Nonwoven fabric for liquid-impregnated skin covering sheet and liquid-impregnated skin covering sheet

Abstract

To provide a nonwoven fabric that gives a liquid-impregnated skin coat sheet, having excellent adhesion to skin when it is impregnated with liquid.SOLUTION: A nonwoven fabric contains 20 mass%-80 mass% of a chemical fiber that has an official moisture regain of 1.0%-7.0% and includes at least one recess or restriction on a fiber cross section, and 20 mass%-80 mass% of a hydrophilic fiber, and when dried, the nonwoven fabric has a specific volume of 12.0 cm / g or more, and a basis weight of 20-55 g / m. The nonwoven fabric is used as a base material for a liquid-impregnated skin coat sheet.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a nonwoven fabric constituting a liquid-impregnated skin application sheet impregnated with a liquid, particularly a cosmetic, and to a liquid-impregnated skin application sheet using the nonwoven fabric. [Background technology]

[0002] Various liquid-impregnated sheets that are used to cover the skin of the human body and apply a specific substance to the skin of the human body have been proposed and put into practical use. Specific examples include liquid-impregnated skin covering sheets (face masks and keratin care sheets used on the heels, elbows, knees, etc.) that are impregnated with a liquid (e.g., cosmetics) containing an active ingredient. Nonwoven fabrics are generally used as the substrate for liquid-impregnated skin covering sheets. Since liquid-impregnated skin covering sheets are often used in contact with the skin for a relatively long time, various nonwoven fabrics have been proposed as the substrate in terms of adhesion, liquid release, touch, convenience, etc. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2002-142861 A [Patent Document 2] JP 2000-27064 A Summary of the Invention [Problem to be solved by the invention]

[0004] In one aspect, the present embodiment aims to provide a nonwoven fabric for a liquid-impregnated skin application sheet that exhibits good adhesion when impregnated with a liquid and applied to cover the skin. In another aspect, the present embodiment aims to provide a liquid-impregnated skin application sheet, particularly a face mask, in which the nonwoven fabric is impregnated with a liquid. [Means for solving the problem]

[0005] In the first aspect, the present embodiment provides a fiber optics fabric that contains 20% by mass to 80% by mass of chemical fibers having an official moisture regain of 1.0% to 7.0% and having at least one recess or constriction in a fiber cross section, and 20% by mass to 80% by mass of hydrophilic fibers, Specific volume when dry is 12.0 cm 3 / g or more, Weight is 20~55g / m 2 That is, Provided is a nonwoven fabric for liquid-impregnated skin covering sheets.

[0006] In the second aspect of the present embodiment, the fabric has an official moisture regain of 1.0% to 7.0% and contains 20% by mass to 80% by mass of chemical fibers having at least one recess or constriction in a fiber cross section, and 20% by mass to 80% by mass of hydrophilic fibers, Specific volume when wet is 8.8cm 3 / g or more, Weight is 20~55g / m 2 That is, Provided is a nonwoven fabric for liquid-impregnated skin covering sheets.

[0007] In a third aspect, the present embodiment provides a liquid-impregnated skin application sheet obtained by impregnating the nonwoven fabric according to the first or second aspect with a liquid. Effect of the Invention

[0008] The nonwoven fabric of the present embodiment exhibits good adhesion when it is impregnated with a liquid and applied to the skin, making it possible to reduce or eliminate the portion of the nonwoven fabric that is "floating" from the skin, thereby enabling the liquid to be distributed over the entire surface of the covered skin. [Brief description of the drawings]

[0009] [Figure 1] FIG. 2 is a cross-sectional view of an example of a chemical fiber having a recess in its cross section, which is included in the nonwoven fabric of the present embodiment. [Diagram 2] FIG. 2 is a cross-sectional view of an example of a chemical fiber having a recess in its cross section, which is included in the nonwoven fabric of the present embodiment. [Diagram 3]FIG. 2 is a cross-sectional view of an example of a chemical fiber having a recess in its cross section, which is included in the nonwoven fabric of the present embodiment. [Figure 4] FIG. 2 is a cross-sectional view of an example of a chemical fiber having a recess in its cross section, which is included in the nonwoven fabric of the present embodiment. [Diagram 5] FIG. 2 is a cross-sectional view of an example of a chemical fiber having a recess in its cross section, which is included in the nonwoven fabric of the present embodiment. [Figure 6(a)] 1 is an electron microscope photograph (magnification: 1500 times) showing a cross section of an example of a chemical fiber having a recess in its fiber cross section, which is included in the nonwoven fabric of the present embodiment. [Figure 6(b)] 1 is an electron microscope photograph (magnification: 1500 times) showing the side of an example of a chemical fiber having a recess in its cross section, which is included in the nonwoven fabric of the present embodiment. [Figure 7] FIG. 2 is a cross-sectional view showing a method for measuring the dimensions of recesses in chemical fibers. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] (How this embodiment came about) In consideration of the retention and release of liquid, nonwoven fabrics for liquid-impregnated skin application sheets are often constructed by combining hydrophilic fibers such as rayon and hydrophobic synthetic fibers such as polyester fibers. The adhesion of liquid-impregnated skin application sheets (hereinafter also simply referred to as "sheets") made by impregnating a nonwoven fabric with liquid tends to increase as the bulkiness of the nonwoven fabric increases. In this sense, webs made by carding machines such as parallel cards (usually, nonwoven fabrics are made by subjecting this web to a process of bonding or entangling fibers) have very good adhesion because the fibers are weakly entangled and are very bulky. However, the strength of the web is low due to the weak entanglement of the fibers, and the web itself is not suitable for practical use.

[0011] The present inventors have also investigated a method of obtaining a bulkier nonwoven fabric by reducing the degree of entanglement between fibers, but in the case of a combination of rayon and polyester fibers, if the degree of entanglement between the fibers is small, the strength of the nonwoven fabric is low and a sheet suitable for practical use cannot be obtained. Therefore, the present inventors have investigated the types of fibers constituting the nonwoven fabric, and have found that a nonwoven fabric having high bulkiness while having practical strength can be obtained by using a fiber that has bulkiness itself and shows relatively strong entanglement in a web state as a fiber to be combined with a hydrophilic fiber such as rayon, and have arrived at the present embodiment.

[0012] In this embodiment, the fibers used in combination with the hydrophilic fibers are, for example, one or more fibers selected from acrylic fibers, vinylon, and acetate. These fibers tend to give a bulkier nonwoven fabric compared to polyester fibers and polypropylene fibers having the same fineness and fiber length. In addition, these fibers are often provided as fibers having one or more recesses or constrictions in their fiber cross sections. Therefore, these fibers contribute to stronger entanglement of fibers compared to ordinary polyester fibers and polypropylene fibers (wherein no recesses are observed when observed at a magnification of about 1000 to 2000 times). Therefore, if these fibers are used, a nonwoven fabric with relatively high strength can be obtained, even if the pressure of the fluid is reduced to increase the specific volume of the nonwoven fabric when producing a nonwoven fabric by high-pressure fluid flow processing, for example. Furthermore, it has also been found that these fibers have a function of improving the liquid absorption of the nonwoven fabric because their official moisture regain is higher than that of hydrophobic synthetic fibers such as polyester and polypropylene.

[0013] The use of a nonwoven fabric containing acrylic fibers in a face mask is described, for example, in the above-mentioned Patent Document 1. Patent Document 1 describes a face pack sheet made of a mixture of 30% by mass of 1.7 dtex acrylic fibers and 70% by mass of 1.7 dtex rayon fibers, with a basis weight of 80 g / m 2 , thickness 0.4mm (specific volume 5cm 3 / g) was produced (paragraphs 0076 and 0083, Table 2). According to the study by the present inventors, this nonwoven fabric was found to have poor adhesion due to its small specific volume.

