JP4916014B2 - Skin cosmetics - Google Patents

Description

  The present invention relates to a skin cosmetic that has an effect of making skin finer and brighter by making the skin wrinkles inconspicuous and making the skin beautiful.

  Conventionally, as skin cosmetics containing powders, there are various types of makeup cosmetics such as foundations, white powders, cheeks and eye shadows, body cosmetics such as body powders and baby powders, and lotions such as pre-shave lotions and body lotions. Is provided. These skin cosmetics are blended with spherical resin particles such as nylon particles and polymethyl methacrylate particles for the purpose of improving the elongation on the skin, improving the feel, and making the wrinkles inconspicuous (Patent Documents 1 to 3). 3). However, these particles are not effective enough to make skin wrinkles inconspicuous, and powders that make skin look more beautiful have been desired.

JP-A-9-48707 JP 2001-206814 A Japanese Patent No. 3881887

  There are numerous groove-like folds on the skin. When the skin cosmetic containing the spherical resin fine particles described above is rubbed into the skin, the spherical fine particles are not necessarily in a shape suitable for filling the groove of the small wrinkles. That is, the fit in the groove is not so good, there are many gaps between the particles, and the particles that have entered the heel groove jump out of the groove relatively easily. For example, sweat with a handkerchief etc. Easily detached when wiped.

The present inventors have found that a method for making a cocoon-like polymer particles that did not exist until now have been patent application already established, the cocoon-shaped polymer fine particles obtained by the method in these conventional spherical particles Instead, it has been found that when it is formulated into a skin cosmetic, the unevenness and the wrinkles of the skin become less conspicuous and the skin can be made finer and brighter. The present invention has been completed by further studies based on this finding.
That is, the present invention
(1) Seed particles in a dispersion of seed particles obtained by dispersion polymerization of a polymerizable monomer mixture containing an acrylic acid ester monomer or a methacrylic acid ester monomer and 0.05 to 1% by weight of a crosslinkable monomer The polymer fine particles obtained by adding 1 to 5 times by weight of the polymerizable vinyl monomer and seed polymerization, the shape of which is a cylindrical rotating body whose one end and the other end are hemispherical or a part thereof, When the distance between one end and the other end of the rotation axis X of the rotating body is L, the diameter of the cylinder is W, and the radius of the hemisphere is R,
(1) 1.1 ≦ L / W ≦ 3
(2) 0.3 ≦ R / W ≦ 0.6
In the basic line drawn in (3), the area inside the outline of the projection is the basic line when overlapping so that the outline of the projection obtained by irradiating light perpendicular to the cylindrical side surface of the rod-shaped polymer particles does not protrude. A skin cosmetic comprising cocoon-shaped fine polymer particles made of polyacrylic acid ester having an average particle diameter of 1 to 8 μm, which is 85% or more of the area of the inside ,
(2) The skin cosmetic according to (1), wherein the content of the cocoon-shaped fine polymer particles is 0.5 to 50% by weight,
It is.

The cocoon-shaped fine polymer particles used in the present invention is a columnar rotator whose one end and the other end are hemispherical or a part thereof, and the distance between one end and the other end on the rotation axis X of the rotator. Is L, the diameter of the cylinder is W, and the radius of the hemisphere is R,
(1) 1.1 ≦ L / W ≦ 3
(2) 0.3 ≦ R / W ≦ 0.6
In the basic line drawn in (3), the area inside the outline of the projection is the basic line when overlapping so that the outline of the projection obtained by irradiating light perpendicular to the cylindrical side surface of the rod-shaped polymer particles does not protrude. The particles are 85% or more of the inner area. The average particle size of the polymer fine particles is usually 1 to 8 μm, preferably 2 to 6 μm.

The cage-shaped polymer fine particles exhibit a special light diffusibility due to the unique shape itself and the orientation that is caused by rolling easily in the direction perpendicular to the rotation axis.
When blended in cosmetics, the wrinkles are less noticeable than spherical particles, making the skin look fine and bright.

