JP4863678B2 - Method for producing silica particles - Google Patents

Description

The present invention relates to a process for the preparation of silica particles child. More particularly, the present invention relates to a process for producing silica particles child having specific shapes.

  In the field of cosmetics and adsorbents, silica particles are used as components that adsorb various liquid articles such as fats and oils, petroleum, and solvents. Known methods for producing silica particles include a method for producing amorphous silica particles by a pulverization method, a seed polymerization method, and a method for producing spherical silica particles by a sol-gel method.

  However, all of these particles are spherical or have an irregular shape close to a spherical shape, so the surface area is small and the adsorption capacity is low. Therefore, these silica particles have a problem that makeup collapse occurs due to sebum that could not be adsorbed when blended in cosmetics, for example.

Therefore, a porous silica particle having a higher oil absorption and a production method have been proposed as compared with spherical or amorphous silica particles (Japanese Patent Laid-Open No. 2000-7320, Patent Document 1). These particles are used as a paper ink penetration inhibitor. Moreover, JP, 10-182345, A (patent documents 2) is mentioned as an example of cosmetics using the same porous silica particles, and porous silica particles are used as a sebum control material.
JP-A-2004-307837 (Patent Document 3) reports a spherical or substantially spherical silica particle having a hollow structure at least partially opened.
JP 2000-7320 A Japanese Patent Laid-Open No. 10-182345 JP 2004-307837 A

  However, porous silica particles have a small specific surface area and a small amount of oil absorption. On the other hand, the silica particles having a hollow structure are excellent in oil absorption, but the ability to retain the adsorbed components is not high. That is, it is desired to improve the sustained release so that a drug containing components such as a fragrance and a fragrance is released at a controlled rate for a longer time.

  The inventor of the present invention has conducted extensive research to solve the above problems, and as a result, the polymerizable vinyl monomer is polymerized by aqueous suspension polymerization in the presence of a polyalkoxysiloxane oligomer and a specific silanol group-forming silane compound. Silica composite in which the polyalkoxysiloxane oligomer and the silanol group-forming silane compound-derived silica component are unevenly distributed in the polymer component by condensing the polyalkoxysiloxane oligomer and the silanol group-forming silane compound. By obtaining polymer particles and calcining this composite polymer component, it is possible to obtain silica particles having a unique shape, and surprisingly find that the obtained silica particles are excellent in sustained release properties, The present invention has been reached.

Thus, according to the present invention, 100 parts by weight of a polymerizable vinyl monomer, 10 to 500 parts by weight of a polyalkoxysiloxane oligomer inert to the polymerizable vinyl monomer, and the following general formula (R ¹ O) _m SiR ² _4-m
(R ¹ is a hydrogen atom or a group selected from a substituted or unsubstituted alkyl group and an acyl group, R ² is a group selected from a substituted or unsubstituted alkyl group, a cycloalkyl group, an aryl group and an aralkyl group; Are integers of 1 to 3, R ¹ may be the same or different when m is 2 or 3, and R ² may be the same or different when m is 1 or 2.
A mixture containing 0.5 to 100 parts by weight of a silanol group-forming silane compound represented by the formula and 0.01 to 10 parts by weight of a polymerization initiator is suspended in an aqueous system in the presence of a suspension stabilizer, By polymerizing the polymerizable vinyl monomer in the mixture, suspension polymer particles composed of the polyalkoxysiloxane oligomer and silanol group-forming silane compound and a polymer component derived from the polymerizable vinyl monomer are obtained. Obtaining a step;
A step of condensing the polyalkoxysiloxane oligomer and silanol group-forming silane compound in the suspension polymerized particles by adding an acid or a base catalyst to obtain silica composite polymer particles containing a silica component; and the silica composite polymer particles And a step of obtaining silica particles by removing the polymer component by baking and providing a method for producing silica particles.

The silica particles of the present invention have a larger oil absorption than the conventional porous silica particles, and are excellent in retention of adsorbed substances because of their numerous pleats. Therefore, it is excellent in the sebum controllability of cosmetics, the ability to prevent makeup collapse due to sebum, and the sustained release of active ingredients such as fragrances.
Moreover, the high adsorption capability is acquired by mix | blending the silica particle of this invention with an adsorbent.

