WO2025183150A1 - 水中油型乳化組成物 - Google Patents

水中油型乳化組成物

Info

Publication number
WO2025183150A1
WO2025183150A1 PCT/JP2025/007080 JP2025007080W WO2025183150A1 WO 2025183150 A1 WO2025183150 A1 WO 2025183150A1 JP 2025007080 W JP2025007080 W JP 2025007080W WO 2025183150 A1 WO2025183150 A1 WO 2025183150A1
Authority
WO
WIPO (PCT)
Prior art keywords
mass
oil
water emulsion
emulsion composition
less
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
PCT/JP2025/007080
Other languages
English (en)
French (fr)
Japanese (ja)
Inventor
貴之 白川
純 栗原
泰輔 青崎
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Kao Corp
Original Assignee
Kao Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Kao Corp filed Critical Kao Corp
Priority to JP2025536117A priority Critical patent/JP7817505B2/ja
Publication of WO2025183150A1 publication Critical patent/WO2025183150A1/ja
Pending legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K8/00—Cosmetics or similar toiletry preparations
    • A61K8/02—Cosmetics or similar toiletry preparations characterised by special physical form
    • A61K8/04—Dispersions; Emulsions
    • A61K8/06—Emulsions
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K8/00—Cosmetics or similar toiletry preparations
    • A61K8/18—Cosmetics or similar toiletry preparations characterised by the composition
    • A61K8/19—Cosmetics or similar toiletry preparations characterised by the composition containing inorganic ingredients
    • A61K8/26—Aluminium; Compounds thereof
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K8/00—Cosmetics or similar toiletry preparations
    • A61K8/18—Cosmetics or similar toiletry preparations characterised by the composition
    • A61K8/19—Cosmetics or similar toiletry preparations characterised by the composition containing inorganic ingredients
    • A61K8/29—Titanium; Compounds thereof
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K8/00—Cosmetics or similar toiletry preparations
    • A61K8/18—Cosmetics or similar toiletry preparations characterised by the composition
    • A61K8/30—Cosmetics or similar toiletry preparations characterised by the composition containing organic compounds
    • A61K8/33—Cosmetics or similar toiletry preparations characterised by the composition containing organic compounds containing oxygen
    • A61K8/34—Alcohols
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K8/00—Cosmetics or similar toiletry preparations
    • A61K8/18—Cosmetics or similar toiletry preparations characterised by the composition
    • A61K8/30—Cosmetics or similar toiletry preparations characterised by the composition containing organic compounds
    • A61K8/33—Cosmetics or similar toiletry preparations characterised by the composition containing organic compounds containing oxygen
    • A61K8/36—Carboxylic acids; Salts or anhydrides thereof
    • A61K8/368—Carboxylic acids; Salts or anhydrides thereof with carboxyl groups directly bound to carbon atoms of aromatic rings
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K8/00—Cosmetics or similar toiletry preparations
    • A61K8/18—Cosmetics or similar toiletry preparations characterised by the composition
    • A61K8/30—Cosmetics or similar toiletry preparations characterised by the composition containing organic compounds
    • A61K8/33—Cosmetics or similar toiletry preparations characterised by the composition containing organic compounds containing oxygen
    • A61K8/37—Esters of carboxylic acids
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K8/00—Cosmetics or similar toiletry preparations
    • A61K8/18—Cosmetics or similar toiletry preparations characterised by the composition
    • A61K8/30—Cosmetics or similar toiletry preparations characterised by the composition containing organic compounds
    • A61K8/40—Cosmetics or similar toiletry preparations characterised by the composition containing organic compounds containing nitrogen
    • A61K8/44—Aminocarboxylic acids or derivatives thereof, e.g. aminocarboxylic acids containing sulfur; Salts; Esters or N-acylated derivatives thereof
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K8/00—Cosmetics or similar toiletry preparations
    • A61K8/18—Cosmetics or similar toiletry preparations characterised by the composition
    • A61K8/30—Cosmetics or similar toiletry preparations characterised by the composition containing organic compounds
    • A61K8/46—Cosmetics or similar toiletry preparations characterised by the composition containing organic compounds containing sulfur
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K8/00—Cosmetics or similar toiletry preparations
    • A61K8/18—Cosmetics or similar toiletry preparations characterised by the composition
    • A61K8/72—Cosmetics or similar toiletry preparations characterised by the composition containing organic macromolecular compounds
    • A61K8/73—Polysaccharides
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K8/00—Cosmetics or similar toiletry preparations
    • A61K8/18—Cosmetics or similar toiletry preparations characterised by the composition
    • A61K8/72—Cosmetics or similar toiletry preparations characterised by the composition containing organic macromolecular compounds
    • A61K8/81—Cosmetics or similar toiletry preparations characterised by the composition containing organic macromolecular compounds obtained by reactions involving only carbon-to-carbon unsaturated bonds
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61Q—SPECIFIC USE OF COSMETICS OR SIMILAR TOILETRY PREPARATIONS
    • A61Q17/00—Barrier preparations; Preparations brought into direct contact with the skin for affording protection against external influences, e.g. sunlight, X-rays or other harmful rays, corrosive materials, bacteria or insect stings
    • A61Q17/04—Topical preparations for affording protection against sunlight or other radiation; Topical sun tanning preparations
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61Q—SPECIFIC USE OF COSMETICS OR SIMILAR TOILETRY PREPARATIONS
    • A61Q19/00—Preparations for care of the skin

