JP5543722B2 - Method for producing polyorganosiloxane particles and organic-inorganic composite particles - Google Patents

Description

  The present invention relates to a method for producing polyorganosiloxane particles and organic-inorganic composite particles, and more specifically, polyorganosiloxane particles having a desired particle size and having a small variation in particle size between production lots. And a method for producing organic-inorganic composite particles.

  Fill in spacers for cell gaps (or panel gaps) for display displays such as liquid crystal display devices and touch panels, and conductive gap members such as conductive adhesives and anisotropic conductive adhesives for mounting micro devices. Polymer particles are widely used as an agent. In these applications, it is required that the particle shape is substantially uniform, flexible and excellent in elasticity, and from such a viewpoint, as a material of polymer particles, an organic material, an organic component and an inorganic component are used. An organic-inorganic composite material using a combination of these is used (Patent Document 1, etc.).

  Among the above required characteristics, there is a particularly high demand for particle size, and many methods for producing monodisperse polymer particles having a narrow particle size (particle size) distribution have been studied. For example, in Patent Document 2, polyorganosiloxane particles obtained by hydrolyzing and condensing a silicon compound are diluted at a dilution rate derived by a specific calculation formula, and the particle size is measured until a desired particle size is obtained. A method for carrying out the growth reaction is described. Further, in Patent Document 3, assuming that the cause of the variation in the particle size of the spherical silicone fine particles is the chlorine and ionic substances present in the reaction system, the chlorine content and the amount of ionic substances present in the reaction system It has been proposed to reduce.

Japanese Patent Laid-Open No. 11-199671, claims, etc. JP 2002-80598 A, claims, [0006], etc. Japanese Patent Application Laid-Open No. 6-248081, claims, etc.

  In addition, the polymer particles used for the above applications are required to have a small variation in particle diameter between production lots from the viewpoint of suppressing quality variation between final products. However, in the conventional method, it is pointed out that even when the same conditions are adopted, when the polymer particles are produced a plurality of times, there is a variation of about 40% with respect to the target particle diameter. (Patent Document 2). Thus, when the particle diameter varies between production lots, when used for a product using the polymer particles, particularly a spacer for a cell gap in the image display device as described above, a conductive gap member, There was a problem that it was difficult to keep product quality constant.

  The present invention has been made by paying attention to the above-described problems, and the object thereof is to provide polyorganosiloxane particles and organic materials having a desired particle diameter and little variation in particle diameter between production lots. It is to provide a method for producing inorganic composite particles.

  The inventors of the present invention have made extensive studies to solve the above-mentioned problems, and are inevitably present in the synthesis reaction system of the polyorganosiloxane particles and cannot be visually confirmed, but are observed with a particle counter or the like. The present inventors have found that there is a correlation between (particles) and the particle diameter of the polyorganosiloxane particles to be produced.

  That is, the method of the present invention that has solved the above-mentioned problems is a method for producing polyorganosiloxane particles, in which a polyorganosiloxane compound is subjected to a hydrolytic condensation reaction of an alkoxysilane compound in a mixed solvent in which alcohol is essential. It includes a synthesis step of synthesizing siloxane particles, and the gist is that in the synthesis step, alcohol having an inevitable impurity particle diameter of 2 μm or more is used in an amount of 5/200 to 200 / ml.

  The inventors consider as follows why the particle diameter variation among production lots can be suppressed and particles having a desired particle diameter can be obtained with high accuracy by the production method of the present invention. In the production method of the present invention, first, fine primary condensate particles are generated by the hydrolysis and condensation reaction of the alkoxysilane compound as a starting material. Thereafter, in the reaction system, the coalescence of the primary condensate particles proceeds until the attractive force and the repulsive force (electrostatic repulsive force) are balanced, and as a result, nuclei are formed (nucleation by coalescence). Next, hydrolysis and condensation reaction further proceeds around the generated nucleus, and the nucleus grows to produce polyorganosiloxane particles. In such a generation process, when there is a particle of a specific size, it is considered that the coalescence starting from this particle also proceeds. In other words, since the number of particles (number of nuclei) in the reaction system is affected by the number of particles, specifically, when the number of particles is small, the number of nuclei generated decreases, and when the number of particles increases, the number of nuclei generated The number also increases. Therefore, even if the starting material concentration and other reaction conditions are kept constant, if the amount of particles present in the reaction system differs between production lots, the particles in the reaction system vary between production lots. Since the numbers are different, it is considered that there was a variation in the particle size of the particles generated between the production lots. That is, if the other reaction conditions are the same, when the number of nuclei is large (the number of particles is large), the particle diameter of the generated particles is small, while when the number of nuclei is small (the number of particles is The particle size is large). In addition, the influence which the particle which exists in alcohol which is a reaction solvent has on the formation of the nucleus becomes saturated and constant when the number of particles exceeds a certain amount, but in the region where the number of particles is small, depending on the number of particles, The amount of nuclei generated varies. The number of particles contained in commercially available alcohol is included in the region where the amount of nuclei produced varies, and the present inventors have determined that the particles in the reaction solvent have a large variation in particle diameter in the prior art. I found out.

  In the production method of the present invention, the synthesis step includes a generation step of generating a primary seed particle of polyorganosiloxane by performing a hydrolytic condensation reaction of an alkoxysilane compound in a mixed solvent in which alcohol is essential, and the generation step. The reaction solution containing the primary seed particles obtained in (1) may be further divided into two stages of a growth process in which an alkoxysilane compound is further added to grow primary seed particles to obtain secondary seed particles, In this case, it is preferable that the amount A of alkoxysilane compound added in the growth step is an amount calculated by the following formula (I).

[In the above formula (I), A is the mass (g) of the alkoxysilane compound added in the growth step, r is the primary seed particle size, R is the set particle size of the secondary seed particle, and B is used in the production step. Means the mass (g) of the obtained alkoxysilane compound. ]

  Thereby, since the variation in the particle diameter of the secondary seed particle between production lots is suppressed, as a result, the variation in the particle diameter of the organic-inorganic composite particle that is the final object can be further reduced.

  The alcohol is preferably methanol.

  The present invention also includes a method for producing organic-inorganic composite particles using the polyorganosiloxane particles obtained by the above production method. The production method refers to radical polymerization of the polyorganosiloxane particles obtained by the above method. The present invention has a gist in that it includes an absorption step of absorbing a functional vinyl monomer component and a polymerization step of radical polymerization of the monomer component absorbed in the absorption step.

