JPH0959384A - Organopolysiloxane fine particle, its production and liquid crystal display unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an organopolysiloxane fine particles useful for a liquid crystal display unit, comprising two kinds of organopolysiloxane fine particles having a specific structure wherein the peak areas of respective<29> S-NMR spectra satisfies specific conditions. SOLUTION: The organopolysiloxane fine particles contain siloxane bonding of formula I and formula II (X is H or an element selected from among IB- group, IIA, IIB, IIIA, IIIB, IVA, IVB, VA, VB, VIA, VIIA and VIII-group in the periodical table; R is monofunctional organic group) and a total area and ST of total peaks observed within from 0 to -120ppm chemical shift by<29> Si- NMR spectra measurement of the fine particles, a peak area Si corresponding to a siloxane bonding of formula I and a peak area SII of formula II satisfy the followings; (SII/SI)∞2 and [(SI+SII)/ST]>=0.3, preferably 5<=(SII/SI)<=50, and 0.5<=[(SI+SII)/ST]<=0.99. An Si content in the fine particles is preferably 50-90wt.% in reduced to SiO2 .

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an organopolysiloxane fine particle, a method for producing the same, and a liquid crystal display device in which the organopolysiloxane fine particle is interposed as a spacer between electrodes of a liquid crystal cell.

[0002]

BACKGROUND OF THE INVENTION A spacer is provided between a pair of electrodes provided in a liquid crystal cell for a liquid crystal display device, and a liquid crystal substance is enclosed to form a liquid crystal layer. If the unevenness is not uniform, the image displayed on the liquid crystal cell may have color unevenness and a decrease in contrast during lighting. Also,
It is required that the thickness of the liquid crystal layer inside the liquid crystal cell be uniform even when the display image is switched at high speed or when an image with a wide viewing angle is displayed.

Further, in order to display a large screen without color unevenness in the currently used STN mode large screen liquid crystal display device, it is required that the thickness of the liquid crystal layer in the liquid crystal cell is made more uniform. Has been done.

In order to make the thickness of the liquid crystal layer inside the liquid crystal cell uniform, conventionally, spherical particles having a uniform particle size are interspersed between the electrodes of the liquid crystal cell, that is, spacers between electrodes of the liquid crystal cell. Is used as an organic resin particle such as polystyrene, etc.
Silica fine particles are used.

However, when organic resin particles such as polystyrene are used as the inter-electrode spacers of the liquid crystal cell, these organic resin particles are too soft to keep the thickness of the liquid crystal layer inside the liquid crystal cell uniform. There was a problem that it was difficult. For example, when a non-uniform pressure is applied to the liquid crystal layer inside the liquid crystal cell, the spacer is deformed according to the variation in the pressure, and the thickness of the liquid crystal layer inside the liquid crystal cell cannot be maintained uniform.

Further, when silica fine particles are used as spacers between electrodes of a liquid crystal cell, unless the particle size distribution of the silica fine particles is sharp, the compression deformation of the silica fine particles is small, resulting in the thickness of the liquid crystal layer inside the liquid crystal cell. There was a problem that the thickness was non-uniform. Furthermore, when the liquid crystal display device is exposed to a low temperature, since the thermal expansion coefficient of the liquid crystal layer and the thermal expansion coefficient of the spacer are different inside the liquid crystal cell, a gap is generated between the electrode of the liquid crystal cell and the liquid crystal layer. There is a problem that low temperature bubbles are generated.

In order to solve the above problems, in JP-A-6-250193, a hydrolyzable silicon compound such as tetraethoxysilane is hydrolyzed to prepare silica fine particles, and the surface of the silica fine particles is prepared. It has been proposed to use the silica fine particles produced by the method of esterifying the silanol group of 1) with an organic compound as a spacer between electrodes of a liquid crystal cell.

The silica fine particles produced by this method are said to be suitable as a spacer between electrodes of a liquid crystal cell because they have an appropriate hardness and a mechanical restoration property. Therefore, it is insufficient as a spacer between electrodes of a liquid crystal cell.

Further, _{JP-A-7-140472, R 'm Si (OR} 2) 4-m (R in the formula', R ² is
Each represents a specific organic group. m is an integer of 0-3. It is disclosed that spacer particles for a liquid crystal cell having a specific compressive elastic modulus can be obtained by heat-treating particles obtained by hydrolyzing and condensing an organosilicon compound represented by) at a temperature of 100 to 1000 ° C. ing. The compressive elastic modulus of the spacer particles is controlled by the amount of the remaining organic groups after thermal decomposition of a part of the organic groups existing inside the particles in the heat treatment step.

However, when the particle diameter is different, the amount of the organic groups remaining inside the particles after the heat treatment step is different, and it is difficult to control the amount of the remaining organic groups.
There is a problem in that the compression deformation rates of the particles are not the same, and therefore it is difficult to adjust the compression elastic modulus of the spacer particles for liquid crystal cells to a desired value by the amount of organic groups remaining inside the particles. In addition, since the amount of residual organic groups is different between the outside and inside of the particles, the compressive elastic modulus is not uniform throughout the particles, and further, voids are generated in the organic groups inside the particles that are thermally decomposed in the heat treatment step. As a result, there is a problem that the compressive strength of the obtained spacer particles for liquid crystal cell is lowered.

