JP2021138663A - Humectant - Google Patents

Abstract

To provide a new application for a cationic group-containing copolymer.SOLUTION: A humectant has a cationic group-containing copolymer, the copolymer having cationic group-containing monomer-derived constitutional units and hydrophobic monomer-derived constitutional units, the content of the cationic group-containing monomer-derived constitutional units being 36-99.9 mass% relative to 100 mass% of all the constitutional units, a weight average molecular weight of the humectant being 4000-1,000,000, the hydrophobic monomers having a homopolymer solubility parameter of 15 or less.SELECTED DRAWING: None

Description

The present invention relates to a moisturizer. More specifically, the present invention relates to a moisturizer useful for skin cosmetics, external preparations for skin, hair cosmetics and the like.

It is known that a polymer having a cationic group is suitably used as an antibacterial agent because the cationic group is adsorbed on the surface of a microorganism having a negative charge and contributes to the destruction of the cell membrane. For example, Patent Document 1 describes an antibacterial agent containing a cationic group-containing copolymer.
The copolymer has a structural unit (a) derived from the cationic group-containing monomer (A) and a structural unit (b) derived from the hydrophobic monomer (B), and the structural unit (a). The ratio of the above is 36 to 99.9% by mass with respect to 100% by mass of the total structural unit, the weight average molecular weight is 4000 to 1,000,000, and the hydrophobic monomer (B) dissolves the copolymer. An antibacterial agent containing a cationic group-containing copolymer characterized by having a sex parameter of 15 or less is disclosed. Patent Document 2 discloses an antiseptic and antibacterial agent for cosmetics containing a cationic group-containing copolymer.

International Publication No. 2017/057571 Japanese Unexamined Patent Publication No. 2018-058813

As described above, although the cationic group-containing copolymer has been disclosed as an antibacterial agent in various uses, there is no particular report on other uses, and a new use for the cationic group-containing copolymer will be developed. There was room.

The present invention has been made in view of the above situation, and an object of the present invention is to provide a new use of a cationic group-containing copolymer.

As a result of various studies on the cationic group-containing copolymer, the present inventor has a structural unit derived from a cationic group-containing monomer and a structural unit derived from a specific hydrophobic monomer, and contains a cationic group. We have found that a copolymer having a specific range of structural units derived from a monomer and a weight average molecular weight has excellent moisturizing properties, and have found a new use of the copolymer as a moisturizing agent. We came up with the idea that it can be solved in the above, and arrived at the present invention.

That is, the present invention is a moisturizing agent containing a cationic group-containing copolymer, wherein the copolymer contains a structural unit (a) derived from the cationic group-containing monomer (A) and a hydrophobic monomer (a). It has a structural unit (b) derived from B), and the ratio of the structural unit (a) derived from the cationic group-containing monomer (A) is 36 to 99.9 with respect to 100% by mass of the total structural unit. The hydrophobic monomer contains a cationic group-containing copolymer characterized by a solubility parameter of 15 or less, which is% by mass, has a weight average molecular weight of 4000 to 1,000,000, and the hydrophobic monomer has a solubility parameter of 15 or less. It is a moisturizer.

The cationic group-containing monomer (A) is selected from the group consisting of a primary to tertiary amino group-containing monomer and / or a neutralized product of these acids and a quaternary ammonium base-containing monomer. It is preferable that the amount is at least one.

The hydrophobic monomer (B) preferably contains at least one (meth) acrylic acid ester.

The present invention is also a cosmetic containing the above moisturizer.

The content of the moisturizer is preferably 0.001 to 10% by mass with respect to 100% by mass of the cosmetic.

Since the moisturizer of the present invention has the above-mentioned structure and can improve the keratinous water content of the skin, it can be suitably used as a moisturizer or the like in cosmetics or the like.

Hereinafter, preferred embodiments of the present invention will be specifically described, but the present invention is not limited to the following description, and can be appropriately modified and applied without changing the gist of the present invention. A form in which two or three or more of the individual preferred forms of the present invention described below are combined also falls under the preferred form of the present invention.

<Cationic group-containing copolymer>

The moisturizer of the present invention has a co-weight having a structural unit (a) derived from a cationic group-containing monomer (A) and a structural unit (b) derived from a hydrophobic monomer (B) in the above-mentioned specific ratios. It includes coalescence. When a moisturizer containing such a copolymer is applied to the skin or the like, the copolymer having a hydrophobic group forms a film, and the keratinous water of the skin is prevented from evaporating the water retained by the hydrophilic cationic group. It is thought to improve the amount (exhibit moisturizing properties).

The cationic group-containing copolymer has a structural unit (a) derived from the cationic group-containing monomer (A) in a proportion of 36 to 99.9% by mass with respect to 100% by mass of the total structural unit. It is preferably 40 to 99% by mass, more preferably 45 to 99% by mass, further preferably 50 to 95% by mass, still more preferably 60 to 90% by mass, and particularly preferably 60 to 80% by mass. be.

The cationic group-containing copolymer of the present invention has 0.1 to 64% by mass of the structural unit (b) derived from the hydrophobic monomer (B) with respect to 100% by mass of the total structural unit. Is preferable. It is more preferably 1 to 60% by mass, further preferably 1 to 55% by mass, still more preferably 5 to 50% by mass, still more preferably 10 to 40% by mass, and particularly preferably 20 to 40% by mass. %.

In the copolymer of the present invention, the content ratio of the structural unit (b) derived from the monomer (B) in the copolymer is 100% by mass of the structural unit (a) derived from the cationic group-containing monomer (A). It is preferably 1 to 170% by mass. It is more preferably 1 to 150% by mass, further preferably 5 to 100% by mass, still more preferably 10 to 80% by mass, and particularly preferably 20 to 70% by mass. When the content ratio of the structural unit (b) in the copolymer of the present invention is within such a range, the moisturizing performance of the copolymer tends to be improved.

As will be described later, the copolymer of the present invention contains a structural unit (e) derived from a monomer (E) other than the cationic group-containing monomer (A) and the hydrophobic monomer (B). The content ratio of the structural unit (e) derived from the other monomer (E) is preferably 0 to 10% by mass with respect to 100% by mass of the total structural unit. More preferably, it is 0 to 8% by mass, and further preferably 0 to 5% by mass.

As the copolymer of the present invention, a copolymer composed of only a structural unit (a) derived from a cationic group-containing monomer (A) and a structural unit (b) derived from a hydrophobic monomer (B) is also used. , Which is one of the preferred forms. In this case, the total ratio of the structural unit (a) derived from the cationic group-containing monomer (A) and the structural unit (b) derived from the hydrophobic monomer (B) is 100% by mass, and these structures. The ratio of each unit is obtained by subtracting the ratio of the structural unit (a) derived from the above-mentioned cationic group-containing monomer (A) or the ratio of the structural unit (b) derived from the monomer (B) from 100% by mass. Value.

The weight average molecular weight of the cationic group-containing copolymer of the present invention is 4000 to 1,000,000. When the weight average molecular weight of the cationic group-containing copolymer is in such a range, the adsorptivity of the moisturizer to the skin or the like is improved, so that the moisturizer is sufficiently suppressed from being washed away by washing or the like, and the moisturizing effect is maintained. Improves sex.
The weight average molecular weight is preferably 4,000 to 800,000, more preferably 5,000 to 600,000, further preferably 6,000 to 400,000, still more preferably 7,000 to 200,000, and even more preferably 10,000. It is 100,000, particularly preferably 20,000 to 80,000. The weight average molecular weight of the cationic group-containing copolymer can be measured by the method described in Examples.

