Aerosol hair cosmetics

Abstract

To provide an aerosol type cosmetic hair preparation that allows an organic acid, which is an active ingredient for hair modification, to efficiently permeate into the hair.SOLUTION: This aerosol type cosmetic hair preparation contains: a cosmetic hair preparation stock solution containing a surfactant (A) and an organic acid excluding citric acid or a salt thereof (B); and a propellant (C) containing carbon dioxide. The aerosol type cosmetic hair preparation has a pH at 20°C of 3.0-5.0.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an aerosol type hair cosmetic composition. [Background technology]

[0002] Aerosol cosmetics have the advantage that they can be used by discharging the cosmetic, which is an aerosol concentrate, in the form of foam, making them easy to spread on the skin or hair and allowing the active ingredients in the cosmetic to penetrate the skin or hair effectively. In the field of aerosol cosmetics, improvements in the adhesion of skin / hair care ingredients have been studied. For example, Patent Document 1 discloses that a personal cleansing product comprising a foamable composition of a predetermined viscosity containing a predetermined amount of water and a predetermined amount of a specific surfactant, a propellant gas containing carbon dioxide, nitrous oxide, or a mixture thereof, and a container can improve foaming properties, mildness, and adhesion of skin / hair care ingredients to the skin. It also discloses that the foamable composition contains about 1 to about 50% by weight of a water-insoluble skin or hair care ingredient. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2001-507034 Summary of the Invention [Problem to be solved by the invention]

[0004] Age-related changes in hair include a decrease in hair diameter, an increase in gray hair, a decrease in firmness and strength, and an increase in wavy hair. A decrease in firmness and strength leads to a decrease in hair volume, and an increase in wavy hair leads to hair problems such as poor manageability and loss of hair luster. Various physical and chemical methods have been investigated to alleviate these hair problems, but one important technique is to modify the hair from within by penetrating active ingredients into the hair. Organic acids such as malic acid (to give firmness and body) and p-toluenesulfonic acid (to reduce frizz) are known to be used as such active ingredients.

[0005] However, the skin / hair care ingredients disclosed in Patent Document 1 are water-insoluble ingredients such as cosmetic oils, and there is no mention of penetration technology for organic acids, which are water-soluble ingredients that are active ingredients for hair modification. An object of the present invention is to provide an aerosol-type hair cosmetic that can efficiently penetrate an organic acid, which is an active ingredient for hair modification, into the interior of the hair. [Means for solving the problem]

[0006] The present inventors have discovered that the above-mentioned problems can be solved by an aerosol-type hair cosmetic composition containing a hair cosmetic concentrate solution including a surfactant and an organic acid other than citric acid or a salt thereof, and a propellant including carbon dioxide, and having a pH within a specified range. That is, the present invention relates to an aerosol-type hair cosmetic composition containing a hair cosmetic concentrate containing a surfactant (A), an organic acid other than citric acid or a salt thereof (B), and a propellant (C) containing carbon dioxide, and having a pH of 3.0 or more and 5.0 or less at 20°C. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide an aerosol type hair cosmetic composition that can efficiently penetrate an organic acid, which is an active ingredient for hair modification, into the interior of the hair. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a TOF-SIMS analysis and mapping image of p-toluenesulfonic acid present in the cross section of hair washed with the hair wash of Example 6. [Figure 2]1 is a TOF-SIMS analysis and mapping image of p-toluenesulfonic acid present in the cross section of hair washed with the hair wash of Comparative Example 12. DETAILED DESCRIPTION OF THE INVENTION

[0009] [Aerosol-type hair cosmetics] The aerosol-type hair cosmetic of the present invention (hereinafter also referred to simply as "the hair cosmetic of the present invention") contains a hair cosmetic concentrate containing a surfactant (A) and an organic acid other than citric acid or a salt thereof (B), and a propellant (C) containing carbon dioxide, and has a pH of 3.0 to 5.0 at 20° C. Use of the hair cosmetic of the present invention allows the organic acid, an active ingredient for hair modification, to efficiently penetrate into the interior of the hair. In the present invention, "comprises component X" or "contains component X" also means "composed of component X."

[0010] The reason why the hair cosmetic composition of the present invention having the above-described structure exhibits the effects of the present invention is not clear, but is presumed to be as follows. The aerosol concentrate for use in the aerosol type hair cosmetic of the present invention contains a surfactant (A) and an organic acid other than citric acid or a salt thereof (B). The surfactant, component (A), is used to provide the foam ejection properties of the aerosol and the desired performance of the hair cosmetic. Component (B), an organic acid or its salt, is used as an active ingredient to modify hair. By penetrating the organic acid into the hair, it is thought that, for example, the bending elasticity inside the hair is increased, improving hair strength and body, and stress relaxation inside the hair can suppress the occurrence of hair frizz. The aerosol hair cosmetic composition of the present invention uses a propellant (C) containing carbon dioxide. Carbon dioxide as a propellant allows for the ejection of fine, dense foam, which allows the active ingredients in the ejected hair cosmetic composition to be evenly applied to the hair. Furthermore, it is believed that the carbon dioxide dissolved in the foam acts on the hair, promoting the penetration of the organic acid into the hair. Furthermore, the dissociation state of carbon dioxide changes depending on the pH of the liquid it is dissolved in; as the pH increases, it releases hydrogen ions and exists as bicarbonate ions. When the pH of a hair cosmetic product is between 3.0 and 5.0 at 20°C, the proportion of carbon dioxide molecules in the product increases, which is thought to improve the penetration-promoting effect of carbon dioxide on organic acids.

[0011] The hair cosmetic of the present invention has a pH of 3.0 or more and 5.0 or less at 20° C. This pH is the pH at 20° C. of an aqueous solution obtained by diluting an aerosol-type hair cosmetic containing a hair cosmetic concentrate and propellant (C) 20 times with water after ejection from an aerosol container. From the viewpoint of improving the effect of promoting penetration of organic acids into the interior of hair, the pH of the hair cosmetic at 20°C is preferably 3.2 or higher, more preferably 3.4 or higher, and preferably 4.8 or lower, more preferably 4.5 or lower, and even more preferably 4.2 or lower. The specific pH range of the hair cosmetic at 20°C is 3.0 to 5.0, preferably 3.0 to 4.8, more preferably 3.0 to 4.5, even more preferably 3.0 to 4.2, more preferably 3.2 to 4.2, and even more preferably 3.4 to 4.2. Specifically, the pH of the hair cosmetic can be measured by the method described in the Examples.

[0012] In the present invention, the increase in the bending modulus or stress relaxation rate of hair after treatment with a hair cosmetic is used as an index of the penetration-promoting effect of an organic acid into the interior of hair. The higher the increase in the bending modulus or the increase in the stress relaxation rate of hair after treatment, the higher the penetration-promoting effect of the organic acid. The increase in the bending modulus and stress relaxation rate of hair after treatment can be specifically measured by the methods described in the Examples.

[0013] Examples of the hair cosmetic composition of the present invention include hair cleansers such as shampoos, rinses, conditioning agents, treatments (including leave-in types), styling agents, hair dyes, and hair growth agents. Among these, for example, when component (A) described below mainly contains an anionic surfactant or a nonionic surfactant, a hair cleanser is preferred. Furthermore, when component (A) mainly contains a cationic surfactant, a rinse, conditioning agent, treatment, or styling agent is preferred. In order to more effectively exert the effects of the present invention, the aerosol hair cosmetic composition of the present invention is preferably an aerosol hair cleanser.

[0014] <Component (A): Surfactant> The hair cosmetic concentrate constituting the hair cosmetic of the present invention contains a surfactant as component (A). Component (A) is used to provide foam ejection properties by aerosol and the desired performance of the hair cosmetic, and can be appropriately selected from anionic surfactants, cationic surfactants, nonionic surfactants, and amphoteric surfactants depending on the type of hair cosmetic. When the hair cosmetic composition of the present invention is a hair cleanser, from the viewpoint of imparting cleansing properties, it is preferable that component (A) contains one or more surfactants selected from the group consisting of anionic surfactants and nonionic surfactants.

