JP3065233B2 - Organopolysiloxane fine particles, method for producing the same, and liquid crystal display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to organopolysiloxane fine particles, a method for producing the same, and a liquid crystal display device in which the organopolysiloxane fine particles are interposed as spacers 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 material is sealed to form a liquid crystal layer. If it is not uniform, the image displayed on the liquid crystal cell may cause color unevenness and decrease in contrast at the time of lighting. Also,
Even when switching the display image at a high speed or displaying an image with a wide viewing angle, the thickness of the liquid crystal layer inside the liquid crystal cell is required to be uniform.

Further, in order to display a large screen without color unevenness in a currently used STN mode large screen liquid crystal display device, it is necessary to further uniform the thickness of the liquid crystal layer inside the liquid crystal cell. Have been.

Conventionally, in order to make the thickness of the liquid crystal layer inside the liquid crystal cell uniform, spherical particles having a uniform particle size are interspersed and interposed between the electrodes of the liquid crystal cell, that is, a spacer between the electrodes of the liquid crystal cell. It is performed as, organic resin particles such as polystyrene as such particles,
Silica fine particles and the like are used.

However, when organic resin particles such as polystyrene are used as inter-electrode spacers of a liquid crystal cell, these organic resin particles are too soft to maintain a uniform thickness of the liquid crystal layer inside the liquid crystal cell. 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 in accordance with the variation in the pressure, and the thickness of the liquid crystal layer inside the liquid crystal cell cannot be maintained uniform.

When silica fine particles are used as a spacer between electrodes of a liquid crystal cell, if the particle size distribution of the silica fine particles is not sharp, the thickness of the liquid crystal layer inside the liquid crystal cell is reduced due to the small compression deformation of the silica fine particles. However, there is a problem that the non-uniformity is not uniform. Further, when the liquid crystal display device is exposed to a low temperature, since the coefficient of thermal expansion of the liquid crystal layer and the coefficient of thermal expansion 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, JP-A-6-250193 discloses a method of preparing silica fine particles by hydrolyzing a hydrolyzable silicon compound, for example, tetraethoxysilane. It has been proposed to use silica fine particles produced by a method of esterifying a silanol group with an organic compound as a spacer between electrodes of a liquid crystal cell.

[0008] The silica fine particles produced by this method are said to be suitable as spacers between electrodes of a liquid crystal cell because they have moderate hardness and mechanical resilience. However, it is insufficient as a spacer between electrodes of a liquid crystal cell.

Japanese Patent Application Laid-Open No. Hei 7-140472 discloses that R ' _m Si (OR ² ) _4-m (where R' and R ² are
Each represents a specific organic group. m is an integer of 0 to 3. Is disclosed that by subjecting the particles obtained by hydrolyzing and condensing the organosilicon compound represented by the formula) to a heat treatment at a temperature of 100 to 1000 ° C., spacer particles for a liquid crystal cell having a specific compression elastic modulus can be obtained. ing. The compression elastic modulus of the spacer particles is controlled by the amount of residual organic groups after a part of the organic groups present inside the particles are thermally decomposed in the heat treatment step.

However, if the particle diameter is different, the amount of organic groups remaining inside the particles after the above heat treatment step is different, and it is difficult to control the amount of the remaining organic groups.
There is a problem that the compressive deformation rate of each particle is not the same, and therefore, it is difficult to adjust the compression elastic modulus of the liquid crystal cell spacer particles to a desired value by the amount of organic groups remaining inside the particles. Further, since the amount of residual organic groups is different between the outside and the inside of the particles, the compression elastic modulus is not uniform over the entire particles, and voids are generated in the organic groups inside the particles thermally decomposed in the heat treatment step. As a result, there is a problem that the compressive strength of the obtained spacer particles for a liquid crystal cell is reduced.

Therefore, the present inventors produced organopolysiloxane microparticles by a specific method using a specific organosilicon compound, and found that the organic group inside the organopolysiloxane microparticles did not undergo the above-mentioned heat treatment step. The amount is controlled, and as a result, fine particles having a high elastic recovery rate and a uniform particle size are obtained. The fine particles are found to be suitable as a spacer between electrodes of a liquid crystal cell, and the present invention is completed. Reached.

