JP4772488B2 - Method for producing oil-in-water emulsion composition - Google Patents

Description

  The present invention relates to an oil-in-water emulsion composition having a small particle size, excellent storage stability, and no surfactant, and a method for producing the same, and a cosmetic containing the oil-in-water emulsion composition.

  In recent years, higher safety is expected for cosmetics, and from this viewpoint, it has been studied to produce an emulsified composition without using a low-molecular surfactant (active agent-free). For example, PEMULEN TR-1 and TR-2 (Noveon), which are cross-linked acrylic acid / alkyl methacrylate copolymers, and ACULYN22 (Rohm & Haas) hydration gel known as a viscosity modifier, There is known a method of dispersing (Patent Documents 1 and 2, Non-Patent Document 1).

  However, these cross-linked hydrophobically modified poly (meth) acrylates and viscosity modifiers do not have sufficient ability to reduce the interfacial tension at the oil / water interface, and therefore it is difficult to produce an emulsion having a fine emulsion particle size. When this is blended in a low-viscosity cosmetic such as water, it causes the emulsification particles to rise over time, called creaming, which is caused by the difference in specific gravity between the emulsification particles and the aqueous phase.

On the other hand, for example, a polymer such as a cross-linked acrylic acid / alkyl methacrylate copolymer or an ethylene oxide-propylene oxide block copolymer is mixed with a cosmetic oil, and a strong shearing force or impact force like a high-pressure emulsifier is used. There has been reported a method of producing an active agent-free fine emulsion by using an emulsifier having a fine emulsion particle (Patent Documents 3, 4, and 5). However, when only the polymers reported in these are used, the resulting emulsion composition has poor stability, and the usability is extremely poor due to gelation and crystallization over time. For this reason, in order to improve the stability of the system, an amphiphilic lipid or the like is blended.
JP 2000-264825 A JP-A-8-217624 FRAGRANCE JOURNAL, 1998-8, p.79 JP-A-7-303829 Japanese Patent Laid-Open No. 9-255529 JP 2000-198711 A

  The problem to be solved by the present invention is to provide an emulsified composition in which various oil components, particularly cosmetic oils, are finely and stably emulsified in an active agent-free manner for the purpose of a less irritating emulsion preparation.

  The present inventors have found that an oil-in-water emulsion composition in which a specific polymer is blended and the volume average particle diameter of the emulsified particles is in a specific range can prevent creaming and solve the above-described problems.

That is, this inventor contains the following (A) component, (B) component, (C) component, and (D) component, and content of (A) component is 1/50 with respect to (B) component. Provided are an oil-in-water emulsion composition in which the volume average particle diameter of emulsion particles is 0.01 to 0.3 μm, a method for producing the same, and a cosmetic containing the oil-in-water emulsion composition To do.
(A) As a structural unit, a structural unit derived from a cationic monomer represented by the general formula (1) (hereinafter also referred to as a cationic polymerization unit (1)) and a hydrophobic monomer represented by the general formula (2) Non-crosslinked cationic polymer containing a derived structural unit (hereinafter also referred to as hydrophobic polymer unit (2))

[In formula, R < ¹ >, R < ² >, R < ³ >, R < ⁴ >, R < ⁵ > and R < ⁶ > are the same or different, and show a hydrogen atom or a C1-C2 alkyl group. R ⁷ represents a linear or branched alkyl group or alkenyl group having 1 to 30 carbon atoms. X ¹ and X ² are the same or different and each represents an oxygen atom or NH. Y ¹ represents an alkylene group having 1 to 8 carbon atoms. Z is a part of an amino group represented by the formula —N (R ⁸ ) R ⁹ (wherein R ⁸ and R ⁹ are the same or different and each represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms) or All the groups are acid salts or quaternary ammonium salts. ]
(B) Oily component (C) Water (D) Water-soluble organic solvent

  According to the present invention, it is possible to obtain a stable oil-in-water emulsion composition in which various cosmetic oils and ceramides are finely emulsified without active agent and crystallization is suppressed, and in particular, a low viscosity agent. Mold compositions can be obtained. The oil-in-water emulsified composition of the present invention can be suitably used as a cosmetic such as a lotion, milky lotion or cream.

[(A) component]
The component (A) of the present invention is a non-crosslinked cationic polymer containing a cationic polymer unit (1) and a hydrophobic polymer unit (2).

In the cationic polymerization unit (1), R ¹ , R ² and R ³ are each independently preferably a hydrogen atom or a methyl group. X ¹ is a linking group represented by —O— or —NH—. Y ¹ is preferably an alkylene group having 1 to 4 carbon atoms, particularly preferably an ethylene group, a propylene group or a trimethylene group.

Z represents a group in which part or all of the amino group represented by the formula —N (R ⁸ ) R ⁹ is an acid salt or a quaternary ammonium salt. R ⁸ and R ⁹ are emulsion stability. From these points, an alkyl group having 1 to 4 carbon atoms is preferable, and examples thereof include a methyl group, an ethyl group, an n-propyl group, and an isopropyl group. Z may contain two or more of an amino group, an acid salt and a quaternary ammonium salt, but preferably 10 to 100% of the amino group is an acid salt or a quaternary ammonium salt.

