Oil-in-water emulsified composition

Abstract

An oil-in-water emulsion composition comprising: (A) an inorganic powder treated with a monoalkyl phosphate ester; (B) polyoxyethylene hydrogenated castor oil; and (C) an acrylamide thickener.

Description

Technical Field

[0001] This invention relates to an oil-in-water emulsion composition. Background Technology

[0002] In recent years, there has been a trend in many countries to require cosmetics to use materials that meet EU standards and are highly safe for human use.

[0003] Among the materials used in cosmetics, surface-treated metal oxides, as ultraviolet scattering agents, are commonly used in sunscreens, foundations, and other cosmetic products. For example, Patent Document 1 discloses zinc oxide particles surface-treated with octyltriethoxysilane, which are considered to have excellent ultraviolet shielding properties, color and feel, and can be applied to cosmetics.

[0004] Existing technical documents Patent documents Patent Document 1: Japanese Patent Application Publication No. 2023-162678 Summary of the Invention The problem that the invention aims to solve However, compared to octyltriethoxysilane used as a surface treatment agent for zinc oxide particles in Patent Document 1, there is currently a need for a safer surface treatment agent.

[0005] However, replacing the surface treatment agents used in existing UV scattering agents, such as octyltriethoxysilane, with those considered safer is a complex process. This can lead to insufficient surface treatment of components like zinc oxide or titanium dioxide, which form the core of the UV scattering agent, resulting in poor emulsion stability when incorporated into cosmetics.

[0006] One embodiment of the present invention aims to provide an oil-in-water emulsion composition with high safety and good emulsification stability.

[0007] Methods for solving problems To address the aforementioned issues, one embodiment of the present invention provides an oil-in-water emulsion composition comprising: (A) Inorganic powder treated with monoalkyl phosphate esters; (B) Polyoxyethylene hydrogenated castor oil; and (C) Acrylamide thickeners.

[0008] The effects of the invention According to one embodiment of the present invention, a water-in-oil emulsion composition with high safety and good emulsification stability can be provided. Detailed Implementation

[0009] The embodiments of the present invention will be described in detail below.

[0010] (Water-in-oil emulsion composition) The oil-in-water emulsion composition of the present invention is an oil-in-water emulsion composition containing the following components: (A) Inorganic powder treated with monoalkyl phosphate esters; (B) Polyoxyethylene hydrogenated castor oil; and (C) Acrylamide thickeners.

[0011] According to the present invention, a water-in-oil emulsion composition with high safety and good emulsification stability can be provided.

[0012] <(A) Inorganic powder treated with monoalkyl phosphate> The oil-in-water emulsion composition of the present invention contains inorganic powder treated with monoalkyl phosphate as component (A). Monoalkyl phosphate treated inorganic powder refers to inorganic powder obtained by hydrophobizing the microparticles serving as the core of the inorganic powder using monoalkyl phosphate, which functions as an ultraviolet scattering agent in the oil-in-water emulsion composition of the present invention.

[0013] In addition, monoalkyl phosphates are surface treatment agents that are safer for the human body than existing UV scattering agents such as octyltriethoxysilane.

[0014] Inorganic powders treated with monoalkyl phosphates remain stable in oil, which contributes to the emulsification stability of the oil-in-water emulsion composition of the present invention.

[0015] In this invention, the content of the inorganic powder treated with monoalkyl phosphate in (A) is not particularly limited, but is preferably 1% by mass or more and 10% by mass or less, more preferably 2% by mass or more and 7% by mass or less, and even more preferably 3% by mass or more and 5% by mass or less. When the content is 1% by mass or more, its effect as an ultraviolet scattering agent can be sufficiently ensured; when it is 10% by mass or less, it is easy to maintain emulsification stability.

[0016] (A) The inorganic powder treated with monoalkyl phosphate, which acts as an ultraviolet scattering agent, can be in the form of granules. In this case, the average primary particle size is not particularly limited, and can be, for example, 5 nm to 200 nm, 8 nm to 100 nm, 10 to 50 nm, or 12 to 30 nm. In addition, the "average primary particle size" can be obtained, for example, as the diameter of the equivalent circle of the projected area of ​​the primary particles in the SEM image.

[0017] <<Inorganic Powders>> As an inorganic powder treated with monoalkyl phosphate that can be used in the oil-in-water emulsion composition of the present invention, examples include substances obtained by hydrophobically treating the surface of particulate metal oxide powders such as titanium dioxide, zinc oxide, iron oxide, cerium oxide, and tungsten oxide with monoalkyl phosphate.

[0018] Examples of monoalkyl phosphates include cetyl phosphate, ethyl phosphate, octyl phosphate, stearyl phosphate, dodecyl phosphate, etc., but cetyl phosphate is preferred.

