Oil-in-water skin topical ingredients

Abstract

The water-in-oil topical skin composition contains an oily component containing an oil-soluble topical skin ingredient and an oily solvent, and an aqueous component containing a water-soluble polymer. The water-soluble polymer contains at least one selected from the group consisting of carboxyvinyl polymer, polyacrylic acid, poly(2-acrylamido-2-methylpropanesulfonic acid), and salts thereof. The content of the oily solvent in the oily component is 50% by mass or more based on the mass of the oily component. The oily solvent has a lower solubility for the oil-soluble topical skin ingredient than diisopropyl sebacate.

Description

Related Applications

[0001] The present invention is based on the priority claim of Japanese Patent Application No. 2018-173099 (filed September 14, 2018), the entire contents of which are incorporated herein by reference. [Technical Field]

[0002] The present disclosure relates to a water-in-oil type topical skin composition for topical use. For example, the present disclosure relates to a water-in-oil type topical skin composition for topical use that contains an oil-soluble topical skin component such as an ultraviolet absorber. [Background technology]

[0003] Cosmetics containing external skin ingredients include, for example, sunscreen cosmetics, which contain ultraviolet absorbers as external skin ingredients (see, for example, Patent Documents 1 and 2).

[0004] Patent Document 1 discloses an oil-in-water emulsion sunscreen cosmetic that contains (a) an oil-soluble UV absorber, (b) a water-soluble thickener, (c) a water-soluble UV absorber, and (d) one or more hydrophilic nonionic surfactants selected from fatty acid PEG glyceryl surfactants, hydrogenated castor oil surfactants, and PEG-PPG alkyl ether surfactants.

[0005] Patent Document 2 attempts to enhance the effectiveness of ultraviolet absorbers in oil-in-water sunscreen cosmetics. Patent Document 2 discloses an oil-in-water sunscreen cosmetic that has an increased sun protection factor (SPF) by combining phenylbenzimidazole sulfonic acid, a water-soluble ultraviolet absorber, with N,N,N',N'-tetrakis(2-hydroxypropyl)ethylenediamine, a neutralizer for phenylbenzimidazole sulfonic acid.

[0006] Patent Document 3 discloses a water-in-oil emulsion sunscreen cosmetic that contains (a) 0.05 to 5 mass % of agar and / or succinoglycan and (b) 0.01 to 30 mass % of an ultraviolet absorber, the cosmetic having a viscosity of 10,000 mPa·s (30°C, B-type viscometer) or less, and an aqueous phase of 45 mass % or less, and that enhances the ultraviolet absorbing ability of component (b). [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-162930 [Patent Document 2] Japanese Patent Application Laid-Open No. 2011-111444 [Patent Document 3] Patent No. 4902752 Summary of the Invention [Problem to be solved by the invention]

[0008] The following analysis is given in light of the present disclosure.

[0009] When a topical skin composition containing topical skin ingredients is applied to the skin, if the distribution of the topical skin ingredients is uneven, the efficacy of the topical skin ingredients cannot be fully exerted. In other words, if the topical skin ingredients can be distributed uniformly (evenly) on the skin, the efficacy of the topical skin ingredients can be further enhanced. For example, in sunscreen cosmetics containing ultraviolet absorbers, it is thought that the ultraviolet protection effect can be further enhanced if the ultraviolet absorber can be distributed uniformly in the application area.

[0010] In the oil-in-water compositions described in Patent Documents 1 and 2, it is difficult to incorporate a sufficient amount of oil-soluble topical skin ingredients. It is also difficult to uniformly disperse the oil-soluble topical skin ingredients dissolved in the oil phase particles by application. Therefore, it is difficult to obtain the sufficient effect of the oil-soluble topical skin ingredients in the oil-in-water compositions.

[0011] The method for enhancing UV protection effect described in Patent Document 2 is a useful means for specific water-soluble UV absorbers, but is not a general-purpose method. Furthermore, UV absorbers are generally organic compounds, and many are water-insoluble (oil-soluble). The method described in Patent Document 2 cannot be applied to oil-soluble UV absorbers.

[0012] Furthermore, there is a demand for additives that can more effectively enhance the effects of oil-soluble topical skin ingredients than the agar and succinoglycan described in Patent Document 3.

[0013] Therefore, there is a demand for a water-in-oil type topical skin composition that can more efficiently exert the effects of oil-soluble topical skin ingredients. [Means for solving the problem]

[0014] According to a first aspect of the present disclosure, there is provided a water-in-oil type topical skin composition containing an oil-soluble UV absorber and a water-soluble polymer, the water-soluble polymer including at least one selected from the group consisting of carboxyvinyl polymer, polyacrylic acid, poly(2-acrylamido-2-methylpropanesulfonic acid), and salts thereof.

[0015] According to a second aspect of the present disclosure, there is provided a water-in-oil type topical skin composition containing an oily component including an oil-soluble topical skin ingredient and an oily solvent, and an aqueous component including a water-soluble polymer. The water-soluble polymer includes at least one selected from the group consisting of carboxyvinyl polymer, polyacrylic acid, poly(2-acrylamido-2-methylpropanesulfonic acid), and salts thereof. The content of the oily solvent in the oily component is 50% by mass or more based on the mass of the oily component. The oily solvent has a lower solubility for the oil-soluble topical skin ingredient than diisopropyl sebacate. [Effects of the Invention]

[0016] The water-in-oil composition of the present disclosure allows oil-soluble skin topical ingredients (e.g., ultraviolet absorbers) to more fully exert their effects. DETAILED DESCRIPTION OF THE INVENTION

[0017] Preferred embodiments of each of the above aspects will be described below.

[0018] According to a preferred embodiment of the first aspect, the oil-soluble ultraviolet absorber is octocobalt. Lille The active ingredient in the formulation includes at least one of benzophenone, homosalate, ethylhexyl methoxycinnamate, and ethylhexyl salicylate.

[0019] According to a preferred embodiment of the first aspect, the water-in-oil composition further comprises 15% by mass to 50% by mass of at least one of a volatile silicone oil and a volatile hydrocarbon oil, which has a lower solubility for the oil-soluble UV absorber than diisopropyl sebacate.

[0020] According to a preferred embodiment of the second aspect, the oily solvent includes at least one of a volatile silicone oil and a volatile hydrocarbon oil.

[0021] According to a preferred embodiment of the second aspect, the oil-soluble external component for skin contains an ultraviolet absorber.

[0022] According to a preferred embodiment of the second aspect, the ultraviolet absorber is octochlor Lille The active ingredient in the formulation includes at least one of benzophenone, homosalate, ethylhexyl methoxycinnamate, and ethylhexyl salicylate.

[0023] According to a preferred embodiment of the first and second aspects, the water-soluble polymer contains at least one of polyacrylic acid and a salt thereof in an amount of 0.02% by mass to 2% by mass relative to the mass of the composition. The weight-average molecular weight of the polyacrylic acid is 500,000 to 8,000,000. The content of polymers having a molecular weight of 10,000,000 or more in the polyacrylic acid is 10% by mass or less.

[0024] In the following description, POE is an abbreviation for polyoxyethylene, and POP is an abbreviation for polyoxypropylene, and the number in parentheses after POE or POP represents the average number of moles of POE groups or POP groups added in the compound.

[0025] In the present disclosure, the term "substantial amount" refers to an amount that can produce the functional effect of the compound added.

[0026] The emulsion-type external skin composition according to the first embodiment of the present disclosure will be described.

[0027] The water-in-oil type topical skin composition according to the first embodiment contains an oily component and an aqueous component. The oily component contains an oil-soluble topical skin agent and an oily solvent. The aqueous component contains a water-soluble polymer and an aqueous solvent capable of dissolving the water-soluble polymer.

[0028] [(A) Oil-soluble topical skin preparation] Examples of oil-soluble topical skin preparations include ultraviolet absorbers; vitamin A such as retinol, retinol acetate, retinol palmitate, and derivatives thereof; vitamin E such as α-tocopherol, γ-tocopherol, δ-tocopherol, tocopherol nicotinate, and tocopherol acetate, and derivatives thereof; and oil-soluble vitamin C derivatives such as ascorbyl palmitate and ascorbyl stearate.

