Emulsion composition

Abstract

To provide an emulsion composition having excellent emulsion stability.SOLUTION: An emulsion composition contains (A) an oil-based component, (B) an aqueous-based component, and (C) surface-treated, non-porous silica with a primary particle size of 0.15-1.5 μm.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an emulsion composition, and more particularly to an emulsion composition prepared using solid particles. [Background technology]

[0002] In recent years, attention has been drawn to emulsification techniques using solid particles that can serve as alternatives to surfactants. For example, Patent Document 1 discloses an emulsion composition that uses solid particles that have been surface-treated with an amphiphilic substance instead of a surfactant. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2013-545720 Summary of the Invention [Problem to be solved by the invention]

[0004] However, research and development of emulsification techniques using solid particles has not yet progressed sufficiently, and in particular, no technique has been established that can provide an emulsion composition with excellent emulsion stability.

[0005] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an emulsion composition having excellent emulsion stability. [Means for solving the problem]

[0006] The present inventors have conducted extensive research in light of the above circumstances and have unexpectedly found that an emulsion composition with excellent emulsion stability can be obtained by using a component in which the primary particle size of surface-treated nonporous silica is controlled to a specific range of 0.15 to 1.5 μm, thereby arriving at the present invention.

[0007] The present invention provides the following [1] to [6]. [1] An emulsion composition comprising (A) an oil component, (B) an aqueous component, and (C) surface-treated nonporous silica having a primary particle diameter of 0.15 to 1.5 μm. [2] The emulsion composition according to [1], wherein the emulsion composition is a water-in-oil emulsion composition. [3] The emulsion composition according to [1] or [2], wherein the nonporous silica (C) is nonporous silica that has been surface-treated with triethoxycaprylylsilane. [4] The emulsion composition according to any one of [1] to [3], wherein the oil component (A) has a water holding rate of 100% by mass or more. [5] The emulsion composition according to any one of [1] to [4], which contains 3% by mass or less of a surfactant based on the total amount of the emulsion composition. [6] The BET specific surface area of ​​the non-porous silica (C) is 50 m 2 The emulsion composition according to any one of [1] to [5], wherein the emulsion composition has a water solubility of 1000 kJ / g or less.

[0008] The present invention further provides the following [7] to [9]. [7] The emulsion composition according to any one of [1] to [6], wherein the nonporous silica (C) has a methanol wettability of 0 to 47. [8] The emulsion composition according to any one of [1] to [7], wherein the oily component (A) is an ultraviolet absorber. [9] The emulsion composition according to any one of [1] to [8], which contains an ultraviolet scattering agent. [Effects of the Invention]

[0009] According to the present invention, an emulsion composition having excellent emulsion stability can be provided. [Brief explanation of the drawings]

[0010] [Figure 1]This figure shows the results of the coating uniformity evaluation of Example 38 in Test Example 7. The left figure is a binarized image of Raman spectrum imaging, with the white areas indicating the signal intensity of the UV absorber contained in the composition. The right figure is a histogram of the Raman spectrum imaging, expressed as signal intensity and the number of sampling points. [Figure 2] FIG. 1 is a graph showing the results of evaluation of coating film uniformity for emulsion compositions with insufficient emulsion stability. DETAILED DESCRIPTION OF THE INVENTION

[0011] The following describes in detail an embodiment of the present invention, but the present invention is not limited to the following embodiment.

[0012] <Emulsified composition> The emulsion composition according to an embodiment of the present invention contains (A) an oil component, (B) an aqueous component, and (C) surface-treated nonporous silica having a primary particle size of 0.15 to 1.5 μm.

[0013] [(A) Oily component] The component (A) used in the present invention is an oil-soluble component that constitutes the oil phase of the emulsion composition.

[0014] Component (A) can be any oily component typically used in topical compositions or cosmetics, without any particular limitations. Specific examples include hydrocarbon oils, ester oils, silicone oils, higher alcohols, higher fatty acids, natural animal and vegetable oils and fats, and ultraviolet absorbers. These can be used alone or in combination of two or more. Oily components that are solid at room temperature can be dissolved in liquid oil before use.

[0015] As the hydrocarbon oil, paraffinic hydrocarbons and olefinic hydrocarbons are used, and examples thereof include squalane, squalene, ceresin, paraffin, pristane, microcrystalline wax, liquid paraffin, petrolatum, hydrogenated polyisobutene, and light liquid paraffin.

[0016] As the ester oil, synthetic esters and esters of higher alcohols and higher fatty acids are used, and examples thereof include diisobutyl adipate, di-2-hexyldecyl adipate, di-2-heptylundecyl adipate, isostearyl isostearate, trimethylolpropane triisostearate, cetyl 2-ethylhexanoate (cetyl ethylhexanoate), neopentyl glycol di-2-ethylhexanoate, trimethylolpropane tri-2-ethylhexanoate, glyceryl tri-2-ethylhexanoate, and pentaerythritol tetra-2-ethylhexanoate. Pentaerythritol Tetra-2-ethylhexanoate, Octyldodecyl Neopentanoate, Cetyl Octanoate, Caprylic / Caprylic Triglyceride, Neopentyl Glycol Dicaprate, 2-Ethylhexyl Succinate, Isocetyl Stearate, Butyl Stearate, Diisopropyl Sebacate, Cetyl Lactate, Tetradecyl Lactate, Octyldodecyl Lactate, Isopropyl Myristate, Octyldodecyl Myristate, Cetyl Myristate, Myristyl Myristate, Octyl Palmitate, 2-Ethylhexyl Palmitate, 2-Hexyl Palmitate Xyldecyl, 2-heptylundecyl palmitate, cholesteryl 12-hydroxystearate, isononyl isononanoate, triethylhexyl trimellitate, diisostearyl malate, pentaerythrityl tetrarosinate, phytosteryl oleate, phytosteryl macadamia nut fatty acid, dimer dilinoleyl diisostearate, di(isostearyl / phytosteryl) dimer dilinoleate, dimer dilinoleyl dimer dilinoleate, dimer dilinoleyl hydrogenated rosin condensate, phytosteryl / isostearyl dimer dilinoleate Dimer Dilinoleyl Dimer Dilinoleate, Bis(Phytosteryl / Behenyl / Isostearyl), Dimer Dilinoleyl Dimer Dilinoleate, Polyglyceryl-10 Dimer Dilinoleate / Stearic Acid / Hydroxystearic Acid, Polyglyceryl-2 Isostearate / Dimer Dilinoleate Copolymer, Bis-Diglyceryl Polyacyladipate-2, Di(Phytosteryl / Octyldodecyl) Lauroyl Glutamate, Dipentaerythrityl Tri-Polyhydroxystearate, Di(Octyldodecyl / Phytosteryl) Lauroyl Glutamate,Examples include phytosteryl isostearate and diglyceryl triisostearate.

[0017] Examples of silicone oils include siloxanes such as dimethylpolysiloxane, methylphenylpolysiloxane, methylcyclopentasiloxane, highly polymerized methylpolysiloxane, decamethylcyclopentasiloxane, octamethylcyclotetrasiloxane, methylhydrogenpolysiloxane, methyltrimethicone, dimethiconol, and dimethiconol crosspolymer, alkyl-modified silicones such as caprylyl methicone, amino-modified silicones such as aminopropyl dimethicone and amodimethicone, crosslinked methylpolysiloxane, crosslinked alkyl-modified silicone, amino-modified silicone, polyether-modified silicone, polyglycerin-modified silicone, crosslinked polyether-modified silicone, crosslinked alkylpolyether-modified silicone, silicone / alkyl chain co-modified polyether-modified silicone, silicone / alkyl chain co-modified polyglycerin-modified silicone, polyether-modified branched silicone, polyglycerin-modified branched silicone, acrylic silicone, phenyl-modified silicone, and silicone resin.