[0019] The inorganic powder preferably has a silica coating. Specifically, examples include substances with a silica coating on the surface of particulate metal oxide powders such as titanium dioxide, zinc oxide, iron oxide, cerium oxide, and tungsten oxide, which have undergone hydrophobic surface treatment with monoalkyl phosphates. When the inorganic powder has a silica coating, preferably one or more layers of silica coating are present on the entire surface of the particulate metal oxide powder, more preferably two or more layers.

[0020] When the inorganic powder has a silica coating, the catalytic activity of the metal oxide particles is suppressed because the surface of the particles is covered with silica. It exhibits good stability when used with an absorbent, inhibits discoloration, and improves the tactile feel. Furthermore, this effect is further enhanced when the silica coating consists of two or more layers.

[0021] <(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, which contributes to the emulsion stability of the oil-in-water emulsion composition of the present invention.

[0022] For polyoxyethylene hydrogenated castor oil, the higher the average molar number of ethylene oxide added, the higher its hydrophilicity and the better its emulsion stability. Therefore, in this invention, the average molar number of ethylene oxide added to the polyoxyethylene hydrogenated castor oil is preferably 50 moles or more and 100 moles or less. When the average molar number of ethylene oxide added to the polyoxyethylene hydrogenated castor oil is 50 moles or more, it is easy to ensure sufficient hydrophilicity and improve emulsion stability; when it is less than 100 moles, it has less stickiness and better usability.

[0023] In the oil-in-water emulsion composition of the present invention, the content of polyoxyethylene hydrogenated castor oil 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, the emulsion stability can be sufficiently improved; if it is 10% by mass or less, the stickiness caused by the surfactant is reduced, and the usability is good.

[0024] Polyoxyethylene hydrogenated castor oil suitable for the oil-in-water emulsion composition of the present invention includes, for example, PEG-60 hydrogenated castor oil, PEG-100 hydrogenated castor oil, etc.

[0025] <(C) Acrylamide thickeners> The oil-in-water emulsion composition of the present invention contains an acrylamide thickener as component (C). Acrylamide thickeners have a thickening mechanism that thickens the aqueous phase through polymer swelling, which helps to improve the emulsion stability of the oil-in-water emulsion composition of the present invention.

[0026] Examples of acrylamide thickeners include: (dimethacrylamide / sodium acryloyldimethyltaurate) cross-linked polymers, (sodium acrylate / sodium acryloyldimethyltaurate) copolymers, (ammonium acryloyldimethyltaurate / behenol polyether-25 methacrylate) cross-linked polymers, (ammonium acryloyldimethyltaurate / VP) copolymers, and (hydroxyethyl acrylate / sodium acryloyldimethyltaurate) copolymers.

[0027] In the oil-in-water emulsion composition of the present invention, the content of acrylamide thickener 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 acrylamide thickener is 0.01% by mass or more, sufficient viscosity is easily ensured; if it is 2% by mass or less, cosmetics and the like have moderate viscosity, less film-forming feel, and good usability.

[0028] The mass ratio (B) of the content of polyoxyethylene hydrogenated castor oil to the content of (C) acrylamide thickener is preferably 100:1 to 2:1, more preferably 60:1 to 3:1, and even more preferably 30:1 to 5:1. When the mass ratio of the content of (B) of polyoxyethylene hydrogenated castor oil to the content of (C) acrylamide thickener is within the range of 100:1 to 2:1, a balance between stability and usability can be achieved.

[0029] <Other Ingredients> The oil-in-water emulsion composition of the present invention can be appropriately formulated with other components besides those mentioned above, such as: powder components, liquid oils, solid oils, waxes, hydrocarbon oils, higher fatty acids, higher alcohols, synthetic ester oils, silicone oils, silicones, anionic surfactants, cationic surfactants, amphoteric surfactants, nonionic surfactants, surfactants other than surfactants, water-soluble polymers, thickeners, ultraviolet absorbers, humectants, metal ion blocking agents, lower alcohols, polyols, sugars, amino acids, organic amines, polymeric emulsions, neutralizers, pH adjusters, vitamins, antioxidants, antioxidant auxiliaries, stabilizers, fragrances, water, etc., and can be manufactured by conventional methods according to the target dosage form. Specific compatible components are listed below.

