Oil-in-water emulsion composition

Abstract

This oil-in-water emulsion composition contains: (A) an alkoxysalicylic acid represented by general formula (1) or a salt thereof; (B) at least one selected from the group consisting of polyoxyethylene dialkyl esters and polyoxyethylene dialkyl ethers represented by general formula (2); (C) at least one selected from the group consisting of polyoxyethylene alkyl esters and polyoxyethylene alkyl ethers represented by general formula (3); (D) agar; and (E) (i) a carbomer and an alkali agent, (ii) sodium carbomer, or (iii) a carbomer and at least one selected from the group consisting of succinoglycan, xanthan gum, cellulose gum, (acrylic acid / 2-(perfluorohexyl) ethyl acrylate) crosspolymers, and (acrylic acid / lauryl methacrylate / isodecyl methacrylate) crosspolymers. The content of the (A) alkoxysalicylic acid represented by general formula (1) or a salt thereof is greater than 1 mass%.

Description

Oil-in-water emulsion composition

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

[0002] It is known that alkoxysalicylic acid or its salts have an inhibitory effect on melanin production, and that topical skin preparations containing them exhibit excellent whitening effects, and there is a high demand for cosmetics and the like that contain higher concentrations of whitening agents such as alkoxysalicylic acid or its salts. Patent Document 1 discloses an oil-in-water emulsion composition containing 1% by mass of 4-methoxysalicylic acid potassium salt, which is a salt of alkoxysalicylic acid.

[0003] Japanese Patent Application Publication No. 2012-031088

[0004] However, it is generally known that when an alkoxysalicylic acid or a salt thereof, such as 4-methoxysalicylic acid potassium salt, is blended into an oil-in-water emulsion composition at a concentration exceeding 1% by mass, the emulsion stability is generally reduced. One embodiment of the present invention aims to provide an oil-in-water emulsion composition that exhibits excellent emulsion stability even when containing an alkoxysalicylic acid or a salt thereof at a high concentration exceeding 1% by mass.

[0005] In order to solve the above problems, one embodiment of the present invention comprises: (A) an alkoxysalicylic acid or a salt thereof represented by general formula (1); (However, in the general formula (1), R ａ is an alkyl group having 1 to 6 carbon atoms), (B) at least one selected from the group consisting of polyoxyethylene dialkyl esters and polyoxyethylene dialkyl ethers represented by general formula (2), (However, in the general formula (2), R １ and R ２ each independently represents a linear aliphatic acid residue or a linear aliphatic alcohol residue having 16 to 24 carbon atoms, and n represents an integer of 4 to 15. (C) at least one selected from the group consisting of polyoxyethylene alkyl esters and polyoxyethylene alkyl ethers represented by general formula (3), (However, in the general formula (3), R ３(A) is a linear aliphatic residue having 16 to 24 carbon atoms, a linear aliphatic acid residue, or a linear aliphatic alcohol residue, and n is an integer of 5 to 30; (D) agar; and (E) (i) a carbomer and an alkali agent, (ii) carbomer Na, or (iii) at least one selected from the group consisting of succinoglycan, xanthan gum, cellulose gum, (acrylic acid / 2-(perfluorohexyl)ethyl acrylate) crosspolymer, and (acrylic acid / lauryl methacrylate / isodecyl methacrylate) crosspolymer, and a carbomer, wherein the content of (A) the alkoxysalicylic acid represented by general formula (1) or a salt thereof is more than 1 mass %.

[0006] According to one embodiment of the present invention, it is possible to provide an oil-in-water emulsion composition that exhibits excellent emulsion stability even when containing an alkoxysalicylic acid or a salt thereof at a high concentration of more than 1 mass %.

[0007] Hereinafter, an embodiment of the present invention will be described in detail.

[0008] (Oil-in-water emulsion composition) An oil-in-water emulsion composition according to one embodiment of the present invention contains, for example, (A) an alkoxysalicylic acid represented by general formula (1) or a salt thereof.

[0009] However, in the general formula (1), R ａ is, for example, an alkyl group having 1 to 6 carbon atoms.

[0010] The oil-in-water emulsion composition according to this embodiment contains, for example, (B) at least one selected from the group consisting of polyoxyethylene dialkyl esters and polyoxyethylene dialkyl ethers represented by general formula (2).

[0011] However, in the general formula (2), R １ and R ２ are, for example, each independently a linear aliphatic acid residue or a linear aliphatic alcohol residue having 16 to 24 carbon atoms; and n is an integer of 4 to 15.

[0012] The oil-in-water emulsion composition according to this embodiment contains, for example, (C) at least one selected from the group consisting of polyoxyethylene alkyl esters and polyoxyethylene alkyl ethers represented by general formula (3).

[0013] However, in the general formula (3), R ３ represents, for example, a straight-chain aliphatic residue having 16 to 24 carbon atoms, a straight-chain aliphatic acid residue, or a straight-chain aliphatic alcohol residue; and n represents an integer of 5 to 30.

[0014] The oil-in-water emulsion composition according to this embodiment contains, for example, (D) agar.

[0015] The oil-in-water emulsion composition according to this embodiment contains, for example, a thickener with excellent salt tolerance. More specifically, the oil-in-water emulsion composition contains (E) (i) a carbomer and an alkali agent, (ii) carbomer Na, or (iii) at least one selected from the group consisting of succinoglycan, xanthan gum, cellulose gum, (acrylic acid / 2-(perfluorohexyl)ethyl acrylate) crosspolymer, and (acrylic acid / lauryl methacrylate / isodecyl methacrylate) crosspolymer, as well as a carbomer. The (acrylic acid / 2-(perfluorohexyl)ethyl acrylate) crosspolymer is sometimes referred to as (acrylic acid / perfluorohexylethyl acrylate) crosspolymer.

[0016] In the oil-in-water emulsion composition according to this embodiment, the content of (A) the alkoxysalicylic acid or its salt represented by general formula (1) is, for example, more than 1 mass %. This embodiment can provide an oil-in-water emulsion composition that has excellent emulsion stability even when the alkoxysalicylic acid or its salt is contained at a high concentration of more than 1 mass %.

[0017] <Component (A)> The oil-in-water emulsion composition according to this embodiment contains, as component (A), more than 1 mass % of an alkoxysalicylic acid represented by the following general formula (1) or a salt thereof.

[0018] However, in the general formula (1), R ａ is an alkyl group having 1 to 6 carbon atoms.ａ is an alkyl group having 1 to 6 carbon atoms, which may be linear or branched. ａ Examples of the substituent OR include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, and a sec-butyl group, and preferably a methyl group or an ethyl group. ａ The position of is not particularly limited, but is preferably the 3-, 4- or 5-position of salicylic acid, more preferably the 4-position.

[0019] Examples of the alkoxysalicylic acid represented by general formula (1) include 3-methoxysalicylic acid, 3-ethoxysalicylic acid, 4-methoxysalicylic acid, 4-ethoxysalicylic acid, 4-propoxysalicylic acid, 4-isopropoxysalicylic acid, 4-butoxysalicylic acid, 5-methoxysalicylic acid, 5-ethoxysalicylic acid, and 5-propoxysalicylic acid, and preferably 4-methoxysalicylic acid.

