Oil-in-water-type emulsion composition

Abstract

This oil-in-water-type emulsion composition comprises (A) an inorganic powder treated with a monoalkylphosphoric acid, (B) polyoxyethylene hydrogenated castor oil, and (C) an acrylamide-based thickener.

Description

Oil-in-water emulsion composition

[0001] The present invention relates to an oil-in-water emulsion composition.

[0002] In recent years, there has been a trend in several countries to require the use of materials that are highly safe for the human body, such as materials that meet EU standards, for various materials contained in cosmetics. Among the materials contained in cosmetics, surface-treated metal oxides are often used as UV scattering agents in cosmetics such as sunscreens and foundations. For example, Patent Document 1 discloses zinc oxide particles that are surface-treated with octyltriethoxysilane, which have UV screening properties, are excellent in color and feel when used, and are applicable to cosmetics.

[0003] Japanese Patent Application Publication No. 2023-162678

[0004] However, there is a demand for the use of a surface treatment agent that is safer than octyltriethoxysilane, which is used as a surface treatment agent for zinc oxide particles in Patent Document 1. However, replacing the surface treatment agent used in conventional UV scattering agents, such as octyltriethoxysilane, with a surface treatment agent that is thought to be safer is highly difficult, and the surface treatment of zinc oxide or titanium oxide, which form the core of the UV scattering agent, is likely to be insufficient, resulting in poor emulsion stability when blended into cosmetics, etc. An object of one embodiment of the present invention is to provide an oil-in-water emulsion composition that is highly safe and has good emulsion stability.

[0005] In order to solve the above-mentioned problems, one embodiment of the present invention provides an oil-in-water emulsion composition containing: (A) an inorganic powder treated with a monoalkyl phosphate; (B) polyoxyethylene hydrogenated castor oil; and (C) an acrylamide-based thickener.

[0006] According to one embodiment of the present invention, an oil-in-water emulsion composition that is highly safe and has good emulsion stability can be provided.

[0007] Hereinafter, an embodiment of the present invention will be described in detail.

[0008] (Oil-in-water emulsion composition) The oil-in-water emulsion composition of the present invention is an oil-in-water emulsion composition containing: (A) an inorganic powder treated with a monoalkyl phosphate; (B) polyoxyethylene hydrogenated castor oil; and (C) an acrylamide-based thickener.

[0009] According to the present invention, it is possible to provide an oil-in-water emulsion composition that is highly safe and has good emulsion stability.

[0010] <(A) Inorganic Powder Treated with Monoalkyl Phosphate> The oil-in-water emulsion composition of the present invention contains, as component (A), an inorganic powder treated with monoalkyl phosphate. The inorganic powder treated with monoalkyl phosphate is an inorganic powder in which the core microparticles of the inorganic powder have been hydrophobized with monoalkyl phosphate, and acts as an ultraviolet scattering agent in the oil-in-water emulsion composition of the present invention. Note that monoalkyl phosphate is a surface treatment agent that is safer for the human body than surface treatment agents used in conventional ultraviolet scattering agents, such as octyltriethoxysilane. The inorganic powder treated with monoalkyl phosphate is stable in oil and contributes to the emulsion stability of the oil-in-water emulsion composition of the present invention.

[0011] The content of the inorganic powder (A) treated with monoalkyl phosphate in the present invention is not particularly limited, but is preferably 1% by mass to 10% by mass, more preferably 2% by mass to 7% by mass, and even more preferably 3% by mass to 5% by mass. If it is 1% by mass or more, the effect as an ultraviolet scattering agent can be sufficiently ensured, and if it is 10% by mass or less, emulsion stability can be easily maintained.

[0012] The inorganic powder (A) treated with a monoalkyl phosphate, which acts as an ultraviolet scattering agent, may be in the form of particles, and in this case, the average primary particle diameter is not particularly limited and may be, for example, 5 nm to 200 nm, 8 nm to 100 nm, 10 to 50 nm, or 12 to 30 nm. The "average primary particle diameter" may be determined, for example, as the diameter of a circle equivalent to the projected area of ​​the primary particles in an SEM image.