[0014] In addition, the above-mentioned Patent Document 2 describes a woven fabric that contains 5 wt% or more of acrylic fibers, 10 wt% or more of acrylate fibers having a Na-type or Ca-type carboxyl group, or 50 wt% or more of rayon, and has a basis weight of 150 g / m 2 The following nonwoven textile product is disclosed, and it is explained that the textile product can be used in cosmetics. In the patent document, the acrylic fiber is used to provide a warm feeling to the touch (paragraph 0007), and there is no teaching or suggestion that the use of the acrylic fiber can increase the specific volume, and thereby improve the adhesion of the nonwoven fabric to the skin. In addition, all of the nonwoven fabrics in the examples described in the patent document contain heat-fusible fibers and are obtained by the water punch method and the hot air heat fusion method, so their specific volumes are not very large and it is not thought that they will show good adhesion.

[0015] The liquid-impregnated nonwoven fabric for skin application sheet of the present embodiment is The fabric has an official moisture regain of 1.0% to 7.0% and contains 20% to 80% by mass of chemical fibers having at least one recess or constriction in a fiber cross section, and 20% to 80% by mass of hydrophilic fibers, Specific volume when dry is 12.0 cm 3 / g or more, Weight is 20~55g / m 2 It is a nonwoven fabric. Hereinafter, the fibers constituting the nonwoven fabric of this embodiment will first be described.

[0016] (Chemical fiber A) The nonwoven fabric of this embodiment contains chemical fibers (hereinafter, for convenience, referred to as "chemical fibers A") that have an official moisture regain of 1.0% to 7.0% and have at least one recess or constriction in the fiber cross section. The official moisture content is shown in JIS L0105 (2006). If the official moisture content is unknown, the value calculated from the following formula shall be used as the official moisture content. Official moisture content (%) = [(W-W') / W'] x 100 Here, W is the mass (g) of the fiber in an environment with a temperature of 20° C. and a humidity of 65% RH, and W' is the mass (g) of the fiber when completely dry. The mass of the fiber in an environment with a temperature of 20° C. and a humidity of 65% RH means the mass of the fiber when it is left in an environment with a temperature of 20° C. and a humidity of 65% RH and reaches a certain mass, and the mass of the fiber when completely dry means the mass of the fiber when it is left in a dryer set at 105° C. and reaches a certain mass.

[0017] Chemical fiber A has a higher official moisture regain and a higher affinity with water than polyester fiber and polypropylene fiber. Therefore, a nonwoven fabric containing chemical fiber A exhibits higher liquid absorption. If the official moisture regain of chemical fiber A is less than 1.0%, the liquid absorption of the nonwoven fabric may decrease, and if it exceeds 7.0%, the bulk of the nonwoven fabric may decrease when impregnated with liquid, resulting in a smaller specific volume. The official moisture regain of chemical fiber A may be, for example, 1.5% to 6.5%, particularly 1.8% to 5.0%, and more particularly 1.9% to 3.0%.

[0018] Chemical fiber A has at least one recess or constriction in its fiber cross section. Here, the fiber cross section refers to a surface obtained by cutting the fiber in a direction perpendicular to the length, and can also be called a "transverse section". The recess may have a "L" shape. The "L"-shaped recess may be a valley-like shape with a linear bottom surface. In addition, the "L"-shaped recess may have two curved lines extending to the bottom surface when the cross section of the fiber is observed. Chemical fiber A having a recess in its fiber cross section may have a linear portion formed by the bottoms of the recesses being connected in the longitudinal direction when the side surface is observed. In this embodiment, the chemical fiber may have multiple recesses in the fiber cross section, and multiple linear portions may be observed on the side surface of the fiber (FIGS. 1 and 2).

[0019] The depressions or constrictions may be of a size that can be recognized, for example, when the fiber cross section is observed at a magnification of about 1000 to 2000 times. For example, as shown in Fig. 7, the depressions or constrictions may have a size such that the distance d between a straight line m tangent to the outline of the fiber cross section forming the depression or constriction and the bottom b of the depression or constriction is, for example, 0.1 µm to 10 µm, particularly 0.5 µm to 1.5 µm. The depressions or constrictions formed in the fiber cross section may be continuous in the longitudinal direction when the fiber side surface is observed.

[0020] Chemical fiber A may also have many fine recesses in its fiber cross section. Chemical fibers having such recesses in their fiber cross sections may have fine wrinkle-like recesses when the fiber side surface is observed under an electron microscope at a magnification of about 1000 to 2000 times, and the fine wrinkle-like recesses observed on the fiber side surface may be discontinuous in the longitudinal direction (FIG. 6(b)). Alternatively, the fine recesses may be continuous in the longitudinal direction.

[0021] Chemical fiber A may also have many fine recesses and one or more large recesses or constrictions in the fiber cross section. Alternatively, chemical fiber A may be provided as a mixture of fibers having many fine recesses and one or more large recesses or constrictions in the fiber cross section (e.g., fibers marked with a in FIG. 6(a)) and fibers having only many fine recesses in the fiber cross section (e.g., fibers marked with b in FIG. 6(a)), as shown in FIG. 6(a). Note that in FIG. 6(a), the existence of fine recesses is difficult to confirm because the outline of the fiber cross section is distorted when the fiber is cut, but since fine wrinkle-like recesses are formed on the side surface (FIG. 6(b)), it is determined that the fiber cross section has many fine recesses.

[0022] A fiber cross section having at least one recess or constriction is, for example, a fiber having a cross section and side surface as shown in Figures 1 to 6. Since chemical fiber A has such a fiber cross section and side surface, it is easier to provide stronger intertwining of fibers compared to fibers having a smooth outer periphery of the fiber cross section (e.g., commonly used polyester fibers and polypropylene fibers). Therefore, a nonwoven fabric containing chemical fiber A has relatively high strength even when it is produced to have a high specific volume.

[0023] Specific examples of chemical fiber A include acrylic fiber, vinylon, acetate, and triacetate. All of these fibers are chemical fibers and are produced by dry spinning or wet spinning. These fibers are generally provided in a form in which the fiber cross section has a recess or a constriction. In particular, acrylic fiber is preferably used because it is easy to give a bulky nonwoven fabric and has a soft touch.

[0024] The acrylic fiber, vinylon, acetate, and triacetate used as chemical fiber A may be selected from those commonly used as long as they have the above-mentioned range of official moisture regain and the above-mentioned specific fiber cross section. Examples of acrylic fibers that can be used as chemical fiber A include Bonnell (product name) manufactured by Mitsubishi Chemical Corporation and Toraylon (product name) manufactured by Toray Industries, Inc. Examples of vinylon that can be used as chemical fiber A include Vinylon (product name) manufactured by Kuraray Co., Ltd.

[0025] The chemical fiber A is not limited to acrylic, vinylon, acetate, and triacetate, and may be other chemical fibers (synthetic fibers, regenerated fibers) as long as it has the above-mentioned range of official moisture regain and the above-mentioned specific fiber cross section. For example, the chemical fiber A may be a chemical fiber made of a polyamide resin such as nylon 6, nylon 12, and nylon 66, and may have at least one recess or constriction in the fiber cross section. The fiber made of a polyamide resin produced by the melt spinning method can have at least one recess or constriction in the fiber cross section by appropriately selecting the shape of the spinneret.

