JP5503138B2 - Oil-in-water emulsified cosmetic - Google Patents

Description

  The present invention relates to an oil-in-water emulsified cosmetic.

In recent years, more excellent hypoallergenicity is expected for cosmetics. From this viewpoint, various emulsification techniques using so-called polymer emulsifiers have been proposed.
For example, a method for dispersing oil droplets in hydrated gels of PEMULEN TR-1 and TR-2 (Noveon), which are hydrophobically modified poly (meth) acrylates, and ACULYN22 (Rohm & Haas) is known. (Patent Document 1, Non-Patent Document 1).

  However, these hydrophobically modified poly (meth) acrylates have low emulsifying power, and an appropriate viscosity is required to ensure the emulsion stability. That is, since an emulsion having a fine particle size cannot be prepared, creaming occurs when the viscosity is low, and gelation occurs over time when the viscosity is high, and the usability of the emulsion composition is remarkably deteriorated. In particular, there has been a problem that it is impossible to produce a composition having a low viscosity such as a lotion.

Moreover, what has a nonionic group and the functional group which can be neutralized as a hydrophilic group of a polymeric emulsifier is proposed (patent document 2, patent document 3, patent document 4).
However, when these polymer emulsifiers are used for emulsification of oily components, it is difficult to obtain an emulsion composition in which the average particle size of oil droplets is fine, and in particular, an oil-in-water emulsion composition with excellent stability. It was difficult to get.
JP-A-8-217624 JP-A-5-103969 JP-A-8-53504 JP-A-8-52340 FRAGRANANCE JOURNAL, 1998-8, p. 79

  An object of the present invention is to provide an oil-in-water emulsified cosmetic having excellent stability and good usability.

  The present inventors have used a specific polymer emulsifier and an oil component in a specific ratio, and by using a combination of a water-soluble organic solvent and water, the oil-in-water emulsion makeup with excellent stability and good usability. It was found that a fee can be obtained.

The present invention includes the following components (A), (B), (C) and (D):
(A) a polymeric emulsifier comprising a hydrophilic structural unit (a) having a neutralizable functional group, a nonionic hydrophilic structural unit (b), and a hydrophobic structural unit (c);
(B) oily component,
(C) a water-soluble organic solvent,
(D) An oil-in-water emulsified cosmetic containing water and having a mass ratio of components (A) and (B) of (A) / (B) = 0.01 to 10 is provided.

  The oil-in-water emulsified cosmetic of the present invention has a fine average particle size of oil droplets, is excellent in stability, particularly high temperature stability, and has a good feeling in use.

  The polymer emulsifier of component (A) used in the present invention comprises a hydrophilic structural unit (a) having a neutralizable functional group, a nonionic hydrophilic structural unit (b), and a hydrophobic structural unit (c). Is included.

  Here, the hydrophilicity in the hydrophilic structural units (a) and (b) means that the solubility of the monomer forming the structural unit in distilled water at 20 ° C. (g / 100 g water) is 8 or more. The hydrophobicity in the sex structural unit (c) means that the monomer forming the structural unit has a solubility (g / 100 g water) in distilled water at 20 ° C. of less than 8.

  The polymer emulsifier (A) / oil / water emulsion composition forms a solubilized state or a low interfacial tension in a limited temperature range below the cloud point of the polymer emulsifier (A) (unneutralized product). To do. Therefore, from the viewpoint of obtaining an emulsified composition having a large content of oil components and a fine average particle diameter of oil droplets, the cloud point before neutralization of the polymer emulsifier (A) is higher than room temperature (25 ° C.), What is lower than the boiling point of water is preferable. In particular, the thing of 50-90 degreeC is preferable and the thing of 50-70 degreeC is still more preferable. Further, from the viewpoint of obtaining an emulsified composition having good stability at high temperature, the cloud point after neutralization of the polymer emulsifier (A) is preferably as high as possible, more preferably higher than 90 ° C., 91 Those having a temperature of 0 ° C. or higher are more preferable.

  Here, the cloud point is a temperature at which the polymer starts to insolubilize from the solution when the temperature of the aqueous solution of the polymer emulsifier (A) is raised, and details of the cloud point measurement conditions are as shown in the Examples. It is.

The proportion of the hydrophilic structural unit (a) having a functional group capable of neutralization in the total structural units constituting the polymeric emulsifier of component (A) is such that the cloud point after neutralization of the polymeric emulsifier (A) is 90%. From the viewpoint of exceeding ℃, 0.1 to 50% by mass is preferable, and 1 to 20% by mass is more preferable. The proportion of the nonionic hydrophilic structural unit (b) in all the structural units is preferably 30% by mass or more from the viewpoint of setting the cloud point before neutralization of the polymer emulsifier (A) to 50 to 90 ° C. 40 to 80% by mass, and more preferably 50 to 70% by mass. Moreover, 10 mass% or more is preferable from a viewpoint of obtaining sufficient emulsification performance, and the ratio of the hydrophobic structural unit (c) in all the structural units is more preferable 20-60 mass%.
In order to obtain good O / W emulsification, the proportion of the above structural units is preferably selected in the range where the HLB (= IOB × 10) of the polymer emulsifier before neutralization is 6-17.

The monomer forming the hydrophilic structural unit (a) having a neutralizable functional group is a hydrophilic monomer having a neutralizable functional group (hereinafter referred to as hydrophilic monomer (a)).
Examples of the neutralizable functional group include an acidic group or a basic group. Examples of the acidic group include a carboxyl group, a sulfonic acid group, and a phosphoric acid group; examples of the basic group include a tertiary amino group. It is done. In these, an acidic group is preferable and a carboxyl group is still more preferable.

  Specifically, as the hydrophilic monomer having an acidic group, for example, (meth) acrylic acid, maleic acid, itaconic acid, fumaric acid, crotonic acid, styrenesulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, Examples include 3-sulfopropyl (meth) acrylic acid ester, vinyl phosphonic acid, vinyl phosphate and the like.

  Examples of the hydrophilic monomer having a basic group include N, N-dimethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylamide, N, N-dimethylallylamine, 2-vinylpyridine, 4-vinylpyridine, 2-methyl-6-vinylpyridine, 5-ethyl-2-vinylpyridine and the like can be mentioned. .

  In these, the hydrophilic monomer which has an acidic group is preferable, and the carboxylic acid type hydrophilic monomer represented by General formula (4) is more preferable.

(In formula, R < ¹ >, R < ² > and R < ³ > are the same or different and show a hydrogen atom or a C1-C2 alkyl group, and M shows a hydrogen atom or a cationic group.)

In the general formula (4), R ¹ and R ² are hydrogen atoms, R ³ is preferably a methyl group, and M is preferably a hydrogen atom.