[0015] (anionic surfactants) Examples of anionic surfactants include alkylbenzenesulfonates, alkyl or alkenyl ether sulfates, alkyl or alkenyl sulfates, alkyl sulfonates, saturated or unsaturated fatty acid salts, alkyl or alkenyl ether carboxylates, α-sulfofatty acid salts, N-acylamino acid salts, mono- or di-phosphate salts, and sulfosuccinate salts, and one or more of these can be used. The hydrocarbon group such as an alkyl group or an alkenyl group, or the constituent fatty acid of the anionic surfactant preferably has 8 to 22 carbon atoms, more preferably 8 to 18 carbon atoms, and even more preferably 10 to 18 carbon atoms. Examples of counter ions of the anionic group of an anionic surfactant include alkali metal ions such as sodium ion and potassium ion; alkaline earth metal ions such as calcium ion and magnesium ion; ammonium ion; and alkanolammonium having 1 to 3 alkanol groups having 2 or 3 carbon atoms (for example, monoethanolammonium, diethanolammonium, triethanolammonium, triisopropanolammonium, etc.).

[0016] Among the above, from the viewpoint of use in hair cleansing agents, the anionic surfactant is preferably one or more selected from the group consisting of alkyl sulfates, alkyl ether sulfates, alkyl ether carboxylates, and N-acylamino acid salts. Examples of the alkyl sulfates include sodium lauryl sulfate. Examples of the alkyl ether sulfates include polyoxyethylene alkyl ether sulfates such as sodium laureth sulfate and ammonium laureth sulfate, and examples of the alkyl ether carboxylates include polyoxyethylene alkyl ether acetates such as sodium laureth acetate. Examples of the N-acylamino acid salts include N-acyl glutamates such as sodium cocoyl glutamate. The anionic surfactant is more preferably one or more selected from the group consisting of alkyl ether sulfates and N-acylamino acid salts, and even more preferably one or more selected from the group consisting of sodium laureth sulfate, ammonium laureth sulfate, and sodium cocoyl glutamate.

[0017] (nonionic surfactant) Examples of nonionic surfactants include polyoxyalkylene alkyl ethers, polyoxyalkylene alkenyl ethers, polyoxyalkylene sorbitan fatty acid esters, polyoxyalkylene fatty acid esters, alkyl glucosides, alkyl alkanolamides, alkyl glyceryl ethers, higher fatty acid sucrose esters, polyglycerin fatty acid esters, polyoxyalkylene hydrogenated castor oil, and alkyl saccharides, and one or more of these can be used. Among the nonionic surfactants exemplified above, the average number of moles of ethylene oxide added (hereinafter referred to as "average number of moles of EO added") in the polyoxyethylene alkyl ethers, polyoxyethylene alkenyl ethers, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene fatty acid esters, and polyoxyethylene hydrogenated castor oils is preferably 2 or more, more preferably 3 or more, even more preferably 5 or more, still more preferably 6 or more, and still more preferably 8 or more, and is preferably 150 or less, more preferably 80 or less. The average number of moles of EO added is preferably 2 or more and 150 or less, more preferably 3 or more and 80 or less. The average number of moles of EO added is a number average value. Furthermore, the alkyl group in the polyoxyalkylene alkyl ether, alkyl glucoside, alkyl alkanolamide, alkyl glyceryl ether, and alkyl saccharide, the alkenyl group in the polyoxyalkylene alkenyl ether, and the fatty acid in the polyoxyalkylene sorbitan fatty acid ester, polyoxyalkylene fatty acid ester, higher fatty acid sucrose ester, and polyglycerin fatty acid ester preferably has 8 to 22 carbon atoms, more preferably 8 to 18 carbon atoms.

[0018] Among the above, from the viewpoint of use in a hair wash, the nonionic surfactant is preferably one or more selected from the group consisting of polyoxyalkylene alkyl ethers, polyoxyalkylene alkenyl ethers, polyoxyalkylene sorbitan fatty acid esters, polyoxyalkylene fatty acid esters, alkyl glucosides, alkyl alkanolamides, alkyl glyceryl ethers, and polyoxyalkylene hydrogenated castor oils, more preferably one or more selected from the group consisting of polyoxyalkylene alkyl ethers, alkyl glucosides, alkyl alkanolamides, alkyl glyceryl ethers, and polyoxyalkylene hydrogenated castor oils, and even more preferably polyoxyalkylene hydrogenated castor oils.

[0019] (cationic surfactant) Examples of cationic surfactants include (i) alkyltrimethylammonium salts, (ii) alkoxyalkyltrimethylammonium salts, (iii) dialkyldimethylammonium salts, (iv) alkylamidoalkyltrimethylammonium salts, (v) alkyldimethylamines and salts thereof, (vi) alkoxyalkyldimethylamines and salts thereof, and (vii) alkylamidoalkyldimethylamines and salts thereof, and one or more of these can be used. The cationic surfactant preferably has a long-chain alkyl group having 8 to 22 carbon atoms, more preferably 8 to 18 carbon atoms, and even more preferably 12 to 18 carbon atoms. The salts of amines (v) to (vii) include salts with organic or inorganic acids. Examples of organic acids include aliphatic monocarboxylic acids such as acetic acid and propionic acid; aliphatic dicarboxylic acids such as malonic acid, succinic acid, glutaric acid, adipic acid, maleic acid, and fumaric acid; aromatic dicarboxylic acids such as phthalic acid and isophthalic acid; polycarboxylic acids such as polyglutamic acid; hydroxycarboxylic acids such as glycolic acid, lactic acid, hydroxyacrylic acid, glyceric acid, malic acid, tartaric acid, and citric acid; and acidic amino acids such as glutamic acid and aspartic acid. Examples of inorganic acids include hydrochloric acid, sulfuric acid, and phosphoric acid.

[0020] (Amphoteric surfactant) Examples of amphoteric surfactants include betaine surfactants, amine oxide surfactants, and amino acid surfactants, and one or more of these can be used. Examples of betaine surfactants include carboxybetaine surfactants such as alkyldimethylaminoacetic acid betaine and fatty acid amidopropyl betaine; sulfobetaine surfactants such as alkylsulfobetaine and alkylhydroxysulfobetaine; imidazoline betaine surfactants; and phosphobetaine surfactants. The hydrocarbon group such as an alkyl group or an alkenyl group, or the constituent fatty acid of the amphoteric surfactant preferably has 8 to 22 carbon atoms, more preferably 8 to 18 carbon atoms, and even more preferably 12 to 18 carbon atoms.

[0021] The content of component (A) in the hair cosmetic concentrate is preferably 0.05% by mass or more, more preferably 0.10% by mass or more, and even more preferably 0.20% by mass or more, from the viewpoint of foam ejection by aerosol and imparting the desired performance as a hair cosmetic, and is preferably 30% by mass or less, more preferably 20% by mass or less, and even more preferably 15% by mass or less, from the viewpoint of improving storage stability. The specific range of the content of component (A) in the hair cosmetic concentrate is preferably 0.05 to 30% by mass, more preferably 0.10 to 20% by mass, and even more preferably 0.20 to 15% by mass. When component (A) contains an anionic surfactant, the content of the anionic surfactant in the hair cosmetic concentrate is preferably 0.50% by mass or more, more preferably 1.0% by mass or more, even more preferably 3.0% by mass or more, still more preferably 5.0% by mass or more, still more preferably 6.0% by mass or more, and is preferably 30% by mass or less, more preferably 20% by mass or less, and even more preferably 15% by mass or less. When component (A) contains a nonionic surfactant, the content of the nonionic surfactant in the hair cosmetic concentrate is preferably 0.05% by mass or more, more preferably 0.10% by mass or more, even more preferably 0.20% by mass or more, and is preferably 10% by mass or less, more preferably 5.0% by mass or less, even more preferably 3.0% by mass or less.

