JPWO2015046301A1 - Liquid retention sheet and face mask - Google Patents

Abstract

A liquid retention sheet is formed of a nonwoven fabric containing 50% by mass or more of high elastic fibers having a Young's modulus of 30 cN / T or more. The highly elastic fiber may be a core-sheath type composite fiber. The sheath portion of the core-sheath composite fiber may be formed of an ethylene-vinyl alcohol copolymer, and the core portion may be formed of a hydrophobic resin. The average fineness of the highly elastic fiber may be about 1.5 to 10 dtex. This liquid-retaining sheet is suitable for a face mask because the liquid component quickly returns even when pressed with a finger in a state impregnated with a liquid component such as cosmetic liquid.

Description

  The present invention relates to a liquid retention sheet that can absorb a liquid component (liquid compound), and more particularly to a liquid retention sheet for a face mask that is impregnated with a liquid component including a cosmetic component or a medicinal component, and is attached to the skin.

  Conventionally, a skin care sheet (liquid-impregnated biofilm sheet) impregnated with a liquid such as cosmetics has been used as a sheet to be applied to the skin (skin) of the human body. In recent years, a wide variety of products have been developed for skin care sheets represented by face masks because the skin can be easily maintained in a high moist state. In particular, the face mask has a function of transmitting the cosmetic liquid (cosmetics) impregnated in the sheet that constitutes the mask to the skin, but for the transmission of the cosmetic liquid, the sheet itself needs to be in close contact with the skin. There is. Therefore, in the face mask, in order to bring the sheet into good contact with the skin, various ideas are applied to the sheet itself or the shape.

  Japanese Patent Application Laid-Open No. 2008-261067 (Patent Document 1) describes a solvent-spun cellulose fiber having a fiber length of 30 to 60 mm as a water-containing sheet that has a good touch and is excellent in water retention and release properties and form stability. And a core-sheath type composite fiber is a nonwoven fabric sheet entangled with each other, wherein the core-sheath type composite fiber comprises a sheath part and a core part, and the sheath part is an ethylene-vinyl alcohol copolymer. A nonwoven fabric sheet is disclosed in which the core is made of a hydrophobic resin and has a diameter of 5 to 15 μm. This document describes hot drawing for a method of manufacturing a core-sheath composite fiber, but does not describe specific conditions.

  However, this non-woven sheet has excellent flexibility and liquid retention, but the stiffness (rigidity) of the sheet is small, and when it is pressed with a finger to bring the face mask into close contact with the face, the thickness is restored and the cosmetic liquid (cosmetics) ) Is slow to return. For this reason, it is difficult to efficiently spread the cosmetic liquid over the entire face. In particular, in the face mask, it is necessary to press a finger on a portion where the cosmetic liquid is desired to be replenished or a portion where the close contact is difficult. Therefore, in the conventional face mask, the face mask is in close contact with the target portion, but the cosmetic liquid is insufficiently replenished.

  In addition, in order to improve the conformity of the face mask to the skin (face) (in order to be in close contact with the skin), a face mask in which a layer formed of ultrafine fibers is arranged on the skin contact side, or a three-dimensional A face mask having a special structure has also been developed. However, even with these face masks, the conformity to the skin is not sufficient, and the current situation is that the action of pressing and adhering the pasted face mask once with a finger is repeated. Therefore, by repeating the action of pressing on the skin, the cosmetic liquid stored in the pressed part is pushed out each time (exuding around the pressed part), and the insufficient state of the cosmetic liquid is promoted. The result is.

JP 2008-261067 A (Claim 1, paragraph [0033])

  Accordingly, an object of the present invention is to provide a liquid retaining sheet and a face mask in which a liquid component can be quickly returned even when pressed with a finger in a state impregnated with a liquid component such as a cosmetic liquid (cosmetic).

  Another object of the present invention is to provide a liquid retaining sheet and a face mask that can be quickly recovered even when pressed with a finger in a state impregnated with a liquid component.

  Still another object of the present invention is to provide a liquid retaining sheet and a face mask that can efficiently replenish a cosmetic liquid to a desired site.

  Another object of the present invention is to provide a liquid retaining sheet and a face mask which are excellent in flexibility, liquid retaining property, liquid releasing property and form stability.

  As a result of intensive studies to solve the above problems, the present inventors formed a non-woven fabric capable of absorbing a liquid component using a specific highly elastic fiber as a main fiber, and against compression in the thickness direction of the liquid retaining sheet. By controlling the repositioning, the present inventors have found that the liquid component can be quickly returned even when pressed with a finger in a state impregnated with a liquid component such as cosmetic liquid.

That is, the liquid retaining sheet of the present invention is formed of a nonwoven fabric containing 50% by mass or more of high-elasticity fibers having a Young's modulus of 30 cN / T or more. The highly elastic fiber may be a core-sheath type composite fiber. The sheath portion of the core-sheath composite fiber may be formed of an ethylene-vinyl alcohol copolymer, and the core portion may be formed of a hydrophobic resin. The hydrophobic resin may be a polyester resin. The average fineness of the highly elastic fiber may be about 1.5 to 10 dtex. The high elastic fiber may be a fiber obtained by stretching 2.4 times or more at a temperature of 80 ° C. or higher. The nonwoven fabric may further contain cellulosic fibers having an average fineness of 0.3 to 5 dtex. The mass ratio of the highly elastic fiber and the cellulosic fiber is approximately high elastic fiber / cellulosic fiber = 60/40 to 80/20. The liquid retention sheet of the present invention may be a skin care sheet (particularly a face mask) impregnated with a liquid component containing cosmetics. When the liquid retention sheet of the present invention is impregnated with 900% by mass of the cosmetic liquid with respect to its own weight and removed by applying a load of 260 g / cm ² for 1 minute, the repositioning with respect to compression in the thickness direction is 60% or more in 5 minutes. It may be.

  In the present invention, a specific high-elastic fiber is used as a main fiber to form a non-woven fabric capable of absorbing a liquid component, and the reversion of the liquid retaining sheet to compression in the thickness direction is controlled. Even when pressed with a finger in the state of impregnation, the liquid component returns quickly. Further, even when pressed with a finger in a state impregnated with a liquid component, the thickness recovery (compression elasticity in the thickness direction at the time of impregnation with a cosmetic liquid) is fast. Therefore, for example, when used as a face mask, the cosmetic liquid can be efficiently replenished (applied) to a desired part of the face. Furthermore, by using a core-sheath composite fiber having a sheath part formed of an ethylene-vinyl alcohol copolymer, flexibility, liquid retention, liquid release property, and form stability can be improved.

