Composition containing a cationic group-containing polymer

Abstract

To provide a composition that is excellent in antiseptic antibacterial properties, solubility in water, and storage stability when dissolved in water.SOLUTION: A composition contains a polymer (A) having a cationic group-containing monomer-derived structural unit and a hydrophobic monomer-derived structural unit, and an acid. The total amount of the acid relative to 1 mol of the cationic group is 0.10 mol% or more and 1.50 mol% or less.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a composition containing a polymer having a cationic group. The composition containing the polymer having a cationic group of the present invention can be suitably used as a cosmetic composition such as a skin cosmetic, an external preparation for skin, a hair cosmetic, and the like.

Background Art

[0002] In recent years, from the viewpoints of consumers' cleaning orientation and hygiene, various products with antibacterial processing have been commercially available. Various antibacterial agents used in antibacterial processed products have also been developed, and inorganic and organic antibacterial agents have been developed. In Patent Document 1, there is described an antibacterial agent containing a polymer having a cationic group, wherein the polymer has a structural unit derived from a cationic group-containing monomer and a structural unit derived from a hydrophobic monomer, and the proportion of the structural unit derived from the cationic group-containing monomer is 36 to 99.9% by mass based on 100% by mass of all structural units, the weight average molecular weight is 4,000 to 1,000,000, and the hydrophobic monomer is characterized in that the solubility parameter of the homopolymer is 15 or less.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When using an antibacterial agent as a cosmetic additive such as lotion, the polymer described in Patent Document 1 has a hydrophobic group, so its solubility in water may be insufficient. To improve the solubility in water, it is conceivable to neutralize with an acid, but the storage stability of these neutralized aqueous solutions has also been required.

Means for Solving the Problems

[0005] In view of the above-mentioned problems, the inventors conducted research and found that a polymer (A) having structural units derived from cationic group-containing monomers and structural units derived from hydrophobic monomers, and a composition containing an acid, wherein the total amount of acid per mole of cationic group is 0.10 mol% to 1.50 mol%, exhibits excellent preservative and antibacterial properties when used as a cosmetic, as well as excellent solubility in water and excellent storage stability when dissolved in water, thus completing the present invention. [Effects of the Invention]

[0006] According to the present invention, it is possible to provide a composition that has excellent antiseptic and antibacterial properties, excellent solubility in water, and excellent storage stability when dissolved in water. Furthermore, it is possible to provide a cosmetic composition that suppresses stickiness and provides a refreshing feel. [Modes for carrying out the invention]

[0007] The details of this disclosure are described below. The composition of this disclosure comprises a polymer (A) having structural units derived from cationic group-containing monomers and structural units derived from hydrophobic monomers, and an acid, characterized in that the total amount of acid per mole of cationic group is 0.10 mol% or more and 1.50 mol% or less. The polymer (A) of the present disclosure has structural units derived from cationic group-containing monomers and structural units derived from hydrophobic monomers. The structural units derived from cationic group-containing monomers in this disclosure are those with the same structure as a cationic group-containing monomer in which at least one carbon-carbon double bond is replaced by a carbon-carbon single bond, and are not limited to structural units formed by polymerization of cationic group-containing monomers, but may also be structural units formed by post-reactions after polymerization, for example. The structural units derived from the cationic group-containing monomer in this disclosure are structural units derived from monomers containing cationic groups.

[0008] The cationic group in this disclosure is a group having a cation or a group that generates a cation, and is not particularly limited, but examples include primary to tertiary amino groups and quaternary ammonium bases. Among the above cationic groups, tertiary amino groups or quaternary ammonium bases are preferred, and tertiary amino groups are more preferred from the viewpoint of having antibacterial properties and low skin irritation. From the viewpoint of skin irritation, primary to tertiary amino groups may also be used.

[0009] <Primary to tertiary amino groups> Primary to tertiary amino groups are given by the following formula (1);

[0010] [ka]

[0011] The structure is preferably represented by the formula (wherein R1 and R2 are the same or different, and represent a hydrogen atom and a hydrocarbon group having 1 to 12 carbon atoms). 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. The number of carbon atoms in the hydrocarbon group is preferably 1 to 10, more preferably 1 to 8, particularly preferably 1 to 5, and most preferably 1 to 2. Preferably, at least one of R1 and R2 is a hydrocarbon group having 1 to 12 carbon atoms, and more preferably, both R1 and R2 are hydrocarbon groups having 1 to 12 carbon atoms. Among primary to tertiary amino groups, tertiary amino groups are preferred. Dimethylamino groups and diethylamino groups are preferred as tertiary amino groups.

[0012] <Quaternary ammonium base> The above quaternary ammonium base is given by the following formula (2);

[0013] [ka]

[0014] The structure is preferably represented by the formula (wherein R3 to R5 are the same or different hydrocarbon groups having 1 to 12 carbon atoms). 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. The number of carbon atoms in R3 to R5 is more preferably 1 to 10, even more preferably 1 to 7, and particularly preferably 1 to 5. For the hydrocarbon groups R3 to R5, methyl or ethyl groups are most preferred.

[0015] <Monomers containing cationic groups> In this disclosure, a cationic group-containing monomer includes, for example, monomers containing the above-mentioned primary to tertiary amino groups in their structure, and monomers containing a quaternary ammonium base in their structure. Specifically, N,N-dimethylaminoethyl (meth)acrylate, N,N-diethylaminoethyl (meth)acrylate, N,N-dimethylaminopropyl (meth)acrylate, N,N-diethylaminopropyl (meth)acrylate, and other N,N-dialkylamino group-containing (meth)acrylates and monomers obtained by adding a quaternizing agent to the above monomers or their neutralization products with acids; N,N-dimethylaminoethyl (meth)acrylamide, N,N-diethylaminoethyl (meth)acrylamide, N,N-dimethylaminopropyl (meth)acrylamide, N,N-diethylaminopropyl (meth)acrylamide, and other N,N-dialkylamino group-containing (meth)acrylamides and monomers obtained by adding a quaternizing agent to the above monomers or their neutralization products with acids; monomethylaminoethyl (meth)acrylate, monoethylaminoethyl (meth)acrylate, monomethylaminopropyl (meth)acrylate, monoethylaminopropyl (meth)acrylate, (meth)acrylic acid 2-(tert- Examples include monoalkylamino group-containing (meth)acrylates such as butylamino)ethyl and their neutralization products with acids; monoalkylamino group-containing (meth)acrylamides such as monomethylaminoethyl (meth)acrylamide, monoethylaminoethyl (meth)acrylamide, monomethylaminopropyl (meth)acrylamide, monoethylaminopropyl (meth)acrylamide and their neutralization products with acids; esters of (meth)acrylic acid and alkanolamines such as (meth)acrylic acid-2-aminoethyl and their neutralization products with acids; N,N-diallylmethylamine and monomers obtained by adding a quaternizing agent thereto or their neutralization products with acids; allylamine and their neutralization products with acids; addition reaction products of unsaturated monomers having a cyclic ether-containing group with 2 to 8 carbon atoms, such as 1-allyloxy-3-dibutylamino-2-ol and 1-allyloxy-3-diethanolamino-2-ol, and amine compounds with 1 to 24 carbon atoms, and monomers obtained by adding a quaternizing agent thereto or their neutralization products with acids.Particularly preferred are N,N-dialkylamino group-containing (meth)acrylates such as N,N-dimethylaminoethyl (meth)acrylate, N,N-diethylaminoethyl (meth)acrylate, N,N-dimethylaminopropyl (meth)acrylate, N,N-diethylaminopropyl (meth)acrylate, and monomers obtained by adding a quaternizing agent to the above monomers or neutralized products of these acids.