[0020] The alkoxysalicylic acids represented by general formula (1) can be easily synthesized by the methods described, for example, in "Beil, 10227" for 5-methoxysalicylic acid and in "Beil, 10379" for 4-methoxysalicylic acid. In addition, commercially available products are also available from Aldrich Chemicals and the like.

[0021] The alkoxysalicylic acid represented by general formula (1) is preferably contained as a salt, and the type of salt is not particularly limited as long as it is a pharmacologically acceptable salt. Examples of the salt include alkali metal salts such as sodium salt, potassium salt, and lithium salt; alkaline earth metal salts such as calcium salt and magnesium salt; ammonium salt; and amino acid salts. Potassium salt is preferred, and from the viewpoints of cosmetic effects and availability, potassium 4-methoxysalicylate is even more preferred.

[0022] The oil-in-water emulsion composition according to this embodiment contains more than 1% by mass of an alkoxysalicylic acid or a salt thereof relative to the total amount of the composition. This allows for the provision of a composition containing a high concentration of a whitening agent. In this embodiment, the oil-in-water emulsion composition may contain one or more alkoxysalicylic acids or salts thereof represented by general formula (1).

[0023] The content of the alkoxysalicylic acid or its salt represented by general formula (1) may be 1.5% by mass or more, 2% by mass or more, or 3% by mass or more, relative to the total amount of the oil-in-water emulsion composition. According to this embodiment, the oil-in-water emulsion composition contains agar and a thickener with excellent salt tolerance. This allows for the provision of an oil-in-water emulsion composition with excellent emulsion stability, even when the alkoxysalicylic acid or its salt is contained at a high concentration, such as 1.5% by mass or more, 2% by mass or more, or 3% by mass or more.

[0024] The content of the alkoxysalicylic acid or salt thereof represented by general formula (1) is preferably 1.5 to 5 mass%, more preferably 2 to 5 mass%, and even more preferably 3 to 5 mass%, relative to the total mass of the oil-in-water emulsion composition. When the content of the alkoxysalicylic acid or salt thereof represented by general formula (1) relative to the total mass of the oil-in-water emulsion composition is 1.5 to 5 mass%, an oil-in-water composition having a sufficiently higher concentration of alkoxysalicylic acid or salt thereof than conventional compositions can be obtained. According to this embodiment, an oil-in-water emulsion composition having excellent emulsion stability can be provided even when containing an alkoxysalicylic acid or salt thereof at a concentration greater than 1 mass%.

[0025] <Component (B)> The oil-in-water emulsion composition according to this embodiment contains, as component (B), at least one selected from the group consisting of polyoxyethylene dialkyl esters and polyoxyethylene dialkyl ethers represented by the following general formula (2):

[0026] However, in the general formula (2), R １ and R ２ each independently represents a linear aliphatic acid residue or a linear aliphatic alcohol residue having 16 to 24 carbon atoms; and n is an integer of 4 to 15.

[0027] In one embodiment, "independently" means that R １ and R ２ may be different linear aliphatic acid residues or linear aliphatic alcohol residues having 16 to 24 carbon atoms, or may be the same linear aliphatic acid residue or linear aliphatic alcohol residue having 16 to 24 carbon atoms.

[0028] In general formula (2), R １ and R ２ are each independently a linear aliphatic acid residue or a linear aliphatic alcohol residue having 16 to 24 carbon atoms, with a linear aliphatic acid residue having 16 to 24 carbon atoms being preferred. The bonding mode between the polyoxyethylene chain and the alkyl group in one molecule of each of the polyoxyethylene dialkyl ester and polyoxyethylene dialkyl ether represented by general formula (2) may be an ester bond or an ether bond, or may include both of these bonding modes, or may include both of these bonding modes.

[0029] In the oil-in-water emulsion composition according to the present embodiment, the polyoxyethylene dialkyl ester and polyoxyethylene dialkyl ether represented by general formula (2) have a linear aliphatic acid residue or a linear aliphatic alcohol residue having 16 to 24 carbon atoms, and the polyoxyethylene chain is 4 to 15 moles.

[0030] Specific examples of polyoxyethylene dialkyl esters or polyoxyethylene dialkyl ethers represented by general formula (2) include polyoxyethylene (4 moles) distearate (PEG-4 distearate), polyoxyethylene (6 moles) distearate (PEG-6 distearate), polyoxyethylene (8 moles) distearate (PEG-8 distearate), polyoxyethylene (12 moles) distearate (PEG-12 distearate), steareth-4 stearate, steareth-6 stearate, steareth-9 stearate, and polyoxyethylene (8 moles) dibehenyl ether. These may be used alone or in combination of two or more. The number of moles in parentheses indicates the average number of moles of ethylene oxide added, represented by n in general formula (2).

[0031] The polyoxyethylene dialkyl ester or polyoxyethylene dialkyl ether represented by the general formula (2) may be synthesized by a known method or may be a commercially available product. Commercially available polyoxyethylene dialkyl esters or polyoxyethylene dialkyl ethers represented by general formula (2) include polyoxyethylene (4 mol) distearate (e.g., Emalex 200DIS, manufactured by Nippon Emulsion Co., Ltd.), polyoxyethylene (6 mol) distearate (e.g., Emalex 300DIS, manufactured by Nippon Emulsion Co., Ltd.), polyoxyethylene (8 mol) distearate (e.g., Emalex 400DIS, manufactured by Nippon Emulsion Co., Ltd.), polyoxyethylene (12 mol) distearate (e.g., Emalex 600DIS, manufactured by Nippon Emulsion Co., Ltd.), steareth-4 stearate (e.g., Emalex SWS-4, manufactured by Nippon Emulsion Co., Ltd.), steareth-6 stearate (e.g., Emalex SWS-6, manufactured by Nippon Emulsion Co., Ltd.), and steareth-9 stearate (e.g., Emalex SWS-8, manufactured by Nippon Emulsion Co., Ltd.). SWS-9), polyoxyethylene (8 moles) dibehenyl ether, etc. These may be used alone or in combination of two or more. The number of moles in parentheses indicates the average number of moles of ethylene oxide added, which is represented by n in general formula (2).

[0032] In the oil-in-water emulsion composition according to this embodiment, the content of the polyoxyethylene dialkyl ester or polyoxyethylene dialkyl ether represented by general formula (2) is preferably 0.05 to 10% by mass, more preferably 0.1 to 5% by mass, and even more preferably 0.15 to 3% by mass, relative to the total mass of the oil-in-water emulsion composition. When the content of the polyoxyethylene dialkyl ester or polyoxyethylene dialkyl ether represented by general formula (2) is 0.05 to 10% by mass, a stable emulsion system without stickiness can be obtained.

[0033] <Component (C)> The oil-in-water emulsion composition according to this embodiment contains, as component (C), at least one selected from the group consisting of polyoxyethylene alkyl esters and polyoxyethylene alkyl ethers represented by the following general formula (3):

[0034] However, in the general formula (3), R ３ represents a straight-chain aliphatic residue having 16 to 24 carbon atoms, a straight-chain aliphatic acid residue, or a straight-chain aliphatic alcohol residue; and n is an integer of 5 to 30.

[0035] In general formula (3), R ３ represents a straight chain aliphatic residue having 16 to 24 carbon atoms, a straight chain aliphatic acid residue, or a straight chain aliphatic alcohol residue, with a straight chain aliphatic residue having 16 to 24 carbon atoms being preferred.

