JP2007231079A - Silicone microparticle, composite microparticle using the same, and method for producing them - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide silicone microparticles capable of being uniformly dispersed over various substrates to improve their properties, e.g., mechanical properties, heat resistance, flame retardancy, and light diffusibility, to provide composite microparticles using the same, and to provide their production methods. <P>SOLUTION: Provided are the silicone microparticles having a structure comprising RSiO<SB>3/2</SB>units (wherein R is at least one member selected from among a 1 to 4C alkyl group, a 6 to 24C aromatic group, a vinyl group, a γ-(meth)acryloxypropyl group, and an SH-containing organic group) and SiO<SB>4/2</SB>units, the rate of the RSiO<SB>3/2</SB>being not less than 20 mol%, and synthesized into particles having a volume-mean particle diameter of 0.01 to 5 μm by using an emulsifier in an aqueous system; the composite microparticles prepared by grafting a vinyl monomer onto the microparticles; and their production methods. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention is excellent in compatibility and dispersibility with a base material, and can be incorporated into various base materials to improve the mechanical strength, heat resistance, flame retardancy, light diffusibility, etc. of the base material. , Composite fine particles using the same, and methods for producing them.

  Attempts have been made to improve various properties by blending various resins with inorganic substances and silicone fine particles. For example, an inorganic substance is blended with a polyester resin to improve mechanical strength (see Patent Documents 1 and 2), or silica, muscovite, alumina, calcium carbonate, etc. are blended with a methacrylic resin to improve light diffusibility. The technique to do is disclosed (refer patent document 3). In addition, a technique for improving light diffusibility by blending silicone-based fine particles made of silicone rubber powder with an acrylic resin is also disclosed (see Patent Document 4).

However, in these techniques, the inorganic substances and the silicone fine particles are originally large, and the problems expected due to poor dispersion and aggregation are not sufficiently improved.
Japanese Patent Laid-Open No. 10-259016 JP-A-10-310420 JP 60-46503 A Japanese Patent Laid-Open No. 10-87941

  The present invention can be uniformly dispersed in various substrates, for example, silicone fine particles that can improve properties such as mechanical strength, heat resistance, flame retardancy, and light diffusibility of the substrate, and composites using the same It is an object of the present invention to provide fine particles and a production method thereof.

  As a result of intensive studies on the above problems, the present inventors have used specific silicone fine particles synthesized in the form of particles using an emulsifier in an aqueous system, and composite fine particles synthesized using the silicone fine particles. The present inventors have found that the above problems can be solved and have completed the present invention.

That is, the present invention relates to RSiO _3/2 units (wherein R is an alkyl group having 1 to 4 carbon atoms, an aromatic group having 6 to 24 carbon atoms, a vinyl group, a γ- (meth) acryloxypropyl group, or An organic group having an SH group) and a SiO _4/2 unit structure, the ratio of RSiO _3/2 unit is 20 mol% or more, and the volume of the aqueous system is obtained using an emulsifier. The present invention relates to silicone fine particles synthesized in the form of particles having an average particle diameter of 0.01 to 5 μm.

  A preferred embodiment relates to the silicone-based fine particles described above, wherein the weight-average molecular weight is 300,000 or more.

  The present invention relates to a composite fine particle obtained by graft polymerization of a vinyl monomer to any one of the silicone fine particles.

The present invention relates to RSiO _3/2 units (wherein R is an alkyl group having 1 to 4 carbon atoms, an aromatic group having 6 to 24 carbon atoms, a vinyl group, a γ- (meth) acryloxypropyl group, or an SH group). And a silane compound having SiO _4/2 units are synthesized using an emulsifier in an aqueous system so that the ratio of RSiO _3/2 units is 20 mol% or more. The present invention relates to a method for producing silicone fine particles having a volume average particle diameter of 0.01 to 5 μm.

The present invention relates to RSiO _3/2 units (wherein R is an alkyl group having 1 to 4 carbon atoms, an aromatic group having 6 to 24 carbon atoms, a vinyl group, a γ- (meth) acryloxypropyl group, or an SH group). And a silane compound having a SiO _4/2 unit in an aqueous system using an emulsifier in an aqueous system so that the ratio of RSiO _3/2 units is 20 mol% or more. The present invention relates to a method for producing composite fine particles, which comprises synthesizing silicone fine particles having an average particle size of 0.01 to 5 μm, and further graft-polymerizing a vinyl monomer in the presence of silicone fine particles.