  In the present specification, the compression elasticity in the thickness direction at the time of impregnation of the cosmetic liquid (compression elasticity at the time of impregnation) means that the sheet impregnated with the cosmetic liquid is compressed (after being crushed) for a predetermined time and load. ), A characteristic (%) indicating how much the thickness of the crushed sheet is restored after the load is removed (return condition of the compressed sheet thickness).

FIG. 1 is a schematic diagram for explaining a method for measuring compressive elasticity in the thickness direction at the time of impregnation with a cosmetic liquid in Examples. FIG. 2 is a schematic diagram for explaining a method of measuring liquid return to the original fabric in the example.

[Nonwoven fabric]
The liquid retaining sheet of the present invention is formed of a nonwoven fabric that can absorb a liquid component (particularly an aqueous liquid component). The non-woven fabric is a liquid containing a cosmetic component or a medicinal component (for example, a moisturizing component, a cleansing component, an antiperspirant component, an aroma component, a whitening component, a blood circulation promoting component, a cooling component, an ultraviolet absorption component, a skin itch suppressing component, etc.) It has wettability necessary for impregnating components (liquid compounds) and voids for retaining liquids, and it covers the specified part of the body (for example, the face) without dripping even during handling. It holds and sticks or stands still, and has the role which transfers liquid cosmetics to the skin side little by little. The liquid retaining sheet (nonwoven fabric) of the present invention is excellent in liquid retaining properties and has an appropriate stiffness or elasticity, and when impregnated with a liquid component, the reversion to compression and the return of the liquid are fast. When formed with a specific high-elasticity fiber, the returnability of the liquid is excellent, and the thickness is also quickly recovered, so that it can be recovered in a short time in a liquid retaining state similar to the uncompressed portion.

Specifically, when the cosmetic solution is impregnated with 900% by mass of the cosmetic liquid with respect to its own weight and a load of 260 g / cm ² is applied and removed for 1 minute, the recovery to compression in the thickness direction is 60% or more in 5 minutes. (60 to 100%), preferably 65 to 99%, more preferably about 70 to 98%. If the repositioning is less than 60%, a liquid component such as a cosmetic liquid cannot sufficiently return to the pressing portion. In addition, the decompression with respect to compression can be measured in detail by the method described in the examples described later.

  Regarding the return of the liquid, specifically, when the cosmetic liquid was impregnated with 900% by mass with respect to its own weight and the load of 620 g was applied to the circular portion having a diameter of 1.2 cm and removed for 1 minute, the cosmetic liquid after 5 minutes The liquid return may be 55% or more (55 to 100%), preferably 60 to 99%, more preferably 65 to 98%, and still more preferably about 70 to 97%. If the liquid return is too low, the liquid component after pressing is insufficient, and the face mask cannot sufficiently penetrate the cosmetic liquid into the skin. In addition, in detail, the liquid return of a cosmetic liquid can be measured by the method as described in the Example mentioned later.

  Nonwoven fabric (liquid retention sheet) is excellent in flexibility when wet, and has moderately intertwined fibers so that it can follow the skin such as the face, and stress at 30% elongation when wet according to JIS L1913 However, in at least one direction, for example, it is about 0.5 to 10 N / 5 cm, preferably about 1 to 8 N / 5 cm, and more preferably about 1.5 to 5 N / 5 cm. If the stress at the time of elongation is too small, it will be too difficult to handle when it is attached to the skin such as the face, and if it is too large, the adhesion to the skin will be reduced. The stress at 30% elongation in a wet state can be measured in detail by the method described in the examples described later.

  The non-woven fabric (liquid holding sheet) is also excellent in liquid holding ratio, and the water holding ratio in accordance with JIS L1907 7.2 may be 800% or more, for example, 900 to 3000%, preferably 950 to 2000%, Preferably it is about 1000-1500%. If the water retention rate is too low, it will be difficult to supply a sufficient amount of cosmetic (beauty liquid) to the skin.

The basis weight of the nonwoven fabric is, for example, about 30 to 100 g / m ² , preferably 35 to 80 g / m ² , and more preferably 40 to 70 g / m ² (particularly 50 to 65 g / m ² ). If the basis weight is too small, it will be difficult to secure a void for the liquid retention formed by the fibers. On the other hand, when too large, since thickness will become large, the alongness to skin will fall. In addition, the amount of liquid retention increases, and many of the active ingredients remain in the liquid retention layer without reaching the skin, and the active ingredients are easily consumed wastefully.

  The thickness of a nonwoven fabric can be selected from the range of about 100-3000 micrometers, for example, is 200-2000 micrometers, Preferably it is about 300-1500 micrometers, More preferably, it is about 400-1200 micrometers (especially 500-1000 micrometers).

(High elastic fiber)
In order to have moderate stiffness or elasticity, the nonwoven fabric includes, as main fibers, highly elastic fibers having Young's modulus (initial tensile resistance) of 30 cN / T or more (for example, about 40 to 500 cN). The high modulus fiber may have a Young's modulus of about 30 to 100 cN / T (for example, 30 to 90 cN / T), preferably 30 to 80 cN / T (for example, 35 to 70 cN / T), and more preferably 40. It is about -60 cN / T (especially 45-55 cN / T). If the Young's modulus is too low, the stiffness and elasticity of the nonwoven fabric cannot be improved.

  The structure of the highly elastic fiber is not particularly limited as long as it has the Young's modulus. For example, it may be a polyester fiber such as polyethylene terephthalate or a polyphenylene sulfide-based fiber (single-phase fiber) of polyphenylene sulfide. The core-sheath type composite fiber is preferable from the viewpoint of easily achieving both elasticity, liquid retention and liquid release properties.

  In the core-sheath type composite fiber, the sheath part is preferably composed of a hydrophilic resin in order to ensure wettability and liquid retention. The sheath part made of hydrophilic resin plays an important role for taking liquid into the nonwoven fabric when liquid such as cosmetics (beauty liquid) is added to the liquid retaining sheet, and once taken into the nonwoven fabric. When handling a large amount of cosmetic liquid at the time of use, it plays a role to keep it from dripping.

