JPH11218769A - Color spacer for liquid crystal display plate, its production and liquid crystal display plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a spacer for a liquid crystal display plate which has enough strength and hardness to make the gap control easy without causing irregular gap, which causes no coloring or bleeding of impurities due to the coloring agent, and which hardly leaks light, by chemically bonding a coloring agent to a coating polymer to constitute the spacer. SOLUTION: The functional group Y has a coating polymer and reacts with the functional group X present on the surface of a coloring agent (pigment). Both of the functional groups X, Y react shown as the arrow to complete the chemical bond between the coloring agent and the coating polymer. The group Y is preferably hydrolyzable silyl groups, epoxy groups, oxazoline groups, aziridine groups, NCO groups, unsatd. double bond groups or the like. The group X is preferably hydrolyzable silyl groups, NH2 groups, COOH groups, OH groups, SH groups or the like. The group X and the group Y may be designed vice versa. The bond between the coloring agent and the coating polymer is a kind of graft bond.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a colored spacer for a liquid crystal display panel, a method for producing the same, and a liquid crystal display panel.

[0002]

2. Description of the Related Art A liquid crystal display panel includes a spacer and a liquid crystal (LC) between two electrode substrates for maintaining a uniform gap distance (cell gap) between the substrates. When a backlight is applied to this liquid crystal display panel, since there is no liquid crystal in the portion where the spacer is present, light from the backlight escapes, and the contrast of the image is reduced and the display quality is deteriorated. Was. In particular, in the STD-LCD, since the display is in a normally black mode, it is required to suppress light leakage from a portion where the spacer exists.

As a method for suppressing light leakage from the spacer portion, a method of coloring spacer particles has been attempted. Conventionally known coloring methods include a method using a coloring agent such as a dye or a pigment. The method of coloring with a dye includes a method of post-dying the obtained particles with a dye (JP-A-3-33165, JP-A-4-103633, JP-A-4-351639, etc.) and a monomer. Suspension polymerization of dye and dye (JP-A-5-30)
1909).

However, in the above method, the particle structure on the particle surface is cut off during dyeing, so that the strength of the particles is reduced. When such a particle is used as a spacer to form a liquid crystal display panel, two electrodes are used. When combining the substrates, the spacer existing between the electrode substrates is easily deformed, and in some cases it is difficult to break down, so that it is difficult to make the cell gap uniform,
Gap non-uniformity may occur, which may cause color non-uniformity of an image due to the gap non-uniformity.

[0005] On the other hand, in the other method, a dye having a polymerization inhibiting action may be contained in the dye, and the resulting polymer has a low degree of polymerization, or particles having sufficient strength cannot be obtained. Or it may be soft. When a liquid crystal display panel is assembled using such particles as spacers, the strength of the spacers is insufficient, so that gap control is difficult and gap unevenness occurs, and as a result, image color unevenness may occur.

[0006] In any of the above methods, when a dye is used, it is difficult to immobilize the dye in the particle matrix, so that the dye or impurities in the dye elute into the liquid crystal, and There may be a problem in reliability such as electric characteristics. Next, a coloring method using a pigment includes a method in which a monomer and a pigment are subjected to suspension polymerization (Japanese Patent Laid-Open No. 7-29).
No. 13, JP-A-9-25309, etc.), but it is difficult to uniformly disperse the pigment in the monomer because the pigment is easily agglomerated, and even if polymerized, uncolored particles may be obtained. . In particular, carbon black is advantageous because the resulting particles can be made black, but the hydroxyl and carboxyl groups on the carbon black surface have the effect of inhibiting or inhibiting the polymerization, so that the degree of polymerization of the monomer during polymerization is reduced. If it is too low, the resulting particles may not have sufficient strength or may be too soft. When assembling a liquid crystal display panel using such particles as spacers,
As in the case of the dye method, there is a problem that it is difficult to perform gap control, gap unevenness occurs, and color unevenness of an image easily occurs. In addition, in the case of carbon black,
There is a problem that the insulating property of the spacer is reduced due to the conductivity of the carbon black and light leakage around the spacer is large, so that it may be difficult to use the liquid crystal display panel.

Further, recently, LCDs for monitors have been developed, and there is a growing demand for larger LCD panels (13 inches or more), higher display quality (contrast and color unevenness), and improved reliability. Therefore, it is also desired to improve the quality of the spacer.

[0008]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to improve such a problem, and when assembled on a liquid crystal display panel, gap unevenness does not occur and gap control is easily performed. It is an object of the present invention to provide a colored spacer for a liquid crystal display panel which has strength and hardness, has no bleeding of a coloring agent and impurities derived therefrom, and has little light leakage around the spacer.

Another object of the present invention is to provide a method for producing the colored spacer for a liquid crystal display panel. Another object of the present invention is to provide a liquid crystal display panel using the colored spacer for a liquid crystal display panel.

