Water-in-oil type external composition

Abstract

To provide a water-in-oil type external composition with excellent applicability.SOLUTION: A water-in-oil type external composition is prepared containing: (A) two or more types of film-forming agents containing at least trimethylsiloxysilicate, the film-forming agent being selected from the group consisting of silicone resins, acrylic-silicone graft copolymers, fluorine-modified silicone resins, vinylpyrrolidone-based film-forming agents, and oxazoline-modified silicones; (B) a metal oxide; (C) an ultraviolet absorber; and (D) a thickener. When applying the water-in-oil type external composition, the user can feel the thickness with their fingers, so they can control the application force to maintain a uniform thickness, and they can grasp the area that has been applied, so they can prevent areas from being left unapplied. The fact that the composition has been applied uniformly can be felt by the feeling of the applied film being formed, and can also be felt by the fact that the applied area has no uneven color.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a water-in-oil type external composition. [Background technology]

[0002] In various situations in daily life, in order to protect the human body from harmful rays such as ultraviolet rays, attempts have been made to incorporate ultraviolet ray protection agents into topical compositions. When incorporating ultraviolet ray protection agents, there have been many difficulties in realizing topical compositions that are stable and comfortable to use. If the topical composition applied to the surface of the human body is uneven, there will be areas where the ultraviolet ray protection ability cannot be effectively exerted, and the human body will be adversely affected by rays such as ultraviolet rays. In daily life, topical compositions applied to the surface of the human body are easily lost due to sweat, rainwater, sebum, rubbing of clothes, etc. There is a demand for topical compositions that exhibit high ultraviolet ray protection ability throughout the day.

[0003] Attempts have been made to provide a sunscreen cosmetic that contains a wax with a melting point of 55° C. or higher, a (meth)acrylic silicone resin, and an ultraviolet blocking agent, and that has good skin comfort and abrasion resistance (Patent Document 1), but there is still room for improvement in terms of usability and abrasion resistance. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-054820 Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to provide a water-in-oil type external composition that has excellent applicability. [Means for solving the problem]

[0006] The present inventors have discovered that a water-in-oil type topical composition containing (A) two or more film-forming agents selected from the group consisting of silicone resins, acrylic-silicone graft copolymers, fluorine-modified silicone resins, vinylpyrrolidone-based film-forming agents, and oxazoline-modified silicones, (B) a metal oxide, (C) an ultraviolet absorber, and (D) a thickener, wherein component (A) contains at least trimethylsiloxysilicate, has excellent application properties.

[0007] The present invention has been completed based on the above findings, and provides the following water-in-oil type external composition.

[0008] That is, the present invention provides [1] (A) two or more types of film-forming agents containing at least trimethylsiloxysilicate, the film-forming agent being selected from the group consisting of silicone resins, acrylic-silicone graft copolymers, fluorine-modified silicone resins, vinylpyrrolidone-based film-forming agents, and oxazoline-modified silicones; (B) a metal oxide, (C) an ultraviolet absorber, and (D) Thickener a water-in-oil type external composition comprising: [2] The water-in-oil type topical composition according to [1], wherein the total content of (A) trimethylsiloxysilicate is 0.1 to 10 mass%; [3] The water-in-oil type topical composition according to [1] or [2], wherein the total content of the film-forming agent (A) is 0.1 to 12 mass%; [4] The water-in-oil type topical composition according to any one of [1] to [3], containing 0.01 to 0.99 parts by mass of (A) trimethylsiloxysilicate per 1 part by mass of two or more types of film-forming agents selected from the group consisting of (A) silicone resins, acrylic-silicone graft copolymers, fluorine-modified silicone resins, vinylpyrrolidone-based film-forming agents, and oxazoline-modified silicones; [5] The water-in-oil type topical composition according to any one of [1] to [4], wherein the (A) film-forming agent is at least one selected from the group consisting of trimethylsiloxysilicate, trimethylsiloxysilicate, polyalkylsilsesquioxane (polypropylsilsesquioxane), phenylpropyldimethylsiloxysilicate, (acrylates / dimethicone) copolymer, (alkyl acrylate / dimethicone) copolymer, (acrylates / polytrimethylsiloxy methacrylate) copolymer, (trimethylsiloxysilicate / dimethiconol) crosspolymer, trifluoroalkyldimethylsiloxytrimethylsiloxysilicate, (vinylpyrrolidone / hexadecene) copolymer, (eicosene / vinylpyrrolidone) copolymer, tricontanyl PVP, and poly(N-acylalkyleneimine)-modified silicone; [6] (B) The water-in-oil type topical composition according to any one of [1] to [5], wherein the metal oxide is at least one selected from the group consisting of titanium oxide, zinc oxide, yellow iron oxide, black iron oxide, red iron oxide, cerium oxide, and zirconium oxide; [7] (B) The water-in-oil type topical composition according to any one of [1] to [6], wherein the metal oxide has been subjected to a hydrophobizing treatment; [8] (B) The water-in-oil type topical composition according to any one of [1] to [7], wherein the average particle size of the metal oxide is 1 to 500 nm; [9] (B) The water-in-oil type topical composition according to any one of [1] to [8], wherein the content of the metal oxide is 1.0 to 20 mass%;

