KR101475492B1 - Polyalkylsilsesquioxane particulates and a preparation method thereof - Google Patents

Abstract

More particularly, the present invention relates to a process for producing polyalkylsilsesquioxane fine particles, which comprises adding an acid catalyst to an aqueous medium to prepare an acidic homogeneous aqueous solution and then adding an alkyltrialkoxysilane to hydrolysis Stage reaction in which an alkoxytrialkylsilane group containing a triorganosilyl group is added and end-capping is performed by adding an alkoxytrialkylsilane containing a triorganosilyl group to a polyalkylsilane There is provided a process for preparing sesquioxane and polyalkylsilsesquioxane microparticles prepared therefrom. According to the present invention, it is possible to obtain polyalkyl silsesquioxane fine particles having a particle size distribution and a narrow particle size distribution while maintaining physical properties equal to or higher than those of the prior art by adding a diol having three or more carbon atoms before the introduction of the alkyltrialkoxysilane.

Polyalkyl silsesquioxane, silicon fine particles, particle size distribution

Description

TECHNICAL FIELD The present invention relates to polyalkylsilsesquioxane fine particles, and polyalkylsilsesquioxane particulates and a preparation method thereof,

More particularly, the present invention relates to polyalkyl silsesquioxane fine particles having a large particle diameter and a narrow particle size distribution, and a method for producing the same.

Since the polyalkyl silsesquioxane particles have a structure crosslinked with a dense three-dimensional network structure, they have a low specific gravity as compared with the organic polymer. They have little weight change up to about 400 ° C. and have excellent heat resistance and fluidity .

In general polyalkyl silsesquioxanes were first introduced by Brown, Jr. et al. Of GE in the 1960s with the synthesis of high molecular weight soluble polyphenylsilsesquioxane. Such polyalkyl silsesquioxanes are collectively referred to as compounds of any structure having the structure of "RSiO _{3/2 &} quot ;, where R is hydrogen, any alkyl, alkylene, aryl, arylene, Organic functional group derivatives, and the like.

As a conventional method for producing polyalkyl silsesquioxane fine particles known as silicone resin powders, there has been proposed a method for hydrolytic condensation polymerization of a trifunctional silane such as organotrichlorosilane or organotrialkoxysilane.

Japanese Unexamined Patent Publication (Kokai) No. 4-70335 discloses a method in which a methyltrialkoxysilane and / or a partial hydrolysis condensate thereof and an aqueous ammonia or amine solution are stirred at a low rate to form a layered structure of methyltrialkoxysilane and / And the hydrolysis and condensation reaction is carried out while maintaining the temperature of the reaction mixture. However, this method tends to increase the particle size distribution, and it is impossible to obtain particles having a particle size of 5 mu m or more, because it is difficult to control the stirring speed and to hydrolyze and maintain the interface at the condensation polymerization reaction. In addition, there is a disadvantage in that the reaction rate is slow due to the low possibility of contact with alkali and thus the polymerization time and production efficiency relative to the apparatus volume are low.

Korean Patent Publication No. 1993-0006260 discloses a method of hydrolyzing an organotrialkoxysilane under an organic acid condition, adding a water / alcohol solution, then adding an alkaline aqueous solution, and then condensing the mixture in a stationary state. In this method, condensation reaction is carried out without stirring or stirring to obtain fine particles which do not cause agglomerates even in the case of a low concentration catalyst, but they are not suitable for producing fine particles having a particle size of 1 탆 or more.

Korean Patent Laid-Open No. 1998-0024929 discloses a method for hydrolyzing and condensing organotrialkoxysilane in an aqueous solution containing an anionic surfactant, a polymer stabilizer and a hydroxy base. In this method, it is possible to obtain fine particles which do not cause agglomerates even at a low concentration catalyst amount by adding a dispersion stabilizer. However, it is difficult to obtain the reproducibility of the generated particle size at the low concentration catalyst amount. In order to suppress agglomerate generation, There is a problem that the production efficiency is low because silane can not be used much.

