Water-in-oil emulsion cosmetics

Abstract

To provide an oil-in-water type emulsion cosmetic capable of blending an ultraviolet scattering agent and a pigment in a high ratio in a cosmetic base which suppresses an amount of blending of a silicone compound.SOLUTION: There is provided an oil-in-water type emulsion cosmetic which comprises (A) a pigment subjected to a surface treatment with a surface-treating agent containing amino acid or a salt thereof, (B) an oil component, (C) a hydrophobic ultraviolet scattering agent and (D) an oil phase thickener, where the amount of blending of an ultraviolet absorber is less than 1 mass% based on the total amount of the cosmetic and the amount of a silicone oil is 10 mass% or less based on the total amount of the cosmetic.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a water-in-oil emulsion cosmetic that can incorporate a high amount of an ultraviolet scattering agent and a pigment in a cosmetic base containing a reduced amount of silicone compound. [Background technology]

[0002] Silicone compounds such as silicone oils are characterized by high water repellency, a non-sticky, light feel when used, and good spreadability on the skin, and are effective in improving the water resistance and feel of cosmetics containing them, as well as the dispersibility of other ingredients. Furthermore, silicone compounds are widely used as surface treatment agents for powder ingredients.

[0003] Although silicone compounds have the advantages described above, they have the problem of making cosmetics difficult to remove with water due to their high water repellency, resulting in poor cleansing properties. Furthermore, since silicone compounds are not usually biodegradable, there are concerns that they may accumulate in the environment for a long period of time, posing a risk of environmental pollution and disrupting the ecosystem. Therefore, in recent years, so-called "silicone-free" cosmetics that do not contain silicone compounds have been attracting attention.

[0004] However, removing the silicone compound that contributes to improving the dispersibility of other ingredients such as powders in conventional cosmetics causes problems such as difficulty in maintaining the stability of the cosmetics.

[0005] On the other hand, cosmetics generally contain ultraviolet absorbers and ultraviolet scattering agents to protect the skin from the harmful effects of ultraviolet rays. Typically, organic compounds such as ethylhexyl methoxycinnamate and octocrylene are used as ultraviolet absorbers, and inorganic powder components such as titanium dioxide and zinc oxide are used as ultraviolet scattering agents.

[0006] UV absorbers have the advantages of being highly transparent, spreading easily on the skin, and not easily worn down by sweat, but because they protect against the effects of UV rays by converting them into other forms of energy such as heat, they can be irritating to users with sensitive skin. Therefore, there is demand for UV absorber-free, so-called "non-chemical" cosmetics that achieve UV protection through UV scattering agents rather than UV absorbers.

[0007] For example, Patent Document 1 proposes a water-in-oil emulsion cosmetic that has improved cleansing properties by using an N-acyl amino acid instead of a silicone compound as a powder surface treatment agent, and also describes a formulation example that does not contain an ultraviolet absorber.

[0008] However, the cosmetic described in Patent Document 1 uses a silicone compound as a powder dispersion medium and is not a silicone-free cosmetic. Silicone-free cosmetics, in which the silicone compound has been removed from the cosmetic described in Patent Document 1, have the problem that the powder tends to re-aggregate during storage, making it impossible to achieve excellent powder dispersibility. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Japanese Patent Application Publication No. 2018-177736 DISCLOSURE OF THE INVENTION [Problem to be solved by the invention]

[0010] The present invention aims to provide a water-in-oil emulsion base that is a cosmetic base containing a reduced amount of silicone compound and that has excellent stability over time and powder dispersibility even when a high amount of ultraviolet scattering agent and pigment is incorporated. [Means for solving the problem]

[0011] As a result of extensive research into solving the above-mentioned problems, the inventors discovered that by surface-treating the pigment to be incorporated into the oil phase with a surface treatment agent containing an amino acid or a salt thereof and by incorporating an oil-phase thickener, it is possible to incorporate a high amount of pigment and UV scattering agent into the oil phase without incorporating a silicone compound, and thus completed the present invention.