Hereinafter, the present invention will be described in more detail.
The silica particles of the present invention have a specific surface area of 50 to 300 m ² / g and many pleats on the surface as shown in FIG. By having such a structure, oil absorption is improved, and more adsorbing components such as ink, oil agent, sebum, etc. can be adsorbed. In addition, since the retention is improved, the sustained release of active ingredients such as fragrances can be expected. The numerous folds present on the surface are similar to the shape of rose petals and the shape of the back of a mushroom umbrella.

When the specific surface area is smaller than 50 m ² / g, it is not preferable because sufficient adsorptivity is difficult to obtain. When it is larger than 300 m ² / g, it is not preferable because the particles are easily broken and stable production is difficult. The method for measuring the specific surface area is described in the examples. A preferred specific surface area is 70 to 250 m ² / g.

  Moreover, the silica particle which has the oil absorption amount (a measuring method is described in the column of an Example) measured by 400-600 ml / 100g JISK5101 can be obtained by having the said shape and specific surface area. In addition, the adsorption | suction component of the silica particle of this invention is not limited to oil, The component containing water may be sufficient.

Hereinafter, the silica particles of the present invention will be described with reference to the production method.
First, a mixture containing a polymerizable vinyl monomer, a polyalkoxysiloxane oligomer, a silanol group-forming silane compound, and a polymerization initiator is suspended in an aqueous system in the presence of a suspension stabilizer, and then in the mixture. A polymer component is obtained by polymerizing the polymerizable vinyl monomer.

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 and its derivatives such as chlorostyrene,
Vinyl esters such as vinyl acetate, vinyl propionate and vinyl butyrate,

Methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, lauryl acrylate, 2-acrylate Chlorethyl, phenyl acrylate, methyl α-chloroacrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate , Stearyl methacrylate, lauryl methacrylate, phenyl methacrylate, dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate, diethyl methacrylate α- methylene aliphatic monocarboxylic acid esters such as aminoethyl,

There are acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylonitrile, acrylamide, methacrylamide, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, and the like. 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-vinyl compounds such as N-vinylpyrrolidone, 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 the polymerizable vinyl monomers, styrene, methyl methacrylate, etc., which are inexpensive in terms of cost, are preferable.
The polymer component 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, which is a precursor of silica particles, is inert to the polymerizable vinyl monomer (meaning that it is not copolymerized), and those having the following structural formula can be used.

In the formula, R may be the same or different.
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 the silica particles of the present invention.

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 it is less than 10 parts by weight or more than 500 parts by weight, it is not preferable because it is difficult to form the silica particles of the present invention.

  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.

As the silanol group-forming silane compound, a compound represented by the following general formula can be used.
(R ¹ O) _m SiR ² _4-m
(R ¹ is a hydrogen atom or a group selected from a substituted or unsubstituted alkyl group and an acyl group, R ² is a group selected from a substituted or unsubstituted alkyl group, a cycloalkyl group, an aryl group and an aralkyl group; Are integers of 1 to 3, R ¹ may be the same or different when m is 2 or 3, and R ² may be the same or different when m is 1 or 2.
In R ¹ and R ² , the alkyl group is preferably a lower alkyl group, and more preferably an alkyl group having 1 to 4 carbon atoms. Specific examples include methyl, ethyl, propyl, i-propyl, butyl, i-butyl, sec-butyl, and tert-butyl.

In R ¹ , the acyl group is preferably a lower acyl group having 1 to 4 carbon atoms. Specific examples include formyl, acetyl, propionyl, butyryl and the like.
In R ² , the cycloalkyl group is preferably a cycloalkyl group having 3 to 6 carbon atoms. Specific examples include cyclopropane, cyclobutane, cyclopentane, and cyclohexane.

In R ² , the aryl group is preferably an aryl group having 4 to 10 carbon atoms. Specific examples include hydrocarbon compounds such as phenyl and naphthyl.
In R ² , the aralkyl group is preferably an alkyl group having 1 to 4 carbon atoms substituted with an aryl group having 4 to 10 carbon atoms. Specific examples include phenylmethyl, phenylethyl, phenylbutyl and the like.

