Gel composition for external use and cosmetic

Abstract

To provide a gel composition for external use which forms a gel having excellent salt resistance, acid resistance and alkali resistance and forms a film having no stickiness and excellent rubbing resistance even under high humidity, and to provide a cosmetic containing the same.SOLUTION: The gel composition for external use contains a copolymer (A) containing a constitutional unit represented by formula (a), a constitutional unit represented by formula (b) and a constitutional unit represented by formula (c), and a copolymer (B) containing a constitutional unit represented by formula (a) and a constitutional unit represented by formula (c) or a constitutional unit represented by formula (d). (a) - (CH2-C (R1) - C (= O) - OCH2CH2O - P (= O) (O -) - O (CH2) 2-N + (CH3) 3) - (b) - (CH2-C (R2) - C (= O) - O-X) - (c) - (CH2-C (R3) - C (= O) - O-X) - (d) - (- C () - C (= O) - - CH (OH) - - N + () 3) - CH3 R4 CH2 CH2 OCH2 R5 SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a novel gel composition for external use and a cosmetic preparation containing the same. [Background technology]

[0002] Hydrogels are polymers with high affinity for water that swell in aqueous solvents. Hydrogels have various properties, such as water absorption, swelling, moisture retention, and adhesiveness, and are used in a wide range of fields, including food, cosmetics, medicine, and medical devices, taking advantage of these properties.

[0003] In the cosmetics field, hydrogels are primarily used as viscosity adjusters and moisturizers, and are used in a wide range of applications, from skin care to cleansing and makeup, including lotions, emulsions, creams, shampoos, conditioners, body soaps, sunscreens, and foundations. For example, Patent Document 1 discloses a gel-type topical skin preparation characterized by containing a carboxyvinyl polymer and a polyquaternium. However, the gel-type topical skin preparation of Patent Document 1 exhibits pH-dependent gel formation behavior, forming a gel only within a specific pH range, posing issues with acid and alkali resistance. Furthermore, its poor salt tolerance limits its applications and the ingredients that can be used in combination with it. Therefore, Patent Document 2 discloses a gelling agent consisting of locust bean gum and polyoxyethylene methyl glucoside, which has excellent acid and alkali resistance and high salt tolerance.

[0004] Meanwhile, in recent years, the duration and frequency of wearing masks has increased due to measures such as preventing infectious diseases and hay fever, and an increasing number of people are suffering from skin discomfort and makeup smearing due to factors such as humidity inside the mask and friction with the skin. Therefore, there has been a demand for the development of an external gel composition that is highly resistant to friction even in high humidity conditions and has a pleasant feel when used without stickiness.

[0005] Furthermore, in the fields of medicine and medical devices, hydrogels are used as coating agents for three-dimensional culture plates and as wound dressing materials. In particular, in recent years, it has been discovered that moistening the wound surface promotes healing, and hydrogels of natural polymers such as hyaluronic acid and carboxymethylcellulose have been used as wound treatment materials that take advantage of this. For example, Patent Document 3 reports a water-soluble hyaluronic acid gel containing hyaluronic acid, sugar, and water. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-298350 [Patent Document 2] Japanese Patent Application Publication No. 2018-131471 [Patent Document 3] WO2017 / 126143 publication Summary of the Invention [Problem to be solved by the invention]

[0007] However, although the gelling agent of Patent Document 2 has excellent resistance to acids, alkalis, and salts, it has the problem of poor abrasion resistance under high humidity. In addition, both the coatings formed by the gelling agents (hydrogels) shown in Patent Documents 1 and 2 tend to be sticky, leaving room for improvement in terms of usability. Furthermore, hydrogels made of natural polymers such as the hyaluronic acid gel of Patent Document 3 have room for improvement in terms of non-stickiness and abrasion resistance under high humidity.

[0008] The present invention aims to provide a gel composition for external use that forms a gel that is highly resistant to salt and acid / alkali, is non-sticky, and forms a coating that is highly resistant to abrasion even under high humidity conditions, and to provide a cosmetic preparation containing the same. [Means for solving the problem]

[0009] As a result of intensive research in light of the above issues, the inventors have discovered that an external gel composition containing two types of copolymers having specific structures and a cosmetic preparation containing the same can solve the above problems.

[0010] That is, the present invention is as follows. (1) A topical gel composition comprising a copolymer (A) containing a structural unit represented by formula (a), a structural unit represented by formula (b), and a structural unit represented by formula (c), and a copolymer (B) containing a structural unit represented by formula (a), and a structural unit represented by formula (c) or a structural unit represented by formula (d).

[0011] [ka]

[0012] (R 1 represents a hydrogen atom or a methyl group.

[0013] [ka]

[0014] (R 2 represents a hydrogen atom or a methyl group, and X represents a hydrogen atom or an alkali metal atom.

[0015] [ka]

[0016] (R 3 represents a hydrogen atom or a methyl group, and R 4 represents an alkyl group having 4 to 18 carbon atoms.

[0017] [ka]

[0018] (R 5 represents a hydrogen atom or a methyl group. (2) A cosmetic preparation containing the gel composition for external use described in (1). [Effects of the Invention]

[0019] According to the present invention, it is possible to obtain a gel composition for external use which forms a gel having excellent salt resistance and acid / alkali resistance, is non-sticky, and forms a coating having excellent abrasion resistance even under high humidity conditions. Furthermore, according to the present invention, it is possible to provide a cosmetic preparation that has excellent salt resistance, acid and alkali resistance, is non-sticky, and has excellent abrasion resistance even under high humidity conditions. DETAILED DESCRIPTION OF THE INVENTION

[0020] In this specification, numerical ranges defined using the symbol "to" are inclusive of the numerical values ​​at both ends (upper and lower limits) of the symbol "to." For example, "2 to 5" means 2 or more and 5 or less.