JP-A-4-313727 and JP-A-5-80343 describe the use of spherical particles having a specific range of elasticity as spacers between electrodes of a liquid crystal cell. Is a vinyl-based plastic bead or a hybrid particle of an inorganic material and an organic material, and has a high elastic recovery rate by controlling the amount of organic groups inside the organopolysiloxane fine particles, and obtains fine particles having a uniform particle size. It is not described.

[0013]

SUMMARY OF THE INVENTION The present invention has been made to improve the elasticity of silica fine particles, and has a high elastic recovery rate and a uniform particle size of organopolysiloxane fine particles, a process for producing the same, and It is an object of the present invention to provide a liquid crystal display device in which the organopolysiloxane fine particles 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 a group IB, IIA, B, IIIA, B of the periodic table,
IVA, B, VA, B, VIA, VIIA,
An element selected from the group VIII;
Is a monovalent organic group. Are fine particles of an organopolysiloxane containing a siloxane bond represented by the formula (1), and the total area S _{T of} all peaks observed within a chemical shift range of 0 to -120 ppm when a ²⁹ Si-NMR spectrum of the fine particles is measured. And a peak area S _I corresponding to the siloxane bond represented by the above formula (I) and a peak area S _II corresponding to the siloxane bond represented by the above formula (II):
The following formulas are satisfied: S _II / S _I ≧ 2 and (S _I + S _II ) / S _T ≧ 0.3.

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

[0018]

Embedded image

Wherein R ⁴ is a propyl or butyl group, Y is one kind of organic group selected from a methyl group, a methoxy group, an ethyl group and an ethoxy group, and M is IB, IIA, B, IIIA, B, IV
An element selected from A, B, VA, VIA, VIIA, and VIII; m is an integer of 0 to 3; n is an integer of 1 to 4; m + n is an integer of 2 to 4. An acetylacetonato chelate compound represented by the formula (c), wherein the spherical fine particle dispersion is heated to a temperature of 20 to 80 ° C.
Maintaining and aging the spherical fine particles; and (d) separating the spherical fine particles from the spherical fine particle dispersion and drying the fine particles.

Further, the above steps (b), (c) or
By subjecting the organopolysiloxane microparticles obtained in (d) to surface treatment to introduce a hydrophilic group on the surface of the organopolysiloxane microparticles, hydrophilic organopolysiloxane microparticles can be provided.

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

When the organopolysiloxane fine particles according to the present invention are used as spacers between electrodes of a liquid crystal cell, the fine particles have a compressive deformation rate of 20 to 60% and a coefficient of variation of 5% or less. It is preferred that

[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

And a siloxane bond represented by the formula:
In the above formula (I), X is a hydrogen atom, or I of the periodic table.
Group B, IIA, B, IIIA, B, IVA, B,
It is an element selected from VA, B, VIA, VIIA, and 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 organopolysiloxane fine particles. It is a group derived from R 'contained in the organosilicon compound. Note that R 'will be described later in detail.

[0028] of the organopolysiloxane particles ²⁹ Si-
When the NMR spectrum was measured, the chemical shift was 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 ppm position, and when R in the above formula (II) is a methyl group, a peak is observed at about -65 ppm. When R in the formula (II) is a vinyl group, a peak is observed at about -60 ppm.

The organopolysiloxane fine particles according to the present invention
In the child, these²⁹Chemical properties of Si-NMR spectrum
All peaks observed within the range of 0 to -120 ppm
Total area S of_TAnd a siloxane represented by the above formula (I)
Peak area S corresponding to the bond _IAnd represented by the above formula (II)
Area S corresponding to the siloxane bond_IIAnd the following
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.

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

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

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

Using a micro compression tester (MCTM-200 manufactured by Shimadzu Corporation) as a measuring device, using one fine particle having a particle size of D as a sample, applying a predetermined load value (reversal) to the sample at a constant load speed. When the load is applied up to the load value and the particles are deformed, 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 a constant load value (the load value for the origin) at the same unloading speed as the above-mentioned load speed, the displacement gradually decreases according to the curve B. When the difference between the amount of displacement of the origin load value when the load and the displacement of the inverted load value and L _1, the difference in the amount of displacement of the load and each of the origin load value at the time of unloading and L _2, the Elastic recovery rate _Rr and compressive deformation rate C of the sample
_r is calculated by the following equation: R _r = [(L ₁ −L ₂ ) / L ₁ ] × 100 _Cr = (L ₁ / D) × 100

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

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

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

As described above, the particle diameter distribution of the organopolysiloxane fine particles according to the present invention is extremely sharp. 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
And an organosilicon compound represented by the formula: R'Si (OR ² ) ₃ (hereinafter referred to as organosilicon compound (B)). Is added to a mixed solvent of water and an organic solvent to effect hydrolysis and polycondensation, thereby preparing seed particles. As a method for preparing the seed particles, a conventionally known method can be employed.