[0036] In each of the polyoxyethylene alkyl ester and polyoxyethylene alkyl ether represented by general formula (3), the bonding mode between the polyoxyethylene chain and the alkyl group in one molecule may be an ester bond, an ether bond, or both.

[0037] In the oil-in-water emulsion composition according to this embodiment, the polyoxyethylene alkyl ester and polyoxyethylene alkyl ether represented by general formula (3) have a linear aliphatic residue, a linear aliphatic acid residue, or a linear aliphatic alcohol residue having 16 to 24 carbon atoms, and in general formula (3), (CH ２ CH ２ In the polyoxyethylene chain represented by (CH ２ CH ２ O) is 5 to 30 moles.

[0038] Specific examples of polyoxyethylene alkyl esters and polyoxyethylene alkyl ethers represented by general formula (3) include polyoxyethylene (5 mol) behenyl ether (beheneth-5), polyoxyethylene (10 mol) behenyl ether (beheneth-10), polyoxyethylene (20 mol) behenyl ether (beheneth-20), polyoxyethylene (30 mol) behenyl ether (beheneth-30), polyoxyethylene (10 mol) stearyl ether (steareth-10), polyoxyethylene (7 mol) cetyl ether (ceteth-7), and PEG-20 stearate. These may be used alone or in combination of two or more. The number of moles in parentheses indicates the average number of moles of ethylene oxide added, represented by n in general formula (3).

[0039] The polyoxyethylene alkyl ester and polyoxyethylene alkyl ether represented by the general formula (3) may be synthesized by a known method or may be a commercially available product. Commercially available polyoxyethylene alkyl esters and polyoxyethylene alkyl ethers represented by the general formula (3) include polyoxyethylene (5 mol) behenyl ether (e.g., Nikkol BB-5, manufactured by Nikko Chemicals Co., Ltd.), polyoxyethylene (10 mol) behenyl ether (e.g., Nikkol BB-10, manufactured by Nikko Chemicals Co., Ltd.), polyoxyethylene (20 mol) behenyl ether (e.g., Nikkol BB-20, manufactured by Nikko Chemicals Co., Ltd.), polyoxyethylene (30 mol) behenyl ether (e.g., Nikkol BB-30, manufactured by Nikko Chemicals Co., Ltd.), polyoxyethylene (10 mol) stearyl ether (steareth-10) (e.g., Emalex 610, manufactured by Nippon Emulsion Co., Ltd.), and polyoxyethylene (7 mol) cetyl ether (ceteth-7) (e.g., Emalex 610, manufactured by Nippon Emulsion Co., Ltd.). 107), PEG-20 stearate (Nihon Emulsion Co., Ltd., EMALEX 820), etc. These may be used alone or in combination of two or more. The number of moles in parentheses indicates the average number of moles of ethylene oxide added, which is represented by n in general formula (3).

[0040] In the oil-in-water emulsion composition according to the present embodiment, the content of the polyoxyethylene alkyl ester and polyoxyethylene alkyl ether represented by general formula (3) is preferably 0.05 to 10% by mass, more preferably 0.1 to 5% by mass, and even more preferably 0.2 to 1% by mass, relative to the total mass of the oil-in-water emulsion composition. When the content of the polyoxyethylene alkyl ester and polyoxyethylene alkyl ether represented by general formula (3) is 0.05 to 10% by mass, a stable emulsion system without stickiness can be obtained.

[0041] <Component (D)> The oil-in-water emulsion composition according to this embodiment contains agar as component (D). Agar acts as a thickener in the oil-in-water emulsion composition.

[0042] The agar is not particularly limited as long as it is composed mainly of agarose with high gelling power. The agar may be a natural product or a processed product. Suitable commercially available agars include Ina Agar PS-84, Z-10, AX-30, AX-100, AX-200, T-1, S-5, and M-7 (manufactured by Ina Food Industry Co., Ltd.). Purified agar may also be used as the agar.

[0043] The content of agar is preferably 0.1 to 3% by mass, more preferably 0.2 to 2% by mass, and even more preferably 0.3 to 1.5% by mass, relative to the total mass of the oil-in-water emulsion composition. When the content of agar is 0.1 to 3% by mass, relative to the total mass of the oil-in-water emulsion composition, non-stickiness and a moist feeling on the skin can be obtained after application of the oil-in-water emulsion composition.

[0044] <Component (E)> The oil-in-water emulsion composition according to this embodiment contains, as component (E), at least one selected from the group consisting of (i) a carbomer and an alkaline agent, (ii) carbomer Na, or (iii) succinoglycan, xanthan gum, cellulose gum, (acrylic acid / 2-(perfluorohexyl)ethyl acrylate) crosspolymer, and (acrylic acid / lauryl methacrylate / isodecyl methacrylate) crosspolymer, as well as a carbomer. Component (E) acts as a thickener in the oil-in-water emulsion composition. Component (E) has superior salt tolerance compared to other thickeners.

[0045] <<(i) Carbomer and Alkali Agent>> Carbomer is an acrylic acid-based crosslinked copolymer, which is a crosslinked polymer of an acrylic acid-based monomer such as acrylic acid, methacrylic acid, substituted acrylic acid such as ethacrylic acid, etc. The acrylic acid-based monomer is preferably acrylic acid, methacrylic acid, or ethacrylic acid, and acrylic acid is most preferred.

[0046] The crosslinking agent in the carbomer is preferably a polyalkenyl polyether of a polyhydric alcohol having two or more carbon-carbon double bonds (alkenyl ether groups) per molecule, and specific examples include allyl ether of sucrose and allyl ether of pentaerythritol.

[0047] Commercially available carbomers can be used, and examples of commercially available carbomers include Carbopol 910, 934, 940, 941, and 981 (all manufactured by B.F. Goodrich Chemical Co.), Hiviswako 104 and 105 (both manufactured by Wako Pure Chemical Industries, Ltd.), and Syntaren K and L (both manufactured by Sigma).

[0048] In the oil-in-water emulsion composition according to the present embodiment, the content of the carbomer is not particularly limited as long as it is an amount effective for enabling the effect of the component to be exhibited, but is preferably 0.01 to 1.5% by mass, more preferably 0.02 to 1% by mass, and even more preferably 0.05 to 0.5% by mass, relative to the total amount of the oil-in-water emulsion composition.

[0049] When component (E) is (i), if the carbomer content is 0.01 to 1.5% by mass, a stable emulsion system with an appropriate viscosity and no stickiness can be obtained.

[0050] Examples of the alkaline agent that can be used include sodium hydroxide, potassium hydroxide, triethanolamine, and aminomethylpropanol, with sodium hydroxide being preferred.

[0051] Furthermore, by blending an appropriate amount of an alkaline agent into the oil-in-water emulsion composition according to this embodiment, it is possible to achieve an appropriate viscosity and stabilize the oil-in-water emulsion composition.

[0052] (i) When a carbomer and an alkali agent are used as component (E), the oil-in-water emulsion composition preferably further contains xanthan gum or other polysaccharides. Xanthan gum is a polysaccharide, and when the oil-in-water emulsion composition contains, for example, xanthan gum, it is possible to obtain an oil-in-water emulsion composition that is less sticky and has an excellent feel when used. Xanthan gum is an anionic polymer, and examples of commercially available products include xanthan gum (Keltrol, Keltrol T, Kelco), etc.

