JP4448718B2 - Silica-coated polymer particles, production method thereof, and cosmetics - Google Patents

Description

  The present invention relates to silica-coated polymer particles, a production method thereof, and a cosmetic. More specifically, the present invention relates to silica-coated polymer particles having excellent light diffuse reflectance, a method for producing the same, and a cosmetic.

  In the field where diffuse light reflectivity is desired, such as paints and cosmetics, polymer particles having various configurations have been studied. For example, nylon fine particles or polymer fine particles made of polymethyl methacrylate are widely used as powder components added to cosmetics because they are excellent in extensibility.

  However, since nylon fine particles adsorb components such as preservatives added to cosmetics, the antiseptic effect changes over time, which is not preferable. Further, conventional polymer fine particles made of polymethyl methacrylate have poor oil resistance and solvent resistance, and have problems such as aggregation between particles in the presence of oil components such as a humectant and alcohol. In addition, cross-linked polymethyl methacrylate, which is a copolymer of methyl methacrylate and polyfunctional vinyl monomer, improves oil resistance and solvent resistance, but improves the feeling of use and the natural finish due to the light diffusion effect of particles. There was room for.

  Therefore, in order to improve the above problems, composite particles in which the surface of the polymer particles is covered with another polymer or an inorganic substance are known.

  Among these, the composite particle in which the surface of the latter polymer particle is covered with an inorganic substance has the advantage that the refractive index at the interface between the polymer particle and the inorganic substance can be made larger than the refractive index at the interface between the former polymers. There is. Further, the latter composite particles have an advantage that the tactile sensation is better than the former composite particles.

  A composite particle in which the surface of a polymer particle is covered with an inorganic substance is reported, for example, in JP-A-5-170924 (Patent Document 1). This publication describes composite particles in which a material that is smaller than a thermoplastic material and excellent in heat resistance is immobilized on the surface of the thermoplastic material. This composite particle is a method of obtaining composite particles by mechanical shearing force by raising the temperature of a thermoplastic substance to a temperature above the softening point and stirring the substance having excellent heat resistance and the thermoplastic substance.

Japanese Patent Laid-Open No. 5-170924

  The composite particles obtained by the above method have a structure in which the surface of the thermoplastic material is substantially uniformly covered with a material having excellent heat resistance, and the diffuse reflectance of light is improved to some extent as compared with the particles of the thermoplastic material. However, further improvement is desired.

  Moreover, in the said method, since a mechanical shear force is added to a thermoplastic material, it is necessary for a thermoplastic material to endure this shear force, and there exists a subject that the substance which can be used has a restriction | limiting.

  Furthermore, it is necessary to manufacture a thermoplastic material in advance before applying the above method, and further reduction of the process is desired from the viewpoint of reducing the manufacturing cost.

  As a result of intensive studies to solve the above problems, the inventors of the present invention have found that a polymerizable vinyl monomer can be converted into an aqueous system in the presence of a polyalkoxysiloxane oligomer that is not copolymerizable with the polymerizable vinyl monomer. After the suspension polymerization, the polyalkoxysiloxane oligomer can be condensed to form a silica coating derived from the polyalkoxysiloxane oligomer so that the surface of the polymer particle is exposed. Surprisingly, it was found to be excellent in reflectivity, and the present invention was achieved.

Thus, according to the present invention, 100 parts by weight of a polymerizable vinyl monomer, 10 to 300 parts by weight of a polyalkoxysiloxane oligomer having a weight average molecular weight of 300 to 3000 inert to the polymerizable vinyl monomer, and a polymerization initiator 0 Uniformly mixing 0.01 to 10 parts by weight to obtain a monomer composition;
A step of obtaining polymer particles by subjecting the polymerizable vinyl monomer in the monomer composition to aqueous suspension polymerization in the presence of a suspension stabilizer;
Silica-coated polymer particles produced by a production method comprising the steps of condensing the polyalkoxysiloxane oligomer with an acid or base catalyst in this order , wherein the weight of the polyalkoxysiloxane oligomer is 0.1 to 0.8. silica-coated polymer particles characterized that you have been coated with a silica coating so as to expose the surface of the coalesced particles are provided.

Furthermore, 100 parts by weight of a polymerizable vinyl monomer, 10 to 300 parts by weight of a polyalkoxysiloxane oligomer having a weight average molecular weight of 300 to 3000 inert to the polymerizable vinyl monomer, and 0.01 to 10 weight of a polymerization initiator. A step of uniformly mixing a part to obtain a monomer composition;
A step of obtaining polymer particles by subjecting the polymerizable vinyl monomer in the monomer composition to aqueous suspension polymerization in the presence of a suspension stabilizer;
By including a step of condensing the polyalkoxysiloxane oligomer by adding an acid or base catalyst in this order, the polyalkoxysiloxane oligomer is coated with a silica coating so as to expose the surface of the polymer particles with an aperture ratio of 0.1 to 1. A method for producing silica-coated polymer particles is provided.

  As described above, the silica-coated polymer particles of the present invention are excellent in the diffuse reflectance of light. For example, when incorporated in cosmetics, the reflection of light in the regular reflection direction can be suppressed. The finish can be expected. In addition, the silica-coated polymer particles of the present invention have good redispersibility without secondary aggregation when blended as a powder component in a cosmetic, particularly a cosmetic containing a moisturizer such as a cosmetic emulsion and / or liquid oil. Indicates.

  Furthermore, since the method for producing silica-coated polymer particles of the present invention can be produced without applying a strong mechanical shearing force, polymer particles having a low Tg can be easily coated with a silica coating.

  As shown in the cross-sectional view of FIG. 1, the silica-coated polymer particles of the present invention have a silica coating 2 so that the surface of the spherical or substantially spherical polymer particles 1 has an opening ratio of 0.1 to 1. It is the structure which has the anisotropy covered. In the figure, reference numeral 3 means silica-coated polymer particles. By having such a structure, complex light reflection and refraction occurs compared to non-anisotropic particles such as spherical silica particles and composite particles in which the surface of polymer particles is completely covered with a silica coating. As a result, strong light diffuse reflectance can be exhibited. If the aperture ratio of the silica coating is less than 0.1, the diffuse reflectance of light becomes poor, which is not preferable. A more preferable aperture ratio is 0.1 to 0.8. The maximum value of the aperture ratio is 1.

  In addition, the measuring method of an aperture ratio is described in an Example. However, in this specification, the aperture ratio is obtained by burning the silica-coated polymer particles to burn the polymer particles into silica particles, and use the aperture ratio of the silica particles. The aperture ratio of the silica particles may be strictly different from the aperture ratio of the silica coating because the silica coating contracts during firing or the thin area at the end of the silica coating is missing. The inventor has confirmed that the opening ratio of the silica coating of the silica-coated polymer particles and the opening ratio of the silica particles are substantially the same.

