JP2009001828A - Polymer composite particle and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polymer composite particle having superb blending stability even in a W/O emulsion cosmetic, a highly effective ultraviolet protection effect and a good feeling in use, a method of manufacturing the same, and a cosmetic composition containing the polymer composite particle. <P>SOLUTION: The polymer composite particle containing a metal oxide coated with a silicone and/or fluorine compound and having an average particle diameter of 1 μm or less, wherein the cosmetic comprising the polymer composite particle in an amount corresponding to 5 mass% of the metal oxide and 1 mass% of 2-ethylhexyl 4-methoxycinnamate has an SPF of 7 or more; its manufacturing method; and the cosmetic containing the composite polymer particle; are provided. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a composite polymer particle containing a metal oxide, which is excellent in blending stability to W / O-based cosmetics, a feeling of use and an ultraviolet protection ability, a process for producing the same, and a cosmetic containing the same.

  Cosmetics contain UV absorbers for the purpose of protecting the skin from UV rays. Ultraviolet absorbers can be broadly classified into organic and inorganic types. The former includes cinnamic acid derivatives, benzophenone derivatives, methylaminobenzoic acid derivatives, salicylic acid derivatives, etc., and the latter includes zinc oxide, titanium oxide, cerium oxide, iron oxide, etc. These metal oxides can be mentioned. In the case of organic ultraviolet absorbers, there are problems that the absorption wavelength region is a low wavelength, the compound is not stable, and penetrates into the skin and the effect is not sustained. In the case of inorganic ultraviolet absorbers, the problem is that the dispersibility in the compounding system is not good and the feeling of use is not so good.

Encapsulation of metal oxides is known as one proposal for achieving both dispersibility in a compounding system and a feeling of use. For example, Patent Document 1 discloses a cosmetic in which a resin powder containing a metal oxide having an average particle size of 0.003 to 0.1 μm is blended in an emulsion cosmetic. However, in this method, an ionic dispersant is used to disperse the metal oxide. Therefore, when the metal oxide is partially present on the surface of the resin powder, In addition, the hydrophilic portion of the metal oxide aggregates, the blending stability is deteriorated, and the UV protection effect may not be sufficiently exhibited.
JP-A-9-208437

  An object of the present invention is to provide composite polymer particles that are excellent in blending stability, have a high UV protection effect and have a good feeling during use, and a method for producing the same, and a cosmetic containing the same.

  The present invention is a composite polymer particle containing a metal oxide having an average particle diameter of 1 μm or less and coated with silicone and / or a fluorine compound, and the amount of the metal oxide in the cosmetic is equivalent to 5% by mass. The composite polymer particle, and a cosmetic material containing 1% by mass of 2-ethylhexyl 4-methoxycinnamate having an SPF of 7 or more, a composite polymer particle production method, and a cosmetic containing the composite polymer particle Provide a fee.

  In order to exert the UV protection ability, the metal oxide has a considerable effective amount in the composite polymer particles and is uniformly dispersed, and the composite polymer particles are uniformly dispersed in the compounding composition. It is necessary to satisfy the two conditions. Usually, when a high concentration of the surface-untreated metal oxide is blended, the monomer is absorbed and the fluidity is lost and emulsification cannot be performed. However, in the present invention, the average particle size is 1 μm or less with silicone and / or fluorine compound By using a coated metal oxide and a monomer having a solubility parameter of less than 8.9, a considerable amount of the metal oxide can be dispersed relatively uniformly in the composite polymer particles, and the fluidity is good. And can be emulsified. And since it can mix | blend stably in cosmetics, the cosmetics which mix | blended the composite polymer particle of this invention have high ultraviolet-ray protective ability, and its usability | use_condition is also favorable.

[Composite polymer particles]
The composite polymer particles of the present invention have a high UV protection ability and excellent usability, so that the average particle size is preferably 0.1 to 20 μm, and more preferably 1 to 20 μm. If it is 20 μm or less, the shielding area becomes large and the ultraviolet ray protection effect becomes high. If the particle size is too small, a “squeaky sensation” is generated. The shape of the particles is not particularly limited, but a spherical shape is preferable because of excellent usability.

  The average particle diameter of the composite polymer particles is a volume average particle diameter measured by a laser (light) diffraction / scattering method (LA-910 manufactured by Horiba, Ltd.) or an electric resistance method (Coulter counter).