[0010]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, the conventional colored spacers are colored to the inside of the particles, resulting in a decrease in strength and hardness. With attention paid to the fact that the reliability derived from the colorant is reduced, it has been found that these problems can be solved at once by using a colored spacer having a light-shielding layer containing a colorant on the particle surface.

That is, the colored spacer for a liquid crystal display panel according to the present invention is a particle in which the surface of the particle body is coated with a colorant and a polymer, and the colorant is chemically bonded to the coating polymer. . In the colored spacer according to the present invention, the polymer covering the particle main body is preferably crosslinked, and the surface of the particle main body and the coating polymer are also preferably chemically bonded.

The method for producing a colored spacer for a liquid crystal display panel according to the present invention includes a step of coating the surface of a particle main body with a colorant graft polymer obtained by chemically bonding a colorant to a coating polymer. The method for producing a colored spacer according to the present invention preferably includes a step of crosslinking the colorant graft polymer, and further preferably includes a step of reacting the surface of the particle body with the colorant graft polymer.

[0013] A liquid crystal display panel according to the present invention is characterized by including the colored spacer.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION In the following, after describing the particle body, the colorant and the polymer, the chemical bond between the colorant and the coating polymer and the chemical bond between the particle body surface and the coating polymer will be described. Particle Body Since the particle body used in the present invention is preferably chemically bonded to the coating polymer as described later, a functional group U (epoxy group, hydroxyl group, carboxyl group,
Mercapto group, amino group, vinyl group, oxazoline group,
Aziringin group, isocyanate group, haloalkyl group,
Those having a hydrolyzable silyl group) are preferably selected. A preferred example is a particle containing a hydrolyzable silyl group. The hydrolyzable silyl group is not particularly limited, and examples thereof include an alkoxysilyl group, a silanol group, an acyloxysilyl group and the like. These may be present alone, or may be present in combination of two or more. it can.

The particle body used in the present invention includes, for example, a particle body A obtained by hydrolyzing and condensing a hydrolyzable silicon compound, an organic polymer skeleton, and at least one of the organic polymer skeleton. Organic-inorganic composite particles (particle body B) containing a polysiloxane skeleton having an organic silicon in which a silicon atom is chemically bonded directly to a carbon atom in the molecule can be exemplified.

Particle Body A The particle body A is a particle obtained by hydrolyzing and condensing a hydrolyzable silicon compound in a solvent containing water. The hydrolyzable silicon compound used for producing the particle main body A is not particularly limited. For example, the following general formula 1: R ′ _m SiX _4-m (1) (where R ′ is Represents an at least one group selected from the group consisting of an alkyl group, an aryl group and an unsaturated aliphatic residue, which may have a substituent; X represents a hydroxyl group, an alkoxy group and an acyloxy group Represents at least one group selected from the group consisting of: m is an integer of 0 to 3), and its derivatives.

The silane compound represented by the general formula 1 is not particularly limited. For example, compounds having m = 0 include tetramethoxysilane, tetraethoxysilane, tetraisopropoxysilane, tetrabutoxysilane and the like. Functional silanes; m = 1 include methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, phenyltrimethoxysilane, methyltriacetoxysilane, 3
Trifunctional silanes such as glycidoxypropyltrimethoxysilane, vinyltrimethoxysilane and 3- (meth) acryloxypropyltrimethoxysilane; those having m = 2 include dimethyldimethoxysilane, dimethyldiethoxysilane, Bifunctional silanes such as acetoxydimethylsilane and diphenylsilanediol; examples of m = 3 include monofunctional silanes such as trimethylmethoxysilane, trimethylethoxysilane and trimethylsilanol.

Among these, in the general formula, R ′ represents an alkyl group having 1 to 6 carbon atoms, a phenyl group, a vinyl group,
A silane compound containing at least one selected from a glycidoxypropyl group and a 3- (meth) acryloxypropyl group, wherein X is a methoxy group or an ethoxy group, and m is an alkoxy group having a structure of 0 or 1, It is preferable because it is easily available and the colored particles can be easily produced. Such silane compounds include, for example, tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, phenyltrimethoxysilane, methyltriacetoxysilane,
Examples thereof include 3-glycidoxypropyltrimethoxysilane, vinyltrimethoxysilane, and 3- (meth) acryloxypropyltrimethoxysilane.

The hydrolyzable silicon compound may be used alone or in an appropriate combination of two or more. When only the silane compound in which m = 2 or 3 and the derivative thereof in the general formula 1 are used as raw materials, the particle main body A cannot be obtained. The solvent used for producing the particle main body A is not particularly limited as long as it contains water as an essential component, and may further contain an organic solvent. Examples of the organic solvent include methanol,
Alcohols such as ethanol, isopropanol, n-butanol, isobutanol, sec-butanol, t-butanol, pentanol, ethylene glycol, propylene glycol and 1,4-butanediol; ketones such as acetone and methyl ethyl ketone; ethyl acetate and the like (Cyclo) paraffins such as isooctane and cyclohexane; ethers such as dioxane and diethyl ether; and aromatic hydrocarbons such as benzene and toluene. These may be used alone or in combination of two or more. Is done.

