JP5554004B2 - 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 having a desired particle size and further having a small variation in particle size between production lots. The present invention relates to a method for producing particles and organic-inorganic composite particles.

  Filling spacers for cell gaps (or panel gaps) for display displays such as liquid crystal display devices and touch panels, conductive adhesives for mounting micro elements, and conductive gap members such as anisotropic conductive adhesives As the agent, polymer particles are widely used. 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. However, a method for performing a 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.

  Furthermore, the polymer particles used in 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 has been pointed out that, even when the same conditions are employed, if the polymer particles are produced a plurality of times, a variation of about 40% occurs with respect to the target particle diameter ( Patent Document 2). Thus, when the particle diameter varies between production lots, in the case of using the polymer particles, particularly when used for a cell gap spacer or a conductive gap member in the image display device as described above. There is a problem that it is difficult to keep the product quality constant.

  The present invention has been made by paying attention to the above-described problems, and its purpose is to have a desired particle size, and in particular, a polyorganosiloxane particle and an organic material having a small variation in particle size between production lots. It is to propose a method for producing inorganic composite particles.

  As a result of intensive investigations to solve the above problems, the present inventors have found that the variation in the particle diameter between production lots seen when the synthesis of polyorganosiloxane particles is repeated, the blending amount of the starting material, the reaction time In addition to the reaction conditions such as temperature, the present inventors have found that it is greatly influenced by the washing method of the reaction vessel used for the synthesis reaction, and completed the present invention.

  That is, the production method of the present invention that has solved the above problems is a method of producing polyorganosiloxane particles by hydrolysis condensation reaction of an alkoxysilane compound, and the reaction prior to the synthesis of the polyorganosiloxane particles. The main point is that after the container is washed with an organic solvent, it is further washed with a mixed solvent of water / organic solvent.

  The present inventors consider the reason why variation in the particle diameter between production lots can be suppressed by the production method of the present invention as follows. In the conventional cleaning method, starting materials, generated seed particles, and organic-inorganic composites are not sufficiently removed from the reaction vessel, and the same reaction vessel is repeatedly used to produce organic-inorganic composite particles. In some cases, these components act as nuclei during seed particle generation, or at the initial stage of nucleation (precipitation stage), which greatly affects the determination of the number of nucleation, so the same conditions are employed. However, it is considered that the number of particles to be generated increased or the particle diameter and the particle size distribution varied between production lots.

  At the laboratory level, if the reaction container is polished and cleaned with a cleanser or the like each time it is operated, residual components adhering to the reaction container can be removed, but the laboratory level is a scale. In an actual operation with a large difference, it is not practical to perform a laboratory level cleaning operation, which not only wastes labor and time, but also reduces the operating rate of the manufacturing apparatus and significantly impairs productivity.

  According to the method of the present invention, even if the polishing operation is not performed, the reaction container is washed with a specific organic solvent to sufficiently remove trace residual components in the reaction container, and the fluctuation of the particle size between production lots can be reduced. Therefore, organic-inorganic composite particles with stable quality can be obtained without harming productivity.

  Such a problem has newly arisen as a result of the demand for more precise particle size fluctuation suppression due to technological advancement. There were no proposals to give technical ideas that would give hints.

  The alkoxysilane compound is preferably a compound having a polymerizable double bond.

  In the production method of the present invention, the organic solvent contained in the mixed solvent is preferably one or more selected from the group consisting of alcohols, ethers and ketones, and more preferable organic solvents are alcohols. More preferably, it is methanol.

  The electric conductivity of water contained in the mixed solvent is preferably 5 μS / cm or less.

  The present invention also includes a method for producing organic-inorganic composite particles using the polyorganosiloxane particles, which includes a radical polymerizable vinyl monomer component added to the polyorganosiloxane particles obtained by the above method. The main point is that it includes an absorption step for absorption, and a polymerization step for radical polymerization of the monomer component absorbed in the absorption step.

  According to the production method of the present invention, variation in the particle diameter of polyorganosiloxane particles between production lots can be suppressed to a low level, so that organic-inorganic composite particles having a desired particle diameter can be obtained.

6 is a graph showing the results of Experimental Example 1. 10 is a graph showing the results of Experimental Example 2. 10 is a graph showing the results of Experimental Example 3. 10 is a graph showing the results of Experimental Example 5. 10 is a graph showing the results of Experimental Example 6.