Japanese Unexamined Patent Publication No. 2002-047348 discloses a method for producing polyorganosilsesquioxane particles having an average particle diameter of 3 to 30 占 퐉 reproducibly in order to solve the above problems. In an aqueous alkaline solution to which metal ions are added, A method of dropping an alkoxysilane or a hydrolyzate thereof, and performing a hydrolysis and condensation reaction is described. However, this method has a problem in that not only the particle size distribution is wide, but also metal ions remain in the product due to the presence of metal ions in the hydrolysis and condensation reaction process, resulting in a decrease in electric characteristics or a change in mechanical properties .

As described above, the polyalkyl silsesquioxane particles produced by the prior art are unsuitable for use as a light diffusing agent for a light diffusion plate or a light diffusion film which has been recently required because the particle size is small or has a wide particle size distribution.

Accordingly, the present inventors have recently proposed a light diffusing agent having a narrow particle size distribution and a relatively large size of an average particle diameter of 5 탆 or more. Therefore, the inventors of the present invention have found that silanol resulting from the hydrolysis of an alkyltrialkoxysilane affects the particle size Respectively.

Accordingly, the present invention relates to a process for producing a hydrolysis product having a particle size distribution of less than 15% and having a coefficient of variation (CV) of less than 15% And a process for producing the polyalkyl silsesquioxane fine particles.

In order to achieve the above object, one embodiment of the present invention provides polyalkyl silsesquioxane fine particles represented by the following formula (4).

[Chemical Formula 4]

RSiO _{(4-m) / 2}

Wherein R is a non-hydrolyzable group selected from the group consisting of an alkyl group having 1 to 20 carbon atoms, an alkyl group having 1 to 20 carbon atoms having a (meth) acryloyloxy group or an epoxy group, an alkenyl group having 2 to 20 carbon atoms, Or an aralkyl group having 7 to 20 carbon atoms, and m is an integer of 0 to 3.

Considering the hydrolytic reactivity, the polyalkyl silsesquioxane is preferably a spherical fine particle composed of polymethylsilsesquioxane having an average unit formula represented by the following formula (4-1).

[Formula 4-1]

CH ₃ SiO _3/2

The polyalkyl silsesquioxane fine particles of the present invention can be obtained by adding a diol having 3 or more carbon atoms before the alkyltrialkoxysilane is added during the hydrolysis reaction. The spherical polyalkyl silsesquioxane particles thus obtained had an average particle diameter of 5 mu m to 30 mu m, which is larger than the conventional one, and C.V. And a narrow particle size distribution of less than 15%.

In another embodiment of the present invention there is provided a process for preparing polyalkyl silsesquioxane microparticles comprising the steps of:

An acid catalyst and a diol having 3 or more carbon atoms are added to an aqueous medium to prepare an acidic homogeneous aqueous solution, and then an alkyltrialkoxysilane represented by the following formula (1) is added to the aqueous solution to perform a hydrolysis reaction, A first step of producing an alkylsilanetriol or a partial hydrolyzate thereof to be displayed;

A second step of homogenizing the alkylsilanetriol or its partial hydrolyzate and then polycondensation to produce a polyalkylsilsesquioxane fine particle having a silanol group on its surface; And

Adding an alkoxytrialkylsilane represented by the following formula (3) to the polyalkyl silsesquioxane fine particle to end-capping the silanol group with an alkyl group;

[Chemical Formula 1]

R-Si- (OR &^lt; ^{1 >} ) ₃

(2)

R-Si- (OH) ₃

(3)

R ² O-Si- (R ³ ) ₃

(Wherein R is a non-hydrolyzable group, and each independently represents an alkyl group having 1 to 20 carbon atoms, an alkyl group having 1 to 20 carbon atoms having a (meth) acryloyloxy group or an epoxy group, an alkenyl group having 2 to 20 carbon atoms, An aryl group having 7 to 20 carbon atoms or an aralkyl group having 7 to 20 carbon atoms; R ¹ and R ² are hydrolyzable groups each independently an alkyl group having 1 to 6 carbon atoms; and R ³ is a non-hydrolyzable group, An alkyl group having 1 to 20 carbon atoms)

Hereinafter, the present invention will be described in more detail.