[0021] The present invention will now be described in further detail. The topical gel composition of the present invention comprises a copolymer (A) containing a structural unit represented by formula (a), a structural unit represented by formula (b), and a structural unit represented by formula (c), and a copolymer (B) containing a structural unit represented by formula (a), and a structural unit represented by formula (c) or a structural unit represented by formula (d).

[0022] <Copolymer (A)> The copolymer (A) used in the present invention contains a structural unit represented by formula (a), a structural unit represented by formula (b), and a structural unit represented by formula (c).

[0023] The structural unit represented by formula (a) in the copolymer (A) used in the present invention is specifically represented by the following formula (a) and is obtained by polymerization of a monomer represented by formula (a').

[0024] [ka]

[0025] [ka]

[0026] In formula (a) and formula (a'), R 1 may be either a hydrogen atom or a methyl group, but is preferably a methyl group. The copolymer (A) used in the present invention has the structural unit (a) in its molecular chain, and therefore the topical gel composition of the present invention can form a coating that is not sticky and has excellent abrasion resistance even under high humidity conditions.

[0027] A suitable example of the monomer represented by formula (a') is 2-methacryloyloxyethyl phosphorylcholine.

[0028] The content of the structural unit (a) in all structural units (total repeating units; the same applies hereinafter) in the copolymer (A) used in the present invention is not particularly limited and can be selected appropriately depending on the application, but is typically 1 to 50 mol %, preferably 1 to 40 mol %, and more preferably 1 to 30 mol %. When the content is 1 mol % or more, for example, in cosmetics containing the topical gel composition of the present invention described below, excellent acid and alkali resistance and excellent abrasion resistance under high humidity conditions can be expected. When the content is 50 mol % or less, for example, in cosmetics containing the topical gel composition of the present invention described below, excellent abrasion resistance under high humidity conditions and a good, non-sticky feel can be expected.

[0029] More specifically, the structural unit (b) in the copolymer (A) used in the present invention is represented by the following formula (b) and is obtained by polymerizing a monomer represented by formula (b').

[0030] [ka]

[0031] [ka]

[0032] In formula (b) and formula (b'), R 2 represents a hydrogen atom or a methyl group, preferably a methyl group. In formula (b) and formula (b'), X represents a hydrogen atom or an alkali metal atom, preferably an alkali metal atom. Examples of alkali metal atoms include sodium and potassium, preferably sodium.

[0033] Suitable examples of the monomer represented by formula (b') include methacrylic acid and its alkali metal salts.

[0034] The topical gel composition of the present invention can exhibit excellent salt resistance, excellent acid and alkali resistance, and excellent abrasion resistance under high humidity conditions because the copolymer (A) used in the present invention has the structural unit (b) in its molecular chain.

[0035] The content of structural unit (b) in all structural units in copolymer (A) used in the present invention is not particularly limited and can be selected appropriately depending on the application, but is typically 30 to 95 mol%, preferably 40 to 95 mol%, and more preferably 50 to 95 mol%. When the content is 30 mol% or more, for example, in cosmetics containing the topical gel composition of the present invention described below, excellent salt resistance, excellent acid and alkali resistance, and excellent abrasion resistance under high humidity conditions can be expected. When the content is 95 mol% or less, for example, in cosmetics containing the topical gel composition of the present invention described below, excellent acid and alkali resistance, excellent abrasion resistance under high humidity conditions, and a good, non-sticky feel can be expected.

[0036] More specifically, the structural unit (c) in the copolymer (A) used in the present invention is represented by the following formula (c) and is obtained by polymerizing a monomer represented by formula (c').

[0037] [ka]

[0038] [ka]

[0039] In formula (c) and formula (c'), R 3 represents a hydrogen atom or a methyl group, preferably a methyl group. 4 represents an alkyl group having 4 to 18 carbon atoms, and may be either a linear or branched alkyl group.

[0040] Specific examples of linear alkyl groups having 4 to 18 carbon atoms include n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, and n-octadecyl. Examples of branched alkyl groups having 4 to 18 carbon atoms include t-butyl, isobutyl, isopentyl, t-pentyl, neopentyl, isohexyl, isoheptyl, isooctyl, isononyl, isodecyl, isoundecyl, isododecyl, isotridecyl, isotetradecyl, isopentadecyl, isohexadecyl, isoheptadecyl, and isooctadecyl. From the viewpoint of the balance between hydrophilicity and lipophilicity of the copolymer (A), it is preferably an alkyl group having 4 to 15 carbon atoms, more preferably an alkyl group having 4 to 12 carbon atoms, still more preferably an alkyl group having 4 to 10 carbon atoms, and most preferably a linear alkyl group having 4 to 10 carbon atoms. Suitable examples include an n-butyl group, an n-pentyl group, an n-hexyl group, and an n-dodecyl group.

[0041] As long as it has a structure satisfying the structural unit (c), the balance between hydrophilicity and lipophilicity of the copolymer (A) is not impaired, and therefore any of them can be used in the copolymer (A) used in the present invention. However, from the viewpoint of further improving the non-stickiness and abrasion resistance under high humidity in cosmetics containing the topical gel composition of the present invention described below, suitable examples of the monomer represented by formula (c') include butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, and dodecyl (meth)acrylate, with butyl (meth)acrylate being the most preferred.

[0042] For example, cosmetics containing the topical gel composition of the present invention described below can exhibit non-stickiness and excellent abrasion resistance under high humidity conditions because the copolymer (A) used in the present invention has the structural unit (c) in its molecular chain.

[0043] The content of the structural unit (c) in all structural units in the copolymer (A) used in the present invention is not particularly limited and can be selected appropriately depending on the application, but is usually 1 to 40 mol %, preferably 1 to 30 mol %, and more preferably 1 to 20 mol %. When the content is 1 mol % or more, for example, in cosmetics containing the topical gel composition of the present invention described below, excellent abrasion resistance under high humidity conditions can be expected, and when the content is 40 mol % or less, for example, in cosmetics containing the topical gel composition of the present invention described below, non-sticky feel in use and excellent abrasion resistance under high humidity conditions can be expected.