[0022] <Component (B): Organic acid or its salt excluding citric acid> The hair cosmetic concentrate constituting the hair cosmetic of the present invention contains an organic acid or its salt, excluding citric acid, as component (B). Component (B) is used as an active ingredient for improving hair quality, such as by imparting body and strength to hair or reducing frizz. The organic acid used in the present invention includes carboxylic acid compounds other than citric acid and sulfonic acid compounds, and one or more of these can be used. Examples of carboxylic acid compounds include aliphatic monocarboxylic acids such as acetic acid and propionic acid, aromatic monocarboxylic acids such as benzoic acid, aliphatic dicarboxylic acids such as malonic acid, succinic acid, glutaric acid, adipic acid, maleic acid, and fumaric acid, aromatic dicarboxylic acids such as phthalic acid and isophthalic acid, polycarboxylic acids such as polyglutamic acid, hydroxycarboxylic acids other than citric acid such as glycolic acid, lactic acid, hydroxyacrylic acid, glyceric acid, malic acid, and tartaric acid, and acidic amino acids such as glutamic acid and aspartic acid. Among these, one or more selected from the group consisting of aliphatic dicarboxylic acids and hydroxycarboxylic acids are preferred from the viewpoint of improving the hair modifying effect and from the viewpoint of solubility in the hair cosmetic concentrate solution, and hydroxycarboxylic acids are more preferred from the viewpoint of improving the effect of imparting firmness and body to hair. Examples of sulfonic acid compounds include aliphatic sulfonic acids such as methanesulfonic acid and ethanesulfonic acid; aromatic sulfonic acids such as p-toluenesulfonic acid; etc. Among these, aromatic sulfonic acids are preferred from the viewpoint of improving the effect of modifying hair (reducing hair frizz) and from the viewpoint of solubility in the undiluted solution of the hair cosmetic composition.

[0023] As the salt of the organic acid salt, from the viewpoints of use in hair cosmetics and easy availability, alkali metal salts are preferred, one or more selected from the group consisting of sodium salts and potassium salts are more preferred, and sodium salts are even more preferred.

[0024] Among the above, from the viewpoint of improving the hair-modifying effect and from the viewpoint of solubility in the hair cosmetic concentrate solution, component (B) is more preferably one or more selected from the group consisting of aliphatic dicarboxylic acids, hydroxycarboxylic acids, aromatic sulfonic acids, or salts thereof, even more preferably one or more selected from the group consisting of aliphatic dicarboxylic acids, hydroxymonocarboxylic acids, hydroxydicarboxylic acids, aromatic sulfonic acids, or salts thereof, and even more preferably one or more selected from the group consisting of aliphatic dicarboxylic acids, hydroxymonocarboxylic acids, hydroxydicarboxylic acids, and aromatic sulfonic acids. Furthermore, of component (B), from the viewpoint of improving the effect of imparting body and tension to hair, hydroxycarboxylic acids are preferred, and one or more selected from the group consisting of hydroxymonocarboxylic acids and hydroxydicarboxylic acids are more preferred. Furthermore, from the viewpoint of improving the effect of reducing hair frizz, one or more selected from the group consisting of aliphatic dicarboxylic acids and aromatic sulfonic acids are preferred. The hydroxycarboxylic acid is preferably at least one selected from the group consisting of lactic acid, malic acid, and tartaric acid, with malic acid being more preferred, from the viewpoint of improving the effect of imparting firmness and body to hair.Furthermore, the aliphatic dicarboxylic acid is more preferably succinic acid, from the viewpoint of improving the effect of reducing hair frizz, and the aromatic sulfonic acid is preferably p-toluenesulfonic acid, from the viewpoint of improving the effect of reducing hair frizz. Furthermore, from the viewpoint of improving the effect of reducing hair frizz, component (B) more preferably contains an aliphatic dicarboxylic acid and an aromatic sulfonic acid, and even more preferably contains succinic acid and p-toluenesulfonic acid.

[0025] The content of component (B) in the hair cosmetic concentrate is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, and even more preferably 0.3% by mass or more, from the viewpoint of improving the hair modifying effect, and is preferably 20% by mass or less, more preferably 15% by mass or less, even more preferably 10% by mass or less, and even more preferably 5.0% by mass or less, from the viewpoint of solubility in the hair cosmetic concentrate. The specific content range of component (B) in the hair cosmetic concentrate is preferably 0.1 to 20% by mass, more preferably 0.2 to 15% by mass, even more preferably 0.3 to 10% by mass, and even more preferably 0.3 to 5.0% by mass. When component (B) is a hydroxycarboxylic acid (preferably one or more selected from the group consisting of hydroxymonocarboxylic acids and hydroxydicarboxylic acids, more preferably one or more selected from the group consisting of glycolic acid, lactic acid, hydroxyacrylic acid, glyceric acid, malic acid, and tartaric acid, even more preferably one or more selected from the group consisting of lactic acid, malic acid, and tartaric acid, and still more preferably malic acid), the content of the hydroxycarboxylic acid in the hair cosmetic concentrate is, from the viewpoint of improving the effect of imparting body and tension to hair, preferably 0.1% by mass or more, more preferably 0.2% by mass or more, even more preferably 0.3% by mass or more, and is preferably 3.0% by mass or less, more preferably 2.0% by mass or less, even more preferably 1.0% by mass or less, and still more preferably 0.8% by mass or less. When component (B) contains an aliphatic dicarboxylic acid and an aromatic sulfonic acid (preferably succinic acid and p-toluenesulfonic acid), the total content of the aliphatic dicarboxylic acid and the aromatic sulfonic acid in the hair cosmetic concentrate is, from the viewpoint of improving the effect of reducing hair frizz, preferably 0.5% by mass or more, more preferably 1.0% by mass or more, even more preferably 1.5% by mass or more, still more preferably 2.0% by mass or more, and is preferably 20% by mass or less, more preferably 15% by mass or less, even more preferably 10% by mass or less, and still more preferably 5.0% by mass or less. When component (B) contains an aliphatic dicarboxylic acid and an aromatic sulfonic acid (preferably succinic acid and p-toluenesulfonic acid), the mass ratio of the aliphatic dicarboxylic acid to the aromatic sulfonic acid in the hair cosmetic concentrate is preferably in the range of 1 / 0.2 to 1 / 10, more preferably 1 / 0.5 to 1 / 5, from the viewpoint of improving the effect of reducing hair frizz. When an organic acid salt is used as component (B), the amount of the organic acid salt in the undiluted hair cosmetic solution, calculated as the organic acid, is preferably within the above range.

[0026] From the viewpoint of improving the hair modifying effect, the mass ratio of component (B) to component (A) in the hair cosmetic concentrate solution [(B) / (A)] is preferably 0.005 or more, more preferably 0.01 or more, and even more preferably 0.1 or more, and from the viewpoint of foam dischargeability, it is preferably 20 or less, more preferably 15 or less, and even more preferably 12 or less. The specific range of the mass ratio of component (B) to component (A) in the hair cosmetic concentrate solution [(B) / (A)] is preferably 0.005 to 20, more preferably 0.01 to 15, and even more preferably 0.1 to 12.

[0027] The total content of components (A) and (B) in the hair cosmetic concentrate is preferably 0.15% by mass or more, more preferably 0.3% by mass or more, and even more preferably 0.5% by mass or more, from the viewpoint of imparting the desired performance as a hair cosmetic and improving the hair modifying effect, and is preferably 40% by mass or less, more preferably 30% by mass or less, and even more preferably 20% by mass or less, from the viewpoint of foam dischargeability. The specific range of the total content of components (A) and (B) in the hair cosmetic concentrate is preferably 0.15 to 40% by mass, more preferably 0.3 to 30% by mass, and even more preferably 0.5 to 20% by mass.