The structure of the cationic group-containing copolymer of the present invention includes a random copolymer structure, a graft structure, a block copolymer structure, a gradient copolymer structure, a star-shaped structure, a dendrimer structure, and the like. There may be.

<Cationic group-containing monomer (A)>
The cationic group-containing copolymer contained in the moisturizer of the present invention has a structural unit (a) derived from the cationic group-containing monomer (A). The cationic group-containing monomer (A) is not particularly limited as long as it has at least one ethylenically unsaturated group and one cationic group. Further, if the "structural unit (a) derived from the cationic group-containing monomer (A)" has the same structure as the structural unit formed by polymerizing the monomer (A), another production method can be used. It may be formed. The same applies to the monomer (B) and the monomer (E) described later. For example, when the monomer (A) is N, N-dimethylaminoethyl methacrylate, the structural unit (a) is -CH _2- C (CH ₃ ) (COCH ₂ CH _2- N (CH ₃ ) ₂ ). It is a structural unit represented by −. Here, the cationic group is a group having a cation or a group for generating a cation, for example, a neutralized product of a primary to tertiary amino group, a neutralized product of a primary to tertiary amino group with an acid, and a quaternary ammonium base. And so on. The primary to primary amino groups include the following formula (1);

(In the formula, R ¹ and R ² are the same or different and represent a hydrogen atom and a hydrocarbon group having 1 to 12 carbon atoms.) It is preferable that the structure is represented by.
The hydrocarbon group may have a chain structure or a ring structure, but a chain structure is preferable. When the hydrocarbon group has a chain structure, it may be linear or have a branch.
The hydrocarbon group is preferably an alkyl group, an alkenyl group or an aryl group, more preferably an alkyl group or an alkenyl group, and even more preferably an alkyl group.
Specific examples of the alkyl group, alkenyl group, and aryl group will be described in the (meth) acrylic acid ester described later.
The number of carbon atoms of the hydrocarbon group is preferably 1 to 10, more preferably 1 to 8, particularly preferably 1 to 5, particularly still more preferably 1 to 2, and most preferably 1. Is.
At least one of ^{R 1} and R ² is preferably a hydrocarbon group having 1 to 12 carbon atoms, and both ^{R 1} and R ^{2 are preferably hydrocarbon groups having 1 to 12 carbon atoms.} More preferred. That is, among the primary to tertiary amino groups, a tertiary amino group is preferable.

The neutralized product of the primary to primary amino groups with an acid is represented by the following formula (2);

(In the formula, R ¹ and R ² represent the same or different hydrocarbon atoms or hydrocarbon groups having 1 to 12 carbon atoms ^{. Y −} represents an anion.) preferable. Specific examples and preferred forms of the hydrocarbon group are as described above.
The quaternary ammonium base is represented by the following formula (3);

(In the formula, R ^{3 to} R ⁵ represent the same or different hydrocarbon groups having 1 to 12 carbon atoms ^{. Y −} represents an anion.) It is preferable that the structure is represented by. Specific examples and preferred forms of hydrocarbon groups having 1 to 12 carbon atoms are as described above.
The hydrocarbon group having 1 to 12 carbon atoms is preferably an alkyl group having 1 to 12 carbon atoms and an alkenyl group having 2 to 12 carbon atoms.
The ^{number of carbon atoms of R 3 to} R ⁵ is more preferably 1 to 10, further preferably 1 to 7, still more preferably 1 to 5, and particularly preferably 1 to 3.
As ^{the hydrocarbon groups of R 3 to} R ⁵ , a methyl group or an ethyl group is most preferable.

^{Y −} in the above formulas (2) and (3) is not particularly limited, but is, for example, a halide ion such as chlorine ion, bromine ion, iodine ion; alkyl sulfate ion such as methyl sulfate ion; organic acid such as acetate ion. Ions and the like can be mentioned.
^{Y −} in the above formula (2) is preferably an ion of an organic acid.
^{The Y −} in the above formula (3) is preferably a halide ion or an alkyl sulfate ion.

Examples of the cationic group include acids of tertiary amino groups and tertiary amino groups among neutralized products of primary to tertiary amino groups and primary to tertiary amino groups with acids and quaternary ammonium bases. A neutralized product of the above or a quaternary ammonium base is preferable. More preferably, it is a neutralized product of a tertiary amino group or a tertiary amino group with an acid. As the neutralized product of the tertiary amino group or the tertiary amino group with an acid, a dimethylamino group, a diethylamino group or a neutralized product of these with an acid such as hydrochloric acid or acetic acid is preferable.

The cationic group-containing monomer (A) is selected from the group consisting of a primary to tertiary amino group-containing monomer and / or a neutralized product of these acids and a quaternary ammonium base-containing monomer. It is preferable that the amount is at least one.
Examples of the cationic group-containing monomer include the following formulas (4-1) to (4-3);

(In formulas (4-1) to (4-3), R ^{6 to} R ⁸ represent the same or different alkyl groups having a hydrogen atom or 1 to 5 carbon atoms. X is a direct bond or divalent. during represents a linking group. formula (4-1) and ^(4-2), R 1, ^{R 2} are the same as ^R 1, ^{R 2} in the formula (1). equation (4-3), R ³ to R ⁵ are the same as ^R 3 to R ⁵ in the formula (3) .Y ^- is more preferably a structure represented by represents an anion)..

Alkyl group of 1 to 5 carbon atoms in the R ⁸ is preferably a methyl group. The R ⁸ is preferably a hydrogen atom or a methyl group. More preferably a methyl group as R ⁸ in terms of hydrolysis resistance.
It is preferable that R ⁶ and R ^{7 are hydrogen atoms.}

The divalent linking group in X of the above formulas (4-1) to (4-3) is not particularly limited, but for example, an alkylene group having 1 to 12 carbon atoms or the following formula (5);

(In the formula, m represents an integer from 0 to 12.), The following formula (6);

(In the formula, e represents an integer from 0 to 4) and the following formula (7);

(In the formula, k represents an integer of 1 to 10).
M in the above formula (5) is preferably 1 to 8, more preferably 1 to 5, and e in the above formula (6) is preferably 1 to 3, more preferably 1 to 2. Is.
K in the above formula (7) is preferably 1 to 8, and more preferably 1 to 5.
As the divalent linking group in X of the above formulas (4-1) and (4-2), the structure represented by the above formula (5) is preferable.

As the divalent linking group in X of the above formula (4-3), the structure represented by the above formula (5) or an alkylene group having 1 to 12 carbon atoms is preferable.

In the cationic group-containing monomer, ^{R 8} in the formula (4-1) to (4-3) is a methyl group, X is, form a structure represented by the above formula (5) is , Is one of the preferred embodiments of the present invention.