[0044] The molar ratio of the structural unit (c) to the structural unit (a) in the copolymer (A) used in the present invention, "formula (c) / formula (a)," is not particularly limited and can be selected appropriately depending on the application, but is typically 0.1 to 10, preferably 0.1 to 5, and more preferably 0.5 to 2.5. When the ratio is 0.1 or more, for example, in cosmetics containing the topical gel composition of the present invention, as described below, excellent abrasion resistance under high humidity conditions can be expected, and when the ratio is 10 or less, for example, in cosmetics containing the topical gel composition of the present invention, as described below, excellent abrasion resistance under high humidity conditions can be expected, with a non-sticky feel during use.

[0045] [Weight-average molecular weight of copolymer (A)] The weight average molecular weight of the copolymer (A) is not particularly limited and can be appropriately selected depending on the application, but is usually 5,000 to 5,000,000, preferably 10,000 or more, more preferably 50,000 or more, even more preferably 100,000 or more, and preferably 4,500,000 or less, more preferably 3,000,000 or less, even more preferably 2,000,000 or less. When the weight-average molecular weight is 5,000 or more, good abrasion resistance under high humidity can be expected in, for example, cosmetics containing the topical gel composition of the present invention described below.When the weight-average molecular weight is 5,000,000 or less, the topical gel composition of the present invention is less likely to become sticky and is less likely to become difficult to handle due to an increase in viscosity.

[0046] The weight-average molecular weight of copolymer (A) refers to a value measured by gel permeation chromatography (GPC). Specifically, chloroform, dimethylformamide, tetrahydrofuran, ethanol, methanol, water, or a combination of these solvents is used as the eluent, and a salt such as sodium sulfate may be added if necessary. Polyethylene glycol, pullulan, polystyrene, polymethyl methacrylate, etc. can be used as a standard substance for the weight-average molecular weight. The molecular weight measured using these eluents and standard substances is called the weight-average molecular weight of copolymer (A).

[0047] [Total content of structural units represented by formula (a), structural units represented by formula (b), and structural units represented by formula (c)] The total content of the structural units represented by formula (a), the structural units represented by formula (b), and the structural units represented by formula (c) relative to all structural units in the copolymer (A) used in the present invention is preferably 70 mol% or more, more preferably 80 mol% or more, even more preferably 90 mol% or more, and even more preferably substantially 100 mol%. When the total content of the structural units represented by formula (a), the structural units represented by formula (b), and the structural units represented by formula (c) is at least the above-mentioned lower limit, for example, cosmetics containing the topical gel composition of the present invention described below can exhibit better salt resistance, good acid / alkali resistance, non-stickiness, and good abrasion resistance under high humidity.

[0048] [Method for producing copolymer (A)] Copolymer (A) can be produced, for example, by polymerizing a monomer represented by formula (a'), a monomer represented by formula (b'), a monomer represented by formula (c'), and, if necessary, other vinyl monomers copolymerizable with these monomers in the presence of a specific polymerization initiator. The monomer represented by formula (a') can be produced by known methods. For example, 2-hydroxyethyl (meth)acrylate and 2-bromoethylphosphoryl dichloride are reacted in the presence of a tertiary base, followed by reaction of the resulting compound with a tertiary amine. Another example is a method in which 2-hydroxyethyl (meth)acrylate is reacted with a cyclic phosphorus compound (e.g., 3-chloro-3-oxo-1,3,2-dioxaphosphorane) to obtain a cyclic compound, followed by ring-opening reaction with triethylamine. The monomer represented by formula (b') and the monomer represented by formula (c') can be produced by known methods or are commercially available.

[0049] The copolymer (A) may be a random polymer, a block polymer, or a mixture thereof of a monomer represented by formula (a'), a monomer represented by formula (b'), a monomer represented by formula (c'), and, if necessary, other vinyl monomers copolymerizable with these monomers, but is preferably a random polymer.

[0050] <Copolymer (B)> The copolymer (B) used in the present invention contains a constitutional unit represented by formula (a) and a constitutional unit represented by formula (c) or a constitutional unit represented by formula (d).

[0051] More specifically, the constituent unit represented by formula (a) in copolymer (B) is represented by the following formula (a) and is obtained by polymerization of a monomer represented by formula (a').

[0052] [ka]

[0053] [ka]

[0054] In formula (a) and formula (a'), R 1 may be either a hydrogen atom or a methyl group, but is preferably a methyl group. The copolymer (B) used in the present invention has the structural unit (a) in its molecular chain, and therefore the topical gel composition of the present invention can form a coating that is not sticky and has excellent abrasion resistance even under high humidity conditions.

[0055] A suitable example of the monomer represented by formula (a') is 2-methacryloyloxyethyl phosphorylcholine.

[0056] The content of structural unit (a) in all structural units in copolymer (B) used in the present invention is not particularly limited and can be selected appropriately depending on the application, but is usually 30 to 95 mol%, preferably 45 to 90 mol%, and more preferably 60 to 90 mol%. When the content is 30 mol% or more, for example, in cosmetics containing the topical gel composition of the present invention described below, excellent acid and alkali resistance and excellent abrasion resistance under high humidity conditions can be expected. When the content is 95 mol% or less, for example, in cosmetics containing the topical gel composition of the present invention described below, excellent abrasion resistance under high humidity conditions and a good, non-sticky feel can be expected.

[0057] More specifically, the structural unit (c) in the copolymer (B) used in the present invention is represented by the following formula (c) and is obtained by polymerizing a monomer represented by formula (c').