A method for producing the cage polymer fine particles used in the present invention will be described.
The soot-like polymer fine particles are dispersed in a seed particle dispersion obtained by dispersing and polymerizing a polymerizable monomer mixture containing a polymerizable vinyl monomer and 0.05 to 1% by weight of a crosslinkable monomer. It can be obtained by seed polymerization by adding double polymerizable vinyl monomer.

A method for synthesizing seed particles using a polymerizable monomer will be described.
In order to synthesize the seed particles of the present invention from a polymerizable monomer mixture containing a polymerizable vinyl monomer and a crosslinkable monomer, a solvent that dissolves the polymerizable monomer but does not dissolve the polymer after polymerization is used. The crosslinkable monomer is usually added in an amount of 0.05 to 1% by weight, preferably 0.1 to 0.6% by weight, more preferably 0.2 to 0.5% by weight, based on the polymerizable vinyl monomer.

When the addition amount of the crosslinkable monomer relative to the polymerizable vinyl monomer is smaller than the above, the polymerizable vinyl monomer added later is easily absorbed inside the seed, causing the seed to swell, and the generated particles are likely to become a true sphere. On the other hand, if the amount is larger than the above, it is easy to cause aggregation during dispersion polymerization, and seed particles having a uniform particle size distribution cannot be obtained.
More specifically, a polymerization initiator is dissolved in a solvent, heated to a temperature suitable for the initiator used, a monomer mixture containing a polymerizable vinyl monomer and a crosslinkable monomer is added, and an inert air stream, for example, A desired seed particle dispersion can be obtained by polymerization in a nitrogen stream for 10 to 24 hours. At this time, in order to improve the dispersion stability of the polymer particles, dispersion stabilizers such as various surfactants or polymer protective colloids may be used.

  Examples of the polymerizable vinyl monomer include styrene monomers such as styrene, p-methylstyrene, p-chlorostyrene, chloromethylstyrene, and α-methylstyrene; ethyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, and dimethylamino. Acrylic ester monomers such as ethyl acrylate and diethylaminoethyl acrylate; methacrylate monomers such as methyl methacrylate, ethyl methacrylate, lauryl methacrylate, dimethylaminoethyl methacrylate and diethylaminoethyl methacrylate; ethylene glycol mono (meth) acrylate, Polyethylene glycol mono (meth) acrylate; alkyl vinyl ethers such as methyl vinyl ether and ethyl vinyl ether; vinyl acetate and vinyl butyrate Vinyl ester monomers such as N; N-alkyl substituted (meth) acrylamides such as N-methylacrylamide, N-ethylacrylamide, N-methylmethacrylamide and N-ethylmethacrylamide; nitrile monomers such as acrylonitrile and methacrylonitrile However, the monomer is not limited to the monomer as long as it is hydrophobic and soluble in an organic solvent.

  Examples of the crosslinkable monomer include aromatic divinyl compounds such as divinylbenzene and divinyltoluene, glycol di (meth) acrylates such as ethylene glycol di (meth) acrylate and diethylene glycol di (meth) acrylate, such as trimethylolpropane tri (meth). Examples thereof include compounds having two or more polymerizable unsaturated bonds in one molecule such as tri (meth) acrylate such as acrylate and pentaerythritol tetra (meth) acrylate, and tetra (meth) acrylate. These monomers can be used alone or in admixture of two or more.

  Examples of the solvent that dissolves the monomer used in the synthesis of the seed particles but does not dissolve the polymer after polymerization include alcohols such as methanol, ethanol, propanol, and isopropyl alcohol. The amount of the solvent used is preferably about 3 to 25 times the weight of the monomer.