  The silicone fine particles of the present invention and the composite fine particles obtained by graft polymerization of a vinyl monomer can be uniformly dispersed on various substrates. Thereby, characteristics, such as mechanical strength of a base material, heat resistance, a flame retardance, and light diffusibility, can be improved, for example.

The present invention has a structure substantially consisting of RSiO _3/2 units and SiO _4/2 units, the ratio of RSiO _3/2 units is 20 mol% or more, and is volume average using an emulsifier in an aqueous system. The present invention provides silicone-based fine particles synthesized in the form of particles having a particle diameter of 0.01 to 5 μm, and composite fine particles obtained by graft polymerization of a vinyl monomer thereon.

R in the RSiO _3/2 unit of the present invention is an organic group having an alkyl group having 1 to 4 carbon atoms, an aromatic group having 6 to 24 carbon atoms, a vinyl group, a γ- (meth) acryloxypropyl group, or an SH group. At least one is selected from the group. Depending on the substrate, an organic group having a small amount of vinyl group, γ- (meth) acryloxypropyl group or SH group for R and a large amount of alkyl group or aromatic group may be selected.

Examples of the raw material of the RSiO _3/2 unit of the present invention include methyltrimethoxysilane, methyltriethoxysilane, methyltripropoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltripropoxysilane, phenyltrimethoxysilane, Examples thereof include phenyltriethoxysilane, phenyltripropoxysilane, γ-mercaptopropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, and the like.

The raw material of the SiO _4/2 unit of the present invention can be selected from the group consisting of silicon tetrachloride, tetraalkoxysilane, water glass and metal silicate, for example. Specific examples of the tetraalkoxysilane include tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, and condensates thereof.

The silicone fine particles of the present invention are preferably composed of RSiO _3/2 units and SiO _4/2 units as main components, but in addition to RSiO _3/2 units and SiO _4/2 units, R ₂ as subcomponents. SiO _2/2 unit (wherein R is at least one of an alkyl group having 1 to 4 carbon atoms, an aromatic group having 6 to 24 carbon atoms, a γ- (meth) acryloxypropyl group, or an SH group). Or R ₃ SiO _1/2 unit (wherein R represents an alkyl group having 1 to 4 carbon atoms or an aromatic group having 6 to 24 carbon atoms). it can.

In the silicone fine particles of the present invention, the total content of RSiO _3/2 units and SiO _4/2 units used as main components is preferably 70 mol% or more in the fine particles, and more preferably 80 mol. % Or more is more preferable.

Examples of the raw material for the R ₂ SiO _2/2 unit include dimethyldimethoxysilane, diphenyldimethoxysilane, methylphenyldimethoxysilane, dimethyldiethoxysilane, diphenyldiethoxysilane, methylphenyldiethoxysilane, diethyldimethoxysilane, and ethylphenyl. Dimethoxysilane, diethyldiethoxysilane, ethylphenyldiethoxysilane, etc., hexamethylcyclotrisiloxane (D3), octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), dodecamethylcyclohexasiloxane (D6) In addition to cyclic compounds such as trimethyltriphenylcyclotrisiloxane, linear or branched organosiloxanes, γ-mercaptopropylmethyldimethoxysilane, - methacryloxypropyl methyl dimethoxy silane, and the like.

Examples of the raw material of the R ₃ SiO _1/2 unit include hexamethyldisiloxane.

The silicone fine particles in the present invention preferably contain RSiO _3/2 units in a proportion of 20 mol% or more, and more preferably 30 mol% or more. When the ratio of the RSiO _3/2 unit is less than 20 mol%, the dispersibility in the substrate may be deteriorated. The upper limit of the ratio of RSiO _3/2 units can be arbitrarily selected, but is preferably 90 mol% or less.

The SiO _4/2 units are preferably contained in a proportion of 10 mol% or more and 80 mol% or less, and more preferably contained in a proportion of 20 mol% or more and 70 mol% or less.