[0012] That is, the present invention is (A) a pigment that has been surface-treated with a surface treatment agent containing an amino acid or a salt thereof; (B) Oil, (C) a hydrophobic ultraviolet scattering agent, and (D) Oil phase thickener Including, The amount of the ultraviolet absorber is less than 1% by mass relative to the total amount of the cosmetic, The present invention provides a water-in-oil emulsion cosmetic, characterized in that the silicone oil content is 10% by mass or less relative to the total amount of the cosmetic. [Effects of the Invention]

[0013] By adopting the above-described configuration, the cosmetic of the present invention can improve the powder dispersibility of an emulsifying base containing a high content of pigment and UV scattering agent without incorporating a silicone compound. Therefore, a silicone-free makeup cosmetic can be realized. Furthermore, according to the present invention, a sufficient UV protection effect can be obtained by incorporating a high content of UV scattering agent without incorporating a UV absorber, thereby realizing a non-chemical cosmetic. DETAILED DESCRIPTION OF THE INVENTION

[0014] The cosmetic preparation of the present invention is characterized by comprising (A) a pigment that has been surface-treated with a surface treatment agent containing an amino acid or its salt, (B) an oil component, (C) a hydrophobic UV scattering agent, and (D) an oil phase thickener. Each of the components constituting the cosmetic preparation of the present invention will be described in detail below.

[0015] <(A) Pigment> The pigment (A) (hereinafter sometimes referred to simply as "component (A)") blended in the cosmetic preparation of the present invention refers to an inorganic pigment that has been surface-treated with a surface treatment agent containing an amino acid or its salt. By using a specific compound as the surface treatment agent, the cosmetic preparation can be one with excellent powder dispersibility. The surface treatment agent for the pigment of the present invention may be the amino acid or its salt alone, as listed below, or may further contain, in addition to the amino acid or its salt, other compounds commonly used as surface treatment agents for powders.

[0016] Specific examples of pigments include red iron oxide (red iron oxide), iron titanate, γ-iron oxide, yellow iron oxide, ochre, black iron oxide, carbon black, low-order titanium oxide, mango violet, cobalt violet, chromium oxide, chromium hydroxide, cobalt titanate, ultramarine, and iron blue. Of these, pigment-grade iron oxides such as yellow iron oxide, red iron oxide, and black iron oxide, and pigment-grade titanium oxide are preferably used as the pigment of the present invention. Here, pigment-grade refers to those having an average particle size of 100 nm to 1 μm.

[0017] Examples of the "amino acid" used as the surface treatment agent for component (A) include glutamic acid, aspartic acid, and lysine, with glutamic acid and aspartic acid being preferred. The "amino acid" may also be an "amino acid acylated with a saturated fatty acid," in which an acyl group, preferably a saturated fatty acid having 12 to 20 carbon atoms, is condensed with the amino group of the amino acid. Examples of the "acyl group" include a stearoyl group and a lauroyl group. The "salt" can be selected from alkali metal salts such as sodium and potassium, and alkaline earth metal salts, with sodium salts being preferred. Specific examples of acylated amino acids include disodium stearoyl glutamate, sodium lauroyl glutamate, and sodium lauroyl aspartate.

[0018] The surface treatment agent of component (A) of the present invention can improve stability over time by further adding an "ester" to the aforementioned "amino acid or salt thereof." The "ester" is a compound in which a monovalent or divalent fatty acid having 8 to 12 carbon atoms is bonded to a saturated aliphatic alcohol having 12 to 20 carbon atoms via an ester bond, and the alkyl chains of the fatty acid and the aliphatic alcohol may be linear or branched. Isostearyl sebacate is particularly preferred.

[0019] The pigment (A) of the present invention can be prepared by adsorbing an amino acid or a salt thereof onto the surface of the pigment in a conventional manner.

[0020] The surface treatment agent for the pigment (A) used in the present invention is preferably a surface treatment agent containing an amino acid selected from disodium stearoyl glutamate and sodium lauroyl glutamate, and more preferably a surface treatment agent containing disodium stearoyl glutamate and isostearyl sebacate (NHS treatment agent).