[0029] Examples of oil-soluble UV absorbers include benzoic acid-based UV absorbers (e.g., para-aminobenzoic acid (hereinafter abbreviated as PABA), PABA monoglycerin ester, N,N-dipropoxy PABA ethyl ester, N,N-diethoxy PABA ethyl ester, N,N-dimethyl PABA ethyl ester, N,N-dimethyl PABA butyl ester, N,N-dimethyl PABA ethyl ester, etc.); anthranilic acid-based UV absorbers (e.g., homomenthyl-N-acetylanthranilate, etc.); salicylic acid-based UV absorbers (e.g., amyl salicylate, menthyl salicylate, homomenthyl salicylate, octyl salicylate, phenyl salicylate, benzyl salicylate, p-isopropanol phenyl salicylate, homosalate, etc.); cinnamic acid-based UV absorbers (e.g., octyl methoxycinnamate, ethyl-4-isopropyl cinnamate, methyl-2,5-diisopropyl cinnamate, ethyl- 2,4-Diisopropyl cinnamate, methyl-2,4-diisopropyl cinnamate, propyl-p-methoxycinnamate, isopropyl-p-methoxycinnamate, isoamyl-p-methoxycinnamate, octyl-p-methoxycinnamate (2-ethylhexyl-p-methoxycinnamate, ethylhexyl methoxycinnamate), 2-ethoxyethyl-p-methoxycinnamate, cyclohexyl-p-methoxycinnamate, ethyl-α- Cyano-β-phenylcinnamate, 2-ethylhexyl-α-cyano-β-phenylcinnamate, glyceryl mono-2-ethylhexanoyl-di-para-methoxycinnamate, etc.; 3-(4'-methylbenzylidene)-d,l-camphor, 3-benzylidene-d,l-camphor; 2-phenyl-5-methylbenzoxazole; 2,2'-hydroxy-5-methylphenylbenzotriazole; 2-(2'-hydroxy-5'-t-octylphenyl) Benzotriazole; 2-(2'-hydroxy-5'-methylphenylbenzotriazole; Dibenzalazine; Dianisoylmethane; 4-Methoxy-4'-t-butyldibenzoylmethane; 5-(3,3-dimethyl-2-norbornylidene)-3-pentan-2-one, dimorpholinopyridazinone; 2-Ethylhexyl-2-cyano-3,3-diphenylacrylate (octohex Lille2,4-bis-{[4-(2-ethylhexyloxy)-2-hydroxy]-phenyl}-6-(4-methoxyphenyl)-(1,3,5)-triazine, benzophenone-based ultraviolet absorbers (e.g., 2,4-dihydroxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2,2',4,4'-tetrahydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxy-4'-methylbenzophenone, 2-hydroxy-4-methoxybenzophenone-5-sulfonate, 4-phenylbenzophenone, 2-ethylhexyl-4'-phenyl-benzophenone-2-carboxylate, 2-hydroxy-4-n-octoxybenzophenone, 4-hydroxy-3-carboxybenzophenone, etc.), and the like.

[0030] Among the above ultraviolet absorbers, the ultraviolet absorber is octochloride, from the viewpoint of the action of the water-soluble polymer described later. Lille Preferably, the composition contains at least one of methylpropional, ...

[0031] The content of the oil-soluble skin topical ingredient in the composition can be appropriately set depending on the purpose.For example, when the oil-soluble skin topical ingredient is an ultraviolet absorber, the content of the oil-soluble skin topical ingredient can be 1% by mass or more, 2% by mass or more, 3% by mass or more, or 5% by mass or more relative to the mass of the composition.The content of the oil-soluble skin topical ingredient can be 15% by mass or less, 12% by mass or less, 10% by mass or less, or 8% by mass or less relative to the mass of the composition.

[0032] [(B) Water-soluble polymer] Examples of the water-soluble polymer that can be used include the compounds listed below. Examples of the water-soluble polymer that can be used include compounds used as thickeners. The water-soluble polymer may also include salt forms. It is believed that the water-soluble polymer acts to distribute the topical skin ingredient (A) in the composition more uniformly (evenly) on the skin when the water-in-oil composition is applied to the skin.

[0033] Examples of water-soluble polymers include at least one of carboxyvinyl polymer, polyacrylic acid, poly(2-acrylamido-2-methylpropanesulfonic acid), and salts thereof. In particular, it is preferable that the water-soluble polymer is a polymer with a controlled molecular weight (distribution). The use of a polymer with a controlled molecular weight can further enhance the efficacy of the topical skin preparation. It is believed that a polymer with a controlled molecular weight can further enhance the uniformity of distribution of the topical skin component (A) when the water-in-oil composition is applied to the skin. Regarding the molecular weight-controlled water-soluble polymer, the description in WO2015 / 052804 can be cited.

[0034] Carboxyvinyl polymers, polyacrylic acid, poly(2-acrylamido-2-methylpropanesulfonic acid) and their salts can enhance the efficacy of oil-soluble topical skin ingredients more efficiently than other water-soluble polymers.

[0035] Examples of salts include alkali metal salts (e.g., sodium salts, potassium salts, magnesium salts, calcium salts, etc.), organic amine salts (e.g., monoethanolamine salts, diethanolamine salts, triethanolamine salts, triisopropanolamine salts, etc.), and salts of basic nitrogen-containing compounds such as 2-amino-2-methyl-1-propanol, 2-amino-2-methyl-1,3-propanediol, 2-amino-2-hydroxymethyl-1,3-propanediol, L-arginine, L-lysine, and L-alkyltaurine. Of these, monovalent alkali metal salts and organic amine salts are preferred, with sodium salts, potassium salts, and triethanolamine salts being more preferred, and sodium salts being most preferred.

[0036] The molecular weight-controlled water-soluble polymer will now be described. The weight average molecular weight of the molecular weight-controlled water-soluble polymer is preferably 500,000 or more. The weight average molecular weight of the molecular weight-controlled water-soluble polymer is preferably 8,000,000 or less. In the molecular weight-controlled water-soluble polymer, polymers having a molecular weight of 10,000,000 or more preferably account for 10 mass% or less of the total. The main polymer chain of the molecular weight-controlled water-soluble polymer is preferably linear. The molecular weight distribution (= weight average molecular weight / number average molecular weight) of the molecular weight-controlled water-soluble polymer is preferably 2 or less, more preferably 1.8 or less.

[0037] Examples of molecular weight-controlled water-soluble polymers include polymers synthesized by the RAFT polymerization method described below. Examples of monomers that can be used include acrylic acid-based monomers such as acrylic acid, methacrylic acid, alkyl acrylate, alkyl methacrylate, and acrylic esters; acrylamide-based monomers such as acrylamide and dimethylacrylamide; vinyl-based monomers such as vinyl alcohol, vinylpyrrolidone, vinyl acetate, carboxyvinyl, and vinyl methyl ether; styrene; urethane; and combinations thereof. Macromonomers in which polyethylene glycol, silicone-based polymers, or the like are added as side chains to a monomer can also be suitably used as structural units. The molecular weight-controlled water-soluble polymer may be a homopolymer or a copolymer. In particular, the molecular weight-controlled water-soluble polymer is preferably a homopolymer or copolymer containing acrylic acid and / or 2-acrylamido-2-methylpropanesulfonic acid as a monomer, or a salt thereof.