  In this specification, “particle” means an inevitable impurity having a particle diameter of 2 μm or more present in the reaction system or in the reaction solvent, and the “particle diameter” is, for example, made by PAMAS. By particle counter for liquid, it means the diameter of the observed particle, not to mention the diameter when the particle is spherical, but when it is oval or needle shape, each shape is made into a sphere It means the diameter when approximated.

  According to the production method of the present invention, polyorganosiloxane particles having a desired particle size and a narrow particle size distribution can be obtained, and the particle sizes of the polyorganosiloxane particles and the organic-inorganic composite particles between production lots can be obtained. Variations can be suppressed to a low level.

FIG. 1 is a graph showing the results of an experimental example.

  The method for producing polyorganosiloxane particles of the present invention includes a synthesis step of synthesizing polyorganosiloxane particles by performing a hydrolysis reaction and a condensation reaction of an alkoxysilane compound in a mixed solvent in which alcohol is essential. The synthesis step is characterized in that an alcohol having an inevitable impurity particle size of 2 μm or more of 5/200 to 200 / ml is used.

  As mentioned above, the specific size particles present in the alcohol used in the synthesis process are considered to correlate with the number of nucleation during the production of polyorganosiloxane particles, and the amount of particles of the specific size varies between production lots. In this case, the particle diameter of the resulting polyorganosiloxane particles (seed particles) varies, and the particle diameter of the finally obtained organic-inorganic composite particles varies. Therefore, in the present invention, the number of particles having a particle diameter of 2 μm or more is set within the above range in order to prevent fluctuations in the particle diameter of the polyorganosiloxane particles and thus the organic / inorganic composite particles. The upper limit of the particle diameter of the particles is not particularly limited, but is preferably 10 μm or less. Since the number of particles having a particle diameter exceeding 10 μm is extremely small, it is difficult to detect and is not suitable for use in determining whether the alcohol is suitable for synthesis.

  The amount of particles of the specific size is preferably 5/150 to 150 / ml, more preferably 10/100 to 100 / ml. When the amount of particles present in the synthesis reaction system is within the above range, fluctuations in the particle diameters of the polyorganosiloxane particles and the organic-inorganic composite particles are suppressed. If the amount of particles exceeds the above range, the effect on the particle size between production lots will be reduced, but there will be variations in the properties of the resulting particles (mechanical properties, optical properties, etc.), and the expected properties will be It may not be obtained. In addition, if the amount of particles is less than the above range, contamination of the synthesizer, foreign matter floating in the air, impurities generated from packings provided in the synthesizer, etc. are inevitably to some extent in the synthesis process. Due to the influence of impurities that are difficult to control, there is a risk that the fluctuation of the particle size between production lots will increase. Therefore, the particle amount is preferably within the above range.

  The particle size and the number of particles (pieces / ml) are determined by the particle counter (PAMAS liquid particle counter, body part type: SVSS-C-16, sensor part type: HCB-LD-50 / 50) It is a value to be measured, and is a value measured using the reaction solvent and alcohol used in the synthesis step as a measurement sample.

  The amount of particles having a specific size present in the alcohol can be set to the above range by previously filtering the alcohol with a filter having a pore size of a predetermined size. Moreover, even if it is a commercially available alcohol, if content of the particle of a specific size is the said range, it can be used for the synthesis | combination of a polyorganosiloxane particle as it is.

  The organic-inorganic composite particles according to the present invention are composite particles essentially comprising polyorganosiloxane particles (seed particles) containing an inorganic component and a vinyl polymer as an organic component. The polyorganosiloxane particles are particles composed of a polysiloxane skeleton structure obtained by hydrolyzing and condensing an inorganic compound raw material containing a silicon compound having a polymerizable unsaturated bond as described later, for example, vinyl groups, in particular, Polyorganosiloxane particles having a (meth) acryloxy group are preferred. And the vinyl polymer which is the said organic component is contained in this polyorganosiloxane particle. That is, the organic-inorganic composite particles according to the present invention are particles in which a component mainly composed of the polyorganosiloxane and a component composed of a vinyl polymer are mixed. The vinyl polymer referred to in the present invention is obtained by radical polymerization of a monomer component essentially containing a radical polymerizable vinyl monomer.

  Hereinafter, the production method of the present invention will be described in detail for each step.

[Synthesis process of polyorganosiloxane particles]
The step of synthesizing the polyorganosiloxane particles according to the present invention is a step of obtaining polyorganosiloxane particles by performing hydrolysis and condensation reaction of the alkoxysilane compound in the presence of a mixed solvent in which alcohol is essential. In this condensation reaction, it is preferable to use a basic catalyst such as ammonia as a catalyst.

  The polyorganosiloxane particles are obtained by using an alkoxysilane compound as a starting material, and a hydrolyzable silicon compound group having a polymerizable unsaturated bond and a hydrolyzable silyl group (hereinafter sometimes referred to as a polymerizable silicon compound). ) Is essential as a starting material, and those having a vinyl group as the polymerizable unsaturated bond are particularly preferable. If such a raw material is used, the polyorganosiloxane particles obtained after the hydrolysis and condensation reaction will have vinyl groups. In the polymerization step described later, since a bond is formed by copolymerization between the vinyl group (polyorganosiloxane particles) and the radical polymerizable vinyl monomer, the mechanical properties of the resulting organic-inorganic composite particles are excellent. Further, since the solvent resistance of the organic / inorganic composite particles is improved, the particles are also suitable for use in ink form.

  Examples of the polymerizable silicon compound include vinyltrimethoxysilane, vinyltriethoxysilane, p-styryltrimethoxysilane, γ- (meth) acryloxypropylmethyldimethoxysilane, and γ- (meth) acryloxypropyltrimethoxysilane. , Γ- (meth) acryloxypropylmethyldiethoxysilane, γ- (meth) acryloxypropyltriethoxysilane, γ- (meth) acryloxypropyltriacetoxysilane, γ- (meth) acryloxyethoxypropyltrimethoxysilane An alkoxysilane having an equal vinyl group can be mentioned. These may be used alone or in combination of two or more.

  Among these, the silicon compound (1) having a (meth) acryloxy group represented by the following formula (1) is preferable. Since this (meth) acryloxy group is excellent in compatibility with the radical polymerizable vinyl monomer described later, the monomer component can easily absorb the radical polymerizable vinyl monomer into the polyorganosiloxane particles.

(In the general formula (1), R ^a represents a hydrogen atom or a methyl group, R ^b represents an optionally substituted divalent organic group having 1 to 20 carbon atoms, and R ^c. They are the same or different, a hydrogen atom, .R ^d representing at least one monovalent group selected from the group consisting of alkyl and acyl groups of 2 to 5 carbon atoms of 1 to 5 carbon atoms, which may be the same or different And at least one monovalent group selected from the group consisting of an alkyl group having 1 to 5 carbon atoms and a phenyl group, l is 1 or 2, and m is 0 or 1.)