  As monomers constituting the cationic polymerization unit (1), dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylate, diethylaminopropyl (meth) acrylate, dimethylaminoethyl (meth) Examples include acrylamide, diethylaminoethyl (meth) acrylamide, dimethylaminopropyl (meth) acrylamide, diethylaminopropyl (meth) acrylamide, and acid salts or quaternary ammonium salts thereof. Of these, dimethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylamide, and acid salts or quaternary ammonium salts thereof are preferable.

  The acid constituting the acid salt may be either an organic acid or an inorganic acid. For example, hydrochloric acid, sulfuric acid, nitric acid, acetic acid, formic acid, citric acid, tartaric acid, adipic acid, sulfamic acid, toluenesulfonic acid, lactic acid, pyrrolidone-2 -Carboxylic acid, succinic acid, aspartic acid, glutamic acid, malic acid, glycolic acid, ascorbic acid and the like. Of these, citric acid, glutamic acid, and succinic acid are preferable.

  Examples of the quaternizing agent constituting the quaternary ammonium salt include alkyl sulfates such as dimethyl sulfate and diethyl sulfate, alkyl halides such as methyl chloride and methyl bromide, and alkyl phosphates such as dimethyl phosphate and diethyl phosphate. Examples thereof include alkyl sulfates and alkyl halides.

In the hydrophobic polymer unit (2), R ⁴ , R ⁵ and R ⁶ are preferably a hydrogen atom or a methyl group. X ² is a linking group represented by —O— or —NH—. R ⁷ is preferably an alkyl group or an alkenyl group having 8 to 30 carbon atoms, particularly 12 to 22 carbon atoms, from the viewpoint of emulsion stability. Specific examples include an octyl group, 2-ethylhexyl group, decyl group, lauryl group, myristyl group, cetyl group, stearyl group, oleyl group, and behenyl group.

  As monomers constituting the hydrophobic polymer unit (2), butyl (meth) acrylate, octyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, behenyl (meth) acrylate, butyl (meth) acrylamide, Examples include octyl (meth) acrylamide, lauryl (meth) acrylamide, stearyl (meth) acrylamide, and behenyl (meth) acrylamide. Of these, lauryl (meth) acrylate and stearyl (meth) acrylate are preferred.

  The sequence of the cationic polymer unit (1) and the hydrophobic polymer unit (2) in the cationic polymer of the component (A) may be random or block. The cationic polymer unit (1) and the hydrophobic polymer unit The copolymerization ratio [cationic polymerization unit (1) / hydrophobic polymerization unit (2)] of (2) is preferably 20/80 to 95/5 (mass ratio), particularly preferably 30/70 to 95/5. . Moreover, 1 or more types of polymerization units other than a cationic polymerization unit (1) and a hydrophobic polymerization unit (2) may be included.

  The weight average molecular weight of the cationic polymer as the component (A) is preferably 1,000 to 1,000,000, and more preferably 10,000 to 200,000. In addition, a weight average molecular weight is the value measured by GPC (gel permeation chromatography), and the detail of measurement conditions is as showing in an Example.

  The cationic polymer as the component (A) can be obtained by a known synthesis method. Of the cationic polymerization units (1), Z is a monomer represented by the general formula (3) constituting a polymerization unit in which an amino group is represented, and a general formula (4) constituting a hydrophobic polymerization unit (2). The monomer obtained is polymerized by a solution polymerization method, and the obtained copolymer is obtained by neutralizing a part or all of amino groups with an organic acid or an inorganic acid to obtain an acid salt.

(In the formula, R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , X ¹ , X ² and Y ¹ have the same meaning as described above.)
The organic acid or inorganic acid is mixed with the monomer represented by the general formula (3) and the copolymer of the monomer represented by the general formula (4) with a water-soluble organic solvent or in water. It may be dissolved and mixed, as long as the cationic polymer is neutralized in the composition.

  Moreover, what contains a quaternary ammonium salt is a quaternary ammonium salt using a quaternizing agent as a copolymer of the monomer represented by the general formula (3) and the monomer represented by the general formula (4). By doing so, it can be obtained. Alternatively, the monomer represented by the following general formula (5) obtained by quaternizing the monomer represented by the general formula (3) in advance may be obtained by copolymerizing with the monomer represented by the general formula (4). it can.

(Wherein R ¹ , R ² , R ³ , R ⁸ , R ⁹ , X ¹ and Y ¹ represent the same meaning as described above, and R ¹⁰ represents a linear or branched alkyl group having 1 to 30 carbon atoms or Represents an alkenyl group, and W ⁻ represents a counter ion of a quaternary ammonium group.)
In the general formula (5), R ¹⁰ is preferably an alkyl group having 1 to 18 carbon atoms, specifically, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an octyl group, a lauryl group, or a stearyl group. Etc.

Examples of W ^- include halogen ions such as chlorine, iodine and bromine; and organic anions such as methosulphate, ethosulphate, methosphosphate and ethosphosphate.