In the hydrolysis and condensation, a catalyst may be used to accelerate the reaction. As a catalyst,
For example, acid catalysts such as inorganic acids such as hydrochloric acid, nitric acid and sulfuric acid, and organic acids such as formic acid and acetic acid; ammonia, urea, ethanolamine, tetramethylammonium hydroxide, alkali metal hydroxide, alkaline earth metal hydroxide And the like, and one or more of them can be used.

In the hydrolysis / condensation, for example, a hydrolyzable silicon compound is added to a solvent.
100 ° C, more preferably in the range of 0 to 70 ° C, 30
It is performed by stirring for minutes to 100 hours. The hydrolysis / condensation can employ any reaction method such as batch, division, and continuous. In addition, the particles obtained by the above method are charged as seed particles in a hydrolysis / condensation reaction system in advance, and a hydrolyzable silicon compound is added to grow the seed particles. A may be manufactured.

By hydrolyzing and condensing the hydrolyzable silicon compound in a solvent under appropriate conditions, a slurry in which the particle bodies A are precipitated is generated. The particle main body A is isolated from the slurry using a conventionally known method such as filtration, centrifugation, and concentration under reduced pressure. Further, after the isolation, a heat treatment similar to that described for the particle main body B described below may be performed to obtain the particle main body A.

Particle Body B The particle body B is an organic-inorganic composite particle containing an organic polymer skeleton and a polysiloxane skeleton. In the polysiloxane skeleton, a silicon atom is directly attached to at least one carbon atom in the organic polymer skeleton. It has chemically bonded organic silicon in the molecule.

The particle body B has high hardness, which is a characteristic of the polysiloxane skeleton, and high strength and mechanical resilience, which are the characteristics of the organic polymer skeleton. The colored spacer composed of colored particles obtained by using the particle body B has strength and mechanical strength necessary for maintaining a constant gap distance between a pair of members to be arranged at an accurate interval in a liquid crystal display panel. It has resilience and hardness required to keep the gap distance constant with a small number, and hardly causes physical damage to those members.

The term "organic polymer skeleton" used herein has a repeating unit of a monomer, and includes, for example, an organic polymer skeleton described later. The organic polymer backbone has high mechanical resilience and breaking strength. The organic polymer skeleton is composed of main chains, side chains, branched chains,
It contains at least the main chain of the crosslinked chains. The molecular weight, composition, structure, presence or absence of a functional group, and the like of the organic polymer are not particularly limited.

The organic polymer is, for example, at least one selected from the group consisting of (meth) acrylic resin, polystyrene, polyvinyl chloride, polyvinyl acetate, polyolefin, and polyester. Preferred organic polymers are those having a main chain composed of repeating units -C-C- (hereinafter, referred to as "vinyl-based polymers") because they form particles with particularly excellent mechanical resilience. There is).

The vinyl polymer is, for example, (meth)
It is at least one selected from the group consisting of acrylic resin, polystyrene, polyvinyl chloride, polyvinyl acetate, and polyolefin. Preferred vinyl polymers are at least one selected from the group consisting of (meth) acrylic resins, (meth) acryl-styrene resins, and polystyrene. More preferred vinyl polymers are (meth) acrylic resins and (meth) acryl-styrene resins.

The polysiloxane skeleton is defined as a three-dimensional network in which siloxane units represented by the following formula 5 are continuously chemically bonded. At least one of the carbon atoms constituting the organic skeleton is directly chemically bonded to a silicon atom in the polysiloxane. The amount of SiO ₂ constituting the polysiloxane skeleton is not particularly limited, but is preferably at least 10 wt%, more preferably 15 to 90 wt%, and most preferably 25 to 85 wt%, based on the weight of the particle body B.
%. When the content is in the above range, the particles have an effective hardness and mechanical resilience. If the content is less than 10 wt%, the hardness which is a feature of the inorganic material is hardly developed. In addition, if it exceeds the above range, its mechanical restorability may be impaired, and the residual displacement may increase.

The amount of SiO ₂ constituting the polysiloxane skeleton is a percentage by weight determined by measuring the weight before and after firing the particles at a temperature of 1000 ° C. or more in an oxidizing atmosphere such as air. The method for producing the particle main body B is not particularly limited, but preferred examples include a production method including the following condensation step and polymerization step.

The condensation step is a step of hydrolyzing and condensing a hydrolyzable radical-polymerizable group-containing silicon compound. The polymerization step is a step of causing a radical polymerization reaction of the radically polymerizable group, and is a step performed before, during, or after the condensation step. Hereinafter, the condensation step and the polymerization step will be described.