[0030] Examples of powder components include: inorganic powders (e.g., talc, kaolin, mica, sericite, muscovite, phlogopite, synthetic mica, red mica, biotite, vermiculite, magnesium carbonate, calcium carbonate, aluminum silicate, barium silicate, calcium silicate, magnesium silicate, strontium silicate, tungstate metal salts, magnesium, silicon dioxide, zeolite, barium sulfate, calcined calcium sulfate (calcined gypsum), calcium phosphate, fluorapatite, hydroxyapatite, ceramic powders, metal soaps (e.g., zinc myristate, calcium palmitate, aluminum stearate), boron nitride, etc.); organic powders. (Examples include: polyamide resin powder (nylon powder), polyethylene powder, polymethyl methacrylate powder, polystyrene powder, styrene-acrylic acid copolymer resin powder, styrene-melamine resin powder, polytetrafluoroethylene powder, cellulose powder, etc.); inorganic white pigments (e.g., titanium dioxide, zinc oxide, etc.); inorganic red pigments (e.g., iron oxide (iron oxide red), iron titanate, etc.); inorganic brown pigments (e.g., γ-iron oxide, etc.); inorganic yellow pigments (e.g., yellow iron oxide, loess, etc.); inorganic black pigments (e.g., black iron oxide, low-cost...) Inorganic pigments include: titanium dioxide, 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.); pearlescent 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.); metallic powder pigments (e.g., aluminum powder, copper powder, etc.); organic pigments such as zirconium, barium, or aluminum lake (e.g., Red 201, Red 202, Red 204, etc.). Organic pigments such as No. 205, No. 220, No. 226, No. 228, No. 405, No. 203, No. 204, No. 205, No. 401, and No. 404; organic pigments such as No. 3, No. 104, No. 106, No. 227, No. 230, No. 401, No. 505, No. 205, No. 4, No. 5, No. 202, No. 203, No. 3, and No. 1; natural pigments (e.g., chlorophyll, β-carotene).

[0031] Examples of liquid oils include: avocado oil, camellia oil, turtle oil, macadamia nut oil, corn oil, mink oil, olive oil, rapeseed oil, egg yolk oil, sesame oil, peach kernel oil, wheat germ oil, camellia oil, castor oil, flaxseed oil, safflower oil, cottonseed oil, perilla oil, soybean oil, peanut oil, tea seed oil, torreya nut oil, rice bran oil, Chinese tung oil, Japanese tung oil, jojoba oil, wheat germ oil, and triglycerides.

[0032] Examples of solid fats include: cocoa butter, coconut oil, horse fat, hydrogenated coconut oil, palm oil, beef tallow, mutton tallow, hydrogenated beef tallow, palm kernel oil, lard, beef bone fat, wood wax kernel oil, hydrogenated oil, beef foot fat, wood wax, and hydrogenated castor oil.

[0033] Examples of waxes include: beeswax, candelilla wax, cotton wax, carnauba wax, bayberry wax, insect wax, whale wax, montan wax, rice bran wax, lanolin, kapok wax, lanolin acetate, liquid lanolin, sugarcane wax, lanolin fatty acid isopropyl ester, 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 ester, POE hydrogenated lanolin alcohol ether, etc.

[0034] Examples of hydrocarbon oils include: liquid paraffin, ceresin, squalane, pterostilbene, paraffin wax, pure ceresin, squalene, petrolatum, microcrystalline wax, etc.

[0035] Examples of high-grade fatty acids include: lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, oleic acid, undecenoic acid, tall acid, isostearic acid, linoleic acid, linolenic acid, eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), etc.

[0036] Examples of higher alcohols include: straight-chain alcohols (e.g., lauryl alcohol, cetyl alcohol, stearyl alcohol, behenyl alcohol, myristyl alcohol, oleyl alcohol, cetearyl alcohol, etc.); branched-chain alcohols (e.g., monostearate glyceryl ether (squalene), 2-decyltetradecanool, lanolin alcohol, cholesterol, phytosterol, hexyldodecanool, isostearyl alcohol, octyldodecanool, etc.).

[0037] Examples of synthetic ester oils include: isopropyl myristate, cetyl octanoate, octyl dodecyl myristate, isopropyl palmitate, butyl stearate, hexyl laurate, myristyl myristate, decyl oleate, hexyl decyl dimethyl octanoate, cetyl lactate, myristyl lactate, lanolin acetate, isocetyl stearate, isocetyl isostearate, cholesterol 12-hydroxystearate, ethylene glycol di-2-ethylhexanoate, dipentaerythritol fatty acid ester, N-alkyl diol monoisostearate, neopentyl glycol didecanoate, diisostearate malate, glyceryl di-2-heptyl undecanoate, trimethylolpropane tri-2-ethylhexanoate, trimethylolpropane triisostearate, pentaerythritol tetra-2-ethylhexanoate. Tetraol esters, tri-2-ethylhexanoic acid glycerides, tricaprylic acid glycerides, triisopalmitoyl glycerides, trimethylolpropane triisostearate, cetyl 2-ethylhexanoate, 2-ethylhexyl palmitate, trimyristic acid glycerides, tri-2-heptylundecanoate glycerides, castor oil fatty acid methyl esters, oleic acid esters, acetylglycine glycerides, 2-heptylundecyl palmitate, diisobutyl adipate, N-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, triethyl citrate, etc.