[0016] <Hydrophobic monomer> In the present disclosure, the structural unit derived from a hydrophobic monomer represents a structural unit having the same structure as the structure formed by polymerization of the hydrophobic monomer. That is, the structural unit derived from a hydrophobic monomer is not limited to the structural unit actually formed by polymerization of the hydrophobic monomer, and as long as it has the same structure, a structural unit formed by another production method is also included in the structural unit derived from the hydrophobic monomer. For example, the structural unit derived from methyl acrylate, CH2=CH(-COOCH3), can be represented by -CH2-CH(-COOCH3)-. The above hydrophobic monomer preferably has a solubility parameter of 15 or less with respect to the homopolymer obtained by homopolymerization. Note that even if the solubility parameter is 15 or less, those having a cationic group and containing a quaternary ammonium base are included in the cationic group-containing monomers.

[0017] The solubility parameter in the present disclosure is a value calculated by the method described in "POLYMER ENGINEERING AND SCIENCE" (1974, Vol. 14, No. 2, pages 147 to 154). The method is outlined below. The solubility parameter (δ) (cal / cm3)1 / 2 of the homopolymer is calculated by the following calculation method based on the evaporation energy (Δei) and molar volume (Δvi) of the constituent units forming the homopolymer. δ=(Δei / Δvi)1 / 2 (cal / cm3)1 / 2 If the solubility parameter of the homopolymer obtained by polymerizing the hydrophobic monomer alone is 15 or less, the hydrophobicity in the polymer of the present invention is sufficient, the affinity for the cell membrane of bacteria is improved, and the physiological activity of the cell membrane is inhibited, so that the antibacterial performance is excellent.

[0018] Examples of the hydrophobic monomer include esters ((meth)acrylates) of (meth)acrylic acid and an alcohol optionally having a substituent (hereinafter also referred to as (meth)acrylic acid ester); unsaturated monocarboxylic acids such as (meth)acrylic acid, crotonic acid, α-allyloxyacrylic acid and salts thereof; aromatic vinyl monomers such as styrene; olefin monomers such as ethylene and propylene; esters of unsaturated alcohols and carboxylic acids such as vinyl acetate; vinyl halides such as vinyl chloride; alkyl vinyl ethers such as methyl vinyl ether and ethyl vinyl ether; addition reaction products of unsaturated monomers having a cyclic ether-containing group with 2 to 8 carbon atoms such as 1-allyloxy-3-butoxypropan-2-ol and an alcohol having 1 to 20 carbon atoms; alkylene oxide adducts of unsaturated alcohols having 2 to 20 carbon atoms such as ethylene oxide adducts of allyl alcohol, ethylene oxide adducts of methallyl alcohol, and ethylene oxide adducts of isoprenol, and terminal hydrophobic modified products thereof; cyclic vinyl monomers such as N-vinylpyrrolidone. As the hydrophobic monomer, those having an alkyl group with 2 or more carbon atoms are preferable. When the hydrophobic monomer has an alkyl group with 2 or more carbon atoms, the affinity with the cell membrane of microorganisms increases and the antibacterial property is further improved. Examples of the salt of the unsaturated monocarboxylic acid 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 halogeno group such as a fluoro group; an epoxy group such as a glycidyl group; a carbonyl group such as an aldehyde group.

[0019] Examples of alkyl (meth)acrylates that do not have substituents as described above include 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, tridecyl (meth)acrylate, cyclohexyl (meth)acrylate and other cycloalkyl (meth)acrylates, n-lauryl (meth)acrylate, dodecyl (meth)acrylate, stearyl (meth)acrylate, isobornyl methacrylate, and the like.

[0020] Examples of hydroxyl group-containing (meth)acrylates include hydroxyl group-containing (meth)acrylates with ester groups having 1 to 18 carbon atoms, such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate. Examples of alkoxyalkyl (meth)acrylates include methoxyethyl (meth)acrylate, methoxypropyl (meth)acrylate, methoxybutyl (meth)acrylate, ethoxybutyl (meth)acrylate, and trimethylolpropane tripoxy (meth)acrylate. Examples of oxo group-containing (meth)acrylates include (di)ethylene glycol (methoxy)(meth)acrylates such as ethylene glycol (meth)acrylate, ethylene glycol methoxy(meth)acrylate, diethylene glycol (meth)acrylate, and diethylene glycol methoxy(meth)acrylate; alkoxy polyalkylene glycol (meth)acrylates with 1 to 100 repeating alkylene glycols such as alkoxy polyethylene glycol methacrylate (Anthox LMA-10); sulfopropyl (meth)acrylate; and (meth)acryloyloxyethyl phosphate.

[0021] Examples of fluorogroup-containing (meth)acrylates include trifluoroethyl (meth)acrylate, tetrafluoropropyl (meth)acrylate, octafluoropentyl (meth)acrylate, and other alkyl (meth)acrylates containing fluorogroups with 2 to 6 carbon atoms in the ester group. Examples of epoxy group-containing (meth)acrylates include glycidyl (meth)acrylate, α-methylglycidyl (meth)acrylate, and glycidyl allyl ether. Examples of carbonyl group-containing (meth)acrylates include acetonyl (meth)acrylate, diacetone (meth)acrylate, 2-hydroxypropyl (meth)acrylate acetylacetate, butanediol-1,4-acrylate acetylacetate, 2-(acetoacetoxy)ethyl (meth)acrylate, and (meth)acryloyloxyalkylpropenal.

[0022] The polymers of this disclosure preferably contain at least one structural unit derived from a (meth)acrylic acid ester as a structural unit derived from a hydrophobic monomer. The structural unit derived from the (meth)acrylic acid ester is given by the following formula (2);

[0023] [ka]

[0024] (In the formula, R5 represents a hydrogen atom or a methyl group. R6 represents a hydrocarbon group having 1 to 30 carbon atoms.) It is preferable that the structural unit is represented by .

[0025] The above (meth)acrylic acid ester and the structural units derived from the above (meth)acrylic acid ester preferably have 1 to 20 carbon atoms in the hydrocarbon group, more preferably 1 to 16, even more preferably 1 to 12, and particularly preferably 2 to 8. When the number of carbon atoms in the hydrocarbon group is 2 to 8, the water solubility and viscosity of the polymer can be set to a suitable range, and the polymer can be manufactured easily. Furthermore, safety is improved and antibacterial properties are further enhanced.

[0026] The hydrocarbon groups mentioned above are not particularly limited and include linear hydrocarbon groups such as alkyl groups, alkenyl groups, and alkynyl groups, aromatic hydrocarbon groups, and cyclic hydrocarbon groups such as cycloalkyl groups and cycloalkenyl groups. The hydrocarbon groups may be branched, and in the case of branching, the number of carbon atoms in the hydrocarbon group refers to the total number of carbon atoms in the main chain and the branched chain. Examples of alkyl groups include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, hexyl group, heptyl group, 2-ethylhexyl group, octyl group, nonyl group, decyl group, dodecyl group, stearyl group, and eicosyl group. Examples of alkenyl groups include vinyl group, allyl group, 1-butenyl group, 2-butenyl group, pentenyl group, hexenyl group, heptenyl group, octenyl group, nonenyl group, decenyl group, dodecenyl group, octadecenyl group, and eicosenyl group. Examples of the alkynyl groups mentioned above include ethynyl group, 1-propynyl group, 2-propynyl group, butynyl group, pentynyl group, hexynyl group, heptynyl group, octinyl group, noninyl group, desinyl group, dodecynyl group, octadecynyl group, and icosinyl group.

[0027] Examples of the above aromatic hydrocarbon groups include phenyl, benzyl, tolyl, and o-xylyl groups. Examples of the above cycloalkyl groups include cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl groups. Examples of the above cycloalkenyl groups include cyclopropenyl, cyclobutenyl, cyclopentenyl, and cyclohexenyl groups. The above hydrocarbon groups are preferably alkyl and alkenyl groups, and more preferably alkyl groups. That is, the above (meth)acrylic acid ester is preferably an alkyl (meth)acrylate.