[0028] <Aqueous medium> The hair cosmetic concentrate typically contains an aqueous medium for dissolving or dispersing component (A), component (B), and other components. Examples of the aqueous medium include water and organic solvents. Examples of the organic solvent include lower alcohols such as ethanol and isopropyl alcohol; and low-molecular-weight diols and triols having 6 or less carbon atoms, such as 1,3-butylene glycol, glycerin, ethylene glycol, propylene glycol, and dipropylene glycol. Among these, water is preferred as the aqueous medium. The content of the aqueous medium in the hair cosmetic concentrate is preferably 60% by mass or more, more preferably 70% by mass or more, and is preferably 99.85% by mass or less, more preferably 99% by mass or less, from the viewpoint of dissolving or dispersing component (A), component (B), and other components, and from the viewpoint of improving foam dischargeability and foam quality. The specific range of the content of the aqueous medium in the hair cosmetic concentrate is preferably 60 to 99.85% by mass, more preferably 70 to 99% by mass.

[0029] <Component (D): Polymer> The hair cosmetic concentrate constituting the hair cosmetic of the present invention preferably further contains a polymer as component (D) from the viewpoint of improving foam dischargeability and foam quality. Examples of the polymer include anionic polymers, cationic polymers, nonionic polymers, and amphoteric polymers, and one or more of these can be used. From the viewpoint of solubility in the hair cosmetic concentrate, the polymer used as component (D) is preferably a water-soluble polymer. From the viewpoint of improving the ejection properties and foam quality of the aerosol foam, and from the viewpoint of storage stability, the polymer is preferably one or more selected from the group consisting of anionic polymers and nonionic polymers, and more preferably a nonionic polymer.

[0030] From the viewpoint of improving foam dischargeability and foam quality, the weight-average molecular weight (Mw) of component (D) is preferably 10,000 or more, more preferably 50,000 or more, even more preferably 100,000 or more, still more preferably 200,000 or more, still more preferably 500,000 or more, and still more preferably 1,000,000 or more. From the viewpoint of improving storage stability, it is preferably 5,000,000 or less, more preferably 4,000,000 or less, and still more preferably 3,500,000 or less. The specific range of the weight-average molecular weight of component (D) is preferably 10,000 to 5,000,000, more preferably 50,000 to 5,000,000, even more preferably 100,000 to 4,000,000, still more preferably 200,000 to 4,000,000, still more preferably 500,000 to 3,500,000, and still more preferably 1,000,000 to 3,500,000. The weight average molecular weight of component (D) can be measured, for example, by gel permeation chromatography (GPC) under the following conditions. Mobile phase: 50 mM LiBr, 1% CH3COOH / ethanol:water = 3:7 (w / w) Column: TSK gel α-M (Tosoh Corporation) (two columns in series) Standard substance: polyethylene glycol

[0031] As the anionic polymer, a polymer having a carboxy group as the anionic group is preferred from the viewpoint of solubility in the hair cosmetic concentrate solution and improving the dischargeability and quality of foam. Specific examples of anionic polymers include xanthan gum, carboxyvinyl polymer, (meth)acrylic acid / (meth)acrylic acid ester copolymer, (meth)acrylic acid / (meth)acrylic acid ester / alkylacrylamide copolymer, vinylpyrrolidone / (meth)acrylic acid ester / (meth)acrylic acid copolymer, methyl vinyl ether / maleic anhydride monoalkyl ester copolymer, vinyl acetate / crotonic acid copolymer, vinyl acetate / crotonic acid / vinyl propionate copolymer, vinyl acetate / crotonic acid / vinyl neodecanoate copolymer, vinyl acetate / maleic acid monoalkyl ester / (meth)acrylic acid ester copolymer, and the like, and one or more of these may be used. Among the above, from the viewpoints of solubility in the hair cosmetic concentrate solution and improving the foam dischargeability and foam quality, the anionic polymer is preferably at least one selected from the group consisting of xanthan gum, carboxyvinyl polymer, (meth)acrylic acid / (meth)acrylic acid ester copolymer, (meth)acrylic acid / (meth)acrylic acid ester / alkylacrylamide copolymer, and vinylpyrrolidone / (meth)acrylic acid ester / (meth)acrylic acid copolymer, more preferably xanthan gum.

[0032] Examples of nonionic polymers include water-soluble polysaccharides such as starch, cellulose, guar gum, tara gum, locust bean gum, and glucomannan; hydroxyalkylated water-soluble polysaccharides such as hydroxyethyl cellulose and hydroxypropyl cellulose; high-polymerization polyalkylene glycols such as high-polymerization polyethylene glycol and high-polymerization polyethylene glycol-polypropylene glycol copolymer; and polyvinyl alcohol, among which one or more can be used. The term "high polymerization degree" used herein means that the weight-average molecular weight is preferably within the above-mentioned range. Among the above, from the viewpoint of solubility in the hair cosmetic concentrate solution and improving the dischargeability and quality of foam, the nonionic polymer is preferably one or more selected from the group consisting of water-soluble polysaccharides, hydroxyalkylated water-soluble polysaccharides, and high-polymerization polyalkylene glycols, more preferably one or more selected from the group consisting of starch, cellulose, guar gum, tara gum, locust bean gum, glucomannan, hydroxyethyl cellulose, hydroxypropyl cellulose, high-polymerization polyethylene glycol, and high-polymerization polyethylene glycol-polypropylene glycol copolymer, even more preferably one or more selected from the group consisting of hydroxyethyl cellulose, hydroxypropyl cellulose, high-polymerization polyethylene glycol, and high-polymerization polyethylene glycol-polypropylene glycol copolymer, and still more preferably one or more selected from the group consisting of hydroxyethyl cellulose and high-polymerization polyethylene glycol.

[0033] When component (D) is used, the content of component (D) in the hair cosmetic concentrate is preferably 0.005% by mass or more, more preferably 0.01% by mass or more, even more preferably 0.02% by mass or more, still more preferably 0.05% by mass or more, and even more preferably 0.1% by mass or more, from the viewpoints of improving foam dischargeability and foam quality. Furthermore, from the viewpoints of adjusting the hair cosmetic concentrate to an appropriate viscosity and improving storage stability, the content is preferably 5% by mass or less, more preferably 2% by mass or less, even more preferably 1% by mass or less, and even more preferably 0.5% by mass or less. The specific range of the content of component (D) in the hair cosmetic concentrate is preferably 0.005 to 5% by mass, more preferably 0.01 to 2% by mass, even more preferably 0.02 to 1% by mass, still more preferably 0.02 to 0.5% by mass, still more preferably 0.05 to 0.5% by mass, and even more preferably 0.1 to 0.5% by mass.

[0034] When component (D) is used, the mass ratio of component (D) to component (A) in the hair cosmetic concentrate [(D) / (A)] is preferably 0.001 or more, more preferably 0.002 or more, from the viewpoint of improving foam dischargeability and foam quality, and is preferably 5 or less, more preferably 3 or less, and even more preferably 2 or less, from the viewpoint of adjusting the viscosity of the hair cosmetic concentrate to an appropriate level and improving storage stability. The specific range of the mass ratio of component (D) to component (A) in the hair cosmetic concentrate [(D) / (A)] is preferably 0.001 to 5, more preferably 0.001 to 3, and even more preferably 0.002 to 2.

[0035] <Other ingredients> The hair cosmetic concentrate may contain other ingredients as appropriate within the scope of the present invention, such as antioxidants, oils, antidandruff agents, vitamins, disinfectants, anti-inflammatory agents, preservatives, chelating agents, moisturizers, pearlizing agents, ceramides, fragrances, UV absorbers, and pH adjusters, which are commonly used in hair cosmetics.

[0036] There are no particular limitations on the method for producing the hair cosmetic concentrate, and it can be produced by blending and mixing component (A) and component (B), as well as other components used as needed, in a conventional manner.

