Hydrogel

Abstract

The present invention provides a hydrogel comprising the following components (A), (B), (C) and (D): (A) Anionic polymer (B) Trivalent metal salt and / or borate (C) A nonionic surfactant with an IOB value of 0.1 or more and 2 or less. (D)Water

Description

[Technical Field]

[0001] This invention relates to a hydrogel. [Background technology]

[0002] In China, as the number of facial mask products increased, consumers gradually became more aware of the different types of facial masks available and began using them as an essential part of their skincare routine. In particular, facial masks impregnated with essence into non-woven fabric offer high skincare benefits, but they are inconvenient to use because you have to repeatedly adjust their position to ensure they adhere well to your face. Furthermore, because the essence must seep out of the non-woven fabric to provide its skincare benefits, these facial masks have a very sticky texture, which has drawn criticism from consumers.

[0003] On the other hand, there are also gel-type facial mask materials, which are usually only suitable for applying to specific areas of the face, such as around the eyes, and use materials that cannot be reshaped, thus failing to meet the diverse needs of consumers. Therefore, consumers are looking for facial masks that are comfortable to use, do not cause dryness or stickiness, maintain their original skincare functions, and can be conveniently applied to any part of the face. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Chinese Patent Application Publication No. 110430859 Specification [Patent Document 2] Chinese Patent Application Publication No. 101002722 Specification [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] In view of the above, the present invention aims to provide a hydrogel that has the excellent effect of being free from stickiness and dryness, provides a good feel and usability, and can be easily applied to any position on the face. [Means for solving the problem]

[0006] The inventors have found that by including a nonionic surfactant in the hydrogel, the feeling of dryness and stickiness can be improved, and a hydrogel that does not feel sticky or dry when applied to the skin can be obtained.

[0007] The present invention provides a hydrogel containing the following components (A), (B), (C), and (D). (A) Anionic polymers (B) Trivalent metal salts and / or borates (C) Nonionic surfactants with an IOB value between 0.1 and 2. (D)Water

[0008] The mechanism by which the hydrogel of the present invention achieves the excellent effects of being free from stickiness and dryness has not yet been elucidated, but the following is considered possible. In other words, the main reason why hydrogels cause a feeling of dryness is the presence of trivalent metal ions or borate anions in the hydrogel. However, when a nonionic surfactant is included in the hydrogel, the lipophilic ends of the surfactant exhibit good affinity to the skin, thereby reducing the feeling of congestion caused by ions. Furthermore, when a surfactant is added, the hydrogel becomes lubricated, improving the feeling of stickiness.

[0009] Furthermore, the present invention provides for the use of hydrogels as topical skin preparations. Furthermore, the present invention provides a skincare method for applying the hydrogel of the present invention to the skin. [Modes for carrying out the invention]

[0010] Hereinafter, the hydrogel of the present invention, its manufacturing method, and its usage method will be described in detail respectively.

[0011] <Hydrogel> [Component (A)] Component (A) used in the present invention is an anionic polymer. Since a certain amount of polar groups are contained in its molecular chain, it can form a large network structure with specific ions by bonding modes such as hydrogen bonds, ionic bonds, or coordination bonds.

[0012] Examples of the anionic polymer of component (A) include one or more selected from the following components (A1), (A2), and (A3). (A1) Anionic polyvinyl alcohol (A2) An acrylic copolymer obtained by polymerizing at least one monomer selected from acrylic acid, methacrylic acid, and acrylic acid alkyls having 1 to 30 carbon atoms (A3) Carboxymethyl cellulose

[0013] The carboxyl groups present in components (A1), (A2), and (A3) are polar groups. When other ions are present in the solution, the carboxyl groups can combine with other ions to form a three-dimensional network structure.

[0014] Ingredients(A1) The hydrogel of the present invention contains anionic polyvinyl alcohol as component (A1). Component (A1) is, for example, polyvinyl alcohol having an anionic group such as a sulfonic acid group, a sulfuric acid group, a carboxyl group, a phosphoric acid group, or a phosphonic acid group. From the viewpoint of further suppressing the sticky feeling, component (A1) is preferably polyvinyl alcohol having at least one anionic group of a sulfonic acid group and a carboxyl group, and more preferably polyvinyl alcohol having a carboxyl group. Here, in this specification, an anionic group refers to an anionic group itself or a group that can be ionized to become an anionic group. Examples of the polyvinyl alcohol having a carboxy group include those obtained by (1) graft polymerization or block polymerization of polyvinyl alcohol and an unsaturated monomer having a carboxy group, (2) copolymerization of a vinyl ester compound and an unsaturated monomer having at least one selected from a carboxy group and a carboxylic acid ester group, followed by saponification, (3) polymerization of a vinyl ester compound using a chain transfer agent having a carboxy group, followed by saponification, and (4) reaction of polyvinyl alcohol with a carboxylating agent.