[0026] The fineness of the chemical fiber A may be, for example, about 0.6 dtex to 4.0 dtex, particularly about 0.6 dtex to 3.3 dtex, and more particularly about 0.8 dtex to 2.0 dtex. Chemical fiber A having a fineness within this range is suitable for ensuring the flexibility of the nonwoven fabric. If the fineness of the chemical fiber A is too small, the carding property during the production of the fiber web may deteriorate, the productivity of the nonwoven fabric may decrease, and the strength of the obtained nonwoven fabric may become low. If the fineness of the chemical fiber A is too large, the nonwoven fabric may become coarse and the touch may deteriorate. In addition, if the fineness of the chemical fiber A is too large, the capillary phenomenon may not occur easily, and the liquid absorption property may decrease.

[0027] The fiber length of the chemical fiber A may be appropriately selected depending on the manufacturing method of the nonwoven fabric. For example, when a carded web is produced to manufacture a nonwoven fabric, the chemical fiber A may be a staple fiber. When the chemical fiber A is a staple fiber, the fiber length may be, for example, 20 mm to 80 mm, particularly 28 mm to 75 mm, and more particularly 30 mm to 65 mm. Alternatively, when an air-laid web is produced to manufacture a nonwoven fabric, the fiber length of the chemical fiber A may be 1 mm to 50 mm, particularly 5 mm to 30 mm. When a wet-laid papermaking web is produced to manufacture a nonwoven fabric, the fiber length of the chemical fiber A may be 0.5 mm to 20 mm, particularly 1 mm to 10 mm.

[0028] (hydrophilic fiber) The nonwoven fabric of this embodiment includes hydrophilic fibers. The hydrophilic fibers serve to retain the liquid impregnated in the nonwoven fabric. The hydrophilic fibers are fibers having a higher nominal moisture regain than the chemical fiber A, specifically, a nominal moisture regain of more than 7%, particularly a nominal moisture regain of 8.5% or more, and more particularly a nominal moisture regain of 11.0% or more. The nominal moisture regain of the hydrophilic fibers may be 15.0% or less, particularly 14.0% or less, and more particularly 12.0% or less.

[0029] Specific examples of hydrophilic fibers include natural fibers such as pulp, cotton, hemp, silk, and wool, regenerated fibers such as viscose rayon, cupra, and solvent-spun cellulose fibers, as well as synthetic fibers with hydrophilic properties, or synthetic fibers with low hydrophilicity (synthetic fibers with an official moisture regain of less than 7%) that have been subjected to a hydrophilization treatment to improve their hydrophilicity, etc. Examples of hydrophilization treatments include corona discharge treatment, sulfonation treatment, graft polymerization treatment, kneading a hydrophilizing agent into the fiber, and application of a durable oil agent.

[0030] The hydrophilic fiber is preferably a cellulosic fiber, more specifically, (1) regenerated fibers such as viscose rayon, cupra, and solvent-spun cellulosic fibers (e.g., lentigned lyocell (registered trademark) and Tencel (registered trademark)), (2) pulp such as mechanical pulp, regenerated pulp, and chemical pulp, and (3) natural plant fibers such as cotton and hemp.

[0031] Among regenerated fibers, viscose rayon is preferably used because it has a proven track record of use in the fields of cosmetic puffs and wet sheets that come into contact with human skin, it is also widely used in face masks, and it is relatively inexpensive.

[0032] Among natural plant fibers, cotton has a long history of use as a natural material and is widely used as a material for clothing and sanitary materials, giving the general consumer the impression that it is gentle on the skin, pleasant to the touch, and safe. Therefore, by using cotton, it is possible to provide products that are more likely to be accepted by consumers. When using cotton, any cotton that is generally used in the manufacture of nonwoven fabrics can be used. Specifically, cotton having a fiber length (average fiber length) of about 20 to 60 mm can be used. Multiple cottons with different fiber lengths and types may be used.

[0033] The fineness of the hydrophilic fiber may be, for example, about 0.6 dtex to 5.6 dtex, particularly about 0.6 dtex to 3.3 dtex, and more particularly about 0.9 dtex to 2.2 dtex. A hydrophilic fiber having a fineness within this range is suitable for ensuring the flexibility of the nonwoven fabric. If the fineness of the hydrophilic fiber is too small, the carding property during the production of the fiber web may deteriorate, the productivity of the nonwoven fabric may decrease, and the strength of the obtained nonwoven fabric may become low. If the fineness of the hydrophilic fiber is too large, the nonwoven fabric may become coarse and the touch may decrease. In addition, if the fineness of the hydrophilic fiber is too large, the capillary phenomenon may not occur easily, and the liquid absorption may decrease.

[0034] The fiber length of the hydrophilic fiber may be appropriately selected depending on the manufacturing method of the nonwoven fabric, etc. Examples of fiber lengths depending on the manufacturing method of the nonwoven fabric are as described for the chemical fiber A. The fiber length of the hydrophilic fiber may be the same as or different from the fiber length of the chemical fiber A.

[0035] (Other fibers) The nonwoven fabric of this embodiment may contain other fibers than the chemical fiber A and the hydrophilic fiber. The other fibers may be, for example, chemical fibers with a standard moisture regain of less than 1.0%. A nonwoven fabric containing such chemical fibers has improved liquid release properties, and when used by applying it to the skin, for example, it makes it easier to transfer liquid to the skin. Such chemical fibers may be fibers made of a thermoplastic resin having hydrophobicity, and may be, for example, fibers made of a polyester-based resin such as polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, polyethylene naphthalate, polylactic acid, polybutylene succinate and copolymers thereof, polypropylene, polyethylene (including high-density polyethylene, low-density polyethylene, linear low-density polyethylene, etc.), polybutene-1, ethylene-propylene copolymer, and ethylene-vinyl acetate copolymer.

[0036] Alternatively, the other fibers may be chemical fiber A or hydrophilic fibers whose surfaces have been treated to give hydrophobicity (hydrophobization treatment) to reduce the official moisture regain to less than 1.0%. For example, regenerated fibers whose surfaces have been treated with a hydrophobizing agent, or fibers made of polyamide resins such as nylon 6, nylon 12, and nylon 66 whose surfaces have been treated with a hydrophobizing agent may be used as the other fibers.

[0037] When the other fibers are fibers made of a hydrophobic thermoplastic resin, the other fibers may be single fibers or composite fibers. The composite fibers may be, for example, sheath-core composite fibers or islands-in-sea composite fibers in which a hydrophobic thermoplastic resin or a thermoplastic resin that has been subjected to a hydrophobic treatment is arranged to constitute the fiber surface. Alternatively, the composite fibers may be fibers in which the fiber surface is constituted by a plurality of hydrophobic thermoplastic resins, for example, splittable composite fibers.

[0038] When the other fiber is a composite fiber made of two or more thermoplastic resins, the combination of two or more resins can be a polyethylene resin / polyester resin, and a polyethylene resin / polypropylene resin. Specifically, the combination of two or more resins can be a combination of high density polyethylene / polyethylene terephthalate, low density polyethylene / polyethylene terephthalate, linear low density polyethylene / polyethylene terephthalate, ethylene-propylene copolymer / polyethylene terephthalate, polypropylene / polyethylene terephthalate, high density polyethylene / polytrimethylene terephthalate, low density polyethylene / polytrimethylene terephthalate, linear low density polyethylene / polytrimethylene terephthalate, ethylene-propylene copolymer / polytrimethylene terephthalate, polypropylene / polytrimethylene terephthalate, high density polyethylene / polypropylene, linear low density polyethylene / polypropylene, etc.

