Oil-dispersible micellar composition and hair cosmetic containing same

Abstract

To provide a micelle composition comprising keratin protein and having excellent dispersibility in an oily medium and to provide a hair cosmetic stably comprising a keratin protein and having excellent permeability and retention in the hair application site.SOLUTION: The oil-dispersible micelle composition of the present invention comprises: (A) a polyether-modified silicone or an ethylene glycol-based or glycerin-based nonionic surfactant, and (B) an alkylated keratin protein. The hair cosmetic of the present invention comprises the oil-dispersible micelle composition of the present invention.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a micelle composition containing keratin protein and having excellent dispersibility in an oily medium. The present invention also relates to a hair cosmetic composition containing keratin protein stably and having excellent penetration and retention into the application site of hair. [Background technology]

[0002] Hair cosmetics are used not only to make hair look beautiful and to improve its texture, but also to protect the area where they are applied, or to repair or improve the functions and properties of the area where they are applied. For example, keratin, a protein found in feathers and wool, is an effective ingredient in hair cosmetics and is known to be easily absorbed into hair and to be effective in repairing and improving hair quality.

[0003] Keratin protein is a polymer composed of amino acids. The protein, which has been processed so that it can be incorporated into cosmetics, is hydrophilic and solubilized in water or an aqueous solvent. Most common cosmetics are formulated based on an aqueous medium, and such formulations allow for easy incorporation of the protein. Meanwhile, some formulations, such as hair oil, are based on an oily medium.

[0004] Patent Document 1 discloses a technology for incorporating acylated keratin protein into cosmetics. To make the keratin protein more compatible with oil, the keratin protein is derivatized to include a lauric acid or myristic acid side chain. The keratin protein disclosed in Patent Document 1 also contains structures such as carboxylates that are compatible with water during derivatization, and functions as a surfactant, making it suitable for cleansing cosmetics.

[0005] Patent Document 2 discloses the isostearoylation of peptides derived from keratin protein. This isostearoylation allows hydrolyzed keratin to be incorporated into oil-based cosmetics and also provides hair with excellent tensile strength, bounce, and body. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-159388 [Patent Document 2] Japanese Patent Application Publication No. 2018-095622 Summary of the Invention [Problem to be solved by the invention]

[0007] Hair contains over 80% keratin protein. When hair is damaged, the protein breaks down and is lost, causing the hair to lose its elasticity and luster and its tensile strength to decrease. By incorporating keratin protein obtained from wool or feathers into hair cosmetics, damaged hair can be repaired. This is because keratin protein penetrates into the hair, replacing the lost protein and improving elasticity, body, and tensile strength. It also coats the surface of the hair, straightening out any cuticle irregularities and adding luster.

[0008] Keratin protein is a polymer composed of amino acids and has many electrical charges, which poses some usage challenges, such as insolubility in oily media. Patent Documents 1 and 2 address these challenges by using keratin protein that is compatible with or soluble in oil. Meanwhile, for keratin protein to effectively repair damaged hair, the molecular weight of the protein is also important. However, the higher the polymer of a protein, the lower its solubility, and because it is a polar compound with an electrical charge, it is particularly difficult to dissolve in oily solvents, even after lipophilic derivatization, making it difficult to incorporate high-molecular-weight keratin protein into oily cosmetics. [Means for solving the problem]

[0009] As a result of extensive research, the present inventors have discovered that keratin protein can be stably incorporated into cosmetics, particularly oil-based cosmetics, by using an oil-dispersible micellar composition containing (A) a polyether-modified silicone or an ethylene glycol-based or glycerin-based nonionic surfactant and (B) an alkylated keratin protein.

[0010] Furthermore, hair cosmetics containing the oil-dispersible micelle composition stably contain keratin protein, and therefore can effectively exert protective, repairing, and improving powers on the area of ​​the hair to which the composition is applied.

[0011] In particular, for the formation of oil-dispersible micelles, polyether-modified silicones or nonionic surfactants having an ethylene glycol or glycerin structure with a degree of polymerization of 1 to 60 per molecule as a hydrophilic group are preferred because they enable stable micelle formation.