[0015] Examples of the unsaturated monomer having a carboxy group used in the methods (1) and (2) above and the unsaturated monomer having a carboxylic acid ester group used in the method (2) include ethylenically unsaturated dicarboxylic acids such as maleic acid, fumaric acid, and itaconic acid; ethylenically unsaturated dicarboxylic acid monoesters such as maleic acid monoalkyl ester, fumaric acid monoalkyl ester, and itaconic acid monoalkyl ester; ethylenically unsaturated dicarboxylic acid diesters such as maleic acid dialkyl ester, fumaric acid dialkyl ester, and itaconic acid dialkyl ester; ethylenically unsaturated carboxylic acid anhydrides such as maleic anhydride and itaconic anhydride; unsaturated monocarboxylic acids such as (meth)acrylic acid; and unsaturated monocarboxylic acid esters such as (meth)acrylic acid alkyl ester. Further, salts of the above compounds may be used as the unsaturated monomer having at least one selected from a carboxy group and a carboxylic acid ester group. These compounds may be used alone or in combination of two or more.

[0016] Examples of the vinyl ester compound used in the methods (2) and (3) above include vinyl acetate, vinyl formate, vinyl propionate, vinyl versatate, and vinyl pivalate. Among these, vinyl acetate is preferable from the viewpoints of reactivity during synthesis and availability. These compounds may be used alone or in combination of two or more.

[0017] Examples of carboxylating agents used in the method described in (4) above include succinic anhydride, maleic anhydride, acetic anhydride, trimellitic anhydride, phthalic anhydride, pyromellitic anhydride, glutaric anhydride, hydrogenated phthalic anhydride, naphthalenedicarboxylic anhydride, and other carboxylic acid anhydrides. These may be used individually or in combination of two or more.

[0018] The amount of anionic groups in anionized polyvinyl alcohol (the proportion derived from monomers having anionic groups) is preferably 0.1 mol% or more, more preferably 0.5 mol% or more, and even more preferably 1 mol% or more, from the viewpoint of further suppressing stickiness and improving water retention and gel strength, and preferably 10 mol% or less, more preferably 5 mol% or less, and even more preferably 3 mol% or less, from the viewpoint of further improving adhesion and improving water supply and moisturizing sensation when applied to the skin.

[0019] The amount of anionic groups in anionized polyvinyl alcohol can be determined by analyzing the anionized polyvinyl alcohol before saponification using 1H-NMR (solvent: CDCl3).

[0020] The degree of saponification of anionized polyvinyl alcohol is 90 mol% or higher, more preferably 95 mol% or higher, and even more preferably 98 mol% or higher, from the viewpoint of further suppressing stickiness and improving water retention and gel strength. The upper limit of the degree of saponification is not particularly limited, but for example, it is 100.0 mol% or lower, preferably 99.9 mol% or lower, and more preferably 99.5 mol% or lower. The degree of saponification of anionized polyvinyl alcohol is measured in accordance with JIS K6726:1994.

[0021] The degree of polymerization of anionized polyvinyl alcohol is preferably 100 or more, more preferably 500 or more, and even more preferably 1,000 or more, from the viewpoint of further suppressing stickiness and improving water retention and gel strength, and preferably 200,000 or less, more preferably 10,000 or less, and even more preferably 4,000 or less, from the viewpoint of further improving adhesion and improving flexibility and elongation. The degree of polymerization of anionized polyvinyl alcohol can be calculated from the relative viscosity of a fully saponified aqueous solution of polyvinyl alcohol and water (see JIS K6726:1994).

[0022] Specific examples of anionized polyvinyl alcohol include KL-118, KL-318, KL-506, KM-118, and KM-618 manufactured by Kuraray Co., Ltd.; Gosenex CKS50, Gosenex T-330H, Gosenex T-330, and Gosenex T-350 manufactured by Mitsubishi Chemical Corporation; and AP-17, AT-17, and AF-17 manufactured by Nippon Vinegar-Poval Co., Ltd.

[0023] The component (A1) of the present invention may be used alone or in combination of two or more components.

[0024] From the viewpoint of obtaining suitable hardness, the viscosity of a 4% aqueous solution of component (A1) anionic polyvinyl alcohol at 20°C (measured using a Brookfield viscometer under measurement conditions of an S61 rotor and a rotation speed of 20 rpm) is preferably 10 mPa·s or more, more preferably 20 mPa·s or more, and even more preferably 25 mPa·s or more. From the viewpoint of obtaining suitable flexibility, the viscosity is preferably 50 mPa·s or less, more preferably 40 mPa·s or less, and even more preferably 35 mPa·s or less. Therefore, from the viewpoint of combining suitable hardness and flexibility, the viscosity is preferably 10 to 50 mPa·s, more preferably 20 to 40 mPa·s, and even more preferably 25 to 35 mPa·s.

[0025] From the viewpoint of obtaining suitable hardness, in the hydrogel of the present invention, the content of component (A1) is 5% by mass or more, preferably 8% by mass or more, and 20% by mass or less, preferably 12% by mass or less. In short, in the hydrogel of the present invention, the content of component (A1) is 5% by mass or more and 20% by mass or less, preferably 8% by mass or more and 12% by mass or less.