[0039] The thermoplastic resins exemplified as components of the single fiber or composite fiber may contain other components as long as they contain 50% by mass or more of the specifically indicated thermoplastic resin. The specifically indicated thermoplastic resin may be contained in an amount of 80% by mass or more, or 90% by mass or more, or the components may essentially consist of the specifically indicated thermoplastic resin. The term "essentially" is used here in consideration of the fact that thermoplastic resins usually contain various additives, etc. For example, in the combination of high density polyethylene / polyethylene terephthalate, "high density polyethylene" may contain other thermoplastic resins and additives, etc., as long as it contains 50% by mass or more of high density polyethylene.

[0040] The other fibers may include polyester single fibers in particular. When such single fibers are included as the other fibers, the fibers may be well entangled when producing a nonwoven fabric. As described above, the polyester single fiber is a fiber containing 50% by mass or more of polyester, and may be substantially composed of polyester.

[0041] The fineness of the other fibers may be about 0.6 dtex to 5.6 dtex, particularly about 0.6 dtex to 3.3 dtex, and more particularly about 0.9 dtex to 2.2 dtex. If the fineness of the other fibers is within this range, the nonwoven fabric can be made soft. If the fineness of the other fibers is too small, the carding property during the production of the fiber web may deteriorate, the productivity of the nonwoven fabric may decrease, and the strength of the obtained nonwoven fabric may become low. If the fineness of the other fibers is too large, the nonwoven fabric may become coarse and the touch may decrease. In addition, if the fineness of the other fibers is too large, the capillary phenomenon is difficult to occur, and the liquid absorption ability may decrease.

[0042] The fiber length of the other fibers may be appropriately selected depending on the manufacturing method of the nonwoven fabric, etc. Examples of fiber lengths depending on the manufacturing method of the nonwoven fabric are as described for chemical fiber A. The fiber length of the other fibers may be different from the fiber length of both chemical fiber A and the hydrophilic fiber, and may be the same as the fiber length of either or both of chemical fiber A and the hydrophilic fiber.

[0043] (Composition of nonwoven fabric) The nonwoven fabric of this embodiment includes chemical fiber A and hydrophilic fiber. Chemical fiber A allows the nonwoven fabric to have a relatively large strength even when it is manufactured to have a relatively large specific volume. The hydrophilic fiber ensures the liquid retention of the nonwoven fabric, and the liquid impregnated in the nonwoven fabric remains in the nonwoven fabric, making the skin sufficiently wet with the liquid. Therefore, according to the nonwoven fabric of this embodiment, the use of chemical fiber A realizes a high specific volume and improves adhesion to the skin, and the use of hydrophilic fiber makes it easier for the liquid to remain on the skin, and the surface tension of the liquid can be used to improve adhesion to the skin.

[0044] The nonwoven fabric of this embodiment contains 20% to 80% by mass of chemical fiber A and 20% to 80% by mass of hydrophilic fiber. If the proportion of chemical fiber A is less than 20% by mass, the effect of containing chemical fiber A may not be obtained, and if the proportion of chemical fiber A exceeds 80% by mass, the proportion of hydrophilic fiber is reduced, and the liquid retention of the nonwoven fabric is reduced. If the proportion of hydrophilic fiber is less than 20% by mass, the liquid retention of the nonwoven fabric is also reduced, and if the proportion of hydrophilic fiber is more than 80% by mass, the proportion of chemical fiber A is reduced, and the effect of containing chemical fiber A may not be obtained.

[0045] The proportion of chemical fiber A may be particularly 25% to 70% by mass, more particularly 35% to 60% by mass. The proportion of hydrophilic fiber may be particularly 25% to 70% by mass, more particularly 40% to 60% by mass.

[0046] When the nonwoven fabric of this embodiment contains other fibers, the ratio of the other fibers may be 60% by mass or less of the nonwoven fabric. If the ratio of the other fibers exceeds 60% by mass, the ratio of the chemical fiber A and / or the hydrophilic fiber becomes small, and the effect of containing these fibers may not be obtained. The ratio of the other fibers may be particularly 50% by mass or less, more particularly 35% by mass or less, and even more particularly 30% by mass or less. The ratio of the other fibers may be, for example, 0% by mass or more, particularly 10% by mass or more, and more particularly 20% by mass or more.

[0047] The nonwoven fabric of the present embodiment may have a laminated structure as long as it contains the chemical fiber A and the hydrophilic fiber in the above-mentioned predetermined ratio when the mass of the entire nonwoven fabric is taken as 100% by mass. For example, the nonwoven fabric of the present embodiment may be composed of a fiber layer (conveniently called "first fiber layer") made of the chemical fiber A and the hydrophilic fiber, and a fiber layer (conveniently called "second fiber layer") made of other fibers. In this case, the nonwoven fabric may have, for example, a first / second two-layer structure, or a first / second / first three-layer structure. The second fiber layer may be a spunbonded nonwoven fabric, meltblown nonwoven fabric, net-like material, wet-laid nonwoven fabric, or a nonwoven fabric in which fibers are bonded together by one component of the fibers (for example, a thermally bonded nonwoven fabric). The first fiber layer may further contain other fibers. Alternatively, the nonwoven fabric of this embodiment may be composed of a plurality of fiber layers each having a different mixing ratio of chemical fiber A and hydrophilic fiber.

[0048] The nonwoven fabric of this embodiment may have a single-layer structure. The single-layer nonwoven fabric has a basis weight of 20 to 55 g / m 2 Even if the size of the nonwoven fabric is relatively small, the nonwoven fabric can have a relatively uniform texture.

[0049] In the nonwoven fabric of this embodiment, the manner of integration of the fibers is not particularly limited. The fibers may be integrated by entangling using a high-pressure fluid flow or a needle punching method, or may be integrated by bonding the fibers together. The fibers may be bonded together by making at least one component of at least one type of fiber constituting the nonwoven fabric function as an adhesive component. In this case, the component that functions as an adhesive component may be melted or softened by heating (thermal bonding), or the fibers may be bonded together by irradiation with an electron beam or the like, or ultrasonic welding. Alternatively, the fibers may be bonded together by applying a binder (adhesive).

[0050] In this embodiment, the fibers may be integrated by entanglement and not bonded to each other. When the fibers are bonded to each other, the bonded points between the fibers are generally harder than other parts, and the bonded points may irritate the skin. Furthermore, the presence of bonded points may cause the texture of the nonwoven fabric to become hard.

[0051] The weight of the entire nonwoven fabric of this embodiment is 20 g / m 2 ~55g / m 2 The weight is selected from this range in consideration of the amount of liquid impregnated and the part of the skin to be covered. 2 ~55g / m 2 More particularly, 40 g / m 2 ~50g / m 2 If the basis weight is too small, the amount of liquid that can be impregnated into the nonwoven fabric is reduced, and a predetermined amount of liquid may not be supplied to the skin. If the basis weight is too large, the internal space is reduced, the specific volume is likely to be small, and the adhesion is reduced. In addition, the larger the basis weight, the greater the bending resistance is likely to be. If the bending resistance is large, it is difficult to make the sheet conform to the curved surface of the skin, and the sheet may partially lift up, making it difficult for the entire sheet to cover the skin evenly. In addition, if the basis weight is too large, the number of sheets that can be accommodated in one packaging bag or packaging container is reduced.

