JP5355295B2 - Biodegradable face cover - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a biodegradable face cover made of a nonwoven fabric that is obtainable by spunbonding technique because of being good in yarn manufacturing performance and openability, excellent in flexibility and heat sealability, and slight in shrinkage even after undergoing any processing, and, in addition, enabling its own composting treatment after used. <P>SOLUTION: The biodegradable face cover is made of a nonwoven fabric whose constituent fibers are conjugate fibers each containing a polylactic acid-based polymer having a melting point of not less than 160&deg;C, and an aliphatic polyester polymer having a melting point of not less than 50&deg;C, lower than that of the polylactic acid-based polymer. The aliphatic polyester polymer forms at least part of the surface of the conjugate fiber, and is constituted by 1,4-butanediol and succinic acid as the constituent components, and contains at least one selected from higher fatty acid, higher fatty acid metal salt, phenylphosphonic acid metal salt, and amide wax in an amount of 0.1-1 mass%. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a biodegradable face cover for covering a face when clothes are attached and detached.

When a person who applies makeup to the face attaches or detaches the clothes, if the clothes come into contact with the face, the makeup may be disturbed and the clothes may become dirty due to the adhesion of the cosmetic.
In order to solve such a problem, a bag-shaped face cover that covers the head including the face when attaching and detaching clothes has been proposed (for example, Patent Document 1 and Patent Document 2). The face covers as described above are all made of nonwoven fabric.

However, the face cover formed from a conventional non-woven fabric sometimes requires a complicated process such as requiring an additional adhesive when the bag body is formed.
In order to solve the above problems, a face cover made of a nonwoven fabric made of self-adhesive fibers has been studied. This non-woven fabric made of self-adhesive fibers is one in which the fibers are fused and integrated by melting a part of the fibers by heating, that is, has heat sealability.

  In recent years, synthetic fibers using petroleum as a raw material have a large amount of heat generated during incineration, and therefore need to be reviewed from the viewpoint of protecting the natural environment. Along with this, fibers made of aliphatic polyester that biodegrades in nature have been developed, and face covers that can be formed from non-woven fabric made of fibers that contribute to environmental protection are expected. Among the above-mentioned aliphatic polyesters, polylactic acid polymers are expected to be used in a wide range of fields because of their relatively high melting point of about 180 ° C.

In view of the above, a face cover that is self-adhesive and can be formed from a nonwoven fabric made of a biodegradable polymer such as a polylactic acid-based polymer is desired.
In response to the above-mentioned demand, a non-woven fabric made of self-adhesive fibers using a polylactic acid-based polymer and judged to be capable of forming a face cover is provided with polylactic acid in the core and D-lactic acid in the sheath. A non-woven fabric composed of a core-sheath composite fiber in which a copolymer with L-lactic acid (D, L-lactic acid copolymer) is disposed and the sheath part has a lower melting point than the core part is known ( For example, Patent Document 3 and Patent Document 4).

  In the face cover formed into a bag shape by heat-sealing the nonwoven fabric, it is preferable to use a nonwoven fabric made of a composite fiber having a large melting point difference between the core portion and the sheath portion in consideration of thermal processing stability. It is considered that it is preferable to select a copolymer having a low melting point (for example, a copolymer having a melting point of about 120 ° C.). However, in the D, L-lactic acid copolymer, those having a melting point of about 120 ° C. have low crystallinity, so that they shrink in the heat bonding step when forming the face cover, or are fused to a heat roll. In addition, the obtained face cover is inferior in heat resistance.

  Instead, when a polymer having a low melting point other than polylactic acid is selected as the sheath component, the glass transition temperature is often low. Therefore, even if it tries to obtain the nonwoven fabric by applying it to the spunbond method that can obtain the most efficient nonwoven fabric, the spunbond method is the distance until the yarn discharged from the nozzle hole is pulled and thinned (spinning process-cooling / stretching) Because the process distance) is extremely short, there are problems such as rubber elasticity not being fully cooled during the cooling process, and yarns blocking each other during the fiber opening process, resulting in poor operability. It is difficult to obtain a nonwoven fabric.

  As a method for solving this problem, when using a polymer having a low melting point other than polylactic acid as the sheath component for the nonwoven fabric that is judged to be capable of forming a face cover, the crystallization rate is obtained by a crosslinking reaction using an organic peroxide. Is known to be controlled in a short cooling process (for example, Patent Document 5). In a face cover formed from a nonwoven fabric made of a composite fiber obtained by this technique, a crosslinking reaction is known. By speeding up the crystallization speed of the polymer used for the sheath component, it becomes possible to sufficiently cool the yarn even in a process with a short cooling process such as the spunbond method, eliminating the blocking between the yarns, and good Openness (nonwoven fabric formation) can be obtained. However, on the other hand, since the rubber elasticity of the polymer becomes stronger than the state without cross-linking in order to perform the cross-linking reaction, the range of reaction conditions for achieving both the cross-linking reaction that can withstand high-speed spinning and the opening property is narrow.

  Patent Document 6 discloses a composite fiber composed of a biodegradable first component and a second component, and the half crystallization time of the second component at 85 ° C. is longer than the half crystallization time of the first component at 85 ° C. Biodegradable composite fibers characterized by a long length, and structures and water-absorbent articles using the same are described. That is, in the case of producing a composite fiber using different biodegradable resins, if biodegradable resins having a small difference in crystallization speed are used, a biodegradable resin having a short semi-crystallization time is obtained in the spinning process. Heat generated during crystallization hinders cooling of the biodegradable resin having a long half-crystallization time. For this reason, the difference in the half crystallization time between the first component and the second component is increased, and thereby the heat generated when the biodegradable resin having a short half crystallization time is crystallized has a long half crystallization time. The cooling of the degradable resin is not hindered.

  According to the composite fiber described in Patent Document 6, it can be sufficiently applied when the length of the cooling zone in the spinning process can be sufficiently secured, but in the spunbond method with a short cooling zone, the half of the polymer of the sheath component is used. When a resin having a long crystallization time is applied, there are problems such as adhesion of spread yarns. Therefore, the face cover formed from the nonwoven fabric made of this composite fiber has a problem that the flexibility is insufficient.

JP 2000-125934 A JP 2006-087789 A JP 07-310236 A JP-A-07-133511 Japanese Patent Laid-Open No. 2007-084988 JP 2007-119928 A

  The present invention improves the above-described problems of the conventional face cover. That is, this invention makes it a subject to provide the face cover excellent in the softness | flexibility and heat seal property using the nonwoven fabric with few shrinkage | contractions at the time of heat seal processing. It is another object of the present invention to provide a biodegradable face cover that can be composted after use.

  As a result of intensive studies to solve the above problems, the present inventors have made a specific polymer an adhesive component, and by using a nonwoven fabric formed from a composite fiber having a specific fiber cross section, Obtaining the knowledge that a biodegradable face cover that solves the above problems can be obtained, the present invention has been achieved.