[0026] Ingredient (A2) Component (A2) is an acrylic polymer obtained by polymerizing at least one monomer selected from acrylic acid, methacrylic acid, and alkyl (meth)acrylates having 1 to 30 carbon atoms in the alkyl group. The acrylic polymer as component (A2) includes polyacrylic acid and sodium polyacrylate, crosslinked sodium polyacrylate, carbomer, and acrylic resin.

[0027] Polyacrylic acid is a polymer formed by the addition polymerization of acrylic acid monomers, and sodium polyacrylate is obtained by neutralizing polyacrylic acid with sodium hydroxide. The polyacrylic acid and sodium polyacrylate have a molecular weight of preferably 100 to 4,000,000 and a viscosity of preferably 100 to 50,000 mPa·s (0.5% aqueous, 25°C, using a Brookfield viscometer with S61 to S64 rotors, the specific rotor and rotation speed are selected according to the viscosity of the sample being measured). Commercially available products include Merck's 323667, 181285, 306215, 306231, 306223, 447013, 420344, 81123, etc., Nihon Junyaku's AC-10H and Jurymer AC-10LHP, Synthron's Modarez V 1300 PX, Orient Stars' Oristar PALA, and CIT's Creagel TN 500, etc. Carbomer is a polyacrylic acid polymer and a high molecular weight crosslinked homopolymer. The viscosity is preferably 500 to 80,000 mPa·s (measured using a Brookfield viscometer with a Brookfield viscometer, using S61 to S64 rotors, with the specific rotor and rotation speed selected according to the viscosity of the sample being measured). Commercially available examples include Lubrizol's Ultrez 10, Ultrez 21, and Ultrez 30.

[0028] Acrylate copolymers are polymers obtained by copolymerizing monomers such as methacrylate, acrylate, and acrylic acid in a certain ratio. In the present invention, all methacrylates and acrylates are alkyl (meth)acrylates in which the alkyl group has 1 to 30 carbon atoms, and among these, methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, and C10 to 30 alkyl acrylates are preferred. The acrylate copolymer has a viscosity of preferably 100 to 80,000 mPa·s (0.2% aqueous solution, 25°C, pH adjusted to neutral with KOH, using a Brookfield viscometer with S61 to S64 rotors, the specific rotor and rotation speed selected according to the viscosity of the sample to be measured). Commercially available examples include Pemuren TR-1, Pemuren TR-2, SF-1, SF-2, ETD 2020 from Lubrizol, and ACULYN 88, ACULYN 22, ACULYN 28, ACULYN 38 from Rohm and Haas.

[0029] From the viewpoint of obtaining suitable hardness, in the hydrogel of the present invention, the content of component (A2) is 0.1% by mass or more and 20% by mass or less, preferably 15% by mass or less. In short, in the hydrogel of the present invention, the content of component (A2) is 0.1% by mass or more and 20% by mass or less, preferably 0.1% by mass or more and 15% by mass or less.

[0030] Ingredient (A3) Component (A3) is carboxymethylcellulose (CMC), a cellulose ether compound obtained by carboxymethylation of cellulose.

[0031] From the viewpoint of obtaining suitable hardness, the viscosity of a 1% aqueous solution of component (A3) carboxymethylcellulose at 20°C (using a Brookfield viscometer with S61-S64 rotors, the specific rotor and rotation speed are selected according to the viscosity of the aqueous solution) is 200 mPa·s or higher. From the viewpoint of obtaining suitable flexibility, the viscosity is preferably 5000 mPa·s or lower. Therefore, from the viewpoint of combining suitable hardness and flexibility, the viscosity is preferably 200-5000 mPa·s.

[0032] Examples of commercially available carboxymethylcellulose include Ashland's Aqualon, Blanose, and Bondwell series, such as TH10A and 9H4FU.

[0033] From the viewpoint of obtaining suitable hardness, in the hydrogel of the present invention, the content of component (A3) is 0.2% by mass or more, preferably 0.5% by mass or more, 20% by mass or less, and preferably 15% by mass or less. In short, in the hydrogel of the present invention, the content of component (A3) is 0.2% by mass or more and 20% by mass or less, preferably 0.5% by mass or more and 15% by mass or less.

[0034] In the present invention, component (A) is one or more selected from components (A1), (A2), and (A3), and preferably, component (A) is polyvinyl alcohol.

[0035] From the viewpoint of obtaining a gel with a suitable viscosity, the total content of component (A) is 0.1% by mass or more and 30% by mass or less, preferably 20% by mass or less. In short, in the hydrogel of the present invention, the total content of component (A) is 0.1% by mass or more and 30% by mass or less, preferably 0.5% by mass or more and 20% by mass or less.

[0036] [Component (B)] The component (B) used in the present invention is one or more selected from trivalent metal salts and borates. The trivalent metal salt of component (B) used in this invention is iron ion (Fe 3+Iron salts containing ) manganese ions (Mn 3+ ) containing manganese salts, chromium ions (Cr 3+ Chromium salts containing ) and aluminum ions (Al 3+ Examples include aluminum salts containing aluminum ions (Al), and among them, aluminum ions (Al) are readily available. 3+ Aluminum salts containing ) are preferred.