Step 1

The first step in the present invention comprises adding an alkyltrialkoxysilane represented by the general formula (1) to an aqueous solution in the presence of an organic acid, followed by hydrolysis. Particularly, the present invention relates to a process for preparing an alkyltrialkoxysilane represented by the general formula (1), wherein a diol having 3 or more carbon atoms is added to an aqueous solution in an amount of 1 to 50 parts by weight per 100 parts by weight of the compound Ol or a partial hydrolyzate thereof.

That is, the present invention is characterized in that a diol having 3 or more carbon atoms is added to an aqueous solution in the presence of an organic acid, followed by stirring to prepare a homogeneous aqueous solution.

The diol having a carbon number of 3 or more is contained in the aqueous solution prior to the addition of the alkyltrialkoxysilane of the formula (1) during the hydrolysis reaction and serves as a stabilizer in the polycondensation reaction in the second step, And also serves to make the particle size uniform. Therefore, the polyol silsesquioxane particles having an average particle diameter of 5 mu m to 30 mu m, which is larger in size than conventional ones, and C.V. And has a narrow particle size distribution of less than 15%.

The diol having 3 or more carbon atoms used in the hydrolysis has 3 or more carbon atoms and 2 hydroxy groups in the molecule, and the carbon skeleton can be any combination of linear, branched, and cyclic. More specifically, the diol is selected from the group consisting of 1,4-butanediol, 1,2-propanediol, 1,4-pentanediol, 1,5-hexanediol, 2-hexadecanediol, 1,2-cyclohexanediol, 1,3-cyclopentanediol, 2,5-dimethyl-2,5-hexanediol, 2-phenyl- Methyl-2,4-pentanediol, 3-methoxy-1,2-propanediol and 3-ethoxy-1,2-propanediol, among which 1,6- Hexanediol is particularly preferred. The amount of the diol having 3 or more carbon atoms is preferably 1 to 50 parts by weight, more preferably 5 to 20 parts by weight, per 100 parts by weight of the alkyltrialkoxysilane used, and is preferably added before the addition of alkyltrialkoxysilane during the hydrolysis reaction Do. When the amount of the diol to be used is less than 1 part by weight per 100 parts by weight of the alkyltrialkoxysilane of formula 1, the effect as a stabilizer is not sufficient and the size of the generated particles may be small and the particle size distribution may be high. The relative amount is too high and it may become difficult to obtain particles of the desired size.

The organic acid catalyst is used for hydrolysis of alkyltrialkoxysilane. The organic acid catalyst may be hydrochloric acid, sulfuric acid, formic acid, acetic acid, propionic acid, oxalic acid, and citric acid. The amount of the organic acid catalyst to be used is preferably 0.001 to 1 part by weight based on 100 parts by weight of the aqueous medium. When the amount of the organic acid catalyst is less than 0.001 parts by weight, the hydrolysis reaction does not proceed sufficiently. When the amount of the organic acid catalyst is more than 1 part by weight, the reaction efficiency is lowered as the concentration of the organic acid increases.

In consideration of the reactivity, the alkyltrialkoxysilane compound of Formula 1 is preferably a compound having an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms. More specifically, the compound of Formula 1 may be selected from the group consisting of methyltrimethoxysilane, methyltriethoxysilane, methyltripropoxysilane, methyltriisopropoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, propyltriethoxysilane, But are not limited to, methoxysilane, propyltriethoxysilane, butyltrimethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, gamma -glycidoxypropyltrimethoxysilane ,? -acryloyloxypropyltrimethoxysilane,? -methacryloxypropyltrimethoxysilane, dimethyldimethoxysilane, and methylphenyldimethoxysilane is preferably used. The compound of Formula 1 is not particularly limited, but methyltrimethoxysilane or vinyltrimethoxysilane is preferable, and methyltrimethoxysilane is more preferable because methyltrimethoxysilane is more reactive.

