JP3452562B1 - Method for producing spherical polyorganosilsesquioxane fine particles - Google Patents

Abstract

Abstract: PROBLEM TO BE SOLVED: To produce spherical polyorganosilsesquioxane fine particles by hydrolyzing and condensing an organotrialkoxysilane and / or a partial hydrolyzate thereof in a reaction solution, in the past, the particles are likely to aggregate. To produce monodispersed spherical fine particles even under reaction conditions where monodispersed spherical fine particles cannot be produced. SOLUTION: When adding an organotrialkoxysilane and / or a partial hydrolyzate thereof to a reaction solution, a polymer dispersant exemplified as polyvinyl alcohol was present in the reaction solution.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing spherical polyorganosilsesquioxane fine particles, particularly 0.5 to 20.
The present invention relates to a novel production method for efficiently producing monodisperse spherical polyorganosilsesquioxane fine particles having a particle diameter of μm (micrometer) by a simple production method.

[0002]

2. Description of the Related Art As a method of obtaining spherical polyorganosilsesquioxane fine particles, a method of hydrolyzing an organotrialkoxysilane and then condensing the same has been conventionally used. And as such a thing, JP-A-63-7
There is a Japanese Patent No. 7940 publication, which discloses that methyltrialkoxysilane and / or its hydrolyzate or a mixture of methyltrialkoxysilane and / or its hydrolyzate and an organic solvent is used as an upper layer, and ammonia and / or Or use a mixture of amine and organic solvent as the lower layer,
A method of hydrolyzing and polycondensing methyltrialkoxysilane and / or its hydrolyzate at these interfaces to obtain spherical polymethylsilsesquioxane fine particles having a spherical shape is disclosed. In addition, JP-A-6-
No. 248081 discloses that methyltrialkoxysilane and / or a hydrolyzate thereof are stirred and mixed to form a uniform solution, and then alkali is added to allow hydrolysis / condensation to proceed. / Or the amount of chlorine contained in the hydrolysis-condensation product is 10 ppm or less, and the specific conductivity of the water is 30 µS /
cm (microsiemens per centimeter) or less, the average particle diameter is 0.1 to 20μ.
A method for obtaining spherical particles of m is disclosed.

[0003]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention JP-A-63-77
In the method according to Japanese Patent Publication No. 940, since the reaction takes place at the interface, there are problems that the chance of contact with alkali is small, the reaction rate is extremely limited, and the process control is complicated. Further, the method according to the above-mentioned JP-A-6-248081 has a problem that it is necessary to adjust the amount of chlorine contained in methyltrialkoxysilane and / or its hydrolysis-condensation product and the specific conductivity of water. Has been done. Further, in general, an organotrialkoxysilane and / or a partial hydrolyzate thereof is hydrolyzed.
When the polyorganosilsesquioxane fine particles are condensed to obtain fine particles of the polyorganosilsesquioxane, the particles are apt to aggregate due to the influence of chlorine, impurities and by-produced salts in the raw materials, and therefore the reaction conditions are limited. Furthermore, in these conventional methods, when the addition amount of the organotrialkoxysilane and / or its partial hydrolyzate is 0.2 parts by weight or more relative to 1 part by weight of the reaction solution, the particles are agglomerated with each other and cannot be obtained as dispersed particles. Therefore, the production amount per unit volume was low.

[0004]

An object of the present invention is to provide a method for producing spherical polyorganosilsesquioxane fine particles which has solved the above disadvantages and disadvantages of the prior art. In producing spherical polyorganosilsesquioxane fine particles by hydrolyzing and condensing an organotrialkoxysilane and / or a partial hydrolyzate thereof , a protective colloid is prepared in an acidic aqueous solution in a solvent.
In the presence of a polymeric dispersant and salt
Ganotrialkoxysilane and / or its partial hydrolysis
After adding hydrolyzate to obtain hydrolyzed partial condensate,
To promote the condensation reaction under alkaline conditions.
Manufactured Kompei sugar-like particles with protrusions on the surface of more spherical particles
A method for producing spherical polyorganosilsesquioxane fine particles, which is characterized in that it is manufactured. According to the invention of claim 2, in claim 1, the salt added to the acidic aqueous solution is an ammonium salt.
A method for producing spherical polyorganosilsesquioxane fine particles, which is characterized by being a sodium salt .