  Examples of the hydrophilic resin include a resin having a hydrophilic group (particularly a hydroxyl group) such as a hydroxyl group, a carboxyl group, or a sulfonic acid group in the molecule. A hydrophilic resin having a hydroxyl group in the monomer unit is preferred, An ethylene-vinyl alcohol copolymer is particularly preferred from the viewpoint of uniformly having hydroxyl groups. The ethylene-vinyl alcohol copolymer has biocompatibility based on hydrophilicity, non-water absorption, and thermal conductivity. In addition, the ethylene-vinyl alcohol copolymer has not only hydrophilicity but also moderate lipophilicity, and it contains not only shampoo of cosmetic liquid but also fat and water, including sweat and dirt. Improves skin adhesion and feel.

  In the ethylene-vinyl alcohol copolymer, the ethylene unit content (copolymerization ratio) can be selected from the range of about 25 to 70 mol%, and from the viewpoint of hydrophilicity and melt spinnability, it is about 30 to 65 mol%. From the point which can maintain hydrophilicity, suppressing the trouble on melt spinning by deterioration of a residence resin, it is 35-60 mol%, for example, Preferably it is 37-55 mol%, More preferably, it is 40-50 mol % May be sufficient. When the proportion of the ethylene unit is too large, the hydrophilicity is lowered, and when it is too little, the melt spinnability is lowered and the shape stability in the wet state is lowered.

  The saponification degree of the vinyl alcohol unit may be 80 mol% or more, and is 90 mol% or more (for example, 90 to 99.99 mol%), preferably 95 mol% or more from the viewpoint of hydrophilicity and melt spinnability. (For example, 95 to 99.98 mol%), more preferably about 96 to 99.97 mol%. If the degree of saponification is too small, the hydrophilicity and heat resistance will decrease.

  In order to improve the stability against hot water, the ethylene-vinyl alcohol copolymer is usually subjected to a crosslinking treatment such as acetalization after fiberization to improve hot water resistance. Therefore, it is preferable not to perform the crosslinking treatment.

  The ethylene-vinyl alcohol copolymer may contain other copolymer units. As a polymerization component for constituting the copolymer unit, other fatty acid vinyl esters (vinyl propionate, vinyl pivalate, etc.), vinyl silane compounds (vinyl trimethoxysilane, vinyl triethoxysilane, vinyl tri (β-methoxy-ethoxy) Silane, γ-methacryloxypropylmethoxysilane, etc.). These polymerization components can be used alone or in combination of two or more. Of these, vinylsilane compounds such as vinyltrimethoxysilane and vinyltriethoxysilane are preferred. The ratio of the vinylsilane compound is, for example, about 0.0001 to 0.3 mol% (particularly 0.0002 to 0.2 mol%) with respect to the entire polymerization component.

  The viscosity average degree of polymerization of the ethylene-vinyl alcohol copolymer is, for example, about 200 to 2500, preferably about 300 to 2000, and more preferably about 400 to 1500.

  When the sheath is formed of an ethylene-vinyl alcohol copolymer, it has excellent adhesion to the skin and touch, and can improve the liquid absorbency and retention of cosmetics, but the rigidity decreases due to water absorption. In order to maintain the desired bulkiness (porosity) in the processing step and to secure water absorption, the core is preferably formed of a hydrophobic resin whose rigidity is not reduced by water absorption.

  Examples of hydrophobic resins include resin components such as polyolefin resins, acrylic resins, polyvinyl acetal resins, polyvinyl chloride resins, polyvinylidene chloride resins, polyester resins, polyamide resins, and polyurethane resins. And the like. These hydrophobic resins can be used alone or in combination of two or more.

  Among these hydrophobic resins, resins having an official moisture content of less than 2.0% in a standard state (20 ° C., 65% RH), for example, polyolefin resins such as polyethylene and polypropylene generally used for nonwoven fabrics, Polyester resins such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, polyamide resins such as polyamide 6, polyamide 6,6, and polyamide 4, 6, polyurethane resins such as polyester polyol type urethane resin, polyacrylonitrile resin In general, fibers formed from the above are widely used, have higher elastic modulus than ethylene-vinyl alcohol copolymers, and have excellent spinnability with ethylene-vinyl alcohol copolymers. Preferably, elastic modulus High shape stability in the fine hot, non-woven fabric shrinkage can be suppressed, from the viewpoint of excellent workability, polyester resins are particularly preferable.

Examples of the polyester resin include polyalkylene arylate resins such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, and aliphatic polyester resins such as polylactic acid. These polyester resins can be used alone or in combination of two or more. Among these polyester resins, poly C _2-4 alkylene arylate resins containing 80 mol% or more of C _2-4 alkylene arylate units such as ethylene terephthalate and butylene terephthalate are preferable.

  In the core-sheath type composite fiber, it is preferable that the sheath part continuously occupies an area of 50% or more (particularly 90 to 100%) of the fiber surface area in the length direction, and generally the sheath part occupies substantially the entire surface area. .

  The ratio (mass ratio) between the core portion and the sheath portion is, for example, sheath / core = 90/10 to 10/90 (for example, 60/40 to 10/90), preferably 80/20 to 15/85. More preferably, it is about 60/40 to 20/80. When there are too many ratios of a sheath part, a core part cannot hold | maintain the form of a fiber, and it will become difficult to ensure the intensity | strength of fiber itself. Further, depending on the diameter of the core part, the stiffness of the fiber is lowered, the density of the nonwoven fabric is increased, and the liquid retaining property is lowered. When the ratio of the sheath portion is too small, the hydrophilicity is lowered. Moreover, depending on the diameter of the core part, the stiffness becomes too strong, and the flexibility and conformity to the skin are deteriorated.

  High-elasticity fibers are commonly used additives such as stabilizers (heat stabilizers such as copper compounds, UV absorbers, light stabilizers, antioxidants), colorants, dispersants, fine particles, antistatic agents, difficult A flame retardant, a plasticizer, a lubricant, a crystallization rate retarder, and the like may be contained. These additives can be used alone or in combination of two or more. In particular, the sheath ethylene-vinyl alcohol copolymer contains trace amounts of acids (fatty acids such as acetic acid) and metal salts (alkali metals such as phosphoric acid and acetic acid) in order to suppress thermal degradation during melt molding. Alternatively, an alkaline earth metal salt or the like may be added. These additives may be carried on the surface of the fiber or may be contained in the fiber.