Definitions

  • the present invention relates to an oil-in-water emulsion composition.
  • sunscreen cosmetics usually contain ultraviolet absorbers and ultraviolet scattering agents.
  • UV absorbers include specific sunscreen cosmetics that contain ⁇ -gel particles encapsulating an oil-soluble UV absorber (Patent Documents 1 and 2).
  • Patent Document 1 JP 2017-7969 A (Patent Document 2) JP 2020-63239 A (Patent Document 3) JP 2022-186915 A (Patent Document 4) JP 2022-117486 A (Patent Document 5) WO2023/286780
  • the present invention relates to a polymerizable composition
  • a polymerizable composition comprising a core part comprising the following components (a1) and (a2): (a1) a hydrophobized ultraviolet scattering agent; (a2) an oil agent that is liquid at 25°C, and a shell portion comprising the following components (b1) and (b2); (b1) an anionic surfactant; (b2) a core-shell particle containing a hydrophobic amphiphilic substance; (e1) a second hydrophobized ultraviolet scattering agent; and (c4) an aqueous thickener;
  • the present invention relates to an oil-in-water emulsion composition in which the core-shell particles and (e1) a second hydrophobized UV scattering agent are dispersed.
  • FIG. 1 is a scanning electron microscope (SEM) image of the cross section of a core-shell particle obtained in Example 3.
  • FIG. 1 shows the cross section and average film thickness of the coating film of the oil-in-water sunscreen cosmetic of Example 3.
  • FIG. 1 is a diagram showing the cross section and average film thickness of the coating film of the oil-in-water sunscreen cosmetic of Comparative Example 1.
  • sunscreen cosmetics that are gentler on the skin
  • non-chemical sunscreen cosmetics that do not contain UV absorbers
  • UV absorbers it is necessary to increase the content of UV scattering agents in sunscreen cosmetics.
  • One such cosmetic is a water-in-oil sunscreen cosmetic that contains a total of approximately 25% by weight of a combination of hydrophobized zinc oxide particles and hydrophobized titanium oxide particles as hydrophobized UV scattering agents, along with a water-soluble polymer compound and spherical powder (Patent Document 3).
  • Another reported example is a specific oil-in-water sunscreen cosmetic that contains 10 to 20% by weight of titanium oxide that has been hydrophobized with an aluminum-based surface treatment agent in addition to a (sodium acrylate/sodium acryloyldimethyltaurate) copolymer or a (hydroxyethyl acrylate/sodium acryloyldimethyltaurate) copolymer and an oily compound (Patent Document 4). Furthermore, as a technique for suppressing white cast, it has been proposed to prepare an oil-in-water sunscreen cosmetic using an oil component containing polar oil as the main component, a specific amount of a hydrophobic treated UV scattering agent, and polyhydroxystearic acid (Patent Document 5).
  • the present invention relates to providing an oil-in-water emulsion composition that, when applied to the skin, exhibits moisturizing properties and provides a feeling of moisturization, exhibits excellent UV protection effects, is less likely to cause a white cast, and reduces irritation when the applied surface is rubbed.
  • an oil-in-water emulsion composition comprising core-shell particles containing a hydrophobized UV scattering agent and an oil that is liquid at 25°C in the core, and an anionic surfactant and a hydrophobic amphiphilic substance in the shell, and a second hydrophobized UV scattering agent and an aqueous thickener outside the core-shell particles, in which the core-shell particles and the second hydrophobized UV scattering agent are dispersed, exhibits moisturizing properties and a moisturizing feel when applied to the skin, exhibits excellent UV protection effects, is less likely to cause a white cast, and can reduce irritation when the surface of the applied area is rubbed, thereby completing the present invention.
  • the oil-in-water emulsion composition of the present invention When applied to the skin, the oil-in-water emulsion composition of the present invention exhibits moisturizing properties, provides a feeling of moisturization, exhibits excellent UV protection, is less likely to cause a white cast, and can reduce irritation when the applied surface is rubbed.
  • the core-shell particles used in the present invention have a core portion comprising the following components (a1) and (a2): (a1) a hydrophobized ultraviolet scattering agent; (a2) an oil agent that is liquid at 25°C, and a shell portion comprising the following components (b1) and (b2); (b1) Anionic surfactant (b2) A hydrophobic amphiphilic substance.
  • core-shell type particle refers to a particle having a core portion and a shell portion that encloses the core portion.
  • the core-shell structure can be confirmed by observing the cross section of the particle with a scanning electron microscope (SEM).
  • SEM scanning electron microscope
  • the oil-in-water emulsion composition of the present invention contains the core-shell particles dispersed in the aqueous phase of the oil-in-water emulsion composition.
  • “dispersed” also includes particles or hydrophobic treated ultraviolet scattering agents in which some or all of the particles have settled, as long as they can be redispersed in part or in whole by stirring or shaking.
  • hydrophobic treated ultraviolet scattering agent is preferably a hydrophobic treated metal oxide fine particle.
  • metal oxide used for the hydrophobic treated metal oxide microparticles from the viewpoint of easy availability, one or more metal oxides selected from zinc oxide, titanium oxide, cerium oxide, iron oxide and chromium oxide are preferred.
  • these metal oxides from the viewpoint of ultraviolet protection effect, one or more metal oxides selected from zinc oxide, titanium oxide and cerium oxide are preferred, one or more metal oxides selected from zinc oxide and titanium oxide are more preferred, and titanium oxide is even more preferred.
  • trace elements with a valence of +2 or more can be contained in the metal oxide microparticles, and metals such as iron, zirconium, calcium, manganese, magnesium, yttrium, etc. can be contained alone or in combination of two or more.
  • the shape of the "fine particle metal oxide” is not particularly limited, and examples thereof include spherical, plate-like, rod-like, spindle-like, needle-like, and irregular shapes.
  • the average particle size of the "fine particle metal oxide” is preferably 0.01 ⁇ m or more, more preferably 0.012 ⁇ m or more, and even more preferably 0.015 ⁇ m or more, and is preferably 1 ⁇ m or less, more preferably 0.8 ⁇ m or less, and even more preferably 0.5 ⁇ m or less.
  • the specific range of the average particle size is preferably 0.01 ⁇ m or more and 1 ⁇ m or less, more preferably 0.012 ⁇ m or more and 0.8 ⁇ m or less, and even more preferably 0.015 ⁇ m or more and 0.5 ⁇ m or less.
  • the average particle size of the fine particle metal oxide means the average particle size measured by a laser diffraction/scattering method.
  • zinc oxide particles include FINEX-25, FINEX-30, FINEX-50, and FINEX-75 (manufactured by Sakai Chemical Industry Co., Ltd.), the MZ300 series, MZ500 series, and MZ700 series (manufactured by Teika Corporation), and ZnO-350 (manufactured by Sumitomo Osaka Cement Co., Ltd.).
  • titanium oxide particles include the TTO-55 series, TTO-51 series (manufactured by Ishihara Sangyo Kaisha), the JR series, and the JA series (manufactured by Teika Corporation).
  • cerium oxide particles include high-purity cerium sold by Nikki Co., Ltd. or Seimi Chemical Co., Ltd.
  • the hydrophobic treatment of the fine particle metal oxide may be carried out using a known surface treatment agent for hydrophobization, and examples thereof include fluorine compound treatment, silicone treatment, silicone resin treatment, pendant treatment, silane coupling agent treatment, titanium coupling agent treatment, oil treatment, N-acylated lysine treatment, polyacrylic acid treatment, metal soap treatment, amino acid treatment, inorganic compound treatment, plasma treatment, mechanochemical treatment, silane compound treatment, and silazane compound treatment.
  • treatment with silicone or silicone resin, treatment with a silane compound or silazane compound, and treatment with a metal soap such as aluminum stearate, aluminum isostearate, or aluminum laurate are preferred from the viewpoint of dispersion stability, etc.
  • silicones or silicone resins examples include methylpolysiloxane, methylphenylpolysiloxane, methylhydrogenpolysiloxane, methylhydrogenpolysiloxane-dimethylpolysiloxane copolymer, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane, octamethyltrisiloxane, tetradecamethylhexasiloxane, dimethylsiloxane-methyl(polyoxyethylene)siloxane-methyl(polyoxypropylene)siloxane copolymer, dimethylsiloxane-methyl(polyoxyethylene)siloxane copolymer, dimethylsiloxane-methyl(polyoxypropylene)siloxane copolymer, dimethylsiloxane-methylcetyloxysiloxane copo
  • n and n are integers of 0 or greater, and 1 ⁇ m+n ⁇ 60.
  • the above-mentioned silane compound or silazane compound is preferably a silane compound or silazane compound having an alkyl group having 1 to 20 carbon atoms or a fluoroalkyl group having 1 to 20 carbon atoms and reactive with inorganic oxides, and more preferably a silane compound represented by the following formula (2) or a silazane compound represented by the following formula (3). These compounds may be used alone or in combination of two or more.
  • R4 represents a linear or branched alkyl group having 1 to 20 carbon atoms, or a linear or branched fluoroalkyl group having 1 to 20 carbon atoms
  • R5 represents a linear or branched alkyl group having 1 to 6 carbon atoms
  • Z represents a halogen atom or an alkoxy group
  • p represents 0 or 1.
  • R 6 to R 11 each independently represent a linear or branched alkyl group having 1 to 20 carbon atoms, or a linear or branched fluoroalkyl group having 1 to 20 carbon atoms.
  • alkylalkoxysilane or fluoroalkylalkoxysilane is preferred, and alkyltrialkoxysilane or fluoroalkyltrialkoxysilane is more preferred.
  • Specific examples include hexyltrimethoxysilane, octyltrimethoxysilane, octyltriethoxysilane (triethoxycaprylylsilane), decyltrimethoxysilane, octadecyltrimethoxysilane, trifluoropropyltrimethoxysilane, heptadecafluorodecyltrimethoxysilane etc.It should be noted that one of these may be used alone or two or more may be used in combination.
  • Specific examples of the silazane compound include hexamethyldisilazane.
  • the coating amount of the surface treatment agent used in the hydrophobic treatment is preferably 3 parts by mass or more, more preferably 9 parts by mass or more, per 100 parts by mass of the fine particle metal oxide, from the viewpoints of emulsion stability, dispersion stability, etc.; and is preferably 27 parts by mass or less, more preferably 22 parts by mass or less, per 100 parts by mass of the fine particle metal oxide, from the viewpoints of emulsion stability, dispersion stability, etc.
  • the hydrophobic treatment can be carried out by appropriately selecting a conventionally known method.
  • the treatment with silicone or silicone resin includes a method described in Japanese Patent No. 3187440, in which a fine particle metal oxide is coated in a non-gas phase with at least one silicone compound (excluding silane compounds) composed of organopolysiloxanes and silicone resins, and then baked at a temperature of 600 to 950°C in an oxygen-containing atmosphere, thereby coating the surface of the fine particle metal oxide with silicon oxide.
  • Examples of treatment methods using silane or silazane compounds include chemical bonding methods, and more specifically, methods include mixing a silane or silazane compound with finely divided metal oxide particles in an organic solvent such as n-hexane, cyclohexane, or a lower alcohol, finely pulverizing the mixture as needed, and then removing the organic solvent by heating (e.g., 80 to 250°C) or reducing pressure. Also included is a method described in JP-A-2007-326902 in which the particles are coated with a polysiloxane compound and then surface-treated with a silane compound in water.
  • hydrophobic treated UV scattering agents may be used alone or in combination of two or more.
  • the content of the hydrophobized UV scattering agent in the core-shell particles is preferably 0.1% by mass or more, more preferably 1% by mass or more, even more preferably 2.5% by mass or more, even more preferably 5% by mass or more, even more preferably 10% by mass or more, and even more preferably 18% by mass or more, based on the total mass of the core-shell particles, from the viewpoint of UV protection effect, etc., and is preferably 40% by mass or less, more preferably 30% by mass or less, and even more preferably 25% by mass or less, based on the total mass of the core-shell particles, from the viewpoint of dispersion stability, etc.
  • the content is preferably 0.1% by mass or more and 40% by mass or less, more preferably 1% by mass or more and 30% by mass or less, even more preferably 2.5% by mass or more and 25% by mass or less, even more preferably 5% by mass or more and 25% by mass or less, even more preferably 10% by mass or more and 25% by mass or less, even more preferably 18% by mass or more and 25% by mass or less, based on the total mass of the core-shell particles.
  • the content of the hydrophobized UV scattering agent in the core-shell particles is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, even more preferably 1.5% by mass or more, and even more preferably 2.5% by mass or more, based on the total mass of the oil-in-water emulsion composition of the present invention, from the viewpoints of UV protection effect, moisturizing feeling, moisturizing properties, irritation resistance, etc., and is preferably 24% by mass or less, more preferably 18% by mass or less, even more preferably 12% by mass or less, and even more preferably 5% by mass or less, based on the total mass of the oil-in-water emulsion composition of the present invention, from the viewpoints of absence of white cast, storage stability, etc.
  • Specific ranges are preferably 0.1% by mass or more and 24% by mass or less, more preferably 0.5% by mass or more and 18% by mass or less, more preferably 1.5% by mass or more and 12% by mass or less, and even more preferably 2.5% by mass or more and 5% by mass or less, based on the total mass of the oil-in-water emulsion composition of the present invention.
  • the content of the hydrophobized UV scattering agent in the core-shell particles is 1.5% by mass or more or 2.5% by mass or more, the UV protection effect, moisturizing feeling, moisturizing properties, irritation resistance, and storage stability are further improved, and when the content is 5% by mass or less, the absence of white foliage is further improved.
  • the content mass ratio of the hydrophobic treated UV scattering agent in the core-shell particles of component (a1) to the sum of all hydrophobic treated UV scattering agents in the oil-in-water emulsion composition of the present invention is preferably from 0.05 to 1, more preferably from 0.1 to 0.9, even more preferably from 0.1 to 0.8, and even more preferably from 0.2 to 0.29, from the viewpoints of UV protection effect, absence of white cast, moisturizing feel, moisturizing properties, irritation resistance, storage stability, and the like.
  • the content mass ratio [(a1)/(total hydrophobic treated UV scattering agent)] is 0.1 or more or 0.2 or more, the UV protection effect, moisturizing feeling, moisturizing properties, irritation resistance, and storage stability are particularly improved. When it is 0.29 or less, the UV protection effect and the absence of white cast are further improved.
  • the “total of all hydrophobized UV scattering agents in the oil-in-water emulsion composition” means the total of the hydrophobized UV scattering agents in the core-shell particles and the hydrophobized UV scattering agents outside the core-shell particles.
  • oil agent that is liquid at 25°C By incorporating an oily agent that is liquid at 25°C together with a hydrophobic ultraviolet scattering agent in the core portion of the core-shell particle, the hydrophobic ultraviolet scattering agent is dispersed in the oily agent that is liquid at 25°C, improving the ultraviolet protection effect when applied to the skin and reducing the likelihood of white cast.
  • oil agent that is liquid at 25°C may be any oil agent that is liquid at 25°C under 1 atmosphere, and is broadly divided into oil-soluble UV absorbers that are liquid at 25°C under 1 atmosphere and others, with those that are not oil-soluble UV absorbers being preferred.
  • an oil agent that is liquid at 25°C is a concept that excludes powder dispersants.
  • the liquid oil may be either a volatile oil or a non-volatile oil, but a non-volatile oil is preferred from the viewpoints of the absence of white cast, moisturizing feel, moisturizing properties, irritation resistance, UV protection effect, etc.
  • a volatile oil is an oil that is volatile at 25°C
  • a non-volatile oil is an oil that is not volatile at 25°C.
  • volatile oils examples include light isoparaffin, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane, methyltrimethicone, decamethyltetrasiloxane, ethyltrisiloxane, and volatile methylpolysiloxane.
  • Light isoparaffin products include Isopar H (manufactured by Esso Chemical Co., Ltd.), Isododecane (manufactured by Bayer), Isohexadecane (manufactured by Uniqema), IP Solvent 1620MU, IP Solvent 2028MU, and IP Solvent 2835 (all manufactured by Idemitsu Kosan Co., Ltd.).
  • decamethylcyclopentasiloxane products include TSF405 (manufactured by Momentive Performance Materials Japan LLC), SH245, DC345 (manufactured by Dow Corning Toray Co., Ltd.), and KF-995 (manufactured by Shin-Etsu Chemical Co., Ltd.).
  • Commercially available methyl trimethicone products include Silicone TMF-1.5 (manufactured by Shin-Etsu Chemical Co., Ltd.).
  • decamethyltetrasiloxane products include KF-96L-1.5CS (manufactured by Shin-Etsu Chemical Co., Ltd.).
  • ethyltrisiloxanes include SILSOFTETS (manufactured by Momentive Performance Materials Japan, LLC), and commercially available volatile methylpolysiloxanes include KF-96L-2CS (manufactured by Shin-Etsu Chemical Co., Ltd.).
  • non-volatile oils include non-volatile hydrocarbon oils such as liquid paraffin (light liquid paraffin, light liquid isoparaffin, heavy liquid isoparaffin, etc.) and squalane; non-volatile silicone oils such as non-volatile dimethylpolysiloxane and non-volatile methylphenylpolysiloxane; non-volatile fatty acid ester oils such as cetyl 2-ethylhexanoate, isononyl isononanoate, isotridecyl isononanoate, isopropyl myristate, isopropyl palmitate, 2-ethylhexyl palmitate, 2-ethylhexyl stearate, and stearyl stearate; and C12-15 alkyl benzoates.
  • non-volatile hydrocarbon oils such as liquid paraffin (light liquid paraffin, light liquid isoparaffin, heavy liquid isoparaffin, etc.) and squalane