[0038] Examples of silicone oils include: chain polysiloxanes (e.g., dimethyl polysiloxane, methylphenyl polysiloxane, diphenyl polysiloxane, etc.); cyclic polysiloxanes (e.g., octamethylcyclotetrasiloxane, decamethylcyclopentanolsiloxane, dodecylmethylcyclohexylsiloxane, etc.); organosilicon resins forming three-dimensional network structures; silicone rubber; and various modified polysiloxanes (amino-modified polysiloxanes, polyether-modified polysiloxanes, alkyl-modified polysiloxanes, fluorinated polysiloxanes, etc.).

[0039] Examples of silicones include: stearyl-modified polydimethylsiloxane, behenyl-modified polydimethylsiloxane and other alkyl and alkoxy silicone waxes, organosilicon resins that form three-dimensional network structures, silicone rubber, etc.

[0040] Examples of anionic surfactants include: fatty acid soaps (e.g., sodium lauryl sulfate, sodium palmitate, etc.); higher alkyl sulfates (e.g., sodium dodecyl sulfate, potassium dodecyl sulfate, etc.); alkyl ether sulfates (e.g., POE-triethanolamine dodecyl sulfate, POE-sodium dodecyl sulfate, etc.); N-acylsarcosine salts (e.g., sodium lauroyl sarcosine, etc.); higher fatty acid amide sulfonates (e.g., sodium N-myristoyl-N-methyl taurate, sodium coconut oil fatty acid methyl taurate, sodium lauryl methyl taurate, etc.); phosphate salts (POE-oil-based ether phosphate, POE-stearyl ether phosphate, etc.); sulfosuccinates (e.g., sodium di-2-ethylhexyl sulfosuccinate, sodium monolauroyl monoethanolamide polyoxyethylene sulfosuccinate, etc.). Dialkyl polypropylene glycol sulfosuccinate sodium salt, etc.); alkylbenzene sulfonates (e.g., linear dodecylbenzene sulfonate sodium salt, linear dodecylbenzene sulfonate triethanolamine, linear dodecylbenzene sulfonic acid, etc.); higher fatty acid ester sulfate salts (e.g., hydrogenated coconut oil fatty acid glycerol sulfate sodium salt, etc.); N-acyl glutamate salts (e.g., N-lauroyl glutamate monosodium salt, N-stearoyl glutamate disodium salt, N-myristoyl-L-glutamate monosodium salt, etc.); sulfated oils (e.g., Turkish red oil, etc.); POE-alkyl ether carboxylic acids; POE-alkyl allyl ether carboxylates; α-olefin sulfonates; higher fatty acid ester sulfonates; secondary alcohol sulfate salts; higher fatty acid alkanolamide sulfate salts; lauroyl monoethanolamide succinate sodium salt; N-palmitoyl aspartate di(triethanolamine); casein sodium salt, etc.

[0041] Examples of cationic surfactants include: alkyl trimethylammonium salts (e.g., stearyltrimethylammonium chloride, lauryltrimethylammonium chloride, etc.); alkyl pyridinium salts (e.g., cetylpyridinium chloride, etc.); distearate dimethylammonium chloride, dialkyl dimethylammonium salts; chlorinated poly(N,N'-dimethyl-3,5-methylenepiperidinium); alkyl quaternary ammonium salts; alkyl dimethyl benzylammonium salts; alkyl isoquinolineium salts; dialkyl morpholineium salts; POE-alkylamines; alkylamine salts; polyamine fatty acid derivatives; pentanol fatty acid derivatives; benzalkonium chloride; benzyl chloride, etc.

[0042] Examples of amphoteric surfactants include: imidazoline amphoteric surfactants (e.g., sodium 2-undecyl-N,N,N-(hydroxyethylcarboxymethyl)-2-imidazoline, disodium 2-cocoyl-2-imidazoline hydroxide-1-carboxyethoxy, etc.); betaine surfactants (e.g., 2-heptadecyl-N-carboxymethyl-N-hydroxyethylimidazoline betaine, lauryl dimethylaminoacetic acid betaine, alkyl betaine, amide betaine, sulfobetaine, etc.).

[0043] 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, pent-2-ethylhexanoate diglyceride, tetra-2-ethylhexanoate diglyceride, etc.); glycerol polyglycerol fatty acids (e.g., cottonseed oil fatty acid glycerides, glycerol monoerucate, sesquioleate glycerides, glycerol monostearate, α,α'-oleic acid pyroglutamic acid glycerides, glycerol monostearate malate, etc.); propylene glycol fatty acid esters (e.g., propylene glycol monostearate); hydrogenated castor oil derivatives; glycerol alkyl ethers, etc.