  As the dispersion stabilizer, surfactants such as sodium dodecylbenzenesulfonate and sodium lauryl sulfate, water-soluble polymers such as gelatin, methylcellulose, hydroxyethylcellulose, polyvinyl alcohol, polyvinylpyrrolidone, polyacrylate, tricalcium phosphate, A poorly water-soluble inorganic substance such as magnesium carbonate is used. These dispersion stabilizers may be used alone or in combination of two or more. These dispersion stabilizers can be suitably polymerized in the amounts used in ordinary dispersion polymerization.

  Examples of the polymerization initiator include organic peroxides such as benzoyl peroxide, o-methoxybenzoyl peroxide, o-chlorobenzoyl peroxide, lauroyl peroxide, cumene hydroperoxide, and 2,2′-azobisisobutyrate. Examples thereof include azo compounds such as rhonitrile, 2,2′-azobis 2,4-dimethylvaleronitrile, and the like. The amount used is about 0.5 to 5% by weight based on the monomer mixture.

The synthesized particles are taken out by filtration or centrifugation and used in the next step.
The average particle diameter of the seed fine particles is 0.6 to 6 μm, preferably 1.2 to 4.5 μm.

In order to prepare cage-like polymer fine particles from the obtained seed particles, the seed fine particles are completely dispersed in an aqueous medium. For this purpose, it is desirable to add seed fine particles to an aqueous medium such as water and disperse by ultrasonic dispersion or the like, if necessary, in the presence of a dispersion stabilizer.
Dissolve 1-5 times by weight of seed fine particles, preferably 1.5-3.5 times by weight of polymerizable vinyl monomer and oil-soluble initiator in an aqueous dispersion of seed particles, and use surface activity such as sodium lauryl sulfate. Disperse in an aqueous agent solution with a homomixer or the like or perform ultrasonic dispersion to obtain a monomer emulsion. This monomer dispersion is added to the seed particle dispersion and stirred to allow the seed to absorb the monomer. In order to improve the solvent resistance of the fine polymer particles obtained by the polymerization reaction, 20% by weight or less, preferably 5 to 15% by weight of a crosslinkable monomer can be added to the monomer emulsion with respect to the polymerizable vinyl monomer. The end of absorption can be confirmed using an optical microscope or the like. When the amount of the polymerizable monomer relative to the seed is less than the above, the particles obtained after the polymerization are almost spherical, which is not preferable. Further, when the amount of the monomer added is larger than the above, irregular particles having irregularities are formed after polymerization, and when the amount is excessive, it becomes undesirably spherical. After confirming that the monomer has been completely absorbed, the temperature is raised and polymerization is performed. At this time, various dispersion stabilizers may be used in order to improve the dispersion stability of the polymer particles.

In the seed polymerization of the present invention, in addition to the polymerization initiator, an appropriate amount of a chain transfer agent, a polymerization inhibitor or the like may be used as necessary.
As the polymerization initiator, those usually used in this kind of reaction, for example, peroxide initiators such as benzoyl peroxide and lauroyl peroxide, 2,2'-azobisisobutyronitrile, 2,2'-azo Examples include azo polymerization initiators such as bisvaleronitrile. These polymerization initiators are used by dissolving in a polymerizable monomer. Chain transfer agents may also be those commonly used for this type of reaction, such as monothiol, polythiol, xanthogen disulfide, thiuram disulfide, mercaptoacetic acid 2-ethylhexyl ester, octanoic acid 2-mercaptoethyl ester, mercaptoacetic acid methoxybutyl ester, mercapto. Propionic acid methoxybutyl ester, α-methylstyrene dimer, terpinolene and the like are preferably used. As the polymerization inhibitor, for example, an appropriate amount of a commonly used polymerization inhibitor such as sodium nitrite, sodium sulfite, cupric chloride and the like is used.

  The average particle size of the polymer fine particles is 1.3 to 1.5 times the particle size of the seed used, and is obtained by the subsequent polymerization reaction. Therefore, the particle system of the polymer fine particles can be adjusted in the range of 1 to 8 μm by arbitrarily changing the particle size of the seed used.