[0012] By introducing the lipophilic group dodecyl PG (propylene glycol) into keratin protein, the keratin protein can exist stably in the aqueous phase inside the micelles, and the molecular membrane of the micelles can also be stabilized. Furthermore, high molecular weight alkylated keratin protein with a molecular weight of 5000 or more can maintain stable micelle formation while providing high hair repair power. [Effects of the Invention]

[0013] The oil-dispersible micelle composition of the present invention has excellent dispersibility in oily media. Furthermore, the hair cosmetic of the present invention can stably contain and retain keratin protein, which has high hair repair properties, even in cosmetics, particularly oil-based cosmetics that generally cannot solubilize keratin protein. Therefore, the hair cosmetic of the present invention can effectively protect, repair, and improve the hair at the application site. DETAILED DESCRIPTION OF THE INVENTION

[0014] Oil-dispersible micellar composition The micelle composition of the present invention (hereinafter referred to as "the composition") contains (A) a polyether-modified silicone or an ethylene glycol- or glycerin-based nonionic surfactant (hereinafter referred to as "component (A)") and (B) an alkylated keratin protein.

[0015] The polyether-modified silicone and ethylene glycol- or glycerin-based nonionic surfactant are not particularly limited in type when forming oil-dispersed micelles. Furthermore, the content of component (A) is not limited and can be set arbitrarily as long as micelles can be formed. The content of component (A) in the present composition is typically 0.1 to 70% by mass.

[0016] Specific examples of the polyether-modified silicones include PEG-3 dimethicone, PEG-10 dimethicone, PEG-12 dimethicone, PEG-11 methyl ether dimethicone, PEG-32 methyl ether dimethicone, PEG-9 polydimethylsiloxyethyl dimethicone, lauryl PEG-9 polydimethylsiloxyethyl dimethicone, PEG-7 amodimethicone, PEG-10 dimethicone crosspolymer, bis-PEG-12 dimethicone, bis-PEG-15 methyl ether dimethicone, avocado oil fatty acid PEG-8 dimethicone, and PEG-8 adipate dimethicone. The polyether-modified silicones may be used alone or in combination of two or more.

[0017] Specific examples of the ethylene glycol-based nonionic surfactant include PEG-30 hydrogenated castor oil PCA isostearate, PEG-40 hydrogenated castor oil (PCA / isostearate), PEG-60 hydrogenated castor oil PCA isostearate, PEG-6PPG-7 ethylhexyl ether, PEG-11 avocado oil fatty acid glycerides, PEG-10 rapeseed sterol, PEG-8 olive oil esters, PEG-8 (caprylic / capric acid) glycerides, PEG-30 glyceryl cocoate, PEG-6 cocamide, PEG-10 cocamine, PEG-5 Hydrogenated Castor Oil, PEG-20 Hydrogenated Castor Oil, PEG-40 Hydrogenated Castor Oil, PEG-60 Hydrogenated Castor Oil, PEG-10 Hydrogenated Lanolin, PEG-40 Hydrogenated Lanolin, PEG-10 Soybean Sterol, PEG-30 Soybean Sterol, PEG-20 Sorbitan Cocoate, PEG-5 Castor Oil, PEG-10 Castor Oil, PEG-30 Castor Oil, PEG-10 Sunflower Glycerides, PEG-8 Jojoba Oil Esters, PEG-8 Jojoba Oil Esters, PEG-20 Lanolin, PPG-7 / PEG-30 Phytosterols, Almond Oil PEG-8 Esters , Argan Oil PEG-8 Esters, PEG-3 Isostearate, PEG-20 Isostearate, PEG-40 Isostearate, PEG-5 Glyceryl Isostearate, PEG-15 Glyceryl Isostearate, PEG-5 Hydrogenated Castor Oil Isostearate, PEG-30 Hydrogenated Castor Oil Isostearate, PEG-60 Hydrogenated Castor Oil Isostearate, PEG-5 Oleate, PEG-5 Glyceryl Oleate, PEG-6 Sorbitan Oleate, PEG-8 Caprylic / Capric Acid, PEG-3 Diisostearate, P Diisostearate EG-20 glyceryl, PEG-10 dioleate, PEG-12 distearate, PEG-4 glyceryl distearate, PEG-20 hydrogenated dimer dilinoleate, PEG-5 stearate, PEG-40 stearate, PEG-15 glyceryl stearate, PEG-40 sorbitan stearate, PEG-10 camellia oil fatty acid glycerides, PEG-20 glyceryl triisostearate, PEG-10 glyceryl trioleate, PEG-6 palmitate, PEG-4 laurate, PEG-10 sorbitan laurate, oleth-3, oleth-20,Examples of the ethylene glycol-based nonionic surfactants include (C9-11) Pareth-8, (C12-15) Pareth-10, (C20-40) Pareth-10, (C12-14) s-Pareth-20, laureth-3 isostearate, laureth-5, and laureth-20. One type of the ethylene glycol-based nonionic surfactant may be used alone, or two or more types may be used in combination.