That is, the means for solving the above problems are as follows.
(1) It consists of a nonwoven fabric formed by a spunbond method using a composite fiber as a constituent fiber, and the composite fiber has a polylactic acid polymer having a melting point of 160 ° C. or higher and a melting point of 50 ° C. or lower than the polylactic acid polymer. An aliphatic polyester polymer, the aliphatic polyester polymer forms at least part of the surface of the composite fiber, and the aliphatic polyester polymer comprises 1,4-butanediol and succinic acid. with a constituent component, biodegradable face cover, wherein the calcium montanate, that at least one selected et Toka phenylphosphonic acid zinc salt containing 0.1 to 1 wt%.
(2) The biodegradable face according to (1), wherein the basis weight is 15 to 50 g / m ² , the flexibility is 15 cN or more and 60 cN or less, and the drape coefficient is 0.650 or more and 0.950 or less. Cover .
(3 ) The composite fiber is a core-sheath composite long fiber in which a polylactic acid-based polymer forms a core part and an aliphatic polyester polymer forms a sheath part, and the composite ratio of the core part and the sheath part is mass. The biodegradable face cover according to (1) or (2) , wherein the core part / sheath part is 3/1 to 1/3.
( 4 ) When the composite long fiber is melted at a rate of temperature increase of 10 ° C./min and then subjected to differential thermal analysis at a rate of temperature decrease of 10 ° C./min, there is a temperature decrease crystallization temperature due to the aliphatic polyester polymer, the crystallization temperature is at 80 ° C. or higher 90 ° C. or less, heat of crystallization due to the aliphatic polyester polymer is equal to or less than 20 J / g or more 40 J / g (1) to (3) Biodegradable face cover.
( 5 ) The biodegradable face cover according to (1) to ( 4 ), which is formed into a bag shape by having a heat seal part in which constituent fibers are bonded to each other by melting or softening of an aliphatic polyester polymer. A biodegradable face cover.

The biodegradable face cover of the present invention is formed from a non-woven fabric having a composite long fiber containing a polylactic acid polymer and an aliphatic polyester polymer having a melting point lower than that of the polylactic acid polymer as constituent fibers. Further, the and the aliphatic polyester polymer forms at least a part of the surface of the fibers constituting the aliphatic polyester polymer, calcium montanate, at least one selected et Toka phenylphosphonic acid zinc salt By containing 0.1-1 mass%, the friction between the fibers at the time of fiber opening can be reduced. For this reason, the biodegradable face cover of the present invention can be manufactured by a web having good spreadability, and can be manufactured by a nonwoven fabric having good formation. Moreover, said nonwoven fabric can be manufactured by the spunbond method, and the face cover formed from this nonwoven fabric is excellent in the softness | flexibility. Furthermore, the biodegradable face cover of the present invention can be composted after use.

  In addition, according to the present invention, a polylactic acid polymer and an aliphatic polyester polymer are included, and the aliphatic polyester polymer includes 1,4-butanediol and succinic acid as constituent components, and a polylactic acid heavy polymer. Since it has a melting point that is lower by 50 ° C. or more than the melting point of the coalescence, a biodegradable face cover can be obtained with a nonwoven fabric that has excellent stability during heat treatment and excellent heat sealability.

It is a figure which shows the mode of the surface of the long fiber obtained when a calcium montanate is used. It is a figure which shows the mode of the surface of the long fiber obtained when a phenylphosphonic acid metal salt is used.

Hereinafter, the present invention will be described in detail.
The biodegradable face cover of the present invention (hereinafter sometimes simply referred to as “face cover”) is formed from a nonwoven fabric. The nonwoven fabric is obtained from a composite fiber containing a polylactic acid polymer having a melting point of 160 ° C. or higher and an aliphatic polyester polymer having a melting point that is 50 ° C. lower than the melting point of the polylactic acid polymer. The aliphatic polyester polymer is a heat-bonding component that is heat-sealed.

First, the polylactic acid polymer will be described.
As the polylactic acid polymer used for the nonwoven fabric capable of forming the biodegradable face cover of the present invention, a polymer having a melting point of 160 ° C. or higher or a blend of polymers having a melting point of 160 ° C. or higher is used. When the melting point of the polylactic acid polymer is 160 ° C. or higher, it can have high crystallinity. For this reason, when the nonwoven fabric is heat-sealed to obtain a face cover in the form of a bag, shrinkage during heat treatment is less likely to occur, and heat treatment can be performed stably. As described below, the melting point of the polylactic acid polymer is usually less than 180 ° C.

  The melting point of poly-L-lactic acid, which is a homopolymer of polylactic acid, and poly-D-lactic acid is about 180 ° C. When a copolymer of L-lactic acid and D-lactic acid is used as the polylactic acid polymer, the copolymerization ratio of the monomer components is determined so that the melting point of the copolymer is 160 ° C. or higher. That is, the copolymerization ratio of L-lactic acid and D-lactic acid is (L-lactic acid) / (D-lactic acid) = 2.0 / 98.0 to 0/100, or (L-lactic acid) in molar ratio. / (D-lactic acid) = 98.0 / 2.0 to 100/0 is used. When the copolymerization ratio is out of the above range, the melting point of the copolymer becomes less than 160 ° C., and the object of the present invention cannot be achieved. The melting point of the copolymer is more preferably 165 ° C. or higher.

  The viscosity of the polylactic acid polymer is a melt flow rate (hereinafter abbreviated as “MFR1”) measured at a temperature of 210 ° C. and a load of 20.2 N (2160 gf) according to the method described in ASTM-D-1238 (E). ) Is preferably 10 to 80 g / 10 minutes, more preferably 20 to 70 g / 10 minutes. When the MFR1 is less than 10 g / 10 minutes, the viscosity is too high, and the burden on the screw during melting in the production process increases. On the other hand, when MFR1 exceeds 80 g / 10 min, the viscosity is too low, and yarn breakage is likely to occur in the spinning process, and the operability tends to be impaired.

  As a method for controlling the melt flow rate of the polylactic acid polymer to a predetermined range, when the melt flow rate is too large, a small amount of chain extender, such as a diisocyanate compound, a bisoxazoline compound, an epoxy compound, an acid anhydride, is used. And a method of increasing the molecular weight of the polymer by using a product. On the other hand, when the melt flow rate is too small, a method of mixing with a polylactic acid polymer or a low molecular weight compound having a higher melt flow rate can be used.

As the polylactic acid polymer, a commercially available product can be suitably used, and specifically, a product name “6201D” manufactured by Nature Works, etc. can be used.
In addition, additives such as a crystal nucleating agent, a heat stabilizer, an antioxidant, and an antistatic agent can be added to the polylactic acid polymer as long as the effects of the present invention are not impaired.