  The cross-sectional shape (cross-sectional shape perpendicular to the length direction) of the highly elastic fiber is not particularly limited. For example, a round cross-section, an irregular cross-section (flat shape, elliptical cross-section, etc.), a polygonal cross-section, a multi-lobed cross-section Various cross-sectional shapes such as a (3-14 leaf-shaped cross section), a hollow cross section, a V-shaped cross section, a T-shaped cross section, an H-shaped cross section, a Y-shaped cross section, an I-shaped (dogbone-shaped) cross section, and an array-shaped cross section may be used. Among these, the shape that does not have an acute angle part (protrusion part) or a groove part, in particular, a round shape from the point that it is superior to the shape having an acute angle part (protrusion part) or a groove part such as a polygonal cross section or a Y-shaped cross section. A mold section (substantially circular section such as a perfect circular section) and an elliptical section are preferable, and a substantially circular section is particularly preferable.

  The average fineness of the highly elastic fiber is, for example, about 1.5 to 10 dtex, preferably 1.7 to 5 dtex, and more preferably 1.8 to 4.5 dtex (particularly 1.9 to 4 dtex). Furthermore, the average fineness is, for example, about 1.5 to 5 dtex, preferably about 1.6 to 3 dtex, and more preferably about 1.7 to 2 dtex because the water retention rate is high and the properties such as the return of the liquid component are excellent. There may be. If the highly elastic fiber is too thick, the touch is liable to decrease, and the liquid absorption and liquid retention properties tend to decrease. On the other hand, since elasticity will fall when too thin, when a nonwoven fabric is pushed with a finger | toe, recovery | restoration of thickness and a return of a liquid component will become slow. Moreover, since the density of a nonwoven fabric becomes high and the space | gap between fibers reduces, liquid retention property also falls.

  The fiber length (average fiber length) of the highly elastic fiber is not particularly limited, but is, for example, about 20 to 70 mm, preferably 30 to 60 mm, and more preferably 45 to 60 mm (particularly 45 to 55 mm). When the fiber length is too long, uniform entanglement between the fibers becomes difficult, the touch is lowered, and the liquid absorbability and the liquid release property are lowered. On the other hand, if the fiber length is too short, the fibers are easily removed from the nonwoven fabric, and the flexibility and stretchability are also lowered.

  The production method of the highly elastic fiber is not particularly limited, and a conventional method can be used. High elastic fibers can be produced, for example, by a spinning method through melt-kneading extrusion, but in order to impart a high elastic modulus to the fibers, it is preferable to perform a drawing treatment after spinning. In the present invention, it is possible to improve the crystallinity of a resin component (for example, a polyester-based resin that forms a core portion) that forms a highly elastic fiber by stretching at a predetermined heating temperature after spinning. The rigidity and stiffness can be improved, and the elasticity required for the face mask can be imparted to the nonwoven fabric.

  As the stretching method, a conventional method can be used. For example, when the fiber discharged from the nozzle at the time of spinning is pulled by a godet roller, it may be a one-step method of stretching between hot godet rolls. A two-step method may be used in which hot drawing is performed at low speed in a hot stove.

  The draw ratio may be 2.0 times or more, specifically, can be selected from the range of about 2 to 10 times, for example, 2.1 to 8 times, preferably 2.2 to 5 times, more preferably It is about 2.3 to 4 times (especially 2.4 to 3 times). If the draw ratio is too low, the elasticity of the highly elastic fiber cannot be sufficiently improved, and if it is too high, thread breakage occurs.

  Although the heating temperature in stretching can be selected according to the type of fiber, it may be, for example, about 80 ° C. or higher, preferably 80 to 150 ° C., more preferably about 85 to 120 ° C. (especially 85 to 100 ° C.).

  The highly elastic fiber may be subjected to a mechanical crimping treatment using a conventional method, for example, a crimping device, or may be heated and dried after the treatment. A drying temperature is 100-150 degreeC, for example, Preferably it is 120-150 degreeC, More preferably, it is about 140-150 degreeC (especially 145-150 degreeC) grade. By drying at such a high temperature, the elasticity of the highly elastic fiber can be further improved.

  The ratio of the highly elastic fiber should just be 50 mass% or more with respect to the whole nonwoven fabric, for example, 50-100 mass%, Preferably it is 60-100 mass%, More preferably, it is 65-100 mass% (especially 70-100 mass%). Mass%). From the point that it is excellent in liquid retention, the thickness is restored to compression and the liquid returns quickly, and the balance between liquid retention and liquid return is excellent. 50-90 mass%, Preferably it is 55-85 mass%, More preferably, about 60-80 mass% (especially 65-75 mass%) may be sufficient. If the proportion of highly elastic fibers is too small, the elasticity of the nonwoven fabric cannot be improved.

(Other fibers)
The non-woven fabric may further contain other fibers (low-elasticity fibers) in addition to the high-elasticity fibers as long as the rigidity and stiffness are not impaired. As another fiber, a cellulose fiber is preferable from the point which can improve a liquid absorptivity and liquid retention.

  Cellulosic fibers may be natural fibers (wood pulp, cotton or cotton, hemp, etc.), but recycled fibers are preferred from the standpoint of handleability. Recycled fibers include regenerated cellulose fibers (viscose rayon, polynosic, etc.) obtained by the viscose method, regenerated cellulose fibers (cupra, etc.) obtained by the copper ammonia method, and solvent spinning (cellulose is once chemically treated). Solvent-spun cellulosic fibers (such as lyocell such as Tencel (registered trademark)) obtained by a direct method that does not convert to). These cellulosic fibers can be used alone or in combination of two or more.

  Of these cellulosic fibers, solvent-spun cellulosic fibers are preferred because they are soft to the touch and excellent in fiber strength in a wet state. Further, the solvent-spun cellulose fiber is a cellulose fiber produced by a method in which a spinning stock solution in which cellulose is dissolved in amine oxide is dried and wet-spun into water to precipitate the cellulose, and the fiber is further drawn. Also good. A typical example of such solvent-spun cellulosic fibers is lyocell, which is sold by the Austrian Lenzing company under the trade name “Tencel” (registered trademark).