  Examples of the monomer that forms the nonionic hydrophilic structural unit (b) include the following nonionic hydrophilic monomers (hereinafter referred to as nonionic hydrophilic monomers (b)).

  Examples of the nonionic hydrophilic monomer (b) include methoxypolyethylene glycol (meth) acrylate, methoxypoly (ethylene glycol / propylene glycol) mono (meth) acrylate, ethoxypoly (ethylene glycol / propylene glycol) mono (meth) acrylate, polyethylene Examples include glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, hydroxyethyl acrylamide, and polyethylene glycol monoacrylamide.

  In these, the nonionic hydrophilic monomer represented by General formula (5) is preferable.

Wherein R ⁴ , R ⁵ and R ⁶ are the same or different and each represents a hydrogen atom or an alkyl group having 1 to 2 carbon atoms, and R ⁷ represents a linear or branched alkylene group having 1 to 4 carbon atoms. R ⁸ represents an alkyl group having 1 to 2 carbon atoms, X ¹ represents an oxygen atom or NH, and n represents a number of 1 to 30.)

In the general formula (5), R ⁴ and R ⁵ are preferably hydrogen atoms, and R ⁶ and R ⁸ are preferably methyl groups. R ⁷ is preferably an ethylene group or a propylene group, and more preferably an ethylene group. X ¹ is preferably an oxygen atom. Moreover, n is preferably 2 to 14, more preferably 4 to 9.

Examples of the monomer that forms the hydrophobic structural unit (c) include the following hydrophobic monomers (hereinafter referred to as hydrophobic monomers (c)).
As the hydrophobic monomer (c), a hydrophobic monomer represented by the general formula (6) is preferable.

(Wherein R ⁹ , R ¹⁰ and R ¹¹ are the same or different and each represents a hydrogen atom or an alkyl group having 1 to 2 carbon atoms, and R ¹² represents a linear or branched alkyl group having 1 to 30 carbon atoms or Represents an alkenyl group, and X ² represents an oxygen atom or NH.)

In the general formula (6), R ⁹ and R ¹⁰ are preferably hydrogen atoms, and R ¹¹ is preferably a methyl group. R ¹² is preferably an alkyl group or an alkenyl group having 4 to 24 carbon atoms, particularly 8 to 22 carbon atoms, and further 12 to 18 carbon atoms from the viewpoint of emulsion stability. Specific examples include octyl group, 2-ethylhexyl group, decyl group, lauryl group, myristyl group, cetyl group, stearyl group, oleyl group, and behenyl group. X ² is preferably an oxygen atom.

  Specific examples of the hydrophobic monomer (c) include butyl (meth) acrylate, octyl (meth) acrylate, lauryl (meth) acrylate, myristyl (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate, and isostearyl. (Meth) acrylate, behenyl (meth) acrylate, butyl (meth) acrylamide, octyl (meth) acrylamide, lauryl (meth) acrylamide, myristyl (meth) acrylamide, cetyl (meth) acrylamide, stearyl (meth) acrylamide, isostearyl ( Examples include meth) acrylamide and behenyl (meth) acrylamide. Of these, lauryl (meth) acrylate and stearyl (meth) acrylate are preferred.

  Particularly preferred as the polymer emulsifier for component (A) are the structural unit (a) represented by the general formula (1), the structural unit (b) represented by the general formula (2), and the general formula (3). It has the structural unit (c) represented by these.

(Wherein R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁹ , R ¹⁰ and R ¹¹ are the same or different and represent a hydrogen atom or an alkyl group having 1 to 2 carbon atoms, R ⁷ represents a linear or branched alkylene group having 1 to 4 carbon atoms, R ⁸ represents an alkyl group having 1 to 2 carbon atoms, and R ¹² represents a linear or branched alkyl group having 1 to 30 carbon atoms. A group or an alkenyl group, X ¹ and X ² are the same or different and represent an oxygen atom or NH, M represents a hydrogen atom or a cationic group, and n represents a number of 1 to 30.)

The arrangement of the hydrophilic structural unit (a) having a neutralizable functional group, the nonionic hydrophilic structural unit (b), and the hydrophobic structural unit (c) may be random, block, or graft. Moreover, structural units other than these structural units may be included.
The polymer emulsifier (A) can be obtained by a known synthesis method. For example, it can be obtained by polymerizing a monomer component containing a hydrophilic monomer (a), a nonionic hydrophilic monomer (b) and a hydrophobic monomer (c) by a solution polymerization method.

  Examples of the solvent used for the solution polymerization include aromatic hydrocarbons (toluene, xylene, etc.), lower alcohols (ethanol, isopropanol, etc.), ketones (acetone, methyl ethyl ketone, etc.), ethers (tetrahydrofuran, diethylene glycol dimethyl ether, etc.), etc. The organic solvent can be used. The solvent amount (mass basis) is preferably 0.5 to 10 times the total amount of 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. The amount of the polymerization initiator is preferably from 0.01 to 5 mol%, more preferably from 0.01 to 3 mol%, particularly preferably from 0.01 to 1 mol%, based on the total amount of the monomer components.
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 weight average molecular weight of the polymer emulsifier (A) is preferably from 5,000 to 1,000,000, more preferably from 10,000 to 200,000, and even more preferably from 10,000 to 100,000, from the viewpoints of irritation to the skin and emulsification performance. . The weight average molecular weight is a value measured by GPC (gel permeation chromatography), and details of the measurement conditions are as shown in the examples.