[0052] The total thickness of the nonwoven fabric is 1 cm when dry. 2 With a load of 294 Pa applied per cm, the thickness may be, for example, 0.40 mm or more, particularly 0.60 mm or more, and more particularly 0.75 mm or more. The thickness of the entire nonwoven fabric is, for example, 2.00 mm or less, particularly 1.50 mm or less, and more particularly 1.00 mm or less. The thickness of the entire nonwoven fabric is, for example, 1 cm2 of the nonwoven fabric when dry. 2 With a load of 1.96 kPa applied per unit area, the thickness of the nonwoven fabric may be, for example, 0.30 mm or more, particularly 0.45 mm or more, more particularly 0.55 mm or more. The thickness of the entire nonwoven fabric may be, for example, 1.5 mm or less, particularly 1.0 mm or less, more particularly 0.70 mm or less. If the thickness of the entire nonwoven fabric is too small, the amount of liquid that can be impregnated into the nonwoven fabric may be reduced, and a predetermined amount of liquid may not be supplied to the skin. If the thickness of the entire nonwoven fabric is too large, it may be difficult to make the sheet conform to the curved surface of the skin, and the sheet may partially float, making it difficult to evenly cover the skin with the entire sheet.

[0053] The total thickness of the nonwoven fabric is 1 cm when wet. 2 The thickness of the nonwoven fabric may be, for example, 0.10 mm or more, particularly 0.30 mm or more, and more particularly 0.40 mm or more, when a load of 294 Pa is applied per cm 2 of the nonwoven fabric when wet. The thickness of the entire nonwoven fabric may be, for example, 1.50 mm or less, particularly 1.00 mm or less, and more particularly 0.70 mm or less. 2 With a load of 1.96 kPa applied per unit area, the thickness may be, for example, 0.10 mm or more, particularly 0.25 mm or more, more particularly 0.35 mm or more. The thickness of the entire nonwoven fabric may be, for example, 1.00 mm or less, particularly 0.80 mm or less, more particularly 0.65 mm or less. The problems when the thickness of the nonwoven fabric is too small or too large when wet are the same as those when dry. The "thickness when wet" refers to the thickness measured when 100 parts by mass of the nonwoven fabric is impregnated with 1000 parts by mass of distilled water.

[0054] The nonwoven fabric of this embodiment has a thickness of 1 cm when dry. 2With a load of 1.96 kPa applied per unit area, the 3 / g or more. Nonwoven fabrics with a specific volume in this range show good adhesion when soaked in liquid. This is thought to be because nonwoven fabrics with a specific volume in this range have space inside that allows easy movement of the fibers, and the movement of the fibers improves the ability to conform to the skin, providing high adhesion. The specific volume when dry is particularly high at 12.2 cm 3 / g or more, more particularly 13.0 cm 3 / g or more. The specific volume when dry is, for example, 18.0 cm 3 / g or less, and in particular 15.0 cm 3 / g or less, more particularly 14.0 cm 3 If the specific volume is too large, the nonwoven fabric becomes thick, which may make it difficult to fit the sheet to the curved surface of the skin, and may be difficult to handle and difficult to retain liquid.

[0055] The nonwoven fabric of this embodiment has a thickness of 1 cm when wet. 2 With a load of 1.96 kPa applied per unit area, the 3 / g or more. Nonwoven fabrics with a specific volume in this range exhibit good adhesion when saturated with liquid. The specific volume when wet is particularly high at 9.5 cm 3 / g or more, more particularly 10.0 cm 3 / g or more. The specific volume when wet is, for example, 13.0 cm 3 / g or less, and in particular 12.0 cm 3 / g or less, more particularly 11.0 cm 3 / g or less. The problems with a wet specific volume that is too high are the same as those with a high dry specific volume.

[0056] Next, a method for producing the nonwoven fabric of this embodiment will be described. When the nonwoven fabric of this embodiment has a single-layer structure, it can be produced by mixing chemical fiber A, hydrophilic fiber, and other fibers as necessary to prepare a fiber web, and subjecting the web to a process for integrating the fibers. The process for integrating the fibers includes a process for entangling the fibers, a thermal bonding process, a bonding process using a solvent-based adhesive, a bonding process using a hot-melt resin, a bonding process using electron beams, and an ultrasonic welding process.

[0057] The fiber web may be any one selected from, for example, parallel webs, cross webs, card webs such as semi-random webs and random webs, air-laid webs, and wet-laid paper webs. The fiber web is preferably a parallel web. A parallel web has high productivity and is likely to give a nonwoven fabric with a high bulk and a large specific volume. In addition, since a soft nonwoven fabric is likely to be obtained by using a parallel web, the liquid-impregnated skin application sheet produced using the parallel web is also likely to be soft and have an excellent texture.

[0058] The nonwoven fabric of the present invention may be manufactured by integrating the fibers together through a process for entangling the fibers together, thereby obtaining a nonwoven fabric with good touch without any adhesive points. The process for entangling the fibers is, for example, a needle punch process or a high-pressure fluid flow (particularly a water flow) entanglement process. In the high-pressure fluid flow process, the high-pressure fluid is, for example, a high-pressure gas such as compressed air, or a high-pressure liquid such as high-pressure water. In the manufacture of nonwoven fabric, a water flow entanglement process using high-pressure water as the high-pressure fluid is often used, and in the present embodiment, the water flow entanglement process is preferably used from the viewpoint of ease of implementation, etc. In the following, a manufacturing method in the case where high-pressure water (hereinafter also simply referred to as "water flow") is used as the high-pressure fluid will be described.

[0059] The hydroentanglement treatment is carried out by placing the fiber web on a support and spraying a columnar water stream. For example, the support is preferably a plain weave support of 80 mesh or more and 100 mesh or less. The hydroentanglement treatment may be carried out by spraying a water stream with a water pressure of 1 MPa or more and 15 MPa or less on the front and back surfaces of the fiber web 1 to 5 times each from a nozzle having orifices with a hole diameter of 0.05 mm or more and 0.5 mm or less, spaced 0.3 mm or more and 1.5 mm or less. The water pressure is preferably 1 MPa or more and 10 MPa or less, more preferably 1 MPa or more and 7 MPa or less.

[0060] The nonwoven fabric obtained by the hydroentanglement treatment is then subjected to a drying treatment, which may be carried out using, for example, a hot air penetration type heat treatment machine (also called an air-through type heat processing machine), a hot air blowing type heat treatment machine, or an infrared type heat treatment machine.

[0061] When the nonwoven fabric of the present embodiment is a laminated nonwoven fabric consisting of a plurality of fiber layers, fiber webs constituting each fiber layer are prepared, and the fiber webs are laminated and subjected to a process for integrating the fiber webs and the fibers with each other. Even when a laminated nonwoven fabric is produced, the process for integrating the fiber webs and the fibers with each other may be a process for entangling the fibers, particularly a high-pressure fluid flow entangling process, or any of the adhesive processes exemplified above.

[0062] (Liquid-impregnated skin covering sheet) The nonwoven fabric of this embodiment is impregnated with a liquid to form a liquid-impregnated skin covering sheet for covering the skin of a human or animal. The liquid to be impregnated and the amount of impregnation are appropriately selected depending on the application. When the sheet is provided as a liquid-impregnated skin covering sheet for humans, such as a face mask for humans, a keratin care sheet, and a décolleté sheet, the liquid (e.g., a cosmetic) containing an active ingredient may be impregnated in an amount of 600 parts by mass or more and 2500 parts by mass or less, particularly 600 parts by mass or more and 1500 parts by mass or less, and more particularly 700 parts by mass or more and 1500 parts by mass or less, per 100 parts by mass of the nonwoven fabric. Examples of the active ingredient include, but are not limited to, moisturizing ingredients, keratin softening ingredients, antiperspirant ingredients, fragrance ingredients, whitening ingredients, blood circulation promoting ingredients, UV protection ingredients, and slimming ingredients.

