Coacervate formation promoter

Abstract

The purpose of the present invention is to provide an agent having an exceptional effect for promoting coacervate formation. The present invention is a coacervate formation promoter containing a polymer having a structural unit (a) derived from an amino-group-containing monomer (A).

Description

Coacervate formation promoter

[0001] The present invention relates to a coacervate formation promoter, and more particularly to a coacervate formation promoter useful in body wash applications.

[0002] Conventionally, polymers having cationic groups (cationic polymers) have been suitably used as antibacterial agents (see, for example, Patent Document 1). It is also known that when a cationic polymer is combined with an anionic surfactant, a coacervate, which is a complex of these two, is formed. When a shampoo or the like containing a cationic polymer and an anionic surfactant is diluted by rinsing or the like, a coacervate is formed in a certain concentration range, and the coacervate adheres to hair, thereby providing a conditioning effect or the like.

[0003] Regarding coacervates, for example, Patent Document 2 discloses a hair wash composition having a composition comprising: (A) 0.1 to 10.0 wt % of succinylarginine Na represented by a given formula, (B) 0.3 to 0.8 wt % of a specific cationic polymer (at least one of polyquaternium-10 and guar hydroxypropyltrimonium chloride), and (C) 2.0 to 10.0 wt % of an amphoteric surfactant. For example, Patent Document 3 discloses a cleanser that contains at least an anionic surfactant, an amphoteric surfactant, and a cationic polymer, and that becomes two phases at 20 to 40°C and appears separated into two layers, wherein the lower of the two layers has viscoelastic properties such that G' (storage modulus) is greater than G'' (loss modulus) at 40°C in an angular velocity range of 30 to 100 rad / s.

[0004] JP 2017-214346 A JP 2021-134192 A JP 2006-274016 A

[0005] As described above, various polymers having cationic groups have been disclosed in the past, and cationic polymers that form coacervates have also been reported. However, these have not been sufficient from the viewpoint of promoting coacervate formation, and there is room for the development of an agent that has an excellent effect of promoting coacervate formation.

[0006] The present invention has been made in view of the above-mentioned current situation, and an object of the present invention is to provide an agent that has an excellent effect of promoting coacervate formation.

[0007] The present inventors have conducted extensive research into compounds that promote the formation of coacervates, and have found that polymers having structural units derived from amino group-containing monomers are highly effective in promoting the formation of coacervates between cationic polymers and anionic surfactants. This has led to the realization that the above-mentioned problems can be solved successfully, and has resulted in the present invention.

[0008] The present invention encompasses the following coacervate formation accelerators and the like. [1] A coacervate formation accelerator comprising a polymer having structural units (a) derived from an amino group-containing monomer (A). [2] The coacervate formation accelerator according to [1] above, wherein the polymer further has structural units (b) derived from a hydrophobic monomer (B). [3] The coacervate formation accelerator according to [1] or [2] above, wherein the polymer contains structural units (a) in an amount of 50 to 90% by mass, based on 100% by mass of all structural units. [4] A personal cleansing composition comprising the coacervate formation accelerator according to any one of [1] to [3] above, an anionic surfactant, and a cationic polymer. [5] The personal cleansing composition according to [4] above, wherein the coacervate formation accelerator is contained in an amount of 0.01 to 10% by mass, based on 100% by mass of the personal cleansing composition. [6] A method for imparting antibacterial properties to hair and / or skin, the method comprising the steps of applying the coacervate formation accelerator according to any one of [1] to [3] above to hair and / or skin, and rinsing the hair and / or skin after the application step.

[0009] The coacervate formation promoter of the present invention has the above-mentioned constitution and has an excellent coacervate formation promoting effect, and therefore can be suitably used in body cleansing compositions and the like.

[0010] FIG. 1 is a graph showing the antibacterial activity against Malassezia fungi when the concentration of the composition was changed for Example 7, Comparative Example 5, and Reference Examples 3 and 4 in Antibacterial Test 2.

[0011] Preferred embodiments of the present invention will be specifically described below, but the present invention is not limited to the following description and can be appropriately modified and applied within the scope of the present invention. Note that a combination of two or more of the individual preferred embodiments of the present invention described below also falls within the scope of the present invention.

[0012] [Coacervate Formation Accelerator] The coacervate formation accelerator of the present invention contains a polymer (hereinafter also referred to as amino group-containing polymer) having a structural unit (a) derived from an amino group-containing monomer (A). It is presumed that the amino group-containing polymer enhances the interaction between an anionic surfactant and a cationic polymer, thereby promoting coacervate formation between them. Furthermore, the amino group-containing polymer also has excellent antibacterial properties against Malassezia, a causative agent of dandruff. It is believed that the cationic amino groups of the amino group-containing polymer adsorb to the negatively charged cell surface of Malassezia, disrupting the cell membrane, thereby exerting antibacterial properties against Malassezia. It is also believed that the coacervate formation accelerator of the present invention effectively exerts antibacterial activity even at low concentrations by forming a coacervate and allowing the dissociated amino group-containing polymer to act on Malassezia, thereby exerting antibacterial activity. The use of a polymer having a structural unit (a) derived from an amino group-containing monomer (A) to promote coacervate formation is also a part of the present invention. The present invention also relates to a method for promoting coacervate formation, which includes a step of adding a polymer having a structural unit (a) derived from an amino group-containing monomer (A) to a composition containing an anionic surfactant and a cationic polymer.

[0013] The content of the amino group-containing polymer in the coacervate formation accelerator of the present invention is not particularly limited, but is preferably 0.001 to 100% by mass, more preferably 1 to 100% by mass, even more preferably 30 to 100% by mass, and particularly preferably 50 to 100% by mass, relative to 100% by mass of the coacervate formation accelerator.

[0014] The coacervate formation accelerator of the present invention may contain other components in addition to the amino group-containing polymer. The content of the other components is not particularly limited, but is preferably 0 to 99.999% by mass relative to 100% by mass of the coacervate formation accelerator. It is more preferably 0 to 99% by mass, even more preferably 0 to 70% by mass, and particularly preferably 0 to 50% by mass.

[0015] <Amino Group-Containing Polymer> The amino group-containing polymer has a structural unit (a) derived from an amino group-containing monomer (A). The content of the structural unit (a) in the amino group-containing polymer is not particularly limited, but is preferably 1 to 99% by mass relative to 100% by mass of all structural units. This allows the coacervate formation-promoting effect to be more fully exhibited. The content of the structural unit (a) is more preferably 10 to 97% by mass, even more preferably 36 to 96% by mass, and particularly preferably 50 to 95% by mass. In one embodiment, the content of the structural unit (a) may be 50 to 90% by mass, preferably 50 to 85% by mass, more preferably 50 to 80% by mass, even more preferably 50 to 75% by mass, and particularly preferably 50 to 70% by mass relative to 100% by mass of all structural units.

[0016] The amino group-containing polymer preferably further contains a structural unit (b) derived from the hydrophobic monomer (B), which improves the balance between hydrophilicity and hydrophobicity in the amino group-containing polymer, further improves the interaction between the anionic surfactant and the cationic polymer, and further promotes coacervate formation.