  The cationic polymer as the component (A) is a non-crosslinked polymer having the cationic polymer unit (1) and the hydrophobic polymer unit (2) as essential constituent units. Here, “non-crosslinked” means that the structural unit derived from the crosslinkable monomer may not be included at all or may be included in a range not impairing the intended effect of the present invention. Examples of the crosslinkable monomer include (meth) acrylic acid esters of polyhydric alcohols such as ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, and polyethylene glycol di (meth) acrylate, and 1,6-hexane. Examples thereof include crosslinkable monomers having a plurality of epoxy groups such as diol diglycidyl ether. The amount of these crosslinkable monomers used is less than 0.1% by mass in all monomers, preferably 0.05% by mass or less, and more preferably 0.01% by mass or less.

  Solution polymerization of the monomer constituting the cationic polymerization unit (1) and the monomer constituting the hydrophobic polymerization unit (2) can be performed, for example, by the following method.

  As a solvent for the polymerization reaction, organic solvents such as aromatic compounds (toluene, xylene, etc.), lower alcohols (ethanol, isopropanol, etc.), ketones (acetone, methyl ethyl ketone, etc.), tetrahydrofuran, diethylene glycol dimethyl ether, etc. can be used. . The amount of solvent (mass basis) is preferably equivalent to 20 times, particularly preferably 10 to 10 times the amount of all monomers.

  As the polymerization initiator, known radical polymerization initiators can be used, and examples thereof include azo polymerization initiators, hydroperoxides, dialkyl peroxides, diacyl peroxides, and ketone peroxides. If necessary, basic catalysts (metals such as lithium, sodium, potassium, cesium, alkoxides, hydroxides, etc.) or acidic catalysts (sulfuric acid, hydrochloric acid, etc.) may be used. The amount of the polymerization initiator is preferably in the range of 0.01 to 5 mol%, particularly 0.01 to 3 mol%, more preferably 0.01 to 1 mol%, based on the total monomers.

The polymerization reaction is preferably performed in a temperature range of 60 to 180 ° C. under a nitrogen stream, and the reaction time is preferably 0.5 to 20 hours. The quaternization reaction is preferably carried out at a temperature range of 50 to 80 ° C. under normal pressure, and the reaction time is preferably 2 to 8 hours.
(A) The cationic polymer of a component can use 1 type (s) or 2 or more types.

[Component (B)]
The component (B) of the present invention is an oily component. An oily component means an organic substance having a solubility in 100 g of water at 20 ° C. of 2 g or less. The oil component may be either volatile or non-volatile, and the form at normal temperature may be any of solid, paste, and liquid. For example, hydrocarbons such as solid or liquid paraffin, petrolatum, ceresin, ozokerite, montan wax, squalane, squalene; eucalyptus oil, mint oil, camellia oil, macadamia nut oil, avocado oil, beef fat, pork fat, horse oil, egg yolk oil Oils such as olive oil, carnauba wax, lanolin, jojoba oil; glycerol monostearate, glycerol distearate, glycerol monooleate, isopropyl palmitate, isopropyl stearate, butyl stearate, isopropyl myristate, neocapric acid neo Pentyl glycol, diethyl phthalate, myristyl lactate, diisopropyl adipate, cetyl myristate, cetyl lactate, 1-isostearoyl-3-myristoyl glycerol, 2-ethylhexa Cetyl acid, 2-ethylhexyl palmitate, 2-octyldodecyl myristate, neopentyl glycol di-2-ethylhexanoate, 2-octyldecyl oleate, glycerol triisostearate, diparamethoxycinnamate mono-2-ethylhexanoate glyceryl, etc. Ester oil; higher fatty acids such as stearic acid, palmitic acid and oleic acid; higher alcohols such as stearyl alcohol and cetyl alcohol; natural essential oils such as rosemary, rooibos, royal jelly, and hamelis; A derivatives, ceramides, ceramide-like structural substances (for example, N- (3-hexadecyloxy-2-hydroxypropyl) -N-2-hydroxyethylhexadecanamide: see JP-A-62-228048) , Oil-soluble ultraviolet absorber, the functional oil substances such as perfumes; silicones, and fluorine-based oil and the like.

  Ceramides are generic names of natural ceramides and structurally similar substances, and include those represented by the general formula (6) or (7).