[0018] Specific examples of the glycerin-based nonionic surfactants include polyglycerin fatty acid esters, which are obtained by esterifying polyglycerin with one or more fatty acids selected from fatty acids having 6 to 22 carbon atoms. Specific examples of the fatty acids having 6 to 22 carbon atoms include caproic acid, capric acid, caprylic acid, lauric acid, myristic acid, palmitic acid, stearic acid, isostearic acid, oleic acid, linoleic acid, linolenic acid, arachidic acid, and behenic acid. More specific examples of the glycerin-based nonionic surfactants include polyglyceryl-6 laurate, polyglyceryl-6 stearate, polyglyceryl-10 laurate, polyglyceryl-10 stearate, polyglyceryl-10 oleate, polyglyceryl-10 isostearate, polyglyceryl-10 diisostearate, and polyglyceryl-10 trioleate. The glycerin-based nonionic surfactants may be used alone or in combination of two or more.

[0019] The degree of polymerization of the ethylene glycol or glycerin in the nonionic surfactant is not particularly limited as long as it can form oil-dispersible micelles. However, as a result of comparing the stability when dispersed in an oil-based medium, it is preferable that the degree of polymerization be 1 to 60, which is easily compatible with an oil-based medium.

[0020] (B) As long as the alkylated keratin protein can form oil-dispersible micelles, there are no restrictions on the molecular weight, length and content of the alkyl group, or the method of binding to the keratin protein or the content. Typically, the alkyl group has 6 to 24 carbon atoms and may be either linear or branched. The content is typically 0.001 to 5% of the keratin protein in the micelles, and may be in a solvent-dissolved state.

[0021] Examples of the solvent include water, ethanol, propanol, isopropanol, propylene glycol, butylene glycol, dipropylene glycol, polyethylene glycol, and polyglycerin, and two or more of these may be contained.

[0022] (B) As mentioned above, there are no restrictions on the length of the alkyl group or the method of bonding of the alkylated keratin protein. However, after comparing the stability in micelles, it was found that dodecyl PG-added keratin protein, in which the dodecyl group is bonded to the alkylated keratin protein in an ether form via propanediol, is particularly preferred.

[0023] The method for preparing the alkylated keratin protein is not limited as long as it can add an alkyl group as a lipophilic group to the keratin protein. Examples of such methods include a method using a fatty acid chloride or an alkyl glycidyl ether. When a fatty acid chloride is used, an ester or amide bond is formed with the keratin protein, and when a glycidyl ether is used, an ether bond is formed via propanediol.

[0024] The source of keratin from which the keratin protein is obtained is not limited, and examples thereof include keratin-containing human and animal hair (human hair, wool, feathers, etc.), horns, and nails, and the extraction method is not limited. The keratin protein may be hydrolyzed, but in order to have a hair repair effect, the molecular weight is preferably 5,000 or more, more preferably 10,000 or more, and even more preferably 15,000 or more.

[0025] The present composition may contain other ingredients in addition to (A) and (B) as needed, as long as they do not inhibit micelle formation and allow the alkylated keratin protein to be stably contained in the hair cosmetic.

[0026] The method for obtaining the composition is not particularly limited. The composition can be prepared, for example, by preparing a liquid or paste containing components (A) and (B) by adding components (A) and (B) individually to other components such as a solvent, or by pre-mixing components (A) and (B), and then adding the mixture of (A) and (B) to the external phase liquid while stirring in a conventional manner, specifically, for example, while stirring the mixture with a homomixer at high temperature.

[0027] Various oily components can be used in the micellar external phase liquid. Specific examples of the oily components include dimethicone, dimethiconol, cyclic silicone oil, squalane, polyisobutene, saturated hydrocarbons, higher alcohols, fatty acids, fatty acid esters, and vegetable oils such as jojoba oil and olive oil. The micellar external phase liquid may be used alone or in combination of two or more types.