  The height h of the silica coating and the diameter D of the silica-coated polymer particles preferably have a relationship of 0.5 ≦ h / D <1. When h / D is 1, the diffuse reflectivity of light becomes poor, and when h / D is less than 0.5, the coating is liable to peel off, which is not preferable.

  In addition, the measuring method of h / D is described in an Example. However, in this specification, h / D is obtained by burning the silica-coated polymer particles to burn out the polymer particles into silica particles, and the h / D of the silica particles is used. The h / D of the silica particles is strictly different from the h / D of the silica-coated polymer particles due to shrinkage of the silica coating during firing or lack of a thin region at the end of the silica coating. In some cases, the inventor has confirmed that the h / D of the silica-coated polymer particles and the h / D of the silica particles are substantially the same.

Hereinafter, the silica-coated polymer particles of the present invention will be described with reference to the production method thereof.
First, the polymerizable vinyl monomer that can be used in the present invention is not particularly limited. For example, styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, pn-butylstyrene, p-tert-butylstyrene, pn-hexyl Styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl styrene, p-methoxy styrene, p-phenyl styrene, p-chloro styrene, 3,4-di Styrene such as chlorostyrene and its derivatives, vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyrate, methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, n-acrylate Octyl, dodecyl acrylate, 2-ethylhexyl acrylate, acrylic Stearyl, lauryl acrylate, 2-chloroethyl acrylate, phenyl acrylate, methyl α-chloroacrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate Α-methylene fat such as dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, lauryl methacrylate, phenyl methacrylate, dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate, diethylaminoethyl methacrylate Group monocarboxylic acid esters, acrylonitrile, methacrylonitrile, acrylamide, methacrylamide, 2-hydroxyethyl acrylate, 2-hydride acrylate Kishipuropiru, 2-hydroxyethyl methacrylate, is acrylic acid or methacrylic acid derivatives such as 2-hydroxypropyl methacrylate. In some cases, acrylic acid, methacrylic acid, maleic acid, fumaric acid and the like can also be used. Further, two or more of these may be used in combination.

Further, vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether, vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, methyl isopropenyl ketone, N-vinyl pyrrole, N-vinyl carbazole, N-vinyl indole, N -N-vinyl compounds such as vinyl pyrrolidone, vinyl naphthalene salts and the like can be used alone or in combination of two or more in a range not impeding the effects of the present invention.
Among these, inexpensive styrene, methyl methacrylate and the like are preferable in terms of cost.

  The polymer particles may be crosslinked with a monomer having two or more functional groups such as ethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, divinylbenzene and the like.

  In the present invention, the polyalkoxysiloxane oligomer that is a precursor of the silica coating is inactive to the polymerizable vinyl monomer (meaning that it is not copolymerized), and those having the following structural formula can be used.

  Among the above structural formulas, for example, oligomers such as polymethoxysiloxane, polyethoxysiloxane, polypropoxysiloxane, polybutoxysiloxane, and the like can be given. Among these, polymethoxysiloxane oligomers and polybutoxysiloxane oligomers that are poorly water-soluble and have good phase separation from the resin are preferable. Particularly preferred are polymethoxysiloxane oligomers and polybutoxysiloxane oligomers having a weight average molecular weight of 300 to 3000, more preferably 300 to 2000. When the weight average molecular weight is less than 300 or more than 3000, it is difficult to form a film, which is not preferable.

In addition, a weight average molecular weight is measured on condition of the following using GPC.
Column: “TSK GEL” (manufactured by Tosoh Corporation)
G-1000H,
G-2000H
G-4000H
Effluent: Tetrahydrofuran Outflow rate: 1 ml / min Outflow temperature: 40 ° C

  In low molecular weight alkoxysiloxanes such as tetramethoxysilane and tetraethoxysilane where n = 1-2 in the above molecular formula, the water solubility becomes stronger due to hydrolysis of the functional group, so it should be stably present in the monomer droplets. Is difficult and undesirable. In addition, a polyalkoxysiloxane oligomer in which n = 40 or more in the above molecular formula is not preferable because compatibility and condensability with a polymerizable vinyl monomer are lowered.

  The addition amount of the polyalkoxysiloxane oligomer is preferably 10 to 500 parts by weight, more preferably 20 to 300 parts by weight with respect to 100 parts by weight of the polymerizable vinyl monomer. When the amount is less than 10 parts by weight, it is difficult to obtain the coating state of the present invention. When the amount is more than 500 parts by weight, it is not preferable because the polymer particles are hardly exposed.

  In addition, hydrolysable alkoxy metal compounds other than silicon-based compounds can be added to these polyalkoxysiloxane oligomers for the purpose of adding functions such as ultraviolet absorption.

  A polymerization initiator is used for the polymerization of the polymerizable vinyl monomer. Examples of the polymerization initiator include oil-soluble peroxide polymerization initiators and azo polymerization initiators that are usually used in aqueous suspension polymerization. Specifically, benzoyl peroxide, lauroyl peroxide, octanoyl peroxide, orthochlorobenzoyl peroxide, orthomethoxybenzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxydicarbonate, cumene hydroperoxide, cyclohexanone peroxide, t-butyl Peroxide polymerization initiators such as hydroperoxide and diisopropylbenzene hydroperoxide, 2,2′-azobisisobutyronitrile, 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2 '-Azobis (2,3-dimethylbutyronitrile), 2,2'-azobis (2-methylbutyronitrile), 2,2'-azobis (2,3,3-trimethylbutyronitrile), 2, 2'-azobis (2-isopropylbuty Nitrile), 1,1′-azobis (cyclohexane-1-carbonitrile), 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile, (2-carbamoylazo) isobutyronitrile, 4, Examples thereof include azo initiators such as 4′-azobis (4-cyanovaleric acid) and dimethyl-2,2′-azobisisobutyrate.

  Among these, 2,2′-azobisisobutyronitrile, 2,2′-azobis (2,4-dimethylvaleronitrile), benzoyl peroxide, lauroyl peroxide, and the like are in terms of the decomposition rate of the polymerization initiator. Is preferable. The polymerization initiator is preferably used in an amount of 0.01 to 10 parts by weight, more preferably 0.1 to 5.0 parts by weight with respect to 100 parts by weight of the polymerizable vinyl monomer. When the polymerization initiator is less than 0.15 parts by weight, it is difficult to achieve the function of initiating polymerization, and when it exceeds 10 parts by weight, it is uneconomical in terms of cost.

  In order to color the silica film, metal oxide pigments such as titanium oxide, zinc oxide, magnesium oxide, chromium oxide, and zirconium oxide may be used.

  The polymerizable vinyl monomer, polyalkoxysiloxane oligomer, polymerization initiator, and other components are uniformly mixed by a known method to obtain a monomer composition.

  Next, examples of the aqueous medium for aqueous suspension polymerization of the monomer composition include water or a mixed medium of water and a water-soluble solvent such as alcohol. The amount of the aqueous medium used is usually 100 to 1000 parts by weight with respect to a total of 100 parts by weight of the polymerizable vinyl monomer and polyalkoxysiloxane oligomer in order to stabilize the suspension polymerized particles.