[0053] <<(ii) Carbomer Na>> Carbomer Na is the sodium salt of carbomer, and when carbomer and sodium hydroxide are neutralized, the product may be displayed as "carbomer" and "sodium hydroxide" separately, or as a combined product such as "carbomer Na." Therefore, "(i) carbomer and alkaline agent" where the "alkaline agent" is sodium hydroxide and "(ii) carbomer Na" may mean the same thing.

[0054] Commercially available carbomer Na products that can be preferably used in the present invention include AQUAKEEP (manufactured by Sumitomo Seika Chemicals Co., Ltd.) and AQUPEC MGN40R (manufactured by Sumitomo Seika Chemicals Co., Ltd.).

[0055] In the oil-in-water emulsion composition according to this embodiment, the content of carbomer Na is not particularly limited as long as it is an amount effective for enabling the effect of the component to be exerted, but is preferably 0.03 to 3 mass %, more preferably 0.05 to 2 mass %, and even more preferably 0.1 to 1 mass %, relative to the total amount of the oil-in-water emulsion composition. When the content of carbomer Na is 0.03 to 3 mass %, the content of carbomer Na is appropriate, and a stable emulsion system without stickiness can be obtained.

[0056] As in (i), when (ii) carbomer Na is component (E), it is preferable that the oil-in-water emulsion composition of the present invention further contains xanthan gum. Xanthan gum is a polysaccharide, and when the oil-in-water emulsion composition of the present invention contains xanthan gum, it is possible to obtain an oil-in-water emulsion composition that is less sticky and has an excellent feel when used.

[0057] <<(iii) At least one selected from the group consisting of succinoglycan, xanthan gum, cellulose gum, (acrylic acid / 2-(perfluorohexyl)ethyl acrylate) crosspolymer, and (acrylic acid / lauryl methacrylate / isodecyl methacrylate) crosspolymer, and a carbomer>> When component (E) contains (iii) at least one selected from the group consisting of succinoglycan, xanthan gum, cellulose gum, (acrylic acid / 2-(perfluorohexyl)ethyl acrylate) crosspolymer, and (acrylic acid / lauryl methacrylate / isodecyl methacrylate) crosspolymer, and a carbomer, component (E) preferably contains two or more components selected from the group consisting of succinoglycan, xanthan gum, cellulose gum, (acrylic acid / 2-(perfluorohexyl)ethyl acrylate) crosspolymer, and (acrylic acid / lauryl methacrylate / isodecyl methacrylate) crosspolymer, and a carbomer.

[0058] Succinoglycan is a water-soluble polymeric polysaccharide, and examples of commercially available products include Rheozan (trade name: molecular weight 600, manufactured by Rhodia) and Rheozan SH (manufactured by Rhodia).

[0059] In the oil-in-water emulsion composition according to the present embodiment, the content of succinoglycan is not particularly limited as long as it is an amount effective for achieving the effects of the component, but is preferably 0.05 to 0.5% by mass, more preferably 0.07 to 0.4% by mass, and even more preferably 0.08 to 0.3% by mass, relative to the total amount of the oil-in-water emulsion composition. When the content of succinoglycan is 0.05 to 0.5% by mass, a stable emulsion system without stickiness can be obtained.

[0060] Xanthan gum is a polysaccharide, and since the inclusion of xanthan gum in an oil-in-water emulsion composition results in an oil-in-water emulsion composition that is less sticky and has an excellent feel when used, it is preferable that component (E) contains xanthan gum. Xanthan gum is an anionic polymer, and examples of commercially available xanthan gum include xanthan gum (Keltrol, Keltrol T, Kelco), etc.

[0061] In the oil-in-water emulsion composition according to the present embodiment, the content of xanthan gum is not particularly limited as long as it is an amount effective for achieving the effects of the component, but is preferably 0.1 to 5% by mass, more preferably 0.1 to 3% by mass, and even more preferably 0.1 to 1% by mass, relative to the total amount of the oil-in-water emulsion composition. When the xanthan gum content is 0.1 to 10% by mass or more, a stable emulsion system without stickiness can be obtained.

[0062] Cellulose gum (sodium carboxymethylcellulose) is a water-soluble polymer of cellulose, and examples of commercially available products include Cellogen F-SR (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.).

[0063] In the oil-in-water emulsion composition according to the present embodiment, the content of cellulose gum is not particularly limited as long as it is an amount effective for achieving the effects of the component, but is preferably 0.05 to 2% by mass, more preferably 0.1 to 1.5% by mass, and even more preferably 0.1 to 1% by mass, based on the total amount of the oil-in-water emulsion composition. When the cellulose gum content is 0.05 to 2% by mass, a stable emulsion system without stickiness can be obtained.

[0064] Acrylic acid / 2-(perfluorohexyl)ethyl acrylate crosspolymer is a hydrophilic thickener obtained by crosslinking a copolymer of acrylic acid and perfluorohexylethyl acrylate with diethylene glycol diallyl ether. Commercially available products of acrylic acid / 2-(perfluorohexyl)ethyl acrylate crosspolymer include, for example, Soltorela (Fujifilm Corporation).

[0065] Acrylic acid / lauryl methacrylate / isodecyl methacrylate crosspolymer is a copolymer of acrylic acid, lauryl methacrylate, and isodecyl methacrylate, and is a hydrophilic thickener. Commercially available products of acrylic acid / lauryl methacrylate / isodecyl methacrylate crosspolymer include Soltrela Neo (Fujifilm Corporation).

[0066] The carbomer used when the component (E) is (iii) may have the same structure as in the cases of (i) and (ii).

[0067] When component (E) is (iii), the content of the carbomer in the oil-in-water emulsion composition is not particularly limited as long as it is an amount effective for exhibiting the effects of the component, but is preferably 0.01 to 1.5% by mass, more preferably 0.02 to 1% by mass, and even more preferably 0.05 to 0.5% by mass, relative to the total amount of the oil-in-water emulsion composition of the present invention. When component (E) is (iii), a carbomer content of 0.01 to 1.5% by mass will result in a non-sticky, stable emulsion system.

[0068] The water in the oil-in-water emulsion composition according to this embodiment may be selected as needed from ion-exchanged water, purified water, tap water, natural water, etc. The water content is the amount remaining after subtracting the sum of the amounts of the essential components according to the present invention and the amounts of other optional components (% by mass relative to the total amount of the oil-in-water emulsion composition). In general, the water content is preferably 30 to 70% by mass relative to the total amount of the oil-in-water emulsion composition.

[0069] <Other Components> The oil-in-water emulsion composition according to this embodiment may contain, as necessary, appropriate components other than the components (A) to (E), such as components typically used in cosmetics, such as oily components, ultraviolet absorbers, surfactants, moisturizers, thickeners, polyhydric alcohols, powder components, synthetic resin emulsions, amino acids, neutralizing agents, pH adjusters, antioxidants, antioxidant aids, preservatives, chelating agents, cosmetic ingredients, and stabilizers.

[0070] The oily component is not particularly limited, and examples thereof include fats and oils, waxes, hydrocarbon oils, higher fatty acids, higher alcohols, synthetic ester oils, silicone oils, and silicones.

[0071] Examples of fats and oils include liquid fats and oils such as avocado oil, camellia oil, evening primrose 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, triglycerin, glycerin trioctanoate, and glycerin triisopalmitate; and solid fats and oils such as cacao butter, coconut oil, horse tallow, 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 leg fat, Japan wax, hardened castor oil, and shea butter.