  The method for producing polyorganosiloxane particles of the present invention is a method for producing particles of polyorganosiloxane by hydrolysis reaction or condensation reaction of an alkoxysilane compound, and prior to the synthesis of the polyorganosiloxane particles, a reaction vessel Is washed with an organic solvent and then washed with a mixed solvent of water / organic solvent.

  First, a method for washing a reaction vessel performed prior to the synthesis step of polyorganosiloxane particles will be described (hereinafter sometimes referred to as a washing step).

  In the production method of the present invention, first, a reaction vessel used for synthesis of polyorganosiloxane particles is washed with an organic solvent (first washing step). For the washing with the organic solvent, a stirring device provided in the reaction vessel may be used. That is, the inside of the reaction vessel may be washed by stirring the organic solvent added to the reaction vessel with a stirring device. In addition, even if it is a case where the stirring apparatus is not provided, what is necessary is just to use a stirring apparatus suitably.

  The amount of the organic solvent used in the first washing step may be determined according to the volume of the reaction vessel and the amount of the reaction solution at the time of synthesis of the polyorganosiloxane particles or organic-inorganic composite particles in the previous lot. It is preferable to use an organic solvent in an amount of about 120% to 250% of the amount of the reaction solution in the synthesis of the polyorganosiloxane particles.

  The time required for cleaning is preferably 0.5 to 24 hours. More preferably, it is 0.5 hour-12 hours, More preferably, it is 0.5 hour-4 hours.

The organic solvent used in the production method of the present invention is preferably one that completely dissolves polyorganosiloxane particles that are starting materials and products. For example, it is preferable to use an organic solvent having a solubility parameter (SP value) of about 9 (cal / cm ³ ) ^1/2 to 15 (cal / cm ³ ) ^1/2 . Examples of the organic solvent having an SP value within the above range include alcohols such as methanol, ethanol, isopropanol, ethylene glycol and propylene glycol, ethers such as tetrahydrofuran, tetrahydropyran and ethylene glycol monomethyl ether, and ketones such as acetone. Etc. Among these, alcohols are preferable, and methanol, ethanol, and isopropanol are particularly preferable.

  Next, after discharging the organic solvent used in the first washing step from the reaction vessel, the reaction vessel is washed with a mixed solvent composed of water / organic solvent (second washing step).

  The mixed solvent used in the second washing step preferably contains 60% by mass to 95% by mass of the organic solvent with respect to 100% by mass of water and the total amount of the organic solvent. More preferably, it is 65 mass%-90 mass%, More preferably, it is 70 mass%-90 mass%.

The organic solvent contained in the mixed solvent may be selected using the solubility parameter (SP value) as a guide, as in the organic solvent in the first washing step. For example, the SP value is 9 (cal / cm ³ ) ^1/2 to An organic solvent of 15 (cal / cm ³ ) ^1/2 is preferred. This is because an organic solvent having a solubility parameter in the above-mentioned range can dissolve the polyorganosiloxane particles, so that a cleaning effect is easily obtained. Specifically, it is recommended to use one or more organic solvents selected from the group consisting of alcohols, ethers, and ketones. Examples of alcohols include methanol, ethanol, isopropanol, ethylene glycol, and propylene glycol. Ethers include tetrahydrofuran, tetrahydropyran, and ethylene glycol monomethyl ether. Ketones include acetone. Among these, alcohols are preferable, methanol, ethanol and isopropanol are more preferable, and methanol is particularly preferable. In addition, the said organic solvent may be used independently and may be used in combination of 2 or more type. When using 2 or more types of organic solvents, it is preferable that methanol is included. In this case, the blending amount of methanol in 100% by mass of the organic solvent is preferably 50% by mass to 99% by mass. More preferably, it is 70 mass%-98 mass%.

  The water contained in the mixed solvent preferably has, for example, an electric conductivity of 5 μS / cm or less. More preferably, it is 3 μS / cm or less, and further preferably 1 μS / cm or less. Water whose electrical conductivity satisfies the above requirements can be prepared by treating with pure water or ultrapure water production equipment.