  In the composite polymer particle of the present invention, the metal oxide content is preferably 25 to 90% by mass, and more preferably 30 to 70% by mass, based on the entire composite polymer particle. Within this range, it has excellent UV protection ability.

The composite polymer particles of the present invention preferably have an SPF of 7 or more as measured by the SPF measurement method in the formulation composition of Test Example 1 described later.
That is, the composite polymer particle of the present invention is a composite polymer particle coated with silicone and / or a fluorine compound and containing a metal oxide having an average particle diameter of 1 μm or less, and the amount of metal oxide in the cosmetic is 5 mass. % Of the composite polymer particles in an amount corresponding to%, and a cosmetic polymer containing 1% by mass of 2-ethylhexyl 4-methoxycinnamate having an SPF of 7 or more.

  In order for a cosmetic containing an amount of composite polymer particles corresponding to 5% by mass of metal oxide and 1% by mass of 2-ethylhexyl 4-methoxycinnamate to have an SPF of 7 or more in the measurement method described later. It is necessary that the metal oxide is dispersed in the cosmetic. Therefore, SPF is also a dispersion index indicating that a metal oxide is dispersed in polymer particles.

[Metal oxide]
Examples of the metal oxide include silicon dioxide, iron oxide, zirconium oxide, aluminum oxide, zinc oxide, titanium oxide, cerium oxide, and the like, but because of their high ultraviolet protection ability, zinc oxide, titanium oxide and / or cerium oxide. One or more selected from the group consisting of

  As the metal oxide, one coated with silicone and / or a fluorine compound is used. By coating with silicone and / or fluorine compound and making it hydrophobic, the dispersibility with the monomer is improved, and even if it exists on the surface of the composite polymer particle, the metal oxide surface is made hydrophobic, so the polymer While preventing aggregation of each other, the UV protection ability is enhanced.

  In order to coat with silicone and / or a fluorine compound, it is preferable to perform a metal oxide surface treatment. Examples of the treating agent include methyl hydrogen polysiloxane, dimethyl polysiloxane, a hydroxy group, a halogen atom, an amino hydrogen group, or an alkoxy group as described in JP-A-5-339518 and JP-A-7-196946. (These functional groups may be present at one end, both ends, or in the side chain, and may be a divalent hydrocarbon group which may be directly or substituted on a silicon atom.) And fluorine group-containing hydrogen polysiloxane described in JP-A-6-23262. These can be reacted with the metal oxide by heating or the like if necessary. Further, commercially available metal oxides coated with silicone and / or fluorine compounds can also be used.

  0.1-20 mass parts is preferable with respect to 100 mass parts of metal oxides, and, as for the coating amount of a silicone and / or a fluorine compound, 1-10 mass parts is still more preferable.

  The average particle diameter of the metal oxide is preferably 1 μm or less, more preferably 0.01 to 1 μm, and particularly preferably 0.1 to 1 μm from the viewpoint of enhancing the ultraviolet protection ability and the transparency of the composite polymer particles.

  The average particle diameter of the metal oxide is a volume average particle diameter measured by a dynamic light scattering method (ELS-8000 manufactured by Otsuka Electronics).

[monomer]
The vinyl monomer used as the raw material of the composite polymer particle of the present invention increases the dispersibility of the metal oxide coated with silicone and / or fluorine compound, and reduces the non-uniformity in the metal oxide particle as much as possible. From the viewpoint, it is preferable to use a monomer having a solubility parameter of less than 8.9, more preferably a monomer having a solubility parameter of 8.8 or less, and a lower limit of 6.0 or more is preferable, and 7.0 or more is more preferable because of the availability of the monomer. preferable. The solubility parameter is a value obtained by rounding off the value of the second digit of the decimal point. When the solubility parameter is high, the metal oxide is uniformly dispersed in the monomer, but in the composite polymer particles after polymerization, the metal oxide is collected in the vicinity of the surface layer, and the UV protection effect is lowered.

The solubility parameter referred to in this specification is a value δ (cal / cm ³ ) calculated by the following formula (I) by the method of Fedors [RF Fedors. Polyme. Eng. Sic., 14, 147 (1974)]. ) ^1/2 value (hereinafter also referred to as SP value).