Specific examples of the cationic group-containing monomer (A) include N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, and N, N-dimethylaminopropyl (meth). ) N, N-dialkylamino group-containing (meth) acrylates such as acrylate, N, N-diethylaminopropyl (meth) acrylate, and the above-mentioned monomers with a quaternizing agent added, or their acids such as hydrochloric acid and acetic acid. Neutralized by: N, N-dimethylaminoethyl (meth) acrylamide, N, N-diethylaminoethyl (meth) acrylamide, N, N-dimethylaminopropyl (meth) acrylamide, N, N-diethylaminopropyl (meth) acrylamide N, N-dialkylamino group-containing (meth) acrylamides such as, and monomers obtained by adding a quaternizing agent to the above monomers or neutralized products of these with acids such as hydrochloric acid; monomethylaminoethyl (meth) acrylate, monoethyl Monoalkylamino group-containing (meth) acrylates such as aminoethyl (meth) acrylate, monomethylaminopropyl (meth) acrylate, monoethylaminopropyl (meth) acrylate, 2- (tert-butylamino) ethyl (meth) acrylate. And these neutralized products with acids such as hydrochloric acid; monoalkylamino such as monomethylaminoethyl (meth) acrylamide, monoethylaminoethyl (meth) acrylamide, monomethylaminopropyl (meth) acrylamide, and monoethylaminopropyl (meth) acrylamide. Group-containing (meth) acrylamides and their neutralized products with acids such as hydrochloric acid; esters of (meth) acrylic acids such as -2-aminoethyl (meth) acrylate and alkanolamines and acids such as these hydrochloric acids. Neutralized product with N, N-diallylmethylamine and a monomer to which a quaternizing agent is added or a neutralized product with an acid such as hydrochloric acid thereof; An unsaturated monomer having a cyclic ether-containing group having 2 to 8 carbon atoms such as −allyloxy-3-dibutylamino-2-ol and 1-allyloxy-3-diethanolamino-2-ol and an unsaturated monomer having 1 to 24 carbon atoms. Examples thereof include an addition reaction product with an amine compound, a monomer having a quaternizing agent added thereto, and a neutralized product thereof with an acid such as hydrochloric acid.

The amine compound having 1 to 24 carbon atoms is not particularly limited as long as it can react with the cyclic ether structure of an unsaturated monomer having an amino group and having a cyclic ether-containing group having 2 to 8 carbon atoms. The amine compound having 1 to 24 carbon atoms preferably has 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms. Examples of the amine compound having 1 to 24 carbon atoms include primary amines and secondary amines, for example, (di) alkylamines having 1 to 24 carbon atoms, (di) alkanolamines having 1 to 24 carbon atoms, and the like. Examples thereof include alkylalkanolamines having 1 to 24 carbon atoms.
Examples of (di) alkylamines having 1 to 24 carbon atoms include methylamine, ethylamine, propylamine, butylamine, dimethylamine, diethylamine, dipropylamine, dibutylamine, pentylamine, dipentylamine, hexylamine, dihexylamine and heptylamine. , Diheptylamine, octylamine, dioctylamine, dodecylamine, didodecylamine and the like are preferable.
As the (di) alkanolamine having 1 to 24 carbon atoms, methanolamine, ethanolamine, propanolamine, butanolamine, dimethanolamine, diethanolamine, dipropanolamine, dibutanolamine, hexanolamine and the like are preferable.
As the alkylalkanolamine having 1 to 24 carbon atoms, methylethanolamine or the like is preferable.

The cationic group-containing monomer is preferably an N, N-dialkylamino group-containing (meth) acrylate, a neutralized product of these with an acid such as hydrochloric acid, or a monomer obtained by adding a quaternizing agent to these. N, N-dialkylamino group-containing (meth) acrylamides, neutralized products of these with acids such as hydrochloric acid, and monomers to which a quaternizing agent is added, among them, N, N-dimethylaminoethyl (meth) acrylate, More preferably, N, N-diethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylamide, acid neutralized products such as hydrochloric acid thereof, and monomers to which a quaternizing agent is added are preferable.
The quaternizing agent is not particularly limited, but is an alkyl halide such as methyl chloride, ethyl chloride, methyl bromide, methyl iodide; dimethyl sulfate, diethyl sulfate, di-n-propyl sulfate and the like. Examples thereof include general alkylating agents such as alkyl sulfate.

<Hydrophobic monomer (B)>
The hydrophobic monomer (B) has a solubility parameter of 15 or less with respect to the homopolymer obtained by homopolymerization. Even if the solubility parameter is 15 or less, those having a cationic group are included in the cationic group-containing monomer.
Here, the solubility parameter is a value calculated by the method described on pages 147 to 154 of "POLYMER ENGINEERING AND SCIENCE" (1974, Vol. 14, No. 2).
The method is outlined below. The solubility parameter (δ) (cal / cm ³ ) ^1/2 of the homopolymer is as follows, based on the evaporation energy (Δei) and molar volume (Δvi) of the constituent units forming the polymer. It is calculated by the calculation method of.
δ = (Δei / Δvi) ^1/2 (cal / cm ³ ) ^1/2

If the solubility parameter for the homopolymer obtained by polymerizing the hydrophobic monomer (B) alone is 15 or less, it is formed when the moisturizer of the present invention is applied to the skin or the like. The hydrophobicity of the film to be formed becomes sufficient, and the evaporation of water in the keratin can be sufficiently suppressed. The solubility parameter is preferably 14 or less, more preferably 13 or less, and further preferably 12 or less. The solubility parameter is usually 5 or more.

The hydrophobic monomer (B) is not particularly limited as long as the solubility parameter in the homopolymer is 15 or less, but it is an ester of (meth) acrylic acid and an alcohol which may have a substituent. ((Meta) acrylate) types; unsaturated monocarboxylic acids such as (meth) acrylic acid, crotonic acid, α-allyloxyacrylic acid and salts thereof; aromatic vinyl-based monomers such as styrene; ethylene, propylene, etc. Olefin-based monomer; ester of unsaturated alcohol such as vinyl acetate and carboxylic acid; vinyl halide such as vinyl chloride; alkyl vinyl ethers such as methyl vinyl ether and ethyl vinyl ether; 1-allyloxy-3-butoxypropane-2 -Additional reaction product of unsaturated monomer having a cyclic ether-containing group having 2 to 8 carbon atoms such as oar and alcohol having 1 to 20 carbon atoms; ethylene oxide adduct of allyl alcohol, ethylene oxide adduct of metallic alcohol, Examples thereof include alkylene oxide adducts of unsaturated alcohols having 2 to 20 carbon atoms such as ethylene oxide adducts of isoprenol and terminal hydrophobic modified products thereof; cyclic vinyl-based monomers such as N-vinylpyrrolidone.
As the hydrophobic monomer (B), among those having a solubility parameter of 15 or less, those having an alkyl group having 2 to 12 carbon atoms are preferable. As a result, the hydrophobicity of the hydrophobic monomer (B) is in a more preferable range, and the water retention property is further improved.

Examples of the unsaturated monocarboxylic acid salt include metal salts. Examples of the metal of the metal salt include alkali metals such as lithium, sodium and potassium.

Examples of the substituent in the (meth) acrylate include a hydroxyl group; an alkoxy group having 1 to 18 carbon atoms such as a methoxy group and an ethoxy group; an oxo group-containing group such as an oxyalkylene group, a sulfonic acid group and a phosphoric acid group; a fluoro group and the like. Harogeno group; epoxy group such as glycidyl group; carbonyl group such as aldehyde group and the like.

Examples of the alkyl (meth) acrylate having no substituent as described above include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, and n-butyl (meth) acrylate. ) Acrylate, Isobutyl (meth) acrylate, tert-butyl (meth) acrylate, sec-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, tridecyl (meth) acrylate, cyclohexyl (meth) ) Cycloalkyl (meth) acrylate such as acrylate, n-lauryl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, isobornyl methacrylate and the like.

Examples of the hydroxyl group-containing (meth) acrylate include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, and 4-hydroxy. Examples thereof include hydroxyl group-containing (meth) acrylates having 1 to 18 carbon atoms in ester groups such as butyl (meth) acrylates.