[0021] Commercially available products can also be used as the pigment (A) of the present invention, and preferred commercially available products include, for example, NHS-treated powders such as NHS-Titanium CR-50, NHS-Red R516PS, NHS-Yellow LL-100P, NHS-Black BL-100P, NHS-Mica M-102, and NHS-Talc JA-46R (all manufactured by Miyoshi Chemical Industry Co., Ltd.).

[0022] The cosmetic of the present invention may contain one or more of the pigments treated with the surface treatment agent described above. The total amount of (A) pigment is not particularly limited as long as the desired color is obtained, but is usually 0.1% by mass or more, for example, 1 to 20% by mass, and preferably 2 to 10% by mass, of the total amount of the cosmetic. If the amount is less than 1% by mass, a sufficient color cannot be obtained, and if it exceeds 20% by mass, stability tends to be poor.

[0023] <(B) Oil> The oil (B) (hereinafter sometimes referred to simply as "component (B)") blended into the cosmetic preparation of the present invention is not particularly limited as long as it is an oil typically blended into cosmetics, and examples include hydrocarbon oils, ester oils, higher alcohols having 12 to 22 carbon atoms, fatty acids having 12 to 22 carbon atoms, fats and oils, etc. The cosmetic preparation of the present invention can stably blend even polar oils, which have traditionally been thought to reduce emulsion stability.

[0024] However, in the cosmetic of the present invention, the amount of silicone oil blended is 10% by mass or less, preferably 5% by mass or less, and more preferably 1% by mass or less, based on the total amount of the cosmetic. The cosmetic of the present invention also includes embodiments in which substantially no silicone oil is blended.

[0025] Examples of hydrocarbon oils include liquid paraffin, squalane, squalene, pristane, paraffin, isoparaffin, hydrogenated polyisobutene, olefin oligomers, and volatile hydrocarbon oils (such as isododecane, isohexadecane, undecane, and tridecane).

[0026] Examples of ester oils include isopropyl myristate, cetyl ethylhexanoate, octyldodecyl myristate, isopropyl palmitate, butyl stearate, hexyl laurate, myristyl myristate, decyl oleate, hexyldecyl dimethyloctanoate, cetyl lactate, myristyl lactate, isocetyl stearate, isocetyl isostearate, cholesteryl 12-hydroxystearate, ethylene glycol di-2-ethylhexanoate, dipentaerythritol fatty acid esters, N-alkyl glycol monoisostearate, neopentyl glycol dicaprate, diisostearyl malate, glycerin di-2-heptylundecanoate, trimethylolpropane tri-2-ethylhexanoate, trimethylolpropane triisostearate, glycerin triisostearate, pentaerythrityl tetraethylhexanoate, ... Triethylhexanoin (glyceryl tri-2-ethylhexanoate), cetyl 2-ethylhexanoate, 2-ethylhexyl palmitate, glycerin trimyristate, tri-2-heptylundecanoic acid glyceride, castor oil fatty acid methyl ester, oleyl oleate, cetostearyl alcohol, acetoglyceride, 2-heptylundecyl palmitate, diisobutyl adipate, N-lauroyl-L-glutamic acid Examples of the oils include 2-octyldodecyl, di-2-heptylundecyl adipate, ethyl laurate, di-2-ethylhexyl sebacate, 2-hexyldecyl myristate, 2-hexyldecyl palmitate, 2-hexyldecyl adipate, diisopropyl sebacate, 2-ethylhexyl succinate, polypropylene glycol dipivalate, triester oils such as ethyl acetate, butyl acetate, amyl acetate, and triethyl citrate.

[0027] Examples of higher alcohols having 12 to 22 carbon atoms include oleyl alcohol, 2-decyltetradecynol, dodecanol, isostearyl alcohol, octyldodecanol, etc. Examples of fatty acids having 12 to 22 carbon atoms include oleic acid, isostearic acid, linoleic acid, linolenic acid, etc.

[0028] Examples of fats and oils include cacao butter, avocado oil, camellia oil, macadamia nut oil, corn oil, olive oil, rapeseed oil, sesame oil, persic oil, wheat germ oil, camellia oil, castor oil, linseed oil, safflower oil, cottonseed oil, perilla oil, soybean oil, peanut oil, tea seed oil, kaya oil, rice bran oil, Chinese tung oil, Japanese tung oil, jojoba oil, germ oil, triglycerin, glycerin trioctanoate, and glycerin triisopalmitate.