[0072] 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.

[0073] Examples of hydrocarbon oils include oils such as liquid paraffin, ozokerite, squalane, pristane, paraffin, ceresin, squalene, petrolatum, microcrystalline wax, and hydrogenated polyisobutene.

[0074] Examples of higher fatty acids include lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, oleic acid, 12-hydroxystearic acid, undecylenic acid, tall acid, isostearic acid, linoleic acid, linolenic acid, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA).

[0075] Examples of higher alcohols include straight-chain alcohols such as lauryl alcohol, cetyl alcohol, stearyl alcohol, behenyl alcohol, myristyl alcohol, oleyl alcohol, and cetostearyl alcohol; and branched-chain alcohols such as monostearyl glycerin ether (batyl alcohol), 2-decyltetradecynol, lanolin alcohol, cholesterol, phytosterol, hexyldodecanol, isostearyl alcohol, and octyldodecanol.

[0076] 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-ethylhexylate, dipentaerythritol fatty acid esters, N-alkyl glycol monoisostearate, neopentyl glycol dicaprate, diisostearyl malate, glycerin di-2-heptylundecanoate, trimethylolpropane tri-2-ethylhexylate, trimethylolpropane triisostearate, pentaerythritol tetraethylhexanoate, Taerythrityl, glycerin tri-2-ethylhexanoate, trimethylolpropane triisostearate, cetyl 2-ethylhexanoate, 2-ethylhexyl palmitate, glycerin trimyristate, tri-2-heptylundecanoic acid glyceride, castor oil fatty acid methyl ester, oleic acid oil, acetoglyceride, 2-heptylundecyl palmitate, diisobutyl adipate, N- Lauroyl-L-glutamic acid 2-octyldodecyl ester, di-2-heptylundecyl adipate, ethyl laurate, di-2-ethylhexyl sebacate, 2-hexyldecyl myristate, 2-hexyldecyl palmitate, 2-hexyldecyl adipate, diisopropyl sebacate, 2-ethylhexyl succinate, ethyl acetate, butyl acetate, amyl acetate, triethyl citrate, crotamiton (C １３ H １７ NO), macadamia nut fatty acid phytosteryl, dipivalic acid PPG-3, diisopropyl sebacate, diethylhexyl succinate, etc.

[0077] Examples of silicone oils include chain silicone oils such as dimethylpolysiloxane (dimethicone), methylphenylpolysiloxane, and methylhydrogenpolysiloxane; cyclic silicone oils such as octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane, and tetramethyltetrahydrogencyclopolysiloxane; alkyl-modified silicone oils that are liquid at room temperature such as caprylmethicone, capryltrimethicone, and stearylmethicone; and fluorine-modified silicone oils such as dimethylsiloxane-diphenylsiloxane-methyl(perfluoroalkyl)siloxane copolymers.

[0078] Examples of silicones include alkyl and alkoxy silicone waxes such as stearyl-modified dimethicone and behenyl-modified dimethicone, silicone resins forming a three-dimensional network structure, and silicone rubber.

[0079] Examples of ultraviolet absorbers include benzoic acid-based ultraviolet absorbers such as para-aminobenzoic acid, para-aminobenzoic acid monoglycerin ester, N,N-dipropoxypara-aminobenzoic acid ethyl ester, and N,N-dimethylpara-aminobenzoic acid ethyl ester; anthranilic acid-based ultraviolet absorbers such as homomenthyl-N-acetylanthranilate; amyl salicylate, homomenthyl salicylate, octyl salicylate, phenyl salicylate, benzyl salicylate, and p-isopropanol phenyl salicylate. salicylic acid-based ultraviolet absorbers such as octyl methoxycinnamate, glyceryl di-para-methoxycinnamate-mono-2-ethylhexanoate, 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, octyl-p-methoxycinnamate, Cyclocinnamate (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, 3,4,5-trimethoxycinnamate-3-methyl-4-[methylbis(trimethylsiloxy)silyl]butyl, methyl trimethoxycinnamate Cinnamic acid-based ultraviolet absorbers such as bis(trimethylsiloxy)silylisopentyl; benzophenone-based ultraviolet absorbers such as 2,4-dihydroxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2,2',4,4'-tetrahydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxybenzophenone-5-sulfonate, 4-phenylbenzophenone, and 2-ethylhexyl-4'-phenylbenzophenone-2-carboxylate;Examples include 3-(4'-methylbenzylidene)-d,l-camphor, 3-benzylidene-d,l-camphor, urocanic acid, urocanic acid ethyl ester, 2,2'-hydroxy-5-methylphenylbenzotriazole, 2-(2'-hydroxy-5'-t-octylphenyl)benzotriazole, dibenzalazine, dianisoylmethane, 4-methoxy-4'-t-butyldibenzoylmethane, 5-(3,3-dimethyl-2-norbornylidene)-3-pentan-2-one, and dimorpholinopyridazinone.

[0080] The surfactant is not particularly limited, and examples thereof include lipophilic nonionic surfactants, hydrophilic nonionic surfactants, silicone surfactants, anionic surfactants, cationic surfactants, and amphoteric surfactants.

[0081] Examples of lipophilic nonionic surfactants include sorbitan fatty acid esters such as sorbitan monooleate, sorbitan monoisostearate, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan sesquioleate, and diglycerol sorbitan penta-2-ethylhexylate; glycerin or polyglycerin esters such as glycerin monostearate, α,α'-oleic acid pyroglutamic acid glycerin, and glycerin monostearate malate; propylene glycol fatty acid esters such as propylene glycol monostearate; hydrogenated castor oil derivatives; and glycerin alkyl ethers.

[0082] Examples of hydrophilic nonionic surfactants include polyoxyethylene sorbitan fatty acid esters such as polyoxyethylene sorbitan monooleate and polyoxyethylene sorbitan monostearate; polyoxyethylene sorbitan fatty acid esters such as polyoxyethylene sorbit monolaurate, polyoxyethylene sorbit monooleate and polyoxyethylene sorbit monostearate; polyoxyethylene glycerin fatty acid esters such as polyoxyethylene glycerin monostearate, polyoxyethylene glycerin monoisostearate and polyoxyethylene glycerin triisostearate; polyoxyethylene fatty acid esters such as polyoxyethylene monooleate and polyoxyethylene distearate; polyoxyethylene lauryl ether, polyoxyethylene oleyl ether, polyoxyethylene stearyl ether and polyoxyethylene-2-octyldodecyl ether. polyoxyethylene alkyl ethers such as polyoxyethylene octylphenyl ether, polyoxyethylene nonylphenyl ether, polyoxyethylene dinonylphenyl ether, etc.; Pluronic (registered trademark) surfactants such as Pluronic (registered trademark); polyoxyethylene polyoxypropylene cetyl ether, polyoxyethylene polyoxypropylene-2-decyltetradecyl ether, polyoxyethylene polyoxypropylene monobutyl ether, polyoxyethylene polyoxypropylene, hydrogenated lanolin, polyoxyethylene polyoxypropylene glycerin ether, PPG-13 decyltetradeceth-24, etc.; tetrapolyoxyethylene-tetrapolyoxypropylene ethylenediamine condensates such as Tetronic;Examples of suitable additives include polyoxyethylene castor oil derivatives or polyoxyethylene hydrogenated castor oil derivatives such as polyoxyethylene castor oil, polyoxyethylene hydrogenated castor oil monoisostearate, polyoxyethylene hydrogenated castor oil triisostearate, polyoxyethylene hydrogenated castor oil monopyroglutamic acid monoisostearate diester, and polyoxyethylene hydrogenated castor oil maleate ester; alkanolamides such as coconut oil fatty acid diethanolamide, lauric acid monoethanolamide, and fatty acid isopropanolamide, as well as polyoxyethylene propylene glycol fatty acid esters, polyoxyethylene alkylamines, polyoxyethylene fatty acid amides, sucrose fatty acid esters, polyoxyethylene nonylphenyl formaldehyde condensates, alkylethoxydimethylamine oxide, and trioleyl phosphate;