[10] A water-in-oil type topical composition according to any one of [1] to [9], containing 5 to 15 parts by mass of (B) a metal oxide per 1 part by mass of (A) one or more film-forming agents selected from the group consisting of silicone resins, acrylic-silicone graft copolymers, fluorine-modified silicone resins, vinylpyrrolidone-based film-forming agents, and oxazoline-modified silicones;

[11] (C) The water-in-oil type topical composition according to any one of [1] to

[10] , wherein the ultraviolet absorber is at least one selected from the group consisting of benzoic acid derivatives, salicylic acid derivatives, cinnamic acid derivatives, dibenzoylmethane derivatives, β,β-diphenylacrylate derivatives, benzophenone derivatives, benzylidene camphor derivatives, phenylbenzimidazole derivatives, triazine derivatives, phenylbenzotriazole derivatives, anthranil derivatives, imidazoline derivatives, benzalmalonate derivatives, and 4,4-diarylbutadiene derivatives;

[12] (C) the water-in-oil type topical composition according to any one of [1] to

[11] , wherein the content of the ultraviolet absorber is 2 to 50 mass%;

[13] The water-in-oil type topical composition according to any one of [1] to

[12] , wherein (D) the thickener is one or more selected from the group consisting of dextrin fatty acid esters, inulin fatty acid esters, oils and fats, and organically modified clay minerals;

[14] (D) the water-in-oil type topical composition according to any one of [1] to

[13] , wherein the content of the thickening agent is 0.1 to 5 mass%;

[15] The water-in-oil type topical composition according to any one of [1] to

[11] , containing 0.8 to 40 parts by mass of (A) a film-forming agent per 1 part by mass of (C) an ultraviolet absorber;

[16] The medium-sized oil composition for external use according to any one of [1] to

[15] , further comprising an ascorbic acid derivative;

[17] (C) A water-in-oil type topical composition containing an ultraviolet absorber, A method for improving the applicability of a water-in-oil type topical composition by blending (B) a metal oxide, (D) a thickener, and (A) two or more types of film-forming agents containing at least trimethylsiloxysilicate, the film-forming agents being selected from the group consisting of silicone resins, acrylic-silicone graft copolymers, fluorine-modified silicone resins, vinylpyrrolidone film-forming agents, and oxazoline-modified silicones; etc. Effect of the Invention

[0009] The water-in-oil type topical composition of the present invention contains (A) two or more film-forming agents selected from the group consisting of silicone resins, acrylic-silicone graft copolymers, fluorine-modified silicone resins, vinylpyrrolidone film-forming agents, and oxazoline-modified silicones, (B) a metal oxide, (C) an ultraviolet absorber, and (D) a thickener, and since (A) the film-forming agent is two or more types including at least trimethylsiloxysilicate, it has improved applicability. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, the embodiment for carrying out the present invention will be described in detail. However, the present invention is not limited to the following embodiment. In this specification, the term "salt" is not particularly limited as long as it is medicamentarily, pharmacologically, or physiologically acceptable. Specifically, there are basic salts such as salts with inorganic bases such as alkali metal salts, alkaline earth metal salts, and typical metal salts, and salts with organic bases. "Salt" includes solvates and hydrates of salts. In this specification, polyethylene glycol is also abbreviated as PEG, polypropylene glycol as PPG, ethylene oxide as EO, propylene oxide as PO, polyoxyethylene as POE, polyoxypropylene as POP, and vinylpyrrolidone as VP.

[0011] [1. Water-in-oil external composition] The water-in-oil type topical composition according to this embodiment is a water-in-oil type topical composition containing (A) two or more types of film-forming agents selected from the group consisting of silicone resins, acrylic-silicone graft copolymers, fluorine-modified silicone resins, vinylpyrrolidone-based film-forming agents, and oxazoline-modified silicones (also referred to simply as "component (A)"), (B) a metal oxide (also referred to simply as "component (B)"), (C) an ultraviolet absorber (also referred to simply as "component (C)"), and (D) a thickener (also referred to simply as "component (D)"), wherein the (A) film-forming agent is two or more types including at least trimethylsiloxysilicate.

