JP7661012B2 - Oil-in-water emulsion composition - Google Patents

Description

The present invention relates to an oil-in-water emulsion composition suitable for use in cleansing cosmetics or massage cosmetics.

In oil-in-water emulsion compositions, oil-soluble and water-soluble components can be applied at the same time, and because the external phase is an aqueous phase, a composition that is light to use and has an excellent feel to the touch can be obtained. Among these oil-in-water emulsion compositions, high internal phase oil-in-water emulsion compositions have a higher content of the oil phase, which is the internal phase, compared to normal oil-in-water emulsion compositions, and are therefore used in massage cosmetics, skin care or hair care cosmetics, cleansing cosmetics, and the like. However, with such high internal phase oil-in-water emulsion compositions, it is difficult to reverse to oil, which is the indicator for the end of rubbing, and the reversal is difficult to detect, which may cause a burden on the skin due to rubbing, and there has been a demand for improvements in the ease of detecting the reversal.

On the other hand, it is known that acrylic acid/sodium acryloyldimethyltaurate copolymers and the like are used as thickeners in oil-in-water emulsion compositions (Patent Documents 1 and 2). However, their use in high internal phase oil-in-water emulsion compositions is not known.

JP 2013-028542 A JP 2019-137611 A

The present invention was made to address the above-mentioned issues, and aims to provide a cleansing cosmetic or massage cosmetic that improves the ease of understanding of reversal.

The present inventors have conducted studies to solve the above problems and have found that by blending a high internal phase oil-in-water emulsion composition with a hydrogel-forming polymer consisting of one or more types selected from a polymer containing at least a monomer derived from acryloyldimethyltaurine or a salt thereof and a polysaccharide, a cleansing cosmetic or massage cosmetic with improved ease of reversal can be obtained, thereby completing the present invention.
That is, the gist of the present invention relates to the following.

[1] a surfactant,
An oil phase component in an amount of 30% by mass or more based on the total composition;
Aqueous phase components, and
A hydrogel-forming polymer comprising one or more polymers selected from the group consisting of a polymer containing at least a monomer derived from acryloyldimethyltaurine or a salt thereof, and a polysaccharide;
An oil-in-water emulsion composition comprising:
[2] The oil-in-water emulsion composition according to [1], wherein the polymer containing at least a monomer derived from acryloyldimethyltaurine or a salt thereof includes one or more selected from the group consisting of a copolymer of a (meth)acrylate salt and an acryloyldimethyltaurine salt, and a copolymer of a (meth)acrylic acid ester and an acryloyldimethyltaurine salt.
[3] The oil-in-water emulsion composition according to [1] or [2], wherein the polymer containing at least a monomer derived from acryloyldimethyltaurine or a salt thereof includes one or more selected from the group consisting of (sodium acrylate/sodium acryloyldimethyltaurate) copolymer and (hydroxyethyl acrylate/sodium acryloyldimethyltaurate) copolymer.
[4] The oil-in-water emulsion composition according to any one of [1] to [3], wherein the polysaccharide comprises one or more selected from agar, agarose, alginic acid, celluloses, dextrans, glycosaminoglycans, chitins, chitosans, and salts thereof.
[5] The oil-in-water emulsion composition according to any one of [1] to [4], wherein the polysaccharide comprises one or more selected from the group consisting of agar and sodium alginate.

[6] The oil-in-water emulsion composition according to any one of [1] to [5], wherein the content of the hydrogel-forming polymer is 0.01 to 5% by mass based on the total mass of the composition.
[7] The oil-in-water emulsion composition according to any one of [1] to [6], wherein the content of the oil phase component constituting the internal phase of the oil-in-water emulsion composition is 30 to 90 mass% based on the total mass of the composition.
[8] A composition comprising a first surfactant and a second surfactant as surfactants,
The oil-in-water emulsion composition according to any one of [1] to [7], wherein the first surfactant forms an L _α phase in at least one aqueous solution containing 40 to 80% by mass, and the second surfactant forms an H ₁ phase in at least one aqueous solution containing 40 to 80% by mass.
[9] The oil-in-water emulsion composition according to [8], wherein the first surfactant comprises one or more selected from surfactin and a salt thereof, mannosylerythritol lipid, polyglycerol fatty acid ester, sophorolipid, polyoxyethylene fatty acid glyceryl, difatty acid polyethylene glycol, and phospholipid.
[10] The oil-in-water emulsion composition according to [8] or [9], wherein the second surfactant comprises one or more selected from the group consisting of an alkyl glycoside represented by the following general formula (1), an acylamino acid lysine and/or a salt thereof, a sucrose fatty acid ester, a polyglycerol alkyl ether, a fatty acid glycoside, and a monoalkyl phosphate ester and a salt thereof:

(In the formula, G represents a sugar residue, R independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and n represents an integer of 1 to 4.)
[11] The oil-in-water emulsion composition according to any one of [8] to [10], wherein the content of the first surfactant is 0.1 to 5% by mass based on the total mass of the composition.
[12] The oil-in-water emulsion composition according to any one of [8] to [11], wherein the content of the second surfactant is 0.1 to 5% by mass based on the total mass of the composition.
[13] The oil-in-water emulsion composition according to any one of [8] to [12], wherein the total content of the first surfactant and the second surfactant is 0.2 to 8% by mass based on the total composition. [14] The oil-in-water emulsion composition according to [1] to [13], wherein the total content of the first surfactant and the second surfactant is 0.2 to 8% by mass based on the total composition.
3. The oil-in-water emulsion composition according to any one of the preceding items.
[15] The oil-in-water emulsion composition according to any one of [1] to [14], wherein the oil-in-water emulsion composition is a skin topical preparation.