[0037] <Component (C): Propellant> The propellant (C) constituting the hair cosmetic composition of the present invention contains carbon dioxide. By including carbon dioxide in component (C), it is possible to eject a fine, dense foam and also to promote the penetration of the organic acid (component (B)) into the interior of the hair, thereby enhancing the hair-modifying effect through the aforementioned mechanism of action. The content of carbon dioxide in the propellant (C) is preferably 50% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, still more preferably 90% by mass or more, and still more preferably 100% by mass, from the viewpoints of improving the dischargeability and quality of the foam and promoting the penetration of the organic acid into the interior of the hair to enhance the hair modifying effect. In other words, the propellant (C) preferably consists solely of carbon dioxide. Component (C) may contain other liquefied gases as propellants other than carbon dioxide, such as nitrogen, propane, normal butane, isobutane, and mixtures thereof such as liquefied petroleum gas (LPG), dimethyl ether, and isopentane, within a range that does not impair the effects of the present invention.

[0038] The amount of propellant (C) filled in the aerosol hair cosmetic of the present invention is preferably at least 0.5% by mass, more preferably at least 1% by mass, and preferably at most 5% by mass, more preferably at most 3% by mass, based on 100% by mass of the total amount of the hair cosmetic concentrate and propellant (C), from the viewpoints of improving foam dischargeability and foam quality, promoting penetration of the organic acid into the hair to enhance the hair-modifying effect, and obtaining an appropriate spray speed. The specific range of the amount of propellant (C) filled is preferably 0.5 to 5% by mass, more preferably 1 to 3% by mass, based on 100% by mass of the total amount of the hair cosmetic concentrate and propellant (C). To obtain an appropriate spray speed, the internal pressure of the aerosol container after filling with propellant (C) is adjusted to preferably 0.1 MPa or more, more preferably 0.3 MPa or more, and preferably 1.3 MPa or less, more preferably 1.0 MPa or less at 25° C. The specific range of the internal pressure of the aerosol container after filling with propellant (C) is preferably 0.1 to 1.3 MPa, more preferably 0.3 to 1.0 MPa.

[0039] <Aerosol container> The aerosol-type hair cosmetic composition of the present invention is filled into an aerosol container for use. Examples of the aerosol container include known pressure-resistant containers made of metal, plastic, etc., and double-structure containers in which an inner bag is housed inside a pressure-resistant container. In the case of a double-structure container, it is preferable that the inner bag is filled with the hair cosmetic concentrate, and a propellant (C) is filled between the pressure-resistant container and the inner bag.

[0040] The method for preparing the aerosol hair cosmetic of the present invention is not particularly limited. For example, it can be prepared by filling a pressure-resistant container that constitutes an aerosol container with the hair cosmetic concentrate, attaching a valve, and then filling the propellant (C) through the valve.

[0041] <How to use the aerosol hair cosmetic> The method of using the aerosol hair cosmetic composition of the present invention is not particularly limited as long as it includes a step of discharging the hair cosmetic composition in foam form from an aerosol container and applying it to hair. The hair cosmetic composition discharged in the form of foam may be applied to wet hair or to dry hair, depending on the type of hair cosmetic composition. For example, when the hair cosmetic composition of the present invention is a hair cleanser, examples of the method include a method comprising a step of applying the hair cosmetic composition discharged in a foam form to hair and washing the hair. The step of washing the hair also includes an operation of lathering the hair cleanser on the hair and a subsequent operation of rinsing the hair cleanser off. When the hair cosmetic composition of the present invention is a rinse, a conditioning agent, or a treatment agent, examples of the method include applying the hair cosmetic composition discharged in foam form from an aerosol container to wet or dry hair after washing, allowing it to absorb into the hair, and then rinsing it off as necessary. The hair cosmetic composition of the present invention, discharged in a foam form, contains carbon dioxide gas, has good applicability, can be spread evenly over the entire hair, and can be fully absorbed into the hair. Therefore, by using the hair cosmetic composition of the present invention, for example, in the above-mentioned method, active ingredients such as organic acids can easily penetrate into the interior of the hair.

[0042] The amount of the hair cosmetic applied to the hair is preferably 0.002 or more, more preferably 0.003 or more, and preferably 0.6 or less, more preferably 0.5 or less, in terms of mass ratio to the mass of the hair (mass of hair cosmetic / mass of hair). The hair to be treated may be at least a portion of the head hair.

[0043] <Hair modification method and use> The present invention can also provide a method for modifying hair, which comprises the step of applying the aerosol hair cosmetic composition to hair. The present invention also provides a method for penetrating an organic acid into the interior of hair, the method comprising the step of applying to hair an aerosol-type hair cosmetic composition, preferably the aerosol-type hair cosmetic composition, which contains a hair cosmetic concentrate solution containing a surfactant (A) and an organic acid or a salt thereof (B1), and a propellant (C) containing carbon dioxide and has a pH of 3.0 or more and 5.0 or less at 20°C. Furthermore, the present invention also provides an aerosol-type hair cosmetic composition containing a hair cosmetic concentrate containing a surfactant (A) and an organic acid or a salt thereof (B1), and a propellant (C) containing carbon dioxide, and having a pH of 3.0 or more and 5.0 or less at 20°C, preferably use of the aerosol-type hair cosmetic composition for improving hair quality. The above-mentioned method and use may comprise a step of discharging an aerosol-type hair cosmetic, preferably the aerosol-type hair cosmetic of the present invention, in the form of foam from an aerosol container, and applying the foam to hair by spreading or the like, the foam containing a hair cosmetic concentrate containing a surfactant (A) and an organic acid or its salt (B1), and a propellant (C) containing carbon dioxide, and a pH of 3.0 to 5.0 at 20°C. This allows the organic acid, an active ingredient for hair modification, to easily penetrate into the hair, thereby providing hair modification effects such as imparting firmness and body to hair and reducing frizz, through the aforementioned mechanism of action. The hair cosmetic composition discharged in the form of foam may be applied to wet hair or to dry hair, depending on the type of hair cosmetic composition. The method of applying the hair cosmetic composition to hair, the amount of the hair cosmetic composition to be applied to hair, and preferred embodiments thereof are the same as those described above. The organic acid or salt thereof (B1) is the same as the component (B) described above, except that it may contain citric acid or a salt thereof.

