Skin cosmetic

Abstract

To provide a skin cosmetic which has no rubbing at the time of application and has no stickiness after application, in which a film formed after application shows high adsorption performance even with respect to mixed sebum containing unsaturated fatty acids.SOLUTION: Provided is a skin cosmetic containing the following components (A), (B), and (C): (A) an emulsion containing (a) a nonionic surfactant having an HLB of 1 to 8, (b) a nonionic surfactant having an HLB of 9 to 20, (c) water, and (d) an oil agent, the emulsion having an average diameter of emulsion particles of 1 to 150 nm; (B) a polymer having a cellulose skeleton in which substituents selected from a hydroxypropyl group, a hydroxybutyl group, and an amide group are substituted at 2.4 or more per glucose unit; and (C) water.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a skin cosmetic. [Background technology]

[0002] Among sebum, unsaturated fatty acids such as oleic acid, 8Z-octadecenoic acid, petroselinic acid, vaccenic acid, and palmitoleic acid have been known to cause skin problems such as mild inflammation, rough surfaces including scaling and peeling, lack of smoothness, noticeable irregularities such as pores, makeup breakdown, stickiness, uneven redness, dullness, dullness, lack of brightness, lack of transparency, and increased transepidermal water loss. Various studies have been conducted to improve the effects of unsaturated fatty acids on the skin. For example, Patent Document 1 describes that an emulsion composition containing a polymer having a specific cellulose skeleton, a dihydric alcohol, and one or more compounds selected from sphingosine, a salt of sphingosine, a pseudosphingosine, a salt of pseudosphingosine, an anionic surfactant, and a cationic surfactant has a high effect of suppressing rough skin caused by sebum. Patent Document 2 describes that a cosmetic containing a polymer having a specific cellulose skeleton, a dihydric alcohol, and a water-soluble polymer having a carboxyl group is highly effective in suppressing rough skin caused by sebum. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-104616 [Patent Document 2] Japanese Patent Publication No. 2022-104617 Summary of the Invention [Problem to be solved by the invention]

[0004] However, while conventional cosmetics have a high adsorption effect on unsaturated fatty acids such as oleic acid, they do not have a sufficient adsorption effect on mixed sebum that contains unsaturated fatty acids and also other sebum components actually secreted from skin. Therefore, there has been concern that the adsorption effect on mixed sebum actually secreted from skin and the resulting skin improvement effect are not fully satisfactory. On the other hand, hydroxypropyl cellulose and its derivatives have conventionally been used as water-soluble thickeners in pharmaceuticals, cosmetics, and the like. However, cosmetics containing hydroxypropyl cellulose have problems such as creasing during application and stickiness after application. [Means for solving the problem]

[0005] The inventors have discovered that by combining a fine emulsion made of two types of nonionic surfactants with different HLB values ​​with a polymer having a specific cellulose skeleton, the film formed after application exhibits a high adsorption effect even on mixed sebum containing unsaturated fatty acids, and that a skin cosmetic can be obtained that does not crumble upon application and is not sticky after application.

[0006] The present invention comprises the following components (A), (B) and (C): (A) (a) a nonionic surfactant with an HLB of 1 to 8; (b) a nonionic surfactant with an HLB of 9 to 20; (c) water; (d) Oil an emulsion containing the above, wherein the average particle size of the emulsion particles is 1 to 150 nm; (B) a polymer having a cellulose skeleton in which 2.4 or more substituents selected from hydroxypropyl groups, hydroxybutyl groups, and amide groups are substituted per glucose; (C)Water The present invention relates to a skin cosmetic containing the compound. [Effects of the Invention]

[0007] The skin cosmetic of the present invention does not crease when applied, does not leave a sticky feeling on the skin after application, and the film formed after application can exhibit a high adsorption effect even against mixed sebum containing unsaturated fatty acids. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 2 is a diagram showing the evaluation criteria for evaluating sebum adsorption to the formed film in the examples. DETAILED DESCRIPTION OF THE INVENTION

[0009] The component (A) used in the present invention is (a) a nonionic surfactant with an HLB of 1 to 8; (b) a nonionic surfactant with an HLB of 9 to 20; (c) water; (d) Oil The emulsion contains the above, and the average particle size of the emulsion particles is 1 to 150 nm.

[0010] The nonionic surfactant of component (a) having an HLB of 1 to 8 preferably has an HLB of 2 to 8, more preferably an HLB of 2 to 6, from the viewpoint of improving the adsorption effect of the film formed after application on mixed sebum containing unsaturated fatty acids. Here, HLB (Hydrophilic-Lipophilic Balance) indicates the molecular weight of the hydrophilic group portion in the total molecular weight of the surfactant, and in the present invention, for nonionic surfactants, it is determined by Griffin's formula.