[16] The oil-in-water emulsion composition according to [15], wherein the topical skin preparation is a cosmetic.
[17] The oil-in-water emulsion composition according to [16], wherein the cosmetic is a cleansing cosmetic or a massage cosmetic.

According to the present invention, it is possible to provide a cleansing cosmetic or a massage cosmetic in which the ease of reversal is improved.
In this specification, the "inversion" feeling refers to the feeling when the oil phase and the water phase of an oil-in-water emulsion type are inverted and change into an oil-like state. If the inversion is good and easy to notice, the user can enjoy the feeling of the change and can obtain a comfortable usability with a melting, light, frictionless feel.

The present invention will now be described.
<Oil-in-water emulsion composition>
One aspect of the present invention relates to an oil-in-water emulsion composition (hereinafter, sometimes referred to as the "oil-in-water emulsion composition of the present invention") containing a surfactant, an oil phase component in an amount of 30% by mass or more relative to the total composition, an aqueous phase component, and a hydrogel-forming polymer comprising one or more types selected from a polymer containing at least a monomer derived from acryloyldimethyltaurine or a salt thereof, and a polysaccharide.

High internal phase oil-in-water emulsion compositions generally have a hard interface and are difficult to invert, which poses the problem that inversion is difficult to detect.
The present inventors have conducted various studies in search of an oil-in-water emulsion composition with improved ease of understanding of inversion. In the course of the studies, they have found that the ease of understanding of inversion can be improved by blending a high internal phase oil-in-water emulsion composition with a hydrogel-forming polymer consisting of at least one polymer containing a monomer derived from acryloyldimethyltaurine or a salt thereof, and at least one selected from polysaccharides, and have thus completed the present invention.

<Hydrogel-forming polymer>
The hydrogel-forming polymer contained in the oil-in-water emulsion composition of the present invention can improve the clarity of inversion of the oil-in-water emulsion composition of the present invention. One or more types of hydrogel-forming polymers can be used.

Specifically, the hydrogel-forming polymer is a hydrogel-forming polymer that is composed of one or more types selected from a polymer that contains at least a monomer derived from acryloyldimethyltaurine or a salt thereof, and a polysaccharide.

<Polymer containing at least a monomer derived from acryloyldimethyltaurine or a salt thereof>
The polymer containing at least a monomer derived from acryloyldimethyltaurine or a salt thereof contained in the oil-in-water emulsion composition of the present invention can improve the clarity of inversion of the oil-in-water emulsion composition of the present invention. One or more types of polymer containing at least a monomer derived from acryloyldimethyltaurine or a salt thereof can be used.

The acryloyldimethyltaurine or its salt in the monomer derived from acryloyldimethyltaurine or its salt is not limited, but may be acryloyldimethyltaurine, sodium acryloyldimethyltaurine, potassium acryloyldimethyltaurine, etc., and is preferably sodium acryloyldimethyltaurine. The polymer containing at least a monomer derived from acryloyldimethyltaurine or its salt may be a copolymer containing a monomer component other than the monomer derived from acryloyldimethyltaurine or its salt.

Monomer components other than monomers derived from acryloyldimethyltaurine or its salts include, but are not limited to, (meth)acrylic acid monomers such as acrylic acid; (meth)acrylate monomers such as sodium acrylate; acrylic acid ester monomers such as hydroxyethyl acrylate; and acrylamide monomers such as dimethylacrylamide.

Examples of the polymer containing at least a monomer derived from acryloyldimethyltaurine or its salt include, but are not limited to, copolymers of (meth)acrylic acid and acryloyldimethyltaurine or its salt, copolymers of (meth)acrylic acid salts and acryloyldimethyltaurine or its salt, copolymers of (meth)acrylic acid esters and acryloyldimethyltaurine or its salt, copolymers of acrylamides and acryloyldimethyltaurine or its salt, copolymers of (meth)acrylic acid, (meth)acrylic acid salts, acrylamides and acryloyldimethyltaurine or its salt, copolymers of (meth)acrylic acid salts, acrylamides and acryloyldimethyltaurine or its salt, etc. Among these, copolymers of (meth)acrylic acid salts and acryloyldimethyltaurine salts, and copolymers of (meth)acrylic acid esters and acryloyldimethyltaurine salts are preferred. Specifically, for example, compounds such as (sodium acrylate/sodium acryloyldimethyltaurate) copolymer and (hydroxyethyl acrylate/sodium acryloyldimethyltaurate) copolymer are preferable.

As the polymer containing at least a monomer derived from acryloyldimethyltaurine or a salt thereof, those used as thickeners in cosmetics can be used.
As the polymer containing at least a monomer derived from acryloyldimethyltaurine or a salt thereof, a commercially available product or the like can be used.

<Polysaccharides>
The polysaccharide contained in the oil-in-water emulsion composition of the present invention can improve the clarity of inversion of the oil-in-water emulsion composition of the present invention. One type of polysaccharide can be used, or two or more types can be used.

Examples of polysaccharides include, but are not limited to, agar, agarose, alginic acid, celluloses (cellulose, carboxymethylcellulose, etc.), dextrans (dextran, carboxymethyldextran, etc.), glycosaminoglycans (chondroitin sulfate, hyaluronic acid, etc.), chitins (chitin, deacetylated chitin, etc.), chitosans (chitosan, deacetylated chitosan, etc.), and salts thereof. Among these, agar and alginates are preferred. Examples of salts include alkali metal salts such as sodium and potassium, and alkaline earth metal salts such as magnesium and calcium.

As the polysaccharide, those used as thickeners in cosmetics can be used.
The polysaccharides used may be those produced according to a conventional method or commercially available products.