[0044] In addition to the above-described embodiments, the present invention also discloses the following embodiments. <1> The aerosol-type hair cosmetic contains a hair cosmetic concentrate containing a surfactant (A), an organic acid other than citric acid or its salt (B), and a propellant (C) containing carbon dioxide, and has a pH of 3.0 or more and 5.0 or less at 20°C. <2> Component (A) contains one or more surfactants selected from the group consisting of anionic surfactants and nonionic surfactants. <1> 1. The aerosol type hair cosmetic composition according to claim 1. <3> The anionic surfactant is at least one selected from the group consisting of alkylbenzenesulfonates, alkyl or alkenyl ether sulfates, alkyl or alkenyl sulfates, alkyl sulfonates, saturated or unsaturated fatty acid salts, alkyl or alkenyl ether carboxylates, α-sulfofatty acid salts, N-acylamino acid salts, phosphoric acid mono- or diester salts, and sulfosuccinate salts, preferably at least one selected from the group consisting of alkyl sulfates, alkyl ether sulfates, alkyl ether carboxylates, and N-acylamino acid salts, more preferably at least one selected from the group consisting of alkyl ether sulfates and N-acylamino acid salts, and even more preferably at least one selected from the group consisting of sodium laureth sulfate, ammonium laureth sulfate, and sodium cocoyl glutamate; <2> 1. The aerosol type hair cosmetic composition according to claim 1. <4> the nonionic surfactant is one or more selected from the group consisting of polyoxyalkylene alkyl ethers, polyoxyalkylene alkenyl ethers, polyoxyalkylene sorbitan fatty acid esters, polyoxyalkylene fatty acid esters, alkyl glucosides, alkyl alkanolamides, alkyl glyceryl ethers, higher fatty acid sucrose esters, polyglycerol fatty acid esters, polyoxyalkylene hydrogenated castor oil, and alkyl saccharides, preferably one or more selected from the group consisting of polyoxyalkylene alkyl ethers, polyoxyalkylene alkenyl ethers, polyoxyalkylene sorbitan fatty acid esters, polyoxyalkylene fatty acid esters, alkyl glucosides, alkyl alkanolamides, alkyl glyceryl ethers, and polyoxyalkylene hydrogenated castor oil, more preferably one or more selected from the group consisting of polyoxyalkylene alkyl ethers, alkyl glucosides, alkyl alkanolamides, alkyl glyceryl ethers, and polyoxyalkylene hydrogenated castor oil, and even more preferably polyoxyalkylene hydrogenated castor oil; <2> or <3> 1. The aerosol type hair cosmetic composition according to claim 1. <5> The content of component (A) in the hair cosmetic concentrate is preferably 0.05 to 30% by mass, more preferably 0.10 to 20% by mass, and even more preferably 0.20 to 15% by mass. <1> ~ <4> 10. The aerosol hair cosmetic composition according to claim 1, <6> The content of the anionic surfactant in the hair cosmetic concentrate is preferably 0.50% by mass or more, more preferably 1.0% by mass or more, even more preferably 3.0% by mass or more, still more preferably 5.0% by mass or more, still more preferably 6.0% by mass or more, and is preferably 30% by mass or less, more preferably 20% by mass or less, even more preferably 15% by mass or less. <2> ~ <5> 10. The aerosol hair cosmetic composition according to claim 1, <7> The content of the nonionic surfactant in the hair cosmetic concentrate is preferably 0.05% by mass or more, more preferably 0.10% by mass or more, even more preferably 0.20% by mass or more, and is preferably 10% by mass or less, more preferably 5.0% by mass or less, even more preferably 3.0% by mass or less. <2> ~ <6> 10. The aerosol hair cosmetic composition according to claim 1, <8> Component (B) is at least one selected from the group consisting of carboxylic acid compounds and sulfonic acid compounds excluding citric acid, preferably at least one selected from the group consisting of aliphatic dicarboxylic acids, hydroxycarboxylic acids, aromatic sulfonic acids, or salts thereof, more preferably at least one selected from the group consisting of aliphatic dicarboxylic acids, hydroxymonocarboxylic acids, hydroxydicarboxylic acids, aromatic sulfonic acids, or salts thereof, and even more preferably at least one selected from the group consisting of aliphatic dicarboxylic acids, hydroxymonocarboxylic acids, hydroxydicarboxylic acids, and aromatic sulfonic acids, <1> ~ <7> 10. The aerosol hair cosmetic composition according to claim 1, <9> The aliphatic dicarboxylic acid is at least one selected from the group consisting of malonic acid, succinic acid, glutaric acid, adipic acid, maleic acid, and fumaric acid, preferably succinic acid; <8> 1. The aerosol type hair cosmetic composition according to claim 1. <10> The hydroxycarboxylic acid is at least one selected from the group consisting of hydroxymonocarboxylic acids and hydroxydicarboxylic acids, preferably at least one selected from the group consisting of glycolic acid, lactic acid, hydroxyacrylic acid, glyceric acid, malic acid, and tartaric acid, more preferably at least one selected from the group consisting of lactic acid, malic acid, and tartaric acid, and even more preferably malic acid. <8> or <9> 1. The aerosol type hair cosmetic composition according to claim 1.

[0045] <11> The aromatic sulfonic acid is p-toluenesulfonic acid; <8> ~ <10> 10. The aerosol hair cosmetic composition according to claim 1, <12> Component (B) comprises an aliphatic dicarboxylic acid and an aromatic sulfonic acid, preferably succinic acid and p-toluenesulfonic acid; <1> ~ <11> 10. The aerosol hair cosmetic composition according to claim 1, <13> The content of component (B) in the hair cosmetic concentrate is preferably 0.1 to 20% by mass, more preferably 0.2 to 15% by mass, even more preferably 0.3 to 10% by mass, and still more preferably 0.3 to 5.0% by mass. <1> ~ <12> 10. The aerosol hair cosmetic composition according to claim 1, <14> The content of hydroxycarboxylic acid in the hair cosmetic concentrate is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, even more preferably 0.3% by mass or more, and is preferably 3.0% by mass or less, more preferably 2.0% by mass or less, even more preferably 1.0% by mass or less, and still more preferably 0.8% by mass or less. <8> ~ <13> 10. The aerosol hair cosmetic composition according to claim 1, <15> The total content of aliphatic dicarboxylic acids and aromatic sulfonic acids in the hair cosmetic concentrate is preferably 0.5% by mass or more, more preferably 1.0% by mass or more, even more preferably 1.5% by mass or more, still more preferably 2.0% by mass or more, and is preferably 20% by mass or less, more preferably 15% by mass or less, even more preferably 10% by mass or less, and still more preferably 5.0% by mass or less. <8> ~ <14> 10. The aerosol hair cosmetic composition according to claim 1, <16> The mass ratio of the aliphatic dicarboxylic acid to the aromatic sulfonic acid in the hair cosmetic concentrate is preferably in the range of 1 / 0.2 to 1 / 10, more preferably 1 / 0.5 to 1 / 5. <8> ~ <15> 10. The aerosol hair cosmetic composition according to claim 1, <17> The mass ratio of component (B) to component (A) in the hair cosmetic concentrate solution [(B) / (A)] is preferably 0.15 to 40 mass%, more preferably 0.3 to 30 mass%, and even more preferably 0.5 to 20 mass%. <1> ~ <16> 10. The aerosol hair cosmetic composition according to claim 1, <18> The total content of component (A) and component (B) in the hair cosmetic concentrate is preferably 0.15 to 40% by mass, more preferably 0.3 to 30% by mass, and even more preferably 0.5 to 20% by mass. <1> ~ <17> 10. The aerosol hair cosmetic composition according to claim 1, <19> The hair cosmetic concentrate contains an aqueous medium in an amount of preferably 60 to 99.85% by mass, more preferably 70 to 99% by mass. <1> ~ <18> 10. The aerosol hair cosmetic composition according to claim 1, <20> the aqueous medium is at least one selected from the group consisting of water, lower alcohols, and low-molecular-weight diols and triols having 6 or less carbon atoms, preferably at least one selected from the group consisting of water, ethanol, isopropyl alcohol, 1,3-butylene glycol, glycerin, ethylene glycol, propylene glycol, and dipropylene glycol, more preferably water; <19> 1. The aerosol type hair cosmetic composition according to claim 1.