Specific examples of the polymer emulsifier of component (A) include methacrylic acid / methoxypolyethylene glycol (9) methacrylate / behenyl methacrylate copolymer, methacrylic acid / methoxypolyethylene glycol (12) methacrylate / behenyl. Methacrylate copolymer, methacrylic acid / methoxypolyethylene glycol (23) methacrylate / behenyl methacrylate copolymer, methacrylic acid / methoxypolyethylene glycol (9) methacrylate / stearyl methacrylate copolymer, methacrylic acid / Methoxypolyethylene glycol (12) methacrylate / stearyl methacrylate copolymer, methacrylic acid / methoxypolyethylene glycol (23) methacrylate / stearyl methacrylate Relate copolymer, methacrylic acid / methoxypolyethylene glycol (9) methacrylate / isostearyl methacrylate copolymer, methacrylic acid / methoxypolyethylene glycol (12) methacrylate / isostearyl methacrylate copolymer, methacrylic acid / Methoxypolyethylene glycol (23) methacrylate / isostearyl methacrylate copolymer, methacrylic acid / methoxypolyethylene glycol (9) methacrylate / cetyl methacrylate copolymer, methacrylic acid / methoxypolyethylene glycol (12) methacrylate / Cetyl methacrylate copolymer, methacrylic acid / methoxypolyethylene glycol (23) methacrylate / cetyl methacrylate copolymer, Acrylic acid / methoxypolyethylene glycol (9) methacrylate / myristyl methacrylate copolymer, methacrylic acid / methoxypolyethylene glycol (12) methacrylate / myristyl methacrylate copolymer, methacrylic acid / methoxypolyethylene glycol (23) meta Acrylate / myristyl methacrylate copolymer, methacrylic acid / methoxypolyethylene glycol (9) methacrylate / lauryl methacrylate copolymer, methacrylic acid / methoxypolyethylene glycol (12) methacrylate / lauryl methacrylate copolymer, meta Acrylic acid / methoxypolyethylene glycol (23) methacrylate / lauryl methacrylate copolymer, methacrylic acid / methoxypolyethylene Lenglycol (9) methacrylate / butyl methacrylate copolymer, methacrylic acid / methoxypolyethylene glycol (12) methacrylate / butyl methacrylate copolymer, methacrylic acid / methoxypolyethylene glycol (23) methacrylate / butylmethacrylate Acrylate copolymer, N, N-dimethylaminoethyl methacrylate / mexipolyethylene glycol (9) methacrylate / butyl methacrylate copolymer, N, N-dimethylaminoethyl methacrylate / mexipolyethylene glycol (12) methacrylate / butylmeta An acrylate copolymer etc. are mentioned.
Among these, methacrylic acid / methoxypolyethylene glycol (9) methacrylate / stearyl methacrylate copolymer, methacrylic acid / methoxypolyethylene glycol (9) methacrylate / cetyl methacrylate copolymer, methacrylic acid / methoxy Polyethylene glycol (9) methacrylate / myristyl methacrylate copolymer and methacrylic acid / methoxypolyethylene glycol (9) methacrylate / lauryl methacrylate copolymer are preferred.

  One or more polymeric emulsifiers of component (A) can be used, and from the viewpoint of obtaining excellent emulsification stability, preferably 0.1 to It is contained at 20% by mass, more preferably 0.5-10% by mass.

  The oil component of the component (B) used in the present invention 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 Fats and oils such as oil, olive oil, carnauba wax, lanolin, jojoba oil; glycerol monostearate, glycerol distearate, glycerol monooleate, isopropyl palmitate, isopropyl stearate, butyl stearate, isopropyl myristate, dicapric acid Neopentyl glycol, diethyl phthalate, myristyl lactate, diisostearyl malate, diisopropyl adipate, di-2-heptyl undecyl adipate, cetyl myristate, cetyl lactate, 1 Isostearoyl-3-myristoylglycerol, cetyl 2-ethylhexanoate, 2-ethylhexyl palmitate, 2-octyldodecyl myristate, neopentyl glycol di-2-ethylhexanoate, 2-octyldodecyl oleate, glycerol triisostearate , Ester oils such as diparamethoxycinnamate mono-2-ethylhexanoate glyceryl; ether oils such as cetyl 1,3-dimethylbutyl ether; higher fatty acids such as stearic acid, palmitic acid and oleic acid; higher alcohols such as stearyl alcohol and cetyl alcohol Natural oils such as rosemary, rooibos, royal jelly, hamamelis; lignan, vitamin E, oil-soluble vitamin C, vitamin A derivatives, ceramides, ceramide-like structural substances (for example, N- (3-he (Sadesiloxy-2-hydroxypropyl) -N-2-hydroxyethylhexadecanamide; see JP-A-62-228048), oil-soluble UV absorbers, functional oils such as fragrances, etc., silicones, Fluorine-based oils are listed.

  The oil component of the component (B) can be used alone or in combination of two or more, and from the viewpoint of obtaining excellent emulsion stability, preferably 0.01 to 10 in the entire composition of the emulsified cosmetic of the present invention. It is contained by mass%, more preferably 0.1-5 mass%.

  Moreover, the mass ratio of (A) polymer emulsifier and (B) oil component is (A) / (B) = 0.01-10 from a viewpoint of obtaining the outstanding emulsion stability, Preferably it is 0.1. Is 10 to 10, more preferably 0.2 to 2, and particularly preferably 0.5 to 1. When (A) / (B) is from 0.01 to 0.1, a milky white emulsion is obtained, and from 0.1 to 10, a transparent to translucent emulsion can be obtained. Moreover, when it is 0.5 to 1, an emulsion having no stickiness and excellent touch is obtained.

  As the water-soluble organic solvent of the component (C) used in the present invention, any water-soluble organic solvent that is liquid at ordinary temperatures used in ordinary cosmetics can be used. For example, lower alcohols such as ethanol and isopropanol; ethylene glycol, Glycols such as propylene glycol, dipropylene glycol, isoprene glycol, 1,3-butylene glycol, polyethylene glycol (average molecular weight 200-1540); polyhydric alcohols such as polyoxyethylene methyl glucoside, glycerin, diglycerin; Tris (2 -(2-Ethoxyethoxy) ethyl) phosphate and the like.

  Component (C) can adjust the apparent HLB in the composition by combining with component (A). For this reason, the apparent HLB in the composition can be brought close to the required HLB of the component (B) by selecting and combining the types of the component (C) with respect to the required HLB of the oily component (B) to be emulsified, The emulsion particle diameter obtained can be made finer.

  The water-soluble organic solvent of component (C) can be used singly or in combination of two or more, and in order to obtain good emulsification, preferably 0.1 to 30 mass%, More preferably, 0.1-20 mass% is contained.

  Although the water of a component (D) can be contained arbitrarily, from the viewpoint of obtaining excellent emulsification stability, the total composition of the emulsified cosmetic of the present invention is preferably 50 to 99% by mass, more preferably 60 to 99% by mass. % Content.

The cosmetic of the present invention can further contain a whitening agent, and a high whitening effect can be obtained.
The whitening agent is not particularly limited as long as it is used in normal cosmetics. For example, hydroquinones such as L-ascorbic acid and arbutin, kojic acids, tranexamic acids, ellagic acids, lucinols, linoleic acids, 4- Examples include alkoxysalicylic acids such as methoxysalicylic acid potassium salt, and placenta extract.

  Among these, L-ascorbic acids are not particularly limited, and for example, L-ascorbic acid phosphate sodium salt, which is a monovalent metal salt of L-ascorbic acid phosphate, L-ascorbic acid phosphate L-ascorbic acid phosphate magnesium salt, L-ascorbic acid phosphate calcium calcium salt, trivalent metal salt L-ascorbic acid phosphate aluminum salt; L-ascorbic acid sulfate sodium salt, L-ascorbic acid sulfate potassium salt, divalent metal salt L-ascorbic acid sulfate potassium magnesium salt, L-ascorbic acid sulfate, monovalent metal salt of acid sulfate L-a which is a calcium salt and a trivalent metal salt L-ascorbic acid sodium salt, L-ascorbic acid potassium salt, divalent metal salt L-ascorbic acid magnesium salt, L-ascorbic acid calcium salt Preferable examples include salts such as L-ascorbic acid aluminum salt, L-ascorbic acid-2-O-glucoside, and ascorbyl tetra-2-hexyldecanoate, which are trivalent metal salts.