  Next, an aliphatic polyester polymer having a melting point lower than that of the polylactic acid polymer will be described. In the present invention, the difference in melting point between the polylactic acid polymer and the aliphatic polyester polymer must be 50 ° C. or more. When the difference between the melting points is 50 ° C. or more, when obtaining a nonwoven fabric capable of forming a biodegradable face cover, the thermal adhesiveness for making the nonwoven fabric is good. Moreover, it is possible to improve the heat sealability of the nonwoven fabric that can form the obtained biodegradable face cover.

The aliphatic polyester-based polymer is 1,4-butanediol and succinic acid in the aliphatic polyester whose main constituent, calcium montanate, at least one selected et Toka phenylphosphonic acid zinc salt obtained by melt-mixing It is. Aliphatic polyesters, calcium montanate, by adding at least 1 selected et Toka phenylphosphonic acid zinc salt, and to increase the crystallization rate of the aliphatic polyester polymer, the fibers in the spreading step - between fibers It is possible to reduce the frictional resistance and effectively prevent the occurrence of blocking in the fiber opening process.

  As the aliphatic polyester mainly composed of 1,4-butanediol and succinic acid, any aliphatic polyester to which isocyanate is not added can be used. When the isocyanate is added, the isocyanate and the urethane bond in the aliphatic polyester react, so when obtaining a nonwoven fabric capable of forming a biodegradable face cover, depending on the conditions, May cause problems such as coloring or generation of microgel.

  The aliphatic polyester is heated to 200 ° C. at a heating rate of 500 ° C./min using a DSC apparatus, held for 5 minutes in that state, melted, and then cooled to 90 ° C. at a cooling rate of 500 ° C./min. The crystallization rate index (hereinafter sometimes abbreviated as “tmax1”) when subjected to differential thermal analysis by holding at 90 ° C. for isothermal crystallization is preferably 3 to 10 minutes. This crystallization rate index tmax1 is the time (minutes) required to reach half the crystallinity finally reached when the polymer is cooled from a molten state of 200 ° C. and crystallized at 90 ° C. The smaller the crystallization rate index, the faster the crystallization rate. Therefore, as the aliphatic polyester polymer contained in the composite fiber, a crystallization rate index tmax1 having a high crystallization rate of 3 to 10 minutes is used as described above, so that the cooling property when melt spinning is good. Thus, blocking can be made difficult to occur during fiber opening.

  In the present invention, the aliphatic polyester used as the raw material for the aliphatic polyester polymer includes 230 ° C. melt flow rate and 190 ° C. melt flow rate measured according to the method described in ASTM-D-1238 (E). It is preferable that the melt viscosity gradient, which is the difference between the two, is in the range of 20 g / 10 min or less. The aliphatic polyester having such characteristics is less likely to have a decrease in fluidity due to temperature and can have a higher-order structure close to a crosslinked structure. Therefore, tmax1 can be set to 3 to 10 minutes as described above. . That is, the crystallization speed of the aliphatic polyester polymer can be increased, and the spunbond must be a short distance from the spinning process to the cooling / stretching process compared to the manufacturing process of short fiber nonwoven fabrics. Even in the production process of the nonwoven fabric, the aliphatic polyester polymer does not exhibit the elasticity at the time of melting as expressed by the crosslinking reaction, and can be cooled and crystallized well. For this reason, the nonwoven fabric which can form the biodegradable face cover of this invention can prevent effectively generation | occurrence | production of the blocking in a fiber opening process.

  As the aliphatic polyester used as the raw material for the aliphatic polyester polymer, a commercially available product can be suitably used. Specifically, the product name “GSPla” (crystal melting point: 110 ° C.) manufactured by Mitsubishi Chemical Corporation can be used. Can be used.

  Measured according to the method described in ASTM-D-1238 (E) of the polylactic acid polymer and aliphatic polyester polymer constituting the composite long fiber, measured at 210 ° C. and a load of 20.2 N (2160 gf). The ratio of melt flow rate (MFR1) (MFR1 of aliphatic polyester polymer / MFR1 of polylactic acid polymer) (hereinafter sometimes abbreviated as “MFR ratio 1”) is 0.3 to 1.5. Preferably there is. Furthermore, it measured according to the method as described in ASTM-D-1238 (E) of the polylactic acid polymer and the aliphatic polyester polymer constituting the composite long fiber at 230 ° C. and a load of 20.2 N (2160 gf). The ratio of measured melt flow rate (MFR2) (MFR2 of aliphatic polyester polymer / MFR2 of polylactic acid polymer) (hereinafter sometimes abbreviated as “MFR ratio 2”) is 0.7 or less. It is preferable. When both the MFR ratio 1 and the MFR ratio 2 are in the above ranges, the aliphatic polyester polymer is cooled by the heat generated when the polylactic acid polymer is crystallized when the composite long fiber is melt-spun. For this reason, blocking can be made difficult to occur in the opening process after cooling the yarn.

And shine to the object of the present invention of increasing the crystallization rate of the fat-aliphatic polyester polymer, Ru necessary der that have use calcium montanate.

  When calcium montanate is used, the openability is good. The reason is presumed to be due to the form of fibers constituting the nonwoven fabric. That is, by adding calcium montanate to an aliphatic polyester and performing melt spinning, the reason is not clear, but the fiber surface has at least one shape selected from the following (a) to (c): Can be.

(B) A fine concave part is formed on the fiber surface. (B) A fine convex part is formed on the fiber surface. (C) A concave part is formed in a line shape in the fiber axis direction of the fiber surface. When the concave or convex portions are formed on the fiber surface as described above, the surface friction between the fibers and the fibers constituting the nonwoven fabric capable of forming the biodegradable face cover of the present invention is reduced, and good opening at the time of opening is achieved. Presumed to be in a fine state.

FIG. 1 shows the appearance of the surface of long fibers obtained when calcium montanate is used. As shown in the figure, fine irregularities are formed on the fiber surface.
The purpose or al of the present invention of increasing the crystallization rate of the aliphatic polyester polymer, Ru required der is Rukoto using phenylphosphonic acid zinc salt.

When using phenylphosphonic acid zinc salt, the opening property is also good. The reason is that the surface form of the fiber when the nonwoven fabric capable of forming the biodegradable face cover of the present invention is the same as that of calcium montanate is the same reason. Guessed.

  FIG. 2 shows a state of the surface of the long fiber obtained when a phenylphosphonic acid metal salt is used. As shown, fine irregularities are formed on the fiber surface. In this case, the uneven portions are finer than the uneven portions on the surface of the long fiber obtained when calcium montanate is used.