[0083] Examples of silicone surfactants include polyoxyalkylene-modified silicones, polyoxyalkylene / alkyl co-modified silicones, polyglycerin-modified silicones, and polyglycerin / alkyl co-modified silicones, and specific examples include PEG-10 dimethicone, PEG-9 polydimethylsiloxyethyl dimethicone, cetyl PEG / PPG-10 / 1 dimethicone, lauryl PEG-9 polydimethylsiloxyethyl dimethicone, bisbutyl dimethicone polyglyceryl-3, and the like.

[0084] Examples of anionic surfactants include fatty acid soaps such as sodium laurate and sodium palmitate, higher alkyl sulfates such as sodium lauryl sulfate and potassium lauryl sulfate, alkyl ether sulfates such as polyoxyethylene triethanolamine lauryl sulfate and polyoxyethylene sodium lauryl sulfate, N-acyl sarcosinates such as sodium lauroyl sarcosinate, higher fatty acid amide sulfonates such as sodium N-myristoyl-N-methyl taurate, sodium N-stearoyl-N-methyl taurate, sodium coconut oil fatty acid methyl taurate, and sodium lauryl methyl taurate, phosphate salts such as polyoxyethylene oleyl ether sodium phosphate and polyoxyethylene stearyl ether sodium phosphate, sodium di-2-ethylhexyl sulfosuccinate, monolauroyl monoethanolamide polyoxyethylene, and the like. Examples of the surfactant include sulfosuccinates such as sodium diethylene sulfosuccinate and sodium lauryl polypropylene glycol sulfosuccinate; alkylbenzenesulfonates such as sodium linear dodecylbenzenesulfonate and triethanolamine linear dodecylbenzenesulfonate; N-acylglutamates such as monosodium N-lauroylglutamate and disodium N-stearoylglutamate; higher fatty acid ester sulfates such as hydrogenated coconut oil fatty acid glycerin sodium sulfate; as well as polyoxyethylene alkyl ether carboxylates, α-olefin sulfonates, higher fatty acid ester sulfonates, secondary alcohol sulfates, higher fatty acid alkylolamide sulfates, sodium lauroylmonoethanolamide succinate, N-palmitoylaspartic acid, ditriethanolamine, and coconut oil fatty acid collagen hydrolyzed alkali salts.

[0085] Examples of cationic surfactants include alkyltrimethylammonium salts such as stearyltrimethylammonium chloride and lauryltrimethylammonium chloride, dialkyldimethylammonium salts such as distearyldimethylammonium chloride, alkylpyridinium salts such as poly(N,N'-dimethyl-3,5-methylenepiperidinium chloride) and cetylpyridinium chloride, as well as alkyl quaternary ammonium salts, alkyldimethylbenzylammonium salts, alkylisoquinolinium salts, dialkylmorphonium salts, polyoxyethylene alkylamines, alkylamine salts, polyamine fatty acid derivatives, amyl alcohol fatty acid derivatives, benzalkonium chloride, benzethonium chloride, cationic polymers, and β-N-N-dimethyl-N-ethylammonioethyl acrylate vinylpyrrolidone chloride copolymers.

[0086] Examples of amphoteric surfactants include imidazoline-based amphoteric surfactants such as 2-undecyl-N,N,N-(hydroxyethylcarboxymethyl)-2-imidazoline sodium and 2-cocoyl-2-imidazolinium hydroxide-1-carboxyethyloxy disodium salt; and betaine-based amphoteric surfactants such as 2-heptadecyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine, lauryldimethylaminoacetic acid betaine, alkyl betaine, amido betaine, and sulfobetaine.

[0087] Examples of moisturizing agents include 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.

[0088] Examples of thickeners include gum arabic, carrageenan, tragacanth gum, quince seed, casein, sodium caseinate, dextrin, gelatin, sodium alginate, methylcellulose, ethylcellulose, carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, polyvinyl alcohol, sodium polyacrylate, carboxyvinyl polymer, guar gum, magnesium aluminum silicate, bentonite, hectorite, (PEG-240 / decyltetradeceth-20 / HDI) copolymer, stearoxyhydroxypropylmethylcellulose, and hydroxypropylmethylcellulose.

[0089] Examples of polyhydric alcohols include ethylene glycol, propylene glycol, erythritol, trimethylolpropane, pentaerythritol, sorbitol, maltitol, diglycerin, and polyethylene glycol.

[0090] Examples of powder components include inorganic powders such as talc, kaolin, mica, sericite, phlogopite, synthetic mica, magnesium carbonate, calcium carbonate, aluminum silicate, silica, zeolite, barium sulfate, calcined calcium sulfate (calcined gypsum), calcium phosphate, fluorapatite, hydroxyapatite, ceramic powder, metal soap (zinc myristate, calcium palmitate, aluminum stearate, etc.), and boron nitride; organic powders such as polyamide resin powder (nylon powder), polyethylene powder, polymethyl methacrylate powder, polystyrene powder, styrene-acrylic acid copolymer resin powder, polymethylsilsesquioxane powder, and cellulose powder; titanium dioxide, Examples of suitable pigments include inorganic pigments such as zinc oxide, iron oxide (red iron oxide), iron titanate, yellow iron oxide, black iron oxide, carbon black, low-order titanium oxide, mango violet, cobalt violet, chromium oxide, ultramarine, and iron blue; pearl pigments such as titanium oxide-coated mica, titanium oxide-coated bismuth oxychloride, colored titanium oxide-coated mica, bismuth oxychloride, and fish scale foil; metal powder pigments such as aluminum powder; organic pigments such as Red No. 201, Red No. 202, Orange No. 203, Yellow No. 205, Yellow No. 401, and Blue No. 404; organic pigments such as zirconium, barium, and aluminum lake, such as Red No. 3, Yellow No. 4, Green No. 3, and Blue No. 1; and natural pigments such as chlorophyll and β-carotene.

[0091] Examples of synthetic resin emulsions include acrylic resin emulsions and polyvinyl acetate resin emulsions.

[0092] Examples of amino acids include glycine, leucine, phenylalanine, tyrosine, aspartic acid, glutamic acid, sodium glutamate, arginine, histidine, lysine, cystine, cysteine, sodium acyl sarcosine (sodium lauroyl sarcosine), acyl glutamate, glutathione, and pyrrolidone carboxylic acid.

[0093] 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.

[0094] Examples of pH adjusters include buffers such as lactic acid-sodium lactate, citric acid-sodium citrate, and succinic acid-sodium succinate.

[0095] Examples of antioxidants include tocopherols, dibutylhydroxytoluene (BHT), butylhydroxyanisole, and gallic acid esters.