(In the formula, R ¹¹ represents a hydrocarbon group having 4 to 30 carbon atoms which may be substituted by a hydroxyl group, a carbonyl group or an amino group. Z ¹¹ represents a methylene group, a methine group or an oxygen atom, and is a broken line. And X ¹¹ , X ¹² and X ¹³ each independently represents a hydrogen atom, a hydroxyl group or an acetoxy group, and when Z ¹¹ is a methine group, X ¹¹ and X Any one of ¹² is a hydrogen atom, and the other does not exist, X ¹⁴ represents a hydrogen atom, an acetyl group or a glyceryl group, or X ¹³ —C—O—X ¹⁴ represents C═O, in which case X ¹³ and X ¹⁴ do not exist, R ¹² and R ¹³ each independently represent a hydrogen atom, a hydroxyl group, a hydroxymethyl group or an acetoxymethyl group, and R ¹⁴ is substituted with a hydroxyl group, a carbonyl group or an amino group. Well, ether in the main chain If either .R ¹⁵ showing the hydrocarbon group of the ester or amide bond carbon atoms 5 to 60 which may have a represents a hydrogen atom, selected from hydroxyl group, hydroxyalkoxy group, an alkoxy group, and an acetoxy group A hydrocarbon group having 1 to 8 carbon atoms which may have a substituent, and R ¹⁶ represents a hydrocarbon group having 10 to 30 carbon atoms.
In the general formulas (6) and (7), R ¹¹ is preferably a hydrocarbon group having 7 to 22 carbon atoms which may be substituted with a hydroxyl group. Z ¹¹ , X ¹¹ , X ¹² and X ¹³ have the above-mentioned meanings. It is particularly preferable that 0 to 1 of X ¹¹ , X ¹² and X ¹³ is a hydroxyl group and the remainder is a hydrogen atom. When Z ¹¹ is a methine group, only one of X ¹¹ and X ¹² is a hydrogen atom, and the other does not exist. X ¹⁴ is preferably a hydrogen atom or a glyceryl group.

R ¹² and R ¹³ have the above-mentioned meanings. Preferred R ¹² is a hydrogen atom or a hydroxymethyl group, and preferred R ¹³ is a hydrogen atom.

R ¹⁴ is preferably a hydrocarbon group having 5 to 35 carbon atoms which may be substituted with a hydroxyl group or an amino group, or 8 carbon atoms which a hydroxyl group may be substituted at the ω-position of the hydrocarbon group. ˜22 fatty acids are ester-bonded or amide-bonded. As the fatty acid to be bonded, isostearic acid, 12-hydroxystearic acid or linoleic acid is preferable.

R ¹⁵ is preferably a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms in which 1 to 3 groups selected from a hydroxyl group, a hydroxyalkoxy group and an alkoxy group may be substituted. Here, as a hydroxy alkoxy group and an alkoxy group, a C1-C7 thing is preferable.

  The ceramides represented by the general formula (6) are particularly represented by natural or natural ceramides represented by the following general formula (8) and derivatives thereof (hereinafter referred to as natural ceramides) or the general formula (9). Ceramides (hereinafter referred to as pseudo-ceramide) are preferred.

(In the formula, R ²¹ represents a linear, branched or cyclic saturated or unsaturated hydrocarbon group having 7 to 19 carbon atoms which may be substituted by a hydroxyl group. Z ¹² represents a methylene group or a methine group. The broken line portion indicates that it may be an unsaturated bond, X ¹⁵ , X ¹⁶ and X ¹⁷ each independently represent a hydrogen atom, a hydroxyl group or an acetoxy group, and when Z ¹² is a methine group, ^{One of 15} and X ¹⁶ is a hydrogen atom and the other does not exist, X ¹⁸ represents a hydrogen atom, or X ¹⁷ —C—O—X ¹⁸ represents C═O, in which case X ¹⁷ and X ¹⁸ does not exist, R ²² represents a hydroxymethyl group or an acetoxymethyl group, R ²³ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R ²⁴ may be substituted with a hydroxyl group. C5-C30 linear, branched or cyclic saturated or unsaturated hydrocarbons Or a straight chain or branched chain 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 hydrocarbon group. )

(In the formula, R ²⁵ 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 ¹⁹ represents a hydrogen atom or an acetyl group; Or a glyceryl group; R ²⁶ 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; Indicate 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 hydrogen group; does R ²⁷ represent a hydrogen atom? , A hydroxyalkoxy group, an alkoxy group, or an acetoxy group represents an alkyl group having 1 to 8 carbon atoms that may be substituted.)
In the natural ceramide represented by the general formula (8), preferably, R ²¹ is a linear alkyl group having 7 to 19 carbon atoms, more preferably 13 to 15 carbon atoms; and R ²⁴ is substituted with a hydroxyl group. Examples thereof include a compound having a good linear alkyl group having 9 to 27 carbon atoms or a linear alkyl group having 9 to 27 carbon atoms in which linoleic acid is ester-bonded. X ¹⁸ preferably represents a hydrogen atom or forms an oxo group together with an oxygen atom. In particular, R ²⁴ 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. And porcine and human ceramides described in FIG. 4 of J. Lipid. Res., 35: 2069 (1994)).

  Specific examples include those represented by the following formula.

  Furthermore, these N-alkyl bodies (for example, N-methyl body) are also included. These may be any of natural extracts and synthetic products, and commercially available products can be used.

  These ceramides may be either natural (D (−)) optically active or non-natural (L (+)) optically active, or a mixture of natural and nonnatural. May be used. The relative configuration of the above compound may be a natural configuration, a non-natural configuration other than that, or a mixture thereof. In particular, compounds of CERAMIDE1, CERAMIDE2, CERAMIDE3, CERAMIDE5, CERAMIDE6II (above, INCI, 8th Edition) and those represented by the following formula are preferable.