[0011] Examples of the nonionic surfactant of component (a) include those commonly used in cosmetics, such as silicone surfactants such as polyoxyethylene fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene alkyl ethers, polyoxyethylene sorbitol fatty acid esters, polyoxyethylene glycerin fatty acid esters, polyoxyethylene propylene glycol fatty acid esters, polyoxyethylene castor oil, polyoxyethylene hydrogenated castor oil, polyoxyethylene hydrogenated castor oil fatty acid esters, polyoxyethylene phytostanol ether, polyoxyethylene phytosterose ether, polyoxyethylene cholestanol ether, polyoxyethylene cholesteryl ether, and polyether-modified silicones; sucrose fatty acid esters, glycerin fatty acid esters; alkyl saccharides; alkyl glyceryl ethers such as isostearyl glyceryl ether; and sorbitan fatty acid esters such as sorbitan isostearate and sorbitan stearate.

[0012] From the viewpoint of improving the adsorption effect of the film formed after application on mixed sebum containing unsaturated fatty acids, component (a) preferably contains one or more selected from polyether-modified silicone, glycerin fatty acid ester, alkyl glyceryl ether, and sorbitan fatty acid ester, more preferably contains one or more selected from alkyl glyceryl ether, glycerin fatty acid ester, and sorbitan fatty acid ester, even more preferably contains one or more selected from alkyl glyceryl ether and sorbitan fatty acid ester, still more preferably contains one or more selected from isostearyl glyceryl ether and sorbitan isostearate, and especially preferably contains isostearyl glyceryl ether.

[0013] Component (a) can be used alone or in combination of two or more types, and from the viewpoints of reducing creasing when applied to the skin, reducing stickiness after application to the skin, and improving the adsorption effect of the film formed after application on mixed sebum containing unsaturated fatty acids, the content is preferably 0.3 to 3 mass% of the total composition, more preferably 0.5 to 2 mass%, and even more preferably 0.7 to 1.2 mass%.

[0014] The nonionic surfactant of component (b) having an HLB of 9 to 20 preferably has an HLB of 10 to 18, more preferably an HLB of 12 to 16, from the viewpoints of reducing creasing when applied to the skin, improving the adsorption effect of the film formed after application on mixed sebum containing unsaturated fatty acids, and improving the compatibility when component (a) is mixed into component (A). Examples of the nonionic surfactant of component (b) include polyoxyethylene hydrogenated castor oils such as polyoxyethylene hydrogenated castor oil (40 E.O.), polyoxyethylene alkyl ethers, polyoxyethylene fatty acid esters, polyoxyethylene alkanol ethers, polyoxyethylene sorbitan fatty acid esters such as polyoxyethylene sorbitan fatty acid ester (20 E.O.), polyglycerin fatty acid esters, and sucrose fatty acid esters. Of these, from the viewpoints of reducing creasing when applied to the skin, improving the absorption effect of the film formed after application on mixed sebum containing unsaturated fatty acids, and improving the compatibility when mixing component (a) into component (A), it is preferable to contain one or more components selected from polyoxyethylene hydrogenated castor oil, polyoxyethylene alkyl ether, polyoxyethylene fatty acid ester, polyoxyethylene sorbitan fatty acid ester, and polyglycerin fatty acid ester, more preferably one or more components selected from polyoxyethylene hydrogenated castor oil and polyoxyethylene sorbitan fatty acid ester, and even more preferably polyoxyethylene sorbitan fatty acid ester.

[0015] Component (b) can be used alone or in combination of two or more types, and from the viewpoints of reducing creasing when applied to the skin, reducing stickiness after application to the skin, and improving the adsorption effect of the film formed after application on mixed sebum containing unsaturated fatty acids, the content is preferably 0.1 to 3 mass% of the total composition, more preferably 0.3 to 2 mass%, and even more preferably 0.5 to 1.2 mass%.

[0016] In the present invention, the mass ratio (a) / (b) of component (a) to component (b) is preferably 0.1 to 5, more preferably 0.3 to 2.5, even more preferably 0.6 to 2, and even more preferably 0.8 to 1.5, from the viewpoints of reducing creasing when applied to the skin, reducing stickiness after application to the skin, and improving the adsorption effect of the film formed after application on mixed sebum containing unsaturated fatty acids.

[0017] The content of water as component (c) contained in component (A) is preferably 10 to 60 mass %, more preferably 15 to 60 mass %, and even more preferably 20 to 40 mass %, of the total composition, from the viewpoints of reducing stickiness after application to the skin and improving the compatibility when component (a) is mixed into component (A).

