JP4778256B2 - Oil-in-water emulsion and method for producing the same - Google Patents

Description

  The present invention contains ceramides, has a low surfactant content, is excellent in storage stability and use feeling, and is suitable for cosmetics such as skin cosmetics, and a method for producing the oil-in-water emulsions About.

  The stratum corneum, which is the outermost layer of the skin, suppresses the ingress of substances from the outside and the evaporation of moisture from the inside of the skin, and at the same time functions to maintain the skin's flexibility and smooth appearance by retaining moisture. have. In the space between the stratum corneum constituting the stratum corneum, a lipid called a stratum corneum lipid (hereinafter referred to as “corneal layer ICL”) exists so as to fill the gap of the stratum corneum.

  About 50% of the lipid composition of the stratum corneum ICL is ceramide, which is composed of cholesterol, cholesterol ester, fatty acid and the like. In general, when stratum corneum ICL, especially ceramide is reduced, it is known to cause unfavorable skin conditions such as rough skin, dry skin, and aging skin. The lowered stratum corneum state can be improved (see Non-Patent Document 1 and Non-Patent Document 2).

  However, since ceramide has high crystallinity and a high melting point, there is a problem that it is difficult to stabilize in a preparation. Therefore, in order to stably blend in the external preparation for skin, combined use with various surfactants and various types of oils is unavoidable, and as a result, the feeling of use is reduced and the properties of the preparation are limited. It was inevitable.

  When an amphiphilic solid fat with a high melting point, such as ceramides, is blended into an oil-in-water (O / W) emulsion, the emulsion will be separated, gelled, and solid fat will be crystallized over time. It is difficult to blend in. In order to solve this, an emulsification technique using a surfactant has been studied. However, a large amount of an emulsifier is required for ceramide, and there is a problem that the skin is not well adapted to use (patent) Reference 1 and Patent Document 2).

Japanese Patent Laid-Open No. 2003-12486 JP 7-223934 A J. Invest. Dermatol., 84: 282 (1985), J. Invest. Dermatol., 87: 758 (1986)

  An object of the present invention is to provide an oil-in-water emulsion that can be blended without crystallizing ceramides and has excellent storage stability.

The present inventor has found that an oil-in-water emulsion obtained via a lamellar phase can maintain a good emulsified state in the process of producing an emulsion containing ceramides.
That is, the present invention comprises (A) a linear fatty acid having 10 to 30 carbon atoms in total and / or a salt thereof of 0.0001 to 20% by mass , (B) an organic base having a molecular weight of 30 to 200, 0.00001 to 10% by mass , (C) Ceramides 0.0001-15 mass% , (D) Water 20-99.9979 mass% , and (E) Polyoxyethylene alkyl ethers, polyoxyethylene hydrogenated castor oil, polyoxyethylene sorbitan fatty acid ester s, sorbitan fatty acid esters, polyglycerol fatty acid esters, alkyl phosphates, polyoxyethylene alkyl ether phosphates such, and, blended surfactant selected from among acyl taurine salts, (E) component / ( The content ratio (mass ratio) of component C) is 2 or more, and the content ratio (mass ratio) of component (E) / component (A) The present invention provides an oil-in-water emulsion in which R is 0 <R <0.5, the components (A), (B), and (C), and the component (E) that is added as necessary. And a part of the component (D) is mixed to form a lamellar phase, and then the remaining component (D) and component (E) are added to provide a method for producing an oil-in-water emulsion. .

  The oil-in-water emulsion of the present invention can be blended without crystallizing ceramides and has good storage stability. Moreover, by using this as cosmetics, it is excellent in rough skin improvement effect and skin barrier property, and also the feeling of use is good, and it can be particularly excellent in familiarity with the skin.