Therefore, the present inventors have produced organopolysiloxane fine particles by a specific method using a specific organosilicon compound. As a result, the organic groups in the organopolysiloxane fine particles are not subjected to the heat treatment step as described above. The amount was controlled, and as a result, fine particles having a high elastic recovery rate and a uniform particle size were obtained. It was found that the fine particles are suitable as an interelectrode spacer of a liquid crystal cell, and the present invention is completed. Came to.

[0012] Incidentally, JP-A-4-313727 and JP-A-5-80343 describe that spherical particles having elasticity in a specific range are used as spacers between electrodes of a liquid crystal cell. Is a vinyl-based plastic bead or a hybrid particle of an inorganic substance and an organic substance. By controlling the amount of organic groups in the organopolysiloxane fine particle, a fine elastic particle having a high elastic recovery rate and a uniform particle size is obtained. There is no mention of this.

[0013]

DISCLOSURE OF THE INVENTION The present invention has been made to improve the elasticity of fine silica particles, and has a high elastic recovery rate and a uniform particle size of organopolysiloxane fine particles, a method for producing the same, and a method for producing the same. It is an object of the present invention to provide a liquid crystal display device in which the fine particles of organopolysiloxane are interposed as spacers between electrodes of a liquid crystal cell.

[0014]

SUMMARY OF THE INVENTION The organopolysiloxane fine particles according to the present invention have the following formulas (I) and (II):

[0015]

Embedded image

(In the above formula (I), X is a hydrogen atom, or Group IB, Group IIA, Group B, Group IIIA, Group B of the periodic table,
Group IVA, Group B, Group VA, Group B, Group VIA, Group VIIA,
Is an element selected from Group VIII, and in the above formula (II), R
Is a monovalent organic group. ) Organopolysiloxane fine particles containing a siloxane bond represented by the formula (4), wherein the total area S _{T of} all peaks observed within the chemical shift of 0 to −120 ppm when the ²⁹ Si-NMR spectrum of the fine particles is measured. And a peak area S _I corresponding to the siloxane bond represented by the formula (I) and a peak area S _II corresponding to the siloxane bond represented by the formula (II):
It is characterized by satisfying the following formulas: S _II / S _I ≧ 2 and (S _I + S _II ) / S _T ≧ 0.3.

The method for producing organopolysiloxane fine particles according to the present invention comprises: (a) Formula: Si (OR ¹ ) ₄ (wherein R ¹ is selected from a hydrogen atom or an alkyl group, an alkoxyalkyl group and an acyl group). 1 to 1 carbon atoms
0 is an organic group. ) And an organic silicon compound represented by the formula: R′Si (OR ² ) ₃ (In the formula, R ² is the same group as the above R ^1, and R ′ is
1 to 1 carbon atoms selected from a substituted or unsubstituted hydrocarbon group
10 groups. ) A step of preparing seed particles by hydrolyzing and polycondensing a mixture with an organosilicon compound represented by the formula (1) in a mixed solvent of water and an organic solvent, (b) in the dispersion liquid of the seed particles, Formula (1)-
A step of adding one or more compounds represented by (3) and subjecting them to hydrolysis and polycondensation, thereby growing seed particles to prepare a spherical fine particle dispersion: (1) Formula: R'Si (OR ² ) ₃ (wherein R ² and R ′ are the same groups as described above); (2) Formula: R′R ″ Si (OR ³ ) ₂ (formula In the above, R ′ and R ″ may be the same or different from each other, and are a group having 1 to 10 carbon atoms selected from a substituted or unsubstituted hydrocarbon group, and R ³ is the same as R ¹ above. An organic silicon compound represented by the same group): (3) Formula:

[0018]

Embedded image

(Wherein R ⁴ is a propyl or butyl group, Y is one organic group selected from a methyl group, a methoxy group, an ethyl group and an ethoxy group, and M is a group of the periodic table. Group IB, Group IIA, Group B, Group IIIA, Group B, Group IV
An element selected from A, B, VA, VIA, VIIA, and VIII, m is an integer of 0 to 3, and n is an integer of 1 to 4, m + n is an integer of 2-4. ) An acetylacetonato chelate compound represented by the formula (c), (c) a step of separating the spherical fine particles from the spherical fine particle dispersion, and then drying the fine particles.

Further, the organopolysiloxane fine particles obtained in the above step (b) or (c) are surface-treated to introduce a hydrophilic group to the surface of the organopolysiloxane fine particles to provide hydrophilic organopolysiloxane fine particles. can do.

The liquid crystal display device according to the present invention has a liquid crystal cell having a pair of electrodes, and the organopolysiloxane fine particles according to the present invention are interposed between the electrodes as spacers.

Thus, when the organopolysiloxane fine particles according to the present invention are used as spacers between electrodes of a liquid crystal cell, the compression deformation rate of the fine particles is 20 to 60% and the variation coefficient of the fine particles is 5% or less. Is preferred.

[0023]

DETAILED DESCRIPTION OF THE INVENTION Organopolysiloxane Fine Particles First, the organopolysiloxane fine particles according to the present invention will be specifically described.