[0037] Examples of aluminum salts include one or more selected from aluminum chloride, potassium alum, ammonium alum, aluminum acetate, aluminum magnesium methylsilicate, aluminum magnesium silicate, aluminum magnesium metasilicate, EDTA aluminum, aluminum allantoinate, aluminum hydroxide, aluminum magnesium hydroxide, p-hydroxyaluminum glycine, aluminum sulfate, potassium aluminum sulfate, aluminum lactate, dihydroxyaluminum aminoacetate, aluminum glycinate, aluminum oxide, and aluminum borate.

[0038] Among these, from the viewpoint of ease of availability, aluminum chloride, potassium alum, ammonium alum, aluminum acetate, aluminum magnesium methylsilicate, aluminum allantoinate, aluminum sulfate, potassium aluminum sulfate, aluminum lactate, dihydroxyaluminum aminoacetate, and aluminum glycinate are preferred, aluminum chloride, aluminum sulfate, potassium alum, and aluminum glycinate are more preferred, and aluminum chloride and aluminum sulfate are even more preferred.

[0039] The borate in component (B) used in the present invention mainly consists of tetraborate (M[B4O5(OH)4], where M is sodium, potassium, or ammonium) and pentaborate (M[B5O6(OH)4], where M is sodium, potassium, or ammonium). From the viewpoint of availability, sodium tetraborate is preferred. A commercially available example is BORAX manufactured by Wako Pure Chemical Industries, Ltd.

[0040] When dissolving borate in water to form an aqueous borate solution, the borate anions present in the aqueous solution are mainly [B(OH)4] - , [B3O3(OH)4] - , [B4O5(OH)4] 2- , [B5O6(OH)4] - and the like are included.

[0041] When mixing an aqueous solution of the anionic polymer of component (A1) with an aqueous solution of the borate of component (B), an irreversible gelation reaction occurs. Among them, the trivalent boron ions in the borate form a covalent coordination bond with the hydroxyl groups in component (A1) to form a network gel.

[0042] The hydrogel formed by connecting covalent coordination bonds has good hardness and ductility, and can maintain its shape even when pasted on the skin for a long time.

[0043] Component (B) is dissolved in water and used as an aqueous solution. And component (B) may be used alone or in combination of two or more. From the viewpoint of obtaining the ductility of the hydrogel, in the hydrogel of the present invention, the content of component (B) is 0.2% by mass or more and 3% by mass or less. In short, in the hydrogel of the present invention, the content of component (B) is 0.2% by mass or more and 3% by mass or less.

[0044] Therefore, from the viewpoint of obtaining the stability of the network structure of the hydrogel, the relationship between component (B) and component (A) is that the ratio of the molar amount of the trivalent metal ions contained in component (B) to the molar amount of the carboxyl groups contained in component (A) ((molar amount of trivalent metal ions in (B)) / (molar amount of carboxyl groups in (A))) is 0.5 to 10, preferably 3 to 6. This ratio is obtained by the following method. First, the trivalent metal ions in component (B) are obtained from the method of calculating the molar amount of the trivalent metal ions in component B and are represented by M1. Next, the molar amount of the anionic groups in component (A) is obtained by the method of measuring the molar amount of the carboxylic acid groups in component (A1) and is represented by M2. Dividing M1 by M2 gives the above-mentioned molar ratio.

[0045] On the other hand, from the viewpoint of obtaining stability of the hydrogel's net-like structure, the mass ratio of component (B) to component (A) (content of (B) / content of component (A)) is 0.001 to 0.5, preferably 0.01 to 0.06.

[0046] [Component (C)] The component (C) used in this invention is a nonionic surfactant having an IOB value of 0.1 or more and 2 or less. Nonionic surfactants with an IOB value of 2 or less possess surfactant activity and exhibit amphiphilicity (both hydrophilic and lipophilic). When added to a gel system, the lipophilic ends of the nonionic surfactant provide a soft and smooth feel, exhibiting strong affinity to the skin and playing a role in improving stickiness and dryness. If the IOB value is greater than 2, the surfactant activity of the nonionic surfactant decreases and its solubility in water increases, but the soft and smooth feel exhibited by its lipophilic ends decreases, and the effect of improving dryness is not good. If the IOB value is less than 0.1, it is undesirable for the stability of the gel system. From the viewpoint of obtaining the effect of a hydrogel that does not feel sticky or dry, the IOB value of the nonionic surfactant is 2.0 or less, preferably 1 to 1.5, and more preferably 1.16 to 1.37. From the viewpoint of obtaining the stability of the gel system, the IOB value of the nonionic surfactant is 0.1 or more.

[0047] Examples of nonionic surfactants for component (C) include PEG fatty acid esters, PEG hydrogenated castor oil, PEG fatty acid glycerides, PPG glucose polyethers, PPG polyglyceryl ethers, polyglycerin fatty acid esters, PEG polydimethylsiloxane, sorbitan fatty acid esters, PEG sorbitan fatty acid esters, aliphatic alcohol polyethers, glucosides, etc., among which PEG fatty acid esters and PEG fatty acid glycerides are preferred.