[0018] The oil of component (d) may be any oil commonly used in cosmetics, and may be either a solid or semi-solid oil at 25°C, or a liquid oil at 25°C. "Solid or semi-solid at 25°C" means that the viscosity at 25°C is greater than 10,000 mPa·s. Viscosity is measured using a B-type viscometer (VISCOMETER TVB-10, manufactured by Toki Sangyo Co., Ltd.) with a rotor No. 4, at 12 rpm, for 1 minute. Examples of oils that are solid or semi-solid at 25°C include natural ceramides such as ceramide NG, ceramides such as N-(hexadecyloxyhydroxypropyl)-N-hydroxyethylhexadecanamide, sphingolipids such as sphingosines (including natural and synthetic products) such as phytosphingosine, sterols such as cholesterol and phytosterol, fatty acids having 16 to 22 carbon atoms, alcohols having 16 to 22 carbon atoms, and hydrocarbon oils such as petrolatum. N-(hexadecyloxyhydroxypropyl)-N-hydroxyethylhexadecanamide is a pseudo-ceramide and a functional ingredient of ceramide, which complements the function of ceramide and can improve skin condition (moisture content, etc.). The INCI name for N-(hexadecyloxyhydroxypropyl)-N-hydroxyethylhexadecanamide is Cetyl-PG Hydroxyethyl Palmitamide.

[0019] The oil agent that is solid or semi-solid at 25°C preferably contains one or more selected from sphingolipids and sterols, and more preferably contains one or more selected from phytosphingosine, N-(hexadecyloxyhydroxypropyl)-N-hydroxyethylhexadecanamide, and cholesterol, from the viewpoints of reducing smearing when applied to the skin and reducing stickiness after application to the skin.

[0020] For oils that are liquid at 25°C, liquid means that the viscosity at 25°C is 10,000 mPa·s or less. Examples of oils that are liquid at 25°C include hydrocarbon oils, ester oils, ether oils, higher alcohols, silicone oils, and higher fatty acids.

[0021] More specifically, examples of hydrocarbon oils include squalane, liquid paraffin, liquid isoparaffin, light liquid isoparaffin, and heavy liquid isoparaffin. The hydrocarbon oil preferably contains one or more selected from squalane, liquid paraffin, liquid isoparaffin, and light liquid isoparaffin, more preferably one or more selected from squalane, liquid paraffin, and liquid isoparaffin, even more preferably one or more selected from squalane and liquid isoparaffin, and even more preferably liquid isoparaffin. Liquid isoparaffin is also called hydrogenated polyisobutene.

[0022] Ester oils include monoester oils, diester oils, triester oils and tetraester oils. Specific examples of monoester oils include cetyl 2-ethylhexanoate, cetyl octanoate, isononyl isononanoate, isotridecyl isononanoate, isopropyl myristate, octyldodecyl myristate, isopropyl palmitate, octyl methoxycinnamate, and alkyl benzoates (C12 to C15). The monoester oil preferably contains one or more selected from isononyl isononanoate, isotridecyl isononanoate, and octyldodecyl myristate, more preferably contains one or more selected from isononyl isononanoate and isotridecyl isononanoate, and even more preferably contains isononyl isononanoate.

[0023] Specific examples of diester oils include propylene glycol dicaprylate and neopentyl glycol dicaprate. The diester oil preferably contains one or more selected from propylene glycol dicaprylate and neopentyl glycol dicaprate, and more preferably contains neopentyl glycol dicaprate.

[0024] Specific examples of triester oils include tri(caprylic / capric acid)glyceryl, triglyceride 2-ethylhexanoate, and vegetable oils such as olive oil, macadamia nut oil, meadowfoam oil, castor oil, safflower oil, sunflower oil, avocado oil, canola oil, apricot kernel oil, rice germ oil, and rice bran oil. The triester oil preferably contains one or more selected from caprylic / capric triglyceride, glyceryl tri-2-ethylhexanoate, and vegetable oil, more preferably one or more selected from caprylic / capric triglyceride and olive oil, and even more preferably caprylic / capric triglyceride.

[0025] As the ester oil, from the viewpoint of reducing slippage when applied to the skin and reducing stickiness after application to the skin, it is preferable to include one or more types selected from monoester oil, diester oil, and triester oil, more preferably to include one or more types selected from monoester oil and diester oil, and even more preferably to include a diester oil.

[0026] The ether oil includes dialkyl ethers, specifically dihexyl ether, dicaprylyl ether, cetyl-1,3-dimethylbutyl ether, etc., and preferably contains cetyl-1,3-dimethylbutyl ether.

[0027] Examples of higher alcohols include isocetyl alcohol, isostearyl alcohol, 2-octyldodecanol, and oleyl alcohol.

[0028] Examples of silicone oils include volatile and non-volatile linear dimethylpolysiloxanes such as dimethylpolysiloxane (1cs), dimethylpolysiloxane (1.5cs), dimethylpolysiloxane (2cs), and dimethylpolysiloxane (6cs); branched siloxanes such as methyltrimethicone, tris(trimethylsilyl)methylsilane, and tetrakis(trimethylsilyl)silane; cyclic dimethylsiloxanes such as octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, and dodecamethylcyclohexasiloxane; and methylphenylpolysiloxanes such as diphenylsiloxyphenyl trimethicone. The silicone oil preferably contains one or more selected from linear dimethylpolysiloxane and branched siloxane, more preferably contains linear dimethylpolysiloxane, even more preferably contains one or more selected from dimethylpolysiloxane (2cs) and dimethylpolysiloxane (6cs), and even more preferably contains dimethylpolysiloxane (2cs).