[0018] Examples of higher alcohols include cetanol, cetostearyl alcohol, stearyl alcohol, behenyl alcohol, octyldodecanol, isostearyl alcohol, lauryl alcohol, myristyl alcohol, palmityl alcohol, hexadecyl alcohol, oleyl alcohol, hexyldodecanol, batyl alcohol, phytosterol, and cholesterol.

[0019] Examples of higher fatty acids that can be used include saturated or unsaturated, straight-chain or branched-chain fatty acids having 8 or more carbon atoms, and specific examples include lauric acid, myristic acid, palmitic acid, stearic acid, isostearic acid, isopalmitic acid, caprylic acid, capric acid, heptanoic acid, pelargonic acid, behenic acid, undecylenic acid, 2-palmitoleic acid, oleic acid, elaidic acid, ricinoleic acid, linoleic acid, linolenic acid, linoelaidic acid, arachidonic acid, petroselinic acid, ricinoleic acid, and polyhydroxystearic acid.

[0020] Examples of natural animal and vegetable oils and fats include avocado oil, linseed oil, almond oil, olive oil, cacao oil, beef tallow, tung oil, wheat germ oil, sesame oil, rice germ oil, rice bran oil, safflower oil, soybean oil, evening primrose oil, camellia oil, corn oil, rapeseed oil, horse fat, persic oil, palm oil, palm kernel oil, castor oil, sunflower oil, lard, grape oil, jojoba oil, macadamia nut oil, mink oil, cottonseed oil, Japan wax oil, coconut oil, hardened coconut oil, peanut oil, lanolin, egg yolk oil, and rosehip oil.

[0021] Examples of ultraviolet absorbers include ethylhexyl paramethoxycinnamate, octocrylene, ethylhexyl salicylate, homosalate, diethylamidohydroxybenzoylhexylbenzoate, bisethylhexyloxyphenol methoxyphenyl triazine, t-butylmethoxybenzoylmethane, ethylhexyl triazone, dimethicodiethylbenzalmalonate, and polysilicone-15.

[0022] From the viewpoint of significantly achieving the effects of the present invention, it is preferable that the component (A) contains an oil component with a water holding percentage of 100% by mass or more (hereinafter, sometimes referred to as a "high water holding percentage oil component.") As the high water holding percentage oil component, an oil component with a water holding percentage of 100 to 1200% by mass is more preferable, an oil component with a water holding percentage of 200 to 1000% by mass is particularly preferable, and an oil component with a water holding percentage of 250 to 900% by mass is most preferable.

[0023] Specific examples of high water-holding oily components include macadamia nut fatty acid phytosteryl (water holding rate: 350% by mass), polyhydroxystearic acid (water holding rate: 300% by mass), polyglyceryl-10 (dimer dilinoleate / stearic acid / hydroxystearic acid) (water holding rate: 800% by mass), di(isostearyl / phytosteryl) dimer dilinoleate (water holding rate: 250% by mass), dimer dilinoleate (phytosteryl / isostearyl / cetyl / stearyl / behenyl) (water holding rate: 300% by mass), and bis-diglyceryl polyacyladipate-2 (water holding rate: 200% by mass). , di(phytosteryl / octidodecyl) lauroyl glutamate (water holding rate: 400% by mass), lanolin (water holding rate: 400% by mass), cholesteryl hydroxystearate (water holding rate: 300% by mass), dipentaerythrityl tri-polyhydroxystearate (water holding rate: 1200% by mass), di(octyldodecyl / phytosteryl) lauroyl glutamate (water holding rate: 220% by mass), phytosteryl isostearate (water holding rate: 270% by mass), diglyceryl triisostearate (water holding rate: 1600% by mass), and polysilicone-15 (water holding rate: 100% by mass). Among these, macadamia nut fatty acid phytosteryl, polyhydroxystearic acid, polyglyceryl-10 (dimer dilinoleate / stearic acid / hydroxystearic acid), and diglyceryl triisostearate are preferred, macadamia nut fatty acid phytosteryl, polyhydroxystearic acid, and polyglyceryl-10 (dimer dilinoleate / stearic acid / hydroxystearic acid) are more preferred, and polyhydroxystearic acid is even more preferred.

[0024] The total content of the high water-holding oily ingredients can be appropriately set depending on the types and amounts of other ingredients, dosage form, etc., and is not limited, but is usually 0.1 to 10% by mass relative to the total amount of the emulsion composition, preferably 0.5 to 9% by mass, more preferably 1 to 8% by mass, even more preferably 2 to 7% by mass, and particularly preferably 2 to 6% by mass.

[0025] When two or more types of components (A) are used in combination, the types are not particularly limited, but from the viewpoint of significantly achieving the effects of the present invention, it is preferable to use at least one high water holding oil component in combination with at least one oil component with a water holding rate of less than 100% (hereinafter sometimes referred to as a "low water holding oil component").

[0026] Specific examples of low water holding oily components include hydrocarbon oils such as petrolatum, methylpolysiloxane, methylphenylpolysiloxane, decamethylcyclopentasiloxane, methylcyclopentasiloxane, highly polymerized methylpolysiloxane, octamethylcyclotetrasiloxane, methylhydrogenpolysiloxane, methyltrimethicone, caprylyl methicone, dimethicone, isononyl isononanoate, isostearyl isostearate, caprylic / caprylic triglyceride, neopentyl glycol dicaprate, 2-ethylhexyl succinate, isocetyl stearate, butyl stearate, diisopropyl sebacate, cetyl ethylhexanoate, ethylhexyl paramethoxycinnamate, octocrylene, ethylhexyl salicylate, and homosalate.

[0027] In this specification, the "water holding percentage" is calculated by weighing the sample to be measured for water holding percentage (initial amount), heating it to 70°C, gradually adding water (70°C) to the sample while stirring, and measuring the amount of water added up to the end point when water begins to float to the surface of the sample, using the following formula: Water holding rate (mass%) = [amount of water added (g) / initial amount of sample (g)] x 100 In addition, for samples that are volatile at 70°C or solid at 70°C, the water holding rate is set to 0 mass%.

[0028] The total content of component (A) can be appropriately set depending on the types and amounts of other components, dosage form, etc., and is not limited, but is usually 20 to 85% by mass relative to the total amount of the emulsion composition, preferably 25 to 80% by mass, more preferably 30 to 75% by mass, even more preferably 32 to 70% by mass, and particularly preferably 35 to 65% by mass.

[0029] [(B) Aqueous component] The component (B) used in the present invention is a water-soluble component that constitutes the aqueous phase of the emulsion composition.

[0030] Component (B) can be any aqueous component typically used in topical compositions or cosmetics, without any particular limitations. Examples include purified water, ion-exchanged water, and other water-soluble alcohols, water-soluble polymers, and ultraviolet absorbers. These can be used alone or in combination of two or more.

[0031] Examples of water-soluble alcohols include lower alcohols such as ethanol, propanol, isopropanol, and isobutyl alcohol; glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, dipropylene glycol monoethyl ether, and dipropylene glycol monopropyl ether; and polyhydric alcohols such as ethylene glycol, propylene glycol, dipropylene glycol, 1,3-butylene glycol, isoprene glycol, glycerin, diglycerin, triglycerin, tetraglycerin, pentaglycerin, hexaglycerin, heptaglycerin, octaglycerin, decaglycerin, polyglycerin, polyoxyalkylene-added glycerin, and polyoxyalkylene-added diglyceryl.

[0032] Examples of water-soluble polymers include acrylic acid-based thickeners such as acrylic acid / alkyl methacrylate copolymer, hydroxyethyl acrylate / acryloyldimethyl taurate copolymer, polyacrylic acid, or salts thereof; cellulose-based thickeners such as methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, hydroxymethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, hydrophobized hydroxypropyl methyl cellulose, carboxymethyl cellulose, carboxyethyl cellulose, and stearoxyhydroxypropyl methyl cellulose; hyaluronic acid, hyaluronic acid derivatives and salts thereof; mucopolysaccharide-based thickeners such as sodium chondroitin sulfate; amino acid-based thickeners such as collagen; carrageenan; Examples include seaweed-based thickeners such as alginate, propylene glycol alginate, and agar; microbial-derived thickeners such as xanthan gum, hydroxypropyl xanthan gum, dextran, sclerotium gum, and gellan gum; polyethylene glycol-based thickeners such as polyethylene glycol, polyethylene glycol distearate, (PEG-240 / decyl tetradeceth-20 / HDI) copolymer, and glyceryl behenate / polyglyceryl-6 octastearate; starch-based thickeners such as hydroxypropyl starch phosphate and corn starch; and water-soluble anionic polymer-based thickeners (including copolymers, homopolymers, and crosspolymers) containing, as structural units, monomers with anionic groups such as carboxyl groups, sulfonate groups, and phosphate groups.