[0048] The nonionic surfactants in component (C) specifically include PPG-9 dipolyglycerol ether (IOB value: 0.90), PPG-10 methyl glucose ether (IOB value: 0.95), PEG-7 glycerol cocoate (IOB value: 1.16), PEG-6 caprylic / capric glyceride (IOB value: 1.25), PEG-60 castor oil (IOB value: 1.36), PEG-12 laurate (IOB value: 1.37), polyglycerol-6 distearate (IOB value: 0.76), PEG-11 methyl ether polydimethylsiloxane (IOB value: 1.45), sorbitan laurate (IOB value: 0.86), and PEG-6 Examples include sorbitan stearate (IOB value: 0.96), polysorbate-40 (IOB value: 1.56), laureth-9 (IOB value: 1.34), ceteth-13 (IOB value: 1.42), and decyl glucoside (IOB value: 1.57).

[0049] Component (C) can be used as a single component or in combination of two or more components. From the viewpoint of obtaining the effect of the hydrogel not feeling dry or sticky, its content is 2.0% by mass or more, preferably 3.0% by mass or more, and 10.0% by mass or less, preferably 5.0% by mass or less, in the total composition. In short, in the hydrogel of the present invention, the content of component (C) is 2.0% by mass or more and 10.0% by mass or less, preferably 2.0% by mass or more and 5.0% by mass or less, more preferably 2.0% by mass or more and 4.0% by mass or less.

[0050] Furthermore, from the viewpoint of improving both stickiness and dryness, the mass ratio of the content of component (C) to the content of component (A) [content of component (C) / content of component (A)] is 0.15 to 2.0, preferably 0.15 to 0.5.

[0051] [Component (D)] The component (D) used in this invention is water. The component (D) water used in this invention includes water commonly used in the cosmetics field, such as deionized water, distilled water, high-purity water, and ultra-high-purity water. In the present invention, from the viewpoint of maintaining the shape of the hydrogel well and from the viewpoint of improving the dryness and stickiness of the hydrogel, the content of component (D) water in the hydrogel is 60% by mass or more, preferably 70% by mass or more, and 97% by mass or less, preferably 95% by mass or less. In short, in the hydrogel of the present invention, the content of component (D) water is 60% by mass or more and 97% by mass or less, preferably 70% by mass or more and 95% by mass or less.

[0052] Furthermore, in the hydrogel of the present invention, water may be specially added water or water contained in other raw materials (for example, water contained in components (A) to (C)).

[0053] [Other ingredients] The hydrogel of the present invention may also contain polyols with a molecular weight of 50 to 380. From the viewpoint of minimizing the impact on hydrogel viscosity, alcohols with alkyl groups in the main chain are preferred, more preferably diols, and even more preferably diols having non-adjacent hydroxyl structures in the main chain. Examples of polyols with a molecular weight of 50 to 380 include 1,2-propanediol, 1,3-propanediol, glycerin, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, dipropylene glycol, and trehalose. Of these, one or more of 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,2-propanediol, glycerin, and trehalose are preferred, and one or more of 1,3-propanediol, 1,3-butanediol, and 1,4-butanediol are more preferred, as they have little effect on the hydrogel viscosity and ensure the appropriate viscosity of the hydrogel.

[0054] From the viewpoint of the stability of the hydrogel, the polyol content is 0.1% by mass or more of the total composition, preferably 2% by mass or more, more preferably 5% by mass or more, preferably 27% by mass or less, preferably 20% by mass or less, more preferably 16.5% by mass or less, even more preferably 10% by mass or less, and even more preferably 8% by mass or less.

[0055] Furthermore, in the hydrogel of the present invention, in addition to the above-mentioned components, ingredients commonly used in cosmetics, such as moisturizers, whitening agents, blood circulation promoters, anti-inflammatory agents, bactericides, UV absorbers, colorants, preservatives, antioxidants, fragrances, pH adjusters, and chelating agents, may be used, as long as they do not affect the effects of the present invention.

[0056] <Method for preparing hydrogels> The following is an example of a method for preparing the hydrogel of the present invention. Specifically, components (A), (C), and (D) are mixed to form an aqueous solution, component (B) is dissolved in component (D) to form an aqueous solution, and then the aqueous solution of component (B) is added to the aqueous solutions of components (A) and (C), stirred, and left to stand to obtain a hydrogel.

[0057] While viscosity is not limited, the viscosity of the hydrogel of the present invention at room temperature (25°C) is preferably 500 Pa·s or more and 8000 Pa·s or less.

[0058] The hydrogel of the present invention can be easily removed without remaining in the package, even when filled in a tubular or pouch-shaped package that is easy to carry. The hydrogel of the present invention is used by applying it to any part of the skin, preferably the face, body, hands, and feet, other than the scalp. It can be freely stretched and spread during use, has a good fit to the skin, excellent moisturizing properties, does not feel sticky or dry, and peels off easily from the skin after use.