  Specific examples of silanol group-forming silane compounds include methyltrimethoxysilane, methyltriethoxysilane, isobutyltrimethoxysilane, isobutyltriethoxysilane, propyltrimethoxysilane, propyltriethoxysilane, phenyltriethoxysilane, and phenyltrimethoxy. Silane, methyltriacetoxysilane, methylsilanetriol, dimethyldimethoxysilane, dimethyldiethoxysilane, diphenyldimethoxysilane, diethoxymethylsilane, dimethoxymethylsilane, dimethyldiacetoxysilane, dimethylsilanediol, diethylsilanediol, dimethoxymethylphenylsilane , Trimethylmethoxysilane, trimethylethoxysilane, triethylethoxysilane, triethylmethoxysilane, Acetoxytrimethylsilane include trimethyl silanol.

The addition amount of the silanol group-forming silane compound is preferably 0.5 to 100 parts by weight and more preferably 0.55 to 80 parts by weight with respect to 100 parts by weight of the polymerizable vinyl monomer. If it is less than 0.5 part by weight, it is not preferable because it is difficult to form the silica particles of the present invention. On the other hand, when the amount is more than 100 parts by weight, the water solubility of the silane compound is increased by hydrolysis of the substituents R ¹ and / or R ² , so that it is difficult for the silane compound to be stably present in the mixture. It is not preferable.

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. Specific examples include 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, 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-isopropylbutyronitrile), 1,1′-azobis (Cyclohexane-1-carbonitrile), 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile, (2-carbamoylazo) isobutyronitrile, 4,4′-azobis (4-cyanovaleric acid) ), And azo initiators such as dimethyl-2,2′-azobisisobutyrate.

  Among these, 2,2′-azobisisobutyronitrile, 2,2′-azobis (2,4-dimethylvaleronitrile), benzoyl peroxide, lauroyl peroxide, etc. are suitable for the decomposition rate of the polymerization initiator. It is preferable in a certain point.

  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 0.01 parts by weight, it is difficult to achieve the function of initiating the polymerization, and when it exceeds 10 parts by weight, it is not preferable because it is not economical.

In order to color the silica component, metal oxide pigments such as titanium oxide, zinc oxide, magnesium oxide, chromium oxide, and zirconium oxide may be used.
The polymerizable vinyl monomer, the polyalkoxysiloxane oligomer, the polymerization initiator, and other components are uniformly mixed by a known method to form a mixture.

  Next, examples of the aqueous medium for aqueous suspension polymerization of the mixture include water or a mixed medium of water and a water-soluble solvent such as alcohol (for example, methanol, ethanol). 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.

  The suspension stabilizer is not particularly limited, and any known suspension stabilizer can be used. 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 dispersion stabilizers of poorly water-soluble inorganic compounds such as magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate, and colloidal silica. Of these, tricalcium phosphate, magnesium pyrophosphate, calcium pyrophosphate, and colloidal silica produced by the metathesis method are preferable because the polymer component 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 polymer component to be obtained and the dispersion stability during polymerization, the suspension stabilizer Are used by appropriately adjusting the selection and usage amount. 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 aqueous suspension polymerization is performed by adding the mixture to the aqueous medium thus prepared.
As a dispersion method of the mixture, for example, a method in which the mixture is directly added to the aqueous medium and dispersed in the aqueous medium as monomer droplets by stirring force of a propeller blade or the like, a disperser using a high shear force composed of a rotor and a stator And a method of dispersing using a homomixer or an ultrasonic disperser. Among these, the mixture is pressed into an aqueous medium through a high-pressure disperser using a collision between monomer droplets such as a microfluidizer or a nanomizer or a collision force against the wall of the machine, or through an MPG (microporous glass) porous film. Dispersion by a method is preferable because the particle diameter can be made more uniform.

  The aqueous suspension in which the mixture is dispersed as spherical monomer droplets is then heated to initiate suspension polymerization. During the polymerization reaction, it is preferable to stir the aqueous suspension, and the stirring may be performed so gently as to prevent the monomer droplets from floating and the particles from being settled after the polymerization.

