Oil-in-water emulsion cosmetic composition

Abstract

Provided is an oil-in-water emulsion cosmetic composition capable of stably containing pigment particles that have been surface-treated with an ester- or metal soap-based surface treatment agent into emulsion particles and having excellent stability at high temperatures over time.　An oil-in-water emulsion cosmetic composition contains an oil component and pigment particles dispersed in the oil component. The pigment particles contain pigment particles that are surface-treated with an ester compound of a fatty acid having 8 to 20 carbon atoms and glycerol, pigment particles that are surface-treated with a metal soap surface treatment agent, or a combination thereof, and the pigment particles have a maximum particle diameter of 15 μm or less as measured by a grindometer.

Description

Oil-in-water emulsion cosmetic composition

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

[0002] Oil-in-water emulsion cosmetic compositions containing an aqueous phase as a continuous phase provide a fresh and moist feel when used, and are therefore widely used as base materials for, for example, makeup cosmetics such as foundations, base cosmetics, sunscreens, and basic cosmetics such as emulsions.

[0003] For example, Patent Document 1 discloses an oil-in-water emulsion cosmetic comprising: (A) a pigment that has been surface-treated with a surface treatment agent containing glutamic acid or aspartic acid acylated with a saturated fatty acid having 8 to 14 carbon atoms or a salt thereof; (B) an oil; (C) a hydrophobic ultraviolet scattering agent; and (D) a water-soluble alkyl-substituted polysaccharide derivative; 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 10% by mass or less relative to the total amount of the cosmetic; and the components (A) and (C) are dispersed in the oil phase.

[0004] Japanese Patent Application Laid-Open No. 2022-102581

[0005] It is known that in oil-in-water emulsion cosmetic compositions, surface-treated pigment particles are incorporated into emulsion particles (oil droplets).

[0006] Generally, when attempting to incorporate such pigment particles into emulsion particles, there is a problem in that it is difficult to incorporate the pigment particles into emulsion particles in the first place, and even if it is possible to incorporate the pigment particles into emulsion particles, it is difficult to maintain the stability of the resulting emulsion cosmetic composition.

[0007] To address this issue, for example, as disclosed in Patent Document 1, pigment particles that have been surface-treated with an amino acid-based surface treatment agent are blended into emulsion particles, thereby maintaining the stability of the emulsion cosmetic composition.

[0008] However, it remains difficult to stably maintain emulsion cosmetic compositions in which pigment particles that have been surface-treated with an ester-based or metal soap-based surface treatment agent are blended within emulsion particles, particularly at high temperatures (e.g., 37°C).

[0009] The present invention aims to improve the above-mentioned circumstances, and its object is to provide an oil-in-water emulsion cosmetic composition in which pigment particles that have been surface-treated with an ester-based or metal soap-based surface treatment agent can be stably incorporated into emulsion particles, and which also has excellent stability over time at high temperatures.

[0010] The present invention that achieves the above object is as follows.

[0011] Aspect 1: An oil-in-water emulsion cosmetic composition comprising an oil and pigment particles dispersed in the oil, wherein the pigment particles are surface-treated with an ester compound of a fatty acid having 8 to 20 carbon atoms and glycerin, surface-treated with a metal soap surface treatment agent, or a combination thereof, and the pigment particles have a maximum particle size of 15 μm or less as measured with a grindometer. Aspect 2: The composition of Aspect 1, further comprising a nonionic surfactant. Aspect 3: The composition of Aspect 2, wherein the nonionic surfactant comprises a fatty acid polyglycerin ester and / or polyoxyethylene hydrogenated castor oil. Aspect 4: The composition of any one of Aspects 1 to 3, further comprising a water-soluble alkyl-substituted polysaccharide derivative. Aspect 5: The composition of Aspect 4, wherein the water-soluble alkyl-substituted polysaccharide derivative comprises stearoxyhydroxypropylmethylcellulose. Aspect 6: The composition of any one of Aspects 1 to 5, further comprising an acrylic acid-based thickener. <Aspect 7> The composition according to any one of Aspects 1 to 6, wherein the oil component comprises a non-volatile oil. <Aspect 8> The composition according to Aspect 7, wherein the viscosity of the non-volatile oil is 25 Pa·s or more. <Aspect 9> The composition according to Aspect 7 or 8, wherein the non-volatile oil comprises at least one selected from the group consisting of trimethylpentaphenyltrisiloxane, pentaerythrityl tetraethylhexanoate, triethylhexanoin, diphenylsiloxyphenyl trimethicone, and polyglyceryl-2 triisostearate. <Aspect 10> The composition according to any one of Aspects 1 to 9, wherein the ester compound is at least one selected from the group consisting of diglyceryl tetraisostearate, diglyceryl triisostearate, caprylic / capric triglyceride, glyceryl dilaurate, glyceryl triisostearate, decaglyceryl monoisostearate, and decaglyceryl diisostearate. <Aspect 11> The composition according to any one of Aspects 1 to 10, wherein the metal soap surface treatment agent is at least one selected from the group consisting of calcium stearate, aluminum dimyristate, and magnesium stearate.Aspect 12: The composition according to any one of Aspects 1 to 11, wherein the pigment particles are present in an amount of 50 to 150 parts by mass per 100 parts by mass of the oil component. Aspect 13: A method for producing an oil-in-water emulsion cosmetic composition comprising an oil component and pigment particles dispersed in the oil component, wherein the pigment particles are surface-treated with an ester compound of a fatty acid having 8 to 20 carbon atoms and glycerin, surface-treated with a metal soap surface treatment agent, or a combination thereof, and the method comprises the steps of: (a) preparing an aqueous phase part, (b) dispersing the pigment particles in the oil component by mechanical force to obtain an oil phase part having a maximum particle size of 15 μm or less as measured by a grindmeter, and (c) adding the oil phase part to the aqueous phase part and emulsifying. Aspect 14: The production method according to Aspect 13, wherein a nonionic surfactant and / or a water-soluble alkyl-substituted polysaccharide derivative is added to the aqueous phase part obtained in step (a), and then in step (c), the oil phase part is added to the aqueous phase part.