  Further, the silicone fine particles in the present invention must be synthesized into particles having a volume average particle size of 0.01 to 5 μm using an emulsifier in an aqueous system, and further synthesized into particles of 0.05 to 1 μm. More preferably. When the volume average particle diameter of the silicone-based fine particles is less than 0.01 μm, the dispersibility on the substrate tends to be poor, and conversely, particles of 5 μm or more tend to be difficult to synthesize. The volume average particle diameter can be measured, for example, by using MICROTRAC UPA manufactured by LEED & NORTHRUP INSTRUMENTS.

  The weight average molecular weight of the silicone-based fine particles obtained from the present invention is preferably set in a range from 300,000 or more to infinitely insoluble in a solvent, from the viewpoint of obtaining a stable molded product that is not affected by molding conditions. . In addition, the weight average molecular weight of the silicone-based fine particles when dissolved in a solvent can be measured using, for example, gel permeation chromatography (GPC).

In the present invention, when it is desired to give flexibility to the silicone-based fine particles, a small amount of R ₂ SiO _2/2 units can be mixed in the fine particles within a range of about 20 mol% or less.

The method for producing the silicone fine particles of the present invention is not particularly limited as long as it is a method of synthesizing particles in an aqueous system using an emulsifier, and examples thereof include an emulsion polymerization method, a suspension polymerization method, and a micro suspension polymerization method. can do. Specifically, for example, an emulsified liquid obtained by emulsifying an emulsifier, an RSiO _3/2 unit raw material, and a mixture of SiO _4/2 unit raw material and water with water at 5 to 120 ° C. containing an acid catalyst with a line mixer or a homogenizer. By continuously adding, silicone-based fine particles synthesized in the form of particles can be obtained.

In the production of the above-mentioned silicone fine particles, the seed polymer in an amount smaller than the total amount of RSiO _3/2 unit raw material and SiO _4/2 unit raw material is used to control the stability and particle size of the silicone fine particles. May be carried out by adding to an aqueous medium containing an acid catalyst. This seed polymer can be obtained, for example, by a usual emulsion polymerization method, but the synthesis method is not particularly limited. For example, it may be a rubber component such as butyl acrylate rubber, butadiene rubber, silicone rubber, butyl acrylate-styrene copolymer, butyl acrylate-butadiene copolymer, butyl acrylate-acrylonitrile copolymer, acrylic Even if it is hard polymers, such as acid butyl-styrene-acrylonitrile copolymer and a styrene-acrylonitrile copolymer, there is no problem.

  As the emulsifier used in the present invention, an anionic emulsifier and a nonionic emulsifier can be suitably used. Specific examples of the anionic emulsifier include sodium alkylbenzene sulfonate, sodium lauryl sulfonate, potassium oleate and the like, and sodium dodecylbenzene sulfonate can be particularly preferably used. Specific examples of nonionic emulsifiers include polyoxyethylene nonylphenyl ether and polyoxyethylene lauryl ether.

  Examples of the acid catalyst that can be used in the present invention include sulfonic acids such as aliphatic sulfonic acid, aliphatic substituted benzenesulfonic acid, and aliphatic substituted naphthalenesulfonic acid, and mineral acids such as sulfuric acid, hydrochloric acid, and nitric acid. Among these, aliphatic substituted benzenesulfonic acid is preferable and n-dodecylbenzenesulfonic acid is particularly preferable from the viewpoint of excellent emulsion stability of the organosiloxane.

  The heating for the synthesis of the polyorganosiloxane is preferably 5 to 120 ° C, more preferably 20 to 80 ° C in that an appropriate polymerization rate can be obtained.

  In the present invention, composite fine particles obtained by graft polymerization of a vinyl monomer on the silicone fine particles obtained as described above can be obtained. The vinyl monomer used for the production of the composite fine particles of the present invention is a component having a function of ensuring compatibility with the base material in which the composite fine particles are blended and helping the fine particles to be uniformly dispersed in the base material. It is.

