Oil-in-water type emulsion cosmetic

Abstract

Provided is an oil-in-water type emulsion cosmetic containing (A) an amphiphilic substance and (B) a hydrophobized microparticlulate metal oxide that has been hydrophobized by a monoalkylphosphoric acid. The amphiphilic substance (A) includes one or more components selected from the group consisting of alkylene oxide derivatives represented by general formula (1) and general formula (2).　[Chemical formula 1] (In general formula (1), AO represents an oxyalkylene group having 3-4 carbon atoms, EO represents an oxyethylene group, R1 and R2 each independently represent a hydrocarbon group having 1-4 carbon atoms or a hydrogen atom, and m and n represent integers respectively satisfying the following formulae: 1≤m≤70 and 1≤n≤70.)　[Chemical formula 2] (In general formula (2), R3, R4 and R5 each independently represent a hydrogen atom or an alkyl group having 1-4 carbon atoms, A represents an alkylene group having 2-4 carbon atoms, and p and q each independently represent an integer of 1-50. A polymer represented by general formula (2) has a number average molecular weight of 10,000 or less and an IOB value of 0.4-1.8.)

Description

Oil-in-water emulsion cosmetics

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

[0002] In recent years, there has been a trend in several countries to require that various ingredients contained in cosmetics be made of materials that are highly safe for the human body, such as materials that meet EU standards. Among the ingredients contained in cosmetics, surface-treated metal oxides are often used as UV scattering agents in cosmetics such as sunscreens and foundations. For example, Patent Document 1 discloses zinc oxide particles that have been surface-treated with octyltriethoxysilane, which have UV screening properties, are excellent in color and feel when used, and are applicable to cosmetics.

[0003] Japanese Patent Application Publication No. 2023-162678

[0004] However, there is a demand for the use of a surface treatment agent that is safer than octyltriethoxysilane, which is used as a surface treatment agent for zinc oxide particles in Patent Document 1. However, replacing the surface treatment agent used in conventional UV scattering agents, such as octyltriethoxysilane, with a surface treatment agent that is thought to be safer is highly difficult, and the surface treatment of the zinc oxide or titanium oxide that forms the core of the UV scattering agent is likely to be insufficient, which can lead to poor emulsion stability when incorporated into cosmetics, etc. An object of one embodiment of the present invention is to provide an oil-in-water emulsion cosmetic that is highly safe and has good emulsion stability.

[0005] In order to solve the above-mentioned problems, one embodiment of the present invention provides an oil-in-water emulsion cosmetic comprising: (A) an amphiphilic substance; and (B) a hydrophobized metal oxide fine particle that has been hydrophobized with a monoalkyl phosphoric acid, wherein the amphiphilic substance (A) comprises one or more alkylene oxide derivatives selected from the group consisting of alkylene oxide derivatives represented by the following general formula (1) and the following general formula (2):

[0006] (In the general formula (1), AO represents an oxyalkylene group having 3 to 4 carbon atoms, EO represents an oxyethylene group, and R １ and R ２each independently represents a hydrocarbon group having 1 to 4 carbon atoms or a hydrogen atom, and m and n are integers satisfying the conditions of 1≦m≦70 and 1≦n≦70.

[0007] (In the general formula (2), R ３ , R ４ and R ５ are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, A is an alkylene group having 2 to 4 carbon atoms, and p and q are each independently an integer of 1 to 50. The polymer represented by the general formula (2) has a number average molecular weight of 10,000 or less and an IOB value of 0.4 to 1.8.

[0008] According to one embodiment of the present invention, it is possible to provide an oil-in-water emulsion cosmetic that is highly safe and has good emulsion stability.

[0009] Hereinafter, an embodiment of the present invention will be described in detail.

[0010] (Oil-in-water emulsion cosmetic) The oil-in-water emulsion cosmetic of the present invention comprises: (A) an amphiphilic substance; and (B) a hydrophobized metal oxide fine particle that has been hydrophobized with a monoalkylphosphoric acid, wherein the amphiphilic substance (A) comprises one or more alkylene oxide derivatives selected from the group consisting of alkylene oxide derivatives represented by the following general formula (1) and the following general formula (2):

[0011] (In the general formula (1), AO represents an oxyalkylene group having 3 to 4 carbon atoms, EO represents an oxyethylene group, and R １ and R ２ each independently represents a hydrocarbon group having 1 to 4 carbon atoms or a hydrogen atom, and m and n are integers satisfying the conditions of 1≦m≦70 and 1≦n≦70.

[0012] (In the general formula (2), R ３ , R ４ and R ５are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, A is an alkylene group having 2 to 4 carbon atoms, and p and q are each independently an integer from 1 to 50. The polymer represented by general formula (2) has a number average molecular weight of 10,000 or less and an IOB value of 0.4 to 1.8.) According to the present invention, it is possible to provide an oil-in-water emulsion cosmetic that is highly safe and has good emulsion stability.

[0013] <(A) Amphiphilic Substance> The oil-in-water emulsion cosmetic of the present invention contains, as component (A), one or more amphiphilic substances selected from the group consisting of alkylene oxide derivatives represented by the following general formula (1) and the following general formula (2).

[0014] (In the general formula (1), AO represents an oxyalkylene group having 3 to 4 carbon atoms, EO represents an oxyethylene group, and R １ and R ２ each independently represents a hydrocarbon group having 1 to 4 carbon atoms or a hydrogen atom, and m and n are integers satisfying the conditions of 1≦m≦70 and 1≦n≦70.

[0015] (In the general formula (2), R ３ , R ４ and R ５ are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, A is an alkylene group having 2 to 4 carbon atoms, and p and q are each independently an integer of 1 to 50. The polymer represented by the general formula (2) has a number average molecular weight of 10,000 or less and an IOB value of 0.4 to 1.8.

[0016] The oil-in-water emulsion cosmetic of the present invention contains an amphiphilic substance, and thus has a moisturizing effect, is excellent in texture, particularly smoothness, and is not sticky. The content of the amphiphilic substance in the oil-in-water emulsion cosmetic of the present invention is preferably 0.1% by mass or more and 10% by mass or less, more preferably 0.5% by mass or more and 7% by mass or less, and even more preferably 1% by mass or more and 5% by mass or less. When the content of the amphiphilic substance in the oil-in-water emulsion cosmetic is 0.1% by mass or more, a sufficient moisturizing effect can be obtained, and when it is 10% by mass or less, stickiness is unlikely to be felt after use.

[0017] <<Alkylene oxide derivative represented by general formula (1)>> In the alkylene oxide derivative represented by the following general formula (1), AO represents an oxyalkylene group having 3 to 4 carbon atoms, and EO represents an oxyethylene group.

[0018]

[0019] When the alkylene oxide derivative represented by the general formula (1) is contained, the cosmetic composition can have a moisturizing effect, has an excellent feel when used, particularly smoothness, and is not sticky.

[0020] Specific examples of the oxyalkylene group having 3 to 4 carbon atoms represented by AO include an oxypropylene group, an oxybutylene group, an oxyisobutylene group, an oxytrimethylene group, and an oxytetramethylene group, and preferred examples include an oxypropylene group and an oxybutylene group.

[0021] In the general formula (1), m represents the average number of moles of AO added per molecule, and is 1≦m≦70, preferably 1≦m≦30, and more preferably 1≦m≦20. In the general formula (1), n ​​represents the average number of moles of EO added per molecule, and is 1≦n≦70, preferably 1≦n≦30, and more preferably 1≦n≦20. When the number of oxyalkylene groups and oxyethylene groups each having 3 to 4 carbon atoms is 1 or more, a sufficient moist feeling can be achieved, and when the number is 70 or less, a sufficient non-sticky, smooth feeling can be achieved. Note that if m+n is too large, stickiness may occur, so it is preferably 8 to 100, and m+n is preferably 8 to 40, more preferably 8 to 25 or less, and even more preferably 8 to 20 or less.

[0022] The order of addition of AO and EO in the alkylene oxide derivative represented by the general formula (1) is not particularly limited, and the alkylene oxide derivative may be a block copolymer in which AO and EO are added in blocks, or a random copolymer in which AO and EO are added randomly, but a random copolymer is preferred. Block copolymers include not only two-stage block copolymers but also copolymers containing three or more stages of blocks.