In this embodiment, the content of the hydrogel-forming polymer is preferably 0.01 to 5% by mass, more preferably 0.05 to 3% by mass, and even more preferably 0.1 to 2% by mass, based on the total mass of the composition. From the viewpoint of sufficient inversion, the above ranges are preferred.
The hydrogel-forming polymer may have a weight-average molecular weight of, for example, about 100 to 10,000,000. The molecular weight of the hydrogel-forming polymer is determined by gel permeation chromatography (GPC).

<Surfactants>
The surfactant contained in the oil-in-water emulsion composition of the present invention is not particularly limited in type, etc., as long as it can emulsify the composition. Examples of the surfactant include anionic surfactants such as fatty acid soaps (sodium laurate, sodium palmitate, etc.), potassium lauryl sulfate, and alkyl sulfate triethanolamine ethers, cationic surfactants such as stearyl trimethylammonium chloride, benzalkonium chloride, and laurylamine oxide, imidazoline-based amphoteric surfactants (2-cocoyl-2-imidazolinium hydroxide-1-carboxyethyloxy disodium salt, etc.), amphoteric surfactants such as acylmethyltaurine, sorbitan fatty acid esters (sorbitan monostearate, sorbitan monooleate, sorbitan sesquioleate, etc.), glycerin fatty acids (glycerin monostearate, etc.), polyglycerin fatty acids (polyglyceryl-2 tetraoleate, etc.), propylene glycol fatty acid esters (propylene glycol monostearate, etc.), hydrogenated castor oil derivatives, glycerin alkyl ethers, Examples of the surfactant include POE sorbitan fatty acid esters (POE sorbitan monooleate, polyoxyethylene sorbitan monostearate, etc.), POE sorbitol fatty acid esters (POE-sorbitol monolaurate, etc.), POE glycerin fatty acid esters (POE-glycerin monoisostearate, etc.), POE fatty acid esters (polyethylene glycol monooleate, POE stearate, POE isostearate, POE distearate, etc.), POE alkyl ethers (POE 2-octyldodecyl ether, etc.), POE alkyl phenyl ethers (POE nonylphenyl ether, etc.), Pluronic types, POE-POP alkyl ethers (POE-POP 2-decyltetradecyl ether, etc.), Tetronics, POE castor oil-hydrogenated castor oil derivatives (POE castor oil, POE hydrogenated castor oil, etc.), sucrose fatty acid esters, nonionic surfactants such as alkyl glucosides, etc.
One or more types of surfactants may be used in the present invention.
These surfactants may be added in an amount necessary to maintain emulsification, which is usually 0.01% by mass or more, preferably 0.05% by mass or more, more preferably 0.1% by mass or more, and usually 30% by mass or less, preferably 10% by mass or less, more preferably 5% by mass or less.
Such an oil-in-water emulsion composition can be produced based on a conventionally known method for producing an oil-in-water emulsion composition.

Another aspect of the present invention relates to an oil-in-water emulsion composition comprising a first surfactant and a second surfactant, the first surfactant forming an L _α phase in at least one aqueous solution having a concentration of 40 to 80% by mass, and the second surfactant forming an H ₁ phase in at least one aqueous solution having a concentration of 40 to 80% by mass. Such an oil-in-water emulsion composition has an emulsion backbone capable of emulsifying various oils, has excellent stability over time and at temperature, and exhibits a good feeling when used, and therefore can be preferably used in the present invention.

Such an oil-in-water emulsion composition can be produced, for example, by a production method including a step of mixing a first surfactant, a second surfactant, and water to form an intermediate phase, a step of adding an oil phase component to the intermediate phase, and a step of further adding an aqueous phase component. Such a production method can be carried out using a conventionally known production method. For example, it can be carried out using the method described in WO 2017/104734.

(L: First surfactant capable of forming _{an α-} phase)
The first surfactant in the present invention preferably contains one or more selected from surfactin and its salts, mannosylerythritol lipid, polyglycerol fatty acid ester, sophorolipid, polyoxyethylene fatty acid glyceryl, difatty acid polyethylene glycol, and phospholipid.

The surfactin that can be used as the first surfactant is a biosurfactant having a cyclic peptide. The surfactin is not limited as long as it exhibits the effects of the present invention, and any known surfactin can be used. The surfactin may be a cyclic peptide produced by Bacillus subtilis natto. Examples of the cyclic peptide include 2-Deamino-3-(10-methylundecyl)-cyclo[L-Ser*-L-Glu-L-Leu-D-Leu-L-Val-L-Asp-D-Leu-L-Leu-] (* indicates an optically active site). In addition, examples of the cyclic peptide include those in which the hydrocarbon chain is a C9-18 alkyl group, and those in which the terminal L-Leu- of the cyclic peptide is selected from leucine, isoleucine, and valine.
The salt of surfactin is not limited to, but may be a lithium salt, a sodium salt, a potassium salt, etc., and the sodium salt may be preferably used in the present invention. One or more types selected from surfactin and its salts may be used in the present invention.
Surfactin and its salts may be natural products extracted and purified from bacteria or the like, or chemically synthesized products, or commercially available products (manufactured by Kaneka Corporation or the like) may be used.

Mannosylerythritol lipid (MEL), which can be used as the first surfactant, can also be used as the first surfactant.
It is a biosurfactant, and any of MEL-A, B, C and D can be used in the present invention, with MEL-B being particularly preferred.