[0038] Molecular weight-controlled water-soluble polymers can be synthesized by known living polymerization methods. Examples of living polymerization include living anionic polymerization, living cationic polymerization, and living radical polymerization (precise radical polymerization or controlled radical polymerization). Examples of living radical polymerization include nitroxide-mediated radical polymerization, nitroxide-mediated radical polymerization (NLRP), atom transfer radical polymerization (ATRP), and reversible addition-fragmentation chain transfer (RAFT) polymerization. Examples of atom transfer radical polymerization (ATRP) include electron transfer-derived activator ATRP or activator ATRP generated by electron transfer (AGET ATRP), electron transfer-derived regenerated activator ATRP or activator ATRP regenerated by electron transfer (ARGET ATRP), initiator ATRP for continuously regenerating active species or initiator ATRP with constantly regenerating activator (ICAR ATRP), and reverse ATRP. Derivatives of reversible addition-fragmentation chain transfer (RAFT) polymerization include living radical polymerization using organotellurium as a growing terminal, or organotellurium-mediated living radical polymerization (TERP), antimony-mediated living radical polymerization (SBRP), and bismuth-mediated living radical polymerization (BIRP). Other living radical polymerizations include iodine transfer radical polymerization (IRP) and cobalt-mediated radical polymerization (CMRP). Among these, reversible addition-fragmentation chain transfer polymerization (RAFT) is preferred because it allows the synthesis of polymers with narrow molecular weight distributions. Dithio- and trithio-type chain transfer agents are preferred. Polymerization initiators with a similar chemical structure to the chain transfer agent are preferred, with azo-based initiators being preferred. The polymerization solvent is not particularly limited; a solvent with high solubility in the monomer and polymer can be selected. The polymerization time is preferably from several hours to approximately 100 hours.

[0039] The molecular weight of the molecular weight-controlled water-soluble polymer can be measured by known methods such as light scattering, ultracentrifugation, and chromatography for the weight average molecular weight, and osmotic pressure method and chromatography for the number average molecular weight. Among these, chromatography is preferred because it allows the weight average molecular weight, number average molecular weight, and molecular weight distribution to be easily obtained with a small amount of sample, and gel permeation chromatography (hereinafter abbreviated as GPC) is even more preferred. The molecular weight distribution can be expressed as the value obtained by dividing the weight average molecular weight obtained by GPC analysis by the number average molecular weight.

[0040] The content of the water-soluble polymer is preferably 0.02% by mass or more, more preferably 0.05% by mass or more, and even more preferably 0.08% by mass or more, relative to the mass of the composition. If the content of the water-soluble polymer is less than 0.02% by mass, the effectiveness of the topical skin ingredient cannot be enhanced. The content of the water-soluble polymer is preferably 2% by mass or less, more preferably 1% by mass or less, and even more preferably 0.5% by mass or less, relative to the mass of the composition.

[0041] In addition to the water-soluble polymer, the following water-soluble components may also be contained.

[0042] Examples of natural water-soluble polymers include plant-based polymers (e.g., gum arabic, tragacanth gum, galactan, guar gum, carob gum, karaya gum, carrageenan, pectin, agar, quince seed (marmella), algae colloid (cassowia extract), starch (rice, corn, potato, wheat), glycyrrhizic acid); microbial-based polymers (e.g., xanthan gum, dextran, succinoglucan, pullulan, etc.); and animal-based polymers (e.g., collagen, casein, albumin, gelatin, etc.).

[0043] Examples of semi-synthetic water-soluble polymers include starch-based polymers (e.g., carboxymethyl starch, methylhydroxypropyl starch, etc.); cellulose-based polymers (methyl cellulose, ethyl cellulose, methylhydroxypropyl cellulose, hydroxyethyl cellulose, sodium cellulose sulfate, hydroxypropyl cellulose, carboxymethyl cellulose, sodium carboxymethyl cellulose, crystalline cellulose, cellulose powder, etc.); and alginic acid-based polymers (e.g., sodium alginate, propylene glycol alginate, etc.).

[0044] Examples of synthetic water-soluble polymers include vinyl polymers (e.g., polyvinyl alcohol, polyvinyl methyl ether, polyvinylpyrrolidone, carboxyvinyl polymer, etc.); polyoxyethylene polymers (e.g., polyoxyethylene-polyoxypropylene copolymers of polyethylene glycol 20,000, 40,000, 60,000, etc.); acrylic polymers (e.g., sodium polyacrylate, polyethyl acrylate, polyacrylamide, etc.); polyethyleneimine; cationic polymers, etc.

[0045] Examples of thickeners include gum arabic, carrageenan, karaya gum, tragacanth gum, carob gum, quince seed, casein, dextrin, gelatin, sodium pectinate, sodium alginate, methylcellulose, ethylcellulose, carboxymethylcellulose (CMC), hydroxyethylcellulose, hydroxypropylcellulose, polyvinyl alcohol (PVA), polyvinyl methyl ether (PVM), PVP (polyvinylpyrrolidone), sodium polyacrylate, carboxyvinyl polymer, locust bean gum, guar gum, tamarind gum, dialkyldimethylammonium cellulose sulfate, xanthan gum, aluminum magnesium silicate, bentonite, hectorite, aluminum magnesium silicate (Bee Gum), Laponite, silicic anhydride, taurate-based synthetic polymers, and acrylate-based synthetic polymers.

[0046] [(C) Oil-based solvent] It is preferable that at least a portion of the oily solvent is capable of dissolving the oil-soluble topical skin component. The oily solvent may be liquid as a whole and may contain solid components. Examples of oily solvents that can be used include liquid oils, solid oils, waxes, hydrocarbons, higher fatty acids, higher alcohols, synthetic ester oils, and silicone oils.

[0047] Examples of liquid oils and fats include avocado oil, camellia oil, turtle oil, macadamia nut oil, corn oil, mink oil, olive oil, rapeseed oil, egg yolk oil, sesame oil, persic oil, wheat germ oil, camellia oil, castor oil, linseed oil, safflower oil, cottonseed oil, perilla oil, soybean oil, peanut oil, tea seed oil, kaya oil, rice bran oil, Chinese tung oil, Japanese tung oil, jojoba oil, germ oil, and triglycerin.

[0048] Examples of solid fats and oils include cacao butter, coconut oil, horse fat, hardened coconut oil, palm oil, beef tallow, mutton tallow, hardened beef tallow, palm kernel oil, lard, beef bone fat, Japan wax kernel oil, hardened oil, beef trotter fat, Japan wax, and hardened castor oil.

[0049] Examples of waxes include beeswax, candelilla wax, cotton wax, carnauba wax, bayberry wax, ivory wax, whale wax, montan wax, rice bran wax, lanolin, kapok wax, lanolin acetate, liquid lanolin, sugarcane wax, lanolin fatty acid isopropyl, hexyl laurate, reduced lanolin, jojoba wax, hard lanolin, shellac wax, POE lanolin alcohol ether, POE lanolin alcohol acetate, POE cholesterol ether, lanolin fatty acid polyethylene glycol, and POE hydrogenated lanolin alcohol ether.

[0050] Examples of hydrocarbon oils include liquid paraffin, ozokerite, squalane, pristane, paraffin, ceresin, squalene, petrolatum, and microcrystalline wax.

[0051] Examples of higher fatty acids include lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, oleic acid, undecylenic acid, tall acid, isostearic acid, linoleic acid, linolenic acid, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA).

[0052] Examples of higher alcohols that can be used include straight-chain alcohols (e.g., lauryl alcohol, cetyl alcohol, stearyl alcohol, behenyl alcohol, myristyl alcohol, oleyl alcohol, cetostearyl alcohol, etc.); branched-chain alcohols (e.g., monostearyl glycerin ether (batyl alcohol), 2-decyltetradecynol, lanolin alcohol, cholesterol, phytosterol, hexyldodecanol, isostearyl alcohol, octyldodecanol, etc.); and the like.

[0053] Synthetic ester oils include isopropyl myristate, cetyl octanoate, octyldodecyl myristate, isopropyl palmitate, butyl stearate, hexyl laurate, myristyl myristate, decyl oleate, hexyldecyl dimethyloctanoate, cetyl lactate, myristyl lactate, lanolin acetate, isocetyl stearate, isocetyl isostearate, cholesteryl 12-hydroxystearate, ethylene glycol di-2-ethylhexanoate, dipentaerythritol fatty acid esters, N-alkyl glycol monoisostearate, neopentyl glycol dicaprate, diisostearyl malate, glycerin di-2-heptylundecanoate, trimethylolpropane tri-2-ethylhexanoate, trimethylolpropane triisostearate, pentaerythritol tetra-2-ethylhexanoate. Ingredients: Glycerin Tri-2-Ethylhexanoate, Glycerin Trioctanoate, Glycerin Triisopalmitate, Trimethylolpropane Triisostearate, Cetyl 2-Ethylhexanoate, 2-Ethylhexyl Palmitate, Glycerin Trimyristate, Tri-2-Heptylundecanoic Acid Glyceride, Castor Oil Fatty Acid Methyl Ester, Oleyl Oleate, Acetoglyceride, 2-Heptyl Palmitate Examples of suitable glycerin-based copolymers include 2-hexyldecyl lauroyl glutamate, 2-hexyldodecyl lauroyl glutamate, 2-hexyldodecyl lauroyl glutamate, 2-hexylun ...