  The polymerizable silicon compound (1) is not particularly limited, and specifically, for example, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-acryloxypropyltrimethoxysilane, γ-acryloxypropyltriethoxysilane, γ-methacryloxypropyltriacetoxysilane, γ-methacryloxyethoxypropyltrimethoxysilane (also referred to as γ-trimethoxysilylpropyl-β-methacryloxyethyl ether), γ-methacrylic Examples include loxypropylmethyldimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, and γ-acryloxypropylmethyldimethoxysilane. These may be used alone or in combination of two or more. Among the alkoxysilanes having the (meth) acryloxy group, 3-methacryloxypropyltrimethoxysilane is most preferable.

Together with the polymerizable silicon compound (1), if necessary, the following general formula (2)
R ^e _n Si (OR ^f ) _4-n (2)
(In the above general formula (2), R ^e is the same or different and includes an alkyl group having 1 to 20 carbon atoms, an alkyl group having 1 to 20 carbon atoms having an epoxy group, and an alkenyl group having 2 to 20 carbon atoms. , Represents at least one monovalent group selected from the group consisting of an aryl group having 6 to 20 carbon atoms; R ^f is the same or different and represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, and 2 carbon atoms. An alkoxysilane (hereinafter referred to as non-polymerizable silicon compound (2)) represented by at least one monovalent group selected from the group consisting of ˜5 acyl groups, wherein n is an integer of 0-3. May be used in combination.

  Although it does not specifically limit as a non-polymerizable silicon compound (2), Specifically, for example, the said general formula (tetramethoxysilane, tetraethoxysilane, tetraisopropoxysilane, tetrabutoxysilane, tetraacetoxysilane etc.) 2) a tetrafunctional silane in which n = 0; methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, phenyltrimethoxysilane, methyltriacetoxysilane, β- (3,4-epoxy (Cyclohexyl) ethyltrimethoxysilane, 3,4-epoxybutyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, etc. Functional silane; dimethyl dimethoxy And the like can be given; silane, dimethyl diethoxy silane, diacetoxy dimethyl silane, difunctional silane of n = 2 in the above general formula such as diphenyl disilane diol (2). These may be used alone or in combination of two or more.

The derivatives of the silicon compounds (1) and (2) are not particularly limited. Specifically, for example, at least one of the OR ^c group or the OR ^f group contained in the silicon compounds (1) and (2) may be used. By partially hydrolyzing and condensing a compound substituted with a β-dicarbonyl group and / or a group capable of forming another chelate compound and the silicon compounds (1) and (2) and / or the chelate compound. At least one selected from the group consisting of the obtained low condensate is preferable.

  The polyorganosiloxane particles (seed particles) according to the present invention are obtained by hydrolyzing and condensing the silicon compound group in a solvent containing water. About hydrolysis and condensation, arbitrary methods, such as a lump, a division | segmentation, and a continuation, can be taken. In the hydrolysis and condensation, a catalyst such as ammonia, urea, ethanolamine, tetramethylammonium hydroxide, alkali metal hydroxide, or alkaline earth metal hydroxide may be used.

  As described above, in the production method of the present invention, a mixed solvent in which alcohol is essential is used in the synthesis step. The alcohol used as the reaction solvent is not particularly limited, and may be appropriately changed according to the silicon compound to be used. Preferred alcohols include methanol, ethanol, isopropanol, n-butanol, isobutanol, sec-butanol, t-butanol, pentanol, ethylene glycol, propylene glycol, 1,4-butanediol, and more preferably methanol. It is. For example, when methoxysilane is used as the silicon compound, methanol is preferably used as the reaction solvent, and when ethoxysilane is used as the silicon compound, ethanol is recommended as the reaction solvent.

  The mixed solvent may contain water and other organic solvents in addition to the alcohol. Preferably it is water. When water is contained in the mixed solvent, the mixing ratio of water / alcohol is 95/5 to 50/50 (mass ratio), more preferably 95/5 to 60/40, and still more preferably 90/10. ~ 65/35.

  Examples of water used as the reaction solvent include ion exchange water and ultrapure water. Among these, ultrapure water having an electric conductivity of 1 μS / cm or less is preferable. Note that ultrapure water is obtained by removing inorganic ions, dissolved gas, solid particles, and the like with an ion exchange device, a reverse osmosis membrane pure water production device, an ultrafiltration device, or the like.

  Other organic solvents are not particularly limited, but specific examples include ketones such as acetone and methyl ethyl ketone; esters such as ethyl acetate; (cyclo) paraffins such as isooctane and cyclohexane; dioxane and diethyl ether Preferred examples include ethers such as benzene, and aromatic hydrocarbons such as toluene. These may be used alone or in combination of two or more.

  Instead of setting the number of particles of a specific size in the alcohol within a predetermined range, a part of the alcohol used as a reaction solvent is sampled for each production lot, and the polyorganosiloxane particles (seed Particles) may be synthesized to confirm the particle diameter of the resulting polyorganosiloxane particles. Such a pre-inspection is effective for more accurate particle size control.

  The conditions during the hydrolysis and condensation reaction are not particularly limited. For example, the above silicon compound group and an organic solvent are added to a solvent containing water, and the temperature is 0 ° C to 100 ° C, preferably 0 ° C to 70 ° C. More preferably, it is carried out by stirring in a temperature range of 10 ° C. to 50 ° C. for 30 minutes to 100 hours.

  In carrying out the hydrolysis and condensation, the water concentration is 50% by mass to 99.99% by mass, the catalyst concentration is 0.01% by mass to 10% by mass, the organic solvent concentration is 0% by mass to 90% by mass, and the silicon The concentration of the compound group is preferably set to 0.1 mass% to 30 mass%, the addition time of the silicon compound group is set to 0.001 hour to 500 hours, and the reaction temperature is preferably set to 0 ° C to 100 ° C.

  In the method according to the present invention, the silicon compound group is thus hydrolyzed and condensed under a suitable condition in a solvent containing water, whereby particles are precipitated and a slurry is produced. The precipitated particles are obtained using the above-described polymerizable silicon compound as an essential component, so that polyorganosiloxane particles having a polymerizable unsaturated bond can be obtained. Here, the appropriate conditions are not particularly limited. Specifically, for example, in the obtained slurry, the concentration of the polymerizable silicon compound (1) and the non-polymerizable silicon compound (2) (in the raw material compound) (Conversion) is preferably 20% by mass or less, a water concentration of 50% by mass or more, and a catalyst concentration of 10% by mass or less.