[0046] <21> Further, the composition contains, as component (D), a polymer, preferably one or more selected from the group consisting of anionic polymers and nonionic polymers, more preferably a nonionic polymer. <1> ~ <20> 10. The aerosol hair cosmetic composition according to claim 1, <22> The nonionic polymer is preferably one or more selected from the group consisting of water-soluble polysaccharides, hydroxyalkylated water-soluble polysaccharides, and high-polymerization polyalkylene glycols, more preferably one or more selected from the group consisting of starch, cellulose, guar gum, tara gum, locust bean gum, glucomannan, hydroxyethyl cellulose, hydroxypropyl cellulose, high-polymerization polyethylene glycol, and high-polymerization polyethylene glycol-polypropylene glycol copolymer, even more preferably one or more selected from the group consisting of hydroxyethyl cellulose, hydroxypropyl cellulose, high-polymerization polyethylene glycol, and high-polymerization polyethylene glycol-polypropylene glycol copolymer, and still more preferably one or more selected from the group consisting of hydroxyethyl cellulose and high-polymerization polyethylene glycol. <21> 1. The aerosol type hair cosmetic composition according to claim 1. <23> The content of component (D) in the hair cosmetic concentrate is preferably 0.005 to 5 mass%, more preferably 0.01 to 2 mass%, even more preferably 0.02 to 1 mass%, still more preferably 0.02 to 0.5 mass%, even more preferably 0.05 to 0.5 mass%, and still more preferably 0.1 to 0.5 mass%, <21> or <22> 1. The aerosol type hair cosmetic composition according to claim 1. <24> the mass ratio of component (D) to component (A) in the hair cosmetic concentrate solution [(D) / (A)] is preferably 0.001 to 5, more preferably 0.001 to 3, and even more preferably 0.002 to 2; <21> ~ <23> 10. The aerosol hair cosmetic composition according to claim 1, <25> The content of carbon dioxide in the propellant (C) is preferably 50% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, still more preferably 90% by mass or more, and still more preferably 100% by mass. <1> ~ <24> 10. The aerosol hair cosmetic composition according to claim 1, <26> The amount of the propellant (C) filled in the aerosol-type hair cosmetic is preferably 0.5 to 5% by mass, and more preferably 1 to 3% by mass, when the total amount of the hair cosmetic concentrate and the propellant (C) is taken as 100% by mass. <1> ~ <25> 10. The aerosol hair cosmetic composition according to claim 1, <27> The pH of the hair cosmetic at 20°C is preferably 3.0 to 4.8, more preferably 3.0 to 4.5, even more preferably 3.0 to 4.2, more preferably 3.2 to 4.2, and even more preferably 3.4 to 4.2. <1> ~ <26> 10. The aerosol hair cosmetic composition according to claim 1, <28> The aerosol-type hair cosmetic is an aerosol-type hair cleanser, rinse, conditioning agent, treatment agent, styling agent, hair dye, or hair growth agent, and is preferably an aerosol-type hair cleanser. <1> ~ <27> 10. The aerosol hair cosmetic composition according to claim 1, <29> The method comprises a step of discharging the hair cosmetic composition in foam form from an aerosol container and applying the foam to hair. <1> ~ <28> A method for using the aerosol hair cosmetic composition according to any one of the above. <30> <1> ~ <28> A method for modifying hair, comprising the step of applying the aerosol hair cosmetic composition according to any one of the above to hair.

[0047] <31> An aerosol-type hair cosmetic composition containing a hair cosmetic concentrate containing a surfactant (A) and an organic acid or its salt (B1), and a propellant (C) containing carbon dioxide, and having a pH of 3.0 or more and 5.0 or less at 20°C, preferably <1> ~ <28> Use of the aerosol hair cosmetic composition according to any one of the above for improving hair quality. <32> An aerosol-type hair cosmetic composition containing a hair cosmetic concentrate containing a surfactant (A) and an organic acid or its salt (B1), and a propellant (C) containing carbon dioxide, and having a pH of 3.0 or more and 5.0 or less at 20°C, preferably <1> ~ <28> 1. A method for penetrating an organic acid into the interior of hair, comprising the step of applying the aerosol hair cosmetic composition according to any one of the above items to hair. [Example]

[0048] The present invention will be described below with reference to examples, but the present invention is not limited to the scope of the examples. In these examples, pH was measured by the following method.

[0049] (pH) The pH at 20°C of the aerosol-type hair cleanser containing a propellant (or the undiluted hair cleanser solution for those not containing a propellant) was measured using a pH meter (HM-30R, manufactured by DKK-TOA Corporation) for the aqueous solution obtained by diluting the hair cleanser or undiluted hair cleanser solution 20 times with water and stirring thoroughly.

[0050] Examples 1 to 6 and Comparative Examples 1 to 12 (Preparation and Evaluation of Hair Cleansing Agents) The components to be incorporated into the hair cleanser concentrate were blended according to the compositions shown in Tables 1 to 3 and then mixed until uniform to prepare a hair cleanser concentrate. For those containing a propellant, 50 g of the hair cleanser concentrate and the propellant shown in each table were then filled into a 100 mL aerosol container (manufactured by Toyo Seikan Co., Ltd., container type: BL35A115-H, inner coating: epoxy phenolic, outer surface: plain silver (or white)) in the mass ratio shown in the table to prepare the aerosol hair cleanser. The internal pressure of the aerosol container after filling with the propellant was adjusted to a range of 0.65 to 0.85 MPa. The prepared hair cleansing agents were evaluated by the following methods, and the results are shown in Tables 1 to 3. The blending amounts shown in each table are the amount of active ingredient (mass %) of each component, excluding hydrochloric acid.

[0051] <Increase in bending modulus of hair> For the hair cleansing agents listed in Table 1, the increase in the bending modulus of hair was measured using the following method, and the effect of improving hair quality (giving hair elasticity and body) was evaluated. The hair used was a Japanese woman's hair bundle that had been treated with bleach four times. 20 strands each of untreated and treated hair were randomly selected from this. These were immersed in ion-exchanged water for 10 minutes and then immersed in a 10% aqueous solution of plain shampoo with the following composition for 60 seconds. After rinsing with ion-exchanged water for 90 seconds, the hair was naturally dried at a temperature of 20°C and a humidity of 65% to prepare two hair samples. One of the hair samples was untreated, and the other was treated as follows: [Composition of plain shampoo] Ingredients (mass%) Sodium Polyoxyethylene (2) Lauryl Ether Sulfate (*1) 15.5 Lauric acid diethanolamide (*2) 1.5 edetic acid tetrasodium salt 0.3 Sodium benzoate 1.43 Purified water remaining amount Total 100.0 *1: 57.4% by mass of Emeral 227 (manufactured by Kao Corporation, active ingredient 27% by mass) *2: Aminone L-02 (Kao Corporation)

[0052] (Hair treatment) The hair cleanser listed in Table 1 was dispensed from an aerosol container (for those not containing a propellant, the undiluted hair cleanser was used), diluted 10-fold with water (a total of 3.0 g was used for each), and the hair sample was immersed in the diluted solution at room temperature for 15 minutes to treat the hair. After treatment, the hair was washed with ion-exchanged water for 90 seconds and then air-dried at 20°C and 65% humidity to prepare treated hair.

[0053] (Measurement of flexural modulus) The bending modulus of untreated and treated hair was measured. The bending modulus was measured using a hair bending modulus test system (Keystone Scientific Co., Ltd., FBS900) under the following conditions: temperature 20°C, humidity 65%. Note that for both untreated and treated hair, measurements were made on 20 strands of hair. [Measurement conditions] Proportion gain: 25 Integrated gain: 2 Derivative gain: 50 Fiber width: 1 Sample interval: 200mS Deflection(mm):0.1 Offset move(mm):0.5 Maximum force (mg): 400 Gauge force (mg): 2 Repair cycle: 1 Rate (mm / sec): 0.01 Start angle: 0 Rotation angle: 0 End angle: 0 Relaxation time: 0 Bend analysis option ·Start analysis at:0 Microns deflection ·End analysis at:100 Microns deflection Analysis angle: 0 Degrees ·Cantilever length:2250 Microns The increase rate (%) in the bending modulus of the hair was calculated by (bending modulus of the treated hair) / (bending modulus of the untreated hair)×100 (%). The results are shown in Table 1. The higher the rate of increase in the bending modulus of hair, the greater the effect of improving hair quality (giving hair firmness and body). Furthermore, the increase in bending modulus was statistically analyzed for the values ​​of bending modulus of untreated and treated hair, and judged according to the following criteria based on the statistical significance level. The results are shown in Table 1. A rating of A or B indicates a significant hair improvement effect (giving hair bounce and body). A: There is a significant difference at a statistical significance level of 0.01 or less. B: There is a significant difference at a statistical significance level of over 0.01 and below 0.05. C: No statistically significant difference

