JPH02255837A - Particulate polyorganosiloxane and its production - Google Patents

Abstract

PURPOSE:To obtain the title particle which can be easily mixed or dispersed with various plastics by forming a polyorganosiloxane so that it may have a specified average compositional formula, a spherical particulate form and a specified mean particle diameter. CONSTITUTION:An organosilanol and/or its partial condensate obtained by partially or fully hydrolyzing an organoalkoxysilane mixture desirably containing 1mol of an organotrialkoxysilane of formula I (wherein R<1> is a hydrocarbon group; and R<2> is an alkyl) and 0.01-2mol of a diorganodialkoxysilane of formula II in the presence of an organic acid (e.g. acetic acid) is polycondensed in an aqueous alkali solution (e.g. ammonia water) or a mixture of an aqueous alkali solution with an organic solvent to obtain a dispersion of polyorganosiloxane particles, and these particles are separated and dried to obtain the title particles being spherical and having a mean particle diameter of 0.01-100mum and an average composional formula: RaSiOb (wherein R is a monovalent hydrocarbon group; 1<a<1.7; 1<b<1.5; and a+2b=4).

Description

Detailed Description of the Invention [Objective of the Invention] (Industrial Field of Application) The present invention relates to polyorganosiloxane fine particles2, more specifically, polyorganosiloxane fine particles having a small average particle size, a uniform composition, and a spherical shape. The present invention relates to polyorganosiloxane fine particles and a method for producing the same.

(Prior art) Fine particles with siloxane bonds include fumed silica,
Silicas such as precipitated silica and ground quartz are known. These fine particles have a thickening, thixotropic effect, and
It is used as an additive for the purpose of preventing pigment aggregation, reinforcing organic rubber, making liquids into fine particles, preventing film blocking, matting paint, preventing toner aggregation, and adjusting the amount of charge.

However, since these silica fine particles have an average composition formula of SiO□ and a true specific gravity (hereinafter abbreviated as specific gravity) of about 2.0, they tend to cause sedimentation and separation when used in dispersions, etc.
Due to its high hydrophilicity, it has poor compatibility with various plastics and is difficult to blend, and is unsuitable for applications that require water resistance.

For the purpose of improving compatibility and water resistance, JP-A-63-6062 discloses a method for producing hydrophobic fine particles, in which fine silica powder has hydrolyzable groups or halogen atoms at both ends. The method of treatment with polyorganosiloxane and organogylene compound is also disclosed in Japanese Patent Publication No. 57-5007.
No. 38 discloses that a silica filler is produced by mixing an alkyl silicate, water that completely hydrolyzes the alkoxy group of the alkyl silicate, an alcohol, and a hydrophobizing agent of an organosilicon compound in the presence of a basic catalyst. A method is disclosed. However, the fine particles obtained by these methods all have the surface of inorganic phosphor powder treated with a silicone compound. Therefore, there remains a drawback that the fine particles produced by such a manufacturing method have a large specific gravity. In addition, the production method described in Japanese Patent Publication No. 57-500738 is a complicated process in which a hydrophobizing agent for an organosilicon compound must be added and mixed before gelation occurs during hydrolysis of the alkyl silicate. However, there is a problem in that it is difficult to obtain fine particles with homogeneous particle components and stable characteristics.

On the other hand, as a method for obtaining rubber-like fine particles having hydrophobicity and a low specific gravity, JP-A-59-68333 discloses a method in which a curable polyorganosiloxane composition is ejected into hot air and cured. JP-A-62-2
43621 discloses a method of emulsifying an addition-type liquid rubber composition in water and then dispersing it in hot water of 25° C. or higher to harden it into granules. No. 17959 has the above-mentioned Japanese Patent Application Laid-open No. 17959.
JP-243621 discloses a method in which the constituent components of an addition-type liquid rubber composition are mixed at a low temperature of -60 to +5°C, and then sprayed into hot air and cured in the sprayed state.