When melt mixing the aliphatic polyester, calcium montanate, at least one of the amount selected et Toka phenylphosphonic acid zinc salt is required to be 0.1 to 1 mass% in the total, 0 0.1 to 0.7% by mass is preferable, and 0.1 to 0.5% by mass is more preferable. If the blending amount is less than 0.1% by mass, the frictional resistance between the fibers cannot be reduced, which is insufficient for suppressing the occurrence of blocking in the fiber opening process. Moreover, when it exceeds 1 mass%, the spinning operability tends to be inferior.

In connection with the above points, 200 and calcium montanate, an aliphatic polyester polymer at least one melted mixture selected et Toka phenylphosphonic acid zinc salt, at a Atsushi Nobori rate of 500 ° C. / min using a DSC apparatus The crystal when heated to 90 ° C., held for 5 minutes in that state and melted, then cooled to 90 ° C. at a cooling rate of 500 ° C./min, held at 90 ° C. to cause isothermal crystallization and differential thermal analysis The conversion rate index (hereinafter sometimes abbreviated as “tmax2”) is preferably 2 minutes or less. The crystallization rate index tmax2 is the time (minutes) required to reach half the crystallinity finally reached when the polymer is cooled from a molten state of 200 ° C. and crystallized at 90 ° C. The smaller the crystallization speed index, the faster the crystallization speed. Therefore, used as a raw material of the composite fibers, the aliphatic polyester, calcium montanate, an aliphatic polyester polymer and the at least one mixing predetermined amounts molten selected et Toka phenylphosphonic acid zinc salt, crystallization rate index tmax2 It is possible to reduce the friction resistance between the fibers in addition to keeping the fiber length to 2 minutes or less, so that the cooling property when melt spinning is good and the blocking is unlikely to occur at the time of fiber opening. Can be. Therefore, it is useful for forming the biodegradable face cover of the present invention.

Next, the relationship between the crystallization speeds of the polylactic acid polymer and the aliphatic polyester polymer will be described.
The crystallization rate of the polylactic acid polymer is slow, and isothermal crystallization does not occur at the temperature (90 ° C.) at which the crystallization rate of the aliphatic polyester polymer described above is measured. Therefore, it is assumed that the polylactic acid polymer is slower in crystallization rate than the aliphatic polyester polymer.

In the nonwoven fabric capable of forming the biodegradable face cover of the present invention, the aliphatic polyester polymer forms at least a part of the composite fiber surface. In the process of producing the composite fiber, the heat generated when the polylactic acid polymer having a low crystallization rate is crystallized inhibits the cooling of the aliphatic polyester polymer that forms at least a part of the fiber surface. However, the crystallization rate of the aliphatic polyester polymer is within the above range, further calcium montanate, by adding at least one selected et Toka phenylphosphonic acid zinc salt, it is possible to increase the crystallization rate . As a result, the nonwoven fabric can be produced without blocking the fibers in the spinning process and the fiber opening process of the composite fiber without being inhibited by the heat generated when the polylactic acid polymer is crystallized. The biodegradable face cover formed by the above has excellent flexibility.

  The polylactic acid polymer is heated to 200 ° C. at a temperature rising rate of 500 ° C./min using a DSC apparatus, held in that state for 5 minutes to dissolve, and then heated to 130 ° C. at a temperature lowering rate of 500 ° C./min. The crystallization rate index (hereinafter sometimes abbreviated as “tmax3”) when the temperature is lowered, held at 130 ° C. and subjected to isothermal crystallization for differential thermal analysis is preferably 10 minutes or less.

  In the nonwoven fabric capable of forming the biodegradable face cover of the present invention, the aliphatic polyester polymer forms at least a part of the surface of the composite fiber. As a fiber cross-sectional form for constituting such a fiber, for example, a side-by-side composite cross section in which a polylactic acid polymer and an aliphatic polyester polymer are bonded together, the polylactic acid polymer forms a core and is aliphatic. Examples include a core-sheath composite cross section in which a polyester polymer forms a sheath, a split composite cross section in which a polylactic acid polymer and an aliphatic polyester polymer are alternately present on the fiber surface, and a multileaf composite cross section. It is done. Since the aliphatic polyester polymer plays a role as a heat-adhesive component as will be described later, the aliphatic polyester polymer forms the entire surface of the fiber in consideration of heat sealability when forming the face cover. The core-sheath type composite cross section is preferable.

  The nonwoven fabric capable of forming the biodegradable face cover of the present invention is preferably a composite fiber having a core-sheath type composite cross section. In such a case, the polylactic acid polymer forms a core as a fiber forming component. Furthermore, the aliphatic polyester polymer forms a sheath that functions as a thermal adhesive component for maintaining the form of a non-woven fabric capable of forming a biodegradable face cover and being bonded to other members by heat sealing. . In the case of such a core-sheath composite cross section, the composite ratio (mass ratio) of the core part and the sheath part is preferably core part / sheath part = 3/1 to 1/3. When the ratio of the core part exceeds 3/1, the ratio of the sheath part becomes too small, so that the thermal adhesiveness tends to be inferior, and the shape retention and mechanical properties of the face cover formed from the nonwoven fabric tend to be inferior. In addition, it becomes difficult to obtain sufficient heat sealability. On the other hand, when the ratio of the core portion is less than 1/3, the mechanical strength of the obtained face cover tends to be insufficient.

The biodegradable face cover of the present invention is obtained from a nonwoven fabric formed by the spunbond method in which the above-described composite fibers are deposited.
The form of the nonwoven fabric capable of forming the biodegradable face cover of the present invention is preferably a fiber in which the aliphatic polyester polymer component is melted or softened so that the fibers are thermally bonded to each other to maintain the shape. The shape may be held by entanglement. As a form of heat bonding, it may be one that is heat-bonded via a molten or softened aliphatic polyester polymer at a contact point between fibers, or partially formed by passing through a heat embossing device. The heat-bonding part and the other non-heat-bonding part may be included, and the aliphatic polyester polymer component may be melted or softened and held in the form of a nonwoven fabric in the heat-bonding part.

  The single yarn fineness of the composite fiber constituting the nonwoven fabric capable of forming the biodegradable face cover of the present invention is preferably 7 dtex or less, and more preferably 5 dtex or less. This is because when the single yarn fineness exceeds 7 dtex, when the face cover is worn, it feels hard when it comes into contact with the skin, and it becomes easy to feel discomfort during wearing. In addition, the minimum of single yarn fineness shall be about 1 dtex from a viewpoint of operativity at the time of obtaining a nonwoven fabric.

The basis weight of the biodegradable face cover of the present invention is preferably in the range of 15 to 50 g / ^{m 2,} 2
0-40 g / m < ² > is more preferable. If the basis weight is less than 15 g / m ² , the mechanical properties tend to be poor in practicality as a face cover. On the other hand, when the basis weight exceeds 50 g / m ² , the constituent fibers in the nonwoven fabric capable of forming the biodegradable face cover of the present invention are dense, and thus the texture of the face cover tends to be hard.