[0012] According to the present invention, it is possible to provide an oil-in-water emulsion cosmetic composition in which pigment particles that have been surface-treated with an ester-based or metal soap-based surface treatment agent can be stably incorporated into emulsion particles, and which also has excellent stability over time at high temperatures.

[0013] In the present invention, the term "high temperature stability over time" refers to stability after long-term storage (for example, 2 weeks) at 37°C to 45°C.

[0014] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the preferred embodiments. However, the present invention is not limited to the following embodiments, and various modifications can be made within the scope of the present invention.

[0015] <Oil-in-water emulsion cosmetic composition> The oil-in-water emulsion cosmetic composition of the present invention (hereinafter also simply referred to as "the composition of the present invention") is an oil-in-water emulsion cosmetic composition containing an oil and pigment particles dispersed in the oil, wherein the pigment particles are surface-treated with an ester compound of a fatty acid having 8 to 20 carbon atoms and glycerin, or surface-treated with a metal soap surface treatment agent, or a combination thereof, and the pigment particles have a maximum particle size of 15 μm or less as measured with a grindometer.

[0016] The present inventors focused on the maximum particle size of surface-treated pigment particles, and prepared an oil-in-water emulsion cosmetic composition by dispersing pigment particles that had been surface-treated with an ester compound of a fatty acid having 8 to 20 carbon atoms and glycerin, pigment particles that had been surface-treated with a metal soap surface treatment agent, or a combination thereof, in oil droplets so that the maximum particle size was a specific size or less. As a result, they were able to obtain a composition of the present invention in which the pigment particles were stably incorporated into the emulsion particles and which also had excellent stability over time at high temperatures.

[0017] Without being limited to theory, this is thought to be due to the following reason: When the maximum particle size of the pigment in the emulsion particles in an oil-in-water emulsion cosmetic composition is large, the emulsion particles containing these large pigment particles become unstable, which then becomes the starting point for destabilization of other emulsion particles, whereas when there are no large pigment particles that can trigger such destabilization, it is possible to stably blend the pigment particles into the emulsion particles, and it is also thought that a composition can be provided that has excellent stability over time at high temperatures.

[0018] In the present invention, the maximum particle size of the pigment particles can be measured using a grindometer in accordance with the method described in JIS K5400-1990.

[0019] More specifically, an oil dispersion containing surface-treated pigment particles is dropped into the groove of a grindmeter, and a scraper is used to create an oil dispersion layer with a continuously changing thickness in the scraping groove. At this time, the thickness of the layer at the point where three or more lines of pigment particles in the oil dispersion begin to appear is read and taken as the maximum particle diameter of the pigment particles. The measurement is carried out three times, and the average of the three measurements is calculated.

[0020] In the composition of the present invention, the pigment particles of the present invention may have a maximum particle size of 15 μm or less as measured by a grindometer. More specifically, the maximum particle size of the pigment particles may be, for example, 15 μm or less, 14 μm or less, 13 μm or less, 12 μm or less, 11 μm or less, or 10 μm or less, or may be 0.5 μm or more, 1.0 μm or more, or 1.5 μm or more.

[0021] Furthermore, in the present invention, there are no particular limitations on the means for adjusting the maximum particle size of the surface-treated pigment particles to 15 μm or less as measured by a grindmeter. More specifically, for example, the desired pigment particles can be obtained by kneading the surface-treated pigment particles with oil, or by pasting the surface-treated pigment particles with oil using a three-roller roller (for example, manufactured by Imex Co., Ltd.). Here, the oil used to adjust the particle size of the surface-treated pigment particles is preferably a non-volatile oil, and more preferably a non-volatile oil having a viscosity of 25 mPa·s or more, and more preferably a non-volatile oil having a viscosity of 25 mPa·s or more but 5000 mPa·s or less.

[0022] Oil The composition of the present invention comprises one or more oils, which constitute the internal phase of the composition of the present invention.

[0023] In the composition of the present invention, the oil content is not particularly limited, and may be, for example, 5.0 mass% or more, 7.0 mass% or more, 10 mass% or more, 11 mass% or more, 12 mass% or more, 13 mass% or more, 14 mass% or more, 15 mass% or more, 16 mass% or more, or 17 mass% or more, relative to the entire composition, and may be 30 mass% or less, 25 mass% or less, 20 mass% or less, or 18 mass% or less.

[0024] In the composition of the present invention, the oil is not particularly limited and may be a liquid, solid, or semi-solid oil, or a mixture thereof, at room temperature (25°C) and atmospheric pressure (1 atm). In addition, the oil may be a non-volatile oil, a volatile oil, or a mixture thereof.

[0025] In the present invention, non-volatile oil refers to oil having a boiling point of more than 260°C at room temperature and normal pressure. In contrast, volatile oil refers to oil having a boiling point of 60 to 260°C at room temperature and normal pressure.

[0026] In the present invention, specific examples of oil components are not particularly limited, and include hydrocarbon oils, ester oils, vegetable oils, higher alcohols, higher fatty acids, oil-based ultraviolet absorbers, and silicone oils.

[0027] Non-volatile hydrocarbon oils include, but are not limited to, liquid paraffin, paraffin, hydrogenated polydecene, squalane, squalene, pristane, petrolatum, etc. Furthermore, volatile hydrocarbon oils may be relatively low molecular weight hydrocarbon oils (boiling points of 250°C or less), and specific examples thereof include, but are not limited to, light liquid isoparaffin (also known as "hydrogenated polyisobutene"), isododecane, isohexadecane, etc.