  In order to suppress the generation of emulsified particles in an aqueous system, water-soluble polymerization inhibitors such as nitrites, sulfites, hydroquinones, ascorbic acids, water-soluble vitamin Bs, citric acid, and polyphenols may be used. Good.

Furthermore, you may add a suspension stabilizer to an aqueous medium as needed. For example, phosphates such as calcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, pyrophosphates such as calcium pyrophosphate, magnesium pyrophosphate, aluminum pyrophosphate, zinc pyrophosphate, calcium carbonate, magnesium carbonate, calcium hydroxide And suspension stabilizers of poorly water-soluble inorganic compounds such as magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate and colloidal silica. Among these, tricalcium phosphate, magnesium pyrophosphate, calcium pyrophosphate, and colloidal silica produced by the metathesis method are preferable because polymer particles can be stably obtained.

  The suspension stabilizer can be used in combination with a surfactant such as an anionic surfactant, a cationic surfactant, an amphoteric surfactant, and a nonionic surfactant.

  Examples of the anionic surfactant include fatty acid oils such as sodium oleate and castor oil potassium, alkyl sulfate salts such as sodium lauryl sulfate and ammonium lauryl sulfate, alkylbenzene sulfonates such as sodium dodecylbenzenesulfonate, and alkylnaphthalene sulfone. Acid salts, alkane sulfonates, dialkyl sulfosuccinates, alkyl phosphate esters, naphthalene sulfonate formalin condensates, polyoxyethylene alkyl phenyl ether sulfates, polyoxyethylene alkyl sulfates and the like.

  Nonionic surfactants include, for example, polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester, polyoxysorbitan fatty acid ester, polyoxyethylene alkylamine, glycerin fatty acid ester, oxy Examples include ethylene-oxypropylene block polymers.

  Examples of the cationic surfactant include alkylamine salts such as laurylamine acetate and stearylamine acetate, and quaternary ammonium salts such as lauryltrimethylammonium chloride.

  Examples of the zwitterionic surfactant include lauryl dimethylamine oxide and phosphate ester or phosphite ester surfactants.

  These suspension stabilizers and surfactants may be used alone or in combination of two or more. However, in consideration of the particle diameter of the obtained polymer particles and the dispersion stability during polymerization, the suspension stabilizer It is used by appropriately adjusting the selection and use amount of the agent. Usually, the addition amount of the suspension stabilizer is 0.5 to 15 parts by weight with respect to 100 parts by weight of the polymerizable vinyl monomer, and the addition amount of the surfactant is 0.00 with respect to 100 parts by weight of the aqueous medium. 001 to 0.1 parts by weight.

  The monomer composition is added to the aqueous medium thus prepared, and aqueous suspension polymerization is performed.

  As a method for dispersing the monomer composition, for example, a method in which the monomer composition is directly added to an aqueous medium and dispersed in the aqueous medium as monomer droplets by a stirring force of a propeller blade or the like, a high shear force composed of a rotor and a stator is used. Examples thereof include a method of dispersing using a homomixer that is a dispersing machine to be used, an ultrasonic dispersing machine, or the like. Among these, the monomer composition is pressed into an aqueous medium through a high-pressure type disperser or MPG (microporous glass) porous film using collision of monomer droplets such as microfluidizer and nanomizer and collision force to the machine wall. It is preferable to disperse by a method such as that because the particle diameters can be made more uniform.

  Next, suspension polymerization is initiated by heating the aqueous medium in which the monomer composition is dispersed as spherical monomer droplets. During the polymerization reaction, it is preferable to stir the aqueous medium. For example, the stirring may be performed so gently that the droplets of the monomer and the particles after polymerization are prevented from being settled.

  In the suspension polymerization, the polymerization temperature is preferably about 30 to 100 ° C, more preferably about 40 to 80 ° C. The time for maintaining this polymerization temperature is preferably about 0.1 to 20 hours.

  In addition, when the boiling point of the polymerizable vinyl monomer and the polyalkoxysiloxane oligomer is near the polymerization temperature or higher than the polymerization temperature, the pressure resistant polymerization equipment such as an autoclave is prevented so that the polymerizable vinyl monomer and the polyalkoxysiloxane oligomer do not volatilize. It is preferable to polymerize under sealing or under pressure.

  Next, the silica-coated polymer particles of the present invention can be obtained by condensing the polyalkoxysiloxane oligomer. Examples of the condensation method of the polyalkoxysiloxane oligomer include dehydration condensation using an acid catalyst or a base catalyst. As the acid catalyst and the base catalyst, hydrochloric acid, sulfuric acid, nitric acid, ammonia, sodium hydroxide, potassium hydroxide, ammonium nitrate and the like can be used. When the production container is made of steel or stainless steel, basic sodium hydroxide, ammonia, or the like is preferable from the viewpoint of corrosion or the like. The addition amount of the catalyst is preferably 0.01 to 30 parts by weight with respect to 100 parts by weight of the polyalkoxysiloxane oligomer. More preferably, it is 1 to 15 parts by weight.

  After the condensation, if necessary, the suspension stabilizer is decomposed with hydrochloric acid, etc., and the silica-coated polymer particles are separated as a hydrous cake by a method such as suction filtration, centrifugal dehydration, centrifugal separation, and pressure dehydration. The obtained water-containing cake can be washed with water and dried to obtain the desired silica-coated polymer particles.

  As described above, the production method of the present invention is not a method of applying silica particles to polymer particles by applying a high shearing force. Therefore, Tg (glass transition point) is a polymer particle having low heat resistance of less than 80 ° C. Even if it exists, it can coat | cover easily. Examples of the polymer having a Tg lower than 80 ° C. include polyethyl acrylate, poly (n-butyl acrylate), poly (isobutyl acrylate), poly (lauryl acrylate), poly (stearyl acrylate), poly (2-ethylhexyl acrylate), and poly (methacrylic acid). Examples include ethyl, poly (n-butyl methacrylate), poly (isobutyl methacrylate), poly (lauryl methacrylate), poly (stearyl methacrylate), and poly (2-ethylhexyl methacrylate).

  The size and shape of the silica-coated polymer particles of the present invention are not particularly limited. According to the method for producing silica-coated polymer particles, particles having an average particle diameter of 1 to 100 μm can be obtained.

  Here, the average particle diameter of the particles can be adjusted by adjusting the mixing conditions of the monomer composition and water, the addition amount of the suspension stabilizer and the surfactant, the stirring conditions of the agitator, and the dispersion conditions. is there.

  The silica-coated polymer particle composite particles of the present invention preferably contain 10 to 500 parts by weight of silica coating, more preferably 20 to 300 parts by weight, per 100 parts by weight of polymer particles.