  Specific examples of the vinyl monomer include (i) aromatic vinyl monomers such as styrene, α-methylstyrene, p-methylstyrene, p-butylstyrene, chlorostyrene, bromostyrene, ( ii) vinyl cyanide monomers such as acrylonitrile and methacrylonitrile; (iii) methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, glycidyl acrylate, hydroxy acrylate (Meth) acrylate monomers such as ethyl, methyl methacrylate, ethyl methacrylate, butyl methacrylate, lauryl methacrylate, glycidyl methacrylate, hydroxyethyl methacrylate, (iv) itaconic acid, (meth) acrylic acid , Carboxy such as fumaric acid, maleic acid Group-containing vinyl monomer. Further, as necessary, (v) maleimide-based compounds such as maleimide, N-methylmaleimide, N-ethylmaleimide, N-propylmaleimide, N-butylmaleimide, N-phenylmaleimide, N- (p-methylphenyl) maleimide A mer may be used. These may be used alone or in combination of two or more.

  The amount of the vinyl monomer used for producing the composite fine particles of the present invention is preferably 1 to 40% by weight, more preferably 10 to 25% by weight in the composite fine particles. The composite fine particles of the present invention can be obtained, for example, by graft polymerization of the monomer in the presence of silicone fine particles by using a usual emulsion polymerization method.

  In the present invention, when the silicone-based fine particles or composite fine particles are obtained in the form of latex, there is no particular limitation on the method of finally converting this latex into powder form. For example, the latex is calcium chloride, magnesium chloride, magnesium sulfate. Examples include a method in which the latex is coagulated by adding a metal salt such as, neutralized with an aqueous NaOH solution, and then dehydrated, washed with water, and dried. A spray drying method can also be used. Furthermore, if necessary, the silicone fine particles can be washed with an organic solvent such as methanol.

  The silicone-based fine particles and the composite fine particles of the present invention can be mixed with various substrates to be molded, film-formed, and the like. An example of the substrate is a resin. The resin may be a thermoplastic resin or a thermosetting resin, or may be a synthetic resin or a resin existing in nature. Specific resins include aromatic polycarbonate resins, aromatic polyester resins, polyphenylene ether resins, aromatic vinyl resins, polyphenylene sulfide resins, N-aromatic substituted maleimide resins, polyimide resins, vinyl chloride. It is preferable to use at least one selected from the group consisting of a series resin, a styrene resin, an acrylic resin, and a polymer alloy consisting of at least two of these. These resins may be used alone, or may be used as an alloy with various other resins.

  The method for obtaining a molded body from the resin composition obtained by mixing the silicone-based fine particles and composite fine particles of the present invention is not particularly limited. For example, it can be molded by a known method such as a melt kneading method in a melt kneader such as a single screw or twin screw extruder.

  The present invention will be specifically described based on examples, but the present invention is not limited thereto. Measurements and tests in the following examples and comparative examples were performed as follows.

[Volume average particle diameter]
The volume average particle diameter of the seed polymer, silicone fine particles, and composite fine particles was measured in the latex state. The volume average particle diameter (μm) was measured by a light scattering method using a MICROTRAC UPA manufactured by LEED & NORTHRUUP INSTRUMENTS as a measuring device.

[Weight average molecular weight of silicone fine particles]
The weight average molecular weight of the silicone fine particles was converted from the GPC measurement data using a calibration curve prepared with a polystyrene standard sample.

[Confirmation of dispersion state of silicone fine particles and composite fine particles in molded product]
Confirmation of the dispersion state of the silicone fine particles and composite fine particles in the molded body was performed by TEM observation of the molded body after osmium staining.

Example 1
In a 5-neck flask equipped with a stirrer, reflux condenser, nitrogen inlet, monomer addition port, thermometer, 400 parts by weight of water (total amount of water including various dilution water) and sodium dodecylbenzenesulfonate (SDBS) ) After 8 parts by weight (solid content) were taken and mixed, the temperature was raised to 50 ° C., and after the liquid temperature reached 50 ° C., nitrogen substitution was performed. Thereafter, a mixed solution of 10 parts by weight of butyl acrylate, 3 parts by weight of t-dodecyl mercaptan, and 0.01 parts by weight of paramentane hydroperoxide was added. After 30 minutes, add 0.002 parts by weight of ferrous sulfate (FeSO ₄ .7H ₂ O), 0.005 parts by weight of ethylenediaminetetraacetic acid 2Na salt, and 0.2 parts by weight of sodium formaldehydesulfoxylate. The polymerization was further continued for 1 hour. Thereafter, a mixed solution of 90 parts by weight of butyl acrylate, 27 parts by weight of t-dodecyl mercaptan, and 0.1 parts by weight of paramentane hydroperoxide was continuously added over 3 hours. Post-polymerization was performed for 2 hours to obtain seed latex (S-1). The latex had a volume average particle size of 0.04 μm.