  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, a silica composite polymer particle can be obtained by condensing a polyalkoxysiloxane oligomer and a silanol group-forming silane compound. Examples of the condensation method of the polyalkoxysiloxane oligomer and the silanol group-forming silane compound 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, sodium pyrophosphate and the like can be used. When the production container is made of steel or stainless steel, basic sodium hydroxide, ammonia, sodium pyrophosphate and the like are preferable from the viewpoint of corrosion and 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, the silica composite polymer particles are separated as a water-containing cake by a method such as suction filtration, centrifugal dehydration, centrifugal separation, pressure dehydration, and the obtained water-containing cake is washed with water and dried to obtain the desired silica composite weight. Combined particles can be obtained.

  By firing the silica composite polymer particles thus obtained, the silica particles of the present invention derived from the silica component unevenly distributed on the surface and inside of the polymer component can be obtained. Although it does not specifically limit as a baking method, There exist the method of baking in inert gas atmosphere, such as argon, xenon, nitrogen, or the method of baking in air, for example in air. In view of economics, firing in air is preferable. Moreover, it is preferable that a calcination temperature is 500 degreeC or more. When the firing temperature is less than 500 ° C., silica particles are colored due to the residue of carbon residue and the like of the fired polymer component, which is not preferable. A more preferable firing temperature is 500-1500 ° C.

  The size of the silica particles of the present invention is not particularly limited. However, according to the above production method, silica particles having an average particle diameter of usually 1 to 500 μm can be obtained. The average particle size can be adjusted by adjusting the mixing conditions of the mixture and water, the addition amount of a suspension stabilizer, a surfactant and the like, the stirring conditions and dispersion conditions of the stirrer, and the like.

  The present invention can provide silica particles having a residual ratio of silicone oil of 60% by weight or more (definition is described in Examples) after 168 hours at 25 ° C. This value indicates that the silica particles of the present invention are excellent in sustained release properties.

The silica particles of the present invention are preferably used as a raw material for adsorbents, cosmetics and paints.
When used as an adsorbent, it is preferable to use silica particles having a maximum diameter of 3 to 500 μm. In the present specification, the adsorbent is an ink permeation suppression material used for paper surface treatment, an adsorbent particle or adsorbent mat for adsorbing oil or oil, a cleaning article for adsorbing and cleaning oil and fat components, etc. In addition, it is used for adsorbing all liquid articles such as petroleum, solvent, ink, and water, and may be used alone or absorbed or dispersed in a substrate.

  Here, in order to use silica particles alone as an adsorbent, a maximum diameter of about 100 to 500 μm, which is difficult to cause scattering and is easy to handle, is preferable. Especially preferably, it is about 200-500 micrometers. When the maximum diameter exceeds 500 μm, the retention of the oil agent once absorbed in the particles is weak, and it is not preferable because it easily desorbs.

  Moreover, when making a silica particle support on a base material, the largest diameter of 3-100 micrometers is preferable, and 3-50 micrometers is more preferable in order to prevent the drop-off from a base material. In particular, when the base material is paper, a maximum diameter of about 3 to 20 μm is preferable because unevenness due to particles does not appear on the surface of the paper.

  The base material is not particularly limited, but paper made from known papermaking pulp such as sulfite pulp, kraft pulp, soda pulp, semi-chemical pulp, mechanical pulp, or rayon, acetate, acrylic, polyester, polypropylene Polyurethane, polyamide, cotton, and woven or non-woven fabrics of these may be used.

  Examples of the method for supporting the silica particles on the base material include a method in which when the base material is paper, the silica particles are made into a slurry state and mixed with the raw material of the paper, and supported by making paper using a known wet paper machine. . In addition, the silica particles can be directly mixed with the raw material of the paper without making it into a slurry state and re-dispersed in water to make paper.

  When the base material is a fiber, for example, silica particles made into a slurry form with water, a solvent, or the like can be permeated into the fiber, and can be supported as it is or dried and attached to the fiber surface or inside. .

  As the wet paper machine, for example, a commercial paper machine such as a round net paper machine, a short net paper machine, a long net paper machine, or a twin wire paper machine can be used according to the purpose.

  In addition, sizing agents, slime control agents, dyes, coloring pigments, fluorescent dyes, dry paper strength enhancers, wet paper strength enhancers, drainage improvers, starch, polyvinyl alcohol, polyacrylamide, and yield improvers are required. Can be added to raw materials.