[0013] <<Inorganic Powder>> Examples of inorganic powders treated with a monoalkyl phosphate that can be used in the oil-in-water emulsion composition of the present invention include fine particle metal oxide powders such as titanium oxide, zinc oxide, iron oxide, cerium oxide, and tungsten oxide, whose surfaces have been hydrophobized with a monoalkyl phosphate. Examples of the monoalkyl phosphate include cetyl phosphate, ethyl phosphate, octyl phosphate, stearyl phosphate, and dodecyl phosphate, with cetyl phosphate being preferred.

[0014] The inorganic powder preferably has a silica coating. Specific examples include fine particle metal oxide powders such as titanium oxide, zinc oxide, iron oxide, cerium oxide, and tungsten oxide, which have a silica coating on the surface and have been subjected to a hydrophobic surface treatment with monoalkyl phosphate. When the inorganic powder has a silica coating, the silica coating preferably exists in one or more layers over the entire surface of the fine particle metal oxide powder, and more preferably in two or more layers. When the inorganic powder has a silica coating, the fine particle surfaces of the metal oxide are covered with silica, thereby suppressing the catalytic activity of the metal, improving stability when used in combination with an absorbent, suppressing discoloration, and improving the feel when used. Furthermore, if the silica coating has two or more layers, the effect can be further enhanced.

[0015] <(B) Polyoxyethylene hydrogenated castor oil> The oil-in-water emulsion composition of the present invention contains polyoxyethylene hydrogenated castor oil as component (B). Polyoxyethylene hydrogenated castor oil is a nonionic surfactant and contributes to the emulsion stability of the oil-in-water emulsion composition of the present invention. Since the greater the average number of moles of ethylene oxide added, the higher the hydrophilicity of the polyoxyethylene hydrogenated castor oil and the better the emulsion stability, the polyoxyethylene hydrogenated castor oil of the present invention preferably has an average number of moles of ethylene oxide added of 50 to 100 moles. When the average number of moles of ethylene oxide added in the polyoxyethylene hydrogenated castor oil is 50 moles or more, sufficient hydrophilicity can be easily ensured and emulsion stability can be easily improved, while when it is 100 moles or less, stickiness is reduced and usability is good.

[0016] The content of polyoxyethylene hydrogenated castor oil in the oil-in-water emulsion composition of the present invention is preferably 0.1% by mass to 10% by mass, more preferably 0.5% by mass to 5% by mass, and even more preferably 1% by mass to 3% by mass. If the content of polyoxyethylene hydrogenated castor oil is 0.1% by mass or more, emulsion stability can be sufficiently improved, and if it is 10% by mass or less, stickiness derived from surfactants is reduced and usability is good.

[0017] Examples of polyoxyethylene hydrogenated castor oils suitable for the oil-in-water emulsion composition of the present invention include PEG-60 hydrogenated castor oil and PEG-100 hydrogenated castor oil.

[0018] <(C) Acrylamide-Based Thickener> The oil-in-water emulsion composition of the present invention contains an acrylamide-based thickener as component (C). The acrylamide-based thickener has a thickening mechanism in which the polymer swells to thicken the aqueous phase, and contributes to improving the emulsion stability of the oil-in-water emulsion composition of the present invention.

[0019] Examples of acrylamide thickeners include (dimethylacrylamide / sodium acryloyldimethyltaurate) crosspolymer, (sodium acrylate / sodium acryloyldimethyltaurate) copolymer, (ammonium acryloyldimethyltaurate / beheneth-25 methacrylate) crosspolymer, (ammonium acryloyldimethyltaurate / VP) copolymer, and (hydroxyethyl acrylate / sodium acryloyldimethyltaurate) copolymer.

[0020] The content of the acrylamide thickener in the oil-in-water emulsion composition of the present invention is preferably 0.01% by mass or more and 2% by mass or less, more preferably 0.05% by mass or more and 1% by mass or less, and even more preferably 0.1% by mass or more and 0.5% by mass or less. If the content of the acrylamide thickener is 0.01% by mass or more, sufficient viscosity can be easily ensured, and if it is 2% by mass or less, the cosmetic composition etc. will have an appropriate viscosity, will have little filmy feeling, and will be easy to use.