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, and may be the same or different. It is preferable that the organic silicon compound A and the organic silicon compound B are the same groups because they are simultaneously hydrolyzed in a mixed solvent of water and an organic solvent and co-polymerize the hydrolysates. Is preferred.

R ′ in the above formula represents a hydrocarbon group having 1 to 10 carbon atoms selected from a substituted or unsubstituted hydrocarbon group. Among them, 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.
A substituted hydrocarbon group is a group in which part or all of the hydrogen atoms of a hydrocarbon is substituted with a non-hydrocarbon group or an element other than hydrogen, and specifically, a chloroalkyl group, a γ-methacryloxypropyl group, a γ -Glycidoxypropyl group, aminopropyl group, 3,4-epoxycyclohexylethyl group,
γ-mercaptopropyl group, trifluoropropyl group,
And a fluorocarbon group.

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

Specific examples of the organosilicon compound (B) include methyltrimethoxysilane, methyltriethoxysilane, methyltriisopropoxysilane, methyltris (methoxyethoxy) silane, ethyltrimethoxysilane, vinyltrimethoxysilane, and phenyltrimethoxysilane. Methoxysilane, γ-chloropropyltrimethoxysilane, γ-
Glycidoxypropyltrimethoxysilane, methyltriacetoxysilane, phenyltriacetoxysilane and the like can be mentioned.

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

In the above 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 above 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)
Hydrolysis occurs simultaneously in a mixed solvent of water and an organic solvent, and these hydrolysates are co-condensed to prepare seed particles, but when the mixed solvent of water and the organic solvent is kept alkaline. , These reactions are promoted.

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

The average particle size of the obtained seed particles is preferably 0.05 to 2.0 μm. (B) Next, the dispersion of the seed particles obtained in the above step (a) is added to the dispersion of the compound represented by the following formulas (1) to (3).
The seed particles are grown by adding a seed or two or more kinds and subjecting them to hydrolysis and polycondensation to prepare a spherical fine particle dispersion having an arbitrary particle diameter.

(1) An organosilicon compound represented by the 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 (wherein R ′ and R ″ may be the same or different from each other, and may be a substituted or unsubstituted carbonized An organosilicon compound (hereinafter, referred to as an organosilicon 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 R ¹ above; Equation (3):

[0052]

Embedded image

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

When R ′ in the organosilicon compounds (C) and (D) and R ″ in the organosilicon compound (D) used in this step (b) each have a large number of carbon atoms, the organosilicon compound When (C) and / or (D) are added to the seed particle dispersion, a gel is likely to be formed in the seed particle dispersion, and the growth of the seed particles becomes difficult.

For this reason, it is preferable that both R ′ and R ″ are 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, dimethylacetoxysilane, and the like.

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

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

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

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

When ammonia is used as the hydrolysis catalyst in the above step (b), the compound may be added to the seed particle dispersion to which ammonia water has been added, and the ammonia water and the compound may be simultaneously added to the seed particle dispersion. It may be added. At this time, the concentration of ammonia in the seed particle dispersion is preferably lower than the concentration in the solvent adjusted in the step (a).

When one or more of the compounds represented by the above formulas (1) to (3) are added to the seed particle dispersion as described above, these compounds are hydrolyzed, and The seed particles or the hydrolysates are polycondensed and adhere to the seed particles, whereby the seed particles grow.

[0063] The reaction temperature is not lower than the reaction temperature in the step (a). Specifically, the temperature is preferably about -10 to 20C. (C) The spherical fine particle dispersion is maintained at a temperature of 20 to 80 ° C. for about 0.5 to 24 hours to mature the spherical fine particles.

(D) The matured spherical fine particles are separated from the spherical fine particle dispersion by a centrifugation method or the like, and then dried. Further, in order to promote and complete the polycondensation of the compound, if necessary, a treatment such as baking the aged spherical fine particles or irradiating the spherical fine particles with electromagnetic waves such as ultraviolet rays is performed.

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.