[0044] 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-sorbitan fatty acid esters (e.g., POE-sorbitan monolaurate, POE-sorbitan monooleate, POE-sorbitan pentaoleate, POE-sorbitan monostearate, etc.); POE-glycerol fatty acid esters (e.g., POE-glyceryl monostearate, POE-glyceryl monoisostearate, POE-glyceryl triisostearate, etc.; POE-fatty acid esters (e.g., POE-distearate, POE-monodioleate, ethylene distearate, etc.); POE-alkyl ethers (e.g., POE-lauryl ether, POE-oleyl ether, POE-stearyl ether, POE-behenyl ether, POE-2-octyldodecyl ether, POE-cholesterol ether, etc.); Pluronic (registered trademark) type (e.g., Pluronic (registered trademark), 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-glycerol ether, etc.); tetra(POE·tetra(POP)-ethylenediamine condensates (e.g., Tetronic, etc.); POE-caster oil / hydrogenated castor oil derivatives (e.g., POE-caster oil, POE-hydrogenated castor oil, POE-hydrogenated castor oil monobutyl ether, etc.). Isostearates, POE-hydrogenated castor oil triisostearate, POE-hydrogenated castor oil monopyroglutamic acid monoisostearate, POE-hydrogenated castor oil maleic acid, etc.; POE-beeswax-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 oxides; trioleophosphates, etc.

[0045] Surfactants other than surfactants can include, for example, surfactants that emulsify via microparticles, and more specifically, surfactants for Pickering emulsification. Examples of surfactants for Pickering emulsification include: (acrylamide / DMAPA acrylic acid / methoxyPEG methacrylate) copolymers, hydrophobic silica, etc. Because (acrylamide / DMAPA acrylic acid / methoxyPEG methacrylate) copolymers are water-resistant, they are preferred when water resistance is required in oil-in-water emulsion compositions.

[0046] Examples of natural water-soluble polymers include: plant-based polymers (e.g., gum arabic, tragacanth, galactomannan, guar gum, carob gum, tussock gum, carrageenan, pectin, agar, quince seed (wood pear), seaweed gum (brown algae extract), starch (rice, corn, potato, wheat), glycyrrhizic acid); and microbial polymers (e.g., xanthan gum, dextran, succinyl polysaccharide, pullulan, etc.).

[0047] Examples of semi-synthetic water-soluble polymers include: starch-based polymers (e.g., carboxymethyl starch, methyl hydroxypropyl starch, etc.); cellulose-based polymers (methyl cellulose, ethyl cellulose, methyl hydroxypropyl cellulose, hydroxyethyl cellulose, sodium cellulose sulfate, hydroxypropyl cellulose, carboxymethyl cellulose, sodium carboxymethyl cellulose, crystalline cellulose, cellulose powder, etc.); and alginate-based polymers (e.g., sodium alginate, propylene glycol alginate, etc.).

[0048] Examples of synthetic water-soluble polymers include: vinyl polymers (e.g., polyvinyl alcohol, polyvinyl methyl ether, polyvinylpyrrolidone, carboxyvinyl polymers, etc.); polyoxyethylene polymers (e.g., polyethylene glycol 20,000, 40,000, 60,000 polyoxyethylene-polyoxypropylene copolymers, etc.); acrylic polymers (e.g., sodium polyacrylate, polyethyl acrylate, polyacrylamide, etc.); polyethyleneimine; cationic polymers, etc.

[0049] Examples of thickeners include: gum arabic, carrageenan, ebony gum, tragacanth gum, carob gum, quince seed, casein, dextrin, gelatin, sodium pectate, sodium alginate, methylcellulose, ethylcellulose, CMC, hydroxyethylcellulose, hydroxypropylcellulose, PVA, PVM, PVP, sodium polyacrylate, carboxyvinyl polymers, locust bean gum, guar gum, tamarind gum, dialkyldimethylammonium sulfate cellulose, xanthan gum, magnesium aluminum silicate, bentonite, hydropyrite, veegum, lithium saponite, anhydrous silicate, carbomer, and cross-linked polymers of acrylates / alkyl (C10-30) acrylates. Furthermore, cross-linked polymers of acrylates / alkyl (C10-30) acrylates also exhibit the functions of surfactants and emulsifiers.