[0028] Preferably, the alkyl (meth)acrylate is 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, or n-octyl (meth)acrylate. More preferably, the alkyl (meth)acrylate is 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, or 2-ethylhexyl (meth)acrylate. Particularly preferred is ethyl (meth)acrylate.

[0029] <Other ingredients> The polymers of this disclosure may have structural units derived from monomers other than the cationic group-containing monomers and hydrophobic monomers mentioned above. The other monomers are not particularly limited, and the solubility parameter of the homopolymer of the other monomers may be 15 or less, or greater than 15. Even if the solubility parameter of the other monomers is 15 or less, or greater than 15, the hydrophobicity of the polymer will be sufficiently maintained as long as the hydrophobic monomers are polymerized in a preferred proportion. Furthermore, from the viewpoint of adjusting viscosity, monomers having two or more ethylenically unsaturated groups may be included regardless of the value of the solubility parameter. Monomers having two or more ethylenically unsaturated groups include esters of (meth)acrylic acid with two or more substituted hydroxyl groups of polyols such as ethylene glycol, propylene glycol, polyoxyethylene glycol, polyoxypropylene glycol, glycerin, polyglycerin, trimethylolpropane, pentaerythritol, saccharose, sorbitol, and 1,4-butanediol; methacrylic acid esters with two or more substituted hydroxyl groups of the above polyols; ethers of unsaturated alcohols such as allyl alcohol and vinyl alcohol with two or more substituted hydroxyl groups of the above polyols; diallyl phthalate, triallyl phosphate, allyl methacrylate, tetraallyloxyethane, triallyl cyanurate, divinyl adipate, vinyl crotonate, 1,5-hexadiene, and divinylbenzene. These other monomers may be used individually or in combination of two or more. From the viewpoint of improving antibacterial properties, the polymer of the present invention may also be copolymerized with polymerizable metal salts as other monomers. Examples of polymerizable metal salts include heavy metal salts of unsaturated carboxylic acids such as zinc acrylate, zinc methacrylate, and zinc α-allyloxyacrylate. This disclosure

[0030] <Molecular weight> The weight-average molecular weight of the cationic group-containing polymer contained in the antibacterial agent of the present invention is preferably 4,000 to 1,000,000. When the weight-average molecular weight of the cationic group-containing polymer is within this range, the adsorption of the antibacterial agent to the material on which it is used tends to improve, thereby suppressing washing away during cleaning and tending to improve the antibacterial effect on the material. The weight-average molecular weight is preferably 4,000 to 800,000, more preferably 5,000 to 600,000, even more preferably 6,000 to 400,000, even more preferably 7,000 to 200,000, even more preferably 7,000 to 100,000, and particularly preferably 7,000 to 80,000. The weight-average molecular weight of the cationic group-containing polymer can be measured by the method described in the examples.

[0031] <Composition of polymer> The polymers of this disclosure have 36 to 99.9% by mass of structural units derived from cationic group-containing monomers, based on 100% by mass of the total amount of structural units forming the polymer. Preferably, this is 40 to 99% by mass, more preferably 42 to 98% by mass, even more preferably 43 to 97% by mass, even more preferably 45 to 96% by mass, particularly preferably 47 to 95% by mass, and most preferably 50 to 94% by mass. The polymers of this disclosure preferably contain 80 parts by mass or more, 90 parts by mass or more, more preferably 95 parts by mass or more, and may also contain 100 parts by mass, of primary to tertiary amines per 100 parts by mass of structural units derived from cationic group monomers, from the viewpoint of low skin irritation.

[0032] The polymer of this disclosure preferably has 0.01 to 64% by mass of structural units derived from hydrophobic monomers, based on 100% by mass of the total amount of structural units forming the polymer. More preferably 0.05 to 60% by mass, even more preferably 0.1 to 58% by mass, even more preferably 0.5 to 56% by mass, even more preferably 1 to 54% by mass, particularly preferably 3 to 52% by mass, and most preferably 5 to 50% by mass. The polymers of this disclosure preferably have a content of hydrophobic monomer-derived structural units in the polymer of 1 to 100% by mass, relative to 100% by mass of cationic group-containing monomer-derived structural units in the polymer. More preferably, it is 2 to 95% by mass, even more preferably 3 to 90% by mass, even more preferably 4 to 85% by mass, even more preferably 5 to 80% by mass, and particularly preferably 10 to 75% by mass. When the content of hydrophobic monomer-derived structural units in the polymer of the present invention is within this range, the antibacterial performance of the polymer tends to improve.

[0033] When the polymer of this disclosure has structural units derived from alkyl (meth)acrylate as structural units derived from hydrophobic monomers, the proportion of structural units derived from alkyl (meth)acrylate is preferably 0.01 to 64% by mass, based on 100% by mass of the total amount of structural units forming the polymer. More preferably, it is 1 to 54% by mass, and even more preferably 3 to 52% by mass. In the polymers of this disclosure, the content of structural units derived from unsaturated monocarboxylic acids is preferably 0 to 10% by mass, relative to 100% by mass of the total amount of structural units forming the polymer, from the viewpoint of storage stability such as promoting hydrolysis of the polymer. More preferably, it is 0 to 8% by mass, and even more preferably 0 to 5% by mass.

[0034] In the polymers of this disclosure, the content of structural units derived from unsaturated monocarboxylic acids is preferably 0 to 10% by mass, relative to 100% by mass of the total amount of structural units derived from hydrophobic monomers, from the viewpoint of promoting hydrolysis of the polymer. More preferably, it is 0 to 8% by mass, and even more preferably 0 to 5% by mass. The polymers of this disclosure preferably have a content of structural units derived from other monomers of 0 to 10% by mass, relative to 100% by mass of the total amount of structural units forming the polymer. More preferably, it is 0 to 8% by mass, and even more preferably 0 to 5% by mass. Among the other monomers, the content of structural units derived from monomers having two or more ethylenically unsaturated groups is preferably 0 to 1% by mass, more preferably 0 to 0.5% by mass, and even more preferably 0 to 0.1% by mass, relative to 100% by mass of the total amount of structural units forming the polymer.

[0035] <acid> In this disclosure, the acid is not particularly limited, but is used, for example, to neutralize primary to tertiary amino groups among structural units derived from cationic group-containing monomers. In the compositions of this disclosure, the acid may exist in the form of a salt after being neutralized by the above-mentioned amino group or other base, or it may exist in an unneutralized form. The acid used for neutralization is not particularly limited, but examples include inorganic acids or organic acids. Examples of inorganic acids include phosphoric acid, sulfuric acid, nitric acid, and hydrochloric acid, with phosphoric acid being preferred from the viewpoint of storage stability after neutralization and compatibility with cosmetics. Examples of organic acids include compounds containing carboxyl groups, compounds containing phosphate groups, compounds containing hydroxycarboxylic acid groups, alkyl sulfates, alkyl phosphorics, amino acid derivatives, ascorbic acid, and taurine.

[0036] Examples of carboxyl group-containing compounds in this disclosure include compounds having one carboxyl group, such as acetic acid, propionic acid, benzoic acid, and aliphatic monocarboxylic acids; and compounds containing multiple carboxyl groups, such as malonic acid, succinic acid, glutaric acid, adipic acid, maleic acid, fumaric acid, phthalic acid, oxalic acid, and diethylenetriaminepentaacetic acid, with compounds containing multiple carboxyl groups being more preferred. The above-mentioned compounds containing multiple carboxyl groups may have two or more carboxyl groups, but for example, it is preferable to have 2 to 10 carboxyl groups in one molecule, preferably 2 to 5 carboxyl groups, and preferably 2 to 3 carboxyl groups. When the number of carboxyl groups in one molecule is within the above range, the storage stability of the composition in this disclosure tends to improve.