[0033] Examples of ultraviolet absorbers include phenylbenzimidazole sulfonic acid.

[0034] From the viewpoint of significantly achieving the effects of the present invention, the component (B) preferably contains glycerins such as glycerin, diglycerin, triglycerin, tetraglycerin, pentaglycerin, hexaglycerin, heptaglycerin, octaglycerin, decaglycerin, polyglycerin, polyoxyalkylene-added glycerin, and polyoxyalkylene-added diglyceryl. The polyoxyalkylene-added glycerin and polyoxyalkylene-added diglyceryl are products obtained by addition polymerization of alkylene oxide to glycerin or diglycerin. The number of carbon atoms in the alkylene oxide is not particularly limited, but is preferably 2 to 4, and more preferably 2 to 3. The degree of polymerization of the alkylene oxide is also not particularly limited, but is preferably 3 to 30, and more preferably 9 to 26. For example, glycereth-26 can be mentioned.

[0035] The total content of glycerins can be appropriately set depending on the types and amounts of other ingredients, dosage form, etc., and is not limited, but is usually 1 to 20% by mass relative to the total amount of the emulsion composition. In water-in-oil (W / O) emulsion compositions, it is usually 1 to 10% by mass, preferably 1 to 5% by mass, and more preferably 2 to 5% by mass relative to the total amount of the emulsion composition. In oil-in-water (O / W) emulsion compositions, it is usually 1 to 20% by mass, preferably 1 to 10% by mass, and more preferably 2 to 5% by mass relative to the total amount of the emulsion composition.

[0036] When two or more kinds of components (B) are used in combination, the types are not particularly limited, but from the viewpoint of significantly achieving the effects of the present invention, it is preferable to use one or more selected from the group consisting of glycerins in combination with other aqueous components. Among these, it is particularly preferable that component (B) contains at least one of glycerin and polyoxyethylene-added glycerin, and water.

[0037] The total content of component (B) can be appropriately set depending on the types and amounts of other components, dosage form, etc., and is not limited, but is usually 10 to 75% by mass relative to the total amount of the emulsion composition, preferably 20 to 70% by mass, more preferably 25 to 65% by mass, even more preferably 30 to 65% by mass, and particularly preferably 35 to 65% by mass.

[0038] The ratio of the internal phase to the external phase (internal phase:external phase) of the emulsion composition of the present invention can be appropriately set and is not limited, but is usually 1:9 to 9:1. From the viewpoint of significantly exhibiting the effects of the present invention, the ratio is preferably 3:7 to 6:4, and more preferably 4:6 to 6:4.

[0039] The internal phase of the emulsion composition in the present invention refers to the phase present as droplets in the emulsion composition, and refers to the aqueous phase (containing component (B)) in a water-in-oil (W / O) emulsion composition, and refers to the oil phase (containing component (A)) in an oil-in-water (O / W) emulsion composition. The external phase of the emulsion composition in the present invention refers to the phase present as a continuous phase in the emulsion composition, and refers to the oil phase (containing component (A)) in a water-in-oil (W / O) emulsion composition, and refers to the aqueous phase (containing component (B)) in an oil-in-water (O / W) emulsion composition.

[0040] [(C) Surface-treated nonporous silica having a primary particle diameter of 0.15 to 1.5 μm] The nonporous silica that serves as the base for component (C) used in the present invention can be any silica that is typically used in topical compositions or cosmetics, without any particular limitations. The shape of the nonporous silica is not limited, but it may be spherical or irregular, with spherical being preferred.

[0041] The surface treatment applied to the nonporous silica that is the base of component (C) used in the present invention means modifying the surface of the nonporous silica. Specifically, it means introducing a compound onto the surface of the nonporous silica via a chemical bond such as a covalent bond, a hydrogen bond, an ionic bond, or a van der Waals bond, or via physical or chemical adsorption. The surface treatment method is not particularly limited as long as it can modify the surface of the nonporous silica, and various known methods such as a gas phase method, a liquid phase method, and an autoclave method can be used.

[0042] The surface treatment agent for modifying the surface of nonporous silica can be any agent that is normally used in external compositions or cosmetics, without any particular limitations. Specific examples of hydrophobic surface treatment agents include silane compounds such as trialkoxyalkylsilanes, such as trimethoxyhexylsilane, trimethoxycaprylylsilane, trimethoxydecylsilane, trimethoxyoctadecylsilane, triethoxyhexylsilane, triethoxycaprylylsilane, triethoxydecylsilane, and triethoxyoctadecylsilane; silicones such as dimethicone, triethoxysilylethyl polydimethylsiloxyethylhexyl dimethicone, triethoxysilylethyl polydimethylsiloxyethyl dimethicone, methylhydrogenpolysiloxane, methylhydrogenpolysiloxane-dimethylpolysiloxane copolymer, and dimethylpolysiloxane; fatty acids such as palmitic acid, stearic acid, and isostearic acid; metal soaps such as alkali metal salts or alkaline earth metal salts of fatty acids; and fluorine compounds such as perfluoroalkylphosphoric acid diethanolamine salt and perfluoroalkyltrimethoxysilane. Examples of hydrophilic surface treatment agents include polyhydric alcohols, polysaccharides, water-soluble polymers, and amino acids. These can be used alone or in combination of two or more. Among them, from the viewpoint of significantly achieving the effects of the present invention, stearic acid, isostearic acid, dimethicone, triethoxycaprylylsilane, and triethoxysilylethyl polydimethylsiloxyethylhexyl dimethicone are preferred, triethoxycaprylylsilane and triethoxysilylethyl polydimethylsiloxyethylhexyl dimethicone are more preferred, and triethoxycaprylylsilane is even more preferred.

[0043] The surface treatment in component (C) preferably involves partial treatment of the silica surface. The amount of the surface treatment agent used for the surface treatment is not particularly limited, but is preferably 0.1 to 2.5% by mass relative to 100% by mass of the nonporous silica base. From the viewpoint of significantly achieving the effects of the present invention, the amount is preferably 0.8 to 1.7% by mass, more preferably 0.9 to 1.5% by mass, in a water-in-oil (W / O) emulsion composition. From the viewpoint of significantly achieving the effects of the present invention, the amount is preferably 0.1 to 0.7% by mass, more preferably 0.1 to 0.5% by mass, and even more preferably 0.1 to 0.3% by mass in an oil-in-water (O / W) emulsion composition.

[0044] The degree of surface treatment in the present invention can be appropriately determined depending on the type of surface treatment agent, the shape of the silica particles, and the primary particle size of the silica, and can be determined using, but is not limited to, the methanol wettability.

[0045] The methanol wettability indicates the hydrophobicity of the powder. The minimum methanol mass % value among the aqueous methanol solutions at which the powder precipitates is shown as the methanol wettability.

[0046] The methanol wettability can be measured by the following method. (1) Prepare aqueous methanol solutions with varying methanol concentrations at 5% by mass intervals, and place 5 mL of each solution in a 10 mL test tube. (2) Add 0.2 g of the powder to be measured, put the lid on the test tube, and turn it upside down three times. (3) Immediately place the test tube at rest and observe the movement of the powder in the methanol aqueous solution. (4) The lowest methanol concentration in the test tube in which partial or total sedimentation of the powder is observed is taken as the methanol wettability. For example, for aqueous methanol solutions with methanol contents of 20 mass%, 25 mass%, and 30 mass%, the methanol wettability of a powder that shows no sedimentation in the 20 mass% aqueous methanol solution but shows sedimentation in the 25 mass% aqueous methanol solution and the 30 mass% aqueous methanol solution is 25.