[0017] The content of the structural unit (b) in the amino group-containing polymer is not particularly limited, but is preferably 1 to 99% by mass relative to 100% by mass of all structural units. It is more preferably 3 to 90% by mass, even more preferably 4 to 70% by mass, and particularly preferably 5 to 50% by mass. Furthermore, in one embodiment, the content of the structural unit (b) may be 10 to 50% by mass relative to 100% by mass of all structural units, preferably 15 to 50% by mass, more preferably 20 to 50% by mass, even more preferably 25 to 50% by mass, and particularly preferably 30 to 50% by mass.

[0018] The amino group-containing polymer may have a structural unit (c) derived from a monomer (C) other than the amino group-containing monomer (A) and the hydrophobic monomer (B). The content of the structural unit (c) is preferably 0 to 10% by mass, more preferably 0 to 5% by mass, even more preferably 0 to 1% by mass, particularly preferably 0 to 0.1% by mass, and most preferably 0% by mass, relative to 100% by mass of all structural units.

[0019] The mass ratio of the structural unit (a) derived from the amino group-containing monomer (A) to the structural unit (b) (mass of the structural unit (a) derived from the amino group-containing monomer (A) / mass of the structural unit (b)) in the amino group-containing polymer may be 99 / 1 to 1 / 99, preferably 95 / 5 to 40 / 60, more preferably 80 / 20 to 50 / 50, and particularly preferably 70 / 30 to 55 / 45.

[0020] The weight-average molecular weight of the amino group-containing polymer is not particularly limited, but is preferably 4,000 to 800,000. This allows the effects of the present invention to be more fully exhibited. The weight-average molecular weight is more preferably 6,000 to 400,000, even more preferably 7,000 to 80,000, even more preferably 8,000 to 70,000, still more preferably 10,000 to 60,000, even more preferably 15,000 to 55,000, and particularly preferably 20,000 to 50,000. The weight-average molecular weight of the amino group-containing polymer can be measured by the method described in the Examples.

[0021] (Amino Group-Containing Monomer (A)) Specific examples of the amino group in the amino group-containing monomer (A) include primary to tertiary amino groups, neutralized products of primary to tertiary amino groups with acids, and quaternary ammonium bases. Examples of the primary to tertiary amino groups include those represented by the following formula (1);

[0022]

[0023] (In the formula, R １ and R ２ are the same or different and represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms. ) is preferred. The hydrocarbon group may have a chain structure or a ring structure, but a chain structure is preferred. When the hydrocarbon group has a chain structure, it may be linear or branched. 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. The R １ and R ２ At least one of R is preferably a hydrocarbon group having 1 to 12 carbon atoms. １ and R ２ and (b) are more preferably hydrocarbon groups having 1 to 12 carbon atoms. That is, among the primary to tertiary amino groups, a tertiary amino group is preferred.

[0024] The primary to tertiary amine bases include those represented by the following formula (2):

[0025]

[0026] (In the formula, R １ , R ２ are the same or different and represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms. － represents an anion. Specific examples and preferred forms of the hydrocarbon group are as described above.

[0027] The quaternary ammonium base may be a compound represented by the following formula (3):

[0028]

[0029] (In the formula, R ３ ~R ５ are the same or different and represent a hydrocarbon group having 1 to 12 carbon atoms. － represents an anion. Specific examples and preferred forms of the hydrocarbon group 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 or an alkenyl group having 2 to 12 carbon atoms. R ３ ~R ５ The number of carbon atoms in R is more preferably 1 to 10, further preferably 1 to 7, and particularly preferably 1 to 5. ３ ~R ５ The hydrocarbon group is most preferably a methyl group or an ethyl group.

[0030] Y in the above formulas (2) and (3) － is not particularly limited, and examples thereof include halide ions such as chloride ions, bromide ions, and iodide ions; alkyl sulfate ions such as methyl sulfate ions; and ions of organic acids such as acetate ions. － is preferably an ion of an organic acid. － is preferably a halide ion or an alkyl sulfate ion.

[0031] As the amino group, among primary to tertiary amino groups, neutralized products of primary to tertiary amino groups with acids, and quaternary ammonium bases, a tertiary amino group, a neutralized product of a tertiary amino group with acids, or a quaternary ammonium base is preferred. As the tertiary amino group or a neutralized product of a tertiary amino group with acids, a dimethylamino group, a diethylamino group, or neutralized products thereof with acids such as hydrochloric acid or acetic acid is preferred.

[0032] The amino group-containing monomer (A) may be any of the following formulae (4-1) to (4-3):

[0033]

[0034] (In formulas (4-1) to (4-3), R ６ ~R ８are the same or different and represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. X represents a direct bond or a divalent linking group. In formulas (4-1) and (4-2), R １ , R ２ is R in the above formula (1). １ , R ２ In formula (4-3), R ３ ~R ５ is R in the above formula (3). ３ ~R ５ It is the same as Y. － represents an anion.

[0035] The above R ８ The alkyl group having 1 to 5 carbon atoms in the above R is preferably a methyl group. ８ is preferably a hydrogen atom or a methyl group. From the viewpoint of antibacterial properties and hydrolysis resistance, R ８ A methyl group is more preferred as the R ６ , R ７ is preferably a hydrogen atom.

[0036] The divalent linking group for X in the above formulas (4-1) and (4-2) is not particularly limited, but may be, for example, an alkylene group having 1 to 12 carbon atoms or a group represented by the following formula (5):

[0037]

[0038] (wherein m represents an integer of 0 to 12), the following formula (6);

[0039]

[0040] (wherein e represents an integer of 0 to 4) and the following formula (7);

[0041]

[0042] (wherein k represents an integer of 1 to 10). In the above formula (5), m is preferably 1 to 8, more preferably 1 to 5. In the above formula (7), k is preferably 1 to 8, more preferably 1 to 5.

[0043] The divalent linking group for X in the above formula (4-3) is preferably an alkylene group having 1 to 12 carbon atoms.

[0044] Specific examples of the amino group-containing monomer (A) include N,N-dialkylamino group-containing (meth)acrylates such as N,N-dimethylaminoethyl (meth)acrylate, N,N-diethylaminoethyl (meth)acrylate, N,N-dimethylaminopropyl (meth)acrylate, and N,N-diethylaminopropyl (meth)acrylate, as well as monomers obtained by adding a quaternizing agent to the above monomers, or neutralized products thereof with an acid such as hydrochloric acid or acetic acid; N,N-dimethylaminoethyl (meth)acrylamide, N,N-diethylaminoethyl N,N-dialkylamino group-containing (meth)acrylamides such as (meth)acrylamide, N,N-dimethylaminopropyl (meth)acrylamide, N,N-diethylaminopropyl (meth)acrylamide, and monomers obtained by adding a quaternizing agent to the above monomers, or products thereof neutralized with an acid such as hydrochloric acid; monoalkylamino group-containing (meth)acrylates such as monomethylaminoethyl (meth)acrylate, monoethylaminoethyl (meth)acrylate, monomethylaminopropyl (meth)acrylate, monoethylaminopropyl (meth)acrylate, and 2-(tert-butylamino)ethyl (meth)acrylate, and products thereof neutralized with an acid such as hydrochloric acid; monoalkylamino group-containing (meth)acrylamides such as monomethylaminoethyl (meth)acrylamide, monoethylaminoethyl (meth)acrylamide, monomethylaminopropyl (meth)acrylamide, and monoethylaminopropyl (meth)acrylamide, and products thereof neutralized with an acid such as hydrochloric acid; esters of (meth)acrylic acid and alkanolamines such as 2-aminoethyl (meth)acrylate. and their neutralization with an acid such as hydrochloric acid; N,N-diallylmethylamine and a monomer obtained by adding a quaternizing agent thereto, or a neutralization product thereof with an acid such as hydrochloric acid; allylamine and their neutralization with an acid such as hydrochloric acid; addition reaction products of unsaturated monomers having a cyclic ether-containing group having 2 to 8 carbon atoms, such as 1-allyloxy-3-dibutylamino-2-ol and 1-allyloxy-3-diethanolamino-2-ol, with an amine compound having 1 to 24 carbon atoms, and their monomers obtained by adding a quaternizing agent thereto, or a neutralization product thereof with an acid such as hydrochloric acid.