[0037] Examples of phosphate-containing compounds in this disclosure include etidronic acid and phytic acid. Examples of hydroxycarboxylic acids in this disclosure include glycolic acid, lactic acid, hydroxyacrylic acid, oxybutyric acid, glyceric acid, malic acid, tartaric acid, citric acid, mandelic acid, salicylic acid, gluconic acid, and gallic acid, with citric acid, lactic acid, malic acid, tartaric acid, and mandelic acid being more preferred. Examples of amino acid derivatives of this disclosure include glycine, alanine, valine, leucine, isoleucine, threonine, serine, cysteine, methionine, aspartic acid, asparagine, glutamic acid, diiodotyrosine, lysine, arginine, histidine, phenylalanine, tyrosine, tryptophan, proline, oxyproline, glutamine, and the like, with glutamic acid and aspartic acid being more preferred.

[0038] From the viewpoint of solubility in water and storage stability, the acids of this disclosure are preferably phosphoric acid, compounds containing multiple carboxyl groups, compounds containing multiple phosphate groups, compounds containing hydroxycarboxylic acid groups, amino acid derivatives, and ascorbic acid, and more preferably citric acid, lactic acid, succinic acid, malic acid, tartaric acid, glutamic acid, and aspartic acid. When a composition of this disclosure contains an acid selected from the above, the storage stability of the composition tends to improve. On the other hand, from the viewpoint of odor, the content of acetic acid per 100 parts by mass of the acid of this disclosure is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, and even more preferably no acetic acid at all. In this disclosure, "not included" means intentionally not used.

[0039] <Composition> The composition of this disclosure is characterized by comprising a polymer (A) having structural units derived from cationic group-containing monomers and structural units derived from hydrophobic monomers, and an acid. The composition disclosed herein contains polymer (A) in 100 parts by mass of the composition, which may be 0.00001 parts by mass or more, preferably 0.00005 parts by mass or more, more preferably 0.00007 parts by mass or more, even more preferably 0.0001 parts by mass or more, and may be 5.0 parts by mass or less, preferably 4.0 parts by mass or less, more preferably 3.0 parts by mass or less, and even more preferably 2.0 parts by mass or less. The composition disclosed herein may contain 0.00001 parts by mass or more, preferably 0.00005 parts by mass or more, more preferably 0.0001 parts by mass or more, and even more preferably 0.0005 parts by mass or more, from the viewpoint of compatibility and storage stability, 1.0 part by mass or less, preferably 0.7 parts by mass or less, more preferably 0.6 parts by mass or less, and even more preferably 0.5 parts by mass or less. The composition disclosed herein may contain 0.1 parts by mass or less, preferably 0.05 parts by mass or less, more preferably 0.02 parts by mass or less, from the viewpoint of odor, and it is even more preferable that the composition does not contain acetic acid. In this disclosure, "not containing" means intentionally not using it.

[0040] In the compositions of this disclosure, the total amount of acid per mole of cationic group contained in polymer (A) may be 0.10 mol% or more, preferably 0.15 mol% or more, more preferably 0.20 mol% or more, even more preferably 0.25 mol% or more, and may be 1.50 mol% or less, preferably 1.40 mol% or less, more preferably 1.30 mol% or less, and even more preferably 1.20 mol% or less. When the amount is within the above range, the storage stability of the composition tends to improve.

[0041] The compositions of this disclosure may have a total amount of acid per mole of structural units derived from cationic group monomers of 0.10 mol% or more, preferably 0.15 mol% or more, more preferably 0.20 mol% or more, even more preferably 0.25 mol% or more, and may be 1.50 mol% or less, preferably 1.40 mol% or less, more preferably 1.30 mol% or less, and even more preferably 1.20 mol% or less.

[0042] The pH of the compositions of this disclosure can be determined according to the intended use. For example, in skincare applications such as lotions, serums, gels, emulsions, creams, and mist cosmetics; in haircare applications such as shampoos, hair rinses, hair conditioners, hair treatments, hair milks, hair mists, hair growth lotions, hair waxes, hair gels, and hair sprays; and in makeup applications such as liquid foundations and blushes, the pH is preferably 2.5 or higher, more preferably 3.0 or higher, even more preferably 3.5 or higher, preferably 8.0 or lower, more preferably 7.5 or lower, and even more preferably 7.0 or lower. In fatty acid-based body soaps, fatty acid-based facial cleansing foams, and bar soaps, the pH is preferably 7.5 or higher, more preferably 8.0 or higher, even more preferably 8.5 or higher, preferably 12.0 or lower, more preferably 11.5 or lower, and even more preferably 11.0 or lower. For sun care applications; in O / W gels, milks, etc., a pH of 4.5 or higher is preferred, 5.0 or higher is more preferred, 5.5 or higher is even more preferred, 9.0 or lower is preferred, 8.5 or lower is more preferred, and 8.0 or lower is even more preferred.

[0043] The compositions of this disclosure may contain compounds other than polymer (A) and acids. Compounds other than polymer (A) and acids are not particularly limited, but include, for example, water, nonionic surfactants, alcohols, thickeners, powder components, pH adjusters, anionic surfactants, cationic surfactants, amphoteric surfactants, oils, humectants, water-soluble polymers, antioxidants, UV absorbers, chelating agents, preservatives, antibacterial agents, colorants, fragrances, etc. For example, 3-hydroxy-2,2'iminodisuccinic acid or its salt (e.g., tetrasodium salt), which is a biodegradable chelating agent, may be included in the cosmetic compositions of this disclosure because it has antibacterial properties, scum-inhibiting effects, oil oxidation-inhibiting effects and yellowing-inhibiting effects in the acidic to alkaline range.

[0044] In this disclosure, "water" refers to purified water, distilled water, ion-exchanged water, pure water, soft water, hard water, natural water, deep-sea water, alkaline ionized water, and purified water obtained by various other methods. The compositions of this disclosure preferably contain 1% by mass or more of water, more preferably 5% by mass or more, and more preferably 10% by mass or more, based on 100% by mass of the total cosmetic composition. On the other hand, the cosmetic compositions of this disclosure preferably contain 99% by mass or less of water, more preferably 95% by mass or less, and more preferably 90% by mass or less, based on 100% by mass of the total cosmetic composition. When the water content is within the above range, the feel of use and storage stability when used as a cosmetic tend to be improved.

[0045] In this disclosure, a nonionic surfactant is a compound that does not exhibit ionic properties when dissolved in water, but possesses surfactant properties. Examples of nonionic surfactants in this disclosure include ester-type nonionic surfactants and ether-type nonionic surfactants. For example, ester-type nonionic surfactants are esters of fatty acids and alcohols, or esters of fatty acids and sugars. Examples include glycerin fatty acid esters, sorbitan fatty acid esters, sucrose fatty acid esters, and polyglycerin fatty acid esters. The fatty acid is a carboxylic acid having a hydrocarbon group, and the number of carbon atoms in the hydrocarbon group is preferably 2 to 25, more preferably 8 to 22, and particularly preferably 8 to 18. For example, ether-type nonionic surfactants include alkyl polyalkylene glycols, which are compounds obtained by adding alkylene oxide to a long-chain alcohol, such as alkyl polyethylene glycol and polyoxyethylene alkylphenyl ether.

[0046] In the nonionic surfactant of this disclosure, one preferred form is the use of two or more nonionic surfactants with different HLB (Hydrophilic-Lipophilic Balance) values. The HLB (Hydrophilic-Lipophilic Balance) value is a value that indicates the degree of affinity of a surfactant to water and oil. For example, if the HLB value is 8 to 16, it can be stably dispersed in water and suitably used as an O / W type emulsifier, and if the HLB value is 3 to 6, it has low solubility in water but can be slightly dispersed and suitably used as a W / O type emulsifier.