The organopolysiloxane fine particles according to the present invention have the following formulas (I) and (II):

[0025]

Embedded image

It contains a siloxane bond represented by:
In the above formula (I), X is a hydrogen atom, or I of the periodic table.
Group B, IIA, B group, IIIA, B group, IVA, B group,
It is an element selected from Group VA, Group B, Group VIA, Group VIIA, and Group VIII.

In the above formula (II), R represents a monovalent organic group and is represented by the formula: R'Si (OR ² ) ₃ used as a raw material when producing the organopolysiloxane fine particles. It is a group derived from R ′ contained in the organosilicon compound. Note that R ′ will be described in detail later.

²⁹ Si-of organopolysiloxane fine particles
When the NMR spectrum is measured, the chemical shift is 0-
Within the range of 120 ppm, peaks corresponding to various siloxane bonds including the siloxane bonds represented by the above formulas (I) and (II) are observed. For example, about -99 to -110
A peak corresponding to the siloxane bond represented by the above formula (I) is observed at the position of ppm, and when R in the above formula (II) is a methyl group, a peak is observed at the position of about -65 ppm. When R in the above formula (II) is a vinyl group, a peak is observed at a position of about -60 ppm.

Organopolysiloxane fine particles according to the present invention
In the child these²⁹Chemical analysis of Si-NMR spectrum
All peaks observed within the range of 0 to -120 ppm
Total area S_TAnd a siloxane represented by the above formula (I)
Peak area S corresponding to binding _IAnd expressed by the above formula (II)
Area S corresponding to the siloxane bond_IIAnd next
Formula: S_II/ S_I≧ 2, preferably 5 ≦ S_II/ S_I≦ 50 and (S_I+ S_II) / S_T≧ 0.3, preferably 0.
5 ≦ (S_I+ S_II) / S_T≦ 0.99 is satisfied.

The content of silicon in the organopolysiloxane fine particles according to the present invention is, in terms of SiO ₂ , preferably 50 to 90% by weight, more preferably 60 to 80% by weight, and the content other than silicon is , Derived from an organic group bonded to a silicon atom of an organosilicon compound used as a raw material when producing the organopolysiloxane fine particles.

From the analysis result of the siloxane bond described above,
The organopolysiloxane fine particles according to the present invention are so-called
It is considered to have a three-dimensional mesh structure based on the ladder structure.

The organopolysiloxane fine particles according to the present invention have organic groups derived from the raw materials in the particles, and thus have a high elastic recovery rate and a high compression deformation rate. The methods for evaluating the elastic recovery rate and the compressive deformation rate are as follows.

A micro compression tester (MCTM-200 manufactured by Shimadzu Corporation) was used as a measuring instrument, and one fine particle having a particle size of D was used as a sample, and a predetermined load value (reversal) was applied to the sample at a constant load speed. When a load is applied up to the load value) to deform the particles, the displacement increases from zero according to the curve A as the load increases as shown in FIG.

Next, when the load is unloaded to the constant load value (origin load value) at the same unloading speed as the above-mentioned loading speed, the displacement gradually decreases according to the curve B. Let L ₁ be the difference between the displacement amount of the load value for origin and the displacement amount of the reversal load value under load, and let L ₂ be the difference between the displacement amounts of the load value for origin during load and unload. Elastic recovery rate R _r and compressive deformation rate C of the sample
_r is calculated by the following equation: R _r = [(L ₁ −L ₂ ) / L ₁ ] × 100 C _r = (L ₁ / D) × 100.

In the present specification, with respect to 10 particles, the load value for origin is set to 0.1 g, the reversal load value is set to 1.0 g, and the elastic recovery rate and compressive deformation rate of each particle are determined according to the above equations. The elastic recovery rate and compressive deformation rate of the particles were evaluated based on these average values.

Further, the compressive strength was defined as the load value when the particles were broken by applying a load exceeding the above-mentioned reversal load value. The average elastic recovery rate (R
_r ) ^m is usually 40 to 90%, and the average compression deformation ratio (C _r ) ^m of the fine particles is usually 15% or more.

Further, the organopolysiloxane fine particles according to the present invention usually have an average particle diameter of 1 to 20 μm. The coefficient of variation CV [= (standard deviation / average particle size) × 100] of this particle size is usually 5% or less, preferably 3
% Or less.

As described above, the organopolysiloxane fine particles according to the present invention have an extremely sharp particle size distribution. Method for Producing Organopolysiloxane Fine Particles Next, the method for producing the organopolysiloxane fine particles according to the present invention will be specifically described.

(A) In the method for producing organopolysiloxane fine particles according to the present invention, first, the formula: Si (OR ¹ ) ₄
An organosilicon compound represented by the following (hereinafter referred to as the organosilicon compound (A)) and an organosilicon compound represented by the formula: R′Si (OR ² ) ₃ (hereinafter referred to as the organosilicon compound (B)). The mixture of is added to a mixed solvent of water and an organic solvent to cause hydrolysis and polycondensation, thereby preparing seed particles. As a method for preparing the seed particles, a conventionally known method can be adopted.

R ¹ and R ² in the above formula represent a hydrogen atom or an organic group having 1 to 10 carbon atoms selected from an alkyl group, an alkoxyalkyl group and an acyl group, which may be the same or different. However, it is preferable that the organosilicon compound A and the organosilicon compound B are the same group from the viewpoint of simultaneously hydrolyzing the organosilicon compound B in a mixed solvent of water and an organic solvent to copolycondensate these hydrolysates. Is preferred.