[0047] The methanol wettability of component (C) can be appropriately set depending on the type and amount of other components, dosage form, etc., and is not limited, but is typically 0 to 47. In the case of a water-in-oil (W / O) emulsion composition, from the viewpoint of significantly achieving the effects of the present invention, the methanol wettability is preferably 5 to 45, more preferably 5 to 40, and even more preferably 10 to 35. In the case of an oil-in-water (O / W) emulsion composition, the methanol wettability is typically 0 to 5, and from the viewpoint of significantly achieving the effects of the present invention, 0 is preferred.

[0048] The primary particle size of component (C) is controlled within a specific range of 0.15 to 1.5 μm in order to achieve the effects of the present invention. In order to achieve the effects of the present invention more significantly, the primary particle size is preferably 0.2 to 1.2 μm, more preferably 0.2 to 1.0 μm, even more preferably 0.2 to 0.8 μm, particularly preferably 0.2 to 0.6 μm, and most preferably 0.2 to 0.4 μm. The "primary particle size" of component (C) can be determined by observing the surface-treated nonporous silica with an electron microscope. Specifically, 50 particles observed under the electron microscope are randomly selected, and the average particle size is calculated to determine the primary particle size.

[0049] The term "non-porous" in component (C) does not necessarily mean that there are no pores at all, but rather that the material is substantially non-porous. Specifically, the term refers to a non-porous silica that has been subjected to a surface treatment and has a BET specific surface area of ​​50 m2 or more, as measured by the BET method (gas adsorption method). 2 / g or less. From the viewpoint of significantly exhibiting the effects of the present invention, the BET specific surface area is 1 to 30 m 2 / g is preferred, and 2 to 25m 2 / g is more preferable, and 2 to 20m 2 / g is more preferred.

[0050] The total content of component (C) can be appropriately set depending on the types and amounts of other components, dosage form, etc., and is not limited, but is typically 0.001 to 10% by mass relative to the total amount of the emulsion composition. From the viewpoint of significantly achieving the effects of the present invention, the content is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, even more preferably 0.3% by mass or more, and particularly preferably 0.4% by mass or more, relative to the total amount of the emulsion composition. Furthermore, from the viewpoint of significantly achieving the effects of the present invention and from the viewpoint of the feeling when used, the content is preferably 7% by mass or less, more preferably 6% by mass or less, even more preferably 5% by mass or less, and particularly preferably 4% by mass or less, based on the total amount of the emulsion composition.

[0051] [Ultraviolet Scattering Agent] The emulsion composition according to the embodiment of the present invention contains the above components (A) to (C), and preferably further contains an ultraviolet scattering agent. Examples of ultraviolet scattering agents include inorganic compounds such as hydrous silicic acid, zinc silicate, cerium silicate, titanium silicate, fine particle zinc oxide, zirconium oxide, cerium oxide, fine particle titanium oxide, and iron oxide, and those inorganic compounds coated with inorganic powder such as hydrous silicic acid, aluminum hydroxide, mica, and talc, those composited with resin powder such as polyamide, polyethylene, polyester, polystyrene, and nylon, and those treated with silicone oil, fatty acid aluminum salt, etc. From the viewpoint of improving emulsion stability, fine particle titanium oxide and fine particle zinc oxide are preferred.

[0052] The fine particles in the UV scattering agent used in the emulsion composition according to an embodiment of the present invention refer to particles having a primary particle diameter of 100 nm or less. The primary particle diameter of the UV scattering agent is preferably 50 nm or less, more preferably 40 nm or less, and even more preferably 35 nm or less. The lower limit of the primary particle diameter of the UV scattering agent is not particularly limited, but is, for example, 5 nm or more, preferably 10 nm or more. The primary particle diameter can be observed using an electron microscope, as described above. Specifically, 50 particles observed under an electron microscope are randomly selected, and the average particle diameter of these particles is calculated to determine the primary particle diameter.

[0053] The ultraviolet scattering agent used in the emulsion composition according to an embodiment of the present invention is preferably surface-treated, and is particularly preferably surface-treated to be hydrophobic.

[0054] The type of surface treatment agent for the UV scattering agent used in the emulsion composition according to an embodiment of the present invention is not particularly limited, and examples thereof include trimethoxyhexylsilane, trimethoxycaprylylsilane, trimethoxydecylsilane, trimethoxyoctadecylsilane, triethoxyhexylsilane, triethoxycaprylylsilane, triethoxydecylsilane, triethoxyoctadecylsilane, triethoxysilylethyl polydimethylsiloxyethylhexyl dimethicone, triethoxysilylethyl polydimethylsiloxyethyl dimethicone, methicone, and the like. Examples of suitable surface treatment agents include perfluoroalkyldiethanolamine phosphate, perfluoroalkyltrimethoxysilane, methylhydrogenpolysiloxane, methylhydrogenpolysiloxane-dimethylpolysiloxane copolymer, dimethylpolysiloxane, palmitic acid, stearic acid, isostearic acid, perfluoroalkylphosphoric acid diethanolamine salt, and perfluoroalkyltrimethoxysilane. Of these, it is preferred that the surface treatment be performed with one or more surface treatment agents selected from triethoxycaprylylsilane, methylhydrogenpolysiloxane, dimethylpolysiloxane, stearic acid, and isostearic acid.

[0055] The total content of the ultraviolet scattering agents used in the emulsion composition according to an embodiment of the present invention is preferably 1% by mass or more, and more preferably 3% by mass or more, based on the total amount of the emulsion composition, from the viewpoint of improving emulsion stability. Furthermore, from the viewpoint of usability, the total content of the ultraviolet scattering agent is preferably 30% by mass or less, more preferably 25% by mass or less, particularly preferably 20% by mass or less, and most preferably 15% by mass or less, relative to the total amount of the emulsion composition.

[0056] In the present invention, by including an ultraviolet scattering agent, not only the emulsion stabilizing effect of the formulation but also ultraviolet protection ability can be imparted to the formulation. Therefore, the sunscreen emulsion composition is preferably one that includes an ultraviolet absorber.

[0057] [Other ingredients] The emulsion composition according to the embodiment of the present invention may contain other ingredients as long as the effects of the present invention are not impaired. Examples of ingredients that may be included include, but are not limited to, colorants, vitamins, peptides or derivatives thereof, amino acids or derivatives thereof, and cell-activating ingredients. These ingredients may be used alone or in combination of two or more.

[0058] Examples of colorants include inorganic pigments such as titanium oxide, yellow iron oxide, red iron oxide, black iron oxide, cerium oxide, carbon, kaolin, manganese oxide, and ultramarine, as well as organic dyes and natural dyes.