The component (A) of the present invention is a carboxylic acid having 10 to 30 carbon atoms in total and / or a salt thereof, and is preferably a monocarboxylic acid, a dicarboxylic acid or a mixture thereof.
Specific examples include myristic acid, palmitic acid, stearic acid, behenic acid, isostearic acid, oleic acid, linoleic acid, 12-hydroxystearic acid, pentadecanedioic acid, heptadecanedioic acid, octadecanedioic acid and the like. Among these, a carboxylic acid having a total carbon number of 14 to 24 is preferable, and a linear fatty acid having a carbon number of 14 to 22 is particularly preferable. More specific particularly preferred examples include myristic acid, palmitic acid, stearic acid, behenic acid and the like. Moreover, the carboxylic acid of (A) component can be used individually or in mixture of 2 or more types.
The amount of component (A) in the oil-in-water emulsion of the present invention is preferably in the range of 0.0001 to 20% by mass, more preferably in the range of 0.1 to 10% by mass. Here, the mass of the component (A) is calculated as an acid. The same applies hereinafter.

Next, the component (B) of the present invention is a base. The base is not particularly limited and may be an organic base or an inorganic base, but an organic base having a molecular weight of 30 to 200 is more preferable, and basic amino acids and alkanolamines are particularly preferable.
Specific examples of basic amino acids include L-arginine, lysine, histidine and the like, and specific examples of alkanolamines include monoethanolamine, diethanolamine, triethanolamine, aminomethylpropanol, aminomethylpropanediol, Examples include aminoethylpropanediol and trishydroxymethylaminoethane. Examples of inorganic bases include sodium hydroxide and potassium hydroxide. Of these, L-arginine, triethanolamine, aminomethylpropanol, and aminomethylpropanediol are particularly preferable. These can be used alone or in admixture of two or more.
The amount of component (B) in the oil-in-water emulsion of the present invention is preferably in the range of 0.00001 to 10% by mass, and more preferably in the range of 0.1 to 5% by mass.
In addition, the ratio of the blending amount of the (A) component and the (B) component ((A) component / (B) component, molar ratio) is preferably in the range of 0.3 to 5 in order to form a lamellar phase, More preferably, it is 0.5-2, Furthermore, it is preferable that it is substantially equimolar.

Next, (C) component of this invention is ceramides, and is an active ingredient. Ceramides may be natural, pseudo-type, and mixtures thereof.
Natural ceramides are represented by the following general formula (I).

In the formula, R ¹ represents a linear, branched or cyclic saturated or unsaturated hydrocarbon group having 7 to 19 carbon atoms which may be substituted with a hydroxyl group; Z represents a methylene group or a methine group; X ¹ , X ² and X ³ each independently represent a hydrogen atom, a hydroxyl group or an acetoxy group; X ⁴ represents a hydrogen atom, but together with an adjacent oxygen atom, forms an oxo group (provided that when Z is a methine group, when X ¹ and one of X ² is absent is the other a hydrogen atom .X ⁴ forms an oxo group, X ³ is absent);. R ² is hydroxy A methyl group or an acetoxymethyl group; R ³ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms; R ⁴ represents a straight chain having 5 to 30 carbon atoms which may be substituted by a hydroxyl group; A branched or cyclic saturated or unsaturated hydrocarbon group, or The ω-terminal of the kill group shows an ester bond of a linear or branched saturated or unsaturated fatty acid having 8 to 22 carbon atoms which may be substituted with a hydroxyl group, and the broken line part is an unsaturated bond. Indicates that it may be.

Preferably, R ¹ is a linear alkyl group having 7 to 19 carbon atoms, more preferably a linear alkyl group having 13 to 15 carbon atoms; R ⁴ is a straight chain optionally substituted by a hydroxy group having 9 to 27 carbon atoms. Examples thereof include compounds having a linear alkyl group having 9 to 27 carbon atoms in which a chain alkyl group or linoleic acid is ester-bonded. X ⁴ preferably represents a hydrogen atom or forms an oxo group together with an oxygen atom. In particular, R ⁴ is preferably tricosyl, 1-hydroxypentadecyl, 1-hydroxytricosyl, heptadecyl, 1-hydroxyundecyl, or a nonacosyl group in which linoleic acid is ester-bonded to the ω position.

  Specific examples of natural ceramides include ceramide types 1 to 7 in which sphingosine, dihydrosphingosine, phytosphingosine or sphingadienin is amidated (for example, J. Lipid Res., 24: 759 (1983), FIG. 2). And porcine and human ceramides described in FIG. 4 of J. Lipid. Res., 35: 2069 (1994)). Furthermore, these N-alkyl bodies (for example, N-methyl body) are also contained.