However, with these methods, it is difficult to obtain fine particles with a uniform composition, a small average particle diameter on the order of microns, or fine particles with a uniform spherical particle shape. Therefore, it has the disadvantage that it is difficult to uniformly disperse it when blended into a glass stick, and it is not suitable for use as an additive to films or the like.

On the other hand, the present inventors created polystyrene particles with excellent free-flowing properties and uniform spherical shape by hydrolyzing and condensing methyltrialkoxysilane in an aqueous solution of ammonia or amine with 10 fine particles containing siloxane bonds. It was discovered that methylsilsesquioxane particles could be obtained (Japanese Unexamined Patent Publication No. 1983-1999)
13813, JP-A-63-77940, etc.).

However, the fine particles obtained by this method have a specific gravity of about 1.32.
Although the particle shape is uniform, it has poor elasticity, and when applied to delicate objects such as semiconductors, it may destroy the object to be sealed, or the particles themselves may not be able to deform due to external pressure. ,
Problems such as cracking may occur due to stress concentration. Further, it has not yet been possible to provide fine particles that have compatibility with various plastics, a refractive index adjuster #fi:, or a modifying function using a reactive group by introducing an organic group other than a methyl group.

(Problems to be Solved by the Invention) The present invention provides particles that have a small true specific gravity, a small average particle diameter, a spherical particle shape, hydrophobicity, and have a homogeneous composition that is difficult to break and incorporates various organic groups. It is an object of the present invention to provide polyorganosiloxane fine particles with uniform diameter and a method for producing the same.

[Structure of the Invention] (Means for Solving the Problems) In order to obtain such polyorganosiloxane fine particles, the present inventors further developed the method based on the manufacturing method described in JP-A No. 01-217039 proposed earlier. As a result of repeated studies, two types of alkoxysilanes were hydrolyzed in the presence of an organic acid to obtain two types of organosilanols and/or their hydrolyzed condensates, and these were subjected to a polycondensation reaction in an alkaline solution to form particles. The inventors have discovered that the desired polyorganosiloxane fine particles can be obtained by drying and then drying, and have completed the present invention.

That is, the present invention has an average compositional formula % formula % (wherein R represents a substituted or unsubstituted monovalent hydrocarbon group, and a and 1) are 1<a≦1, 7.1<b<1, respectively.
．． 5 and a+2b=4), and the average particle diameter is 0. O1~]0OII7+, and relates to polyorganic and nosiloxane fine particles having a spherical particle shape.

In the above average compositional formula, substituted or unsubstituted monovalent hydrocarbon groups include alkyl groups such as methyl, ethyl, propyl, phidel, hexyl, hebutyl, octyl, nonyl, decyl, and dodecyl; cycloargyl groups such as cyclohexyl; groups; aralgyl groups such as 2-phenylpropyl; aryl groups such as phenyl and tolyl; alkenyl groups such as vinyl and allyl; and chloromethyl, γ-chloropropyl, γ-methacryloxypropyl, γ-glycidoxy Brovyl, 3,4-epoxycyclohexylethyl, γ-mercaptopropyl, γ-aminopropyl, N
-(β-aminoethyl)-Tm aminopropyl, 3.3
．． Examples include substituted hydrocarbon groups such as 3-trifluoropropyl, and one type or two or more types of these may be bonded together.

In the average compositional formula, a and b are 1<a≦1.7.1<
This is a number that satisfies the relationship b<1.5 and a+2 +=4.