[0023] The molecular weight of the alkylene oxide derivative represented by the general formula (1) is preferably 100 to 10,000, more preferably 200 to 5,000, and even more preferably 300 to 2,000. The ratio of EO to the total of AO and EO in one molecule [EO / (AO+EO)] is preferably within the range of 20 to 80% by mass. When the ratio of EO [EO / (AO+EO)] is 20% by mass or more, a moist feeling is achieved, and when it is 80% by mass or less, a smooth feeling is achieved.

[0024] R in the general formula (1) １ and R ２ each independently represents a hydrocarbon group having 1 to 4 carbon atoms or a hydrogen atom, and examples of the hydrocarbon group include alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, and tert-butyl groups, with methyl and ethyl groups being preferred.

[0025] R in one molecule of the alkylene oxide derivative represented by the general formula (1) １ and R ２ may be the same hydrocarbon group, or may contain a mixture of hydrocarbon groups and hydrogen atoms, or may contain a mixture of multiple hydrocarbon groups with different numbers of carbon atoms. １ and R ２ For each of the above, the ratio of hydrocarbon groups to hydrogen atoms is preferably 0.15 or less, more preferably 0.06 or less, where Y / X is the ratio of the number of hydrocarbon groups (X) to the number of hydrogen atoms (Y). When Y / X is 0.15 or less, the product does not feel sticky.

[0026] Specific examples of the alkylene oxide derivative represented by the general formula (1) that can be preferably used in the present invention include, but are not limited to, the following:

[0027] PEG / PPG-9 / 2 dimethyl ether PEG / PPG-17 / 4 dimethyl ether PEG / PPG-14 / 7 dimethyl ether PEG / PPG-11 / 9 dimethyl ether PEG / PPG-55 / 28 dimethyl ether PEG / PPG-36 / 41 dimethyl ether PEG / PPG-6 / 3 dimethyl ether PEG / PPG-8 / 4 dimethyl ether PEG / PPG-6 / 11 dimethyl ether PEG / PPG-14 / 27 dimethyl ether

[0028] Alkylene oxide derivatives with relatively smaller molecular weights tend to be more effective in improving UV protection ability due to heat. Therefore, among the alkylene oxide derivatives represented by the general formula (1) listed above, PEG / PPG-9 / 2 dimethyl ether is particularly preferred.

[0029] The alkylene oxide derivative represented by the general formula (1) can be produced by known methods. For example, it can be obtained by addition polymerization of ethylene oxide and an alkylene oxide having 3 to 4 carbon atoms to a compound having a hydroxyl group, followed by an etherification reaction with an alkyl halide in the presence of an alkali catalyst. The content of the alkylene oxide derivative represented by the general formula (1) in the present invention is not particularly limited, but is preferably 0.1 to 10% by mass, more preferably 0.5 to 7% by mass, and even more preferably 1 to 5% by mass. A content of 0.1% by mass or more can provide a sufficient moisturizing effect, and a content of 10% by mass or less can reduce stickiness after use.

[0030] The alkylene oxide derivative represented by the general formula (1) has a moisturizing effect. Furthermore, when other moisturizing agents such as glycerin are further blended, the effect of suppressing stickiness is observed. Examples of moisturizing agents that can be used together include polyethylene glycol, propylene glycol, glycerin, 1,3-butylene glycol, xylitol, sorbitol, maltitol, chondroitin sulfate, hyaluronic acid, mucoitin sulfate, caronic acid, atelocollagen, cholesteryl-12-hydroxystearate, sodium lactate, bile salts, dl-pyrrolidone carboxylate, short-chain soluble collagen, diglycerin (EO)PO adduct (diglycerin ethylene oxide / propylene oxide adduct), Rosa robur extract, Achillea millefolium extract, and Melilot extract.

[0031] The alkylene oxide derivative represented by the general formula (1) also has the effect of promoting the stratum corneum penetration of other moisturizers. Therefore, by using the alkylene oxide derivative represented by the general formula (1) in combination with other moisturizers in the oil-in-water emulsion cosmetic of the present invention, an extremely high moisturizing effect can be obtained due to the synergistic effect. Examples of such moisturizers include those described above, with glycerin and xylitol being particularly preferred.

[0032] The content of the other moisturizing agent in the present invention is not particularly limited, but is preferably 0.001 to 20% by mass, more preferably 0.1 to 10% by mass. In addition, the alkylene oxide derivative represented by the general formula (1) also has the effect of promoting the stratum corneum penetration of hydrophilic drugs other than moisturizing agents, for example, whitening agents such as arbutin.

[0033] <<Alkylene oxide derivative represented by general formula (2)>> In the alkylene oxide derivative represented by the following general formula (2), R ３ , R ４ and R ５ are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, A is an alkylene group having 2 to 4 carbon atoms, and p and q are each independently an integer of 1 to 50. The polymer represented by the following general formula (2) has a number average molecular weight of 10,000 or less and an IOB value of 0.4 to 1.8.

[0034]

[0035] When the alkylene oxide derivative represented by the general formula (2) is contained, the cosmetic composition can have a moisturizing effect, and has an excellent feel when used, particularly smoothness, without stickiness.

[0036] R in the general formula (2) ３ , R ４ and R ５ is an alkyl group having 1 to 4 carbon atoms, R ３ , R ４ and R ５ Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, and a tert-butyl group. These alkyl groups may further have a substituent, provided that the effects of the present invention are not impaired. The substituent is not particularly limited, and examples thereof include a halogeno group.

[0037] In the general formula (2), R ３ , R ４ and R ５may each independently be a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, or a tert-butyl group.

[0038] In the general formula (2), R ３ is preferably a hydrogen atom, a methyl group, or an ethyl group. ３ If present, each R ３ may be the same or different, and in particular, R ３ At least a part of R is preferably a methyl group. ３ It is particularly preferable from the viewpoint of improving the feeling when used, when at least a part of the groups is a methyl group.

[0039] In the general formula (2), R ３ may be in a state where a hydrogen atom and an alkyl group having 1 to 4 carbon atoms are mixed. ３ A part of R may be a hydrogen atom, and another part may be an alkyl group having 1 to 4 carbon atoms. ３ Some of these are hydrogen atoms and some are methyl groups.

[0040] According to one embodiment of the present invention, in the general formula (2), R ４ is preferably a hydrogen atom, a methyl group, or an ethyl group, and more preferably a methyl group.

[0041] According to one embodiment of the present invention, in the general formula (2), R ４ may be in a state where a hydrogen atom and an alkyl group having 1 to 4 carbon atoms are mixed. ４ A part of R may be a hydrogen atom, and another part may be an alkyl group having 1 to 4 carbon atoms. ４ Some of the R are hydrogen atoms and some are methyl groups. ３ and R ４ is present and at least a portion of which is a methyl group, R ３ and R ４ The ratio of methyl groups to hydrogen (CH ３ / H) is not particularly limited and may be, for example, 0.05 or more, 0.10 or more, 0.15 or more, 0.20 or more, 0.25 or more, 0.30 or more, or 0.35 or more, and may be 0.99 or less, 0.90 or less, 0.80 or less, 0.70 or less, or 0.60 or less.

[0042] According to one embodiment of the present invention, in the general formula (2), R ５ is preferably a hydrogen atom, a methyl group, or an ethyl group, and more preferably a methyl group. ３ is present and at least a part of it is a methyl group, ３ and R ４ In line with ３ , R ４ and R ５ The ratio of methyl groups to hydrogen (CH ３ / H) is not particularly limited and may be, for example, 0.05 or more, 0.10 or more, 0.15 or more, 0.20 or more, 0.25 or more, 0.30 or more, or 0.35 or more, and may be 0.99 or less, 0.90 or less, 0.80 or less, 0.70 or less, or 0.60 or less.

[0043] According to one embodiment of the present invention, in the general formula (2), R ４ and R ５ At least one of these is preferably a methyl group.

[0044] In the general formula (2), A is an alkylene group having 2 to 4 carbon atoms. More specifically, A may be, for example, an ethylene group, a propylene group, a butylene group, an isobutylene group, etc., but is not limited to these. In particular, A is preferably represented by the following general formula (3):

[0045]

[0046] In the general formula (3), R ６ is an alkyl group having 1 or 2 carbon atoms. More specifically, R ６ may be a methyl group or an ethyl group.

[0047] In the general formula (2), p and q each represent the average number of moles of the respective structural units added. p and q are each independently an integer of 1 to 50, and specifically may be 1 or more, 2 or more, 3 or more, 4 or more, 5 or more, 6 or more, 7 or more, 8 or more, 9 or more, 10 or more, 15 or more, or 20 or more, or may be 50 or less, 45 or less, 40 or less, 35 or less, 34 or less, 32 or less, 30 or less, 28 or less, 26 or less, 25 or less, 24 or less, 22 or less, 20 or less, 18 or less, 16 or less, 15 or less, 14 or 12 or less, 10 or less, or 5 or less.