  The present invention can provide silica-coated polymer particles having a specular reflectance of 3 to 13% (definitions are described in the Examples). This value is lower than about 14% when the polymer particles are completely covered with a silica coating, and indicates that the silica-coated polymer particles of the present invention are excellent in light diffuse reflectance. Yes. When the specular reflectance is 3 to 13%, when the silica-coated polymer particles are used in cosmetics such as a foundation, unnatural reflection of light during use can be prevented, and a natural finish can be realized. When the specular reflectance is less than 3%, light is hardly reflected, and when blended in a cosmetic, the gloss is lowered, which is not preferable. If it is greater than 13%, the reflection of light in the specular reflection direction is strong, and when incorporated in cosmetics, it causes unnatural light and is not preferable. A more preferable specular reflectance is in the range of 5 to 13%.

The silica-coated polymer particles of the present invention are preferably used as a raw material for cosmetics and paints.
When used for cosmetics, the average particle diameter is preferably about 3 to 50 μm from the viewpoint of the feeling of use. When it exceeds 50 μm, the usability may be deteriorated. Particularly preferably, it is about 3 to 20 μm which makes the feel smoother.

  Specific cosmetics to be blended with the silica-coated polymer particles of the present invention include solid cosmetics such as funny and foundation, powdery cosmetics such as baby powder and body powder, lotion, milky lotion, cream and body lotion. And liquid cosmetics.

  The blending ratio in these cosmetics varies depending on the type of cosmetic, but it is preferably 1 to 20% by weight and particularly preferably 3 to 15% by weight in the case of solid cosmetics such as funny and foundation. Moreover, in the case of powdery cosmetics such as baby powder and body powder, the content is preferably 1 to 20% by weight, particularly preferably 3 to 15% by weight. Furthermore, in the case of liquid cosmetics such as lotion, milky lotion, cream, liquid foundation, body lotion, pre-shave lotion, the content is preferably 1 to 15% by weight, more preferably 3 to 10% by weight.

  In addition, these cosmetics include inorganic compounds such as mica and talc, pigments for coloring such as iron oxide, titanium oxide, ultramarine blue, bitumen, and carbon black, or azo for improving optical function and touch. Synthetic dyes and the like such as those can be added. In the case of liquid cosmetics, the liquid medium is not particularly limited, but water, alcohol, hydrocarbons, silicone oil, vegetable or animal oils and the like can also be used. To these cosmetics, in addition to the above-mentioned other ingredients, moisturizers, anti-inflammatory agents, whitening agents, UV care agents, bactericides, antiperspirants, refreshing agents, fragrances and the like commonly used in cosmetics are added. Thus, various functions can be added.

  In particular, the silica-coated polymer particles can be suitably used as a raw material for liquid cosmetics. In liquid cosmetics, moisturizers, oils, surfactants, UV absorbers, drugs, colorants, salts, polymer compounds, perfume ingredients, stabilizers that are commonly used in cosmetics as long as the quality is not impaired. A buffering agent etc. can be mix | blended.

  Examples of the moisturizing material used in the present invention include polyethylene glycol, propylene glycol, glycerin, 1,3-butylene glycol, xylitol, sorbitol, maltitol, chondroitin sulfate, hyaluronic acid, mucoitin sulfate, caronic acid, atelocollagen, cholesteryl-12. Examples include hydroxystearate, sodium lactate, bile salt, d, l-pyrrolidone carboxylate, short-chain soluble collagen, diglycerin (EO) PO adduct, Izayoi rose extract, yarrow extract, and merirot extract. However, it is not limited to these.

  Oils used in liquid cosmetics include liquid oils such as avocado oil, camellia oil, turtle oil, macadamia nut oil, corn oil, mink oil, olive oil, rapeseed oil, egg yolk oil, sesame oil, persic oil, wheat germ oil, southern oil Oil, castor oil, linseed oil, safflower oil, cottonseed oil, eno oil, soybean oil, peanut oil, teaseed oil, kaya oil, rice bran oil, cinnagiri oil, Japanese kiri oil, jojoba oil, germ oil, triglycerin, trioctane Examples include glycerin acid and glycerin triisopalmitate. As solid fats and oils, cacao butter, palm oil, horse fat, hardened palm oil, palm oil, beef tallow, sheep fat, hardened beef tallow, palm kernel oil, pork fat, beef bone fat, owl kernel oil, hardened oil, cow leg fat, Owl, hydrogenated castor oil and the like can be mentioned. As waxes, beeswax, candelilla wax, cotton wax, carnauba wax, bayberry wax, ipotarou, whale wax, montan wax, nukarou, lanolin, kapok wax, lanolin acetate, liquid lanolin, sugarcane wax, lanolin fatty acid isopropyl, lauric acid hexyl, reduced lanolin, jojopalo C, hard lanolin, shellac wax, POE lanolin alcohol ether, POE lanolin alcohol acetate, POE cholesterol ether, lanolin fatty acid polyethylene glycol, POE hydrogenated lanolin alcohol ether, and the like. Examples of the hydrocarbon oil include liquid paraffin, ozokerite, squalene, pristane, paraffin, ceresin, petrolatum, microcrystalline wax, and the like, but the oil content is not limited thereto.

  Examples of surfactants used in liquid cosmetics include sorbitan monooleate, sorbitan monoisostearate, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan sesquioleate, sorbitan trioleate, penter Sorbitan fatty acid esters such as 2-ethylhexyl diglycerol sorbitan, tetra-2-ethylhexyl diglycerol sorbitan, mono-cotton oil fatty acid glycerin, monoerucic acid glycerin, sesquioleate glycerin, monostearate glycerin, α, α '-Glycerin polyglycerol fatty acids such as glycerin pyroglutamate oleate, glyceryl monostearate malate, propylene glycol such as propylene glycol monostearate Fatty acid esters, hydrogenated castor oil derivatives, glycerin alkyl ether, POE sorbitan monooleate, POE-sorbitan monostearate, POE-sorbitan tetraoleate, and other sorbitan fatty acid esters, POE-sorbite monolaurate, POE-sorbitol POE such as monooleate, POE-sorbite pentaoleate, POE sorbite fatty acid esters such as POE-sorbite monostearate, POE-glycerol monostearate, POE-glycerol monoisostearate, POE-glycerol triisostearate POE fatty acid esters such as glycerin fatty acid esters, POE monooleate, POE distearate, POE monodiolate, ethylene glycol stearate, POE la POE alkyl ethers such as ril ether, POE oleyl ether, POE stearyl ether, POE behenyl ether, POE2-octyldodecyl ether, POE cholestanol ether, POE such as POE octyl phenyl ether, POE nonyl phenyl ether, POE dinonyl phenyl ether POE / POP such as alkylphenyl ethers, pluronic types such as Pluronic, POE / POP cetyl ether, POE / POP2-decyltetradecyl ether, POE / POP monobutyl ether, POE / POP hydrogenated lanolin, POE / POP glycerin ether, etc. Alkyl ethers, Tetronic PTE / Tetra POP ethylenediamine condensates, POE castor oil, POE hydrogenated castor oil, PO Hardened castor oil monoisostearate, POE hardened castor oil triisostearate, POE hardened castor oil monopyroglutamic acid monoisostearic acid diester, POE hardened castor oil maleic acid and other POE castor oil hardened castor oil derivatives, POE sorbite beeswax, etc. POE beeswax / lanolin derivatives, alkanolamides such as coconut oil fatty acid diethanolamide, lauric acid monoethanolamide, fatty acid isopropanolamide, POE propylene glycol fatty acid ester, POE alkylamine, POE fatty acid amide, sucrose fatty acid ester, POE nonylphenyl formaldehyde condensation Products, alkylethoxydimethylamine oxide, trioleyl phosphate, and the like, but are not limited thereto.