The polyorganosiloxane fine particles have an average particle diameter of 001
~100p+++, more preferably 0.01-2
6, which is 0F. The present invention also provides the following method: -Removal RaSiOb() (wherein, R1 represents a substituted or unsubstituted monovalent hydrocarbon group, and R2 represents a substituted or unsubstituted alkenyl group)
consisting of an organotrialkoxysilane represented by the formula RaSiOb() (wherein the meanings of R' and R2 are as described above), and a diorganodialkoxysilane represented by r,
A mixture of luganoalkoxysilanes containing 0.01 to 2 moles of diorganodialkoxysilane per 1-E of organotrialkoxysilane is partially or fully hydrolyzed in the presence of an organic acid, A step of obtaining an organosilanol and/or a partial condensate thereof; and carrying out a polycondensation reaction of the organosilanol and/or a partial condensate thereof in an aqueous alkali solution or a mixture of an aqueous alkali solution and an organic solvent. A second step of obtaining a desversion of polyorganosiloxane fine particles and water or a mixture of water and an organic solvent; and a third step of drying the polyorganosiloxane fine particles from the dispersion. This is a method for producing polyorganosiloxane fine particles obtained by.

Each step will be explained below.

The first step is to partially or completely hydrolyze the two types of organoalkoxysilanes represented by the above-mentioned removal allowances (I) and (II) in the presence of an organic acid to produce organosilanol and/or
or a step of obtaining a partial condensate thereof.

The substituted or unsubstituted monovalent hydrocarbon group for R' in the above-mentioned -replacement CI) and (II) is the same monovalent carbide group as that bonded to the silicon atom of the polyorganosiloxane fine particles as described above. A hydrogen group can be exemplified. Moreover, these groups are γ-glycidoxyprobyl group, 3.4-
In the case of epoxy ring-containing groups such as epoxycyclohexylethyl, some of the epoxy rings are opened by organic acids that are catalysts for hydrolysis reactions and alkalis that are catalysts for polycondensation reactions. When ammonia is used, a ring-opening reaction produces nitrogen-containing groups, which does not in any way detract from the purpose of the invention.

The substituted or unsubstituted alkyl group of R2 in the above-mentioned replacement allowances (I) and (IN) includes methyl, ethyl, propyl,
Examples include alkyl groups such as butyl, and substituted alkyl groups such as methoxyethyl, ethoxyethyl, and butoxyethyl.

Among these, methyl group and ethyl group are preferred from the viewpoint of reaction rate, and methyl group is particularly preferred.

As the organotrialkoxysilane represented by the above-mentioned allowance (I), methyltrimethoxysilane, methyltriethoxysilane, methyl]-liisobroboxysilane,
Methyltris(methoxyethoxy)silane, ethyltrimethoxysilane, vinyltrimethoxysilane, vinyltris(methoxyethoxy)silane, phenyltrimethoxysilane, γ-chloropropyltrimethoxysilane, γ
Examples include methacryloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, 3,4-epoxycyclohexylethyltrimethoxysilane, and γ-mercaptopropyltrimethoxysilane. However, there is no problem in using two or more types together.

The organodialkoxysilane represented by the formula (II) includes dimethyldimethoxysilane, dimethyljethoxysilane, diphenyldimethoxysilane, diphenyljethoxysilane, γ-chloropropylmethyldimethoxysilane, N-(β-aminoethyl)- Examples include γ-aminopropylmethyldimethoxysilane and γ-glycidoxypropylmethyldimethoxysilane, and these may be used alone or in combination of two or more.

The amount of the organoalkoxysilane represented by the -receiving amount (I) and (II) to be used is the amount of the -receiving amount (II) per mol of the organotrialcosine silane represented by the -receiving amount (1).
The diorganodialkoxysilane represented by O,03~
It is 2 moles. If the amount used exceeds 2 moles, it becomes difficult to obtain polyorganosiloxane fine particles with a homogeneous composition.

Further, if it is less than 0.01 mole, it is impossible to impart functionality or elasticity by introducing an organic group.

In the first step, the strain water splitting reaction, an organic acid serving as a catalyst is dissolved in excess water to form an aqueous solution.