[0059] Examples of vitamins include vitamin E such as dl-α-tocopherol, d-δ-tocopherol, dl-α-tocopherol succinate, and dl-α-tocopherol calcium succinate; vitamin B2 such as riboflavin, flavin mononucleotide, flavin adenine dinucleotide, riboflavin butyrate, riboflavin tetrabutyrate, riboflavin 5'-phosphate sodium, and riboflavin tetranicotinate; dl-α-tocopherol nicotinate, benzyl nicotinate, methyl nicotinate, and β-butoxyethylene nicotinate. Nicotinic acids such as 1-(4-methylphenyl)ethyl nicotinate, ascorbigen-A, L-ascorbic acid 2-glucoside, ascorbic acid stearate, ascorbic acid palmitate, L-ascorbyl dipalmitate, and other vitamin Cs, methylhesperidin, ergocalciferol, cholecalciferol, and other vitamin Ds, phylloquinone, farnoquinone, and other vitamin Ks, γ-oryzanol, dibenzoylthiamine, dibenzoylthiamine hydrochloride, thiamine hydrochloride, thiamine cetyl hydrochloride, thiamine thiocyanate, thiamine Vitamin B1 compounds such as thiamine lauryl hydrochloride, thiamine nitrate, thiamine monophosphate, thiamine lysine salt, thiamine triphosphate, thiamine monophosphate phosphate, thiamine monophosphate, thiamine diphosphate, thiamine diphosphate hydrochloride, thiamine triphosphate, thiamine triphosphate monophosphate, vitamin B6 compounds such as pyridoxine hydrochloride, pyridoxine acetate, pyridoxal hydrochloride, 5'-pyridoxal phosphate, pyridoxamine hydrochloride, cyanocobalamin, hydroxocobalamin, deoxyadenosylcobalamin, etc. Vitamin B12, folic acids such as folic acid and pteroylglutamic acid, nicotinic acids such as nicotinic acid and nicotinamide, pantothenic acid, calcium pantothenate, pantothenyl alcohol (panthenol), D-pantethesine, D-pantethine, coenzyme A, pantothenyl ethyl ether, and other pantothenic acids, biotin, bioticin, and other biotins, ascorbic acid, sodium ascorbate, dehydroascorbic acid, sodium ascorbyl phosphate, magnesium ascorbyl phosphate, and other ascorbic acid derivatives of vitamin C,Vitamin-like factors such as carnitine, ferulic acid, α-lipoic acid, and orotic acid are included.

[0060] Examples of peptides or derivatives thereof include keratin hydrolyzed peptides, hydrolyzed keratin, collagen, fish-derived collagen, atelocollagen, gelatin, elastin, elastin hydrolyzed peptides, collagen hydrolyzed peptides, hydrolyzed collagen, hydroxypropylammonium chloride hydrolyzed collagen, elastin hydrolyzed peptides, conchiolin hydrolyzed peptides, hydrolyzed conchiolin, silk proteolytic peptides, hydrolyzed silk, sodium lauroyl hydrolyzed silk, soybean proteolytic peptides, hydrolyzed soybean protein, wheat protein, wheat proteolytic peptides, hydrolyzed wheat protein, casein hydrolyzed peptides, and acylated peptides (palmitoyl oligopeptide, palmitoyl pentapeptide, palmitoyl tetrapeptide, etc.).

[0061] Examples of amino acids or derivatives thereof include betaine (trimethylglycine), proline, hydroxyproline, arginine, lysine, serine, glycine, alanine, phenylalanine, β-alanine, threonine, glutamic acid, glutamine, asparagine, aspartic acid, cysteine, cystine, methionine, leucine, isoleucine, valine, histidine, taurine, γ-aminobutyric acid, γ-amino-β-hydroxybutyric acid, carnitine, carnosine, and creatine.

[0062] Examples of cell activation components include amino acids such as γ-aminobutyric acid and ε-aminocaproic acid, vitamins such as retinol, thiamine, riboflavin, pyridoxine hydrochloride and pantothenic acids, α-hydroxy acids such as glycolic acid and lactic acid, tannin, flavonoid, saponin, photosensitizer No. 301, etc.

[0063] [Surfactant] The emulsion composition according to the embodiment of the present invention can contain a low content of surfactant or no surfactant at all because it uses component (C). The emulsion composition according to the embodiment of the present invention contains a low concentration of surfactant such as anionic surfactant, nonionic surfactant, cationic surfactant, or amphoteric surfactant, or no surfactant, and is therefore highly useful in that it can be suitably used on skin with a reduced barrier function or skin with a lowered threshold for irritation that is sensitive to irritation.

[0064] The surfactant is not particularly limited as long as it is typically used in topical compositions or cosmetics, and examples thereof include PEG-10 dimethicone, PEG-3 dimethicone, PEG-12 dimethicone, PEG / PPG-19 / 19 dimethicone, polysilicone 13, PEG-9 polydimethylsiloxyethyl dimethicone, methylpolysiloxane-cetylmethylpolysiloxane-poly(oxyethylene-oxypropylene)methylpolysiloxane copolymer, cetyl dimethicone copolyol, cetyl PEG / PPG-10 / 1 dimethicone, lauryl PEG-9 Polydimethylsiloxyethyl Dimethicone, Bis-Butyl Dimethicone Polyglyceryl-3, Polyglyceryl-3 Polydimethylsiloxyethyl Dimethicone, Polyglyceryl-3 Disiloxane Dimethicone, Lauryl Polyglyceryl-3 Polydimethylsiloxyethyl Dimethicone, Polyethylene Glycol Dipolyhydroxystearate, Sorbitan Oleate, Sorbitan Isostearate, Sorbitan Stearate, Polyoxyethylene (20) Sorbitan Monostearate (Polysorbate 60), Self-Emulsifying Stearin Glyceryl acetate, glyceryl stearate, glyceryl isostearate, polyglyceryl-2 isostearate, polyglyceryl-2 diisostearate, polyglyceryl-10 triisostearate, polyglyceryl-10 tristearate, polyglyceryl-10 condensed ricinoleate, polyglyceryl-10 pentastearate, polyglyceryl-10 pentaisostearate, polyglyceryl-10 pentaoleate, polyglyceryl-10 pentahydroxystearate, polyglyceryl-6 condensed ricinoleate, Examples of suitable oils include polyglyceryl-6 pentaisostearate, polyglyceryl-6 pentaoleate, polyglyceryl-6 pentahydroxystearate, glyceryl oleate, glyceryl sesquioleate, glyceryl trioleate, glyceryl sesquiisostearate, glyceryl isostearate, glyceryl triisostearate, glyceryl sesquistearate, glyceryl tristearate, PEG-5 hydrogenated castor oil, PEG-10 hydrogenated castor oil, PEG-20 hydrogenated castor oil, and PEG-60 hydrogenated castor oil.Among these, polysilicone 13, PEG-9 polydimethylsiloxyethyl dimethicone, cetyl PEG / PPG-10 / 1 dimethicone, lauryl PEG-9 polydimethylsiloxyethyl dimethicone, sorbitan isostearate, sorbitan stearate, polyglyceryl-2 isostearate, polyglyceryl-2 diisostearate, polyglyceryl-10 pentaisostearate, and polyethylene glycol dipolyhydroxystearate are preferred, and cetyl PEG / PPG-10 / 1 dimethicone, polysilicone 13, sorbitan isostearate, polyglyceryl-2 isostearate, polyglyceryl-2 diisostearate, polyglyceryl-10 pentaisostearate, and polyethylene glycol dipolyhydroxystearate are more preferred, with polyglyceryl-10 pentaisostearate, polyethylene glycol dipolyhydroxystearate, and polyglyceryl-2 isostearate being most preferred.

[0065] The HLB of the surfactant is preferably 7 or less, more preferably 6 or less, from the viewpoint of significantly exhibiting the effects of the present invention. Specifically, these ingredients include polysilicone 13 (HLB=2.5), PEG-9 polydimethylsiloxyethyl dimethicone (HLB=4.0), cetyl PEG / PPG-10 / 1 dimethicone (HLB=3.5), lauryl PEG-9 polydimethylsiloxyethyl dimethicone (HLB=3.0), self-emulsifying glyceryl stearate (HLB=5.5), glyceryl stearate (HLB=3.0), glyceryl isostearate (HLB=4.0), sorbitan stearate (HLB=4.5), and sorbitan isostearate (HLB=5.0). 0), polyglyceryl-2 stearate (HLB=5.0), polyglyceryl-2 isostearate (HLB=5.5), polyglyceryl-10 tristearate (HLB=7.0), polyglyceryl-10 triisostearate (HLB=6.5), polyglyceryl-10 pentastearate (HLB=3.5), polyglyceryl-10 pentaisostearate (HLB=3.5), PEG-5 hydrogenated castor oil (HLB=6.0), polyethylene glycol dipolyhydroxystearate (HLB=5.0), etc.