  The first and second washing steps may be performed while the reaction apparatus is warmed, or an organic solvent and a mixed solvent used for washing may be heated and used. When heating, it is recommended that the temperature of the solvent in the reaction vessel used for washing be 0 ° C to 65 ° C. More preferably, it is 10 degreeC-65 degreeC, More preferably, it is 20 degreeC-65 degreeC.

  Moreover, it is preferable to wash away the inner wall of the reaction vessel with the solvent used for cleaning after the first and second cleaning steps. This is because dirt contained in the cleaning liquid slightly remaining in the reaction vessel can be washed away.

  Furthermore, a step of drying the reaction vessel may be provided after the end of the washing step. The drying method is not particularly limited. For example, the reaction vessel may be dried under reduced pressure. At this time, it is preferable to prevent minute impurities from entering the reaction vessel. Such impurities are considered to act as nuclei during the production of polyorganosiloxane particles, and even when the above-described cleaning process is provided, the particle diameter of the produced polyorganosiloxane particles (seed particles) varies, and finally obtained. This is because the particle diameter of the organic / inorganic composite particles to be produced may vary.

  The reaction vessel used for producing the organic-inorganic composite particles according to the present invention is not particularly limited, and any conventionally known ones such as a metal reaction vessel such as stainless steel and a glass reaction vessel can be used. Among these, when a metal reaction vessel is used, the effect of the method of the present invention is remarkably obtained.

  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. As will be described later, 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, for example, vinyl groups, particularly ( 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 vinyl polymer and a polyorganosiloxane are mixed in the outer shell mainly composed of the polyorganosiloxane. 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 of water / alcohol. In this condensation reaction, a basic catalyst such as ammonia may be used 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. This is because copolymerization with a radical polymerizable monomer that is absorbed after particle formation is possible. Examples of these polymerizable silicon compounds include vinyltrimethoxysilane, vinyltriethoxysilane, p-styryltrimethoxysilane, γ- (meth) acryloxypropylmethyldimethoxysilane, and γ- (meth) acryloxypropyltrimethoxy. Silane, γ- (meth) acryloxypropylmethyldiethoxysilane, γ- (meth) acryloxypropyltriethoxysilane, γ- (meth) acryloxypropyltriacetoxysilane, γ- (meth) acryloxyethoxypropyltrimethoxy A silane etc. can be mentioned. These may be used alone or in combination of two or more.

  Among the polymerizable silicon compounds, the polymerizable silicon compound (1) having a (meth) acryloxy group represented by the following formula (1) is preferable.

(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 thereof include silicon compounds having a vinyl group such as 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)

(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 aryl group having 6 to 20 carbon atoms. At least one monovalent group selected from the group consisting of: R ^f is the same or different and is selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, and an acyl group having 2 to 5 carbon atoms. An alkoxysilane represented by at least one selected monovalent group (n is an integer of 0 to 3) (hereinafter sometimes referred to as non-polymerizable silicon compound (2)) 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). Among these, it is particularly preferable to use a trifunctional silane of n = 1 from the viewpoint that the hydrolysis rate is large to some extent and the polyorganosiloxane particles are rapidly formed. The non-polymerizable silicon compound (2) may be used alone or in combination of two or more.

The derivatives of the silicon compounds (1) and (2) are not particularly limited. For example, at least one of the OR ^c group or the OR ^f group contained in the silicon compounds (1) and (2) is β-di- A compound obtained by partially hydrolyzing and condensing a compound substituted with a group capable of forming a carbonyl group and / or another chelate compound and the silicon compounds (1) and (2) and / or the chelate compound. At least one selected from the group consisting of condensates 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.

  In the synthesis step according to the present invention, a mixed solvent containing alcohol as an essential component is used. 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, a preferable water / alcohol mixing ratio 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 for the mixed solvent include ion exchange water, pure water, and ultrapure water. Among these, ultrapure water having an electric conductivity of 5 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.

  The reaction solvent may contain other organic solvent in addition to water and alcohol. 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.

  The conditions during the hydrolysis and condensation reaction are not particularly limited. For example, the above silicon compound group, reaction solvent and, if necessary, a catalyst are added to and mixed in the reaction vessel, and 0 ° C. to 100 ° C., preferably 0 It is carried out by stirring for 30 minutes to 100 hours in a temperature range of from C to 70C.

  In performing 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, It is preferable to add the silicon compound group over 0.001 hour to 500 hours so that the concentration of the silicon compound group is 0.1% by mass to 30% by mass. preferable. It is recommended to set the reaction temperature between 0 ° C and 100 ° C.