[0012] <(A) Film-forming agent> The film-forming agent (A) according to this embodiment is not particularly limited as long as it exhibits the effects of the present invention, but a film-forming agent that does not have a glass transition point or has a glass transition point in the range of 0 to 500°C is preferably used. The film-forming agent may be used alone or in combination of two or more. There is no particular limitation as long as it is used in cosmetics, medicines, and foods. Commercially available products can be used. Examples of the component (A) include silicone resins, acrylic-silicone graft copolymers, fluorine-modified silicone resins, vinylpyrrolidone film-forming agents, and oxazoline-modified silicones. Specific examples include silicone resins such as trimethylsiloxysilicate, polyalkylsilsesquioxane (polypropylsilsesquioxane), and phenylpropyldimethylsiloxysilicate; acrylic-silicone graft copolymers such as (acrylates / dimethicone) copolymer, (alkyl acrylate / dimethicone) copolymer, (acrylates / polytrimethylsiloxy methacrylate) copolymer, and (trimethylsiloxysilicate / dimethiconol) crosspolymer; fluorine-based film-forming agents such as trifluoroalkyldimethylsiloxytrimethylsiloxysilicate; hydrophobic (oil-soluble) vinylpyrrolidone-based film-forming agents such as (vinylpyrrolidone / hexadecene) copolymer, (eicosene / vinylpyrrolidone) copolymer, and tricontanyl PVP; and oxazoline-modified silicones such as poly(N-acylalkyleneimine)-modified silicones.

[0013] The content of the (A) component in the water-in-oil type external composition according to this embodiment is not particularly limited, and is appropriately set according to the type of the (A) component, the type and content of other blended components, the use of the water-in-oil type external composition, the formulation form, etc. The content of the (A) component may be, for example, 0.1 to 12% by mass, or 0.1 to 10% by mass, preferably 0.3 to 9% by mass, more preferably 0.5 to 8% by mass, even more preferably 0.8 to 7% by mass, even more preferably 1.0 to 6% by mass, particularly preferably 1.0 to 5.5% by mass, and most preferably 1.0 to 5% by mass, based on the total amount of the water-in-oil type external composition, from the viewpoint of more significantly exhibiting the effects of the present invention.

[0014] In the water-in-oil type external composition according to the present embodiment, it is preferable to contain two or more kinds of (A) components. When one of them is trimethylsiloxysilicate, the content of trimethylsiloxysilicate is not particularly limited, and from the viewpoint of more significantly exhibiting the effects of the present invention, for example, based on the total amount of the water-in-oil type external composition, the total content of (A) components may be 0.01-10% by mass, preferably 0.05-9% by mass, more preferably 0.1-8% by mass, even more preferably 0.2-7% by mass, even more preferably 0.3-6% by mass, particularly preferably 0.4-5.5% by mass, and most preferably 0.5-5% by mass.

[0015] The content ratio of (A) trimethylsiloxysilicate relative to 1 part by mass of two or more types of film-forming agents selected from the group consisting of (A) silicone resin, acrylic-silicone graft copolymer, fluorine-modified silicone resin, vinylpyrrolidone-based film-forming agent, and oxazoline-modified silicone in the water-in-oil type topical composition according to this embodiment is not particularly limited, but from the viewpoint of more significantly exhibiting the effects of the present invention, the total content of (A) trimethylsiloxysilicate relative to 1 part by mass of the total content of two or more types of film-forming agents selected from the group consisting of (A) silicone resin, acrylic-silicone graft copolymer, fluorine-modified silicone resin, vinylpyrrolidone-based film-forming agent, and oxazoline-modified silicone contained in the water-in-oil type topical composition according to this embodiment is 0.01 parts by mass or more, 0.05 parts by mass or more, 0.1 parts by mass or more, 0.2 parts by mass or more, or 0.3 parts by mass or more, and is 0.99 parts by mass or less, 0.92 parts by mass or less, 0.88 parts by mass or less, 0.85 parts by mass or less, or 0.8 parts by mass or less.

[0016] <(B) Metal oxide> The (B) metal oxide in the water-in-oil type external composition according to this embodiment may be used alone or in combination of two or more. There is no particular limitation as long as it is used in cosmetics, medicines, and foods. Commercially available products can be used. In order to more significantly exhibit the effects of the present invention, the component (B) may include titanium oxide, zinc oxide, yellow iron oxide, black iron oxide, red iron oxide, cerium oxide, zirconium oxide, iron oxide, and chromium oxide. Titanium oxide, zinc oxide, yellow iron oxide, black iron oxide, and red iron oxide are more preferred, and titanium oxide and zinc oxide are even more preferred. Fine particle titanium oxide and fine particle zinc oxide are preferred. The shape of the particles of the component (B) may be any of spherical, plate-like, spindle-like, and needle-like. Titanium oxide may be either rutile or anatase type, and rutile type is preferred.