  Among these whitening agents, L-ascorbic acid-2-O-glucoside, arbutin, kojic acid, linoleic acid, ellagic acid, and lucinol derivatives are particularly preferable.

  One or more kinds of these whitening agents can be used. From the viewpoint of the whitening effect, the emulsion stability and the feeling of use, 0.01 to 30% by mass, particularly 0.01 to 10% by mass, in addition, The content of 0.01 to 5% by mass is preferable because a sufficient whitening effect can be obtained and the usability and stability are excellent.

  Moreover, in this invention, the plant extract which has a whitening effect | action can also be used as a whitening agent. Such plant extracts include, for example, Asen, Altea, Aloe, Ogon, Dutch mustard, oysters, cuckoo, chamomile, licorice, kina, magnolia, ginseng, comfrey, hawthorn, citrus, ginger, ginger, mulberry. Examples thereof include extracts obtained from plants such as leather, tea, clove, spruce, elderberry, barley winter, loquat, matsukasa, rosemary, funnel, and bitumen.

  These plant extracts were pulverized by drying or without drying one or more parts (hereinafter referred to as “raw materials”) of the whole plant or its leaves, flowers, bark, roots, branches, etc. Thereafter, it can be obtained by extraction with a solvent or extraction using an extraction tool such as a Soxhlet extractor at room temperature or under heating. Here, the solvent used is not particularly limited. For example, water; primary alcohol such as methanol, ethanol, propanol; liquid polyhydric alcohol such as propylene glycol, 1,3-butylene glycol; liquid fatty acid such as ethyl acetate. Lower alkyl esters; hydrocarbons such as benzene, hexane, liquid paraffin; solvents such as ethyl ether and acetone; castor oil, persic oil, soybean oil, isopropyl myristate, lower fatty acid triglycerides, intermediate fatty acid triglycerides, sunflower oil, dicapric acid neo It can be obtained by extraction with an oil such as pentyl glycol or squalane. One or more of these solvents can be used. Among these, as the extraction solvent, ethanol, 1,3-butylene glycol, neopentyl glycol dicaprate, and squalane are preferable.

  As a specific example of a preferred method for extracting from the active ingredient, 1000 mL of 50 v / v% ethanol is added to 100 g of the dry pulverized product, and extraction is performed for 3 days while occasionally stirring at room temperature. The obtained extract is filtered, and the filtrate is allowed to stand at 5 ° C. for 3 days and then filtered again to obtain a supernatant. The plant extract obtained under the above conditions may be used as it is, but it can be further subjected to concentration, filtration or the like if necessary.

  Of these, chamomile extract generally contains azulene, camazulene, umbelliferone, 7-methoxycoumarin, matricin, matricalin, taraxasterol, lupeol, apiin, chroman, spiroether and the like. As a preferable method for extracting chamomile, for example, the following method may be mentioned.

  Dry and shred the chamomile flowers. Squalane is added thereto, and the mixture is immersed from room temperature to 50 ° C. with occasional stirring, followed by pressing and separation to obtain an extract. This extract is filtered to obtain a chamomile extract.

  One or more kinds of these plant extracts can be used, and in terms of dry solid content, the total composition is 0.0001 to 20% by mass, particularly 0.0001 to 10% by mass, and further 0.0001 to 5%. The content by mass% is preferable because an excellent effect of preventing and improving stains and freckles can be obtained, and the feeling of use and stability are excellent.

The oil-in-water emulsified cosmetic of the present invention can further contain a water-soluble polymer other than the component (A). By containing a small amount of a water-soluble polymer, a large amount of an oil component can be emulsified and the stability of the composition can be improved.
Specifically, carboxyvinyl polymer (trade name: Carbopol 981, etc., Lubrizol Advanced Materials, Inc.), acrylic acid / alkyl methacrylate copolymer (trade names: PEMULEN TR-1, PEMULEN TR-2, Lubrizol Advanced). Materials, Inc.), alkyl acrylate, alkyl methacrylate, polyoxyethylene (20) stearyl ether copolymer emulsion (trade name: Aculin 22, Rohm and Haas Company), ammonium acryloyl dimethyl taurate / POE ( 25) Behenyl methacrylate copolymer (trade name: Aristoflex HMB, Clariant Japan), hydroxyethyl cellulose hydroxypropi Stearyl ether hydroxypropyl sodium sulfonate (Kao Corporation), and the like.

  One or more kinds of these water-soluble polymers can be used. From the viewpoints of feeling of use such as sliminess and emulsification stability and feeling of use, 0.01 to 2% by mass, particularly 0.01 It is preferable to add ˜1% by mass, and more preferably 0.01 to 0.5% by mass, because it is excellent in use feeling and stability.

  In addition to the above components, the oil-in-water emulsified cosmetic of the present invention is a component used in ordinary cosmetics such as preservatives, antioxidants, fragrances, ultraviolet absorbers, moisturizers, blood circulation promoters, and cooling sensates. , Antiperspirants, bactericides, skin protectants, water-soluble polymers, plant extracts, surfactants, pH adjusters, thickeners, and the like.

The oil-in-water emulsified cosmetic of the present invention can be produced by mixing and emulsifying the blending components. As the emulsifier, a normal propeller stirrer, paddle stirrer, homomixer, static mixer, ultrasonic emulsifier, high-pressure homogenizer, and the like can be used.
The oil-in-water emulsified cosmetic of the present invention can be produced by the following two methods.

Manufacturing method (1):
After the system in which the components (A) to (D) are mixed is solubilized, or after the interface tension in the temperature range of the cloud point of the component (A) is low, the system is cooled to 40 ° C. or lower, and It can manufacture by including the process of neutralizing after that. The details of the conditions for confirming that the system is in a solubilized state are as shown in the examples. The temperature range of the cloud point is preferably in the range of 10 ° C. below the cloud point to 5 ° C. higher than the cloud point, more preferably in the range of 5 ° C. lower than the cloud point to 3 ° C. higher than the cloud point. It is.

  More specifically, for example, the components (A) to (D) are mixed and heated with stirring to a solubilized state, or when the amount of the oil agent is large and the solubilized state is not obtained, the component (A ) In a state where the interfacial tension in the temperature range of the cloud point is low, after holding for a certain period of time, preferably 10 minutes or more, after cooling to 40 ° C. or less, preferably 30 ° C. or less, more preferably 0 to 30 ° C. It is manufactured by adding a neutralizer and neutralizing.