R'in the above formula represents a hydrocarbon group having 1 to 10 carbon atoms selected from substituted or unsubstituted hydrocarbon groups. Among these, examples of the unsubstituted hydrocarbon group include an alkyl group (chain alkyl group or cyclic alkyl group), an alkenyl group, an aralkyl group, an aryl group, and the like.
The substituted hydrocarbon group is a group in which a part or all of hydrogen atoms of hydrocarbon are substituted with a non-hydrocarbon group or an element other than hydrogen, specifically, a chloroalkyl group, γ-methacryloxypropyl group, γ -Glycidoxypropyl group, aminopropyl group, 3,4-epoxycyclohexylethyl group,
γ-mercaptopropyl group, trifluoropropyl group,
Examples thereof include a fluorocarbon group.

Specific examples of the organosilicon compound (A) include tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetramethylmethoxysilane,
Examples thereof include tetraethylethoxysilane and tetraacetoxysilane.

Specific examples of the organosilicon compound (B) include methyltrimethoxysilane, methyltriethoxysilane, methyltriisopropoxysilane, methyltris (methoxyethoxy) silane, ethyltrimethoxysilane, vinyltrimethoxysilane and phenyltri. Methoxysilane, γ-chloropropyltrimethoxysilane, γ-
Examples thereof include glycidoxypropyltrimethoxysilane, methyltriacetoxysilane, and phenyltriacetoxysilane.

The mixing ratio of the organosilicon compound (A) and the organosilicon compound (B) used in the step (a) is
It is preferable that 0.1 to 3.0 mol of the organosilicon compound (B) is mixed with 1 mol of the organosilicon compound (A).

In the step (a), a mixed solvent of water and an organic solvent is used as a solvent, and it is preferable that water is contained in a ratio of 10 to 100 parts by weight with respect to 100 parts by weight of the organic solvent.

As the organic solvent, an organic solvent compatible with water, for example, one or more selected from alcohols, glycols, glycol ethers, ketones and the like is used.

In the step (a), an alkali such as ammonia is added to a solvent as a catalyst for hydrolysis of the organosilicon compounds (A) and (B), and water and an organic solvent are mixed during the hydrolysis of these compounds. It is preferable that the mixed solvent is kept alkaline.

The organosilicon compounds (A) and (B) are
It is hydrolyzed simultaneously in a mixed solvent of water and an organic solvent, and these hydrolyzates are copolycondensed to prepare seed particles, but when the mixed solvent of water and an organic solvent is kept alkaline. , These reactions are accelerated.

The reaction temperature is preferably about 10 to 20 ° C. Further, the concentration of seed particles in the seed particle dispersion liquid obtained as described above is preferably about 0.05 to 5% by weight in terms of SiO ₂ .

Further, the average particle size of the obtained seed particles is preferably 0.05 to 2.0 μm. (B) Next, 1 part of the compound represented by the following formulas (1) to (3) is added to the dispersion liquid of the seed particles obtained in the above step (a).
Seed particles are grown by adding one or more species and conducting hydrolysis / polycondensation to prepare a spherical fine particle dispersion having an arbitrary particle size.

(1) Formula: R'Si (OR ² ) ₃ (In the formula, R ² and R'are the same groups as described above.) An organosilicon compound (hereinafter, organosilicon compound ( C)), (2) Formula: R′R ″ Si (OR ³ ) ₂ (In the formula, R ′ and R ″ may be the same or different from each other, and may be substituted or unsubstituted carbonization. An organic silicon compound (hereinafter referred to as an organic silicon compound (D)) represented by a group having 1 to 10 carbon atoms selected from a hydrogen group and R ³ is the same group as the above R ¹ . Formula (3):

[0052]

[Chemical 6]

(Wherein R ⁴ is a propyl or butyl group, Y is one organic group selected from a methyl group, a methoxy group, an ethyl group and an ethoxy group, and M is a group of the periodic table. Group IB, Group IIA, Group B, Group IIIA, Group B, Group IV
An element selected from A, B, VA, VIA, VIIA, and VIII, m is an integer of 0 to 3, and n is an integer of 1 to 4, m + n is an integer of 2-4. ) An acetylacetonato chelate compound represented by.

R'in the organosilicon compounds (C) and (D) used in this step (b) and R "in the organosilicon compound (D) are both organic silicon compounds when the number of carbon atoms is large. When (C) and / or (D) is added to the seed particle dispersion liquid, a gel is easily generated in the seed particle dispersion liquid, and the seed particles are difficult to grow.

Therefore, R'and R "are preferably groups having a small number of carbon atoms such as a methyl group, a vinyl group, a trifluoromethyl group and a phenylamino group.

As the organosilicon compound (C), the organosilicon compound (B) used in the step (a) can be used. Specific examples of the organosilicon compound (D) include dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldiethoxysilane, phenylmethyldimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, and dimethylacetoxysilane.

Specific examples of the acetylacetonato chelate compound represented by the above formula (3) include dibutoxy-bisacetylacetonatozirconium, tributoxy-monoacetylacetonatozirconium and triisopropoxy-monoacetylacetonatotitanium. , Dibutoxy
Examples thereof include bisacetylacetonato titanium, bisacetylacetonato lead, trisacetylacetonato iron, dibutoxy-bisacetylacetohafnium, and tributoxy-monoacetylacetonatohafnium.