  Examples of ultraviolet absorbers used in liquid cosmetics include paraaminobenzoic acid (hereinafter abbreviated as PABA), PABA monoglycerin ester, N, N-dipropoxy PABA ethyl ester, N, N-diethoxy PABA ethyl ester, N, N -Benzoic acid-based UV absorbers such as dimethyl PABA ethyl ester, N, N-dimethyl PABA butyl ester, anthranilic acid-based UV absorbers such as homomenthyl-N-acetylanthranylate, amyl salicylate, menthyl salicylate, homomenthyl salicylate, Salicylic acid UV absorbers such as octyl salicylate, phenyl salicylate, benzyl salicylate, p-isopropanol phenyl salicylate, octyl cinnamate, ethyl-4-isopropyl cinnamate, ethyl-2 5-diisopropylcinnamate, ethyl-2,4-diisopropylcinnamate, methyl-2,4-diisopropylcinnamate, propyl-p-methoxycinnamate, isopropyl-p-methoxycinnamate, isoamyl-p-methoxycinnamate, Octyl-p-methoxycinnamate (2-ethylhexyl-p-methoxycinnamate), 2-ethoxyethyl-p-methoxycinnamate, cyclohexyl-p-methoxycinnamate, ethyl-α-cyano-β- Phenyl cinnamate, 2-ethylhexyl-α-cyano-β-phenyl cinnamate, glyceryl mono-2-ethylhexanoyl-diparamethoxy cinnamate, 3,4,5-trimethoxycinnamate 3-methyl- 4- [Methylbis (trimethylsiloxy) silyl] bu Cinnamic acid-based ultraviolet absorbers such as 2,4'-dihydroxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2,2 ', 4 , 4′-tetrahydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxy-4′-methylbenzophenone, 2-hydroxy-4methoxybenzophenone-5-sulfonate, 4-phenylbenzophenone, Benzophenone ultraviolet absorbers such as 2-ethylhexyl-4′-phenyl-benzophenone-2-carboxylate, hydroxy-4-n-octoxybenzophenone, 4-hydroxy-3-carboxybenzophenone, 3- (4′- Methylbenzylidene) -d, l-camph -, 3-benzylidene-d, l-camphor, urocanic acid, urocanic acid ethyl ester, 2-phenyl-5-methylbenzoxazole, 2,2'-hydroxy-5-methylphenylbenzotriazole, 2- (2 ' -Hydroxy-5'-t-octylphenyl) benzotriazole, 2- (2'-hydroxy-5'-methylphenyl) benzotriazole, dibenzalazine, dianisoylmethane, 4-methoxy-4'-t-butyldibenzoylmethane , 5- (3,3-dimethyl-2-norbornylidene) -3-pentan-2-one and the like, but is not limited thereto.

  Drugs used in liquid cosmetics include nonyl acid valenylamide, nicotinic acid benzyl ester, nicotinic acid β-butoxyethyl ester, capsaicin, gingerone, cantalis tincture, ictamol, caffeine, tannic acid, α-borneol, nicotinic acid tocopherol , Inositol hexanicotinate, cyclandrate, cinnarizine, trazoline, acetylcholine, verapamil, cephalanthin, γ-oryzanol, clotrimazole, pentachlorophenol, trichlorophenolcaproate, tribromophenolcaproate, lauryltriphenylphosphonium pro Amide, diantazole hydrochloride, paraacetylaminophenyl rhodan, methylosal, undecylenic acid, zinc undecylenate, dermaside, valithione Prolone nitrone, siccanin, miconazole, econazole, isoconazole, sulconazole, thioconazole, bifonazole, oxyconazole, ketoconazole, cyclopirox olamine, tolcyclate, naphthifine, griseofulvin, 5-fluorocytosine, etc. It is not something.

  Colorants used in liquid cosmetics include inorganic white pigments such as titanium dioxide and zinc oxide, inorganic red pigments such as iron oxide (Bengara) iron titanate, inorganic brown pigments such as γ-iron oxide, and yellow iron oxide , Inorganic yellow pigments such as ocher, inorganic black pigments such as black iron oxide, carbon black, low-order titanium oxide, inorganic purple pigments such as mango violet and cobalt violet, chromium oxide, chromium hydroxide, cobalt titanate, etc. Green pigments, blue pigments such as ultramarine and bitumen, titanium oxide coated mica, titanium oxide coated bismuth oxychloride, titanium oxide coated talc, colored titanium oxide coated mica, bismuth oxychloride, pearl pigments such as fish scale foil, aluminum powder , Metal powder pigments such as copper powder, red 201, red 202, red 204, red Organic pigments such as 05, Red 220, Red 226, Red 228, Red 405, Orange 203, Orange 204, Yellow 205, Yellow 401 and Blue 404, Red 3 and Red 104 Red 106, red 227, red 230, red 401, red 505, orange 205, yellow 4, yellow 5, yellow 202, yellow 203, green 3 and blue 1 Examples include organic pigments such as zirconium, barium, and aluminum lakes, and natural pigments such as chlorophyll and β-caroline, but are not limited thereto.

  Examples of the salt used in the liquid cosmetic include natural salts such as rock salt, sea salt, and mineral spring lake salt.

  Examples of the polymer compound used in the liquid cosmetic include gum arabic, gum tragacanth, galactan, guar gum, carop gum, caraya gum, carrageenan, pectin, agar, quince seed, quince seed, alge colloid (gypsum extract), starch (rice, rice, Corn, potato, wheat), plant polymers such as glycyrrhizic acid, microbial polymers such as xanthan gum, dextran, succinoglucan, pullulan, animal polymers such as collagen, casein, alpmin, gelatin, carboxymethyl starch, Starch polymers such as methylhydroxypropyl starch, methylcellulose, nitrocellulose, ethylcellulose, methylhydroxypropylcellulose, hydroxyethylcellulose, cellulose sulfate Cellulose polymers such as sodium, hydroxypropylcellulose, sodium carboxymethylcellulose (CMC), crystalline cellulose, cellulose powder, alginic acid polymers such as sodium alginate and propylene glycol alginate, polyvinyl alcohol, polyvinyl methyl ether, polyvinylpyrrolidone, carboxy Vinyl polymers such as vinyl polymers (Carbopol), polyoxyethylene polymers such as polyethylene glycol 2000, 4000 and 6000, polyoxyethylene polyoxypropylene copolymer copolymers, sodium polyacrylate, poly Examples include, but are not limited to, acrylic polymers such as ethyl acrylate and polyacrylamide, polyethyleneimine, and cationic polymers. There.