  So far, as a synthesis step according to the present invention, a method for obtaining polyorganosiloxane particles by adding the above alkoxysilane compound to the reaction system at a time and performing hydrolysis and condensation reaction in one step has been described. From the viewpoint of controlling the particle size with high accuracy, it is also a recommended embodiment of the present invention to divide the synthesis step into a plurality of steps of two or more steps. For example, if polyorganosiloxane particles are obtained by adopting a two-step process, the synthesis process includes a production process for obtaining primary seed particles of polyorganosiloxane, and primary seed particles obtained in the production process. Can be performed separately from the growth process of obtaining secondary seed particles. Control of the particle size is also desired from the viewpoint of stabilizing the physical properties of the obtained organic-inorganic composite particles. For example, the particle size variation itself can be adjusted to some extent by the amount of the monomer component to be absorbed by the seed particles in the absorption step described later. However, when such adjustment is performed, the concentration of the silane compound in the reaction system varies, so the yield of particles varies between production lots. If the primary seed particles are too small, the particle concentration is high. Therefore, coalescence and aggregation are likely to occur. Further, since the contents of the organic component amount and the inorganic component amount are different from the particles not adjusted in the same manner, the physical properties (mechanical characteristics, optical characteristics, etc.) of the organic-inorganic composite particles vary. Therefore, it is preferable that the seed particle diameter has a small variation between production lots, and it is preferable to adjust the seed particle diameter in advance in the generation and / or growth process (or synthesis process). Hereinafter, a case where the synthesis process is performed in two stages will be described.

[Primary seed particle generation process]
As described above, the primary seed particle generating step is a step of performing a hydrolysis and condensation reaction of the alkoxysilane compound to generate a condensate that becomes the nucleus of the polyorganosiloxane particle. As the alkoxysilane usable at this time, the same ones as described above are used. Moreover, the reaction solvent should just employ | adopt the conditions similar to the said synthetic process. Of course, it is needless to say that the number of particles of a specific size existing in the reaction system is preferably within the above-mentioned range also in this generation step.

  When the synthesis process is performed in two stages, the concentration of the silicon compound group as a starting material is preferably 1% by mass to 30% by mass in the primary seed particle generation process. More preferably, it is 2 mass%-20 mass%, More preferably, it is 2 mass%-15 mass%. If the starting material concentration is less than 1% by mass, the reaction hardly proceeds, and it may take a long time to produce a condensate, or the number of particles of the condensate obtained may increase. On the other hand, when the concentration is too high, a large number of particles are generated, and even when the growth step described later is adopted, the growth of the organic-inorganic polymer as the final product becomes insufficient, and particles having the desired size are obtained. It is not possible to obtain it, or it is necessary to increase or decrease the raw materials in the absorption process described later, which is undesirable from the economical and stable operation aspects.

[Growth process to secondary seed particles]
The growth process to secondary seed particles refers to the addition of an alkoxysilane compound as a starting material to the primary seed particle-containing aqueous solution obtained in the above-mentioned generation process, and the primary seed until a desired particle diameter is obtained. This is a step of increasing (growing) the particle diameter. At this time, as the alkoxysilane compound to be added, the same compounds as those exemplified in the production step can be used. The addition amount of the alkoxysilane compound is preferably an amount that satisfies the following formula (I).

  Here, in the above formula (I), r is the primary seed particle diameter, R is the set particle diameter of the secondary seed particles, B is the mass (g) of the alkoxysilane compound used in the production process, and A is the growth process. Means the amount (g) of alkoxysilane compound to be added.

  Thus, by adopting a two-step process, it becomes much easier to control the amount of condensate that is initially produced and becomes a nucleus. In addition, in the growth process, the condensate that has already been generated is used as a nucleus, so that the growth reaction proceeds in preference to the generation of new particles.

  By the way, when polyorganosiloxane particles (or organic-inorganic composites) are produced industrially, when continuously synthesizing seed particles, the reaction vessel after completion of the reaction is usually washed and used again as a reaction vessel. At this time, when only methanol was used as a cleaning solvent, it became clear by examination of the present inventors that the lot-to-lot variation of the seed particle size was increased. In the laboratory level, the primary particle size can be stabilized by polishing the reaction vessel with a cleanser or the like and rinsing with ultrapure water. However, it is not practical to carry out the same cleaning method at the actual operation level. Thus, as a result of repeated studies by the present inventors, it was found that it is preferable to wash the reaction vessel with methanol and then wash with a water / methanol mixed solvent. The mixing ratio of water / methanol is preferably 3/7 to 1/9.

[Polyorganosiloxane particles]
The number average particle size of the primary and secondary seed particles (polyorganosiloxane particles) may be appropriately determined according to the particle size of the target organic / inorganic composite particles (final product after vinyl monomer polymerization). However, for example, when it is desired to obtain organic / inorganic composite particles of 3 μm to 30 μm, the primary seed particles preferably have a particle size of 0.3 μm to 12 μm, more preferably 0.4 μm to 10 μm. The particle diameter of the secondary seed particles (polyorganosiloxane particles) is preferably 0.5 μm to 12 μm, more preferably 0.6 μm to 11 μm, and most preferably 0.7 μm to 10 μm. If the average particle diameter of the polyorganosiloxane particles is within the above range, an advantageous effect that absorption of a vinyl polymerizable monomer described later proceeds efficiently can be exhibited. Further, if the average particle size of the primary seed particles (polyorganosiloxane particles) is less than 0.5 μm, the amount of the silane compound added is too large (at the time of secondary seed particle synthesis) to achieve the target particle size. As a result, the concentration of the seed particle slurry becomes too high, and the coalescence and aggregation of the seed particles are likely to occur. On the other hand, if it exceeds 12 μm, the mass of the particles becomes large, and the polymer particles may settle in the reactor, and the particles may easily aggregate. The average particle diameter is a value measured by a precision particle size distribution measuring apparatus (for example, “Multisizer II” manufactured by Beckman Coulter, Inc.) employing the Coulter principle.

  If the production method according to the present invention is employed, the polyorganosiloxane particles can have a sharpness of the particle size distribution represented by a coefficient of variation (CV value) described in Examples described later, of 15% or less. Thus, when the particle size distribution of the polyorganosiloxane particles is narrow, the particle size distribution of the organic-inorganic composite fine particles produced through the absorption process and the polymerization process, which will be described later, is also narrow. When the coefficient of variation (CV value) is within the above range, an advantageous effect that the vinyl polymerizable monomer described later can be efficiently absorbed can be exhibited. When it exceeds 15%, the variation in the particle diameter of the obtained organic-inorganic composite particles becomes large.