  The polymerization temperature in the polymerization reaction of the present invention varies depending on the type of polymerization initiator used, monomer, polymerization inhibitor added as necessary, chain transfer agent, etc., but is usually 30 to 100 ° C., preferably 50-90 ° C. After the polymerization, the polymer fine particles are filtered off, washed with water and dried to obtain a dry powder composed of Ryukyu polymer fine particles.

By the method described above, cage-like polymer fine particles as shown in the electron micrographs of FIGS. 1 to 3 are obtained. Some of the photos look like spheres, but many of them look like spheres or ellipsoids depending on the angle taken, and are actually saddle-shaped.
As shown in FIG. 4, the shape of the cocoon-shaped polymer fine particle is a cylindrical rotator in which one end and the other end are hemispherical or a part thereof, and the distance between one end and the other end on the rotation axis X of the rotator When L, the diameter of the cylinder is W, and the radius of the hemisphere is R,
(1) 1.1 ≦ L / W ≦ 3
(2) 0.3 ≦ R / W ≦ 0.6
In the basic line drawn in (3), the area inside the outline of the projection is the basic line when overlapping so that the outline of the projection obtained by irradiating light perpendicular to the cylindrical side surface of the rod-shaped polymer particles does not protrude. It is 85% or more of the area.
The baseline is preferably
(1) 1.2 ≦ L / W ≦ 2.3
(2) 0.35 ≦ R / W ≦ 0.55
The polymer fine particles produced by the production method of the present invention, in which the area within the contour of the projected view can be 90% or more of the area within the basic line, has a substantially uniform average particle diameter, At least 80% by weight of the fine particles are cage-like polymer fine particles, and usually 90% by weight or more.

The content of the spherical composite polymer particles in the cosmetic varies depending on the dosage form and is not particularly limited, but is 0.1 to 50% by weight, preferably 1 to 20% by weight for a liquid or creamy cosmetic. In the case of solid cosmetics such as powder, the content is desirably 2 to 40% by weight. If the content of the cage polymer fine particles is within the above range, it is preferable because it is excellent in the effect of making conspicuous lines such as fine lines less visible and the feeling in use is good.
Further, the cosmetic of the present invention may be blended into a normal cosmetic as necessary, as long as the cocoon-like polymer fine particles do not impair the effect of making small wrinkles inconspicuous due to the light diffusibility due to its unique shape. Ingredients can be blended.

  The oil agent may be any oil used in cosmetics, for example, liquid oil such as liquid paraffin, squalane, petrolatum, paraffin wax, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, behenic acid. Higher fatty acids such as undecylenic acid, oxystearic acid, linoleic acid, lanolin fatty acid, synthetic fatty acid, glyceryl trioctanoate, propylene glycol dicaprate, cetyl 2-ethylhexanoate, isocetyl stearate, beeswax, whale wax, Waxes such as lanolin, carnauba wax and candelilla wax, oilseed such as linseed oil, cottonseed oil, castor oil, egg yolk oil, coconut oil, metal soaps such as zinc stearate and zinc laurate, cetyl alcohol stearyl alcohol, oleyl alcohol, etc. The higher alcohol And the like.

Examples of the fats and waxes include avocado oil, almond oil, olive oil, cacao butter, beef tallow, sesame oil, wheat germ oil, safflower oil, shea butter, turtle oil, straw oil, persic oil, castor oil, grape oil, macadamia nut Oil, mink oil, egg yolk oil, owl, palm oil, rosehip oil, hydrogenated oil, silicone oil, orange luffy oil, carnauba wax, candelilla wax, whale wax, jojoba oil, montan wax, beeswax, lanolin and the like.
Examples of the hydrocarbon include liquid paraffin, petrolatum, paraffin, ceresin, microcrystalline wax, squalane and the like.