[0066] Here, the HLB (Hydrophile-Lipophile Balance) in the present invention is an index showing the balance of hydrophilicity and lipophilicity, and is known to be calculated by Oda and Teramura et al. using the following formula (1): HLB=(ΣInorganic value / ΣOrganic)×10...(Formula 1) The Σinorganic value / Σorganic value is called the IOB (Inorganic-Organic balance), and can be calculated by adding up the "inorganic value" and "organic value" of the atoms and functional groups that make up organic compounds such as surfactants, based on the "inorganic value" and "organic value" set for each type of atom and functional group (see "Organic Conceptual Diagram - Fundamentals and Applications" by Yoshio Koda, pp. 11-17, Sankyo Publishing, 1984).

[0067] The total content of surfactants is not limited, but from the viewpoint of significantly achieving the effects of the present invention and from the viewpoint of usability, it may be 3% by mass or less, 2% by mass or less, preferably 1.6% by mass or less, more preferably 1.2% by mass or less, even more preferably 0.8% by mass or less, and particularly preferably 0.6% by mass or less, based on the total amount of the emulsion composition. From the viewpoint of significantly achieving the effects of the present invention, it is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, based on the total amount of the emulsion composition.

[0068] The ratio of the total content of surfactants to the total content of component (B) (surfactant / component (B)) is preferably 0.0025 or more, more preferably 0.005 or more, and even more preferably 0.0075 or more, and is preferably 0.025 or less, more preferably 0.02 or less, and even more preferably 0.0175 or less.

[0069] [Manufacturing method] The method for producing the emulsion composition according to the embodiment of the present invention can be a known method and is not particularly limited, and the stirring method during emulsification, emulsification temperature, order of adding the oil phase and the aqueous phase, adding speed, etc. may be appropriately set. Specifically, for example, a method may be used in which an oil phase and an aqueous phase are separately prepared by heating and dissolving as necessary and then mixing, water is gradually added to the oil phase at room temperature, and emulsification is carried out by mechanical stirring using a homogenizer or the like, but is not particularly limited to this. Furthermore, the emulsion composition of the present invention may be either a water-in-oil emulsion composition or an oil-in-water emulsion composition, and is not particularly limited and can be appropriately selected from the viewpoints of the formulation form, application, etc., but from the viewpoint of significantly exhibiting the effects of the present invention, a water-in-oil emulsion composition is preferred.

[0070] [Form of formulation] The formulation of the emulsion composition according to the present invention is not particularly limited, and examples thereof include solutions, suspensions, emulsions, creams, ointments, gels, liniments, lotions, patches, and aerosols. Among these, solutions, suspensions, emulsions, creams, ointments, gels, lotions, and patches are preferred, with creams, emulsions, ointments, lotions, and gels being more preferred. These formulations can be produced according to the methods described in the General Provisions for Preparations of the Japanese Pharmacopoeia, 17th Edition.

[0071] The emulsion composition according to an embodiment of the present invention contains an oily component and an aqueous component, and is typically preferably in the form of a cream, emulsion, or the like.

[0072] When the emulsion composition according to the embodiment of the present invention is used as an emulsion composition for quasi-drugs or cosmetics, examples of uses include basic cosmetics such as lotions, milky lotions, gels, creams, beauty serums, sunscreen cosmetics, packs, masks, hand creams, and body creams; face makeup cosmetics such as foundations and makeup bases; lip cosmetics such as lipsticks, lip balms, lip glosses, and lip liners; and external skin compositions or external skin cosmetics; and hair cosmetics such as styling agents.

[0073] [container] The emulsion composition according to the present invention can be stored in a container of a shape and material appropriately selected depending on the intended use and application. Examples of container shapes include bottles, tubes, jars, droppers, dispensers, sticks, pouches, and cheer packs. Examples of materials include polyethylene terephthalate, polypropylene, polyethylene (HDPE, LDPE, LLDPE, etc.), ABS resin, ethylene vinyl alcohol resin, polystyrene, glass, and metal (aluminum, etc.). These materials can be used as container materials by applying various coatings, combining them by mixing, or laminating them, taking into consideration strength, flexibility, weather resistance, and component stability. Those skilled in the art can also select the diameter and material of the container nozzle and formulation dissolution portion to limit the amount dispensed from the container and reduce adhesion to the container.

[0074] [Emulsification method etc.] The present invention is based on the discovery that an emulsion composition with excellent emulsion stability can be obtained by using a component in which the primary particle size of surface-treated nonporous silica has been controlled to a specific range of 0.15 to 1.5 μm. Therefore, one embodiment of the present invention is preferably provided as, for example, a method for emulsifying or emulsion stabilizing an emulsion composition, which comprises a step of blending and mixing (A) an oily component, (B) an aqueous component, and (C) surface-treated nonporous silica having a primary particle size of 0.15 to 1.5 μm.

[0075] Furthermore, one embodiment of the present invention is preferably provided as an emulsification method or emulsion stabilization method using surface-treated nonporous silica having a primary particle diameter of 0.15 to 1.5 μm as an emulsifier.

[0076] Furthermore, as one embodiment of the present invention, it is also preferably provided as an emulsifier made of surface-treated nonporous silica having a primary particle size of 0.15 to 1.5 μm.

[0077] In addition, as one embodiment of the present invention, it is also preferably provided as an emulsion composition containing (A) an oil component, (B) an aqueous component, and (C) an emulsifier consisting of surface-treated nonporous silica having a primary particle diameter of 0.15 to 1.5 μm.

[0078] In one embodiment of the present invention, the present invention is also suitably provided as surface-treated nonporous silica having a primary particle diameter of 0.15 to 1.5 μm for use in emulsion compositions or emulsion compositions for topical application to skin.

[0079] <Usefulness of the present invention> The emulsion composition according to an embodiment of the present invention is useful in that it has excellent emulsion stability by being an emulsion composition containing (A) an oily component, (B) an aqueous component, and (C) surface-treated nonporous silica having a primary particle diameter of 0.15 to 1.5 μm. Here, "excellent emulsion stability" means that separation and the like can be suppressed at least immediately after preparation of the emulsion composition. Furthermore, "excellent emulsion stability" may mean, but is not limited to, that separation or the like can be suppressed even after a predetermined period of time has passed since the emulsion composition was prepared and stored at room temperature. Furthermore, "excellent emulsion stability" may more preferably mean, but is not limited to, a small emulsion particle size.

[0080] The emulsion composition according to an embodiment of the present invention is an emulsion composition containing (A) an oily component, (B) an aqueous component, and (C) surface-treated nonporous silica having a primary particle diameter of 0.15 to 1.5 μm, and is therefore extremely useful in that it not only has excellent emulsion stability but also provides an excellent feel when used. [Example]

[0081] The present invention will be explained in more detail below, but the present invention is not limited thereto. The contents shown in the following tables are in mass %.

[0082] The emulsion compositions shown in Table 1 below were prepared by a conventional method. In Table 1, the primary particle diameter of each of the component (C), surface-untreated nonporous silica, and fumed silica contained in each composition is shown in the column "(C) primary particle diameter (μm)," and the BET specific surface area of ​​each is shown in the column "(C) BET specific surface area (m 2 The methanol wettability of each is shown in the column "(C) Methanol wettability," along with the components of the surface treatment agent and the amount of the surface treatment agent added relative to 100% by mass of nonporous silica. Example 1 is an oil-in-water emulsion composition, and Examples 2 to 12 and Comparative Examples 1 and 2 are water-in-oil emulsion compositions.

[0083] <<Test Example 1: Emulsion Stability Test 1>> Each composition was filled into a transparent glass vial and allowed to stand at room temperature (23°C). The appearance of each composition was visually observed immediately after preparation, and after 1 hour, 3 hours, and 24 hours, and the emulsion stability was evaluated according to the following evaluation criteria. The results of the appearance evaluation are shown in Table 1. (Evaluation criteria) Appearance evaluation ⊚: The emulsified state did not change from immediately after preparation until 24 hours later, and the emulsification was maintained. ○: The emulsified state did not change from immediately after preparation until 3 hours later, and the emulsification was maintained. △: The emulsified state did not change from immediately after preparation until 1 hour later, and the emulsification was maintained. ×: Separation occurred immediately after preparation.