  As the neutralizing agent used here, an inorganic or organic base can be used when the polymer emulsifier (A) has an acidic group as a neutralizable functional group. Examples of inorganic or organic bases include alkali metal hydroxides such as sodium and potassium; alkaline earth metal hydroxides such as calcium and magnesium; ammonia; amines such as monoethanolamine, diethanolamine, and triethanolamine Etc. When the polymer emulsifier (A) has a basic group as a neutralizable functional group, an inorganic or organic acid can be used as the neutralizing agent. Examples of inorganic acids include boric acid, carbonic acid, iodic acid, nitrous acid, nitric acid, phosphoric acid, sulfuric acid, and hydrochloric acid. Examples of organic acids include formic acid, acetic acid, maleic acid, fumaric acid, succinic acid, and malon. Examples include acid, oxalic acid, glycolic acid, lactic acid, malic acid, tartaric acid, citric acid, benzoic acid, and phthalic acid. The neutralizing agent may be added as it is, or may be added as an aqueous solution.

  In the oil-in-water emulsified cosmetic of the present invention, particularly when it is desired to obtain a fine emulsion, the components (A), (B), (C) and (D) are mixed, and the cloud point of the component (A) is exceeded. It is preferably produced by heating to a solubilized state and then cooling to 40 ° C. or lower to neutralize part or all of the component (A).

  The amount of neutralizing agent added may be any amount as long as it is greater than the amount necessary for the cloud point of the polymer emulsifier (A) after neutralization to reach a temperature exceeding 90 ° C. It is preferable to neutralize 1 mol% or more. In order to obtain an emulsified composition having a large content of the oil component (B) and a fine average particle diameter of oil droplets, the polymer emulsifier (A) is at a certain concentration or more, particularly 5 masses in the step before neutralization. % Is preferably used. Therefore, in the emulsification step, only a part of the water in the entire composition can be used, and the emulsified composition after cooling and neutralization can be diluted with the remaining water. In addition, a water-soluble organic solvent can be added in all steps, but in order to control the average particle size of oil droplets with the water-soluble organic solvent (C), it is added in the emulsification step before neutralization. It is desirable.

In the present invention, the average particle size of the oil droplets is controlled by selecting the ratio of the polymer emulsifier (A) and the oil component (B) and the type and amount of the water-soluble organic solvent (C). Can do. The average particle size of the oil droplets in the oil-in-water emulsified cosmetic of the present invention is preferably 5 to 200 nm, more preferably 5 to 100 nm.
In order to control the average particle size of the oil droplets with the water-soluble organic solvent (C), it is particularly preferable to use 5-30% by mass of the water-soluble organic solvent (C) in the emulsification step before neutralization. By reducing the average particle size and increasing the emulsification efficiency, stability and usability can be expected.

Manufacturing method (2):
When it is desired to emulsify a large amount of oily component, from the viewpoint of preventing coalescence of oil droplets, the component (A) is used from the beginning as a charged anionic surfactant. That is, it can be produced by adding a mixture of components (A) and (B) to a mixture of component (C), component (D), and component (A) neutralizer and emulsifying it. it can.
The hydrophilic part of the component (A) dissolved in the component (B) is neutralized and emulsified during emulsification, so that the component (A) can be efficiently adsorbed on the interface and is a polymer and anionic. Due to the steric repulsive force and electrostatic repulsive force of the component (A) having a large amount, it becomes possible to stably emulsify a large amount of oily components. In addition, the same thing as what was shown previously can be used for the neutralizing agent of a component (A).

In the present invention, the average particle diameter of the emulsified oil droplets is 6 μm or more, the arithmetic average diameter obtained from the micrograph is used, and those having an average particle diameter of 6 μm or less are the dynamic light scattering particle size distribution measuring device LB. The arithmetic average diameter (volume average) calculated | required from the scattered light intensity | strength measured using -500 (made by HORIBA) or LA-920 (made by HORIBA) is used.
Moreover, the transmittance | permeability% uses the transmittance | permeability% of the 1-cm cell of visible light which has a wavelength of 550 nm measured using UV-VISIBLE RECORDING SPECTROMETER (made by SHIMADZU).
These measurements are performed at 25 ° C.

  The oil-in-water emulsified cosmetics of the present invention include, for example, foundations, lotions, creams, emulsions, skin lotions, skin softening cosmetics, nutritional cosmetics, astringent cosmetics, whitening cosmetics, wrinkle improving cosmetics, and anti-aging cosmetics. It can be applied as skin cosmetics such as antiperspirants and deodorants, and as a skin external preparation.

  The measurement conditions and evaluation methods for each physical property in the following synthesis examples and examples are summarized below.

<Weight average molecular weight measurement conditions>
The weight average molecular weight of the polymer emulsifier is a weight average molecular weight in terms of polystyrene measured by GPC using a 0.5% by mass solution obtained by dissolving the polymer emulsifier in chloroform under the following conditions.
GPC measurement conditions Column: KF-804L (manufactured by Showa Denko), 2 eluents: 1 mmol / L Farmin DM20 (manufactured by Kao) / CHCl ₃ , flow rate: 1.0 mL / min, column temperature: 40 ° C., detection Instrument: Differential refractometer

<NMR measurement conditions>
The proportion of each structural unit in all the structural units of the polymer emulsifier was determined by measuring a 1% by mass solution of the polymer emulsifier dissolved in deuterium-substituted dimethyl sulfoxide by proton nuclear magnetic resonance spectrum.

<Cloud point measurement conditions>
The cloud point was confirmed according to the following method in accordance with the book written by Shinsei Surfactant, Takehiko Fujimoto, Sanyo Chemical Industries, 1992). That is, a 5% by mass aqueous solution of the polymer emulsifier is held at a constant temperature for 30 minutes to observe whether the polymer emulsifier is insolubilized from the solution. The temperature at which the polymer emulsifier began to become insoluble when the temperature was raised was taken as the cloud point.
Alternatively, in the mixed solution of the polymer emulsifier, the oil component, and water, the temperature at which the entire system becomes cloudy when the temperature is raised is defined as the cloud point.

<Solubilization condition confirmation conditions>
It was confirmed according to the following method that the system was in a solubilized state. That is, a mixed solution of a polymer emulsifier, an oil component, and water is held at a constant temperature for 10 minutes to observe whether the turbidity of the solution changes. Since the turbidity of the solution increases when the system is not in the solubilized state, the system is said to be in the solubilized state when the turbidity of the solution does not change.

<Average particle size>
At 25 ° C., the average particle diameter obtained from the micrograph is used for those having a particle diameter of 6 μm or more, and the dynamic light scattering particle size distribution analyzer LB-500 (manufactured by HORIBA) is used for those having a particle diameter of 6 μm or less. The arithmetic average diameter (volume average) obtained from the scattered light intensity measured by using was used.