[0029] In the cosmetic of the present invention, the dispersion stability of the powder is improved when the ratio of polar oil to the total amount of oil is 40% or more by mass. Therefore, in the cosmetic of the present invention, the ratio of polar oil to the total amount of oil (B) is preferably 40% or more.

[0030] Polar oils include oils with an IOB value of 0.05 to 0.80, particularly ester oils. Specific examples of polar oils include isostearic acid, jojoba oil, isopropyl myristate, cetyl octanoate, octyldodecyl myristate, isopropyl palmitate, butyl stearate, hexyl laurate, myristyl myristate, decyl oleate, hexyldecyl dimethyloctanoate, isononyl isononanoate, cetyl lactate, myristyl lactate, isocetyl stearate, isocetyl isostearate, cetyl ethylhexanoate, cholesteryl 12-hydroxystearate, and ethyl 2-ethylhexanoate. Styrene glycol, dipentaerythritol fatty acid ester, N-alkyl glycol monoisostearate, neopentyl glycol dicaprate, diisostearyl malate, glycerin di-2-heptylundecanoate, trimethylolpropane tri-2-ethylhexanoate, trimethylolpropane triisostearate, pentaerythritol tetra-2-ethylhexanoate, glyceryl tri-2-ethylhexanoate (triethylhexanoin), cetyl isooctanoate, cetyl 2-ethylhexanoate, paprika 2-Ethylhexyl Palmitate, C12-15 Alkyl Benzoate, Cetearyl Isononanoate, Caprylic / Capric Triglyceride, Butylene Glycol Dicaprylic / Capric Triglyceride, Glycerin Trimyristate, 2-Heptylundecanoic Triglyceride, Castor Oil Fatty Acid Methyl Ester, Oleyl Oleate, Cetostearyl Alcohol, Acetoglyceride, 2-Heptylundecyl Palmitate, Diisobutyl Adipate, 2-Octyl N-Lauroyl-L-Glutamate decyl ester, di-2-heptylundecyl adipate, ethyl laurate, di-2-ethylhexyl sebacate, 2-hexyldecyl myristate, 2-hexyldecyl palmitate, 2-hexyldecyl adipate, diisopropyl sebacate, di-2-ethylhexyl succinate, ethyl acetate, butyl acetate, amyl acetate, triethyl citrate, 2-ethylhexyl paramethoxycinnamate, tripropylene glycol dipivalate, and 2-ethylhexyl 2-cyano-3,3-diphenylacrylate.

[0031] The amount of (B) oil component is not particularly limited as long as it is an amount normally used when blending powders such as pigments and UV scattering agents into the oil phase, but for example, it is preferably 5 to 50% by mass relative to the total amount of the cosmetic. If the amount of oil component is less than 5% by mass, stability decreases, and if it exceeds 50% by mass, stability and usability tend to decrease.

[0032] <(C) Hydrophobic UV scattering agent> The hydrophobic ultraviolet scattering agent (C) (hereinafter sometimes referred to simply as "component (C)") blended in the cosmetic of the present invention can be appropriately selected from those commonly used in cosmetics and is not particularly limited, but refers to those with a hydrophobic particle surface. Specific examples include metal oxides such as titanium oxide, zinc oxide, iron oxide, cerium oxide, and tungsten oxide. In the present invention, titanium oxide and zinc oxide are preferred. Furthermore, fine particles with an average particle diameter of 0.1 μm or less are preferred. The lower limit of the average particle diameter is not particularly limited, but is usually about 5 nm.

[0033] The ultraviolet scattering agent used in the present invention may be either surface-untreated or hydrophobized, so long as the particle surface is hydrophobic. The hydrophobizing surface treatment agent is not particularly limited, but examples thereof include silicone treatment agents, fluorine compound treatment agents, amino acid treatment agents, fatty acid treatment agents, fatty acid soap treatment agents, fatty acid ester treatment agents, lecithin treatment agents, alkyl phosphate ester treatment agents, etc.