In the step (b), the organosilicon compound (D) or the acetylacetonato chelate compound alone may be added to the seed particle dispersion, but at least about 50.
It is preferable to add mol% or more of the organosilicon compound (C).

In the step (b), when the compound is added to the seed particle dispersion liquid, if the addition speed to the seed particle dispersion liquid is too fast, the particles may aggregate in the seed particle dispersion liquid or the seed particles may be aggregated. In some cases, the growth of particles becomes non-uniform, and finally, it is not possible to obtain organopolysiloxane fine particles having a sharp particle size distribution. Therefore, the addition rate of these compounds is 0.001 per 1 g of water contained in the dispersion medium.
It is preferable to set it to 0.05 g / hour.

In addition, in the step (b), when the compound is added to grow the seed particles, an alkali such as ammonia is used as a hydrolysis catalyst for these alkoxysilanes, if necessary, as in the case of preparing the seed particles. Used.

When ammonia is used as the hydrolysis catalyst in the step (b), the compound may be added to the seed particle dispersion liquid to which the ammonia water is added, or the ammonia water and the compound may be simultaneously added to the seed particle dispersion liquid. You may add. At this time, the concentration of ammonia in the seed particle dispersion liquid is preferably lower than the concentration in the solvent prepared in the step (a).

In this way, when one or more compounds represented by the above formulas (1) to (3) are added to the seed particle dispersion liquid, these compounds are hydrolyzed, and then these hydrolyzates are mixed. The seed particles or the hydrolyzates are polycondensed with each other and adhere to the seed particles, whereby the seed particles grow.

The reaction temperature is preferably lower than the reaction temperature in the step (a), specifically about -10.
It is preferable that it is -20 degreeC. Then, preferably,
This spherical fine particle dispersion was added at a temperature of about 20 to 80 ° C. to about 0.
It is maintained for 5 to 24 hours to age the spherical fine particles.

(C) The spherical fine particles after aging are separated from the spherical fine particle dispersion liquid by a centrifugal separation method or the like, and then dried. Further, in order to accelerate and complete the polycondensation of the compound, a treatment such as baking the aged spherical fine particles or irradiating the spherical fine particles with an electromagnetic wave such as ultraviolet rays is carried out, if necessary.

Through the above steps, the organopolysiloxane fine particles according to the present invention having an average particle diameter of about 1 to 20 μm and a CV value of the particle diameter of 5% or less, preferably 3% or less are obtained. Manufactured.

Although the basic structure of the method for producing the organopolysiloxane fine particles according to the present invention has been specifically described above, the method for producing the organopolysiloxane fine particles according to the present invention includes the steps (a) to There is no particular limitation as long as the organopolysiloxane fine particles according to the present invention containing (c) are produced, and for example, the following step may be included after the step (b) or (c). .

The organopolysiloxane fine particles obtained through the above steps are hydrophobic. However, hydrophilic organopolysiloxane fine particles may be required depending on the application.

In such a case, for example, a hydrophilic treatment such as introducing a hydrophilic group to the surface of the fine particles of organopolysiloxane is carried out. Such hydrophilic treatment is not particularly limited, for example, a hydrolyzable organosilicon compound such as tetraalkoxylane,
Examples of the method include coating the surface of the organopolysiloxane fine particles with another metal alkoxide or a hydrolyzate obtained by hydrolyzing a mixture thereof.

In the present invention, the organopolysiloxane fine particles obtained in the above step are dispersed in a hydrosilicofluoric acid-alcohol mixed aqueous solution, and boric acid or an aqueous sodium borohydride solution is added to the resulting dispersion, whereby It is preferable to coat the surface of the organopolysiloxane fine particles with the obtained silicon oxide. This makes it possible to obtain hydrophilic organopolysiloxane fine particles having a more excellent elastic modulus or at least maintaining the elastic modulus before coating.

When the organopolysiloxane fine particles are dispersed in a hydrofluoric acid silicofluoride-alcohol mixed solution and an aqueous sodium borohydride solution is added to the resulting dispersion,
The following reaction formula: 2H ₂ SiF ₆ + 3NaBH ₄ + 4H ₂ O → 2SiO ₂
Silicon oxide (SiO ₂ ) formed according to + 3NaBF ₄ + 12H ₂ is deposited on the surface of the fine particles of organopolysiloxane.

According to this method, the surface of the fine particles of organopolysiloxane can be made hydrophilic, but the film thickness of silicon oxide deposited on the surfaces of the fine particles of organopolysiloxane can be controlled arbitrarily. Therefore, the particle size of the organopolysiloxane fine particles can be finally adjusted by this method.

Liquid Crystal Display Device Finally, the liquid crystal display device according to the present invention will be specifically described. The liquid crystal display device according to the present invention has a liquid crystal cell having a pair of electrodes, and the organopolysiloxane fine particles according to the present invention are interposed as spacers between the electrodes.

The above-mentioned liquid crystal cell is constructed in the same manner as a known liquid crystal cell except that the organopolysiloxane fine particles according to the present invention are interposed and the distance between the electrodes of the liquid crystal cell is kept constant by the fine particles. ing.

