Water-in-oil emulsion cosmetics

Abstract

To provide a water-in-oil emulsified cosmetic preparation having an excellent sebum solidification effect.SOLUTION: A water-in-oil emulsified cosmetic preparation is used which includes zinc oxide and a metal salt selected from the group consisting of water-soluble aluminum compounds, water-soluble zirconium compounds, and zinc sulfonate compounds, wherein the metal salt is present in an aqueous phase.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a water-in-oil emulsion cosmetic comprising zinc oxide and a water-soluble aluminum compound. [Background technology]

[0002] Sebum secreted from the skin mixes with the components of makeup cosmetics and causes makeup to break down over time. When a large amount of sebum is secreted, the sebum floats on the surface of the face, causing the sebum to break down. As a countermeasure against the sebum to break down, it is known to incorporate powder containing zinc oxide or the like that solidifies sebum, thereby solidifying the sebum and suppressing the sebum to break down (for example, Patent Document 1). Consumers are highly conscious of preventing sebum-induced breakdown, and there is a demand for the development of cosmetics that can further prevent sebum-induced breakdown.

[0003] It is known that aluminum salts, like zinc oxide, are incorporated as astringents in pressed solid cosmetics (e.g., Patent Document 2), and that aluminum salts are incorporated in combination with zinc oxide into solid deodorant compositions (e.g., Patent Document 3). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2020-033274 A [Patent Document 2] Japanese Patent Application Publication No. 59-225106 [Patent Document 3] JP 2015-7005 A Summary of the Invention

[0005] The present inventors have surprisingly found that a water-in-oil emulsion cosmetic comprising a combination of zinc oxide and a specific metal salt, in which the specific metal salt is present in the aqueous phase, can provide a cosmetic that has an excellent sebum solidification effect and is capable of suppressing makeup from coming off. The present invention is based on these findings.

[0006] Therefore, the present invention discloses a water-in-oil emulsion cosmetic comprising zinc oxide and a specific metal salt, the specific metal salt being present in an aqueous phase.

[0007] According to the present invention, the following inventions are provided. (1) A water-in-oil emulsion cosmetic comprising zinc oxide and a metal salt selected from the group consisting of water-soluble aluminum compounds, water-soluble zirconium compounds, and zinc sulfonate compounds, wherein the metal salt is present in an aqueous phase. (2) The cosmetic preparation according to (1), wherein the metal salt is selected from the group consisting of aluminum chloride, aluminum sulfate, aluminum chlorohydrate, aluminum chlorohydrate allantoin, aluminum dihydroxyaluminum allantoin, aluminum bromohydroxyaluminum, aluminum acetate, aluminum lactate, aluminum zirconium chlorohydrate, zirconium chlorohydrate, aluminum potassium sulfate, and zinc paraphenolsulfonate. (3) The cosmetic preparation according to (1) or (2), wherein the metal salt is aluminum chlorohydrate or zinc paraphenolsulfonate. (4) The cosmetic preparation according to any one of (1) to (3), wherein the zinc oxide comprises hydrophobic zinc oxide. (5) The cosmetic preparation according to any one of (1) to (4), wherein the hydrophobic zinc oxide is zinc oxide that has been surface-treated with an alkylalkoxysilane or a fatty acid dextrin. (6) The cosmetic preparation according to (4) or (5), wherein the zinc oxide further comprises non-hydrophobic zinc oxide. (7) The cosmetic preparation according to (6), wherein the average aspect ratio of the non-hydrophobic zinc oxide is 4 or more. (8) The cosmetic preparation according to any one of (1) to (7), wherein the blending amount of the metal salt is 0.5 to 30 mass % based on the total amount of the metal salt and the zinc oxide.

[0008] The water-in-oil emulsion cosmetic composition according to the present invention has an excellent sebum solidification effect and can prevent makeup from coming off.

[0009] The present invention relates to a water-in-oil emulsion cosmetic (hereinafter also simply referred to as "cosmetic") comprising zinc oxide and a metal salt selected from the group consisting of water-soluble aluminum compounds, water-soluble zirconium compounds, and zinc sulfonate compounds, wherein the metal salt is present in an aqueous phase.