<Viscosity>
The measurement was performed at 25 ° C. using a B8L viscometer (manufactured by Tokyo Keiki Co., Ltd.).

<Transparency>
At 25 ° C., the transmittance% of a 1 cm cell of visible light having a wavelength of 550 nm, which was measured using UV-VISIBLE RECORDING SPECTROMETER (manufactured by SHIMADZU), was used.

<Stability>
After the oil-in-water emulsion composition was stored at room temperature for 1 month, the degree of creaming and separation was visually evaluated according to the following criteria.
A: No change.
B: Although the transmittance slightly decreases, there is no difference in visual evaluation.
C: Slightly lower transparency and slightly creaming, but with a slight share, the creaming is unknown.
D: Creaming and separation are clearly recognized.

Synthesis Example 1 (Synthesis of polymer emulsifier (A-1))
In a reactor equipped with a stirrer, reflux condenser, thermometer, and nitrogen inlet tube, 82.5 g of methoxypolyethylene glycol (9 mol) methacrylate, 60 g of lauryl methacrylate, 7.5 g of methacrylic acid, and 100 g of polymerization solvent methyl ethyl ketone, an initiator V-65 (made by Wako Pure Chemical Industries) 1.5g was prepared, and the polymerization reaction was performed at 65 degreeC for 6 hours. Thereafter, drying was performed to obtain a polymer emulsifier (A-1). The weight average molecular weight of the obtained polymer emulsifier (A-1) was 84,000. The proportion of the structural unit derived from methoxypolyethylene glycol (9 mol) methacrylate in the total structural unit of the obtained polymer emulsifier (A-1) is 58% by mass, the proportion of the structural unit derived from lauryl methacrylate is 36% by mass, methacrylic The proportion of the structural unit derived from the acid was 6% by mass. The cloud point of the polymer emulsifier (A-1) (unneutralized product) was 60 ° C.
In addition, after neutralizing 20% or more of the structural units derived from methacrylic acid in the polymer emulsifier (A-1) with potassium hydroxide, the cloud point of the polymer emulsifier (A-1) becomes 100 ° C. or more. It was. The HLB (calculated value) was 11.6.

Synthesis Example 2 (Synthesis of polymer emulsifier (A-2))
A polymer emulsifier (A-2) having a weight average molecular weight of 69,000 was obtained by synthesis under the same conditions as in Synthesis Example 1 except that 60 g of stearyl methacrylate was used instead of 60 g of lauryl methacrylate. The proportion of the structural unit derived from methoxypolyethylene glycol (9 mol) methacrylate in all the structural units of the obtained polymer emulsifier (A-2) is 55% by mass, the proportion of the structural unit derived from stearyl methacrylate is 40% by mass, methacrylic The proportion of the structural unit derived from the acid was 5% by mass. The cloud point of the polymer emulsifier (A-2) (unneutralized product) was 60 ° C.
In addition, after neutralizing 20% or more of the structural units derived from methacrylic acid in the polymer emulsifier (A-2) with potassium hydroxide, the cloud point of the polymer emulsifier (A-2) becomes 100 ° C. or more. It was. The HLB (calculated value) was 9.8.

Synthesis Example 3 (Synthesis of polymer emulsifier (A-3))
A polymer emulsifier (A-3) having a weight average molecular weight of 73,000 was synthesized under the same conditions as in Synthesis Example 2 except that 5 g of N, N-dimethylaminoethyl methacrylate was used instead of 7.5 g of methacrylic acid. Obtained. The proportion of the structural unit derived from methoxypolyethylene glycol (9 mol) methacrylate in the total structural unit of the obtained polymer emulsifier (A-3) is 54% by mass, the proportion of the structural unit derived from stearyl methacrylate is 41% by mass, N The proportion of structural units derived from N-dimethylaminoethyl methacrylate was 5% by mass. The cloud point of the polymer emulsifier (A-3) (unneutralized product) was 60 ° C.
In addition, after neutralizing 20% or more of the structural units derived from N, N-dimethylaminoethyl methacrylate in the polymer emulsifier (A-3) with succinic acid, the cloud point of the polymer emulsifier (A-3) is It became 100 degreeC or more. The HLB (calculated value) was 9.6.

Example 1 and Comparative Examples 1 to 4
Oil-in-water emulsified cosmetics having the composition shown in Table 1 were produced, and the average particle size and viscosity were measured, and the stability was evaluated. The results are also shown in Table 1.

(Production method)
(1) Example 1
The polymer emulsifier was dissolved in 9 times the amount of purified water, and squalane was added thereto, followed by mixing and stirring at 65 to 85 ° C. The mixture was kept at that temperature for 30 minutes under stirring, and then cooled to room temperature. The obtained emulsion was neutralized by adding a 1% aqueous solution of potassium hydroxide. This was mixed with the remaining water and other components by a conventional method to obtain an oil-in-water emulsion cosmetic.

(2) Comparative Examples 1 to 4:
After mixing and dissolving paraoxybenzoic acid methyl ester, 86% glycerin, and purified water at 80 ° C., an acrylic acid / alkyl methacrylate copolymer was added with stirring, and after dissolution, neutralized with an aqueous L-arginine solution. Thereafter, squalane was added with stirring, held for 20 minutes, and then cooled to room temperature to obtain an emulsified composition.

  The oil-in-water emulsified cosmetic of the present invention has low viscosity and excellent stability at high temperature, whereas the comparative example using an acrylic acid / alkyl methacrylate copolymer has a large emulsion particle size and low viscosity. Those with viscosity are unstable.

Examples 2-4
An oil-in-water emulsified cosmetic composition having the composition shown in Table 2 was produced, and the average particle size, permeability and stability were evaluated. The results are also shown in Table 2.

(Production method)
The polymer emulsifier was dissolved in 3 times the amount of water, and a water-soluble organic solvent and neopentyl glycol dicaprate were added thereto, followed by mixing and stirring at 60 to 85 ° C. The mixture was kept at that temperature for 30 minutes under stirring, and then cooled to room temperature. The obtained emulsion was neutralized by adding a 1% aqueous potassium hydroxide solution and then mixed with the remaining water and other components by a conventional method to obtain an oil-in-water emulsion cosmetic. In Example 2, the water-soluble organic solvent was not added at the time of preparing the emulsion, and was finally added simultaneously with the remaining components.

Examples 5-7, Comparative Example 5
An oil-in-water emulsified cosmetic composition having the composition shown in Table 3 was produced, and the average particle size, permeability and stability were evaluated. The results are also shown in Table 3.