Examples of the alkoxyalkyl (meth) acrylate include methoxyethyl (meth) acrylate, methoxypropyl (meth) acrylate, methoxybutyl (meth) acrylate, ethoxybutyl (meth) acrylate, and trimethylolpropane tripropoxy (meth) acrylate. Can be mentioned.

Examples of the oxo group-containing (meth) acrylate include (di) ethylene glycol (methoxy) such as ethylene glycol (meth) acrylate, ethylene glycol methoxy (meth) acrylate, diethylene glycol (meth) acrylate, and diethylene glycol methoxy (meth) acrylate. Meta) acrylate; alkoxypolyalkylene glycol (meth) acrylate having 1 to 100 repetitions of alkylene glycol such as alkoxypolyethylene glycol methacrylate (Antox LMA-10); sulfopropyl (meth) acrylate; (meth) acryloyloxyethyl phosphate And so on.

Examples of the fluorogroup-containing (meth) acrylate include fluorogroups having 2 to 6 carbon atoms in ester groups such as trifluoroethyl (meth) acrylate, tetrafluoropropyl (meth) acrylate, and octafluoropentyl (meth) acrylate. Alkyl (meth) acrylate and the like can be mentioned.

Examples of the epoxy group-containing (meth) acrylate include glycidyl (meth) acrylate, α-methylglycidyl (meth) acrylate, and glycidyl allyl ether.

Examples of the carbonyl group-containing (meth) acrylate include acetonyl (meth) acrylate, diacetone (meth) acrylate, 2-hydroxypropyl (meth) acrylate acetyl acetate, butanediol-1,4-acrylate acetyl acetate, and 2- (aceto). Examples thereof include acetoxy) ethyl (meth) acrylate and (meth) acryloyloxyalkylpropenal.

The hydrophobic monomer (B) preferably contains at least one (meth) acrylic acid ester (hereinafter, also referred to as a monomer (B1)).
The (meth) acrylic acid ester is represented by the following formula (8);

(In the formula, R ⁸ represents a hydrogen atom or a methyl group. R ⁹ represents a hydrocarbon group having 1 to 30 carbon atoms.) It is preferable that the compound is represented by.
The hydrocarbon group preferably has 1 to 20 carbon atoms. It is more preferably 1 to 16, still more preferably 1 to 12, particularly preferably 1 to 8, and most preferably 2 to 8.
When the number of carbon atoms of the hydrocarbon group is 1 to 20, the water solubility and viscosity of the polymer can be in a suitable range, and the handling is excellent. When the hydrocarbon group has 1 to 12 carbon atoms, the polymer can be easily produced, and the hydrophobicity is in a preferable range, so that the water retention property is excellent.

The hydrocarbon group is not particularly limited, and examples thereof include a chain hydrocarbon group such as an alkyl group, an alkenyl group, and an alkynyl group, and a cyclic hydrocarbon group such as an aromatic hydrocarbon group, a cycloalkyl group, and a cycloalkenyl group. .. The above-mentioned hydrocarbon group may have a branch, and the number of carbon atoms of the hydrocarbon group when having a branch means the total number of carbon atoms of the main chain and the branched chain.
Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a hexyl group, a heptyl group, a 2-ethylhexyl group, an octyl group, a nonyl group, a decyl group and a dodecyl group. , Stearyl group, icosyl group and the like.
Examples of the alkenyl group include a vinyl group, an allyl group, a 1-butenyl group, a 2-butenyl group, a pentenyl group, a hexenyl group, a heptenyl group, an octenyl group, a nonenyl group, a decenyl group, a dodecenyl group, an octadecenyl group and an icosenyl group. And so on.
Examples of the alkynyl group include an ethynyl group, a 1-propynyl group, a 2-propynyl group, a butynyl group, a pentynyl group, a hexynyl group, a heptynyl group, an octynyl group, a nonynyl group, a decynyl group, a dodecynyl group, an octadecynyl group and an icocinyl group. And so on.

Examples of the aromatic hydrocarbon group include a phenyl group, a benzyl group, a tolyl group, an o-kisilyl group and the like.
Examples of the cycloalkyl group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group and the like.
Examples of the cycloalkenyl group include a cyclopropenyl group, a cyclobutenyl group, a cyclopentenyl group, a cyclohexenyl group and the like.
The hydrocarbon group is preferably an alkyl group or an alkenyl group, and more preferably an alkyl group.
That is, as the (meth) acrylic acid ester, a (meth) acrylic acid alkyl ester (alkyl (meth) acrylate) is preferable.

The alkyl (meth) acrylate is preferably methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, tert-. Butyl (meth) acrylate, sec-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, more preferably methyl (meth) acrylate, ethyl (meth) acrylate, n- With propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, sec-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate be.

In the above copolymer, the content ratio of the structural unit (b1) derived from the monomer (B1) is preferably 0.1 to 64% by mass with respect to 100% by mass of the total structural unit. It is more preferably 1 to 60% by mass, further preferably 1 to 55% by mass, still more preferably 5 to 50% by mass, still more preferably 10 to 40% by mass, and particularly preferably 20 to 40% by mass.

The cationic group-containing copolymer contained in the moisturizer of the present invention also has a structural unit derived from (meth) acrylic acid alkyl ester as a hydrophobic monomer and a solubility parameter of 15 or less, and is carboxyl. It may have a structural unit derived from a monomer having at least one functional group selected from the group consisting of a group, a hydroxyl group and an ether group. Copolymers having such structural units are also one of the preferred embodiments of the present invention.
The monomer having at least one functional group selected from the group consisting of the carboxyl group, the hydroxyl group and the ether group has a solubility parameter of 15 or less and has any functional group of the carboxyl group, the hydroxyl group and the ether group. It may have at least one functional group selected from the group consisting of a carboxyl group, a hydroxyl group and an ether group, even if it has a (meth) acrylic acid ester structure. It shall be classified as a monomer.
In the present invention, as the hydrophobic monomer, the above (meth) acrylic acid alkyl ester is copolymerized with a monomer having at least one functional group selected from the group consisting of a carboxyl group, a hydroxyl group and an ether group. Since the water solubility of the obtained copolymer is improved and the precipitation of the copolymer due to salt or pH change can be more sufficiently suppressed, the copolymer can be used in a wide pH range.
Examples of the monomer having at least one functional group selected from the group consisting of a carboxyl group, a hydroxyl group and an ether group include the above-mentioned unsaturated monocarboxylic acids; hydroxyl group-containing (meth) acrylates; alkyl vinyl ethers; and 2 to 2 carbon atoms. Examples thereof include an alkylene oxide adduct of 20 unsaturated alcohols; an addition reaction product of an unsaturated monomer having a cyclic ether-containing group having 2 to 8 carbon atoms and an alcohol having 1 to 20 carbon atoms.

Examples of the monomer having at least one functional group selected from the group consisting of a carboxyl group, a hydroxyl group and an ether group include unsaturated monocarboxylic acids; hydroxyl group-containing (meth) acrylates; and alkylenes of unsaturated alcohols having 2 to 20 carbon atoms. Oxide adduct; an addition reaction product of an unsaturated monomer having a cyclic ether-containing group having 2 to 8 carbon atoms and an alcohol having 1 to 20 carbon atoms is preferable.
As the unsaturated monocarboxylic acids, (meth) acrylic acid and salts thereof are preferable.
As the hydroxyl group-containing (meth) acrylate, 2-hydroxyethyl (meth) acrylate is preferable.