[0028] Examples of ester oils include isopropyl myristate, cetyl octanoate, octyldodecyl myristate, isopropyl palmitate, butyl stearate, hexyl laurate, myristyl myristate, decyl oleate, hexyldecyl dimethyloctanoate, cetyl lactate, myristyl lactate, lanolin acetate, isocetyl stearate, isocetyl isostearate, cholesteryl 12-hydroxystearate, ethylene glycol di-2-ethylhexanoate, dipentaerythritol fatty acid esters, N-alkyl glycol monoisostearate, neopentyl glycol dicaprate, diisostearyl malate, glycerin di-2-heptylundecanoate, trimethylolpropane tri-2-ethylhexanoate, trimethylolpropane triisostearate, glycerin trioctanoate, Examples of the glyceryl triisopalmitate include glyceryl triisopalmitate, cetyl 2-ethylhexanoate, pentaerythritol tetra-2-ethylhexanoate, glyceryl tri-2-ethylhexanoate, 2-ethylhexyl palmitate, glyceryl trimyristate, tri-2-heptylundecanoic acid glyceride, castor oil fatty acid methyl ester, oleyl oleate, acetoglyceride, 2-heptylundecyl palmitate, diisobutyl adipate, N-lauroyl-L-glutamic acid-2-octyldodecyl ester, di-2-heptylundecyl adipate, ethyl laurate, di-2-ethylhexyl sebacate, 2-hexyldecyl myristate, 2-hexyldecyl palmitate, di-2-hexyldecyl adipate, diisopropyl sebacate, and triethyl citrate, but are not limited to these.

[0029] Examples of vegetable oils include, but are not limited to, avocado oil, camellia oil, macadamia nut oil, corn oil, olive oil, rapeseed oil, sesame oil, castor oil, peanut oil, almond oil, soybean oil, tea seed oil, jojoba oil, and germ oil.

[0030] Examples of higher alcohols include oleyl alcohol, isostearyl alcohol, octyldodecanol, decyltetradecanol, jojoba alcohol, cetyl alcohol, myristyl alcohol, etc. Examples of higher fatty acids include, but are not limited to, oleic acid, isostearic acid, linoleic acid, linolenic acid, eicosapentaenoic acid, docosahexaenoic acid, palmitic acid, stearic acid, etc.

[0031] The oil-based UV absorber is not particularly limited as long as it is one that is commonly used in cosmetics. For example, UV absorbers selected from octocrylene, ethylhexyl methoxycinnamate, ethylhexyl salicylate, 4-tert-butyl-4'-methoxydibenzoylmethane, methylenebisbenzotriazolyltetramethylbutylphenol, bisethylhexyloxyphenol methoxyphenyl triazine, diethylaminohydroxybenzoylhexyl benzoate, ethylhexyl triazone, diethylhexylbutamidotriazone, 2-hydroxy-4-methoxybenzophenone, benzalmalonate, benzotriazole, and the like can be used in appropriate combination.

[0032] Silicone oil can be selected from volatile and non-volatile linear, branched or cyclic silicone oil.More specifically, silicone oil can include, but is not limited to, methylpolysiloxane, methylphenylpolysiloxane, methylpolycyclosiloxane, methylhydrogenpolysiloxane, dimethylsiloxane, dimethylsiloxane-methyl (POE) siloxane copolymer, high polymerized methylpolysiloxane, dimethylsiloxane-methyl (POP) siloxane copolymer, tetradecamethylhexasiloxane, octamethyltrisiloxane, dimethylsiloxane-methylcetyloxysiloxane copolymer, decamethyltetrasiloxane, cyclopentasiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane, hexadecamethylcycloheptasiloxane etc.

[0033] In the composition of the present invention, the oil preferably contains a non-volatile oil, because a non-volatile oil is preferable as the oil used to adjust the maximum particle size of the surface-treated pigment particles.

[0034] In the present invention, from the viewpoint of easily adjusting the maximum particle size of the surface-treated pigment particles, the viscosity of the non-volatile oil component is 25 mPa·s or more, 50 mPa·s or more, 100 mPa·s or more, 150 mPa·s or more, 200 mPa·s or more, 250 mPa·s or more, 300 mPa·s or more, 350 mPa·s or more, 400 mPa·s or more, or 450 mPa·s or more. The viscosity of the oil may be 5000 mPa·s or less, 4000 mPa·s or less, 3000 mPa·s or less, 2000 mPa·s or less, 1000 mPa·s or less, 800 mPa·s or less, 500 mPa·s or less, 480 mPa·s or less, 450 mPa·s or less, 420 mPa·s or less, 400 mPa·s or less, 380 mPa·s or less, or 350 mPa·s or less. The viscosity of the oil can be measured, for example, at room temperature (25°C) using a BL viscometer.

[0035] Furthermore, in the present invention, from the viewpoint of easily adjusting the maximum particle size of the surface-treated pigment particles, the non-volatile oil preferably contains, more specifically, at least one selected from the group consisting of trimethylpentaphenyltrisiloxane, pentaerythrityl tetraethylhexanoate, triethylhexanoin, diphenylsiloxyphenyl trimethicone, and polyglyceryl-2 triisostearate.

[0036] The pigment particles of the present invention include those surface-treated with an ester compound of a fatty acid having 8 to 20 carbon atoms and glycerin, those surface-treated with a metal soap surface treatment agent, or a combination thereof, and have a maximum particle size of 15 μm or less as measured with a grind meter. The pigment particles of the present invention are dispersed in the above-mentioned oil.

[0037] In the composition of the present invention, the content of the pigment particles of the present invention is not particularly limited. For example, the content of the pigment particles of the present invention relative to 100 parts by mass of the oil content may be 50 parts by mass or more, 55 parts by mass or more, 60 parts by mass or more, 65 parts by mass or more, 70 parts by mass or more, 73 parts by mass or more, 75 parts by mass or more, 80 parts by mass or more, 85 parts by mass or more, 90 parts by mass or more, 95 parts by mass or more, 100 parts by mass or more, 105 parts by mass or more, 110 parts by mass or more, 115 parts by mass or more, 120 parts by mass or more, 125 parts by mass or more, 130 parts by mass or more, It may be 135 parts by mass or more, 140 parts by mass or more, 145 parts by mass or more, or 150 parts by mass or more, and may be 150 parts by mass or less, 145 parts by mass or less, 140 parts by mass or less, 135 parts by mass or less, 130 parts by mass or less, 125 parts by mass or less, 120 parts by mass or less, 115 parts by mass or less, 110 parts by mass or less, 105 parts by mass or less, 100 parts by mass or less, 95 parts by mass or less, 80 parts by mass or less, or 75 parts by mass or less.