  Since the polyorganosiloxane particles (seed particles) referred to in the present invention are obtained by using the above silicon compound group as a raw material inorganic compound, the polyorganosiloxane particles (seed particles) include an inorganic portion (polysiloxane skeleton) derived from silicon atoms in the inorganic compound. And has an organic group such as a (meth) acryloxy group. The polyorganosiloxane particles referred to in the present invention can easily absorb and retain the radical polymerizable vinyl monomer described later in the particles, that is, between the polysiloxane skeletons constituting the particles. Particles. This is because the (meth) acryloxy group of the polyorganosiloxane particles is very compatible with organic compounds such as vinyl monomers, and the polyorganosiloxane particles absorb vinyl monomers. It can also be said that the degree of condensation (molecular weight) is suitable for this.

[Method for producing organic-inorganic composite particles]
In the organic-inorganic composite particles of the present invention, the radically polymerizable vinyl monomer is absorbed into the polyorganosiloxane particles (seed particles) obtained in the synthesis step (or the production step and / or the growth step) after the synthesis step. Then, the monomer component absorbed in the absorption step is subjected to radical polymerization (polymerization step). By using the polyorganosiloxane particles obtained by the above production method as seed particles, organic-inorganic composite particles with little variation in particle diameter between production lots can be obtained. Hereinafter, the absorption process will be described in order.

[Absorption process]
In the absorption step, the polyorganosiloxane particles are allowed to absorb the radical polymerizable vinyl monomer component. In this absorption step, the amount of seed particles introduced into the absorption step may be adjusted in order to control the particle diameter of the obtained organic-inorganic composite particles. By changing the blending ratio of the seed particles and the radical polymerizable vinyl monomer, organic-inorganic composite particles having various particle sizes can be produced from seed particles having a single particle size.

  In the absorption step, the polyorganosiloxane particles may be allowed to absorb the monomer component essentially containing the radical polymerizable vinyl monomer, and the embodiment thereof is not particularly limited. Accordingly, the monomer component may be added to the solvent in which the polyorganosiloxane particles are dispersed, or the polyorganosiloxane particles may be added to the solvent containing the monomer component. Eventually, it is sufficient if the absorption step proceeds in a state where the polyorganosiloxane particles and the monomer component coexist. Among them, like the former, a form in which a monomer component is added to a solvent in which polyorganosiloxane particles are dispersed in advance is preferable, and further, from a polyorganosiloxane particle dispersion obtained by synthesizing polyorganosiloxane particles, The form in which the monomer component is added to the dispersion without taking out the polyorganosiloxane particles does not require a complicated process and is excellent in productivity, which is preferable.

  The radically polymerizable vinyl monomer that can be used in the present invention is not particularly limited as long as it is a compound containing at least one ethylenically unsaturated group in the molecule. The monomer component can be appropriately selected so that the composite particles can exhibit desired physical properties. Specific monomer components include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, monomers having a hydroxyl group such as 2-hydroxybutyl (meth) acrylate; methoxypolyethylene glycol (meth) Monomers having a polyethylene glycol component such as acrylate; butyl (meth) acrylate, methyl (meth) acrylate, ethyl (meth) acrylate, isoamyl (meth) acrylate, lauryl (meth) acrylate, (meth ) Alkyl (meth) acrylates such as benzyl acrylate and tetrahydrofurfuryl (meth) acrylate; trifluoroethyl (meth) acrylate, tetrafluoropropyl (meth) acrylate, pentanefluoropropyl (meth) acrylate, octafluoroa Fluorine atom-containing (meth) acrylates such as ru (meth) acrylate; styrene, α-methylstyrene, vinyltoluene, α-chlorostyrene, o-chlorostyrene, m-chlorostyrene, p-chlorostyrene, p-ethylstyrene It is preferable to use aromatic vinyl compounds such as glycidyl (meth) acrylate, (meth) acrylic acid, (meth) acrylamide, (meth) acrylonitrile and the like. These radical polymerizable vinyl monomers may be used alone or in combination of two or more.

  In order to efficiently absorb the monomer component in the polyorganosiloxane particles, it is preferable to preliminarily emulsify and disperse the monomer component to produce an emulsion. Moreover, it is preferable to use a crosslinkable monomer as the monomer component because the mechanical properties of the polymer particles obtained can be easily adjusted. Although it does not specifically limit as said crosslinkable monomer, Specifically, for example, divinylbenzene, ethylene glycol di (meth) acrylate, polyethyleneglycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate , Neopentyl glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, tetramethylolmethane tri (meth) acrylate, tetramethylolpropane tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, diallyl phthalate and its Isomers, triallyl isocyanurate and derivatives thereof, and the like. These may be used alone or in combination of two or more.

  The absorption step is preferably performed under various conditions set so that the monomer component described above is easily absorbed into the structure of the polyorganosiloxane particles (seed particles). Such conditions include the respective concentrations of the polyorganosiloxane particles and the monomer component, the mixing ratio of the polyorganosiloxane particles and the monomer component, the processing method and means for mixing, the temperature and time at the time of mixing, and after mixing. These processing methods and means are listed. These conditions may be appropriately determined according to the type of polyorganosiloxane particles and monomer components used. Moreover, these conditions may employ | adopt only 1 type, or may employ | adopt in combination of 2 or more types.

  The amount of the monomer component used in the absorption step is preferably 0.01 to 100 times by mass with respect to the mass of the silicon compound used as the raw material for the polyorganosiloxane particles. When the addition amount is smaller than 0.01 times, the absorption amount of the monomer component of the polyorganosiloxane particles is reduced, and it is difficult to obtain the intended particle diameter, or the mechanical properties of the polymer particles are impaired. On the other hand, if it exceeds 100 times, it becomes difficult to completely absorb the added monomer component in the polyorganosiloxane particles, and the unabsorbed monomer component remains, so that the final composition obtained is organic-inorganic. It becomes a mixture of composite particles and organic particles, and there is a possibility that aggregation between particles is likely to occur in the subsequent polymerization stage.

  In the absorption process, the method for adding the monomer component is not particularly limited, and the entire amount of the monomer component to be used may be added to the reaction system all at once, or may be added in several batches, or fed at an arbitrary rate. May be. Further, at this time, only the monomer component may be added, or a monomer component solution in which the monomer component is dispersed or dissolved in a solvent may be added. Addition to the particles is preferable because absorption into the polyorganosiloxane particles is performed more efficiently.