[0010] [Zinc oxide] The cosmetic according to the present invention contains zinc oxide. Zinc oxide can gel and fix free fatty acids contained in sebum. The zinc oxide contained in the present invention is not particularly limited as long as it is one that is usually used in cosmetics, and may be either hydrophobic zinc oxide or non-hydrophobic zinc oxide, but is preferably hydrophobic zinc oxide in order to improve dispersibility in oil. The zinc oxide is preferably present in the oil phase.

[0011] Hydrophobic zinc oxide is formed by hydrophobizing the surface of zinc oxide particles. By hydrophobizing the surface, water resistance and dispersibility in oil are improved. As a method of hydrophobizing the surface, the hydrophobizing treatment is preferably an alkylalkoxysilane treatment or a fatty acid dextrin treatment. Examples of alkylalkoxysilane include octyltriethoxysilane and octyltrimethoxysilane, and octyltriethoxysilane treatment is preferred. Examples of fatty acid dextrin treatment include palmitic acid dextrin treatment. More preferred are octyltriethoxysilane treatment or palmitic acid dextrin treatment. The hydrophobic zinc oxide may be a combination of two or more types.

[0012] The average particle size of the hydrophobic zinc oxide is preferably 20 to 60 nm, and more preferably 30 to 55 nm. Note that the average particle size in the present invention means the average primary particle size, and can be determined, for example, as the arithmetic mean of the long and short axes of the particles from image analysis using a transmission electron microscope. The particle shape of the hydrophobic zinc oxide is not particularly limited, and examples thereof include spherical, plate-like, and crushed shapes.

[0013] It is also preferred that the zinc oxide is a mixture of hydrophobic and non-hydrophobic zinc oxide. Non-hydrophobic zinc oxide refers to zinc oxide whose surface has not been subjected to a hydrophobic treatment, and is hydrophilic. The average particle size of the non-hydrophobic zinc oxide is not particularly limited, but is preferably 30 to 5,000 nm, and more preferably 50 to 4,000 nm. The particle shape of the non-hydrophobic zinc oxide is not particularly limited, but is preferably plate-like, more preferably hexagonal plate-like. The average aspect ratio of the non-hydrophobic zinc oxide is not particularly limited, but is preferably 4 or more. Here, in the present invention, the average aspect ratio represents (average particle size) / (average thickness). The average thickness can be determined, for example, from image analysis using a transmission electron microscope as the arithmetic mean of the thicknesses of 20 particles.

[0014] The blending amount of zinc oxide is preferably 4 to 15 mass %, and more preferably 6 to 13 mass %, based on the total amount of the cosmetic according to the present invention. The amount of hydrophobic zinc oxide blended is preferably 40 to 100% by mass, more preferably 60 to 95% by mass, and further preferably 80 to 95% by mass, based on the total amount of zinc oxide.

[0015] [Metal salts] The cosmetic preparation according to the present invention contains a metal salt (hereinafter, simply referred to as "metal salt") selected from the group consisting of water-soluble aluminum compounds, water-soluble zirconium compounds, and zinc sulfonate compounds in the aqueous phase. Without being bound by theory, it is believed that by combining the zinc oxide and the metal salt, the sebum solidification speed of the zinc oxide is further accelerated, and the metal salt itself also contributes to the solidification of sebum, thereby exhibiting a significantly excellent sebum solidification effect.

[0016] Examples of the water-soluble aluminum compound include aluminum chloride, aluminum sulfate, aluminum chlorohydrate, aluminum allantoin chlorohydrate, aluminum allantoin dihydroxyaluminum, bromohydroxyaluminum, aluminum acetate, aluminum lactate, aluminum chlorohydrate zirconium, and aluminum potassium sulfate. Preferred are aluminum chloride, aluminum sulfate, aluminum chlorohydrate, aluminum allantoin chlorohydrate, aluminum allantoin dihydroxyaluminum, bromohydroxyaluminum, aluminum acetate, aluminum lactate, and aluminum potassium sulfate, and more preferred is aluminum chlorohydrate. Examples of the water-soluble zirconium compound include chlorohydroxyaluminum zirconium and chlorohydroxyzirconium, with chlorohydroxyzirconium being preferred. Aluminum zirconium chlorohydrate is a composite salt of aluminum and zirconium, and specific examples thereof include aluminum zirconium octachlorohydrate, aluminum zirconium tetrachlorohydrate, and aluminum zirconium trichlorohydrate. An example of the zinc sulfonate compound is zinc paraphenolsulfonate.