(Production method)
The polymer emulsifier was dissolved in 9 times the amount of purified water, the oil agent was added thereto, and the mixture was stirred at 65 to 85 ° C. The mixture was kept at that temperature for 30 minutes under stirring, and then cooled to room temperature. The obtained emulsion was neutralized with a 1% aqueous solution of potassium hydroxide, and then mixed with the remaining water and other components by a conventional method to obtain an oil-in-water emulsion cosmetic.
An emulsified cosmetic of Comparative Example 5 was obtained in the same manner as in Example 6 except that polyoxyethylene stearyl ether was used instead of the polymer emulsifier and neutralization was omitted.

Example 8
A whitening oil-in-water emulsified cosmetic composition having the following composition was produced. The mass ratio of components (A) and (B) is (A) / (B) = 0.67.
The obtained oil-in-water emulsion composition had an average particle diameter of oil droplets of 78 nm.

(Production method)
The polymer emulsifier was dissolved in 7.65 times purified water, and 1,3-butylene glycol, neopentyl glycol dicaprate and chamomile extract were added thereto, and mixed and stirred at 65 to 85 ° C. The mixture was kept at that temperature for 30 minutes under stirring, and then cooled to room temperature. The obtained emulsion was neutralized with a 1% aqueous potassium hydroxide solution and then mixed with the remaining water and other components by a conventional method to obtain a whitening oil-in-water emulsion cosmetic.

(component)
Polymer emulsifier (A-2) 1 (mass%)
Neopentyl glycol dicaprate 1
Chamomile extract 0.5
86% glycerin 2.5
1,3-butylene glycol 1.35
Ethanol 5
Polyethylene glycol 1540 0.3
Eucalyptus extract 1
Sodium monohydrogen phosphate 0.033
Sodium dihydrogen phosphate 0.017
P-Hydroxybenzoic acid methyl ester 0.15
Pullulan PI-20 0.01
Potassium hydroxide 0.004
Purified water balance

Example 9
A whitening oil-in-water emulsified cosmetic composition having the following composition was produced. The mass ratio of components (A) and (B) is (A) / (B) = 0.67.
The obtained oil-in-water emulsion composition had an average particle size of oil droplets of 54 nm.

(Production method)
A polymer emulsifier is dissolved in 9.56 times purified water, and 1,3-butylene glycol, squalane, neopentyl glycol dicaprate, N- (hexadecyloxyhydroxypropyl) -N-hydroxyethylhexadecanamide And silicone (6cs) were added and mixed and stirred at 85 ° C. The mixture was kept at that temperature for 30 minutes under stirring, and then cooled to room temperature. The obtained emulsion was neutralized by adding a 1% aqueous potassium hydroxide solution and then mixed with the remaining water and other components by a conventional method to obtain a whitening oil-in-water emulsion cosmetic.

(component)
Polymer emulsifier (A-2) 0.8 (mass%)
Squalane 0.5
Neopentyl glycol dicaprate 0.4
N- (hexadecyloxyhydroxypropyl) -N-
Hydroxyethyl hexadecanamide 0.2
Silicone (6cs) 0.1
86% glycerin 2.5
1,3-butylene glycol 1.35
Jiyu extract 1
Potassium hydroxide 0.004
P-Hydroxybenzoic acid methyl ester 0.15
Purified water balance

Example 10
A whitening oil-in-water emulsified cosmetic composition having the following composition was produced. The mass ratio of components (A) and (B) is (A) / (B) = 1.5.
The obtained oil-in-water emulsion composition had an oil droplet average particle size of 42 nm.

(Production method)
The polymer emulsifier was dissolved in 17-fold purified water, and 1,3-butylene glycol and neopentyl glycol dicaprate were added thereto, followed by mixing and stirring at 65 to 85 ° C. The mixture was kept at that temperature for 30 minutes under stirring, and then cooled to room temperature. The obtained emulsion was neutralized by adding a 1% aqueous potassium hydroxide solution and then mixed with the remaining water and other components by a conventional method to obtain a whitening oil-in-water emulsion cosmetic.

(component)
Polymer emulsifier (A-2) 0.45 (mass%)
Neopentyl glycol dicaprate 0.3
86% glycerin 2.5
1,3-butylene glycol 1.35
L-ascorbic acid-2-glucoside 2
Jiyu extract 1
Potassium hydroxide 0.004
P-Hydroxybenzoic acid methyl ester 0.15
Sodium monohydrogen phosphate 0.033
Sodium dihydrogen phosphate 0.017
Purified water balance

Example 11
An oil-in-water emulsified cosmetic for sensitive skin having the following composition was produced. The mass ratio of components (A) and (B) is (A) / (B) = 0.67.
The obtained oil-in-water emulsion composition had an oil droplet average particle size of 63 nm.

(Production method)
The polymer emulsifier was dissolved in 9.56 times purified water, and 1,3-butylene glycol and neopentyl glycol dicaprate were added thereto, and mixed and stirred at 65 to 85 ° C. The mixture was kept at that temperature for 30 minutes under stirring, and then cooled to room temperature. The obtained emulsion was neutralized by adding a 1% aqueous potassium hydroxide solution, and then mixed with the remaining water and other components by a conventional method to obtain an oil-in-water emulsified cosmetic for sensitive skin.

(component)
Polymer emulsifier (A-2) 0.8 (mass%)
Neopentyl glycol dicaprate 1.2
86% glycerin 2.5
1,3-butylene glycol 1.35
Dipotassium glycyrrhizinate 0.1
Asunaro Extract 1
Potassium hydroxide 0.004
P-Hydroxybenzoic acid methyl ester 0.15
Sodium monohydrogen phosphate 0.033
Sodium dihydrogen phosphate 0.017
Purified water balance

Example 12
A whitening oil-in-water emulsified cosmetic composition having the following composition was produced. The mass ratio of components (A) and (B) is (A) / (B) = 0.67.
The obtained oil-in-water emulsion composition had an average particle size of oil droplets of 80 nm.

(Production method)
After the polymer emulsifier was dissolved in 7.65 times purified water, 1,3-butylene glycol, neopentyl glycol dicaprate and chamomile extract were added and mixed and stirred at 65 to 85 ° C. The mixture was kept at that temperature for 30 minutes under stirring, and then cooled to room temperature. The obtained emulsion was neutralized by adding a 1% aqueous potassium hydroxide solution and then mixed with the remaining water and other components by a conventional method to obtain a whitening oil-in-water emulsion cosmetic.