[0048] In the general formula (2), p is preferably 1 or more and 25 or less, 1 or more and 20 or less, or 1 or more and 14 or less, and more preferably 2 or more and 20 or less, 2 or more and 15 or less, or 2 or more and 5 or less. In the general formula (2), q is preferably 2 or more and 40 or less, 2 or more and 35 or less, or 2 or more and 34 or less, and more preferably 6 or more and 35 or less, or 6 or more and 12 or less.

[0049] According to one embodiment of the present invention, in the general formula (2), p+q may be 4 or more, 5 or more, 6 or more, 7 or more, 8 or more, 9 or more, 10 or more, 11 or more, 12 or more, 13 or more, 14 or more, 15 or more, or 17 or more, and may be 55 or less, 53 or less, 50 or less, 45 or less, 42 or less, 40 or less, 35 or less, 30 or less, 25 or less, 20 or less, 15 or less, or 12 or less.

[0050] According to one embodiment of the present invention, in the general formula (2), p:q may be 1:10 to 10:1, 1:6 to 6:1, or 1:5 to 5:1.

[0051] The number average molecular weight of the polymer represented by the general formula (2) is 10,000 or less. More specifically, the number average molecular weight of the polymer represented by the general formula (2) may be, for example, 10,000 or less, 5,000 or less, 3,500 or less, 3,000 or less, 2,800 or less, 2,600 or less, 2,500 or less, 2,000 or less, 1,500 or less, 1,400 or less, 1,300 or less, 1,200 or less, 1,100 or less, 1,000 or less, 900 or less, 800 or less, 700 or less, or 600 or less, or may be 130 or more, 150 or more, 200 or more, 250 or more, 300 or more, 350 or more, 400 or more, 450 or more, or 500 or more.

[0052] The number average molecular weight of the polymer represented by the general formula (2) is preferably 300 or more and 3,500 or less, more preferably 500 or more and 3,500 or less, or more preferably 500 or more and 1,200 or less.

[0053] The IOB value of the polymer represented by the general formula (2) is 0.4 to 1.8, and more specifically, may be, for example, 0.4 or more, 0.5 or more, 0.6 or more, 0.7 or more, 0.8 or more, or 0.9 or more, and may be 1.8 or less, 1.6 or less, 1.4 or less, 1.2 or less, or 1.0 or less. The IOB value of the polymer represented by the general formula (2) is preferably 0.7 or more and 1.2 or less.

[0054] Here, the IOB value is an abbreviation for Inorganic / Organic Balance (Inorganic / Organic Ratio), and is a value that represents the ratio of inorganic value to organic value, and is an index that indicates the degree of polarity of an organic compound. Specifically, the IOB value is expressed as IOB value = inorganic value / organic value. For each of the "inorganic value" and "organic value," "inorganic value" and "organic value" are set according to various atoms or functional groups, for example, an "organic value" of 20 for one carbon atom in a molecule and an "inorganic value" of 100 for one hydroxyl group. The IOB value of an organic compound can be calculated by adding up the "inorganic value" and "organic value" of all atoms and functional groups in the organic compound (see, for example, Yoshio Koda, "Organic Conceptual Diagram - Fundamentals and Applications," pp. 11-17, Sankyo Publishing, 1984).

[0055] The polymer represented by the general formula (2) may be a block copolymer or a random copolymer.

[0056] The method for producing the polymer represented by the general formula (2) is not particularly limited, and may be, for example, the addition polymerization of epoxides corresponding to each structural unit. The addition polymerization may be block polymerization or random polymerization.

[0057] The method for producing the polymer represented by the general formula (2) may further include reacting the polymer obtained by the addition polymerization with an alkyl halide. Through the reaction with the alkyl halide, the hydroxyl groups in the obtained polymer molecule are blocked with alkyl groups, thereby allowing the hydrophobicity of the entire polymer to be adjusted as desired. In the polymer molecule represented by the general formula (2), the blocking rate of hydroxyl groups with alkyl groups may be, for example, 20% or more, 30% or more, 35% or more, 40% or more, 45% or more, 50% or more, or 55% or more, or may be 60% or less, 59% or less, 58% or less, 57% or less, 56% or less, or 55% or less.

[0058] The polymer represented by the general formula (2) has both high water solubility and high fat solubility.

[0059] The solubility of the polymer represented by the general formula (2) in water can be, for example, 5% by mass or more, 10% by mass or more, 20% by mass or more, 30% by mass or more, 40% by mass or more, or 50% by mass or more.

[0060] Furthermore, the solubility in olive oil can be used as an index of the fat-solubility of the polymer represented by the general formula (2). The solubility in olive oil of the polymer represented by the general formula (2) can be, for example, 0.01% by mass or more, 0.05% by mass or more, 0.10% by mass or more, 0.50% by mass or more, or 1.00% by mass or more. The upper limit of the solubility in olive oil of the polymer represented by the general formula (2) is not particularly limited, and may be, for example, 10% by mass or less.

[0061] The content of the alkylene oxide derivative represented by the general formula (2) in the present invention is not particularly limited, but is preferably 0.1% by mass to 10% by mass, more preferably 0.5% by mass to 7% by mass, and even more preferably 1% by mass to 5% by mass. If it is 0.1% by mass or more, a sufficient moisturizing effect can be obtained, and if it is 10% by mass or less, stickiness is unlikely to be felt after use.

[0062] <(B) Hydrophobized Metal Oxide Fine Particles Hydrophobized with Monoalkyl Phosphate> The oil-in-water emulsion cosmetic of the present invention contains, as component (B), a hydrophobized metal oxide fine particle hydrophobized with a monoalkyl phosphoric acid. The hydrophobized metal oxide fine particle hydrophobized with a monoalkyl phosphoric acid is a core metal oxide fine particle hydrophobized with a monoalkyl phosphoric acid, and functions as an ultraviolet light scattering agent in the oil-in-water emulsion composition of the present invention. Examples of hydrophobized metal oxide fine particles hydrophobized with a monoalkyl phosphoric acid that can be used in the oil-in-water emulsion cosmetic of the present invention include those in which the surface of a fine particle of a metal oxide such as titanium oxide, zinc oxide, iron oxide, cerium oxide, or tungsten oxide has been hydrophobized with a monoalkyl phosphoric acid. Examples of the monoalkyl phosphoric acid include cetyl phosphoric acid, ethyl phosphoric acid, octyl phosphoric acid, stearyl phosphoric acid, and dodecyl phosphoric acid, with cetyl phosphoric acid being preferred.

[0063] The (B) hydrophobized fine particle metal oxide that acts as an ultraviolet scattering agent and has been hydrophobized with a monoalkyl phosphate may be in the form of particles, and in this case, the average primary particle diameter is not particularly limited and may be, for example, 5 nm to 200 nm, 8 nm to 100 nm, 10 to 50 nm, or 12 to 30 nm. The "average primary particle diameter" may be determined, for example, as the diameter of a circle equivalent to the projected area of ​​the primary particles in an SEM image.

[0064] The hydrophobized metal oxide microparticles hydrophobized with monoalkyl phosphoric acid preferably have a silica coating. Specifically, for example, titanium oxide, zinc oxide, iron oxide, cerium oxide, tungsten oxide, or other metal oxide microparticles having a silica coating on the surface thereof are hydrophobized with monoalkyl phosphoric acid. When the metal oxide microparticles have a silica coating, the silica coating preferably exists in one or more layers on the entire surface of the metal oxide microparticles, more preferably in two or more layers. When the metal oxide microparticles have a silica coating, the metal oxide surface is covered with silica, thereby suppressing the catalytic activity of the metal, improving the stability when used in combination with an ultraviolet absorber, suppressing discoloration, and improving the feel when used. In addition, when the silica coating is two or more layers, the effect can be further enhanced.

[0065] The content of the (B) hydrophobized metal oxide fine particles hydrophobized with monoalkyl phosphoric acid in the present invention is not particularly limited, but is preferably 1% by mass to 10% by mass, more preferably 2% by mass to 7% by mass, and even more preferably 3% by mass to 5% by mass. If it is 1% by mass or more, the effect as an ultraviolet scattering agent can be sufficiently ensured, and if it is 10% by mass or less, the feel when used is good.