  In addition, 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 Inc.), CERAMIDE II (made by Quest International), DS-Ceramide VI, DS-CLA-Phytoceramide, C6-Phytoceramide, DS-ceramide Y3S (made by DOOSAN), CERAMIDE2 (made by Sederma).

In the pseudoceramide represented by the general formula (9), as R ²⁶ , nonyl, tridecyl, pentadecyl, an undecyl group in which linoleic acid is ester-bonded at the ω position, a pentadecyl group in which linoleic acid is ester-bonded at the ω position, ω A pentadecyl group in which 12-hydroxystearic acid is ester-bonded at the position and an undecyl group in which methyl-branched isostearic acid is amide-bonded at the ω position are preferable. The hydroxyalkoxy or alkoxy group R ²⁷ preferably has 1 to 8 carbon atoms.

As the pseudo-ceramide represented by the general formula (9), R ²⁵ is a hexadecyl group, X ¹⁹ is a hydrogen atom, R ²⁶ is a pentadecyl group, and R ²⁷ is a hydroxyethyl group (N- (3-hexadecyloxy- 2-hydroxypropyl) -N-2-hydroxyethyl-hexadecanol cyanamide: see JP-A-62-228048); R ²⁵ is hexadecyl, X ¹⁹ is a hydrogen atom, R ²⁶ is a nonyl group, R ²⁷ is hydroxy Preferred are pseudo-ceramides having an ethyl group; or R ²⁵ is a hexadecyl group, X ¹⁹ is a glyceryl group, R ²⁶ is a tridecyl group, and R ²⁷ is a 3-methoxypropyl group, and R ^{25 in the} general formula (9) is hexadecyl. Particularly preferred are those wherein X ¹⁹ is a hydrogen atom, R ²⁶ is a pentadecyl group and R ²⁷ is a hydroxyethyl group.

  Examples of silicones are those usually used in toiletry products. For example, octamethylpolysiloxane, tetradecamethylpolysiloxane, methylpolysiloxane, highly polymerized methylpolysiloxane, methylphenylpolysiloxane; octamethylcyclotetrasiloxane, decamethylcyclo Methylcyclopolysiloxane such as pentasiloxane; trimethylsiloxysilicic acid; alkyl-modified silicone, polyether-modified silicone, amino acid-modified silicone, amino-modified silicone, fluorine-modified silicone, alkylglyceryl ether-modified silicone, alkyl, alkenyl or fluoroalkyl-modified silicone, etc. Of the modified silicone.

As the fluorinated oil agent, perfluoropolyether which is a perfluoro organic compound which is liquid at normal temperature is preferable. For example, perfluorodecalin, perfluoroadamantane, perfluorobutyltetrahydrofuran, perfluorooctane, perfluorononane, perfluoropentane. Perfluorodecane, perfluorododecane, perfluoropolyether and the like.
One or more of these oil components can be used.

[Oil-in-water emulsion composition]
The oil-in-water emulsion composition of the present invention contains (A) component, (B) component, (C) component and (D) component as essential components. The content of the component (A) in the emulsion composition of the present invention is preferably from 0.01 to 10% by mass, more preferably from 0.01 to 1% by mass, from the viewpoint of obtaining a good feeling during use. The content of the component (B) is preferably 0.01 to 30% by mass, and more preferably 0.1 to 10% by mass, from the viewpoint of obtaining a good usability. The content of the component (A) is preferably 1/50 times by weight or more, more preferably 1/20 times by weight or more with respect to the component (B) from the viewpoint of obtaining good emulsion stability. Is more preferably 1/15 times by weight or more, and particularly preferably 1/5 times by weight or more. The upper limit is preferably 5 times by weight or less, more preferably 2 times by weight or less, and still more preferably 1 by weight or less.

  Although the water of (C) component can be arbitrarily mix | blended in the composition of this invention, content of (C) component in the emulsion composition of this invention is 50-95 from a viewpoint of obtaining a favorable usability | use_condition. % By mass is preferable, and 60 to 95% by mass is more preferable.

  The water-soluble organic solvent of component (D) is, for example, a lower alcohol such as ethanol or isopropanol; ethylene glycol, propylene glycol, dipropylene glycol, isoprene glycol, 1,3-butylene glycol, polyethylene glycol (average molecular weight 200 to 1540), etc. Glycols; polyoxyethylene methyl glucoside, polyhydric alcohols such as glycerin and diglycerin; tris (2- (2-ethoxyethoxy) ethyl) phosphate, and the like, glycols and polyhydric alcohols are preferred, polyhydric alcohols Is more preferable, and glycerin is particularly preferable. One or more of these can be used.

  The content of the component (D) in the emulsified composition of the present invention is preferably 0.1 to 30% by mass, and more preferably 0.1 to 20% by mass from the viewpoint of obtaining a good feeling of use.

  The pH of the emulsified composition of the present invention is preferably pH 3.0 to 6.8, particularly preferably pH 4.0 to 6.5.

  From the viewpoint of obtaining good storage stability, the emulsion composition of the present invention has an average particle diameter of the emulsion particles of 0.01 to 0.3 μm, preferably 0.05 to 0.2 μm, and preferably 0.1 to 0 .18 μm is more preferable.