[0050] Examples of UV absorbers include: benzoic acid UV absorbers (e.g., para-aminobenzoic acid (hereinafter referred to as PABA), PABA monoglyceride, 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 UV absorbers (e.g., homosalyl-N-acetyl anthranilic benzoate, etc.); and salicylic acid UV absorbers (e.g., amyl salicylate, menthyl salicylate, homosalyl salicylate, etc.). Octyl salicylate, phenyl salicylate, benzyl salicylate, p-isopropanol phenyl salicylate, etc.; cinnamic acid UV absorbers (e.g., octyl cinnamate, ethyl 4-isopropylcinnamate, methyl 2,5-diisopropylcinnamate, ethyl 2,4-diisopropylcinnamate, methyl 2,4-diisopropylcinnamate, propyl p-methoxycinnamate, isopropyl p-methoxycinnamate, isoamyl p-methoxycinnamate, octyl p-methoxycinnamate (ethylhexyl p-methoxycinnamate), 2-ethoxyethyl p-methoxycinnamate, cyclohexyl p-methoxycinnamate, ethyl α-cyano-β-phenylcinnamate, α-cyano- β-phenylcinnamic acid-2-ethylhexyl ester, mono-2-ethylhexanoyl-di-p-methoxycinnamic acid glyceryl ester, etc.; 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- Carboxylic acid esters, 2-hydroxy-4-n-octyloxybenzophenone, 4-hydroxy-3-carboxybenzophenone, etc.); 3-(4'-methylbenzylene)-d,l-camphor, 3-benzylene-d,l-camphor; 2-phenyl-5-methylbenzoxazole; 2,2'-hydroxy-5-methylphenylbenzotriazole; 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole; 2-(2'-hydroxy-5'-methylphenylbenzotriazole; dibenzylazine; dianiloylmethane; 4-methoxy-4'-tert-butyldibenzoylmethane; 5-(3,3-dimethyl-2-norbornenyl)-3-pent-2-one, etc.

[0051] Examples of moisturizers include glycerin, nitroglycerin, dipropylene glycol, 1,3-butanediol, 12-hydroxystearic acid cholesterol ester, sodium lactate, dl-pyrrolidone carboxylate, urea, and diglyceride ethylene oxide-propylene oxide adducts. In particular, when combined with acidic mucopolysaccharides such as chondroitin sulfate or hyaluronic acid, they enhance the whitening effect of alkoxysalicylic acid and / or its salts.

[0052] Examples of metal ion blocking agents include: 1-hydroxyethane-1,1-diphosphonic acid, tetrasodium 1-hydroxyethane-1,1-diphosphonic acid, disodium ethylenediaminetetraacetate, trisodium ethylenediaminetetraacetate, tetrasodium ethylenediaminetetraacetate, sodium citrate, sodium polyphosphate, sodium metaphosphate, gluconic acid, phosphoric acid, citric acid, ascorbic acid, succinic acid, ethylenediaminetetraacetic acid, and trisodium ethylenediaminehydroxyethyltriacetate.

[0053] Examples of lower alcohols include ethanol, propanol, isopropanol, isobutanol, tert-butanol, etc.

[0054] Examples of polyols include: diols (e.g., ethylene glycol, propylene glycol, trimethylene glycol, 1,2-butanediol, 1,3-butanediol, tetramethylene glycol, 2,3-butanediol, pentamethylene glycol, 2-buten-1,4-diol, hexanediol, octanediol, etc.); triols (e.g., glycerol, trimethylolpropane, etc.); tetraols (e.g., pentaerythritol such as 1,2,6-hexanetriol); pentaols (e.g., xylitol, etc.); hexaols (e.g., sorbitol, mannitol, etc.); and polyol polymers (e.g., diethylene glycol, dipropylene glycol, triethylene glycol, etc.). Alcohols, polypropylene glycol, tetraethylene glycol, diglycerol, polyethylene glycol, triglycerol, tetraglycerol, polyglycerol, etc.; diol 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 isopentyl ether, ethylene glycol benzyl ether, ethylene glycol isopropyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, etc.); diol 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 dibutyl ... Ethers, including diethylene glycol methyl ethyl ether, triethylene glycol monomethyl 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.; diol 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). Acetates, propylene glycol monophenyl ether acetate, etc.); glyceryl monoalkyl ethers (e.g., squalene, squalene, etc.); sugar alcohols (e.g., sorbitol, maltitol, maltotriose, mannitol, sucrose, erythritol, glucose, fructose, starch-degrading sugars, maltose, xylitol, starch-degrading sugar reducing alcohols, etc.); Glysolid; tetrahydrofurfuryl alcohol; POE-tetrahydrofurfuryl alcohol; POP-butyl ether; POP·POE-butyl ether; trioxypropylene glyceryl ether; POP-glyceryl ether; POP-glyceryl ether phosphate; POP·POE-pentaerythritol ether; polyglycerol, etc.

[0055] Examples of monosaccharides include: trioses (e.g., D-glyceraldehyde, dihydroxyacetone, etc.); teuses (e.g., D-erythrose, D-erythritol, D-threose, erythritol, etc.); pentoses (e.g., L-arabinose, D-xylose, L-lysose, D-arabinose, D-ribose, D-ribulose, D-xylulose, L-xylulose, etc.); and hexoses (e.g., D-glucose, D-tarose, D-alulose, D-galactose, D-fructose, L-galactose, L-mannose). Examples of sugars include: D-tagatose, heptose (e.g., heptaldehyde, heptulose), octose (e.g., octulose), deoxyglucose (e.g., 2-deoxy-D-ribose, 6-deoxy-L-galactose, 6-deoxy-L-mannose), aminoglucose (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).

[0056] Examples of oligosaccharides include: sucrose, gentiotriose, umbelliferose, lactose, psyllium syrup, isocorhizonose, α,α-trehalose, raffinose, succinose, umbilicin, stachyose, and mustachyose.