  As a vinyl monomer having a solubility parameter of less than 8.9, an alkyl (meth) acrylate having a linear or branched alkyl group having 8 or more carbon atoms (more preferably 8 to 40 carbon atoms) which may be fluorinated, More preferably, an alkyl (meth) acrylate having a linear or branched alkyl group having 10 to 22 carbon atoms which may be fluorinated, or a dimethylpolysiloxane compound having a radical polymerizable group at one end of the molecular chain. Can be mentioned. Here, (meth) acrylate means acrylate or methacrylate. Specific examples include octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, myristyl (meth) acrylate, palmityl (meth) acrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate, Examples include behenyl (meth) acrylate and 2- (perfluoroalkyl) ethyl (meth) acrylate having 6 or more carbon chains. The dimethylpolysiloxane compound having a radically polymerizable group at one end is preferably a compound represented by the general formula (II) described in JP-A No. 11-181003.

[Where,
A: A group represented by CH ₂ ═C (R ¹ ) COO—, CH ₂ ═C (R ¹ ) CONR ² — or CH ₂ ═CH—C ₆ H ₄ —. However, R ¹ = H or CH ₃ , R ² = H or C _Y H _{2Y + 1} (Y is an integer of 1 to 4)
B: A group represented by — (CH ₂ O) _m —C _n H _2n — (m = 0 or 1, n = 1 to 10).
E: A group represented by C _p H _{2p + 1} (p = 1 to 4).
a: Number from 3 to 1500. ]

The number average molecular weight (Mn) of the dimethylpolysiloxane compound having a radically polymerizable group at one end is not particularly limited, but is preferably 500 to 100,000, more preferably 1,000 to 50,000. It is.

  Unless the effect of the present invention is impaired, a vinyl monomer having a solubility parameter of 8.9 or more such as styrene or methyl methacrylate may be copolymerized. The vinyl monomer having a solubility parameter of less than 8.9 is preferably 25 parts by mass or more, more preferably 40 parts by mass or more, and more preferably 99.9 parts by mass with respect to 100 parts by mass in total of all monomers and the crosslinking agent. Part or less, preferably 97 parts by weight or less, more preferably 90 parts by weight or less.

[Crosslinking agent]
In the present invention, a crosslinking agent is used to physically and chemically strengthen the coating of the composite polymer particles. Examples of the crosslinking agent include a crosslinkable vinyl compound having at least two radical polymerizable groups (reactive unsaturated groups) in the molecule.

  Specific examples of the crosslinkable vinyl compound having at least two radical polymerizable groups include (1) ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, polyethylene glycol di (Meth) acrylate, 1,3-butanediol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1,10-decanediol di (meth) acrylate, propylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pen (Meth) acrylic acid ester compounds of polyhydric alcohols having two or more (meth) acrylate residues such as taerythritol tetra (meth) acrylate and dipentaerythritol hexa (meth) acrylate; (2) N-methylallylacrylamide; Acrylamide compounds such as N-vinylacrylamide, N, N'-methylenebis (meth) acrylamide, bisacrylamideacetic acid; (3) Divinyl compounds such as divinylbenzene, divinyl ether, divinylethyleneurea; (4) diallyl phthalate, diallyl malate Polyallylation of diallylamine, triallylamine, triallylammonium salt, allyl etherified pentaerythritol, allyl etherified sucrose having at least two allyl ether units in the molecule Things; (5) vinyl (meth) acrylate, allyl (meth) acrylate, 2-hydroxy-3-acryloyloxy propyl (meth) (meth) acrylic acid esters of unsaturated alcohols acrylate and the like.

  The crosslinking agent is preferably 0.1 parts by mass or more, more preferably 3 parts by mass or more, particularly preferably 10 parts by mass or more, and the upper limit is 75 parts by mass or less with respect to 100 parts by mass in total of all monomers and the crosslinking agent. Preferably, 60 parts by mass or less is more preferable, and 55 parts by mass or less is particularly preferable.

[Production method of composite polymer particles]
The composite polymer particle of the present invention is a step of dispersing and mixing a metal component coated with silicone and / or a fluorine compound, a monomer component containing a vinyl monomer having a solubility parameter of less than 8.9, and a crosslinking agent (hereinafter referred to as step 1). Then, it is produced by a step of suspension polymerization (hereinafter referred to as step 2).

  In Step 1, a metal oxide and a monomer component (including a vinyl monomer having a solubility parameter of less than 8.9 and optionally a monomer of 8.9 or more if necessary) and a crosslinking agent coated with silicone and / or a fluorine compound The total mass of the metal oxide / monomer component and the crosslinking agent is preferably 25/75 to 90/10, and more preferably 30/70 to 70/30.