[0029] Examples of higher fatty acids include oleic acid, isostearic acid, and undecylenic acid.

[0030] The oil of component (d) preferably contains an oil that is solid or semi-solid at 25°C, from the viewpoint of reducing smearing when applied to the skin and reducing stickiness after application to the skin.

[0031] Component (d) can be used alone or in combination of two or more types, and the content is preferably 0.01 to 3 mass% of the total composition, more preferably 0.1 to 2 mass%, and even more preferably 0.8 to 1.5 mass%, from the viewpoint of reducing creasing when applied to the skin and reducing stickiness after application to the skin.

[0032] In the present invention, the mass ratio (a) / (d) of component (a) to component (d) is preferably 0.1 to 5, more preferably 0.2 to 2.5, and even more preferably 0.6 to 1, from the viewpoints of reducing creasing when applied to the skin, reducing stickiness after application to the skin, and improving the adsorption effect of the film formed after application on mixed sebum containing unsaturated fatty acids.

[0033] The emulsion of component (A) may further contain (e) an ionic surfactant, which can reduce smudging when applied to the skin. The ionic surfactant of component (e) is one that is commonly used in cosmetics, and examples thereof include anionic surfactants, cationic surfactants, and amphoteric surfactants. Examples of anionic surfactants include fatty acid salts (preferably fatty acid salts having 12 to 24 carbon atoms) such as sodium laurate, potassium palmitate, and arginine stearate; alkyl sulfates (preferably alkyl sulfates having 12 to 24 carbon atoms) such as sodium lauryl sulfate, potassium lauryl sulfate, and sodium cetyl sulfate; polyoxyethylene alkyl ether sulfates (preferably polyoxyethylene alkyl ether sulfates having 12 to 24 carbon atoms) such as polyoxyethylene lauryl ether triethanolamine sulfate; N-acyl sarcosine salts (preferably N-acyl sarcosine salts having an acyl group having 12 to 24 carbon atoms) such as sodium lauroyl sarcosine; alkyl phosphates (preferably alkyl phosphates having 12 to 24 carbon atoms) such as sodium monostearyl phosphate; and polyoxyethylene sodium oleyl ether phosphate and polyoxyethylene sodium stearyl ether phosphate. Alkyl ether phosphates (preferably polyoxyethylene alkyl ether phosphates having 12 to 24 carbon atoms); dialkyl sulfosuccinates (preferably di(alkyl)sulfosuccinates having 6 to 12 carbon atoms) such as sodium di(2-ethylhexyl) sulfosuccinate; N-alkyloylmethyl taurine salts (preferably N-alkyl methyl taurine salts having an alkyloyl group having 12 to 24 carbon atoms) such as sodium N-stearoyl-N-methyl taurine and sodium N-myristoyl-N-methyl taurine. N-acyl glutamates (preferably N-acyl glutamates having an acyl group having 12 to 24 carbon atoms) such as monosodium N-lauroyl-L-glutamate, sodium N-myristoyl-L-glutamate, sodium N-stearoyl-L-glutamate, disodium N-stearoyl-L-glutamate, potassium N-stearoyl-L-glutamate, and arginine N-stearoyl-L-glutamate.

[0034] Of these anionic surfactants, from the viewpoint of reducing smearing when applied to the skin, it is preferable to include one or more selected from N-acyl glutamic acid salts having an acyl group with 12 to 24 carbon atoms, fatty acid salts having 12 to 24 carbon atoms, polyoxyethylene alkyl ether phosphates having 12 to 24 carbon atoms, and N-alkyloylmethyl taurines having an alkyloyl group with 12 to 24 carbon atoms; it is more preferable to include one or more selected from N-acyl glutamic acid salts having an acyl group with 12 to 24 carbon atoms and N-alkyloylmethyl taurines having an alkyloyl group with 12 to 24 carbon atoms; it is even more preferable to include N-acyl glutamic acid salts having an acyl group with 12 to 20 carbon atoms; and it is even more preferable to include N-stearoyl-L-glutamic acid salt. The anionic surfactant may be a commercially available product or may be synthesized according to a conventional method.

[0035] Examples of cationic surfactants include quaternary ammonium salt cationic surfactants and amine salt cationic surfactants, with quaternary ammonium salt cationic surfactants being preferred. Examples of amine salt cationic surfactants include alkylamine salts.