[0045] The amine compound having 1 to 24 carbon atoms is not particularly limited as long as it has an amino group and can react with the cyclic ether structure of the unsaturated monomer having a cyclic ether-containing group having 2 to 8 carbon atoms. The number of carbon atoms in the amine compound having 1 to 24 carbon atoms is preferably 1 to 20, and more preferably 1 to 16. Examples of the amine compound having 1 to 24 carbon atoms include primary amines and secondary amines, such as (di)alkylamines having 1 to 24 carbon atoms, (di)alkanolamines having 1 to 24 carbon atoms, and alkylalkanolamines having 1 to 24 carbon atoms. Examples of the (di)alkylamines having 1 to 24 carbon atoms include methylamine, ethylamine, propylamine, butylamine, dimethylamine, diethylamine, dipropylamine, dibutylamine, pentylamine, dipentylamine, hexylamine, dihexylamine, heptylamine, diheptylamine, octylamine, dioctylamine, dodecylamine, and didodecylamine. Preferred C1-24 (di)alkanolamines include methanolamine, ethanolamine, propanolamine, butanolamine, dimethanolamine, diethanolamine, dipropanolamine, dibutanolamine, hexanolamine, etc. Preferred C1-24 alkylalkanolamines include methylethanolamine, etc.

[0046] The divalent linking group represented by X in the above formulas (4-1) to (4-3) is preferably a structure represented by the above formula (5). ８ is preferably a methyl group, and X is preferably a structure represented by the above formula (5).

[0047] The amino group-containing monomer (A) is preferably N,N-dialkylamino group-containing (meth)acrylates and their neutralization products with acids such as hydrochloric acid, or monomers obtained by adding a quaternizing agent to these; N,N-dialkylamino group-containing (meth)acrylamides and their neutralization products with acids such as hydrochloric acid, or monomers obtained by adding a quaternizing agent to these; among these, N,N-dimethylaminoethyl (meth)acrylate, N,N-diethylaminoethyl (meth)acrylate, N,N-dimethylaminopropyl (meth)acrylamide and their neutralization products with acids such as hydrochloric acid, or monomers obtained by adding a quaternizing agent to these are more preferred. The quaternizing agent is not particularly limited, but examples include common alkylating agents such as alkyl halides such as methyl chloride, ethyl chloride, methyl bromide, and methyl iodide; and alkyl sulfates such as dimethyl sulfate, diethyl sulfate, and di-n-propyl sulfate.

[0048] (Hydrophobic Monomer (B)) The hydrophobic monomer (B) has a solubility parameter of 15 or less in a homopolymer obtained by homopolymerization. Even if the solubility parameter is 15 or less, if the monomer has an amino group, it is included in the amino group-containing monomer (A). Here, the solubility parameter is a value calculated by the method described on pages 147-154 of "POLYMER ENGINEERING AND SCIENCE" (1974, Vol. 14, No. 2). The method is outlined below. Solubility parameter (δ) (cal / cm) of a homopolymer ３ ) １／２ is calculated by the following calculation method based on the evaporation energy (Δei) and molar volume (Δvi) of the structural units forming the polymer: δ=(Δei / Δvi) １／２ (cal / cm ３ ) １／２

[0049] If the solubility parameter of the homopolymer obtained by polymerizing the hydrophobic monomer (B) alone is 15 or less, the hydrophobicity of the copolymer of the present invention will be sufficient, the affinity for the cell membrane of microorganisms will be improved, and the interaction with the cell membrane will be increased, damaging the physiological activity of the cell membrane and resulting in superior antibacterial performance. The solubility parameter is preferably 14 or less, more preferably 13 or less, and even more preferably 12 or less. The solubility parameter is usually 5 or more.

[0050] The hydrophobic monomer (B) is not particularly limited as long as the solubility parameter of the homopolymer is 15 or less, and examples thereof include esters ((meth)acrylates) of (meth)acrylic acid and alcohols which may have a substituent; 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; and methyl vinyl. Examples of suitable hydrophobic monomers include alkyl vinyl ethers such as ether and ethyl vinyl ether; addition reaction products of unsaturated monomers having a cyclic ether-containing group containing 2 to 8 carbon atoms, such as 1-allyloxy-3-butoxypropan-2-ol, with alcohols having 1 to 20 carbon atoms; alkylene oxide adducts of unsaturated alcohols having 2 to 20 carbon atoms, such as the ethylene oxide adduct of allyl alcohol, the ethylene oxide adduct of methallyl alcohol, and the ethylene oxide adduct of isoprenol, and terminally hydrophobically modified products thereof; and cyclic vinyl monomers such as N-vinylpyrrolidone. Among the hydrophobic monomers (B) having a solubility parameter of 15 or less, those having an alkyl group containing 2 or more carbon atoms are preferred. When the hydrophobic monomer (B) has an alkyl group containing 2 or more carbon atoms, affinity with the cell membranes of microorganisms is increased, resulting in improved antibacterial properties.

[0051] The salt of the unsaturated monocarboxylic acid may be a metal salt, and examples of the metal in the metal salt include alkali metals such as lithium, sodium, and potassium.

[0052] 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 or an ethoxy group; an oxo group-containing group, such as an oxyalkylene group, a sulfonic acid group or a phosphate group; a halogeno group, such as a fluoro group; an epoxy group, such as a glycidyl group; and a carbonyl group, such as an aldehyde group.

[0053] Examples of the alkyl(meth)acrylate having no substituent as described above include cycloalkyl(meth)acrylates such as 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, and cyclohexyl(meth)acrylate, n-lauryl(meth)acrylate, dodecyl(meth)acrylate, stearyl(meth)acrylate, and isobornyl methacrylate.

[0054] Examples of hydroxyl group-containing (meth)acrylates include hydroxyl group-containing (meth)acrylates having an ester group containing 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.

[0055] Examples of alkoxyalkyl (meth)acrylates include methoxyethyl (meth)acrylate, methoxypropyl (meth)acrylate, methoxybutyl (meth)acrylate, ethoxybutyl (meth)acrylate, and trimethylolpropane tripropoxy (meth)acrylate.

[0056] Examples of oxo group-containing (meth)acrylates include (di)ethylene glycol (meth)acrylates such as ethylene glycol (meth)acrylate, ethylene glycol methoxy (meth)acrylate, diethylene glycol (meth)acrylate, and diethylene glycol methoxy (meth)acrylate; alkoxypolyalkylene glycol (meth)acrylates having an alkylene glycol repeat number of 1 to 100, such as alkoxypolyethylene glycol methacrylate (Antox LMA-10); sulfopropyl (meth)acrylate; and (meth)acryloyloxyethyl phosphate.