  The biodegradable face cover of the present invention preferably has a flexibility measured according to the handle ohm method described in JIS L 1906: 2000 of 15 cN or more and 90 cN or less, and more preferably 15 cN or more and 60 cN or less. When the flexibility exceeds 60 cN, the texture of the nonwoven fabric becomes hard and is not preferable as a face cover. Further, if the flexibility is less than 15 cN, it is not preferable because it may be too soft and difficult to handle.

  The biodegradable face cover of the present invention preferably has a drape coefficient of 0.91 or less measured according to the method described in JIS L 1096: 1999. This drape coefficient represents the drape property (one of the indices of flexibility) of the nonwoven fabric, and the smaller the value, the better the drape property appears. If it exceeds 0.91, the texture tends to be hard. In the present invention, the lower limit of the drape coefficient is about 0.650. This is because if it is too small, it is too clinging to the face when the face cover is attached.

By adjusting the single fiber fineness of the composite fiber to 7 decix or less and the basis weight of the face cover to 15 to 50 g / m ² as described above and adjusting each within these ranges, a face cover with excellent flexibility can be obtained. .

  When the biodegradable face cover of the present invention is dissolved at a temperature increase rate of 10 ° C./min and then subjected to differential thermal analysis at a temperature decrease rate of 10 ° C./min, the temperature decrease crystallization temperature Tc1 caused by the polylactic acid polymer is There is a temperature lowering crystallization temperature Tc2 due to the aliphatic polyester polymer. In the present invention, Tc2 is preferably 80 ° C. or higher and 90 ° C. or lower. The temperature drop crystallization temperature Tc indicates, for example, a temperature at which the seal portion cools and solidifies when heat sealing is performed in order to manufacture a bag-shaped face cover. It means that it takes. Therefore, when the temperature-falling crystallization temperature Tc2 resulting from the aliphatic polyester polymer is less than 80 ° C., when the heat seal process is performed to produce the biodegradable face cover of the present invention, the seal portion is cooled. This is not preferable because it takes a long time and the processing speed becomes slow.

  Moreover, it is preferable that crystallization heat amount Hexo2 resulting from an aliphatic polyester polymer is 20 J / g or more and 40 J / g or less. The amount of heat of crystallization Hexo is an ability required for cooling. When this value is small, a phenomenon occurs in which the heat-sealed portion is not easily cooled and solidified. When the crystallization heat amount Hexo2 is less than 20 J / g, it takes time until the seal portion is cooled when heat-sealing to produce the biodegradable face cover of the present invention, and the processing speed is high. Since it becomes late, it is not preferable.

  The biodegradable face cover of the present invention is formed of the nonwoven fabric as described above. That is, the nonwoven fabric is cut into an appropriate size to form a heat seal portion, thereby forming a bag-like form.

  In the heat seal portion, the aliphatic polyester polymer is melted or softened so that the fibers are in close contact with each other, and the polylactic acid polymer is in a state of maintaining the fiber form without being affected by heat. Thus, in order to form a heat seal part in a nonwoven fabric and to obtain a face cover, the bag making process by a well-known heat sealer can be applied. The processing conditions (setting temperature, linear pressure, processing speed) of the heat sealer at this time are such that the aliphatic polyester polymer is melted or softened, and the polylactic acid polymer having a higher melting point than the aliphatic polyester polymer is heated. Appropriate conditions that do not have an influence can be set.

Next, based on an Example, this invention is demonstrated concretely. However, the present invention is not limited only to these examples.
In addition, measurement of various physical property values and evaluation of various physical properties in the following examples and comparative examples were performed by the following methods.
(1) Melting point (° C.): Using a differential scanning calorimeter (trade name “DSC-2”, manufactured by Perkin Elma Co., Ltd.), the sample mass was measured at 5 mg and the heating rate was 10 ° C./min. The temperature giving the maximum value of the obtained melting endothermic curve was defined as the melting point (° C.).
(2) Decreasing crystallization temperature Tc (° C.), crystallization calorific value Hexo (J / g): using a differential scanning calorimeter (manufactured by Perkin Elma, trade name “DSC-7”), a sample mass of 10 mg, Temperature rising to 210 ° C at a rate of temperature increase of 10 ° C / min, followed by temperature-down crystallization that gives the extreme value of the exothermic peak of the crystallization exothermic curve obtained when the temperature was decreased at a rate of 10 ° C / min The temperature was Tcc (° C.), and the area of the exothermic peak portion was the crystallization heat amount Hexo (J / g).
(3) Crystallization rate index (min):
tmax1, tmax2
Using a differential scanning calorimeter (manufactured by Perkin Elma, trade name “DSC-2”), 5 mg of the sample was heated to 200 ° C. at a heating rate of 500 ° C./min and held in that state for 5 minutes. Thereafter, the temperature is lowered to 90 ° C. at a temperature lowering rate of 500 ° C./min, and is held at 90 ° C. for isothermal crystallization and differential thermal analysis, and the crystallization index tmax1 of the aliphatic polyester polymer and the aliphatic polyester polymer The crystallization rate index tmax2 of the molten mixture obtained by melt-mixing at least one selected from higher fatty acids, higher fatty acid metal salts, phenylphosphonic acid metal salts, and amide waxes and extruding at a melting temperature of 200 ° C. Asked.
tmax3
Using a differential scanning calorimeter (Perkin Elma, trade name “DSC-2”), 5 mg of the sample was heated to 200 ° C. at a heating rate of 500 ° C./min, and held in that state for 5 minutes to melt. Then, the temperature was lowered to 130 ° C. at a temperature lowering rate of 500 ° C./min, held at 130 ° C. for isothermal crystallization, and subjected to differential thermal analysis to obtain a crystallization rate index tmax3 of the polylactic acid polymer.

(4) Fineness (decitex): In a nonwoven fabric capable of forming a face cover, the fiber diameter of 50 composite fibers in a web state was measured with an optical microscope, and the average value obtained by density correction was taken as the fineness.
(5) Weight per unit area (g / m ² ): In a non-woven fabric capable of forming a face cover, 10 pieces of a sample piece having a sample length of 10 cm and a sample width of 5 cm were prepared from a sample in a standard state. The weight (g) of the sample piece was weighed, and the average value of the obtained values was converted per unit area to obtain the basis weight (g / m ² ).
(6) Flexibility (cN): Measured according to the handle ohm method described in JIS L 1906: 2000.
(7) Drape coefficient: Measured according to the method described in JIS L 1096: 1999.
(8) Wearability of face cover A face cover was attached to a person who applied makeup, and after changing clothes, the face cover was removed. About the state after desorption, sensory evaluation was carried out in the following two steps.
○: Flexibility and draping properties were maintained, and the face cover was kept attached to the head with almost no displacement, and the face was not exposed due to displacement. Moreover, when the detached clothes were observed, adhesion of cosmetics was not confirmed.
X: Since it was hard and drapeability was insufficient, the face cover was not attached to the head. Further, when the detached clothes were observed, the adhesion of the cosmetics was somewhat observed.