[0017] The metal oxide (B) in the water-in-oil type external composition according to the present embodiment may be hydrophobized, and the hydrophobization treatment may be performed using one type alone or two or more types in combination. The metal oxide may be coated with silica before the hydrophobization treatment. From the viewpoint of more prominently exerting the effects of the present invention, examples of hydrophobic treatments include silicone treatment; alkylalkoxysilane treatment; fatty acid treatment; fluorine-containing compound treatment using perfluoroalkyl phosphate ester, perfluoroalcohol, etc.; amino acid treatment using N-acylglutamic acid, etc.; lecithin treatment; metal soap treatment; alkyl phosphate ester treatment; and ASI treatment using N-acylamino acid metal salt (sodium lauroyl aspartate), zinc chloride, and alkoxytitanium alkylate (isopropyl titanium triisostearate). Silicone treatment is preferred, and examples of surface treatment agents used in silicone treatment include methylpolysiloxane, dimethylpolysiloxane (dimethicone), methylphenylpolysiloxane, methylhydrogenpolysiloxane, dimethylsiloxane / methylhydrogensiloxane copolymer (hydrogen dimethicone), methylcyclopolysiloxane, dodecamethylcyclohexasiloxane, tetradecamethylhexasiloxane, dimethylsiloxane / methyl(polyoxyethylene)siloxane / methyl(polyoxypropylene)siloxane copolymer, dimethylsiloxane / methyl(polyoxyethylene)siloxane copolymer, dimethylsiloxane / methyl(polyoxypropylene)siloxane copolymer, dimethylsiloxane / methylcetyloxysiloxane copolymer, dimethylsiloxane / methylstearoxysiloxane copolymer, and (alkyl acrylate / dimethicone) copolymer. From the viewpoint of more significantly exhibiting the effects of the present invention, dimethylpolysiloxane (dimethicone), methylhydrogenpolysiloxane, and dimethylsiloxane / methylhydrogensiloxane copolymer (hydrogen dimethicone) are preferred.

[0018] The content of the (B) component in the water-in-oil type external composition according to this embodiment is not particularly limited, and is appropriately set according to the type of the (B) component, the type and content of other blended components, the use of the water-in-oil type external composition, the formulation form, etc. The content of the (B) component is, for example, preferably 8% by mass or more, more preferably 9% by mass or more, even more preferably 10% by mass or more, and even more preferably 11% by mass or more, based on the total amount of the water-in-oil type external composition, from the viewpoint of more prominently exhibiting the effects of the present invention. The content of the (B) component is preferably 45% by mass or less, more preferably 40% by mass or less, even more preferably 35% by mass or less, and even more preferably 30% by mass or less, based on the total amount of the water-in-oil type external composition.

[0019] The content ratio of the film-forming agent (A) per 1 part by mass of the metal oxide (B) in the water-in-oil type topical composition of this embodiment is not particularly limited; however, from the viewpoint of more prominently exhibiting the effects of the present invention, for example, the total content of the component (A) per 1 part by mass of the total content of the component (B) contained in the water-in-oil type topical composition of this embodiment is preferably 0.003 to 1.5 parts by mass, more preferably 0.01 to 1.5 parts by mass, even more preferably 0.05 to 1.0 parts by mass, even more preferably 0.08 to 0.8 parts by mass, and particularly preferably 0.1 to 0.5 parts by mass.

[0020] <(C) Ultraviolet absorber> The (C) ultraviolet absorbent in the water-in-oil type external composition according to the present embodiment may be used alone or in combination of two or more. There is no particular limitation as long as it is used in cosmetics, medicines, and foods. Commercially available products can be used. Examples of the component (C), from the viewpoint of more significantly exhibiting the effects of the present invention, include ultraviolet absorbers such as benzoic acid derivatives, salicylic acid derivatives, cinnamic acid derivatives, dibenzoylmethane derivatives, β,β-diphenylacrylate derivatives, benzophenone derivatives, benzylidene camphor derivatives, phenylbenzimidazole derivatives, triazine derivatives, phenylbenzotriazole derivatives, anthranil derivatives, imidazoline derivatives, benzalmalonate derivatives, and 4,4-diarylbutadiene derivatives. Preferred examples thereof include 2-ethylhexyl paramethoxycinnamate, dimethicodiethyl benzalmalonate, octocrylene, diethylaminohydroxybenzoyl benzoic acid hexyl ester, paraaminobenzoic acid, 2,4-bis{[4-(2-ethylhexyloxy)-2-hydroxy]-phenyl}-6-(4-methoxyphenyl)-1,3,5-triazine, 2,4,6-tris[4-(2-ethylhexyloxycarbonyl)anilino]-1,3,5-triazine, 4-tert-butyl-4'-methoxydibenzoylmethane, homomenthyl salicylate, ethylhexyl salicylate, octyl salicylate, oxybenzone, and dihydroxydimethoxybenzophenone.

[0021] The content of the (C) component in the water-in-oil type external composition according to this embodiment is not particularly limited, and is appropriately set according to the type of the (C) component, the type and content of other blended components, the use and formulation form of the water-in-oil type external composition, etc. From the viewpoint of more prominently exhibiting the effects of the present invention, the content of the (C) component is, for example, preferably 0.0001% by mass or more, more preferably 0.0005% by mass or more, even more preferably 0.001% by mass or more, and even more preferably 0.005% by mass or more, based on the total amount of the water-in-oil type external composition. In addition, the content of the (B) component is preferably 50% by mass or less, more preferably 40% by mass or less, even more preferably 30% by mass or less, and even more preferably 20% by mass or less, based on the total amount of the oil-in-water type external composition.