In the liquid crystal display device according to the present invention, the organopolysiloxane fine particles may be present as interelectrode spacers of the liquid crystal cell over the entire electrode surface, but they may be present in the adhesive layer at the peripheral edge of the electrodes. May be.

When the organopolysiloxane fine particles according to the present invention are used as spacers between electrodes of a liquid crystal cell, the particle size and CV value of the organopolysiloxane fine particles are selected according to the required cell gap size and uniformity. To be done.

The uniformity of the particle size is particularly important, and the CV value, which is an index thereof, is preferably 5% or less, particularly 3% or less. In addition, when granular spacers are used between the electrodes of the liquid crystal cell, the thickness of the liquid crystal layer inside the liquid crystal cell becomes uneven due to the small compressive deformation of the spacer particles. When the organopolysiloxane fine particles according to the present invention are used as spacers between electrodes of a liquid crystal cell, in order to prevent low-temperature bubbles generated due to the difference between the thermal expansion coefficient and the thermal expansion coefficient of the spacer, the average elastic recovery defined above is used. The rate (R _r ) ^m is preferably 60 to 90%, and the average compression deformation rate (C _r ) ^m defined above is preferably 30% or more.

When the organopolysiloxane fine particles according to the present invention are used as spacers between electrodes of a liquid crystal cell, the organopolysiloxane fine particles are used on one electrode surface (when a protective film is formed on the electrode surface, the surface of the protective film). ) By a wet method or a dry method, and then on the other electrode surface (or surface of the protective film) on the organopolysiloxane fine particles dispersed on one electrode surface (or the surface of the protective film).
Is placed and overlapped, the liquid crystal material is filled in the cell gap formed by this, the peripheral portions of both electrode surfaces are pasted with a sealing resin, and the liquid crystal display device according to the present invention is sealed. The liquid crystal cell used is obtained. In this case, the organopolysiloxane fine particles according to the present invention may be mixed in the sealing resin.

Further, in the liquid crystal cell used in the liquid crystal display device according to the present invention, the sealing resin mixed with the organopolysiloxane fine particles according to the present invention is applied to the peripheral portion of one electrode surface (or the surface of the protective film). Liquid crystal material excluding the liquid crystal material injection port, then place the other electrode surface (or the surface of the protective film) on top of it, inject it, and inject the liquid crystal material from the liquid crystal material injection port. It can also be obtained by sealing the inlet with a sealing resin.

[0079]

EFFECTS OF THE INVENTION According to the present invention, there are provided organopolysiloxane fine particles having an extremely sharp particle size distribution and having a high elastic recovery rate and high compression deformation rate.

When the organopolysiloxane fine particles according to the present invention are used as spacers between electrodes of a liquid crystal cell, since the particle size distribution of the fine particles is sharp, a cell gap of the liquid crystal cell, that is, formed between electrodes of the liquid crystal cell. Since the thickness of the liquid crystal layer can be kept uniform, and the elastic recovery rate and compression deformation rate of the fine particles are high, low-temperature air bubbles generated inside the liquid crystal cell are prevented, and as a result, there is no image unevenness. A high-performance liquid crystal display device can be provided.

[0081]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

[0082]

Example 1 A solution (solution A) was prepared by dissolving 8 g of methyltrimethoxysilane and 8 g of tetramethoxysilane in 350 g of ethanol. On the other hand, 6g of pure water, 28%
A mixed solution (Liquid B) of 78 g of ammonia water and 350 g of ethanol was prepared.

Solution A and solution B were mixed and stirred at room temperature for 3 hours to hydrolyze and polycondense the alkoxysilane to obtain a seed particle dispersion. The average particle size of the seed particles in this seed particle dispersion was 0.15 μm as a result of measurement by a centrifugal particle size distribution measuring method.

After concentrating the seed particle dispersion until the obtained seed particle dispersion reached 160 g, 5000 g of pure water and butanol 250 were added to the concentrated seed particle dispersion.
g was added. After adding 100 g of 0.28% aqueous ammonia to the diluted seed particle dispersion, the seed particle dispersion to which the aqueous ammonia was added was cooled to -5 ° C, and while maintaining this temperature, the seed particles were Methyltrimethoxysilane 500 g in the dispersion is 0.005 g /
Pure water was added dropwise at an addition rate of −g · hour, and methyltrimethoxysilane was hydrolyzed and polycondensed on the seed particles to grow the seed particles.

After completion of the dropping, the liquid was heated to 60 ° C. and stirred at this temperature for 5 hours to ripen the grown seed particles.
The obtained fine particles were separated from the liquid, dried, and then baked at 300 ° C.

Organopolish obtained as described above
Of roxane particles²⁹Si-NMR spectrum, average grain
Diameter, CV value, compressive strength, average elastic recovery rate (R_r)^mAnd
And average compressive deformation rate (C_r)^mWas measured. In addition, Olga
The average particle size and CV value of the nopolysiloxane fine particles are
Measured from electron micrographs of Luganopolysiloxane particles
-Calculate, compressive strength, average elastic recovery rate (R_r)^mand
Average compressive deformation rate (C_r) ^mWas measured by the method described above.