[0036] Examples of cationic surfactants include alkyltrimethylammonium salts such as octyltrimethylammonium chloride, decyltrimethylammonium chloride, lauryltrimethylammonium chloride, tetradecyltrimethylammonium chloride, hexadecyltrimethylammonium chloride, hexadecyltrimethylammonium bromide, stearyltrimethylammonium chloride, and behenyltrimethylammonium chloride; dialkyldimethylammonium salts such as didecyldimethylammonium chloride and distearyldimethylammonium chloride; and trialkylmethylammonium salts. Of these cationic surfactants, it is preferable to include one or more selected from dialkyldimethylammonium salts, more preferably one or more selected from didecyldimethylammonium chloride and distearyldimethylammonium chloride, and even more preferably distearyldimethylammonium chloride. The cationic surfactant may be a commercially available product or one synthesized according to a conventional method.

[0037] Furthermore, amphoteric surfactants include those used in ordinary cosmetics, such as alkyldimethylamine oxide, alkylcarboxybetaine, alkylsulfobetaine, amide amino acid salts, and alkylamidopropylbetaine, with alkylamidopropylbetaine being preferred.

[0038] From the viewpoints of reducing creasing when applied to the skin, reducing stickiness after application to the skin, and improving the compatibility when mixing component (a) into component (A), component (e) preferably contains one or more selected from quaternary ammonium salt-type cationic surfactants and N-acyl glutamates, more preferably N-acyl glutamates, even more preferably N-acyl glutamates having an acyl group having 12 to 20 carbon atoms, still more preferably N-stearoyl-L-glutamate, and particularly preferably sodium N-stearoyl-L-glutamate.

[0039] Component (e) can be used alone or in combination of two or more types. The content is preferably 0.01 to 5 mass %, more preferably 0.05 to 3 mass %, and even more preferably 0.1 to 1 mass %, of the total composition from the viewpoints of reducing stickiness after application to the skin and improving the compatibility when mixing component (a) into component (A). When the component (e) contains an anionic surfactant, the content of the anionic surfactant indicates the content as an acid.

[0040] In the present invention, the mass ratio (a) / (e) of component (a) to component (e) is preferably 0.1 to 20, more preferably 0.5 to 10, even more preferably 1 to 7, and even more preferably 1.8 to 3, from the viewpoints of reducing creasing when applied to the skin, reducing stickiness after application to the skin, improving the adsorption effect of the film formed after application on mixed sebum containing unsaturated fatty acids, and improving the blendability when mixing component (a) into component (A).

[0041] The emulsion of component (A) contains the above components, and can be produced, for example, by heating and dissolving components (a), (b), (d) and other oily components at 80°C or higher to prepare a homogeneous oil phase mixture X. Component (c) and other aqueous components are then heated and dissolved at 80°C or higher to prepare a homogeneous aqueous phase mixture Y. Subsequently, mixtures X and Y are heated to 80°C or higher, stirred in a homomixer, and then placed in a high-pressure emulsifier (manufactured by Starburst).

[0042] In the emulsion of component (A), the average particle size of the emulsion particles is 1 to 150 nm, preferably 30 to 100 nm, and more preferably 50 to 80 nm, from the viewpoint of reducing smearing when applied to the skin. The average particle size of the emulsified particles is measured by dynamic light scattering using a fluorescence measurement cuvette (Polystyrol / Polystyrene, 10 x 10 x 45 mm; manufactured by Sarstedt) as a cell and a particle size analyzer (Zetasizer Nano ZS manufactured by Malvern Instruments).

[0043] The content of the emulsion of component (A) is preferably 10 to 70% by mass, more preferably 20 to 60% by mass, and even more preferably 30 to 50% by mass of the total composition, from the viewpoint of reducing creasing when applied to the skin and reducing stickiness after application to the skin.

[0044] The component (B) used in the present invention is a polymer having a cellulose skeleton in which 2.4 or more substituents selected from hydroxypropyl groups, hydroxybutyl groups and amide groups are substituted per glucose. Component (B) is a cellulose in which 2.4 or more hydroxyl groups per glucose are substituted with substituents selected from hydroxypropyl groups, hydroxybutyl groups, and amide groups (substitution degree of 2.4 or more), and the substitution degree is preferably 3 or more. Here, the degree of substitution is the average number of substituted hydroxyl groups per glucose. When the substituents, such as hydroxypropyl groups, also contain hydroxyl groups, the hydroxyl groups of these substituents are also etherified during the reaction, and the molar substitution, which is the number of substituents per glucose, becomes greater than 3, for example, for hydroxypropyl groups. Hydroxypropyl cellulose is preferred as component (B) from the viewpoint of improving the adsorption effect of the film formed after application on mixed sebum containing unsaturated fatty acids. Furthermore, the polymer of component (B) preferably has no substituents other than hydroxypropyl groups, hydroxybutyl groups, and amide groups.

[0045] Furthermore, from the viewpoint of improving the adsorption effect of the film formed after application on mixed sebum containing unsaturated fatty acids, component (B) preferably has an average molecular weight of 40,000 to 2,500,000, more preferably 100,000 to 2,500,000. Here, the average molecular weight is measured by GPC (Gel Permeation Chromatograph).