  In the present invention, the average particle diameter of the emulsified particles is a volume average diameter measured at 25 ° C. using a laser Doppler dynamic light scattering particle size distribution analyzer. Laser Doppler dynamic light scattering particle size distribution measuring device has a Doppler shift amount (amount of wavelength change) of scattered light according to the Brownian motion speed, that is, the particle diameter when irradiating light to a fine particle dispersion that performs Brownian motion. This is a measuring device that utilizes the difference, and for example, MICROTRAC UPA (manufactured by HONEYWELL) is exemplified.

  Since the fine emulsified state is stably maintained in the emulsified composition of the present invention, it is not necessary to use a low molecular surfactant. Here, the “low molecular surfactant” refers to a surfactant having a molecular weight of 10,000 or less.

[Method for producing emulsified composition]
Although the manufacturing method of the emulsion composition of this invention is not specifically limited, The mixture containing (A) component, (B) component, (C) component, and (D) component is powerful using a high-pressure emulsifier etc. A method of emulsifying with a shearing force or impact force is preferred.

  Specifically, for example, the component (A) is dissolved or dispersed in the component (D), the component (B) is added and mixed with the component, and then the mixture obtained by adding the component (C) is mixed with the existing high-pressure emulsification. The method of emulsifying with a machine is mentioned. Moreover, after mixing each component of (A)-(D) and performing a high pressure emulsification process, water may be added and diluted as a 2nd process.

  The liquid composition at the time of the high-pressure emulsification treatment can obtain an emulsified liquid with a smaller amount of component (C), preferably 90% by weight or less, more preferably 60% by weight or less, and further 30% by weight or less. preferable. From the viewpoint of viscosity during dispersion, the component (C) is preferably 1% by weight or more, and more preferably 5% by weight or more. The more the component (D) is, the more finely divided emulsion can be obtained. The composition of the component (D) during the high-pressure emulsification treatment is preferably 5% by weight or more, more preferably 25% by weight or more, further preferably 50% by weight or more, and particularly preferably 60% by weight or more.

  The composition of the component (A) during the high-pressure emulsification treatment is preferably 0.1 to 10% by weight. Moreover, 0.1-10 weight% is preferable and, as for the composition of (B) component at the time of a high pressure emulsification process, 1-10 weight% is more preferable.

  Here, the high-pressure emulsifier is an apparatus capable of performing emulsification that gives a high shearing force by applying a high pressure to the flow path, and further, by bending the flow path or uniting a plurality of flow paths. You may have the structure which gives the impact force to a liquid. Examples thereof include a microfluidizer (manufactured by Mizuho Kogyo Co., Ltd.), DeBee2000 (manufactured by BEE International Co., Ltd.), and the like.

In order to give a high shearing force or a high impact force, it is preferable to apply an injection pressure of 300 kg / cm ² or more. In order to obtain fine particles, 500 kg / cm ² or more is more preferable, and 1000 kg / cm ² or more is more preferable. Although not specified upper limit of the injection pressure is particularly from structural constraints of the device, it is suitably 5000 kg / cm ² or less, 3000 kg / cm ² or less being more preferred. The emulsification temperature is not particularly defined, but a temperature range of 5 to 50 ° C. is preferably used.

  In addition, a desired fine emulsification is performed by subjecting a preliminary emulsion obtained by an emulsification method using an emulsifier other than a high-pressure emulsifier, such as a propeller-type stirrer and a homogenizer, to a high shear force treatment using a high-pressure emulsifier. A liquid can also be obtained. Moreover, you may perform this high shearing force process repeatedly as needed. Furthermore, after producing a fine emulsion having a high concentration of the component (B), it can be diluted with water or an aqueous medium to obtain a fine emulsion having a desired concentration.

[Cosmetics]
The oil-in-water emulsion composition of the present invention can be suitably used as a cosmetic. Examples of cosmetics include foundations, lotions, creams, emulsions, skin lotions, skin softening cosmetics, nutritional cosmetics, astringent cosmetics, whitening cosmetics, wrinkle improving cosmetics, anti-aging cosmetics, antiperspirants, and deodorants. Skin cosmetics such as agents; hair cosmetics such as hair styling agents and hair nourishing agents.

  Cosmetics contain preservatives, antioxidants, fragrances, UV absorbers, moisturizers, blood circulation promoters, cooling agents, antiperspirants, fungicides, skin protectants, water-soluble polymers, plant extracts, etc. can do. A preferable pH as a cosmetic is the same as that of the above-mentioned emulsion composition.