  The emulsifier is not particularly limited, and examples thereof include an anionic surfactant, a cationic surfactant, a nonionic surfactant, an amphoteric surfactant, a polymer surfactant, and one or more in the molecule. Examples thereof include polymerizable surfactants having a polymerizable carbon-carbon unsaturated bond. Among these, anionic surfactants and nonionic surfactants are preferable because they can stabilize the dispersion state of polyorganosiloxane particles, polyorganosiloxane particles having absorbed monomer components, and polymer particles. These emulsifiers may be used alone or in combination of two or more.

  Although it does not specifically limit as said anionic surfactant, For example, Alkali metal alkyl sulfates, such as sodium dodecyl sulfate and potassium dodecyl sulfate; Ammonium alkyl sulfates, such as ammonium dodecyl sulfate; Sodium dodecyl polyglycol ether Alkylsulfonates such as sulfate, sodium sulfosinoate, alkali metal salts of sulfonated paraffin, ammonium salt of sulfonated paraffin; fatty acid salts such as sodium laurate, triethanolamine oleate, triethanolamine abiate; sodium dodecylbenzene Alkyl aryl sulfonates such as sulfonates and alkali metal sulfates of alkali phenol hydroxyethylene S; higher alkyl naphthalene sulfonate, naphthalenesulfonic acid formalin condensates, dialkyl sulfosuccinate, polyoxyethylene alkyl sulfate salt, and preferably a polyoxyethylene alkylaryl sulfate salts.

  The cationic surfactant is not particularly limited, and examples thereof include amine salts, quaternary ammonium salts, oxyethylene addition type ammonium hydrochlorides, and the like, and specifically, trimethylalkylammonium hydrochloride. Dimethyldialkylammonium hydrochloride, monoalkylamine acetate, alkylmethyldipolyoxyethyleneammonium hydrochloride, and the like.

  The nonionic surfactant is not particularly limited, and specific examples include polyoxyethylene alkyl ether, polyoxyethylene alkyl aryl ether, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, and monoglycerol glycerol. Preferable examples include fatty acid monoglycerides such as laurate; polyoxyethyleneoxypropylene copolymers, condensation products of ethylene oxide and fatty acid amines, amides or acids.

  The polymer surfactant is not particularly limited. For example, polyvinyl alcohol, sodium poly (meth) acrylate, potassium poly (meth) acrylate, ammonium poly (meth) acrylate, polyhydroxyethyl (Meth) acrylates, polyhydroxypropyl (meth) acrylates, copolymers of two or more polymerizable monomers that are constituent units of these polymers, or copolymers with other monomers, crown ethers Preferred examples include a phase transfer catalyst.

  The polymerizable surfactant is not particularly limited. For example, sodium propenyl-2-ethylhexylbenzenesulfosuccinate, sulfate of polyoxyethylene (meth) acrylate, polyoxyethylene alkylpropenyl ether ammonium sulfate Anionic polymerizable surfactants such as salts, phosphoric acid esters of (meth) acrylic acid polyoxyethylene esters; polyoxyethylene alkylbenzene ether (meth) acrylic acid esters, polyoxyethylene alkyl ether (meth) acrylic acid esters, etc. Preferred examples include nonionic polymerizable surfactants.

  The amount of the emulsifier used is not particularly limited. Specifically, the amount used is 0.01% by mass to 10% by mass with respect to the total mass of the monomer components essentially including the radical polymerizable vinyl monomer. More preferably, it is 0.05 mass%-8 mass%, More preferably, it is 1 mass%-5 mass%. When the amount of the emulsifier used is less than 0.01% by mass, a stable monomer emulsified dispersion may not be obtained. When the amount exceeds 10% by mass, emulsion polymerization or the like occurs as a side reaction. There is a risk that. About the said emulsification dispersion | distribution, it is preferable to usually make the said monomer component into an emulsion state in water using a homomixer, an ultrasonic homogenizer, etc. with an emulsifier.

  In the above absorption step, whether or not the monomer component has been absorbed can be easily determined, for example, by observing the particle diameter with a microscope before adding the monomer and after the absorption step. That is, if the particle diameter after the absorption process is larger than the particle diameter before the absorption process, it can be determined that the monomer component is absorbed in the polyorganosiloxane particles.

[Polymerization process]
In the polymerization step, the radical polymerizable vinyl monomer absorbed in the seed particles in the absorption step is subjected to radical polymerization. In the polymerization step, the radical polymerization method is not particularly limited, and examples thereof include a method using a radical polymerization initiator, a method of irradiating ultraviolet rays and radiation, and a method of applying heat.

  The radical polymerization initiator is not particularly limited. Specifically, for example, persulfate such as potassium persulfate, hydrogen peroxide, peracetic acid, benzoyl peroxide, lauroyl peroxide, orthochlorobenzoyl peroxide, Orthomethoxybenzoyl peroxide, 3,5,5-trimethylhexanoyl peroxide, t-butylperoxy-2-ethylhexanoate, di-t-butyl peroxide, benzoyl peroxide, 1,1-bis (t -Butylperoxy) -3,3,5-trimethylcyclohexane, peroxide initiators such as t-butyl hydroperoxide; azobisisobutyronitrile, azobiscyclohexacarbonitrile, azobis (2,4 -Dimethylvaleronitrile), 2'-azobisisobutyronitrile, 2,2'-azobis 2-amidinopropane) · dihydrochloride, 4,4′-azobis (4-cyanopentanoic acid), 2,2′-azobis- (2-methylbutyronitrile), 2,2′-azobisisobutyro Preferred examples include nitriles and azo compounds such as 2,2′-azobis (2,4-dimethylvaleronitrile). These radical polymerization initiators may be used alone or in combination of two or more.

  The amount of the radical polymerization initiator used is preferably 0.001% by mass to 20% by mass, more preferably 0.01% by mass, based on the total mass of the monomer components essentially including the radical polymerizable vinyl monomer. % To 10% by mass, more preferably 0.1% to 5% by mass. When the usage-amount of the said radical polymerization initiator is less than 0.001 mass%, the polymerization degree of a radically polymerizable vinyl monomer may not rise. The method for charging the radical polymerization initiator to the solvent is not particularly limited. First, the whole amount is charged first (before the start of the polymerization reaction) (in the absorption process, the radical polymerization initiator is dissolved in the monomer component and emulsified. A mode of dispersing, a mode in which a radical polymerization initiator is charged after absorbing a polymerizable component in seed particles); a mode in which a part is charged first, and the rest is continuously fed, or pulse addition is intermittently performed Any conventionally known method such as an embodiment to be performed or an embodiment in which these are combined can be employed.