[0034] Examples of silicone treating agents include silicone oils such as methylhydrogenpolysiloxane, dimethylpolysiloxane, and methylphenylpolysiloxane; alkylsilanes such as methyltrimethoxysilane, ethyltrimethoxysilane, hexyltrimethoxysilane, and octyltrimethoxysilane; and fluoroalkylsilanes such as trifluoromethylethyltrimethoxysilane and heptadecafluorodecyltrimethoxysilane. Examples of fluorine compound treating agents include perfluoroalkyl phosphate esters and perfluoroalcohols. Examples of amino acid treating agents include N-acyl glutamic acid, N-acylaspartic acid, and N-acylysine. Examples of fatty acid treating agents include palmitic acid, isostearic acid, stearic acid, lauric acid, myristic acid, behenic acid, oleic acid, rosin acid, and 12-hydroxystearic acid. Examples of fatty acid soap treating agents include aluminum stearate, calcium stearate, and aluminum 12-hydroxystearate. Examples of fatty acid ester treating agents include dextrin fatty acid esters, cholesterol fatty acid esters, sucrose fatty acid esters, starch fatty acid esters, etc. These hydrophobic treatments can be carried out according to conventional methods.

[0035] According to the cosmetic of the present invention, the ultraviolet scattering agent can be incorporated into the oil phase at a high concentration, thereby achieving sufficient ultraviolet protection effect without incorporating an ultraviolet absorber. Therefore, in the cosmetic of the present invention, the amount of ultraviolet absorber incorporated is 3% by mass or less, preferably 1% by mass or less, based on the total amount of the cosmetic. The cosmetic of the present invention also includes an embodiment in which substantially no ultraviolet absorber is incorporated. By incorporating substantially no ultraviolet absorber, a "non-chemical" cosmetic can be obtained.

[0036] "Non-chemical" cosmetics refer to cosmetics that contain inorganic UV scattering agents rather than organic UV absorbers, thereby providing skin protection from UV rays.

[0037] The blending amount of (C) hydrophobic UV scattering agent is the amount required to obtain the desired UV protection effect and is not particularly limited, but is usually 1% by mass or more, for example 5 to 30% by mass, and preferably 10 to 30% by mass, relative to the total amount of the cosmetic. If the blending amount is less than 5% by mass, it is difficult to obtain a sufficient UV protection effect, and if it exceeds 30% by mass, stability tends to deteriorate. When the cosmetic of the present invention is prepared as a non-chemical cosmetic, it is preferable that the total content of UV scattering agents is 10% by mass or more.

[0038] <(D) Oil phase thickener> The oil phase thickener (D) (hereinafter sometimes simply referred to as "component (D)") blended in the cosmetic preparation of the present invention can be appropriately selected from substances used as components that thicken the oil phase by dissolving in or swelling with oil in ordinary emulsion-type cosmetics, etc. Examples include dextrin fatty acid esters, sucrose fatty acid esters, solid or semi-solid hydrocarbon oils, organically modified clay minerals, and fatty acids or salts thereof.

[0039] The dextrin fatty acid ester is an ester of dextrin or reduced dextrin with a higher fatty acid, and any dextrin commonly used in cosmetics can be used without any particular limitation. It is preferable to use dextrin or reduced dextrin with an average degree of glycopolymerization of 3 to 100. Furthermore, it is preferable to use saturated fatty acids having 8 to 22 carbon atoms as the constituent fatty acids of the dextrin fatty acid ester. Specific examples include dextrin palmitate, dextrin oleate, dextrin stearate, dextrin myristate, and dextrin (palmitate / 2-ethylhexanoate).

[0040] The sucrose fatty acid ester can preferably be one in which the fatty acid is linear or branched, saturated or unsaturated, and has a carbon number of 12 to 22. Specific examples include sucrose caprylate, sucrose caprate, sucrose laurate, sucrose myristate, sucrose palmitate, sucrose stearate, sucrose oleate, and sucrose erucate.