  To disperse the vinyl monomer, an organic solvent may be added as necessary in order to increase the dispersion efficiency. Examples of such organic solvents include linear or cyclic saturated hydrocarbon solvents (n-pentane, n-hexane, n-heptane, n-octane, n-nonane, n-decane, cyclohexane, etc.), direct Chain or cyclic unsaturated hydrocarbon solvents (toluene, xylene, etc.), ketone organic solvents (acetone, methyl ethyl ketone, etc.), ester organic solvents (ethyl acetate, butyl acetate, etc.), linear or cyclic polydimethylsiloxane, etc. Is mentioned.

  Here, for the dispersion, a disperser such as a homogenizer, a high-pressure homogenizer, an ultrasonic disperser, an attritor mill, a ball mill, or a sand mill is used.

  The dispersion / emulsifier added in Step 2 may be added in Step 1 as necessary. When adding, it is preferable to add 1-30 mass parts with respect to 100 mass parts of metal oxides. The dispersion time is preferably about 30 minutes to 5 hours.

  In Step 2, the dispersion liquid obtained in Step 1 is mixed with water, a polymerization initiator, and a dispersion / emulsifier, emulsified or suspended, and then polymerized.

  Dispersing and emulsifying agents for suspension polymerization include anionic surfactants such as sodium lauryl sulfate, sodium cetyl sulfate, sodium polyoxyethylene lauryl ether sulfate, sodium fatty acid, sodium alkyl (methyl) taurine, and other cationic Low molecular surfactants such as surfactants and nonionic surfactants; polymer dispersants such as polyvinyl alcohol, polyvinyl pyrrolidone, hydroxyethyl cellulose, hydroxypropyl cellulose, gelatin, starch, carboxymethyl cellulose, polyvinyl alkyl ether; barium sulfate And poorly water-soluble inorganic salts such as potassium sulfate, barium carbonate, calcium carbonate, magnesium carbonate and calcium phosphate. The dispersion / emulsifier is preferably added in an amount of 0.1 to 20 parts by mass with respect to 100 parts by mass of the dispersion obtained in Step 1.

  The polymerization initiator is determined according to the reaction system, and examples thereof include peroxide-based initiators, organic or inorganic peracids or salts thereof, redox-based compounds alone or in combination with a reducing agent.

  For example, t-butyl peroxide, t-amyl peroxide, cumyl peroxide, acetyl peroxide, propionyl peroxide, benzoyl peroxide (BPO), benzoylisobutyryl peroxide, lauroyl peroxide (LPO), t-butyl hydro Peroxide, cyclohexyl hydroperoxide, tetralin hydroperoxide, t-butyl peracetate, t-butyl perbenzoate, bis (2-ethylhexyl peroxydicarbonate), 2,2'-azobisisobutyronitrile (AIBN) 2,2'-azobisisovaleronitrile, 2,2'-azobis (2-methylbutyronitrile), phenylazotriphenylmethane, 2,2'-azobis (2-amidinopropane) dihydrochloride, 2 , 2'-azobis [2- (5-mes Ru-2-imidazolin-2-yl) propane] dihydrochloride, 2,2′-azobis [2- (2-imidazolin-2-yl) propane] dihydrochloride, sodium persulfate, potassium persulfate, ammonium persulfate And combinations of hydrogen peroxide, persulfates and tertiary amines such as triethylamine, triethanolamine, and dimethylaniline.

  The polymerization initiator is preferably 0.1 to 5% by mass with respect to the total amount of the vinyl monomer and the crosslinking agent. The polymerization initiation temperature is preferably 20 to 95 ° C., and the polymerization time is preferably 3 to 48 hours.

  As described above, a metal component coated with silicone and / or a fluorine compound, a monomer component containing a vinyl monomer having a solubility parameter of less than 8.9, and a crosslinking agent are dispersed or suspended in water according to a known method as described above. The target composite polymer particles can be produced by turbidizing the droplets and conducting a polymerization reaction.

  After the polymerization, the composite polymer particles are separated into solid and liquid by filtration, centrifugation, etc., the aqueous phase is removed, washed with water if necessary, and then simply powdered by ordinary means such as reduced pressure drying, spray drying, freeze drying and the like. Can be separated. In addition, the aggregate is crushed as necessary. As a crushing method, a dry method such as a jet mill, a pin mill, a comb mill, a hammer mill, a feather mill or the like, or a wet method such as a line mixer, a disper, a homogenizer, a milder or a homomixer can be used.