  Examples of commercially available natural ceramides include Ceramide I, Ceramide III, Ceramide IIIA, Ceramide IIIB, Ceramide IIIC, Ceramide VI (above, manufactured by Cosmo Farm), Ceramide TIC-001 (manufactured by Takasago Fragrance Co., Ltd.), CERAMIDE II (manufactured by Quest International), DS-Ceramide VI, DS-CLA-Phytoceramide, C6-Phytoceramide, DS-ceramide Y3S (manufactured by DOOSAN), and CERAMIDE2 (manufactured by Sederma).

  Next, pseudo-ceramides are represented by the following general formula (II).

In the formula, R ⁵ represents a linear, branched or cyclic saturated or unsaturated hydrocarbon group having 10 to 22 carbon atoms which may be substituted with a hydroxyl group; X ⁴ represents a hydrogen atom, an acetyl group or R ⁶ represents a glyceryl group; R ⁶ is a linear, branched or cyclic saturated or unsaturated hydrocarbon group having 5 to 22 carbon atoms which may be substituted by a hydroxyl group or an amino group, or the hydrocarbon An ester bond of a linear or branched saturated or unsaturated fatty acid having 8 to 22 carbon atoms which may be substituted with a hydroxyl group at the ω-terminal of the group; and R ⁷ represents a hydrogen atom, The alkyl group having 1 to 8 carbon atoms which may be substituted by a hydroxyalkoxy group, an alkoxy group or an acetoxy group is shown. As R ⁶ , nonyl, tridecyl, pentadecyl, undecyl group in which linoleic acid is ester-bonded at the ω position, pentadecyl group in which linoleic acid is ester-bonded in the ω position, and pentadecyl in which 12-hydroxystearic acid is ester-bonded in the ω position An undecyl group in which methyl branched isostearic acid is amide-bonded at the ω position is preferred. The hydroxyalkoxy group or alkoxy group for R ⁷ is preferably a group having 1 to 8 carbon atoms.

In general formula (II), R ⁵ is a hexadecyl group, X ⁴ is a hydrogen atom, R ⁶ is a pentadecyl group, and R ⁷ is a hydroxyethyl group (N-hexadecyloxyhydroxypropyl-N-hydroxyhexadecanamide) ); R ⁵ is a hexadecyl group, X ⁴ is a hydrogen atom, R ⁶ is a nonyl group, those wherein R ⁷ is a hydroxyethyl group (N- hexadecene siloxy hydroxypropyl -N- hydroxydecanoyl cyanamide); or R ⁵ is a hexadecyl Group, X ⁴ is glyceryl group, R ⁶ is tridecyl group, R ⁷ is 3-methoxypropyl group (N- [2- (2,3-dihydroxypropyloxy) -3-hexadecyloxypropyl] -N-3- pseudo type ceramides methoxypropyl tetradecanamido) are preferred, those wherein R ⁵ is a hexadecyl radical of general formula (II), X ⁴ is a hydrogen atom, R ⁶ is a pentadecyl group, R ⁷ is a hydroxyethyl group (N- Hekisadeshiro Shi hydroxypropyl) -N- hydroxy-hexadecanol cyanamide) it is particularly preferred.
In addition, two or more components (C) may be used in combination.

  The blending amount of (C) in the oil-in-water emulsion of the present invention is preferably in the range of 0.0001 to 15% by mass, more preferably in the range of 0.01 to 10% by mass.

  The component (D) of the present invention is water. In this invention, the compounding quantity in the emulsion of (D) component has the preferable range of 20-99.9979 mass%, Furthermore, 50-99.997 mass% is preferable, Especially 60-99 mass% is preferable. When the blending amount of (D) water in the oil-in-water emulsion of the present invention is 20% by mass or more, there is no stickiness and a refreshing feeling of use is obtained.