The polyglycerol fatty acid ester that can be used as the first surfactant is an ester of a branched or straight chain, saturated or unsaturated fatty acid and glycerin, and the number of carbon atoms of the fatty acid is preferably 8 to 20, more preferably 12 to 18. The degree of polymerization of glycerin is preferably 2 to 10, more preferably 4 to 10, and even more preferably 4 to 6. The number of fatty acids added is not particularly limited, and may be mono-, di-, tri-, or higher, but monoesters are preferred. The HLB value of the first surfactant is not particularly limited, but is preferably 3 to 18. In this specification, the HLB value refers to a value calculated from Griffin's formula.
Furthermore, in order to easily form the _Lα phase, that is, to easily arrange on a plate due to the polarity of the molecules, it is preferable that the critical packing parameter (CPP), which represents the geometric ratio of the hydrophilic part and the hydrophobic part of the amphiphilic substance, is 1/2 to 1.
Preferred examples of polyglycerin fatty acid esters include polyglyceryl monooleate, polyglyceryl monolaurate, polyglyceryl monopalmitate, polyglyceryl monoisostearate, and polyglyceryl dilaurate. More preferred examples include polyglyceryl monooleate (polyglyceryl monooleate-5, etc.), polyglyceryl monolaurate (polyglyceryl monolaurate-4, polyglyceryl monolaurate-6, polyglyceryl monolaurate-10, etc.), and polyglyceryl monopalmitate (polyglyceryl monopalmitate-6, etc.) having a glycerin polymerization degree of 4 to 10. Further preferred examples include polyglyceryl monolaurate (polyglyceryl monolaurate-4, polyglyceryl monolaurate-6) having a glycerin polymerization degree of 4 to 6.

Sophorolipids are so-called biosurfactants, and refer to glycolipids consisting of sophorose or sophorose with some of the hydroxyl groups acetylated, and hydroxyl fatty acids. In general, sophorolipids exist in the form of a mixture of molecules with lactone rings (lactone type) and molecules in which the ring is opened (acid type). In the present invention, either type is acceptable, and the mixing ratio is not particularly important.

The fatty acid constituting the polyoxyethylene fatty acid glyceryl that can be used as the first surfactant is preferably a branched or linear, saturated or unsaturated fatty acid having 8 to 20 carbon atoms, more preferably a branched fatty acid having 18 carbon atoms. The average number of moles of oxyethylene added in the polyoxyethylene group is preferably 5 to 30, more preferably 10 to 25. The fatty acid residue may be added to only one of the three hydroxyl groups of the glyceryl group to which polyoxyethylene is added, or may be added to two or three of the three hydroxyl groups. A structure with three added groups is preferred, but a structure containing two or more types selected from a mono-adduct, a di-adduct and a tri-adduct is also preferred. These may be commercially available products.

The fatty acid constituting the difatty acid polyethylene glycol that can be used as the first surfactant is preferably a branched or linear, saturated or unsaturated fatty acid having 8 to 20 carbon atoms, more preferably a branched fatty acid having 18 carbon atoms. The average number of moles of ethylene oxide added is preferably 3 to 60, more preferably 5 to 30, and even more preferably 10 to 15. Commercially available products can also be used.
These may be used alone or in combination of two or more.

Examples of phospholipids that can be used as the first surfactant include glycerophospholipids and sphingophospholipids.
Glycerophospholipids are substances having a glycerophosphate skeleton and have fatty acid esters, long-chain alkyl ethers, vinyl ethers, etc. as lipophilic groups. Specific examples include phosphatidylcholine (lecithin), phosphatidylethanolamine, phosphatidylserine, phosphadiylinositol, phosphatidylinositol polyphosphate, phosphatidylglycerol, diphosphatidylglycerol (cardiolipin), phosphatidic acid, lysophosphatidylcholine, lysophosphatidylethanolamine, lysophosphatidylserine, lysophosphatidylinositol, lysophosphatidylglycerol, lysophosphatidic acid, etc.
Sphingophospholipids have a long-chain base such as sphingosine or phytosphingosine, or a long-chain fatty acid, and a phosphoric acid or a phosphonic acid. Specific examples include ceramide 1-phosphate derivatives (sphingomyelin, etc.) and ceramide 1-phosphonic acid derivatives (ceramide aminoethylphosphonic acid, etc.).
In the present invention, the phospholipid may be a natural product extracted and purified from animals and plants, a chemically synthesized product, or a product processed by hydrogenation, hydroxylation, etc. For example, hydrogenated lecithin is preferred. As a natural product, lecithin extracted and purified from soybeans or egg yolk is preferred because it is easily available commercially.

In a more preferred embodiment of the present invention, the first surfactant does not have an ethylene oxide (EO) group.

(Second surfactant capable of forming _H1 phase)
The second surfactant in the present invention preferably contains one or more selected from alkyl glycosides represented by the following general formula (1), acylamino acid lysine and/or a salt thereof, sucrose fatty acid esters, polyglycerin alkyl ethers, fatty acid glycosides, and monoalkyl phosphate esters and salts thereof, and more preferably alkyl glycosides represented by the following general formula (1):

(In the formula, G represents a sugar residue, R independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and n represents an integer from 1 to 4.)

The acylamino acid lysine and/or a salt thereof that can be used as the second surfactant is preferably diacylglutamic acid lysine in which the acyl group is derived from a fatty acid, and more preferably includes dilauroylglutamic acid lysine, dimyristoylglutamic acid lysine, distearoylglutamic acid lysine, dilinoleoylglutamic acid lysine, and the like.
Examples of these salts include alkali metal salts such as sodium salts and potassium salts, organic amine salts such as triethanolamine salts, and basic amino acid salts such as arginine salts.
These can be obtained by a synthetic reaction between lysine hydrochloride and an acylamino acid anhydride, or commercially available products can be used.

Sucrose fatty acid esters that can be used as the second surfactant preferably include sucrose laurate, sucrose myristic acid ester, sucrose palmitate, sucrose stearate, and sucrose oleate, with sucrose laurate being more preferred. Commercially available products can also be used.