Here, when the organotrialkoxysilane and / or its partial hydrolyzate is added to the reaction solution for hydrolysis / condensation, a polymer dispersant is added to the reaction solution. A method for producing spherical polyorganosilsesquioxane fine particles, which has excellent dispersibility even under reaction conditions in which monodisperse particles cannot be synthesized under conventional synthesis conditions due to the protective colloid effect of the polymer dispersant. It was found that spherical polyorganosilsesquioxane fine particles can be efficiently produced by a simple method. In this, the polymer dispersant is added to the reaction initial solution in advance by adding organotrialkoxysilane and / or partial hydrolyzate thereof together with organotrialkoxysilane and / or partial hydrolyzate thereof. Ru is selected from those added after hydrolyzing partial condensate. Then, in these, after obtaining a hydrolysis partial condensation reaction product of organotrialkoxysilane and / or its partial hydrolysis product in the state where a salt is present in the reaction solution, it is possible to proceed the condensation reaction under alkaline conditions. Ru Monodea characterized.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention relates to a synthetic method as conventionally known, for example, organotrialkoxysilane and / or
Or add the partial hydrolyzate to the alkaline aqueous solution,
Method for obtaining particles by hydrolysis / condensation, or hydrolysis / condensation of organotrialkoxysilane and / or its partial hydrolyzate by adding organotrialkoxysilane and / or its partial hydrolyzate to water or an acidic solution After obtaining the product, a method of obtaining a particle by adding an alkali to proceed a condensation reaction, an organotrialkoxysilane and / or a hydrolyzate thereof is used as an upper layer, and an alkali or a mixed solution of an alkali and an organic solvent is used as a lower layer. In any method, such as a method of hydrolyzing and polycondensing the organotrialkoxysilane and / or its hydrolyzate at the interface of to obtain particles, by adding a polymer dispersant to the reaction solution, The chlorine concentration in trialkoxysilane and / or its partial hydrolysates, impurities in water, etc. Not only not observed aggregation by Symphony, the addition ratio of the starting materials for the reaction volume 1 part by weight 0.
Even under a high particle concentration, which is less than 5 parts by weight, which has never been seen before, the particles hardly aggregated, which made it possible to dramatically improve the production amount per unit volume.

Further, by adding a polymer dispersant, the particles synthesized in an alkaline aqueous solution are made into core particles, and an acid is added to the reaction solution to make it acidic, and then organotrialkoxysilane and / or a portion thereof is added. After adding a hydrolyzate to form a hydrolyzed partial condensate of the organotrialkoxysilane and / or its partial hydrolyzate, an alkali is further added to the reaction solution to make the reaction solution alkaline again. It is also possible to grow the core particles by advancing the condensation reaction of the hydrolyzed partial condensate. Then , various salts are added and dissolved in the reaction solution containing the polymer dispersant, and the hydrolysis / condensation reaction of the organotrialkoxysilane and / or its partial hydrolyzate proceeds in the solution to obtain spherical particles. It is also possible to produce so-called Kompei sugar particles having protrusions on the particle surface. Thus, by using a polymer dispersant, it becomes possible to suppress the aggregation of particles,
Since the reaction conditions can be set in a wide range, its application range is wide.

The organotrialkoxysilane which is a raw material used in the present invention is represented by the general formula R ¹ Si (OR ² ) ₃ . In the general formula, R ¹ is a linear or branched alkyl group having 1 to 6 carbon atoms such as a methyl group, an ethyl group, a propyl group, a butyl group, a phenyl group, an amino group, an epoxy group or a vinyl group. Is a monovalent organic group having at least one of R ¹ and R ² has the same carbon number of 1 to R ¹ .
6 is a linear or branched alkyl group.

[0009] More specifically, examples of the organotrialkoxysilane, methyltrimethoxysilane, methyltriethoxysilane, methyl tri -n- Propo Kishishiran, methyltri -i- Propo Kishishiran, methyltri -
n-butoxysilane, methyltri-i-butoxysilane, methyltri-s-butoxysilane, methyltri-t
-Butoxysilane, ethyltrimethoxysilane, n-propyltrimethoxysilane, i-propyltrimethoxysilane, n-butyltributoxysilane, i-butyltributoxysilane, s-butyltrimethoxysilane, t
-Butyltributoxysilane, N-β (aminoethyl)
Examples are γ-aminopropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, vinyltrimethoxysilane, phenyltrimethoxysilane and the like.