[0054] Examples of silicone oils include dimethylpolysiloxane, methylhydrogenpolysiloxane, methylphenylpolysiloxane, stearoxymethylpolysiloxane, polyether-modified organopolysiloxane, fluoroalkyl-polyoxyalkylene-co-modified organopolysiloxane, alkyl-modified organopolysiloxane, terminal-modified organopolysiloxane, fluorine-modified organopolysiloxane, amino-modified organopolysiloxane, silicone gel, acrylic silicone, trimethylsiloxysilicate, silicone RTV rubber, and silicone compounds such as cyclopentasiloxane.

[0055] The oily solvent preferably contains a volatile oily component. The volatile oily component may be one that can dissolve an oil-soluble topical skin component (e.g., an oil-soluble UV absorber), or one that is difficult to dissolve an oil-soluble topical skin component. Examples of the volatile oily component include hydrocarbons and silicone oils. Examples of the volatile oily component include linear silicone oils (e.g., volatile dimethicone), volatile cyclic silicone oils (e.g., volatile cyclomethicone), isododecane, isohexadecane, etc.

[0056] The effect of water-soluble polymers does not depend on the solubility and / or volatility of the oil-soluble topical skin ingredient in the oily solvent. However, if the solubility of the oil-soluble topical skin ingredient in the oily solvent is low and / or the volatility is high, the effectiveness of the oil-soluble topical skin ingredient is thought to be reduced. This reduction in effectiveness is thought to be due to uneven distribution of application due to low solubility and / or high volatility. Therefore, compositions that mainly use oily solvents in which the oil-soluble topical skin ingredient is low in solubility and / or highly volatile can more effectively exhibit the effect of water-soluble polymers.

[0057] As the volatile oily component, for example, a solvent that dissolves oil-soluble topical skin components less than diisopropyl sebacate can be used.Also, as the volatile oily component, for example, a solvent can be selected that has a solubility of bis-ethylhexyloxyphenol methoxyphenyl triazine of 1 g or less per 100 g of solvent at 0°C.If the solubility of the oil-soluble topical skin component is low and / or the volatility of the oily solvent is high, it is difficult to distribute the oil-soluble topical skin component uniformly over the application area.However, according to the present disclosure, even when using such an oily solvent, the oil-soluble topical skin component can be applied so that it is uniformly distributed over the application area.

[0058] When the oil-soluble ingredient for topical application to the skin has low solubility in the volatile oily ingredient, the oil-soluble ingredient for topical application to the skin can be dissolved by other ingredients in the composition.

[0059] The proportion of the volatile oily component in the oily solvent can be 50% by mass or more, 60% by mass or more, 70% by mass or more, 80% by mass or more, or 90% by mass or more relative to the mass of the oily solvent.

[0060] The content of the volatile oil component is preferably 15% by mass or more, more preferably 20% by mass or more, based on the mass of the composition. The content of the volatile oil component can be 50% by mass or less, 40% by mass or less, or 30% by mass or less, based on the mass of the composition. The content of the volatile oil component can be appropriately set depending on the application.

[0061] The content of the oily solvent may be 15% by mass or more, 20% by mass or more, or 30% by mass or more, based on the mass of the composition. The content of the oily solvent may be 60% by mass or less, 50% by mass or less, or 40% by mass or less, based on the mass of the composition. The content of the oily solvent may be appropriately set depending on the application.

[0062] [(D) Aqueous solvent] At least a portion of the aqueous solvent is capable of dissolving the water-soluble polymer. The aqueous solvent preferably contains water. As the water, water used in cosmetics, quasi-drugs, etc., such as purified water, ion-exchanged water, tap water, etc., can be used.

[0063] The aqueous solvent may further contain a water-soluble alcohol, such as at least one selected from lower alcohols, polyhydric alcohols, polyhydric alcohol polymers, dihydric alcohol alkyl ethers, dihydric alcohol alkyl ethers, dihydric alcohol ether esters, glycerin monoalkyl ethers, sugar alcohols, monosaccharides, oligosaccharides, polysaccharides, and derivatives thereof.

[0064] Examples of lower alcohols include ethanol, propanol, isopropanol, isobutyl alcohol, and t-butyl alcohol.

[0065] Examples of polyhydric alcohols include dihydric alcohols (e.g., ethylene glycol, propylene glycol, trimethylene glycol, 1,2-butylene glycol, 1,3-butylene glycol, tetramethylene glycol, 2,3-butylene glycol, pentamethylene glycol, 2-butene-1,4-diol, hexylene glycol, octylene glycol, etc.); trihydric alcohols (e.g., glycerin, trimethylolpropane, etc.); tetrahydric alcohols (e.g., pentaerythritol such as 1,2,6-hexanetriol, etc.); pentahydric alcohols (e.g., xylitol, etc.); hexahydric alcohols (e.g., sorbitol, mannitol, etc.); polyhydric alcohol polymers (e.g., diethylene glycol, dipropylene glycol, triethylene glycol, etc.); glycol, polypropylene glycol, tetraethylene glycol, diglycerin, polyethylene glycol, triglycerin, tetraglycerin, polyglycerin, etc.); dihydric alcohol alkyl ethers (e.g., ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol monophenyl ether, ethylene glycol monohexyl ether, ethylene glycol mono-2-methylhexyl ether, ethylene glycol isoamyl ether, ethylene glycol benzyl ether, ethylene glycol isopropyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, etc.);Dihydric alcohol alkyl ethers (e.g., diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol butyl ether, diethylene glycol methyl ethyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monobutyl ether, propylene glycol isopropyl ether, dipropylene glycol methyl ether, dipropylene glycol ethyl ether, dipropylene glycol butyl ether, etc.); dihydric alcohol ether esters (e.g., ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monophenyl ether acetate, ethylene glycol diadipate, ethylene glycol Disuccinate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monophenyl ether acetate, etc.; glycerin monoalkyl ethers (e.g., chimyl alcohol, selachyl alcohol, batyl alcohol, etc.); sugar alcohols (e.g., sorbitol, maltitol, maltotriose, mannitol, sucrose, erythritol, glucose, fructose, starch hydrolysis sugars, maltose, xylitol, starch hydrolysis sugar reducing alcohols, etc.); glycolide; tetrahydrofurfuryl alcohol; POE-tetrahydrofurfuryl alcohol; POP-butyl ether; POP·POE-butyl ether; tripolyoxypropylene glycerin ether; POP-glycerin ether; POP-glycerin ether phosphate; POP·POE-pentaneerythritol ether, polyglycerin, etc.;

[0066] Examples of monosaccharides include trioses (e.g., D-glyceryl aldehyde, dihydroxyacetone, etc.), tetraoses (e.g., D-erythrose, D-erythrulose, D-threose, erythritol, etc.), pentoses (e.g., L-arabinose, D-xylose, L-lyxose, D-arabinose, D-ribose, D-ribulose, D-xylulose, L-xylulose, etc.), hexoses (e.g., D-glucose, D-talose, D-psicose, D-galactose, D-fructose, L-galactose, L-mannose, D- The sugar may be at least one selected from the group consisting of sugars such as tagatose, heptoses (e.g., aldoheptose, heptulose), octose (e.g., octulose), deoxysugars (e.g., 2-deoxy-D-ribose, 6-deoxy-L-galactose, 6-deoxy-L-mannose), aminosugars (e.g., D-glucosamine, D-galactosamine, sialic acid, aminouronic acid, muramic acid), and uronic acids (e.g., D-glucuronic acid, D-mannuronic acid, L-guluronic acid, D-galacturonic acid, L-iduronic acid).

[0067] Examples of oligosaccharides include at least one selected from sucrose, gunthianose, umbelliferose, lactose, planteose, isolychnoses, α,α-trehalose, raffinose, lychnoses, umbilicin, stachyose, verbascoses, and the like.