(component)
Polymer emulsifier (A-2) 1 (mass%)
Neopentyl glycol dicaprate 1
Chamomile extract 0.5
86% glycerin 1
1,3-butylene glycol 1.35
Ethanol 5
Polyethylene glycol 1540 0.3
Altea extract 1
Sodium monohydrogen phosphate 0.033
Sodium dihydrogen phosphate 0.017
Carboxyvinyl polymer (Carbopol 980, manufactured by Noveon) 0.3
Potassium hydroxide 0.15
P-Hydroxybenzoic acid methyl ester 0.15
Purified water balance

Example 13
An oil-in-water emulsified cosmetic composition having the following composition was produced. The mass ratio of components (A) and (B) is (A) / (B) = 0.033.
The obtained oil-in-water emulsion composition had an average particle diameter of oil droplets of 1.6 μm.

(Production method)
(1) 86% glycerin, polyethylene glycol 1540, and methyl paraoxybenzoate are dissolved in purified water at 80 ° C.
(2) The acrylic acid / alkyl methacrylate copolymer dispersed in dimethicone is added to the aqueous phase of (1), and stirred and held at 80 ° C. for 60 minutes.
(3) An aqueous potassium hydroxide solution (dissolved in 2% by mass of purified water) is added to the aqueous phase of (2) and neutralized.
(4) Cetyl PG hydroxyethyl palmitamide, squalane, olive oil, and polymer emulsifier (A-2) were dissolved at 80 ° C., and then gradually added to the aqueous phase of (3), and a homogenizer (TK) Stir at 9000 rpm for 4 minutes.
(5) The emulsion of (4) is cooled to room temperature with stirring, phenoxyethanol is added, and stirring is maintained for 5 minutes to obtain an oil-in-water emulsion composition.

(component)
Polymer emulsifier (A-2) 0.5 (mass%)
Acrylic acid / alkyl methacrylate copolymer (PEMULEN TR-1) 0.1
Cetyl PG hydroxyethyl palmitamide 2
Squalane 5
Olive oil 3
Dimethicone 5
86% glycerin 17
Potassium hydroxide 0.066
Methyl paraoxybenzoate 0.2
Phenoxyethanol 0.3
Purified water balance

Example 14
An oil-in-water emulsified cosmetic composition having the following composition was produced. The mass ratio of components (A) and (B) is (A) / (B) = 0.040.
The obtained oil-in-water emulsion composition had an oil droplet average particle size of 1.2 μm.

(Production method)
(1) 86% glycerin, polyethylene glycol 1540, and methyl paraoxybenzoate are dissolved in purified water at 80 ° C.
(2) The acrylic acid / alkyl methacrylate copolymer dispersed in dimethicone is added to the aqueous phase of (1), and stirred and held at 80 ° C. for 60 minutes.
(3) An aqueous potassium hydroxide solution (dissolved in 2% by mass of purified water) is added to the aqueous phase of (2) and neutralized.
(4) Cetyl PG hydroxyethyl palmitamide, olive oil, hydrogenated polyisobutene, cholesteryl isostearate, and polymer emulsifier (A-2) are dissolved at 80 ° C., and then gradually added to the aqueous phase of (3). , And stirred at 9000 rpm for 4 minutes with a homogenizer (TK Robotics, manufactured by Tokushu Kika Kogyo Co., Ltd.).
(5) Cool the emulsion of (4) to room temperature with stirring, add phenoxyethanol, and hold stirring for 5 minutes.

(component)
Polymer emulsifier (A-2) 1 (mass%)
Stearoxy PG hydroxyethyl cellulose sulfonate Na 0.25
Cetyl PG hydroxyethyl palmitamide 2
Olive oil 3
Hydrogenated polyisobutene 14
Cholesteryl isostearate 3
Dimethicone 3
86% glycerin 17
Polyethylene glycol 1540 3
Potassium hydroxide 0.066
Methyl paraoxybenzoate 0.2
Phenoxyethanol 0.3
Purified water balance

  All of the oil-in-water emulsified cosmetics obtained in Examples 8 to 14 had excellent stability and good usability.

Claims (9)

The following components (A), (B), (C) and (D):
(A) A hydrophilic structural unit (a) having a neutralizable functional group represented by the general formula (1), a nonionic hydrophilic structural unit (b) represented by the general formula (2 ), and general 0.1 to 20% by mass of a polymer emulsifier containing a hydrophobic structural unit (c) represented by the formula (3) ,

(Wherein R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁹ , R ¹⁰ and R ¹¹ are the same or different and represent a hydrogen atom or an alkyl group having 1 to 2 carbon atoms, R ⁷ represents a linear or branched alkylene group having 1 to 4 carbon atoms, R ⁸ represents an alkyl group having 1 to 2 carbon atoms, and R ¹² represents a linear or branched alkyl group having 12 to 18 carbon atoms. A group or an alkenyl group, X ¹ and X ² represent an oxygen atom, M represents a hydrogen atom or a cationic group, and n represents a number of 1 to 30.)
(B) Oil component 0.01 to 10% by mass,
(C) 0.1-30 mass% of water-soluble organic solvent,
(D) An oil-in-water emulsified cosmetic containing water and having a mass ratio of components (A) and (B) of (A) / (B) = 0.01-10. In component (A), the nonionic hydrophilic structural unit (b) contains methoxypolyethylene glycol (meth) acrylate, methoxypoly (ethylene glycol / propylene glycol) mono (meth) acrylate, ethoxypoly (ethylene glycol / propylene glycol) mono ( meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate is derived from a preparative claim 1 oil-in-water type emulsified cosmetic according. , In the component (A), but the hydrophobic structural unit (c) is derived from butyl (meth) acrylate, octyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, a behenyl (meth) acrylate bets The oil-in-water emulsified cosmetic according to claim 1 or 2 . The oil-in-water emulsified cosmetic according to any one of claims 1 to 3 , wherein the average particle size of the oil droplets is 5 to 200 nm. After the system in which the components (A), (B), (C) and (D) are mixed is in a solubilized state or after the interfacial tension in the temperature range of the cloud point of the component (A) is low, The oil-in-water emulsified cosmetic according to any one of claims 1 to 4 , which is obtained by a production method including a step of cooling to 40 ° C or lower and then neutralizing. Obtained by a production method including a step of adding and emulsifying components (A) and (B) to a mixture of component (C), component (D), and component (A) neutralizer. The oil-in-water emulsified cosmetic according to any one of claims 1 to 4 . Furthermore, the oil-in-water emulsion cosmetic of any one of Claims 1-6 containing water-soluble polymers other than a component (A). The proportion of the hydrophilic structural unit (a) having a functional group capable of neutralization is 0.1 to 50% by mass, and the proportion of the nonionic hydrophilic structural unit (b) in all the structural units constituting the component (A). The oil-in-water emulsified cosmetic according to any one of claims 1 to 7 , wherein 30 to 80% by mass and the proportion of the hydrophobic structural unit (c) is 10 to 60% by mass. The oil-in-water emulsified cosmetic according to any one of claims 1 to 8 , wherein the component (A) has a weight average molecular weight of 10,000 to 200,000.