  Solvent-spun cellulosic fibers are usually fibrillated by beaters, refiners, high-speed disintegrators, etc., but in the present invention, fiber fibrillation prevents fine fibers from adhering to the skin. Therefore, a solvent-spun cellulose fiber that is not substantially fibrillated is preferred.

  Other fibers may also contain a conventional additive, like the highly elastic fibers.

  The Young's modulus of other fibers is less than 30 cN / T, for example, about 1 to 29 cN / T, preferably 5 to 25 cN / T, more preferably 10 to 23 cN / T (particularly 15 to 20 cN / T). .

  The cross-sectional shape of other fibers may also be the shape exemplified in the section of highly elastic fibers, but from the viewpoint of excellent touch, a round cross-section or an elliptic cross-section is preferable like solvent-spun cellulose fibers. .

  The average fineness of other fibers (particularly cellulosic fibers) is, for example, 0.3 to 5 dtex, preferably 0.5 to 2 dtex, more preferably 0.6 to 1.7 dtex (particularly 0.8 to 1.5 dtex). Degree. If the other fibers are too thick, the touch is liable to decrease, and the liquid absorbency and liquid retention are likely to decrease. On the other hand, if it is too thin, the density of the nonwoven fabric is increased and the interfiber gap is reduced, so that the liquid retention is lowered.

  The fiber length (average fiber length) of other fibers is not particularly limited, but is, for example, about 20 to 70 mm, preferably about 30 to 60 mm, and more preferably about 35 to 50 mm. When the fiber length is too long, uniform entanglement between the fibers becomes difficult, the touch is lowered, and the liquid absorbability and the liquid release property are lowered. On the other hand, if the fiber length is too short, the fibers are easily removed from the nonwoven fabric, and the flexibility and stretchability are also lowered.

  The ratio (mass ratio) of highly elastic fibers and other fibers (especially cellulosic fibers) is particularly high in balance between liquid retention and liquid return properties, and therefore high elasticity fibers / other fibers (especially solvent spinning). Cellulosic fiber) = 60/40 to 80/20, preferably about 65/35 to 75/25. If the proportion of the high elastic fiber is too small, the elasticity of the nonwoven fabric is lowered, and if it is too much, the effect of blending other fibers is lowered. For example, if the proportion of the cellulosic fiber is small, the liquid retaining property and the liquid absorbing property are reduced. Cannot be improved.

  In the present invention, the total proportion of the highly elastic fiber and the cellulosic fiber may be 50% by mass or more, for example, 80 to 100% by mass, preferably 90 to 100% by mass, and more preferably, with respect to the entire nonwoven fabric. Is about 95 to 100% by mass, and the non-woven fabric may be formed of only highly elastic fibers and cellulosic fibers. In particular, the liquid-retaining sheet of the present invention has a low content of conventional binder fibers that reduce touch, unlike industrial water-absorbing sheets that require dimensional stability, etc., when used for applications that come into contact with the skin. For example, the ratio of the binder fiber may be 10% by mass or less, preferably 5% by mass or less, and more preferably 1% by mass or less with respect to the entire nonwoven fabric.

[Method for producing nonwoven fabric]
The nonwoven fabric (liquid holding sheet) can be produced by, for example, a spunlace method, a needle punch method, a steam jet method, or the like. Of these methods, the spunlace method is preferable from the viewpoint of simplicity.

In the spunlace method, staple fibers, for example, high elastic fibers (or mixed cotton of high elastic fibers and other fibers) may be opened by carding with a card machine to form a nonwoven web. This non-woven web includes a parallel web arranged in the traveling direction of the card machine according to a blending ratio of fibers constituting the web, a cross web in which parallel webs are cross-laid, a random web arranged randomly, or a parallel web and a random web. Any of the semi-random webs arranged in the middle of the above may be used, but the entanglement of fibers occurs in the transverse direction, and the elongation in the transverse direction is hindered, so the alongness to the skin tends to decrease during use Parallel webs and semi-random webs that can ensure the softness and extensibility of the laminated sheet in the transverse direction are preferred to random webs and cross webs.
Further, in the spunlace method, the obtained nonwoven web is subjected to a hydroentanglement process. In the water entanglement treatment, for example, injection holes having a diameter of 0.05 to 0.3 mm (especially 0.08 to 0.2 mm) and an interval of 0.3 to 1.5 mm (especially 0.4 to 1 mm) are arranged 1 to 1. The three-dimensional entanglement of the fibers constituting the nonwoven web is made by colliding the water flow jetted in a columnar shape from the nozzle plates arranged in three rows (especially 1-2 rows) with the nonwoven fabric web placed on the porous support member. Integrate with caulking. When three-dimensional entanglement is applied to the nonwoven web, the nonwoven web is placed on the moving porous support member, and the water pressure is, for example, 1 to 15 MPa, preferably 2 to 12 MPa, more preferably about 3 to 10 MPa. The method of processing once or several times is preferable. The injection holes are arranged in a row in a direction perpendicular to the traveling direction of the nonwoven web, and the nozzle plate on which the injection holes are arranged is perpendicular to the traveling direction of the nonwoven web placed on the porous support member. It is preferable that the water flow is caused to collide uniformly with the nonwoven fabric web by causing the water flow to swing at the same interval as the spray hole interval. The porous support member on which the nonwoven fabric web is placed is not particularly limited as long as the water flow can penetrate the nonwoven fabric web, such as a mesh screen such as a wire mesh or a perforated plate. Although the distance of a jet hole and a nonwoven fabric web can be selected according to water pressure, it is about 1-10 cm, for example. If it is outside this range, the texture of the nonwoven fabric tends to be disturbed or the three-dimensional entanglement is insufficient.

  After the water entanglement process, a drying process may be performed. As the drying treatment, it is preferable to remove excess moisture from the nonwoven web after treatment, and a known method can be used to remove excess moisture. For example, excessive moisture may be removed to some extent using a squeezing device such as a mangle roll, and then the remaining moisture may be removed using a drying device such as a suction band type hot air circulation dryer.

[Liquid retention sheet]
The liquid retaining sheet of the present invention may be a sheet obtained by impregnating a nonwoven fabric with a liquid component, for example, a skin care sheet (particularly a face mask) obtained by impregnating a nonwoven fabric with a liquid component containing cosmetics (beauty liquid).