[0068] Examples of polysaccharides include at least one selected from cellulose, quince seed, chondroitin sulfate, starch, galactan, dermatan sulfate, glycogen, gum arabic, heparan sulfate, hyaluronic acid, tragacanth gum, keratan sulfate, chondroitin, xanthan gum, mucoitin sulfate, guar gum, dextran, keratosulfate, locust bean gum, succinoglucan, and caronic acid.

[0069] Examples of other polyols include at least one selected from polyoxyethylene methyl glucoside (Glucam E-10), polyoxypropylene methyl glucoside (Glucam P-10), and the like.

[0070] The content of the aqueous solvent can be, for example, 10% by mass or more, 20% by mass or more, or 30% by mass or more, based on the mass of the composition. The content of the aqueous solvent can be, for example, 60% by mass or less, 50% by mass or less, or 40% by mass or less, based on the mass of the composition. The content of the aqueous solvent can be appropriately set depending on the application.

[0071] The ratio of the oily component to the aqueous component can be set appropriately.

[0072] [(E) Surfactant] The water-in-oil type topical skin composition of the present disclosure may further contain a surfactant. Examples of the surfactant include the following surfactants:

[0073] [Anionic surfactants] Examples of anionic surfactants include fatty acid soaps (e.g., sodium laurate, sodium palmitate, etc.); higher alkyl sulfates (e.g., sodium lauryl sulfate, potassium lauryl sulfate, etc.); alkyl ether sulfates (e.g., POE-lauryl triethanolamine sulfate, sodium POE-lauryl sulfate, etc.); N-acyl sarcosinates (e.g., sodium lauroyl sarcosinate, etc.); higher fatty acid amide sulfonates (e.g., sodium N-stearoyl-N-methyl taurate, sodium N-myristoyl-N-methyl taurate, sodium coconut oil fatty acid methyl taurate, sodium lauryl methyl taurate, etc.); phosphate salts (sodium POE-oleyl ether phosphate, sodium POE-stearyl ether phosphate, etc.); sulfosuccinates (e.g., sodium di-2-ethylhexyl sulfosuccinate, sodium monolauroyl monoethanolamide polyoxyethylene sulfosuccinate, sodium lauryl polypropylene Sodium glycol sulfosuccinate, etc.); alkylbenzenesulfonates (e.g., sodium linear dodecylbenzenesulfonate, triethanolamine linear dodecylbenzenesulfonate, linear dodecylbenzenesulfonic acid, etc.); higher fatty acid ester sulfates (e.g., sodium hydrogenated coconut oil fatty acid glycerin sulfate, etc.); N-acylglutamates (e.g., monosodium N-lauroylglutamate, disodium N-stearoylglutamate, monosodium N-myristoyl-L-glutamate, etc.); sulfated oils (e.g., turmeric oil, etc.); POE-alkyl ether carboxylic acids; POE-alkyl allyl ether carboxylates; α-olefin sulfonates; higher fatty acid ester sulfonates; secondary alcohol sulfates; higher fatty acid alkylolamide sulfates; sodium lauroylmonoethanolamide succinate; N-palmitoyl aspartic acid ditriethanolamine; sodium caseinate, etc.

[0074] [Cationic surfactants] Examples of cationic surfactants include alkyltrimethylammonium salts (e.g., stearyltrimethylammonium chloride, lauryltrimethylammonium chloride, etc.); alkylpyridinium salts (e.g., cetylpyridinium chloride, etc.); dialkyldimethylammonium salts (e.g., distearyldimethylammonium chloride); poly(N,N'-dimethyl-3,5-methylenepiperidinium chloride); alkyl quaternary ammonium salts (alkyldimethylbenzylammonium salts); alkylisoquinolinium salts; dialkylmorphonium salts; POE-alkylamines; alkylamine salts; polyamine fatty acid derivatives; amyl alcohol fatty acid derivatives; benzalkonium chloride; benzethonium chloride, etc.

[0075] [Amphoteric surfactants] Examples of amphoteric surfactants include imidazoline-based amphoteric surfactants (e.g., 2-undecyl-N,N,N-(hydroxyethylcarboxymethyl)-2-imidazoline sodium, 2-cocoyl-2-imidazolinium hydroxide-1-carboxyethyloxy disodium salt, etc.); betaine-based surfactants (e.g., 2-heptadecyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine, lauryldimethylaminoacetic acid betaine, alkyl betaine, amido betaine, sulfobetaine, etc.).

[0076] [Hydrophilic nonionic surfactants] Examples of hydrophilic nonionic surfactants include POE-sorbitan fatty acid esters (e.g., POE-sorbitan monooleate, POE-sorbitan monostearate, POE-sorbitan monooleate, POE-sorbitan tetraoleate, etc.); POE-sorbitol fatty acid esters (e.g., POE-sorbitol monolaurate, POE-sorbitol monooleate, POE-sorbitol pentaoleate, POE-sorbitol monostearate, etc.); POE-glycerin fatty acid esters (e.g., POE-glycerin monostearate, POE-monooleates such as POE-glycerol monoisostearate, POE-glycerol triisostearate, etc.; POE-fatty acid esters (e.g., POE-distearate, POE-monodioleate, ethylene glycol distearate, etc.); POE-alkyl ethers (e.g., POE-lauryl ether, POE-oleyl ether, POE-stearyl ether, POE-behenyl ether, POE-2-octyldodecyl ether, POE-cholestanol ether, etc.); Pluronic types (e.g., Pluronic etc.); POE·POP-alkyl ethers (e.g., POE·POP-cetyl ether, POE·POP-2-decyltetradecyl ether, POE·POP-monobutyl ether, POE·POP-hydrogenated lanolin, POE·POP-glycerin ether, etc.); tetraPOE·tetraPOP-ethylenediamine condensates (e.g., Tetronic, etc.); POE-castor oil hydrogenated castor oil derivatives (e.g., POE-castor oil, POE-hydrogenated castor oil, POE-hydrogenated castor oil monoisostearate, POE-hydrogenated castor oil triisostearate, POE -hydrogenated castor oil monopyroglutamic acid monoisostearate diester, POE-hydrogenated castor oil maleic acid, etc.); POE-beeswax and lanolin derivatives (e.g., POE-sorbitol beeswax, etc.); alkanolamides (e.g., coconut oil fatty acid diethanolamide, lauric acid monoethanolamide, fatty acid isopropanolamide, etc.); POE-propylene glycol fatty acid esters; POE-alkylamines; POE-fatty acid amides; sucrose fatty acid esters; alkylethoxydimethylamine oxide; trioleyl phosphate, etc.

[0077] [Lipophilic nonionic surfactants] Examples of lipophilic nonionic surfactants include sorbitan fatty acid esters (e.g., sorbitan monooleate, sorbitan monoisostearate, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan sesquioleate, sorbitan trioleate, diglycerol sorbitan penta-2-ethylhexylate, diglycerol sorbitan tetra-2-ethylhexylate, etc.); glycerin polyglycerin fatty acids (e.g., glycerin monocottonseed oil fatty acid, glycerin monoerucate, glycerin sesquioleate, glycerin monostearate, glycerin α,α'-oleic acid pyroglutamate, glycerin monostearate malate, etc.); propylene glycol fatty acid esters (e.g., propylene glycol monostearate, etc.); hydrogenated castor oil derivatives; and glycerin alkyl ethers.

[0078] The surfactant content is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, based on the mass of the composition. If the surfactant content is less than 0.1% by mass, an emulsion composition cannot be obtained. The surfactant content is preferably 10% by mass or less, based on the mass of the composition. If the surfactant content exceeds 10% by mass, the skin irritation will be too strong.

[0079] [UV scattering agent] The water-in-oil type skin topical composition of the present disclosure may further contain an ultraviolet light scattering agent, which may include at least one of the following powders:

[0080] The content of the ultraviolet scattering agent can be, for example, 2% by mass or more, 5% by mass or more, or 10% by mass or more, relative to the mass of the composition. The content of the ultraviolet scattering agent can be, for example, 20% by mass or less, 15% by mass or less, or 10% by mass or less, relative to the mass of the composition. The content of the ultraviolet scattering agent can be appropriately set depending on the application.