  As a fragrance ingredient used in liquid cosmetics, animal-based, plant-based, mineral-based natural fragrances and synthetic fragrances can be used.

  Examples of stabilizers used in liquid cosmetics include 1-hydroxyethane-1,1-diphosphonic acid, 1-hydroxyethane-1,1-diphosphonic acid tetrasodium salt, disodium edetate, and trisodium edetate. , Tetrasodium edetate, citric acid, sodium citrate, sodium polyphosphate, sodium metaphosphate, gluconic acid, phosphoric acid, ascorbic acid, succinic acid, edetic acid, lactic acid, sodium lactate solution, etc. Is not to be done.

  Examples of the buffer used in the liquid cosmetic include phosphates such as sodium phosphate and potassium phosphate, and organic acid salts such as sodium ascorbate and sodium benzoate, but are not limited thereto. Absent.

  EXAMPLES Next, although an Example further demonstrates this invention in detail, this invention is not restrained by these description.

  The average particle diameter, specular reflectance, Tg, silica particle opening ratio and h / D of the silica-coated polymer particles of the present invention were measured by the following methods.

(Measurement method of average particle diameter)
The average particle diameter was measured using a multi-image analyzer (Beckman Coulter, Inc.). The multi-image analyzer irradiates a light beam with a strobe behind the aperture tube when particles pass through the aperture, and takes a projected image of each particle passing through the aperture with a CCD camera. It is a device that calculates as a value. The value of the average particle diameter is a number average value of measured values of 1000 to 1500 particles.
The measuring method is shown below.

Device preparation A 100 μm aperture was set in the device, and the position was adjusted so that the whole image of the aperture pore was reflected on the CCD camera. To adjust the focus, the focus was first adjusted to the aperture pore and the focus adjustment knob was moved back by 4 scales.
Sample preparation 0.01 g of a sample was dispersed in 10 ml of a nonionic surfactant 0.1% aqueous solution.

Measurement The beaker provided with the apparatus was filled with ISOTON II (manufactured by Beckman Coulter), and the prepared sample dispersion was dropped with a 1 to 3 drop pipette. The sample is gently stirred so that the sample does not settle in the beaker, and the measurement is performed according to the multi-image analyzer instruction manual (Beckman Coulter), and 1000 to 1500 particles passing through the aperture are photographed with a CCD camera having a lens magnification of 40 times. For each photographed particle image, the average particle diameter was measured with a pixel calibration value of 0.219 μm.

(Measurement method of Tg)
Tg was measured using TG / DTA6200 (manufactured by Seiko Instruments Inc.).
-Measurement About 0.02g of the sample was weighed in an aluminum oven container (manufactured by Seiko Instruments Inc.) and set in an autosampler of TG / DTA6200. The temperature was raised at 5 ° C./min, and a differential thermal analysis was performed from room temperature (about 25 ° C.) to 400 ° C. in an air atmosphere.

-Analysis From the graph (vertical axis: temperature, horizontal axis: time) obtained by the above operation, the inflection point portion of the graph derived from the Tg of the polymer was found, and the inflection point was defined as the Tg temperature. In the case where Tg does not exist, there is no inflection point and the temperature rises linearly until decomposition of the measurement object starts.

(Measurement method of specular reflectance)
Sample preparation A double-sided tape (Nitto Denko: NITTO TAPE) was applied to the entire surface of a black and white masking paper (BYK-Gardner) cut to 50 mm x 100 mm, 1 g of particles were placed on the adhesive surface, and a cosmetic sponge was used. After extending 10 times each in the vertical and horizontal directions equally, the excess particles were blown off by spraying 1.5 kg / cm ² of compressed air over the entire surface for 30 seconds from a location about 20 cm away from the sample. The specular reflectance was measured.
・ Measurement For the measurement of the specular reflectance, VGS-300A and VGS-SENSOR (manufactured by Nippon Denshoku Industries Co., Ltd.) are used, and the specular reflection at 60 ° incident light is applied to the particle adhesion surface in accordance with JIS Z8741. The rate was measured. The number of measurements is five, and the average value is the specular reflectance in this specification.

(Method for confirming silica-coated polymer particles)
The silica-coated polymer particles were confirmed by dropping an aqueous dispersion of silica-coated polymer particles on a single slide glass and using a microscope using a sodium lamp as a light source (used lens: 600 times). This is a method of visually observing silica-coated polymer particles.

(Measurement method of aperture ratio)
First, 1 g of silica-coated polymer particles was taken into a 50 ml magnetic crucible and baked at 500 ° C. for 2 hours using an electric furnace (manufactured by ISUZU). The silica shown in FIG. Particles having only the silica portion of the coated polymer particles (hereinafter referred to as silica particles) were obtained.

  Next, the silica particles were gently taken out from the inside of the magnetic crucible with a spatula, and a photograph was taken with a scanning electron microscope (manufactured by JEOL Ltd .: GMS-820-A).

  Furthermore, from the photographed photograph, arbitrary 50 pieces having the silica particle opening portion on the top are selected, and each of them is manually measured by using a trace measurement of an image analysis apparatus (manufactured by OMRON: Image-Ana LITE). The contour of the silica particle and the contour of the opening portion were designated, and the projected area (S2) and the area (S1) of the opening portion of the silica particle were measured as illustrated in FIG.

From the measured areas, the aperture ratios of the individual silica particles were determined by the following formula, and the average value was shown in the examples.
Opening ratio = area of the opening of silica particles (S1) ÷ projected area of silica particles (S2)

(Measurement of h / D of silica particles)
In addition, as shown in FIG. 2, when the diameter of the silica particle is D and the height of the silica particle is h, the value of h / D is measured by the following method, and the value is taken as an example. Indicated.

  In the same manner as the aperture ratio measurement method, a scanning electron micrograph of silica particles is taken, and 50 particles whose silica particle opening surface is perpendicular to the imaging surface are selected from the photographed images. did. The value of D and h of each particle was measured with the image analysis apparatus, and h / D was calculated. In this specification, h / D means an average value of 50 h / Ds.

Example 1
A dispersion medium in which 5 g of magnesium pyrophosphate by metathesis method is mixed as a suspension stabilizer with 200 g of water is placed in a 500 ml separable flask, 0.04 g of sodium lauryl sulfate as a surfactant, and sodium nitrite as a polymerization inhibitor. 0.02 g was dissolved in the dispersion medium.

  Separately, 70 g of methyl methacrylate as a monofunctional polymerizable vinyl monomer, MKC silicate MS57 (Mitsubishi Chemical Corporation: average molecular weight 1300 to 1500 as polyalkoxysiloxane oligomer), R in the above structural formula is methyl, and the average of n is 15 -18) 30 g and a monomer composition prepared by uniformly dissolving 0.25 g of 2,2′-azobis (2,4-dimethylvaleronitrile) as a polymerization initiator was prepared.