The partial hydrolyzate of organotrialkoxysilane is a product obtained by hydrolyzing and condensing the alkoxy group of the organotrialkoxysilane, and is a water or aqueous solution necessary for hydrolyzing the organotrialkoxysilane. Is contained in a stoichiometric amount or less, and is itself liquid and soluble in organotrialkoxysilane, water, an organic solvent, or a mixed solution thereof. Further, the amount of chlorine contained in the organotrialkoxysilane and / or its partial hydrolyzate is not particularly limited, and it is also possible to use an organotrialkoxysilane having a very high chlorine amount obtained by mixing the organotrichlorosilane and alcohol. Not only
It can also be used for organotrichlorosilane, which has hitherto been difficult to synthesize monodisperse spherical particles. These organotrialkoxysilanes and / or their hydrolyzates may be used alone or in combination.

The polymer dispersant used in the present invention is a water-soluble polymer, and any synthetic polymer or natural polymer can be used as long as it acts as a protective colloid in a solvent. Examples thereof include polyvinyl alcohol and polyvinylpyrrolidone. As a method of adding the polymer dispersant, a method of previously adding to the reaction initial liquid,
Examples thereof include a method of adding the organotrialkoxysilane and / or its partial hydrolyzate at the same time, and a method of adding the organotrialkoxysilane and / or its partial hydrolyzate after the hydrolysis and partial condensation, and any of these methods You can also choose. The addition amount of the polymer dispersant is 5 × 10 ^{−7 to} 0.
The range of 05 parts by weight (5 × 10 ^{−5 to} 5% by weight) is preferable, and if it is out of this range, aggregation of particles tends to occur.

The reaction initial solution used in the present invention has a pH of
Is 0.5 to 13, and the pH of the reaction initial liquid is adjusted by using an alkali, an acid or a salt. Examples of the alkali type for adjusting the pH of the reaction initial solution and the reaction solution used in the present invention are generally hydroxides, oxides, carbonates and organic nitrogen compounds of the metals of Group Ia and Group IIa, ammonia, etc. Is used, but an aqueous ammonia solution is particularly preferable because it is easily removed after the reaction. As the type of acid, either an inorganic acid or an organic acid can be used, and examples of the inorganic acid include hydrochloric acid and sulfuric acid.
Examples of organic acids include formic acid, acetic acid, oxalic acid, citric acid and the like. The type of salt may be either an acidic salt or an alkaline salt, and specific examples thereof include sodium carbonate and ammonium acetate. These may be used alone or in combination of two or more, and may be used even if they contain a water-soluble organic solvent such as alcohols, ketones and ethers.

Regarding the reaction initial solution having a pH of 0.5 to 7.5, organotrialkoxysilane and / or a partial hydrolyzate thereof is added to the reaction initial solution,
After obtaining the hydrolyzed partial condensate of the organotrialkoxysilane and / or its partial hydrolyzate, an alkali may be added to the reaction solution to bring the pH of the reaction solution to 7.6 to 13 to allow the condensation reaction to proceed. is necessary. At this time, the particle size can be controlled by the pH of the reaction solution.
When H is set low, relatively large particles are obtained. After the addition of alkali, 30
Spherical polyorganosilsesquioxane fine particles can be obtained by performing aging for 10 minutes to 10 hours, preferably 30 minutes to 5 hours under weak stirring or standing. When organotrialkoxysilane or a mixture of organotrichlorosilane and alcohol with a very high chlorine content is used as a raw material, the pH of the organotrialkoxysilane drops as a by-product of hydrochloric acid, and if it goes out of the proper range, the viscosity will decrease. Therefore, it is necessary to adjust the pH so that it falls within an appropriate range by simultaneously adding an alkali.

The pH of the initial reaction solution is 7.6-13.
In addition, when the organotrialkoxysilane and / or its partial hydrolyzate is added to allow hydrolysis / condensation to proceed, the pH of the reaction solution becomes 7.6 to 13 even during the reaction. It is preferable to adjust so that. At this time, the particle size can be controlled by the pH of the reaction solution, and relatively large particles can be obtained by setting the pH low. The addition rate of the organotrialkoxysilane and / or its partial hydrolyzate is preferably such that the initial liquid aqueous solution and the raw material do not separate into two layers. Organotrialkoxysilane and /
Alternatively, after completion of addition of the partial hydrolyzate, spherical polyorganosyl can be obtained by aging for 30 minutes to 10 hours, preferably 30 minutes to 5 hours under weak agitation or standing for the purpose of completing the condensation reaction. Sesquioxane fine particles can be obtained. Furthermore, after adding organotrialkoxysilane and / or its partial hydrolyzate to the initial liquid of the reaction to promote hydrolysis / condensation to precipitate particles, an acid is added to the reaction solution to improve the reaction liquidity. After acidifying and further adding organotrialkoxysilane and / or its partial hydrolyzate to form its hydrolyzed partial condensate, add alkali to make the reaction liquid alkaline again,
By allowing the condensation reaction to proceed, the particles that have been previously deposited become core particles, and the particles can be grown. This production method is effective for producing relatively large particles having a particle size of 10 μm or more, and the particle size can be controlled by the core particle size and the addition amount of the organotrialkoxysilane and / or its partial hydrolyzate added in the acidic liquid state. Can be controlled.