The use of an organic acid as a catalyst in this way is advantageous in that the reaction rate is fast and that impurities such as ionic substances that limit the uses of the ultimately obtained polyorganosiloxane particles are not left behind, or even if they are left behind. It is excellent because it is a small amount. Examples of such organic acids include formic acid, acetic acid, propionic acid, monochloroacetic acid, oxalic acid, and citric acid. Formic acid and acetic acid are preferred because of their inhibition.

The amount of organic acid used varies depending on the type of silane and organic acid, but it is lXl0-'' per 100 parts by weight of water used when hydrolyzing Orga, Noalfoxysilane.
-1 part by weight is preferable, and 5 x 10''□S - 0.1 part by weight is more preferable.If it is less than 1 x 10-3 parts by weight, the reaction will not proceed sufficiently, and if it exceeds 1 part by weight. In this case, not only the concentration of acid groups in impurities remaining in the system increases, but also the produced organosilanol tends to condense.

The amount of water used in the hydrolysis reaction is preferably 2 to 10 moles per mole of organoalkoxysilane. If the amount of water is less than 2 moles, the hydrolysis reaction will not proceed sufficiently,
If the amount exceeds 10 moles, the partial condensate of organosilanol will separate and precipitate as a gel-like substance.

The temperature during hydrolysis is not particularly limited and may be carried out at room temperature or in a heated state, but in order to obtain organosilanol in a good yield, it is preferable to carry out the reaction at a temperature of 5 to 80°C.

The second step is a step of obtaining polyorganosilanol particles by polycondensation reaction from the organosilanol and/or its partial condensate obtained in the first step. This second
The reaction in the step is carried out in an aqueous alkali solution or a mixture of the aqueous alkali solution and an organic solvent.

The aqueous solution of the alkali is basic, and it acts as a neutralizing agent for the organic acid used in the first step and as a catalyst for the polycondensation reaction in the second step. Examples of such alkalis include metal hydroxides such as lithium hydroxide, sodium hydroxide, and potassium hydroxide; ammonia; and organic amines such as monomethylamine and dimethylamine. Among these,
Ammonia and organic amines are preferred because they do not leave trace amounts of impurities that would limit the uses of the polyorganosiloxane fine particles, and ammonia is particularly preferred because it has low toxicity and is easy to remove.

Alkali is used in the form of an aqueous solution because it is easy to handle and control reactions.

The amount of alkali used is the amount that neutralizes the organic acid and acts effectively as a catalyst for the polycondensation reaction. For example, when ammonia is used as the alkali, it is added to 100 parts by weight of water or a mixture of water and organic solvent. 0.05 part by weight or more is used.

In the second step, it is preferable to use an organic solvent together with an aqueous alkali solution in order to obtain fine particles with an average particle diameter of 0.5 μm or less and a specific surface area of 100 rn''/g or more.

Such organic solvents are preferably water-soluble, and include alcohols such as methanol, ethanol, n-propatool, impropatol, n-butanol, isobutanol, and diacetone alcohol; glycols such as ethylene glycol and propylene glycol; ethylene; Examples include glycol ethers such as glycol monoethyl ether; ketones such as acetone; and cyclic ethers such as tetrahydrofuran and dioxane; at least one selected from these may be used.

The polycondensation reaction in the second step is performed using an aqueous alkali solution or a mixture of this and an organic solvent (hereinafter referred to as "alkaline solution").
is charged into a reaction vessel, and then the aqueous solution of the organosilanol obtained in the first step or its partial condensate (hereinafter referred to as "silanol compound") or the aqueous solution of this silanol compound is added to the reaction vessel with water or the above-mentioned aqueous solution. A solution diluted with an organic solvent (hereinafter referred to as "silanol solution")
This is carried out by adding and bringing it into contact with the alkaline solution, and stirring or standing as necessary.

The method of adding the silanol solution is not particularly limited.

The rate of addition of the silanol solution is also not particularly limited, and, for example, the optimum rate of addition is determined by the type of silanol compound, the presence or absence of an organic solvent in the alkaline solution, and the type thereof.