[Cosmetics]
Cosmetics that can be blended with the composite polymer particles of the present invention can be blended into ordinary cosmetics as long as they can exhibit a UV shielding effect and a skin hiding effect. Specifically, makeup cosmetics such as foundation, blusher, eye shadow, mascara, eyeliner, eyebrow, lipstick, nail enamel, sunscreen cosmetics, and base cosmetics are preferable. 0.1-60 mass parts is preferable and, as for content of the composite polymer particle in cosmetics, 1-40 mass parts is still more preferable.

Furthermore, in cosmetics, other components used as usual raw materials for cosmetics, such as white pigments (titanium oxide, etc.), extender pigments (mica, talc, sericite, barium sulfate, etc.), color pigments (bengala, Yellow iron oxide, black iron oxide, yellow 401, red 226, encapsulated colored pigment, organic pigment, pearl pigment, natural mineral, organic powder, oil (petrol, lanolin, ceresin, olive oil, jojoba oil, castor oil, Solids such as squalane, liquid paraffin, ester oil, diglyceride, triglyceride, silicone oil, perfluoropolyether, fluorine-modified silicone oil), UV protection agent, gelling agent, wax (microcrystalline wax, higher fatty acid and higher alcohol) Semi-solid oil etc.), metal soap, surfactant, moisturizer, preservative, fragrance, thickener, oxidation Stop, fungicides, antiperspirants, can be formulated by selecting the other various additives as appropriate.
The cosmetic of the present invention is used in the form of products such as solid cosmetics, wax cosmetics, emulsion (O / W, W / O) cosmetics, liquid cosmetics, gel cosmetics and the like.

Example 1
Using a bead mill, 60 g of Teica silicone-treated zinc oxide (MZ-507S) was stirred in 45 g of lauryl methacrylate (SP value 8.7) and 45 g of ethylene glycol dimethacrylate (measured with ELS-8000 manufactured by Otsuka Electronics). Zinc oxide average particle size 0.3 μm). Thereafter, 3 g of lauroyl peroxide was added. 20 g of sodium lauryl sulfate was dissolved in 1500 g of ion-exchanged water, added to the above-mentioned zinc oxide slurry, and dispersed using a milder (average particle diameter of emulsion measured by LA-910 manufactured by Horiba, Ltd.). The dispersion was then charged into a 2000 mL separable flask, purged with nitrogen, heated to 70 ° C. with stirring at 200 r / min, raised to 70 ° C. for 10 hours, further raised to 80 ° C., and then heated to 80 ° C. Polymerization was performed in a nitrogen atmosphere for 10 hours. After completion of the polymerization, the solid was collected by centrifugation, washed with water, freeze-dried, and crushed with a jet mill to obtain 120 g of composite polymer particles (inclusion ratio of zinc oxide 40% by mass).
A scanning electron micrograph of the obtained composite polymer particles is shown in FIG. 1, and a transmission electron micrograph is shown in FIG.

Example 2
Using a bead mill, 90 g of Teica silicone-treated zinc oxide (MZ-507S) was stirred for 3 hours in 45 g of stearyl methacrylate (SP value 8.7), 45 g of 1,6-hexanediol dimethacrylate, and 30 g of heptane (Otsuka (The average particle diameter of zinc oxide measured by ELS-8000 manufactured by Denshi Co., Ltd. 0.4 μm). Thereafter, 3 g of lauroyl peroxide was added. 15 g of sodium cocoylmethyl taurate was dissolved in 1500 g of ion-exchanged water, added to the above-mentioned zinc oxide slurry, and dispersed using a homogenizer (average particle diameter of emulsion measured by LA-910 manufactured by Horiba, Ltd. 1.6 μm). The dispersion was then charged into a 2000 mL separable flask, purged with nitrogen, heated to 70 ° C. with stirring at 200 r / min, raised to 70 ° C. for 10 hours, further raised to 80 ° C., and then heated to 80 ° C. Polymerization was performed in a nitrogen atmosphere for 10 hours. After completion of the polymerization, the solid was collected by centrifugation, washed with water, freeze-dried, and crushed with a jet mill to obtain 120 g of composite polymer particles (inclusion ratio of zinc oxide 50% by mass).