  The liquid retention sheet of the present invention is used for absorbing liquid components for use, for example, surface materials such as napkins and diapers, diaper liners, sheets for absorbing body fluids such as wet tissues (or skin cleaning sheets), and the like. Can also be used, but because it has a good balance between liquid retention and release properties and can be easily adhered to the skin, it can be used to adhere a sheet impregnated with a liquid component such as a cosmetic component or a medicinal component to the skin, for example, Used for various skin care sheets such as face masks, makeup removing sheets or cleansing sheets, body washing sheets (sweat wiping sheets, oil removing sheets, etc.), cooling sheets, medicinal or therapeutic sheets (itch prevention sheets, compresses, etc.) It is particularly preferable to use it for a face mask because the liquid component quickly returns even when pressed with a finger.

  The liquid retaining sheet of the present invention may be a sheet used by impregnating these liquid components at the time of use, or may be a sheet (so-called wet sheet) used by impregnating the liquid components in advance.

In the present invention, liquid components include liquid substances such as solvents and liquid oils, and solutions or dispersions in which the liquid substances contain active ingredients such as cosmetic ingredients or medicinal (efficacy) ingredients (such as cosmetics and emulsions). ) Is also included. The solvent may be a lipophilic solvent, but is preferably a hydrophilic solvent from the viewpoint of safety to the human body. Examples of the hydrophilic solvent include water, lower aliphatic alcohols (eg, C _1-4 alkyl alcohols such as ethanol and isopropanol), and alkylene glycols (eg, ethylene glycol, diethylene glycol, propylene glycol, etc.) and the like. . These hydrophilic solvents can be used alone or in combination of two or more. Examples of the liquid oil include unsaturated higher fatty acids (eg, oleic acid, oleyl alcohol), animal and vegetable oils (eg, jojoba oil, olive oil, palm oil, camellia oil, macadamian nut oil, avocado oil, corn Oil, sesame oil, wheat germ oil, linseed oil, castor oil, squalane, etc.), mineral oil (eg, liquid paraffin, polybutene, silicone oil, etc.), synthetic oil (eg, synthetic ester oil, synthetic polyether oil, etc.), etc. Is mentioned. These liquid oils can be used alone or in combination of two or more.

  These liquid substances can be used alone or in combination of two or more. For example, liquid oil may be used in combination as an additive (oil) for a hydrophilic solvent such as water or ethanol. Of these liquid substances, water, lower alcohols or mixtures thereof are usually used, preferably water and / or ethanol (especially water). For example, when water and a lower alcohol (particularly ethanol) are used in combination, the ratio (volume ratio) of the two is water / lower alcohol = 100/0 to 30/70, preferably 100/0 to 50/50, More preferably, it is about 100/0 to 70/30, for example, about 99/1 to 80/20 may be sufficient.

  As active ingredients, conventional additives such as physiologically active ingredients (emulsifiers, whitening agents, antiperspirants, rough skin prevention agents, anti-inflammatory agents, skin itching inhibitors, blood circulation promoters, cell activators, etc.) Moisturizers, emollients, cleansing agents, UV absorbers, surfactants, astringents, enzymes, cooling agents, bactericides or antibacterial agents, antioxidants, amino acids, cooling agents, fragrances, coloring agents, etc. . These additives can be used alone or in combination of two or more. Among these additives, for example, humectants, ultraviolet absorbers, surfactants, cooling agents, enzymes, astringents, bactericides, or antibacterial agents are commonly used for skin care sheets. In particular, in a face mask (face pack), for example, a humectant or an emollient may be blended in a hydrophilic solvent. Examples of the humectant or emollient include dipropylene glycol, 1,3-butylene glycol, polyethylene glycol, polyoxyethylene-polyoxypropylene block copolymer, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene sucrose fatty acid ester. Glycerin, sodium hyaluronate, polyoxymethylglycoside, polyvinyl alcohol, polyvinylpyrrolidone, water-soluble cellulose ether (methylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxyethylmethylcellulose, hydroxypropylmethylcellulose, etc.). The total ratio of the humectant and the emollient is, for example, 0.1 to 50% by mass in the solution, preferably 1 to 30% by mass, and more preferably about 5 to 20% by mass.

  The proportion of these additives can be appropriately selected depending on the application. For example, the proportion of a liquid substance such as water or ethanol is usually 30 to 99% by mass, preferably 40 to 95% in the total liquid components including the additive. It is about 50 mass%, More preferably, it is about 50-90 mass%.

  The liquid-retaining sheet of the present invention is particularly suitable as a sheet to be fixed to the skin such as a face mask or a poultice because it has excellent adhesion to the skin. For example, since the floating part can be easily corrected without being in close contact, the sheet can be in close contact with minute gaps (irregularities) such as the base of the nose, and the active ingredient of the face mask can be effectively penetrated into the skin.

  The liquid retaining sheet of the present invention is also suitable for a cleansing sheet, a skin cleaning sheet, and the like. That is, the liquid-retaining sheet of the present invention can adhere the sheet to minute gaps on the face, and therefore can effectively remove makeup (makeup cosmetics such as foundation, white powder, lipstick, and eye makeup).

  As described above, when the liquid-retaining sheet of the present invention is used as a liquid-impregnated biological coating sheet (such as a face mask), the liquid-retaining sheet is usually impregnated into the liquid-retaining sheet and applied or contacted to the skin of a living body. used.

  The liquid-retaining sheet of the present invention may be laminated with other layers. For example, a non-porous film or sheet may be laminated on the side not in contact with the skin in order to promote absorption of the active ingredient.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to the following examples. In addition, each physical property value in the following examples and comparative examples was measured or evaluated by the following method. Details of the fibers used in the following examples and comparative examples are as follows.

[Melt viscosity (Pa · s)]
Using a melt viscometer, after preheating at a temperature of 290 ° C. for 10 minutes, the molten thermoplastic resin was extruded from a nozzle and measured.

[MI (melt index) (g / 10 min)]
A certain amount of synthetic resin (2160g) is heated and pressurized at a specified temperature (190 ° C) in a cylindrical container heated by a heater, and extruded from the opening (nozzle) provided at the bottom of the container every 10 minutes. The amount of resin formed was measured.