  In a 5-neck flask equipped with a stirrer, reflux condenser, nitrogen inlet, monomer addition port, thermometer, 250 parts by weight of water (total amount of water including various dilution waters), seed latex (S-1) Then, dodecylbenzenesulfonic acid (DBSA) was mixed in the amount (solid content) shown in Table 1 and then heated to 80 ° C. to perform nitrogen substitution. Thereafter, 100 parts by weight of pure water, 0.5 parts by weight of SDBS (solid content), methyltrimethoxysilane (MTMS), and ethyl silicate 40 (corresponding to a tetramer of tetraethoxysilane) manufactured by Tama Chemical Industry are shown in Table 1. The emulsion obtained by stirring the mixture at 7000 rpm for 5 minutes with a homogenizer was continuously added over 3 hours. After completion of the addition, stirring was continued for 5 hours, followed by cooling to 25 ° C. and leaving for 20 hours to obtain latex-like silicone fine particles. Table 1 shows the volume average particle diameter and the weight average molecular weight of the silicone fine particles.

  Subsequently, the latex silicone fine particles were diluted with pure water to make the solid content concentration about 5% by weight, and then 5 parts by weight (solid content) of 25% by weight calcium chloride aqueous solution was added to obtain a coagulated slurry. . The coagulated slurry was neutralized to pH = 7 with 2.5 wt% NaOH aqueous solution. The coagulated slurry was dehydrated, mixed and stirred with 10 times the amount of methanol, and then dried again to obtain silicone-based fine particle powder.

  Next, the composition shown in Table 1 was blended using a polycarbonate resin (Taflon FN1900A manufactured by Idemitsu Petrochemical Co., Ltd.) and the above silicone fine particle powder. At this time, 0.3 parts by weight of polytetrafluoroethylene (Daikin Kogyo Co., Ltd., Polyflon FA-500) was used as a dripping inhibitor, and a phosphorus-based antioxidant (Adeka Stub PEP36, Asahi Denka Co., Ltd.) as a stabilizer. 3 parts by weight and 0.3 parts by weight of a phenol-based stabilizer (Topanol CA manufactured by ICI Japan) were also mixed. The obtained blend was melt-kneaded at 270 ° C. with a twin-screw extruder (TEX44SS manufactured by Nippon Steel) to produce pellets. Using the obtained pellets, a 1 / 16-inch test piece was prepared with a FAS100B injection molding machine manufactured by FANUC, which was set to a cylinder temperature of 280 ° C. The dispersion state of the silicone fine particles in the obtained test piece was observed. The results are shown in Table 1.

(Example 2 and Comparative Example 2)
In a 5-neck flask equipped with a stirrer, reflux condenser, nitrogen inlet, monomer addition port, thermometer, 250 parts by weight of water (total amount of water including various dilution waters), seed latex (S-1) Then, dodecylbenzenesulfonic acid (DBSA) was mixed in the amount (solid content) shown in Table 1 and then heated to 80 ° C. to perform nitrogen substitution. Thereafter, 100 parts by weight of pure water, 0.5 parts by weight of SDBS (solid content), methyltrimethoxysilane (MTMS), and ethyl silicate 40 (corresponding to a tetramer of tetraethoxysilane) manufactured by Tama Chemical Industry are shown in Table 1. The emulsion obtained by stirring the mixture at 7000 rpm for 5 minutes with a homogenizer was continuously added over 3 hours. After completion of the addition, stirring was continued for 5 hours, followed by cooling to 25 ° C. and allowing to stand for 20 hours to obtain latex-like silicone fine particles. Table 1 shows the volume average particle diameter and the weight average molecular weight of the silicone fine particles.