Synthesis Example 1 (Synthesis of Polymer A1)
A reactor equipped with a dropping funnel, a stirrer, a reflux condenser, a thermometer, and a nitrogen introduction tube was used, and the reaction temperature was 75 ° C. A mixed solution of 80 g of dimethylaminoethyl methacrylate, 20 g of stearyl methacrylate, 0.5 g of initiator V-65 (manufactured by Wako Pure Chemical Industries, Ltd.) and 67 g of methyl ethyl ketone was added dropwise over 2.5 hours using a dropping funnel, and 1 hour after the completion of dropping. After aging, 0.2 g of initiator V-65 was added 3 times every 30 minutes. Thereafter, the reaction temperature was raised to 80 ° C., and after 1 hour, the reaction was terminated. As for the reaction product, polymer A1 was obtained by removing unreacted monomer and initiator residue with a ceramic membrane purifier made of alumina having a pore size of 500 mm and drying. The obtained polymer A1 was dissolved in chloroform and the molecular weight of the 0.5% solution was measured by GPC. As a result, the weight average molecular weight was 76,000 (polystyrene conversion). The GPC measurement conditions are as follows.
Column: 2 KF-804L manufactured by Showa Denko KK Eluent: 1 mmol / L Farmin DM20 (manufactured by Kao) / chloroform solution Flow rate: 1.0 mL / min
-Column temperature: 40 ° C
Detector: Differential refractometer Synthesis example 2 (Synthesis of polymer A2)
A polymer A2 having a weight average molecular weight of 60,000 was obtained by synthesis under the same conditions as in Synthesis Example 1 except that 60 g of dimethylaminoethyl methacrylate and 40 g of stearyl methacrylate were used.

Synthesis Example 3 (Synthesis of polymer A3)
A polymer A3 having a weight average molecular weight of 14,000 was obtained by synthesizing under the same conditions as in Synthesis Example 1 except that 20 g of dimethylaminoethyl acrylate was used instead of dimethylaminoethyl methacrylate and 80 g of methyl acrylate was used instead of stearyl methacrylate. .

Examples 1-5
At 80 ° C., 3 g of the polymer A1 or A2, 3 g of an appropriate amount of succinic acid, 30 g of an oil component, 330 g of glycerin and 129 g of purified water were mixed with a propeller stirrer and then cooled to 20 ° C., and 2000 kgf / cm ² Under pressure conditions, the solution was passed 10 times through a microfluidizer M-140K (manufactured by Mizuho Kogyo Co., Ltd.) to obtain an emulsion having the composition shown in Table 1. 83.6 g of an aqueous solution in which 0.2 g of methylparaben (methyl paraoxybenzoate) was dissolved in 16.4 g of this emulsion was added with stirring to prepare a lotion having the composition shown in Table 1. In addition, when methyl paraben aqueous solution was dripped at the emulsion, it mixed uniformly, and since the water droplet of paraben aqueous solution was not formed, it was confirmed that an emulsion is an oil-in-water emulsion composition.

  When the lotion obtained in Examples 1 to 5 was used on the skin, it was easy to fit and had a good feeling of moistness.

Example 6
An emulsion and lotion having the composition shown in Table 1 were prepared in the same manner as in Example 1 except that 0.6 g of A1 was added as a polymer. The emulsion was oil-in-water emulsified in the same manner as in Example 1. It was confirmed to be a composition.

Example 7
An emulsion and lotion having the composition shown in Table 1 were prepared in the same manner as in Example 1 except that 1.5 g of A1 was added as a polymer, and the emulsion was oil-in-water emulsified in the same manner as in Example 1. It was confirmed to be a composition.

Example 8
An emulsion and a lotion having the composition shown in Table 1 were prepared in the same manner as in Example 1 except that 30 g of A1 was added as a polymer, and the emulsion was an oil-in-water emulsion composition in the same manner as in Example 1. It was confirmed that.

  When the lotion obtained in Examples 6 to 8 was used on the skin, it was easy to fit and had a good feeling of moistness.

Comparative Example 1
At 80 ° C., with stirring, 0.1 g of Polymer A1, an appropriate amount of succinic acid, 1 g of oil component, 11 g of glycerin, 0.2 g of methylparaben and 87.7 g of purified water were mixed at a rotation speed of 300 rpm with a propeller stirrer. A lotion having the composition shown in 1 was prepared.

Comparative Example 2
A lotion was prepared in the same manner as in Example 1 except that polyoxyethylene-polyoxypropylene glycol block copolymer (Adekapluronic F-108 manufactured by Asahi Denka Co., Ltd.) was used instead of the component (A) and succinic acid was not added. did.

  The cosmetic particles obtained in Examples 1 to 8 and Comparative Examples 1 and 2 were measured immediately after preparation, after measuring for 3 months at 0 ° C. and after 3 months storage at 50 ° C., the average particle size of the emulsified particles was measured, and the appearance was determined. Observed. The results are shown in Table 1.