  When using for cosmetics, about 3-50 micrometers is preferable as a maximum diameter from a viewpoint which prevents the drop-off from a base material when it is made into a sheet form. 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 include solid cosmetics such as funny and foundation, powder cosmetics such as baby powder and body powder, liquid cosmetics such as lotion, milky lotion, cream and body lotion, and body wiping Examples thereof include sheet-like cosmetics such as sheets and oil removing paper.

  In the cosmetic of the present invention, other necessary components can be used in addition to the silica particles. For example, in order to improve the slipperiness with the skin, it can be used by mixing with organic fine particles or spherical silica. In addition, in order to improve optical functions and touch, inorganic compounds such as mica and talc, coloring pigments such as iron oxide, titanium oxide, ultramarine blue, bitumen, and carbon black, or synthetic dyes such as azo-based compounds, etc. 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.
In the case of sheet-like cosmetics, any of woven or non-woven fabrics of natural fibers or synthetic fibers can be used as the base material. Specifically, rayon, acetate, acrylic, polyester, polypropylene, polyurethane, polyamide, cotton, and woven or non-woven fabrics of these, as well as dry and wet pulp sheets, thermoplastic resins (polyethylene, polypropylene, polyethylene terephthalate, etc.) And pulp sheet reinforced with The pulp sheet reinforced with the thermoplastic resin can be embossed or the like, and a sheet with a wiping finish can be obtained by using several sheets stacked.

  In addition to these other ingredients, these cosmetics have various functions by adding moisturizers, anti-inflammatory agents, whitening agents, UV care agents, bactericides, antiperspirants, refreshing agents, fragrances, and the like. It can also be added.

  The cosmetic material of the present invention can absorb and remove excess sebum and suppress makeup collapse by using silica particles having a high oil absorption. In particular, by having an oil absorption amount exceeding 400 ml / 100 g, a high sebum adsorption ability can be exhibited, and a range of sebum controllability can be provided when blending cosmetics.

Hereinafter, although an example and a comparative example explain the present invention, the present invention is not limited to this. In addition, the evaluation method of each property in an Example and a comparative example is described below.
(Measurement of average particle size)
The average particle diameter is a value measured with Multisizer II (manufactured by Beckman Coulter). The value is measured by calibrating with a 50 μm aperture according to Reference MANUAL FOR THE COULTER MULTISIZER (1987) published by Coulter Electronics Limited.

  Specifically, 0.1 g of particles were predispersed in 10 ml of a 0.1% nonionic surfactant solution using a touch mixer and ultrasonic waves, and this was equipped with an ISOTON II (manufactured by Beckman Coulter, Inc .: measurement) In a beaker filled with an electrolytic solution), dripping with a dropper while gently stirring, adjust the reading of the densitometer on the main body screen to about 10%. Next, an aperture size of 50 μm, a current of 800, a gain of 4, and a polarity of + are input to the Multisizer II main body (the aperture size and the like can be changed as required) and measured manually. During the measurement, the beaker is stirred gently to the extent that bubbles do not enter, and the measurement is terminated when 100,000 particles are measured. The average particle diameter is an average value of the measured values.

(Measurement of specific surface area)
The specific surface area is an automatic specific surface area / pore distribution measuring device (Tristar 3000 manufactured by Shimadzu Corporation) based on the BET multipoint constant volume method of JIS Z 8830: 2001, which is a method for measuring the specific surface area of particles (solid) by gas adsorption. / Bacuprep 061LB) and measure with nitrogen gas.

(Measurement of oil absorption)
The oil absorption is measured by the method of JIS K 5101. Details are as follows.
-Apparatus and instrument measuring plate A smooth glass plate larger than 300 x 400 x 5 mm.
Spatula A handle with a steel or stainless steel blade.
Weighing instrument: Can measure up to 10mg order.
Buret JIS R 3505, up to 10ml.
-Material linseed oil (as defined in JIS K 5421; this time, special grade linseed oil (Wako Pure Chemical Industries) was used.)