For example, for the purpose of obtaining polyorganosiloxane fine particles with a small average particle size, when adding a silanol solution to an aqueous alkali solution, it is preferable to add the silanol solution to an aqueous alkali solution for 5 minutes or more, and more preferably for 10 to 240 minutes.

When adding the silanol solution to an alkaline solution containing an organic solvent, it is preferable to add the silanol solution within 5 minutes.

By carrying out the polycondensation reaction in this manner, polyorganosiloxane fine particles can be obtained as a gel-like dispersion having fluidity or thixotropy in water or a water/organic solvent mixture.

Although the polyorganosiloxane fine particles of the present invention can be used as they are after such dispersion, drying is further performed as a third step, where the specific surface area is LOOm.
When producing fine particles of ”/g or more,
In this third step, in addition to the drying process, it is necessary to perform a crushing process to loosen the aggregates of fine particles and separate the particles independently.

That is, if only drying treatment is performed in the third step, the particles can be obtained as aggregates, but if drying and crushing treatment is performed in the third step, the particles constituting the agglomerated and aggregated particles are separated. 12, each with independent microparticles.

This drying or crushing method is not particularly limited, but
In order to obtain a specific surface area of g/g or more or independent spherical fine particles, it is necessary to dry the fine particle powder obtained by drying the dispersion until the volatile content of the fine particle powder becomes 5% by weight or less. Pile drying and crushing are usually carried out using a micron dryer (trade name, manufactured by Hosokawa Micron) or a thermojet dryer (
Trademark names, ■Manufactured by Seishinki Corporation), etc. can be used.

The process conditions for the second and third steps described above are summarized in relation to the average particle diameter of the polyorganosiloxane fine particles as shown in the following table.

However, the above is an example of conditions summarized to explain the process in an easy-to-understand manner, and the method is not actually limited to the above method.

[Effects of the Invention] The polyorganosiloxane fine particles obtained by the present invention have a small average particle diameter of 0.01 to 100P and have a spherical particle shape, so they can be easily blended and dispersed into various plastics. It is. In addition, from the viewpoint of addition to plastics and dispersibility, it is more preferable that the average particle diameter is 0.01 to 20 pm.

According to the production method of the present invention, polyorganosiloxane fine particles containing various organic groups, which have been difficult to produce using conventional methods, can be obtained in good yield with the same composition as the raw material composition. Further, according to the manufacturing method of the present invention, a material having a specific surface area of 100 m'/g or more can be obtained.

The polyorganosiloxane fine particles obtained by the production method of the present invention are useful as fillers and additives for paints, plastics, rubber, paper, etc., and are particularly useful as slipperiness improvers for plastic films, fillers for transparent plastics, and reinforcements. It is suitable as an agent, and those into which an organic functional group has been introduced can be used for surface modification treatment of plastic molded articles.

(Examples) Hereinafter, the present invention will be explained in more detail with reference to Examples and Comparative Examples. In these examples, parts represent parts by weight.

Example 1 1. Water was added to a reaction vessel equipped with an earthworm thermometer, a reflux device, and a stirrer. ．．
836 parts were charged, and 1 part of acetic acid was added to make a homogeneous solution. While stirring this at 30°C, 2,040 parts of methyltrimethoxysilane and 360 parts of dimethyldimethoxysilane were added.
When a mixture of parts was added, the hydrolysis reaction proceeded,
The temperature rose to 60° C. in 60 minutes to obtain a transparent reaction solution.Next, stirring was continued for 10 hours and then clarified to obtain a silanol solution.

Add 1.5 L of water to a reaction vessel equipped with a thermometer, reflux and stirrer.
60 parts and 40 parts of a 28% ammonia aqueous solution were taken, and 400 parts of the silanol solution obtained in the first step was added dropwise over about 10 minutes while stirring the mixture at a temperature of 25°C. After the completion of the dropwise addition, 16 hours Continued stirring. Polymethylsiloxane fine particles precipitated during stirring, and the reaction solution turned into a milky white dispersion.