[0038] Furthermore, in the composition of the present invention, relative to 100 parts by mass of the non-volatile oil used to adjust the particle size of the surface-treated pigment particles (particularly, a non-volatile oil having a viscosity of 25 mPa·s or more and 5000 mPa·s or less), the amount of the pigment particles of the present invention may be, for example, 50 parts by mass or more, 100 parts by mass or more, 120 parts by mass or more, 150 parts by mass or more, or 180 parts by mass or more, and may be 500 parts by mass or less, 400 parts by mass or less, 300 parts by mass or less, or 200 parts by mass or less.

[0039] In the present invention, any pigment particles can be used for the surface treatment, regardless of their shape (spherical, rod-like, needle-like, plate-like, irregular, scaly, spindle-like, etc.), particle size (aerosol-like, fine particles, pigment-grade, etc.), or particle structure (porous, non-porous, etc.). Examples of pigment particles that can be used for the surface treatment include, but are not limited to, inorganic pigment powders (including natural mineral pigments or synthetic inorganic pigments, etc.), organic dyes, and organic pigment particles.

[0040] More specifically, examples of inorganic pigments include, but are not limited to, titanium oxide, yellow iron oxide, red iron oxide, black iron oxide, talc, zinc oxide, silicon oxide, pearl mica, mica, carbon black, red iron oxide, cerium oxide, manganese violet, cobalt violet, chromium oxide, chromium hydroxide, cobalt titanate, ultramarine, Prussian blue, magnesium oxide, zirconium oxide, kaolin, sericite, muscovite, phlogopite, synthetic mica, lepidolite, biotite, and vermiculite.

[0041] Examples of organic dyes include, but are not limited to, Red No. 3, Red No. 10, Red No. 106, Red No. 201, Red No. 202, Red No. 204, Red No. 205, Red No. 220, Red No. 226, Red No. 227, Red No. 228, Red No. 230, Red No. 401, Red No. 405, Red No. 505, Yellow No. 4, Yellow No. 5, Yellow No. 202, Yellow No. 203, Yellow No. 205, Yellow No. 401, Orange No. 201, Orange No. 203, Orange No. 204, Orange No. 205, Orange No. 206, Orange No. 207, Blue No. 1, Blue No. 2, Blue No. 201, Blue 404, Green No. 3, Green No. 201, Green No. 204, and Green No. 205.

[0042] Examples of organic pigment powders include, but are not limited to, tar pigments, nylon powder, cellulose powder, polyethylene powder, polymethyl methacrylate powder, polystyrene powder, acrylic powder, and silicone powder.

[0043] These pigment particles can be used alone or in combination.

[0044] In the present invention, from the viewpoint of use in makeup cosmetics such as foundation, eye shadow, eyebrow, and blusher, among the above-mentioned examples, the pigment particles may contain at least one selected from the group consisting of titanium oxide, yellow iron oxide, red iron oxide, black iron oxide, talc, zinc oxide, silicon oxide, pearl mica, mica, and sericite.

[0045] (Ester Compound Surface Treatment Agent) In the present invention, the surface treatment agent for the pigment particles of the present invention may be an ester compound surface treatment agent. Here, the ester compound according to the present invention is an ester compound of a fatty acid having 8 to 20 carbon atoms and glycerin.

[0046] The ester compound according to the present invention is not particularly limited, and is preferably one that does not color or is unlikely to color the pigment particles that are the subject of surface treatment.

[0047] Specifically, the fatty acid having 8 to 20 carbon atoms in the ester compound according to the present invention may be, for example, a fatty acid having 8 or more, 10 or more, 12 or more, 14 or more, 16 or more, or 18 or more carbon atoms, or a fatty acid having 20 or less, 19 or less, or 18 or less carbon atoms. Of these, fatty acids having 8 to 18 carbon atoms are preferred, and fatty acids having 12 to 18 carbon atoms are more preferred. Furthermore, such fatty acids may be branched or linear.

[0048] Furthermore, the glycerin in the ester compound according to the present invention may be unpolymerized (i.e., a monomer) monoglycerin or polymerized (i.e., a polymer) polyglycerin. When polyglycerin is used, its degree of polymerization is not particularly limited, but is preferably 2 or more and 10 or less. As the glycerin, monoglycerin, which is a monomer, diglycerin having a degree of polymerization of 2, or decaglycerin having a degree of polymerization of 10 is preferred.

[0049] The ester compound according to the present invention may contain, for example, at least one selected from the group consisting of diglyceryl tetraisostearate, diglyceryl triisostearate, diglyceryl diisostearate, diglyceryl monoisostearate, caprylic / capric triglyceride, glyceryl triethylhexanoate, glyceryl dilaurate, glyceryl triisostearate, decaglyceryl monoisostearate, and decaglyceryl diisostearate. Among these, for example, from the viewpoint of improving the lipophilicity of the surface-treated pigment particles and from the viewpoint of being a naturally-derived material, preferred ester compounds according to the present invention are, for example, diglyceryl tetraisostearate, diglyceryl triisostearate, glyceryl dilaurate, glyceryl triisostearate, decaglyceryl monoisostearate, and decaglyceryl diisostearate.

[0050] The method for surface treatment of pigment particles using the ester compound according to the present invention is not particularly limited, and for example, the "Method for producing powder materials for cosmetics" disclosed in WO 2022 / 030462 may be referred to as appropriate.

[0051] (Metal soap surface treatment agent) In the present invention, the surface treatment agent for the pigment particles of the present invention may be a metal soap surface treatment agent.

[0052] In the present invention, the metal soap surface treatment agent is not particularly limited and may include, for example, a salt of a higher fatty acid with an alkali metal such as sodium or potassium, or a salt of a higher fatty acid with a divalent or trivalent metal (non-alkali metal) such as calcium, zinc, magnesium, or aluminum.

[0053] In the present invention, the higher fatty acid in the metal soap surface treatment agent is not particularly limited and may be, for example, a linear or branched, saturated or unsaturated higher fatty acid having about 6 to 24 carbon atoms, and specific examples include lauric acid, myristic acid, palmitic acid, stearic acid, isostearic acid, and ricinoleic acid.