[0059] <How to use hydrogels> The hydrogel of the present invention can be applied to the skin as a topical agent in any case, thereby achieving skincare. Specifically, when using it, the hydrogel can be stretched to an appropriate size and then applied to the skin, or the hydrogel can be applied to the skin first, then held on the skin for a certain period of time, preferably 1 minute to 2 hours, more preferably 5 minutes to 1 hour, and then stretched to an appropriate size. After use, it can be easily peeled off, thereby providing a good skincare effect. Furthermore, the hydrogel can be used in conjunction with massage, which can be done directly by hand or using tools such as a sponge.

[0060] Furthermore, the present invention provides a method for moisturizing the skin by applying the hydrogel of the present invention to the skin.

[0061] Hereinafter, preferred embodiments of the present invention will be further disclosed with respect to the above-mentioned embodiments. <1> A hydrogel containing the following components (A), (B), (C), and (D). (A) Anionic polymers (B) Trivalent metal salts and / or borates (C) Nonionic surfactants with an IOB value between 0.1 and 2. (D)Water

[0062] <2> Component (A) is one or more selected from the following components (A1), (A2), and (A3), as described above. <1> The hydrogel described above. (A1) Anionic polyvinyl alcohol (A2) Acrylic copolymers obtained by polymerizing at least one monomer selected from acrylic acid, methacrylic acid, and alkyl (meth)acrylates having 1 to 30 carbon atoms in the alkyl group. (A3) Carboxymethylcellulose

[0063] <3> (A1) The viscosity of a 4% aqueous solution of anionic polyvinyl alcohol at 20°C is 10 mPa·s or more, more preferably 20 mPa·s or more, even more preferably 25 mPa·s or more, and preferably 50 mPa·s or less, more preferably 40 mPa·s or less, even more preferably 35 mPa·s or less, and preferably 10 to 50 mPa·s, more preferably 20 to 40 mPa·s, even more preferably 25 to 35 mPa·s. <2> The hydrogel described above.

[0064] <4> In the hydrogel, the content of component (A1) is 5% by mass or more and 20% by mass or less, preferably 12% by mass or less; and the content of component (A1) is 5% by mass or more and 20% by mass or less, preferably 8% by mass or more and 12% by mass or less, the same <2> or <3> The hydrogel described above.

[0065] <5> Component (A2) is one or more selected from polyacrylic acid and sodium polyacrylate, carbomer, methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, and C10-30 alkyl acrylate, as described above. <2> ~ <4> A hydrogel as described in any one of the items.

[0066] <6> In the hydrogel, the content of component (A2) is 0.1% by mass or more and 20% by mass or less, preferably 15% by mass or less, and further, the content of component (A2) is 0.1% by mass or more and 20% by mass or less, preferably 0.1% by mass or more and 15% by mass or less, the above <2> ~ <5> A hydrogel as described in any one of the items.

[0067] <7> The viscosity of a 1% aqueous solution of component (A3) carboxymethylcellulose at 20°C is 200 mPa·s or more, preferably 5000 mPa·s or less, and more preferably 200 to 5000 mPa·s. <2> ~ <6> A hydrogel as described in any one of the items.

[0068] <8> In the hydrogel, the content of component (A3) is 0.2% by mass or more and 20% by mass or less, preferably 15% by mass or less; furthermore, in the hydrogel, the content of component (A3) is 0.2% by mass or more and 20% by mass or less, preferably 0.5% by mass or more and 15% by mass or less, the above <2> ~ <7> A hydrogel as described in any one of the items.

[0069] <9> In the hydrogel, the total content of component (A) is 0.1% by mass or more, preferably 0.5% by mass or more, and 30% by mass or less, preferably 20% by mass or less, and furthermore, the content of component (A) is 0.1% by mass or more and 30% by mass or less, preferably 0.5% by mass or more and 20% by mass or less, as described above. <1> ~ <8> A hydrogel as described in any one of the items.

[0070] <10> Component (B) is iron ions (Fe 3+ Iron salts containing ) manganese ions (Mn 3+ ) containing manganese salts, chromium ions (Cr 3+ Chromium salts containing ) and aluminum ions (Al 3+ One or more aluminum salts selected from those containing ) Component (B) is preferably an aluminum salt and / or a borate. Component (B) is more preferably one or more selected from aluminum chloride, potassium alum, ammonium alum, aluminum acetate, aluminum magnesium methylsilicate, aluminum magnesium silicate, aluminum magnesium metasilicate, EDTA aluminum, aluminum allantoinate, aluminum hydroxide, aluminum magnesium hydroxide, p-hydroxyaluminum glycine, aluminum sulfate, potassium aluminum sulfate, aluminum lactate, dihydroxyaluminum aminoacetate, aluminum glycinate, aluminum oxide, aluminum borate, sodium tetraborate, potassium tetraborate, ammonium tetraborate, sodium pentaborate, potassium pentaborate, and ammonium pentaborate. <1> ~ <9> A hydrogel as described in any one of the items.

[0071] <11> In the hydrogel, the content of component (B) is 0.2% by mass or more and 3% by mass or less in terms of the amount converted to sodium borate, and further, in the hydrogel, the content of component (B) is 0.2% by mass or more and 3% by mass or less in terms of the amount converted to sodium borate, the above <1> ~ <10> A hydrogel as described in any one of the items.