[0063] The face mask is provided in a shape suitable for covering the face, and further in a form in which, for example, openings or cutouts are provided by punching as necessary in areas corresponding to the eyes, nose, and mouth. Alternatively, the face mask may be shaped to cover only a part of the face (e.g., the eyes, mouth, nose, or cheeks). Alternatively, the face mask may be provided as a set consisting of a sheet covering the area around the eyes and a sheet covering the area around the mouth, or as a set of sheets separately covering three or more areas.

[0064] The keratin care sheet is a skin covering sheet used on the heels, elbows, knees, etc., where the keratin is thick and easily hardened, and by impregnating it with a liquid containing a keratin softening component and a moisturizing component, etc., it exhibits the effect of promoting moisturization and softening of the keratin and promoting the removal of excess keratin. The nonwoven fabric of this embodiment can be used as a substrate in a keratin care sheet that exhibits either of these effects and efficacy. A keratin care sheet, for example a keratin care sheet for the heel, is provided in a form having cuts and / or notches and / or openings punched out of a part of the sheet so that the sheet can easily fit the curve of the heel when applied.

[0065] Alternatively, the liquid-impregnated skin covering sheet may be used as a cleansing sheet containing a cleansing component as an active ingredient. The cleansing sheet may be used, for example, by adhering it to the part (skin) from which dirt (makeup) is to be removed, keeping it attached for a while so that the cleansing component blends with the makeup, and then wiping off the makeup. The cleansing sheet, like a face mask, can be said to be a type of liquid-impregnated skin covering sheet for personal use. However, unlike a face mask used for the purpose of allowing an active ingredient to act on the skin, the cleansing sheet is attached to the skin to blend with the makeup, so the time for attaching the cleansing sheet to the skin is generally shorter than that of a face mask. When used as a cleansing sheet, the nonwoven fabric may be impregnated with a liquid (e.g., a cosmetic) containing an active ingredient in an amount of 100 to 700 parts by mass, more particularly 200 to 600 parts by mass.

[0066] The liquid-impregnated skin covering sheet may be a moisturizing sheet impregnated with a liquid containing a moisturizing component or other active ingredient, which is used to moisturize or otherwise care for any part of the body (e.g., the neck, the back of the hand, or the area from the neck to the chest (also called the décolleté)). Alternatively, the liquid-impregnated skin covering sheet may be a slimming sheet impregnated with a liquid containing a slimming component. The slimming sheet is used by being attached to, for example, the thighs or abdomen.

[0067] The liquid-impregnated skin application sheet may be provided in a state where the nonwoven fabric substrate is folded. The folding may be performed only in one direction of the nonwoven fabric, or may be performed once or more in each of different directions of the nonwoven fabric. For example, the liquid-impregnated nonwoven fabric may be provided by folding it once or more in a direction parallel to the machine direction (i.e., with the folds parallel to the machine direction) and once or more in a direction parallel to the cross direction (i.e., with the folds parallel to the cross direction).

[0068] The liquid-impregnated skin application sheet is flexible and exhibits good adhesion to the skin because the nonwoven fabric substrate has a relatively large specific volume due to the inclusion of chemical fiber A. Furthermore, the chemical fiber A contained in the nonwoven fabric of this embodiment has an official moisture regain of 1.0% to 7.0%, so that the liquid-impregnated skin application sheet exhibits good liquid absorption and is uniformly impregnated with liquid.

[0069] The liquid-impregnated skin application sheet may be provided by storing a plurality of sheets in one packaging bag or container. In such products, it may be desired to store a large number of sheets in one packaging bag or container. The nonwoven fabric of this embodiment has a basis weight of 20 to 55 g / m 2 Since the size is relatively small and the thickness is relatively thin, it meets such a demand. EXAMPLES

[0070] The present embodiment will now be described with reference to examples. The following fibers were prepared for use in this example. Acrylic fiber: wet-spun acrylic fiber (trade name: Bonnell, manufactured by Mitsubishi Chemical Corporation) with a fineness of 1.0 dtex and a fiber length of 44 mm, mainly made of acrylonitrile. The official moisture regain was 2.0%. As shown in FIG. 6(a) (electron microscope photograph at 1500 times), the fiber cross section had a circular or elliptical shape, and some fibers had large depressions or constrictions. As shown in FIG. 6(b) (electron microscope photograph at 1500 times), the fiber side had fine wrinkled depressions and many discontinuous depressions in the length direction, and it was confirmed that the fiber cross section had many small depressions. The large depressions or constrictions had a size such that the distance d between the straight line m tangent to the outline of the fiber cross section and the bottom b of the depression or constriction was 0.5 μm to 1.5 μm. Rayon fiber: Viscose rayon having a fiber size of 1.7 dtex, a fiber length of 40 mm, and a chrysanthemum-shaped fiber cross section (product name: Corona CD, manufactured by Daiwabo Rayon Co., Ltd.). The official moisture regain was 11.0%. PET fiber: A single fiber with a circular cross section made of polyethylene terephthalate having a fineness of 1.45 dtex and a fiber length of 38 mm (product name: Tetoron T403, manufactured by Toray Industries, Inc.). The official moisture regain was 0.4%. PP fiber: A single fiber made of polypropylene with a fineness of 1.5 dtex and a fiber length of 38 mm and a circular fiber cross section (product name: PN, manufactured by Daiwabo Polytech Co., Ltd.). The official moisture regain was 0.0%.

[0071] Example 1 A mixture of 25% by mass of acrylic fiber, 50% by mass of rayon fiber, and 25% by mass of PET fiber was used to card the web at a target weight of approximately 40 g / m using a parallel carding machine. 2 A parallel fiber web was prepared. The fiber web was placed on a 90 mesh plain weave support and transported at a speed of 4 m / min. A water stream of 2.5 MPa water pressure was sprayed once from one surface side, followed by a water stream of 3.0 MPa water pressure sprayed once from the other surface side. The nozzle used in the water stream entanglement treatment was a nozzle with orifices of 0.1 mm diameter provided at 0.6 mm intervals, and the interval between the nozzle and the fiber web during treatment was 20 mm. The fiber web after the water stream entanglement treatment was then dried using a hot air penetration type heat treatment machine set at 80 ° C. to obtain a nonwoven fabric.

[0072] (Examples 2 to 6, Comparative Examples 1 to 4) The types and proportions of fibers and the web target weight were as shown in Tables 1 and 2, and hydroentanglement and drying were carried out under the same conditions as those employed in Example 1 to obtain nonwoven fabrics. The evaluation results of each of the examples and comparative examples are shown in Tables 1 to 4.

[0073] [Table 1]

[0074] [Table 2]

[0075] [Table 3]

[0076] [Table 4]

[0077] The physical properties in the table were measured by the following methods. [Thickness, specific volume] The thickness of the nonwoven fabric in the dry state was measured using a thickness gauge (product name THICKNESS GAUGE model CR-60A, manufactured by Daiei Scientific Instruments Co., Ltd.) under a load of 294 Pa or 1.96 kPa. The thickness of the nonwoven fabric in the wet state was measured using the same thickness gauge, with 100 parts by mass of the nonwoven fabric impregnated with 1000 parts by mass of distilled water and a load of 294 Pa or 1.96 kPa being applied. The specific volume was calculated from the basis weight of the nonwoven fabric and its thickness under a load of 1.96 kPa.