[0046] Such polymers can be produced, for example, by adding propylene oxide to alkali cellulose activated by alkali mercerization. For example, hydroxypropyl cellulose, which has hydroxypropyl groups as substituents, can be produced by subjecting cellulose to a very complicated activation treatment called alkali cellulose mercerization, in which cellulose is mixed in a slurry state with a large amount of water and a large excess of an alkali metal hydroxide such as sodium hydroxide, and then reacting this alkali cellulose with propylene oxide.

[0047] In addition, as component (B), for example, commercially available products such as HPC-SSL, HPC-SL, HPC-L, HPC-M, HPC-H, and HPC-VH (all manufactured by Nippon Soda Co., Ltd.), KLUCEL MF Pharm, and KLUCEL HPC (manufactured by Ashland Pharmaceuticals) can be used.

[0048] Component (B) can be used alone or in combination of two or more types, and the content is preferably 0.01 to 2.5 mass% of the total composition, more preferably 0.1 to 1.5 mass%, and even more preferably 0.2 to 0.8 mass%, from the viewpoint of improving the adsorption effect of the film formed after application on mixed sebum containing unsaturated fatty acids, and from the viewpoint of reducing creasing when applied to the skin.

[0049] In the present invention, the mass ratio (A) / (B) of component (A) to component (B) is preferably 1 to 1,000, more preferably 10 to 800, even more preferably 20 to 500, and even more preferably 80 to 200, from the viewpoints of reducing creasing when applied to the skin, reducing stickiness after application to the skin, and improving the adsorption effect of the film formed after application on mixed sebum containing unsaturated fatty acids.

[0050] In the present invention, the mass ratio (a) / (B) of component (a) to component (B) is preferably 0.1 to 40, more preferably 0.5 to 20, and even more preferably 1.8 to 5, from the viewpoints of reducing creasing when applied to the skin, reducing stickiness after application to the skin, and improving the adsorption effect of the film formed after application on mixed sebum containing unsaturated fatty acids.

[0051] The content of water in component (C), excluding the amount of water in component (c) in component (A), is preferably 30 to 80 mass % of the total composition, more preferably 40 to 70 mass %, and even more preferably 50 to 60 mass %, from the viewpoint of reducing creasing when applied to the skin and reducing stickiness after application to the skin. Furthermore, the total content of the water of component (c) and the water of component (C) in component (A) is preferably 40 to 95 mass%, more preferably 55 to 93 mass%, and even more preferably 70 to 90 mass% of the total composition.

[0052] The skin cosmetic of the present invention may further contain a polyol. The polyol is a compound having two or more hydroxyl groups in the molecule, and may be any polyol that is commonly used in cosmetics. Examples of dihydric alcohols include polyethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, 1,3-butylene glycol, 1,3-propanediol, and pentanediol. Examples of trihydric alcohols include glycerin and trimethylolpropane. Examples of tetrahydric alcohols include diglycerin and erythritol. Examples of pentahydric or higher polyhydric alcohols include polyglycerins such as triglycerin; sugars and sugar alcohols such as glucose, maltose, maltose, sucrose, xylitol, sorbitol, maltitol, polyoxyethylene methyl glucoside, polyoxyethylene ethyl glucoside, and polyoxyethylene propylene glucoside. Of these, from the viewpoint of reducing smearing when applied to the skin and reducing stickiness after application to the skin, it is preferable to contain one or more selected from dihydric alcohols and trihydric alcohols, more preferably one or more selected from polyethylene glycol, propylene glycol, dipropylene glycol, 1,3-butylene glycol, and glycerin, and even more preferably one or more selected from dipropylene glycol, 1,3-butylene glycol, and glycerin.

[0053] The polyols can be used alone or in combination of two or more. The content is preferably 0.01 to 30% by mass, more preferably 0.1 to 20% by mass, and even more preferably 1 to 10% by mass of the total composition, from the viewpoint of reducing creasing when applied to the skin and reducing stickiness after application to the skin.

[0054] In addition to the above-mentioned components, the skin cosmetic of the present invention may contain components commonly used in cosmetics, such as polymeric compounds other than component (B), powders, antioxidants, fragrances, preservatives, pH adjusters, blood circulation promoters, cooling agents, antiperspirants, disinfectants, skin activators, moisturizers, and refreshing agents.

[0055] The skin cosmetic of the present invention can be produced according to a conventional method. For example, components (a), (b), (d), and other oily components are heated and dissolved at 80°C or higher to prepare a homogeneous oil phase mixture X. Furthermore, component (c) and other aqueous components are heated and dissolved at 80°C or higher to prepare a homogeneous aqueous phase mixture Y. Mixtures X and Y are then heated to 80°C or higher, stirred in a homomixer, and then passed through a high-pressure emulsifier (Starburst) to prepare component (A). Meanwhile, component (B) and a portion of water are uniformly mixed and stirred at high temperature and cooled to room temperature to prepare an aqueous solution containing component (B). Subsequently, the aqueous solution containing components (A) and (B) is mixed and stirred with component (C) and other components at room temperature to produce a skin cosmetic.