From the ²⁹ Si-NMR spectrum, the total area S _T , peak area S _I and peak area S _II of all the above-mentioned peaks were measured, and S _II / S _I and (S _I +
The value of S _II ) / S _T was calculated.

S _II / S _I , (S _I + S _II ) / S _T , average particle size, CV of the obtained organopolysiloxane fine particles.
Table 1 shows the values, compressive strength, average elastic recovery rate (R _r ) ^m, and average compressive deformation rate (C _r ) ^m .

[0089]

Example 2 In the step of growing seed particles, 500 g of vinyltrimethoxysilane and 70.3 g of triisopropoxy-monoacetylacetonatotitanium were used instead of the methyltrimethoxysilane of Example 1 to grow the seed particles. . The fine particles thus obtained were aged, separated, dried and then irradiated with 6000 mJ of ultraviolet rays.
S _II / S _I , (S _I + S _II ) / S _T , average particle size,
Organopolysiloxane fine particles having a CV value, a compressive strength, an average elastic recovery rate (R _r ) ^m and an average compressive deformation rate (C _r ) ^m were obtained.

Of the obtained organopolysiloxane fine particles
²⁹ Si-NMR spectrum (Chemical shift -50-
(Including the 120 ppm region) is shown in FIG.

[0091]

Example 3 N-phenyl-γ-aminopropyltrimethoxysilane was used in place of methyltrimethoxysilane in the step of growing seed particles, and the firing temperature of the fine particles was adjusted to 2
In the same manner as in Example 1 except that the temperature was 70 ° C., S _II / S _I , (S _I + S _II ) / S _T , average particle diameter, and CV shown in Table 1.
Organopolysiloxane microparticles having values, compressive strength, average elastic recovery (R _r ) ^m and average compressive deformation (C _r ) ^m were obtained.

[0092]

Example 4 In the process of growing seed particles, methyltris is used.
Methyltrimethoxysilane instead of 500 g of methoxysilane
400 g of orchid and 100 g of dimethyldimethoxysilane
S shown in Table 1 was used in the same manner as in Example 1 except that it was used._II
/ S_I, (S_I+ S_II) / S _T, Average particle size, CV value, pressure
Shrinkage strength, average elastic recovery rate (R_r)^mAnd average compression deformation
Rate (C_r)^mOrganopolysiloxane fine particles having
Obtained.

[0093]

Example 5 The seed particle dispersion liquid obtained in Example 1 was 1
After concentrating the seed particle dispersion liquid to 60 g, pure water 5000 g and isopropanol 500 g were added to the concentrated seed particle dispersion liquid. After adding 100 g of 0.28% aqueous ammonia to the diluted seed particle dispersion liquid, the seed particle dispersion liquid added with the ammonia water was cooled to 0 ° C., and the seed particle dispersion liquid was maintained at this temperature. 500 g of methyltrimethoxysilane and 7 parts of dibutoxy-bisacetylacetonato zirconium were added to the liquid.
8.8 g was added dropwise at an addition rate of 0.01 g / pure water-g · hour to grow seed particles.

Then, under the same conditions as in Example 2, UV irradiation was performed.
S, shown in Table 1_II/ S_I, (S _I+ S_II) / S_T,
Average particle size, CV value, compressive strength, average elastic recovery rate (R_r)
^m, Average compression deformation rate (C_r)^mOrganopoly with
Roxane fine particles were obtained.

[0095]

Example 6 The average particle size is 0.43 μm in the same manner as in Example 1 except that the amount of methyltrimethoxysilane is 12 g.
m seed particle dispersion was obtained.

After concentrating the seed particle dispersion until the obtained seed particle dispersion reached 160 g, butanol 50 was added.
S _II / S _I shown in Table 1 in the same manner as in Example 1 except that 1000 g of ethylene glycol was used instead of 0 g, and the addition rate of methyltrimethoxysilane was 0.01 g / pure water-g · hour. (S _I + S _II ) / S _T , average particle size, C
Organopolysiloxane fine particles having V value, compressive strength, average elastic recovery (R _r ) ^m and average compressive deformation (C _r ) ^m were obtained.

[0097]

Example 7 The seed particle dispersion liquid obtained in Example 6 was 1
After concentrating the seed particle dispersion to 60 g,
In place of 250 g of nol, 500 g of tetrahydrofuran
Used instead of methyltrimethoxysilane.
Same as Example 1 except that tiltimethoxysilane was used.
And S shown in Table 1_II/ S_I, (S_I+ S_II) /
S _T, Average particle size, CV value, compressive strength, average elastic recovery rate
(R_r)^mAnd the average compression deformation rate (C_r)^mHaving
Luganopolysiloxane fine particles were obtained.

[0098]

[Table 1]

[0099]

Examples 8 to 14 10 g of the organopolysiloxane fine particles obtained in Examples 1 to 7 were mixed with 100 g of a mixed solvent of pure water and methanol [water / methanol = 50/50].
(Weight ratio)].

To this dispersion, 2 g of a 33 wt% aqueous solution of hydrosilicofluoric acid was added, and then 50 g of a 0.6 wt% aqueous solution of sodium borohydride was added over 1 hour. Then, the particles were washed with pure water and dried.