Measurement method (1) Before performing the following operations, check the approximate value of oil absorption in advance by a preliminary test. (2) Take 1 g of particles in the center of the measuring plate, drop linseed oil from the burette 4 or 5 drops at a time into the center of the particles, and knead the whole thoroughly with a spatula each time. (3) Repeat dripping and kneading. When the whole becomes a hard putty-like lump, knead each drop, and when the last one drop is ready to be spirally wound with a spatula, end point And However, if it cannot be spirally wound, the end point is the point immediately before it softens suddenly with one drop of linseed oil. (4) Adjust the operations (1) and (2) so that the operation time to the end point is 7 to 15 minutes. (5) When the end point is reached, read out the amount of linseed oil dropped on the burette.

・ Calculation method Oil absorption is calculated by the following formula.
O = (V / m) × 100
O: Oil absorption (ml / 100g)
m: mass of particles (g)
V: Volume of dropped linseed oil (ml)

(Measurement of residual rate of silicone oil-sustained release test)
0.5 g of particles and 2 g of silicone oil (manufactured by Shin-Etsu Chemical Co., Ltd .; cyclic dimethylpolysiloxane KF995, boiling point 210 ° C.) are weighed and uniformly kneaded with a mixer to coat the particles with silicone oil. The coated particles are placed in a wide-mouth bottle without a lid, left in an environment of 25 ° C. or 50 ° C., and the weight is measured over time to examine the remaining amount of silicone oil. The remaining amount of the silicone oil after a predetermined time with respect to the weight of the initially coated silicone oil is defined as the remaining rate (% by weight).

Example 1
A dispersion medium in which 250 g of Snowtex O-40 (manufactured by Nissan Chemical Industries, Ltd.) as a suspension stabilizer was mixed with 1750 g of water was placed in a polymerization vessel having a stirring device.
Separately, 700 g of methyl methacrylate as a monofunctional polymerizable vinyl monomer, and MKC silicate MS57 (Mitsubishi Chemical Corporation: average molecular weight 1300 to 1500, R is methyl, n is 15 to 18) 285 g as a polyalkoxysiloxane oligomer , isobutyl trimethoxy silane as a silanol-forming silane compound (Toray Dow Corning AY43-048: R ¹ is methyl, R ² is isobutyl, m is 3) and 15 g, as a polymerization initiator 2,2'-azobis ( A mixture formed by uniformly dissolving 0.5 g of 2,4-dimethylvaleronitrile) was prepared.

This mixture was added to the dispersion medium and stirred at 7,000 rpm for about 10 minutes with a homomixer to finely disperse the mixture.
Thereafter, stirring is continued at a stirring speed of 300 rpm, and the polymerization vinyl monomer is polymerized by performing suspension polymerization for 4 hours after the temperature of the dispersion medium added with the mixture reaches 60 ° C. 60 g of sodium pyrophosphate was added to condense the polyalkoxysiloxane oligomer and the silanol group-forming silane compound.

  Next, the reaction liquid in the polymerization vessel was cooled to room temperature while stirring to obtain silica composite polymer particles. The target particles were taken out by dehydrating and drying the obtained particles. The average particle diameter of the obtained silica composite polymer particles is 7.2 μm.

  Next, the silica composite polymer particles were baked in an electric furnace at 500 ° C. to remove the polymer component, thereby obtaining silica particles (average particle diameter: 4.9 μm). The shape of the obtained silica particles was observed with an electron microscope. The silica particles had a shape having a large number of pleats as shown in FIG. Table 1 shows the measurement results of the specific surface area, the oil absorption, and the residual ratio of the silicone oil.

Example 2
In Example 1, silica composite polymer particles were obtained in the same manner as in Example 1 except that 900 g of methyl methacrylate, 95 g of MKC silicate MS57, and 5 g of isobutyltrimethoxysilane were used. The average particle diameter of the obtained composite polymer particles was 7.5 μm. As a result of firing in the same manner as in Example 1, the obtained silica particles (average particle size: 4.1 μm) had a shape having many pleats as shown in FIG. Table 1 shows the measurement results of the specific surface area, the oil absorption, and the residual ratio of the silicone oil.