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 comprises the above steps (a) to (d). There is no particular limitation as long as the organopolysiloxane fine particles according to the present invention are produced including (d) , and for example, the following steps are included after the above steps (b) , (c) or (d). You may go out.

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

In such a case, for example, a hydrophilic treatment such as introduction of a hydrophilic group on the surface of the organopolysiloxane fine particles is performed. Such a hydrophilization treatment is not particularly limited, for example, a hydrolyzable organosilicon compound such as tetraalkoxylan,
A method of coating the surface of the organopolysiloxane fine particles with another metal alkoxide or a hydrolyzate obtained by hydrolyzing a mixture thereof is exemplified.

In the present invention, the organopolysiloxane fine particles obtained in the above step are dispersed in an aqueous solution of a mixture of hydrofluorosilicic acid and alcohol, and an aqueous solution of boric acid or sodium borohydride is added to the obtained dispersion. It is preferable to coat the surface of the organopolysiloxane fine particles with the obtained silicon oxide. By doing so, hydrophilic organopolysiloxane fine particles having a further excellent elastic modulus or at least maintaining the elastic modulus before coating can be obtained.

The organopolysiloxane fine particles are dispersed in an aqueous solution of a hydrofluoric acid-alcohol mixture, and an aqueous solution of sodium borohydride 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 ) generated according to + 3NaBF ₄ + 12H ₂ adheres to the surface of the organopolysiloxane fine particles.

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

Finally, the liquid crystal display device according to the present invention will be specifically described. A liquid crystal display device according to the present invention includes a liquid crystal cell having a pair of electrodes, wherein the organopolysiloxane fine particles according to the present invention are interposed between the electrodes as spacers.

The liquid crystal cell has the same structure as the 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 interposed as a spacer between the electrodes of the liquid crystal cell over the entire surface of the electrode, but may be interposed in the adhesive layer at the peripheral portion between the electrodes. May be.

When the organopolysiloxane fine particles according to the present invention are used as a spacer 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. Is done.

The uniformity of the particle size is particularly important, and the CV value as an index thereof is preferably 5% or less, particularly preferably 3% or less. Also, 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 compression deformation of the spacer particles. When the organopolysiloxane fine particles according to the present invention are used as an inter-electrode spacer of a liquid crystal cell, in order to prevent low-temperature bubbles generated due to a difference between the thermal expansion coefficient and the thermal expansion coefficient of the spacer, the average elasticity recovery defined above. The rate (R _r ) ^m is preferably 60 to 90%, and the average compressive 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 a spacer between electrodes of a liquid crystal cell, the organopolysiloxane fine particles are applied to one of the electrode surfaces (the surface of the protective film when a protective film is formed on the electrode surface). ) Is uniformly dispersed by a wet method or a dry method, and then on the organopolysiloxane fine particles dispersed on one electrode surface (or the surface of the protective film), and on the other electrode surface (or the surface of the protective film).
The liquid crystal material is filled in the cell gap formed by this, and the peripheral portions of both electrode surfaces are bonded with a sealing resin, and sealed, thereby providing a liquid crystal display device according to the present invention. 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.

In the liquid crystal cell used in the liquid crystal display device according to the present invention, the sealing resin in which the organopolysiloxane fine particles according to the present invention are mixed is applied to the periphery of one electrode surface (or the surface of the protective film). Is applied except for the liquid crystal material injection port, and then the other electrode surface (or the surface of the protective film) is placed and overlapped. After the liquid crystal material is injected from the liquid crystal material injection port, the liquid crystal material is injected. It can also be obtained by sealing the inlet with a sealing resin.

[0079]

According to the present invention, organopolysiloxane fine particles having an extremely sharp particle size distribution and a high elastic recovery rate and a high compressive deformation rate are provided.

When the organopolysiloxane fine particles according to the present invention are used as a spacer between electrodes of a liquid crystal cell, the particle size distribution of the fine particles is sharp. Since the thickness of the liquid crystal layer can be kept uniform and the fine particles have a high elastic recovery rate and a high compressive deformation rate, low-temperature 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, pure water 6g and 28%
A mixed solution (solution B) of 78 g of aqueous ammonia and 350 g of ethanol was prepared.

The above solution A and solution B were mixed, stirred at room temperature for 3 hours, and hydrolyzed and polycondensed 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 measured by a centrifugal particle size distribution measuring method.