  • non-volatile fatty acid ester oils examples include fatty acid triglycerides such as glyceryl tri(caprylate/caprate) and glyceryl tri(2-ethylhexanoate); esters of fatty acids and neopentyl glycol such as neopentyl glycol dicaprate and neopentyl glycol diethylhexanoate; and polyhydric alcohol fatty acid ester oils.
  • Commercially available liquid paraffin products include Parleam 4 (manufactured by NOF Corporation).
  • non-volatile dimethylpolysiloxane products include KF-96A-10CS (manufactured by Shin-Etsu Chemical Co., Ltd.).
  • Commercially available isopropyl palmitate products include Exepar IPP (manufactured by Kao Corporation).
  • commercially available alkyl benzoate (C12-15) products include FINSOLV TN (manufactured by Innospec Active Chemicals).
  • neopentyl glycol dicaprate products include Estemol N-01 (manufactured by Nisshin Oillio Group, Ltd.).
  • the content of the oil agent that is liquid at 25°C in the core-shell particles is preferably 40% by mass or more, and more preferably 50% by mass or more, based on the total mass of the core-shell particles, from the viewpoints of dispersion stability, UV protection effect, etc.; and from the viewpoints of UV protection effect, storage stability, etc., it is preferably 80% by mass or less, and more preferably 75% by mass or less, based on the total mass of the core-shell particles.
  • the content is preferably 40% by mass or more and 80% by mass or less, and more preferably 50% by mass or more and 75% by mass or less, based on the total mass of the core-shell particles.
  • the content of the oil agent in a liquid state at 25°C in the core-shell particles is preferably 0.5% by mass or more, more preferably 1% by mass or more, based on the total mass of the oil-in-water emulsion composition of the present invention, from the viewpoints of dispersion stability, UV protection effect, etc.; and is preferably 25% by mass or less, more preferably 20% by mass or less, based on the total mass of the oil-in-water emulsion composition of the present invention, from the viewpoints of UV protection effect, storage stability, etc.
  • the specific range is preferably 0.5% by mass or more and 25% by mass or less, and more preferably 1% by mass or more and 20% by mass or less, based on the total mass of the oil-in-water emulsion composition of the present invention.
  • the mass ratio of component (a1) to component (a2) [(a1)/(a2)] is preferably 0.01 or more, more preferably 0.05 or more, and even more preferably 0.1 or more, from the viewpoints of the absence of white cast and UV protection effect, etc., and is preferably 2 or less, more preferably 1 or less, and even more preferably 0.5 or less, from the viewpoints of dispersion stability and UV protection effect, etc. Specific ranges are preferably 0.01 or more and 2 or less, more preferably 0.05 or more and 1 or less, and even more preferably 0.1 or more and 0.5 or less.
  • the core of the core-shell particle preferably contains, in addition to components (a1) and (a2), (a3) a powder dispersant.
  • the powder dispersant may be any that facilitates dispersion of the hydrophobized UV scattering agent in a liquid oil at 25° C.
  • Examples include polyether-modified silicones; polyhydroxy fatty acids such as polyhydroxystearic acid; dipentaerythrityl tri-polyhydroxy fatty acids such as dipentaerythrityl tri-polyhydroxystearate; and diglycerin difatty acid esters such as polyglyceryl diisostearate, polyglyceryl dilaurate, polyglyceryl distearate, and polyglyceryl dioleate.
  • polyhydroxystearic acid is preferred as the powder dispersant to be contained in the core-shell particles.
  • powder dispersants may be used alone or in combination of two or more.
  • the content of the powder dispersant in the core-shell particles is preferably 0.03% by mass or more, more preferably 0.05% by mass or more, even more preferably 0.1% by mass or more, and even more preferably 0.3% by mass or more, relative to the total mass of the core-shell particles.
  • the content is preferably 5% by mass or less, more preferably 3% by mass or less, even more preferably 1.5% by mass or less, and even more preferably 1% by mass or less, relative to the total mass of the core-shell particles.
  • Specific ranges are preferably 0.03% by mass or more and 5% by mass or less, more preferably 0.05% by mass or more and 3% by mass or less, even more preferably 0.1% by mass or more and 1.5% by mass or less, and even more preferably 0.3% by mass or more and 1% by mass or less, relative to the total mass of the core-shell particles.
  • the content of the powder dispersant in the core-shell particles is preferably 0.005% by mass or more, and more preferably 0.01% by mass or more, based on the total mass of the oil-in-water emulsion composition of the present invention, from the viewpoints of the absence of white cast, dispersion stability, UV protection effect, etc.; and from the viewpoints of dispersion stability, emulsion stability, etc., it is preferably 1% by mass or less, and more preferably 0.3% by mass or less, based on the total mass of the oil-in-water emulsion composition of the present invention.
  • a specific range is preferably 0.005% by mass or more and 1% by mass or less, and more preferably 0.01% by mass or more and 0.3% by mass or less, based on the total mass of the oil-in-water emulsion composition of the present invention.
  • the mass ratio of component (a3) to component (a1) [(a3)/(a1)] is preferably 0.005 or more, more preferably 0.0075 or more, and even more preferably 0.01 or more, from the viewpoints of the absence of white cast, dispersion stability, UV protection effect, etc., and is preferably 0.15 or less, more preferably 0.1 or less, and even more preferably 0.05 or less, from the viewpoints of dispersion stability, emulsion stability, etc. Specific ranges are preferably 0.005 or more and 0.15 or less, more preferably 0.0075 or more and 0.1 or less, and even more preferably 0.01 or more and 0.05 or less.
  • the core-shell particles used in the present invention have a shell portion containing (b1) anionic surfactant and (b2) a hydrophobic amphiphilic substance.
  • a shell portion that encapsulates a core portion containing a hydrophobically treated UV scattering agent when applied to the skin, the particles exhibit excellent UV protection effects and excellent moisturizing properties, providing a moisturizing feeling and reducing the occurrence of a whitish cast.
  • irritation caused by friction of the applied surface with a mask or the like is reduced, and the particles are easily washed off during cleansing.
  • anionic surfactants include fatty acid salts (preferably fatty acid salts having 12 to 24 carbon atoms) such as sodium laurate, potassium palmitate, and arginine stearate; alkyl sulfates (preferably alkyl sulfates having 12 to 24 carbon atoms) such as sodium lauryl sulfate, potassium lauryl sulfate, and sodium cetyl sulfate; polyoxyethylene alkyl ether sulfates (preferably polyoxyethylene alkyl ether sulfates having 12 to 24 carbon atoms) such as polyoxyethylene lauryl ether triethanolamine sulfate; N-acyl sarcosine salts (preferably N-acyl sarcosine salts having an acyl group having 12 to 24 carbon atoms) such as sodium lauroyl sarcosine; alkyl phosphates (preferably alkyl phosphates having 12 to 24 carbon atoms) such as sodium lauroyl sarc
  • Alkyl ether phosphates preferably polyoxyethylene alkyl ether phosphates having 12 to 24 carbon atoms
  • dialkyl sulfosuccinates preferably di(alkyl)sulfosuccinates having 6 to 12 carbon atoms
  • sodium di(2-ethylhexyl)sulfosuccinate N-alkyloylmethyl taurine salts (preferably N-alkyl methyl taurine salts having an alkyloyl group having 12 to 24 carbon atoms) such as sodium N-stearoyl-N-methyl taurine and sodium N-myristoyl-N-methyl taurine
  • N-acyl glutamates preferably N-acyl glutamates having an acyl group having 12 to 24 carbon atoms
  • monosodium N-lauroyl-L-glutamate sodium N-myristoyl-L-glutamate, sodium N-stearoyl-L-glutamate, disodium N-stearoyl-L
  • N-acyl glutamate salts having an acyl group with 12 to 24 carbon atoms N-alkyloyl methyl taurine salts having an alkyloyl group with 12 to 24 carbon atoms, fatty acid salts having 12 to 24 carbon atoms, and polyoxyethylene alkyl ether phosphates having 12 to 24 carbon atoms are preferred, with N-acyl glutamate salts having an acyl group with 12 to 24 carbon atoms and N-alkyloyl methyl taurine salts having an alkyloyl group with 12 to 24 carbon atoms being even more preferred.
  • anionic surfactants may be used alone or in combination of two or more.
  • the content of the anionic surfactant in the core-shell particles is preferably 0.5% by mass or more, more preferably 1% by mass or more, based on the total mass of the core-shell particles, from the viewpoints of moisturizing feel, moisturizing properties, storage stability, etc.; and from the viewpoint of storage stability, etc., it is preferably 15% by mass or less, more preferably 10% by mass or less, based on the total mass of the core-shell particles.
  • the content is preferably 0.5% by mass or more and 15% by mass or less, more preferably 1% by mass or more and 10% by mass or less, based on the total mass of the core-shell particles.
  • the content of the anionic surfactant in the core-shell particles is preferably 0.05% by mass or more, and more preferably 0.1% by mass or more, relative to the total mass of the oil-in-water emulsion composition of the present invention, from the viewpoints of moisturizing feel, moisturizing properties, storage stability, etc.; and from the viewpoint of storage stability, etc., it is preferably 3% by mass or less, and more preferably 1.5% by mass or less, relative to the total mass of the oil-in-water emulsion composition of the present invention.
  • the content is preferably 0.05% by mass or more and 3% by mass or less, and more preferably 0.1% by mass or more and 1.5% by mass or less, relative to the total mass of the oil-in-water emulsion composition of the present invention.
  • the mass ratio of component (b1) to component (a1) [(b1)/(a1)] is preferably 0.05 or more, more preferably 0.075 or more, and even more preferably 0.1 or more. Also, from the viewpoint of storage stability, etc., it is preferably 1.5 or less, more preferably 1 or less, and even more preferably 0.5 or less. Specific ranges are preferably 0.05 or more and 1.5 or less, more preferably 0.075 or more and 1 or less, and even more preferably 0.1 or more and 0.5 or less.
  • hydrophobic amphiphilic substances include higher alcohols, ceramides, linear saturated fatty acids having 10 to 24 carbon atoms, polyhydric alcohol mono-C10 to 24 fatty acid esters, sorbitan di-C10 to 24 fatty acid esters, and polyhydric alcohol mono-C10 to 24 alkyl ethers.
  • the higher alcohol is preferably a monohydric alcohol having 10 to 24 carbon atoms, more preferably a monohydric alcohol having 12 to 22 carbon atoms, and even more preferably a monohydric alcohol having 14 to 22 carbon atoms.
  • the higher alcohol may be linear or branched, and may be a saturated or unsaturated alcohol, but linear saturated or unsaturated alcohols are preferred.
  • Examples of higher alcohols include lauryl alcohol, myristyl alcohol, cetanol, stearyl alcohol, behenyl alcohol, oleyl alcohol, etc. Among these, cetanol, stearyl alcohol, and behenyl alcohol are preferred, and cetanol is more preferred.
  • the higher alcohols may be used alone or in combination of two or more.
  • Ceramides include one or more types selected from natural ceramides and pseudo-ceramides. Preferred ceramides are those described in JP 2013-53146 A.
  • natural ceramides include ceramide Types 1 to 7, in which sphingosine, dihydrosphingosine, phytosphingosine, or sphingadienine is amidated (e.g., porcine and human ceramides shown in Figure 2 of J. Lipid Res., 24:759 (1983) and Figure 4 of J. Lipid. Res., 35:2069 (1994)). Furthermore, N-alkylated forms (e.g., N-methylated forms) of these ceramides are also included in natural ceramides.
  • ceramides may be used in their natural (D(-)) optically active form, or in their non-natural (L(+)) optically active form, or may be a mixture of the natural and non-natural forms.
  • the relative configuration of the compound may be that of the natural form, or may be any other non-natural form, or may be a mixture of these.
  • the compounds CERAMIDE 1, CERAMIDE 2, CERAMIDE 3, CERAMIDE 5, and CERAMIDE 6II (all INCI, 8th Edition) and those represented by the following formula are preferred.
  • Natural ceramides include, for example, Ceramide I, Ceramide III, Ceramide IIIA, Ceramide IIIB, Ceramide IIIC, and Ceramide VI (all manufactured by Cosmopharm Co., Ltd.), Ceramide TIC-001 (manufactured by Takasago International Corporation), CERAMIDE II (manufactured by Quest International), DS-Ceramide VI, DS-CLA-Phytoceramide, C6-Phytoceramide, DS-ceramide Y3S (manufactured by DOOSAN Co., Ltd.), and CERAMIDE 2 (manufactured by Sederma Co., Ltd.).
  • Ceramide I Ceramide III
  • Ceramide IIIA Ceramide IIIA
  • Ceramide IIIB Ceramide IIIC
  • Ceramide VI all manufactured by Cosmopharm Co., Ltd.
  • Ceramide TIC-001 manufactured by Takasago International Corporation
  • CERAMIDE II manufactured by Quest International
  • DS-Ceramide VI DS-CLA-Phytoceramide
  • the pseudo-ceramide is preferably a pseudo-ceramide represented by the following general formula:
  • R 1 represents a linear, branched, or cyclic, saturated or unsaturated hydrocarbon group having 10 to 22 carbon atoms which may be substituted with a hydroxyl group, or a hydrogen atom
  • X represents a hydrogen atom, an acetyl group, or a glyceryl group
  • R2 is a linear, branched or cyclic, saturated or unsaturated hydrocarbon group (the hydrocarbon group is preferably an alkyl group) having 5 to 22 carbon atoms which may be substituted with a hydroxyl group or an amino group, or the hydrocarbon group (the hydrocarbon group is preferably an alkyl group) to which a linear or branched, saturated or unsaturated fatty acid having 8 to 22 carbon atoms which may be substituted with a hydroxyl group is ester-bonded to the ⁇ -terminus thereof;
  • R3 represents a hydrogen atom or a hydrocarbon group having a total of 1 to 30 carbon atoms (the hydrocarbon group is preferably an alkyl
  • pseudo-ceramides those represented by the following formula are preferred, with N-(hexadecyloxyhydroxypropyl)-N-hydroxyethylhexadecanamide being even more preferred.
  • linear saturated fatty acids having 10 to 24 carbon atoms linear saturated fatty acids having 12 to 24 carbon atoms are preferred, linear saturated fatty acids having 14 to 22 carbon atoms are more preferred, and linear saturated fatty acids having 16 to 18 carbon atoms are even more preferred.
  • Examples include lauric acid, myristic acid, palmitic acid, stearic acid, and behenic acid.
  • polyhydric alcohol mono-C10-24 fatty acid esters examples include glycerin mono-C10-24 fatty acid esters and sorbitan mono-C10-24 fatty acid esters.
  • the fatty acid residue of the polyhydric alcohol mono-C10-24 fatty acid ester is preferably a fatty acid residue having 12 to 24 carbon atoms, more preferably a fatty acid residue having 14 to 24 carbon atoms, and even more preferably a fatty acid residue having 16 to 22 carbon atoms.
  • the fatty acid residue may be a saturated fatty acid residue or an unsaturated fatty acid residue, and may be a straight-chain fatty acid residue or a branched fatty acid residue.
  • Examples of glycerin mono C10-24 fatty acid esters include glycerin monolaurate, glycerin monomyristate, glycerin monopalmitate, glycerin monostearate, glycerin monobehenate, glycerin monooleate, and glycerin monoisostearate.
  • Examples of sorbitan mono C10-24 fatty acid esters include sorbitan monolaurate, sorbitan monomyristate, sorbitan monopalmitate, sorbitan monostearate, and sorbitan monobehenate.
  • the fatty acid residue of the sorbitan di-C10-24 fatty acid ester is preferably a fatty acid residue having 12 to 24 carbon atoms, more preferably a fatty acid residue having 14 to 24 carbon atoms, and even more preferably a fatty acid residue having 16 to 22 carbon atoms.
  • the fatty acid residue may be a saturated fatty acid residue or an unsaturated fatty acid residue, and may be a straight-chain fatty acid residue or a branched fatty acid residue.
  • Examples of sorbitan di-C10-24 fatty acid esters include sorbitan dilaurate, sorbitan dimyristate, sorbitan dipalmitate, sorbitan distearate, and sorbitan dibehenate.
  • the polyhydric alcohol mono-C10-24 alkyl ether is preferably mono-C10-24 alkyl glyceryl ether, more preferably mono-C12-22 alkyl glyceryl ether, and even more preferably mono-C14-22 alkyl glyceryl ether.
  • mono C10-24 alkyl glyceryl ethers include monolauryl glyceryl ether, monomyristyl glyceryl ether, monocetyl glyceryl ether, monostearyl glyceryl ether, and monobehenyl glyceryl ether.
  • Hydrophobic amphiphilic substances may be used alone or in combination of two or more.
  • the content of the hydrophobic amphiphilic substance of component (b2) in the core-shell particles is preferably 1% by mass or more, more preferably 5% by mass or more, based on the total mass of the core-shell particles, from the viewpoints of moisturizing feel, moisturizing properties, storage stability, etc.; and from the viewpoint of storage stability, etc., it is preferably 20% by mass or less, more preferably 10% by mass or less, based on the total mass of the core-shell particles.
  • the content is preferably 1% by mass or more and 20% by mass or less, more preferably 5% by mass or more and 10% by mass or less, based on the total mass of the core-shell particles.
  • the content of the hydrophobic amphiphilic substance of component (b2) in the core-shell particles is preferably 0.025% by mass or more, more preferably 0.05% by mass or more, even more preferably 0.075% by mass or more, and even more preferably 0.1% by mass or more, based on the total mass of the oil-in-water emulsion composition of the present invention, from the viewpoints of moisturizing feel, moisturizing properties, storage stability, etc.; and from the viewpoint of storage stability, etc., it is preferably 10% by mass or less, more preferably 8% by mass or less, even more preferably 5% by mass or less, and even more preferably 2% by mass or less, based on the total mass of the oil-in-water emulsion composition of the present invention.
  • Specific ranges are preferably 0.025% by mass or more and 10% by mass or less, more preferably 0.05% by mass or more and 8% by mass or less, more preferably 0.075% by mass or more and 5% by mass or less, and even more preferably 0.1% by mass or more and 2% by mass or less, based on the total mass of the oil-in-water emulsion composition of the present invention.
  • the mass ratio of component (b2) to component (a1) [(b2)/(a1)] is preferably 0.05 or more, more preferably 0.075 or more, and even more preferably 0.1 or more. Also, from the viewpoint of storage stability, etc., it is preferably 1.5 or less, more preferably 1 or less, and even more preferably 0.75 or less. Specific ranges are preferably 0.05 or more and 1.5 or less, more preferably 0.075 or more and 1 or less, and even more preferably 0.1 or more and 0.75 or less.