The unsaturated alcohol having 2 to 20 carbon atoms preferably has 2 to 18 carbon atoms, and examples of the unsaturated alcohol having 2 to 20 carbon atoms include vinyl alcohol, allyl alcohol, and isoprenyl alcohol.
The carbon number of the alkylene oxide in the alkylene oxide adduct of the unsaturated alcohol having 2 to 20 carbon atoms is preferably 2 to 16, more preferably 2 to 12, and further preferably 2 to 6. , Particularly preferably 2 to 4, and most preferably 2 to 3. Examples of the alkylene oxide include ethylene oxide, propylene oxide, butylene oxide, isobutylene oxide, 1-butene oxide, 2-butene oxide, and styrene oxide. Ethylene oxide, propylene oxide and butylene oxide are more preferable, and ethylene oxide and propylene oxide are more preferable.
The average number of moles of the alkylene oxide added is preferably 1 to 100. It is more preferably 1 to 80, still more preferably 1 to 70, and particularly preferably 1 to 50.
As the alkylene oxide adduct of the unsaturated alcohol having 2 to 20 carbon atoms, an ethylene oxide adduct of isoprenol is preferable.

Examples of the alcohol having 1 to 20 carbon atoms include alkyl alcohols such as methanol, ethanol, propanol, butanol, pentanol and hexanol. It is preferably an alkyl alcohol having 2 to 16 carbon atoms such as ethanol, propanol and butanol.
As the addition reaction product of the unsaturated monomer having a cyclic ether-containing group having 2 to 8 carbon atoms and an alcohol having 1 to 20 carbon atoms, 1-allyloxy-3-butoxypropan-2-ol is preferable.

The copolymer of the present invention has a structural unit (e) derived from the monomer (E) other than the cationic group-containing monomer (A) and the hydrophobic monomer (B). May be good. The other monomer (E) is not particularly limited as long as it does not have a cationic group and can be copolymerized with a cationic group-containing monomer and a hydrophobic monomer. The solubility parameter of the other monomer in the homopolymer may be 15 or less or more than 15. Regardless of whether the solubility parameter of the other monomer is 15 or less or more than 15, the hydrophobicity as a copolymer is as long as the above hydrophobic monomer is polymerized at a preferable ratio. It will be sufficiently maintained.
Further, from the viewpoint of adjusting the viscosity, a monomer having two or more ethylenically unsaturated groups may be contained regardless of the value of the solubility parameter. Examples of the monomer having two or more ethylenically unsaturated groups include ethylene glycol, propylene glycol, polyoxyethylene glycol, polyoxypropylene glycol, glycerin, polyglycerin, trimethylolpropane, pentaerythritol, saccharose, sorbitol, 1, Esters of disubstituted or higher hydroxyl groups of polyols such as 4-butanediol and (meth) acrylic acid; disubstituted or higher methacrylic acid esters of the above polyols; disubstituted or higher hydroxyl groups of the polyols, allyl alcohols, vinyl alcohols Ethers with unsaturated alcohols such as diallyl phthalate, triallyl phosphate, allyl methacrylate, tetraallyloxyethane, triallyl cyanurate, divinyl adipate, vinyl crotonate, 1,5-hexadien, divinylbenzene, etc. Can be mentioned. These other monomers may be used alone or in combination of two or more.
Further, from the viewpoint of imparting antibacterial properties, the copolymer of the present invention may be copolymerized with a polymerizable metal salt as another monomer. Examples of the polymerizable metal salt include heavy metal salts of unsaturated carboxylic acids such as zinc acrylate, zinc methacrylate, and zinc α-allyloxyacrylate.

<Method for producing cationic group-containing copolymer>
The production of the copolymer of the present invention is not particularly limited, but it can be produced by polymerizing the monomer components, and specific examples of the monomer components, preferable examples and preferable ratios of each monomer are co-produced. The composition is similar to that of the polymer.

The copolymer is preferably produced by a method of polymerizing the monomer component in the presence of a polymerization initiator. When polymerizing the monomer component, a polymerization initiator can be appropriately used depending on the polymerization method. As the polymerization initiator, commonly used ones can be used, for example, hydrogen peroxide; persulfate such as sodium persulfate and ammonium persulfate; dimethyl 2,2'-azobis (2-methylpropionate). ), 2,2'-Azobis (isobutyronitrile), 2,2'-azobis (2-methylbutyronitrile), 2,2'-azobis (isobutyric acid) dimethyl, 4,4'-azobis (4) -Cyanovaleric acid), 2,2'-azobis (2-methylpropion amidine) dihydrochloride, 2,2'-azobis [N- (2-carboxyethyl) -2-methylpropion amidine] n hydrate, 2,2'-Azobisisobuty [2- (2-imidazolin-2-yl) propane] dihydrochloride, 2,2'-azobis [2- (2-imidazolin-2-yl) propane] disulfate dihydration , 1,1'-azobis (cyclohexane-1-carbonitrile), 2,2'-azobis [N- (2-propenyl) -2-methylpropionamide], 2,2'-azobis (2,4- Azo-based compounds such as dimethylvaleronitrile); organic peroxides such as benzoyl peroxide, lauroyl peroxide, peracetic acid, and di-t-butyl peroxide are suitable. Of these polymerization initiators, azo compounds are preferable. The polymerization initiator is not limited to these examples. These polymerization initiators may be used alone or in combination of two or more.

The amount of the polymerization initiator used is not particularly limited as long as it can initiate the polymerization of the monomer component, but is usually 0.01 to 50 parts by mass with respect to 100 parts by mass of all the monomer components. , It is preferably 0.05 to 30 parts by mass, and more preferably 0.05 to 20 parts by mass.

As a method of using the cationic group-containing monomer used in the present invention, they may be used as an acid neutralized product neutralized with an acid.
The acid used for neutralizing the cationic group-containing monomer is not particularly limited, but is not particularly limited. Inorganic acids such as hydrochloric acid and sulfuric acid; acetic acid, citric acid, tartaric acid, toluenesulfonic acid, lactic acid, succinic acid and glycol. Examples include organic acids such as acids.

When the above acids are used, the amounts of these acids used are not particularly limited as long as some or all of the above cationic group-containing monomers are neutralized or quaternized, but the cationic group-containing singles used in the polymerization reaction are used. It is preferable that the acid is 0.5 to 2.0 specified with respect to 1 specified amount. It is more preferably 0.7 to 1.5, and particularly preferably 1.0 to 1.2.

In the above copolymerization method, as a method of adding the monomer component, the polymerization initiator, etc. to the reaction vessel, all the monomer components are charged in the reaction vessel, and the polymerization initiator is added into the reaction vessel. Method of performing polymerization: A part of the monomer component is charged into the reaction vessel, and the polymerization initiator and the remaining monomer component are added continuously or stepwise (preferably continuously) into the reaction vessel. Method of performing polymerization by: A method of charging a polymerization solvent in a reaction vessel and adding the entire amount of the monomer component and the polymerization initiator; one of the monomers (for example, a cationic group-containing monomer) A method of carrying out copolymerization by charging a part into a reaction vessel and adding a polymerization initiator and the remaining monomer component into the reaction vessel (preferably continuously) is preferable. Even in such a method, since the molecular weight distribution of the obtained copolymer can be narrowed (sharpened), the copolymerization is carried out by a method in which the polymerization initiator and the monomer component are sequentially added dropwise to the reaction vessel. Is preferable.