[0058] [ka]

[0059] [ka]

[0060] In formula (c) and formula (c'), R 3 represents a hydrogen atom or a methyl group, preferably a methyl group. 4 represents an alkyl group having 4 to 18 carbon atoms, and may be either a linear or branched alkyl group.

[0061] Specific examples of linear alkyl groups having 4 to 18 carbon atoms include n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, and n-octadecyl. Examples of branched alkyl groups having 4 to 18 carbon atoms include t-butyl, isobutyl, isopentyl, t-pentyl, neopentyl, isohexyl, isoheptyl, isooctyl, isononyl, isodecyl, isoundecyl, isododecyl, isotridecyl, isotetradecyl, isopentadecyl, isohexadecyl, isoheptadecyl, and isooctadecyl. From the viewpoint of the balance between hydrophilicity and lipophilicity of the copolymer (A), it is preferably an alkyl group having 4 to 15 carbon atoms, more preferably an alkyl group having 4 to 12 carbon atoms, still more preferably an alkyl group having 4 to 10 carbon atoms, and most preferably a linear alkyl group having 4 to 10 carbon atoms. Suitable examples include an n-butyl group, an n-pentyl group, an n-hexyl group, and an n-dodecyl group.

[0062] As long as it has a structure satisfying the structural unit (c), the balance between the hydrophilicity and lipophilicity of the copolymer (B) is not impaired, and therefore any of them can be used in the copolymer (B) used in the present invention. However, from the viewpoint of further improving the non-stickiness and abrasion resistance under high humidity in cosmetics containing the topical gel composition of the present invention described below, suitable examples of the monomer represented by formula (c') include butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, and dodecyl (meth)acrylate, with butyl (meth)acrylate being the most preferred.

[0063] For example, cosmetics containing the topical gel composition of the present invention described below can exhibit excellent abrasion resistance and non-stickiness under high humidity conditions because the copolymer (B) used in the present invention has the structural unit (c) in its molecular chain.

[0064] The content of the structural unit (c) in all structural units in the copolymer (B) used in the present invention is not particularly limited and can be selected appropriately depending on the application, but is usually 1 to 70 mol %, preferably 10 to 50 mol %, and more preferably 10 to 30 mol %. When the content is 1 mol % or more, for example, in cosmetics containing the topical gel composition of the present invention described below, excellent abrasion resistance under high humidity conditions can be expected, and when the content is 70 mol % or less, for example, in cosmetics containing the topical gel composition of the present invention described below, excellent abrasion resistance under high humidity conditions can be expected.

[0065] The molar ratio of the structural unit (c) to the structural unit (a) in the copolymer (B) used in the present invention, "formula (c) / formula (a)," is not particularly limited and can be selected appropriately depending on the application, but is typically 0 to 10, preferably 0.1 to 5, and more preferably 0.1 to 2.5. When the ratio is 0.1 or more, for example, in cosmetics containing the topical gel composition of the present invention, which will be described later, excellent abrasion resistance under high humidity conditions can be expected, and when the ratio is 10 or less, for example, in cosmetics containing the topical gel composition of the present invention, which will be described later, excellent abrasion resistance under high humidity conditions can be expected, as well as a non-sticky feel during use.

[0066] More specifically, the structural unit (d) in the copolymer (B) used in the present invention is represented by the following formula (d) and is obtained by polymerizing a monomer represented by formula (d').

[0067] [ka]

[0068] [ka]

[0069] In formula (d) and formula (d'), R 5 represents a hydrogen atom or a methyl group, preferably a methyl group.

[0070] A suitable example of the monomer represented by formula (d') is N,N,N-trimethyl-N-(2-hydroxy-3-methacryloyloxypropyl)ammonium chloride.

[0071] For example, cosmetics containing the topical gel composition of the present invention, which will be described later, can exhibit excellent salt tolerance, excellent chafing resistance under high humidity conditions, and a non-sticky feel when used, because the copolymer used in the present invention has structural unit (d) in its molecular chain.Furthermore, cosmetics containing the topical gel composition of the present invention, which will be described later, can exhibit excellent salt tolerance, excellent acid / alkali resistance, excellent chafing resistance under high humidity conditions, and a non-sticky feel when used, because the copolymer (B) used in the present invention has structural unit (a) and structural unit (c) or structural unit (d) in the same polymer chain.

[0072] The content of structural unit (d) in all structural units in copolymer (B) used in the present invention is not particularly limited and can be selected appropriately depending on the application, but is usually 1 to 60 mol%, preferably 10 to 50 mol%, and more preferably 20 to 50 mol%. If the content is 1 mol% or more, for example, in cosmetics containing the topical gel composition of the present invention described below, excellent salt tolerance and excellent abrasion resistance under high humidity can be expected, and if the content is 50 mol% or less, for example, in cosmetics containing the topical gel composition of the present invention described below, non-sticky feel in use and excellent abrasion resistance under high humidity can be expected.

[0073] [Weight-average molecular weight of copolymer (B)] The weight average molecular weight of the copolymer (B) is not particularly limited and can be appropriately selected depending on the application, but is usually 5,000 to 5,000,000, preferably 10,000 or more, more preferably 100,000 or more, even more preferably 200,000 or more, and preferably 3,000,000 or less, more preferably 2,000,000 or less, even more preferably 1,500,000 or less. When the weight-average molecular weight is 5,000 or more, good abrasion resistance under high humidity can be expected in, for example, cosmetics containing the topical gel composition of the present invention described below.When the weight-average molecular weight is 5,000,000 or less, the topical gel composition of the present invention is less likely to become sticky and is less likely to become difficult to handle due to an increase in viscosity.

[0074] The weight-average molecular weight of copolymer (B) refers to a value measured by gel permeation chromatography (GPC). Specifically, chloroform, dimethylformamide, tetrahydrofuran, ethanol, methanol, water, or a combination of these solvents is used as the eluent, and a salt such as sodium sulfate may be added if necessary. Polyethylene glycol, pullulan, polystyrene, polymethyl methacrylate, etc. can be used as a standard substance for the weight-average molecular weight. The molecular weight measured using these eluents and standard substances is called the weight-average molecular weight of copolymer (B).