[0057] Examples of the fluoro group-containing (meth)acrylate include fluoro group-containing alkyl (meth)acrylates having an ester group containing 2 to 6 carbon atoms, such as trifluoroethyl (meth)acrylate, tetrafluoropropyl (meth)acrylate, and octafluoropentyl (meth)acrylate.

[0058] Examples of epoxy group-containing (meth)acrylates include glycidyl (meth)acrylate, α-methylglycidyl (meth)acrylate, and glycidyl allyl ether.

[0059] 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.

[0060] The hydrophobic monomer (B) preferably contains at least one (meth)acrylic acid ester, such as a (meth)acrylic acid ester represented by the following formula (8):

[0061]

[0062] (In the formula, R ９ represents a hydrogen atom or a methyl group. １０represents a hydrocarbon group having 1 to 30 carbon atoms. ) is preferred. The number of carbon atoms in the hydrocarbon group is preferably 1 to 20. It is more preferably 2 to 16, even more preferably 2 to 12, and particularly preferably 2 to 8, and in one embodiment, it may be 2 to 4, or even 2. When the hydrocarbon group has 1 to 20 carbon atoms, the water solubility and viscosity of the polymer can be set within suitable ranges, resulting in excellent handleability. When the hydrocarbon group has 1 to 12 carbon atoms, the polymer can be easily produced and, further, the polymer will have excellent safety in addition to antibacterial properties. Furthermore, when the hydrocarbon group has 2 to 8 carbon atoms, not only the polymer can be easily produced, but the polymer will also have excellent safety and increased affinity with bacterial cell membranes, further improving antibacterial properties.

[0063] The hydrocarbon group is not particularly limited, and examples thereof include chain hydrocarbon groups such as alkyl groups, alkenyl groups, and alkynyl groups, and cyclic hydrocarbon groups such as aromatic hydrocarbon groups, cycloalkyl groups, and cycloalkenyl groups. The hydrocarbon group may be branched, and when the hydrocarbon group is branched, the number of carbon atoms in the hydrocarbon group means the total number of carbon atoms in the main chain and the branched chains. Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group (amyl group), an n-hexyl group, an n-heptyl group, an n-octyl group, an n-nonyl group, an n-decyl group, an n-undecyl group, an n-dodecyl group, an n-tridecyl group, an n-tetradecyl group, an n-pentadecyl group, an n-hexadecyl group, an n-heptadecyl group, an n-octadecyl group, an n-nonadecyl group, an n-icosyl group, an i-propyl group, a sec-butyl group, an i-butyl group, a t-butyl group, a 1-methylbutyl group, a 1-ethylpropyl group, a 2-methylbutyl group, an i-amyl group, a neopentyl group, a 1,2-dimethylpropyl group, a 1,1-dimethylpropyl group, a t-amyl group, a 1,3-dimethylbutyl group, and a 3,3-dimethylbutyl group. aliphatic alkyl groups such as a 2-ethylbutyl group, a 2-ethyl-2-methylpropyl group, a 1-methylheptyl group, a 2-ethylhexyl group, a 1,5-dimethylhexyl group, a t-octyl group, a branched nonyl group, a decyl group, an undecyl group, a dodecyl group, a tridecyl group, a tetradecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group, a stearyl group, and an icosyl group; and alicyclic alkyl groups such as a cyclopropyl group, a cyclopropylmethyl group, a cyclobutyl group, a cyclobutylmethyl group, a cyclopentyl group, a cyclohexyl group, a cyclohexylmethyl group, a cycloheptyl group, a cyclooctyl group, a cyclohexylpropyl group, a cyclododecyl group, a norbornyl group (C7), an adamantyl group (C10), and a cyclopentylethyl group.

[0064] Examples of the alkenyl group include vinyl, allyl, 1-butenyl, 2-butenyl, pentenyl, hexenyl, heptenyl, octenyl, nonenyl, decenyl, dodecenyl, octadecenyl, and icosenyl groups. Examples of the alkynyl group include ethynyl, 1-propynyl, 2-propynyl, butynyl, pentynyl, hexynyl, heptynyl, octynyl, nonynyl, decynyl, dodecynyl, octadecenyl, and icosenyl groups.

[0065] Examples of the aromatic hydrocarbon group include a phenyl group, a benzyl group, a tolyl group, and an o-xylyl group. Examples of the cycloalkyl group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group. Examples of the cycloalkenyl group include a cyclopropenyl group, a cyclobutenyl group, a cyclopentenyl group, and a cyclohexenyl group. The hydrocarbon group is preferably an alkyl group or an alkenyl group, and more preferably an alkyl group. That is, the (meth)acrylic acid ester is preferably an alkyl (meth)acrylic acid ester (alkyl (meth)acrylate).

[0066] 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, or n-octyl(meth)acrylate, and more 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, or 2-ethylhexyl(meth)acrylate. Of these, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, and sec-butyl (meth)acrylate are preferred, ethyl (meth)acrylate and n-butyl (meth)acrylate are more preferred, and ethyl (meth)acrylate is particularly preferred.

[0067] The amino group-containing polymer may have a structural unit (c) derived from a monomer (C) other than the amino group-containing monomer (A) and the hydrophobic monomer (B). The other monomer (C) is not particularly limited as long as it is copolymerizable with the amino group-containing monomer (A) and the hydrophobic monomer (B). For example, the solubility parameter of the other monomer as a homopolymer may be 15 or less or greater than 15. Whether the solubility parameter of the other monomer is 15 or less or greater than 15, as long as the hydrophobic monomer (B) is polymerized in a preferred ratio, the hydrophobicity of the copolymer is sufficiently maintained. Furthermore, in order to adjust the viscosity, a monomer having two or more ethylenically unsaturated groups may be included regardless of the solubility parameter value. Examples of monomers having two or more ethylenically unsaturated groups include esters of (meth)acrylic acid with di- or more substituted hydroxyl groups of polyols such as ethylene glycol, propylene glycol, polyoxyethylene glycol, polyoxypropylene glycol, glycerin, polyglycerin, trimethylolpropane, pentaerythritol, sucrose, sorbitol, and 1,4-butanediol; di- or more substituted methacrylic acid esters of the above polyols; ethers of di- or more substituted hydroxyl groups of the above polyols with unsaturated alcohols such as allyl alcohol and vinyl alcohol; diallyl phthalate, triallyl phosphate, allyl methacrylate, tetraallyloxyethane, triallyl cyanurate, divinyl adipate, vinyl crotonate, 1,5-hexadiene, and divinylbenzene. These other monomers may be used alone or in combination of two or more. From the viewpoint of improving antibacterial properties, the amino group-containing polymer may be copolymerized with a polymerizable metal salt as the other 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.

[0068] [Body Cleansing Composition] The present invention also relates to a body cleansing composition comprising the coacervate formation promoter of the present invention, an anionic surfactant, and a cationic polymer. The present invention also relates to the use of a composition for body cleansing, comprising a polymer having a structural unit (a) derived from the amino group-containing monomer (A), an anionic surfactant, and a cationic polymer. In the body cleansing composition, the coacervate formation between the anionic surfactant and the cationic polymer is promoted by the coacervate formation promoter. During coacervate formation, the amino group-containing polymer is incorporated into the coacervate. After applying the body cleansing composition to hair and / or skin, coacervate is formed as described above when the hair and / or skin is rinsed. Furthermore, when the body cleansing composition is diluted with water, the coacervate is destroyed. During this process, the amino group-containing polymer in the coacervate is released, allowing the amino group-containing polymer to effectively exert its antibacterial effect, even when the body cleansing composition is diluted.