Example 1
Melting point: 168 ° C., MFR1: 20 g / 10 min, MFR2: 40 g / 10 min, crystallization rate index tmax3: 7.4 min, (L-lactic acid) / (D-lactic acid) (molar ratio) = 98.4 A /1.6 copolymer of L-lactic acid and D-lactic acid (manufactured by Nature Works, trade name “6201D”) (hereinafter abbreviated as “P1”) was prepared as a core component polymer.

  In addition, an aliphatic polyester (polybutylene succinate resin) having a melting point of 114 ° C., MFR1 of 22 g / 10 minutes, and MFR2 of 25 g / 10 minutes and comprising 1,4-butanediol and succinic acid as constituent components ( A product name “GSPla FZ71PD” (hereinafter abbreviated as “P2”) manufactured by Mitsubishi Chemical Corporation was prepared as a raw material for the sheath component polymer. The aliphatic polyester had a crystallization rate index tmax1 of 7.4 minutes.

Furthermore, a masterbatch containing 20% by mass of talc (hereinafter abbreviated as “TA”) of a crystal nucleating agent based on P1 was prepared.
Further, the composite ratio of P1 and P2 is P1: P2 = 1: 1 in terms of mass ratio, and P2 is further added so that 0.5% by mass of talc is contained in the melt polymerization of P1. 0.5% by mass of calcium montanate (trade name “Recommont Ca salt V101” manufactured by Clariant) (hereinafter abbreviated as “V101”), which is a higher fatty acid metal salt, is contained in the molten polymer. In addition, after individually weighing, P1 and P2 were melted at a temperature of 200 ° C. using respective extruder type melt extruders. The crystallization rate index tmax2 of P2 to which calcium montanate was added was 1.0 minute. Next, melt spinning was performed at a single-hole discharge rate of 0.70 g / min using a spinneret having a cross section of the core-sheath composite fiber so that P1 constitutes the core and P2 constitutes the sheath.

  After cooling the spun yarn with a known cooling device, it is subsequently pulverized at a traction speed of 2000 m / min with an air soccer provided below the spinneret, and opened using a known fiber opening device, It was collected and accumulated as a web on a moving screen conveyor. At the time of opening, no adhesive yarn and convergent yarn were observed, and the opening property was good. The single yarn fineness of the deposited composite long fiber was 3.5 dtex.

Next, the web was passed through a hot embossing device composed of an embossing roll and a smooth metal roll, and heat treated to obtain a polylactic acid-based long fiber nonwoven fabric having a basis weight of 30 g / m ² . As heat embossing conditions, the surface temperature of both rolls is 90 ° C., and the embossing roll is a circular sculpture pattern with an individual area of 0.6 mm ² , the pressure contact density is 20 / cm ² , and the pressure contact area ratio is 15 % Was used.

Subsequently, the face cover of Example 1 was formed using this nonwoven fabric. That is, a sheet having a width of 40 cm and a length of 40 cm was cut out from the nonwoven fabric and folded back at a length of 20 cm. Then, both ends in the width direction were heat-sealed at a temperature of 120 ° C., a surface pressure of 98 N / cm ² , and a treatment time of 1 second to form a heat-sealed portion having a width of 0.5 cm, thereby forming a bag-like face cover. When the heat seal part of the obtained face cover was visually observed, there was no occurrence of shrinkage due to heat, and it was well sealed.

  Table 1 shows the performance of the face cover made of the obtained polylactic acid-based long fiber nonwoven fabric.

(Example 2)
A face cover of Example 2 was obtained in the same manner as in Example 1 except that the basis weight of the nonwoven fabric capable of forming the face cover was 50 g / m ² . Table 1 shows the performance of the obtained face cover.

(Example 3)
A master batch containing 20% by mass of TA based on P1 used in Example 1 was prepared as the core component polymer. P2 used in Example 1 was prepared as a raw material for the sheath component polymer.

  Then, the composite ratio of P1 and P2 is P1: P2 = 1: 1 in terms of mass ratio, and further, P2 is added so that 0.5 mass% of TA is included in the melt polymerization of P1. After individually weighing so that 0.3 mass% of V101 was contained in the molten polymer, P1 and P2 were melted at a temperature of 220 ° C. using respective extruder type melt extruders. The crystallization rate index tmax2 of P2 to which calcium montanate was added was 2.0 minutes. Next, melt spinning was performed at a single-hole discharge rate of 0.70 g / min using a spinneret having a cross section of the core-sheath composite fiber so that P1 constitutes the core and P2 constitutes the sheath.

  After cooling the spun yarn with a known cooling device, it is subsequently pulverized at a traction speed of 2600 m / min with an air soccer provided below the spinneret, and opened using a known opening device, It was collected and accumulated as a web on a moving screen conveyor. At the time of opening, no adhesive yarn and convergent yarn were observed, and the opening property was good. The single yarn fineness of the deposited composite long fibers was 3.2 dtex.

Next, the web was passed through a hot embossing device composed of an embossing roll and a smooth metal roll, and heat treated to obtain a polylactic acid-based long fiber nonwoven fabric having a basis weight of 30 g / m ² . As heat embossing conditions, the surface temperature of both rolls is 90 ° C., and the embossing roll is a circular sculpture pattern with an individual area of 0.6 mm ² , the pressure contact density is 20 / cm ² , and the pressure contact area ratio is 15 % Was used.

Subsequently, the face cover of Example 3 was formed using this nonwoven fabric. That is, a sheet having a width of 40 cm and a length of 40 cm was cut out from the nonwoven fabric and folded back at a length of 20 cm. Then, both ends in the width direction were heat-sealed at a temperature of 120 ° C., a surface pressure of 98 N / cm ² , and a treatment time of 1 second to form a heat-sealed portion having a width of 0.5 cm, thereby forming a bag-like face cover. When the heat seal part of the obtained face cover was visually observed, there was no occurrence of shrinkage due to heat, and it was well sealed.

  Table 1 shows the performance of the face cover made of the obtained polylactic acid-based long fiber nonwoven fabric.

Example 4
As a core component polymer, a master batch was prepared containing 20% by mass of TA as a crystal nucleating agent based on P1 used in Example 1. P2 used in Example 1 was prepared as a raw material for the sheath component polymer.

  Further, the composite ratio of P1 and P2 is P1: P2 = 2: 1 in terms of mass ratio, and 0.5 mass% of talc is included in the melt polymerization of P1, and further P2 After individually weighing so that 0.5 mass% of V101 was contained in the molten polymer, P1 and P2 were melted at a temperature of 200 ° C. using an individual extruder type melt extruder. The crystallization rate index tmax2 of P2 to which calcium montanate was added was 1.0 minute. Next, melt spinning was performed at a single-hole discharge rate of 0.70 g / min using a spinneret having a cross section of the core-sheath composite fiber so that P1 constitutes the core and P2 constitutes the sheath.