[0056] The skin cosmetic of the present invention is suitable as a leave-on type skin cosmetic such as a lotion, a beauty serum, a milky lotion, a cream, an ultraviolet protection agent, a makeup base, or a foundation. The skin cosmetic of the present invention is preferably in a liquid form and is suitable as a lotion or a beauty serum, more preferably as a beauty serum. The reason why the skin cosmetic of the present invention has such a high adsorption effect on mixed sebum containing unsaturated fatty acids is not fully understood, but it is thought that by combining components (A), (B), and (C) of the present invention, the film formed after application can selectively solidify the unsaturated fatty acids in the mixed sebum, and therefore, can also solidify the sebum components actually secreted from the skin. [Example]

[0057] Examples 1 to 8 and Comparative Examples 1 to 3 Skin cosmetics were prepared with the compositions shown in Table 1, and were evaluated for the lack of creasing during application, the lack of stickiness after application, and the sebum adsorption to the formed film. The results are also shown in Table 1.

[0058] (Manufacturing method) (I) Examples 1 to 8 and Comparative Examples 2 to 3: (1) Preparation of emulsion of component (A): An oil phase component containing components (a), (b), and (d) was heated and dissolved at 80°C or higher to prepare a homogeneous oil phase mixture X. Next, an aqueous phase component containing components (c) and (e) was heated and dissolved at 80°C or higher to prepare a homogeneous aqueous phase mixture Y. Mixtures X and Y were heated to 80°C or higher, stirred in a homomixer, and then cooled to 25°C to obtain emulsion Z. An emulsion of component (A) was prepared by passing emulsion Z through a high-pressure emulsifier (manufactured by Starburst). (2) Preparation of hydroxypropyl cellulose aqueous solution: Hydroxypropyl cellulose powder as component (B) was added to water at 80°C, and after stirring uniformly, the mixture was slowly cooled to room temperature to prepare an aqueous hydroxypropyl cellulose solution. (3) Preparation of skin cosmetics: The emulsion obtained in (1) was mixed with the aqueous solution obtained in (2), and then other ingredients including component (C) were added to obtain a skin cosmetic.

[0059] (II) Comparative Example 1: (1) Preparation of emulsion of component (A): An oil phase component containing components (a), (b), and (d) was heated and dissolved at 80°C or higher to prepare a homogeneous oil phase mixture X. Next, an aqueous phase component containing components (c) and (e) was heated and dissolved at 80°C or higher to prepare a homogeneous aqueous phase mixture Y. Mixtures X and Y were heated to 80°C or higher, stirred in a homomixer, and then cooled to 25°C to obtain emulsion Z. (2) Preparation of hydroxypropyl cellulose aqueous solution: 3 to 10 g of hydroxypropyl cellulose powder as component (B) was added to 90 to 97 g of water at 80°C, stirred uniformly, and then slowly cooled to 25°C to prepare an aqueous hydroxypropyl cellulose solution. (3) Preparation of skin cosmetics: The emulsion obtained in (1) was mixed with the aqueous solution obtained in (2), and then other ingredients including component (C) were added to obtain a skin cosmetic.

[0060] (Evaluation method) (1) No creasing when applied: 50 μL of each skin cosmetic was applied to artificial leather (4.5 cm × 4.5 cm, black, Laforet S2923, Okamoto Chemicals Co., Ltd.) and spread with a finger at a speed of one stroke per second for 120 seconds. The absence of creasing upon drying was evaluated according to the following criteria. "No creasing" means that no stringy residue was formed. 5: There is clearly no wrinkling. 4;No wrinkles. 3: Almost no wrinkling. 2: Slightly wrinkled. 1: There is some crease.

[0061] (2) Non-stickiness after application: 50 μL of each skin cosmetic was applied to artificial leather (4.5 cm × 4.5 cm, black, Laforet S2923, Okamoto Chemicals Co., Ltd.), spread with a finger at a speed of one stroke per second for 120 seconds, and the artificial leather was evaluated for non-stickiness one minute after drying according to the following criteria: Non-stickiness means that the finger does not stick to the artificial leather when touched with the applied artificial leather. 5: Not obviously sticky. 4;No stickiness. 3. Almost no stickiness. 2: Slightly sticky. 1: Sticky.

[0062] (3) Evaluation of sebum adsorption to the formed film: (3-1) 400 mg (20 mg / cm) of each skin care product was applied to the entire surface of a 76 mm × 26 mm slide glass (model number: S2111, manufactured by Matsunami Glass Industry Co., Ltd.). 2 ) was applied evenly. (3-2) The slide glass of (3-1) was left standing at 25°C and a relative humidity of 50% for 24 hours, and the skin cosmetic applied to the slide glass was dried to form a coating film.