[0028] Hair cosmetics The hair cosmetic of the present invention (hereinafter referred to as "the cosmetic") contains the composition. The cosmetic contains alkylated keratin in a stable micellar form, thereby enhancing the repair effect on the area of ​​hair to which it is applied.

[0029] The content of the present composition in the present cosmetic is not particularly limited, as long as it is an amount effective for the functions and properties of the hair at the application site. The present composition is not limited to oil-based hair cosmetics (hair cosmetics containing 50% by mass or more, preferably 60% by mass or more, more preferably 70% by mass or more, and even more preferably 80% by mass or more of oily components) and can be incorporated into general hair cosmetics. However, since the present composition can stably disperse alkylated keratin in an oil-based medium, oil-based hair cosmetics are preferred. Furthermore, in the present cosmetic, alkylated keratin micelles can be dispersed in an oily component and then further dispersed and emulsified in an aqueous external phase. An example of this embodiment is a hair cosmetic formulated with an aqueous phase (W) / oil phase (O) / aqueous phase (W) system.

[0030] There are no particular limitations on the method for incorporating the present composition into the present cosmetic. For example, the present composition may be prepared separately and then added to the hair cosmetic. Alternatively, all or part of the components (A) and (B) constituting the present composition may be blended with other components constituting the hair cosmetic, and the micelle composition may be prepared simultaneously during the preparation of the hair cosmetic.

[0031] The present cosmetic may contain other components in addition to the present composition. Examples of such other components include components that have been known to be contained in conventional hair cosmetics, as well as other functional components. Specific examples of such other components include fats and oils, hydrocarbon oils, higher fatty acids, higher alcohols, ester oils, silicone oils, surfactants (nonionic, anionic, cationic, amphoteric), moisturizers, water-soluble polymers, film-forming agents, UV absorbers, sequestering agents, lower alcohols, polyhydric alcohols, sugars, amino acids, pH adjusters, vitamins, antioxidants, colorants, preservatives, and fragrances.

[0032] There are no particular limitations on the specific uses of the present cosmetic. Because the present cosmetic contains alkylated keratin protein, it can be used, for example, to improve hair physical properties (strength, elongation, etc.), to improve hair ends that are messy due to frizz or wavy hair, or to further improve hair texture (moisturized feel, smooth feel, softness, etc.). Specific embodiments of the present cosmetic are preferably hair oils, shampoos, rinses, treatments, conditioners, hair styling products, permanent wave agents, curling agents, hair coloring agents, hair growth and care products, and pre- or post-treatment agents for these products. [Example]

[0033] The present invention will be specifically illustrated below with reference to examples. However, the present invention is not limited to the embodiments shown in the examples. The embodiments of the present invention can be modified in various ways within the scope of the present invention depending on the purpose and application. It should be noted that all discussions of the results in the examples are merely the inventor's views and are not intended to define the present invention.

[0034] Preparation Example 1 of Oil-Dispersible Micelle Composition A paste-like substance was prepared by mixing 1 g of an aqueous solution containing 5% dodecyl PG keratin (molecular weight 25,000-35,000) with 30 g of PEG-9 polydimethylsiloxyethyl dimethicone. The mixture was then heated to 80°C and added to 69 g of dimethicone heated to 80°C and stirred at 3,000 rpm in a homomixer to prepare a micellar composition.

[0035] Preparation Example 2 of Oil-Dispersible Micelle Composition 10 g of an aqueous solution containing 10% capryloylated keratin protein (molecular weight 5,000 to 10,000) was added to 10 g of dipropylene glycol, and 20 g of polyglyceryl-10 diisostearate were mixed uniformly at 300 rpm with a paddle mixer at 50° C. The resulting milky white paste was added to 60 g of squalane while stirring at 300 rpm with a paddle mixer to prepare a micellar composition.

[0036] Preparation Example 3 of Oil-Dispersible Micelle Composition A micelle composition was prepared by uniformly mixing 10 g of a 50% aqueous ethanol solution containing 0.1% isostearoyl keratin protein (molecular weight 10,000-15,000) with 20 g of PEG-60 hydrogenated castor oil heated to 60°C, and gradually adding and dispersing this mixture into 64.9 g of a mixed oil (equal parts by weight) of jojoba oil, cyclic silicone oil, and isononyl isononanoate, which had previously contained 5 g of PEG-12 dimethicone and 0.1 g of vitamin E.