[0021] The ratio of the content of (B) polyoxyethylene hydrogenated castor oil to the content of (C) acrylamide-based thickener is preferably 100:1 to 2:1 by mass, more preferably 60:1 to 3:1, and even more preferably 30:1 to 5:1. When the ratio of the content of (B) polyoxyethylene hydrogenated castor oil to the content of (C) acrylamide-based thickener is 100:1 to 2:1 by mass, both stability and usability can be achieved.

[0022] <Other Components> The oil-in-water emulsion composition of the present invention can be produced by a conventional method according to the desired dosage form by appropriately blending, as necessary, other components in addition to those described above, such as powder components, liquid oils and fats, solid oils and fats, waxes, hydrocarbon oils, higher fatty acids, higher alcohols, synthetic ester oils, silicone oils, silicones, anionic surfactants, cationic surfactants, amphoteric surfactants, nonionic surfactants, active agents other than surfactants, water-soluble polymers, thickeners, UV absorbers, humectants, sequestering agents, lower alcohols, polyhydric alcohols, sugars, amino acids, organic amines, polymer emulsions, neutralizing agents, pH adjusters, vitamins, antioxidants, antioxidant aids, stabilizers, fragrances, and water. Specific components that can be blended are listed below.

[0023] Examples of the powder component include inorganic powders (e.g., talc, kaolin, mica, sericite, muscovite, phlogopite, synthetic mica, lepidolite, biotite, vermiculite, magnesium carbonate, calcium carbonate, aluminum silicate, barium silicate, calcium silicate, magnesium silicate, strontium silicate, metal tungstate, magnesium, silica, zeolite, 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 (for example, 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, etc.); inorganic white pigments (for example, titanium dioxide, zinc oxide, etc.); inorganic red pigments (for example, iron oxide (red iron oxide), iron titanate, etc.); inorganic brown pigments (for example, γ-iron oxide, etc.); inorganic yellow pigments (for example, yellow iron oxide, yellow ochre, etc.); inorganic Black pigments (e.g., black iron oxide, low-order titanium oxide, etc.); inorganic purple pigments (e.g., mango 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 dioxide-coated mica, titanium dioxide-coated bismuth oxychloride, titanium dioxide-coated talc, colored titanium dioxide-coated mica, bismuth oxychloride, fish scale foil, etc.); metal powder pigments (e.g., aluminum powder, copper powder, etc.); zirconium, barium organic pigments such as sodium or aluminum lakes (e.g., organic pigments such as Red No. 201, Red No. 202, Red No. 204, Red No. 205, Red No. 220, Red No. 226, Red No. 228, Red No. 405, Orange No. 203, Orange No. 204, Yellow No. 205, Yellow No. 401, and Blue No. 404, Red No. 3, Red No. 104, Red No. 106, Red No. 227, Red No. 230, Red No. 401, Red No. 505, Orange No. 205, Yellow No. 4, Yellow No. 5, Yellow No. 202, Yellow No. 203, Green No. 3, and Blue No. 1); natural pigments (e.g., chlorophyll, β-carotene, etc.).

[0024] 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.

[0025] 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.

[0026] 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.

[0027] Examples of hydrocarbon oils include liquid paraffin, ozokerite, squalane, pristane, paraffin, ceresin, squalene, petrolatum, microcrystalline wax, etc. 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), docosahexaenoic acid (DHA), etc.

[0028] Examples of higher alcohols 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.

[0029] Examples of 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, Glyceryl tri-2-ethylhexanoate, glyceryl trioctanoate, glyceryl triisopalmitate, trimethylolpropane triisostearate, cetyl 2-ethylhexanoate, 2-ethylhexyl palmitate, glyceryl trimyristate, tri-2-heptylundecanoic acid glyceride, castor oil fatty acid methyl ester, oleyl oleate, acetoglyceride, 2-heptyl palmitate lauroyl-L-glutamic acid 2-octyldodecyl ester, di-2-heptylundecyl adipate, ethyl laurate, di-2-ethylhexyl sebacate, 2-hexyldecyl myristate, 2-hexyldecyl palmitate, 2-hexyldecyl adipate, diisopropyl sebacate, 2-ethylhexyl succinate, and triethyl citrate.