[0084] [Table 1]

[0085] As shown in Table 1, it was confirmed that Examples 1 to 12 had good emulsion stability. Examples 1 to 12 were emulsion compositions in which component (C) was adsorbed to the interface between component (A) and component (B), and were considered to be compositions in which Pickering emulsions with good emulsion stability were formed. The emulsion compositions of Examples 1 to 12 were observed under an electron microscope, and emulsions in which particles were adsorbed to the interface between the oil phase and the aqueous phase were confirmed. Comparative Example 1 containing surface-untreated nonporous silica and Comparative Example 2 containing fumed silica separated immediately after preparation, confirming poor emulsification.

[0086] <<Test Example 2: Emulsion Stability Test 2>> The water-in-oil emulsion compositions (Examples 5, 13 to 16) shown in Table 2 below were prepared by a conventional method. Table 2 also shows the water holding percentage of component (A) contained in each composition. The emulsion stability was evaluated visually using the same test method and evaluation criteria as in Test Example 1. Furthermore, each emulsion composition was observed under a stereomicroscope to evaluate the emulsion particle size. Specifically, the particle diameters of 50 randomly selected emulsion particles in one field of view of the microscope were measured, and the average value was taken as the emulsion particle size and evaluated according to the following evaluation criteria. The results are shown in Table 2. (Evaluation criteria) Emulsion particle size ◎◎: Less than 10 μm ◎: 10 μm or more and less than 30 μm ○: 30 μm or more and less than 100 μm △:100μm or more

[0087] [Table 2]

[0088] As shown in Table 2, Examples 13 to 16, which contained two types of component (A), had appearance evaluations and emulsion particle sizes that were equal to or better than those of Example 5, which contained one type of component (A).It was confirmed that emulsion compositions containing component (A) with a high water holding rate had small emulsion particle sizes and further improved emulsion stability.

[0089] <<Test Example 3: Emulsion Stability Test 3>> The water-in-oil emulsion compositions (Examples 5, 17 to 20) shown in Table 3 below were prepared by a conventional method. The emulsion stability was evaluated using the same test method and evaluation criteria as in Test Example 2. The results are shown in Table 3.

[0090] [Table 3]

[0091] As shown in Table 3, Examples 17 to 20 containing two types of (B) component had appearance evaluations and emulsion particle sizes that were equal to or better than those of Example 5 containing one type of (B) component. It was confirmed that emulsion compositions containing glycerins as the (B) component had smaller emulsion particle sizes and further improved emulsion stability.

[0092] <<Test Example 4: Emulsion Stability Test 4>> The water-in-oil emulsion compositions (Examples 5, 21, and 22) shown in Table 4 below were prepared by a conventional method. Table 4 also shows the components of the surface treatment agent for each of the component (C), nonporous silica, particulate titanium oxide, and particulate zinc oxide, the amount of the surface treatment agent added relative to 100% by mass of the base, and the primary particle size. The emulsion stability was evaluated using the same test method and evaluation criteria as in Test Example 2. The results are shown in Table 4.

[0093] [Table 4]

[0094] As shown in Table 4, the appearance evaluation and emulsion particle size of Examples 21 and 22, which further contained fine particle titanium oxide or fine particle zinc oxide, were equal to or better than those of the emulsion composition containing components (A), (B), and (C) (Example 5). It was confirmed that the emulsion particle size became smaller and emulsion stability was further improved by further containing fine particle titanium oxide or fine particle zinc oxide.

[0095] <<Test Example 5: Emulsion Stability Test 5>> The water-in-oil emulsion compositions (Examples 23 to 31) shown in Table 5 below were prepared by a conventional method. Table 5 shows the primary particle size, BET specific surface area, methanol wettability, surface treatment agent components, and the amount of surface treatment agent added relative to 100% by mass of nonporous silica of component (C), as well as the HLB value of the surfactant. The emulsion stability was evaluated using the same test method and evaluation criteria as in Test Example 2. The results are shown in Table 5.

[0096] [Table 5]

[0097] As shown in Table 5, the compositions (Examples 24 to 31) that further contained a surfactant had similar or better appearance evaluations and emulsion particle sizes than the emulsion composition containing components (A), (B), and (C) (Example 23). It was confirmed that emulsion compositions containing a surfactant with a low HLB had smaller emulsion particle sizes and further improved emulsion stability.

[0098] <<Test Example 6: Emulsion stability test and usability test>> The water-in-oil emulsion compositions shown in Table 6 below were prepared by a conventional method. Table 6 shows the primary particle size of component (C), BET specific surface area, methanol wettability, surface treatment agent components, and the amount of surface treatment agent added relative to 100% by mass of nonporous silica, as well as the HLB value of the surfactant. Emulsion stability was evaluated using the same test method and evaluation criteria as in Test Example 2. Next, a panel of five cosmetic evaluation experts applied the compositions to the skin and scored the feel of use according to Evaluation Criteria A below. The average scores were then calculated and evaluated according to Evaluation Criteria B below. The results are shown in Table 6. (Evaluation Criteria A) [Rating] 5 points: Feels easy to spread. 4 points: Feels a little easy to spread. 3 points: Can't say either way. 2 points: It feels a little difficult to spread. 1 point: It is difficult to spread. (Judgment Criteria B) [judgement] ◎: 4.0 points or more ○: 3.0 points or more and less than 4.0 points △: 2.0 points or more and less than 3.0 points ×: Less than 2.0 points

[0099] [Table 6]

[0100] As shown in Table 6, Examples 32 to 37 were excellent in appearance evaluation and emulsion particle size, confirming high emulsion stability. Each Example also had an excellent feel when used. In particular, the feel when used was remarkably excellent for compositions with a low surfactant content.

[0101] <<Test Example 7: Coating uniformity evaluation and emulsion stability test>> The water-in-oil emulsion composition (Example 38) shown in Table 7 below was prepared by a conventional method. The nonporous silica contained in Example 38 was the same as the nonporous silica contained in the emulsion composition of Example 23. The coating uniformity of the water-in-oil emulsion composition was evaluated immediately after preparation. After washing the inner part of a human forearm and allowing it to rest for 15 minutes, 260 mg of the water-in-oil emulsion composition was applied to an area of ​​38 mm x 50 mm. 15 minutes after application, adhesive tape (Scotch Book Tape, manufactured by 3M) was applied to the application area and then peeled off. The coating film of the water-in-oil emulsion composition was transferred to a piece of adhesive tape to obtain a sample (tape stripping method). Raman spectra were measured for every 5 μm x 5 μm square in a 1500 μm x 1500 μm area of ​​the adhesive tape. The wavelength of the irradiated laser was selected from the settable wavelengths of 532 nm, 660 nm, 785 nm, 1064 nm, etc., and 532 nm was selected. Measurements were performed using a confocal Raman microscope (In Via Confocal Raman microscope, manufactured by Renishaw). Specifically, the wavelength region showing strong signal intensity for the target component on a two-dimensional coordinate system (1595 to 1645 cm for various UV absorbers) was selected. -1 An image (Raman spectrum imaging) was obtained by plotting the signal intensity in the region (region). Next, a histogram was created for the Raman spectrum imaging, with the horizontal axis being signal intensity and the vertical axis being the number of sampling points. Samples for which the area ratio of the image binarized using Otsu's binarization method approached 50% and the histogram approached a normal distribution were evaluated as having high coating uniformity. The binarized image and histogram results of Raman spectral imaging of the emulsion composition of Example 38 are shown in Figure 1. The area ratio of the binarized image of Raman spectral imaging was 43%, and the histogram was close to a normal distribution. Next, emulsion stability was evaluated using the same test method and evaluation criteria as in Test Example 1. The results are shown in Table 7. As shown in Table 7, Example 38 was favorable in appearance evaluation and emulsion particle size, confirming high emulsion stability.