[0054] Examples of metals that form salts with the above-mentioned higher fatty acids include alkali metals such as sodium and potassium, and divalent or trivalent non-alkali metals such as calcium, magnesium, lithium, barium, and zinc.

[0055] In the present invention, the metal soap surface treatment agent may be, for example, at least one selected from the group consisting of calcium stearate, aluminum dimyristate, and magnesium stearate.

[0056] <Water> The composition of the present invention contains water, which constitutes the external phase of the composition of the present invention.

[0057] The water is not particularly limited and may be, for example, water used in cosmetics and quasi-drugs, such as ion-exchanged water, distilled water, ultrapure water, and tap water.

[0058] In the composition of the present invention, the water content is not particularly limited and may be, for example, 30% by mass or more, 35% by mass or more, or 40% by mass or more, and 95% by mass or less, 90% by mass or less, 80% by mass or less, or 70% by mass or less, based on the total mass of the composition. The water content may be adjusted as appropriate depending on the intended use of the cosmetic composition.

[0059] <Other Components> The composition of the present invention may further contain other components in addition to the components described above. The other components will be described below by way of example, but the present invention is not limited to these examples.

[0060] (Nonionic Surfactant) The composition of the present invention preferably further contains a nonionic surfactant.

[0061] In the present invention, the nonionic surfactant is not particularly limited, and may be, for example, one having an HLB value of 6 or more and 18 or less. The HLB (Hydrophilic-Lypophilic Balance) value is an index showing the balance of hydrophilicity and lipophilicity of a nonionic surfactant, and is defined, for example, in the Kawakami method as HLB value = 7 + 11.7 log (sum of formula weights of hydrophilic moieties / sum of formula weights of lipophilic moieties).

[0062] In the present invention, the nonionic surfactant may include, for example, fatty acid polyglycerol ester and / or polyoxyethylene hydrogenated castor oil.

[0063] The fatty acid constituting the fatty acid polyglycerol ester may be selected from monovalent (monohydroxy) fatty acids having 12 to 22 carbon atoms. For example, saturated monovalent fatty acids such as isostearic acid and unsaturated monovalent fatty acids such as ricinoleic acid are preferred, and among these, polymers of ricinoleic acid are preferably used.

[0064] Furthermore, the fatty acid polyglycerol ester may be selected from those having a polyglycerin repeating unit number of 3 to 8. In the present invention, a specific example of the fatty acid polyglycerol ester is polyglyceryl-6 polyricinoleate, but is not limited thereto.

[0065] Specific examples of polyoxyethylene hydrogenated castor oils include PEG-10 hydrogenated castor oil, PEG-20 hydrogenated castor oil, PEG-25 hydrogenated castor oil, PEG-30 hydrogenated castor oil, PEG-40 hydrogenated castor oil, PEG-50 hydrogenated castor oil, PEG-60 hydrogenated castor oil, PEG-80 hydrogenated castor oil, and PEG-100 hydrogenated castor oil, but are not limited to these.

[0066] When the composition of the present invention contains a nonionic surfactant, its content is not particularly limited and may be, for example, 0.5% by mass or more, 1.0% by mass or more, 1.5% by mass or more, 2.0% by mass or more, or 2.2% by mass or more, based on the entire composition, and may be 10% by mass or less, 8.0% by mass or less, 5.0% by mass or less, 4.5% by mass or less, 4.0% by mass or less, 3.5% by mass or less, 3.0% by mass or less, or 2.5% by mass or less.

[0067] Water-Soluble Alkyl-Substituted Polysaccharide Derivatives The compositions of the present invention may further comprise a water-soluble alkyl-substituted polysaccharide derivative.

[0068] In the present invention, the water-soluble alkyl-substituted polysaccharide derivative is not particularly limited, and examples thereof include hydrophobically modified alkyl cellulose, hydrophobically modified sulfonated polysaccharide derivatives, etc. Water-soluble alkyl-substituted polysaccharide derivatives, particularly hydrophobically modified alkyl cellulose, are usually classified as "polymer surfactants."

[0069] In the present invention, hydrophobically modified alkyl cellulose refers to alkyl cellulose that has been hydrophobically modified with an alkyl group having 14 to 22 carbon atoms. This hydrophobically modified alkyl cellulose is a compound in which a long-chain alkyl group, which is a hydrophobic group, has been introduced into a water-soluble cellulose ether derivative, and is represented by the following general formula (I):

[0070] [wherein R may be the same or different and is a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a -[CH ２ CH (CH ３ ) O] ｍ -H (wherein m is an integer of 1 to 5, preferably 1 to 3), a group -CH ２ CH ２ OH and the group —CH ２ CH(OH)CH ２ OR' (wherein R' is an alkyl group having 14 to 22 carbon atoms), but the group -CH ２ CH(OH)CH ２ OR' is always included. A is a group -(CH ２ ) ｑ - (q is an integer of 1 to 3, preferably 1), and n is an integer of 100 to 10,000, preferably 500 to 5,000.

[0071] The method for producing the hydrophobically modified alkyl cellulose of formula (I) generally involves the use of a water-soluble cellulose ether derivative as a base, specifically, methyl cellulose (wherein R is a hydrogen atom or a methyl group), ethyl cellulose (wherein R is a hydrogen atom or an ethyl group), propyl cellulose (wherein R is a hydrogen atom or a propyl group), butyl cellulose (wherein R is a hydrogen atom or a butyl group), hydroxypropyl cellulose (wherein R is a hydrogen atom or a hydroxypropyl group (group -[CH ２ CH (CH ３ ) O]ｍ -H (wherein m is an integer of 1 to 5, preferably 1 to 3)], hydroxypropyl methylcellulose (wherein R is a hydrogen atom, a methyl group, or a hydroxypropyl group (same as above)), or the like, can be contacted with a compound for introducing a long-chain alkyl group having 14 to 22 carbon atoms, specifically, a long-chain alkyl glycidyl ether of the following formula (II), in the presence of an alkali catalyst.

[0072] [wherein R' is an alkyl group having 14 to 22 carbon atoms.]