Example 3
In Example 1, tribasic calcium phosphate (produced by Taihei Chemical Industrial Co., Ltd.), methyl methacrylate 200 g, MKC silicate MS51 (produced by Mitsubishi Chemical Co., Ltd .: average molecular weight 500 to 700, R is methyl, and n average is 5 as suspension stabilizer. to 10) 700 g, dimethyldimethoxysilane (Dow Corning Toray silicone Co. AY43-004: R ¹ and R ² is methyl, m is 2) except for using 100g in the same manner as in example 1 silica composite polymer particles Got. The average particle diameter of the obtained composite polymer particles was 8.2 μm. When fired in the same manner as in Example 1, the obtained silica particles (average particle size: 7.3 μm) had a shape having a large number of pleats. Table 1 shows the measurement results of the specific surface area, the oil absorption, and the residual ratio of the silicone oil.

Example 4
In Example 1, 200 g of methyl methacrylate, MKC silicate MS58B15 (Mitsubishi Chemical Corporation: average molecular weight 1600 to 1800, R is butyl, n average is 11 to 13), 700 g, methyltrimethoxysilane (TSL8113 manufactured by Toshiba GE Silicone) : Silica composite polymer particles were obtained in the same manner as in Example 1 except that 100 g of R ¹ and R ² were methyl and m was 3). The average particle diameter of the obtained composite polymer particles was 10.2 μm. As a result of firing in the same manner as in Example 1, the obtained silica particles (average particle size 9.5 μm) had a shape having a large number of creases as shown in FIG. Table 1 shows the measurement results of the specific surface area, the oil absorption, and the residual ratio of the silicone oil.

Example 5
In Example 1, styrene was used as the polymerizable vinyl monomer, and phenyltrimethoxysilane (TSL8173 manufactured by Toshiba GE Silicone; R ¹ was methyl, R ² was phenyl, and m was 3) was used as the silanol group-forming silane compound. Except for the above, silica composite polymer particles were obtained in the same manner as in Example 1. The average particle diameter of the obtained composite polymer particles was 7.9 μm. As a result of firing in the same manner as in Example 1, the silica particles (average particle diameter 6.5 μm) had a shape having a large number of pleats. Table 1 shows the measurement results of the specific surface area, the oil absorption, and the residual ratio of the silicone oil.

Comparative Example 1
Composite in the same manner as in Example 1 except that γ-methacryloxypropyltrimethoxysilane (SZ6030 manufactured by Toray Dow Corning Silicone Co., Ltd.) having polymerizability with a polymerizable vinyl monomer was used instead of the polyalkoxysiloxane oligomer. Polymer particles were obtained (average particle size 7.4 μm). When the obtained composite polymer particles were fired, pleat-free porous particles were obtained (average particle size: 7.0 μm). From this result, it is considered that the resin derived from the polymerizable vinyl monomer was in the form of particles and was uniformly dispersed in the composite polymer particles. Table 1 shows the measurement results of the specific surface area, the oil absorption, and the residual ratio of the silicone oil.

Comparative Example 2
Styrene as a polymerizable vinyl monomer, vinyltrimethoxysilane having polymerizability with a polymerizable vinyl monomer instead of isobutyltrimethoxysilane (SZ6300 manufactured by Toray Dow Corning Silicone; R ¹ is methyl, R ² is vinyl, m is Except for using 3), composite polymer particles were obtained in the same manner as in Example 1 (average particle size 7.5 μm). When the obtained composite polymer particles were fired, pleat-free porous particles were obtained (average particle size 7.1 μm). From this result, it is considered that the resin derived from the polymerizable vinyl monomer was in the form of particles and was uniformly dispersed in the composite polymer particles. Table 1 shows the measurement results of the specific surface area, the oil absorption, and the residual ratio of the silicone oil.

Comparative Example 3
In Example 1, composite polymer particles were obtained in the same manner as in Example 1 except that 950 g of methyl methacrylate and 50 g of MKC silicate MS57 were used. The average particle diameter of the obtained composite polymer particles was 7.8 μm. When the obtained composite polymer particles were baked, silica particles having no creases on the surface were obtained (average particle size 3.1 μm). Table 1 shows the measurement results of the specific surface area, the oil absorption, and the residual ratio of the silicone oil.

Comparative Example 4
In Example 1, suspension polymerization was performed in the same manner as in Example 1 except that 50 g of methyl methacrylate and 950 g of MKC silicate MS57 were used. However, the water solubility of the mixture became strong due to hydrolysis of methyltrimethoxysilane, and the finely dispersed state of the mixture could not be stably maintained, and particles could not be obtained.