[0075] [Total content of structural units represented by formula (a) and structural units represented by formula (c) or structural units represented by formula (d)] The total content of the structural units represented by formula (a), and the structural units represented by formula (c), or the structural units represented by formula (d) relative to all structural units in copolymer (B) used in the present invention is preferably 70 mol% or more, more preferably 80 mol% or more, even more preferably 90 mol% or more, and even more preferably substantially 100 mol%. When the total content of the structural units represented by formula (a), and the structural units represented by formula (c), or the structural units represented by formula (d) is at least the above-mentioned lower limit, the topical gel composition of the present invention forms a gel with superior salt resistance and acid / alkali resistance, and for example, cosmetics containing the topical gel composition of the present invention, as described below, can exhibit superior abrasion resistance under high humidity conditions and a non-sticky feel when used.

[0076] [Method for producing copolymer (B)] Copolymer (B) can be produced, for example, by polymerizing a monomer represented by formula (a'), a monomer represented by formula (c') or a monomer represented by formula (d'), and, if necessary, other vinyl monomers copolymerizable with these monomers, in the presence of a specific polymerization initiator. The methods for producing the monomer represented by formula (a') and the monomer represented by formula (c') are as described above for the method for producing copolymer (A). The monomer represented by formula (d') can be produced by a known method or is commercially available.

[0077] The copolymer (B) may be a random polymer, a block polymer, or a mixture thereof of a monomer represented by formula (a'), a monomer represented by formula (c') or a monomer represented by formula (d'), and, if necessary, other vinyl monomers copolymerizable with these monomers, but is preferably a random polymer.

[0078] [Other vinyl monomers] Examples of other copolymerizable vinyl monomers that can be used as needed in producing the copolymer (A) and the copolymer (B) include 2-hydroxyethyl methacrylate, styrene, α-methylstyrene, methyl-nucleus-substituted styrene, chloro-nucleus-substituted styrene, vinyl chloride, vinylidene chloride, ethylene, propylene, isobutylene, vinyl acetate, vinyl propionate, ethyl vinyl ether, n-butyl vinyl ether, diethyl itaconate, and di-n-butyl itaconate.

[0079] [Polymerization initiator] The polymerization initiator used in producing the copolymer (A) and the copolymer (B) is not particularly limited as long as it is a common radical polymerization initiator, and examples thereof include 2,2'-azobisisobutyronitrile, benzoyl peroxide, diisopropyl peroxydicarbonate, t-butylperoxy-2-ethylhexanoate, t-butylperoxypivalate, t-butylperoxydiisobutyrate, succinic acid peroxide, 2,2'-azobis(2-methylpropionamidine) dihydrochloride, persulfates, and persulfate-bisulfites. The amount of the polymerization initiator used is preferably 0.001 to 10.0 parts by mass, and more preferably 0.01 to 5 parts by mass, relative to 100 parts by mass of all monomers.

[0080] [Polymerization conditions] The temperature for polymerizing the copolymer (A) and the copolymer (B) is preferably 30 to 90°C, particularly preferably 40 to 80°C. At this time, a solvent may be used to facilitate the polymerization reaction. Examples of the polymerization solvent include water, methanol, ethanol, propanol, t-butanol, benzene, toluene, dimethylformamide, tetrahydrofuran, chloroform, and mixtures thereof. The resulting copolymers can be purified by known methods.

[0081] <Composition ratio of copolymer (A) and copolymer (B)> The blending ratio (A) / (B) of copolymer (A) to copolymer (B) in the topical gel composition of the present invention is not particularly limited as long as it allows the formation of a hydrogel. Preferably, the (A) / (B) mass ratio is 0.01 to 15, more preferably 0.01 to 10, and particularly preferably 0.1 to 5. When (A) / (B) is 0.01 or more, the amount of copolymer (A) added is not too small, and excellent abrasion resistance under high humidity can be expected, for example, in cosmetics containing the topical gel composition of the present invention, as described below. When (A) / (B) is 15 or less, excellent salt tolerance, excellent abrasion resistance under high humidity, and a non-sticky feel can be expected, for example, in cosmetics containing the topical gel composition of the present invention, as described below.

[0082] Copolymer (A) and copolymer (B) may each be in a solid state such as powder, or may be dissolved separately in an aqueous medium, particularly water, but preferably in a solution state in water. A hydrogel can be obtained by mixing the solids or solutions of copolymer (A) and copolymer (B). Copolymer (A) and copolymer (B) may also be in a solid state such as a mixed powder, or may be dissolved in an aqueous medium, particularly water. The concentration of the solution is not particularly limited as long as it is dissolved. However, if the concentration relative to the aqueous medium is extremely low, a hydrogel may not be formed. Therefore, the total concentration of copolymer (A) and copolymer (B) is usually preferably 0.01 to 70% by mass, more preferably 0.05 to 50% by mass, and particularly preferably 0.1 to 25% by mass. When the total concentration of copolymers (A) and (B) is 0.01% by mass or more, the amounts of copolymers (A) and (B) added are so small that the hydrogel-forming ability is not significantly reduced, and excellent salt resistance, excellent abrasion resistance under high humidity, and a non-sticky feel can be expected in cosmetics containing the topical gel composition of the present invention, as described below.When the total concentration of copolymers (A) and (B) is 70% by mass or less, excellent abrasion resistance under high humidity and a non-sticky feel commensurate with the blending amounts can be expected in cosmetics containing the topical gel composition of the present invention, as described below, and this is economically advantageous.