The radical-polymerizable group-containing silicon compound used in the condensation step is a hydrolyzable silicon compound containing a radical-polymerizable group. The radically polymerizable group-containing silicon compound is not particularly limited. For example, the following general formula 2:

[0032]

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(Wherein, R ¹ represents a hydrogen atom or a methyl group; R ² has 1 to 5 carbon atoms which may have a substituent)
R ³ represents at least one monovalent group selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, and an acyl group having 2 to 5 carbon atoms; Show)
And the following general formula 3:

[0034]

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(Where R ⁴ represents a hydrogen atom or a methyl group; R ⁵ is selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, and an acyl group having 2 to 5 carbon atoms) At least one monovalent group), and the following general formula 4:

[0036]

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(Wherein, R ⁶ represents a hydrogen atom or a methyl group; R ⁷ has 1 to 5 carbon atoms which may have a substituent)
R ⁸ represents at least one monovalent group selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, and an acyl group having 2 to 5 carbon atoms; Show)
Preferred are at least one radical-polymerizable group-containing silicon compound selected from the group consisting of at least one compound represented by the general formula selected from the group consisting of: and derivatives thereof.

In the general formulas 2 to 4, the radically polymerizable groups are CH ₂ ＣC (—R ¹ ) —COOR ² — and CH ₂ ＣC
(—R ⁴ ) — or CH ₂ ＣC (—R ⁶ ) —R ⁷ —
It is. An organic polymer skeleton derived from a vinyl polymer is generated by a radical polymerization reaction of the radical polymerizable group. The radical polymerizable group includes an acryloxy group (when R ¹ is a hydrogen atom in the general formula 2), a methacryloxy group (when R ¹ is a methyl group in the general formula 2), and a vinyl group (when R ⁴ is a general formula 3) A hydrogen atom), an isopropenyl group (R ^{4 in the} general formula 3)
Is a methyl group), a 1-alkenyl group or a vinylphenyl group (when R ⁶ is a hydrogen atom in the general formula 4), or an isoalkenyl group or an isopropenylphenyl group (where R ⁶ is a methyl group in the general formula 4) If it is a group).

In the general formulas 2 to 4, the hydrolyzable group is R
³ O, R ⁵ O and R ⁸ O. The R ³ O group, R ⁵ O group and R ⁸ O group are monovalent groups selected from the group consisting of a hydroxyl group, an alkoxy group having 1 to 5 carbon atoms, and an acyloxy group having 2 to 5 carbon atoms. In the general formulas 2 to 4, three R
^{The 3} O group, the three R ⁵ O groups and the R ⁸ O group are
They may be different from each other, or two or more may be the same. Preferred R ³ O, R ⁵ O, and R ⁸ O groups are selected from the group consisting of methoxy, ethoxy, propoxy, and acetoxy in view of high hydrolysis / condensation rate. And ethoxy groups are more preferred. The radical polymerizable group-containing silicon compound is represented by R
³ O group · R ⁵ O groups · R ⁸ O group is hydrolyzed by water, by further condensation to form a polysiloxane skeleton represented by formula 5 above.

In the general formulas 2 to 4, R ² and R ⁷
The group is a divalent organic group having 1 to 20 carbon atoms which may have a substituent. The divalent organic group is not particularly limited. For example, an ethylene group, a propylene group, a butylene group, a hexylene group, which may have a substituent,
Examples include an alkylene group such as an octylene group, a phenylene group which may have a substituent, or a group in which an alkylene group or a phenylene group which may have these substituents is bonded via an ether bond. Can be. It is preferable that R ² and R ⁷ are a propylene group or a phenylene group because they are easily available.

The compound represented by at least one general formula selected from the group consisting of general formulas 2, 3 and 4 has one silicon atom, three hydrolyzable groups bonded to the silicon atom, It has one radically polymerizable group bonded to a silicon atom. Examples of the compound represented by the general formula 2 include γ-methacryloxypropyltrimethoxysilane,
γ-methacryloxypropyltriethoxysilane, γ-
Acryloxypropyltrimethoxysilane, γ-acryloxypropyltriethoxysilane, γ-methacryloxypropyltriacetoxysilane, γ-methacryloxyethoxypropyltrimethoxysilane (or γ-trimethoxysilylpropyl-β-methacryloxyethyl ether Etc.), and these are 1
Seeds or two or more are used.

The compound represented by the general formula 3 includes, for example, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane and the like, and one or more of these are used. Examples of the compound represented by the general formula 4 include 1-hexenyltrimethoxysilane, 1-octenyltrimethoxysilane, 1-decenyltrimethoxysilane, γ-trimethoxysilylpropyl vinyl ether, ω-trimethoxysilylundecane Acid vinyl esters, p-trimethoxysilylstyrene and the like can be mentioned, and one or more of these are used.

As the radically polymerizable group-containing silicon compound, a compound represented by the general formula 2 or 3 is preferable because it is easy to form a particle body B having a sharp particle size distribution, and γ-methacryloxypropyltrimethoxy is preferred. Silane, γ-methacryloxypropyltriethoxysilane, γ-acryloxypropyltrimethoxysilane,
At least one selected from the group consisting of γ-acryloxypropyltriethoxysilane, vinyltrimethoxysilane and vinyltriethoxysilane is particularly preferred.