Examples of the higher fatty acid include lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, behenic acid, undecylenic acid, oxystearic acid, linoleic acid, lanolin fatty acid, and synthetic fatty acid.
Examples of higher alcohols include lauryl alcohol, cetyl alcohol, cetostearyl alcohol, stearyl alcohol, oleyl alcohol, behenyl alcohol, lanolin alcohol, hydrogenated lanolin alcohol, hexyl decanol, octyl decanol, isostearyl alcohol, jojoba alcohol, decyl. Examples include tetradecanol.
Examples of sterols include lesterol, dihydrocholesterol, phytocholesterol and the like.

  Examples of fatty acid esters include ethyl linoleate, isopropyl myristate, lanolin fatty acid isopropyl, hexyl laurate, myristyl myristate, cetyl myristate, octyl dodecyl myristate, decyl oleate, octyl dodecyl oleate, hexyl decyl dimethyloctanoate , Cetyl octanoate, cetyl isooctanoate, decyl palmitate, glyceryl trimyristate, glycerin tri (capryl / capric acid), propylene glycol dioleate, glyceryl triisostearate, glyceryl triisooctanoate, cetyl lactate, myristyl lactate, malic acid Examples include cyclic alcohol fatty acid esters such as diisostearyl, cholesteryl isostearate, and cholesteryl 12-hydroxystearate. It is.

Examples of the metal soap include zinc laurate, zinc myristate, magnesium myristate, zinc palmitate, zinc stearate, aluminum stearate, calcium stearate, magnesium stearate, zinc undecylenate and the like.
Examples of the humectant include glycerin, propylene glycol, 1,3-butylene glycol, polyethylene glycol, sodium dl-pyrrolidonecarboxylate, sodium lactate, sorbitol, sodium hyaluronate, polyglycerin, xylit, maltitol and the like.

  Examples of the surfactant include anionic surfactants such as higher fatty acid soaps, higher alcohol sulfates, N-acyl glutamates, phosphate esters and alkyl sulfates, amine salts, quaternary ammonium salts and the like. Cationic surfactant, amphoteric surfactant such as betaine type, amino acid type, imidazoline type, lecithin, fatty acid monoglyceride, propylene glycol fatty acid ester, sorbitan fatty acid ester, sucrose fatty acid ester, polyglycerin fatty acid ester, alkylalkanolamide, oxidation Nonionic surfactants such as ethylene condensates can be mentioned.

  Examples of the polymer compound include gum arabic, tragacanth gum, guar gum, locust bean gum, karaya gum, iris moss, quince seed, gelatin, shellac, rosin, casein and other natural polymer compounds such as sodium carboxymethyl cellulose, hydroxyethyl cellulose, methyl cellulose, Semi-synthetic polymer compounds such as ethyl cellulose, sodium alginate, ester gum, nitrocellulose, hydroxypropyl cellulose, crystalline cellulose, polyvinyl alcohol, polyvinyl pyrrolidone, sodium polyacrylate, carboxyvinyl polymer, polyvinyl methyl ether, polyamide resin, silicone oil, Nylon particles, polymethyl methacrylate particles, crosslinked polystyrene particles, silicone particles, urethane particles, Synthetic polymer compounds such as synthetic resin particles such as ethylene particles.

  Examples of the color material raw material include iron oxide, ultramarine, conger, chromium oxide, chromium hydroxide, carbon black, manganese violet, titanium oxide, zinc oxide, talc, kaolin, mica, calcium carbonate, magnesium carbonate, mica, and silicic acid. Inorganic pigments such as aluminum, barium silicate, calcium silicate, magnesium silicate, silica, zeolite, barium sulfate, calcined calcium sulfate (baked gypsum), calcium phosphate, hydroxyapatite, ceramic powder, azo, nitro, nitroso, Examples include tar dyes such as xanthene, quinoline, anthraquinoline, indigo, triphenylmethane, phthalocyanine, and pyrene.