  • the core-shell particles used in the present invention have a shell portion comprising (b1) an anionic surfactant and (b2) a hydrophobic amphiphilic substance. Therefore, the core-shell particles of the present invention can have an ⁇ -gel structure.
  • a coating film containing the core-shell particles is likely to be uniform and of appropriate thickness, further improving the UV protection effect, moisturizing properties, moisturizing feeling, and lack of white cast.
  • irritation caused by rubbing the surface of the applied area with a mask or the like is further reduced, and the particles are easier to wash off during cleansing.
  • the ⁇ -gel structure can be confirmed by X-ray diffraction (XRD). Specifically, particles that show at least one sharp diffraction peak at a Bragg angle of approximately 21 to 22° in wide-angle X-ray diffraction can be determined to have the ⁇ -gel structure.
  • the core-shell particles preferably contain, in addition to the components (a1) to (a2) and (b1) to (b2) (preferably the components (a1) to (a3) and (b1) to (b2)), one or more selected from (b3) an oil-based thickener and (b4) water, It is more preferable that the composition further contains at least component (b3) in addition to components (a1) to (a2) and (b1) to (b2) (preferably components (a1) to (a3) and (b1) to (b2)), It is more preferable to further contain components (b3) and (b4) in addition to components (a1) to (a2) and (b1) to (b2) (preferably components (a1) to (a3) and (b1) to (b2)). (b3) The oil-based thickener is preferably contained in the core portion, and (b4) Water is preferably contained at least in the shell portion.
  • oil-based thickeners examples include sugar fatty acid ester-based oil-based thickeners such as inulin fatty acid esters and dextrin fatty acid esters, as well as polyglyceryl isostearate, glyceryl (behenate/eicosanedioate), organically modified clay minerals, etc. These may be used alone or in combination of two or more. Among these, sugar fatty acid ester-based oil-based thickeners are preferred from the viewpoints of UV protection effect, dispersion stability, etc.
  • the fatty acid residue in the sugar fatty acid ester-based oil-based thickener is preferably a linear or branched saturated fatty acid residue.
  • the number of carbon atoms in the fatty acid residue is preferably 8 to 24, more preferably 12 to 22, and even more preferably 14 to 20.
  • the sugar fatty acid ester-based oil-based thickener is preferably a dextrin fatty acid ester, and specific examples thereof include dextrin myristate, dextrin palmitate, dextrin stearate, dextrin (palmitate/2-ethylhexanoate), and dextrin (palmitate/hexyldecanoate).
  • oil-based thickeners may be used alone or in combination of two or more.
  • the content of the oil-based thickener in the core-shell particles is preferably 0.075% by mass or more, more preferably 0.1% by mass or more, based on the total mass of the core-shell particles, from the viewpoint of the dispersion stability of component (a1). Furthermore, from the viewpoint of storage stability, it is preferably 3% by mass or less, more preferably 1% by mass or less, based on the total mass of the core-shell particles. Specifically, the content is preferably 0.075% by mass or more and 3% by mass or less, and more preferably 0.1% by mass or more and 1% by mass or less, based on the total mass of the core-shell particles.
  • the content of the oil-based thickener in the core-shell particles is preferably 0.0075% by mass or more, and more preferably 0.01% by mass or more, based on the total mass of the oil-in-water emulsion composition of the present invention, from the viewpoints of storage stability, moisturizing feel, moisturizing properties, irritation resistance, UV protection effect, etc.; and is preferably 0.5% by mass or less, and more preferably 0.1% by mass or less, based on the total mass of the oil-in-water emulsion composition of the present invention, from the viewpoints of storage stability, UV protection effect, etc.
  • the specific range is preferably 0.0075% by mass or more and 0.5% by mass or less, and more preferably 0.01% by mass or more and 0.1% by mass or less, based on the total mass of the oil-in-water emulsion composition of the present invention.
  • the mass ratio of component (b3) to component (a1) [(b3)/(a1)] is preferably 0.005 or more, more preferably 0.01 or more, from the viewpoints of storage stability, moisturizing feel, moisturizing properties, irritation resistance, UV protection effect, etc., and is preferably 0.1 or less, more preferably 0.05 or less, from the viewpoints of storage stability, UV protection effect, etc.
  • a specific range is preferably 0.005 or more and 0.1 or less, and more preferably 0.01 or more and 0.05 or less.
  • the water of component (b4) refers to the water in the core-shell particles.
  • the water content in the core-shell particles is preferably 0% by mass or more, more preferably 5% by mass or more, based on the total mass of the core-shell particles from the viewpoints of moisturizing feeling, moisturizing properties, anti-irritation effect, etc., and is preferably 50% by mass or less, more preferably 30% by mass or less, based on the total mass of the core-shell particles from the viewpoints of storage stability, etc.
  • the mass ratio of the component (b4) to the component (a1) [(b4)/(a1)] is preferably 1 or more and 10 or less from the viewpoints of ultraviolet protection effect, storage stability, etc.
  • the core-shell particles of the present invention may contain surfactants (excluding anionic surfactants and hydrophobic amphiphiles), oils that are solid at 25°C (note that oils that are solid at 25°C exclude hydrophobic amphiphiles, and examples include waxes such as ceresin, paraffin wax, polyolefin wax, and microcrystalline wax), powders (excluding hydrophobically treated UV scattering agents), water-soluble polymers, thickeners, disinfectants, moisturizers, humectants, colorants, preservatives, texture enhancers, fragrances, anti-inflammatory agents, whitening agents, antiperspirants, antioxidants, and pH adjusters. These may be used alone or in combination of two or more.
  • surfactants excluding anionic surfactants and hydrophobic amphiphiles
  • oils that are solid at 25°C exclude hydrophobic amphiphiles, and examples include waxes such as ceresin, paraffin wax, polyolefin wax, and microcrystalline wax
  • powders excluding hydrophob
  • Surfactants other than anionic surfactants and hydrophobic amphiphilic substances include cationic surfactants and amphoteric surfactants.
  • the content of surfactants other than anionic surfactants and hydrophobic amphiphilic substances in the core-shell particles is preferably 0% by mass or more and 1% by mass or less, more preferably 0% by mass or more and 0.1% by mass or less, even more preferably 0% by mass or more and 0.01% by mass or less, and still more preferably 0% by mass, based on the total mass of the core-shell particles.
  • the content of oils other than hydrophobic amphiphilic substances that are solid at 25°C in the core-shell particles is preferably 0% by mass or more and 1% by mass or less, more preferably 0% by mass or more and 0.1% by mass or less, even more preferably 0% by mass or more and 0.01% by mass or less, and even more preferably 0% by mass, relative to the total mass of the core-shell particles.
  • the content of the UV absorber in the core-shell particles is preferably 0% by mass or more and 1% by mass or less, more preferably 0% by mass or more and 0.1% by mass or less, even more preferably 0% by mass or more and 0.01% by mass or less, and even more preferably 0% by mass, relative to the total mass of the core-shell particles.
  • the oil-in-water emulsion composition of the present invention has excellent UV protection effect even when the content of the UV absorber is within this range.
  • the average particle size of the core-shell particles is preferably 0.01 ⁇ m or more, more preferably 0.05 ⁇ m or more, even more preferably 0.075 ⁇ m or more, even more preferably 0.1 ⁇ m or more, and even more preferably 0.2 ⁇ m or more from the viewpoints of UV protection effect, storage stability, etc., and is preferably 15 ⁇ m or less, more preferably 7.5 ⁇ m or less, even more preferably 5 ⁇ m or less, even more preferably 2.5 ⁇ m or less, and even more preferably 0.5 ⁇ m or less from the viewpoints of usability upon application, etc.
  • the average particle size of the core-shell type particles is preferably from 0.01 ⁇ m to 15 ⁇ m, more preferably from 0.05 ⁇ m to 7.5 ⁇ m, even more preferably from 0.075 ⁇ m to 5 ⁇ m, even more preferably from 0.1 ⁇ m to 2.5 ⁇ m, and even more preferably from 0.2 ⁇ m to 0.5 ⁇ m.
  • the average particle size of the core-shell particles means the median diameter (D50), specifically, a value measured at 25°C using a laser diffraction/scattering particle size distribution measuring device.
  • the content of the core-shell particles is preferably 3% by mass or more, more preferably 7.5% by mass or more, and even more preferably 12.5% by mass or more, based on the total mass of the oil-in-water emulsion composition of the present invention, from the viewpoints of UV protection effect, increasing the thickness of the coating film, etc., and is preferably 35% by mass or less, more preferably 30% by mass or less, even more preferably 27.5% by mass or less, and even more preferably 20% by mass or less, based on the total mass of the oil-in-water emulsion composition of the present invention, from the viewpoints of storage stability at high temperatures, etc.
  • a specific range is preferably 3% by mass or more and 35% by mass or less, more preferably 7.5% by mass or more and 30% by mass or less, and even more preferably 12.5% by mass or more and 27.5% by mass or less, based on the total mass of the oil-in-water emulsion composition of the present invention.
  • the content of the core-shell particles is 7.5% by mass or more or 12.5% by mass or more, the UV protection effect, moisturizing feeling, moisturizing properties, irritation resistance, and storage stability are particularly improved, and when the content is 20% by mass or less, the UV protection effect and the absence of whitish cast are further improved.
  • the oil-in-water emulsion composition of the present invention contains (e1) a second hydrophobized UV scattering agent outside the core-shell particles, and (e1) the second hydrophobized UV scattering agent is dispersed in the oil phase of the oil-in-water emulsion composition.
  • the ultraviolet protection effect is improved.
  • Examples of the second hydrophobic treated ultraviolet scattering agent include those similar to the hydrophobic treated ultraviolet scattering agents that can be used as component (a1).
  • hydrophobic treated ultraviolet scattering agent hydrophobic treated fine particle metal oxides are preferred, as with the hydrophobic treated ultraviolet scattering agent that can be used as component (a1).
  • metal oxide used for the hydrophobized metal oxide fine particle from the viewpoint of availability, one or more metal oxides selected from zinc oxide, titanium oxide, cerium oxide, iron oxide and chromium oxide are preferred.
  • these metal oxides from the viewpoint of ultraviolet protection effect, etc., one or more metal oxides selected from zinc oxide, titanium oxide and cerium oxide are preferred, one or more metal oxides selected from zinc oxide and titanium oxide are more preferred, and titanium oxide is even more preferred.
  • hydrophobized titanium dioxide fine particles are used as the second hydrophobized ultraviolet scattering agent, the ultraviolet protection effect and storage stability are particularly improved.
  • the shape of the "fine particle metal oxide” is not particularly limited, and examples thereof include spherical, plate-like, rod-like, spindle-like, needle-like, and irregular shapes.
  • the average particle size of the "fine particle metal oxide” is preferably 0.01 ⁇ m or more, more preferably 0.012 ⁇ m or more, and even more preferably 0.015 ⁇ m or more, and is preferably 1 ⁇ m or less, more preferably 0.8 ⁇ m or less, and even more preferably 0.5 ⁇ m or less.
  • the specific range of the average particle size is preferably 0.01 ⁇ m or more and 1 ⁇ m or less, more preferably 0.012 ⁇ m or more and 0.8 ⁇ m or less, and even more preferably 0.015 ⁇ m or more and 0.5 ⁇ m or less.
  • the average particle size of the fine particle metal oxide means the average particle size measured by a laser diffraction/scattering method.
  • the hydrophobic treatment of the fine particle metal oxide may be carried out using a known surface treatment agent for hydrophobization, and examples thereof include fluorine compound treatment, silicone treatment, silicone resin treatment, pendant treatment, silane coupling agent treatment, titanium coupling agent treatment, oil treatment, N-acylated lysine treatment, polyacrylic acid treatment, metal soap treatment, amino acid treatment, inorganic compound treatment, plasma treatment, mechanochemical treatment, silane compound treatment, and silazane compound treatment.
  • treatment with silicone or silicone resin, treatment with a silane compound or silazane compound, and treatment with a metal soap such as aluminum stearate, aluminum isostearate, or aluminum laurate are preferred from the viewpoint of dispersion stability, etc.
  • the second hydrophobized UV scattering agent may be used alone or in combination of two or more.
  • the content of the second hydrophobized UV scattering agent of component (e1) is preferably 3% by mass or more, more preferably 5% by mass or more, relative to the total mass of the oil-in-water emulsion composition of the present invention. Furthermore, from the viewpoint of the absence of white cast, storage stability, etc., the content is preferably 25% by mass or less, more preferably 22.5% by mass or less, even more preferably 20% by mass or less, even more preferably 18% by mass or less, and even more preferably 15% by mass or less, relative to the total mass of the oil-in-water emulsion composition of the present invention.
  • Specific ranges are preferably 3% by mass or more and 25% by mass or less, more preferably 5% by mass or more and 22.5% by mass or less, even more preferably 5% by mass or more and 20% by mass or less, even more preferably 5% by mass or more and 18% by mass or less, and even more preferably 5% by mass or more and 15% by mass or less, relative to the total mass of the oil-in-water emulsion composition of the present invention.
  • the oil-in-water emulsion composition of the present invention contains an aqueous thickener (c4) in addition to the core-shell particles, which improves the UV protection effect when applied to the skin, as well as the moisturizing properties, moisturizing feeling, and resistance to irritation.
  • aqueous thickeners examples include poly(meth)acrylamide, copolymers of hydroxyethyl (meth)acrylate and (meth)acryloyldimethyl taurine salt, copolymers of (meth)acrylate and (meth)acryloyldimethyl taurine salt, copolymers of (meth)acrylamide and (meth)acrylate, copolymers of (meth)acrylic acid, (meth)acrylic acid amide, (meth)acrylate and (meth)acryloyldimethyl taurine salt, and copolymers of (meth)acryloyldimethyl taurine salt and vinylpyrrolidone.
  • Poly(meth)acrylamide-based aqueous thickeners include copolymers of hydroxyethyl (meth)acrylate and (meth)acryloyldimethyl taurine salt, and copolymers of vinylpyrrolidone.
  • aqueous thickeners include xanthan gum, dextrin, methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, carboxymethyl chitin, chitosan, and other polysaccharide-based thickeners, polyvinyl alcohol, polyacrylic acid, polymethacrylic acid, carboxyvinyl polymers, acrylic acid / alkyl acrylate copolymers (e.g., (acrylic acid / alkyl acrylate (C10-30)) copolymers), and the like.
  • those using at least a poly(meth)acrylamide-based aqueous thickener are preferred, and those using a combination of a poly(meth)acrylamide-based aqueous thickener and a polysaccharide-based aqueous thickener are more preferred.
  • a copolymer of hydroxyethyl (meth)acrylate and (meth)acryloyldimethyltaurate salt such as (hydroxyethyl acrylate/sodium acryloyldimethyltaurate) copolymer, is used, storage stability and the absence of white cast are improved.
  • polyacrylamides include Sepigel 305 (a mixture of polyacrylamide, hydrogenated polyisobutene, laureth-7, and water).
  • copolymers of hydroxyethyl acrylate and acryloyldimethyltaurate include SEPINOV EMT 10 (a mixture of (hydroxyethyl acrylate/sodium acryloyldimethyltaurate) copolymer, sorbitan isostearate, and polysorbate 60), SIMULGEL NS (a mixture of (hydroxyethyl acrylate/sodium acryloyldimethyltaurate) copolymer, squalane, polysorbate 60, and water), SIMULGEL FL (a mixture of (hydroxyethyl acrylate/sodium acryloyldimethyltaurate) copolymer, isohexadecane, polysorbate 60, and water), and SEPIPLUS S (a mixture of (hydroxyethyl acrylate/so
  • copolymers of acrylates and acryloyldimethyltaurate include SIMULGEL EG (a mixture of (sodium acrylate/sodium acryloyldimethyltaurate) copolymer, isohexadecane, polysorbate 80, sorbitan oleate, and water).
  • copolymers of acrylamide and acrylate include SEPIPLUS 265 (a mixture of (acrylamide/ammonium acrylate) copolymer, polyisobutene, polysorbate 20, and water).
  • copolymers of acrylic acid, acrylic acid amide, acrylic acid salts and acryloyldimethyltaurate salts include SEPIPLUS 400 (a mixture of polyacrylate-13, polyisobutene, polysorbate 20 and water).
  • SEPIPLUS 400 a mixture of polyacrylate-13, polyisobutene, polysorbate 20 and water.
  • a commercially available copolymer of acryloyldimethyltaurate and vinylpyrrolidone is Aristoflex AVC ((ammonium acryloyldimethyltaurate/VP) copolymer).
  • acid-type aqueous thickeners such as polyacrylic acid, carboxyvinyl polymer, and (acrylic acid/C10-30 alkyl acrylate) copolymer may be neutralized with an alkali metal hydroxide such as potassium hydroxide or sodium hydroxide and used as a water-soluble or water-dispersible salt.
  • an alkali metal hydroxide such as potassium hydroxide or sodium hydroxide
  • aqueous thickeners may be used alone or in combination of two or more.
  • the content of the aqueous thickener is preferably 0% by mass or more, more preferably 0.05% by mass or more, even more preferably 0.1% by mass or more, even more preferably 0.5% by mass or more, even more preferably 0.8% by mass or more, and even more preferably 0.85% by mass or more, relative to the total mass of the oil-in-water emulsion composition of the present invention; and from the viewpoints of UV protection effect, absence of white cast, ease of rinsing, storage stability, etc., the content of the aqueous thickener is preferably 5% by mass or less, more preferably 3% by mass or less, even more preferably 2% by mass or less, even more preferably 1.5% by mass or less, and even more preferably 1% by mass or less, relative to the total mass of the oil-in-water emulsion composition of the present invention.