[0066] <(C) Active Agent> The oil-in-water emulsion cosmetic of the present invention may further contain an active agent as component (C), for example, a surfactant. Amphiphilic substances have the property of being compatible with both water and oil, and therefore tend to detach from the interface, and when used together with a surfactant, the emulsion generally becomes unstable. However, surprisingly, although the oil-in-water emulsion cosmetic of the present invention contains an amphiphilic substance, it does not undergo emulsion destruction even when a surfactant is included, and the emulsion is stable.

[0067] Examples of surfactants that can be included in the oil-in-water emulsion cosmetic of the present invention as component (C) include polyoxyethylene hydrogenated castor oil, and it is preferable to include polyoxyethylene hydrogenated castor oil. Polyoxyethylene hydrogenated castor oil has higher hydrophilicity and better emulsion stability as the average number of added moles of ethylene oxide increases. Therefore, when component (C) is polyoxyethylene hydrogenated castor oil, the average number of added moles of ethylene oxide in the polyoxyethylene hydrogenated castor oil of the present invention is preferably 40 moles or more, and more preferably 50 moles or more and 100 moles or less. When the average number of added moles of ethylene oxide in polyoxyethylene hydrogenated castor oil is 40 moles or more, it has a certain degree of hydrophilicity, making it easy to ensure hydrophilicity, and is suitable for oil-in-water emulsification and easy to improve emulsion stability. When it is 100 moles or less, it is less sticky and easy to use.

[0068] The content of the (C) surfactant in the oil-in-water emulsion cosmetic of the present invention is preferably 0.1 to 10% by mass, more preferably 0.5 to 5% by mass, and even more preferably 0.5 to 3% by mass. When the content of the (C) surfactant is 0.1% by mass or more, emulsion stability can be sufficiently improved, and when it is 10% by mass or less, the feel when used is good.

[0069] Examples of polyoxyethylene hydrogenated castor oils suitable for the oil-in-water emulsion cosmetic of the present invention include PEG-40 hydrogenated castor oil, PEG-50 hydrogenated castor oil, PEG-60 hydrogenated castor oil, PEG-80 hydrogenated castor oil, and PEG-100 hydrogenated castor oil.

[0070] <Other Components> The oil-in-water emulsion cosmetic of the present invention can be produced by conventional methods according to the desired formulation by appropriately blending, as needed, other components in addition to those described above, such as powder components, liquid oils and fats, solid oils and fats, waxes, hydrocarbon oils, higher fatty acids, higher alcohols, synthetic ester oils, silicone oils, silicones, anionic surfactants, cationic surfactants, amphoteric surfactants, nonionic surfactants, active agents other than surfactants, water-soluble polymers, thickeners, UV absorbers, moisturizers, sequestering agents, lower alcohols, polyhydric alcohols, sugars, amino acids, organic amines, polymer emulsions, neutralizing agents, pH adjusters, vitamins, antioxidants, antioxidant aids, stabilizers, fragrances, and water. Specific components that can be blended are listed below.

[0071] Examples of the powder component include inorganic powders (e.g., talc, kaolin, mica, sericite, muscovite, phlogopite, synthetic mica, lepidolite, biotite, vermiculite, magnesium carbonate, calcium carbonate, aluminum silicate, barium silicate, calcium silicate, magnesium silicate, strontium silicate, metal tungstate, magnesium, silica, zeolite, barium sulfate, calcined calcium sulfate (calcined gypsum), calcium phosphate, fluorapatite, hydroxyapatite, ceramic powder, metal soap (e.g., zinc myristate), , calcium palmitate, aluminum stearate), boron nitride, etc.); organic powders (for example, polyamide resin powder (nylon powder), polyethylene powder, polymethyl methacrylate powder, polystyrene powder, styrene-acrylic acid copolymer resin powder, benzoguanamine resin powder, polytetrafluoroethylene powder, cellulose powder, etc.); inorganic white pigments (for example, titanium dioxide, zinc oxide, etc.); inorganic red pigments (for example, iron oxide (red iron oxide), iron titanate, etc.); inorganic brown pigments (for example, γ-iron oxide, etc.); inorganic yellow pigments (for example, yellow iron oxide, yellow ochre, etc.); inorganic Black pigments (e.g., black iron oxide, low-order titanium oxide, etc.); inorganic purple pigments (e.g., mango violet, cobalt violet, etc.); inorganic green pigments (e.g., chromium oxide, chromium hydroxide, cobalt titanate, etc.); inorganic blue pigments (e.g., ultramarine, Prussian blue, etc.); pearl pigments (e.g., titanium dioxide-coated mica, titanium dioxide-coated bismuth oxychloride, titanium dioxide-coated talc, colored titanium dioxide-coated mica, bismuth oxychloride, fish scale foil, etc.); metal powder pigments (e.g., aluminum powder, copper powder, etc.); zirconium, barium organic pigments such as sodium or aluminum lakes (e.g., organic pigments such as Red No. 201, Red No. 202, Red No. 204, Red No. 205, Red No. 220, Red No. 226, Red No. 228, Red No. 405, Orange No. 203, Orange No. 204, Yellow No. 205, Yellow No. 401, and Blue No. 404, Red No. 3, Red No. 104, Red No. 106, Red No. 227, Red No. 230, Red No. 401, Red No. 505, Orange No. 205, Yellow No. 4, Yellow No. 5, Yellow No. 202, Yellow No. 203, Green No. 3, and Blue No. 1); natural pigments (e.g., chlorophyll, β-carotene, etc.).

[0072] Examples of liquid oils and fats include avocado oil, camellia oil, turtle oil, macadamia nut oil, corn oil, mink oil, olive oil, rapeseed oil, egg yolk oil, sesame oil, persic oil, wheat germ oil, camellia oil, castor oil, linseed oil, safflower oil, cottonseed oil, perilla oil, soybean oil, peanut oil, tea seed oil, kaya oil, rice bran oil, Chinese tung oil, Japanese tung oil, jojoba oil, germ oil, and triglycerin.

[0073] Examples of solid fats and oils include cacao butter, coconut oil, horse fat, hardened coconut oil, palm oil, beef tallow, mutton tallow, hardened beef tallow, palm kernel oil, lard, beef bone fat, Japan wax kernel oil, hardened oil, beef trotter fat, Japan wax, and hardened castor oil.

[0074] Examples of waxes include beeswax, candelilla wax, cotton wax, carnauba wax, bayberry wax, ivory wax, whale wax, montan wax, rice bran wax, lanolin, kapok wax, lanolin acetate, liquid lanolin, sugarcane wax, lanolin fatty acid isopropyl, hexyl laurate, reduced lanolin, jojoba wax, hard lanolin, shellac wax, POE lanolin alcohol ether, POE lanolin alcohol acetate, POE cholesterol ether, lanolin fatty acid polyethylene glycol, and POE hydrogenated lanolin alcohol ether.

[0075] Examples of hydrocarbon oils include liquid paraffin, ozokerite, squalane, pristane, paraffin, ceresin, squalene, petrolatum, and microcrystalline wax.

[0076] Examples of higher fatty acids include lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, oleic acid, undecylenic acid, tall acid, isostearic acid, linoleic acid, linolenic acid, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA).

[0077] Examples of higher alcohols include straight-chain alcohols (e.g., lauryl alcohol, cetyl alcohol, stearyl alcohol, behenyl alcohol, myristyl alcohol, oleyl alcohol, cetostearyl alcohol, etc.); branched-chain alcohols (e.g., monostearyl glycerin ether (batyl alcohol), 2-decyltetradecynol, lanolin alcohol, cholesterol, phytosterol, hexyldodecanol, isostearyl alcohol, octyldodecanol, etc.); and the like.