[0102] The emulsion composition of Example 38 demonstrated high coating uniformity based on the area ratio and histogram distribution shape of the binarized image of Raman spectral imaging (Figure 1) and also demonstrated high emulsion stability (Table 7). On the other hand, for an emulsion composition with insufficient emulsion stability in terms of appearance (rated as ◯ according to the evaluation criteria of Test Example 1) and emulsion particle size (rated as △ according to the evaluation criteria of Test Example 2), coating uniformity was evaluated immediately after preparation using the same method as Test Example 7. The area ratio of the binarized image of Raman spectral imaging was 13%, and the histogram distribution shape was non-normal (Figure 2). The coating film formed by applying an emulsion composition with a small emulsion particle size was able to cover the skin uniformly, with its emulsion structure remaining resistant to breakdown even under conditions such as the unevenness of the skin on the application surface and body temperature. On the other hand, emulsion compositions with a large emulsion particle size were thought to be more likely to break down their emulsion structure during the coating film formation process, resulting in an uneven coating film.

[0103] [Table 7]

[0104] Formulation examples of the present invention are shown below, where the total amount of each composition is 100% by mass.

[0105] [Formulation Example 1] W / O emulsion sunscreen Dimethylpolysiloxane (1.5cs) 7% by mass Methyl trimethicone 3% by mass 2-Ethylhexyl succinate 10% by mass Isononyl isononanoate 7% by mass Triethylhexyl trimellitate 7% by mass Bis-ethylhexyloxyphenol methoxyphenyl triazine 2% by mass Ethylhexyl triazone 1.5% by mass Diethylamidohydroxybenzoylhexyl benzoate 0.5% by mass Polyhydroxystearic acid 1% by mass Diisostearyl malate 1% by mass Polyglyceryl-10 (dimer dilinoleate / stearic acid / hydroxystearic acid) 1% by mass Non-porous silica (surface treatment agent: triethoxycaprylylsilane, primary particle size: 0.2 μm) 0.5% by mass Polyethylene glycol dipolyhydroxystearate *1 0.3% by mass Disteardimonium hectorite 0.3% by mass Hydrophobic treated zinc oxide particles (surface treatment agent: isostearic acid, primary particle size: 35 nm) 8% by mass Hydrophobic treated titanium dioxide fine particles (surface treatment agent: isostearic acid, aluminum hydroxide, primary particle size: 10 nm) 3% by mass Porous silica (surface treatment: none, primary particle diameter 3 μm) 4 mass% water residue Ethanol 10% by mass 1,3-butylene glycol 5% by mass Glycerin 3% by mass Decyl glucoside 0.2% by mass Methylenebisbenzotriazolyltetramethylbutylphenol 1.5% by mass (*1 CITHROL DPHS (manufactured by Croda))

[0106] [Formulation Example 2] W / O emulsion sunscreen Dimethylpolysiloxane (1.5cs) 10% by mass Methyl trimethicone 5% by mass 2-Ethylhexyl succinate 7% by mass Isononyl isononanoate 7% by mass Triethylhexyl trimellitate 3% by mass Bis-ethylhexyloxyphenol methoxyphenyl triazine 2% by mass Ethylhexyl salicylate 10% by mass Diethylamidohydroxybenzoylhexyl benzoate 2% by mass Polyhydroxystearic acid 2% by mass Polyglyceryl-10 (dimer dilinoleate / stearic acid / hydroxystearic acid) 0.5% by mass Non-porous silica (surface treatment agent: triethoxycaprylylsilane, primary particle size: 0.2 μm) 0.5% by mass Polyglyceryl-10 pentastearate 0.5% by mass Dextrin palmitate 0.5% by mass Hydrophobic treated zinc oxide particles (surface treatment agent: methyl hydrogen polysiloxane, hydrated silica, primary particle size: 25 nm) 4% by mass Hydrophobic treated titanium dioxide fine particles (surface treatment agent: methyl hydrogen polysiloxane, primary particle size: 15 nm) 3% by mass Porous silica (surface treatment: none, primary particle diameter 3 μm) 4 mass% water residue Ethanol 5% by mass 1,3-butylene glycol 5% by mass Glycerin 3% by mass

[0107] [Formulation Example 3] W / O emulsion cream foundation Decamethylcyclopentasiloxane 20% by mass 2-Ethylhexyl succinate 5% by mass Glyceryl tri-2-ethylhexanoate 3% by mass Bis-ethylhexyloxyphenol methoxyphenyl triazine 1% by mass Ethylhexyl paramethoxycinnamate 10% by mass Diethylamidohydroxybenzoylhexyl benzoate 2% by mass Polyhydroxystearic acid 1% by mass Polyglyceryl-10 (dimer dilinoleate / stearic acid / hydroxystearic acid) 0.5% by mass Non-porous silica (surface treatment agent: triethoxycaprylylsilane, primary particle size: 0.2 μm) 1.5% by mass Polyethylene glycol dipolyhydroxystearate *1 0.5% by mass Disteardimonium hectorite 1% by mass Hydrophobic treated zinc oxide fine particles (surface treatment agent: methylhydrogenpolysiloxane, primary particle size: 25 nm) 5% by mass Pigment-grade titanium dioxide (surface treatment agent: dimethylpolysiloxane, aluminum hydroxide, primary particle size: 250 nm) 3% by mass Hydrophobic treated yellow iron oxide 0.8% by mass Hydrophobic treated red iron oxide 0.2% by mass Hydrophobic treated black iron oxide 0.1% by mass Porous silica (surface treatment: none, primary particle diameter 3 μm) 3 mass% water residue Ethanol 3% by mass 1,3-butylene glycol 5% by mass Glycerin 5% by mass

[0108] [Formulation Example 4] W / O emulsion sunscreen Dimethylpolysiloxane (1.5cs) 5% by mass Isododecane 5% by mass Hydrogenated polyisobutene 20% by mass Diethylhexyl succinate 5% by mass Isononyl isononanoate 7% by mass Neopentyl glycol diethylhexanoate 1% by mass Polyhydroxystearic acid 2% by mass Diisostearyl malate 1% by mass Polyglyceryl-10 (dimer dilinoleate / stearic acid / hydroxystearic acid) 2% by mass Macadamia nut fatty acid phytosteryl 2% by mass Stearic acid 0.5% by mass Phytosteryl oleate 1% by mass Non-porous silica (surface treatment agent: triethoxycaprylylsilane, primary particle size: 0.2 μm) 0.5% by mass Inulin stearate 0.5% by mass Hydrophobic treated zinc oxide particles (surface treatment agent: isostearic acid, primary particle size: 35 nm) 5% by mass Hydrophobic treated titanium dioxide fine particles (surface treatment agent: isostearic acid, aluminum hydroxide, primary particle size: 10 nm) 5% by mass Hydrophobic treated zinc oxide particles (surface treatment agent: methyl hydrogen polysiloxane, hydrated silica, primary particle size: 25 nm) 3% by mass Porous silica (surface treatment: none, primary particle diameter 3 μm) 3 mass% water residue Ethanol 10% by mass 1,3-butylene glycol 5% by mass Glycerin 3% by mass Hydrophobized hydroxypropyl methylcellulose 0.1% by mass

Claims

1. An emulsion composition comprising (A) an oil component, (B) an aqueous component, and (C) surface-treated nonporous silica having a primary particle size of 0.15 to 1.5 μm.

2. The emulsion composition according to claim 1, wherein the emulsion composition is a water-in-oil emulsion composition.

3. 3. The emulsion composition according to claim 1, wherein the nonporous silica (C) is nonporous silica that has been surface-treated with triethoxycaprylylsilane.

4. The emulsion composition according to any one of claims 1 to 3, wherein the oil component (A) is an oil component having a water holding rate of 100% by mass or more.

5. The emulsion composition according to any one of claims 1 to 4, comprising 3 mass% or less of a surfactant based on the total amount of the emulsion composition.

6. The BET specific surface area of ​​the non-porous silica (C) is 50 m 2 The emulsion composition according to any one of claims 1 to 5, wherein the solubility is 0.01g / g or less.

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