[0047] When using two or more nonionic surfactants with different HLB values, at least one nonionic surfactant with an HLB value of 8 to 16 and one nonionic surfactant with an HLB value of 3 to 6 should be used. By using two nonionic surfactants with different HLB values ​​in this way, the bimolecular film structure constituting the α-gel is fixed, resulting in a strong bimolecular film and increased strength and stability of the formed oil droplets. For example, a nonionic surfactant with an HLB value of 8 to 16 is a polyglycerin fatty acid ester, and polyglyceryl 5 stearate is particularly preferred. For example, a nonionic surfactant with an HLB value of 3 to 6 is a glycerin fatty acid ester, and glyceryl stearate is particularly preferred.

[0048] When using one or more nonionic surfactants selected from those with an HLB value of 8 to 16 and one or more nonionic surfactants selected from those with an HLB value of 3 to 6, it is preferable that the proportion of one or more nonionic surfactants selected from those with an HLB value of 8 to 16 relative to the total mass% of nonionic surfactants is 30% to 90% by mass. Within this range, the crystalline structure of the α-gel is stable. When mixing two or more types with different HLB values ​​as described above, higher alcohols may be used as needed. Higher alcohols are alcohols having hydrocarbon groups with 8 or more carbon atoms, and the hydrocarbon groups may be linear or branched. Particularly preferable is the use of one or more types with 14 to 22 carbon atoms in combination. In the nonionic surfactant of this disclosure, when using a nonionic surfactant with an HLB of 8 to 16 as another preferred form, it is preferable to use a higher alcohol when not using one or more nonionic surfactants selected from those with an HLB of 3 to 6. By using such a nonionic surfactant with a high HLB value and a higher alcohol, the bilayer structure constituting the α-gel is fixed, resulting in a high-strength bilayer and increased strength and stability of the formed oil droplets. The higher alcohol is an alcohol having a hydrocarbon group with 8 or more carbon atoms, and the hydrocarbon group may be linear or branched. Particularly preferred is a combination of one or more alcohols having 14 to 22 carbon atoms. Examples of oils in this disclosure include hydrocarbons such as liquid paraffin and squalane, waxes such as jojoba oil and liquid lanolin, esters such as isopropyl myristate, glyceryl tri-2-ethylhexanoate, diglyceryl diisostearate, and trimethylolpropane tri-2-ethylhexanoate, fats and oils such as castor oil and macadamia nut oil, linear polysiloxanes such as dimethylpolysiloxane and methylphenylpolysiloxane, cyclic polysiloxanes such as octamethylcyclotetrasiloxane and decamethylcyclopentasiloxane, and silicone oils such as amino-modified silicones. Examples of humectants in this disclosure include polyhydric alcohols and sugars, specifically propylene glycol, 1,3-butylene glycol, 1,3-propanediol, dipropylene glycol, 1,2-pentanediol, 1,2-hexanediol, isoprene glycol, diglycerin, methylpropanediol, glycerin, xylitol, sorbitol, maltitol, mannitol, erythritol, and the like. When the composition of this disclosure contains a polyhydric alcohol, the polyhydric alcohol used as the solvent during the polymerization of polymer (A) may be used as is. The humectants used in this disclosure may contain two or more humectants. For example, a mixture may be used which is a mixture of a divalent alcohol compound such as propylene glycol, 1,3-butylene glycol, 1,3-propanediol, dipropylene glycol, 1,2-pentanediol, 1,2-hexanediol, isoprene glycol, diglycerin, or methylpropanediol, and a trivalent or higher alcohol compound such as glycerin, xylitol, sorbitol, maltitol, mannitol, or erythritol. Propylene glycol, 1,3-butylene glycol, 1,3-propanediol, dipropylene glycol, 1,2-pentanediol, and 1,2-hexanediol are more preferred as the divalent alcohol compound, propylene glycol, 1,3-butylene glycol, 1,3-propanediol, and dipropylene glycol are even more preferred, and 1,3-butylene glycol is particularly preferred. Glycerin is more preferred as the trivalent or higher alcohol compound. By using a mixture of two or more humectants, improvements in usability and moisturizing properties can be expected. While the mixture may be added separately during the preparation of the cosmetic, it is also preferable to mix them beforehand. Examples of mixtures containing two or more humectants include combinations of divalent alcohol compounds and trivalent or higher alcohol compounds. The mass ratio of the divalent alcohol compound to the trivalent or higher alcohol compound (mass of divalent alcohol compound / mass of trivalent or higher alcohol compound) may be 90.0 / 10.0 to 99.9 / 0.1, 95 / 5 to 99.7 / 0.3, 99.0 / 1.0 to 99.5 / 0.5, 99.0 / 1.0 to 99.4 / 0.6, or 99.1 / 0.9 to 99.3 / 0.7. Including a trivalent or higher alcohol compound within the above range can be expected to improve the feel and moisturizing effect. Examples of mixtures containing two or more humectants include a combination of 1,3-butylene glycol and glycerin. The mass ratio of 1,3-butylene glycol to glycerin (mass of 1,3-butylene glycol / mass of glycerin) can be 90.0 / 10.0 to 99.9 / 0.1, 95 / 5 to 99.7 / 0.3, 99.0 / 1.0 to 99.5 / 0.5, 99.0 / 1.0 to 99.4 / 0.6, or 99.1 / 0.9 to 99.3 / 0.7. Including glycerin within the above range can be expected to improve usability and moisturizing properties. Examples of colorants in this disclosure include inorganic pigments and natural pigments. Examples of cooling agents in this disclosure include menthol, menthoxypropanediol, monomenthyl glyceryl ether, menthyl lactate, camphor, eugenol, mint oil, and peppermint oil.

[0049] <Method for producing polymer (A)> The production of polymer (A) of the present invention is not particularly limited, but it can be produced by including a step of polymerizing monomer components (hereinafter also referred to as the "polymerization step"), and specific examples and preferred examples of monomer components are as described above. The polymer (A) described above is preferably produced by polymerizing the monomer components in the presence of a polymerization initiator. That is, the polymerization step is preferably carried out in the presence of a polymerization initiator. When polymerizing the monomer components, a polymerization initiator can be used as appropriate depending on the polymerization method.

[0050] As the polymerization initiators mentioned above, commonly used ones can be used, for example, hydrogen peroxide; persulfates 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-methylpropionamidine) dihydrochloride, 2,2'-azobis[N-(2-carboxyethyl)-2-methylpropionate] Azo compounds such as ionamidine n-hydrate, 2,2'-azobis[2-(2-imidazolin-2-yl)propane] dihydrochloride, 2,2'-azobis[2-(2-imidazolin-2-yl)propane] disulfate dihydrate, 1,1'-azobis(cyclohexane-1-carbonitride), 2,2'-azobis[N-(2-propenyl)-2-methylpropionamide], and 2,2'-azobis(2,4-dimethylvaleronitrile); and organic peroxides such as benzoyl peroxide, lauroyl peroxide, peracetic acid, and di-t-butyl peroxide are preferred. Of these polymerization initiators, azo compounds are preferred. The above examples of polymerization initiators are not limited to these. These polymerization initiators may be used individually or in combination of two or more types. The amount of polymerization initiator used is not particularly limited as long as it is an amount that can start the polymerization of the monomer components, but it is usually 0.01 to 50 parts by mass, preferably 0.05 to 30 parts by mass, and more preferably 0.05 to 20 parts by mass, per 100 parts by mass of the total monomer components.

[0051] The cationic group-containing monomers of this disclosure may be used as quaternary ammonium salts that have been quaternized with a quaternizing agent. The quaternizing agents for cationic group-containing monomers are as described above. The amount of quaternizing agent used is preferably 0.1 to 1 mole per mole of cationic group-containing monomer. Regarding the method of quaternizing cationic group-containing monomers, a post-addition method is also preferred, in which the quaternizing agent is added after polymerization of the polymer of the present invention. The amount of quaternizing agent used is preferably 0.1 to 1 mole per mole of cationic group-containing monomer.