[0081] [others] The water-in-oil type topical skin composition of the present disclosure may contain other ingredients, such as powders, moisturizers, water-soluble polymers, thickeners, film-forming agents, water-soluble UV absorbers, sequestering agents, amino acids, organic amines, polymer emulsions, pH adjusters, skin nutrients, vitamins, antioxidants, antioxidant aids, fragrances, and the like, as needed, within the scope of not impairing the effects of the present disclosure.

[0082] The term "powder" used in this specification is synonymous with "powder." There are no particular limitations on the powder as long as it can be generally used for cosmetic applications and the like. Examples of powders include inorganic powders (e.g., talc, kaolin, mica, sericite, muscovite, phlogopite, synthetic mica, lepidolite, biotite, lithia mica, calcined mica, calcined talc, vermiculite, magnesium carbonate, calcium carbonate, aluminum silicate, barium silicate, calcium silicate, magnesium silicate, strontium silicate, tungstate metal salts, magnesium, silica, zeolite, glass, barium sulfate, calcined calcium sulfate (calcined gypsum), calcium phosphate, fluorapatite, hydroxyapatite, ceramic powder, metal soap (e.g., zinc myristate, calcium palmitate, aluminum stearate), boron nitride, etc.); organic powders (e.g., polyamide resin powder (nylon powder), polyethylene powder, polymethyl methacrylate powder, polystyrene powder, styrene-acrylic acid copolymer resin powder, benzoguanamine resin powder, Polytetrafluoroethylene powder, cellulose powder, silicone resin powder, silk powder, wool powder, urethane powder, etc.; inorganic white pigments (e.g., titanium dioxide, zinc oxide, etc.); inorganic red pigments (e.g., iron oxide (red ochre), iron titanate, etc.); inorganic brown pigments (gamma-iron oxide, etc.), inorganic yellow pigments (yellow iron oxide, ochre, etc.), inorganic black pigments (black iron oxide, carbon black, low-order titanium oxide, etc.), inorganic purple pigments (e.g., manganese violet, cobalt violet, etc.); inorganic green pigments (e.g., chromium oxide, chromium hydroxide, cobalt titanate, etc.); inorganic blue pigments (e.g., ultramarine, Prussian blue, etc.); pearl pigments (e.g., titanium oxide-coated mica, titanium oxide-coated bismuth oxychloride, titanium oxide-coated talc, colored titanium oxide-coated mica, bismuth oxychloride, fish scale foil, etc.); metal powder pigments (e.g., aluminum powder, copper powder, etc.);Organic pigments such as zirconium, barium, or aluminum lakes (e.g., organic pigments such as Red 201, Red 202, Red 204, Red 205, Red 220, Red 226, Red 228, Red 405, Orange 203, Orange 204, Yellow 205, Yellow 401, and Blue 404, Red 3, Red 104, Red 106, Red 227, Red 230, Red 401, Red 505, Orange 205, Yellow 4, Yellow 5, Yellow 202, Yellow 203, Green 3, and Blue 1, etc.); natural pigments (e.g., chlorophyll, β-carotene, etc.), etc. may be used.

[0083] Examples of moisturizing agents include polyethylene glycol, propylene glycol, glycerin, 1,3-butylene glycol, xylitol, sorbitol, maltitol, chondroitin sulfate, hyaluronic acid, mucoitin sulfate, caronic acid, atelocollagen, cholesteryl-12-hydroxystearate, sodium lactate, bile salts, dl-pyrrolidone carboxylate, alkylene oxide derivatives, short-chain soluble collagen, diglycerin (EO)PO adduct, Rosa illustrator extract, Yarrow extract, and Melilot extract.

[0084] Examples of coating agents include anionic coating agents (e.g., (meth)acrylic acid / (meth)acrylic acid ester copolymers, methyl vinyl ether / maleic anhydride polymers, etc.), cationic coating agents (e.g., cationized cellulose, dimethyldiallylammonium chloride polymers, dimethyldiallylammonium chloride / acrylamide copolymers, etc.), and nonionic coating agents (e.g., polyvinyl alcohol, polyvinylpyrrolidone, polyvinyl acetate, polyacrylic acid ester copolymers, (meth)acrylamide, polymeric silicone, silicone resins, trimethylsiloxysilicate, etc.).

[0085] Examples of water-soluble ultraviolet absorbers include benzophenone-based ultraviolet absorbers (e.g., 2-hydroxy-4-methoxybenzophenone-5-sulfonate, etc.), benzylidene camphor-based ultraviolet absorbers (benzylidene camphorsulfonic acid, terephthalidene discamphorsulfonic acid, etc.), and phenylbenzimidazole-based ultraviolet absorbers (phenylbenzimidazole sulfonic acid, etc.).

[0086] Examples of sequestering agents include 1-hydroxyethane-1,1-diphosphonic acid, 1-hydroxyethane-1,1-diphosphonic acid tetrasodium salt, edetate disodium, edetate trisodium, edetate tetrasodium, sodium citrate, sodium polyphosphate, sodium metaphosphate, gluconic acid, phosphoric acid, citric acid, ascorbic acid, succinic acid, edetic acid, and ethylenediaminehydroxyethyltriacetate trisodium salt.

[0087] Examples of amino acids include neutral amino acids (e.g., threonine, cysteine, etc.), basic amino acids (e.g., hydroxylysine, etc.), etc. Examples of amino acid derivatives include sodium acyl sarcosine (sodium lauroyl sarcosine), acyl glutamate, sodium acyl β-alanine, glutathione, pyrrolidone carboxylic acid, etc.

[0088] Examples of organic amines include monoethanolamine, diethanolamine, triethanolamine, morpholine, triisopropanolamine, 2-amino-2-methyl-1,3-propanediol, and 2-amino-2-methyl-1-propanol.

[0089] Examples of polymer emulsions include acrylic resin emulsion, polyethyl acrylate emulsion, acrylic resin liquid, polyacrylic alkyl ester emulsion, polyvinyl acetate resin emulsion, and natural rubber latex.

[0090] Examples of pH adjusters include buffers such as lactic acid-sodium lactate, citric acid-sodium citrate, and succinic acid-sodium succinate.

[0091] Examples of vitamins include vitamins A, B1, B2, B6, C, E and their derivatives, pantothenic acid and its derivatives, biotin, etc.

[0092] Examples of antioxidants include tocopherols, dibutylhydroxytoluene, butylhydroxyanisole, and gallic acid esters.

[0093] Examples of antioxidant aids include phosphoric acid, citric acid, ascorbic acid, maleic acid, malonic acid, succinic acid, fumaric acid, cephalin, hexametaphosphate, phytic acid, and ethylenediaminetetraacetic acid.

[0094] Other ingredients that can be added include, for example, preservatives (ethylparaben, butylparaben, chlorphenesin, phenoxyethanol, etc.); anti-inflammatory agents (for example, glycyrrhizinic acid derivatives, glycyrrhetinic acid derivatives, salicylic acid derivatives, hinokitiol, zinc oxide, allantoin, etc.); whitening agents (for example, placenta extract, saxifrage extract, arbutin, etc.); various extracts (for example, Phellodendron bark, Coptis chinensis, Lithospermum root, Peony, Swertia japonica, Birch, Sage, Loquat, Carrot, Aloe, Mallow, Iris, Grape, Job's tears, Loofah, Lily, Saffron, Cnidium rhizome, Ginger, Hypericum perforatum, Ononis, Garlic, Chili pepper, Citrus fruit, Tomato, float, seaweed, etc.), activators (e.g., royal jelly, photosensitizers, cholesterol derivatives, etc.); blood circulation promoters (e.g., nonylic acid vanillylamide, nicotinic acid benzyl ester, nicotinic acid β-butoxyethyl ester, capsaicin, zingerone, cantharides tincture, ichthammol, tannic acid, α-borneol, tocopherol nicotinate, inositol hexanicotinate, cyclandelate, cinnarizine, tolazoline, acetylcholine, verapamil, cepharanthine, γ-oryzanol, etc.); antiseborrheic agents (e.g., sulfur, thianthol, etc.); anti-inflammatory agents (e.g., tranexamic acid, thiotaurine, hypotaurine, etc.), etc.