[0037] Below is a formulation example of a hair cosmetic containing the oil-dispersible micelle composition of the present invention. The blending amounts are in mass %. Note that in this formulation example, there are no limitations on the method of preparing the oil-dispersible micelles or blending them into the hair cosmetic. In this example, the micelle composition is prepared first, and then other ingredients are mixed to produce the hair cosmetic.

[0038] (Prescription example 1: Shampoo) Component Content (mass%) TEA-Cocoyl Glutamate 12.00 Sodium Lauroyl Methylalanine 4.00 Cocamidopropyl Betaine 3.00 Cocamide DEA 1.50 Polyquaternium-10 0.40 Urea 1.00 Etidronic acid 0.05 Sodium benzoate 0.40 Oil-dispersible micelle composition of Preparation Example 1 10.00 Rooibos extract 0.10 Aloe vera juice 0.10 Fragrance (appropriate amount) Remaining purified water Total amount 100.00

[0039] (Formulation example 2: Hair treatment) Component Content (mass%) Behentrimonium chloride 1.50 Steartrimonium chloride 1.50 Glyceryl stearate 1.00 Cetyl Alcohol 6.00 Behenyl Alcohol 1.00 Hydrogenated polyisobutene 6.00 Dimethicone 3.00 Amodimethicone 1.00 Dimethiconol 1.00 Polysilicone-29 0.30 Cyclohexane-1,4-dicarboxylic acid bisethoxydiglycol 0.20 Glycerin 1.00 BG 2.00 Caesalpinia spinosa gum 0.40 Lactic acid 0.05 Cholesterol 0.10 Ceramide NP 0.10 Methylparaben 0.20 Propylparaben 0.10 Oil-dispersible micelle composition of Preparation Example 2 10.00 Fragrance (appropriate amount) Remaining purified water Total amount 100.00

[0040] (Formulation example 3: Hair mist) Component Content (mass%) PEG-60 Hydrogenated Castor Oil 1.00 BG 5.00 Glycerin 2.00 Ethoxydiglycol 1.00 Urea 1.00 Citric acid 0.05 Dimethicone 0.50 Amodimethicone 0.50 Bis-cetearyl amodimethicone 0.50 Dimethiconol 0.50 Ceramide AG 0.10 Hydrolyzed silk 0.50 Arginine Ethyl HCl 0.50 Blackcurrant Fruit Extract 0.01 Methylparaben 0.20 Oil-dispersible micelle composition of Preparation Example 3 10.00 Fragrance (appropriate amount) Remaining purified water Total amount 100.00

[0041] (Prescription Example 4: Treatment Agent) Component Content (mass%) PG 5.00 Glycerin 2.00 Betaine 2.00 Urea 1.00 Trehalose 0.50 Polyquaternium-7 0.50 Decyl glucoside 0.10 Lauramidopropyl Betaine 0.10 Hydrolyzed Keratin 1.00 Hydrolyzed Collagen 1.00 Hydrolyzed Silk 1.00 Ceramide AP 0.50 Arginine 0.01 Citric acid 0.05 Methylparaben 0.20 Oil-dispersible micelle composition of Preparation Example 1 5.00 Fragrance (appropriate amount) Remaining purified water Total amount 100.00

[0042] (Formulation example 5: Hair wax) Component Content (mass%) Candelilla wax 3.00 Cetearyl Alcohol 2.00 Glyceryl stearate 1.00 Stearic acid 2.00 Seteth -40 1.00 Hydrogenated polyisobutene 4.00 Dimethicone 2.00 Polyacrylamide 0.50 BG 2.00 Sodium hydroxide 0.02 Jojoba seed oil 0.10 Phenoxyethanol 0.80 Oil-dispersible micelle composition of Preparation Example 2 2.00 Fragrance (appropriate amount) Remaining purified water Total amount 100.00

[0043] (Formulation example 6: Hair cream) Component Content (mass%) Mineral oil 10.00 Grape seed oil 3.00 Vaseline 3.00 Glyceryl Isostearate 2.00 Seteth -40 2.00 Camellia Seed Extract 0.50 Polysorbate-20 1.00 Carbomer 0.50 Arginine 0.10 Glycerin 3.00 Methylparaben 0.20 Propylparaben 0.10 Oil-dispersible micelle composition of Preparation Example 3 4.00 Fragrance (appropriate amount) Remaining purified water Total amount 100.00