[0078] Examples of synthetic ester oils include isopropyl myristate, cetyl octanoate, octyldodecyl myristate, isopropyl palmitate, butyl stearate, hexyl laurate, myristyl myristate, decyl oleate, hexyldecyl dimethyloctanoate, cetyl lactate, myristyl lactate, lanolin acetate, isocetyl stearate, isocetyl isostearate, cholesteryl 12-hydroxystearate, ethylene glycol di-2-ethylhexanoate, dipentaerythritol fatty acid esters, N-alkyl glycol monoisostearate, neopentyl glycol dicaprate, diisostearyl malate, glycerin di-2-heptylundecanoate, trimethylolpropane tri-2-ethylhexanoate, trimethylolpropane triisostearate, pentaerythritol tetra-2-ethylhexanoate, Glyceryl tri-2-ethylhexanoate, glyceryl trioctanoate, glyceryl triisopalmitate, trimethylolpropane triisostearate, cetyl 2-ethylhexanoate, 2-ethylhexyl palmitate, glyceryl trimyristate, tri-2-heptylundecanoic acid glyceride, castor oil fatty acid methyl ester, oleyl oleate, acetoglyceride, 2-heptyl palmitate lauroyl-L-glutamic acid 2-octyldodecyl ester, di-2-heptylundecyl adipate, ethyl laurate, di-2-ethylhexyl sebacate, 2-hexyldecyl myristate, 2-hexyldecyl palmitate, 2-hexyldecyl adipate, diisopropyl sebacate, 2-ethylhexyl succinate, and triethyl citrate.

[0079] Examples of silicone oils include chain polysiloxanes (e.g., dimethylpolysiloxane, methylphenylpolysiloxane, diphenylpolysiloxane, etc.); cyclic polysiloxanes (e.g., octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane, etc.), silicone resins that form a three-dimensional network structure, silicone rubber, and various modified polysiloxanes (e.g., amino-modified polysiloxanes, polyether-modified polysiloxanes, alkyl-modified polysiloxanes, fluorine-modified polysiloxanes, etc.).

[0080] Examples of silicones include alkyl and alkoxy silicone waxes such as stearyl-modified dimethicone and behenyl-modified dimethicone, silicone resins that form a three-dimensional network structure, and silicone rubber.

[0081] Examples of anionic surfactants include fatty acid soaps (e.g., sodium laurate, sodium palmitate, etc.); higher alkyl sulfates (e.g., sodium lauryl sulfate, potassium lauryl sulfate, etc.); alkyl ether sulfates (e.g., POE-lauryl triethanolamine sulfate, POE-lauryl sodium sulfate, etc.); N-acyl sarcosinates (e.g., sodium lauroyl sarcosinate, etc.); higher fatty acid amide sulfonates (e.g., sodium N-myristoyl-N-methyl taurate, sodium coconut oil fatty acid methyl tauride, sodium lauryl methyl tauride, etc.); phosphate salts (sodium POE-oleyl ether phosphate, POE-stearyl ether phosphate, etc.); sulfosuccinates (e.g., sodium di-2-ethylhexyl sulfosuccinate, sodium monolauroyl monoethanolamide polyoxyethylene sulfosuccinate, sodium lauryl polypropylene glycol ... sodium succinate, etc.); alkylbenzenesulfonates (for example, sodium linear dodecylbenzenesulfonate, triethanolamine linear dodecylbenzenesulfonate, linear dodecylbenzenesulfonic acid, etc.); higher fatty acid ester sulfate salts (for example, sodium hydrogenated coconut oil fatty acid glycerin sulfate, etc.); N-acylglutamates (for example, monosodium N-lauroylglutamate, disodium N-stearoylglutamate, monosodium N-myristoyl-L-glutamate, etc.); sulfated oils (for example, turmeric oil, etc.); POE-alkyl ether carboxylic acids; POE-alkyl allyl ether carboxylate salts; α-olefin sulfonates; higher fatty acid ester sulfonates; secondary alcohol sulfate salts; higher fatty acid alkylolamide sulfate salts; sodium lauroylmonoethanolamide succinate; ditriethanolamine N-palmitoyl aspartate; and sodium caseinate.

[0082] Examples of cationic surfactants include alkyltrimethylammonium salts (e.g., stearyltrimethylammonium chloride, lauryltrimethylammonium chloride, etc.); alkylpyridinium salts (e.g., cetylpyridinium chloride, etc.); distearyldimethylammonium chloride dialkyldimethylammonium salts; poly(N,N'-dimethyl-3,5-methylenepiperidinium) chloride; alkyl quaternary ammonium salts; alkyldimethylbenzylammonium salts; alkylisoquinolinium salts; dialkylmorphonium salts; POE-alkylamines; alkylamine salts; polyamine fatty acid derivatives; amyl alcohol fatty acid derivatives; benzalkonium chloride; and benzethonium chloride.

[0083] Examples of amphoteric surfactants include imidazoline-based amphoteric surfactants (e.g., 2-undecyl-N,N,N-(hydroxyethylcarboxymethyl)-2-imidazoline sodium, 2-cocoyl-2-imidazolinium hydroxide-1-carboxyethyloxy disodium salt, etc.); betaine-based surfactants (e.g., 2-heptadecyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine, lauryldimethylaminoacetic acid betaine, alkyl betaine, amido betaine, sulfobetaine, etc.).

[0084] Examples of lipophilic nonionic surfactants include sorbitan fatty acid esters (e.g., sorbitan monooleate, sorbitan monoisostearate, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan sesquioleate, sorbitan trioleate, diglycerol sorbitan penta-2-ethylhexylate, diglycerol sorbitan tetra-2-ethylhexylate, etc.); glycerin polyglycerin fatty acids (e.g., glycerin monocottonseed oil fatty acid, glycerin monoerucate, glycerin sesquioleate, glycerin monostearate, glycerin α,α'-oleic acid pyroglutamate, glycerin monostearate malate, etc.); propylene glycol fatty acid esters (e.g., propylene glycol monostearate, etc.); hydrogenated castor oil derivatives; and glycerin alkyl ethers.

[0085] Examples of hydrophilic nonionic surfactants include POE-sorbitan fatty acid esters (e.g., POE-sorbitan monooleate, POE-sorbitan monostearate, POE-sorbitan monooleate, POE-sorbitan tetraoleate, etc.); POE sorbit fatty acid esters (e.g., POE-sorbitan monolaurate, POE-sorbitan monooleate, POE-sorbitan pentaoleate, POE-sorbit monostearate, etc.); POE-glycerin fatty acid esters (e.g., POE-glycerin monostearate, POE-monooleates such as POE-glycerin monoisostearate and POE-glycerin triisostearate; POE-fatty acid esters (for example, POE-distearate, POE-monodioleate, ethylene glycol distearate, etc.); POE-alkyl ethers (for example, POE-lauryl ether, POE-oleyl ether, POE-stearyl ether, POE-behenyl ether, POE-2-octyldodecyl ether, POE-cholestanol ether, etc.); Pluronic® types (for example, Pluronic POE·POP-alkyl ethers (e.g., POE·POP-cetyl ether, POE·POP-2-decyltetradecyl ether, POE·POP-monobutyl ether, POE·POP-hydrogenated lanolin, POE·POP-glycerin ether, etc.); tetraPOE·tetraPOP-ethylenediamine condensates (e.g., Tetronic, etc.); POE-castor oil hydrogenated castor oil derivatives (e.g., POE-castor oil, POE-hydrogenated castor oil, POE-hydrogenated castor oil monoisostearate, POE-hydrogenated castor oil triisostearate, etc.); , POE-hydrogenated castor oil monopyroglutamic acid monoisostearate diester, POE-hydrogenated castor oil maleic acid, etc.); POE-beeswax / lanolin derivatives (for example, POE-sorbitol beeswax, etc.); alkanolamides (for example, coconut oil fatty acid diethanolamide, lauric acid monoethanolamide, fatty acid isopropanolamide, etc.); POE-propylene glycol fatty acid esters; POE-alkylamines; POE-fatty acid amides; sucrose fatty acid esters; alkylethoxydimethylamine oxide; trioleyl phosphate, etc.

[0086] Examples of active agents other than surfactants include active agents that emulsify by microparticles, and specific examples include active agents for Pickering emulsification. Examples of active agents for Pickering emulsification include (acrylamide / DMAPA acrylate / methoxy PEG methacrylate) copolymer and hydrophobic silica. (acrylamide / DMAPA acrylate / methoxy PEG methacrylate) copolymer is water-resistant, and therefore can be suitably used when water resistance is required for oil-in-water emulsion cosmetics. In the case of active agents that emulsify by microparticles, it is presumed that the amphiphilic substance penetrates into the gaps on the surface of the microparticles, thereby improving emulsion stability.

[0087] Furthermore, when the oil-in-water emulsion cosmetic of the present invention contains an active agent that emulsifies by microparticles and polyoxyethylene hydrogenated castor oil, since polyoxyethylene hydrogenated castor oil is a surfactant with a relatively small molecular weight, it is presumed that the emulsion stability of the oil-in-water emulsion cosmetic can be improved by using it in combination with an active agent that emulsifies by microparticles, such as a Pickering emulsification active agent.