[Fiber fineness (dtex)]
Five sets of 30 single yarn samples cut to 30 mm were prepared, and the weight of each sample was measured twice.

    Fineness (dtex) = weight (g) / (number of fibers 30 × fiber length 30 mm) × 10000 m.

[Weight per unit (g / m ² )]
In accordance with JIS L1906, the sample is allowed to stand for 24 hours in a standard state at a temperature of 20 ° C. and a humidity of 65%, then a sample of 1 m in the width direction and 1 m in the length direction is taken, and the weight (g) is measured using a balance. The weight (g) obtained was rounded off to the basis weight.

[Thickness (mm)]
Using a razor ("Feather Razor S Single Blade" manufactured by Feather Safety Razor Co., Ltd.), the sample was cut in the MD direction perpendicular to the surface, and a digital microscope [DIGITAL MICROSCOPE manufactured by Keyence Co., Ltd.] was used. ) VHX-900] was used to observe the cross section of the sample and measure the thickness.

[Compression elasticity in the thickness direction when impregnating with serum (compression elasticity when impregnating) (%)]
A sample cut in 5 cm in the MD direction and 5 cm in the CD direction is prepared, and impregnated with 900% of a cosmetic liquid (“Freschel Essence Lotion NA” manufactured by Kanebo Cosmetics Co., Ltd.) with respect to the sample weight, as shown in FIG. The sample 3 was spread on an acrylic plate (measuring table) 4 and allowed to stand, and the initial thickness was measured with a laser displacement meter 1. Next, a load 2 of 260 g / cm ² was placed in the center of the raw fabric (nonwoven fabric) for 60 seconds, and the displacement from immediately after removing the load until 300 seconds was measured. The thickness of the original fabric before measurement is A, the thickness immediately after removing the load is B, and the thickness after 300 seconds after removing the load is C. Obtained according to the formula.

    Compression elasticity (%) with respect to the thickness direction when the cosmetic liquid is impregnated (%) = [(CB) / (AB)] × 100.

[Water retention rate (%)]
It measured according to JIS L1907 7.2 water absorption. A test piece is cut into a 5 cm square and the weight is measured (Ag). The test piece was immersed in water for 30 seconds. After immersion, one side of the test piece was picked up from the liquid and the weight (Bg) after 1 minute was measured. The liquid retention rate (C%) is calculated by the following formula.

    C (%) = [(BA) / A] × 100.

[Liquid return to original fabric (%)]
A sample cut in MD direction 5 cm × CD direction 5 cm was prepared, and impregnated with 900% beauty liquid (“Freschel Essence Lotion NA” manufactured by Kanebo Cosmetics Co., Ltd.) with respect to the sample weight, as shown in FIG. The sample 13 was spread on an acrylic plate (measuring table) 14 and allowed to stand, and a 620 g load 12 was placed on a circular central portion having a diameter of 1.2 cm for 60 seconds, and the serum immediately after the load was removed. The width of the part where there was no was measured. Furthermore, the width | variety of the part which does not have a cosmetic liquid 300 seconds after removing a load was measured. When the width of the part without the cosmetic liquid immediately after removing the load is A, and the width of the part without the cosmetic liquid after 300 seconds after removing the load is B, the liquid return (%) to the original fabric is expressed according to the following formula. Asked.

    Liquid return to original fabric (%) = [(A−B) / A] × 100.

[30% elongation stress when wet (N / 5cm)]
It measured based on the method as described in JIS L1913 (general short fiber nonwoven fabric) 6.3.2 (tensile strength and elongation rate test at the time of wetness). Specifically, the sample is placed in water at 20 ° C. ± 2 ° C. until it settles under its own weight, or after being submerged in water for 1 hour or longer, the sample is taken out from the immersion liquid and quickly stressed at 30% elongation (WET stress). ) Was measured.

[Method for producing core-sheath composite fiber]
(Core-sheath composite fiber A)
An ethylene-vinyl alcohol copolymer having an ethylene content of 44 mol% and an MI value of 12 g / 10 min (“Eval” manufactured by Kuraray Co., Ltd.) is the sheath component, and the melt viscosity at 290 ° C. is 12000 [Pa · s. ] Using a polyester chip (polyethylene terephthalate, manufactured by Kuraray Co., Ltd., intrinsic viscosity = 0.61), using a composite melt spinning apparatus at a temperature of 290 ° C., with a round cross-section die, a composite ratio (core Part / sheath part) = 50/50 (weight ratio). The spun yarn was cooled and solidified, and then wound on a bobbin through a take-up roller at a speed of 1000 m / min to obtain a 5.3 dtex take-up yarn. Next, this crimped yarn was heat-drawn at a drawing temperature of 90 ° C. at a draw ratio of 2.8 times, and after applying an oil agent in an oil agent bath, a mechanical crimping treatment was performed. The mechanical crimping treatment was performed using a normal stuffer type crimping device. Subsequent to the crimping treatment, the fiber is dried with hot air at 150 ° C., and then cut to 51 mm to obtain a single fiber fineness of 1.9 dtex, a number of crimps of 23/25 mm, a short fiber having a Young's modulus of 51.0 cN / T ( A core-sheath composite fiber A) was obtained. Both spinnability and stretchability were good.

(Core-sheath composite fiber B)
The single yarn fineness is 1.9 dtex, the fiber length is 51 mm, the number of crimps is 23/25 mm, except that the draw ratio is 2.4 times and the drying temperature by hot air is 150 ° C. A core-sheath composite fiber B having a Young's modulus of 40.1 cN / T was obtained.

(Core-sheath composite fiber C)
Core-sheath composite fiber A except that the draw ratio is 2.5 times and the drying temperature with hot air is 140 ° C.
In the same manner as in Production Method 1, a core-sheath composite fiber C having a single yarn fineness of 1.9 dtex, a fiber length of 51 mm, a crimp number of 23/25 mm, and a Young's modulus of 30.8 cN / T was obtained.

(Core-sheath composite fiber D)
The single yarn fineness is 1.9 dtex, the fiber length is 51 mm, the number of crimps is 23/25 mm, except that the draw ratio is 2.3 times and the drying temperature with hot air is 140 ° C. A core-sheath composite fiber D having a Young's modulus of 23.3 cN / T was obtained.