[0052] In the polymerization method or step described above, suitable methods for adding monomer components and polymerization initiators to the reaction vessel include: a method in which all monomer components are placed in the reaction vessel and copolymerization is carried out by adding the polymerization initiator to the reaction vessel; a method in which a portion of the monomer components are placed in the reaction vessel and copolymerization is carried out by adding the polymerization initiator and the remaining monomer components to the reaction vessel continuously or stepwise (preferably continuously); a method in which the polymerization solvent is placed in the reaction vessel and the entire amount of monomer components and polymerization initiator is added; and a method in which a portion of one of the monomers (for example, a cationic group-containing monomer) is placed in the reaction vessel and copolymerization is carried out by adding the polymerization initiator and the remaining monomer components to the reaction vessel (preferably continuously). Among these methods, copolymerization is preferred by sequentially dropping the polymerization initiator and monomer components into the reaction vessel, as this can narrow (sharpen) the molecular weight distribution of the resulting polymer.

[0053] The copolymerization method described above can be carried out by methods such as solution polymerization, bulk polymerization, suspension polymerization, emulsion polymerization, living polymerization, or graft polymerization, and is not particularly limited, but solution polymerization is preferred. The solvent that can be used in this case is preferably water alone or a mixed solvent of water and a solvent. When water alone is used, it is preferable in that the desolventing step can be omitted. The polymerization method or polymerization step described above can be carried out in batches or in a continuous manner. In addition, as solvents used as necessary during copolymerization, known solvents can be used, and are preferred to be 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 (1,3-butanediol), and dipropylene glycol; aromatic or aliphatic hydrocarbons such as benzene, toluene, xylene, cyclohexane, and n-heptane; esters such as ethyl acetate; ketones such as acetone and methyl ethyl ketone; amides such as dimethylformamide; and ethers such as diethyl ether and dioxane. These may be used individually or in combination of two or more. Among these, it is preferable to use one or more solvents selected from the group consisting of water and lower alcohols having 1 to 4 carbon atoms, from the viewpoint of the solubility of monomer components and the resulting polymer. The above solvents are relatively inexpensive, and the production method of the present invention is economically superior. Furthermore, in the above copolymerization method, polymerization may be carried out by adding a polyhydric alcohol solvent such as propylene glycol or ethylene glycol to water. By using the above polyhydric alcohol solvent in combination with water, the solubility of the polymer can be increased, and soap-free polymerization can be suppressed more effectively. This can more effectively suppress the formation of polymers with poor water solubility and further improve the transparency of the solution. When using the above polyhydric alcohol solvent and water in combination, the ratio of the polyhydric alcohol solvent to 100% by mass of water is preferably 0 to 200% by mass. The polymer production method of the present invention may use any chain transfer agent, pH adjuster, buffer, etc., as needed.The resulting polymer may be either arbitrarily soluble in water or arbitrarily dispersed, but arbitrarily soluble in water is particularly preferred. The temperature during polymerization is not particularly limited, but is usually 50 to 120°C, preferably 60 to 110°C. When the polymerization temperature is within this range, the amount of residual monomer components tends to decrease. The polymerization temperature does not need to be kept constant throughout the polymerization reaction. For example, polymerization may be started at room temperature, and the temperature may be raised to the set temperature at an appropriate heating time or rate, and then the set temperature may be maintained thereafter. Alternatively, the polymerization temperature may be varied over time (heated or cooled) during the polymerization reaction, depending on the dropwise addition method of monomer components and initiators.

[0054] Furthermore, when polymerizing monomer components, it is preferable to stir the mixture as needed to ensure that the monomer components polymerize uniformly. The polymerization time in the above polymerization is not particularly limited and can be set appropriately according to the progress of the polymerization reaction, but it is usually about 2 to 9 hours. In this invention, "polymerization time" refers to the time spent heating and stirring before dropping the monomer, the time spent adding the monomer, and the maturation time after dropping the monomer. The pressure within the reaction system in the above polymerization may be at normal pressure (atmospheric pressure), under reduced pressure, or under increased pressure, or a combination of these. The atmosphere within the reaction system may be either air or an inert atmosphere.

[0055] In the polymerization reaction system described above, the solid content concentration in the aqueous solution at the time the polymerization reaction is completed (i.e., the concentration of polymerized monomer solids) is preferably 20% by mass or more, and more preferably 25 to 80% by mass. When the solid content concentration at the end of the polymerization reaction is as high as 20% by mass or more, polymerization can be carried out at a high concentration in a single step. Therefore, the concentration step, which was sometimes necessary in conventional manufacturing methods, can be omitted, allowing for the efficient production of an antibacterial agent containing a polymer. Consequently, the manufacturing efficiency can be significantly increased, resulting in a substantial improvement in the productivity of the antibacterial agent of the present invention and a suppression of increases in manufacturing costs.

[0056] The polymer production method of the present invention may include a maturation step after all raw materials have been added, for the purpose of increasing the polymerization rate of the monomers. The maturation time is usually 1 to 240 minutes, preferably 1 to 180 minutes, and more preferably 1 to 120 minutes. If the maturation time is less than 1 minute, the maturation is insufficient and monomer components may remain, which can lead to problems such as toxicity and odor caused by the remaining monomers. Furthermore, the preferred temperature of the polymer solution during the maturation process is within the same range as the polymerization temperature. Therefore, the temperature here may be maintained at a constant temperature (preferably the temperature at the time the dropping process is completed), or the temperature may be changed over time during maturation. The method for producing the polymer of this disclosure may include, in addition to the polymerization step described above, other optional steps as needed. Examples of such optional steps include a maturation step, a concentration step, a purification step, a drying step, a dilution step, and so on.

[0057] <Method for producing the composition> The compositions of this disclosure include the step of adding an acid to the polymer (A) obtained by the above manufacturing method. Specific examples and preferred examples of the acid are as described above. In the method for producing the composition of the present disclosure, the total amount of acid per mole of cationic group monomer of polymer (A) may be 1.50 mol% or less, preferably 1.40 mol% or less, more preferably 1.30 mol% or less, and even more preferably 1.20 mol% or less, from the viewpoint of solubility in water and storage stability when dissolved in water. The compositions of this disclosure may also contain other additives as described above.

[0058] <Application> The compositions disclosed herein are preferably used in cosmetic applications such as skin cosmetics, topical skin preparations, or hair cosmetics. The above skin cosmetics are not particularly limited. For example, skin care cosmetics such as lotion, cream, gel, emulsion, essence, etc.; makeup cosmetics such as liquid foundation, base emulsion, cheek color, eye shadow, mascara, lipstick, etc.; cleansing cosmetics such as cleansing cream, facial wash foam, liquid facial cleanser, etc.; cosmetics (including quasi-drugs) such as sunscreen cosmetics; bath cosmetics such as bath agents, etc. Skin external preparations include external pharmaceuticals such as liniments, lotions, ointments, etc. The above hair cosmetics are not particularly limited. For example, shampoo, conditioner, treatment, wax, spray, gel, mist, etc.