  This monomer composition was added to the dispersion medium, and the mixture was stirred for about 10 seconds at 8000 rpm with a homomixer (manufactured by IKA: ULTRA TURRAX T-25) to finely disperse the monomer composition. A separable flask, a thermometer and a reflux condenser were attached to the separable flask, and after replacing with nitrogen, it was placed in a constant temperature water bath (water bath) at 60 ° C. Stirring is continued in the separable flask at a stirring speed of 200 rpm, and the polymerizable vinyl monomer is subjected to suspension polymerization for 10 hours after the temperature of the dispersion medium added with the monomer composition in the separable flask reaches 60 ° C. And 2 g of sodium hydroxide was added to condense the polyalkoxysiloxane oligomer.

  Next, the separable flask is taken out from the constant temperature water bath, the reaction liquid in the separable flask is cooled to room temperature while stirring the separable flask, and hydrochloric acid is added until the pH of the slurry becomes about 2 to obtain a suspension stabilizer. To obtain silica-coated polymer particles in which the surface of the polymer particles is exposed. The obtained particles were subjected to suction filtration with a Buchner funnel using filter paper, washed with 1.2 L of ion exchange water to remove the suspension stabilizer, and dried to take out the target particles. The resulting silica-coated polymer particles have an average particle diameter of 5.8 μm, and the polymer portion derived from the polymerizable vinyl monomer has a Tg of 105 ° C. Table 1 shows the specular reflectance, aperture ratio, and h / D of the particles.

Example 2
The polymer particles were prepared in the same manner as in Example 1 except that 30 g of methyl methacrylate, 70 g of MKC silicate MS57, and 2,2′-azobis (2,4-dimethylvaleronitrile) were changed to 0.15 g. Silica-coated polymer particles with exposed surfaces were obtained. The obtained silica-coated polymer particles have an average particle diameter of 116.3 μm, and the polymer portion derived from the polymerizable vinyl monomer has a Tg of 105 ° C. Table 1 shows the specular reflectance, aperture ratio, and h / D of the particles.

Example 3
The same method as in Example 1 except that MKC silicate MS51 (Mitsubishi Chemical Co., Ltd .: average molecular weight of 500 to 700, R in the above structural formula is methyl, and n is an average of 5 to 10) was used as the polyalkoxysiloxane oligomer. Thus, silica-coated polymer particles in which the surface of the polymer particles was exposed were obtained. The obtained silica-coated polymer particles have an average particle diameter of 6.4 μm, and the polymer portion derived from the polymerizable vinyl monomer has a Tg of 105 ° C. Table 1 shows the specular reflectance, aperture ratio, and h / D of the particles.

Example 4
The same method as in Example 1 except that MKC silicate MS58B15 (manufactured by Mitsubishi Chemical Corporation: average molecular weight of 1600 to 1800, R in the above structural formula is butyl, and n is an average of 11 to 13) was used as the polyalkoxysiloxane oligomer. Thus, silica-coated polymer particles in which the surface of the polymer particles was exposed were obtained. The obtained silica-coated polymer particles have an average particle diameter of 17.1 μm, and the polymer portion derived from the polymerizable vinyl monomer has a Tg of 105 ° C. Table 1 shows the specular reflectance, aperture ratio, and h / D of the particles.

Example 5
Except that styrene was used as the polymerizable vinyl monomer, silica-coated polymer particles in which the surface of the polymer particles was exposed were obtained in the same manner as in Example 1. The obtained silica-coated polymer particles have an average particle diameter of 12.5 μm, and the polymer portion derived from the polymerizable vinyl monomer has a Tg of 84 ° C. Table 1 shows the specular reflectance, aperture ratio, and h / D of the particles.

Example 6
Except that n-butyl acrylate was used as the polymerizable vinyl monomer, silica-coated polymer particles in which the surfaces of the polymer particles were exposed were obtained in the same manner as in Example 1. The resulting silica-coated polymer particles have an average particle diameter of 19.5 μm, and the polymer portion derived from the polymerizable vinyl monomer has a Tg of −54 ° C. Table 1 shows the specular reflectance, aperture ratio, and h / D of the particles.

Comparative Example 1
A method similar to Example 1 except that instead of the polyalkoxysiloxane oligomer, γ-methacryloxypropyltrimethoxysilane (SZ6030, manufactured by Toray Dow Corning Silicone Co., Ltd.) having a polymerization property with a polymerizable vinyl monomer was used. In the obtained particles, the resin part derived from the polymer vinyl monomer was dispersed in the particles.

Comparative Example 2
A dispersion medium in which 18 g of magnesium pyrophosphate by metathesis method is mixed with 900 g of water as a suspension stabilizer is placed in a 2 L stainless steel beaker, 0.18 g of sodium lauryl sulfate as a surfactant, and sodium nitrite as a polymerization inhibitor. 0.1 g was dissolved in the dispersion medium.

  Separately, a monomer composition was prepared by uniformly dissolving 270 g of methyl methacrylate as a monofunctional polymerizable vinyl monomer, 30 g of ethylene glycol dimethacrylate, and 0.3 g of azobisisobutyronitrile as a polymerization initiator. .

  This monomer composition was added to the above dispersion medium, and the mixture was stirred for about 10 seconds at 4000 rpm with a homomixer (TK homomixer manufactured by Tokushu Kika Kogyo Co., Ltd.) to finely disperse the monomer composition. The dispersion medium was put into a polymerization machine equipped with a stirrer and a thermometer, and stirring was continued at 50 ° C. for 5 hours to complete the suspension polymerization.

  After cooling, hydrochloric acid is added to the suspension, the suspension stabilizer is decomposed, the polymer particles are isolated, washed with water, and dried under reduced pressure to obtain spherical polymer particles (average particle diameter of 13.1 μm). It was. Since these spherical polymer particles have a cross-linked structure, Tg could not be confirmed until 260 ° C. when decomposition by heating of the particles started.

  Composite particles in which 21 g of spherical polymer particles and 9 g of Aerosil R972 (manufactured by Nippon Aerosil Co., Ltd., average particle diameter of 16 nm) are treated with a hybridizer (manufactured by Nara Machinery Co., Ltd.) at 50 ° C. and 14,000 rpm for 5 minutes, and the surface is coated with silica particles. (Average particle diameter 13.6 μm). Table 1 shows the specular reflectance of the particles.

Comparative Example 3
The polymer particles were prepared in the same manner as in Example 1 except that 97 g of methyl methacrylate, 3 g of MKC silicate MS57, and 0.45 g of 2,2′-azobis (2,4-dimethylvaleronitrile) were changed. Silica-coated polymer particles with exposed surfaces were obtained. The obtained silica-coated polymer particles have an average particle diameter of 15 μm, and the polymer portion derived from the polymerizable vinyl monomer has a Tg of 105 ° C. Since the obtained particles had a small silica-coated region, the silica coating sometimes peeled off. Table 1 shows the specular reflectance, aperture ratio, and h / D of the particles.