[0088] Examples of natural water-soluble polymers include plant-derived polymers (e.g., gum arabic, tragacanth gum, galactan, guar gum, carob gum, karaya gum, carrageenan, pectin, agar, quince seed (marmelo), algae colloid (cassowia extract), starch (rice, corn, potato, wheat), glycyrrhizic acid); and microbial-derived polymers (e.g., xanthan gum, dextran, succinoglucan, pullulan, etc.).

[0089] Examples of semi-synthetic water-soluble polymers include starch-based polymers (e.g., carboxymethyl starch, methylhydroxypropyl starch, etc.); cellulose-based polymers (methyl cellulose, ethyl cellulose, methylhydroxypropyl cellulose, hydroxyethyl cellulose, sodium cellulose sulfate, hydroxypropyl cellulose, carboxymethyl cellulose, sodium carboxymethyl cellulose, crystalline cellulose, cellulose powder, etc.); and alginic acid-based polymers (e.g., sodium alginate, propylene glycol alginate, etc.).

[0090] Examples of synthetic water-soluble polymers include vinyl polymers (e.g., polyvinyl alcohol, polyvinyl methyl ether, polyvinylpyrrolidone, carboxyvinyl polymer, etc.); polyoxyethylene polymers (e.g., polyoxyethylene polypropylene copolymers of polyethylene glycol 20,000, 40,000, 60,000, etc.); acrylic polymers (e.g., sodium polyacrylate, polyethyl acrylate, polyacrylamide, etc.); polyethyleneimine; cationic polymers, etc.

[0091] Examples of thickeners include gum arabic, carrageenan, karaya gum, tragacanth gum, carob gum, quince seed (marmelo), casein, dextrin, gelatin, sodium pectinate, sodium allaginate, methylcellulose, ethylcellulose, CMC, hydroxyethylcellulose, hydroxypropylcellulose, PVA, PVM, PVP, sodium polyacrylate, carboxyvinyl polymer, locust bean gum, guar gum, tamarind gum, dialkyldimethylammonium cellulose sulfate, xanthan gum, aluminum magnesium silicate, and benzoate. Examples of suitable surfactants include silicic acid, hectorite, magnesium aluminum silicate (Veegum), laponite, silicic anhydride, carbomer, dimethylacrylamide / sodium acryloyldimethyltaurate crosspolymer, sodium acrylate / sodium acryloyldimethyltaurate copolymer, ammonium acryloyldimethyltaurate / beheneth-25 methacrylate crosspolymer, ammonium acryloyldimethyltaurate / VP copolymer, hydroxyethyl acrylate / sodium acryloyldimethyltaurate copolymer, and acrylates / C10-30 alkyl acrylate crosspolymer. Note that acrylates / C10-30 alkyl acrylate crosspolymer also functions as a surfactant and emulsifier.

[0092] Examples of the ultraviolet absorber include benzoic acid-based ultraviolet absorbers (e.g., para-aminobenzoic acid (hereinafter abbreviated as PABA), PABA monoglycerin ester, N,N-dipropoxy PABA ethyl ester, N,N-diethoxy PABA ethyl ester, N,N-dimethyl PABA ethyl ester, N,N-dimethyl PABA butyl ester, N,N-dimethyl PABA ethyl ester, etc.); anthranilic acid-based ultraviolet absorbers (e.g., homomenthyl-N-acetylanthranilate, etc.); salicylic acid-based ultraviolet absorbers (e.g., amyl salicylate, etc.); cinnamic acid-based ultraviolet absorbers (e.g., octyl cinnamate, ethyl-4-isopropyl cinnamate, methyl-2,5-diisopropyl cinnamate, ethyl-2,4-diisopropyl cinnamate, methyl-2,4-diisopropyl cinnamate, propyl-p-methoxycinnamate, isopropyl-p-methoxycinnamate, isoamyl-p-methoxycinnamate, methyl-p-isopropyl ... cyclohexyl-p-methoxycinnamate, octyl-p-methoxycinnamate (2-ethylhexyl-p-methoxycinnamate), 2-ethoxyethyl-p-methoxycinnamate, cyclohexyl-p-methoxycinnamate, ethyl-α-cyano-β-phenylcinnamate, 2-ethylhexyl-α-cyano-β-phenylcinnamate, glyceryl mono-2-ethylhexanoyl-di-para-methoxycinnamate, etc.); benzophenone-based ultraviolet absorbers (for example, 2,4-dihydroxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, non, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2,2',4,4'-tetrahydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxy-4'-methylbenzophenone, 2-hydroxy-4-methoxybenzophenone-5-sulfonate, 4-phenylbenzophenone, 2-ethylhexyl-4'-phenyl-benzophenone-2-carboxylate, 2-hydroxy-4-n-octoxybenzophenone, 4-hydroxy-3-carboxybenzophenone, etc.);Examples include 3-(4'-methylbenzylidene)-d,l-camphor, 3-benzylidene-d,l-camphor; 2-phenyl-5-methylbenzoxazole; 2,2'-hydroxy-5-methylphenylbenzotriazole; 2-(2'-hydroxy-5'-t-octylphenyl)benzotriazole; 2-(2'-hydroxy-5'-methylphenylbenzotriazole; dibenzalazine; dianisoylmethane; 4-methoxy-4'-t-butyldibenzoylmethane; 5-(3,3-dimethyl-2-norbornylidene)-3-pentan-2-one, and the like;

[0093] Examples of moisturizing agents include glycerin, dynamite glycerin, dipropylene glycol, 1,3-butylene glycol, cholesteryl-12-hydroxystearate, sodium lactate, dl-pyrrolidone carboxylate, urea, diglycerin ethylene oxide-propylene oxide adduct, and in particular, when an acidic mucopolysaccharide such as chondroitin sulfate or hyaluronic acid is added, the whitening effect of the alkoxysalicylic acid and / or its salt is enhanced.

[0094] Examples of sequestering agents include 1-hydroxyethane-1,1-diphosphonic acid, 1-hydroxyethane-1,1-diphosphonic acid tetrasodium salt, disodium edetate, trisodium edetate, tetrasodium edetate, sodium citrate, sodium polyphosphate, sodium metaphosphate, gluconic acid, phosphoric acid, citric acid, ascorbic acid, succinic acid, edetic acid, and trisodium ethylenediaminehydroxyethyltriacetate.

[0095] Examples of the lower alcohol include ethanol, propanol, isopropanol, isobutyl alcohol, and t-butyl alcohol.

[0096] Examples of polyhydric alcohols include dihydric alcohols (e.g., ethylene glycol, propylene glycol, trimethylene glycol, 1,2-butylene glycol, 1,3-butylene glycol, tetramethylene glycol, 2,3-butylene glycol, pentamethylene glycol, 2-butene-1,4-diol, hexylene glycol, octylene glycol, etc.); trihydric alcohols (e.g., glycerin, trimethylolpropane, etc.); tetrahydric alcohols (e.g., pentaerythritol such as 1,2,6-hexanetriol, etc.); pentahydric alcohols (e.g., xylitol, etc.); hexahydric alcohols (e.g., sorbitol, mannitol, etc.); polyhydric alcohol polymers (e.g., diethylene glycol, dipropylene glycol, triethylene glycol, etc.); dihydric alcohol alkyl ethers (e.g., ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol monophenyl ether, ethylene glycol monohexyl ether, ethylene glycol mono-2-methylhexyl ether, ethylene glycol isoamyl ether, ethylene glycol benzyl ether, ethylene glycol isopropyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, etc.);Dihydric alcohol alkyl ethers (e.g., diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol butyl ether, diethylene glycol methyl ethyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monobutyl ether, propylene glycol isopropyl ether, dipropylene glycol methyl ether, dipropylene glycol ethyl ether, dipropylene glycol butyl ether, etc.); dihydric alcohol ether esters (e.g., ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monophenyl ether acetate, ethylene glycol diadipate, ethylene glycol disuccinate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monophenyl ether acetate, etc.); glycerin monoalkyl ethers (e.g., xyl alcohol, selachyl alcohol, batyl alcohol, etc.); sugar alcohols (e.g., sorbitol, maltitol, maltodextrin, etc.); Examples of such sugars include erythritol, mannitol, sucrose, erythritol, glucose, fructose, starch-decomposed sugars, maltose, xylitose, starch-decomposed sugar-reduced alcohols, etc.; glysolid; tetrahydrofurfuryl alcohol; POE-tetrahydrofurfuryl alcohol; POP-butyl ether; POP·POE-butyl ether; tripolyoxypropylene glycerin ether; POP-glycerin ether; POP-glycerin ether phosphate; POP·POE-pentaneerythritol ether, polyglycerin, etc.;