  After cooling the spun yarn with a known cooling device, it is subsequently pulverized at a traction speed of 2000 m / min with an air soccer provided below the spinneret, and opened using a known fiber opening device, It was collected and accumulated as a web on a moving screen conveyor. At the time of opening, no adhesive yarn and convergent yarn were observed, and the opening property was good. The single yarn fineness of the deposited composite long fiber was 4.8 dtex.

Next, the web was passed through a hot embossing device composed of an embossing roll and a smooth metal roll, and heat treated to obtain a polylactic acid-based long fiber nonwoven fabric having a basis weight of 20 g / m ² . As heat embossing conditions, the surface temperature of both rolls is 90 ° C., and the embossing roll is a circular sculpture pattern with an individual area of 0.6 mm ² , the pressure contact density is 20 / cm ² , and the pressure contact area ratio is 15 % Was used.

Subsequently, the face cover of Example 4 was formed using this nonwoven fabric. That is, a sheet having a width of 40 cm and a length of 40 cm was cut out from the nonwoven fabric and folded back at a length of 20 cm. Then, both ends in the width direction were heat-sealed at a temperature of 120 ° C., a surface pressure of 98 N / cm ² , and a treatment time of 1 second to form a heat-sealed portion having a width of 0.5 cm, thereby forming a bag-like face cover. When the heat seal part of the obtained face cover was visually observed, there was no occurrence of shrinkage due to heat, and it was well sealed.

  Table 1 shows the performance of the face cover made of the obtained polylactic acid-based long fiber nonwoven fabric.

(Example 5)
P1 used in Example 1 was prepared as the core component polymer. P2 used in Example 1 was prepared as a raw material for the sheath component polymer.

  Then, the composite ratio of P1 and P2 is P1: P2 = 1: 1 by mass, and phenylphosphonic acid zinc salt (trade name “manufactured by Nissan Chemical Co., Ltd. (PPA-Zn ") (hereinafter may be abbreviated as" PPA-Zn ") is further contained in an amount of 0.5% by mass in the molten polymer of P2 so that 1% by mass is contained. Thus, after weighing individually, P1 and P2 were melted at a temperature of 200 ° C. using individual extruder-type melt extruders. The crystallization rate index tmax2 of P2 to which calcium montanate was added was 1.0 minute. Next, melt spinning was performed at a single-hole discharge rate of 0.70 g / min using a spinneret having a cross section of the core-sheath composite fiber so that P1 constitutes the core and P2 constitutes the sheath.

  After cooling the spun yarn shape with a known cooling device, it is subsequently pulverized at a traction speed of 2100 m / min with an air football provided below the spinneret, and is opened and moved using a known opening device. It was collected and deposited as a web on a screen conveyor. At the time of opening, no adhesive yarn and convergent yarn were observed, and the opening property was good. The single yarn fineness of the deposited composite long fiber was 3.3 dtex.

Next, the web was passed through a hot embossing device composed of an embossing roll and a smooth metal roll, and heat treated to obtain a polylactic acid-based long fiber nonwoven fabric having a basis weight of 20 g / m ² . As heat embossing conditions, the surface temperature of both rolls is 100 ° C., and the embossing roll is a circular sculpture pattern with an individual area of 0.6 mm ² , the pressure contact density is 20 / cm ² , and the pressure contact area ratio is 15 % Was used.

Subsequently, the face cover of Example 5 was formed using this nonwoven fabric. That is, a sheet having a width of 40 cm and a length of 40 cm was cut out from the nonwoven fabric and folded back at a length of 20 cm. Then, both ends in the width direction were heat-sealed at a temperature of 120 ° C., a surface pressure of 98 N / cm ² , and a treatment time of 1 second to form a heat-sealed portion having a width of 0.5 cm, thereby forming a bag-like face cover. When the heat seal part of the obtained face cover was visually observed, there was no occurrence of shrinkage due to heat, and it was well sealed.

  Table 1 shows the performance of the face cover made of the obtained polylactic acid-based long fiber nonwoven fabric.

( Reference Example 1 )
As a core component polymer, a master batch was prepared containing 20% by mass of TA as a crystal nucleating agent based on P1 used in Example 1. P2 used in Example 1 was prepared as a raw material for the sheath component polymer.

  Further, P2 is further adjusted so that the composite ratio of P1 and P2 is P1: P2 = 1: 1 in terms of mass ratio, and 0.5 mass% of talc is contained in the molten polymer of P1. After individually weighing so that 0.5% by mass of N, N′-ethylenebisstearic acid amide (hereinafter abbreviated as “Amide Wax 1”), which is an amide wax, is contained in the molten polymer. , P1 and P2 were melted at a temperature of 220 ° C. using individual extruder melt extruders. The crystallization rate index tmax2 of P2 to which amide wax 1 was added was 1.1 minutes.

Next, using a spinneret having a cross section of the core-sheath composite fiber, melt spinning was performed at a single hole discharge rate of 0.70 g / min so that P1 constitutes the core and P2 constitutes the sheath.
After cooling the spun yarn with a known cooling device, it is subsequently pulverized at a traction speed of 2250 m / min with an air football provided below the spinneret, and opened using a known fiber opening device, It was collected and deposited as a web on a moving screen conveyor. At the time of opening, no adhesive yarn and convergent yarn were observed, and the opening property was good. The single yarn fineness of the deposited composite long fiber was 3.1 dtex.

Next, the web was passed through a hot embossing device composed of an embossing roll and a smooth metal roll, and heat treated to obtain a polylactic acid-based long fiber nonwoven fabric having a basis weight of 50 g / m ² . As heat embossing conditions, the surface temperature of both rolls is 90 ° C., and the embossing roll is a circular sculpture pattern with an individual area of 0.6 mm ² , the pressure contact density is 20 / cm ² , and the pressure contact area ratio is 15 % Was used.

Subsequently, the face cover of Reference Example 1 was formed using this nonwoven fabric. That is, a sheet having a width of 40 cm and a length of 40 cm was cut out from the nonwoven fabric and folded back at a length of 20 cm. Then, both ends in the width direction were heat-sealed at a temperature of 120 ° C., a surface pressure of 98 N / cm ² , and a treatment time of 1 second to form a heat-sealed portion having a width of 0.5 cm, thereby forming a bag-like face cover. When the heat seal part of the obtained face cover was visually observed, there was no occurrence of shrinkage due to heat, and it was well sealed.

  Table 1 shows the performance of the face cover made of the obtained polylactic acid-based long fiber nonwoven fabric.

( Reference Example 2 )
P1 and P2 used in Example 1 were prepared as the core component polymers.