  • the content is preferably from 0% by mass to 5% by mass, more preferably from 0.05% by mass to 3% by mass, even more preferably from 0.1% by mass to 2% by mass, even more preferably from 0.5% by mass to 1.5% by mass, even more preferably from 0.8% by mass to 1% by mass, and even more preferably from 0.85% by mass to 1% by mass, relative to the total mass of the oil-in-water emulsion composition of the present invention.
  • the UV protection effect, moisturizing feeling, moisturizing properties, irritation resistance, and storage stability when applied to the skin are further improved, while when the content is 1% by mass or less, the UV protection effect, lack of white cast, ease of rinsing, and storage stability when applied to the skin are further improved.
  • the mass ratio of the aqueous thickener (c4) to the core-shell particles [(c4)/(core-shell particles)] is preferably 0.005 or more, more preferably 0.0075 or more, and even more preferably 0.01 or more, from the viewpoints of UV protection effect, absence of white cast, moisturizing feel, moisturizing properties, resistance to irritation, etc., and is preferably 1 or less, more preferably 0.75 or less, and even more preferably 0.5 or less, from the viewpoints of UV protection effect, absence of white cast, etc. Specific ranges are preferably 0.005 or more and 1 or less, more preferably 0.0075 or more and 0.75 or less, and even more preferably 0.01 or more and 0.5 or less.
  • the oil-in-water emulsion composition of the present invention contains, in addition to the core-shell particles, (e1) a second hydrophobized UV scattering agent, and (c4) an aqueous thickener, (c1) water and (d1) a second oil agent that is liquid at 25°C.
  • the composition further contains one or more selected from the group consisting of (c2) a volatile medium other than water, (c3) a polyhydric alcohol, (d2) a second surfactant, (d3) a second powder dispersant, and (d4) an amphiphilic solid fat, It is more preferable that the composition contains at least component (d2), It is more preferable that the composition contains at least components (d2) and (d4), More preferred are those containing component (c3) and components (d2) to (d4).
  • the second oil agent that is liquid at 25°C of component (d1) means an oil agent that is liquid at 25°C outside the core-shell particles.
  • the second oil agent that is liquid at 25°C may be the same as the oil agent that is liquid at 25°C that can be used as component (a2), and is preferably not an oil-soluble ultraviolet absorber.
  • the liquid oil may be a volatile oil or a non-volatile oil, but a non-volatile oil is preferred from the viewpoints of UV protection effect, absence of white cast, moisturizing property, moisturizing feeling, irritation resistance, storage stability, etc.
  • One type of oil may be used alone, or two or more types may be used in combination.
  • volatile oils examples include light isoparaffin, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane, methyltrimethicone, decamethyltetrasiloxane, ethyltrisiloxane, and volatile methylpolysiloxane.
  • Light isoparaffin products include Isopar H (manufactured by Esso Chemical Co., Ltd.), Isododecane (manufactured by Bayer), Isohexadecane (manufactured by Uniqema), IP Solvent 1620MU, IP Solvent 2028MU, and IP Solvent 2835 (all manufactured by Idemitsu Kosan Co., Ltd.).
  • decamethylcyclopentasiloxane products include TSF405 (manufactured by Momentive Performance Materials Japan LLC), SH245, DC345 (manufactured by Dow Corning Toray Co., Ltd.), and KF-995 (manufactured by Shin-Etsu Chemical Co., Ltd.).
  • Commercially available methyl trimethicone products include Silicone TMF-1.5 (manufactured by Shin-Etsu Chemical Co., Ltd.).
  • decamethyltetrasiloxane products include KF-96L-1.5CS (manufactured by Shin-Etsu Chemical Co., Ltd.).
  • ethyltrisiloxanes include SILSOFTETS (manufactured by Momentive Performance Materials Japan, LLC), and commercially available volatile methylpolysiloxanes include KF-96L-2CS (manufactured by Shin-Etsu Chemical Co., Ltd.).
  • non-volatile oils include non-volatile hydrocarbon oils such as liquid paraffin (light liquid paraffin, light liquid isoparaffin, heavy liquid isoparaffin, etc.), hydrogenated polyisobutene, isohexadecane, and squalane; non-volatile silicone oils such as non-volatile dimethylpolysiloxane and non-volatile methylphenylpolysiloxane; non-volatile fatty acid ester oils such as cetyl 2-ethylhexanoate, isononyl isononanoate, isotridecyl isononanoate, isopropyl myristate, isopropyl palmitate, 2-ethylhexyl palmitate, 2-ethylhexyl stearate, and stearyl stearate; and alkyl benzoates (C12-15).
  • non-volatile hydrocarbon oils such as liquid paraffin (light liquid paraffin, light liquid isopar
  • non-volatile fatty acid ester oils examples include fatty acid triglycerides such as glyceryl tri(caprylate/caprate) and glyceryl tri(2-ethylhexanoate); esters of fatty acids and neopentyl glycol such as neopentyl glycol dicaprate and neopentyl glycol diethylhexanoate; and polyhydric alcohol fatty acid ester oils.
  • Commercially available liquid paraffin products include Parleam 4 (manufactured by NOF Corporation).
  • non-volatile dimethylpolysiloxane products include KF-96A-10CS (manufactured by Shin-Etsu Chemical Co., Ltd.).
  • Commercially available isopropyl palmitate products include Exepar IPP (manufactured by Kao Corporation).
  • commercially available alkyl benzoate (C12-15) products include FINSOLV TN (manufactured by Innospec Active Chemicals).
  • neopentyl glycol dicaprate products include Estemol N-01 (manufactured by Nisshin Oillio Group, Ltd.).
  • the content of the second oil that is liquid at 25°C is preferably 7.5% by mass or more, more preferably 10% by mass or more, and even more preferably 15% by mass or more, based on the total mass of the oil-in-water emulsion composition of the present invention, from the viewpoints of UV protection effect, absence of white cast, moisturizing feel, moisturizing properties, irritation resistance, etc.; and from the viewpoint of storage stability, etc., it is preferably 35% by mass or less, more preferably 30% by mass or less, and even more preferably 25% by mass or less, based on the total mass of the oil-in-water emulsion composition of the present invention.
  • Specific ranges are preferably 7.5% by mass or more and 35% by mass or less, more preferably 10% by mass or more and 30% by mass or less, and even more preferably 15% by mass or more and 25% by mass or less, based on the total mass of the oil-in-water emulsion composition of the present invention.
  • the mass ratio of the content of the second oil agent (d1) that is liquid at 25°C to the core-shell particles [(d1)/(core-shell particles)] is preferably 0.05 or more, more preferably 0.1 or more, and even more preferably 0.3 or more, from the viewpoints of UV protection effect, absence of white cast, moisturizing feel, moisturizing properties, irritation resistance, etc., and is preferably 9 or less, more preferably 7 or less, and even more preferably 5 or less, from the viewpoint of storage stability, etc. Specific ranges are preferably 0.05 or more and 9 or less, more preferably 0.1 or more and 7 or less, and even more preferably 0.3 or more and 5 or less.
  • the second surfactant of component (d2) refers to a surfactant outside the core-shell particles.
  • the second surfactant (d2) include nonionic surfactants, anionic surfactants, cationic surfactants, and amphoteric surfactants. These surfactants may be used alone or in combination. Among these, nonionic surfactants are preferred.
  • nonionic surfactant When a nonionic surfactant is used as the second surfactant, the ultraviolet protection effect, absence of white cast, moisturizing properties, moisturizing feel, irritation resistance, ease of washing, and storage stability are further improved.
  • nonionic surfactants include sorbitan fatty acid esters such as sorbitan monostearate and sorbitan monoisostearate; polyoxyalkylene sorbitan fatty acid esters such as polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan monolaurate and polyoxyethylene sorbitan monooleate; polyoxyalkylene alkyl ethers such as polyoxyethylene (average number of moles of EO added: 7) lauryl ether; and polyoxyalkylene hydrogenated castor oils such as polyoxyethylene hydrogenated castor oil (average number of moles of EO added: 60) and polyoxyethylene hydrogenated castor oil (average number of moles of EO added: 40).
  • the content of the second surfactant is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and even more preferably 1% by mass or more, based on the total mass of the oil-in-water emulsion composition of the present invention, from the viewpoints of UV protection effect, moisture retention, moisturizing feel, irritation resistance, ease of washing, etc., and is preferably 5% by mass or less, more preferably 2.5% by mass or less, based on the total mass of the oil-in-water emulsion composition of the present invention, from the viewpoints of UV protection effect, absence of white cast, moisture retention, moisturizing feel, irritation resistance, ease of washing, storage stability, etc.
  • a specific range is preferably 0.1% by mass or more and 5% by mass or less, more preferably 0.5% by mass or more and 5% by mass or less, and even more preferably 1% by mass or more and 2.5% by mass or less, based on the total mass of the oil-in-water emulsion composition of the present invention.
  • the content of the second surfactant in the oil-in-water emulsion composition is 1% by mass or more, the UV protection effect, moisturizing effect, moisturizing feeling, irritation resistance, and ease of cleansing are further improved, and when the content is 2.5% by mass or less, the moisturizing effect, moisturizing feeling, irritation resistance, ease of cleansing, and storage stability are further improved.
  • the mass ratio of the content of the second surfactant (d2) to the core-shell particles [(d2)/(core-shell particles)] is preferably 0.005 or more, more preferably 0.0075 or more, and even more preferably 0.01 or more, from the viewpoints of moisturizing feel, moisturizing properties, irritation resistance, storage stability, etc., and is preferably 1 or less, more preferably 0.75 or less, and even more preferably 0.5 or less, from the viewpoint of storage stability, etc. Specific ranges are preferably 0.005 or more and 1 or less, more preferably 0.0075 or more and 0.75 or less, and even more preferably 0.01 or more and 0.5 or less.
  • volatile media other than water examples include lower alcohols such as ethanol and isopropanol.
  • the content of the volatile medium other than water is preferably from 0% by mass to 1% by mass, more preferably from 0% by mass to 0.1% by mass, even more preferably from 0% by mass to 0.01% by mass, and even more preferably 0% by mass, relative to the total mass of the oil-in-water emulsion composition of the present invention.
  • the polyhydric alcohol of component (c3) means a polyhydric alcohol outside the core-shell particles.
  • polyhydric alcohols include glycols and glycerins.
  • glycols include alkylene glycols such as ethylene glycol, propylene glycol, trimethylene glycol (1,3-propanediol), and 1,3-butylene glycol; dialkylene glycols such as diethylene glycol and dipropylene glycol; and polyalkylene glycols such as polyethylene glycol and polypropylene glycol.
  • Examples of glycerins include glycerin, diglycerin, and polyglycerin. Among these, glycols are preferred, and alkylene glycols are more preferred, from the viewpoints of storage stability, moisturizing properties, moisturizing feeling, irritation resistance, UV protection effect, and the like.
  • the content of polyhydric alcohol is preferably 1% by mass or more, more preferably 2% by mass or more, and even more preferably 3% by mass or more, relative to the total mass of the oil-in-water emulsion composition of the present invention.
  • the content is preferably 20% by mass or less, more preferably 17.5% by mass or less, and even more preferably 15% by mass or less, relative to the total mass of the oil-in-water emulsion composition of the present invention.
  • Specific ranges are preferably 1% by mass or more and 20% by mass or less, more preferably 2% by mass or more and 17.5% by mass or less, and even more preferably 3% by mass or more and 15% by mass or less, relative to the total mass of the oil-in-water emulsion composition of the present invention.
  • the second powder dispersant of component (d3) means a powder dispersant outside the core-shell particles.
  • the second powder dispersant may be any that facilitates dispersion of the hydrophobized UV scattering agent in a liquid oil at 25°C.
  • Examples include polyether-modified silicones; polyhydroxy fatty acids such as polyhydroxystearic acid; dipentaerythrityl tri-polyhydroxy fatty acids such as dipentaerythrityl tri-polyhydroxystearate; diglycerin difatty acid esters such as polyglyceryl diisostearate, polyglyceryl dilaurate, polyglyceryl distearate, and polyglyceryl dioleate; and sorbitan difatty acid esters such as sorbitan dilaurate, sorbitan dimyristate, sorbitan dipalmitate, sorbitan distearate, and sorbitan dibehenate.
  • dipentaerythrityl tri-polyhydroxy fatty acid, diglycerin difatty acid esters, and sorbitan difatty acid esters are preferred from the viewpoint of dispersion stability, etc.
  • the second powder dispersant may be used alone or in combination of two or more types.
  • the content of the second powder dispersant is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, based on the total mass of the oil-in-water emulsion composition of the present invention, from the viewpoints of UV protection effect, absence of white cast, etc., and is preferably 5% by mass or less, more preferably 1.5% by mass or less, based on the total mass of the oil-in-water emulsion composition of the present invention, from the viewpoints of storage stability, etc.
  • the specific range is preferably 0.1% by mass or more and 5% by mass or less, and more preferably 0.5% by mass or more and 1.5% by mass or less, based on the total mass of the oil-in-water emulsion composition of the present invention.
  • the content mass ratio of the second powder dispersant (d3) to the second hydrophobized UV scattering agent (e1) [(d3)/(e1)] is preferably 0.01 or more, more preferably 0.05 or more, and even more preferably 0.075 or more, from the viewpoints of UV protection effect, absence of white cast, etc., and is preferably 1 or less, more preferably 0.5 or less, and even more preferably 0.3 or less, from the viewpoint of storage stability, etc. Specific ranges are preferably 0.01 or more and 1 or less, more preferably 0.05 or more and 0.5 or less, and even more preferably 0.075 or more and 0.3 or less.
  • amphiphilic solid fat means the amphiphilic solid fat outside the core-shell particles.
  • amphiphilic solid fat include higher alcohols, ceramides, polyhydric alcohol mono-C10-24 fatty acid esters, polyhydric alcohol mono-C10-24 alkyl ethers, etc.
  • the higher alcohols, ceramides, polyhydric alcohol mono-C10-24 fatty acid esters, and polyhydric alcohol mono-C10-24 alkyl ethers include the same substances as those listed as (b2) hydrophobic amphiphilic substances.
  • higher alcohols are preferred.
  • higher alcohols monohydric alcohols having 10 to 24 carbon atoms are preferred, monohydric alcohols having 12 to 22 carbon atoms are more preferred, and monohydric alcohols having 14 to 22 carbon atoms are even more preferred.
  • higher alcohols may be linear or branched, and may be saturated or unsaturated alcohols, but linear saturated or unsaturated alcohols are preferred. Examples of higher alcohols include lauryl alcohol, myristyl alcohol, cetanol, stearyl alcohol, behenyl alcohol, oleyl alcohol, etc. Among these, cetanol, stearyl alcohol, and behenyl alcohol are preferred, and cetanol is more preferred.
  • amphiphilic solid fats may be used alone or in combination of two or more types.
  • the content of the amphiphilic solid fat is preferably 0.05% by mass or more, more preferably 0.1% by mass or more, based on the total mass of the oil-in-water emulsion composition of the present invention, from the viewpoints of storage stability, moisturizing feel, moisturizing properties, irritation resistance, etc.; and from the viewpoints of UV protection effect, absence of white cast, etc., it is preferably 1% by mass or less, more preferably 0.75% by mass or less, based on the total mass of the oil-in-water emulsion composition of the present invention.
  • a specific range is preferably 0.05% by mass or more and 1% by mass or less, and more preferably 0.1% by mass or more and 0.75% by mass or less, based on the total mass of the oil-in-water emulsion composition of the present invention.
  • the mass ratio of the amphiphilic solid fat (d4) to the core-shell particles [(d4)/(core-shell particles)] is preferably 0.005 or more, more preferably 0.01 or more, from the viewpoints of storage stability, moisturizing feel, moisturizing properties, and irritation resistance, and is preferably 0.6 or less, more preferably 0.2 or less, from the viewpoints of UV protection effect, absence of white cast, and the like. Specifically, the range is preferably 0.005 or more and 0.6 or less, and more preferably 0.01 or more and 0.2 or less.
  • oil-in-water emulsion composition of the present invention may also contain basic substances, chelating agents, preservatives, moisturizers, pH adjusters, fragrances, cosmetic ingredients, medicinal ingredients, oil gelling agents, bactericides, antioxidants, etc. These may be used alone or in combination of two or more.
  • the total content of the liquid phase in the oil-in-water emulsion composition is preferably 55% by mass or more, more preferably 60% by mass or more, based on the total mass of the oil-in-water emulsion composition of the present invention, from the viewpoints of UV protection effect, storage stability, moisturizing feeling, moisturizing properties, irritation resistance, etc., and is preferably 95% by mass or less, more preferably 90% by mass or less, based on the total mass of the oil-in-water emulsion composition of the present invention, from the viewpoints of moisturizing feeling, moisturizing properties, irritation resistance, etc.
  • a specific range is preferably 55% by mass or more and 95% by mass or less, more preferably 60% by mass or more and 90% by mass or less, based on the total mass of the oil-in-water emulsion composition of the present invention.
  • the "total content of the liquid phase” refers to the total mass of the oil-in-water emulsion composition excluding particle and powder components.
  • the mass ratio of the core-shell particles to the liquid phase of the oil-in-water emulsion composition is preferably 0.01 or more, more preferably 0.1 or more, from the viewpoints of UV protection effect, moisturizing feel, moisturizing properties, irritation resistance, etc., and is preferably 0.5 or less, more preferably 0.3 or less, from the viewpoint of storage stability, etc.
  • a specific range is preferably 0.01 or more and 0.5 or less, and more preferably 0.1 or more and 0.3 or less.