[0030] Examples of silicone oils include chain polysiloxanes (e.g., dimethylpolysiloxane, methylphenylpolysiloxane, diphenylpolysiloxane, etc.); cyclic polysiloxanes (e.g., octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane, etc.), silicone resins that form a three-dimensional network structure, silicone rubber, and various modified polysiloxanes (e.g., amino-modified polysiloxanes, polyether-modified polysiloxanes, alkyl-modified polysiloxanes, fluorine-modified polysiloxanes, etc.).

[0031] Examples of silicones include alkyl and alkoxy silicone waxes such as stearyl-modified dimethicone and behenyl-modified dimethicone, silicone resins that form a three-dimensional network structure, and silicone rubber.

[0032] 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, POE-lauryl sodium sulfate, etc.); N-acyl sarcosinates (e.g., sodium lauroyl sarcosinate, etc.); higher fatty acid amide sulfonates (e.g., sodium N-myristoyl-N-methyl taurate, sodium coconut oil fatty acid methyl tauride, sodium lauryl methyl tauride, etc.); phosphate salts (sodium POE-oleyl ether phosphate, POE-stearyl ether phosphate, etc.); sulfosuccinates (e.g., sodium di-2-ethylhexyl sulfosuccinate, sodium monolauroyl monoethanolamide polyoxyethylene sulfosuccinate, sodium lauryl polypropylene glycol ... sodium succinate, etc.); alkylbenzenesulfonates (for example, sodium linear dodecylbenzenesulfonate, triethanolamine linear dodecylbenzenesulfonate, linear dodecylbenzenesulfonic acid, etc.); higher fatty acid ester sulfate salts (for example, sodium hydrogenated coconut oil fatty acid glycerin sulfate, etc.); N-acylglutamates (for example, monosodium N-lauroylglutamate, disodium N-stearoylglutamate, monosodium N-myristoyl-L-glutamate, etc.); sulfated oils (for example, turmeric oil, etc.); POE-alkyl ether carboxylic acids; POE-alkyl allyl ether carboxylate salts; α-olefin sulfonates; higher fatty acid ester sulfonates; secondary alcohol sulfate salts; higher fatty acid alkylolamide sulfate salts; sodium lauroylmonoethanolamide succinate; ditriethanolamine N-palmitoyl aspartate; and sodium caseinate.

[0033] Examples of cationic surfactants include alkyltrimethylammonium salts (e.g., stearyltrimethylammonium chloride, lauryltrimethylammonium chloride, etc.); alkylpyridinium salts (e.g., cetylpyridinium chloride, etc.); distearyldimethylammonium chloride dialkyldimethylammonium salts; 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; and benzethonium chloride.

[0034] 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.).

[0035] 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.

[0036] 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 sorbit fatty acid esters (e.g., POE-sorbitan monolaurate, POE-sorbitan monooleate, POE-sorbitan pentaoleate, POE-sorbit monostearate, etc.); POE-glycerin fatty acid esters (e.g., POE-glycerin monostearate, POE-monooleates such as POE-glycerin monoisostearate and POE-glycerin triisostearate; POE-fatty acid esters (for example, POE-distearate, POE-monodioleate, ethylene glycol distearate, etc.); POE-alkyl ethers (for example, POE-lauryl ether, POE-oleyl ether, POE-stearyl ether, POE-behenyl ether, POE-2-octyldodecyl ether, POE-cholestanol ether, etc.); Pluronic® types (for example, Pluronic 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, etc.); , POE-hydrogenated castor oil monopyroglutamic acid monoisostearate diester, POE-hydrogenated castor oil maleic acid, etc.); POE-beeswax / lanolin derivatives (for example, POE-sorbitol beeswax, etc.); alkanolamides (for example, 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.

[0037] Examples of active agents other than surfactants include active agents that emulsify by fine particles, specifically active agents for Pickering emulsification. Examples of active agents for Pickering emulsification include (acrylamide / DMAPA acrylate / methoxy PEG methacrylate) copolymer, hydrophobic silica, etc. Since (acrylamide / DMAPA acrylate / methoxy PEG methacrylate) copolymer is water-resistant, it can be suitably used when water resistance is required for the oil-in-water emulsion composition.

[0038] Examples of natural water-soluble polymers include plant-derived polymers (e.g., gum arabic, tragacanth gum, galactan, guar gum, carob gum, karaya gum, carrageenan, pectin, agar, quince seed (marmelo), algae colloid (cassowia extract), starch (rice, corn, potato, wheat), glycyrrhizic acid); and microbial-derived polymers (e.g., xanthan gum, dextran, succinoglucan, pullulan, etc.).