[0017] The metal salt is more preferably selected from the group consisting of aluminum chloride, aluminum sulfate, aluminum chlorohydrate, aluminum allantoin chlorohydrate, aluminum allantoin dihydroxy, aluminum bromohydroxy, aluminum acetate, aluminum lactate, aluminum zirconium chlorohydrate, zirconium chlorohydrate, aluminum potassium sulfate, and zinc paraphenolsulfonate, and is even more preferably aluminum chlorohydrate or zinc paraphenolsulfonate.

[0018] The amount of the metal salt to be added is preferably 0.5 to 30 mass %, more preferably 1 to 20 mass %, and further preferably 1 to 159 mass %, based on the total amount of the metal salt and zinc oxide.

[0019] [Dispersant] The cosmetic composition according to the present invention preferably further comprises a dispersant. The dispersant is preferably one that disperses zinc oxide in the oil phase. Examples of dispersants include isostearic acid, bisbutyldimethicone polyglyceryl-3, and sorbitan sesquiisostearate, and isostearic acid is preferred. The blending amount of the dispersant is preferably 0.1 to 5 mass %, and more preferably 0.3 to 3 mass %, relative to the total amount of the cosmetic.

[0020] [Ultraviolet absorber] The cosmetic composition according to the present invention may contain an ultraviolet absorbing agent, which may be at least one type selected from ultraviolet absorbing agents that have been conventionally and commonly incorporated into sunscreen cosmetics.

[0021] Specific examples of UVA absorbers include methylene bisbenzotriazolyl tetramethylbutylphenol, t-butyl methoxydibenzoylmethane, diethylamino hydroxybenzoyl hexyl benzoate, dimethoxybenzylidene dioxoimidazolidine propionate 2-ethylhexyl, terephthalidenedicamphorsulfonic acid, and bisethylhexyloxyphenol methoxyphenyl triazine. Specific examples of UVB absorbers include ethylhexyl methoxycinnamate, ethylhexyl triazone, octocrylene, dimethicodethyl benzalmalonate, polysilicone-15, oxybenzone-3, phenylbenzimidazole sulfonic acid, homosalate, drometrizole trisiloxane, and ethylhexyl salicylate.

[0022] [Surfactants] The cosmetic preparation according to the present invention may contain a surfactant. Examples of the surfactant include anionic surfactants, cationic surfactants, amphoteric surfactants, and nonionic surfactants.

[0023] [Pigment] The cosmetic according to the present invention may contain a pigment. Examples of the pigment include inorganic white pigments, inorganic red pigments, inorganic brown pigments, inorganic yellow pigments, inorganic black pigments, inorganic purple pigments, inorganic green pigments, inorganic blue pigments, pearl pigments, metal powder pigments, organic pigments, and natural colorants. Specific examples of the pigment include talc, mica, and sericite.

[0024] [Fine particle metal oxide] The cosmetic composition according to the present invention may contain fine oxide particles other than those mentioned above. Examples of fine oxide particles include fine iron oxide, fine titanium oxide, and cerium oxide.

[0025] [Other powders] The cosmetic composition according to the present invention may contain powders other than pigments and fine metal oxide particles, such as silica, starch powder, and cellulose powder. The blending amount of other powders is preferably 10% by mass or less, more preferably 5% by mass or less, based on the total amount of the cosmetic. It is also an aspect of the present invention that the cosmetic according to the present invention does not contain other powders (0% by mass).