[0083] [Other ingredients] The topical gel composition of the present invention can contain water as a solvent. In addition to water, water-soluble or water-miscible organic solvents, such as alcohols (e.g., ethanol, n-propanol, and isopropanol), can also be used. Among these, water is preferred as the solvent, and water typically used in the production of pharmaceuticals and medical devices can be used. Specifically, ion-exchanged water, purified water, sterilized purified water, distilled water, and water for injection can be used. The content of the solvent in the entire topical gel composition of the present invention is not particularly limited, but is preferably 1 to 99.99% by mass, more preferably 10 to 99.9% by mass, even more preferably 30 to 99.85% by mass, even more preferably 50 to 99.8% by mass, and particularly preferably 70 to 99.7% by mass.

[0084] [Method for producing a gel composition for external use] The topical gel composition of the present invention can be produced by directly mixing copolymer A, copolymer B, and, if necessary, a solvent such as water, or by other production methods commonly used in the fields of cosmetics, pharmaceuticals, etc. The order in which these components are added is not particularly limited and can be appropriately determined depending on the intended use.

[0085] [Uses of topical gel composition] The uses of the topical gel composition of the present invention are not particularly limited, but include, for example, cosmetics, pharmaceuticals, and the like, as well as moisturizers, bioprotective materials, sustained-release drug substrates, hemostatic materials (particularly topical hemostatic materials), and wound dressings. Examples of bioprotective materials include skin protective materials, mucous membrane protective materials, and wound protective materials. Examples of mucous membranes include, but are not particularly limited to, oral mucosa, nasal mucosa, and respiratory tract mucosa. A protective material for oral mucosa may be called an oral mucosal protective material, a protective material for nasal mucosa may be called a nasal mucosal protective material, and a protective material for respiratory tract mucosa may be called an respiratory tract mucosal protective material.

[0086] [Cosmetics] The present invention also provides a cosmetic containing the topical gel composition of the present invention. The content of the topical gel composition of the present invention relative to the total cosmetic is preferably 0.01 to 50% by mass, more preferably 0.1 to 30% by mass. When the content of the topical gel composition of the present invention is 0.01% by mass or more, the effects can be more fully exerted, and when the content of the topical gel composition of the present invention is 50% by mass or less, the feel and stability of the cosmetic are improved.

[0087] The cosmetic of the present invention is preferably a skin cosmetic that is applied directly or indirectly to the skin by application or spraying, etc., and examples thereof include basic cosmetics such as lotions, emulsions, creams, etc., base cosmetics such as base lotions, base creams, etc., finishing (make-up) cosmetics such as liquid foundations, scented cosmetics such as perfumes and hair colognes, anti-wrinkle cosmetics, whitening cosmetics, medicated cosmetics (quasi-drugs) such as sunscreens, shampoos, treatments, rinses, etc. Among these, basic cosmetics and medicated cosmetics are preferred.

[0088] If necessary, the cosmetic composition of the present invention may contain other ingredients commonly used in cosmetics, such as solvents, oils and fats (olive fruit oil, etc.), higher fatty acids, higher alcohols, silicones, esters (beeswax, etc.), surfactants (PEG-75 stearate, polysorbate 80, glyceryl stearate, etc.), moisturizers (glycerin, diglycerin, polyglycerin, hyaluronic acid, etc.), thickeners (carbomer, etc.), antioxidants, stabilizers, preservatives (phenoxyethanol, etc.), pearlizing agents, pH adjusters, UV absorbers, hydrotropes, pigments, colorants, disinfectants, anti-inflammatory agents (dipotassium glycyrrhizinate), whitening agents (ascorbyl glucoside), anti-wrinkle agents (niacinamide), astringents, cooling agents, fragrances, and plant extracts. Examples of solvents include water, ethanol, 1,3-butylene glycol, dipropylene glycol, propylene glycol, 1,3-propanediol, glycerin, etc. The content of the solvent relative to the total cosmetic preparation of the present invention is not particularly limited, but is preferably 1 to 95 mass%, more preferably 10 to 93 mass%, even more preferably 30 to 92 mass%, even more preferably 50 to 91 mass%, and particularly preferably 70 to 90 mass%.

[0089] [Method for producing cosmetics] The cosmetic preparation of the present invention can be produced by directly mixing the topical gel composition of the present invention and, if necessary, the other ingredients described above, or by other production methods commonly used in the field of cosmetics. The order in which these ingredients are added is not particularly limited and can be determined appropriately depending on the intended use. [Example]

[0090] The present invention will be described in detail below with reference to examples, comparative examples, and formulation examples, but the present invention is not limited to these. The copolymers used in these examples and comparative examples are as follows. Various evaluations were also carried out as follows.

[0091] <Synthesis Example 1> Copolymer (A1) corresponding to copolymer (A) 18.6 g (0.063 mol) of 2-methacryloyloxyethyl phosphorylcholine (hereinafter also referred to as "MPC"), 13.7 g (0.126 mol) of sodium methacrylate (hereinafter also referred to as "MA"), and 3.0 g (0.021 mol) of butyl (meth)acrylate (hereinafter also referred to as "BMA") were dissolved in 160 g of purified water, placed in a 500 mL four-neck flask equipped with a thermometer and condenser, and nitrogen was bubbled through for 30 minutes. Then, 1.56 g of succinic acid peroxide was added at 70 °C and polymerization was carried out for 7 hours. After the polymerization reaction was completed, the copolymer (A1) was purified using a dialysis membrane, yielding a clear, colorless copolymer. The structural unit composition and weight-average molecular weight of copolymer (A1) are shown in Table 1.

[0092] [Table 1]

[0093] <Synthesis Example 2> Copolymers (A2) and (A3) corresponding to copolymer (A) were obtained by polymerization in the same manner as in Synthesis Example 1, except that the amounts of monomers charged were changed. The composition of the structural units constituting copolymers (A2) and (A3) and the weight-average molecular weights are shown in Table 1.