  • the total content of all hydrophobized UV scattering agents in the oil-in-water emulsion composition is preferably 4% by mass or more, more preferably 8% by mass or more, and even more preferably 11% by mass or more, based on the total mass of the oil-in-water emulsion composition of the present invention, from the viewpoints of UV protection effect, storage stability, moisturizing property, moisturizing feeling, resistance to irritation, etc.; and from the viewpoints of absence of white cast, storage stability, etc., the total content is preferably 32.5% by mass or less, more preferably 30% by mass or less, even more preferably 27.5% by mass or less, even more preferably 25% by mass or less, even more preferably 22% by mass or less, even more preferably 20% by mass or less, and even more preferably 18% by mass or less, based on the total mass of the oil-in-water emulsion composition of the present invention.
  • the content is preferably from 4% by mass to 32.5% by mass, more preferably from 8% by mass to 30% by mass, even more preferably from 11% by mass to 27.5% by mass, even more preferably from 11% by mass to 25% by mass, even more preferably from 11% by mass to 22% by mass, even more preferably from 11% by mass to 20% by mass, and even more preferably from 11% by mass to 18% by mass, relative to the total mass of the oil-in-water emulsion composition of the present invention.
  • the oil-in-water emulsion composition of the present invention is less likely to cause a white cast after application to the skin, even when the total content of all hydrophobized UV scattering agents is such a high content. Furthermore, when the total content of all hydrophobized UV scattering agents in the oil-in-water emulsion composition is 11% by mass or more, the UV protection effect, moisturizing properties, moisturizing feeling, irritation resistance, and storage stability are further improved.
  • the mass ratio of the total content of all hydrophobized UV scattering agents in the oil-in-water emulsion composition to the total content of all oils that are liquid at 25°C in the oil-in-water emulsion composition is preferably 0.1 or more, more preferably 0.3 or more, and even more preferably 0.4 or more from the viewpoint of UV protection effect, etc., and is preferably 1 or less, more preferably 0.75 or less, even more preferably 0.5 or less, and even more preferably 0.48 or less from the viewpoint of absence of white cast, storage stability, etc.
  • Specific ranges are preferably 0.1 or more and 1 or less, more preferably 0.1 or more and 0.75 or less, more preferably 0.3 or more and 0.5 or less, even more preferably 0.4 or more and 0.48 or less.
  • the content mass ratio [(total hydrophobized UV scattering agents in the oil-in-water emulsion composition)/(total oil agents that are liquid at 25°C in the oil-in-water emulsion composition)] is set to 0.48 or less, the UV protection effect and storage stability are further improved.
  • the mass ratio of the total water content in the oil-in-water emulsion composition to the total content of all hydrophobized UV scattering agents in the oil-in-water emulsion composition is preferably 1 or more, more preferably 1.4 or more, even more preferably 1.8 or more from the viewpoint of storage stability, etc., and is preferably 5.5 or less, more preferably 4.5 or less, even more preferably 3.5 or less from the viewpoint of UV protection effect, etc.
  • the mass ratio of the total content of all oil agents that are liquid at 25°C in the oil-in-water emulsion composition (preferably the total of components (a2) and (d1)) to the total content of water in the oil-in-water emulsion composition [(all oil agents that are liquid at 25°C in the oil-in-water emulsion composition)/(water in the oil-in-water emulsion composition)] is preferably from 0.3 to 2, and more preferably from 0.5 to 1.5, from the viewpoints of UV protection effect, absence of white cast, moisturizing feel, moisturizing properties, irritation resistance, etc.
  • the UV protection effect and storage stability are further improved.
  • the oil-in-water emulsion composition of the present invention can achieve high UV protection effects even when the content of UV absorbers is reduced or no UV absorbers are used.
  • the total content of UV absorbers is preferably 0% by mass or more and 20% by mass or less, more preferably 0% by mass or more and 5% by mass or less, even more preferably 0% by mass or more and 1% by mass or less, even more preferably 0% by mass or more and 0.1% by mass or less, even more preferably 0% by mass or more and 0.01% by mass or less, and even more preferably 0% by mass, based on the total mass of the oil-in-water emulsion composition of the present invention.
  • the viscosity of the oil-in-water emulsion composition of the present invention at 25°C is preferably 6,000 mPa ⁇ s or more, more preferably 15,000 mPa ⁇ s or more, from the viewpoint of resistance to dripping, etc., and is preferably 100,000 mPa ⁇ s or less, more preferably 50,000 mPa ⁇ s or less, from the viewpoint of UV protection effect, spreadability upon application, absence of white cast, etc.
  • the viscosity range is preferably 6,000 mPa ⁇ s or more and 100,000 mPa ⁇ s or less, and more preferably 15,000 mPa ⁇ s or more and 50,000 mPa ⁇ s or less.
  • the viscosity at 25° C. can be measured using a TVB-10 viscometer under the measurement conditions of rotor No. 4, 6 rpm, and 1 min.
  • the pH of the oil-in-water emulsion composition of the present invention at 25°C is preferably 7 or more and 8.5 or less, from the viewpoint of storage stability, etc.
  • the oil-in-water emulsion composition of the present invention has an oil-in-water emulsion composition in the liquid phase. This gives it a fresh, light feel when used and makes it easy to wash off when cleansing. Furthermore, even when the oil-in-water emulsion composition of the present invention is an oil-in-water emulsion composition with a high content of hydrophobized UV scattering agents, it is less likely to leave a white cast after application.
  • the oil-in-water emulsion composition of the present invention can be produced by appropriately combining the methods described in JP-A-2017-7969, JP-A-2020-63239, JP-A-2022-186915, JP-A-2022-117486, WO2023/286780, etc.
  • Step A1 prepares a slurry containing (a1) a hydrophobic treated ultraviolet scattering agent, (a2) an oil agent that is liquid at 25°C, and optionally (a3) a powder dispersant, and heat-mixes (b1) anionic surfactant, (b2) a hydrophobic amphiphilic substance, and optionally (b3) an oil-based thickener; (Step A2) While circulating the composition obtained in Step A1 through a homogenizer, water is added dropwise to the composition at 80 to 120°C to form an oil-in-water emulsion; (Step A3) The core-shell particles can be produced by cooling the oil-in-water emulsion obtained in step A2 at a cooling rate of 0.5 to 5°C/second.
  • Examples of the cooling method in step A3 include a method of continuous rapid cooling using a vibration-type stirring mixer, a scraping-type heat exchanger, a static mixer, a plate-type heat exchanger, a double-pipe heat exchanger, or the like, and a method of stirring and cooling in a general blending tank.
  • the oil-in-water emulsion composition of the present invention can then be produced by mixing the resulting core-shell particles with (c1) water, (c4) an aqueous thickener, and, if necessary, (c2) a volatile medium other than water or (c3) a polyhydric alcohol, and adding an oil phase component prepared by mixing or dispersing (d1) a second oil agent that is liquid at 25°C, (d2) a surfactant, (e1) a second hydrophobized UV scattering agent, and, if necessary, other components.
  • the oil-in-water emulsion composition of the present invention exerts moisturizing properties and provides a moisturizing feeling when applied to the skin, exhibits excellent UV protection effects, is less likely to cause white cast, and can suppress irritation when the applied surface is rubbed.
  • the present inventors speculate that the oil-in-water emulsion composition of the present invention is likely to be due to the fact that, even when applied to the skin and the moisture evaporates, the core-shell particles are resistant to crushing and maintain their thickness, the core-shell particles and the hydrophobized UV scattering agent within the particles do not aggregate with each other and remain dispersed, and the coating film containing the core-shell particles is likely to maintain a uniform and appropriate thickness.
  • the present inventors also speculate that one of the mechanisms for the moisturizing feel and moisturizing properties is the fact that the core-shell particles easily retain moisture. Furthermore, since the hydrophobized UV scattering agent is likely to be distributed uniformly within the core-shell particles, even when the content of the hydrophobized UV scattering agent within the core-shell particles is increased, the composition is likely to exhibit excellent UV protection effects and is less likely to produce a whitish cast.
  • the oil-in-water emulsion composition of the present invention is useful as a cosmetic (for example, sunscreen, foundation, makeup base, lotion, emulsion, cream, gel, serum, sheet-type cosmetic), and is particularly useful as a sunscreen.
  • the oil-in-water emulsion composition of the present invention is also useful for the skin (preferably the skin excluding the scalp, more preferably the face, body, hands, feet, etc.), and can be used as a sunscreen by applying it to the skin using a method appropriate for the type of formulation. The method of use is not particularly limited, but application by hand or with an applicator is preferred.
  • the core part comprises the following components (a1) and (a2); (a1) a hydrophobized ultraviolet scattering agent; (a2) an oil agent that is liquid at 25°C, and a shell portion comprising the following components (b1) and (b2); (b1) an anionic surfactant; (b2) a core-shell particle containing a hydrophobic amphiphilic substance; (e1) a second hydrophobized ultraviolet scattering agent; and (c4) an aqueous thickener; an oil-in-water emulsion composition in which the core-shell particles and (e1) a second hydrophobized UV scattering agent are dispersed;
  • component (a1) is preferably a hydrophobized fine particle metal oxide, more preferably one or more fine particle metal oxides selected from zinc oxide, titanium oxide, cerium oxide, iron oxide, and chromium oxide that have been hydrophobized, even more preferably one or more fine particle metal oxides selected from zinc oxide, titanium oxide, and cerium oxide that have been hydrophobized, even more preferably one or more fine particle metal oxides selected from zinc oxide and titanium oxide that have been hydrophobized, and even more preferably hydrophobized fine particle titanium oxide.
  • component (a1) is preferably a hydrophobized fine particle metal oxide, more preferably one or more fine particle metal oxides selected from zinc oxide, titanium oxide, cerium oxide, iron oxide, and chromium oxide that have been hydrophobized, even more preferably one or more fine particle metal oxides selected from zinc oxide, titanium oxide, and cerium oxide that have been hydrophobized, even more preferably one or more fine particle metal oxides selected from zinc oxide and titanium oxide that have been hydrophobized, and even more
  • hydrophobization treatment of component (a1) is preferably a hydrophobization treatment selected from treatment with a fluorine compound, silicone treatment, silicone resin treatment, pendant treatment, treatment with a silane coupling agent, treatment with a titanium coupling agent, treatment with an oil, treatment with an N-acylated lysine, treatment with polyacrylic acid, treatment with a metal soap, treatment with an amino acid, treatment with an inorganic compound, plasma treatment, mechanochemical treatment, treatment with a silane compound, and treatment with a silazane compound, and more preferably a hydrophobization treatment selected from treatment with a silicone resin, treatment with a silane compound, treatment with a silazane compound, and treatment with a metal soap.
  • ⁇ 4> The oil-in-water emulsion composition according to any one of ⁇ 1> to ⁇ 3>, wherein the content of component (a1) is preferably 0.1% by mass or more, more preferably 1% by mass or more, even more preferably 2.5% by mass or more, even more preferably 5% by mass or more, even more preferably 10% by mass or more, and still more preferably 18% by mass or more, relative to the total mass of the core-shell particles, and is preferably 40% by mass or less, more preferably 30% by mass or less, and even more preferably 25% by mass or less, relative to the total mass of the core-shell particles.
  • ⁇ 5> The oil-in-water emulsion composition according to any one of ⁇ 1> to ⁇ 3>, wherein the content of component (a1) is preferably from 0.1% by mass to 40% by mass, more preferably from 1% by mass to 30% by mass, even more preferably from 2.5% by mass to 25% by mass, even more preferably from 5% by mass to 25% by mass, even more preferably from 10% by mass to 25% by mass, and even more preferably from 18% by mass to 25% by mass, relative to the total mass of the core-shell particles.
  • ⁇ 8> The oil-in-water emulsion composition according to any one of ⁇ 1> to ⁇ 7>, wherein the component (a2) is preferably a non-volatile oil, more preferably one or more non-volatile oils selected from a non-volatile hydrocarbon oil, a non-volatile silicone oil, a non-volatile fatty acid ester oil, and a C12-15 alkyl benzoate.
  • the component (a2) is preferably a non-volatile oil, more preferably one or more non-volatile oils selected from a non-volatile hydrocarbon oil, a non-volatile silicone oil, a non-volatile fatty acid ester oil, and a C12-15 alkyl benzoate.
  • the oil-in-water emulsion composition according to any one of ⁇ 1> to ⁇ 9>, wherein the content of the oil in a liquid state at 25°C in the core-shell particles is preferably 0.5% by mass or more, more preferably 1% by mass or more, relative to the total mass of the oil-in-water emulsion composition, and is preferably 25% by mass or less, more preferably 20% by mass or less, relative to the total mass of the oil-in-water emulsion composition.
  • ⁇ 12> The oil-in-water emulsion composition according to any one of ⁇ 1> to ⁇ 11>, wherein the core of the core-shell particle preferably further contains (a3) a powder dispersant, more preferably one or more selected from polyether-modified silicone, polyhydroxy fatty acid, dipentaerythrityl tri-polyhydroxy fatty acid, and diglycerin difatty acid ester.
  • a powder dispersant more preferably one or more selected from polyether-modified silicone, polyhydroxy fatty acid, dipentaerythrityl tri-polyhydroxy fatty acid, and diglycerin difatty acid ester.
  • component (b1) is preferably one or more selected from fatty acid salts, alkyl sulfate salts, polyoxyethylene alkyl ether sulfate salts, N-acylsarcosinates, alkyl phosphates, polyoxyethylene alkyl ether phosphates, dialkyl sulfosuccinates, N-alkyloylmethyl taurines, and N-acyl glutamates; more preferably one or more selected from N-acyl glutamates having an acyl group of 12 to 24 carbon atoms, N-alkyloylmethyl taurines having an alkyloyl group of 12 to 24 carbon atoms, fatty acid salts having 12 to 24 carbon atoms, and polyoxyethylene alkyl ether phosphates having 12 to 24 carbon atoms; even more preferably one or more selected from N-acyl gluta
  • the oil-in-water emulsion composition according to any one of ⁇ 1> to ⁇ 13>, wherein the content of component (b1) is preferably 0.05% by mass or more, more preferably 0.1% by mass or more, relative to the total mass of the oil-in-water emulsion composition, and is preferably 3% by mass or less, more preferably 1.5% by mass or less, relative to the total mass of the oil-in-water emulsion composition.
  • component (b2) is preferably one or more selected from higher alcohols, ceramides, linear saturated fatty acids having 10 to 24 carbon atoms, polyhydric alcohol mono-C10-24 fatty acid esters, sorbitan di-C10-24 fatty acid esters, and polyhydric alcohol mono-C10-24 alkyl ethers, more preferably one or more selected from monohydric alcohols having 10 to 24 carbon atoms, natural ceramides, pseudo-ceramides, linear saturated fatty acids having 12 to 24 carbon atoms, glycerin mono-C10-24 fatty acid esters, sorbitan mono-C10-24 fatty acid esters, and sorbitan di-C10-24 fatty acid esters, and even more preferably one or more selected from monohydric alcohols having 10 to 24 carbon atoms, glycerin mono-C10-24 fatty acid esters, and sorbitan di-C10-24 fatty acid esters, and even more preferably one or more selected from monohydric alcohols having 10 to 24 carbon
  • ⁇ 17> The oil-in-water emulsion composition according to any one of ⁇ 1> to ⁇ 16>, wherein the core-shell particles preferably have an ⁇ -gel structure.
  • the oil-in-water emulsion composition according to any one of ⁇ 1> to ⁇ 17>, wherein the core-shell particles preferably contain one or more components selected from (b3) an oil-based thickener and (b4) water, more preferably further contain at least component (b3), and even more preferably contain components (b3) to (b4).
  • a sugar fatty acid ester-based oil-based thickener even more preferably a dextrin fatty acid ester
  • dextrin myristate dextrin palmitate, dextrin stearate, dextrin
  • the oil-in-water emulsion composition according to any one of ⁇ 1> to ⁇ 21>, wherein the content of core-shell particles is preferably 3% by mass or more, more preferably 7.5% by mass or more, even more preferably 12.5% by mass or more, relative to the total mass of the oil-in-water emulsion composition, and is preferably 35% by mass or less, more preferably 30% by mass or less, even more preferably 27.5% by mass or less, even more preferably 20% by mass or less, relative to the total mass of the oil-in-water emulsion composition.
  • the component (e1) is preferably a hydrophobized fine particle metal oxide, more preferably one or more fine particle metal oxides selected from zinc oxide, titanium oxide, cerium oxide, iron oxide, and chromium oxide that have been hydrophobized, even more preferably one or more fine particle metal oxides selected from zinc oxide, titanium oxide, and cerium oxide that have been hydrophobized, even more preferably one or more fine particle metal oxides selected from zinc oxide and titanium oxide that have been hydrophobized, and even more preferably hydrophobized fine particle titanium oxide.
  • the component (e1) is preferably a hydrophobized fine particle metal oxide, more preferably one or more fine particle metal oxides selected from zinc oxide, titanium oxide, cerium oxide, iron oxide, and chromium oxide that have been hydrophobized, even more preferably one or more fine particle metal oxides selected from zinc oxide, titanium oxide, and cerium oxide that have been hydrophobized, even more preferably one or more fine particle metal oxides selected from zinc oxide and titanium oxide that have been hydrophobized, and even