[0057] Examples of polysaccharides include: cellulose, quince seed, chondroitin sulfate, starch, galactomannan, dermatan sulfate, glycogen, gum arabic, heparin sulfate, hyaluronic acid, tragacanth gum, keratin sulfate, chondroitin, xanthan gum, mucin sulfate, guar gum, dextran, keratin sulfate, locust bean gum, succinosaccharide, carnosic acid, etc.

[0058] Examples of amino acids include: neutral amino acids (e.g., threonine, cysteine, etc.); basic amino acids (e.g., hydroxylysine, etc.). Furthermore, examples of amino acid derivatives include: sodium lauroyl sarcosinate (sodium lauroyl sarcosinate), acyl glutamate, sodium acyl β-alanine, glutathione, pyrrolidone carboxylic acid, etc.

[0059] Examples of organic amines include: monoethanolamine, diethanolamine, triethanolamine, morpholine, triisopropanolamine, 2-amino-2-methyl-1,3-propanediol, 2-amino-2-methyl-1-propanol, etc.

[0060] Examples of polymeric emulsions include: acrylic resin emulsions, ethyl polyacrylate emulsions, acrylic resin liquids, alkyl polyacrylate emulsions, polyvinyl acetate resin emulsions, and natural rubber latex.

[0061] Neutralizing agents 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.

[0062] Examples of pH adjusters include: lactic acid-sodium lactate, citric acid-sodium citrate, succinic acid-sodium succinate, and other buffers.

[0063] Examples of vitamins include: vitamins A, B1, B2, B6, C, E and their derivatives, pantothenic acid and its derivatives, biotin, etc.

[0064] Examples of antioxidants include: tocopherols, butylated hydroxytoluene, butylated hydroxyanisole, and gallic acid esters.

[0065] Examples of antioxidant auxiliaries include: phosphoric acid, citric acid, ascorbic acid, maleic acid, malonic acid, succinic acid, fumaric acid, phospholipids, hexametaphosphate, phytic acid, and ethylenediaminetetraacetic acid.

[0066] Examples of stabilizers include sodium metabisulfite and EDTA-2Na.

[0067] Other possible complementary ingredients include: preservatives (phenoxyethanol, ethylparaben, butylparaben, chlorphenesin, etc.); anti-inflammatory agents (e.g., glycyrrhizic acid derivatives, glycyrrhetinic acid derivatives, salicylic acid derivatives, saporiol, zinc oxide, allantoin, etc.); whitening agents (e.g., placental extract, saxifrage extract, arbutin, vitamin C, magnesium ascorbate phosphate, ascorbate glucoside, arbutin, alkoxysalicylic acid and its salts, etc.); and various extracts (e.g., Phellodendron bark, Coptis chinensis, Lithospermum erythrorhizon, peony root, Angelica dahurica, birch, sage, loquat, ginseng, aloe vera, mallow, iris, grape, coix seed, loofah, lily). Ingredients include: saffron, chuanxiong, ginger, forsythia, gentian flower, garlic, chili, dried tangerine peel, angelica, seaweed, etc.; activators (e.g., royal jelly, photosensitizers, cholesterol derivatives, etc.); blood circulation promoters (e.g., vanillin nonanoic acid, benzyl nicotinate, β-butoxyethyl nicotinate, capsaicin, gingerone, cantharides tincture, ichthammol, tannic acid, α-borneol, nicotinic acid tocopheryl ester, inositol hexanicotinate, cyclomandelate, cinnarizine, tolazoline, acetylcholine, verapamil, senna extract, γ-oryzanol, etc.); anti-seborrheic agents (e.g., sulfur, dimethylthione, etc.); anti-inflammatory agents (e.g., tranexamic acid, thiotaurine, taurine, etc.).

[0068] The water-in-oil emulsion composition involved in this invention can be appropriately used in various dosage forms such as creams, lotions, and liquids. As a product form, it can be formulated into skin care cosmetics such as sunscreens, or makeup cosmetics such as primers and foundations.

[0069] Example The present invention will be described in more detail below through embodiments, but the present invention is not limited to these embodiments. Furthermore, unless otherwise stated, all contents are expressed as a percentage of mass relative to the total amount.

[0070] [Examples 1-4 and Comparative Examples 1-8] Using the formulations shown in Tables 1-3, oil-in-water emulsion compositions of Examples 1-4 and Comparative Examples 1-8 were prepared according to the following methods, and the emulsification stability of each oil-in-water emulsion composition was evaluated according to the following methods.

[0071] [Preparation of oil-in-water emulsion compositions] (1) Add each thickener to each aqueous phase mixture prepared according to the formulations in Tables 1 to 3 and mix them evenly.