The amount of the alkyltrialkoxysilane of Formula 1 varies depending on the amount of the aqueous medium at the hydrolysis, the amount of the diol having 3 or more carbon atoms, the type and concentration of the organic acid, and the basic catalyst. Specifically, 100 parts by weight or less, more preferably 1 to 90 parts by weight, of alkyltrialkoxysilane relative to 100 parts by weight of an aqueous medium used in the reaction is most preferably used in an amount of 5 to 80 parts by weight Do. When the content of the compound of the formula (1) is more than 90 parts by weight, aggregation or melt adhesion of the particles tends to occur at the time of use, and if it is less than 1 part by weight, the concentration of the silicon fine particles finally produced in the aqueous solution is too low.

As the aqueous medium used for the hydrolysis of the alkyltrialkoxysilane, it is preferable to use ion exchange water. The ion-exchanged water preferably has a smaller cation number, and more preferably has a resistance value of at least 5 megaohms (5 M OMEGA) under a nitrogen stream generated through an ion exchanger. The amount of the aqueous medium used in the hydrolysis reaction is preferably about 50 to about 1400 parts by weight based on 100 parts by weight of the alkyltrialkoxysilane represented by the formula (1) in consideration of the exothermic temperature of the reaction.

Step 2

In the second step, the aqueous medium of the second step is added to the alkylsilanetriol represented by the formula (2) or its partial hydrolyzate obtained in the first step, homogenized using a high-pressure homogenizer or a homomixer, Followed by condensation polymerization to prepare polyalkylsilsesquioxane fine particles.

In the present invention, the high-pressure homogenizer or homomixer used after the introduction of the aqueous medium acts to further homogenize the hydrolyzate, thereby making the particle size distribution of the polyalkyl silsesquioxane fine particles more uniform. The use of a high-pressure homogenizer or a homomixer can obtain a silicon bead having a narrower particle size distribution and having a C.V.% of 15% or less than that of stirring using a mechanical stirrer.

The basic catalyst used in the polycondensation is used as a catalyst for the condensation polymerization reaction, in addition to neutralizing the organic acid catalyst of the partial hydrolyzate of the compound of the formula (1). Examples of the basic catalyst include alkali metal hydroxides such as potassium hydroxide, sodium hydroxide and lithium hydroxide; Alkaline earth metal hydroxides such as calcium hydroxide and barium hydroxide; Alkali metal carbonates such as potassium carbonate and sodium carbonate; And amines such as monomethylamine, dimethylamine, monoethylamine, diethylamine, ethylenediamine, and ammonia, or a combination of two or more thereof. Preferably, the basic catalyst is excellent in water solubility and catalytic activity, less toxic and easy to remove, and in particular, it is preferable to use ammonia which is inexpensive. The amount of the basic catalyst to be used is preferably 0.05 to 3 parts by weight based on 100 parts by weight of the alkylsilanetriol or partial hydrolyzate of the formula (2) obtained in the second step.

The pH of the aqueous solution after the addition of the basic catalyst is in the range of 9.0 to 13.0, and most preferably in the range of 9.5 to 12.0. At this time, if the pH is lower than 9, the rate of condensation polymerization decreases, and the particles tend to flocculate and fuse with each other. As a result, the aqueous suspension can gel, and if the pH is higher than 13.0, the rate of condensation polymerization of the organotrialkoxysilane increases The reaction efficiency is lower than the input amount and the yield is low because an irregular gel is produced.

The amount of the aqueous medium used in the second step of the condensation polymerization reaction is 50 to 500 parts by weight based on 100 parts by weight of the alkylsilanetriol or partial hydrolyzate obtained in the second step in consideration of the exothermic temperature of the reaction desirable.