[Fiber used]
Tencel fiber: “TENCEL” manufactured by LENZING, fineness of 1.7 dtex, average fiber length of 38 mm, Young's modulus of 19.2 cN / T
Rayon fiber: “Hope” manufactured by Omikenshi Co., Ltd., fineness of 1.7 dtex, average fiber length of 38 mm, Young's modulus of 13.3 cN / T
Polyphenylene sulfide (PPS) fiber: “Procon” manufactured by Toyobo Co., Ltd., 2.2 dtex, Young's modulus 441.0 cN / T
PET fiber: manufactured by Toray Industries, Inc., fineness 1.7 dtex, average fiber length 51 mm, Young's modulus 29.8 cN / T
Cotton fiber: manufactured by Marusan Sangyo Co., Ltd., fineness 1.6 dtex, Young's modulus 12.8 cN / T.

Examples 1-7 and Comparative Examples 1-4
The fibers shown in Table 1 were blended (without blending when a single fiber was used) to produce a card web. Next, a water flow was sprayed on the card web, and an entanglement treatment was performed to obtain a water entangled nonwoven fabric. In addition, the hydroentanglement process used the nozzle with which the orifice of diameter 0.1mm was provided for every 0.6 mm space | interval in the width direction of the web, and water pressure 3-5MPa was injected in 2 steps | paragraphs of back and back, and was entangled.

  Table 1 shows the evaluation results of the nonwoven fabrics obtained in the examples and comparative examples.

  As is clear from the results in Table 1, the nonwoven fabric of the example has a high water retention rate, and both the compression elasticity (compression elasticity at the time of impregnation) and the return in the thickness direction when impregnating the cosmetic liquid are fast, and the nonwoven fabric of the comparative example is fast. In, the compression elasticity during impregnation and the return are slow. In particular, in the comparative example, the liquid return to the original fabric is constant at a low liquid return of about 50% regardless of the ratio of the compression elasticity at the time of impregnation, whereas in the example, it is proportional to the compression elasticity at the time of impregnation. In addition, the liquid return to the original fabric is improved, and in particular, the nonwoven fabric containing 70% by mass or more of the core-sheath conjugate fiber A having a high Young's modulus shows a high liquid return to the original fabric exceeding 80%.

Reference Examples 1-12
In order to further clarify the relationship between the compression elasticity during impregnation and liquid return in Comparative Examples 1 to 4, the fibers shown in Table 2 were blended (without blending when a single fiber was used), and various impregnations were performed. Nonwoven fabrics having time compression elasticity were prepared in the same manner as in Examples 1 to 5 and Comparative Examples 1 to 4. Comparative Examples 1 to 4 are Reference Examples 6, 1, 2, and 10, respectively.

  As is apparent from the results in Table 2, in the nonwoven fabric of the reference example, the liquid return to the original fabric does not occur even though the compression elasticity at the time of impregnation is in a wide range from 3.6% to 56.7%. It is constant at a low level of about 40-50%. This tendency indicates that it is difficult to control the liquid return speed when the compression elasticity during impregnation is within a predetermined range.

  On the other hand, as is apparent from the results in Table 1, in the examples, the compression elasticity during impregnation exceeds 60%, the compression elasticity during impregnation is improved and the liquid return to the original fabric is improved, and the compression elasticity during impregnation is improved. When it exceeds 75%, the liquid return to the original fabric also reaches 80% or more.

  That is, as is apparent from the results of Tables 1 and 2, in the present invention, the nonwoven fabric is formed with a high elastic fiber at a predetermined ratio, and the compression elasticity at the time of impregnation can be adjusted to a predetermined level or higher, so that the original fabric is not used for the first time. However, the effect of such an example is a remarkable effect that cannot be predicted from a nonwoven fabric containing conventional low-elasticity fibers.

  The liquid retaining sheet of the present invention absorbs a liquid component and makes contact with the skin, for example, a body fluid absorbing sheet (for example, a surface material such as a napkin or a diaper, a diaper liner, a wet tissue), a skin care sheet (for example, It can be used for face masks, makeup removing sheets, cleansing sheets or body washing sheets (sweat wiping sheets, oil removing sheets, cooling sheets, etc.), medicinal sheets (stagnation suppression sheets, poultices, etc.), etc. The sheet is impregnated with liquid ingredients such as cosmetic liquids (cosmetics), and even when pressed with a finger, the liquid ingredients quickly return, so the entire face, nose, eyes, mouth, neck, etc. are moisturized and whitened. Useful for face masks impregnated with ingredients.

DESCRIPTION OF SYMBOLS 1 ... Laser displacement meter 2,12 ... Load 3,13 ... Sample 4,14 ... Measuring stand

Claims (10)

  A liquid retention sheet formed of a nonwoven fabric containing 50% by mass or more of high-elasticity fibers having a Young's modulus of 30 cN / T or more.   The liquid-retaining sheet according to claim 1, wherein the highly elastic fiber is a core-sheath type composite fiber.   The liquid retention sheet according to claim 2, wherein the sheath portion of the core-sheath composite fiber is formed of an ethylene-vinyl alcohol copolymer, and the core portion is formed of a hydrophobic resin.   The liquid retaining sheet according to claim 3, wherein the hydrophobic resin is a polyester resin.   The liquid retention sheet according to any one of claims 1 to 4, wherein an average fineness of the highly elastic fiber is 1.5 to 10 dtex.   The liquid-retaining sheet according to any one of claims 1 to 5, wherein the highly elastic fiber is a fiber obtained by stretching 2.0 times or more at a temperature of 80 ° C or higher.   Furthermore, it contains a cellulosic fiber having an average fineness of 0.3 to 5 dtex, and the mass ratio of the high elastic fiber to the cellulosic fiber is high elastic fiber / cellulosic fiber = 60/40 to 80/20. The liquid-retaining sheet according to any one of the above.   The liquid retention sheet according to any one of claims 1 to 7, which is a skin care sheet impregnated with a liquid component containing a cosmetic.   It is a face mask, The liquid retention sheet in any one of Claims 1-8. 10. The amount of reversion to compression in the thickness direction is 60% or more in 5 minutes when the cosmetic liquid is impregnated with 900 mass% with respect to its own weight and a load of 260 g / cm ² is applied and removed for 1 minute. The liquid retaining sheet according to any one of the above.

Images