Examples

[0059] Examples are given below to explain the present invention in more detail, but the present invention is not limited only to these examples. Unless otherwise specified, "parts" means "parts by mass" and "%" means "% by mass". <Measurement of weight average molecular weight (Mw)> Apparatus: EcoSEC HLC-8320GPC manufactured by Tosoh Corporation Detector: Differential refractive index meter (RI) detector Column: TSKgel α-M, α-2500 manufactured by Tosoh Corporation Column temperature: 40 °C Flow rate: 0.4 mL / min Injection volume: 20 μL (eluent preparation solution with a sample concentration of 0.4 wt%) Calibration curve: Polyethylene glycol manufactured by GL Sciences Inc. Eluent: 0.5 M acetic acid + 0.2 M sodium nitrate / acetonitrile = 50 / 50 (v / v)

[0060] <Compatibility> Those that could be uniformly mixed were marked as ○, and those that could not be uniformly mixed were marked as ×. <Viscosity measurement> Measured using a B-type viscometer (model: BMII) (manufactured by Toki Sangyo Co., Ltd.) under the conditions of rotor No. 4, rotation speed 12 rpm, measurement time 60 seconds, and temperature 25 °C. <pH measurement> Measured with a pH meter LAQUA pH / ION METER F-72 manufactured by HORIBA. The measurement temperature was 25°C. <Storage stability>Stored in an incubator at room temperature, 5°C, and 50°C for one month, and evaluated by 5 professional panelists. <Usability>Subjected to sensory evaluation by 5 professional panelists. <Evaluation methods for storage stability and usability>Five professional panelists conducted absolute evaluations on storage stability and usability according to the following evaluation criteria, and further determined the average score of the five panelists according to the following determination criteria. The determination criteria were shared for storage stability and usability. <Evaluation criteria>Storage stability / Usability 3 points: No separation or creaming occurred / No stickiness, watery 1 point: Some separation or creaming occurred / Slightly sticky 0 point: Separation or creaming occurred / Sticky <Determination criteria> 〇: 2.5 points or more △: 1.0 point or more and less than 2.5 points ×: Less than 1.0 point

[0061] <MIC (Minimum Inhibitory Concentration)> Aqueous solutions containing the copolymer were sequentially diluted twofold in Mueller-Hinton agar to prepare a series of copolymer-containing media. Then, 50 μL of each copolymer-containing medium was added to a 96-well polystyrene plate. Next, colonies of Escherichia coli (NBRC-3972), Staphylococcus aureus (NBRC-13276), or Pseudomonas aeruginosa (NBRC-13275), grown on Mueller-Hinton agar for 18 hours, were suspended in Butterfield buffer to prepare a bacterial suspension of approximately 10 × 10⁸ cells / mL. The prepared bacterial suspension was diluted to approximately 10 × 10⁶ cells / mL in Mueller-Hinton agar and added to the previously prepared dilution series in 50 μL increments. After standing at 35°C for 20 hours, the minimum antimicrobial agent concentration (ppm) in the medium where no bacteria grew was determined as the minimum inhibitory concentration (MIC). The presence or absence of bacterial growth was determined by visual inspection, specifically by whether the turbidity increased. The MIC value is preferably 300 ppm or less, more preferably 200 ppm or less, even more preferably 100 ppm or less, and particularly preferably 80 ppm or less. An MIC value of 300 ppm or less is preferable because it prevents the amount of antimicrobial agent added to achieve bacteriostatic performance from becoming excessive. <Preservative efficacy test> The preservative efficacy tests of the compositions disclosed herein were conducted in accordance with the methods described in the Japanese Pharmacopoeia. The target bacteria used were Escherichia coli and Staphylococcus aureus. Bacterial survival rates were measured 4 hours, 3 days, and 7 days after inoculation. Antimicrobial activity was determined as follows: ○ (antimicrobial activity present) if the bacterial survival rate after 4 hours was 1% or less of the inoculated bacterial count, and the bacterial count continued to decrease after 3 and 7 days; × (antimicrobial activity absent) otherwise.

[0062] [Synthesis Example - Synthesis of Polymers Containing Cationic Groups] <Synthesis Example 1> In a glass separable flask equipped with a thermometer, reflux condenser, and stirrer, 29.4 g of pure water and 100.0 g of 1,3-butanediol (manufactured by KH Neochem Co., Ltd.) were charged and the mixture was heated to 90°C while stirring. Then, under stirring, monomer solution 1 consisting of 60.0 g of 2-(dimethylamino)ethyl methacrylate (N,N-dimethylaminoethyl methacrylate) (manufactured by Kyoeisha Chemical Co., Ltd., hereinafter referred to as DAM), monomer solution 2 consisting of 40.0 g of ethyl methacrylate (manufactured by Kyoeisha Chemical Co., Ltd., hereinafter referred to as EMA), and initiator aqueous solution consisting of 18.3 g of a 10% aqueous solution of 2,2'-azobis(2-methylpropionamidine) dihydrochloride (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., hereinafter referred to as V-50) were added dropwise from separate dropping nozzles to the polymerization reaction system maintained at a constant temperature of 80°C. Regarding the start time of dropwise addition, monomer solutions 1 and 2 and the initiator aqueous solution were added dropwise simultaneously. Monomer solution 1 was added dropwise for 180 minutes, monomer solution 2 for 170 minutes, and the initiator aqueous solution for 210 minutes. After all dropwise addition was complete, the reaction solution was kept at 80°C for another 30 minutes to mature and complete the polymerization. Then, 55.2 g of pure water and 205.5 g of 1,3-butanediol were added to obtain copolymer 1. The solid content of the obtained copolymer 1 was 19.7%, the pH was 9.0, and the weight-average molecular weight was 30000.

[0063] [Manufacturing Example - Preparation of Copolymer-Containing Aqueous Solution] <Manufacturing Example 1> Citric acid was added to copolymer 1 to adjust the pH to 6, and the solution was prepared as an aqueous solution with a solid content of 2%. <Manufacturing Example 2> The preparation was the same as in Production Example 1, except that citric acid was replaced with lactic acid. <Manufacturing Example 3> The preparation was the same as in Production Example 1, except that the citric acid was replaced with phosphoric acid. <Manufacturing Example 4> The preparation was the same as in Production Example 1, except that citric acid was replaced with succinic acid. <Manufacturing Example 5> The preparation was the same as in Production Example 1, except that citric acid was replaced with malic acid. <Manufacturing Example 6> The preparation was the same as in Production Example 1, except that the citric acid in Production Example 1 was replaced with etidronic acid. <Manufacturing Example 7> The preparation was the same as in Production Example 1, except that citric acid was replaced with ascorbic acid. <Manufacturing Example 8> The preparation was the same as in Production Example 1, except that the citric acid was replaced with mandelic acid. <Manufacturing Example 9> The preparation was the same as in Production Example 1, except that citric acid was replaced with glutamic acid. <Manufacturing Example 10> The preparation was the same as in Production Example 1, except that citric acid was replaced with aspartic acid. <Manufacturing Example 11> The preparation was the same as in Production Example 1, except that citric acid was replaced with tartaric acid. <Comparative Manufacturing Example 1> Deionized water was added to adjust the solid content of copolymer 1 to 2%. <Comparative Manufacturing Example 2> The preparation was the same as in Production Example 1, except that citric acid was replaced with phytic acid. <Comparative Manufacturing Example 3> The preparation was the same as in Production Example 1, except that the citric acid was replaced with serine. <Comparative Manufacturing Example 4> The preparation was the same as in Production Example 1, except that the citric acid was replaced with taurine. Storage stability, pH, and antimicrobial activity (MIC) were evaluated for Production Examples 1 to 11 and Comparative Production Examples 1 to 4. The results are shown in Tables 1, 2, and 3.

[0064] [Table 1]

[0065] [Table 2]

[0066] [Table 3]

[0067] As shown in Tables 1 and 2, Production Examples 1 through 11 were found to have excellent storage stability. As shown in Table 3, it was found that manufacturing examples 1 through 11 exhibited excellent antibacterial properties.