Example 3
Using a bead mill, 40 g of Teica silicone-treated zinc oxide (MZ-507S) was stirred in 30 g of lauryl methacrylate (SP value 8.7) and 30 g of ethylene glycol dimethacrylate (measured with ELS-8000 manufactured by Otsuka Electronics). Zinc oxide average particle size 0.3 μm). Thereafter, 1.5 g of 2,2′-azobis-2,4-dimethylvaleronitrile was added. 30 g of polyvinyl alcohol (EG-30 manufactured by Nippon Synthetic Chemical Industry) and 1 g of stearoylmethyl taurine sodium were dissolved in 500 g of ion-exchanged water, and added to the above zinc oxide slurry and dispersed using a milder (LA-910 manufactured by Horiba, Ltd.). The average particle diameter of the measured emulsion was 2.0 μm). Next, the dispersion was charged into a 1000 mL separable flask, purged with nitrogen, heated to 60 ° C. while stirring at 200 r / min, heated to 60 ° C. for 2 hours, further raised to 80 ° C., and then heated to 80 ° C. Polymerization was carried out under a nitrogen atmosphere for 4 hours. After completion of the polymerization, the solid was collected by centrifugation, washed with water, freeze-dried, and crushed with a jet mill to obtain 90 g of composite polymer particles (inclusion ratio of zinc oxide 40% by mass).

Example 4
Using a bead mill, silicone-treated titanium oxide (titanium oxide with an average particle size of 0.25 μm (manufactured by Ishihara Sangyo Co., Ltd., CR-50) is treated with methylhydrogenpolysiloxane (2 mass% with respect to titanium oxide) for water repellency treatment. 50 g) was stirred for 3 hours in 56 g of lauryl methacrylate (SP value 8.7) and 19 g of ethylene glycol dimethacrylate (average particle diameter of titanium oxide measured by ELS-8000 manufactured by Otsuka Electronics Co., Ltd.). Thereafter, 1.5 g of lauroyl peroxide was added. In 750 g of ion-exchanged water, 7.5 g of polyvinyl alcohol (EG-30, manufactured by Nippon Synthetic Chemical Industry) was dissolved, added to the above-described titanium oxide slurry, and dispersed using a homogenizer (the emulsion measured by LA-910 manufactured by Horiba, Ltd.). (Average particle diameter 11.5 μm). The dispersion was then charged into a 2000 mL separable flask, purged with nitrogen, heated to 75 ° C. with stirring at 150 r / min, and polymerized at 75 ° C. for 8 hours in a nitrogen atmosphere. After completion of the polymerization, the solid was collected by centrifugation, washed with water, freeze-dried, and crushed with a jet mill to obtain 120 g of composite polymer particles (inclusion ratio of titanium oxide 40% by mass).

Example 5
Using a bead mill, silicone-treated titanium oxide manufactured by Ishihara Sangyo (titanium oxide having an average particle size of 0.25 μm (manufactured by Ishihara Sangyo Co., Ltd., CR-50) is used with methylhydrogenpolysiloxane (2% by mass with respect to titanium oxide). 50 g of polydimethylsiloxypropyl methacrylate (manufactured by Chisso Corporation, Silaplane FM0711, MW1000, SP value 7.6) 10 g, isostearyl methacrylate (SP value 8.2) 50 g, ethylene glycol dimethacrylate 40 g The mixture was stirred in 10 g of polydimethylsiloxane (5000cs) for 3 hours (average particle diameter of titanium oxide measured by ELS-8000 manufactured by Otsuka Electronics Co., Ltd.). Thereafter, 3 g of lauroyl peroxide was added. 45 g of polyvinyl alcohol (EG-30 manufactured by Nippon Synthetic Chemical Industry) was dissolved in 1500 g of ion-exchanged water, dispersed in the above-mentioned titanium oxide slurry, and dispersed using a homogenizer (average particle size of emulsion measured with LA-910 manufactured by Horiba, Ltd.) Diameter 1.8 μm). The dispersion was then charged into a 2000 mL separable flask, purged with nitrogen, heated to 70 ° C. with stirring at 200 r / min, raised to 70 ° C. for 10 hours, further raised to 80 ° C., and then heated to 80 ° C. Polymerization was performed in a nitrogen atmosphere for 10 hours. After completion of the polymerization, the solid was collected by centrifugation, washed with water, freeze-dried, and crushed with a jet mill to obtain 120 g of composite polymer particles (inclusion rate of titanium oxide 31 mass%).