  In the method according to the present invention, the silicon compound group is 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-mentioned silicon compound (1) having a (meth) acryloxy group as an essential component, so that polyorganosiloxane particles having a (meth) acryloxy group are obtained. Here, the appropriate conditions are not particularly limited. For example, in the obtained slurry, the concentration of the polymerizable silicon compound (1) and the non-polymerizable silicon compound (2) (converted to the raw material compound) is 20 mass. %, The water concentration is 50% or more, and the catalyst concentration is 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.

  If polyorganosiloxane particles are obtained by adopting a two-stage process, the above synthesis process grows the primary seed particles obtained in the production process to obtain the primary seed particles of the polyorganosiloxane. Thus, it can be performed separately from the growth step 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 increasing or decreasing the amount of the monomer component to be absorbed by the seed particles in the absorption step described later.

  However, when such adjustments are made, the ratio of the organic component content to the inorganic component content in the particles varies depending on the production lot, so the physical properties (mechanical properties, optical properties, etc.) of the organic-inorganic composite particles Variation occurs. Therefore, in order to suppress such variations in physical properties, it is preferable that the seed particle diameter has a small variation between production lots. In the seed particle generation and / or growth process (or synthesis process) in advance, It is preferable to adjust the amounts of these components. 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 generating a condensate that becomes a nucleus of the polyorganosiloxane particle by performing hydrolysis and condensation reaction of the alkoxysilane compound. 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.

  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 concentration of the silicon compound group as a starting material 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 obtained or it is necessary to increase or decrease the raw materials in the absorption process described later, which is not economical and desirable from the viewpoint of stable operation.

[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. In addition, it is preferable to make the addition amount of an alkoxysilane compound into the quantity which satisfies following formula (3).

  Here, in the above formula (3), r is the primary seed particle size, R is the set particle size of the secondary seed particle, B is the mass (g) of the alkoxysilane compound used in the production step, and A is the growth step. 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.

  The concentration of the primary seed particles introduced into the growth process is preferably 0% by mass to 15% by mass. More preferably, it is 0.5 mass%-10 mass%, More preferably, it is 1 mass%-10 mass%.

[Polyorganosiloxane particles]
The shape of the polyorganosiloxane particles (primary and secondary seed particles) obtained in the synthesis step (or generation and / or growth step) is spherical, needle-like, plate-like, scale-like, crushed (crushed), There are no particular limitations on the shape of the particles, such as a bowl shape, a bowl shape, or a confetti shape.

  The 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). For example, if it is desired to obtain organic-inorganic composite particles having a particle size of 3 to 30 μm, the primary seed particles preferably have a particle size of 0.3 to 12 μm, more preferably 0.4 to 10 μm. Yes, the particle size 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. When the particle diameter of the polyorganosiloxane particles is within the above range, it is possible to exert an advantageous effect that absorption of a vinyl polymerizable monomer described later proceeds efficiently. Further, when the particle diameter of the polyorganosiloxane particles is less than 0.5 μm, the vinyl polymerizable monomer may not be sufficiently absorbed. When the particle diameter exceeds 12 μm, the mass of the particles becomes large in the reactor. Sedimentation of the polymer particles may occur and the particles may easily aggregate. In the present invention, the value of the median diameter (50% particle diameter) measured by a precision particle size distribution measuring apparatus (for example, “Multisizer II” manufactured by Beckman Coulter, Inc.) employing the Coulter principle is used as the seed particle. Adopted as the particle size.

  If the production method according to the present invention is employed, the polyorganosiloxane particles can have a coefficient of variation (CV value) indicating the sharpness of the particle size distribution 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 are particles that can easily absorb and retain the radical polymerizable vinyl monomer described later in the particles, that is, between the polysiloxane skeletons constituting the particles. It is. When the polyorganosiloxane particles have a (meth) acryloxy group, the above effects are particularly excellent. This is because the polyorganosiloxane particles having a (meth) acryloxy group have very good compatibility with organic compounds such as vinyl monomers, and the polyorganosiloxane particles absorb the vinyl monomers. It can be said that this is because of a suitable degree of crosslinking.