[0078] [Water retention rate] The nonwoven fabric was cut into a size of 100 mm x 100 mm in the machine direction (MD) x cross direction (CD), the mass of the nonwoven fabric was measured, and then it was immersed in distilled water for 2 minutes. The nonwoven fabric soaked in distilled water was then hung with three corners pinched by clothespins, and the mass was measured after 10 minutes, and the water retention rate was calculated according to the following formula. Water retention rate (%)=[(M2-M1) / M1]×100 M1: Mass of the nonwoven fabric before soaking in distilled water (g) M2: Mass of the nonwoven fabric after soaking in distilled water and hanging for 10 minutes (g)

[0079] [Suction height] The wicking height was measured according to JIS L 1907:2010 7.1.2 Byreck method. A sample (MD direction x CD direction = 200mm x 25mm) was prepared with the water wicking direction in the MD direction, and the sample was set so that the water wicking direction coincided with the MD direction, and the wicking height was measured after 300 seconds. Measurements were taken for three samples, and the average value was taken as the wicking height (mm).

[0080] [Adhesion] The adhesion force was measured using a static and dynamic friction measuring instrument (Tribomaster TL201Ts, manufactured by Trinity Labs, Inc.). A nonwoven fabric measuring 12 cm x 5 cm was prepared as a sample piece. The sample piece was prepared with the MD direction of the nonwoven fabric as the long side. An artificial skin (24 cm long x 12 cm wide, product name: BIO SKIN PLATE, manufactured and sold by Bealux Co., Ltd.) was placed on the measuring table of the measuring instrument (table sliding type). In a state where 100 parts by mass of the sample piece was impregnated with 1000 parts by mass of distilled water, the end of the short side of the sample piece (this part is called the "clip end") was clamped with the clip of the measuring instrument to hold it horizontally. The measuring table was moved, and the sample piece was placed horizontally on top of the artificial skin so that only the area from the end opposite the clip end (this part is called the "non-clip end") to the area of ​​the long side of the sample that was 8 cm long was overlapped with the artificial skin. The maximum resistance force (N) was read when the measurement table was moved parallel to the long side direction of the sample in the direction away from the clip end at a speed of 10 mm / sec along the long side direction of the sample piece. Three sample pieces were measured for each example, and the average value was calculated and used as the adhesion force (N). The initial adhesion force (N) was measured immediately after placing the sample piece on the artificial skin, and the adhesion force (N) was measured 20 minutes after placing the sample piece.

[0081] [Kinematic friction coefficient, coefficient of variation] The dynamic friction coefficient and the coefficient of variation were measured using a static and dynamic friction measuring instrument (Tribomaster TL201Ts, manufactured by Trinity Lab Co., Ltd.). A nonwoven fabric measuring 5 cm x 10 cm was prepared as a sample piece. The sample pieces were prepared with the MD direction of the nonwoven fabric as the long side and the CD direction as the long side. A tactile contactor (manufactured by Trinity Lab Co., Ltd.) was used as the contact terminal of the measuring instrument. In a state where 100 parts by mass of the sample piece was impregnated with 1000 parts by mass of distilled water, the sample piece was fixed to the measuring table of the measuring instrument (table sliding type), and the contact terminal was moved back and forth twice against the surface of the sample piece with a load of 30 gf, a speed of 10 mm / sec, and a distance of 30 mm. The value of the dynamic friction force in the second round trip was read, and the average value of the forward value and the return value was taken as the dynamic friction force (gf) of one sample piece.

[0082] The test piece with the long side in the MD direction was measured three times, and the test piece with the long side in the CD direction was measured three times, and the average value of the total six measurements was taken as the kinetic friction force Fk (gf) for each Example and Comparative Example. The kinetic friction coefficient μk was calculated from the kinetic friction force Fk (gf) and the load (30 gf). In addition, the coefficient of variation CV of the kinetic friction coefficient was calculated according to the following formula from the standard deviation σ of the kinetic friction coefficient obtained during the measurement and the average value μk of the kinetic friction coefficient described above. Coefficient of variation of dynamic friction coefficient CV=σ / μk

[0083] [Bending resistance] The bending resistance of the nonwoven fabric was measured in accordance with JIS L 1096:2010 8.21.5 E method (handle-o-meter method). Specifically, the measurement was performed according to the following procedure. A sample piece measuring 20 cm x 20 cm in the MD x CD directions is placed on the sample stage so that the measurement direction of the sample piece is perpendicular to the slot (gap width 10 mm). Next, the blade of the penetrator, adjusted so that it is 8 mm below the surface of the sample stage, is lowered, and the sample piece is pressed in. When the blade is 6.7 cm (1 / 3 of the width of the sample piece) from one side, the resistance to the pressing is read at different points on both the front and back in the vertical and horizontal directions (a total of four points). The maximum value (mN) indicated by the microammeter is read as the resistance value. The maximum values ​​of the four sides are calculated and the average of the three measurements is calculated, and this is the bending resistance (mN) of the sample.

[0084] [Breaking strength, breaking elongation, stress at 10%-20% elongation] According to JIS L 1096:2010 8.14.1 A method (strip method), a constant-speed tension-type tensile tester was used to perform a tensile test under the conditions of a sample width of 50 mm, a grip distance of 10 cm, and a tensile speed of 30±2 cm / min, and the load value at break (breaking strength), breaking elongation, stress at 10% elongation, and stress at 20% elongation were measured. The tensile test was performed in the machine direction (MD) and cross direction (CD) of the nonwoven fabric as the tensile direction. The evaluation results are shown as the average of the values ​​measured for three samples. The breaking strength when wet was measured in a state where 100 parts by mass of the nonwoven fabric was impregnated with 250 parts by mass of distilled water.

[0085] All of Examples 1 to 6 contain acrylic fiber as chemical fiber A and have a specific volume of 12 cm 3 / g or more, it showed a higher initial adhesion than the comparative examples. Moreover, Examples 1 to 5 showed a higher adhesion after 20 minutes than the comparative examples. Although Example 6 showed a smaller adhesion after 20 minutes than Comparative Example 1, it was sufficiently practical. The reason why the adhesion after 20 minutes in Example 6 is slightly smaller is thought to be that it contains a large amount of acrylic fibers, and the impregnated distilled water evaporates relatively quickly. Acrylic fibers have a relatively lower official moisture regain than hydrophilic fibers, and have wrinkled recesses on the fiber side due to fine recesses formed in the fiber cross section, which is thought to promote evaporation of liquid. Comparative Example 1 had the same type and ratio of fibers as those of Examples 1 and 2, but had a large basis weight and a small specific volume, so the initial adhesion was small. Comparative Examples 2 to 4 did not contain acrylic fibers, so the basis weight was about 50 g / m 2 When the specific volume is 12 cm 3 / g or more, and the initial adhesive strength was still small.

[0086] All of Examples 1 to 6 had high wicking heights and excellent liquid absorption properties compared to Comparative Examples 2 and 4, which did not contain acrylic fibers. The wicking height of Example 5 was lower than the other Examples. This is believed to be because the content of hydrophilic fibers was low and the content of acrylic fibers was not as high as in Example 6, so the liquid was relatively difficult to move.

[0087] The dynamic friction coefficient μk is an index of stickiness, and the larger this is, the easier the nonwoven fabric will adhere to the skin. When comparing nonwoven fabrics with the same target size (Examples 2 to 4), the dynamic friction coefficient μk tends to be higher as the proportion of acrylic fiber increases. This is thought to be because acrylic fiber contains many fine protrusions, which results in high surface friction and makes it difficult to slip.