Examples of the fragrances include natural fragrances such as lavender oil, peppermint oil, and lime oil, and synthetic fragrances such as ethyl phenyl acetate, geraniol, and p-tert-butylcyclohexyl acetate.
Examples of the antiseptic / bactericidal agent include methyl parapen, ethyl parapen, propyl parapen, benzalkonium, benzethonium and the like.
Examples of the antioxidant include dibutylhydroxytoluene, butylhydroxyanisole, propyl gallate, tocopherol and the like.

Examples of the ultraviolet absorber include inorganic absorbents such as fine particle titanium oxide, fine particle zinc oxide, fine particle cerium oxide, fine particle iron oxide, fine particle zirconium oxide, benzoic acid, paraaminobenzoic acid, anthranilic acid, salicylic acid. And organic absorbents such as cinnamic acid, benzophenone, and dibenzoylmethane.
Special blending ingredients include, for example, hormones such as estradiol, estrone, ethinylestradiol, cortisone, hydrocortisone, prednisone, vitamins such as vitamin A, vitamin B, vitamin C, vitamin E, citric acid, tartaric acid, lactic acid, aluminum chloride Skin astringents such as aluminum sulfate / potassium sulfate, allantochlorohydroxyaluminum, zinc paraphenolsulfonate, zinc sulfate, cantalis tincture, pepper tincture, ginger tincture, assembly extract, garlic extract, hinokitiol, carpronium chloride, pentadecanoic acid glyceride , Hair growth promoters such as vitamin E, estrogen, and photosensitizers, and whitening agents such as magnesium phosphate-L-ascorbate and kojic acid.

The present invention will be described more specifically with reference to the following examples. However, the present invention is not limited to these examples. In the examples, “parts” represents parts by weight.
Synthesis of cage-like polymer fine particles

Synthesis example 1
While stirring a solution prepared by dissolving 24 parts of polyvinylpyrrolidone (molecular weight 360,000) and 6.5 parts of tricaprylylmethylammonium chloride (aliquot 336; Cognis Japan) in 840 parts of methanol and 94 parts of ion-exchanged water, under a nitrogen stream The temperature was raised to 50 ° C. Then, 2.4 parts of t-butyl peroxypivalate dissolved in 100 parts of methyl methacrylate and 0.2 part of ethylene glycol dimethacrylate was added and kept at the same temperature for 24 hours to obtain polymer particles (seed). . The average particle size of these particles was 3.34 μm, and the standard deviation of the particle size distribution was 7.84%.
To 44 parts of the obtained seed particles, 0.52 parts of Hytenol NF-13 (Daiichi Kogyo Seiyaku) and 350 parts of ion-exchanged water were added as surfactants and dispersed uniformly. A mixture of 63 parts of methyl methacrylate and 7 parts of ethylene glycol dimethacrylate is mixed with 1.4 parts of benzoyl peroxide and mixed with 280 parts of ion-exchanged water and 1.05 parts of Haitenol NF-13. Sonicated. When the obtained emulsion was added to the seed particle dispersion and stirred for 30 minutes, the monomer was completely absorbed by the seed particles. This dispersion was polymerized at 70 ° C. for 4 hours under a nitrogen stream to obtain a bowl-shaped particle having a uniform particle size distribution. As a result of measuring the obtained particles with a precision particle size distribution analyzer Multisizer IIE manufactured by Beckman Coulter, the average particle size was 4.38 μm and the standard deviation of the particle size distribution was 15.4%. An electron micrograph of the polymer particles is shown in FIG. As a result of observation with a scanning microscope, the L / W value of 50 particles was 1.5 to 1.9, and the R / W was 0.41 to 0.55.