[Method for producing organic-inorganic composite particles]
Following the synthesis step, 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) (absorption step), and then the absorption is performed. By subjecting the monomer component absorbed in the process to radical polymerization (polymerization process), 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 process, the amount of seed particles introduced into the absorption process may be controlled in order to perform planned production and to further reduce the variation in the particle diameter of the organic-inorganic composite particles between production lots. If the amount of particles to be introduced into the absorption process is constant, the final yield and the amount of raw material required in the absorption process are determined, and thus the organic-inorganic composite particles can be produced more stably and systematically.

  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 these, a form in which a monomer component is added to a solvent in which polyorganosiloxane particles are dispersed in advance as in the former 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 and is preferable.

  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.

  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. Moreover, a monomer component can be suitably selected according to a use so that the physical property requested | required of an organic inorganic composite particle can be exhibited. 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 crosslinking | crosslinked monomer, 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 And isocyanurate and derivatives thereof. These may be used alone or in combination of two or more.

  The absorption step is preferably performed under conditions such that the monomer component described above is easily absorbed into the structure of the polyorganosiloxane particles (seed particles). Such conditions include, for example, the concentration 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 during mixing, the mixing Subsequent processing methods and means may be mentioned. 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. More preferably, it is 1 time or more, More preferably, it is 5 times or more. On the other hand, it is more preferably 50 times or less, and further preferably 30 times or less. When the addition amount is less 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 organic-inorganic composite 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. It becomes a mixture of inorganic 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 step, 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. Furthermore, 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 siloxane particles is preferable because absorption into the polyorganosiloxane particles is more efficiently performed.

  The emulsifier is not particularly limited. For example, an anionic surfactant, a cationic surfactant, a nonionic surfactant, an amphoteric surfactant, a polymer surfactant, and one or more polymerizations in the molecule There are polymerizable surfactants having possible carbon-carbon unsaturated bonds. 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. Etc. can be mentioned preferably.

  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, for example, preferably 0.01% by mass to 10% by mass, more preferably 0.05% by mass with respect to the total mass of the monomer components essentially including the radical polymerizable vinyl monomer. It is -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. The method for radical polymerization 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.

  Examples of the radical polymerization initiator include persulfates 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 -Peroxide-based initiators such as trimethylcyclohexane and t-butyl hydroperoxide; azobisisobutyronitrile, azobiscyclohexacarbonitrile, azobis (2,4-dimethylvaleronitrile), 2'-azobis Isobutyronitrile, 2,2'-azobis (2-amidinopropane) dihydrochloride 4,4′-azobis (4-cyanopentanoic acid), 2,2′-azobis- (2-methylbutyronitrile), 2,2′-azobisisobutyronitrile, 2,2′-azobis (2 , 4-dimethylvaleronitrile) and the like; 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 into the solvent is not particularly limited. First, the whole amount is charged first (before the polymerization reaction is started) (in the absorption step, 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 to 100 ° C, more preferably 50 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 to be used, but it is preferably 5 to 600 minutes, more preferably 10 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 median diameter of 3 to 30 μm. Moreover, according to the manufacturing method of this invention, the organic-inorganic composite particle | grains whose variation coefficient (CV value) which shows the sharpness of a particle size distribution are 15% or less are obtained.

  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. For example, when used for optical applications, the refractive index of the 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.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but 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.

[Particle size]
The median size (50% particle size) of the polyorganosiloxane particles and organic-inorganic composite particles is 30000 particles using a precision particle size distribution analyzer (“Coulter Multisizer II”, manufactured by Beckman Coulter, Inc.). The particle diameter was determined by measuring. When fine particles were by-produced and a particle diameter different from the main peak was observed, only the main peak was measured using the edit mode.

Preparation of Measurement Solution 0.1 mL of the seed particle suspension (after 15 minutes and 60 minutes) or 0.03 g of the organic-inorganic composite particles obtained in the following experimental examples were each added with a 1% surfactant aqueous solution (“High A solution for measurement was prepared by dispersing in 5 ml of Tenor (registered trademark) N-08 "(Daiichi Kogyo Seiyaku Co., Ltd.).

  Here, the “seed particles after 15 minutes” mean particles generated 15 minutes after the start of the hydrolysis condensation reaction, while the “seed particles after 60 minutes” mean hydrolysis condensation. The particle | grains produced | generated 60 minutes after the start of reaction (after completion | finish of a hydrolysis reaction) are meant.