Next, the component (E) of the present invention is a surfactant (excluding the surfactant derived from the component (A)). The surfactant is not particularly limited as long as it is usually used in cosmetics, and examples thereof include nonionic surfactants, anionic surfactants, cationic surfactants, and amphoteric surfactants.
Examples of nonionic surfactants include polyoxyethylene alkyl ethers, polyoxyethylene hydrogenated castor oil, polyoxyethylene sorbitan fatty acid esters, sorbitan fatty acid esters, polyethylene glycol fatty acid esters, polyoxyethylene sorbite fatty acid esters , Polyglycerol fatty acid esters, alkyl glycerol ethers, glycerol fatty acid esters, polyoxyethylene cholesteryl ethers, alkyl polyglucosides, sucrose fatty acid esters, amine oxides, and the like.
Examples of anionic surfactants include alkyl sulfates, alkyl amide ether sulfates, alkyl sulfonates, α-olefin sulfonic acids, alkyl amide sulfonates, alkyl aryl sulfonates, alkyl phosphates, polyoxyethylene Examples include alkyl ether phosphates, acyl glutamates, acyl sarcosinates, and acyl taurine salts.
Examples of amphoteric surfactants include alkyl acetate betaines, alkyl imidazolinium betaines, alkylamido betaines, alkyl sulfobetaines, and the like.
Examples of cationic surfactants include primary, secondary or tertiary aliphatic amine salts and quaternary ammonium salts, which may be polyoxyalkylenated.
Among these surfactants, nonionic surfactants and anionic surfactants are preferable, and more preferable examples include polyoxyethylene alkyl ethers, polyoxyethylene hydrogenated castor oil as nonionic surfactants. , Polyoxyethylene sorbitan fatty acid esters, sorbitan fatty acid esters, polyglycerin fatty acid esters, anionic surfactants include alkyl phosphates, polyoxyethylene alkyl ether phosphates, and acyl taurine salts . Moreover, it is preferable that (E) component remove | excludes the carboxylic acid or its salt used as (A) component.
In the present invention, the component (E) is effective for enhancing the dispersibility of the component (C) and oil agent, etc., but the blending ratio (mass ratio) of the component (E) / (C) is 2 or more, Preferably it is 2-100. The blending ratio (mass ratio) R of component (E) / component (A) is 0 <R <0.5 from the viewpoint of feeling such as familiarity with the skin, and further, 0 <R <0.3. It is preferable that When the blending ratio (mass ratio) is 0.0001 or more, a stable oil-in-water emulsion is obtained, and when it is less than 0.5, the familiarity with the skin is good. From the above points, the blending ratio (mass ratio) of component (E) / component (A) is preferably 0.001 or more and 0.3 or less.

  A polyhydric alcohol can be mix | blended with the oil-in-water emulsion of this invention as another component. Examples of the polyhydric alcohol include glycerin, 1,3-butylene glycol, dipropylene glycol, propylene glycol, and polyoxyethylene methyl glucoside. These are added in an amount of 0 to 30% by mass, preferably 1 to 20% by mass as an auxiliary agent for improving the moisturizing effect and forming a lamellar phase.

  Furthermore, an oil component can also be mix | blended with the oil-in-water emulsion of this invention. Examples of oil components include liquid, semi-solid and solid oil components generally used in cosmetics, such as hydrocarbon oils such as liquid paraffin, squalane and petrolatum; isotridecyl isononanoate, neopentyl dicaprate Glyceryl monoisostearate, glyceryl monoisostearate; vegetable oils such as olive oil and soybean oil; animal oils such as beeswax and lanolin; higher alcohols such as cetyl alcohol and stearyl alcohol; volatile and nonvolatile methylpolysiloxanes Silicone oil such as methylcyclopolysiloxane and modified silicone; fluorine oil such as perfluoropolyether, and the like. These are preferably blended in an amount of 0 to 30% by mass, preferably 1 to 20% by mass from the viewpoint of improving touch.

Moreover, when using the oil-in-water emulsion of this invention as cosmetics, in addition to the said (A)-(E) component, the various components normally added to cosmetics can be mix | blended.
For example, various oils, various alcohols, water-soluble polymers, medicinal ingredients, antioxidants, humectants, thickeners, preservatives, ultraviolet absorbers, fragrances, and the like can be mixed.
The oil-in-water emulsion of the present invention is preferably used as a skin cosmetic, and can be suitably used as a skin lotion, milky lotion, moisturizing cosmetic liquid, cream or the like.