[0026] Optional components other than those described above include components commonly used in cosmetics, such as moisturizers, antioxidants, preservatives, alcohols, oil-based thickeners, aqueous phase thickeners, oil-based components such as silicone oils and ester oils, whitening components, and extracts.

[0027] The cosmetic according to the present invention contains water, but the amount of water is not particularly limited. The amount of water is preferably 20 to 80% by mass, more preferably 30 to 60% by mass, based on the total amount of the cosmetic.

[0028] The cosmetic composition according to the present invention can be preferably used as, for example, a makeup cosmetic composition such as a makeup base or foundation, a base cosmetic composition, or a sunscreen cosmetic composition.

[0029] The cosmetic composition of the present invention can be produced according to a conventional method. The emulsification method is not particularly limited, but may be a method in which the aqueous phase is gradually added to a heated oil phase, emulsified in an emulsifier, and then allowed to cool to room temperature. EXAMPLES

[0030] The present invention will be described in detail with reference to the following examples, but the present invention is not limited to these examples. Contents are expressed in mass % based on the total mass, unless otherwise specified.

[0031] [Examples 1 to 9 and Comparative Examples 1 to 4] Water-in-oil emulsion cosmetics of Examples 1 to 9 and Comparative Examples 1 to 4 were prepared according to the formulations shown in Table 1, and the sebum solidifying effect was evaluated. [Table 1] *1: "MZX-304OTS" (manufactured by Teika Corporation), octyltriethoxysilane treatment, amorphous, average particle size 35 nm *2: "WSX-MZ-500" (manufactured by Teika Co., Ltd.), palmitic acid dextrin processing *3: Aluminum chlorohydrate was present dispersed in the oil phase only in Comparative Example 4, and was present dispersed in the water phase in the other Examples and Comparative Examples. *4: Zinc paraphenolsulfonate was present dispersed in the aqueous phase.

[0032] [Method for evaluating sebum solidification effect] The cosmetics of the Examples and Comparative Examples were applied at 2 mg / cm to artificial leather ("Suprale", manufactured by Ideatex Japan Co., Ltd.). 2 The gloss value at 60° was measured 15 minutes after application using a gloss meter "VG-2000" (manufactured by Nippon Denshoku Industries Co., Ltd.). 2The amount of oleic acid was applied, and the gloss value was measured in the same manner 30 minutes after the application of oleic acid. The artificial leather was left on a 37°C hop plate until the measurement 30 minutes after the application of oleic acid. The above measurement was performed three times for each of the examples and comparative examples, and the gloss meter ratio (= gloss value after application of oleic acid / gloss value before application of oleic acid) was calculated using the average value of the three measurements. The results obtained are shown in Table 1. When the same procedure was followed except that no cosmetic was applied to the artificial leather, the gloss meter ratio was 1.407.

[0033] The results in Table 1 show that a water-in-oil emulsion cosmetic comprising zinc oxide and a specific metal salt, in which the specific metal salt is present in the aqueous phase, has a high sebum solidifying effect.

Claims

1. Zinc oxide, Water-soluble aluminum compounds, water-soluble zirconium compounds, and zinc sulfonate compounds and a metal salt selected from the group consisting of comprising the metal salt comprises aluminum chlorohydrate or zinc paraphenolsulfonate; The blending amount of the zinc oxide is 6 to 13 mass% based on the total amount of the cosmetic, the blending amount of the metal salt is 0.5 to 30 mass % based on the total amount of the metal salt and the zinc oxide, A water-in-oil emulsion cosmetic, in which the metal salt is present in an aqueous phase.

2. The cosmetic preparation according to claim 1 , wherein the zinc oxide comprises hydrophobic zinc oxide.

3. The cosmetic preparation according to claim 2 , wherein the hydrophobic zinc oxide is zinc oxide that has been surface-treated with an alkylalkoxysilane or a fatty acid dextrin.

4. The cosmetic preparation according to claim 2 or 3, wherein the zinc oxide further comprises non-hydrophobic zinc oxide.

5. The cosmetic preparation according to claim 4, wherein the non-hydrophobic zinc oxide has an average aspect ratio of 4 or more.

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