  In the following Experimental Examples 1 to 7, synthesis of polyorganosiloxane and production of organic-inorganic composite particles were performed according to the following synthesis method and production method.

[Synthesis Method of Polyorganosiloxane Particles]
Into a stainless steel reaction vessel having a capacity of 2 L equipped with a stirring blade, a reflux pipe, a dripping port and a thermometer, 451 g of ultrapure water prepared in advance (reverse osmosis membrane device (“Purelite (registered trademark) PRA-0030”, Organo After passing through an ultrapure water production apparatus ("PURIC (registered trademark) -MIX II" manufactured by Organo Co., Ltd.), 193 g of methanol (electrical conductivity 0.0549 μS / cm) and methanol (Reagent special grade methanol manufactured by Kojun Pharmaceutical Co., Ltd.) was added and stirred and mixed at a rotation speed of 120. Then, 1.64 g of 25% aqueous ammonia was added, and the temperature of the mixed solution was adjusted to 28 ° C. Next, 71.5 g of 3-methacryloxypropyltrimethoxysilane (“KBM-503” manufactured by Shin-Etsu Chemical Co., Ltd.) was added all at once while stirring the mixed solution, and hydrolysis of 3-methacryloxypropyltrimethoxysilane was performed. A condensation reaction was performed. After several minutes, the inside of the reaction vessel became cloudy, but the hydrolysis condensation reaction was carried out for 60 minutes as it was to obtain a dispersion of polyorganosiloxane particles.

  The median diameter of the silsesquioxane particles (seed particles) 15 minutes and 60 minutes after the start of the hydrolysis condensation reaction (injection of 3-methacryloxypropyltrimethoxysilane) (after completion of the hydrolysis condensation reaction) The coefficient of variation was measured.

[Preparation of monomer suspension]
Into a separately prepared glass flask with a volume of 1 L, 6.6 g of 2,2′-azobis (2,4′-dimethylvaleronitrile) is added to 112.5 g of styrene, 112.5 g of methyl methacrylate and 75 g of ethylene glycol dimethacrylate. After dissolution, 1.5 g of surfactant (“Hytenol (registered trademark) NF-08”, polyoxyethylene distyryl phenyl ether sulfate ammonium salt, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) and 300 g of ion-exchanged water were added. The resultant was added and emulsified and dispersed using a homomixer (“TK Homomixer Mark II”, manufactured by Primex Corporation) to prepare a monomer suspension.

[Method for producing organic-inorganic composite particles]
301 g of the resulting suspension of polyorganosiloxane 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 polyorganosiloxane 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 absorbed the monomer, 600 g of ion-exchanged water was added thereto, and the particle dispersion liquid which absorbed the monomer component and swollen was heated up to 65 ° C., and the polymerization reaction was performed for 3 hours. Inorganic composite particles were obtained. After cooling the reaction solution, solid-liquid separation is performed by suction filtration, and the resulting cake is dried with a vacuum dryer and crushed with a pulverizer, and the aggregated particles generated in the drying step are returned to single particles to be organic. A powder of inorganic composite particles was obtained. Table 1 shows the particle diameters of the obtained particles.

[Experimental Examples 1-1 to 1-4]
1.5 L of methanol was added to a 2 L stainless steel reaction vessel equipped with a stirring blade, a reflux pipe, a dripping port and a thermometer, and the mixture was stirred for 1 hour for washing. After all the methanol in the reaction vessel was poured out, 0.3 L of methanol was poured into the reaction vessel (including attached equipment). Next, a mixed solvent of methanol / ion exchanged water (electric conductivity 0.2 μS / cm) = 7/3 (mass ratio) heated to 50 ° C. was added thereto, and the mixture was stirred and washed for 1 hour. Next, after pouring out the mixed solvent in the reaction vessel, after passing through ultrapure water (reverse osmosis membrane device (“Purelite PRA-0030”, manufactured by Organo Corporation)), ultrapure water production device (“PURIC- MIX II "(manufactured by Organo Co., Ltd.), water (electric conductivity 0.0549 μS / cm) 0.3 L was poured into the reaction vessel, the reaction vessel was tilted, and water was thoroughly drained. Organosiloxane particles were synthesized.