Next, the manufacturing method of the emulsion of this invention is demonstrated in detail.
In the production method of the oil-in-water emulsion of the present invention, the components (A), (B), (C), (E), and a part of the component (D) were mixed in the production process to form a lamellar phase. Thereafter, the remaining component (D) is added.
In the present invention, a lamellar phase is mainly formed by the component (A), the component (B), and the component (D), and the state where the component (C) is arranged between the molecules of the component (A) of the phase. It is thought to take. Therefore, even if (C) component is mix | blended, a lamella phase is maintained, and (C) component can be mix | blended stably even if (E) component is a small quantity.
More specifically, a part of the components (A), (B), (C), and (D), or a part of the components (A), (B), (C), (E) or A lamellar phase is formed by all components and a part of the component (D). The order in which the components (A) to (E) are mixed is not particularly limited as long as it is a composition that forms a lamellar phase (A), (B), and (D) a lamellar phase formed by a part of the components ( After adding the component (C), the remaining amount of the component (D) may be added, or the component (D) in which the component (B) is dissolved in the components (A) and (C) may be added. Moreover, you may add (D) component to (A), (B) and (C) component. More preferably, a method of adding the component (C) to the lamellar phase formed by a part of the components (A), (B) and (D) and then adding the remaining amount of the component (D) is preferable. In addition, as needed, (A)-(E) component can be heated to 50-90 degreeC, and can be mixed.
Regarding the mass ratio of the components (A), (B) and (D), the mass ratio of (D) component to be mixed first ((A) component + (B) component) is 0.005 to 32. The range is suitable, more preferably 0.005 to 2.3, and particularly preferably 0.01 to 1.
Moreover, when forming a lamellar phase here, the compounding quantity with respect to the lamellar phase of (A) component, (B) component, and (D) component is 0.3-70 mass%, 0.2-30 mass%, respectively. And in the range of 3 to 99.5% by mass.

Regarding the mass ratio of the components (A), (B) and (C), the blending ratio (mass ratio) of (C) component / {(A) component + (B) component} is in the range of 0.001 to 10. It is preferable that it is in the range of 0.001 to 0.25, particularly 0.001 to 0.1.
The lamellar structure is confirmed by observation with a polarizing microscope or measurement of small angle X-ray scattering.

  The component (D) is then further added to the lamellar phase comprising the components (A) to (E) obtained as described above, and phase inversion is performed to obtain an oil-in-water emulsion. The oil-in-water emulsion obtained by this method can be stably blended without crystallizing ceramides, and when used as a cosmetic, it is excellent in the feeling of use.

Evaluation method (1) Presence or absence of lamellar phase In the course of producing an oil-in-water emulsion, whether or not the lamellar phase was passed was determined by observation with a polarizing microscope.
○: A lamellar phase was formed. ×: A lamellar phase was not formed. (2) Feeling of use Five professional evaluators applied the cosmetics produced in Examples and Comparative Examples to the face after washing. The determination was made in the following four stages, and the average was evaluated.
4: Good familiarity 3: Good familiarity 2: Not very familiar 1: Not familiar (3) Storage stability The cosmetics produced in Examples and Comparative Examples were allowed to stand at room temperature for 2 weeks and crystallized. The presence or absence of precipitation was observed with an optical microscope and evaluated according to the following criteria.
○: No crystal precipitation ×: Crystal precipitation

Example 1
Among the components shown in Table 1, the (A) component, the (C) component, the polyols, and the oil agent component were dissolved by heating at 85 ° C., and the (D) component 30 was dissolved in the (B) component at 85 ° C. Mass% (based on the total amount of oil-in-water emulsion) was added, stirred and mixed to produce a lamellar phase. Formation of the lamellar phase was confirmed by a polarizing microscope.
Next, the (E) component and the remaining (D) component in which the other components are dissolved are added to the lamellar phase at 85 ° C., phase-inverted, and then cooled to 25 ° C. to form an oil-in-water emulsion. Obtained. The numbers used in Table 1 are in mass%. The results evaluated by the above method are shown in Table 1.