[0097] Examples of monosaccharides include trioses (e.g., D-glyceryl aldehyde, dihydroxyacetone, etc.); tetraoses (e.g., D-erythrose, D-erythrulose, D-threose, erythritol, etc.); pentoses (e.g., L-arabinose, D-xylose, L-lyxose, D-arabinose, D-ribose, D-ribulose, D-xylulose, L-xylulose, etc.); hexoses (e.g., D-glucose, D-talose, D-busicose, D-galactose, D-fructose, L-galactose, L- heptoses (e.g., aldoheptose, heptose, etc.); octose (e.g., octulose, etc.); deoxysugars (e.g., 2-deoxy-D-ribose, 6-deoxy-L-galactose, 6-deoxy-L-mannose, etc.); aminosugars (e.g., D-glucosamine, D-galactosamine, sialic acid, aminouronic acid, muramic acid, etc.); uronic acids (e.g., D-glucuronic acid, D-mannuronic acid, L-guluronic acid, D-galacturonic acid, L-iduronic acid, etc.), etc.

[0098] Examples of oligosaccharides include sucrose, gunthianose, umbelliferose, lactose, planteose, isolychnoses, α,α-trehalose, raffinose, lychnoses, umbilicin, stachyose, verbascoses, and the like.

[0099] Examples of polysaccharides include cellulose, quince seed, chondroitin sulfate, starch, galactan, dermatan sulfate, glycogen, gum arabic, heparan sulfate, hyaluronic acid, tragacanth gum, keratan sulfate, chondroitin, xanthan gum, mucoitin sulfate, guar gum, dextran, keratosulfate, locust bean gum, succinoglucan, and caronic acid.

[0100] Examples of amino acids include neutral amino acids (e.g., threonine, cysteine, etc.) and basic amino acids (e.g., hydroxylysine, etc.). Examples of amino acid derivatives include sodium acyl sarcosine (sodium lauroyl sarcosine), acyl glutamate, sodium acyl β-alanine, glutathione, pyrrolidone carboxylic acid, etc.

[0101] Examples of organic amines include monoethanolamine, diethanolamine, triethanolamine, morpholine, triisopropanolamine, 2-amino-2-methyl-1,3-propanediol, and 2-amino-2-methyl-1-propanol.

[0102] Examples of polymer emulsions include acrylic resin emulsion, polyethyl acrylate emulsion, acrylic resin liquid, polyacrylic alkyl ester emulsion, polyvinyl acetate resin emulsion, and natural rubber latex.

[0103] Examples of the neutralizing agent include inorganic bases such as sodium hydroxide and potassium hydroxide; and organic amines such as monoethanolamine, diethanolamine, triethanolamine, morpholine, triisopropanolamine, 2-amino-2-methyl-1,3-propanediol, and 2-amino-2-methyl-1-propanol.

[0104] Examples of pH adjusters include buffers such as lactic acid-sodium lactate, citric acid-sodium citrate, and succinic acid-sodium succinate.

[0105] Examples of vitamins include vitamins A, B1, B2, B6, C, E and derivatives thereof, pantothenic acid and derivatives thereof, biotin, etc.

[0106] Examples of antioxidants include tocopherols, dibutylhydroxytoluene, butylhydroxyanisole, and gallic acid esters.

[0107] Examples of antioxidant aids include phosphoric acid, citric acid, ascorbic acid, maleic acid, malonic acid, succinic acid, fumaric acid, cephalin, hexametaphosphate, phytic acid, and ethylenediaminetetraacetic acid.

[0108] Examples of the stabilizer include sodium pyrosulfite and EDTA-2Na.

[0109] Other ingredients that can be added include, for example, preservatives (phenoxyethanol, ethylparaben, butylparaben, chlorphenesin, etc.); anti-inflammatory agents (for example, glycyrrhizinic acid derivatives, glycyrrhetinic acid derivatives, salicylic acid derivatives, hinokitiol, zinc oxide, allantoin, etc.); whitening agents (for example, placenta extract, saxifrage extract, vitamin C, magnesium ascorbyl phosphate, ascorbic acid glucoside, arbutin, alkoxysalicylic acid and its salts, etc.); various extracts (for example, Phellodendron bark, Coptis chinensis, Lithospermum root, Peony root, Swertia japonica, Birch, sage, Loquat, Carrot, Aloe, Mallow, Iris, Grape, Job's tears, Loofah, Lily, Saffron, Cnidium rhizome, Angelica juncea, Oto Examples of effective anti-inflammatory agents include: ginseng, ononis, garlic, chili pepper, tangerine peel, angelica tree, seaweed, etc.), activators (for example, royal jelly, photosensitizers, cholesterol derivatives, etc.); blood circulation promoters (for example, nonylic acid valenylamide, nicotinic acid benzyl ester, nicotinic acid β-butoxyethyl ester, capsaicin, zingerone, cantharides tincture, ichthammol, tannic acid, α-borneol, tocopherol nicotinate, inositol hexanicotinate, cyclandelate, cinnarizine, tolazoline, acetylcholine, verapamil, cepharanthine, γ-oryzanol, etc.); antiseborrheic agents (for example, sulfur, thianthol, etc.); and anti-inflammatory agents (for example, tranexamic acid, thiotaurine, hypotaurine, etc.).

[0110] The oil-in-water emulsion cosmetic according to the present invention can be suitably used in various formulations such as cream, emulsion, liquid, etc. The product form can be skin care cosmetics such as sunscreen, or makeup cosmetics such as makeup base and foundation.

[0111] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. Unless otherwise specified, all blend amounts are expressed in mass % relative to the total amount.

[0112] The following amphiphilic substances 1 to 5 and comparative substances 1 to 4 were prepared.

[0113] (Amphiphilic substance 1) PEG / PPG-9 / 2 dimethyl ether (R１ :CH ３ , R ２ :CH ３ , AO:CH(CH ３ ) CH ２ O, EO:CH ２ CH ２ O, m: 2, n: 9)

[0114] (Amphiphilic substance 2) PEG / PPG-14 / 7 dimethyl ether (R １ :CH ３ , R ２ :CH ３ , AO:CH(CH ３ ) CH ２ O, EO:CH ２ CH ２ O, m: 7, n: 14)

[0115] (Amphiphilic substance 3) PEG / PPG-36 / 41 dimethyl ether (R １ :CH ３ , R ２ :CH ３ , AO:CH(CH ３ ) CH ２ O, EO:CH ２ CH ２ O, m: 41, n: 36)

[0116] (Amphiphilic substance 4) PEG / PPG-17 / 4 dimethyl ether (R １ :CH ３ , R ２ :CH ３ , AO:CH(CH ３ ) CH ２ O, EO:CH ２ CH ２ O, m: 4, n: 17)

[0117] (Amphiphilic Substances 5 and 6) Amphiphilic substances 5 and 6 are polymers represented by the general formula (2) above, and A in the general formula (2) is an alkylene group represented by the general formula (3) above. The structure of amphiphilic substance 5 is shown in Table 1 as Synthesis Example 1, and the structure of amphiphilic substance 6 is shown in Table 1 as Synthesis Example 2. Amphiphilic substances 5 and 6 were synthesized by the following method.

[0118] Synthesis of Amphiphilic Substance 5: 128 g of methanol and 6.4 g of potassium hydroxide as a catalyst were charged into an autoclave. The air in the autoclave was replaced with dry nitrogen, and the catalyst was completely dissolved at 80°C with stirring. Next, a mixture of 592 g of glycidol and 1,392 g of propylene oxide was added dropwise using a dropping device at 95°C over 20 hours, followed by stirring for 5 hours. The reaction composition was removed from the autoclave, neutralized with hydrochloric acid to a pH of 6-7, and treated at 100°C under a reduced pressure of -0.095 MPa (50 mmHg) for 1 hour to remove contained water. After further treatment, filtration was performed to remove the salt produced, yielding 2,000 g of Amphiphilic Substance 5.