  The composite ratio of P1 and P2 is P1: P2 = 1: 1 in terms of mass ratio, and 0.5 mass% of TA as a crystal nucleating agent is contained in the molten polymer of P1. Further, after individually weighing so that the amide wax 1 is contained in an amount of 0.3% by mass in the molten polymer of P2, P1 and P2 are each heated to a temperature of 220 by using an individual extruder type melt extruder. Melted at ℃. The crystallization rate index tmax2 of P2 to which amide wax 1 was added was 1.5 minutes.

Next, a polylactic acid-based long fiber nonwoven fabric having a basis weight of 30 g / m ² was obtained by the same production method as in Reference Example 1 .
Subsequently, the face cover of Reference Example 2 was formed in the same manner as Reference Example 1 using this nonwoven fabric.

  Table 1 shows the performance of the face cover made of the obtained polylactic acid-based long fiber nonwoven fabric.

( Reference Example 3 )
A masterbatch containing 20% by mass of TA as a crystal nucleating agent based on P1 used in Example 1 as a core component polymer was prepared. P2 used in Example 1 was prepared as a raw material for the sheath component polymer.

  Further, P2 is further adjusted so that the composite ratio of P1 and P2 is P1: P2 = 2: 1 by mass ratio, and 0.5% by mass of talc is contained in the molten polymer of P1. N, N′-ethylenebispalmitic acid amide (hereinafter abbreviated as “Amide Wax 2”), which is an amide wax, was individually weighed so as to contain 0.5% by mass in the molten polymer of Thereafter, each of P1 and P2 was melted at a temperature of 220 ° C. using an individual extruder-type melt extruder. The crystallization rate index tmax2 of P2 to which amide wax 2 was added was 1.2 minutes.

Next, melt spinning was performed at a single-hole discharge rate of 0.70 g / min using a spinneret having a cross section of the core-sheath composite fiber so that P1 constitutes the core and P2 constitutes the sheath.
After cooling the spun yarn with a known cooling device, it is subsequently pulled and refined at a pulling speed of 2000 m / min with an air soccer installed below the spinneret, and opened using a known opening device and moved. It was collected and deposited as a web on a screen conveyor. At the time of opening, no adhesive yarn and convergent yarn were observed, and the opening property was good. The single yarn fineness of the deposited composite long fiber was 3.1 dtex.

Next, the web was passed through a hot embossing device composed of an embossing roll and a smooth metal roll, and heat treated to obtain a polylactic acid-based long fiber nonwoven fabric having a basis weight of 30 g / m ² . As heat embossing conditions, the surface temperature of both rolls is 100 ° C., and the embossing roll is a circular sculpture pattern with an individual area of 0.6 mm ² , the pressure contact density is 20 / cm ² , and the pressure contact area ratio is 15 % Was used.

Subsequently, the face cover of Reference Example 3 was formed using this nonwoven fabric. That is, a sheet having a width of 40 cm and a length of 40 cm was cut out from the nonwoven fabric and folded back at a length of 20 cm. Then, both ends in the width direction were heat-sealed at a temperature of 120 ° C., a surface pressure of 98 N / cm ² , and a treatment time of 1 second to form a heat-sealed portion having a width of 0.5 cm, thereby forming a bag-like face cover. When the heat seal part of the obtained face cover was visually observed, there was no occurrence of shrinkage due to heat, and it was well sealed.

  Table 1 shows the performance of the face cover made of the obtained polylactic acid-based long fiber nonwoven fabric.

(Comparative Example 1)
In the melt polymerization of P1 of Example 1, 0.5% by mass of talc was contained, and melt spinning was performed from a round metal spinneret at a spinning temperature of 210 ° C. and a single hole discharge rate of 1.67 g / min. Next, after the spinning yarn shape is cooled by a cooling air flow, it is subsequently taken up at 5000 m / min by an air soccer provided below the spinneret, and is opened using a known opening device and moved. The web was formed by depositing on a screen conveyor. The single yarn fineness of the deposited long fibers was 3.3 dtex.

Next, the web was passed through a hot embossing device composed of an embossing roll and a smooth metal roll, and heat treated to obtain a polylactic acid-based long fiber nonwoven fabric having a basis weight of 30 g / m ² . As heat embossing conditions, the surface temperature of both rolls is 130 ° C., and the embossing rolls are circular engraving patterns with individual areas of 0.6 mm ² , the pressure contact density is 20 / cm ² , and the pressure contact area ratio is 15 % Was used.

  Next, using this non-woven fabric, an attempt was made to form a face cover in the same manner as in Example 1, but the heat seal part could not be formed, and heat seal processing could not be performed. For this reason, a face cover was formed by ultrasonic processing.

  The performance of the face cover of Comparative Example 1 is shown in Table 1.

The face covers of Examples 1 to 5 and Reference Examples 1 to 3 were superior in flexibility and texture to the face cover of Comparative Example 1, and were excellent in wearability. In addition, the heat sealing process can be performed satisfactorily and the industrial productivity is good.

Claims (5)

A non-woven fabric formed by a spunbond method using a composite fiber as a constituent fiber, the composite fiber having a polylactic acid polymer having a melting point of 160 ° C. or higher and an aliphatic polyester having a melting point of 50 ° C. or lower than the polylactic acid polymer And the aliphatic polyester polymer forms at least a part of the composite fiber surface, and the aliphatic polyester polymer comprises 1,4-butanediol and succinic acid as components. as well as, biodegradable face cover, wherein the calcium montanate, that at least one selected et Toka phenylphosphonic acid zinc salt containing 0.1 to 1 wt%. Basis weight is 15 to 50 g / ^{m 2,} flexibility is less 60cN least 15 cN, biodegradable face cover according to claim 1, wherein the drape coefficient is equal to or is 0.650 or more 0.950 or less. The composite fiber is a core-sheath composite long fiber in which a polylactic acid-based polymer forms a core part and an aliphatic polyester polymer forms a sheath part, and the composite ratio of the core part and the sheath part is a mass ratio, The biodegradable face cover according to claim 1 or 2, wherein the core part / sheath part = 3/1 to 1/3. When the composite long fiber is melted at a rate of temperature increase of 10 ° C./min and then subjected to differential thermal analysis at a rate of temperature decrease of 10 ° C./min, there is a temperature decrease crystallization temperature due to the aliphatic polyester polymer. temperature is at 80 ° C. or higher 90 ° C. or less, any one of claims 1 to crystallization heat due to the aliphatic polyester polymer is equal to or less than 20 J / g or more 40 J / g to 3 The biodegradable face cover as described. The biodegradable face cover according to any one of claims 1 to 4 , wherein the biodegradable face cover has a heat seal portion in which constituent fibers are bonded to each other by melting or softening of an aliphatic polyester polymer. A biodegradable face cover that is constructed.