Preferably, polyglycerol alkyl ethers that can be used as the second surfactant include polyglycerol monolauryl ether, polyglycerol monomyristyl ether, polyglycerol monopalmityl ether, polyglycerol monostearyl ether, polyglycerol monoisostearyl ether, and polyglycerol monooleyl ether, with polyglycerol monolauryl ether being more preferable. The degree of glycerol polymerization in the polyglycerol alkyl ether is preferably 2 to 10, more preferably 3 to 6, and even more preferably 4. Commercially available products can also be used.

The alkyl glycoside represented by the general formula (1) which can be used as the second surfactant has a structure in which a sugar residue G is condensed with an aliphatic alcohol.
The sugar residue G is the hydrophilic portion of the alkyl glycoside represented by the general formula (1) and is a residue of a monosaccharide or polysaccharide.
Preferred monosaccharides include glucose, galactose, xylose, mannose, lyxose, arabinose, and fructose. The polysaccharides are preferably disaccharides to heptasaccharides, including maltose, xylobiose, isomaltose, cellobiose, lactose, gentiobiose, maltotriose, isomaltotriose, cellotriose, maltotetraose, maltopentaose, maltohexaose, maltoheptaose, isomaltotetraose, isomaltopentaose, isomaltohexaose, and isomaltoheptase. Among these saccharides, glucose, galactose, maltose, and maltotriose are more preferred, and maltose and maltotriose are particularly preferred. The sugar residue may be either α- or β-isomer.
In general formula (1), the sugar residue G is preferably bonded (condensed) with an aliphatic alcohol via the 1-position hydroxyl group of the terminal sugar.

In general formula (1), the fatty chain is the hydrophobic portion of the alkyl glycoside represented by general formula (1).
The aliphatic chain portion may or may not have a branched chain, but preferably has a branched chain. That is, in general formula (1), R independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, preferably an alkyl group having 1 to 3 carbon atoms, and more preferably a methyl group.

As the alkyl glycoside represented by the general formula (1), a compound represented by the following general formula (2) is more preferable.
In general formula (2), N represents an integer of 1 to 7. R independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, more preferably a methyl group. n represents an integer of 1 to 4, more preferably 2 or 3.
Specific examples of alkyl glycosides represented by general formula (2) include the glycoside of maltose and hexahydrofarnesol (Mal ₂ Far) (N=2, n=2, R=methyl), the glycoside of maltotriose and hexahydrofarnesol (Mal ₃ Far) (N=3, n=2, R=methyl), and the glycoside of maltotriose and dihydrophytol (Mal ₃ Phyt) (N=3, n=3, R=methyl).

The alkyl glycoside represented by the general formula (1) can be obtained by various well-known methods, such as glycosylation using sugar bromide, glycosylation using sugar fluoride, glycosylation using trichloroacetimidate, glycosylation using acetylated sugar, etc. More specifically, the synthesis processes described in Japanese Patent No. 3882067, Japanese Patent No. 4817435, Japanese Patent No. 5207420, Japanese Patent Publication No. 2013-129660, Japanese Patent Publication No. 2012-17318, etc. can be mentioned.

In recent years, in consideration of safety and the burden on the environment, there has been a trend toward so-called natural surfactants, which are renewable and have a small environmental burden, rather than the conventional synthetic surfactants derived from petroleum raw materials. Therefore, in the present invention, it is particularly preferable to use an alkyl glycoside represented by general formula (1) as the second surfactant in order to meet the above demand, but the present invention is not limited to this.

The fatty acid glycoside usable as the second surfactant is preferably an ester of a branched or linear, saturated or unsaturated fatty acid having 10 to 16 carbon atoms with a residue of a monosaccharide or polysaccharide, and the sugar residue is preferably one in which the hydroxyl group at the 1-position of the terminal sugar is bonded to the fatty acid (ester condensation). More preferably, the fatty acid glycoside has an HLB value of 12 to 18.
Preferred monosaccharides include glucose, galactose, xylose, mannose, lyxose, arabinose, and fructose. The polysaccharides are preferably disaccharides to heptasaccharides, and include maltose, xylobiose, isomaltose, cellobiose, lactose, gentiobiose, maltotriose, isomaltotriose, cellotriose, maltotetraose, maltopentaose, maltohexaose, maltoheptaose, isomaltotetraose, isomaltopentaose, isomaltohexaose, and isomaltoheptase. Among these saccharides, glucose, galactose, maltose, and maltotriose are more preferred, and maltose and maltotriose are even more preferred. The sugar residue may be either α- or β-isomer.
Preferred examples of fatty acid glycosides include lauroyl maltoside, nonanoyl maltoside, undecanoyl maltoside, tridecanoyl maltoside, tetradecanoyl maltoside, and the like.

As the monoalkyl phosphate ester and its salt that can be used as the second surfactant, an ester of a branched or linear, saturated or unsaturated fatty chain having preferably 8 to 20 carbon atoms, more preferably 12 to 18 carbon atoms, and further preferably 12 carbon atoms, and phosphoric acid is preferred. Examples of the salt include sodium salt, potassium salt, ammonium salt, monoethanolammonium salt, diethanolammonium salt, triethanolammonium salt, and arginine salt, of which arginine salt is preferred. Ethylene oxide may be added, but it is preferable that it is not added.

In a more preferred embodiment of the present invention, the second surfactant does not have an ethylene oxide (EO) group.

In this embodiment, the content of the first surfactant is preferably 0.1 to 5% by mass, more preferably 0.1 to 3% by mass, and even more preferably 0.3 to 2% by mass, based on the total mass of the composition. In addition, the content of the second surfactant is preferably 0.1 to 5% by mass, more preferably 0.1 to 3% by mass, and even more preferably 0.3 to 2% by mass, based on the total mass of the composition.
The content is preferably up to 5% by mass, more preferably 0.1 to 3% by mass, and even more preferably 0.3 to 2% by mass.