  The above washing and polyorganosiloxane particle and organic / inorganic composite particle production operations were repeated four times, and the particle size (median diameter) of the seed particles was measured 15 minutes and 60 minutes after the start of the hydrolysis condensation reaction in each lot. did. The results are shown in Table 1 and FIG.

  From Table 1 and FIG. 1, the seed particles obtained in this experimental example had small particle size variation between lots, and the organic-inorganic composite particles obtained by this experimental example also had small particle size variation (Experiment No. 1). 1-1. Median diameter of organic-inorganic composite particles obtained in 1-1: 7.4 μm).

[Experimental Examples 2-1 to 2-4]
Except that a mixed solvent of methanol / ion-exchanged water (electric conductivity 0.2 μS / cm) = 7/3 (mass ratio) heated to 25 ° C. was used as the mixed solvent in the same manner as in Experimental Example 1. The reaction vessel was washed, and then polyorganosiloxane particles were synthesized according to the synthesis method.

  The above washing and organic / inorganic composite particle synthesis operations were repeated four times, and the particle diameter (median diameter) of the seed particles 15 minutes and 60 minutes after the start of the hydrolysis-condensation reaction was measured in each lot. The results are shown in Table 2 and FIG.

  From Table 2 and FIG. 2, the variation in the particle diameter between the lots of the seed particles obtained in this experimental example was small, and the variation in the particle diameter of the organic-inorganic composite particles obtained in the experimental example was also small ( (Medium diameter of organic-inorganic composite particles obtained in Experiment No. 2-1: 7.5 μm).

[Experimental examples 3-1 to 3-4]
Except that a mixed solution of methanol / ion-exchanged water (electric conductivity: 0.2 μS / cm) = 95/5 (mass ratio) heated to 25 ° C. was used as a mixed solvent in the same manner as in Experimental Example 1. The reaction vessel was washed, and then polyorganosiloxane particles were synthesized according to the synthesis method.

  The above washing and organic / inorganic composite particle synthesis operations were repeated four times, and the particle diameter (median diameter) of the seed particles 15 minutes and 60 minutes after the start of the hydrolysis-condensation reaction was measured in each lot. The results are shown in Table 3 and FIG.

  From Table 3 and FIG. 3, the variation in the particle diameter between the lots of the seed particles obtained in this experimental example was small, and the variation in the particle diameter of the organic-inorganic composite particles obtained in the experimental example was also small ( (Medium diameter of organic-inorganic composite particles obtained in Experiment No. 3-1. 7.3 μm).

[Experimental Example 4]
After synthesizing organic-inorganic composite particles in Experimental Example 3, polyorganosiloxane particles (seed particles) were synthesized according to the synthesis method described above without washing the reaction vessel.

  The particle diameter (median diameter) of the seed particles was measured 15 minutes and 60 minutes after the start of the hydrolysis condensation reaction. The results are shown in Table 4.

  From Table 4, the particle diameter of the seed particles obtained in this experimental example is significantly different from that of the seed particles in Experimental example 3, and the particle diameter of the organic-inorganic composite particles obtained in this experimental example is also experimental. It was significantly different from that obtained in Example 3 (median diameter of organic-inorganic composite particles: 4.8 μm).

[Experimental Examples 5-1 to 5-5]
After synthesizing the organic / inorganic composite particles in Experiment 3, the reaction vessel was washed with methanol, rinsed with methanol, and then the inner surface of the reaction vessel with a sponge scrubber (made of polyurethane) with a cleanser (New Homing, manufactured by Kao Corporation). Polished evenly. Next, rinse well with running water (tap water) so as not to leave a cleanser in the reaction vessel, and then rinse with 0.5 L of methanol and 0.3 L of ultrapure water (electric conductivity 0.0549 μS / cm) in order. Thereafter, polyorganosiloxane particles were synthesized according to the above synthesis method.

  The above washing and organic / inorganic composite particle synthesis operations were repeated 5 times, and the particle diameter (median diameter) of the seed particles 15 minutes and 60 minutes after the start of the hydrolysis-condensation reaction was measured in each lot. The results are shown in Table 5 and FIG.

  From Table 5 and FIG. 4, the particle diameter of the seed particles obtained in this experimental example was stable regardless of the production lot. Moreover, the particle diameter of the organic-inorganic composite particles obtained by the experimental example was small. However, it is difficult to carry out the polishing cleaning employed in this experimental example at the actual operation level, resulting in a decrease in productivity.