[0069] The body cleansing composition can be suitably used for various purposes. Specific examples include hair cleansing compositions such as shampoos, rinses, and hair treatments; and skin cleansing compositions such as facial cleansing foams, liquid soaps, hand soaps, body soaps, liquid baby cleansers, pet shampoos, cleansing creams, cleansing milks, cleansing lotions, bath additives for bubble baths, massage creams, and body shampoos. Hair cleansing compositions are preferred.

[0070] The proportion of the coacervate formation promoter in the body cleansing composition is not particularly limited, but is preferably 0.01 to 10% by mass relative to 100% by mass of the body cleansing composition. It is more preferably 0.05 to 8% by mass, even more preferably 0.1 to 6% by mass, and particularly preferably 0.5 to 5% by mass. Furthermore, the proportion of the amino group-containing polymer in the body cleansing composition is preferably 0.01 to 10% by mass relative to 100% by mass of the body cleansing composition. It is more preferably 0.05 to 8% by mass, even more preferably 0.1 to 6% by mass, and particularly preferably 0.5 to 5% by mass.

[0071] The proportion of the anionic surfactant in the body cleansing composition is not particularly limited, but is preferably 1 to 50% by mass relative to 100% by mass of the body cleansing composition. It is more preferably 2 to 40% by mass, even more preferably 3 to 30% by mass, and particularly preferably 5 to 25% by mass. Furthermore, the proportion of the anionic surfactant is preferably 20 to 500,000% by mass relative to 100% by mass of the amino group-containing polymer. It is more preferably 100 to 250,000% by mass, even more preferably 1,000 to 100,000% by mass, and particularly preferably 10,000 to 50,000% by mass. In one embodiment, the proportion of the anionic surfactant may be 200 to 10,000% by mass relative to 100% by mass of the amino group-containing polymer, preferably 500 to 5,000% by mass, more preferably 700 to 3,000% by mass, and even more preferably 800 to 2,000% by mass.

[0072] The proportion of the cationic polymer in the body cleansing composition is not particularly limited, but is preferably 0.01 to 3% by mass relative to 100% by mass of the body cleansing composition. It is more preferably 0.02 to 2.5% by mass, even more preferably 0.05 to 2% by mass, and particularly preferably 0.1 to 1.5% by mass. The proportion of the cationic polymer is preferably 10 to 5,000% by mass relative to 100% by mass of the amino group-containing polymer. It is more preferably 10 to 4,000% by mass, even more preferably 10 to 3,000% by mass, and particularly preferably 10 to 2,000% by mass. In one embodiment, the proportion of the cationic polymer may be 10 to 1,000% by mass relative to 100% by mass of the amino group-containing polymer, preferably 20 to 800% by mass, more preferably 30 to 600% by mass, even more preferably 40 to 500% by mass, even more preferably 50 to 300% by mass, and particularly preferably 50 to 250% by mass.

[0073] As described below, a preferred embodiment of the present invention is one in which the cationic polymer is hydroxyethyl cellulose hydroxypropyltrimethylammonium chloride ether (cationized cellulose, PQ-10). When the cationic polymer is PQ-10, the content is preferably 0.01 to 3% by mass relative to 100% by mass of the body cleansing composition. More preferably, it is 0.02 to 2.5% by mass, even more preferably 0.05 to 2% by mass, and particularly preferably 0.05 to 1.5% by mass. Furthermore, the content of PQ-10 is preferably 10 to 1000% by mass relative to 100% by mass of the amino group-containing polymer. More preferably, it is 20 to 800% by mass, even more preferably 30 to 600% by mass, particularly preferably 40 to 500% by mass, even more preferably 50 to 300% by mass, even more preferably 50 to 250% by mass, and particularly preferably 55 to 200% by mass.

[0074] As described below, a preferred embodiment of the present invention also includes an embodiment in which the cationic polymer is O-[2-hydroxy-3-(trimethylammonio)propyl]guar gum chloride (cationized guar). When the cationic polymer is cationized guar, the content is preferably 0.01 to 3% by mass relative to 100% by mass of the body cleansing composition. It is more preferably 0.02 to 2.5% by mass, even more preferably 0.05 to 2% by mass, and particularly preferably 0.1 to 1.5% by mass. Furthermore, the content of cationized guar is preferably 10 to 5,000% by mass relative to 100% by mass of the amino group-containing polymer. It is more preferably 20 to 4,000% by mass, even more preferably 30 to 3,000% by mass, even more preferably 40 to 2,000% by mass, even more preferably 50 to 1,000% by mass, even more preferably 60 to 500% by mass, and particularly preferably 70 to 300% by mass.

[0075] The body cleansing composition may contain other components in addition to the coacervate formation accelerator, anionic surfactant, and cationic polymer. The content of the other components is not particularly limited, but is preferably 0 to 95% by mass, more preferably 10 to 95% by mass, even more preferably 20 to 95% by mass, and particularly preferably 30 to 95% by mass, relative to 100% by mass of the body cleansing composition.

[0076] (Anionic Surfactants) The anionic surfactants are not particularly limited, but examples thereof include higher fatty acids such as lauric acid and stearic acid, fatty acid soaps such as sodium palmitate and sodium laureth-4 carboxylate, higher alkyl sulfates such as sodium lauryl sulfate, alkyl ether sulfates such as POE triethanolamine lauryl sulfate, N-acyl sarcosinates such as sodium lauroyl sarcosinate, higher fatty acid amide sulfonates such as sodium coconut oil fatty acid methyl taurate, phosphate ester salts such as POE stearyl ether phosphate, sulfosuccinates such as sodium di-2-ethylhexyl sulfosuccinate, N-acyl glutamates such as monosodium N-lauroyl glutamate, and higher fatty acid ester sulfates such as hydrogenated coconut oil fatty acid glycerin sodium sulfate. Among these, preferred are fatty acid soaps such as sodium laureth-4 carboxylate, higher alkyl sulfates such as sodium lauryl sulfate, and higher fatty acid amide sulfonates such as sodium coconut oil fatty acid methyl taurate.