[0044] (Formulation example 7: Hair manicure) Component content (mass%) Benzyl alcohol 4.00 Ethanol 25.00 Glycolic Acid 2.00 Hydroxyethylcellulose 2.00 Xanthan gum 0.40 Dimethicone 1.00 Black 401 0.50 Oil-dispersible micelle composition of Preparation Example 1 3.00 Fragrance (appropriate amount) Remaining purified water Total amount 100.00

[0045] (Formulation example 8: Hair color treatment) Component Content (mass%) Steartrimonium chloride 1.00 Behenamidopropyl dimethylamine 2.00 Cetearyl Alcohol 8.00 Glyceryl Caprylate 2.00 Decyl glucoside 0.50 Hydroxyethyl cellulose 0.30 Polyquaternium-37 0.50 Dimethicone 1.00 Amodimethicone 1.00 Dimethiconol 1.00 Ethoxydiglycol 3.00 Glyceryl glucoside 1.00 Urea 4.00 Ammonium bicarbonate 0.80 Arginine 0.40 Basic Blue 9 90.20 HC blue 2 0.20 Oil-dispersible micelle composition of Preparation Example 2 5.00 Phenoxyethanol 0.80 Fragrance (appropriate amount) Remaining purified water Total amount 100.00

[0046] (Formulation example 9: Curling agent) (1st agent) Component Content (mass%) Cysteamine HCl 2.00 Cholesterol 0.50 Glucosylceramide 0.50 Monoethanolamine 0.50 Arginine 0.30 Citric acid 0.50 Polyglyceryl-10 Stearate 1.00 Cocamide DEA 1.00 EDTA-2Na 0.10 Phenoxyethanol 0.80 Oil-dispersible micelle composition of Preparation Example 3 2.00 Fragrance (appropriate amount) Remaining purified water Total amount 100.00 (2nd drug) Component content (mass%) Sodium bromate 10.00 BG 4.00 Citric acid 0.10 Sodium citrate 0.60 Phenoxyethanol 0.80 Hydroxyethylcellulose 2.00 PEG-60 Hydrogenated Castor Oil 1.00 Fragrance (appropriate amount) Remaining purified water Total amount 100.00

[0047] (Formulation example 10: Hair spray (aerosol)) Component Content (mass%) (Alkyl acrylate / diacetone acrylamide) copolymer AMP 2.00 BG 1.00 Yuzu Fruit Extract 1.00 Dimethicone 0.10 Oil-dispersible micelle composition of Preparation Example 1 1.00 Purified water 5.00 Fragrance (appropriate amount) Ethanol remaining LPG 6.00 Total amount 100.00

[0048] (Formulation example 11: Setting gel) Component Content (mass%) PVP 4.00 BG 2.00 Ethanol 25.00 Guar Hydroxypropyltrimonium Chloride 1.20 Citric acid 0.05 Sodium citrate 0.10 Algae extract 1.00 Macadamia nut oil 0.10 Oil-dispersible micelle composition of Preparation Example 2 1.00 Fragrance (appropriate amount) Remaining purified water Total amount 100.00

[0049] (Formulation example 12: Hair oil) Component Content (mass%) Cyclopentasiloxane 45.00 Dimethiconol 20.00 PEG-9 Polydimethylsiloxyethyl Dimethicone 10.00 Dodecyl PG keratin protein (molecular weight 25,000-35,000) 0.10 Purified water 4.90 1,3-butylene glycol 2.00 Preservatives (appropriate amount) Vitamin E 0.10 Amodimethicone 3.00 Dimethicone remaining amount Total amount 100.00

[0050] Preparation of Formulation Example 12 An appropriate amount of preservative was dissolved in 2 g of 1,3-butylene glycol by heating and mixed with 5 g of an aqueous solution containing 0.1 g of dodecyl PG keratin protein. 10 g of PEG-9 polydimethylsiloxyethyl dimethicone was added and stirred to obtain a slightly pale yellow paste-like keratin protein / ether-modified silicone mixture. This was then added to 45 g of cyclopentasiloxane at 100 rpm at room temperature and stirred until uniform, yielding an oil-dispersible micellar composition. Finally, 20 g of dimethiconol, 3 g of amodimethicone, and 0.1 g of vitamin E were added, and the total weight was adjusted to 100 g with dimethicone.