In these synthesis methods, after obtaining a hydrolysis partial condensation reaction product of organotrialkoxysilane and / or a partial hydrolysis product thereof in a reaction solution in which a salt is present, the condensation reaction is allowed to proceed to obtain particles. 0.1μ on the surface
It is possible to synthesize Kompei sugar-like particles having protrusions of about m to 3 μm. In order to allow the salt to exist in the reaction solution, the salt may be added directly to the reaction solution, but the reaction solution is made alkaline and an acid is added to the reaction solution (or vice versa) to form the salt. You may do it.
The salt may be any of organic salts, acidic salts containing inorganic, neutral salts, and alkaline salts, specifically, ammonium acetate,
Examples are ammonium chloride and sodium chloride.

The amount of the organotrialkoxysilane and / or its partial hydrolyzate added in the present invention is 0.5 part by weight of the organotrialkoxysilane and / or its partial hydrolyzate per 1 part by weight of the reaction solution. It is preferable that the amount is less than a part, and if the particle concentration is higher than this, aggregation of particles increases. While controlling the particle concentration by simultaneously adding the solvent to the raw material so that the organotrialkoxysilane and / or its partial hydrolyzate is less than 0.5 part by weight per 1 part by weight of the reaction liquid, It is also possible to generate particles.

The stirring in the present invention does not need to be particularly vigorous, and it is preferable that the stirring is such that the liquids are usually mixed. The temperature of the reaction solution in the present invention can be selected from the range of 0 ° C., which is the freezing point of water, to 100 ° C., which is the boiling point of water at atmospheric pressure, and can also be set to 100 ° C. or higher under pressure. However, preferably from 15 ° C
It is 80 ° C.

The spherical polyorganosilsesquioxane fine particles produced in this manner are then filtered and separated, washed with water or washed with an organic solvent, dried and, if necessary, crushed to obtain fine particles.

[0019]

EXAMPLES Hereinafter, the method of the present invention will be described with reference to experimental examples , reference examples, and comparisons.
Examples will be described, but it goes without saying that the present invention is not limited to these examples.

Reference Example 1 A 500 ml (ml) reaction vessel was equipped with a stirrer and a thermometer, and 320 ml of an aqueous solution having a hydrochloric acid concentration of 0.125% by weight was placed in the reaction vessel. A reaction initial solution was prepared by mixing and dissolving the saponification type and the degree of polymerization of 500) to 0.025% by weight. The pH of this reaction initial solution is 1.5, and the conductivity is 1.
It was 4 S / cm. The reaction initial solution was stirred at 200 rpm (rotation per minute), the reaction vessel was thermostatted at 20 ° C., and then 64 g of methyltrimethoxysilane was added with a metering pump at a supply rate of 10 g / min (g / min). ,
A hydrolytic partial condensation solution of the methyltrimethoxysilane was obtained. Next, this was stirred for 10 minutes, then 2% by weight of aqueous ammonia was rapidly added dropwise, and the addition was stopped when the pH reached 8.5. After mixing and stirring for 1 minute, the number of stirring was set to 50 rpm and aging was carried out for 1 hour, followed by filtration, washing with water,
Drying was performed to obtain white particles. The particles were polymethylsilsesquioxane particles. As a result of observing the obtained particles with an electron microscope, they are monodisperse spherical fine particles having an average particle diameter of 5 μm, and the coefficient of variation (CV value (%) = (standard deviation of particle diameter / average particle diameter) × 100, the same applies hereinafter) Was 4.9% (see the electron micrograph of FIG. 1).

Reference Example 2 Polyvinyl alcohol (completely saponified type, polymerization degree 500)
Polymethylsilsesquioxane particles were synthesized by the same method as in Reference Example 1 except that the addition amount of was changed to 0.004% by weight. As a result of observing the obtained particles with an electron microscope,
The particles were monodisperse spherical particles having an average particle diameter of 6.3 μm and a coefficient of variation of 12%.