Comparative Example 1
Using a bead mill, 60 g of Teika silicone-treated zinc oxide (MZ-507S) was stirred for 3 hours in 60 g of styrene (SP value 9.2) and 30 g of divinylbenzene (zinc oxide measured with ELS-8000 manufactured by Otsuka Electronics). Average particle diameter of 0.3 μm). Thereafter, 3 g of lauroyl peroxide was added. 20 g of sodium lauryl sulfate was dissolved in 1500 g of ion-exchanged water, added to the above-mentioned zinc oxide slurry, and dispersed using a milder (average particle diameter of emulsion measured by LA-910 manufactured by Horiba, Ltd. 2.1 μm). The dispersion was then charged into a 2000 mL separable flask, purged with nitrogen, heated to 70 ° C. with stirring at 200 r / min, raised to 70 ° C. for 10 hours, further raised to 80 ° C., and then heated to 80 ° C. Polymerization was performed in a nitrogen atmosphere for 10 hours. After completion of the polymerization, the solid was collected by centrifugation, washed with water, freeze-dried, and crushed with a jet mill to obtain 110 g of composite polymer particles (inclusion ratio of zinc oxide 40% by mass).
A scanning electron micrograph of the obtained composite polymer particle is shown in FIG. 3, and a transmission electron micrograph is shown in FIG.

Comparative Example 2
Using a bead mill, 30 g of Teica silicone-treated zinc oxide (MZ-507S) was stirred in 70 g of methyl methacrylate (SP value 8.9) for 3 hours (average particle diameter of zinc oxide measured by ELS-8000 manufactured by Otsuka Electronics) 0.3 μm). Thereafter, 2.1 g of lauroyl peroxide was added. 5 g of sodium lauryl sulfate was dissolved in 500 g of ion-exchanged water, added to the aforementioned zinc oxide slurry, and dispersed using a milder (average particle diameter of emulsion measured by LA-910 manufactured by Horiba Seisakusho). The dispersion was then charged into a 2000 mL separable flask, purged with nitrogen, heated to 70 ° C. with stirring at 200 r / min, raised to 70 ° C. for 10 hours, further raised to 80 ° C., and then heated to 80 ° C. Polymerization was performed in a nitrogen atmosphere for 10 hours. After completion of the polymerization, the solid was collected by centrifugation, washed with water, freeze-dried, and crushed with a jet mill to obtain 70 g of composite polymer particles (inclusion ratio of zinc oxide 30% by mass).
A scanning electron micrograph of the obtained composite polymer particles is shown in FIG. 5, and a transmission electron micrograph is shown in FIG.

Comparative Example 3
Using a bead mill, 20 g of Teika zinc oxide (MZ-700: particle size 0.02 μm, untreated silicone product according to catalog), 40 g of lauryl methacrylate (SP value 8.7), 40 g of ethylene glycol dimethacrylate, 20 g of heptane For 3 hours. Thereafter, 1.6 g of 2,2′-azobis-2,4-dimethylvaleronitrile was added. 6.5 g of sodium lauryl sulfate was dissolved in 500 g of ion-exchanged water, added to the above zinc oxide slurry, and dispersed using a milder (average particle diameter of emulsion measured by LA-910 manufactured by Horiba, Ltd. 2.0 μm). Next, the dispersion was charged into a 1000 mL separable flask, purged with nitrogen, heated to 60 ° C. while stirring at 200 r / min, heated to 60 ° C. for 2 hours, further raised to 80 ° C., and then heated to 80 ° C. Polymerization was carried out under a nitrogen atmosphere for 4 hours. After completion of the polymerization, the solid was collected by centrifugation, washed with water, freeze-dried, and crushed with a jet mill to obtain 70 g of composite polymer particles (inclusion ratio of zinc oxide 20% by mass).

Test example 1
About the composite polymer particle obtained in Examples 1-5 and Comparative Examples 1-3, SPF was measured with the following method. Moreover, the compounding property to a product and the usability | use_condition were evaluated by the following method. The results are shown in Table 1.