[0039] 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.).

[0040] 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 polypropylene 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.

[0041] Examples of thickeners include gum arabic, carrageenan, karaya gum, tragacanth gum, carob gum, quince seed (marmelo), casein, dextrin, gelatin, sodium pectinate, sodium alginate, methylcellulose, ethylcellulose, CMC, hydroxyethyl cellulose, hydroxypropyl cellulose, PVA, PVM, PVP, sodium polyacrylate, carboxyvinyl polymer, locust bean gum, guar gum, tamarind gum, dialkyldimethylammonium cellulose sulfate, xanthan gum, magnesium aluminum silicate, bentonite, hectorite, magnesium silicate A1 (Bee Gum), laponite, silicic anhydride, carbomer, and acrylates / C10-30 alkyl acrylate crosspolymer, which also functions as a surfactant and emulsifier.

[0042] Examples of the ultraviolet absorber include benzoic acid-based ultraviolet 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 ultraviolet absorbers (e.g., homomenthyl-N-acetylanthranilate, etc.); salicylic acid-based ultraviolet absorbers (e.g., amyl salicylate, etc.); cinnamic acid-based ultraviolet absorbers (e.g., octyl cinnamate, 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, methyl-p-isopropyl ... cyclohexyl-p-methoxycinnamate, octyl-p-methoxycinnamate (2-ethylhexyl-p-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.); benzophenone-based ultraviolet absorbers (for example, 2,4-dihydroxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, non, 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.);Examples include 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, and the like;

[0043] Examples of moisturizing agents include glycerin, dynamite glycerin, dipropylene glycol, 1,3-butylene glycol, cholesteryl-12-hydroxystearate, sodium lactate, dl-pyrrolidone carboxylate, urea, diglycerin ethylene oxide-propylene oxide adduct, and in particular, when an acidic mucopolysaccharide such as chondroitin sulfate or hyaluronic acid is added, the whitening effect of the alkoxysalicylic acid and / or its salt is enhanced.

[0044] Examples of sequestering agents include 1-hydroxyethane-1,1-diphosphonic acid, 1-hydroxyethane-1,1-diphosphonic acid tetrasodium salt, disodium edetate, trisodium edetate, tetrasodium edetate, sodium citrate, sodium polyphosphate, sodium metaphosphate, gluconic acid, phosphoric acid, citric acid, ascorbic acid, succinic acid, edetic acid, and trisodium ethylenediaminehydroxyethyltriacetate.

[0045] Examples of the lower alcohol include ethanol, propanol, isopropanol, isobutyl alcohol, and t-butyl alcohol.

[0046] 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.); 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., xyl alcohol, selachyl alcohol, batyl alcohol, etc.); sugar alcohols (e.g., sorbitol, maltitol, maltodextrin, etc.); Examples of such sugars include erythritol, mannitol, sucrose, erythritol, glucose, fructose, starch-decomposed sugars, maltose, xylitose, starch-decomposed sugar-reduced alcohols, etc.; glysolid; 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.;

[0047] 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-busicose, D-galactose, D-fructose, L-galactose, L- heptoses (e.g., aldoheptose, heptose, etc.); octose (e.g., octulose, etc.); deoxysugars (e.g., 2-deoxy-D-ribose, 6-deoxy-L-galactose, 6-deoxy-L-mannose, etc.); aminosugars (e.g., D-glucosamine, D-galactosamine, sialic acid, aminouronic acid, muramic acid, etc.); uronic acids (e.g., D-glucuronic acid, D-mannuronic acid, L-guluronic acid, D-galacturonic acid, L-iduronic acid, etc.), etc.

[0048] Examples of oligosaccharides include sucrose, gunthianose, umbelliferose, lactose, planteose, isolychnoses, α,α-trehalose, raffinose, lychnoses, umbilicin, stachyose, verbascoses, and the like.

[0049] Examples of polysaccharides include 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.

[0050] Examples of amino acids include neutral amino acids (e.g., threonine, cysteine, etc.) and basic amino acids (e.g., hydroxylysine, etc.). Examples of amino acid derivatives include sodium acyl sarcosine (sodium lauroyl sarcosine), acyl glutamate, sodium acyl β-alanine, glutathione, pyrrolidone carboxylic acid, etc.