Step 3

In the third step, the alkoxytrialkylsilane represented by Formula 3 is added to the surface of the polyalkylsilsesquioxane fine particles having a silanol group on the surface obtained in the second step to end-cap the silanol group with an alkyl group (end -capping) to obtain a polyalkyl silsesquioxane fine particle whose silanol group content on the surface is reduced to 0 to 5%.

In the present invention, the polyalkyl silsesquioxane fine particles obtained in the second step may be used in the form of a powder obtained by drying after the second step and may be used in the form of a powdery redispersion or an aqueous suspension of polyalkylsilsesquioxane fine particles It may be used as it is.

As the alkoxytrialkylsilane compound of Formula 3, it is preferable to use a compound having an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms. More specifically, specific examples of the alkoxytrialkylsilane represented by Formula 3 include trimethylmethoxysilane, trimethylethoxysilane, trimethylpropoxysilane, trimethylisopropoxysilane, trimethylbutoxysilane, trimethylpentoxysilane , Triethylmethoxysilane, tripropylethoxysilane, triethylethoxysilane, tripropylmethoxysilane, tributylmethoxysilane, triphenylmethoxysilane, triphenylethoxysilane, trivinylmethoxysilane, tri Vinyl ethoxysilane and vinylmethylmethoxysilane can be used in combination. Of these, trimethylmethoxysilane and trivinylmethoxysilane are preferable in view of reactivity, and more preferred is trimethylmethoxysilane.

The amount of the alkoxytrialkylsilane of Formula 3 varies depending on the type and amount of the alkyltrialkoxysilane. Specifically, the amount of the alkoxytrialkylsilane to be used is preferably 10 parts by weight or less, more preferably 0.1 to 10 parts by weight, and most preferably 0.5 to 5 parts by weight based on 100 parts by weight of the alkyltrialkoxysilane represented by the general formula (1). If the amount of the alkoxytrialkylsilane of Formula 3 is more than 10 parts by weight, a side reaction such as a dimer form may occur between the alkoxytrialkylsilanes themselves, and the particles easily aggregate or melt. If the amount is less than 0.1 part by weight, end capping is not performed properly.

In the present invention, the reaction temperature of each step depends on the type and amount of the organosilane compound to be used, and is preferably selected within the range of 0 to 55 ° C, more preferably 10 to 55 ° C , More preferably in the range of 10 to 30 占 폚, and to obtain particles having a small particle size distribution, it is preferable that the temperature during the polymerization reaction is maintained at 占 2 占 폚. Preferably, maintaining the temperature at the time of polymerization at 占 폚 is equivalent to the polymerization reaction at the second step, and during the second step reaction, the reaction is carried out at a temperature within the range of 10 to 30 占 폚, It means to maintain ± 2 ° C at the set temperature. If the reaction temperature is lower than 0 ° C, the aqueous medium is frozen to make polymerization difficult, while if it exceeds 55 ° C, the alkoxide is volatilized and the yield is lowered. If the temperature of ± 2 ° C can not be maintained in the temperature range set during the reaction of the second step, it is preferable to maintain the above range since particles with a wide particle size distribution are produced.

Further, in the present invention, especially when the amount of alkyltrialkoxysilane to be used is large, aggregation or fusion of the particles tends to occur when agitation is too strong in hydrolysis and polycondensation reaction. Therefore, it is preferable to perform stirring under mild conditions as far as possible, more preferably, stirring is stopped after polyalkylsilsesquioxane microparticles are formed, and the mixture is left standing for 3 to 48 hours. By doing so, a polyalkyl silsesquioxane fine particle whose desired average particle size and particle size distribution are controlled can be obtained. The produced spherical polyalkyl silsesquioxane fine particles can be obtained by filtration after completion of the reaction, washing, and drying. In some cases, for example, when the particles aggregate at the time of drying, it is preferable to carry out the pulverizing process with a pulverizer such as a jet mill, a ball mill atomizer or a hammer mill.