[0022] <(D) Thickener> The thickener (C) in the water-in-oil type external composition according to the present embodiment may be used alone or in combination of two or more. There is no particular limitation as long as it is used in cosmetics, medicines, and foods. Commercially available products can be used. Examples of component (D) include oil-soluble thickeners from the viewpoint of more prominently exhibiting the effects of the present invention. Specific examples include dextrin fatty acid esters such as dextrin palmitate, dextrin (palmitate / hexyldecanoate), dextrin (palmitate / ethylhexanoate), dextrin myristate, and dextrin isostearate; inulin fatty acid esters such as inulin stearate, inulin palmitate, and inulin myristate; fats and oils such as tricapric acid, trilauric acid, trimyristic acid, tripalmitic acid, tristearic acid, triarachidic acid, and tribehenic acid (tribehenin); dimethylstearyl ammonium hectorite, didimethyldistearyl Examples of the organically modified clay minerals include ammonium bentonite, benzyl dimethylstearyl ammonium hectorite, and distearyl dimethyl ammonium chloride-treated magnesium aluminum silicate; long-chain hydroxy fatty acids such as 12-hydroxystearic acid; fatty acid metal salts such as zinc stearate, aluminum stearate, magnesium stearate, zinc palmitate, aluminum palmitate, zinc myristate, and magnesium myristate; hydrogenated (styrene / isoprene) copolymers; hydrogenated polyisobutene; and surface-lipophilized fine particles such as silylated silica. As the component (D), water-soluble thickeners can be mentioned from the viewpoint of more prominently exhibiting the effects of the present invention. Specific examples of water-soluble thickeners include natural water-soluble polymers such as gum arabic, tragacanth gum, galactan, guar gum, carob gum, karaya gum, carrageenan, pectin, agar, quince seed, algae colloid (cassou extract), starch (rice, corn, potato, wheat), xanthan gum, dextran, succinoglucan, pullulan, collagen, casein, albumin, and gelatin; carboxymethyl starch, methylhydroxypropyl starch, methylcellulose, nitrocellulose, ethylcellulose, methylhydroxypropylcellulose, hydroxyethylcellulose, sodium cellulose sulfate, hydroxypropylcellulose, sodium carboxymethylcellulose, crystalline cellulose, cellulose, etc. Examples of water-soluble polymers include semi-synthetic water-soluble polymers such as cellulose powder, sodium alginate, propylene glycol alginate, and hydroxypropyl methylcellulose stearoxy ether; and synthetic water-soluble polymers such as polyvinyl alcohol, polyvinyl methyl ether, polyvinylpyrrolidone, carboxyvinyl polymer (carbomer), polyoxyethylene-polyoxypropylene copolymer, sodium polyacrylate, polyethyl acrylate, polyacrylamide, acrylic acid / alkyl methacrylate copolymer, (acrylates / alkyl acrylate (C10-30)) crosspolymer (product name "Pemulen TR-1"), (ammonium acryloyldimethyltaurate / VP) copolymer, polyethyleneimine, and cationic polymers.

[0023] The content of the (D) component in the water-in-oil type external composition according to this embodiment is not particularly limited, and is appropriately set according to the type of the (D) component, the type and content of other blended components, the use and formulation form of the water-in-oil type external composition, etc. From the viewpoint of more prominently exhibiting the effects of the present invention, the content of the (D) component is, for example, preferably 0.01% by mass or more, more preferably 0.05% by mass or more, even more preferably 0.1% by mass or more, and even more preferably 0.2% by mass or more, based on the total amount of the water-in-oil type external composition. In addition, the content of the (D) component is preferably 30% by mass or less, more preferably 20% by mass or less, even more preferably 15% by mass or less, and even more preferably 12% by mass or less, based on the total amount of the water-in-oil type external composition.

[0024] The water-in-oil type external composition according to this embodiment may contain one or more aqueous solvents, as long as the effects of the present invention are not hindered. The aqueous solvent is preferably water or a polyhydric alcohol. From the viewpoint of more significantly achieving the effects of the present invention, the content of the aqueous solvent is, for example, preferably 1 to 70% by mass, more preferably 5 to 70% by mass, more preferably 15 to 60% by mass, and even more preferably 20 to 50% by mass, based on the total amount of the water-in-oil type external composition. From the viewpoint of more prominently exhibiting the effects of the present invention, the water content is, for example, preferably 1 to 60 mass%, more preferably 3 to 60 mass%, even more preferably 5 to 50 mass%, and still more preferably 8 to 45 mass%, based on the total amount of the water-in-oil type topical composition.