Synthesis example 2
While stirring a solution prepared by dissolving 24 parts of polyvinylpyrrolidone (molecular weight 360,000) and 5.8 parts of aliquot 336 (Cognis Japan) in 649 parts of methanol and 114 parts of ion-exchanged water, the temperature was raised to 50 ° C. in a nitrogen stream, Next, 1.2 parts of 2,2′-azobisisobutyronitrile dissolved in 79.8 parts of methyl methacrylate and 0.4 part of ethylene glycol dimethacrylate were added, and the mixture was held at the same temperature for 24 hours to obtain polymer particles. Obtained. The average particle size of these particles was 2.50 μm, and the standard deviation of the particle size distribution was 20.8%.
To 35 parts of the obtained particles, 0.52 part of Hytenol NF-13 (Daiichi Kogyo Seiyaku) and 350 parts of ion-exchanged water were added and dispersed uniformly. A mixture of 63 parts of methyl methacrylate and 7 parts of ethylene glycol dimethacrylate was mixed with 1.05 part of benzoyl peroxide and 280 parts of ion-exchanged water and 1.05 part of Haitenol F-13 were sonicated. did. When the obtained emulsion was added to the seed particle dispersion and stirred for 30 minutes, the monomer was completely absorbed by the seed particles. 0.14 parts of sodium nitrite was added to this dispersion, followed by polymerization at 70 ° C. for 4 hours under a nitrogen stream to obtain particles having a bowl-like uniform particle size distribution. The average particle size of the obtained particles was 3.58 μm, and the standard deviation of the particle size distribution was 19.3%. As a result of observation with a scanning microscope, there are 3 particles out of 50 particles that do not satisfy 1.1 ≦ L / W ≦ 3 and 0.3 ≦ R / W ≦ 0.6, and other L / W The value was 1.2 to 1.4, and the R / W value was 0.35 to 0.52.
An electron micrograph of the polymer particles is shown in FIG.

Synthesis example 3
To 35 parts of seed particles obtained in the same manner as in Synthesis Example 2, 0.5 part of Prisurf A210G (Daiichi Kogyo Seiyaku) and 350 parts of ion-exchanged water were added and dispersed uniformly as a surfactant. To 70 parts of methyl methacrylate, 1.05 part of benzoyl peroxide was dissolved, and 280 parts of ion-exchanged water and 1.5 parts of Prisurf A210G were mixed and sonicated. When the obtained emulsion was added to the seed particle dispersion and stirred for 30 minutes, the monomer was completely absorbed by the seed particles. To this dispersion, 0.14 part of sodium nitrite and 15 parts of a 10% aqueous solution of polyvinyl alcohol (GH-17, manufactured by Nippon Synthetic Chemical) were added, followed by polymerization at 70 ° C. for 4 hours under a nitrogen stream to form a bowl-like uniform particle. Particles with a size distribution were obtained. The average particle size of the obtained particles was 3.82 μm, and the standard deviation of the particle size distribution was 20.1%. As a result of observation with a scanning microscope, there are 3 particles out of 50 particles that do not satisfy 1.1 ≦ L / W ≦ 3 and 0.3 ≦ R / W ≦ 0.6, and other L / W The value was 1.2 to 1.45, and the R / W value was 0.43 to 0.55.

Synthesis example 4
The same operation was performed except that 70.0 parts of the seed particles obtained in Synthesis Example 2 were used. The obtained fine particles were true spherical fine particles having an average particle diameter of 2.78 μm.

Oily compact foundation Carnauba wax 4.0 parts Solid paraffin 4.0 parts Cetanol 4.0 parts Lanolin 7.0 parts Liquid paraffin 6.0 parts Behenyl alcohol 4.0 parts Titanium oxide 13.0 parts Iron oxide 10.0 parts Coral polymer Fine particles (Synthesis Example 1 particle size 4.4 μm)
40.0 parts Sericite 8.0 parts An oily compact foundation was produced by the above formulation.

Powder Sprinkled polymer fine particles (Synthesis example 1) 12.0 parts Solid paraffin 5.0 parts Vaseline 14.0 parts Liquid paraffin 40.0 parts Glycerol monostearate 2.0 parts Polyoxyethylene sorbitan monooleate 2.0 parts Purification Water 24.7 parts Soap powder 0.1 part Borax 0.2 part Powder was prepared by the above formulation.