[0068] [Manufacturing Example - Preparation of Copolymer-Containing Composition] <Manufacturing Example 12> (1) Mix 65.5 parts of deionized water, 5.0 parts of 1,3-butylene glycol-P (manufactured by KH Neochem Co., Ltd.), 8.0 parts of concentrated glycerin for cosmetics (manufactured by Sakamoto Pharmaceutical Industry Co., Ltd.), and 5.0 parts of Sunsoft α-C (manufactured by Taiyo Kagaku Co., Ltd.), and heat to 80°C ± 5°C while stirring until uniformly dissolved. (2) Mix 5.0 parts of olive squalane (manufactured by Fuyuho Alcohol Industry Co., Ltd.), 5.0 parts of CEH (manufactured by Fuyuho Alcohol Industry Co., Ltd.), 0.5 parts of KF-96A-100CS (manufactured by Shin-Etsu Chemical Co., Ltd.), and 1.0 part of TAISET 50-C (manufactured by Taiyo Kagaku Co., Ltd.), and heat to 80°C ± 5°C while stirring until uniformly dissolved. (3) While keeping (1) warm at 80°C ± 5°C, stir with a homomixer (Labo-Solution, manufactured by Primix Co., Ltd.) at 5000 rpm, add (2) little by little to emulsify and make a homogeneous mixture, and cool to 35°C. (4) Add citric acid to copolymer 1 to adjust the pH to 6 and adjust the aqueous solution of copolymer 1 to a solid content of 2%, and mix with 5.0 parts while stirring to obtain the O / W type emulsion of production example 12.

[0069] <Manufacturing Example 13> Except for changing the citric acid added to copolymer 1 to lactic acid, the preparation was carried out in the same manner as in Production Example 11 to obtain the O / W type emulsion of Production Example 13. <Manufacturing Example 14> Except for changing the citric acid added to copolymer 1 to phosphoric acid, the preparation was carried out in the same manner as in Production Example 11 to obtain the O / W type emulsion of Production Example 14. <Manufacturing Example 15> The preparation was carried out in the same manner as in Production Example 11, except that the citric acid added to copolymer 1 was changed to succinic acid, to obtain the O / W type emulsion of Production Example 15. <Manufacturing Example 16> Except for changing the citric acid added to copolymer 1 to malic acid, the preparation was carried out in the same manner as in Production Example 11 to obtain the O / W type emulsion of Production Example 16. <Manufacturing Example 17> Except for changing the citric acid added to copolymer 1 to etidronic acid, the preparation was carried out in the same manner as in Production Example 11 to obtain the O / W type emulsion of Production Example 17. <Manufacturing Example 18> Except for changing the citric acid added to copolymer 1 to ascorbic acid, the preparation was carried out in the same manner as in Production Example 11 to obtain the O / W type emulsion of Production Example 18. <Manufacturing Example 19> Except for changing the citric acid added to copolymer 1 to mandelic acid, the preparation was carried out in the same manner as in Production Example 11 to obtain the O / W type emulsion of Production Example 19. <Manufacturing Example 20> Except for changing the citric acid added to copolymer 1 to glutamic acid, the preparation was carried out in the same manner as in Production Example 11 to obtain the O / W type emulsion of Production Example 20. <Manufacturing Example 21> Except for changing the citric acid added to copolymer 1 to aspartic acid, the preparation was carried out in the same manner as in Production Example 11 to obtain the O / W type emulsion of Production Example 21. <Manufacturing Example 22> Except for changing the citric acid added to copolymer 1 to tartaric acid, the preparation was carried out in the same manner as in Production Example 11 to obtain the O / W type emulsion of Production Example 22. <Comparative Manufacturing Example 5> The preparation was carried out in the same manner as in Production Example 11, except that the aqueous solution of copolymer 1, adjusted to a solid content concentration of 2%, was not added, and the O / W type emulsion of Comparative Production Example 5 was obtained. For manufacturing examples 12 through 22 and comparative manufacturing example 5, we evaluated pH, viscosity, storage stability, usability, and antibacterial properties (storage efficacy test). The results are shown in Table 4.

[0070] [Table 4]

[0071] [Table 5]

[0072] As shown in Tables 4 and 5, Production Examples 11 to 20, which used polymers containing cationic groups, showed good compatibility when formulated as an O / W type emulsion and also exhibited excellent storage stability. In terms of usability, Production Examples 11 to 20 were as non-sticky and pleasant as Comparative Production Example 5. Regarding the preservation efficacy test, it was found that production examples 11 to 20, which contained polymers with cationic groups, exhibited antibacterial activity against both E. coli and Staphylococcus aureus. No increase in bacterial count was observed in preservation efficacy tests at 3 and 7 days, indicating that the antibacterial activity was maintained over a long period. Since comparative production example 5 lacked antibacterial activity, it was concluded that polymers containing cationic groups impart antibacterial properties to O / W type emulsions while also providing excellent storage stability and usability.

[0073] Regarding 1,3-butylene glycol and glycerin, mixtures were prepared with mass ratios of 1,3-butylene glycol to glycerin of 90:10, 95:5, 99:1, 99.1:0.9, and 99.4:0.6. Using the above mixture of 1,3-butylene glycol and glycerin, Production Examples 23 to 27 were prepared as compositions with a polymer containing a cationic group, as shown in Table 6 below. In the table, BG is synonymous with 1,3-butylene glycol.

[0074] [Table 6]

[0075] As shown in Table 6, Production Examples 23 to 27, which used a mixture of 1,3-butylene glycol and glycerin and a polymer containing cationic groups, showed good compatibility when formulated as an O / W emulsion and exhibited excellent storage stability. In terms of feel, they were non-sticky and pleasant, comparable to Production Example 12 and Comparative Production Example 5.

[0076] <Raw materials used> *1 Citric acid monohydrate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) *2 Musashino Lactic Acid 50F (manufactured by Musashino Chemical Research Institute Co., Ltd.) *3 Phosphate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) *4 Succinic acid (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) *5 DL-Malic acid (Fujifilm Wako Pure Chemical Industries) *6 Kirest 210SD (manufactured by Kirest) *7 L(+)-ascorbic acid (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) *8 (±)-Mandelic acid (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) *9 L-glutamic acid (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) *10 L-aspartic acid (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) *11 L(+)-Tartaric acid (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) *12 50% phytic acid solution (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) *13 L-serine (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) *14 Taurine (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) *15 1,3-Butylene glycol-P (manufactured by KH Neochem) *16 Cosmetic-grade concentrated glycerin (manufactured by Sakamoto Pharmaceutical Co., Ltd.) *17 Sunsoft α-C (manufactured by Taiyo Kagaku Co., Ltd.) *18-CEH (manufactured by Higher Alcohol Industry Co., Ltd.) *19-Olive Squalane (manufactured by Higher Alcohol Industry Co., Ltd.) *20-KF-96A-100CS (manufactured by Shin-Etsu Chemical Co., Ltd.) *21-TAISET 50-C (manufactured by Taiyo Kagaku Co., Ltd.)

Claims

1. A composition comprising a polymer (A) having structural units derived from a cationic group-containing monomer and structural units derived from ethyl methacrylate, and one or more selected from inorganic phosphoric acid, citric acid, lactic acid, succinic acid, malic acid, etidronic acid, ascorbic acid, mandelic acid, glutamic acid, and aspartic acid, wherein the total amount of acid per mole of cationic group is 0.10 moles or more and 1.50 moles or less, wherein the proportion of structural units derived from the cationic group-containing monomer per 100 parts by mass of polymer (A) is 50% by mass or more and 94% by mass or less, and the proportion of structural units derived from ethyl methacrylate is 5% by mass or more and 50% by mass or less.

2. A cosmetic composition using the composition described in claim 1.

3. A method for producing a composition comprising the steps of polymerizing a cationic group-containing monomer and ethyl methacrylate, and adding one or more substances selected from inorganic phosphoric acid, citric acid, lactic acid, succinic acid, malic acid, etidronic acid, ascorbic acid, mandelic acid, glutamic acid, and aspartic acid to the polymer (A) obtained in the first step, wherein the total amount of acid per mole of cationic group is 0.10 moles or more and 1.50 moles or less, and the proportion of structural units derived from the cationic group-containing monomer per 100 parts by mass of the polymer (A) is 50% by mass or more and 94% by mass or less, and the proportion of structural units derived from ethyl methacrylate is 5% by mass or more and 50% by mass or less.

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