The copolymerization method can be carried out by, for example, solution polymerization, bulk polymerization, suspension polymerization, emulsion polymerization, living polymerization, graft polymerization and the like, and is not particularly limited, but solution polymerization is preferable. The solvent that can be used at this time is preferably water alone or a mixed solvent of water and a solvent. When only water is used, it is preferable in that the solvent removal step can be omitted.

The above copolymerization method can be carried out by either a batch method or a continuous method. In addition, known solvents can be used as the solvent used in the copolymerization as needed, and water; monohydric alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol, butanol, and THF (tetrahydrofuran); Polyhydric alcohols such as glycerin, (poly) ethylene glycol, propylene glycol, 1,3-butylene glycol, dipropylene glycol; aromatic or aliphatic hydrocarbons such as benzene, toluene, xylene, cyclohexane, n-heptane; acetic acid Esters such as ethyl; ketones such as acetone and methyl ethyl ketone; amides such as dimethylformamide; ethers such as diethyl ether and dioxane are suitable. These may be used alone or in combination of two or more. Among these, one or more solvents selected from the group consisting of water and lower alcohols having 1 to 4 carbon atoms may be used from the viewpoint of solubility of the monomer component and the obtained copolymer. preferable. The solvent is relatively inexpensive, and the production method of the present invention is economically excellent. Further, in the above-mentioned copolymerization method, a polyhydric alcohol solvent such as propylene glycol, 1,3-butylene glycol or ethylene glycol may be added to water for polymerization. When the above polyhydric alcohol solvent is used in combination with water, the solubility of the polymer can be enhanced, and soap-free polymerization can be suppressed more sufficiently. As a result, the formation of a polymer having poor water solubility can be more sufficiently suppressed, and the transparency of the solution can be further improved. When the polyhydric alcohol solvent and water are used in combination, the ratio of the polyhydric alcohol solvent to 100% by mass of water is preferably 0 to 200% by mass.
The polyhydric alcohol solvent is more preferably 1,3-butylene glycol.
When 1,3-butylene glycol is used as a solvent, the obtained copolymer contains 1,3-butylene glycol, and in this case, the moisturizing ability is more excellent.
A form in which the moisturizer of the present invention contains 0 to 80% by mass of 1,3-butylene glycol with respect to 100% by mass of the copolymer is also one of the preferred embodiments of the present invention.
The obtained polymer may be arbitrarily dissolved in water or arbitrarily dispersed, but those arbitrarily dissolved in water are particularly preferable. The form in which the copolymer of the present invention has an insoluble content of 1 g or less when 10 g of the copolymer is dissolved in 100 g of water at 25 ° C. is one of the preferred embodiments of the present invention.
The method for producing a copolymer of the present invention can also use any chain transfer agent, pH adjuster, buffer, or the like, if necessary.

The temperature at the time of polymerization is not particularly limited, but is usually 50 to 120 ° C, preferably 60 to 110 ° C. When the temperature at the time of polymerization is within the above range, the residual monomer component tends to decrease. It is not necessary to keep the temperature at the time of polymerization constant during the progress of the polymerization reaction. For example, the polymerization is started from room temperature and the temperature is raised to a set temperature at an appropriate temperature rise time or rate. After that, the set temperature may be maintained, or the polymerization temperature may be changed (increased or lowered) with time during the progress of the polymerization reaction depending on the dropping method of the monomer component, the initiator, or the like. May be good. Further, when the monomer component is polymerized, it is preferable to appropriately stir the monomer component so that the monomer component is polymerized uniformly.

The polymerization time is not particularly limited and may be appropriately set according to the progress of the polymerization reaction, but is usually about 2 to 9 hours.
In the present invention, the "polymerization time" represents the time during which the monomer is heated and stirred before the dropping, the time during which the monomer is added, and the aging time after the dropping of the monomer.

The pressure in the reaction system may be normal pressure (atmospheric pressure), reduced pressure, or pressurized pressure. The atmosphere in the reaction system may be either an air atmosphere or an inert atmosphere.

The solid content concentration in the aqueous solution (that is, the polymerized solid content concentration of the monomer) at the time when the polymerization reaction in the above polymerization reaction system is completed is preferably 20% by mass or more, more preferably 25 to 80% by mass. .. As described above, when the solid content concentration at the end of the polymerization reaction is as high as 20% by mass or more, the polymerization can be carried out at a high concentration and in one step. Therefore, a moisturizer containing a copolymer can be efficiently obtained, for example, the concentration step which is necessary in some cases in the conventional production method can be omitted. Therefore, the production efficiency can be significantly increased, and as a result, the productivity of the moisturizer of the present invention can be significantly improved, and the increase in production cost can be suppressed.

In the method for producing a copolymer of the present invention, an aging step may be provided for the purpose of increasing the polymerization rate of the monomer after the addition of all the raw materials used is completed. The aging time is usually 1-240 minutes, preferably 1-180 minutes, more preferably 1-120 minutes. If the aging time is less than 1 minute, the monomer component may remain due to insufficient aging, and toxicity and odor caused by the residual monomer become a problem.

The temperature of the polymer solution preferable in the aging step is in the same range as the above-mentioned polymerization temperature. Therefore, the temperature here may be maintained at a constant temperature (preferably the temperature at the time when the dropping is completed), or the temperature may be changed over time during aging.

The moisturizer of the present invention preferably contains the copolymer of the present invention in an amount of 0.01 to 100% by mass with respect to 100% by mass of the moisturizer. It is more preferably 0.1 to 90% by mass, further preferably 1 to 80% by mass, particularly preferably 1 to 70% by mass, and most preferably 1 to 60% by mass.
The moisturizer of the present invention may be used in combination with the copolymer of the present invention and other commonly used moisturizers, and such a form is also one of the preferred embodiments. The moisturizer that is usually used is not particularly limited, and examples thereof include moisturizers other than the copolymer of the present invention, which will be described later.

The present invention is also a cosmetic containing the above moisturizer.
The content of the copolymer of the present invention is preferably 0.001 to 10% by mass with respect to 100% by mass of the cosmetic. It is more preferably 0.01 to 10% by mass, further preferably 0.05 to 5% by mass, particularly preferably 0.1 to 5% by mass, and most preferably 0.1 to 2% by mass. Is.

The cosmetic of the present invention may contain other components other than the copolymer of the present invention.
The other components are not particularly limited as long as they do not impair the moisturizing performance of the moisturizer. For example, an oily base, a moisturizer / feel improver other than the copolymer of the present invention, a surfactant, and a polymer. , Thickening / gelling agents, solvents / propellants, antioxidants, reducing agents, oxidizing agents, preservatives / antibacterial agents, chelating agents, pH adjusters / acids / alkalis, powders, inorganic salts, ultraviolet absorbers , Whitening agents, vitamins and their derivatives, anti-inflammatory agents / anti-inflammatory agents, hair growth agents / blood circulation promoters / stimulants, hormones, anti-wrinkle agents / anti-aging agents / tightening agents / cold sensitizers / warming agents , Wound healing promoters / stimulants / painkillers / cell activators, plant / animal / microbial extracts, antipruritic agents, keratin exfoliating / solubilizers, antiperspirants, refreshing agents, astringents, enzymes, nucleic acids, Examples include fragrances, pigments / colorants / dyes / pigments, and water. Specific examples of these components include the following. In addition to the specific examples below, the same ones as those described in JP-A-2007-45776 can also be used.