  • hydrophobization treatment of component (e1) is preferably a hydrophobization treatment selected from treatment with a fluorine compound, silicone treatment, silicone resin treatment, pendant treatment, treatment with a silane coupling agent, treatment with a titanium coupling agent, treatment with an oil, treatment with an N-acylated lysine, treatment with polyacrylic acid, treatment with a metal soap, treatment with an amino acid, treatment with an inorganic compound, plasma treatment, mechanochemical treatment, treatment with a silane compound, and treatment with a silazane compound, and more preferably a hydrophobization treatment selected from treatment with a silicone resin, treatment with a silane compound, treatment with a silazane compound, and treatment with a metal soap.
  • the oil-in-water emulsion composition according to any one of ⁇ 1> to ⁇ 24>, wherein the content of component (e1) is preferably 3% by mass or more, more preferably 5% by mass or more, relative to the total mass of the oil-in-water emulsion composition, and is preferably 25% by mass or less, more preferably 22.5% by mass or less, even more preferably 20% by mass or less, even more preferably 18% by mass or less, and even more preferably 15% by mass or less, relative to the total mass of the oil-in-water emulsion composition.
  • the content of component (e1) is preferably 3% by mass or more, more preferably 5% by mass or more, relative to the total mass of the oil-in-water emulsion composition, and is preferably 25% by mass or less, more preferably 22.5% by mass or less, even more preferably 20% by mass or less, even more preferably 18% by mass or less, and even more preferably 15% by mass or less, relative to the total mass of the oil-in
  • ⁇ 26> The oil-in-water emulsion composition according to any one of ⁇ 1> to ⁇ 25>, wherein, as component (c4), preferably at least one or two or more selected from the group consisting of a poly(meth)acrylamide aqueous thickener, a polysaccharide aqueous thickener, polyvinyl alcohol, polyacrylic acid, polymethacrylic acid, a carboxyvinyl polymer, and an acrylic acid/alkyl acrylate copolymer are used, more preferably at least a poly(meth)acrylamide aqueous thickener is used, and even more preferably a combination of a poly(meth)acrylamide aqueous thickener and a polysaccharide aqueous thickener is used.
  • component (c4) preferably at least one or two or more selected from the group consisting of a poly(meth)acrylamide aqueous thickener, a polysaccharide aqueous thickener,
  • the oil-in-water emulsion composition according to any one of ⁇ 1> to ⁇ 26>, wherein the content of component (c4) is, relative to the total mass of the oil-in-water emulsion composition, preferably 0% by mass or more, more preferably 0.05% by mass or more, even more preferably 0.1% by mass or more, even more preferably 0.5% by mass or more, even more preferably 0.8% by mass or more, and even more preferably 0.85% by mass or more, and is preferably 5% by mass or less, more preferably 3% by mass or less, even more preferably 2% by mass or less, even more preferably 1.5% by mass or less, and even more preferably 1% by mass or less, relative to the total mass of the oil-in-water emulsion composition.
  • the oil-in-water emulsion composition according to any one of ⁇ 1> to ⁇ 27>, preferably further containing one or more selected from (c2) a volatile medium other than water, (c3) a polyhydric alcohol, (d2) a second surfactant, (d3) a second powder dispersant, and (d4) an amphiphilic solid fat, more preferably further containing component (d2), even more preferably further containing components (d2) and (d4), and even more preferably further containing component (c3) and components (d2) to (d4).
  • a volatile medium other than water preferably further containing one or more selected from (c2) a volatile medium other than water, (c3) a polyhydric alcohol, (d2) a second surfactant, (d3) a second powder dispersant, and (d4) an amphiphilic solid fat, more preferably further containing component (d2), even more preferably further containing components (d2) and (d4), and even more preferably further containing component (c3) and components (
  • the oil-in-water emulsion composition according to ⁇ 28> comprising (d1) a second oil that is liquid at 25°C, wherein the component (d1) is preferably a non-volatile oil, more preferably one or more non-volatile oils selected from non-volatile hydrocarbon oils, non-volatile silicone oils, non-volatile fatty acid ester oils, and C12-15 alkyl benzoates.
  • component (d1) is preferably a non-volatile oil, more preferably one or more non-volatile oils selected from non-volatile hydrocarbon oils, non-volatile silicone oils, non-volatile fatty acid ester oils, and C12-15 alkyl benzoates.
  • the component (d2) is preferably one or more selected from the group consisting of nonionic surfactants, anionic surfactants, cationic surfactants, and amphoteric surfactants, more preferably a nonionic surfactant, even more preferably one or more selected from the group consisting of a sorb
  • the oil-in-water emulsion composition according to any one of ⁇ 28> to ⁇ 30>, wherein the content of component (d2) is preferably at least 0.1% by mass, more preferably at least 0.5% by mass, and even more preferably at least 1% by mass, relative to the total mass of the oil-in-water emulsion composition, and is preferably at most 5% by mass, more preferably at most 2.5% by mass, relative to the total mass of the oil-in-water emulsion composition.
  • ⁇ 32> The oil-in-water emulsion composition according to any one of ⁇ 28> to ⁇ 31>, wherein the component (c3) is preferably one or more selected from glycols and glycerins, more preferably a glycol, and even more preferably an alkylene glycol.
  • the oil-in-water emulsion composition according to any one of ⁇ 1> to ⁇ 32>, wherein the total content of the liquid phase in the oil-in-water emulsion composition is preferably 55% by mass or more, more preferably 60% by mass or more, based on the total mass of the oil-in-water emulsion composition, and is preferably 95% by mass or less, more preferably 90% by mass or less, based on the total mass of the oil-in-water emulsion composition.
  • the oil-in-water emulsion composition according to any one of ⁇ 1> to ⁇ 34>, wherein the total content of all hydrophobized UV scattering agents in the oil-in-water emulsion composition is preferably 4% by mass or more, more preferably 8% by mass or more, even more preferably 11% by mass or more, relative to the total mass of the oil-in-water emulsion composition, and is preferably 32.5% by mass or less, more preferably 30% by mass or less, even more preferably 27.5% by mass or less, even more preferably 25% by mass or less, even more preferably 22% by mass or less, even more preferably 20% by mass or less, even more preferably 18% by mass or less, relative to the total mass of the oil-in-water emulsion composition.
  • ⁇ 36> The oil-in-water emulsion composition according to any one of ⁇ 1> to ⁇ 34>, wherein the total content of all hydrophobized UV scattering agents in the oil-in-water emulsion composition is 11 mass% or more, based on the total mass of the oil-in-water emulsion composition.
  • ⁇ 37> The oil-in-water emulsion composition according to any one of ⁇ 1> to ⁇ 34>, wherein the total content of all hydrophobized UV scattering agents in the oil-in-water emulsion composition is 11% by mass or more and 25% by mass or less, based on the total mass of the oil-in-water emulsion composition.
  • the oil-in-water emulsion composition according to any one of ⁇ 1> to ⁇ 26> and ⁇ 28> to ⁇ 34>, wherein the content of component (c4) is from 0.5% by mass to 1.5% by mass, both inclusive, relative to the total mass of the oil-in-water emulsion composition, and the total content of all hydrophobized UV scattering agents in the oil-in-water emulsion composition is from 11% by mass to 25% by mass, both inclusive, relative to the total mass of the oil-in-water emulsion composition.
  • the oil-in-water emulsion composition according to any one of ⁇ 1> to ⁇ 38>, wherein the mass ratio of the total content of all hydrophobized UV scattering agents in the oil-in-water emulsion composition to the total content of all oil agents that are liquid at 25°C in the oil-in-water emulsion composition (preferably the total of components (a2) and (d1)) [(total hydrophobized UV scattering agents in the oil-in-water emulsion composition)/(total oil agents that are liquid at 25°C in the oil-in-water emulsion composition)] is preferably 0.1 or more, more preferably 0.3 or more, even more preferably 0.4 or more, and is preferably 1 or less, more preferably 0.75 or less, even more preferably 0.5 or less, even more preferably 0.48 or less.
  • component (c4) is a combination of a poly(meth)acrylamide aqueous thickener and a polysaccharide aqueous thickener, the content of component (c4) is 0.5% by mass or more and 1.5% by mass or less, relative to the total mass of the oil-in-water emulsion composition, and the mass ratio of the content of all hydrophobized UV scattering agents in the oil-in-water emulsion composition to the total amount of oil agents in the oil-in-water emulsion composition that are liquid at 25°C (preferably the total amount of components (a2) and (d1)) [(total hydrophobized UV scattering agents in the oil-in-water emulsion composition)/(total oil agents in the oil-in-water emulsion composition that are liquid at 25°C)] is 0.3 or more and 0.48 or less
  • the oil-in-water emulsion composition according to any one of ⁇ 1> to ⁇ 42>, wherein the mass ratio of the total water content in the oil-in-water emulsion composition to the total content of all hydrophobized UV scattering agents in the oil-in-water emulsion composition [(water in the oil-in-water emulsion composition)/(total hydrophobized UV scattering agents in the oil-in-water emulsion composition)] is preferably 1 or more, more preferably 1.4 or more, even more preferably 1.8 or more, and is preferably 5.5 or less, more preferably 4.5 or less, even more preferably 3.5 or less.
  • ⁇ 44> The oil-in-water emulsion composition according to any one of ⁇ 1> to ⁇ 42>, wherein the mass ratio of the total water content in the oil-in-water emulsion composition to the total content of all hydrophobized UV scattering agents in the oil-in-water emulsion composition [(water in the oil-in-water emulsion composition)/(total hydrophobized UV scattering agents in the oil-in-water emulsion composition)] is 1.4 or more and 4.5 or less.
  • An oil-in-water emulsion composition according to any one of ⁇ 1> to ⁇ 44>, wherein the mass ratio of the total amount of oils that are liquid at 25°C in the oil-in-water emulsion composition (preferably the total amount of components (a2) and (d1)) to the total amount of water in the oil-in-water emulsion composition [(all oils that are liquid at 25°C in the oil-in-water emulsion composition)/(water in the oil-in-water emulsion composition)] is preferably 0.3 or more and 2 or less, more preferably 0.5 or more and 1.5 or less.
  • ⁇ 48> The oil-in-water emulsion composition according to any one of ⁇ 1> to ⁇ 47>, wherein the core-shell particles are dispersed in the aqueous phase of the oil-in-water emulsion composition, and component (e1) is dispersed in the oil phase of the oil-in-water emulsion composition.
  • the oil-in-water emulsion composition according to any one of ⁇ 1> to ⁇ 48> which is a cosmetic, preferably a sunscreen, foundation, makeup base, lotion, emulsion, cream, gel, serum, or sheet-type cosmetic, more preferably a sunscreen.
  • a cosmetic preferably a sunscreen, foundation, makeup base, lotion, emulsion, cream, gel, serum, or sheet-type cosmetic, more preferably a sunscreen.
  • the oil-in-water emulsion composition according to any one of ⁇ 1> to ⁇ 49> which is preferably for use on the skin, more preferably for use on the skin excluding the scalp, and even more preferably for use on the face, body, hands, and feet.
  • Example 3 (Imaging the cross section of a core-shell particle)
  • the cosmetic material of Example 3 was aspirated using a glass capillary, then rapidly frozen and fractured so that the cross section could be observed.
  • the sample was subjected to a sublimation treatment at -90°C for 20 minutes to prepare a specimen for observation.
  • This specimen for observation was observed and photographed using a cryo-SEM at an accelerating voltage of 1.0 kV and a magnification of 30,000 times.
  • the SEM image is shown in Figure 1.
  • a core portion in which (a1) a hydrophobized ultraviolet scattering agent was dispersed in (a2) an oil agent that was liquid at 25°C was encapsulated in a shell portion having ⁇ -gel.
  • the average value of the VAS evaluations before and after application was calculated, and the inhibition rate was calculated by dividing the VAS value after application by the VAS value before application, and the average itching inhibition rate for the three subjects was calculated.
  • the average value was converted into a score from A to E. It can be said that the smaller the average value, the less irritation when rubbed, and a rating of C was considered acceptable.
  • Conversion table from evaluation value to score (irritation tolerance) A: 0.1 or more and less than 0.6 B: 0.6 or more and less than 0.7 C: 0.7 or more and less than 0.8 D: 0.8 or more and less than 0.85 E: 0.85 or more and 1.0 or less
  • Example 3 The cosmetics of Example 3 and Comparative Example 1 were subjected to a moisturizing test. That is, after washing the face, the subject was allowed to acclimate for 15 minutes at 20° C. and 40% RH, and the moisture content of the stratum corneum before application was measured using a Corneometer (Corneometer CM825, manufactured by Courage+Khazaka).
  • the cosmetic composition of Example 3 or Comparative Example 1 was applied to half of the face of each subject at 2 mg/ cm2 , and the moisture content of the stratum corneum was measured 8 hours later. The moisture content of the stratum corneum before application was subtracted from the moisture content of the stratum corneum after 8 hours to calculate the change after 8 hours from application. The results are shown below.
  • Evaluation value (storage stability) A: Viscosity change immediately after application is less than 10,000 mPa ⁇ s B: Viscosity change immediately after application is 10,000 mPa ⁇ s or more and less than 40,000 mPa ⁇ s C: Viscosity change immediately after application is 40,000 mPa ⁇ s or more and less than 70,000 mPa ⁇ s D: Viscosity change immediately after application is 70,000 mPa ⁇ s or more and less than 110,000 mPa ⁇ s E: Viscosity change immediately after application is 110,000 mPa ⁇ s or more or separation occurs
  • Example 1 Oil-in-water sunscreen cosmetic Using the amounts of ingredients used in Example 1 shown in Table 2, a sunscreen cosmetic was produced in the following manner. 1) Production of Core-Shell Particles A titanium oxide dispersion (a composition of a mixture of fine particle titanium oxide, aluminum hydroxide, stearic acid, caprylic/capric triglyceride, and polyhydroxystearic acid), dextrin palmitate, and the "shell component" in Table 2 were mixed and stirred under heating at 80 to 90°C to obtain an oil phase. Using this oil phase and "Aqueous Phase Component 1" in Table 2, an oil-in-water emulsion was formed in accordance with the method described in JP 2017-7969 A.
  • the emulsion droplets were refined using a homomixer so that the average particle size of the core-shell particles would be the desired value (0.31 ⁇ m), and then the emulsion was continuously cooled to 40°C while stirring to obtain an aqueous dispersion of core-shell particles.
  • the average particle size of the core-shell particles was measured and the ⁇ -gel structure was confirmed. The results are shown in Table 2.
  • Oil phase component 2 (excluding mixture (2) of fine particle titanium dioxide, aluminum hydroxide, and stearic acid)) in Table 2 was heated, dissolved, and mixed, to which "mixture (2) of fine particle titanium dioxide, aluminum hydroxide, and stearic acid” in Table 2 was added and dispersed using a disperser to prepare an oil phase.
  • This oil phase was cooled to 35°C, added to the aqueous phase obtained above, and stirred using a homomixer.
  • phenoxyethanol was added, and the mixture was finely emulsified using a homomixer to produce an oil-in-water sunscreen cosmetic, which was then subjected to various evaluations. The results are shown in Table 2.
  • Example 2 to 13 Comparative Example 3: Oil-in-water sunscreen cosmetics
  • Sunscreen cosmetics were produced and various evaluations were carried out in the same manner as in Example 1, except for using the amounts of ingredients shown in Tables 2 to 4 and 6 for Examples 2 to 13. The results are shown in Tables 2 to 4 and 6.
  • Example 14 Oil-in-water sunscreen cosmetic A sunscreen cosmetic was produced in the same manner as in Example 3, except that the stirring speed during the micronization treatment using a homomixer was adjusted so that the average particle size of the core-shell particles would be 0.25 ⁇ m, and various evaluations were carried out. The results are shown in Table 5.
  • Example 15 Oil-in-water sunscreen cosmetic A sunscreen cosmetic was produced in the same manner as in Example 3, except that the stirring speed during the micronization treatment using a homomixer was adjusted so that the average particle size of the core-shell particles would be 0.41 ⁇ m, and various evaluations were carried out. The results are shown in Table 5.
  • Comparative Examples 1 and 2 Oil-in-water sunscreen cosmetics
  • the sunscreen cosmetics of Comparative Examples 1 and 2 were produced in the amounts shown in Table 6 according to conventional methods, and various evaluations were carried out. The results are shown in Table 6.
  • the numbers in parentheses in each table indicate the active ingredient content. Furthermore, since SIMULGEL EG QD contains sodium acrylate-sodium acryloyldimethyltaurate copolymer (37.5%), as well as isohexadecane (22.5%), water (30%), sorbitan oleate (2.5%), and polysorbate 80 (7.5%), the total content of oils that are liquid at 25°C, the mass ratio [(total hydrophobized UV scattering agent in the oil-in-water emulsion composition)/(total oils that are liquid at 25°C in the oil-in-water emulsion composition)], the mass ratio [(water in the oil-in-water emulsion composition)/(total hydrophobized UV scattering agent in the oil-in-water emulsion composition)], and the mass ratio [(total oils that are liquid at 25°C in the oil-in-water emulsion composition)/(water in the oil-in-water emulsion composition)] were
  • the oil-in-water sunscreen cosmetic of Formulation Example 1 was produced by a conventional method according to the formulation shown in Table 9. The oil-in-water sunscreen cosmetic of Formulation Example 1 was evaluated for UV protection effect, absence of white cast, resistance to irritation, moisturizing feel, ease of rinsing, feasibility as a formulation, and storage stability, and was found to be excellent in all respects.