Comparative Example 5
In Example 1, suspension polymerization was performed in the same manner as in Example 1 except that 50 g of methyl methacrylate and 200 g of methyltrimethoxysilane were used. However, the water solubility of the mixture became strong due to hydrolysis of methyltrimethoxysilane, and the finely dispersed state of the mixture could not be stably maintained, and particles could not be obtained.

Comparative Example 6
A dispersion medium in which 50 g of magnesium pyrophosphate by metathesis method is mixed with 2000 g of water as a suspension stabilizer is placed in a polymerization vessel having a stirrer, and 0.4 g of sodium lauryl sulfate is used as a surfactant, and sub-polymer is used as a polymerization inhibitor. Sodium nitrate (0.2 g) was dissolved in the dispersion medium.

  Separately, 700 g of methyl methacrylate as a monofunctional polymerizable vinyl monomer, 300 g of MKC silicate MS57 as a polyalkoxysiloxane oligomer, and 0.5 g of 2,2′-azobis (2,4-dimethylvaleronitrile) as a polymerization initiator The mixture which melt | dissolved uniformly was prepared.

This mixture was added to the dispersion medium and stirred at 7,000 rpm for about 10 minutes with a homomixer to finely disperse the mixture.
Thereafter, stirring is continued at a stirring speed of 300 rpm, and the polymerizable vinyl monomer is polymerized to form polymerizable particles by performing suspension polymerization for 4 hours after the temperature of the dispersion medium to which the mixture is added reaches 60 ° C., and The polyalkoxysiloxane oligomer was condensed by adding 20 g of sodium hydroxide.

  Next, the reaction solution in the polymerization vessel was cooled to room temperature while stirring, and hydrochloric acid was added until the pH of the slurry was about 2, whereby the suspension stabilizer was decomposed to obtain silica composite polymer particles. The target particles were taken out by dehydrating and drying the obtained particles. The average particle diameter of the obtained silica composite polymer particles is 12.5 μm.

  Next, the silica composite polymer particles were fired in the same manner as in Example 1 to obtain silica particles (average particle size 12.3 μm). The obtained particles were observed with an electron microscope. The silica particles had a hemispherical bowl shape with some openings. Table 1 shows the measurement results of the specific surface area, the oil absorption, and the residual ratio of the silicone oil.

  From Table 1, it was found that the silica particles of Examples 1 to 5 have improved sustained release properties as compared with conventional porous particles or open bowl-shaped silica particles.

2 is an electron micrograph of silica particles of Example 1. FIG. 2 is an electron micrograph of silica particles of Example 2. 4 is an electron micrograph of silica particles of Example 4.

Claims (1)

100 parts by weight of a polymerizable vinyl monomer, 10 to 500 parts by weight of a polyalkoxysiloxane oligomer inert to the polymerizable vinyl monomer, the following general formula (R ¹ O) _m SiR ² _4-m
(R ¹ is a hydrogen atom or a group selected from a substituted or unsubstituted alkyl group and an acyl group, R ² is a group selected from a substituted or unsubstituted alkyl group, a cycloalkyl group, an aryl group and an aralkyl group; Are integers of 1 to 3, R ¹ may be the same or different when m is 2 or 3, and R ² may be the same or different when m is 1 or 2.
A mixture containing 0.5 to 100 parts by weight of a silanol group-forming silane compound represented by the formula and 0.01 to 10 parts by weight of a polymerization initiator is suspended in an aqueous system in the presence of a suspension stabilizer, By polymerizing the polymerizable vinyl monomer in the mixture, suspension polymer particles composed of the polyalkoxysiloxane oligomer and silanol group-forming silane compound and a polymer component derived from the polymerizable vinyl monomer are obtained. Obtaining a step;
A step of condensing the polyalkoxysiloxane oligomer and silanol group-forming silane compound in the suspension polymerized particles by adding an acid or a base catalyst to obtain silica composite polymer particles containing a silica component; and the silica composite polymer particles method for producing silica particles fired to said going through a step of obtaining the silica particles by removing the polymer component.