Examples of the oily base include higher alcohols such as cetanol, oleyl alcohol, myristyl alcohol, stearyl alcohol, behenyl alcohol and octyldodecanol; higher fatty acids such as stearic acid, lauric acid and palmitic acid, and aluminum salts and calcium salts thereof. Metallic soaps such as magnesium salt, zinc salt, potassium salt; monoalcohol carboxylic acid esters such as cetyl octanoate, isostearyl palmitate, isopropyl palmitate, diethyl sebatate; dimethicone (dimethylpolysiloxane), cyclomethicone (cyclic) Silicones such as dimethylsiloxane, decamethylcyclopentasiloxane), trimethylsiloxysilicate, methylphenylpolysiloxane, dimethiconecopolyol; sterol esters such as macadamia nut oil fatty acid phytosteryl; sterols such as cholesterol; phosphorus such as hydrogenated lecithin Fatty acids; Vegetable oils and fats such as olive oil, palm oil, hydrogenated palm oil, macadamia nut oil; hydrocarbons such as liquid paraffin (mineral oil), light liquid isoparaffin, solid paraffin, squalane; triethylhexanoin (trioctanoin) ) And other polyhydric alcohol fatty acid esters; dimer acids or dimerdiol derivatives such as dimer dilinolate di (isostearyl / phytosteryl); waxes such as selecin, microcrystalin wax, candelilla wax; isopropyl myristate, lanolin Examples thereof include oxyacid esters such as fatty acid octyldodecyl.

Moisturizers and feel improvers other than the copolymer of the present invention include polyols such as polyethylene glycol, glycerin and 1,3-butylene glycol and polymers thereof; organic acids such as citric acid, tartrate acid and lactic acid and salts thereof. Amino acids such as arginine and salts thereof; white jellyfish polysaccharides; protein peptides such as soybean proteolytic peptides and derivatives thereof; sugar alcohols such as sorbitol and the like.

Examples of the surfactant include alkyl sulfates such as sodium myristyl sulfate, sodium cetyl sulfate and sodium acetylate; polyoxyethylene alkyl sulfates such as sodium laures sulfate; and acyl N- such as sodium myristylmethyltaurine and sodium lauroylsorbate. Methyl amino acid salts; laures (polyoxyethylene lauryl ethers), ceteth (polyoxyethylene cetyl ethers), oleths (polyoxyethylene oleyl ethers), steares (polyoxyethylene stearyl ethers); sorbitan monostearate (stealer) Polyoxyethylene sorbitan fatty acid ester such as sorbitan acid), sorbitan sesquistearate, sorbitan sesquioleate; Polyoxyethylene cured (hydrogenated) castor oil and cured castor oil derivatives; glycerin fatty acid partial esters such as glyceryl stearate; polyglycerin fatty acid esters such as polyglyceryl stearate-10 and polyglyceryl laurate-6; lauroanho Examples thereof include imidazoline-type betaines such as sodium acetate; fatty acid alkanolamides such as lauramide MPA, PPG-2 cocamide, and cocamide DEA; and polyoxyethylene / polyoxypropylene alkyl ethers such as PPG-6 decyltetradeceth-30.

Examples of the polymer and thickening / gelling agent include xanthan gum; carboxyvinyl polymer (carbomer); polyacrylic acid ester copolymer; celluloses; dextrin fatty acid ester such as dextrin palmitate; dimethyldialylammonium such as polyquaternium-6. Polymers of chloride; cationized cellulose such as polyquaternium-10; acrylic acid / diallyldimethylammonium chloride copolymers such as polyquaternium-22; alkyltrimethylammonium chlorides such as behentrimonium chloride, stearyltrimonium chloride, and cetrimonium chloride; Examples thereof include dialkyldimethylammonium chlorides such as dicocodimonium chloride.

Examples of the solvent / propellant include lower alcohols such as ethanol.
Examples of the antioxidant include tocopherol derivatives such as tocopherol (vitamin E); vitamin C (ascorbic acid) and / or derivatives thereof.
Examples of the reducing agent include cysteine, cysteamine, ammonium thioglycolate and the like.
Examples of the oxidizing agent include hydrogen peroxide solution and sodium bromate.
Examples of the preservative / antibacterial agent include hydroxybenzoic acid such as methylparaben, ethylparaben and propylparaben and a salt thereof or an ester thereof; phenoxyethanol; an isothiazolinone derivative such as methylisothiazolinone; sodium benzoate and the like.
Examples of the chelating agent include edetates (ethylenediaminetetraacetic acid) such as EDTA2Na and EDTA4Na; phosphonic acids such as etidroic acid and salts such as sodium salts thereof; pentetate (diethylenetriaminepentaacetate); sodium pyrophosphate and the like. Examples thereof include sodium polyphosphate.
Examples of the pH adjuster / acid / alkali include hydroxides of alkali metals such as sodium hydroxide and potassium hydroxide; amines such as monoethanolamine and triethanolamine; aqueous ammonia; diammonium phosphate and ammonium hydrogencarbonate. ; Sodium lactate and the like can be mentioned.

Examples of the powders include inorganic powders such as mica, talc, kaolin, and titanium oxide.
Examples of the inorganic salts include sulfates such as magnesium sulfate; and sodium phosphates such as 1Na, 2Na, and 3Na phosphate.
Examples of the ultraviolet absorber include cinnamic acid-based ultraviolet absorbers such as 2-ethylhexyl p-methoxycinnamate (octyl paramethoxycinnamate).
Examples of the whitening agent include ascorbic acid, salts thereof, and derivatives thereof.
Examples of the vitamins and their derivatives include vitamin Cs such as ascorbic acid and salts such as sodium thereof.
Examples of the anti-inflammatory agent / anti-inflammatory agent include glycyrrhizic acid and its derivatives.
Examples of the hair-growth agent, blood circulation promoter, and stimulant include Swertia japonica extract, plant extracts such as tincture, and tinctures.

As the medicinal agents such as the above-mentioned anti-wrinkle agent, anti-aging agent, tightening agent, cooling sensation agent, warming agent, wound healing promoter, irritation palliative agent, analgesic, cell activator, etc., fragrance substances such as menthol and their derivatives thereof. And so on.

The pigments / colorants / dyes / pigments include inorganic red pigments such as iron oxide (Bengala) and iron titanate; titanoic acid (lithium / cobalt); legal pigments such as Red No. 202 and Yellow No. 205; o- , M- or p-aminophenol, resorcin, toluene-2,5-diamine and the like, and oxidation dye intermediates such as salts thereof.
Examples of the water include normal water, purified water, hard water, soft water, natural water, deep ocean water, electrolytic alkaline ionized water, electrolytically acidic ionized water, ionized water, and cluster water.
In addition to these, cosmetic raw material standards, compounding ingredient standards by cosmetic type, Japan Cosmetic Industry Association ingredient display name list, INCI dictionary (The International Cosmetic Ingredient Dictionary and Handbook), non-pharmaceutical raw material standards, Japanese pharmacy, pharmaceutical additives Ingredients described in standards, official standards for food additives, etc., and the international patent classification IPC is described in Japanese and foreign patent gazettes and patent publication gazettes (including published gazettes and republished gazettes) belonging to the A61K7 classification. It is possible to contain known cosmetic ingredients, pharmaceutical ingredients, food ingredients, etc. in known combinations, blending ratios, and blending amounts.

The cosmetic of the present invention is not particularly limited, and examples thereof include skin cosmetics, external preparations for skin, and hair cosmetics.