The total content of the first and second surfactants is preferably 0.2 to 8% by mass, more preferably 0.2 to 6% by mass, and even more preferably 0.6 to 4% by mass, based on the total composition. From the viewpoint of emulsion stability, 0.2% by mass or more is preferred, and from the viewpoint of the coating feel when the produced composition is applied to the skin, 8% by mass or less is preferred.

In addition, the mass ratio of the first surfactant to the second surfactant used in this embodiment is preferably 2:8 to 8:2, and more preferably 4:6 to 8:2. By combining two surfactants with different properties in such a mass ratio, it becomes easier to form a specific intermediate phase, which makes it easier to carry out the subsequent emulsification.

<Oily phase components>
The oil-in-water emulsion composition of the present invention contains an oil phase component that constitutes the internal phase of the oil-in-water emulsion composition.
The oil phase component is usually composed of an oil-based component, and in the present invention, the oil-based component is not limited to so-called oil agents, but refers to a component (excluding surfactants) that undergoes phase separation from water after being suspended in water at 25 to 65°C and left to stand for 1 hour. One type of oil phase component or a combination of two or more types may be used in the present invention.

The oily components that can be incorporated into the oil-in-water emulsion composition of the present invention include oils such as polar oils, natural oils, hydrocarbon oils, silicone oils with no polarity, silicone oils with polarity, UV protection agents such as UV absorbers and UV scattering agents, and oil-soluble vitamins such as vitamins A and E (tocopherol). The oily components can be used in the present invention in one or more combinations. Among these, it is preferable to use polar oils, especially low molecular weight polar oils, and when the oily components are contained in an amount of preferably 50% by mass or more, more preferably 70% by mass or more, and even more preferably 90% by mass or more of the oil phase components, the composition can be given a refreshing feeling of use.

Polar oils include synthetic ester oils such as isopropyl myristate, cetyl octanoate, octyldodecyl myristate, isopropyl palmitate, ethylhexyl palmitate, butyl stearate, hexyl laurate, myristyl myristate, decyl oleate, hexyldecyl dimethyloctanoate, cetyl lactate, myristyl lactate, lanolin acetate, isocetyl stearate, isocetyl isostearate, ethyl isostearate, cholesteryl 12-hydroxystearate, di-2-ethylhexyl Examples of the monomers include ethylene glycol silate, dipentaerythritol fatty acid ester, N-alkyl glycol monoisostearate, neopentyl glycol dicaprate, diisostearyl malate, glyceryl di-2-heptylundecanoate, trimethylolpropane tri-2-ethylhexylate, trimethylolpropane triisostearate, pentaneerythritol tetra-2-ethylhexylate, glyceryl tri-2-ethylhexylate, and trimethylolpropane triisostearate.
Further examples include cetyl 2-ethylhexanoate, 2-ethylhexyl palmitate, glyceryl trimyristate, tri-2-heptylundecanoic acid glyceride, castor oil fatty acid methyl ester, oleic acid oil, cetostearyl alcohol, 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, and octyl methoxycinnamate.
Examples of low molecular weight polar oils include those having a molecular weight of about 300 or less, and although not limited thereto, specific examples include isopropyl myristate, isopropyl palmitate, and diisopropyl sebacate.

Natural oils 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, sasanqua 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, glyceryl trioctanoate, glyceryl triisopalmitate, and tri(caprylic acid/capric acid)glyceryl.

Examples of hydrocarbon oils include isododecane, isohexadecane, squalane, petrolatum, hydrogenated poly(C6-12 olefin), hydrogenated polyisobutene, mineral oil, etc.

Non-polar silicone oils include cyclopentasiloxane, decamethylcyclopentasiloxane, caprylyl methicone, dimethicone, and the like.
Examples of polar silicone oils include diphenylsiloxyphenyl trimethicone.

In the present invention, the content of the oil phase component is 30% by mass or more relative to the entire composition. The content of the oil phase component may be more than 30% by mass, 40% by mass or more, 40% by mass or more, 50% by mass or more, 50% by mass or more, 60% by mass or more, 70% by mass or more, 70% by mass or more, 75% by mass or more, 80% by mass or more, 80% by mass or more, 85% by mass or more, or more than 85% by mass, or 90% by mass or less, 85% by mass or less, 80% by mass or less, 75% by mass or less, or 70% by mass or less, or a combination thereof that is not contradictory. The content of the oil phase component may be, for example, 30 to 90% by mass, 40 to 80% by mass, or 50 to 70% by mass.
By the content of the oil phase component being within such a range, a composition excellent in stability over time and temperature can be obtained, and a good feeling of use can be obtained, and in particular, since the ratio of the oil phase to the water phase (internal phase ratio) in the oil-in-water emulsion composition is large, it can exhibit favorable effects as a skin external preparation such as a cleansing cosmetic or a massage cosmetic. In addition, for example, by emulsifying a polar oil, particularly a low molecular weight polar oil, at a high internal phase ratio, a skin external preparation that has both a refreshing feeling and sufficient moisturizing properties can be obtained.

<Aqueous phase components>
The oil-in-water emulsion composition of the present invention contains an aqueous phase component that constitutes the external phase of the oil-in-water emulsion composition.
The aqueous phase components are usually water-soluble components other than water, and refer to components (excluding surfactants) that dissolve in water after being suspended in water at 25 to 65° C. and left to stand for 1 hour. The aqueous phase components may be used in the present invention alone or in combination of two or more.