[0095] Furthermore, the composition of the present disclosure may also contain, as appropriate, caffeine, tannin, verapamil, tranexamic acid and derivatives thereof, various herbal extracts such as licorice, Chinese quince, and Japanese anemone, drugs such as tocopherol acetate, glycyrrhesic acid, glycyrrhizic acid and derivatives thereof or salts thereof, whitening agents such as vitamin C, magnesium ascorbyl phosphate, ascorbic acid glucoside, arbutin, and kojic acid, and amino acids such as arginine and lysine and derivatives thereof.

[0096] The water-in-oil topical skin composition of the present disclosure can enhance the efficacy of the oil-soluble topical skin ingredients incorporated therein. Generally, when comparing non-emulsified oil-based compositions with water-in-oil-based compositions, the water-in-oil-based composition tends to result in uneven application of the oil-soluble topical skin ingredients. However, the water-in-oil-based topical skin composition of the present disclosure is believed to enhance the uniformity of application of the oil-soluble topical skin ingredients, allowing the topical skin ingredients to exert their effects more fully, comparable to non-emulsified oil-based compositions. For example, when the water-in-oil-based topical skin composition is a sunscreen cosmetic, it is believed to allow the incorporated ultraviolet absorber to act more efficiently. The following describes the mechanism of action improvement of topical skin ingredients considered. However, even if the mechanism of action improvement of topical skin ingredients described below is found to differ from the actual mechanism, this does not affect the scope of the water-in-oil-based topical skin composition of the present disclosure.

[0097] The water-soluble polymer added to the water-in-oil topical skin composition of the present disclosure is believed to have the effect of improving the distribution uniformity of the topical skin ingredients in the coating film on the skin of the water-in-oil topical skin composition.For example, when the solubility of the topical skin ingredients in the oily solvent in which the topical skin ingredients are dissolved is low, or when the oily solvent is highly volatile, the topical skin ingredients are not evenly dispersed in the solvent, or the coating film cannot be applied with a uniform thickness, and the distribution of the topical skin ingredients on the skin is likely to be uneven.However, by adding a water-soluble polymer to the aqueous phase, it is believed that the topical skin ingredients can be evenly dispersed in the solvent, and the composition can be applied with a uniform thickness.This allows the topical skin ingredients to be evenly distributed in the coating film, and is believed to improve the effectiveness of the topical skin ingredients compared to a coating film in which the distribution of the topical skin ingredients is uneven.

[0098] In particular, water-soluble polymers with a narrower molecular weight range (distribution) are believed to be more effective in increasing the uniformity of distribution of topical skin ingredients than water-soluble polymers with an uncontrolled molecular weight range.

[0099] The effect of water-soluble polymers in improving the uniformity of distribution during application may not only affect oil-soluble topical skin ingredients, but also powders of UV scattering agents, etc. For example, the water-soluble polymer may enhance the UV protection effect by uniformly distributing the UV scattering agent.

[0100] [Manufacturing method] The method for producing the water-in-oil type topical skin composition of the present disclosure will be described. The water-in-oil type topical skin composition of the present disclosure does not need to be produced by a specific method, but can be produced by a generally known method. For example, the water-in-oil type topical skin composition can be produced by mixing the above-mentioned components.

[0101] In the water-in-oil type topical skin composition of the present disclosure, it may be difficult or impractical to directly identify the phase structure, etc., by the composition. In such cases, the water-in-oil type topical skin composition of the present disclosure should be allowed to be identified by its manufacturing method. [Example]

[0102] The water-in-oil type topical skin composition of the present disclosure will be described below with reference to examples. However, the water-in-oil type topical skin composition of the present disclosure is not limited to the following examples. Furthermore, in the following examples, examples in which the water-in-oil type topical skin composition of each test example is applied to a sunscreen cosmetic are described, but the composition of the present disclosure is not limited to a sunscreen cosmetic. The content of each component shown in each table is in mass%.

[0103] [Test Examples 1 to 4] Water-in-oil type topical skin compositions were prepared having the compositions shown in Tables 1 and 2. The water-in-oil type topical skin compositions in each test example were sunscreen cosmetics containing an oil-soluble ultraviolet absorber added as an oil-soluble topical skin agent (A).

[0104] "Molecular weight controlled sodium polyacrylate" shown in the table below is sodium polyacrylate synthesized to have a narrow molecular weight distribution, and molecules with a weight-average molecular weight of 10 million or more account for 10 mass% or less of the total mass of sodium polyacrylate. "Non-molecular weight controlled sodium polyacrylate" is sodium polyacrylate that is commonly available commercially, and is considered to contain more than 10 mass% of molecules with a weight-average molecular weight of 10 million or more of the total mass of sodium polyacrylate.

[0105] At room temperature of 25°C, 2 mg / cm2 of polymethyl methacrylate (PMMA) plate (SPFMASTER-PA01) was applied as a skin simulant. 2 Each composition was applied with a finger in an amount of 100 ml for 60 seconds and then dried for 15 minutes to form a sunscreen cosmetic coating. The absorbance of each coating at 280 nm to 500 nm was measured using an absorptiometer (U-3500, manufactured by Hitachi, Ltd.), and the integrated absorbance value was calculated. Using a composition containing the same oil-soluble UV absorber but without component (B) as a control, the rate of increase in the integrated absorbance value of the test example composition was calculated using the following formula. The rate of increase in the integrated absorbance value can be used as an indicator of the UV protection effect of the UV absorber. Tables 1 and 2 show the rate of increase in the integrated absorbance value relative to the control, based on the following evaluation criteria:

[0106] Increase rate of integrated absorbance (%) = (integrated absorbance of test example) / (integrated absorbance of control example) × 100

[0107] [Increase in integrated absorbance value] A: The increase in the integrated absorbance value was 10% or more compared to the control; B: The increase in the integrated absorbance value was 5% or more but less than 10% compared to the control; C: The increase in the integrated absorbance value was 2% or more but less than 5% compared to the control; D: The increase in the integrated absorbance value was less than 2% compared to the control.

[0108] When Control Example 1, which did not contain the water-soluble polymer (Component (B)), was compared with Test Examples 1-2 and 1-3, which contained the water-soluble polymer (Component (B)), an increase in the integrated absorbance value was observed when the water-soluble polymer was added. This suggests that the water-soluble polymer has the effect of enhancing the UV protection effect of the oil-soluble UV absorber.

[0109] Comparing Test Example 1-1 and Test Example 1-2, even though both polyacrylic acids were used, Test Example 1-1, which added polyacrylic acid with a controlled molecular weight distribution, was able to enhance the UV protection effect.

[0110] In Test Examples 2 to 4, the type of oil-soluble UV absorber was changed from that in Test Example 1-1. In Test Examples 2 to 4, the same or better UV protection effect as in Test Example 1-1 was obtained compared to Control Examples 2 to 4, which did not contain the water-soluble polymer (component (B)). This suggests that the improvement in UV protection effect due to the water-soluble polymer does not depend on the type of UV absorber.

[0111] Since the UV protection effect is independent of the type of UV absorber, it is believed that the water-soluble polymer contributed to the uniform distribution of the UV absorber in the composition coating film, resulting in the improved UV protection effect. In particular, since the UV protection effect of Test Example 1-1 was higher than that of Test Examples 1-2 and 1-3, it is believed that the uniformity of the distribution of the UV absorber was improved by aligning the molecular weight, i.e., the length of the polymer chain. Therefore, according to the present disclosure, it is believed that the addition of a water-soluble polymer can improve the uniformity of distribution on the skin of not only UV absorbers but also oil-soluble (organic) topical skin ingredients, thereby enhancing the topical skin effect.

[0112] [Table 1]

[0113] [Table 2]

[0114] [Test Examples 5-6] Water-in-oil topical skin compositions and (non-emulsified) oily topical skin compositions having the compositions shown in Table 3 were prepared and compared for UV protection effects. The composition of Test Example 5 is a water-in-oil sunscreen cosmetic similar to the composition of Test Example 1-1. The composition of Test Example 6 is a non-emulsified oily sunscreen cosmetic. The integrated absorbance values ​​of Test Example 5 and Test Example 6 were compared. The calculation method and evaluation of the integrated absorbance values ​​were the same as in the above Test Examples. In addition, the feel when each composition was applied to the skin was evaluated. Table 3 shows the compositions and comparison results.