Reference Example 3 The polymer dispersant was polyvinylpyrrolidone (polymerization degree: 4000).
Polymethylsilsesquioxane particles were synthesized by the same method as in Reference Example 1, except that the particle size was changed to 0). As a result of observing the obtained particles with an electron microscope, an average particle diameter of 4.3 μm,
The particles were monodisperse spherical particles having a coefficient of variation of 5.2%.

Reference Example 4 A 500 ml reaction vessel was equipped with a stirrer and a thermometer, and 320 ml of an aqueous solution having an acetic acid concentration of 0.3% by weight was placed in the reaction vessel to prepare a reaction initial solution. While stirring the reaction initial solution at 200 rpm, the reaction solution was thermostatted at 20 ° C., and then 10 g / mi of 96 g of methyltrimethoxysilane was fed with a metering pump.
It was added at a feeding rate of n to obtain a hydrolyzed partial condensation solution of the methyltrimethoxysilane. After adding and mixing 25 g of a 2 wt% polyvinyl alcohol aqueous solution (completely saponified type, polymerization degree 500) as a polymer dispersant, 2 wt%
The ammonia water of was rapidly added dropwise, and when the pH reached 10, the addition was stopped. After mixing and stirring for 1 minute, the stirring was stopped, the mixture was aged at room temperature for 1 hour, and then filtered.
It was washed with water and dried to obtain white crystals. The crystals were polymethylsilsesquioxane particles. As a result of observing the obtained particles with an electron microscope, the average particle diameter was 2.1 μm.
It was a monodisperse spherical fine particle.

Reference Example 5 A 500 ml reaction vessel was equipped with a stirrer and a thermometer, and 320 ml of an aqueous solution having an ammonia concentration of 0.5% by weight was placed in the reaction vessel.
The reaction initial solution containing was added. 200r of this reaction solution
After stirring the reaction solution at 20 ° C. with stirring at pm, 10 g of 96 g of methyltrimethoxysilane was measured with a metering pump.
At the same time as adding at a feeding rate of 1 / min, a 1% by weight aqueous solution of polyvinyl alcohol (completely saponified type, polymerization degree 50
0) was added simultaneously at a feed rate of 5 g / min. Five minutes after the start of addition, the reaction solution began to become cloudy and particles were precipitated. After stopping the addition of the polyvinyl alcohol aqueous solution at the same time as the completion of the methyltrimethoxysilane addition, the stirring number was changed to 5
The mixture was aged at 0 rpm for 1 hour, then filtered, washed with water, and dried to obtain white crystals. The crystals were polymethylsilsesquioxane particles. As a result of observing the obtained particles with an electron microscope, they were monodisperse spherical fine particles having an average particle diameter of 1.2 μm.

[Experimental Example 1 ] A 500 ml reaction vessel was equipped with a stirrer and a thermometer, and 320 ml of an aqueous solution having an ammonium acetate concentration of 0.125% by weight and acetic acid of 0.05% by weight was placed in the reaction vessel. As polyvinyl alcohol (completely saponified type,
A reaction initial solution prepared by mixing and dissolving 0.025% by weight of a polymerization degree of 1000) was prepared, and polymethylsilsesquioxane particles were obtained by the same method as in Reference Example 1. As a result of observing the obtained particles with an electron microscope, the particles were monodisperse spherical fine particles having an average particle diameter of 5.6 μm, and were sugar particles of Kompei having protrusions of about 0.5 to 1 μm on the particle surface.

[Experimental Example 2 ] A 500 ml reaction vessel was equipped with a stirrer and a thermometer, and an aqueous solution 320 having an ammonia concentration of 0.025% by weight was attached to the reaction vessel.
ml was added, and polyvinyl alcohol (completely saponified type, polymerization degree 500) was mixed and dissolved so as to be 0.025% by weight to prepare a reaction initial solution. 200r of the reaction initial liquid
After stirring the reaction vessel at a constant temperature of 20 ° C. while stirring at pm, 8.0 g of methyltrimethoxysilane was adjusted to 10 by a metering pump.
It was added at a feed rate of g / min. Approximately 10 minutes after the addition was completed, white turbidity began and particles were deposited. Then, after mixing and stirring for 10 minutes, 8 g of a 5 wt% hydrochloric acid solution was added to make the reaction liquid acidic, and 88 g of methyltrimethoxysilane was further added.
Was added at a supply rate of 10 g / min to obtain a hydrolyzed partial condensation solution of the methyltrimethoxysilane. Next, this was stirred for 10 minutes, then 2% by weight of aqueous ammonia was rapidly added dropwise, and the addition was stopped when the pH reached 8.5. After mixing and stirring for 1 minute, stop stirring and
The mixture was aged for 1 hour under standing, filtered, washed with water and dried to obtain white particles. The particles were polymethylsilsesquioxane particles. As a result of observing the obtained particles with an electron microscope, they were monodisperse spherical fine particles having an average particle diameter of 10 μm. In addition, the surface of the obtained particles was sugar-like particles having a protrusion size of about 0.5 μm (see the electron micrograph of FIG. 2).