[0094] <Synthesis Example 3> Copolymer (B1) corresponding to copolymer (B) 19.94 g (0.07 mol) of MPC and 19.64 g (0.08 mol) of N,N,N-trimethyl-N-(2-hydroxy-3-methacryloyloxypropyl)ammonium chloride (hereinafter also referred to as "QA") were dissolved in 210 g of purified water, placed in a 500 mL four-neck flask equipped with a thermometer and condenser, and nitrogen was bubbled through for 30 minutes. Then, 0.373 g of 2,2'-azobis(2-methylpropionamidine) dihydrochloride was added at 70 °C and polymerization was carried out for 2 hours. After polymerization, purification was carried out using a dialysis membrane to obtain a clear, colorless copolymer (B1). The structural unit composition and weight-average molecular weight of copolymer (B1) are shown in Table 1.

[0095] <Synthesis Example 4> Copolymers (B2) and (B3) corresponding to copolymer (B) were obtained by polymerization in the same manner as in Synthesis Example 3, except that the amounts of monomers charged were changed. The constitutional unit compositions and weight-average molecular weights of copolymers (B2) and (B3) are shown in Table 1.

[0096] <Synthesis Example 5> Copolymer (B4) corresponding to copolymer (B) 18.58 g (0.06 mol) of MPC and 20.9 g (0.15 mol) of BMA were dissolved in 160 g of pure water, placed in a 500 mL four-neck flask equipped with a thermometer and condenser, and nitrogen was bubbled through for 30 minutes. 1.56 g of succinic acid peroxide was then added at 70 °C and polymerization was carried out for 7 hours. After the polymerization reaction was completed, purification was carried out using a dialysis membrane, yielding a colorless and clear copolymer (B4). The structural unit composition and weight-average molecular weight of copolymer (B4) are shown in Table 1.

[0097] <Synthesis Example 6> Copolymers (B5), (B6), and (B7) corresponding to copolymer (B) were obtained by polymerization in the same manner as in Synthesis Example 5, except that the amounts of monomers charged were changed. The constitutional unit compositions and weight-average molecular weights of copolymers (B5), (B6), and (B7) are shown in Table 1.

[0098] <Synthesis Example 7> Copolymers (C), (D), and (E), which do not correspond to copolymer (A), were obtained by polymerization in the same manner as in Synthesis Example 1, except that the amounts of monomers charged were changed. The constitutional unit compositions and weight-average molecular weights of copolymers (C), (D), and (E) are shown in Table 1.

[0099] <Measurement of weight-average molecular weight of copolymer> The weight-average molecular weight of each copolymer was measured by gel permeation chromatography (GPC) using polyethylene glycol as a standard substance. Five mg of each copolymer was dissolved in a methanol / chloroform mixture (80:20) and further diluted with water to a copolymer concentration of 0.5% by mass. This solution was filtered through a 0.45 μm membrane filter and measured under the following conditions.

[0100] Column: PLgel-mixed-C (Tosoh Corporation) Standard substance: polyethylene glycol Detector: Differential refractometer RI-8020 (manufactured by Tosoh Corporation) Calculation method for weight-average molecular weight: Molecular weight calculation program (GPC program for SC-8020) (Tosoh Corporation) Flow rate: 1 mL per minute Injection volume: 100μL Column oven: constant temperature around 40°C

[0101] [Examples 1 to 13, Comparative Examples 1 to 5] Gel compositions for external use (Examples 1-10, Comparative Examples 1-4) were prepared by mixing the components shown in Table 2. Cosmetics (Examples 11-13, Comparative Example 5) with the compositions shown in Table 4 were prepared by mixing the gel compositions for external use prepared in Table 2 with the commonly added ingredients shown in Table 3. The prepared gel compositions for external use and cosmetics were evaluated using the methods described below. The results are shown in Tables 2 and 4.

[0102] [Table 2]

[0103] [Table 3]

[0104] [Table 4]

[0105] (Performance evaluation) (1) Salt tolerance 1% salt was added to the topical gel compositions and cosmetics containing the same described in Examples 1 to 13 and Comparative Examples 1 to 5, and the mixture was mixed and stirred to homogeneity. The appearance was visually inspected immediately after preparation and after leaving the composition to stand at 20°C for one month, and evaluated on a four-point scale from "◎" to "×" as follows. A rating of "◯" or higher indicated that the topical gel compositions and cosmetics containing them had excellent salt tolerance.

[0106] ⊚: A colorless, transparent, uniform gel was formed even after being left standing for one month. ◯: Immediately after preparation, a colorless, transparent, uniform gel was formed, but after leaving it to stand for one month, a non-uniform gel was observed with some water separation and turbidity. △: Immediately after preparation, a non-uniform gel was formed with syneresis and turbidity. ×: Gel-forming ability was not exhibited.

[0107] (2) Acid and alkali resistance The topical gel compositions and cosmetic preparations containing them described in Examples 1 to 13 and Comparative Examples 1 to 5 were adjusted to pH 4 and pH 10 with citric acid and potassium hydroxide. The appearance was visually inspected immediately after adjustment and after leaving to stand at 20°C for one month, and rated on the following four-point scale from "◎" to "×." A rating of "◯" or better indicated that the topical gel compositions and cosmetic preparations containing them had excellent acid-alkali resistance.

[0108] ⊚: A colorless, transparent, uniform gel was formed under all pH conditions, even after standing for one month. ○: Under all pH conditions, a colorless, transparent, uniform gel was formed immediately after adjustment, but after leaving it to stand for one month, a non-uniform gel was observed with syneresis and turbidity. △: Immediately after preparation, an inhomogeneous gel was formed with slight syneresis and turbidity. ×: Gel-forming ability was not exhibited.