In the condensation step, the radically polymerizable group-containing silicon compound is combined with other hydrolyzable and condensable metal compounds used as necessary (hereinafter, these may be referred to as "raw materials"). Hydrolysis in solvents containing water
To condense. The method of hydrolysis / condensation is not particularly limited, but is not limited to the hydrolysis / condensation described in the above-mentioned particle body A.
The method of condensation can be mentioned.

Next, the polymerization step is a step in which a radical polymerizable group undergoes a radical polymerization reaction before, during, or after the condensation step. In the polymerization step, that is, the radical polymerizable group-containing silicon compound may be subjected to radical polymerization before the condensation step, and an intermediate product / particle obtained by hydrolysis / condensation of the radical polymerizable group-containing silicon compound may be used. Radical polymerization may be performed. The radical polymerizable group undergoes a radical polymerization reaction to form an organic polymer skeleton.

As a method for radical polymerization, a radical polymerization initiator may be dissolved in an organic solvent and polymerized by dissolving the radical polymerization initiator in an organic solvent, or the radically polymerizable group-containing silicon compound may be hydrolyzed and condensed. A water-soluble or oil-soluble radical polymerization initiator is added to and dissolved in a solvent slurry containing water of the obtained intermediate product or particles, and may be polymerized as it is, or may be obtained by hydrolysis and condensation. Intermediate products and particles are isolated from the slurry using conventionally known methods such as filtration, centrifugation, and concentration under reduced pressure, and then dispersed and polymerized in a solution containing a radical polymerization initiator in water or an organic solvent. However, the present invention is not limited to these. In particular, it is preferable to carry out the polymerization step during the condensation step and / or after the condensation step because the resulting particles are less likely to aggregate. Among them, a method in which a radical polymerization initiator is allowed to coexist while hydrolyzing and condensing the above-described raw materials to simultaneously perform radical polymerization is preferable. The reason for this is that the formation of a polysiloxane in which siloxane units represented by the following formula 5 are continuously chemically bonded and the formation of an organic polymer by polymerization occur in parallel. This is because it is easy to obtain the particle main body B having the mechanical resilience.

[0047]

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Here, as the radical polymerization initiator, conventionally known ones can be used and are not particularly limited, but are preferably at least one compound selected from azo compounds, peroxides and the like. The amount of the above-mentioned radical polymerization initiator is not particularly limited, but when used in a large amount, the calorific value increases, and it becomes difficult to control the reaction.On the other hand, in the case of using a small amount, the radical polymerization may not progress. It is preferably in the range of 0.1 to 5 wt%, more preferably 0.3 to 2 wt%, based on the weight of the radical polymerizable group-containing silicon compound.

The temperature at the time of radical polymerization can be appropriately selected depending on the radical polymerization initiator to be used, but is preferably in the range of 30 to 100 ° C., more preferably 50 to 80 ° C., in order to easily control the reaction. It is. Further, at the time of radical polymerization, radical polymerization may be carried out in the presence of a monomer having a radical polymerizable group and a radical polymerizable group. Examples of the monomer include unsaturated carboxylic acids such as acrylic acid and methacrylic acid; acrylic esters, methacrylic esters, crotonic esters, itaconic esters, maleic esters,
Unsaturated carboxylic acid esters such as fumaric acid esters; acrylamides; methacrylamides; aromatic vinyl compounds such as styrene, α-methylstyrene, divinylbenzene, etc .; vinyl esters such as vinyl acetate; Examples thereof include vinyl compounds such as vinyl compounds, and these may be used alone or in combination of two or more.

However, if the content of the polysiloxane skeleton described below contained in the particle body B using a large amount of the monomer is less than 10 wt%, the hardness may be insufficient. For this reason, the amount of the monomer is preferably 0 to 200 w with respect to the weight of the radically polymerizable group-containing silicon compound.
t%, more preferably 0 to 100 wt%. The particle body B is isolated from the reaction mixture (slurry) using a conventionally known method such as filtration, centrifugation, and vacuum concentration, and then, if necessary, preferably at a temperature of 500 ° C. or lower,
More preferably, heat treatment for drying and firing may be further performed at a temperature of 100 to 400C, most preferably 100 to 300C.