  Subsequently, the latex silicone fine particles were diluted with pure water to make the solid content concentration about 5% by weight, and then 5 parts by weight (solid content) of 25% by weight calcium chloride aqueous solution was added to obtain a coagulated slurry. . The coagulated slurry was neutralized to pH = 7 with 2.5 wt% NaOH aqueous solution. The coagulated slurry was dehydrated, mixed and stirred with 10 times the amount of methanol, and then dried again to obtain silicone-based fine particle powder.

  Next, 100 parts by weight of a vinyl chloride resin having a polymerization degree of 700 (manufactured by Kaneka Co., Ltd., Kanevinyl S1007), the amount shown in Table 1 of the powder of silicone fine particles, 2.0 parts by weight of octyltin mercaptide, glycerin ricinole -0.5 parts by weight of Tonto and 0.2 parts by weight of montanic acid ester are blended, kneaded in a roll at 160 ° C for 5 minutes, and then press-molded in a hot press at 190 ° C for 15 minutes to form a 2mm A specimen was obtained. The dispersion state of the silicone fine particles of this test piece was observed. The results are shown in Table 1.

(Examples 3 to 5 and Comparative Example 1)
In a 5-neck flask equipped with a stirrer, reflux condenser, nitrogen inlet, monomer addition port, thermometer, 400 parts by weight of water (total amount of water including various dilution water) and sodium dodecylbenzenesulfonate (SDBS) ) After 0.2 parts by weight (solid content) was taken and mixed, the temperature was raised to 50 ° C., and after the liquid temperature reached 50 ° C., nitrogen substitution was performed. Thereafter, a mixed solution of 10 parts by weight of butyl acrylate, 3 parts by weight of t-dodecyl mercaptan, and 0.01 parts by weight of paramentane hydroperoxide was added. After 30 minutes, add 0.002 parts by weight of ferrous sulfate (FeSO ₄ .7H ₂ O), 0.005 parts by weight of ethylenediaminetetraacetic acid 2Na salt, and 0.2 parts by weight of sodium formaldehydesulfoxylate. The polymerization was further continued for 1 hour. Thereafter, a mixed solution of 90 parts by weight of butyl acrylate, 27 parts by weight of t-dodecyl mercaptan, and 0.1 parts by weight of paramentane hydroperoxide was continuously added over 3 hours. In the middle of the addition, 0.1 part by weight of SDBS (solid content) was added three times in total at 1 hour, 2 hours, and 3 hours. Post-polymerization was performed for 2 hours to obtain seed latex (S-2). The latex had a volume average particle size of 0.14 μm.

  In a 5-neck flask equipped with a stirrer, reflux condenser, nitrogen inlet, monomer addition port, thermometer, 250 parts by weight of water (total amount of water including various dilution waters), seed latex (S-2) After mixing the amount shown in Table 1 (solid content) and dodecylbenzenesulfonic acid (DBSA) in the amount shown in Table 1 (solid content), the mixture was heated to 80 ° C. and purged with nitrogen. Separately, 100 parts by weight of pure water, 0.5 part by weight of SDBS (solid content), methyltrimethoxysilane (MTMS), ethyl silicate 40 (corresponding to a tetramer of tetraethoxysilane), octamethylcyclotetrasiloxane An emulsion obtained by stirring the mixture of the amount shown in Table 1 of (D4) at 7000 rpm for 5 minutes with a homogenizer was continuously added over 3 hours. After completion of the addition, stirring was continued for 5 hours, followed by cooling to 25 ° C. and leaving for 20 hours to obtain latex-like silicone fine particles. Table 1 shows the volume average particle diameter and weight average molecular weight of the silicone fine particles.

  Subsequently, the latex silicone fine particles were diluted with pure water to make the solid content concentration about 5% by weight, and then 5 parts by weight (solid content) of 25% by weight calcium chloride aqueous solution was added to obtain a coagulated slurry. . The coagulated slurry was neutralized to pH = 7 with 2.5 wt% NaOH aqueous solution. The coagulated slurry was dehydrated, mixed and stirred with 10 times the amount of methanol, and then dried again to obtain silicone-based fine particle powder.