[0096] 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.

[0097] Examples of preservatives include phenoxyethanol, ethylparaben, butylparaben, chlorphenesin, 1,2-alkanediol, phenoxyethanol, and methylchloroisothiozolinone.

[0098] Examples of chelating 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, trisodium ethylenediaminehydroxyethyltriacetate, and disodium ethylenediaminetetraacetate.

[0099] Examples of cosmetic ingredients include retinol and retinol derivatives. Retinol (also known as vitamin A) is a cosmetic ingredient with various physiological effects, and by containing retinol or a retinol derivative, the oil-in-water emulsion composition of the present invention can exhibit effects such as preventing rough skin and improving wrinkles. Retinol can be in the all-trans form or the 13-cis form. Examples of retinol derivatives include retinol acetate (also known as vitamin A acetate) and retinol palmitate (also known as vitamin A palmitate), but are not limited to these.

[0100] Examples of the stabilizer include sodium pyrosulfite, dibutylhydroxytoluene (BHT), and EDTA-2Na.

[0101] In addition to the above-mentioned components, the oil-in-water emulsion composition of the present invention may contain, for example, drugs such as phospholipids, lecithin, lysolecithin, and ceramide; anti-inflammatory agents (for example, glycyrrhizinic acid derivatives, glycyrrhetinic acid derivatives, salicylic acid derivatives, hinokitiol, zinc oxide, and allantoin); whitening agents (for example, saxifrage extract and arbutin); 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, Luffa, Lily, Saffron, Cnidium rhizome, Angelica acutiloba, Garlic, Chili pepper, Citrus fruit, Angelica acutiloba, and Seaweed); and 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.); anti-inflammatory agents (for example, tranexamic acid, thiotaurine, hypotaurine, etc.); aromatic alcohols (benzyl alcohol, benzyloxyethanol, etc.), etc. In addition, drugs such as caffeine, licorice extract, glabridin, hot water extract of fire thorn fruit, various herbal medicines, and tocopherol acetate may also be appropriately contained; other whitening agents such as vitamin C, magnesium ascorbyl phosphate, and ascorbic acid glucoside; and sugars such as glucose, fructose, mannose, sucrose, and trehalose. In particular, when vitamin E esters such as tocopherol acetate are incorporated into the present invention, they have the effect of enhancing the whitening effect of alkoxysalicylic acid and its salts. In addition, fragrances, scrubs, and the like may also be appropriately incorporated within a range that does not impair emulsion stability.

[0102] (Method for Producing Oil-in-Water Emulsion Composition) The oil-in-water emulsion composition of the present invention can be produced according to conventional methods, and the emulsification method is not particularly limited. For example, the composition can be produced by dissolving components (B) and (C) and other oily components at high temperature to prepare an oil part, adding the oil part to a heated aqueous phase part containing components (A), (D), and (E) and an aqueous component, emulsifying by conventional methods, and cooling. The method for producing the oil-in-water emulsion composition of the present invention is not particularly limited as long as it contains components (A) to (E). For example, the composition is preferably produced by adding components (A), (D), and (E) to a mixture of components (B) and (C) and mixing them. When the oil-in-water emulsion composition of the present invention contains a cosmetic ingredient such as retinol or a retinol derivative, it is preferably produced by adding components (A), (D), and (E) to a mixture of components (B) and (C) and retinol or a retinol derivative and mixing them.

[0103] (Uses) The embodiment of the oil-in-water emulsion composition of the present invention is not particularly limited, and the composition can be widely applied to any embodiment that is conventionally used in cosmetics, such as lotion, milky lotion, cream, facial cleanser, makeup remover, gel, essence (beauty serum), pack and other basic cosmetics, lipstick, eye shadow, eye liner, mascara, foundation, makeup base, sunscreen cosmetics, ointment and other makeup cosmetics, oral cosmetics, fragrance cosmetics, hair cosmetics, body cosmetics, etc.

[0104] 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.

[0105] Oil-in-water emulsion compositions of Examples, Reference Examples, and Comparative Examples were prepared according to the formulations shown in Tables 1 and 2, and were evaluated as follows.

[0106]

[0107]

[0108] <Emulsion Stability> The emulsion stability of each oil-in-water emulsion composition sample prepared was evaluated according to the following evaluation criteria. Here, "50°C 4W" refers to the state after storing the container containing each sample in a thermostatic chamber at 50°C for 4 weeks. Oil-in-water emulsion compositions that received an emulsion stability rating of "A" according to the following evaluation criteria were determined to be applicable to the present invention.

[0109] (Evaluation criteria) The appearance of the oil-in-water emulsion composition was visually observed and evaluated according to the following criteria. In the evaluation below, "separation" means that the oil-in-water emulsion composition is separated into an aqueous phase and an oil phase. A: No separation is observed at 50°C and 4W. B: Separation is observed at 50°C and 4W.

[0110] <Usability> A sample of each oil-in-water emulsion composition that was rated "A" for the above <Emulsion stability> was applied to the hands and arms, and a panel of five experts gave a score for usability (non-stickiness) according to the following evaluation criteria.

[0111] (Evaluation criteria) 3 points: Clearly less sticky (excellent usability). 2 points: Normal stickiness (normal usability). 1 point: Clearly sticky (poor usability). Usability was judged according to the following criteria based on the average scores of the five expert panelists. (Evaluation criteria) A: 2.5 points or more B: 2 points or more but less than 2.5 points C: 1 point or more but less than 2 points

[0112] In the Reference Example, which had the same composition as the conventional product, the potassium 4-methoxysalicylate was 1% by mass, so the effect of the thickener was not reduced and the emulsion stability was rated "A," but in Comparative Example 1, which differed from the Reference Example only in the concentration of potassium 4-methoxysalicylate, the potassium 4-methoxysalicylate was at a high concentration of 3% by mass, so the effect of the thickener was reduced and the emulsion stability was rated "B." Note that with the conventional product, when the concentration of potassium 4-methoxysalicylate was 1.5% by mass or higher, the emulsion state of the composition became unstable, and when it was 2% by mass or higher, the aqueous phase and oil phase were prone to separation.

[0113] Although Comparative Example 1 contained carbomer, it did not satisfy any of the requirements (i) to (iii) of the component (E), and Comparative Examples 3, 5 to 7 contained neither carbomer nor carbomer Na, and therefore Comparative Examples 1, 3, 5 to 7 were compositions that did not contain the component (E). Furthermore, Comparative Example 2 was a composition that did not contain the components (B) and (C), and Comparative Example 4 was a composition that did not contain the component (D).

[0114] Comparative Examples 1 to 7 did not satisfy the constitution of the present invention, and because the concentration of potassium 4-methoxysalicylate was high, the effect of the thickener was reduced, and when stored in a constant temperature bath at 50°C for 4 weeks, the emulsion separated into an aqueous phase and an oily phase, and the emulsion stability was poor, rated "B."

[0115] With respect to component (E), Examples 1 to 3 contained carbomer Na, which corresponds to component (E) (i) or (ii), and Example 4 contained succinoglycan, xanthan gum, and carbomer, which corresponds to component (E) (iii). Those skilled in the art who have seen the results of Examples 1 to 4 above can understand, based on knowledge regarding the salt tolerance of carbomer and various thickeners, that a composition containing, in addition to agar, (a) xanthan gum, cellulose gum, (acrylic acid / 2-(perfluorohexyl)ethyl acrylate) crosspolymer, and (acrylic acid / lauryl methacrylate / isodecyl methacrylate) crosspolymer, and (b) carbomer, has emulsion stability comparable to that of the compositions of Examples 1 to 4.