The skin cosmetics are not particularly limited, but for example, basic cosmetics such as lotion, cream, milky lotion, and beauty liquid; makeup cosmetics such as liquid foundation, base milky lotion, teak color, eye shadow, mascara, and lipstick; Cleansing creams, facial cleansing foams, liquid wash pigments and other cleaning cosmetics; sunscreen cosmetics and other cosmetics (including non-medicinal products); bathing agents and other bath cosmetics.
Examples of the external preparation for skin include external medicines such as liniment, lotion and ointment.
The hair cosmetics are not particularly limited, and examples thereof include shampoos, conditioners, treatments, waxes, sprays, gels, and mists.

The present invention is also a skin cosmetic, an external skin preparation, or a hair cosmetic containing the moisturizer of the present invention.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples. Unless otherwise specified, "parts" means "parts by mass" and "%" means "% by mass".

<Gel Permeation Chromatography (GPC)>
The weight average molecular weight (Mw) of the cationic group-containing copolymer was measured by GPC (gel permeation chromatography).
The measurement conditions, equipment, etc. are as follows.
Equipment: Waters e2695
Detector: Differential Refractometer (RI) Detector Column: Tosoh TSKgel α-M, α-2500
Column temperature: 40 ° C
Flow velocity: 0.8 mL / min
Injection volume: 10 μL (sample concentration 0.4 wt% eluent preparation solution)
Calibration curve: Polyethylene glycol GPC software manufactured by GL Sciences: EMPOWER3 manufactured by Waters
Eluent: 0.5M acetic acid + 0.2M sodium nitrate / acetonitrile = 50/50 (v / v)

<Evaluation of moisturizing property>
The moisturizing property was evaluated by measuring the water content of the stratum corneum of the subject using the Cutometer dual MPA580 and the Corneometer CM825 under the following conditions.
Equipment: Cutometer dual MPA580 (Courage + Khazaka)
Probe: Corneometer CM825 (Courage + Khazaka)
Measurement environment: temperature 25 ° C, humidity 50%
1) Pure water and citric acid monohydrate were added to the copolymer sample and stirred to prepare a 5 wt% copolymer aqueous solution (pH 6 to 7). 4.0 g of a 5 wt% copolymer aqueous solution, 1.0 g of pure water, and 5.0 g of ethanol were mixed to prepare a 2 wt% sample solution.
2) The inside of the subject's forearm was washed to remove excess dirt and sebum. After 15 minutes, the water content was measured using Corneometer CM825.
3) On the inside of the forearm, 20 μL of the sample solution was applied to a ^{1 cm 2 mass.} It was dried for 30 minutes in an environment of a temperature of 25 degrees and a humidity of 50%, and after drying, it was rinsed with running tap water for 5 seconds.
4) The water content was measured 60 minutes after washing with running water.
5) The moisturizing ability was calculated by the following formula (1).
Moisturizing ability (%) = (moisture content after 60 minutes of washing) ÷ (moisture content before application) x 100 (1)

<Synthesis example 1>
In a glass separable flask equipped with a thermometer, a reflux condenser, and a stirrer, 70.0 g of 1,3-butanediol (hereinafter abbreviated as BG) and 30.0 g of pure water are charged and heated to 90 ° C. under stirring. The temperature was raised. Then, under stirring, 72.0 g of 2- (dimethylamino) ethyl methacrylate (hereinafter abbreviated as DAM) and ethyl methacrylate (hereinafter abbreviated as EMA. Solubility parameter: EMA) were placed in a polymerization reaction system at a constant state of 90 ° C. 9.7) 18.0 g and 30.8 g of a 5% aqueous solution of 2,2'-azobis (2-methylpropionamidine) dihydrochloride (hereinafter abbreviated as V-50) were added dropwise from separate dropping nozzles. .. Regarding the dropping time, dropping was started at the same time, DAM was dropped for 180 minutes, EMA was dropped for 170 minutes, and a 5% aqueous solution of V-50 was dropped for 210 minutes. After the completion of all dropping, the reaction solution was kept at 90 ° C. for another 30 minutes for aging to complete the polymerization. Later, 38.6 g of pure water was added to obtain a copolymer 1.
The solid content of the obtained copolymer 1 was 35.2%, and the weight average molecular weight was 35,000.

<Synthesis example 2>
90.0 g of BG and 10.0 g of pure water were placed in a glass separable flask equipped with a thermometer, a reflux condenser, and a stirrer, and the temperature was raised to 80 ° C. under stirring. Then, under stirring, 38.3 g of DAM, 27.0 g of EMA, and 38.3 g of a 5% aqueous solution of V-50 were added dropwise to the polymerization reaction system at a constant state of 80 ° C. from separate dropping nozzles. Regarding the dropping time, dropping was started at the same time, DAM was dropped for 180 minutes, EMA was dropped for 170 minutes, and a 5% aqueous solution of V-50 was dropped for 210 minutes. 180 minutes after the start of dropping, the temperature was raised to 90 ° C. with stirring. After the completion of all dropping, the reaction solution was kept at 90 ° C. for another 30 minutes for aging to complete the polymerization. Later, 34.3 g of BG was added to obtain a copolymer 2.
The solid content of the obtained copolymer 2 was 35.5%, and the weight average molecular weight was 34,000.

<Synthesis example 3>
90.0 g of BG and 10.0 g of pure water were placed in a glass separable flask equipped with a thermometer, a reflux condenser, and a stirrer, and the temperature was raised to 90 ° C. under stirring. Then, under stirring, 54.0 g of DAM, 36.0 g of EMA, and 33.0 g of a 5% aqueous solution of V-50 were added dropwise to the polymerization reaction system at a constant state of 90 ° C. from separate dropping nozzles. Regarding the dropping time, dropping was started at the same time, DAM was dropped for 180 minutes, EMA was dropped for 170 minutes, and a 5% aqueous solution of V-50 was dropped for 210 minutes. After the completion of all dropping, the reaction solution was kept at 90 ° C. for another 30 minutes for aging to complete the polymerization. Later, 38.6 g of BG was added to obtain a copolymer 3.
The solid content of the obtained copolymer 3 was 37.0%, and the weight average molecular weight was 29,000.

<Examples 1-1 to 1-3 and Comparative Example 1-1>
The moisturizing ability of the copolymers obtained in Synthesis Examples 1 to 3 was evaluated. The results are shown in Table 1.

Claims (5)

A moisturizer containing a cationic group-containing copolymer.
The copolymer has a structural unit (a) derived from the cationic group-containing monomer (A) and a structural unit (b) derived from the hydrophobic monomer (B).
The ratio of the structural unit (a) derived from the cationic group-containing monomer (A) is 36 to 99.9% by mass with respect to 100% by mass of all the structural units.
The weight average molecular weight is 4000 to 1,000,000.
The hydrophobic monomer (B) is a moisturizer containing a cationic group-containing copolymer characterized by having a solubility parameter of the homopolymer of 15 or less. The cationic group-containing monomer (A) is selected from the group consisting of a primary to tertiary amino group-containing monomer and / or a neutralized product of these acids and a quaternary ammonium base-containing monomer. The moisturizing agent according to claim 1, wherein the moisturizing agent is at least one kind. The moisturizer according to claim 1 or 2, wherein the hydrophobic monomer (B) contains at least one (meth) acrylic acid ester. A cosmetic containing the moisturizer according to any one of claims 1 to 3. The cosmetic according to claim 4, wherein the content of the cationic group-containing copolymer is 0.001 to 10% by mass with respect to 100% by mass of the cosmetic.