[0073] The group -CH introduced into the hydrophobically modified alkyl cellulose ２ CH(OH)CH ２ The OR' content is preferably about 0.1 to 5.0% by mass based on the total hydrophobically modified alkyl cellulose. To achieve this content, the molar ratio of the water-soluble cellulose ester derivative and the long-chain alkyl glycidyl ether in the reaction, the reaction time, the type of alkali catalyst, and other factors may be appropriately selected. After the reaction, the reaction product may be subjected to purification steps such as neutralization, filtration, washing, drying, and sieving.

[0074] Among the above water-soluble cellulose ether derivatives, it is particularly preferable to select hydroxypropylmethylcellulose (wherein R in formula (I) is a hydrogen atom, a methyl group, a -[CH ２ CH (CH ３ ) O] ｍ H and the group —CH ２ CH(OH)CH ２ OR', and q of the group A is 1, and A is a methylene group).

[0075] Furthermore, R' in the long-chain alkyl glycidyl ether of formula (II) is an alkyl group having 14 to 22 carbon atoms, preferably an alkyl group having 14 to 20 carbon atoms, and more preferably a stearyl group having 18 carbon atoms (-C １８ H ３７ If the alkyl group R′ has less than 14 carbon atoms or 23 or more carbon atoms, the emulsion stability of the resulting hydrophobically modified alkyl cellulose will be insufficient.

[0076] The weight average molecular weight of the hydrophobically modified alkyl cellulose is preferably 100,000 to 1,000,000, more preferably 300,000 to 800,000, and even more preferably 550,000 to 750,000.

[0077] In the present invention, the hydrophobically modified alkyl cellulose is preferably hydrophobically modified hydroxypropyl methylcellulose (hydrophobized hydroxypropyl methylcellulose), more specifically, stearoxy hydroxypropyl methylcellulose, stearoxy hydroxypropyl cellulose, or laureth-13PG hydroxyethyl cellulose. Alternatively, commercially available hydrophobically modified alkyl celluloses may be used, including, but not limited to, Sangelose 90L (display name: hydrophobized hydroxypropyl methylcellulose; manufactured by Daido Chemical Industry Co., Ltd.), Natrosol Plus 330cs (manufactured by Ashland), and Polysurf 67cs (manufactured by Ashland).

[0078] Hydrophobically Modified Sulfonated Polysaccharide Derivatives In the present invention, the hydrophobically modified sulfonated polysaccharide derivative preferably has a polysaccharide or a derivative thereof as a basic skeleton in which some or all of the hydrogen atoms of the hydroxyl groups have been substituted with the following substituents (a) and (b). The substituent (a) is preferably a glyceryl ether group having a hydrophobic moiety selected from an alkyl glyceryl ether group having a linear or branched alkyl group of 10 to 40 carbon atoms and an alkenyl glyceryl ether group having a linear or branched alkenyl group of 10 to 40 carbon atoms. The substituent (b) is preferably a sulfoalkyl group having 1 to 5 carbon atoms, which may be substituted with a hydroxyl group, or a salt thereof. Here, "water-soluble" refers to a compound that dissolves in water at 25°C in an amount of 0.001% by mass or more.

[0079] Specific examples of the substituent (a) include, but are not limited to, a 2-hydroxy-3-alkoxypropyl group, a 2-alkoxy-1-(hydroxymethyl)ethyl group, a 2-hydroxy-3-alkenyloxypropyl group, and a 2-alkenyloxy-1-(hydroxymethyl)ethyl group. The alkyl or alkenyl group having 10 to 40 carbon atoms substituting these glyceryl ether groups is preferably a linear or branched alkyl or alkenyl group having 12 to 36 carbon atoms, more preferably 16 to 24 carbon atoms, and among these, an alkyl group is preferred, with a linear alkyl group being more preferred.

[0080] Specific examples of the substituent (b) include, but are not limited to, a 2-sulfoethyl group, a 3-sulfopropyl group, a 3-sulfo-2-hydroxypropyl group, a 2-sulfo-1-(hydroxymethyl)ethyl group, and the like, all or a part of which may be in the form of a salt with an alkali metal such as Na or K, an alkaline earth metal such as Ca or Mg, an organic cation group such as an amine, an ammonium ion, or the like.

[0081] The degree of substitution with substituent (a) is preferably 0.001 to 1 per constituent monosaccharide residue, more preferably 0.002 to 0.5, and even more preferably 0.003 to 0.1. The degree of substitution with substituent (b) is preferably 0.01 to 2.5 per constituent monosaccharide residue, more preferably 0.02 to 2, and even more preferably 0.1 to 1.5. The ratio of the number of substituents (a) to the number of substituents (b) is preferably 1:1,000 to 100:1, more preferably 1:500 to 10:1, and even more preferably 1:300 to 10:1.

[0082] The polysaccharide or derivative thereof that serves as the basic skeleton of the hydrophobically modified sulfonated polysaccharide derivative is not particularly limited, but examples thereof include cellulose, hydroxyethyl cellulose, methyl cellulose, ethyl cellulose, and hydroxypropyl cellulose. The weight-average molecular weight of these polysaccharides or derivatives thereof is preferably 10,000 to 10,000,000, more preferably 100,000 to 5,000,000, and even more preferably 300,000 to 2,000,000.

[0083] In the present invention, specific examples of hydrophobically modified sulfonated polysaccharide derivatives include, but are not limited to, stearoxy PG hydroxyethyl cellulose sulfonate, etc. Commercially available hydrophobically modified sulfonated polysaccharide derivatives can also be used, such as, but not limited to, Poise 310 (stearoxy PG hydroxyethyl cellulose sulfonate; manufactured by Kao Corporation).

[0084] When the composition of the present invention contains a water-soluble alkyl-substituted polysaccharide derivative, its content is not particularly limited and may be, for example, 0.01% by mass or more, 0.05% by mass or more, or 0.1% by mass or more, and may be 3.0% by mass or less, 2.0% by mass or less, 1.0% by mass or less, 0.5% by mass or less, or 0.3% by mass or less, based on the total mass of the composition.