[0072] (2) Disperse each inorganic powder in the mixture of each oil and each activator prepared by heating and melting according to the formulations in Tables 1 to 3.

[0073] (3) Add the dispersion prepared in (2) to the mixture prepared in (1) and emulsify it.

[0074] [Emulsion stability] The emulsification stability of each prepared oil-in-water emulsion composition was evaluated according to the following evaluation criteria. The prepared oil-in-water emulsion compositions were filled into tubes and allowed to stand at room temperature for one day. The appearance was then visually observed on the second day. If emulsification was disrupted, oil seepage would be observed.

[0075] Furthermore, in the following evaluation, "phase inversion" refers to the change from oil-in-water (O / W) to water-in-oil (W / O).

[0076] (Evaluation criteria) A: The appearance is uniform, with no oil seepage.

[0077] B: Oil seepage can be observed.

[0078] C: Phase inversion occurs during the preparation of oil-in-water emulsion compositions.

[0079] The emulsification stability evaluation results of the oil-in-water emulsion compositions of Examples 1-4 and Comparative Examples 1-8 are shown in Tables 1-3. Oil-in-water emulsion compositions evaluated as "A" in the above evaluation criteria are deemed suitable for implementation in this invention.

[0080] Table 1 Table 2 Table 3 Examples 1-4 contain all of components (A)-(C), and their oil-in-water emulsion compositions exhibit good emulsification stability.

[0081] Comparative Examples 1 and 2, due to the absence of acrylamide thickeners as component (C), resulted in emulsification instability and oil seepage was observed.

[0082] The inorganic powder contained in Comparative Examples 3 to 5 was not the inorganic powder treated with monoalkyl phosphate of component (A). Therefore, the inorganic powder could not exist stably in the oil. Oil seepage was observed in Comparative Example 3, and phase inversion occurred in Comparative Examples 4 and 5. The oil-in-water emulsion composition could not be prepared.

[0083] Comparative Examples 6-8 were not composed of polyoxyethylene hydrogenated castor oil containing component (B), resulting in unstable emulsions. Comparative Examples 6 and 7 underwent phase inversion and failed to form an oil-in-water emulsion composition. Oil exudation was observed in Comparative Example 8.

[0084] Furthermore, the treatment agents used in the inorganic powders "silica-coated titanium dioxide treated with cetyl phosphate," "titanium dioxide treated with Al hydroxide and stearic acid," and "titanium dioxide treated with Al hydroxide and hydrogenated polymethylsiloxane" all have high safety for human use. Moreover, neither "silica-coated titanium dioxide treated with cetyl phosphate" nor "titanium dioxide treated with Al hydroxide and stearic acid" are microplastics, thus having a low environmental impact.

[0085] However, since "titanium dioxide treated with Al hydroxide and stearic acid" and "titanium dioxide treated with Al hydroxide and hydrogenated polymethylsiloxane" are not inorganic powders treated with monoalkyl phosphate esters, they cannot exist stably in oil, and the emulsification stability of the oil-in-water emulsion compositions of Comparative Examples 3 and 4 becomes worse.

[0086] The above demonstrates that the oil-in-water emulsion composition conforming to the present invention can provide an oil-in-water emulsion composition with high safety and good emulsification stability.

[0087] Furthermore, it is demonstrated that, according to the present invention, it is possible to obtain an oil-in-water emulsion composition with low environmental impact.

[0088] As an example of the present invention, the following can be listed: <1> An oil-in-water emulsion composition comprising: (A) Inorganic powder treated with monoalkyl phosphate esters; (B) Polyoxyethylene hydrogenated castor oil; and (C) Acrylamide thickeners.

[0089] <2> As mentioned above <1> The oil-in-water emulsion composition wherein the monoalkyl phosphate ester includes cetyl phosphate ester.

[0090] <3> As mentioned above <1> or <2> The water-in-oil emulsion composition wherein the inorganic powder is an inorganic powder with a silica coating.

[0091] <4> As mentioned above <1> to <3> The oil-in-water emulsion composition according to any one of the following methods, wherein the inorganic powder is titanium dioxide powder.

[0092] <5> As mentioned above <1> to <4> The water-in-oil emulsion composition according to any one of the following, wherein the average number of ethylene oxide addition moles in the (B) polyoxyethylene hydrogenated castor oil is more than 50 moles and less than 100 moles.

[0093] According to the above <1> to <5> The oil-in-water emulsion composition described in any one of these embodiments can solve the existing problems and achieve the objectives of this invention.

[0094] This application claims priority based on Japanese Patent Application No. 2023-223525 filed with the Japan Patent Office on December 28, 2023, and invokes all the contents set forth in the aforementioned application.

Claims

1. An oil-in-water emulsion composition, comprising... (A) Inorganic powder treated with monoalkyl phosphate esters, (B) Polyoxyethylene hydrogenated castor oil, and (C) Acrylamide thickener.

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

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

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

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

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