[0025] The water-in-oil type external composition according to the present embodiment may contain known components used in cosmetics, quasi-drugs and pharmaceuticals, as long as they do not impede the effects of the present invention. In addition to the above (A) to (D) components, for example, antioxidants, functional brightening components, moisturizing agents, anti-inflammatory components, antibacterial agents, repellent components, vitamins, amino acids, biological extracts, and various pharmacologically active components and physiologically active components may be combined and contained in appropriate amounts. In addition, additives such as surfactants, preservatives, pH adjusters, chelating agents, stabilizers, buffers, lipophilic thickeners, gelling agents, irritation reducers, preservatives, colorants, fragrances, minerals, etc. may be added alone or in combination of two or more.

[0026] The water-in-oil type external composition according to the present embodiment can be prepared by, for example, mixing and stirring each component according to a conventional method. The fact that the composition is a water-in-oil type composition can be confirmed by a known method. Although not limited to this, it can be confirmed by putting the composition into water and observing whether it is not dissolved in water (not mixed in water).

[0027] The water-in-oil type external composition according to the present embodiment is not particularly limited in the form of the drug, and can take the form known as cosmetics, quasi-drugs, or pharmaceuticals. Among such known forms, for example, liquids, suspensions, emulsions, creams, gels, liniments, ointments, lotions, aerosols, powders, poultices, sheets such as nonwoven fabrics impregnated with drug solutions, and sticks such as lipsticks can be mentioned. Among them, liquids, suspensions, emulsions, creams, gels, and lotions are preferred in terms of their good usability. They may also be used in the form of basic cosmetics such as milky lotions, creams, body lotions, body creams, and sunscreens, makeup bases, BB creams, CC creams, foundations, lipsticks, blushers, eye makeup, face powders, manicures, pedicures, and other make-up cosmetics, or functional external preparations such as insect repellents, anti-pollution external preparations, and hair growth agents, preferably sunscreen cosmetics.

[0028] The area to which the water-in-oil type topical composition according to this embodiment is applied is not particularly limited, and it can be applied to any of the face, arms, hands, legs, neck, scalp, hair, etc.

[0029] 2. Improving the stability of water-in-oil topical compositions The stability of the water-in-oil type topical composition containing (B) metal oxide, (C) ultraviolet absorber and (D) thickener according to this embodiment is improved by coexisting (A) two or more types of film-forming agents containing at least trimethylsiloxysilicate. Therefore, as one embodiment of the present invention, a method for improving the stability of the water-in-oil type topical composition containing (B) metal oxide, (C) ultraviolet absorber and (D) thickener, comprising coexisting (A) two or more types of film-forming agents containing at least trimethylsiloxysilicate, is provided. The improvement of stability means that the surface of the composition after preparation is smooth, there is no oil syneresis, no uneven emulsification, no separation, and no pigment aggregation. It means that the composition maintains a favorable stability even after storage at high temperatures.

[0030] In this embodiment, the type and content etc. of the (A) component, the type and content etc. of the (B) component, the type and content etc. of the (C) component, the type and content etc. of the (D) component, the type and content etc. of other components, the formulation form and uses etc. of the water-in-oil type topical composition are as described in [1. Water-in-oil type topical composition].

[0031] [3. Improvement of uniformity of coating film of water-in-oil type topical composition] The water-in-oil type topical composition according to this embodiment, which contains (B) a metal oxide, (C) an ultraviolet absorber, and (D) a thickener, is improved in uniformity of the coating film by allowing (A) at least two types of film-forming agents containing at least trimethylsiloxysilicate to coexist in the water-in-oil type topical composition containing (B) a metal oxide, (C) an ultraviolet absorber, and (D) a thickener, to coexist with (A) at least two types of film-forming agents containing at least trimethylsiloxysilicate. The uniformity of the coating film means that when the water-in-oil type topical composition is applied, the thickness of the composition can be uniformly spread, and the composition can be quickly adapted to the application area to form a smooth coating film, which is a preferable feeling when using the water-in-oil type topical composition.

[0032] In this embodiment, the type and content etc. of the (A) component, the type and content etc. of the (B) component, the type and content etc. of the (C) component, the type and content etc. of the (D) component, the type and content etc. of other components, the formulation form and uses etc. of the water-in-oil type topical composition are as described in [1. Water-in-oil type topical composition]. EXAMPLES

[0033] The present invention will be specifically described below based on test examples, but the present invention is not limited to these. In the following examples, the blending amounts are shown in mass %.

[0034] [Test Example 1] Appearance evaluation immediately after preparation A water-in-oil type external composition having the composition shown in Table 1 below was prepared according to a conventional method and allowed to stand at room temperature. After allowing the composition to stand at room temperature overnight, the appearance was observed and evaluated according to the evaluation criteria.