[0041] The solid or semi-solid hydrocarbon oil is a hydrocarbon that is solid or semi-solid at room temperature (25°C), and specific examples include ozokerite, ceresin, petrolatum, microcrystalline wax, hydrogenated palm oil, hydrogenated palm kernel oil, hydrogenated castor oil, hydrogenated peanut oil, hydrogenated rapeseed seed oil, hydrogenated camellia oil, hydrogenated soybean oil, hydrogenated olive oil, hydrogenated macadamia nut oil, hydrogenated sunflower oil, hydrogenated wheat germ oil, hydrogenated rice germ oil, hydrogenated rice bran oil, hydrogenated cottonseed oil, hydrogenated avocado oil, and waxes (carnauba wax, beeswax, candelilla wax, jojoba wax, Japan wax, etc.).

[0042] Organically modified clay minerals are a type of colloidal hydrous aluminum silicate with a three-layer structure, and a typical example is a clay mineral represented by the following general formula (I) modified with a quaternary ammonium salt-type cationic surfactant. (X,Y) 2―3 (Si,Al)O 10 (OH)2Z 1 / 3 nH2O (I) (However, X=Al, Fe(III), Mn(III), Cr(III), Y=Mg, Fe(II), Ni, Zn, Li, Z=K, Na, Ca)

[0043] Specific examples include dimethyl distearyl ammonium hectorite (disteardimonium hectorite), dimethyl alkyl ammonium hectorite, benzyl dimethyl stearyl ammonium hectorite, distearyl dimethyl ammonium chloride-treated magnesium aluminum silicate, etc. Preferred commercially available products include Bentone 27 (benzyl dimethyl stearyl ammonium chloride-treated hectorite: manufactured by Elementis Japan Co., Ltd.) and Bentone 38 (distearyl dimethyl ammonium chloride-treated hectorite: manufactured by Elementis Japan Co., Ltd.).

[0044] The fatty acid is not particularly limited as long as it can be used in cosmetics and the like, and can be selected from linear or branched fatty acids having saturated or unsaturated hydrocarbon groups. Particularly preferred are higher fatty acids that are solid at room temperature and have 8 to 22 carbon atoms, such as lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid (behenic acid), oleic acid, isomyristic acid, and isopalmitic acid. Of these, it is particularly preferred to use one or more fatty acids selected from stearic acid, palmitic acid, and behenic acid. Examples of fatty acid salts include metal salts such as sodium salts, calcium salts, magnesium salts, and aluminum salts. Furthermore, amide derivatives and ester derivatives of fatty acids can also be used.

[0045] The oil phase thickener (D) of the present invention is preferably selected from dextrin fatty acid esters and organically modified clay minerals, and more preferably selected from organically modified clay minerals. As the oil phase thickener of the present invention, one or more kinds selected from the above substances may be blended and used. The blending amount of (D) oil phase thickener can be 0.01 to 10% by mass, preferably 0.1 to 5% by mass, and more preferably 0.1 to 2% by mass, relative to the total amount of the cosmetic. If the blending amount is less than 0.01% by mass, sufficient emulsion stability cannot be obtained, and even if the blending amount exceeds 10% by mass, it tends to be difficult to obtain further enhancement of the effect.

[0046] According to the cosmetic of the present invention, it is possible to realize a "silicone-free" cosmetic that does not contain any silicone compounds. In this specification, "silicone compound" refers to compounds having a siloxane (-Si-O-Si-) structure in the molecule (e.g., silicones and siloxanes) and silanes (monosilane, oligosilane, polysilane, and silane derivatives such as alkylsilane and alkoxysilane), and includes silicone oil, silicone elastomer, silicone surfactant, and powder surface-treated with a silicone compound. Note that silicon dioxide (silica) is not included in the "silicone compound" of this invention.

[0047] By combining the pigment treated with the specific surface treatment agent and the specific oil phase thickener, the cosmetic of the present invention exhibits excellent powder dispersibility and stability even as a silicone-free cosmetic.