After the seed particle dispersion was concentrated until the obtained seed particle dispersion reached 160 g, 5000 g of pure water and 250 ml of butanol were added to the concentrated seed particle dispersion.
g was added. After adding 100 g of 0.28% aqueous ammonia to the seed particle dispersion thus diluted, 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 dispersed. 500 g of methyltrimethoxysilane was added to the dispersion at a rate of 0.005 g /
The solution was added dropwise at a rate of pure water-g · hour, and methyltrimethoxysilane was hydrolyzed and polycondensed on the seed particles to grow the seed particles.

After completion of the dropwise addition, 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 fired at 300 ° C.

The organopolicy obtained as described above
Loxane fine particles²⁹Si-NMR spectrum, average grain
Diameter, CV value, compressive strength, average elastic recovery (R_r)^mAnd
And average compressive deformation rate (C_r)^mWas measured. In addition, Olga
The average particle size and CV value of
Measured from electron micrographs of luganopolysiloxane particles
・ Calculate, compressive strength, average elastic recovery (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 peaks described above were measured, and S _II / S _I and (S _I +
To calculate the value of the S _II) / S _T.

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 (R _r ) ^m and average compressive deformation (C _r ) ^m .

[0089]

Example 2 In the step of growing the seed particles, the seed particles were grown using 500 g of vinyltrimethoxysilane and 70.3 g of titanium triisopropoxy-monoacetylacetonato in place of the methyltrimethoxysilane of Example 1. . The fine particles thus obtained were aged, separated and dried, and then irradiated with 6000 mJ of ultraviolet light.
_SII / S _I , (S _I + S _II ) / S _T , average particle size,
Organopolysiloxane fine particles having a CV value, compressive strength, average elastic recovery (R _r ) ^m and average compressive deformation (C _r ) ^m were obtained.

Of the obtained organopolysiloxane fine particles.
²⁹ Si-NMR spectrum (chemical shift -50 to-
2 (including the 120 ppm region) is shown in FIG.

[0091]

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

[0092]

Embodiment 4 In the step of growing seed particles, methyl tri
Methyltrimethoxysilane instead of 500 g of methoxysilane
400 g of orchid and 100 g of dimethyldimethoxysilane
Except for using, the same as in Example 1_II
/ S_I, (S_I+ S_II) / S _T, Average particle size, CV value, pressure
Shrinkage strength, average elastic recovery (R_r)^mAnd average compression deformation
Rate (C_r)^mOrganopolysiloxane fine particles having
Obtained.

[0093]

Example 5 The seed particle dispersion obtained in Example 1 was 1
After the seed particle dispersion was concentrated to 60 g, 5000 g of pure water and 500 g of isopropanol were added to the concentrated seed particle dispersion. After 100 g of 0.28% ammonia water is added to the seed particle dispersion thus diluted, the seed particle dispersion to which the ammonia water has been added is cooled to 0 ° C., and while maintaining this temperature, the seed particle dispersion is dispersed. 500 g of methyltrimethoxysilane and dibutoxy-bisacetylacetonatozirconium 7
8.8 g was added dropwise at an addition rate of 0.01 g / pure water-g · hour to grow seed particles.

Thereafter, the ultraviolet irradiation was performed under the same conditions as in Example 2.
Shot 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 (R_r)
^m, Average compressive deformation rate (C_r)^mOrganopolicy with
Loxane fine particles were obtained.

[0095]

Example 6 The same procedure as in Example 1 was repeated except that the amount of methyltrimethoxysilane was changed to 12 g, and the average particle size was 0.43 μm.
m of the seed particle dispersion was obtained.

After the seed particle dispersion was concentrated until the obtained seed particle dispersion reached 160 g, butanol 50
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 _II / S _I shown in Table 1 was used. (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 obtained in Example 6 was 1
After concentrating the seed particle dispersion to 60 g,
500 g of tetrahydrofuran instead of 250 g of phenol
Used instead of methyltrimethoxysilane.
Same as Example 1 except that tyltrimethoxysilane 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
(R_r)^mAnd average compressive deformation rate (C_r)^mOh with
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 each mixed with 100 g of a mixed solvent of pure water and methanol [water / methanol = 50/50].
(Weight ratio)].

After adding 2 g of a 33% by weight aqueous solution of hydrosilicofluoric acid to this dispersion, 50 g of a 0.6% by weight aqueous solution of sodium borohydride was added over 1 hour. Thereafter, the particles were washed with pure water and dried.