[0077] (Cationic Polymer) The cationic polymer is not particularly limited as long as it has a cationic group and is a polymer other than the amino group-containing polymer. Examples thereof include dimethyldiallylammonium chloride polymers such as polydimethylmethylenepiperidinium chloride (Polyquaternium-6); dimethyldiallylammonium chloride-acrylamide copolymer (Polyquaternium-7), dimethyldiallylammonium chloride-acrylic acid copolymer (Polyquaternium-22), acrylic acid amide-acrylic acid-dimethyldiallylammonium chloride copolymer (Polyquaternium-39), vinylpyrrolidone-methacrylamidopropyltrimethylammonium chloride copolymer (Polyquaternium-28), a quaternary ammonium salt obtained from a vinylpyrrolidone-dimethylaminoethyl methacrylate copolymer and diethyl sulfate (Polyquaternium-11), and vinylpyrrolidone-dimethylaminopropyl methacrylamido-methacrylamidopropyllauryldimethylammonium chloride copolymer. acrylic cationic copolymers such as a copolymer (Polyquaternium-55); cationic copolymers containing vinylpyrrolidone and vinylimidazolium as monomer units, such as methylvinylimidazolinium chloride-vinylpyrrolidone copolymer (Polyquaternium-16), vinylpyrrolidone-3-methyl-1-vinylimidazolium methyl sulfate copolymer (Polyquaternium-44), vinylcaprolactam-vinylpyrrolidone-methylvinylimidazolium methyl sulfate copolymer (Polyquaternium-46), and vinylpyrrolidone-methacrylic acid amide-vinylimidazolium-3-methyl-1-vinylimidazolium methyl sulfate copolymer (Polyquaternium-68); cationic copolymers containing 2-methacryloyloxyethyl phosphorylcholine as a monomer unit, such as a 2-methacryloyloxyethyl phosphorylcholine-2-hydroxy-3-methacryloyloxypropyltrimethylammonium chloride copolymer (Polyquaternium-64);Examples include cationized celluloses such as O-[2-hydroxy-3-(trimethylammonio)propyl]hydroxyethyl cellulose chloride (Polyquaternium-10) and O-[2-hydroxy-3-(trimethylammonio)propyl]·[2-hydroxy-3-(lauryldimethylammonio)propyl]hydroxyethyl cellulose chloride (Polyquaternium-67); and cationized guar gums such as O-[2-hydroxy-3-(trimethylammonio)propyl]guar gum chloride. Among these, preferred are cationized celluloses such as Polyquaternium-10 and Polyquaternium-67; and cationized guar gums such as O-[2-hydroxy-3-(trimethylammonio)propyl]guar gum chloride, with Polyquaternium-10 and O-[2-hydroxy-3-(trimethylammonio)propyl]guar gum chloride being more preferred.

[0078] The weight average molecular weight of the cationic polymer is not particularly limited, but is preferably 100,000 to 2,500,000, more preferably 150,000 to 2,000,000, even more preferably 500,000 to 2,000,000, and particularly preferably 600,000 to 2,000,000. The weight average molecular weight of the cationic polymer can be measured by the method described in the examples.

[0079] The nitrogen content of the cationic polymer is preferably 0.2 to 3% by mass relative to 100% by mass of the cationic polymer. It is more preferably 0.4 to 2.5% by mass, even more preferably 0.4 to 2.0% by mass, and particularly preferably 0.5 to 2.0% by mass. The nitrogen content of the cationic polymer can be easily calculated if the chemical structure is clear. However, even if the chemical structure, such as the monomer ratio, is unknown, it can be calculated from the measured nitrogen content using the Kjeldahl method or the like. Furthermore, when the cationic polymer is cationized cellulose, the proportion of cationized cellulose in the body cleansing composition is preferably 10 to 5,000% by mass relative to 100% by mass of the amino group-containing polymer. It is more preferably 10 to 4,000% by mass, even more preferably 10 to 3,000% by mass, even more preferably 20 to 2,000% by mass, even more preferably 30 to 1,000% by mass, even more preferably 40 to 500% by mass, and particularly preferably 50 to 300% by mass. Furthermore, when the cationic polymer is cationized guar gum, the proportion of cationized guar gum in the body cleansing composition is preferably 10 to 1,000% by mass, more preferably 10 to 800% by mass, even more preferably 20 to 600% by mass, still more preferably 30 to 500% by mass, still more preferably 40 to 300% by mass, and particularly preferably 40 to 250% by mass, relative to 100% by mass of the amino group-containing polymer.

[0080] The body cleansing composition may contain other ingredients in addition to the coacervate formation promoter, the anionic surfactant, and the cationic polymer. The other components are not particularly limited, and examples thereof include amphoteric surfactants; nonionic surfactants; polymers other than the amino group-containing polymer and cationic polymer of the present invention; polyols; inorganic salts such as salt and Glauber's salt; organic salts; solubilizers such as polyglyceryl monolaurate; antioxidants such as BHT and α-tocopherol; chelating agents such as ethylenediaminetetraacetic acid; disinfectants such as triclosan and trichlorocarban; viscosity modifiers such as fatty acid diethanolamide; ultraviolet absorbers; protein derivatives; animal and plant extracts; antidandruff agents such as piroctone olamine and zinc pyrithione; anti-inflammatory agents such as dipotassium glycyrrhizinate; preservatives such as benzoic acid or a salt thereof, parabens, phenoxyethanol, and methylisothiazolinone; pH adjusters such as citric acid and succinic acid; emulsifiers; hydrotropes; lower alcohols; vitamins; vegetable oils; volatile oils; hydrophobic solvents; diluent solvents such as purified water; pigments; and fragrances. One or more of these can be used.

[0081] Examples of the amphoteric surfactant include imitazoline-based amphoteric surfactants such as 2-cocoyl-2-imidazolinium hydroxide-1-carboxyethyloxy disodium salt, and betaine-based surfactants such as 2-heptadecyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine, lauryldimethylaminoacetic acid betaine, alkyl betaine, amido betaine, and sulfobetaine.

[0082] Examples of the nonionic surfactant include sorbitan fatty acid esters such as sorbitan monostearate and sorbitan sesquioleate, glycerin fatty acids such as glycerin monostearate, propylene glycol fatty acid esters such as propylene glycol monostearate, hydrogenated castor oil derivatives, glycerin alkyl ethers, POE sorbitan fatty acid esters such as POE sorbitan monooleate, POE sorbit fatty acid esters such as POE sorbit monostearate, and POE glycerin fatty acid esters such as POE glycerin monoisostearate. esters, POE fatty acid esters such as POE monooleate, POE alkyl ethers such as POE 2-octyldodecyl ether, Pluronic (registered trademark) types such as Pluronic (registered trademark), POE-POP alkyl ethers such as POE-POP cetyl ether, tetraPOE-tetraPOP ethylenediamine condensates such as Tetronic, POE castor oil derivatives such as POE castor oil, POE hydrogenated castor oil, POE hydrogenated castor oil derivatives such as POE hydrogenated castor oil monoisostearate, sucrose fatty acid esters, alkyl glucosides, and the like.

[0083] The polymer other than the amino group-containing polymer and cationic polymer of the present invention is not particularly limited, and examples thereof include xanthan gum, tuberose polysaccharide, quince seed gum, gellan gum, alginic acid and its salts, pectin, carboxymethyl cellulose, hyaluronic acid and its salts, carrageenan, hydroxyethyl cellulose, hydroxypropyl cellulose, guar gum, agarose, pullulan, locust bean gum, galactan, gum arabic, tara gum, tamarind seed gum, carboxyvinyl polymer, acrylic acid / alkyl methacrylate copolymer, and hydroxypropyl guar gum, polysilicone compounds, N-methacryloylethyl N,N-dimethylammonium α-N-methylcarboxybenzyl esters, N-methyl-N ... Examples of such copolymers include tyne-butyl methacrylate copolymer (trade name: Yukaformer AM-75; manufactured by Mitsubishi Chemical Corporation), hydroxypropyl acrylate-butylaminoethyl methacrylate-octylamide acrylate copolymer (trade name: Amphomer 28-4910; manufactured by Nouryon Corporation), dimethyldiallylammonium chloride-acrylic acid copolymer (trade names: Merquat 280, 295; manufactured by Lubrizol Corporation), dimethyldiallylammonium chloride-acrylamide-acrylic acid terpolymer (trade names: Merquat Plus 3330, 3331; manufactured by Lubrizol Corporation), and acrylic acid-methyl acrylate-methacrylamidopropyltrimethylammonium chloride copolymer (trade name: Merquat 2001; manufactured by Lubrizol Corporation).