[0051] Hair repair effect The repair effect of Formulation Example 12 on damaged hair was evaluated using tensile strength as an index. 100 g of human hair (straight hair) was immersed in 200 mL of a 1.0% SDS aqueous solution for 10 minutes. After rinsing with purified water, the hair was immersed in a bleach solution (200 mL total volume containing 7 mL of 28% ammonia water and 26 mL of 30% hydrogen peroxide water) kept at 40°C for 24 hours. The hair was then washed again with purified water and air-dried at room temperature for 24 hours to create damaged hair.

[0052] Hair bundles weighing 20 g each were prepared from the damaged hair, and 0.5 g of each of the following was applied and combed: (1) Formulation Example 12; (2) a formulation in which the PEG-9 polydimethylsiloxyethyl dimethicone contained in Formulation Example 12 was replaced with PEG-3 diisostearate (an ethylene glycol-based non-surfactant); (3) a formulation in which the PEG-9 polydimethylsiloxyethyl dimethicone contained in Formulation Example 12 was replaced with polyglyceryl-6 laurate (a glycerin-based non-ionic surfactant); and, for comparison, a formulation in which the alkylated keratin contained in Formulation Example 12 was replaced with (4) dodecyl PG keratin (molecular weight 3000-5000) and (5) high molecular weight keratin protein (unalkylated, molecular weight 25000-35000); and (6) Formulation Example 12 without keratin protein as a control.

[0053] The strength of the hair after the above treatment was measured using a digital force gauge manufactured by A&D Co., Ltd. A load was applied to one hair of each sample, and the force (unit: N) at which the hair broke was taken as the tensile strength. Measurements were made on 20 hairs of each sample, and the average value was used for evaluation.

[0054] The measurement results of the tensile strength of each sample were as follows: However, in sample (5), a part of the high molecular weight keratin protein was precipitated. (1) 1.10N (2) 1.13N (3) 1.09N (4) 0.95N (5) 0.72N (6) 0.70N

[0055] Tensile strength tests showed that samples (1), (2), (3), and (4) containing alkylated keratin all exhibited superior hair repair effects compared to sample (6) containing no keratin and sample (5) containing unalkylated high-molecular-weight keratin. Furthermore, superior repair effects were observed in both formulations containing polyether-modified silicone (sample (1)) and ethylene glycol- or glycerin-based nonionic surfactants (samples (2) and (3)). Sample (1), which used high-molecular-weight (25,000-35,000) dodecyl PG keratin as the alkylated keratin, exhibited superior hair repair effects compared to sample (4), which used low-molecular-weight (3,000-5,000) dodecyl PG keratin. These results demonstrate that polyether-modified silicone or ethylene glycol- or glycerin-based nonionic surfactants can be used in the compositions and hair cosmetics of the present invention, and that alkylated keratin with a molecular weight of 5,000 or greater is desirable. On the other hand, sample (5), which contained high molecular weight keratin that had not been alkylated, showed little difference from sample (6), which did not contain keratin, and had a weak repair effect. This is thought to be because the keratin could not be stably maintained in the micellar composition and hair cosmetic.

[0056] As described above, the present composition can stably contain alkylated keratin protein in oil-dispersible micelles. The oil-dispersible micellar composition can be used to incorporate keratin protein into hair cosmetics, particularly oil-based hair cosmetics. As a result, the hair cosmetics can be endowed with excellent beneficial effects such as excellent protection, repair, and improvement at the application site of the hair.

[0057] In particular, alkylated keratin with a molecular weight of 5,000 or more provides excellent hair repair effects, and can stably retain keratin protein even in hair cosmetics, especially oil-based hair cosmetics (such as hair oils) where protein is difficult to dissolve and disperse.

[0058] Furthermore, the present composition can be incorporated not only into oil-based hair cosmetics but also into general hair cosmetics. Therefore, the present cosmetic is versatile and practical, and has great utility in the cosmetics industry.

Claims

1. (A) a polyether-modified silicone or an ethylene glycol- or glycerin-based nonionic surfactant; and (B) alkylated keratin proteins; 1. An oil-dispersible micellar composition comprising:

2. 2. The oil-dispersible micelle composition according to claim 1, wherein the molecular weight of the alkylated keratin protein (B) is 5,000 or more.

3. The oil-dispersible micelle composition according to claim 1 or 2, wherein the alkylated keratin protein (B) is a dodecyl PG-added keratin protein.

4. A hair cosmetic comprising the oil-dispersible micelle composition according to any one of claims 1 to 3.