[0116] Examples 1 to 4, which satisfy the constitution of the present invention, contained 4-methoxysalicylic acid potassium salt, which has a whitening effect, at a high concentration of 3% by mass, but all of them were evaluated for emulsion stability as "A." In addition, in the evaluation of usability, Example 1 was rated as "B," indicating a normal feel when used, while Examples 2 to 4, which contained xanthan gum, were rated as "A," indicating less stickiness and an excellent feel when used.

[0117] Furthermore, it is generally known to those skilled in the art that compositions containing 4-methoxysalicylic acid potassium salt and retinol (or a retinol derivative) have lower emulsion stability than compositions containing 4-methoxysalicylic acid potassium salt but not containing retinol (or a retinol derivative), and that it is difficult to find a composition with excellent emulsion stability. However, in Examples 1 to 4, despite containing both 4-methoxysalicylic acid potassium salt and retinol acetate, all of them were rated "A" as excellent in emulsion stability. Therefore, it was demonstrated that the present invention can provide an oil-in-water emulsion composition containing 4-methoxysalicylic acid potassium salt and retinol (or a retinol derivative) and having good emulsion stability.

[0118] The above results demonstrate that the present invention can provide an oil-in-water emulsion composition that exhibits excellent emulsion stability even when containing an alkoxysalicylic acid or a salt thereof at a high concentration of more than 1% by mass. The present invention also demonstrates that the present invention can provide an oil-in-water emulsion composition that contains an alkoxysalicylic acid or a salt thereof and retinol (or a retinol derivative) and exhibits excellent emulsion stability.

[0119] The present invention provides, for example, the following: <1> (A) an alkoxysalicylic acid or a salt thereof represented by general formula (1), (However, in general formula (1), R ａ is an alkyl group having 1 to 6 carbon atoms), (B) at least one selected from the group consisting of polyoxyethylene dialkyl esters and polyoxyethylene dialkyl ethers represented by general formula (2), (However, in general formula (2), R １ and R ２ each independently represents a linear aliphatic acid residue or a linear aliphatic alcohol residue having 16 to 24 carbon atoms, and n represents an integer of 4 to 15. (C) at least one selected from the group consisting of polyoxyethylene alkyl esters and polyoxyethylene alkyl ethers represented by general formula (3), (However, in general formula (3), R ３(wherein n represents a C16 to C24 linear aliphatic residue, a linear aliphatic acid residue, or a linear aliphatic alcohol residue, and n is an integer of 5 to 30), (D) agar, and (E) (i) a carbomer and an alkali agent, (ii) carbomer Na, or (iii) at least one selected from the group consisting of succinoglycan, xanthan gum, cellulose gum, (acrylic acid / 2-(perfluorohexyl)ethyl acrylate) crosspolymer, and (acrylic acid / lauryl methacrylate / isodecyl methacrylate) crosspolymer, and a carbomer, wherein (A) the content of the alkoxysalicylic acid represented by general formula (1) or a salt thereof is more than 1 mass%. <2> The oil-in-water emulsion composition according to <1>, wherein the alkoxysalicylic acid represented by general formula (1) includes 4-methoxysalicylic acid. <3> The oil-in-water emulsion composition according to <1> or <2>, wherein the polyoxyethylene dialkyl ester represented by general formula (2) includes PEG-6 distearate. <4> The oil-in-water emulsion composition according to any one of <1>, <2>, and <3>, wherein the polyoxyethylene alkyl ether represented by general formula (3) includes Beheneth-10. <5> The oil-in-water emulsion composition according to any one of <1>, <2>, <3>, and <4>, further comprising xanthan gum. <6> The oil-in-water emulsion composition according to any one of <1>, <2>, <3>, <4>, and <5>, further comprising retinol or a retinol derivative. <7> The oil-in-water emulsion composition according to any one of <1>, <2>, <3>, <4>, <5>, and <6>, wherein the content of (A) alkoxysalicylic acid represented by general formula (1) or a salt thereof is 2% by mass or more. <8> The oil-in-water emulsion composition according to any one of <1>, <2>, <3>, <4>, <5>, <6>, and <7>, wherein the content of (A) the alkoxysalicylic acid represented by general formula (1) or a salt thereof is 3% by mass or more.

[0120] According to any one of the oil-in-water emulsion compositions <1> to <8> above, the conventional problems can be solved and the object of the present invention can be achieved.

[0121] This application claims priority based on Japanese Patent Application No. 2023-223676, filed with the Japan Patent Office on December 28, 2023, and incorporates the entire contents of said application by reference.

Claims

1. (A) An alkoxysalicylic acid represented by the general formula (1) or a salt thereof, (wherein in the general formula (1), R ａ is an alkyl group having 1 to 6 carbon atoms), (B) at least one selected from the group consisting of a polyoxyethylene dialkyl ester and a polyoxyethylene dialkyl ether represented by the general formula (2), (wherein in the general formula (2), R １ and R ２ are each independently a linear aliphatic acid residue or a linear aliphatic alcohol residue having 16 to 24 carbon atoms, and n represents an integer of 4 to 15). (C) At least one selected from the group consisting of a polyoxyethylene alkyl ester and a polyoxyethylene alkyl ether represented by the general formula (3), (wherein in the general formula (3), R ３ is a linear aliphatic residue, a linear aliphatic acid residue or a linear aliphatic alcohol residue having 16 to 24 carbon atoms, and n represents an integer of 5 to 30). (D) Agar, and (E) (i) a carbomer and an alkali agent, (ii) carbomer Na, or (iii) at least one selected from the group consisting of succinoglycan, xanthan gum, cellulose gum, (acrylic acid / 2-(perfluorohexyl)ethyl acrylate) cross-polymer, and (acrylic acid / lauryl methacrylate / isodecyl methacrylate) cross-polymer and a carbomer, containing, The content of the (A) alkoxysalicylic acid represented by the general formula (1) or a salt thereof is more than 1% by mass, an oil-in-water type emulsified composition.

2. The oil-in-water type emulsion composition according to claim 1, wherein the alkoxysalicylic acid represented by the general formula (1) contains 4-methoxysalicylic acid.

3. The oil-in-water type emulsion composition according to claim 1 or 2, wherein the polyoxyethylene dialkyl ester represented by the general formula (2) contains PEG-6 distearate.

4. The oil-in-water type emulsion composition according to claim 1 or 2, wherein the polyoxyethylene alkyl ether represented by the general formula (3) contains beheneth-10.

5. The oil-in-water type emulsion composition according to claim 1 or 2, further containing xanthan gum.

6. The oil-in-water type emulsion composition according to claim 1 or 2, further containing retinol or a retinol derivative.

7. The oil-in-water type emulsion composition according to claim 1 or 2, wherein the content of the alkoxysalicylic acid represented by the general formula (1) or a salt thereof in (A) is 2% by mass or more.

8. The oil-in-water type emulsion composition according to claim 1 or 2, wherein the content of the alkoxysalicylic acid represented by the general formula (1) or a salt thereof in (A) is 3% by mass or more.

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