[0035] (Appearance evaluation immediately after preparation) "Evaluation Criteria" A: The surface of the formulation is smooth and does not separate from the surface. No pigment aggregation is observed. B: The surface of the preparation is smooth, with slight separation observed on the surface. No pigment aggregation is observed. C: The surface of the preparation is smooth, with slight separation observed on the surface. Pigment aggregation observed. D: The surface of the preparation is not smooth, and syneresis is observed on the surface. Pigment aggregation is observed.

[0036] [Table 1]

[0037] In Comparative Example 1-1, no oil floating or pigment aggregation was observed, but in Comparative Examples 1-2 and 1-3, which contained a silicone-modified polysaccharide compound or silicone-modified polynorbornene, syneresis and pigment aggregation were observed, and it was found that these components reduce the stability of the composition. In the examples in which an acrylic-silicone graft copolymer, which is a film-forming agent, was contained, no syneresis or pigment aggregation was observed, and the stability was good.

[0038] [Test Example 2] Evaluation of storage stability A water-in-oil type external composition having the composition shown in Table 2 below was prepared according to a conventional method. The composition was filled into a 50 mL glass screw-cap bottle and left in a thermostatic bath at 50°C for one month. The bottle was then left at room temperature for 12 hours, and after confirming that the temperature of the composition had reached room temperature, the appearance of the composition was visually observed and evaluated according to the evaluation criteria. The results are shown in Table 2.

[0039] (Appearance evaluation after storage at 50℃ for 1 month) "Evaluation Criteria" A: The surface of the formulation is smooth and no separation is observed on the surface. No pigment aggregation is observed. B: The surface of the preparation is smooth, with slight separation observed on the surface. No pigment aggregation is observed. C: The surface of the preparation is smooth, with slight separation observed on the surface. Pigment aggregation observed. D: The surface of the preparation is not smooth, and there is some segregation on the surface. Pigment aggregation is observed.

[0040] [Table 2]

[0041] In Comparative Example 2-1, syneresis or pigment aggregation was not observed, but in Comparative Examples 2-2 and 2-3, which contained a silicone-modified polysaccharide compound or silicone-modified polynorbornene, syneresis or pigment aggregation was observed, and it was found that these components reduce the stability of the composition. In the examples in which an acrylic-silicone graft copolymer, which is a film-forming agent, was contained, syneresis or pigment aggregation was not observed, and the stability was good.

[0042] [Test Example 3] Evaluation of coating film uniformity A water-in-oil type topical composition having the composition shown in Table 3 below was prepared according to a conventional method. Three expert panelists evaluated the feel of the fingers when spreading the composition over the entire face, the feel of the applied film one minute after the start of application (the feeling that a coating film has been formed), and the presence or absence of color unevenness when the composition blended into the skin (uniformity of coloring). If no feeling of an applied film was felt one minute after the start of application, the panelists continued spreading the composition until the feeling of an applied film was felt. The results of the discussion by the three panelists are shown in Table 3.

[0043] "Evaluation Criteria" A: The water-in-oil type topical composition can be spread while feeling its thickness on the finger, and one minute after starting application, the formation of a coating film is clearly felt. There is no color unevenness. B: The water-in-oil type topical composition can be spread while feeling its thickness on the finger, and one minute after starting application, a coating film is slightly felt to have formed. There is no color unevenness. C: The thickness of the water-in-oil type topical composition is not felt on the fingers when spreading, and no coating film is felt to have formed 1 minute after starting application. There is some color unevenness. D: The thickness of the water-in-oil type topical composition is not felt on the fingers when spreading, and no coating film is felt to have formed 1 minute after starting application. There is color unevenness.

[0044] [Table 3]

[0045] In the comparative example, the thickness of the water-in-oil type topical composition cannot be felt on the finger when spreading, so it is considered that the panelists could not recognize whether the water-in-oil type topical composition was applied evenly or not. In the example, the thickness of the water-in-oil type topical composition can be felt on the finger when spreading, so it is considered that the panelists were able to control the application force to maintain a uniform thickness and were able to grasp the area that was spread, so that it was possible to prevent uncoated areas. In the comparative example, the formation of the coating film could not be felt 1 minute after the start of application, but in the example, the formation of the coating film could be felt 1 minute after the start of application. In the example, the panelists felt that the coating film was formed, which allowed the composition to be applied evenly, but in the comparative example, they were of the opinion that they could not tell whether the composition was applied evenly. Since the comparative example had color unevenness and the example did not have color unevenness, it was found that the coating film of the water-in-oil type topical composition in the comparative example was uneven, and the coating film of the water-in-oil type topical composition in the example was uniform and had high applicability. It was believed that the ability for the user to adjust the application so that a uniform coating film is formed, that there are no areas left uncoated, and that the coating film is formed at a moderate speed so that the user can feel the formation of the coating film and not damage the coating film with their fingers by spreading the coating too much, all contribute to the formation of a uniform coating film and result in a beautiful appearance without color unevenness.