Step 11 The dispersion obtained in the second step was centrifuged to sediment the fine particles, then taken out and dried in a dryer at 200° C. for 24 hours to obtain 110 parts of white fine particles. This corresponds to 94.8% of the theoretical yield based on methyltrimethoxysilane.

Observation of the fine particles with an electron microscope revealed that most of the particles were spherical, with a maximum particle size of 2P and a minimum particle size of 075 μm, and an average particle size of 1.

When these fine particles were placed in a magnetic crucible and heated to 900° C. in air for thermal decomposition, the remaining amount was 87.0%.

This value is close to the theoretical amount of 87.4% that polymethylsiloxane undergoes oxidative thermal decomposition to form silicon dioxide. Further, as a result of X-ray analysis of this thermal decomposition product, it was confirmed that it was amorphous silica.7 It was also confirmed that the white fine particles obtained from this were polymethylsiloxane.

The characteristics of the polyorganosiloxane fine particles in the pressure plate were measured by the evaluation method described below.

Average particle size and shape: Measured and observed using an electron microscope.

Specific surface area: Based on the BET method.

Bulk specific gravity: Measured according to JISK-5101.

The above results are shown in Table 1.

Example 2 Polyorganosiloxane fine particles were obtained in the same manner as in Example 1, except that the second step was carried out as follows.

300 parts of methanol, 300 parts of water, and 15 parts of 28% ammonia aqueous solution were placed in a reaction vessel equipped with a thermometer, a reflux device, and a stirrer, and the temperature was set at 25°C.Next, while stirring, the reaction was carried out. 300 parts of the silanol solution obtained in the first step of Example was added over about 10 seconds. after that,
Stir for approximately 60 seconds. Next, after stopping stirring, the mixture was allowed to stand still for 24 hours. As a result, polyorganosiloxane fine particles were generated and precipitated. The precipitated fine particles were treated in the same manner as in the third step of Example 1,
Maximum particle size 15P, minimum particle size 5F.

Polyorganosiloxane fine particles having an average particle diameter of 81 JM were obtained. When these fine particles were observed under an electron microscope, most of the particles were spherical.

The above results are shown in Table 1.

Example 3 1 Soil process Water 2.025 parts, acetic acid 0.75 parts, methyl 1-dimethoxysilane 1.530 parts, dimethyldimethoxysilane 1.
A silanol solution was obtained in the same manner as in Example 1, except that 350 parts were used.

1 Main 2 300 parts of the silanol solution obtained in the first step, 600 parts of water,
Example 2 except that 15 parts of 28% ammonia aqueous solution was used.
Polyorganosiloxane fine particles were obtained in the same manner as above.

The same treatment as in the third step of Example 1 was carried out for the fine particles of 1-Uni Dwarf, and the maximum particle size was 5 μrrn, f! & Almost spherical polyorganosiloxane fine particles having a small particle diameter of 2 μm and an average particle diameter of 3 μm were obtained.

The above results are shown in Table 1.

Example 4 In the second step, 300 parts of the silanol solution obtained in the first step of Example 3 was used, and 450 parts of water was used instead of 600 parts of water.
The same treatment as in the second and third steps of Example 3 was performed except that a mixed solution of 150 parts of methanol and 150 parts of methanol was used.

As a result, the obtained polyorganosiloxane fine particles are
A large number of spherical particles of 4 to 8P were adhered and aggregated. Therefore, this aggregate was then crushed using a jet mill to obtain fine particles having an average particle size of 5P.

The above results are shown in Table 1.