[0051] Examples of organic amines include monoethanolamine, diethanolamine, triethanolamine, morpholine, triisopropanolamine, 2-amino-2-methyl-1,3-propanediol, and 2-amino-2-methyl-1-propanol.

[0052] 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.

[0053] Examples of the neutralizing agent include inorganic bases such as sodium hydroxide and potassium hydroxide; and organic amines such as monoethanolamine, diethanolamine, triethanolamine, morpholine, triisopropanolamine, 2-amino-2-methyl-1,3-propanediol, and 2-amino-2-methyl-1-propanol.

[0054] Examples of pH adjusters include buffers such as lactic acid-sodium lactate, citric acid-sodium citrate, and succinic acid-sodium succinate.

[0055] Examples of vitamins include vitamins A, B1, B2, B6, C, E and derivatives thereof, pantothenic acid and derivatives thereof, biotin, etc.

[0056] Examples of antioxidants include tocopherols, dibutylhydroxytoluene, butylhydroxyanisole, and gallic acid esters.

[0057] 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.

[0058] Examples of the stabilizer include sodium pyrosulfite and EDTA-2Na.

[0059] Other ingredients that can be added include, for example, preservatives (phenoxyethanol, ethylparaben, butylparaben, chlorphenesin, 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, vitamin C, magnesium ascorbyl phosphate, ascorbic acid glucoside, arbutin, alkoxysalicylic acid and its salts, etc.); various extracts (for example, Phellodendron bark, Coptis chinensis, Lithospermum root, Peony root, Swertia japonica, Birch, sage, Loquat, Carrot, Aloe vera, Mallow, Iris, Grape, Job's tears, Loofah, Lily, Saffron, Cnidium rhizome, Angelica juncea , St. John's wort, Ononis, garlic, chili pepper, tangerine peel, angelica tree, seaweed, etc.), activators (for example, royal jelly, photosensitizers, cholesterol derivatives, etc.); blood circulation promoters (for example, nonylic acid valenylamide, 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 (for example, sulfur, thianthol, etc.); anti-inflammatory agents (for example, tranexamic acid, thiotaurine, hypotaurine, etc.), etc.

[0060] The oil-in-water emulsion composition according to the present invention can be suitably used in various formulations such as cream, emulsion, liquid, etc. The product form can be skin care cosmetics such as sunscreen, or makeup cosmetics such as makeup base and foundation.

[0061] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. Unless otherwise specified, all contents are expressed in mass % relative to the total amount.

[0062] [Examples 1 to 4 and Comparative Examples 1 to 8] Oil-in-water emulsion compositions of Examples 1 to 4 and Comparative Examples 1 to 8 were prepared according to the formulations shown in Tables 1 to 3 by the methods described below, and the emulsion stability of each oil-in-water emulsion composition was evaluated by the methods described below.

[0063] [Preparation of oil-in-water emulsion compositions] (1) Each thickener was added to the mixture of each aqueous phase prepared according to the formulations in Tables 1 to 3 and mixed uniformly. (2) Each inorganic powder was dispersed in the mixture of each heat-melted oil and each surfactant prepared according to the formulations in Tables 1 to 3. (3) The dispersion prepared in (2) was added to the mixture prepared in (1) and emulsified.

[0064] [Emulsion stability] The emulsion stability of each oil-in-water emulsion composition sample prepared was evaluated according to the following evaluation criteria. The prepared oil-in-water emulsion composition was filled into a tube and left at room temperature for one day, and the appearance was visually observed the next day. If emulsion breakdown occurs, oil seepage is observed. In the evaluation below, "phase inversion" means a change from oil-in-water (O / W) to water-in-oil (W / O). (Evaluation criteria) A: The appearance is uniform and no oil seepage is observed. B: Oil seepage is observed. C: Phase inversion occurs during the preparation of the oil-in-water emulsion composition.

[0065] The evaluation results of emulsion stability for the oil-in-water emulsion compositions of Examples 1 to 4 and Comparative Examples 1 to 8 are shown in Tables 1 to 3. Oil-in-water emulsion compositions that were rated "A" according to the above evaluation criteria were determined to be applicable to the present invention.

