruding portion (flash) that protrudes to the back side at the periphery of the pattern opening as in the prior art. Is not a three-dimensional sheet (see FIG. 8), but a substantially planar sheet in which the base surface is curved in a gentle curve. Therefore, in the conventional sheet shown in FIG. 8, the “burr” protrudes to the back surface side, so that menstrual blood tends to accumulate in a flat portion where the distance from the second sheet 6 between the pattern openings can be increased. The rest occurs.

The result of the specific experiment will be described. On the surface of the surface sheet with the height ratio (H ₂ −H ₁ ) / H ₁ being 75% (Example) and 130% (Comparative Example), 1 cc of horse blood Was dropped twice every 3 minutes, a filter paper was laid on the surface one minute after the second drop, a 5 g / cm ² weight was placed for 5 minutes, and the amount of horse blood adhering to the filter paper was measured. As a result, it was clarified that in the example, the absorption amount was 58.2% compared to the comparative example, and the liquid residue on the surface could be reduced.

The fine openings 8 are preferably circular, and the diameter is 0.05 to 1.0 mm, preferably 0.1 to 0.5 mm, and the number of openings is 100 to 500 / cm ² , preferably 200 to It is desirable that the number is about 400 / cm ² .

  The pattern openings 9 are preferably formed in a vertically long shape in the longitudinal direction of the sanitary napkin 1, and a pattern in which a plurality of the pattern openings 9 are arranged in a staggered pattern is preferable. The vertical dimension of the aperture is 1.0 to 3.0 mm, preferably 1.5 to 2.5 mm, and the width dimension is about 0.1 to 2.0 mm, preferably about 0.3 to 1.0 mm. The pitch of the holes is 0.5 to 2.0 mm, preferably 0.5 to 1.5 mm in the width direction of the sanitary napkin 1, and 0.5 to 3.0 mm in the longitudinal direction, preferably 0. About 5 to 2.0 mm.

  As shown in FIG. 7, the pattern apertures 9 may be formed by arranging a plurality of patterns having two or more aperture shapes. In this case, in order to maintain the strength of the film and improve the liquid permeability and inductivity to the second sheet 6, a pattern in which the shape of the aperture is vertically long and a smaller area is preferable. In the example shown in FIG. 7, a plurality of vertically long openings 9 and circular dot-like openings 9 ′ are arranged in a staggered manner.

  When the pattern opening 9 is provided, the heating embossing may be performed in a state in which the top sheet 3 provided with the fine opening 8 and the second sheet 6 are laminated. As a result, the top sheet 3 and the second sheet 6 can be integrated, and menstrual blood can be more easily drawn into the second sheet 6 from the pattern opening 9, and the base surface 3 a of the top sheet 3 is gently directed toward the pattern opening 9. It becomes easy to bend in a curved shape. On the other hand, since the opening is compressed, the spot absorbability deteriorates. Therefore, when giving priority to spot absorptivity, the processing method can be selected depending on the function to be obtained, such as forming the pattern opening with the top sheet 3 alone without laminating the second sheet 6.

  In order to prevent liquid residue on the surface of the top sheet 3, the following measures can be taken. 1stly, in order to improve liquid fluidity | liquidity, it is preferable to make the plastic film of the surface sheet 3 contain a hydrophilic agent. Secondly, when the pattern opening 9 is formed, the hydrophilicity around the pattern opening 9 can be increased by applying a hydrophilic agent to the protrusion 20a (see FIG. 6) of the embossing roll 20. . Thirdly, in order to induce menstrual blood in the pattern opening 9, it is possible to preferably perform stripe processing in the width direction on the surface side of the plastic film constituting the top sheet 3.

  DESCRIPTION OF SYMBOLS 1 ... Sanitary napkin, 2 ... Impervious back sheet, 3 ... Top sheet, 4 ... Absorber, 5 ... Crepe paper, 6 ... Second sheet, 7 ... Side nonwoven fabric, 8 ... Fine opening, 9 ... Pattern opening Hole

Claims (4)

In an absorbent article in which an absorber is interposed between a top sheet made of a plastic film and a liquid-impermeable back sheet, and a second sheet is disposed between the top sheet and the absorber,
The top sheet has a large number of fine openings having standing edges that rise from the base surface of the plastic film along the periphery of the openings to the surface side, and the plastic film in which the fine openings are formed from the surface side. A plurality of pattern openings that do not have standing edges standing on the back side formed by applying heat embossing, and the fine openings are formed over the entire surface sheet, and the pattern openings Is formed with an opening area and an opening interval larger than the fine opening,
The second sheet has a hydrophilic property and a non-woven fabric having a fiber layer is used, and the pattern is obtained by applying the heating embossing in a state where the surface sheet on which the fine holes are provided and the second sheet are laminated. While the opening is formed, the top sheet and the second sheet are integrated,
The absorbent article , wherein the top sheet is formed by curving the base surface of the top sheet between adjacent pattern openings in a gentle curve. The topsheet, front and back direction of the height and H _1, the front and back direction of the height of the absorbent article in a state of forming the pattern opening to the absorbent article in a state where the formation of the fine opening the when the H _2, the absorbent article according to claim 1, characterized in that formed in the following relationship (1).
(H ₂ −H ₁ ) / H ₁ × 100% <100% (1) 3. The absorbent article according to claim 1 , wherein a plurality of the pattern openings formed in a vertically long shape in the longitudinal direction of the absorbent article are arranged in a staggered manner. 3. The absorbent article according to claim 1 , wherein a plurality of patterns having two or more types of apertures are arranged.

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