  In the polymerization step, the reaction temperature for radical polymerization is preferably 40 ° C to 100 ° C, more preferably 50 ° C to 80 ° C. If the reaction temperature is less than 40 ° C., the degree of polymerization may not be sufficiently increased, and the mechanical properties of the polymer particles may be difficult to obtain. If the reaction temperature exceeds 100 ° C., aggregation between the particles may easily occur during the polymerization. is there. In the polymerization step, the reaction time for radical polymerization can be appropriately changed depending on the type of polymerization initiator used, but it is preferably 5 minutes to 600 minutes, more preferably 10 minutes to 300 minutes. When the reaction time is less than 5 minutes, the polymerization degree does not increase sufficiently, and when it exceeds 600 minutes, aggregation between particles tends to occur.

  Until now, polyorganosiloxane particles (seed particles) have been synthesized, and after the radically polymerizable monomer component is absorbed in the obtained seed particles, a polymerization reaction is performed to produce organic-inorganic composite particles. However, the present invention is not limited to this. For example, when the polyorganosiloxane particles have a polymerizable unsaturated bond (preferably a vinyl group), the organic-inorganic composite particles may be obtained by performing a polymerization reaction without passing through the absorption step. That is, it is one of the preferable embodiments of the present invention to perform the polymerization step after the polyorganosiloxane particle synthesizing step, and the effects of the present invention can also be obtained in this embodiment.

[Organic inorganic composite particles]
The organic-inorganic composite particles obtained by the production method of the present invention have a number average particle diameter of 3 to 30 μm. Further, according to the production method of the present invention, the sharpness of the particle size distribution of the organic-inorganic composite particles represented by the coefficient of variation (CV value) can be reduced to 15% or less for the obtained organic-inorganic composite particles.

  The mechanical characteristics and optical characteristics are designed to have desired characteristics according to various applications by adjusting the content ratio of the inorganic component and the organic component, or the type and amount of the monomer component to be used. be able to. For example, when used for optical applications, the refractive index of organic-inorganic composite particles can be adjusted by selecting the type and amount of the monomer to be absorbed. Specifically, if styrene and methyl methacrylate are used as monomer components to be absorbed by the seed particles, the refractive index can be increased by increasing the amount of styrene, while the amount of methyl methacrylate is increased. By increasing the refractive index, the refractive index can be lowered.

  The shape of the polymer particle of the present invention is not particularly limited, and specifically, for example, a shape such as a spherical shape, a needle shape, a plate shape, a scale shape, a pulverized (crushed) shape, a bowl shape, and a confetti shape. Can be mentioned. The polymer particles according to the present invention may be colored with a dye and / or a pigment. In the case where the organic-inorganic composite particles according to the present invention are colored, the dye and / or pigment may be simply contained in the polymer particles, or the dye and / or pigment and the polymer particles may be combined. Although it may have a structure in which the constituting matrix is linked by chemical bonds, it is not particularly limited thereto.

  The organic-inorganic composite particles according to the present invention are also preferably used as conductive fine particles if a conductor layer is formed on the surface thereof. At this time, the conductor layer should just be formed in at least one part of the organic-inorganic composite particle surface.

  The use of the organic-inorganic composite particles according to the present invention is not particularly limited. Specifically, for example, an in-plane spacer for a liquid crystal display element, a seal portion spacer for a liquid crystal display element, a spacer for an EL display element, Preferable examples include a spacer for a touch panel, a spacer for holding a gap distance such as a gap holding material capable of uniformly holding gaps between various substrates such as ceramic and plastic, and conductive particles.

  Hereinafter, the present invention will be described more specifically by way of examples. However, the present invention is not limited to these examples. Hereinafter, for convenience, “parts by mass” may be simply referred to as “parts”. In addition, “mass%” may be described as “wt%”. First, definitions of measurement values, measurement methods, and evaluation criteria described in the examples of the present invention are shown below.

[Measurement method of the number of particles]
Methanol and the number of particles in the reaction solution were measured using a liquid particle counter manufactured by PAMAS (main body part type: SVSS-C-16, sensor part type: HCB-LD-50 / 50).

[Average particle size and coefficient of variation of particle size]
The average particle diameter of the polyorganosiloxane particles and the organic-inorganic composite particles and the coefficient of variation of the particle diameter were determined as follows. Each 0.1 ml of a dispersion of polyorganosiloxane particles obtained in the following experimental example or a reaction solution of organic-inorganic composite particles was added to a 1% surfactant aqueous solution (“Hytenol (registered trademark) N-08”, No. 1). After dispersing in 5 ml of Ichi Kogyo Seiyaku Co., Ltd., the particle size of 30000 particles was measured by the edit mode of a precision particle size distribution analyzer (“Coulter Multisizer II”, manufactured by Beckman Coulter, Inc.). The particle diameter (number average) was determined.
The variation coefficient of the particle diameter was determined according to the following formula.

[Experimental Example 1]
(Synthesis of silsesquioxane (polyorganosiloxane) particles)
451 g of ultrapure water prepared in advance (reverse osmosis membrane device (“Purelite PRA-0030”, manufactured by Organo Corporation)) in a stainless steel reaction vessel with a capacity of 2 L equipped with a stirring blade, a reflux pipe, a dropping port and a thermometer , Then passed through ultrapure water production equipment ("PURIC-MIX II" Organo Co., Ltd.), electric conductivity 0.0549 μS / cm) and industrial methanol 193 g (Hokuko Chemical Co., Ltd., Particle (12.8 pcs / ml, M1) was added, and the mixture was stirred and mixed at 120 rpm, then 1.64 g of 25% aqueous ammonia was added, and the temperature of the mixed solution was adjusted to 28 ° C. Next, under stirring of this mixed solution, 71.5 g of 3-methacryloxypropyltrimethoxysilane was added over 10 seconds to conduct hydrolysis and condensation reaction of 3-methacryloxypropyltrimethoxysilane. The reaction vessel became cloudy. A hydrolytic condensation reaction was carried out for 60 minutes as it was to obtain a dispersion of silsesquioxane particles (polyorganosiloxane particles).

  When the number average particle diameter of the obtained silsesquioxane particles (seed particles) was measured, the number average particle diameter was 4.96 μm and the coefficient of variation (CV value) was 4.0%. Table 1 shows the particle size of the obtained silsesquioxane particles and the number of particles contained in the methanol used at this time.