Landscapes

  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Veterinary Medicine (AREA)
  • Animal Behavior & Ethology (AREA)
  • General Health & Medical Sciences (AREA)
  • Public Health (AREA)
  • Birds (AREA)
  • Epidemiology (AREA)
  • Chemical & Material Sciences (AREA)
  • Emergency Medicine (AREA)
  • Inorganic Chemistry (AREA)
  • Dermatology (AREA)
  • Dispersion Chemistry (AREA)
  • Cosmetics (AREA)
PCT/JP2025/007080 2024-03-01 2025-02-28 水中油型乳化組成物 Pending WO2025183150A1 (ja)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2025536117A JP7817505B2 (ja) 2024-03-01 2025-02-28 水中油型乳化組成物

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2024031749 2024-03-01
JP2024-031749 2024-03-01

Publications (1)

Publication Number Publication Date
WO2025183150A1 true WO2025183150A1 (ja) 2025-09-04

Family

ID=96921495

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2025/007080 Pending WO2025183150A1 (ja) 2024-03-01 2025-02-28 水中油型乳化組成物

Country Status (3)

Country Link
JP (1) JP7817505B2 (https=)
TW (1) TW202600119A (https=)
WO (1) WO2025183150A1 (https=)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2014091737A (ja) * 2012-11-06 2014-05-19 Kao Corp 水中油型乳化化粧料
JP2016104712A (ja) * 2014-11-20 2016-06-09 花王株式会社 皮膚化粧料
WO2020067561A1 (ja) * 2018-09-28 2020-04-02 花王株式会社 水中油型日焼け止め化粧料

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2014091737A (ja) * 2012-11-06 2014-05-19 Kao Corp 水中油型乳化化粧料
JP2016104712A (ja) * 2014-11-20 2016-06-09 花王株式会社 皮膚化粧料
WO2020067561A1 (ja) * 2018-09-28 2020-04-02 花王株式会社 水中油型日焼け止め化粧料

Also Published As

Publication number Publication date
JP7817505B2 (ja) 2026-02-18
TW202600119A (zh) 2026-01-01
JPWO2025183150A1 (https=) 2025-09-04

Similar Documents

Publication Publication Date Title
JP6535329B2 (ja) 水中油型乳化組成物
JP4422479B2 (ja) 日焼け止め剤組成物
JP3535389B2 (ja) 外用組成物
JP7152161B2 (ja) 皮膚外用剤又は化粧料
JP6887765B2 (ja) 日焼け止め化粧料
KR102875896B1 (ko) 수중유형 유화 화장료
JP7708552B2 (ja) 油中水型乳化化粧料
JP6741836B2 (ja) 水中油型乳化化粧料
JP6802718B2 (ja) 水中油型乳化化粧料
JP2024091980A (ja) 水中油型乳化化粧料
JP7498577B2 (ja) 水中油型乳化化粧料
JP7817505B2 (ja) 水中油型乳化組成物
JP6929333B2 (ja) 油中水型乳化化粧料
JP2008044901A (ja) 水中油型メイクアップ化粧料
JP3511415B2 (ja) 複合粉体及び化粧料
KR20250151634A (ko) 수중 유형 유화 화장료
JP2020128344A (ja) 水中油型乳化化粧料
JP2023145234A (ja) 日焼け止め化粧料
JP2019123674A (ja) 水中油乳化型日焼け止め化粧料
TW202245731A (zh) 水中油型乳化化妝料
JP7808962B2 (ja) 水中油型乳化化粧料
WO2024177089A1 (ja) 油中水型乳化化粧料
EP4599819A1 (en) Gel composition and oil-in-water-type composition
WO2026042767A1 (ja) 水中油型乳化組成物
EP4670707A1 (en) COSMETIC OIL-IN-WATER EMULSION

Legal Events

Date Code Title Description
ENP Entry into the national phase

Ref document number: 2025536117

Country of ref document: JP

Kind code of ref document: A

WWE Wipo information: entry into national phase

Ref document number: 2025536117

Country of ref document: JP

121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 25762062

Country of ref document: EP

Kind code of ref document: A1