[0085] Acrylic Acid-Based Thickener The composition of the present invention may further comprise an acrylic acid-based thickener.

[0086] In the present invention, the acrylic acid-based thickener is not particularly limited, and may include, for example, at least one selected from acrylamide / sodium acryloyldimethyltaurate copolymer, ammonium acryloyldimethyltaurate / beheneth-25 methacrylate crosspolymer, and acrylates / C10-30 alkyl acrylate crosspolymer.

[0087] When the composition of the present invention contains an acrylic acid-based thickener, its content is not particularly limited and may be, for example, 0.05% by mass or more, 0.1% by mass or more, 0.2% by mass or more, 0.3% by mass or more, 0.4% by mass or more, 0.5% by mass or more, or 0.6% by mass or more, and may be 5.0% by mass or less, 3.0% by mass or less, or 1.0% by mass or less, relative to the entire composition.

[0088] (Other Optional Components) The composition of the present invention may contain, for example, other surfactants, other aqueous components, moisturizers, antioxidants, alcohols, cosmetic ingredients, lecithin, glycolipids, plant extracts, preservatives, fragrances, pH adjusters, pigments, etc., within the scope of not impairing the effects of the present invention.

[0089] <<Production Method of the Present Invention>> The present invention can also provide a method for producing an oil-in-water emulsion cosmetic composition.

[0090] The manufacturing method of the present invention is a method for manufacturing an oil-in-water emulsion cosmetic composition containing an oil and pigment particles dispersed in the oil, wherein the pigment particles are surface-treated with an ester compound of a fatty acid having 8 to 20 carbon atoms and glycerin, surface-treated with a metal soap surface treatment agent, or a combination thereof, and the method comprises the following steps: (a) preparing an aqueous phase part; (b) dispersing the pigment particles in a non-volatile oil by mechanical force to obtain an oil phase part having a maximum particle size of 15 μm or less as measured by a grindmeter; and (c) adding the oil phase part to the aqueous phase part and emulsifying.

[0091] According to the production method of the present invention, the composition of the present invention described above can be produced. Therefore, the explanation of each raw material component used in the production method of the present invention can be appropriately referred to the explanation of the "composition of the present invention" described above, and therefore the explanation will be omitted here.

[0092] <Step (a)> In step (a), an aqueous phase part is prepared.

[0093] In the manufacturing method of the present invention, the aqueous phase part can include an aqueous phase containing water and optionally other components such as an aqueous component, a moisturizer, a pH adjuster, etc., optionally a thickener, and optionally a surfactant.

[0094] The aqueous phase part may be prepared by mixing and / or stirring each of the raw material components that may be contained in the aqueous phase part.

[0095] <Step (b)> In step (b), the pigment particles of the present invention are dispersed in oil by mechanical force to obtain an oil phase part having a maximum particle size of 15 μm or less as measured by a grindometer.

[0096] Here, dispersing the pigment particles of the present invention in oil by mechanical force may include kneading the pigment particles of the present invention with oil by mechanical force. Here, the oil used to adjust the particle size of the surface-treated pigment particles is preferably a non-volatile oil, and more preferably a non-volatile oil with a viscosity of 25 mPa·s or more and 5000 mPa·s or less. The machine used here may be, for example, a three-roller machine (e.g., manufactured by Imex Co., Ltd.).

[0097] In the present invention, the oil phase part may further contain, in addition to the pigment particles and non-volatile oil of the present invention, an oily component such as an oil content.

[0098] <Step (c)> In step (c), the oil phase part is added to the aqueous phase part and emulsified.

[0099] The emulsification may be carried out by a conventional method, for example, using a homomixer.

[0100] In addition, in the production method of the present invention, a nonionic surfactant and / or a water-soluble alkyl-substituted polysaccharide derivative may be added to the aqueous phase part obtained in step (a), and then the oil phase part may be added to the aqueous phase part in step (c).

[0101] <<Uses and Formulations of the Composition of the Present Invention>> The composition of the present invention can be suitably used as a makeup cosmetic because the surface-treated pigment particles can be stably incorporated into emulsified particles and the composition has excellent stability over time at high temperatures.

[0102] In the present invention, examples of makeup cosmetics include, but are not limited to, foundation, blush, eyebrow, eye shadow, eyeliner, mascara, lipstick, makeup base, concealer, eye cream, and lip balm.

[0103] Furthermore, the dosage form of the composition of the present invention is not particularly limited, and examples thereof include, but are not limited to, solid, semi-solid, solid paste, stick, emulsion, liquid, gel, sherbet, cream, ointment, and paste.

[0104] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these. Unless otherwise specified, the blending amounts in the tables are expressed in mass %.

[0105] Examples, Comparative Examples, and Reference Examples Oil-in-water emulsion cosmetic compositions of the corresponding Examples, Comparative Examples, and Reference Examples were prepared based on the formulations in Tables 1 to 3 below.

[0106] In addition, in Examples 1 to 6, the surface-treated pigment particles were made into a paste using a triple roller together with the non-volatile oil corresponding to the table, and then measured using a grind meter (Aimex Co., Ltd.) to use pigment particles with a maximum particle size of 15 μm or less.

[0107] Each of the resulting compositions was evaluated for "emulsification" and "high-temperature stability over time" based on the following criteria. The evaluation results are shown in Tables 1 to 3.

[0108] <Evaluation of Emulsification> Each composition was evaluated for emulsification. More specifically, a small amount of a sample of the composition was mixed with water, and the appearance of the composition was judged to determine whether or not the pigment particles in the composition aggregated.

[0109] As a result, samples that had no abnormalities in appearance, i.e., samples that were judged to have been emulsified, were rated as "A", and samples that had abnormalities in appearance (aggregation), i.e., samples that were judged not to have been emulsified, were rated as "B".

[0110] <Evaluation of High-Temperature Stability> Each composition was stored at 37°C for 2 weeks.

[0111] After storage, a small amount of the composition sample was mixed with water, and the appearance of the composition was judged to determine whether the pigment particles in the composition had aggregated. Those that appeared to be blended (i.e., stable) were rated "A," those that showed some aggregation were rated "B," and those that showed significant aggregation were rated "C."