<Other ingredients>
Furthermore, the oil-in-water emulsion composition of the present invention may contain other optional components as long as the effects of the composition are not impaired.
The optional components are not particularly limited as long as they are components that can be normally incorporated into skin external preparations, and include lower and higher alcohols, polyhydric alcohols, various active ingredients, moisturizers, pH adjusters, thickeners other than essential ingredients, preservatives, powders, organically modified clay minerals, antibacterial agents, etc. Preferred examples of antibacterial agents include natural antibacterial substances such as caprylyl glycol, glyceryl caprylate, ethylhexylglycerin, and caprylhydroxamic acid. The optional components may be used in the present invention alone or in combination of two or more.
The active ingredient may be a moisturizing ingredient, a whitening ingredient, an anti-wrinkle ingredient, an anti-inflammatory ingredient, an extract derived from an animal or plant, and the like. Only one kind may be contained, or two or more kinds may be contained.

Among the above optional components, it is particularly preferable to contain a polyhydric alcohol, which enhances the ability of the intermediate phase to hold and retain the oil phase components, thereby improving the emulsion stability of the composition.
In the present invention, the content of the polyhydric alcohol is preferably 1 to 30% by mass, more preferably 1 to 20% by mass, and even more preferably 1 to 15% by mass, based on the total mass of the composition.
From the viewpoint of sufficiently retaining the oil phase components in the intermediate phase, the polyhydric alcohol content is preferably 1% by mass or more, and from the viewpoint of easily obtaining a refreshing feeling when applied to the skin, the content is preferably 30% by mass or less.

The polyhydric alcohol is not particularly limited as long as it is dihydric or higher, but trihydric or higher alcohols are preferred.
Specifically, dihydric alcohols (e.g., ethylene glycol, propylene glycol, trimethylene glycol, 1,2-butylene glycol, 1,3-butylene glycol (BG), 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, polypropylene glycol, tetraethylene glycol, diglycerin, polyethylene glycol, triglycerin, tetraglycerin, polyglycerin, 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 monoethyl ether acetate, 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, maltotriose, mannitol, sucrose, erythritol, glucose, fructose, starch decomposition sugar, maltose, xylitose, starch decomposition sugar reduced alcohols, etc.); glycerin solids; 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, etc.
Of these, 1,3-butylene glycol, glycerin, diglycerin, dipropylene glycol, and polyethylene glycols having a molecular weight of 600 or less are more preferable, and 1,3-butylene glycol and glycerin are particularly preferable.

These optional components can be added at any step in the present invention or before or after the step. For example, depending on the solubility of the optional components in water, they can be added to the system as oil phase components or aqueous phase components in the step of adding the oil phase components or the step of adding the aqueous phase components, or they can be added to the system before or after the step of adding the oil phase components or the step of adding the aqueous phase components.

<External skin preparations and cosmetics>
The oil-in-water emulsion composition of the present invention is a high internal phase oil-in-water emulsion composition, and is a composition that improves the clarity of inversion. In particular, if the oil-in-water emulsion composition is made by an emulsification method such as liquid crystal emulsification method, D phase emulsification method, or phase inversion temperature emulsification method, fine emulsion particles are stably dispersed, so that it has excellent stability over time and temperature. In addition, when applied to the skin, it does not produce a film feeling and has a refreshing feeling, so it exhibits a good feeling of use.
Therefore, the oil-in-water emulsion composition of the present invention can be preferably used as a skin external preparation. In particular, cosmetics (including quasi-drugs) are preferred. In particular, the oil-in-water emulsion composition of the present invention exhibits the characteristic of improved ease of understanding of inversion, and can be preferably applied to cleansing cosmetics, massage cosmetics, etc. As the dosage form, milky lotion, cream, etc. are preferred.
Except for using the oil-in-water emulsion composition of the present invention, the skin external preparation and cosmetic preparation can be produced by using a conventionally known production method.

The present invention will be described in detail below with reference to examples, but these are merely illustrative of the present invention and the scope of the present invention is not limited to these examples.

Oil-in-water emulsion compositions of Examples and Comparative Examples were prepared according to the formulations shown in Table 1. Oil-in-water emulsion compositions of Examples and Comparative Examples were prepared according to the formulations shown in Table 1. Specifically, component (a) was heated to 80°C and homogenized, and then component (b) and component (c), each of which had been heated to 80°C, were added in that order under manual stirring, and the mixture was then cooled to 30°C while stirring.

The usability of the oil-in-water emulsion compositions of the Examples and Comparative Examples was evaluated by a monitor test (n=20). The evaluation criteria were the ease of understanding the inversion (◎: easy to understand, 〇: somewhat easy to understand, △: somewhat difficult to understand, ×: difficult to understand).

The oil-in-water emulsion compositions of Examples 1 to 3, which contain at least a polymer containing a monomer derived from acryloyldimethyltaurine or a salt thereof and a hydrogel-forming polymer such as an alginate, showed a significant improvement in the clarity of inversion compared to Comparative Examples 1 and 2, which did not contain a thickener or contained a different thickener.

Oil-in-water emulsion compositions of the Examples and Comparative Examples were prepared according to the formulations shown in Table 2. Specifically, component (a) was heated to 80°C and homogenized, and then component (b) and component (c), each of which had been heated to 80°C, were added in that order under manual stirring, and the mixture was then cooled to 30°C with stirring.

The usability of the oil-in-water emulsion compositions of the Examples and Comparative Examples was evaluated by a monitor test (n=20). The evaluation criteria were the ease of understanding the inversion (◎: easy to understand, 〇: somewhat easy to understand, △: somewhat difficult to understand, ×: difficult to understand).