In addition, the description of the external appearance in the following table | surfaces has the following meaning.
Uniformity: Creaming to form a visually uniform emulsion: Creamy layer is formed on top, and two layers of oil-water separation: without emulsification, separation into an oil phase and an aqueous phase

* 1: Asahi Denka Co., Ltd. (polyblock copolymer composed of polyethylene oxide-polypropylene oxide-polyethylene oxide, polypropylene oxide molecular weight: 3250, composition ratio of polyethylene oxide: 80%)
* 2: CROPURE OL, made by Croda Japan
* 3: Wako Pure Chemical Industries, Ltd.
* 4: Silicone KF-96A (6cs) manufactured by Shin-Etsu Chemical Co., Ltd.
* 5: Kao Corporation
* 6: Device 1 Microfluidizer M-140K (manufactured by Mizuho Industry Co., Ltd.)
Equipment 2 Propeller stirrer
* 7: Volume average particle diameter measured by MICROTRAC UPA (HONEYWELL) Example 9
At 80 ° C., 10 g of polymer A3, an appropriate amount of glycolic acid, 10 g of olive oil, 100 g of glycerin, and 877 g of purified water were mixed with a propeller stirrer (addition step 1), and then cooled to 20 ° C. and 2000 kgf / A lotion having the composition shown in Table 2 was prepared by passing 10 times through a microfluidizer M-140K (manufactured by Mizuho Kogyo Co., Ltd.) under a pressure condition of cm ² . Furthermore, the average particle diameter measurement and appearance were observed without diluting with purified water. In addition, when water was dripped at an emulsion liquid, it mixed uniformly, and since the water droplet was not formed, it was confirmed that an emulsion liquid is an oil-in-water emulsion composition.

Example 10
At 80 ° C., 50 g of Polymer A3, an appropriate amount of glycolic acid, 50 g of olive oil, 500 g of glycerin and 637.5 g of purified water were mixed with a propeller stirrer (addition step 1), and then cooled to 20 ° C. Under a pressure condition of 2000 kgf / cm ^2, the solution was passed 10 times through a microfluidizer M-140K (manufactured by Mizuho Kogyo Co., Ltd.) to prepare an emulsion having the composition shown in Table 2. 75.2 g of purified water was added to 24.9 g of this emulsified liquid with stirring (addition process 2) to prepare a lotion having the composition shown in Table 2. In addition, when water was dripped at an emulsion liquid, it mixed uniformly, and since the water droplet was not formed, it was confirmed that an emulsion liquid is an oil-in-water emulsion composition.

Example 11
At 80 ° C., 50 g of Polymer A3, an appropriate amount of glycolic acid, 50 g of olive oil, 500 g of glycerin and 220.5 g of purified water were mixed with a propeller stirrer (addition step 1) and then cooled to 20 ° C. Under a pressure condition of 2000 kgf / cm ^2, the solution was passed 10 times through a microfluidizer M-140K (manufactured by Mizuho Kogyo Co., Ltd.) to prepare an emulsion having the composition shown in Table 2. Purified water 83.5 g was added to 16.5 g of this emulsion under stirring (addition step 2) to prepare a lotion having the composition shown in Table 2. In addition, when water was dripped at an emulsion liquid, it mixed uniformly, and since the water droplet was not formed, it was confirmed that an emulsion liquid is an oil-in-water emulsion composition.

* 2, * 6 and * 7 are the same as in Table 1.

Claims (5)

It contains the following component (A), component (B), component (C), and component (D), and the content of component (A) is 1/50 to 5 times the weight of component (B) A method for producing an oil-in-water emulsion composition in which the volume average particle diameter of the emulsified particles is 0.01 to 0.3 μm,
0.1 to 10% by weight of the following component (A), 0.1 to 10% by weight of component (B), 1 to 30% by weight of component (C), and 50% by weight of component (D) The step of emulsifying the mixture containing the above with a high-pressure emulsifier without using a surfactant having a molecular weight of 10,000 or less (hereinafter referred to as the first step),
A method for producing an oil-in-water emulsion composition.
(A) As structural units, derived from a cationic monomer represented by the general formula (1) [hereinafter referred to as a cationic polymerization unit (1)] and derived from a hydrophobic monomer represented by the general formula (2) The copolymerization ratio of the cationic polymerization unit (1) and the hydrophobic polymerization unit (2) is the cationic polymerization unit (1) / hydrophobic polymerization. A non-crosslinked cationic polymer having a weight average molecular weight of 10,000 to 200,000 in units (2) of 20/80 to 95/5 (mass ratio)

[Wherein, R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ are the same or different and each represents a hydrogen atom or an alkyl group having 1 carbon atom. R ⁷ represents a linear alkyl group having 1 to 18 carbon atoms. X ¹ and X ² represent an oxygen atom. Y ¹ represents an alkylene group having 1 to 4 carbon atoms. Z is a part or all of an amino group represented by the formula —N (R ⁸ ) R ⁹ (wherein R ⁸ and R ⁹ are the same or different and each represents an alkyl group having 1 to 4 carbon atoms). A group that is a salt or a quaternary ammonium salt is shown. ]
(B) Water-soluble organic solvent selected from oil component (C) water (D) polyhydric alcohol   (B) The manufacturing method of the oil-in-water emulsion composition of Claim 1 whose component is ceramides.   The manufacturing method of the oil-in-water emulsion composition of Claim 1 or 2 which has a 2nd process of adding water to the emulsion obtained by the 1st process. The manufacturing method of the oil-in-water type emulsion composition of any one of Claims 1-3 emulsified in the range of 300-5000 kg / cm < ² > of injection pressure.   The manufacturing method of the oil-in-water type emulsion composition of any one of Claims 1-4 whose oil-in-water type emulsion composition is cosmetics.