Reference Example 6 After the initial solution was prepared in the same manner as in Reference Example 1, 128 g of methyltrimethoxysilane was added at a supply rate of 10 g / min to give a partial hydrolyzed condensation solution of methyltrimethoxysilane. Got Next, this was stirred for 10 minutes, then 2% by weight of aqueous ammonia was rapidly added dropwise, and the addition was stopped when the pH reached 8.5. After mixing and stirring for 1 minute, the stirring was stopped, the mixture was aged at room temperature for 1 hour, and the mixture was filtered, washed with water, and dried to obtain white particles. This particle is
The particles were polymethylsilsesquioxane particles. As a result of observing the obtained particles with an electron microscope, the average particle diameter was 6.5 μm.
The particles were m monodisperse spherical particles, and even at this particle concentration, particles were hardly aggregated with each other and had high dispersibility.

Reference Example 7 To 64 g of trichlorosilane, 40 g of methanol was added and mixed to prepare a raw material liquid. The initial reaction solution was prepared in the same manner as in Reference Example 1, and the raw material solution was added thereto at a supply rate of 10 g / min, and 25% by weight ammonia water was simultaneously added so that the pH became 1. After the raw materials are added, ammonia water is added to adjust the pH to 8, stirring is stopped, and 1
The mixture was aged for a time, filtered, washed with water and dried to obtain white particles. The particles were polymethylsilsesquioxane particles. As a result of observing the obtained particles with an electron microscope, it was found that the particles were monodisperse spherical fine particles having an average particle diameter of 4.2 μm. Had sex.

Comparative Example Polymethylsilsesquioxane particles were synthesized in the same manner as in Reference Example 1 except that the polymer dispersant was not added.
The composition was an elastic gel. As a result of observing the obtained particles with an electron microscope, the particles were strongly aggregated with each other and could not be obtained as monodisperse particles (see the electron microscope photograph of FIG. 3).

[0030]

According to the method of the present invention, according to the present invention, the conventional can also be suppressed aggregation of particles in the reaction conditions can not be synthesized, in a very simple method, Konpei sugar-like
It is possible to produce spherical polyorganosilsesquioxane particles was.

[Brief description of drawings]

FIG. 1 is an electron micrograph of polymethylsilsesquioxane particles synthesized in Reference Example 1.

FIG. 2 is an electron micrograph showing polymethylsilsesquioxane particles synthesized in Experimental Example 2 .

FIG. 3 is an electron micrograph of polymethylsilsesquioxane particles synthesized in Comparative Example.

Continuation of the front page (56) Reference JP-A-11-92560 (JP, A) JP-A-2002-38049 (JP, A) JP-A-11-286551 (JP, A) JP-A-4-33927 (JP, A) JP 64-69508 (JP, A) JP 4-240110 (JP, A) JP 2000-169583 (JP, A) JP 11-152336 (JP, A) JP 9- 208644 (JP, A) JP 2002-80598 (JP, A) JP 2002-47348 (JP, A) US Patent 3354095 (US, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08G 77/00-77/62 C01B 33/00-33/193 CA (STN) REGISTRY (STN)

Claims (2)

(57) [Claims] 1. An organotrialkoxysilane and / or
Or, when it hydrolyzes and condenses a partial hydrolyzate to produce spherical polyorganosilsesquioxane fine particles, it acts as a protective colloid in a solvent in an acidic aqueous solution.
Organotrix in the presence of a polymeric dispersant and salt
Alkoxysilane and / or its partial hydrolyzate
After obtaining the hydrolyzed partial condensate, add alkali.
Spherical by advancing the condensation reaction under alkaline conditions
Method for producing a spherical polyorganosilsesquioxane particles, wherein the this <br/> to produce a Konpei sugar particles having protrusions on the particle surface. 2. The method according to claim 1, wherein the acidic aqueous solution is added.
The method for producing spherical polyorganosilsesquioxane fine particles, wherein the salt used is an ammonium salt .