[0084] Examples of the polyols include those used in ordinary detergents, such as dihydric alcohols such as ethylene glycol, diethylene glycol, hexylene glycol, polyethylene glycols having an average molecular weight of 10,000 or less, propylene glycol, 1,3-propanediol, dipropylene glycol, polypropylene glycol, isoprene glycol, and 1,3-butylene glycol; trihydric or higher alcohols such as glycerin, diglycerin, triglycerin, tetraglycerin, hexaglycerin, decaglycerin, and trimethylpropanol; and sugars or sugar alcohols such as erythritol, pentaerythritol, dipentaerythritol, glucose, mannose, galactose, sucrose, fructose, maltose, maltitol, xylitol, inositol, sorbitan, and sorbitol. These may be used alone or in combination of two or more.

[0085] [Method for Imparting Antibacterial Properties] The present invention is a method for imparting antibacterial properties to hair and / or skin, the method comprising the steps of applying the coacervate formation accelerator of the present invention to hair and / or skin and rinsing the hair and / or skin after the application step. The step of applying the coacervate formation accelerator to hair and / or skin is not particularly limited as long as the coacervate formation accelerator of the present invention is brought into contact with the hair and / or skin, but it is preferred to bring the hair and / or skin into contact with a composition containing the coacervate formation accelerator, an anionic surfactant, and a cationic polymer. The preferred forms and proportions of the coacervate formation accelerator, anionic surfactant, and cationic polymer are the same as those described for the coacervate formation accelerator and body cleansing composition.

[0086] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. Unless otherwise specified, "parts" means "parts by weight" and "%" means "% by mass."

[0087] (Gel Permeation Chromatography (GPC)) The weight average molecular weight (Mw) of the amino group-containing polymer was measured by GPC (gel permeation chromatography). The measurement conditions, apparatus, etc. are as follows. Apparatus: EcoSEC HLC-8320GPC manufactured by Tosoh Corporation Detector: Differential Refractometer (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 sample concentration of 0.4 wt%) Calibration curve: Polyethylene glycol manufactured by GL Sciences Inc. GPC software: EcoSEC-WS manufactured by Tosoh Corporation Eluent: 0.5 M acetic acid + 0.2 M Na nitrate / acetonitrile = 50 / 50 (v / v)

[0088] (Coacervate Confirmation Test (Measurement Method)) The transmittance (%) at 600 nm at 25°C of the compositions of the Examples, Reference Examples, and Comparative Examples, and solutions obtained by diluting these compositions 2-fold, 4-fold, 8-fold, 10-fold, 16-fold, 50-fold, and 100-fold with tap water, was measured using an ultraviolet-visible spectrophotometer (Ultrospec 3100 pro (manufactured by Biochrom)). Turbidity (%) was calculated from the transmittance using the following formula, and evaluated as the amount of coacervate produced. Turbidity (%) = 100 - Transmittance (%) Criteria for assessing promotion of coacervate formation: Compared to the Comparative Example to which Copolymer 1 was not added, if the turbidity value at 8-fold or 10-fold dilution was higher, it was evaluated as ◯, and if it was lower, it was evaluated as ×. A higher turbidity value means that a larger amount of coacervate was produced.

[0089] (pH Measurement Conditions) Measurement was performed at 25° C. using a pH meter (manufactured by Horiba Ltd.; model LAQUA pH / ION METER F-72).

[0090] (Viscosity Measurement Conditions) Using a Brookfield viscometer (manufactured by Toki Sangyo Co., Ltd.; model BMII), the initial viscosity (unit: mPa s) was measured under the conditions of rotor: No. 3, rotation speed: 6 rpm, measurement time: 60 seconds, and temperature: 25°C.

[0091] [Production Example 1] A separable glass flask equipped with a thermometer, a reflux condenser, and a stirrer was charged with 29.4 g of pure water and 100.0 g of 1,3-butanediol (manufactured by KH Neochem Co., Ltd.), and the temperature was raised to 90°C under stirring. Next, with stirring, into a polymerization reaction system maintained at a constant temperature of 80°C, a monomer solution 1 consisting of 65.0 g of 2-(dimethylamino)ethyl methacrylate (N,N-dimethylaminoethyl methacrylate) (manufactured by Kyoeisha Chemical Co., Ltd., hereinafter referred to as DAM), a monomer solution 2 consisting of 35.0 g of ethyl methacrylate (manufactured by Kyoeisha Chemical Co., Ltd., hereinafter referred to as EMA), and an 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 each added dropwise from separate dropping nozzles. The dropwise addition of Monomer Solutions 1 and 2 and the aqueous initiator solution began simultaneously, with Monomer Solution 1 being added over 180 minutes, Monomer Solution 2 over 170 minutes, and the aqueous initiator solution over 210 minutes. After all of the dropwise additions were completed, the reaction solution was maintained at 80°C for an additional 30 minutes to mature and complete the polymerization, after which 209.6 g of pure water and 522.0 g of 1,3-butanediol were added to obtain Copolymer 1. The resulting copolymer had a solids content of 10.0%, a pH of 9.0, and a weight-average molecular weight of 34,000.

[0092] <Shampoo Formulation 1: Examples 1-2, Comparative Example 1> Compositions were prepared according to the following shampoo formulation 1 so as to have the composition shown in Table 1 below. A. After components 1-4 are uniformly dissolved, component 5 is added and mixed uniformly. (80°C, 10 minutes, paddle: 300 rpm) B. Component 6 is added to A and dissolved uniformly. (80°C, 5 minutes, paddle: 200 rpm) C. B is cooled to 40°C. D. Components 7-9, which have been mixed uniformly in advance, are added to C and mixed uniformly. E. Components 10, 11, and 12 are added sequentially to D and mixed uniformly. The compositions obtained by shampoo formulation 1 were subjected to pH measurement, viscosity measurement, and evaluation of promotion of coacervate formation.

[0093] (Raw materials used) *1 Product name: Chelest 2B-SD (manufactured by Chelest Co., Ltd.) *2 Product name: Sodium benzoate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) *3 Product name: Concentrated glycerin for cosmetics (manufactured by Sakamoto Pharmaceutical Industry Co., Ltd.) *4 Product name: Poise C-60H (manufactured by Kao Corporation) Molecular weight 600,000, nitrogen content 1.5 to 2.5% *5 Product name: Amizol CME (manufactured by Kawaken Fine Chemical Co., Ltd.) *6 Product name: Anhithol 55AB (manufactured by Kao Corporation) *7 Product name: Mydol 10 (manufactured by Kao Corporation) *8 Product name: Viewlight LCA-25F (manufactured by Sanyo Chemical Industries, Ltd.) *9 Product name: MERQUAT 550PR (Lubrizol Japan Co., Ltd.) *10 Product name: Citric acid monohydrate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.)