[0109] (3) Non-stickiness Twenty women (aged 22 to 40) served as panelists, and when 0.5 g of each of the topical gel compositions and cosmetics containing the compositions described in Examples 1 to 13 and Comparative Examples 1 to 5 was applied to the upper arm, they were evaluated and scored according to the following criteria for the feel on the skin. The total score was then used to rank the topical gel compositions and cosmetics containing them on a four-point scale from "◎" to "×," with those scoring 30 points or higher being judged to be excellent in terms of non-stickiness.

[0110] 2 points: When the user felt that the product was very non-sticky. 1 point: When the lack of stickiness is felt to be good. 0 points: If you feel that the lack of stickiness is somewhat poor.

[0111] <4-level evaluation based on the total score> ◎: Total score is 35 points or more ○: The total score is 30 points or more and 34 points or less △: Total score is 20 or more and 29 or less ×: The total score is 19 points or less

[0112] (4) Abrasion resistance under high humidity A blue pigment (Brilliant Blue; manufactured by Tokyo Chemical Industry Co., Ltd.) was added at 1% by mass to the topical gel compositions and cosmetics containing the same described in Examples 1 to 13 and Comparative Examples 1 to 5. After uniform mixing and stirring, 1 g of each was applied to an area of ​​2 cm x 2 cm on artificial leather (manufactured by Viewlux Co., Ltd.), thoroughly dried, and the brightness difference of the artificial leather surface was measured using a spectrophotometer (CM-2500c, manufactured by Konica Minolta, Inc.). The samples were then left to stand for 6 hours in a thermostatic chamber at 30°C and 75% humidity. An 85 g weight was placed on the artificial leather so that it sandwiched a paper wiper (Kimwipe S-200, manufactured by Nippon Paper Crecia Co., Ltd.). The weight and paper wiper were rubbed against the artificial leather, and measurements were taken in the same manner. The percentage change before and after rubbing with the paper wiper was calculated using the following formula. A percentage change of less than 20% was considered to be abrasion-resistant topical gel compositions and cosmetics containing the same.

[0113] Rate of change (%) = (1-ΔEa / ΔEb) x 100 ΔEa = difference in brightness of the artificial leather surface after rubbing with a moving weight ΔEb = difference in brightness of the artificial leather surface before rubbing with the weight

[0114] ◎: Change rate is 0% or more but less than 10% ○: Change rate is 10% or more but less than 20% △: Change rate is 20% or more but less than 30% ×: Change rate is 30% or more and 100% or less

[0115] Examples 1 to 10 show that the topical gel composition of the present invention formed a gel with excellent salt resistance, acid and alkali resistance, was non-sticky, and had a good effect of forming a coating with excellent abrasion resistance even under high humidity. Furthermore, Examples 11 to 13 show that the cosmetic preparations containing the topical gel composition of the present invention had excellent salt resistance, acid and alkali resistance, were non-sticky, and had excellent abrasion resistance even under high humidity.

[0116] On the other hand, the topical gel compositions of Comparative Examples 1 to 5 and cosmetics containing them did not exhibit sufficient performance. That is, in the composition of Comparative Example 1, copolymer (B) was replaced with another component, and therefore the effect of "forming a gel with excellent salt resistance, acid and alkali resistance, and forming a coating that is non-sticky and has excellent abrasion resistance even under high humidity" was insufficient. In the compositions of Comparative Examples 2 to 4, copolymer (A) was replaced with another component, and therefore the effect of "forming a gel with excellent salt resistance, acid and alkali resistance, and forming a coating that is non-sticky and has excellent abrasion resistance even under high humidity" was insufficient. Furthermore, in the cosmetic of Comparative Example 5, copolymer (A) was replaced with another component, and therefore the effect of "providing excellent salt resistance, acid and alkali resistance, non-sticky, and excellent abrasion resistance even under high humidity" was insufficient.

[0117] [Prescription example 1] The components shown in Table 5 were mixed to prepare a lotion.

[0118] [Table 5]

[0119] [Prescription example 2] The components shown in Table 6 were mixed to prepare a lotion.

[0120] [Table 6]

[0121] [Prescription example 3] The components shown in Table 7 were mixed to prepare an emulsion.

[0122] [Table 7]

[0123] [Prescription Example 4] The ingredients shown in Table 8 were mixed to prepare a cream.

[0124] [Table 8]

[0125] [Prescription Example 5] The components shown in Table 9 were mixed together to prepare a sunscreen.

[0126] [Table 9]

[0127] [Prescription Example 6] The components shown in Table 10 were mixed to prepare a treatment.

[0128] [Table 10]

[0129] [Prescription Example 7] The components shown in Table 11 were mixed to prepare a shampoo.

[0130] [Table 11]

[0131] [Prescription Example 8] The components shown in Table 12 were mixed to prepare a liquid foundation.

[0132] [Table 12] [Industrial Applicability]

[0133] According to the present invention, it is possible to obtain a gel composition for external use that forms a gel having excellent salt resistance, acid and alkali resistance, is non-sticky, and forms a coating that has excellent abrasion resistance even under high humidity, and a cosmetic preparation that has excellent salt resistance, acid and alkali resistance, is non-sticky, and has excellent abrasion resistance even under high humidity.

Claims

1. A topical gel composition comprising a copolymer (A) containing a structural unit represented by formula (a), a structural unit represented by formula (b), and a structural unit represented by formula (c), and a copolymer (B) containing a structural unit represented by formula (a), and a structural unit represented by formula (c) or a structural unit represented by formula (d). 【Chemistry 1】 (R 1 represents a hydrogen atom or a methyl group.) 【Chemistry 2】 (R ２ represents a hydrogen atom or a methyl group, and X represents a hydrogen atom or an alkali metal atom. 【Transformation 3】 (R ３ represents a hydrogen atom or a methyl group, and R ４ represents an alkyl group having 4 to 18 carbon atoms. 【Chemistry 4】 (R ５ represents a hydrogen atom or a methyl group.)

2. A cosmetic preparation containing the gel composition for external use according to claim 1.

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