[0054] <Increase in stress relaxation rate of hair> For the hair washes listed in Tables 2 and 3, the rate of increase in the stress relaxation rate of the hair was measured by the following method, and the hair-improving effect (reduction of hair frizz) was evaluated. The hair used was a bundle of untreated Japanese female hair. 20 strands each of untreated and treated hair were randomly selected from the bundle, one for the untreated sample and the other for the treated sample. These were immersed in a 10% aqueous solution of the plain shampoo with the above composition for 60 seconds, and then air-dried at 20°C and 65% humidity. Next, one of the hairs (untreated sample) was immersed in ion-exchanged water at room temperature for 15 minutes, and then dried at a temperature of 20°C and a humidity of 65% for 48 hours to obtain untreated hair. For the other hair (treatment sample), 3.0 g of the hair cleanser shown in Tables 2 and 3 was dispensed from an aerosol container (for those not containing a propellant, 3.0 g of the undiluted hair cleanser was used), and the hair was immersed in the hair cleanser for 15 minutes at room temperature to treat it. After treatment, the hair was washed with ion-exchanged water for 90 seconds and dried for 48 hours at a temperature of 20°C and a humidity of 65% to obtain treated hair. For untreated and treated hair, an automatic tensile tester (Dia-Stron, MTT680) was used to apply a tensile stress to each hair under the following conditions: temperature 20°C, humidity 65%, pulling speed: 18 mm / min, distance between grippers: 30 mm, and the hair was maintained at a 1% tension for 3 minutes. The initial stress value at 0 seconds after the stretched state was used as the reference, and the stress relaxation rate was calculated from the relative stress value after 3 minutes. Measurements were also performed on 10 hairs for each of the untreated and treated hair. The stress relaxation rates of untreated and treated hair, and the increase in stress relaxation rate before and after treatment were calculated using the following formula. Stress relaxation rate (%) = (initial stress value (N) when stretched for 0 seconds - stress value (N) after 3 minutes of stretching) / (initial stress value (N) when stretched for 0 seconds) x 100 (%) Increase in stress relaxation rate (%) = (stress relaxation rate of treated hair - stress relaxation rate of untreated hair) / (stress relaxation rate of untreated hair) x 100 (%) Furthermore, the stress relaxation rate increase rate for untreated hair and treated hair was statistically processed, and a significant difference was determined based on the statistical significance level using the following criteria. The results are shown in Tables 2 and 3. If the stress relaxation rate increase rate is a positive value and the significant difference determination result is an A or B rating, this means that a significant hair improvement effect (reduction of hair frizz) has been obtained. A: There is a significant difference at a statistical significance level of 0.01 or less. B: There is a significant difference at a statistical significance level of over 0.01 and below 0.05. C: No statistically significant difference

[0055] [Table 1]

[0056] [Table 2]

[0057] [Table 3]

[0058] The ingredients used in the table are as follows: <Surfactant (A)> [Anionic surfactants] Sodium laureth sulfate; Polyoxyethylene (2) sodium lauryl ether sulfate, Kao Corporation "Emal 227", active ingredient content 27% by mass Ammonium laureth sulfate; polyoxyethylene (1) alkyl (C10-16) ether ammonium sulfate, "Emeral 125A" manufactured by Kao Corporation, active ingredient content 25% by mass · Sodium cocoyl glutamate; "Amisoft CS-22B" manufactured by Ajinomoto Lucy Supply Co., Ltd., active ingredient content: 25% by mass 〔Nonionic surfactant〕 · PEG-60 hydrogenated castor oil; "Emalex CH-60K" manufactured by Kao Corporation, active ingredient content: 100% by mass <Organic acid or its salt (B)> · Succinic acid; manufactured by Nippon Shokubai Co., Ltd. · Malic acid; manufactured by Kawasaki Kasei Kogyo Co., Ltd., 50% liquid malic acid · p-Toluenesulfonic acid; manufactured by Kono Chemical Co., Ltd., 70% p-toluenesulfonic acid <Acid (B') other than component (B)> · Hydrochloric acid; manufactured by Fujifilm Wako Pure Chemical Corporation, 1 mol / L hydrochloric acid <Polymer (D)> · Hydroxyethyl cellulose; weight average molecular weight 1,500,000, "HEC Daicel SE 850K" manufactured by Daicel Fine Chemical Co., Ltd. · Polyethylene glycol, weight average molecular weight 2,000,000, "Polyox WSR N-60K" manufactured by The Dow Chemical Company <pH adjuster> · Liquid caustic potash (48%); manufactured by Occidental Chemical Corporation, USA

[0059] As shown in Table 1, it can be seen that for the hair to which the aerosol-type hair shampoo of this example was applied, the increase rate of the bending elastic modulus was high for all of them. Also, as shown in Tables 2 and 3, it can be seen that for the hair to which the aerosol-type hair shampoo of this example was applied, a hair modification effect due to an increase in the stress relaxation rate of the hair was obtained. This is considered to be the effect due to the efficient penetration of component (B) into the hair. In contrast, in Comparative Examples 1, 3, 4, 6, 7, and 9 to 12 that do not contain carbon dioxide as the propellant, Comparative Example 2 that does not contain component (B), Comparative Example 3 that does not contain component (A), and Comparative Examples 5 and 8 where the pH is outside the scope of the present invention, no significant hair modification effect was obtained.

[0060] (Evaluation of the penetration state of p-toluenesulfonic acid) Approximately 10 mg of a 30 cm long untreated Japanese female hair bundle was thoroughly moistened with warm water at 35 to 40°C, and then 1 g of the hair cleanser of Example 6 was dispensed in foam form from an aerosol container and applied to the hair bundle. The hair was washed for 60 seconds, and then rinsed with warm water at 35 to 40°C for 60 seconds. This washing procedure was repeated 15 times, and the hair was blow-dried. The remaining p-toluenesulfonic acid in the hair was then analyzed using a TOF-SIMS (manufactured by ION-TOF). In addition, the hair was washed in the same manner as above using the undiluted hair wash solution of Comparative Example 12 instead of the hair wash solution of Example 6, and the p-toluenesulfonic acid remaining in the hair was analyzed.

[0061] Regarding the state of penetration of p-toluenesulfonic acid into the interior of hair, Figure 1 is a TOF-SIMS mapping image based on the above analysis results of the p-toluenesulfonic acid present in the cross section of hair washed with the hair wash of Example 6, and Figure 2 is a TOF-SIMS mapping image based on the above analysis results of the p-toluenesulfonic acid present in the cross section of hair washed with the hair wash of Comparative Example 12. In Figures 1 and 2, bright areas indicate the presence of p-toluenesulfonic acid. A comparison of FIG. 1 and FIG. 2 reveals that the aerosol hair cleanser of the present invention has a high effect of allowing p-toluenesulfonic acid to penetrate deep into the hair. [Industrial Applicability]

[0062] According to the present invention, it is possible to provide an aerosol type hair cosmetic composition that can efficiently penetrate an organic acid, which is an active ingredient for hair modification, into the interior of the hair.

Claims

1. An aerosol-type hair cosmetic comprising a hair cosmetic concentrate containing a surfactant (A) including one or more selected from the group consisting of anionic surfactants and nonionic surfactants, an organic acid or a salt thereof excluding citric acid (B), and a propellant (C) including carbon dioxide, wherein the mass ratio of component (B) to component (A) in the hair cosmetic concentrate is 0.1 or more and 12 or less, and the pH at 20°C is 3.0 or more and 4.2 or less.

2. 2. The aerosol hair cosmetic composition according to claim 1, wherein the content of the component (B) is 0.1% by mass or more and 20% by mass or less.

3. 3. The aerosol hair cosmetic composition according to claim 1, wherein the component (B) is at least one member selected from the group consisting of an aliphatic dicarboxylic acid, a hydroxycarboxylic acid, an aromatic sulfonic acid, or a salt thereof.

4. The aerosol hair cosmetic according to any one of claims 1 to 3, wherein the hair cosmetic concentrate further contains a polymer as component (D).

5. The aerosol hair cosmetic composition according to any one of claims 1 to 4, which is an aerosol hair cleanser.

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