The polyalkyl silsesquioxane fine particles according to the present invention have an average particle diameter of 5 to 30 占 퐉, C.V. The light diffusion of a backlight unit (BLU) in a display material field for a high brightness display material as well as a light diffusion agent of a light diffusion film and a light diffusion plate of a backlight unit (BLU) A light diffusing agent for a film and a light diffusing plate, a surface lubrication in the coating material field, a water repellency, an oil repellency imparting agent, and an anti-blocking agent for paints and coatings.

Hereinafter, the present invention will be described in more detail with reference to the following examples and comparative examples. It is to be understood, however, that the present invention is not limited to the disclosed embodiments.

<Examples>

In the following Examples and Comparative Examples, the coefficient of variation (C.V. value) was obtained by the following equation using a particle size distribution measuring apparatus (Coulter Electronics, Multisizer 3).

[Equation 1]

C.V. (%) = (standard deviation of particle diameter / average particle diameter of particle) 占 100

&Lt; Example 1 >

The polyalkylsilsesquioxane fine particles were prepared through the following steps.

Step 1

630 parts by weight of ion-exchanged water and 0.4 parts by weight of acetic acid were added to the 2-liter round flask while nitrogen was purged, the pH was adjusted to 2 to 4, 36 parts by weight of 1,6-hexane diol was added, and the mixture was stirred at 200 rpm for 30 minutes.

The aqueous solution was stirred for 30 minutes, 600 parts by weight of methyltrimethoxysilane was added thereto, and the mixture was stirred at 200 rpm. The internal temperature of the mixed solution was increased to 40 ° C. after 6 minutes. After about 5 hours, the methyltrimethoxysilane was completely dissolved to obtain methylsilanetriol or partial hydrolyzate as a homogeneous solution.

Step 2

To 500 parts by weight of methylsilanetriol or partial hydrolyzate obtained in the first step, 490 parts by weight of ion-exchanged water was added and stirred at 200 rpm for 30 minutes. After the solution was stirred for 30 minutes, the chamber was subjected to continuous pressure twice using a high pressure homogenizer at a pressure of 4000Pi to obtain a homogeneous solution.

The homogeneous solution thus obtained was cooled to 18 DEG C, and 2 parts by weight of a 29% ammonia aqueous solution was added in one time. At this time, the reaction temperature was maintained at 18 캜, and stirring was carried out at a stirring speed of 50 rpm for 5 minutes. When the reaction mixture became cloudy, the reaction mixture was allowed to stand for 3 hours and then subjected to condensation polymerization reaction to produce polymethylsilsesquioxane particles.

Step 3

3.8 parts by weight of trimethylmethoxysilane was added to the white suspension of the polymethylsilsesquioxane fine particles produced in the second step. After allowing to stand for 12 hours, the reaction product was passed through a 200 mesh wire mesh, washed several times with methanol, and washed to obtain a cake-like powder which was dehydrated. This was dried in a hot air circulating drier at 105 ° C for 4 hours, and the dried product was pulverized by a jet mill to obtain polymethylsilsesquioxane fine particles in the form of a white powder.

The average particle size (d ₅₀ ) of the particles obtained by this polymerization was 11.8 μm and the coefficient of variation (CV) of the particle diameter was 10.5%.

Various physical properties of the prepared polymethylsilsesquioxane fine particles were measured by a conventional method, and the results are shown in Table 1. Further, FIG. 1 shows the particle structure of the polyalkyl silsesquioxane fine particles of Example 1 as measured by an electron microscope photograph.

&Lt; Example 2 >

Polyalklylsilsesquioxane fine particles were prepared in the same manner as in Example 1, except that the homogenizer (WiseMix, HG-15A) was used instead of the high-pressure homogenizer at a high speed for 30 minutes at 25,000 rpm. Various physical properties of the produced polyalkylsilsesquioxane fine particles were measured by a conventional method, and the results are shown in Table 1.

&Lt; Example 3 >

Polyalklylsilsesquioxane fine particles were prepared in the same manner as in Example 1 except that 1,4-pentanediol was used instead of 1.6-hexanediol. Various physical properties of the produced polyalkylsilsesquioxane fine particles were measured by a conventional method, and the results are shown in Table 1.