[Experimental Examples 6-1 to 6-7]
1.5 L of methanol (manufactured by Wako Pure Chemical Industries, Ltd.) was added to the reaction vessel, and the mixture was stirred and washed for 1 hour. Thereafter, all of the methanol in the reaction vessel was poured out, the reaction vessel was rinsed with new methanol 0.3 L, the reaction vessel was tilted and the methanol was thoroughly exhausted, and then the polyorganosiloxane particles were synthesized according to the above synthesis method. .

  The above washing and organic / inorganic composite particle synthesis operations were repeated 7 times, and the particle diameter (median diameter) of the seed particles 15 minutes and 60 minutes after the start of the hydrolysis condensation reaction in each lot was measured. The results are shown in Table 6 and FIG.

  From Table 6 and FIG. 5, in the present experimental example, the variation in the seed particle size between production lots was large, and the variation in the particle size of the organic-inorganic composite particles obtained from the seed particles in the experimental example was also large.

[Experimental Examples 7-1 to 7-2]
1.5 L of methanol (manufactured by Wako Pure Chemical Industries, Ltd.) was added to the reaction vessel, and the mixture was stirred and washed for 1 hour. Thereafter, all the methanol in the reaction vessel was poured out. Next, after passing 1.5 L of ultrapure water (reverse osmosis membrane device (“Purelite PRA-0030”, manufactured by Organo Corporation)), ultrapure water production apparatus (“PURIC-MIX II” manufactured by Organo Corporation) ), Electric conductivity 0.0549 μS / cm) was added, and the mixture was stirred and washed for 1 hour. Thereafter, all of the ultrapure water in the reaction vessel was poured out, rinsed with 0.3 L of ultrapure water, and then polyorganosiloxane particles were synthesized according to the above synthesis method.

  The washing and the synthesis operation of the organic / inorganic composite particles were repeated twice, and the particle diameter (median diameter) of the seed particles 15 minutes and 60 minutes after the start of the hydrolysis-condensation reaction was measured in each lot. The results are shown in Table 7.

  From Table 7, the seed particles obtained in this experimental example have a relatively large variation in the particle size between lots, and the variation in the particle size of the organic-inorganic composite particles obtained using the seed particles was also large ( Organic-inorganic composite particles obtained from Experimental Example No. 7-1 Median diameter: 7.9 μm).

  From the results of the above experimental examples 1 to 7, according to the method of the present invention, a cleaning effect equivalent to that obtained by polishing and cleaning the reaction vessel with a cleanser can be obtained. Therefore, the method of the present invention is also useful for industrial production for producing polyorganosiloxane particles and organic-inorganic composite particles on a large scale.

  According to the production method of the present invention, not only polyorganosiloxane particles and organic-inorganic composite particles having a desired particle size and a narrow particle size distribution can be obtained, but also the variation in particle size between production lots is low. Can be suppressed. Therefore, if the 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 in-plane spacers for liquid crystal display elements, seal spacers for liquid crystal display elements, spacers for EL display elements, spacers for touch panels, and various substrates such as ceramics and plastics. 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 (7)

A method for producing polyorganosiloxane particles by hydrolysis condensation reaction of an alkoxysilane compound,
Prior to the synthesis of the polyorganosiloxane particles, the reaction vessel is washed with an organic solvent, and then further washed with a mixed solvent of water / organic solvent.   The method for producing polyorganosiloxane particles according to claim 1, wherein the alkoxysilane compound is a compound having a polymerizable double bond.   The method for producing polyorganosiloxane particles according to claim 1 or 2, wherein the organic solvent contained in the mixed solvent is at least one selected from the group consisting of alcohols, ethers and ketones.   The method for producing polyorganosiloxane particles according to any one of claims 1 to 3, wherein the organic solvent contained in the mixed solvent is an alcohol.   The method for producing polyorganosiloxane particles according to any one of claims 1 to 4, wherein the organic solvent contained in the mixed solvent is methanol.   The method for producing polyorganosiloxane particles according to any one of claims 1 to 5, wherein the electric conductivity of water contained in the mixed solvent is 5 µS / cm or less. An absorption step of absorbing the radical polymerizable vinyl monomer component in the polyorganosiloxane particles obtained by the method according to claim 1; 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.