[0112]

[0113]

[0114]

[0115] As is clear from Table 1, it was found that in all of the compositions of Examples 1 to 3, the surface-treated pigment particles were stably incorporated into the emulsified particles, and the compositions also had excellent stability over time at high temperatures.

[0116] In contrast, the compositions of Comparative Examples 1 to 3 were found to have poor high-temperature stability over time, although the surface-treated pigment particles were stably incorporated into the emulsion particles. This is thought to be due to the fact that the maximum particle size of the incorporated surface-treated pigment particles, as measured with a grindometer, was greater than 15 μm. In other words, the compositions of Comparative Examples 1 to 3 were found to have poor high-temperature stability over time due to the large maximum particle size of the surface-treated pigment particles.

[0117] Similarly, as is clear from Table 2, it was found that in all of the compositions of Examples 4 to 6, the surface-treated pigment particles were stably blended into the emulsified particles, and the compositions also had excellent stability over time at high temperatures.

[0118] In contrast, the compositions of Comparative Examples 4 to 6 were found to have poor stability over time at high temperatures due to the large maximum particle size of the surface-treated pigment particles.

[0119] Furthermore, as shown in Table 3, Reference Example 1 used pigment particles that had been surface-treated with an amino acid-based surface treatment agent. Although the maximum particle size of the surface-treated pigment particles measured with a grindmeter exceeded 15 μm, the evaluation of high-temperature stability over time was not as good as in Examples 1 to 6, but better results were obtained than in Comparative Examples 1 to 6.

[0120] In addition, in Comparative Examples 7 and 8, the surface-treated pigment particles were dispersed in a low-viscosity oil and treated by mechanical force, but the maximum particle size of the pigment particles measured by a grind meter could not be reduced to 15 μm or less.

[0121] Furthermore, in Comparative Example 9, pigment particles surface-treated with stearoyl glutamate disodium and dimethicone were used, but it was found that poor results were obtained in both the evaluation of emulsification and the evaluation of high-temperature stability over time.

[0122] Oil-in-water emulsion cosmetic compositions were prepared based on Table 3-1 below for Example 7 and Comparative Example 10. In Example 7, the surface-treated pigment particles were mixed with the non-volatile oil corresponding to the table and ground into a paste using a triple roller, and then measured with a grind meter (Aimex Co., Ltd.) to determine whether the maximum particle size was 15 μm or less.

[0123] Each of the resulting compositions was evaluated for "emulsification" and "high-temperature stability over time" in the same manner as above, and the evaluation results are shown in Table 3-1.

[0124]

[0125] As is clear from the results in Table 3-1, the composition of Example 7 was found to be able to stably incorporate the surface-treated pigment particles into the emulsion particles, and also to have excellent high-temperature stability over time, compared to the composition of Comparative Example 10.

[0126] <Formulation Examples> Formulation examples of the composition of the present invention are given below, but the present invention is not limited to the following formulation examples.

[0127] <Prescription Examples 1 and 2>

[0128] In Formulation Examples 1 and 2, the maximum particle size of the surface-treated pigment particles blended was 15 μm or less as measured by a grindometer.

Claims

1. An oil-in-water type emulsified cosmetic composition containing an oil component and pigment particles dispersed in the oil component, wherein the pigment particles are surface-treated with an ester compound of a fatty acid having 8 to 20 carbon atoms and glycerin, surface-treated with a metal soap surface treatment agent, or a combination thereof, and the pigment particles have a maximum particle diameter measured by a grindometer of 15 μm or less.

2. The composition according to claim 1, further comprising a nonionic surfactant.

3. The composition according to claim 2, wherein the nonionic surfactant contains a fatty acid polyglycerin ester and / or a polyoxyethylene hydrogenated castor oil.

4. The composition according to any one of claims 1 to 3, further comprising a water-soluble alkyl-substituted polysaccharide derivative.

5. The composition according to claim 4, wherein the water-soluble alkyl-substituted polysaccharide derivative contains stearoxyhydroxypropylmethylcellulose.

6. The composition according to any one of claims 1 to 5, further comprising an acrylic thickener.

7. The composition according to any one of claims 1 to 6, wherein the oil component contains a non-volatile oil.

8. The composition according to claim 7, wherein the viscosity of the non-volatile oil is 25 mPa·s or more and 5000 mPa·s or less.

9. The composition according to claim 7 or 8, wherein the non-volatile oil contains at least one selected from the group consisting of trimethylphenyltrisiloxane, pentaerythrityl tetraethylhexanoate, triethylhexanoin, diphenylsiloxyphenyltrimethicone, and polyglyceryl-2 triisostearate.

10. The composition according to any one of claims 1 to 9, wherein the ester compound is at least one selected from the group consisting of diglyceryl tetraisostearate, diglyceryl triisostearate, glyceryl tri(caprylic acid / capric acid), glyceryl dilaurate, glyceryl triisostearate, decaglyceryl monoisostearate, and decaglyceryl diisostearate.

11. The composition according to any one of claims 1 to 10, wherein the metal soap surface treatment agent is at least one selected from the group consisting of calcium stearate, aluminum dimyristate, and magnesium stearate.

12. The composition according to any one of claims 1 to 11, wherein the pigment particles are 50 to 150 parts by mass with respect to 100 parts by mass of the oil component.

13. A method for producing an oil-in-water type emulsified cosmetic composition containing an oil component and pigment particles dispersed in the oil component, wherein the pigment particles are surface-treated with an ester compound of a fatty acid having 8 to 20 carbon atoms and glycerin, surface-treated with a metal soap surface treatment agent, or a combination thereof, and the method includes the following steps: (a) preparing an aqueous phase part; (b) dispersing the pigment particles in the oil component by mechanical force to obtain an oil phase part having a maximum particle diameter measured by a grindometer of 15 μm or less; (c) adding the oil phase part to the aqueous phase part and emulsifying it.

14. The production method according to claim 13, wherein a nonionic surfactant and / or a water-soluble alkyl-substituted polysaccharide derivative is added to the aqueous phase part obtained in step (a), and then the oil phase part is added to the aqueous phase part in step (c).

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