<Example 4>

Polyalkylsilsesquioxane fine particles were prepared in the same manner as in Example 1 except that vinyltrimethoxysilane was used in place of methyltrimethoxysilane. Various physical properties of the produced polyalkylsilsesquioxane fine particles were measured by a conventional method, and the results are shown in Table 1.

&Lt; Comparative Example 1 &

Polyalklylsilsesquioxane fine particles were prepared in the same manner as in Example 1, except that 1,6-hexanediol was not used. Various physical properties of the produced polyalkylsilsesquioxane fine particles were measured by a conventional method, and the results are shown in Table 1. 2 shows the particle structure of the polyalkyl silsesquioxane fine particles of Comparative Example 1 as measured by an electron microscope photograph.

&Lt; Comparative Example 2 &

Polyalklylsilsesquioxane fine particles were prepared in the same manner as in Example 1 except that hexane was used instead of 1,6-hexanediol. Various physical properties of the produced polyalkylsilsesquioxane fine particles were measured by a conventional method, and the results are shown in Table 1. 3 shows the particle structure of the polyalkyl silsesquioxane fine particles of Comparative Example 1 as measured by an electron microscope photograph.

&Lt; Comparative Example 3 &

Polyalkylsilsesquioxane fine particles were prepared in the same manner as in Example 1 except that 1,6-hexanethiol was used instead of 1,6-hexanediol. Various physical properties of the produced polyalkylsilsesquioxane fine particles were measured by a conventional method, and the results are shown in Table 1.

[Table 1]

step ingredient Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 Stage 1 Methyltrimethoxysilane (parts by weight) 600 600 600 - 600 600 600 Vinyltrimethoxysilane (parts by weight) - - - 600 - - - Acetic acid (parts by weight) 0.4 0.4 0.4 0.4 0.4 0.4 0.4 Ion-exchanged water (parts by weight) 630 630 630 630 630 630 630 pH 2 to 4 2 to 4 2 to 4 2 to 4 2 to 4 2 to 4 2 to 4 1,6-hexanediol 36 36 - 36 - - - 1-hexanol 1,4-pentanediol - - 36 - - - - Hexane - - - - - 36 - 1,6-hexanthiol - - - - - - 36 Step 2 29% ammonia water (parts by weight) 2 2 2 2 2 2 2 Ion-exchanged water (parts by weight) 1230 1230 1230 1230 1230 1230 1230 pH 9-12 9-12 9-12 9-12 9-12 9-12 9-12 Reaction temperature (캜) 18 18 18 18 18 18 18 Step 3 Trimethylmethoxysilane (parts by weight) 3.8 3.8 3.8 3.8 3.8 3.8 3.8 produce
Particulate shape Genesis Genesis Genesis Genesis Genesis Genesis Genesis Dry weight (parts by weight) 186 186 184 181 183 183 184 Average particle diameter (占 퐉) 11.8 10.6 10.8 11.7 5.2 4.9 4.2 C.V. Value (%) 10.5 12.7 12.9 13.5 36.6 35.3 39.8 True weight 1.3 1.3 1.3 1.3 1.3 1.3 1.3 Moisture content (%) 0.3 0.2 0.2 0.3 0.3 0.2 0.2

From the results of the above Table 1, it can be seen that the embodiment of the present invention has an average particle diameter of 5 mu m or more and a uniformity of the CV distribution within 15% of C.V. compared with the evaluation results of the comparative example in which no diol is used.

The polyalkyl silsesquioxane fine particles of the present invention can be used as a light diffusing agent for a light diffusion plate or a light diffusion film because the particle diameter is larger than that of the conventional art and the particle size variation coefficient is small.

1 is a photograph showing the particle structure of the polyalkyl silsesquioxane fine particles of Example 1 according to the present invention.

2 is a photograph showing the particle structure of the polyalkyl silsesquioxane fine particles of Comparative Example 1. Fig.