Lotion Oil phase Stearic acid 2.0 parts Cetyl alcohol 1.2 parts Petrolatum 5.0 parts Liquid paraffin 1.0 parts Polyoxyethylene oleyl ether (20E.O.)
3.0 parts Polyoxyethylene sorbitan monolaurate (4EO) 3.0 parts Aqueous phase Propylene glycol 4.0 parts Triethanolamine 1.0 part Purified water 64.6 parts Saddle-shaped polymer fine particles (Synthesis Example 1) ) 5.0 parts Titanium oxide 0.2 parts A lotion was prepared with the above formulation.

Comparative Example 1

An oily compact foundation was prepared with the same composition as in Example 1 except that the cage-like polymer fine particles of Synthesis Example 4 were used.
Comparative Example 2

A powder was prepared with the same composition as in Example 2 except that the basket-like polymer fine particles of Synthesis Example 4 were used.
Comparative Example 3

A lotion was prepared with the same composition as in Example 3 except that the basket-like polymer fine particles in Synthesis Example 4 were used.
Experimental example 1

In order to evaluate whether or not the difficulty of conspicuousness such as wrinkles could be improved when making up using each cosmetic material, and whether it was a natural finish, it was evaluated by the following standards by 20 panelists.
〔Evaluation criteria〕
(Double-circle): 16 or more people evaluated that it was improving with respect to a comparative example.
A: 11 to 15 people evaluated that they were able to improve the comparative example.
(Triangle | delta): 6-10 people evaluated that it was improving with respect to the comparative example.
X: Five or less people evaluated that it was improving with respect to a comparative example.
The results are shown in Table 1.

このように、球形樹脂微粒子を配合した皮膚化粧料に対して、本発明の繭型樹脂微粒子を配合した皮膚化粧料は、小皺等の目立ち難さが改善でき、且つ自然な仕上がり効果が得られた。

As described above, the skin cosmetic compounded with the cocoon-shaped resin fine particles of the present invention can improve the inconspicuousness of small wrinkles and the like, and the natural finish effect can be obtained compared to the skin cosmetic compounded with the spherical resin fine particles. It was.

Photomicrograph of cage polymer fine particles obtained in Synthesis Example 1 Micrograph of cage-like polymer fine particles obtained in Synthesis Example 2 Photomicrograph of cage polymer fine particles obtained in Synthesis Example 3 Schematic diagram of the cage polymer fine particles of the present invention

Explanation of symbols

L: distance between one end and the other end of the rod-shaped body used in the present invention W: diameter of the rod-shaped body R: radius of the hemisphere X: rotation axis of the rod-shaped body

Claims (2)

In a dispersion of seed particles obtained by dispersion polymerization of a polymerizable monomer mixture containing an acrylic acid ester monomer or a methacrylic acid ester monomer and 0.05 to 1% by weight of a crosslinkable monomer, Polymer fine particles obtained by seed polymerization by adding 5 times by weight of a polymerizable vinyl monomer, the shape of which is a cylindrical rotator with one end and the other end being hemispherical or a part thereof, When the distance between one end and the other end of the rotation axis X is L, the diameter of the cylinder is W, and the radius of the hemisphere is R,
(1) 1.1 ≦ L / W ≦ 3
(2) 0.3 ≦ R / W ≦ 0.6
In the basic line drawn in (3), the area inside the outline of the projection is the basic line when overlapping so that the outline of the projection obtained by irradiating light perpendicular to the cylindrical side surface of the rod-shaped polymer particles does not protrude. A skin cosmetic comprising cocoon-shaped fine polymer particles made of polyacrylic acid ester having an average particle diameter of 1 to 8 μm, which is 85% or more of the area .   The skin cosmetic according to claim 1, wherein the content of the cocoon-shaped fine polymer particles is 0.5 to 50% by weight.

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