[0072] <12> The ratio of the molar amount of trivalent metal ions in component (B) to the molar amount of anionic groups in component (A) is 0.5 to 10, preferably 3 to 6, and the mass ratio of component (B) to component (A) is 0.001 to 0.5, preferably 0.01 to 0.06. <1> ~ <11> A hydrogel as described in any one of the items.

[0073] <13> The nonionic surfactant having an IOB value of 0.1 or more and a component (C) of 2 or less is preferably one or more selected from PEG fatty acid esters, PEG hydrogenated castor oil, PEG fatty acid glycerides, PPG glucose polyethers, PPG polyglyceryl ethers, polyglycerin fatty acid esters, PEG polydimethylsiloxanes, sorbitan fatty acid esters, PEG sorbitan fatty acid esters, aliphatic alcohol polyethers, and glucosides. <1> ~ <12> A hydrogel as described in any one of the items.

[0074] <14> The IOB value of the nonionic surfactant of component (C) is preferably 1 to 1.5, more preferably 1.16 to 1.37. <1> ~ <13> A hydrogel as described in any one of the items.

[0075] <15> In the hydrogel, the content of component (C) is 2.0% by mass or more, preferably 3.0% by mass or more, and 10.0% by mass or less, preferably 5.0% by mass or less. Furthermore, in the hydrogel, the content of component (C) is 2.0% by mass or more and 10.0% by mass or less, preferably 2.0% by mass or more and 5.0% by mass or less, more preferably 2.0% by mass or more and 4.0% by mass or less. <1> ~ <14> A hydrogel as described in any one of the items.

[0076] <16> The mass ratio of the content of component (C) to the content of component (A) [content of component (C) / content of component (A)] is 0.15 to 2.0, preferably 0.15 to 0.5. <1> ~ <15> A hydrogel as described in any one of the items.

[0077] <17> The water content of component (D) in the hydrogel is 60% by mass or more, preferably 70% by mass or more, and 97% by mass or less, preferably 95% by mass or less. Furthermore, the water content of component (D) in the hydrogel is 60% by mass or more and 97% by mass or less, preferably 70% by mass or more and 95% by mass or less. <1> ~ <16> A hydrogel as described in any one of the items.

[0078] <18> The viscosity of the hydrogel at room temperature (25°C) is between 500 Pa·s and 8000 Pa·s. <1> ~ <17> A hydrogel as described in any one of the items.

[0079] <19> The aforementioned <1> ~ <18> Use of the hydrogel as a topical skin preparation as described in any one of the items.

[0080] <20> The aforementioned <1> ~ <18> A skincare method that involves applying a hydrogel described in any one of the items to the skin for skincare purposes.

[0081] <21> The aforementioned <1> ~ <18> A method for moisturizing the skin by applying a hydrogel described in any one of the items to the skin. [Examples]

[0082] The present invention will be described in more detail below using examples and comparative examples. However, the present invention is not limited to the following examples. The amounts of each component are given in mass percent.

[0083] 1. Preparation method According to the compositions shown in Tables 1-3 (the values ​​in Table 1 indicate the content of the active ingredients), components (A), (C), and optional components other than (A) were dispersed in deionized water at room temperature, stirred in a water bath at 80°C or higher to dissolve all of them, cooled to room temperature to replenish evaporated water, then an aqueous solution of component (B) was added, and the resulting mixture was manually stirred to gel components (A) and (B). After standing, it was stirred again to obtain a hydrogel.

[0084] 2. Evaluation of user experience (1) Evaluation of the effect on improving dryness A sensory evaluation method was used. Two g each of a control group sample without the addition of a nonionic surfactant and comparative samples of the examples and comparative examples of the present invention with the addition of a nonionic surfactant were taken. Participants rubbed the samples with their fingers and perceived the difference between them. The difference in dryness was evaluated according to the following scoring criteria. There were 10 subjects, and each person evaluated and scored the dryness of the control group sample and the examples and comparative examples of the present invention. Finally, the average of the scores of the 10 subjects was taken.

[0085] 3. Compared to the control group, the comparison sample shows improvement. Two points: The comparison sample shows slight improvement compared to the control group. 1 point: There is no improvement in the comparison sample compared to the control group.

[0086] (2) Evaluation of the effect on improving stickiness A sensory evaluation method was used. Two g each of a control group sample (without the addition of a nonionic surfactant) and comparative samples of the examples and comparative examples of the present invention (with the addition of a nonionic surfactant) were taken. Participants pressed the samples with their fingers to feel the difference between them. The difference in stickiness was evaluated according to the following scoring criteria. There were 10 subjects, and each person evaluated and scored the stickiness of the control group sample and the examples and comparative examples of the present invention. Finally, the average of the scores of the 10 subjects was taken.

[0087] 3. Compared to the control group, the comparison sample shows improvement. Two points: The comparison sample shows slight improvement compared to the control group. 1 point: There is no improvement in the comparison sample compared to the control group.