[0119] <Synthesis of Amphiphilic Substance 6> 128 g of methanol and 6.4 g of potassium hydroxide as a catalyst were charged into an autoclave. The air in the autoclave was replaced with dry nitrogen, and the catalyst was completely dissolved at 80°C while stirring. Next, a mixture of 592 g of glycidol and 1392 g of propylene oxide was added dropwise at 95°C over 20 hours using a dropping device, followed by stirring for 2 hours. Next, 244 g of potassium hydroxide was charged, and the system was replaced with dry nitrogen. 200 g of methyl chloride was then added under pressure at a temperature of 80 to 130°C and reacted for 5 hours. The reaction mixture was then removed from the autoclave, neutralized with hydrochloric acid to a pH of 6 to 7, and treated at 100°C under a reduced pressure of -0.095 MPa (50 mmHg) for 1 hour to remove the water content. After further treatment, filtration was performed to remove the salt formed, yielding 1820 g of amphiphilic substance 6.

[0120] <Number Average Molecular Weights of Amphiphilic Substances 5 and 6> The number average molecular weights of amphiphilic substances 5 and 6 were determined by the following method.

[0121] The number-average molecular weights of amphiphiles 5 and 6 were calculated by gel permeation chromatography (GPC). A SHODEX® GPC101 GPC-dedicated system was used, equipped with a SHODEX® RI-71s differential refractometer, a SHODEX® KF-G guard column, and three SHODEX® KF804L columns in series. Tetrahydrofuran was used as the developing solvent at a flow rate of 1 ml / min at a column temperature of 40°C. 0.1 ml of a 0.1 wt % tetrahydrofuran solution of the resulting reaction product was injected, and a chromatogram representing refractive index intensity and elution time was obtained using a BORWING PC calculation program. The number-average molecular weights of amphiphiles 5 and 6 were calculated from this chromatogram using polyethylene glycol as a standard. Table 1 shows the number-average molecular weights of amphiphiles 5 and 6.

[0122] <IOB Values ​​of Amphiphilic Substances 5 and 6> The IOB values ​​of amphiphilic substances 5 and 6 were determined by the method described on pages 11 to 17 of "Organic Conceptual Diagram - Basics and Applications" (by Yoshio Koda, Sankyo Publishing, published in 1984). The IOB values ​​of amphiphilic substances 5 and 6 were as shown in Table 1.

[0123] *1 The synthesized compound was mixed with olive oil to a concentration of 1.0% by mass, and the appearance was checked. If it was uniform, it was marked as "Good."

[0124] (Comparative substance 1) bisethoxydiglycol cyclohexane-1,4-dicarboxylate

[0125] (Comparative substance 2) Di(phytosteryl / octyldodecyl) lauroyl glutamate (ELDEW PS203, Ajinomoto Co., Inc.)

[0126] (Comparative substance 3) PEG-20 (PEG#1000)

[0127] (Comparative substance 4) Diethoxyethyl succinate (CRODAMOL DES, Croda Japan Co., Ltd.) Diethoxyethyl succinate is a compound represented by the following formula.

[0128]

[0129] [Examples 1 to 7 and Comparative Examples 1 to 6] Cosmetics of Examples 1 to 7 and Comparative Examples 1 to 6 were prepared using amphiphilic substances 1 to 6 and comparative substances 1 to 4 according to the formulations shown in Tables 2 and 3, and the emulsion stability of each oil-in-water emulsion cosmetic was evaluated using the method described below.

[0130] [Emulsion stability] After preparing the oil-in-water emulsion cosmetic, the tube was filled and compressed 1000 times or more. The tube was visually inspected for the presence or absence of oil seepage caused by emulsion breakdown, and the emulsion stability was evaluated based on the following evaluation criteria. If emulsion breakdown occurs, oil seepage is observed. (Evaluation criteria) A: The appearance is uniform and no oil seepage is observed. B: Some oil seepage is observed. C: Oil seepage is observed over a wide area.

[0131] Oil-in-water emulsion cosmetics that were rated "A" or "B" according to the above evaluation criteria were judged to be applicable to the present invention.

[0132]

[0133]

[0134] All of Examples 1 to 7 had good emulsion stability at a level that allowed the present invention to be implemented.

[0135] In all of Comparative Examples 1 to 6, oil seepage was observed over a wide area, and the emulsion stability was poor.

[0136] From the above, it has been demonstrated that an oil-in-water emulsion cosmetic satisfying the constitution of the present invention can provide an oil-in-water emulsion cosmetic that is highly safe and has good emulsion stability.

[0137] As the oil-in-water emulsion cosmetic of the present invention, the oil-in-water emulsion cosmetic having the composition of Examples 1 and 2 shown in Table 4 can also be used.

[0138]

[0139] Examples of embodiments of the present invention include the following: <1> An oil-in-water emulsion cosmetic comprising: (A) an amphiphilic substance; and (B) a hydrophobized metal oxide fine particle that has been hydrophobized with a monoalkylphosphoric acid, wherein the amphiphilic substance (A) comprises one or more alkylene oxide derivatives selected from the group consisting of alkylene oxide derivatives represented by the following general formula (1) and the following general formula (2). (In the general formula (1), AO represents an oxyalkylene group having 3 to 4 carbon atoms, EO represents an oxyethylene group, and R １ and R ２ each independently represents a hydrocarbon group having 1 to 4 carbon atoms or a hydrogen atom, and m and n are integers satisfying the conditions of 1≦m≦70 and 1≦n≦70. (In the general formula (2), R ３ , R ４ and R ５ are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, A is an alkylene group having 2 to 4 carbon atoms, and p and q are each independently an integer of 1 to 50. The polymer represented by general formula (2) has a number average molecular weight of 10,000 or less and an IOB value of 0.4 to 1.8. <2> The oil-in-water emulsion cosmetic according to <1> above, further comprising a activator (C). <3> The oil-in-water emulsion cosmetic according to <2> above, wherein the activator (C) includes polyoxyethylene hydrogenated castor oil. <4> The oil-in-water emulsion cosmetic according to <3> above, wherein the average number of moles of ethylene oxide added in the polyoxyethylene hydrogenated castor oil is 50 moles or more and 100 moles or less. <5> The oil-in-water emulsion cosmetic according to any one of <1>, <2>, <3>, and <4>, wherein the (B) hydrophobized metal oxide fine particles that have been hydrophobized with a monoalkyl phosphoric acid are metal oxide fine particles having a silica coating. <6> The oil-in-water emulsion cosmetic according to any one of <1>, <2>, <3>, <4>, and <5>, wherein the monoalkyl phosphoric acid includes cetyl phosphoric acid.

[0140] According to any one of the oil-in-water emulsion cosmetics described above in <1> to <6>, the various problems of the prior art can be solved and the object of the present invention can be achieved.

[0141] This application claims priority based on Japanese Patent Application No. 2023-223656, filed with the Japan Patent Office on December 28, 2023, and incorporates the entire contents of said application by reference.

Claims

1. An oil-in-water type emulsified cosmetic containing (A) an amphiphilic substance and (B) hydrophobically treated fine particle metal oxide hydrophobized with monoalkylphosphoric acid, wherein the (A) amphiphilic substance contains one or more selected from the group consisting of alkylene oxide derivatives represented by the following general formula (1) and the following general formula (2). (In the general formula (1), AO represents an oxyalkylene group having 3 to 4 carbon atoms, EO represents an oxyethylene group, R １ and R ２ each independently represent a hydrocarbon group having 1 to 4 carbon atoms or a hydrogen atom, and m and n are integers of 1 ≦ m ≦ 70 and 1 ≦ n ≦ 70.) (In the general formula (2), R ３ , R ４ and R ５ are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, A is an alkylene group having 2 to 4 carbon atoms, and p and q are each independently integers of 1 to 50. The polymer represented by the general formula (2) has a number average molecular weight of 10,000 or less and an IOB value of 0.4 to 1.8.) 2. The oil-in-water type emulsified cosmetic according to claim 1, further containing (C) an activator.

3. The oil-in-water type emulsified cosmetic according to claim 2, wherein the (C) activator contains polyoxyethylene hydrogenated castor oil.

4. The oil-in-water type emulsified cosmetic according to claim 3, wherein the average number of moles of ethylene oxide added to the polyoxyethylene hydrogenated castor oil is 50 moles or more and 100 moles or less.

5. The oil-in-water type emulsified cosmetic according to claim 1 or 2, wherein the hydrophobically treated fine particle metal oxide hydrophobized with the (B) monoalkyl phosphate is a fine particle metal oxide having a silica coating.

6. The oil-in-water type emulsified cosmetic according to claim 1 or 2, wherein the monoalkyl phosphate contains cetyl phosphate.

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