3 is a photograph showing the particle structure of the polyalkyl silsesquioxane fine particles of Comparative Example 2. Fig.

Claims (10)

A process for producing polyalkyl silsesquioxane fine particles comprising the steps of: An acid catalyst and a diol having 3 or more carbon atoms are added to an aqueous medium to prepare an acidic homogeneous aqueous solution, and then an alkyltrialkoxysilane represented by the following formula (1) is added to the aqueous solution to perform a hydrolysis reaction, A first step of producing an alkylsilanetriol or a partial hydrolyzate thereof to be displayed; A second step of homogenizing the alkylsilanetriol or its partial hydrolyzate and then polycondensation to produce a polyalkylsilsesquioxane fine particle having a silanol group on its surface; And Adding an alkoxytrialkylsilane represented by the following formula (3) to the polyalkyl silsesquioxane fine particle and end-capping the silanol group with an alkyl group; [Chemical Formula 1] R-Si- (OR &^lt; ^{1 &gt;} ) ₃ (2) R-Si- (OH) ₃ (3) R ² O-Si- (R ³ ) ₃ (Wherein R is a non-hydrolyzable group, and each independently represents an alkyl group having 1 to 20 carbon atoms, an alkyl group having 1 to 20 carbon atoms having a (meth) acryloyloxy group or an epoxy group, an alkenyl group having 2 to 20 carbon atoms, An aryl group having 7 to 20 carbon atoms or an aralkyl group having 7 to 20 carbon atoms; R ¹ and R ² are hydrolyzable groups each independently an alkyl group having 1 to 6 carbon atoms; and R ³ is a non-hydrolyzable group, An alkyl group having 1 to 20 carbon atoms) The process for producing polyalkyl silsesquioxane fine particles according to claim 1, wherein the diol having 3 or more carbon atoms is added in an amount of 1 to 50 parts by weight per 100 parts by weight of the compound of formula (1). The process of claim 1, wherein the diol having 3 or more carbon atoms is 1,4-butanediol, 1,2-propanediol, 1,4-pentanediol, 1,5-hexanediol, Diol, 1,2-hexadecanediol, 1,2-cyclohexanediol, 1,3-cyclopentanediol, 2,5-dimethyl-2,5-hexanediol, , 2-propanediol, 2-methyl-2,4-pentanediol, 3-methoxy-1,2-propanediol and 3-ethoxy-1,2-propanediol Wherein the polyalkyl silsesquioxane fine particles are at least one kind of polyalkyl silsesquioxane fine particles. The method according to claim 1, wherein the homogenization in the second step is carried out using a high-pressure homogenizer or a homomixer. The process according to claim 1, wherein the acid catalyst is at least one selected from the group consisting of hydrochloric acid, sulfuric acid, formic acid, acetic acid, propionic acid, oxalic acid and citric acid. The process for producing polyalkyl silsesquioxane fine particles according to claim 1, wherein the hydrolysis of the first stage and the polycondensation of the second stage are carried out at a temperature of 0 to 55 ° C. The method according to claim 1, wherein the hydrolysis reaction is carried out in the presence of at least one organic acid selected from the group consisting of hydrochloric acid, sulfuric acid, formic acid, acetic acid, propionic acid, oxalic acid and citric acid . The method of claim 1, wherein the polycondensation reaction is carried out in the presence of a base such as potassium hydroxide, sodium hydroxide, lithium hydroxide, calcium hydroxide, barium hydroxide, potassium carbonate, sodium carbonate, monomethylamine, dimethylamine, monoethylamine, diethylamine, ethylenediamine and ammonia Wherein at least one of the basic catalysts is selected from the group consisting of the polyalkylene silsesquioxane fine particles and the polyalkylene silsesquioxane fine particles. The method for producing polyalkyl silsesquioxane fine particles according to claim 1, wherein the average particle diameter is 5 to 30 占 퐉 and the particle size distribution is within 15% of Coefficient of variation (CV). delete

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