[0088] The coefficient of variation is an index of the smoothness of the nonwoven fabric surface, and the larger the coefficient of variation, the rougher the nonwoven fabric feels and the worse it feels on the skin. Although there was no significant difference in the coefficient of variation between the examples and the comparative examples, the coefficient of variation in Comparative Example 1 was the largest. This is thought to be due to the fact that the basis weight was the largest. If the specific volume is made small, the coefficient of variation is improved, but if the specific volume is made small, it is difficult to obtain a practical nonwoven fabric for liquid-impregnated skin application sheets that shows good adhesion.

[0089] In Comparative Example 1, the bending resistance was high and the flexibility was poor because the basis weight was large, and therefore the ability to conform to a curved surface was poor.

[0090] In all of Examples 1 to 6, the stress at 10% elongation in the MD direction when dry and wet, and the stress at 20% elongation in the MD direction when dry and wet, were smaller than those of Comparative Examples 1 and 3 containing acrylic fibers. This is believed to be due to the fact that the specific volume of the nonwoven fabrics of Examples 1 to 6 is larger than that of the nonwoven fabrics of Comparative Examples 1 and 3. Since the nonwoven fabrics of Examples 1 to 6 have moderately low stresses at 10% elongation and 20% elongation in the MD direction, when a sheet using the nonwoven fabrics as a base material is applied to the skin, the sheet can be moderately elongated in the vertical direction and cover the skin by following the curved surface and unevenness of the skin. In addition, although the specific volume of all of Examples 1 to 6 is large, the breaking strength was not significantly lower than that of Comparative Examples 1 to 4. This is believed to be due to the fine unevenness on the surface of the acrylic fibers contributing to entanglement and suppressing a decrease in strength.

[0091] The nonwoven fabric of this embodiment includes the following aspects. (Aspect 1) The fabric has an official moisture regain of 1.0% to 7.0% and contains 20% to 80% by mass of chemical fibers having at least one recess or constriction in a fiber cross section, and 20% to 80% by mass of hydrophilic fibers, Specific volume when dry is 12.0 cm 3 / g or more, Weight is 20~55g / m 2 That is, Nonwoven fabric for liquid-impregnated skin covering sheets. (Aspect 2) The fabric has an official moisture regain of 1.0% to 7.0% and contains 20% to 80% by mass of chemical fibers having at least one recess or constriction in a fiber cross section, and 20% to 80% by mass of hydrophilic fibers, Specific volume when wet is 8.8cm 3 / g or more, Weight is 20~55g / m 2 That is, Nonwoven fabric for liquid-impregnated skin covering sheets. (Aspect 3) 3. The nonwoven fabric for liquid-impregnated skin-covering sheets according to embodiment 1 or 2, wherein the chemical fibers are acrylic fibers. (Aspect 4) The liquid-impregnated nonwoven fabric for use in a skin-covering sheet according to any one of embodiments 1 to 3, which has a single-layer structure. (Aspect 5) 5. The nonwoven fabric for use in a liquid-impregnated skin-covering sheet according to any one of Aspects 1 to 4, further comprising a polyester monofilament. (Aspect 6) 6. The nonwoven fabric for use in a liquid-impregnated skin-covering sheet according to any one of embodiments 1 to 5, wherein the fibers are not bonded to each other. (Aspect 7) 7. The liquid-impregnated nonwoven fabric for use in a skin-covering sheet according to any one of aspects 1 to 6, which has a wicking height of 35 mm or more when dry. (Aspect 8) A liquid-impregnated skin application sheet obtained by impregnating the nonwoven fabric of any one of aspects 1 to 7 with a liquid. (Aspect 9) A face mask obtained by impregnating the nonwoven fabric of any one of aspects 1 to 7 with a liquid. [Industrial Applicability]

[0092] The nonwoven fabric of the present disclosure has a relatively large specific volume and adheres well to the skin when impregnated with a liquid, and is therefore useful as a substrate for liquid-impregnated skin-covering sheets such as face masks.

Claims

1. The fabric has an official moisture regain of 1.0% to 7.0% and contains 20% to 80% by mass of chemical fibers having at least one recess or constriction in a fiber cross section, and 20% to 80% by mass of hydrophilic fibers, Specific volume when dry is 12.0 cm 3 / g or more, Weight is 20 to 55 g / m 2 and The fibers are not bonded together, Further, the material contains chemical fibers having an official moisture regain of less than 1.0% in an amount of 15% by mass or more and 35% by mass or less. Nonwoven fabric for liquid-impregnated skin covering sheets.

2. The fabric has an official moisture regain of 1.0% to 7.0% and contains 20% to 80% by mass of chemical fibers having at least one recess or constriction in a fiber cross section, and 20% to 80% by mass of hydrophilic fibers, Specific volume when wet is 8.8 cm 3 / g or more, Weight is 20 to 55 g / m 2 and The fibers are not bonded together, Further, the material contains chemical fibers having an official moisture regain of less than 1.0% in an amount of 15% by mass or more and 35% by mass or less. Nonwoven fabric for liquid-impregnated skin covering sheets.

3. The fabric has an official moisture regain of 1.0% to 7.0% and contains 20% to 80% by mass of chemical fibers having at least one recess or constriction in a fiber cross section, and 20% to 80% by mass of hydrophilic fibers, Specific volume when dry is 12.0 cm 3 / g or more, Weight is 20 to 55 g / m 2 and The fibers are not bonded together, The chemical fiber is an acrylic fiber, Further, the material contains chemical fibers having an official moisture regain of less than 1.0% in an amount of 15% by mass or more and 35% by mass or less. Nonwoven fabric for liquid-impregnated skin covering sheets.

4. The fabric has an official moisture regain of 1.0% to 7.0% and contains 20% to 80% by mass of chemical fibers having at least one recess or constriction in a fiber cross section, and 20% to 80% by mass of hydrophilic fibers, Specific volume when wet is 8.8 cm 3 / g or more, Weight is 20 to 55 g / m 2 and The fibers are not bonded together, The chemical fiber is an acrylic fiber, Further, the material contains chemical fibers having an official moisture regain of less than 1.0% in an amount of 15% by mass or more and 35% by mass or less. Nonwoven fabric for liquid-impregnated skin covering sheets.

5. The fabric has an official moisture regain of 1.0% to 7.0% and contains 20% to 80% by mass of chemical fibers having at least one recess or constriction in a fiber cross section, and 20% to 80% by mass of hydrophilic fibers, Specific volume when dry is 12.0 cm 3 / g or more, Weight is 20 to 55 g / m 2 and The fibers are not bonded together, It has a single layer structure, Further, the material contains chemical fibers having an official moisture regain of less than 1.0% in an amount of 15% by mass or more and 35% by mass or less. Nonwoven fabric for liquid-impregnated skin covering sheets.

6. The fabric has an official moisture regain of 1.0% to 7.0% and contains 20% to 80% by mass of chemical fibers having at least one recess or constriction in a fiber cross section, and 20% to 80% by mass of hydrophilic fibers, Specific volume when wet is 8.8 cm 3 / g or more, Weight is 20 to 55 g / m 2 and The fibers are not bonded together, It has a single layer structure, Further, the material contains chemical fibers having an official moisture regain of less than 1.0% in an amount of 15% by mass or more and 35% by mass or less. Nonwoven fabric for liquid-impregnated skin covering sheets.

7. A liquid-impregnated skin application sheet obtained by impregnating the nonwoven fabric according to any one of claims 1 to 6 with a liquid.

8. A face mask obtained by impregnating the nonwoven fabric according to any one of claims 1 to 6 with a liquid.

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