  Next, the composition shown in Table 1 was blended using a polycarbonate resin (Taflon FN1900A manufactured by Idemitsu Petrochemical Co., Ltd.) and the above silicone fine particle powder. At this time, 0.3 parts by weight of polytetrafluoroethylene (Daikin Kogyo Co., Ltd., Polyflon FA-500) was used as a dripping inhibitor, and a phosphorus-based antioxidant (Adeka Stub PEP36, Asahi Denka Co., Ltd.) as a stabilizer. 3 parts by weight and 0.3 parts by weight of a phenol-based stabilizer (Topanol CA manufactured by ICI Japan) were also mixed. The obtained blend was melt-kneaded at 270 ° C. with a twin-screw extruder (TEX44SS manufactured by Nippon Steel) to produce pellets. Using the obtained pellets, a 1 / 16-inch test piece was prepared with a FAS100B injection molding machine manufactured by FANUC, which was set to a cylinder temperature of 280 ° C. The dispersion state of the silicone fine particles of the obtained test piece was measured. The results are shown in Table 1.

(Example 6)
As shown in Table 1, latex silicone fine particles were obtained in the same manner as in Example 3 except that a part of MTMS was replaced with γ-mercaptopropyltrimethoxysilane (MPrTMS). After heating the silicone-based fine particles to 60 ° C., 0.2 parts by weight of sodium formaldehyde sulfoxylate (SFS), 0.01 parts by weight of ethylenediaminetetraacetic acid (EDTA), 0.0025 parts by weight of ferrous sulfate Was added. A mixture of 20 parts by weight of methyl methacrylate (MMA) and 0.06 part by weight of cumene hydroperoxide (solid content) was added dropwise over 2 hours, and stirring was continued for 1 hour after the addition was completed to obtain composite fine particles. The volume average particle diameter and the weight average molecular weight are shown in Table 1. Molding was performed in the same manner as in Example 2. Table 1 shows the result of observing the dispersion state of the composite fine particles.

It has a structure consisting of RSiO _3/2 units and SiO _4/2 units, the ratio of RSiO _3/2 units is 20 mol% or more, and the volume average particle size is 0.01 to Silicone fine particles synthesized in the form of 5 μm particles and composite fine particles characterized by graft polymerization of a vinyl monomer were uniformly dispersed on various substrates.

Claims (5)

RSiO _3/2 unit wherein R is an organic group having an alkyl group having 1 to 4 carbon atoms, an aromatic group having 6 to 24 carbon atoms, a vinyl group, a γ- (meth) acryloxypropyl group or an SH group. It has a structure comprising at least one indicating a) and SiO _4/2 units, and the proportion of RSiO _3/2 units 20 mol% or more, and a volume average particle size by using an emulsifier in an aqueous system is 0. Silicone-based fine particles synthesized into a particle shape of 01 to 5 μm.   The silicone-based fine particles according to claim 1, wherein the weight-average molecular weight is 300,000 or more.   A composite fine particle obtained by graft polymerization of a vinyl monomer to the silicone fine particle according to claim 1. RSiO _3/2 unit wherein R is an organic group having an alkyl group having 1 to 4 carbon atoms, an aromatic group having 6 to 24 carbon atoms, a vinyl group, a γ- (meth) acryloxypropyl group or an SH group. And a silane compound having SiO _4/2 units are synthesized using an emulsifier in an aqueous system so that the ratio of RSiO _3/2 units is 20 mol% or more. A method for producing silicone fine particles having a particle size of 0.01 to 5 μm. RSiO _3/2 unit wherein R is an organic group having an alkyl group having 1 to 4 carbon atoms, an aromatic group having 6 to 24 carbon atoms, a vinyl group, a γ- (meth) acryloxypropyl group or an SH group. The volume average particle diameter of the silane compound having a silane compound having a SiO _4/2 unit and an SiO _4/2 unit is increased by using an emulsifier in an aqueous system so that the ratio of RSiO _3/2 unit is 20 mol% or more. A method for producing composite fine particles, comprising synthesizing 0.01 to 5 μm silicone fine particles, and further graft-polymerizing a vinyl monomer in the presence of the silicone fine particles.