[0048] In addition to the above-mentioned components, the cosmetic preparation of the present invention may contain other optional components typically used in cosmetics, pharmaceuticals, and other topical skin preparations, as needed, provided that the purpose and effect of the present invention are not impaired. Examples of other optional components include powders other than the components (A) and (C), surfactants, polymeric compounds, chelating agents, lower alcohols, polyhydric alcohols, pH adjusters, antioxidants, fragrances, preservatives, disinfectants, and various pharmaceuticals. However, the optional components are not limited to these examples.

[0049] The cosmetic of the present invention can be produced by a conventional method and can be made into a formulation such as a liquid, emulsion, paste, cream, gel, or solid. The cosmetic of the present invention can be provided as makeup cosmetics such as a makeup base, foundation, concealer, blusher, eye shadow, mascara, eyeliner, eyebrow cream, overcoat, and lipstick; or as skin care cosmetics such as sunscreen, but is particularly suitable as makeup cosmetics, particularly a makeup base and liquid foundation. [Example]

[0050] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. Unless otherwise specified, the blending amount is expressed in mass % relative to the system in which the component is blended. Before describing each example in detail, the evaluation methods used will be described.

[0051] 1. Evaluation of powder dispersibility immediately after preparation Immediately after preparation, the appearance of the sample was visually observed, and the dispersibility of the powder was evaluated based on the following criteria: the fewer color streaks, the more uniformly the powder was dispersed. A: No color streaks are observed. B: A slight color streak was observed, but it was not a problem for use. C: Colored stripes are clearly visible. D: Color stripes were observed and the product was unsuitable for use as a cosmetic.

[0052] 2. Evaluation of powder dispersibility over time (rolling test) To evaluate powder dispersibility over time, a rolling test was conducted. Specifically, a cylindrical container was half-filled with a sample, and the sample was subjected to a rolling test at 45 rpm for 4 hours at room temperature using a rolling tester (manufactured by Nigorikawa Rika Kogyo Co., Ltd.). After the rotation, the sample filled in the container was visually inspected for the presence of color streaks on the container wall, and the dispersibility of the powder was evaluated based on the following criteria: Fewer color streaks indicate more uniformly dispersed powder. A: No color streaks are observed. B: A slight color streak was observed, but it was not a problem for use. C: Colored stripes are clearly visible. D: Color stripes were observed and the product was unsuitable for use as a cosmetic.

[0053] 3. Evaluation of stability over time The sample was filled into a screw tube (50 ml) and left to stand in a thermostatic bath at 50°C for 2 weeks. Before and after standing, the change in viscosity was measured using a rotational viscometer (Vismetron rotational viscometer), and the emulsion particles and appearance were observed, and the results were evaluated based on the following criteria. A: There is no change in viscosity, and there are no problems with the emulsion particles or appearance. B: Slight changes in viscosity and in the appearance of the emulsion were observed, but these were not significant enough to cause problems in use. C: Changes in viscosity, emulsified particles, and appearance are observed. D: Changes in viscosity, emulsified particles, and appearance were observed, making the product unsuitable for use as a cosmetic.

[0054] Water-in-oil emulsion cosmetics having the compositions shown in the table on the next page were prepared by conventional methods. The prepared samples were evaluated for stability and powder dispersibility according to the evaluation methods described above. The results are shown in the table.

[0055] [Table 1]