All the obtained fine particles were well dispersed in pure water. Further, the average elastic recovery rate (R _r ) ^m and the average compression deformation rate (C _r ) ^m of the organopolysiloxane fine particles surface-treated as described above were almost unchanged from those before the treatment.

[0102]

Example 15 A pair of transparent substrates with transparent electrodes used in a liquid crystal cell of a liquid crystal display device was prepared. This transparent substrate with a transparent electrode has ITO as a transparent electrode on one side of a glass substrate.
A thin film and an alignment film for aligning liquid crystal compound molecules contained in the liquid crystal material in a predetermined direction are formed in this order.

Next, the organopolysiloxane fine particles obtained in Examples 1 to 7 were uniformly dispersed on the surface of the alignment film formed on one transparent substrate with a transparent electrode. The surface of the alignment film formed on the transparent substrate with a transparent electrode was contacted, and the transparent substrates with a transparent electrode were superposed.

In this way, a liquid crystal material was filled in the gap formed between the alignment films of the transparent substrates with the transparent electrodes, and the peripheral edge portions of both substrates were bonded with a sealing resin and hermetically sealed to form a liquid crystal cell. Further, the produced liquid crystal cell is adapted to be driven in the STN mode.

When the liquid crystal cell prepared as described above was cooled from room temperature to -40 ° C., no low temperature bubbles were observed inside the liquid crystal cell. Further, when the liquid crystal cell produced as described above was attached to a liquid crystal display device and the liquid crystal display device was driven, no unevenness in the display image was observed when any of the liquid crystal cells was attached.

[Brief description of drawings]

FIG. 1 is a drawing for explaining elastic recovery rate and compressive deformation rate.

FIG. 2 is a drawing showing a typical ²⁹ Si-NMR spectrum of organopolysiloxane fine particles according to the present invention.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yutaka Mitsuo 13-2 Kitaminato-cho, Wakamatsu-ku, Kitakyushu-shi, Fukuoka Prefecture Catalyst Chemical Industry Co., Ltd. Wakamatsu Factory

Claims (4)

[Claims] 1. The following formulas (I) and (II): (In the formula (I), X is a hydrogen atom, or Group IB, Group IIA, Group B, Group IIIA, Group B, Group IVA, or Group B of the periodic table.
It is an element selected from Group VA, Group VA, Group B, Group VIA, Group VIIA, and Group VIII, and in the above formula (II), R is a monovalent organic group. ) Organopolysiloxane fine particles containing a siloxane bond represented by the formula (4), wherein the total area S _{T of} all peaks observed within the chemical shift of 0 to −120 ppm when the ²⁹ Si-NMR spectrum of the fine particles is measured. And the above formula (I)
The peak area S corresponding to the siloxane bond represented by
_I and the peak area S _II corresponding to the siloxane bond represented by the above formula (II) satisfy the following formulas: S _II / S _I ≧ 2 and (S _I + S _II ) / S _T ≧ 0.3 Organopolysiloxane fine particles characterized by the above. 2. (a) Formula: Si (OR ¹ ) ₄ (wherein R ¹ is a hydrogen atom or 1 to 1 carbon atoms selected from an alkyl group, an alkoxyalkyl group and an acyl group).
0 is an organic group. ) And an organic silicon compound represented by the formula: R′Si (OR ² ) ₃ (wherein R ² is the same group as R ¹ above, and R ′ is a substituted or unsubstituted hydrocarbon group). Which is a group having 1 to 10 carbon atoms selected from the group), and a step of preparing seed particles by hydrolyzing and polycondensing a mixture with an organic silicon compound represented by the formula (1) in a mixed solvent of water and an organic solvent. (B) In the dispersion liquid of the seed particles, the following formulas (1) to
A step of adding one or more compounds represented by (3) and subjecting them to hydrolysis and polycondensation, thereby growing seed particles to prepare a spherical fine particle dispersion: (1) Formula: R'Si (OR ² ) ₃ (wherein R ² and R ′ are the same groups as described above); (2) Formula: R′R ″ Si (OR ³ ) ₂ (formula In the above, R ′ and R ″ may be the same or different from each other, and are a group having 1 to 10 carbon atoms selected from a substituted or unsubstituted hydrocarbon group, and R ³ is the same as R ¹ above. An organic silicon compound represented by the same group): (3) Formula: (In the formula, R ⁴ is a propyl or butyl group, Y is one organic group selected from a methyl group, a methoxy group, an ethyl group, and an ethoxy group, M is a periodic table group IB, Group IIA, B, IIIA, B
Group, Group IVA, Group B, Group VA, Group VIA, Group VIIA,
Is an element selected from Group VIII, m is an integer of 0 to 3, n is an integer of 1 to 4, m
+ N is an integer of 2-4. The acetylacetonato chelate compound represented by the formula (4), (c) The method for producing organopolysiloxane fine particles according to claim 1, comprising the step of separating the spherical fine particles from the spherical fine particle dispersion and then drying the fine particles. 3. A liquid crystal display device comprising a liquid crystal cell having a pair of electrodes, wherein the organopolysiloxane fine particles according to claim 1 are interposed between the electrodes as spacers. 4. The liquid crystal display device according to claim 3, wherein the compression deformation rate of the organopolysiloxane fine particles is 20 to 60%, and the variation coefficient of the fine particles is 5% or less.