[0066]

[0067]

[0068]

[0069] Examples 1 to 4 contained all of the components (A) to (C), and the oil-in-water emulsion compositions had good emulsion stability.

[0070] In Comparative Examples 1 and 2, the emulsion was unstable because the acrylamide thickener (component (C)) was not contained, and oil seepage was observed.

[0071] The inorganic powders contained in Comparative Examples 3 to 5 were not inorganic powders treated with the monoalkyl phosphate of component (A), and therefore the inorganic powders could not exist stably in the oil. As a result, oil seepage was observed in Comparative Example 3, and phase inversion occurred in Comparative Examples 4 and 5, making it impossible to prepare an oil-in-water emulsion composition.

[0072] In Comparative Examples 6 to 8, the emulsion was unstable because the polyoxyethylene hydrogenated castor oil of component (B) was not contained, and in Comparative Examples 6 and 7, phase inversion occurred and an oil-in-water emulsion composition could not be prepared, and in Comparative Example 8, oil seepage was observed.

[0073] The processing agents used in the inorganic powders "cetyl phosphate-treated silica-coated titanium oxide," "titanium oxide treated with aluminum hydroxide and stearic acid," and "titanium oxide treated with aluminum hydroxide and hydrogen dimethicone" are all highly safe for the human body. Furthermore, neither "cetyl phosphate-treated silica-coated titanium oxide" nor "titanium oxide treated with aluminum hydroxide and stearic acid" are classified as microplastics, and therefore have a low impact on the natural environment.

[0074] However, since "titanium oxide treated with aluminum hydroxide and stearic acid" and "titanium oxide treated with aluminum hydroxide and hydrogen dimethicone" are not inorganic powders treated with monoalkyl phosphate, they cannot exist stably in oil, and the emulsion stability of the oil-in-water emulsion compositions of Comparative Examples 3 and 4 using these was poor.

[0075] From the above, it has been demonstrated that the oil-in-water emulsion composition satisfying the constitution of the present invention provides an oil-in-water emulsion composition that is highly safe and has good emulsion stability.

[0076] Furthermore, it has been shown that the present invention makes it possible to obtain an oil-in-water emulsion composition that places less strain on the natural environment.

[0077] Examples of aspects of the present invention include the following. <1> An oil-in-water emulsion composition containing (A) an inorganic powder treated with a monoalkyl phosphoric acid, (B) polyoxyethylene hydrogenated castor oil, and (C) an acrylamide-based thickener. <2> The oil-in-water emulsion composition according to <1>, wherein the monoalkyl phosphoric acid includes cetyl phosphoric acid. <3> The oil-in-water emulsion composition according to <1> or <2>, wherein the inorganic powder is an inorganic powder having a silica coating. <4> The oil-in-water emulsion composition according to any of <1> to <3>, wherein the inorganic powder is titanium oxide powder. <5> The oil-in-water emulsion composition according to any of <1> to <4>, wherein the average number of moles of ethylene oxide added in the (B) polyoxyethylene hydrogenated castor oil is 50 to 100 moles.

[0078] According to any one of the oil-in-water emulsion compositions <1> to <5> above, the conventional problems can be solved and the object of the present invention can be achieved.

[0079] This application claims priority based on Japanese Patent Application No. 2023-223525, filed with the Japan Patent Office on December 28, 2023, and incorporates the entire contents of said application by reference.

Claims

1. An oil-in-water type emulsion composition containing (A) an inorganic powder treated with monoalkyl phosphate, (B) polyoxyethylene hydrogenated castor oil, and (C) an acrylamide-based thickener.

2. The oil-in-water type emulsion composition according to claim 1, wherein the monoalkyl phosphate contains cetyl phosphate.

3. The oil-in-water type emulsion composition according to claim 1 or 2, wherein the inorganic powder is an inorganic powder having a silica coating.

4. The oil-in-water type emulsion composition according to claim 1 or 2, wherein the inorganic powder is titanium oxide powder.

5. The oil-in-water type emulsion composition according to claim 1 or 2, wherein the average number of moles of ethylene oxide added to the (B) polyoxyethylene hydrogenated castor oil is 50 moles or more and 100 moles or less.

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