Example 2
Among the components shown in Table 1, (A) component, (C) component, polyols, (E) component POE (60) hydrogenated castor oil, and oil component are dissolved by heating at 85 ° C. 30% by mass of component (D) in which component (B) was dissolved at 0 ° C. (based on the total amount of oil-in-water emulsion) was added, stirred and mixed to produce a lamellar phase. Formation of the lamellar phase was confirmed by a polarizing microscope.
Next, the polyoxyethylene lauryl ether sodium phosphate (E) component and the remaining component (D) in which the other components were dissolved were added to the lamellar phase at 85 ° C., followed by phase inversion, and then 25 ° C. To obtain an oil-in-water emulsion. The results evaluated by the above method are shown in Table 1.

Examples 3 and 4
Among the components shown in Table 1, (A) component, (B) component, polyols, and (D) component 30% by mass (based on the total amount of oil-in-water emulsion) are heated at 85 ° C., stirred and mixed, A lamella phase was formed, and the component (C) and the oil were heated and dissolved at 85 ° C. in the lamella phase, and the mixture was stirred and mixed to produce a lamella phase. Formation of the lamellar phase was confirmed by a polarizing microscope. To this, an aqueous phase obtained by heating and dissolving the other components and (E) sodium N-methyllauroyl taurine in the remaining component (D) was added at 85 ° C., phase-inverted, cooled to 25 ° C. An oil-type emulsion was obtained.

Example 5
Among the components shown in Table 1, (A) component, (C) component, polyols, (E) component POE (60) hydrogenated castor oil, and oil component are dissolved by heating at 85 ° C. 30% by mass of component (D) in which component (B) was dissolved at 0 ° C. (based on the total amount of oil-in-water emulsion) was added, stirred and mixed to produce a lamellar phase. Formation of the lamellar phase was confirmed by a polarizing microscope.
Next, the N-methyllauroyl taurine sodium (E) component and the remaining component (D) in which the other components are dissolved are added to the lamellar phase at 85 ° C., phase-inverted, and then cooled to 25 ° C. An oil-in-water emulsion was obtained. The results evaluated by the above method are shown in Table 1.

Comparative Examples 1 and 2
Among the components shown in Table 1, (A) component, (C) component, polyols, and oil were dissolved by heating at 85 ° C., and (E) component and other components were dissolved in this at 85 ° C. (D ) Ingredients were added, stirred and mixed, then cooled to 25 ° C. to obtain an oil-in-water emulsion.

Comparative Example 3
Among the components shown in Table 1, (C) component, polyols, (E) component POE (60) hydrogenated castor oil, and an oil agent are heated and dissolved at 85 ° C., and then (E) component at 85 ° C. N-methyllauroyl taurine sodium and component (D) in which other components were dissolved were added, stirred and mixed, and then cooled to 25 ° C. to obtain an oil-in-water emulsion.

Comparative Example 4
Among the components shown in Table 1, (A) component, (C) component, polyols, (E) component, and oil agent were heated and dissolved at 85 ° C., and other components were dissolved at 85 ° C. (D ) Component was added, stirred and mixed, and then cooled to 25 ° C. to obtain an oil-in-water emulsion.

  Since Comparative Example 1, 2, and 4 do not use the component (B), and Comparative Example 3 does not use the component (A) and the component (B), the emulsion does not go through the lamellar phase in the production process. The storage stability of was poor. Moreover, the familiarity of the feeling of use to the skin was also bad.

The oil-in-water emulsion of the present invention can be formulated without crystallizing ceramides and has excellent storage stability. Since ceramides are blended in a sufficiently stable amount, when used as a cosmetic, the skin barrier function is improved, and an excellent skin moisturizing effect and protective effect can be obtained. Moreover, the compounding quantity of surfactant is small and it is excellent in a usability | use_condition. Therefore, it can be suitably used as a lotion, milky lotion, moisturizing beauty essence, moisturizing cream and the like.
Moreover, according to the method for producing an oil-in-water emulsion of the present invention, ceramides can be blended without crystallization, and an oil-in-water emulsion excellent in touch can be produced.