When the above heat treatment is carried out at a low temperature, the following formula 6 present in the siloxane unit represented by the formula 5:

[0052]

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Since the dehydration condensation reaction between the silanol groups represented by the formula (1) does not occur sufficiently, the required hardness may not be obtained. In addition, when the heat treatment is performed at a temperature higher than 500 ° C., the decomposition of the organic polymer skeleton in the particle main body becomes remarkable, so that the particle main body B cannot be obtained. Further, the atmosphere at the time of the heat treatment is not particularly limited. However, in order to suppress the decomposition of the organic polymer skeleton, the oxygen concentration in the atmosphere should be less than 10%.
It is more preferable that the content is not more than the volume%. Heat treatment temperature is 2
In the case where the temperature is in the range of 00 ° C. to 500 ° C., in order to obtain the particle body B having preferable physical properties, the oxygen concentration in the atmosphere at the time of heat treatment is preferably 10% by volume or less. When the heat treatment temperature is 200 ° C. or lower, the particle body B having preferable physical properties is generated even in air. Colorant Since the colorant must be chemically bonded to the coating polymer as described below, the functional group X (epoxy group, amino group, isocyanate group, hydroxyl group, carboxyl group, Hydrolyzable silyl groups such as a decomposable silyl group, a mercapto group, a haloalkyl group, a vinyl group, an oxazoline group, and an aziringin group are the same as the groups described in the particle main body). Preferable examples of the coloring agent include a dye and a pigment, and the above-mentioned functional group X is contained in the structure.

The dye is not particularly limited as long as it contains the functional group X in the structure. Examples thereof include azo dyes such as pyrazolone azo dye, stilbene azo dye and thiazole azo dye; Anthraquinone dyes such as anthraquinone derivatives and anthrone derivatives; indigoid dyes such as indigo derivatives and thioindigo derivatives; phthalocyanine dyes; diphenylmethane dyes;
Phenylmethane dyes such as triphenylmethane dyes;
Xanthene dyes; acridine dyes; nitro dyes;
Nitroso dyes; azine dyes; oxazine dyes; thiazine dyes; quinoline dyes; methine dyes such as cyanine (polymethine) dyes and azomethine dyes; benzoquinone dyes; naphthoquinone dyes; naphthalimide dyes; Dyes; azole dyes and the like. Among these, when the dye is at least one selected from anthraquinone dyes, benzoquinone dyes and naphthoquinone dyes, the discoloration is excellent.

The pigment is not particularly limited as long as it contains the above-mentioned functional group. Examples of the pigment include iron oxide and carbon black, and carbon black is preferred because black can be obtained. The color of the dye or pigment is appropriately selected according to the color of the colored particles to be obtained. However, black, dark blue, dark blue, and the like are preferable because they do not easily transmit light. In addition, dyes and pigments
One type may be used alone, or two or more types may be used in appropriate combination. Coating polymer The coating polymer includes a coloring agent and coats the surface of the particle body. It is preferable that the polymer is crosslinked and cured, because the cell gap can be easily controlled. It is preferable that the coating polymer be chemically bonded to the surface of the particle main body because elution of impurities derived from the polymer and the colorant into the liquid crystal is suppressed, and the reliability is improved.

The coating polymer essentially contains a reactive group Y that reacts with the functional group X of the colorant, and preferably reacts with the functional group U on the particle body surface or participates in the crosslinking of the coating polymer. V is also contained. Examples of the reactive groups Y and V include the groups shown in the functional groups X and U. Examples of the coating polymer include a resin containing a homopolymer or a copolymer of an ethylenically unsaturated monomer. Thermoplastic resin is a resin containing a (meth) acrylic polymer containing (meth) acrylate as an essential component as a monomer unit ((meth) acrylic resin), and a styrene compound as a monomer unit. Resin containing styrene-based polymer (styrene-based resin), and resin containing (meth) acryl-styrene-based polymer containing styrene compound and (meth) acrylate as monomer units as essential components ((meth) acryl- At least one member selected from the group consisting of (styrene-based resin) is preferable because of its high adhesion to the particle body. 45 wt% of (meth) acrylate or styrene having an alkyl group having 6 or more carbon atoms as a monomer unit in that the adhesion to the particle body can be increased.
% (Preferably 50 wt% or more, more preferably 60 wt% or more) of a (meth) acryl-styrene resin containing a (meth) acryl-styrene polymer.

The ethylenically unsaturated monomer is not particularly restricted but includes, for example, ethylene, propylene, vinyl chloride, vinyl acetate, styrene, vinyltoluene, α-methylstyrene, (meth) acrylate (for example, , Methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, lauryl (meth) acrylate, cyclohexyl (meth)
Acrylate, 2-ethylhexyl (meth) acrylate, glycidyl (meth) acrylate, trifluoropropyl (meth) acrylate, and the like.

The coating polymer is not limited to the above. For example, polyesters such as polyethylene terephthalate and polybutylene terephthalate; various polyamides; various polycarbonates; various epoxy resins; As the coating polymer, one or more of those mentioned above are used. For typical examples of chemical bonds between the colorant and the polymer of chemical bonding colorant coating polymer is shown in FIG. In FIG. 1, Y is a functional group of the coating polymer, and a functional group X existing on the surface of the colorant (pigment).
Is a functional group that reacts with Both functional groups react as indicated by the arrows in the figure, completing the chemical bond between the colorant and the coating polymer. Preferred examples of the group Y include a hydrolyzable silyl group (silanol group, alkoxysilyl group), an epoxy group,
Examples include an oxazoline group, an aziridine group, an NCO group, and an unsaturated double bond group. Preferred examples of the group X include a hydrolyzable silyl group (silanol group, alkoxysilyl group), NH ₂ group, COOH group, OH And SH groups. The groups X and Y may be provided in reverse.