Each of the obtained fine particles was well dispersed in pure water. In addition, the average elastic recovery (R _r ) ^m and the average compressive deformation (C _r ) ^m of the organopolysiloxane fine particles surface-treated as described above hardly changed from those before the treatment.

[0102]

Example 15 A pair of transparent substrates with transparent electrodes used for a liquid crystal cell of a liquid crystal display device was prepared. This transparent substrate with a transparent electrode is made of 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 spread on the alignment film surface formed on one of the transparent substrates provided with the transparent electrodes. The surfaces of the alignment films formed on the transparent substrates with transparent electrodes were brought into contact with each other, and the transparent substrates with transparent electrodes were overlapped.

The gap formed between the alignment films of the transparent substrates with the transparent electrodes was filled with a liquid crystal material, the peripheral portions of the two substrates were bonded together with a sealing resin, and sealed to form a liquid crystal cell. Further, the created liquid crystal cell is driven in the STN mode.

When the liquid crystal cells prepared as described above were cooled from room temperature to -40 ° C., no low-temperature bubbles were observed inside any of the liquid crystal cells. When the liquid crystal cell prepared as described above was mounted on a liquid crystal display and the liquid crystal display was driven, no unevenness of the displayed image was observed with any of the liquid crystal cells.

[Brief description of the drawings]

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

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

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Yutaka Mitsuo 13-2 Kitaminato-cho, Wakamatsu-ku, Kitakyushu-shi, Fukuoka Prefecture Inside the Wakamatsu Plant of Catalysis Chemical Industry Co., Ltd. (56) References JP-A-5-148364 (JP, A JP-A-6-248081 (JP, A) JP-A-2-255837 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08G 77/14 C08G 77/06 G02F 1 / 1339 500 WPI (DIALOG)

Claims (4)

(57) [Claims] 1. The following formulas (I) and (II): (In the above formula (I), X is a hydrogen atom or a group IB, IIA, B, IIIA, B, IVA, B of the periodic table.
Group, group VA, group B, group VIA, group VIIA, group VIII. In the above formula (II), R is a monovalent organic group. Are fine particles of an organopolysiloxane containing a siloxane bond represented by the formula (1), and the total area S _{T of} all peaks observed within a chemical shift range of 0 to -120 ppm when a ²⁹ Si-NMR spectrum of the fine particles is measured. And the 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 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-mentioned. (A) Formula: Si (OR ¹ ) ₄ (where R ¹ is a hydrogen atom or a C ¹ to C ¹ selected from an alkyl group, an alkoxyalkyl group and an acyl group)
It is an organic group of 0. And an organosilicon compound represented by the formula: R′Si (OR ² ) ₃ (wherein R ² is the same group as R ^1, and R ′ is a substituted or unsubstituted hydrocarbon group) Preparing a seed particle by hydrolyzing and condensing a mixture of an organosilicon compound represented by the formula (1) and an organic silicon compound represented by the formula (1) in a mixed solvent of water and an organic solvent: (B) The dispersion of the seed particles is represented by the following formulas (1) to (1).
A step of adding one or more of the compounds represented by (3) and subjecting them to hydrolysis and polycondensation to thereby grow seed particles to prepare a spherical fine particle dispersion ( the step (b))
Is lower than the reaction temperature of step (a)) : (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 (wherein R ′ and R ″ may be the same or different from each other, and may be substituted or unsubstituted An organic silicon compound represented by the following formula: embedded image wherein R ³ is a group having 1 to 10 carbon atoms selected from a hydrocarbon group, and R ³ is the same as R ¹ . (Wherein, R ⁴ is a propyl or butyl group, Y is one kind of organic group selected from a methyl group, a methoxy group, an ethyl group and an ethoxy group, M is a group IB of the periodic table, Groups IIA and B, III A and B
Groups, IVA, B, VA, VIA, VIIA,
An element selected from Group VIII, m is an integer of 0 to 3, n is an integer of 1 to 4,
+ N is an integer of 2 to 4. An acetylacetonato chelate compound represented by the formula (c), wherein the spherical fine particle dispersion is heated to a temperature of 20 to 80 ° C.
The method for producing organopolysiloxane fine particles according to claim 1, comprising a step of maintaining and aging the spherical fine particles, and (d) a 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 organopolysiloxane fine particles have a compressive deformation ratio of 20 to 60% and a coefficient of variation of the fine particles is 5% or less.