[0063] (3-3) 20 μL of each of the following four types of mixed sebum (all containing oleic acid (OA), an unsaturated fatty acid) was dropped onto the coating film dried on the glass slide in (3-2). The mixed sebum was colored red by adding Sudan III (a red colorant) to the mixed sebum at a concentration of 0.1% by mass. The red coloring was done so that it would be possible to visually confirm whether or not the coating film with the adsorbed mixed sebum remained when the dried coating film was wiped with a paper cloth (Kimtowel, manufactured by Nippon Paper Crecia Co., Ltd.), which is the operation to be performed in the next step (3-4). Mixed sebum A: 10% by weight of oleic acid (OA), 45% by weight of triglyceride (TAG), 45% by weight of squalane (SQ), ·Mixed sebum B: OA 30% by mass, TAG 35% by mass, SQ 35% by mass, ·Mixed sebum C: OA 50% by mass, TAG 25% by mass, SQ 25% by mass, ·Mixed sebum D: OA 70% by mass, TAG 15% by mass, SQ 15% by mass

[0064] (3-4) Five minutes after the operation of (3-3), the entire slide glass of (3-3) was wiped with a paper cloth (Kimtowel, manufactured by Nippon Paper Crecia Co., Ltd.) with a certain amount of force, and the presence or absence of a coating film with the adsorbed mixed sebum remaining on the slide glass plate was evaluated by visually checking for the presence or absence of red coloration and by checking whether the formation of the coating film was maintained when touched with a finger. If a red coating remains on the slide, it indicates that the coating has retained the mixed sebum (trapped the sebum). If no red coating remains, it indicates that the coating cannot retain the mixed sebum. Furthermore, even when the ratio of oleic acid (OA) in the mixed sebum is low (mixed sebum A), the remaining color indicates a higher ability to retain the mixed sebum (trapping ability).

[0065] (3-5) The number of red films of mixed sebum remaining on the slide glass was evaluated according to the following criteria (see Figure 1). 5: All red coatings of mixed sebum A, B, C, and D remain. (High sebum trapping ability) 4: A red coating of mixed sebum B, C, and D remains. 3: A red coating of mixed sebum C and D remains. 2: A red coating remains only on mixed sebum D. 1: No red film remains on any of the mixed sebum A, B, C, and D. (Low sebum trapping ability)

[0066] [Table 1]

[0067] *1 Isostearyl glyceryl ether: GE-IS (Kao Corporation) HLB2, *2 Polyoxyethylene sorbitan monostearate (20E.O.): Rheodol TW-S120V (Kao Corporation) HLB 14.9, *3 Phytosphingosine: Phytosphingosine (manufactured by Evonik Operations GmbH), *4 N-Stearoyl-L-glutamic acid: Amisoft HA-P (Ajinomoto Co., Inc.), *5 N-(hexadecyloxyhydroxypropyl)-N-hydroxyethylhexadecanamide: Sphingolipid E ​​(Kao Corporation), *6 Cholesterol: Cholesterol JSQI (manufactured by Nippon Fine Chemicals Co., Ltd.), *7 Glycerin: Glycerin V (Kao Corporation), *8 Dipropylene glycol: DPG-RF (ADEKA), *9 L-arginine: L-arginine C grade (manufactured by Ajinomoto Co., Inc.), *10 Hydroxypropyl cellulose: HPC-H (manufactured by Nippon Soda Co., Ltd.), *11 Hydroxypropyl cellulose: HPC-L (Nippon Soda Co., Ltd.)

[0068] Prescription examples 1-8 All of the skin cosmetics with the compositions shown in Table 2 do not crease when applied, do not leave a sticky feeling on the skin after application, and the film formed after application shows a high adsorption effect even against mixed sebum containing unsaturated fatty acids. In all of the skin cosmetics of Formulation Examples 1 to 8, the emulsion particles of the emulsion of component (A) have an average particle size of 1 to 150 nm.

[0069] [Table 2]

Claims

1. The following components (A), (B), and (C): (A) (a) a nonionic surfactant having an HLB of 1 to 8; (b) a nonionic surfactant having an HLB of 9 to 20; (c) water; (d) oil an emulsion containing the above, wherein the average particle size of the emulsion particles is 1 to 150 nm; (B) a polymer having a cellulose skeleton in which 2.4 or more substituents selected from hydroxypropyl groups, hydroxybutyl groups, and amide groups are substituted per glucose; (C) Water A skin cosmetic containing

2. 2. The skin cosmetic according to claim 1, wherein component (A) further comprises (e) an ionic surfactant.

3. 3. The skin cosmetic according to claim 1, wherein the mass ratio (A) / (B) of component (A) to component (B) is 1 to 1,000.

4. 3. The skin cosmetic according to claim 1, wherein in component (A), the mass ratio (a) / (b) of component (a) to component (b) is 0.1 to 5.

5. 3. The skin cosmetic according to claim 1, wherein in component (A), the mass ratio (a) / (d) of component (a) to component (d) is 0.1 to 5.

Images