The oil-in-water emulsion composition of Example 4, which contains a polymer containing at least a monomer derived from acryloyldimethyltaurine or a salt thereof, showed a significant improvement in the clarity of inversion compared to Comparative Examples 3 to 5, which contain a different thickener.

Therefore, it can be seen that the oil-in-water emulsion composition of the present invention is an excellent oil-in-water emulsion composition that has excellent ease of inversion.

The present invention can be applied to topical skin preparations, etc.

Claims (12)

Surfactants,
An oil phase component in an amount of 30% by mass or more based on the total composition;
Aqueous phase components, and
A hydrogel-forming polymer comprising one or more polymers selected from the group consisting of a polymer containing at least a monomer derived from acryloyldimethyltaurine or a salt thereof, and a polysaccharide;
An oil-in-water emulsion composition comprising:
the surfactant comprises a nonionic surfactant or comprises a first surfactant and a second surfactant;
the nonionic surfactant comprises one or more selected from sorbitan stearate, glyceryl stearate, polyglyceryl-2 tetraoleate, PEG-12 isostearate, PEG-25 stearate, and PEG-20 glyceryl isostearate;
The first surfactant comprises one or more selected from surfactin and salts thereof,
The second surfactant comprises at least one selected from the group consisting of alkyl glycosides represented by the following general formula (1) and salts thereof:

(In the formula, G represents a sugar residue, R independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and n represents an integer of 1 to 4.)
The oil phase component comprises one or more selected from the group consisting of polar oils, hydrocarbon oils, and oil-soluble vitamins;
The aqueous phase component comprises water,
The polymer containing at least a monomer derived from acryloyldimethyltaurine or a salt thereof includes one or more selected from a copolymer of a (meth)acrylate salt and an acryloyldimethyltaurine salt, and a copolymer of a (meth)acrylic acid ester and an acryloyldimethyltaurine salt,
The oil-in-water emulsion composition, wherein the polysaccharide comprises at least one selected from the group consisting of alginic acid and salts thereof.
(however,
POB(20) POE(20) dimethyl ether 3% by mass,
Tripropylene glycol pivalate 0.2% by mass,
Dipropylene glycol 15% by mass,
α-olefin oligomer 20% by mass,
Tripropylene glycol pivalate 0.8% by mass,
Vaseline 5% by weight,
Glyceryl tri-2-ethylhexanoate 20% by mass,
Dimethylpolysiloxane 2% by mass,
Methylphenylpolysiloxane 15% by mass,
0.5% by mass of batyl alcohol,
Polyoxyethylene (60) hydrogenated castor oil 1% by mass,
Sodium coconut oil fatty acid methyl taurate 1% by mass,
L-serine 0.1% by mass,
Phellodendron Bark Extract 0.1% by mass,
An embodiment containing 0.1% by mass of sodium alginate and water, and 2% by mass of POB(29) POE(32) dimethyl ether,
Octyl methoxycinnamate 0.5% by mass,
Ethanol 5.0% by mass,
Alkyl-modified silicone resin-coated titanium oxide 9.0% by mass,
5.0% by mass of ultrafine titanium dioxide particles coated with alkyl-modified silicone resin having a particle size of 40 nm, 0.5% by mass of alkyl-modified silicone resin coated iron oxide (red),
Alkyl-modified silicone resin-coated iron oxide (yellow) 1.5% by mass,
Alkyl-modified silicone resin-coated iron oxide (black) 0.2% by mass,
Polyoxyalkylene-modified organopolysiloxane 0.5% by mass,
Decamethylpentacyclosiloxane 5.0% by mass,
Octyl paramethoxycinnamate 5.0% by mass,
Acrylic silicone 4.0% by mass,
Glycerin 6.0% by mass,
Xanthan gum 0.1% by mass,
Carboxymethyl cellulose 0.3% by mass,
Sodium acryloyldimethyltaurate/hydroxyethyl acrylate copolymer (content: 35 to 40% by mass) (excluding embodiments containing 1.5% by mass and water). 2. The oil-in-water emulsion composition according to claim 1, wherein the polymer containing at least a monomer derived from acryloyldimethyltaurine or a salt thereof comprises one or more selected from the group consisting of (sodium acrylate/sodium acryloyldimethyltaurate) copolymer and (hydroxyethyl acrylate/sodium acryloyldimethyltaurate) copolymer. 3. The oil-in-water emulsion composition according to claim 1 , wherein the polysaccharide comprises Na alginate . The content of the hydrogel-forming polymer is 0.01 to 5% by mass based on the total composition.
The oil-in-water emulsion composition according to any one of claims 1 to 3 . 5. The oil-in-water emulsion composition according to claim 1 , wherein the content of the oil phase component constituting the internal phase of the oil-in-water emulsion composition is 30 to 90% by mass based on the total mass of the composition. The oil-in-water emulsion composition according to any one of claims 1 to 5 , wherein the content of the first surfactant is 0.1 to 5% by mass based on the total mass of the composition. The oil-in-water emulsion composition according to any one of claims 1 to 6 , wherein the content of the second surfactant is 0.1 to 5% by mass based on the total mass of the composition. The oil-in-water emulsion composition according to any one of claims 1 to 7 , wherein the total content of the first surfactant and the second surfactant is 0.2 to 8% by mass based on the total mass of the composition. The oil-in-water emulsion composition according to any one of claims 1 to 8 , comprising 1 to 30% by mass of a polyhydric alcohol based on the total mass of the composition. The oil-in-water emulsion composition according to any one of claims 1 to 9 , which is an external preparation for skin. The oil-in-water emulsion composition according to claim 10 , wherein the topical skin preparation is a cosmetic. The oil-in-water emulsion composition according to claim 11 , wherein the cosmetic is a cleansing cosmetic or a massage cosmetic.