(Preparation of monomer suspension)
In a separately prepared glass flask with a volume of 1 L, 150 g of styrene, 150 g of ethylene glycol dimethacrylate, 6.6 g of 2,2′-azobis (2,4′-dimethylvaleronitrile), a surfactant (“Hitenol (registered) (Trademark) NF-08 ", 1.5 g of polyoxyethylene distyrylphenyl ether sulfate ammonium salt (Daiichi Kogyo Seiyaku Co., Ltd.) and 204 g of ion-exchanged water were added, and a homomixer (" TK homomixer mark ") was added. II ”(manufactured by Primix Co., Ltd.) was used to prepare a monomer suspension.

(Synthesis of organic-inorganic composite particles)
301 g of the resulting suspension of silsesquioxane particles was added to a 2 L glass flask equipped with a stirring blade and a reflux tube and stirred. The monomer suspension was added all at once and stirred at room temperature for 60 minutes to absorb the monomer component in the silsesquioxane seed particles, thereby producing swollen particles that absorbed the organic monomer. The absorption of the monomer component was confirmed by observing the seed particles taken out from the flask 60 minutes after the addition of the monomer suspension with a microscope, thereby increasing the particle size of the seed particles.

  After confirming that the seed particles had absorbed the monomer, the particle dispersion that had swelled by absorbing the monomer component was heated to 65 ° C. and subjected to a polymerization reaction for 3 hours to obtain organic-inorganic composite particles. After cooling the reaction solution, solid-liquid separation is performed by suction filtration, and the resulting cake is dried with a vacuum dryer, pulverized with a pulverizer to return the aggregated particles to single particles, and the powder of organic-inorganic composite particles Got. Table 1 shows the particle diameters of the obtained particles.

[Experimental Examples 2 to 6]
Silsesquioxane particles were produced in the same manner as in Experimental Example 1 except that M2-M6 methanol shown below was used as a reaction solvent. The particle diameter of the silsesquioxane particles 60 minutes after the introduction of 3-methacryloxypropyltrimethoxysilane, the number of particles contained in each methanol used at this time, and the silsesquioxane 60 minutes after the start of the reaction The particle diameter of the particles, the coefficient of variation (CV value), and the particle diameter after polymerization are also shown in Table 1 below.

(Methanol type)
M1: Industrial methanol (made by Hokuko Chemical Co., Ltd.) was used as it was (number of particles of 2 μm or more 12.8 particles / ml).
M2: Reagent grade methanol (reagent special grade methanol, manufactured by Wako Pure Chemical Industries, Ltd.) was used as it was (99.8 particles / ml of 2 μm or more).
M3: M2 methanol filtered through a 0.1 μm filter (PTFE type membrane filter, T010A090C, manufactured by Advantech Toyo Co., Ltd.) six times (5.2 particles / ml of 2 μm or more particles / ml) was used.
M4: M1 methanol bubbled with compressed air for 5 minutes was used (number of particles of 2 μm or more 27.8 particles / ml). The bubbling is performed in order to reproduce the impurities mixed in the synthesis reaction system in the seed particle synthesis process.
M5: Methanol for electronic industry (Product name: EL methanol, manufactured by Kanto Chemical Co., Inc.) was used as it was (0.6 μm / ml of particles of 2 μm or more).
M6: M5 methanol in which compressed air was bubbled for 5 minutes (number of particles of 2 μm or more 13.8 particles / ml) was used.

  In Table 1, “the number of particles of 2 μm or more” indicates the number of particles of 2 μm or more contained in alcohol (methanol). The “particle size after 60 minutes” means the particle size of the seed particles after 60 minutes from the start of the hydrolysis condensation reaction. “After polymerization” means organic inorganic synthesized by absorbing 10 times the monomer component in mass with respect to 3-methacryloxypropyltrimethoxysilane used to synthesize silsesquioxane particles (seed particles). It means the number average particle size of the composite particles. “CV value” is the CV value of silsesquioxane particles.

  As shown in the graph of FIG. 1, it can be seen that the variation in the particle diameter of the polyorganosiloxane particles among the production lots can be reduced by setting the amount of particles of a specific size in the synthesis reaction system within a predetermined range.

  According to the production method of the present invention, not only polyorganosiloxane particles having a desired particle diameter and a narrow particle size distribution can be obtained, but also the particle diameters of polyorganosiloxane particles and organic-inorganic composite particles between production lots. Variation can be suppressed to a low level. Therefore, if the polyorganosiloxane particles obtained by the production method of the present invention are used, it is considered that the quality variation between the final products can be suppressed to a very low level. In addition, the organic-inorganic composite particles obtained by the production method of the present invention include an in-plane spacer for a crystal display element, a seal spacer for a liquid crystal display element, a spacer for an EL display element, a spacer for a touch panel, and between various substrates such as ceramic and plastic. It is suitable for applications such as a gap distance holding spacer such as a gap holding material that can hold the gap uniformly, and conductive particles.

Claims (5)

A method for producing polyorganosiloxane particles, comprising:
Including a synthesis step of synthesizing polyorganosiloxane particles by performing a hydrolytic condensation reaction of an alkoxysilane compound in a mixed solvent in which alcohol is essential,
In the synthesis step, a mixed solvent containing alcohol having an inevitable impurity particle size of 2 μm or more and 5 to 200 particles / ml of alcohol and ultrapure water having an electric conductivity of 1 μS / cm or less is used. A process for producing polyorganosiloxane particles. The above synthesis process includes a generation process in which an alkoxysilane compound is hydrolyzed and condensed in a mixed solvent in which alcohol is essential to generate primary seed particles of polyorganosiloxane, and a primary seed obtained in the above generation process. An alkoxysilane compound is further added to the reaction solution containing particles to grow primary seed particles to obtain secondary seed particles, and is performed in two stages, and
The method for producing polyorganosiloxane particles according to claim 1, wherein the amount A of alkoxysilane compound added in the growth step is determined by the following formula (I).
[In the above formula (I), A is the mass (g) of the alkoxysilane compound added in the growth step, r is the primary seed particle size, R is the set particle size of the secondary seed particle, and B is used in the production step. Means the mass (g) of the obtained alkoxysilane compound. ]   The method for producing polyorganosiloxane particles according to claim 1 or 2, wherein the alcohol is methanol. The method for producing polyorganosiloxane particles according to any one of claims 1 to 3, wherein an alcohol filtered in advance with a filter is used as the alcohol. An absorption step for causing the polyorganosiloxane particles obtained by the method according to any one of claims 1 to 4 to absorb a radical polymerizable vinyl monomer component; and
The manufacturing method of the organic inorganic composite particle characterized by including the superposition | polymerization process of radical-polymerizing the monomer component absorbed at the said absorption process.