[0056] *1: NHS-Titanium CR-50 (manufactured by Miyoshi Chemical Industry Co., Ltd.) *2: NHS-Yellow LL-100P (Miyoshi Chemical Industry Co., Ltd.) *3: NHS-Red R516PS (manufactured by Miyoshi Chemical Industry Co., Ltd.) *4:ASL-1 TiO2 CR-50 (manufactured by Daito Kasei Kogyo Co., Ltd.) *5: ASL-Yellow LL-100P (manufactured by Daito Kasei Kogyo Co., Ltd.) *6:ASL-Red R516P (manufactured by Daito Kasei Kogyo Co., Ltd.) *7: ASI TiO2 CR-50 (manufactured by Daito Kasei Kogyo Co., Ltd.) *8: ASI-Yellow LL-100P (manufactured by Daito Kasei Kogyo Co., Ltd.) *9: ASI-Red R516P (manufactured by Daito Kasei Kogyo Co., Ltd.) *10: NAI-Titanium CR-50 (manufactured by Miyoshi Chemical Industry Co., Ltd.) *11: NAI-Yellow LL-100P (Miyoshi Chemical Industry Co., Ltd.) *12: NAI-Red R516PS (manufactured by Miyoshi Chemical Industry Co., Ltd.) *13:LL TiO2 CR-50 (manufactured by Daito Kasei Kogyo Co., Ltd.) *14: LL-Yellow LL-100P (manufactured by Daito Kasei Kogyo Co., Ltd.) *15: LL-Red R516P (manufactured by Daito Kasei Kogyo Co., Ltd.) *16: MI-Titanium CR-50 (manufactured by Miyoshi Chemical Industry Co., Ltd.) *17: MI-Yellow LL-100P (Miyoshi Chemical Industry Co., Ltd.) *18: MI-Red R516PS (manufactured by Miyoshi Chemical Industry Co., Ltd.) *19:ST-485SA (Titanium Industries Co., Ltd.) *20:WSX-MZ-500 (manufactured by Teika)

[0057] As shown in the table, the cosmetic of Comparative Example 1, which did not contain the oil phase thickener (D) of the present invention, exhibited poor powder dispersibility over time. Furthermore, the cosmetic of Comparative Examples 2 and 3, which contained pigments that had been hydrophobized using a fatty acid soap treatment (MI treatment) or a silicone treatment (EP1 treatment), showed noticeable color streaks immediately after preparation, and also exhibited poor powder dispersibility and stability over time. On the other hand, the cosmetics of Examples 5 to 8, which contain pigments that have been hydrophobized using a surface treatment agent containing an acylated amino acid metal salt and an amino acid (ASL treatment), a surface treatment agent containing an acylated amino acid metal salt and an ester metal complex (ASI treatment), or an acylated amino acid treatment agent (NAI treatment, LL treatment), were inferior in powder dispersibility and stability over time, but cosmetics in which the powder was sufficiently dispersed were able to be prepared. The cosmetics of Examples 1 to 4, which contain a pigment that has been hydrophobized using a surface treatment agent (NHS treatment) containing an amino acid salt and an ester acylated with a saturated fatty acid as component (A) of the present invention, showed little or no color streaks both immediately after preparation and after the rolling test, and also had excellent stability over time.

Claims

1. (A) a pigment that has been surface-treated with a surface treatment agent containing an amino acid acylated with a saturated fatty acid or a salt thereof, in an amount of 1 to 20% by mass based on the total amount of the cosmetic; (B) Oil, (C) 1 to 30% by mass of a hydrophobic ultraviolet scattering agent relative to the total amount of the cosmetic, and (D) Oil phase thickener Including, The blending amount of the ultraviolet absorber is less than 1% by mass relative to the total amount of the cosmetic, The silicone oil is contained in an amount of 10% by mass or less relative to the total amount of the cosmetic, The ratio of polar oil to the total amount of the (B) oil component is 40% or more by mass ratio, A water-in-oil emulsion cosmetic that does not contain silicone compounds.

2. 2. The water-in-oil emulsion cosmetic according to claim 1, wherein the amino acid used as the surface treatment agent for the pigment (A) is glutamic acid or aspartic acid.

3. the pigment (A) is a pigment that has been surface-treated with a surface treatment agent containing an amino acid acylated with a saturated fatty acid, or a salt or ester thereof, 3. The water-in-oil emulsion cosmetic according to claim 1, wherein the ester is a compound in which a monovalent or divalent fatty acid having 8 to 12 carbon atoms is bonded to a saturated aliphatic alcohol having 12 to 20 carbon atoms via an ester bond.

4. The water-in-oil emulsion cosmetic according to claim 1 , wherein the blending amount of the hydrophobic ultraviolet scattering agent (C) is 10% by mass or more based on the total amount of the cosmetic.

5. The water-in-oil emulsion cosmetic according to claim 1 , wherein the oil phase thickener (D) is an organically modified clay mineral.

6. The water-in-oil emulsion cosmetic according to claim 1 , wherein the oil phase thickener (D) is dimethyl distearyl ammonium hectorite.

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