[0094] <Shampoo Formulation 2: Examples 3 to 5, Comparative Examples 2 and 3> Compositions were prepared according to the following shampoo formulation 2 so as to have the compositions shown in Table 2 below. A. After uniformly dissolving components 1 to 3, component 4 was added and mixed uniformly. (80°C, 10 minutes, paddle: 300 rpm) B. A was cooled to 40°C. C. Component 5 was added to B and mixed uniformly. D. Components 6 and 7 were added sequentially to C and mixed uniformly. The compositions obtained by shampoo formulation 2 were subjected to pH measurement, viscosity measurement, and evaluation of the promotion of coacervate formation. Viscosity measurement was performed as described above, except that the rotor was changed to No. 4 and the rotation speed was changed to 12 rpm.

[0095] (Raw materials used) *4 Product name: Poise C-60H (Kao Corporation) Molecular weight: 600,000, nitrogen content: 1.5 to 2.5% *6 Product name: Anhithol 55AB (Kao Corporation) *10 Product name: Citric acid monohydrate (Fujifilm Wako Pure Chemical Industries, Ltd.) *11 Product name: Poise C-150L (Kao Corporation) Molecular weight: 1.5 million, nitrogen content: 1.0 to 1.5% *12 Product name: Emeral E-27C (Kao Corporation)

[0096] Shampoo Formulation 3: Example 6, Reference Example 1, Comparative Example 4 Compositions were prepared according to the following shampoo formulation 3 so as to have the composition shown in Table 3 below. A. Component 2 was added to component 1 and mixed uniformly. (80°C, 10 minutes, paddle: 300 rpm) B. Components 3, 4, and 5 were added sequentially to A and dissolved uniformly. (80°C, 5 minutes, paddle: 200 rpm) C. Components 6, 7, 8, and 9 were added sequentially to B and dissolved uniformly, followed by cooling to 60°C. D. Components 10 and 11 were added sequentially to C and dissolved uniformly, followed by cooling to 50°C. E. Components 12 and 13 were added sequentially to D and dissolved uniformly, followed by cooling to room temperature. The compositions obtained according to shampoo formulation 3 were subjected to pH measurement, viscosity measurement, and evaluation of the promotion of coacervate formation. Viscosity measurement was performed as described above, except that the rotation speed was changed to 12 rpm.

[0097] (Raw materials used) *6 Product name: Anhithol 55AB (Kao Corporation) *11 Product name: Poise C-150L (Kao Corporation) *12 Product name: Diapon K-TS (NOF Corporation) *13 Product name: TEXAPON N70 (BASF) *14 Product name: Kaosofcare GP-1 (Kao Corporation)

[0098] Shampoo Formulation 4: Example 7, Reference Example 2, Comparative Example 5 Compositions were prepared according to the following shampoo formulation 4 so as to have the composition shown in Table 4 below. A. Components 2 and 3 were added to component 1 and mixed uniformly. (80°C, 10 minutes, paddle: 300 rpm) B. Components 4, 5, and 6 were added sequentially to A and dissolved uniformly. (80°C, 5 minutes, paddle: 200 rpm) C. Components 7, 8, and 9 were added sequentially to B and dissolved uniformly, followed by cooling to 60°C. D. Components 10 and 11 were added sequentially to C and dissolved uniformly, followed by cooling to 50°C. E. Components 12 and 13 were added sequentially to D and dissolved uniformly, followed by cooling to room temperature. The compositions obtained according to shampoo formulation 4 were subjected to pH measurement, viscosity measurement, and evaluation of the promotion of coacervate formation. Viscosity measurement was performed as described above, except that the rotation speed was changed to 12 rpm.

[0099] (Raw materials used) *6 Product name: Anhithol 55AB (manufactured by Kao Corporation) *12 Product name: Diapon K-TS (manufactured by NOF Corporation) *13 Product name: TEXAPON N70 (manufactured by BASF) *14 Product name: Kaosofcare GP-1 (manufactured by Kao Corporation) *15 Product name: JAGUAR EXCEL (manufactured by Solvay S.A.)

[0100] <Antibacterial Test 1: Example 6, Comparative Example 4, Reference Examples 3 and 4> Malassezia fungi (dandruff fungus, Malassezia furfur NBRC-656) provided by NBRC (National Institute of Technology and Evaluation, Biotechnology Center) were streaked onto Chromoagar Malassezia medium (Kanto Chemical Co., Ltd.) and cultured at 35°C for 4 days, taking care not to dry out. The grown colonies were suspended in Butterfield's buffer solution to prepare 5 ml of a solution with an OD660 of 0.1. 15 ml of 0.5% olive oil-supplemented Sabouraud agar medium was added to a petri dish approximately 90 mm in diameter and allowed to solidify, and 0.1 ml of the fungal solution was applied and inoculated. After this, a hole approximately 10 mm in diameter was drilled in the center using a cork borer. Here, a commercially available shampoo A (hereinafter also referred to as commercial product A) (Reference Example 3) containing zinc pyrithione as the active ingredient, a commercially available shampoo B (hereinafter also referred to as commercial product B) (Reference Example 4) containing piroctone olamine as the active ingredient, the shampoo formulation of Example 6, and the shampoo formulation of Comparative Example 4 were each diluted 10-fold and filled into the center. A test was also conducted on a container filled with water for comparison. Then, static culture was conducted at 25°C for 4 days, and the area where colony growth could not be confirmed was confirmed. The evaluation criteria are as follows: +++: Completely inhibited growth ++: Bacterial growth confirmed in a small area +: Bacterial growth confirmed over a fairly wide area -: No bacterial suppression effect The results are shown in Table 5.

[0101]

[0102] Antibacterial Test 2: Example 7, Comparative Example 5, Reference Examples 3 and 4 The substances filled into the perforated parts were changed to the shampoo compositions of Example 7 and Comparative Example 5, commercial product A (Reference Example 3), or commercial product B (Reference Example 4), and the dilution ratios when filling were changed to 10, 16, 25, or 50 times, and the same procedure as in Antibacterial Test 1 was conducted, and the effect against Malassezia fungi was confirmed based on the diameter of the inhibition zone. The results are shown in Table 6.

[0103]

[0104] The above results showed that the inhibition zone diameter tended to decrease in a concentration-dependent manner in the formulations of the commercially available products (Reference Examples 3 and 4) and Comparative Example 5. On the other hand, no concentration dependency was observed in the shampoo formulation of Example 7 containing Copolymer 1. This suggests that Copolymer 1 is released with the formation and destruction of coacervates, and may act efficiently on Malassezia fungi even at low concentrations.

Claims

1. a polymer having a structural unit (a) derived from an amino group-containing monomer (A), The polymer contains the structural unit (a) in an amount of 50 to 90% by mass relative to 100% by mass of all structural units, The amino group in the amino group-containing monomer (A) is represented by the following formula (1): 【Chemistry 1】 (wherein R 1 and R 2 are the same or different and represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms) A coacervate formation promoter having a structure represented by the following formula:

2. The coacervate formation accelerator according to claim 1 , wherein the polymer further comprises a structural unit (b) derived from a hydrophobic monomer (B).

3. A body cleansing composition comprising the coacervate formation promoter according to claim 1 or 2, an anionic surfactant, and a cationic polymer.

4. The body cleansing composition according to claim 3, wherein the content of the coacervate formation promoter is 0.01 to 10% by mass relative to 100% by mass of the body cleansing composition.

5. 1. A method for imparting antimicrobial properties to hair and / or skin, comprising: The method for imparting antibacterial properties comprises the steps of applying the coacervate formation promoter according to claim 1 or 2 to hair and / or skin, and rinsing the hair and / or skin after the application step.

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