[0088] [Table 1]

[0089] [Table 2]

[0090] [Table 3]

[0091] Tables 1 to 3 show that the hydrogel of the present invention has the excellent effect of being free from stickiness and dryness, achieving a good feel and usability.

[0092] (Note) The components listed in Tables 1 to 3 are as follows: Polyvinyl alcohol: GOHSENX T-330H (active ingredient content: 96%), manufactured by Mitsubishi Chemical Corporation. Aluminum chloride: Manufactured by Sinopharm Chemical Reagent Co., Ltd. Aluminum sulfate: Manufactured by Sinopharm Chemical Reagent Co., Ltd. Aluminum glycinate: Manufactured by Sinopharm Chemical Reagent Co., Ltd. Borax: Manufactured by Ken-ei Pharmaceutical Co., Ltd. PPG-9 Dipolyglyceryl Ether: Product name SY-DP9 (Active ingredient content: 100%), manufactured by Sakamoto Yakuhin Kogyo Co., Ltd. PPG-10 Methyl Glucose Ether: Product name MACBIO BRIDE MG-10P (Active ingredient content: 100%), manufactured by Nippon Oil & Fats Co., Ltd. PEG-7 Glyceryl Cocoate: Product name CETIOL HE (active ingredient content: 100%), manufactured by BASF SE. PEG-6 Caprylic / Capric Glyceride: Trade name TEGOSOFT GMC 6 (Active ingredient content: 100%), manufactured by Evonik Operations GmbH. PEG-60 Castor Oil: Product name NIKKOL HCO-60 (Active ingredient content: 100%), manufactured by Nippon Surfactant Industries Co., Ltd. PEG-12 Laurate Ester: Product name EMANON 1112 (Active ingredient content: 100%), manufactured by Kao Corporation. Methylglucitol polyether-20: Product name MACBIO BRIDE MG-20E (active ingredient content: 100%), manufactured by Nippon Oil & Fats Co., Ltd. Methylglucitol polyether-10: Product name MACBIO BRIDE MG-10E (active ingredient content: 100%), manufactured by Nippon Oil & Fats Co., Ltd. PROPYLENE GLYCOL (JSQI): Propylene glycol, trade name (active ingredient content: 100%), manufactured by AGC Inc. 1,3-BUTYLENE GLYCOL-P: 1,3-Butanediol, trade name (active ingredient content: 100%), manufactured by KH NeoChem Co., Ltd. MEKKINS-M (UENO METHYL PARABEN NF): Methylparaben, trade name (active ingredient content: 100%), manufactured by Ueno Fine Chemicals Industry, Ltd.

[0093] The following are examples of formulations for the hydrogel of the present invention. It should be noted that the present invention is by no means limited by these formulation examples. All of the hydrogel formulations are non-sticky and non-drying, and have a good feel and usability.

[0094] Prescription example 1: Polyvinyl alcohol (T330H) 11.2% by mass Aluminum glycinate 0.345% by mass PEG-6 Caprylic / Capric Glyceride 0.33% by mass PEG-12 Laurate Ester 1.67% by mass

[0095] Prescription example 2: Polyvinyl alcohol (T330H) 11% by mass Borax 10% by mass PEG-6 Caprylic / Capric Glyceride 0.33% by mass PEG-12 Laurate Ester 1.67% by mass

Claims

1. It contains the following ingredients (A), (B), (C), and (D): Component (A) is an anionic polymer having a carboxyl group, The mass ratio (C) / (A) of component (C) to component (A) is between 0.15 and 2. The viscosity at 25°C is 500 to 8000 Pa·s. Hydrogel. (A) Anionic polymer 5-20% by mass (B) Aluminum salt 0.111 to 3% by mass (C) A nonionic surfactant having an IOB value of 0.1 or more and being selected from PEG fatty acid ester, PEG hydrogenated castor oil, PEG fatty acid glyceride, PPG glucose polyether, and PPG polyglyceryl ether, 1.3 to 10% by mass (D) Water

2. The hydrogel according to claim 1, wherein component (A) is one or more selected from the following components (A1), (A2), and (A3). (A1) Polyvinyl alcohol having a carboxyl group (A2) Acrylic copolymers obtained by polymerizing at least one monomer selected from acrylic acid, methacrylic acid, and alkyl (meth)acrylates having 1 to 30 carbon atoms in the alkyl group. (A3) Carboxymethylcellulose

3. The hydrogel according to claim 1 or 2, wherein the mass ratio of component (B) to component (A) [(B) / (A)] is 0.01 to 0.

06.

4. The hydrogel according to any one of claims 1 to 3, wherein the ratio of the molar amount of aluminum ions contained in component (B) to the molar amount of carboxyl groups contained in component (A) [molar amount of aluminum ions in (B) / molar amount of carboxyl groups in (A)] is 3.0 to 7.

0.

5. The hydrogel according to any one of claims 1 to 4, wherein the content of component (D) in the hydrogel is 60 to 93% by mass.

6. Use of the hydrogel according to any one of claims 1 to 5 as a topical skin preparation.

7. A skincare method comprising applying the hydrogel described in any one of claims 1 to 5 to the skin.

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