Comparative Example 1 250 parts of the same alkoxysilane mixture as in Example 1,
They were directly added to a mixed solution of 1.725 parts of organic solvent-free water and 100 parts of a 28% ammonia aqueous solution in about 10 seconds in the same manner as in the second step of Example 3 without being hydrolyzed. Thereafter, when the mixture was stirred and left to stand in the same manner as in Example 2, an oily liquid was found floating on the surface. Additionally, there was a large lump of gel material at the bottom of the reaction vessel.

The above results are shown in Table 1.

Example 5 1 Earthwork amount Example 1 except that in the first step of Example 1, 660 parts of γ-glycidoxypropylmethyldimethoxysilane was used instead of 360 parts of dimethyldimethoxysilane.
A silanol solution was obtained in the same manner as above.

1. 5.400 parts of methanol and 90 parts of 28% ammonia aqueous solution were placed in a reaction vessel equipped with only a stirrer.
Add 2.700 parts of the silanol solution obtained in the step,
The mixture was stirred for about S minutes to ensure uniformity. After stopping the stirring, the mixture was kept stationary to allow the reaction to proceed. After the stirring was stopped, the mixed solution gradually thickened, and after about 3 hours it turned into a gel-like dispersion that had no fluidity but had thixotropy.

While drying the disversion obtained in the 11th construction hill second step using a thermojet dryer in hot air at 150°C,
Disintegrated.

By performing the above first to third steps, the specific surface area was 450 and 7 g, the bulk specific gravity was 35 g/β, 150 ° C., 6
Polyorganosiloxane fine particles having a volatile content of 2% or less after drying for 0 minutes were obtained.

The above results are shown in Table 1.

Example 6 N-(β-aminoethyl)-γ instead of 45 parts of the 90 parts of 28% ammonia aqueous solution in the second step of Example 5.
The treatment was carried out in the same manner as in Example 5, except that 45 parts of -aminopropylmethyldimethoxysilane was used. The obtained polyorganosiloxane fine particles have a specific surface area of 550111
''/g, and the bulk specific gravity was 300 g/42.

The above results are shown in Table 1.

Example 7 A silanol solution was prepared in the same manner as in Example 1, except that 360 parts of dimethyldimethoxysilane was replaced with 120 parts and 1,836 parts of water was replaced with 1,692 parts.

The second and third steps were carried out in the same manner as in Example 5 to obtain "C" polyorganosiloxane fine particles.

The obtained spherical polyorganosiloxane fine particles had a maximum particle size of 0.06p, an R small particle size of 0203p, an average particle size of 0.04μm, and a specific surface area of 450 m''7g.

The above results are shown in Table 1.

Example 8 1836 parts of methyltrimethoxysilane, 222 parts of vinyltrimethoxysilane, 360 parts of dimethyldimethoxysilane
Polyorganosiloxane fine particles were obtained in the same manner as in Example 1, except that 1.5% was used.

The obtained fine particles were subjected to the same treatment as in the third step of Example 1 to obtain almost spherical polyorganosiloxane having a maximum particle size of 1.5P, a minimum particle size of 0.5P, and an average particle size of 0.8P. Fine particles were obtained.

The above results are shown in Table 1.

Example 9 1836 parts of methyltrimethoxysilane, 298 parts of phenyltrimethoxysilane, 36 parts of dimethyldimethoxysilane
Polyorganosiloxane was prepared in the same manner as in Example 2, except that in the second step, 600 parts of water was used instead of 300 parts of methanol and 300 parts of water. Fine particles were obtained. The obtained fine particles were subjected to the same treatment as in the third step of Example 1, and the maximum particle size was 5F,
Spherical polyorganosiloxane fine particles having a minimum particle diameter of 0.8 P and an average particle diameter of 2 pm were obtained.

The above results are shown in Table 1.

Example 10 A nranol solution was obtained in the same manner as in the first step of Example 1, except that 2064 parts of hexyltrimethoxysilane, 240 parts of dimethyldimethoxysilane, and 2 parts of acetic acid were used.