[0115] In oil-based cosmetics such as those in Test Example 6, factors inhibiting uniform distribution, such as emulsified aqueous phase particles, are absent, allowing for uniform application of oil-soluble topical skin ingredients. However, the composition of Test Example 5, despite being a water-in-oil type, was able to achieve UV protection effects equivalent to those of the oil-based cosmetic in Test Example 6. This suggests that the water-in-oil type topical skin preparation of the present disclosure, even though it is a water-in-oil composition, is capable of uniformly dispersing oil-soluble topical skin ingredients on the skin equivalent to a single-phase oil-based composition.

[0116] Ten panelists applied the compositions of Test Examples 5 and 6 to their skin to assess their sensations during use. The results indicated that the composition of Test Example 5, a water-in-oil composition, felt fresher and less sticky than the non-emulsified oily composition of Test Example 6. This demonstrates that the water-in-oil topical skin composition of the present disclosure can provide a favorable sensation during use while still providing the same effects of topical skin ingredients as a single-phase oily composition.

[0117] [Table 3]

[0118] [Test Example 7] Oil-in-water topical skin preparations having the compositions shown in Table 4 were prepared and their UV protection effects were measured. The composition of Control Example 7 was similar to that described in the Examples of Patent Document 2. In Test Example 7-1, molecular weight-controlled sodium polyacrylate, a water-soluble polymer, was added to Control Example 7. In Test Example 7-2, carboxyvinyl polymer, a water-soluble polymer, was added to Control Example 7. The rate of increase in the integrated absorbance values ​​of Test Examples 7-1 and 7-2 relative to the integrated absorbance value of Control Example 7 was calculated. The calculation method and evaluation of the integrated absorbance values ​​were the same as in the above Test Examples. Table 4 shows the compositions and comparison results.

[0119] In Test Examples 7-1 and 7-2, no increase in the UV protection effect was observed compared to Control Example 7. That is, even when a water-soluble polymer was added to an oil-in-water composition as described in Patent Document 2, the UV protection effect of the UV absorber could not be enhanced. This suggests that even if the oil-in-water composition is applied to the skin, the water-soluble polymer in the oil-in-water composition does not have the effect of uniformly dispersing the oil-soluble UV absorber dissolved in the oil phase particles.

[0120] [Table 4]

[0121] [Test Examples 8-9] Water-in-oil topical skin preparations having the compositions shown in Table 5 were prepared and their UV protection effects were measured. Cyclopentasiloxane was used as the oily solvent in Test Example 8 and Control Example 8, and diisopropyl sebacate was used as the oily solvent in Test Example 9. Diisopropyl sebacate has a higher solubility for ethylhexyl methoxycinnamate, an oil-soluble topical skin ingredient, than cyclopentasiloxane. A water-soluble polymer was added only in Test Example 8, while no water-soluble polymer was added in Test Example 9 and Control Example 8. The rate of increase in the integrated absorbance values ​​of Test Example 8 and Test Example 9 relative to the integrated absorbance value of Control Example 8 was calculated. The calculation method and evaluation of the integrated absorbance values ​​were the same as in the above Test Examples. Table 5 shows the compositions and comparison results.

[0122] Comparing Test Example 9 with Control Example 8, the use of a solvent with high solubility for the oil-soluble topical skin ingredient resulted in an enhanced UV protection effect. This is believed to be due to the fact that the oil-soluble topical skin ingredient was applied more uniformly due to the increased solubility of the oil-based solvent that dissolves the oil-soluble topical skin ingredient. On the other hand, comparing Test Example 8 with Test Example 9, the addition of a water-soluble polymer resulted in an enhanced UV protection effect compared to the use of an oil-based solvent with high solubility. Therefore, the water-in-oil composition of the present disclosure can further enhance the effect of the oil-soluble topical skin ingredient, even when an oil-based solvent with low solubility for the oil-soluble topical skin ingredient is primarily used. This is believed to be due to the water-soluble polymer in the aqueous phase particles dispersing the oil-soluble topical skin ingredient more uniformly (evenly) upon application.

[0123] [Table 5]

[0124] [Test Example 10] Water-in-oil skin topical compositions having the compositions shown in Table 6 were prepared and compared for UV protection effects. The composition of Test Example 10 is a water-in-oil sunscreen cosmetic in which agar is used instead of component (B). The rate of increase in the integrated absorbance value of Test Example 6 relative to the integrated absorbance value of Control Example 1 was calculated. Control Example 1 has the same composition as the control example used in Test Example 1. The calculation method and evaluation of the integrated absorbance value were the same as those of the above Test Examples. Table 6 shows the compositions and comparison results.

[0125] Test Example 10 showed improved UV protection effect compared to Control Example 1. However, the UV protection effect of agar was lower than that of Test Examples 1-1 to 1-3 (Table 1), which contained similar amounts of the water-soluble polymer of the present disclosure, such as molecular weight-controlled sodium polyacrylate. This demonstrates that the water-soluble polymer of the present disclosure can efficiently enhance UV protection effect with a smaller amount than other water-soluble polymers.

[0126] [Table 6]

[0127] The water-in-oil type topical skin composition of the present invention has been described based on the above embodiments and examples, but is not limited to the above embodiments and examples, and may include various modifications, changes, and improvements to each disclosed element (including elements described in the claims, specification, and drawings) within the scope of the present invention and based on the basic technical idea of ​​the present invention. Furthermore, various combinations, substitutions, and selections of each disclosed element are possible within the scope of the claims of the present invention.

[0128] Further objects, purposes and modes (including modifications) of the present invention will become apparent from the entire disclosure of the present invention including the claims.

[0129] With respect to numerical ranges set forth herein, unless otherwise specified, any numerical value or range falling within that range should be construed as being specifically set forth herein. [Industrial Applicability]

[0130] The water-in-oil type topical skin composition of the present disclosure can be used in cosmetics, cleansers, etc. that are applied to the skin. In particular, the water-in-oil type topical skin composition of the present disclosure can be suitably used in sunscreen cosmetics.

Claims

1. an oil-soluble ultraviolet absorber; a water-soluble polymer; Contains the water-soluble polymer comprises at least one selected from the group consisting of polyacrylic acid and salts thereof; A water-in-oil type external skin composition, wherein the weight-average molecular weight of the polyacrylic acid is 500,000 to 8,000,000, and the content of polymers having a molecular weight of 10,000,000 or more in the polyacrylic acid is 10% by mass or less.

2. Further comprising 15% to 50% by weight of at least one of a volatile silicone oil and a volatile hydrocarbon oil; The composition according to claim 1 , wherein at least one of the volatile silicone oil and the volatile hydrocarbon oil has a lower solubility for the oil-soluble ultraviolet absorber than diisopropyl sebacate.

3. The composition of claim 1 or 2, wherein the water-soluble polymer comprises at least one of polyacrylic acid and its salts in an amount of 0.02% to 2% by weight based on the weight of the composition.

4. an oily component including an oil-soluble ultraviolet absorber and an oily solvent; an aqueous component comprising a water-soluble polymer; Contains the water-soluble polymer comprises at least one selected from the group consisting of polyacrylic acid and salts thereof; the weight average molecular weight of the polyacrylic acid is 500,000 to 8,000,000, and the content of polymers having a molecular weight of 10,000,000 or more in the polyacrylic acid is 10% by mass or less; the content of the oily solvent in the oily component is 50% by mass or more relative to the mass of the oily component, A water-in-oil type topical skin composition, wherein the oil-soluble ultraviolet absorber is less soluble in the oil-based solvent than in diisopropyl sebacate.

5. The composition of claim 4 , wherein the oily solvent comprises at least one of a volatile silicone oil and a volatile hydrocarbon oil.

6. The composition according to claim 4 or 5, wherein the water-soluble polymer comprises at least one of polyacrylic acid and its salts in an amount of 0.02% to 2% by weight based on the weight of the composition.

7. The composition of any one of claims 1 to 6, wherein the oil-soluble UV absorber comprises at least one of octocrylene, homosalate, ethylhexyl methoxycinnamate, and ethylhexyl salicylate.

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