<SPF measurement method>
Formulation composition 1. Polyether-modified silicone (manufactured by Toray Dow Corning Silicone, SH3775M): 1.8% by mass
2. Neopentyl glycol dicaprate: 2.0% by mass
3. Squalane: 4.0% by mass
4.4-Methoxycinnamic acid 2-ethylhexyl: 1.0% by mass
5). Linear dimethyl silicone (2cs): 36.0% by mass
6). Composite polymer particles: 5.0% by mass as metal oxide
7). Glycerin: 4.3% by mass
8). Water: Balance / Blending Procedure a) Components 1 to 4 are uniformly mixed, and dispersions of components 5 and 6 are added and further dispersed.
b) Mix ingredients 7 and 8.
c) Gradually add b) to a) and apply homomixer to make an emulsion.
・ Sample preparation Prepare a medical tape (Transpore surgical tape). Place 80 μL of the above-mentioned emulsion on a 5 × 8 cm ² tape with a syringe and spread it all over with a finger.
・ SPF measurement Set the above sample on a simple SPF measuring instrument (labsphere; UV TRANSMITTANCE ANALYZER) and measure. Measure five times and use the average (round down the last digit).

<Evaluation method of compoundability and usability>
The compoundability in the product is evaluated by the following criteria for the storage stability for one month with the same composition as that for the above SPF measurement, and the feeling of use is the same as that for the above SPF measurement. The feel of the product was evaluated in three stages by the following criteria by one expert panelist.
・ Compoundability (1 month storage stability)
○: Not aggregated at all.
Δ: Some aggregation is observed.
X: Aggregation is remarkably observed.
・ Usage feeling ○: Can be used without any difference.
Δ: Slightly rough.
X: A rough feeling is felt.

Test example 2
The present invention and comparative emulsions having the compositions shown in Table 2 were produced by conventional methods, and SPF and usability were evaluated by the following methods. The results are shown in Table 2.

<SPF measurement method>
Evaluation was performed in the same manner as the sample preparation and SPF measurement described in Test Example 1.
<Evaluation method of feeling of use>
The present invention and comparative emulsions were applied to the backs of the hands of 10 professional panelists to evaluate the feel (amount of application: a circle having a diameter of 2 cm on the back of the hand when removed from the container). When applying the latex, the evaluation is performed in three stages: good, neither, bad, good: 1 point, neither: 0.5 point, bad: 0 point, a total of 10 people, Expressed on a 10-point scale.

2 is a scanning electron micrograph of the composite polymer particles obtained in Example 1. FIG. 2 is a transmission electron micrograph of composite polymer particles obtained in Example 1. FIG. 2 is a scanning electron micrograph of the composite polymer particles obtained in Comparative Example 1. FIG. 2 is a transmission electron micrograph of the composite polymer particles obtained in Comparative Example 1. 4 is a scanning electron micrograph of the composite polymer particles obtained in Comparative Example 2. 3 is a transmission electron micrograph of the composite polymer particles obtained in Comparative Example 2.

Claims (8)

  A composite polymer particle containing a metal oxide having an average particle diameter of 1 μm or less and coated with silicone and / or a fluorine compound, the amount of the composite polymer particle corresponding to 5% by mass as a metal oxide amount in cosmetics , And 1% by mass of 4-methoxycinnamic acid 2-ethylhexyl, a composite polymer particle having an SPF of 7 or more.   The composite polymer particle according to claim 1, wherein the metal oxide is at least one selected from the group consisting of zinc oxide, titanium oxide and / or cerium oxide.   The composite polymer particle according to claim 1 or 2, wherein the content of the metal oxide is 25 to 90% by mass of the entire composite polymer particle.   4. The suspension according to claim 1, wherein a metal oxide coated with silicone and / or a fluorine compound, a monomer component containing a vinyl monomer having a solubility parameter of less than 8.9, and a crosslinking agent are dispersed and mixed, and then subjected to suspension polymerization. The manufacturing method of the composite polymer particle of description.   The process according to claim 4, wherein the vinyl monomer having a solubility parameter of less than 8.9 contains an alkyl (meth) acrylate having a linear or branched alkyl group having 8 or more carbon atoms which may be fluorinated.   The process according to claim 4 or 5, wherein the vinyl monomer having a solubility parameter of less than 8.9 contains a dimethylpolysiloxane compound having a radical polymerizable group at one end of the molecular chain.   The manufacturing method in any one of Claims 4-6 whose crosslinking agent is 0.1-75 mass parts with respect to a total of 100 mass parts of all the monomers and a crosslinking agent. Cosmetics containing the composite polymer particles according to any one of claims 1 to 3.