Claims (6)

The following (A), (B), (C), (D) and (E) components:
(A) A linear fatty acid having a total carbon number of 10 to 30 and / or a salt thereof 0.0001 to 20% by mass,
(B) 0.00001 to 10% by mass of an organic base having a molecular weight of 30 to 200 ,
(C) Ceramides 0.0001 to 15% by mass ,
(D) Water 20-99.9979 mass% ,
(E) Polyoxyethylene alkyl ethers, polyoxyethylene hydrogenated castor oil, polyoxyethylene sorbitan fatty acid esters, sorbitan fatty acid esters, polyglycerin fatty acid esters, alkyl phosphates, polyoxyethylene alkyl ether phosphates And a surfactant selected from acyl taurine salts ,
The blending ratio (mass ratio) of (E) component / (C) component is 2 or more, and the blending ratio (mass ratio) R of (E) component / (A) component is 0 <R <0. An oil-in-water emulsion that is .5. The oil-in-water emulsion according to claim 1, wherein the component (A) is a linear fatty acid having a total carbon number of 14 to 24 and / or a salt thereof. Cosmetics which mix | blend the oil-in-water emulsion of Claim 1 or 2 . (A) A linear fatty acid having a total carbon number of 10 to 30 and / or a salt thereof 0.0001 to 20% by mass , (B) an organic base having a molecular weight of 30 to 200, 0.00001 to 10% by mass , (C) Ceramides 0 0.0001-15 mass% , (D) 20-99.9979 mass% water, and (E) polyoxyethylene alkyl ethers, polyoxyethylene hydrogenated castor oil, polyoxyethylene sorbitan fatty acid esters, sorbitan fatty acid esters , polyglycerol fatty acid esters, alkyl phosphates, polyoxyethylene alkyl ether phosphates such, and acyl blended surfactant selected from taurine salts, (E) component / (C) component of the blend ratio (Mass ratio) is 2 or more, and (E) component / (A) component blending ratio (mass ratio) R is 0 <R <0.5 A method for producing an oil-in-water emulsion, comprising mixing (A), (B), (C) components, (E) component added as necessary, and part of (D) component, A method for producing an oil-in-water emulsion, wherein the remaining component (D) and component (E) are added after the phase is formed. The manufacturing method of the oil-in-water emulsion of Claim 4 which mixes by the mass ratio of following (1) and (2), and forms a lamellar phase (The mass of (A) component is converted as an acid).
(1) The blending ratio (mass ratio) of {(A) component + (B) component} / (D) component that is partially mixed first is 0.005 to 32.
(2) The blending ratio (mass ratio) of (C) component / {(A) component + (B) component} is 0.001-10. (A) A linear fatty acid having a total carbon number of 10 to 30 and / or a salt thereof 0.0001 to 20% by mass , (B) an organic base having a molecular weight of 30 to 200, 0.00001 to 10% by mass , (C) ceramides 0.0001 to 15 % by mass , (D) 20 to 99.9979% by mass of water, and (E) polyoxyethylene alkyl ethers, polyoxyethylene hydrogenated castor oil, polyoxyethylene sorbitan fatty acid esters, sorbitan fatty acid A surfactant selected from esters, polyglycerin fatty acid esters, alkyl phosphates, polyoxyethylene alkyl ether phosphates, and acyl taurine salts is blended, and (E) component / (C) component The blending ratio (mass ratio) is 2 or more, and the blending ratio (mass ratio) R of (E) component / (A) component is 0 <R <0. 5. A method for producing an oil-in-water emulsion, wherein components (A), (B) and (D) are mixed at a mass ratio of (1) below to form a lamellar phase, and then the lamellar phase (C) Component (C) is added at a mass ratio of (2) below to maintain the lamellar phase, and then the remaining (D) component and (E) component are further added. The mass of the component is converted as an acid).
(1) The blending ratio (mass ratio) of {(A) component + (B) component} / (D) component is 0.005 to 32.
(2) The blending ratio (mass ratio) of (C) component / {(A) component + (B) component} is 0.001-10.