The binding between the coloring agent and the coating polymer is as follows.
Type of graft bond (hereinafter referred to as colorant
Polymer)), the coating
It may be done at the same time as the limer is synthesized.Chemical bonding between the particle body surface and the coating polymer Typical examples of chemical bonds between the particle body surface and the coating polymer
FIG. In FIG. 2, U and V are the same as X and Y.
Shows a reactive group. As the reactive groups U and V,
Degradable silyl group (silanol group, alkoxysilyl group)
And combinations of epoxy and amino groups are preferred.
Good. In addition, when the coating polymer is cross-linked,
This cross-linking step and the particle-body-coated polymer chemical bonding step
It may be simultaneous.Crosslinking of coated polymer Crosslinking of the coated polymer is caused by the reaction between the reactive groups V.
Done. The reactive group V is a hydrolyzable silyl group (a sila group).
A hydroxyl group and a alkoxyl group). Reaction of functional groups X and Y and reaction of reactive groups U and V Functional groups X and Y, reactive groups U and V, and reactive group V
Cattle reaction may be carried out under conditions where each group reacts,
Preferably, the colorant and the coating poly in the range of room temperature to 200 ° C.
What is necessary is just to contact a polymer, a particle main body, and a coating polymer.
In order to prevent aggregation of the particle body, use of an organic solvent is
preferable. [Coloring spacer for liquid crystal display panel, liquid crystal display panel]
Colored spacers for LCD panels are coated with a colorant
The particle surface is covered with polymer
Since the mechanical properties of the child body are maintained, a pair of electrode substrates
Strength and hardness required to maintain a constant gap distance
Therefore, the gap distance between the pair of electrode substrates is
It is easy to keep the separation constant. Moreover, colorants and coating polymers
Elution of impurities derived from the
It becomes a spacer with high property.

In a liquid crystal display panel, when a voltage is applied between the electrode substrates, the liquid crystal causes an optical change to form an image. On the other hand, the spacer does not show an optical change by voltage application. Therefore, since the spacer of the present invention is colored, in a dark portion when an image is displayed, light leakage occurs, and it is not confirmed as a bright spot,
The contrast of the image quality does not decrease.

In the liquid crystal display panel of the present invention, the colored spacer of the present invention is interposed between the electrode substrates, and has the same or substantially the same gap distance as the particle diameter of the spacer. The liquid crystal display panel of the present invention includes, for example, a first electrode substrate, a second electrode substrate, a colored spacer for a liquid crystal display panel, a sealing material, and a liquid crystal. The first electrode substrate includes: a first substrate;
A first electrode formed on the surface of the first substrate. Second
The electrode substrate has a second substrate and a second electrode formed on the surface of the second substrate, and faces the first electrode substrate. The colored spacer for a liquid crystal display panel is interposed between the first electrode substrate and the second electrode substrate, and is the colored spacer for a liquid crystal display panel of the present invention. The sealant adheres the first electrode substrate and the second electrode substrate at a peripheral portion. The liquid crystal is filled in a space surrounded by the first electrode substrate, the second electrode substrate, and the sealing material.

For the liquid crystal display panel of the present invention, those other than the spacers, such as an electrode substrate, a sealing material, and a liquid crystal, are the same as those in the related art. The electrode substrate has a substrate such as a glass substrate and a film substrate, and an electrode formed on the surface of the substrate.If necessary, an alignment film formed on the surface of the electrode substrate so as to cover the electrode is formed. Have more. As the sealing material, an epoxy resin adhesive sealing material or the like is used. As the liquid crystal, those conventionally used may be used, for example, biphenyl, phenylcyclohexane, Schiff base, azo, azoxy, benzoate,
Terphenyl, cyclohexylcarboxylate, biphenylcyclohexane, pyrimidine, dioxane, cyclohexylcyclohexaneester,
Liquid crystals such as cyclohexylethane, cyclohexene, and fluorine can be used.

As a method for producing the liquid crystal display panel of the present invention, for example, the colored spacer of the present invention is uniformly dispersed on one of the two electrode substrates by a wet method or a dry method as an in-plane spacer. After dispersing the silica spacer as an adhesive spacer such as an epoxy resin as a seal spacer, place the one applied to the adhesive seal portion of the other electrode substrate by means such as screen printing, and apply an appropriate pressure. In addition, heating at a temperature of 100 to 180 ° C. for 1 to 60 minutes, or an irradiation amount of 40 to 30
After the adhesive sealing material is heated and cured by irradiating ultraviolet rays of 0 mJ / cm ^2, a method of injecting liquid crystal, sealing the injection portion, and obtaining a liquid crystal display panel can be mentioned, but there is a particularly limited method. is not.