The following can be understood from Examples 1 to 6 and Comparative Examples 1 to 3.
From Examples 1-6 and Comparative Example 1, when a polymerizable monomer and a polymerizable silane are used instead of the polyalkoxysiloxane oligomer, the polymerizable monomer and the silane are mixed by polymerization, and the surface of the polymer particles It can be seen that the silica-coated polymer particles with the exposed surface cannot be obtained.

  From Examples 1 to 6 and Comparative Example 2, in the silica-coated polymer particles where the surface of the polymer particles is exposed and the silica-coated polymer particles where the surface is not exposed, as shown in Table 1, the former is the specular reflectance. It can be seen that it has a small and excellent diffuse reflectivity.

  From Examples 1 to 6 and Comparative Example 3, it can be seen that when the amount of the polyalkoxysiloxane oligomer is small, the silica coating may be peeled off, resulting in an increase in the specular reflectance.

  From Example 6, it can be seen that the production method of the present invention is not limited to the kind of polymer particles, and that silica-coated polymer particles can be provided even when Tg is low.

  From Examples 1-6, it turns out that the silica particle which has the value of h / D in the range of 0.5 <= h / D <1 has suitable diffuse reflectance. This is because when the h / D value is less than 0.5, the silica film is easily peeled off from the polymer particles, and when the h / D value is 1, the light diffuse reflectivity becomes poor.

Example 7 Cosmetic milk solution Silica-coated polymer particles obtained in Example 1 10.0% by weight
Stearic acid 2.5% by weight
Cetyl alcohol 1.5% by weight
Vaseline 5.0% by weight
Liquid paraffin 10.0% by weight
Polystyrene (10 mol) monooleate 2.0% by weight
Polyethylene glycol 1500 3.0% by weight
Triethanolamine 1.0% by weight
Purified water 64.5% by weight
Perfume appropriate amount Preservative appropriate amount

  First, stearic acid, cetyl alcohol, petrolatum, liquid paraffin, polystyrene (10 mol) monooleate was dissolved by heating, and the silica-coated polymer particles obtained in Example 1 were added. This was mixed with a kneader and kept at 70 ° C. (oil phase). Separately from this, polyethylene glycol and triethanolamine were added to purified water and heated, and kept at 70 ° C. (water phase). The oil phase was added to the aqueous phase, pre-emulsified, and then uniformly emulsified with a homomixer, and then cooled to 30 ° C. with stirring to obtain a cosmetic emulsion.

Example 8
A cosmetic emulsion was obtained in the same manner as in Example 7, except that the silica-coated polymer particles of the present invention were changed to those in Example 3.

Example 9
A cosmetic emulsion was obtained in the same manner as in Example 7, except that the silica-coated polymer particles of the present invention were changed to those in Example 4.

Comparative Example 4
A cosmetic emulsion was obtained in the same manner as in Example 7 except that the silica-coated polymer of the present invention was changed to commercially available polymethyl methacrylate fine particles (average particle diameter of about 8 μm).

Redispersibility of liquid cosmetics The redispersibility of the liquid cosmetics (skin lotions) of Examples 7 to 9 and Comparative Example 4 was examined. The evaluation method is as shown below.

(Redispersibility evaluation method)
The liquid cosmetics prepared in Examples 7 to 9 and Comparative Example 4 were each filled with 40 ml in a 50-ml lidded sample tube, and centrifuged at 3000 rpm for 10 minutes using a centrifuge to obtain a liquid part and a solid part. Completely separated.

Next, the sample tube subjected to solid-liquid separation as described above was set sideways on a ROTARY SHAKER (manufactured by Taiyo Kagaku Kogyo Co., Ltd.), and was made to swing for 5 minutes under the condition of 60 times / minute.
Thereafter, the dispersion state was visually confirmed and evaluated according to the following criteria.

Good dispersibility without powder mass ○
Some lump of powder remains △
The powder lump remains remarkably ×

Redispersibility evaluation results From the above results, the silica-coated polymer particles of the present invention exhibit excellent light diffusibility, and further, liquid cosmetics containing the silica-coated polymer particles of the present invention as a powder component are conventionally used. Compared with the polymethyl methacrylate particles, the oil resistance is excellent and there is no aggregation even in the presence of a humectant or liquid oil and fat, and the redispersibility is excellent.

It is a schematic sectional drawing of the silica covering polymer particle of this invention. It is a schematic sectional drawing of the silica particle obtained by baking the silica covering polymer particle of this invention. It is a conceptual diagram for demonstrating the measuring method of the aperture ratio in this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Polymer particle 2 Silica coating 3 Silica coating polymer particle S1 Open part area of a silica particle S2 Projection area of a silica particle D Silica particle diameter h Silica particle height

Claims (5)

100 parts by weight of a polymerizable vinyl monomer, 10 to 300 parts by weight of a polyalkoxysiloxane oligomer having a weight average molecular weight of 300 to 3000 inert to the polymerizable vinyl monomer, 0.01 to 10 parts by weight of a polymerization initiator, Mixing monomer uniformly to obtain a monomer composition;
A step of obtaining polymer particles by subjecting the polymerizable vinyl monomer in the monomer composition to aqueous suspension polymerization in the presence of a suspension stabilizer;
Silica-coated polymer particles produced by a production method comprising the steps of condensing the polyalkoxysiloxane oligomer with an acid or base catalyst in this order , wherein the weight of the polyalkoxysiloxane oligomer is 0.1 to 0.8. silica-coated polymer particles characterized that you have been coated with a silica coating so as to expose the surface of the coalesced particles. Polymer particles derived from a polymerizable vinyl monomer, and a silica film covering the polymer particles so as to expose the surface of the polymer particles with an opening ratio of 0.1 to 0.8 , A cosmetic comprising silica-coated polymer particles having an average particle diameter of 3 to 50 μm and comprising a polyalkoxysiloxane oligomer condensate. The cosmetic according to claim 2 , wherein the cosmetic is in a liquid form and further contains a moisturizing agent. The cosmetic according to claim 2 or 3 , wherein the cosmetic is in a liquid form and further contains a liquid fat. 100 parts by weight of a polymerizable vinyl monomer, 10 to 300 parts by weight of a polyalkoxysiloxane oligomer having a weight average molecular weight of 300 to 3,000 inert to the polymerizable vinyl monomer, 0.01 to 10 parts by weight of a polymerization initiator, Mixing monomer uniformly to obtain a monomer composition;
A step of obtaining polymer particles by subjecting the polymerizable vinyl monomer in the monomer composition to aqueous suspension polymerization in the presence of a suspension stabilizer;
By including a step of condensing the polyalkoxysiloxane oligomer by adding an acid or base catalyst in this order, the polyalkoxysiloxane oligomer is coated with a silica coating so as to expose the surface of the polymer particles with an aperture ratio of 0.1 to 1. A method for producing silica-coated polymer particles, wherein:

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