In the second and third steps, polyorganosiloxane fine particles were obtained by the same operation as in Example 4.6 The obtained polyorganosiloxane fine particles had a maximum particle size of 5P, a minimum particle size of 0.4P, and an average particle size of The diameter was 1.2P.

The above results are shown in Table 1.

Comparative Example 2 100 parts of dimethylpolysiloxane having vinyl groups at both ends, represented by the average compositional formula RaSiOb (2 (where rn=100), and 2 parts of methylhydrodiene polysiloxane represented by the average compositional formula, %). and iopp as platinum based on the total amount of polysiloxane.
A mixture of an isopropyl alcohol solution of chloroplatinic acid with a weight equivalent to 0.0 m and 0.1 part of 3-methyl-1-butyne-3-salt was mixed and rotated in a spray dryer with a diameter of 2 m and a height of 4 m. When the mixture was sprayed using a nozzle and cured, a cured powder was obtained at a rate of 50 kg/hour.

Note that the inlet temperature of the hot air of the spray dryer was 230°C. The cured material was collected using Zyclone, but observation using a scanning electron microscope showed that the size of each particle was 2 to 30 mm in diameter.
It was a spherical rubber of P. This spherical rubber powder has a diameter of 31 mm.
It formed a lump of less than tlIll.

Application example 1 Polymethylsiloxane fine powder obtained in Example 1 0.5
and 99.5 parts of polypropylene powder (melting point 162'C) were mixed in a Henschel mixer and extruded and granulated at 250°C in a twin-screw extruder to obtain a depth of a composition to which the fine powder of the present invention was added. .

Chips of the above composition were coextruded at 250°C using a two-layer mold, maintained at 40°C, and solidified by cooling to obtain a two-layer film. Next, this film was heated to 140°C, stretched 5 times in the longitudinal direction, and immediately cooled to 40°C. Next, this film was introduced into a thermometer maintained at 160° C. and stretched 8 times in the width direction. The thickness of the entire film after stretching was 20F, and the layer thickness of the ethylene-propylene random copolymer was 3-F.

The obtained film was transparent, and exhibited extremely good slipperiness when rubbed together. Even if the films are rubbed together many times, the film surface will not turn white.

Transparency was maintained.

Comparative Application Example 1 A film was prepared in the same manner as Application Example 1, except that the fine powder obtained in Comparative Example 2 was used instead of the fine powder obtained in Example 1.

When the obtained films were rubbed together, the slipperiness was small, and when the number of times of rubbing was increased, the film surface turned white. When the whitened film surface was observed using a scanning electron microscope, it was found that the fine powder obtained in Comparative Example 2 had been detached from the film.

Claims (2)

[Claims] (1) Average compositional formula RaSiOb (wherein R represents a substituted or unsubstituted monovalent hydrocarbon group, a and b are 1<a≦1.7, 1<b<1.5 and a+2b=, respectively. Polyorganosiloxane fine particles having an average particle diameter of 0.01 to 100 μm and having a spherical shape. (2) General formula R^1Si(OR^2)_3(I) (wherein, R^1 represents a substituted or unsubstituted monovalent hydrocarbon group, and R^2 represents a substituted or unsubstituted alkyl group. Organotrialkoxysilane represented by the following formula: Consisting of dialkoxysilane,
An organosilanol is obtained by partially or completely hydrolyzing an organoalkoxysilane mixture containing 0.01 to 2 moles of diorganodialkoxysilane per mole of organotrialkoxysilane in the presence of an organic acid. and/or a first step of obtaining a partial condensate thereof; a polycondensation reaction of the organosilanol and/or a partial condensate thereof in an aqueous alkali solution or a mixture of an aqueous alkali solution and an organic solvent to produce fine polyorganosiloxane particles; and a second step of obtaining a dispersion of water or a mixed solution of water and an organic solvent, and a third step of drying the polyorganosiloxane fine particles from the dispersion. A method for producing polyorganosiloxane fine particles.