[0046] An example of a prescription is shown below. Formulation example 1: Cream foundation (component) (mass%) Trimethylsiloxysilicate 0.5 (Acrylates / Dimethicone) Copolymer 0.8 Silicone / amino acid treated titanium dioxide 7.6 Silicone / Amino Acid Treated Yellow Iron Oxide 2.0 Silicone / amino acid treated red iron oxide 0.3 Silicone / amino acid treated black iron oxide 0.1 2-Ethylhexyl paramethoxycinnamate 4.0 Diethylamino hydroxybenzoyl hexyl benzoate 1.0 Dimethyl distearyl ammonium hectorite 1.0 Tribehenin 0.5 Sorbitan monostearate 1.0 Lauryl PEG-9 Polydimethylsiloxyethyl Dimethicone 3.0 Boron Nitride 3.0 Dimethicone 5.0 Cyclopentasiloxane remaining Lauryl Methicone 5.0 Tri(2-ethylhexyl) trimellitate 3.0 Di(2-ethylhexyl) succinate 4.0 Water 30.0 1,3-Butylene glycol 5.0 Phenoxyethanol 0.3

[0047] Formulation example 2: Liquid foundation (component) (mass%) Trimethylsiloxysilicate 2.5 (Acrylates / Dimethicone) Copolymer 2.0 Silicone / Amino acid treated titanium dioxide 5.0 Silicone / Amino Acid Treated Yellow Iron Oxide 1.25 Silicone / amino acid treated red iron oxide 0.15 Silicone / amino acid treated black iron oxide 0.01 2-Ethylhexyl paramethoxycinnamate 8.0 Diethylamino hydroxybenzoyl hexyl benzoate 2.0 Ethylhexyl triazone 1.5 Dimethyl distearyl ammonium hectorite 0.5 Dextrin (palmitic acid / ethylhexanoic acid) 0.5 PEG-9 Polydimethylsiloxyethyl Dimethicone 3.0 Cetyl PEG / PPG-10 / 1 Dimethicone 1.5 Silica 3.0 Silicone-treated talc 2.0 Dimethicone 10.0 Caprylyl Methicone 10.0 Tri(2-ethylhexyl) trimellitate 2.0 Isononyl isononanoate 5.0 Water 35.0 Glycerin 3.0 Phenoxyethanol 0.3

[0048] Formulation example 3: Makeup base (component) (mass%) Trimethylsiloxysilicate 1.0 (Acrylates / Dimethicone) Copolymer 0.4 Silicone / Amino Acid Treated Titanium Dioxide 3.0 Silicone / amino acid treated yellow iron oxide 0.25 Silicone / amino acid treated red iron oxide 0.15 Silicone / amino acid treated black iron oxide 0.01 2-Ethylhexyl paramethoxycinnamate 4.0 Diethylamino hydroxybenzoyl hexyl benzoate 1.0 Dimethyl distearyl ammonium hectorite 0.3 Dextrin (palmitic acid / ethylhexanoic acid) 0.8 PEG-9 Polydimethylsiloxyethyl Dimethicone 3.0 Silica 8.0 Silicone-treated talc 3.0 Dimethicone remaining amount Methylphenylpolysiloxane 5.0 Di(2-ethylhexyl) succinate 5.0 Water 25.0 1,3-Butylene glycol 5.0 Ethanol 5.0

Claims

1. (A) two or more types of film-forming agents containing at least trimethylsiloxysilicate, the film-forming agent being selected from the group consisting of silicone resins, acrylic-silicone graft copolymers, fluorine-modified silicone resins, vinylpyrrolidone film-forming agents, and oxazoline-modified silicones; (B) a metal oxide, (C) an ultraviolet absorber, and (D) Thickener A water-in-oil type external composition comprising:

2. The (A) film-forming agent is trimethylsiloxysilicate and One or more selected from the group consisting of polyalkylsilsesquioxane (polypropylsilsesquioxane), phenylpropyldimethylsiloxysilicate, (acrylates / dimethicone) copolymer, (alkyl acrylate / dimethicone) copolymer, (acrylates / polytrimethylsiloxy methacrylate) copolymer, and (trimethylsiloxysilicate / dimethiconol) crosspolymer. The water-in-oil type external composition according to claim 1,

3. 2. The water-in-oil type topical composition according to claim 1, comprising 0.01 to 0.99 parts by mass of trimethylsiloxysilicate (A) per part by mass of two or more film-forming agents selected from the group consisting of silicone resins, acrylic-silicone graft copolymers, fluorine-modified silicone resins, vinylpyrrolidone-based film-forming agents, and oxazoline-modified silicones.

4. 2. The water-in-oil type topical composition according to claim 1, wherein the metal oxide (B) is one or more selected from the group consisting of titanium oxide, zinc oxide, yellow iron oxide, black iron oxide, red iron oxide, cerium oxide, and zirconium oxide.

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