Since the liquid crystal display panel of the present invention has a colored spacer interposed, it is suitably used for the same applications as conventional liquid crystal display panels, for example, as image display elements for televisions, personal computers, word processors and the like.

[0065]

(Synthesis example of coating polymer grafted with colorant)

[Synthesis Example 1] In a four-necked flask equipped with a cooling tube and a thermometer, "Kayasil Sky Blue R" manufactured by Nippon Kayaku Co., Ltd., which is an acidic anthraquinone dye, represented by the structural formula of Formula 7 (Trade name) 42.2 g (containing two amino groups directly bonded to the benzene ring in one molecule) was added, and methacryl isocyanate was gradually added while stirring.
By heating at 50 ° C. for 10 hours, a deep blue dye (1) having a double bond group was obtained.

[0066]

Embedded image

Next, the dye (1) 4 having a double bond group
0 g, 30 g of γ-methacryloxypropyltrimethoxysilane, 10 g of 2-ethylhexyl acrylate, 20 g of styrene, and 2 g of 2,2′-azobisisobutyrone tolyl as a radical polymerization initiator were mixed in 200 g of isopropyl alcohol. The solution was polymerized by heating at 80 ° C. for 5 hours in an N ₂ atmosphere to obtain an isopropyl alcohol solution (solid content: 30%) of the coating polymer (1) on which the dye (1) was grafted.

Synthesis Example 2 20 g of styrene, 10 g of isopropenyloxazoline, 30 g of γ-methacryloxypropyltrimethoxysilane, 15 methyl methacrylate
g, lauryl methacrylate 25 g, 2,2′-azobisisobutyrone tolyl 3 g as a radical polymerization initiator
And polymerized in 200 g of ethyl cellosolve acetate by heating at 80 ° C. for 5 hours to obtain a solid content of 30%
A polymer solution was obtained.

Next, 25 parts of the above polymer solution, 20 parts of carbon black MA-100R, and 57 parts of ethyl cellosolve acetate were charged and dispersed in a separable flask equipped with a thermometer, a stirring blade, and a cooling tube. 1000 parts of stainless steel beads were charged. Stirring (300 rpm
m), grafting was performed at 160 ° C. for 2 hours.
Further, 100 parts of ethyl cellosolve acetate was added and uniformly dispersed. Thereafter, the stainless steel beads were separated, and the solvent was further removed to obtain a solution of the coating polymer (2) coated with carbon black in ethyl cellosolve acetate (solid content: 30%).

[Synthesis Example 3 of Polymer Not Grafted with Colorant] Solution polymerization was carried out in the same manner as in Synthesis Example 1 except that the dye (1) having a double bond group was not used. An isopropyl alcohol solution of (3) (solid content 30%) was obtained. [Synthesis Example 4 of Polymer Not Grafted with Colorant] In Synthesis Example 2, a polymer solution having a solid content of 30% was used as polymer (4).

[Synthesis Example 5 of Particle Body] Using γ-methacryloxypropyltrimethoxysilane and vinyltrimethoxysilane (45/55 weight ratio), co-hydrolysis / polycondensation of alkoxysilyl group and double bond Was subjected to radical polymerization to obtain white organic-inorganic composite particles.

The composite particles had an average particle diameter of 6.0 μm, a coefficient of variation of the particle diameter of 3.3%, and a polysiloxane skeleton ratio of 55 wt% in terms of SiO _{2 with} respect to the weight of the composite particles.
% (When calcined in air at 1000 ° C.). [Synthesis Example 6 of Particle Main Body] Suspension polymerization was performed using divinylbenzene and ethylene glycol dimethacrylate (70/30 weight ratio), and washing and classification were repeated to obtain white vinyl-based crosslinked particles. .

The crosslinked particles had an average particle diameter of 6.0 μm, a coefficient of variation of the particle diameter of 3.7%, and a particle hardness (10% compression modulus) of 390 kgf / mm ² . [Example 1] Using 10 g of the organic-inorganic composite particles obtained in Synthesis Example 5 as a particle main body, the coating polymer (1) obtained in Synthesis Example 1 was dispersed in a mixed solution of 1 g of an isopropyl alcohol solution and 100 g of isopropyl alcohol. I let it. Next, isopropyl alcohol was distilled off while heating using an evaporator, and the particle main body surface was coated with the coating polymer (1).

Further, vacuum drying at 160 ° C. for 2 hours
Crosslinking of the polymer (1) and bonding of the particle body and the polymer (1) were promoted. The obtained particles were washed by heating at 80 ° C. for 5 hours with isopropyl alcohol, and the washing and filtration were repeated at room temperature with isopropyl alcohol. The obtained particles were crushed into single particles to obtain a dark blue colored spacer (1). The colored spacer (1) has an average particle diameter of 6.1 μm.
m, the coefficient of variation of the particle diameter is 3.5%, the breaking strength of the particles is 4.0 gf,
f / mm ² ).

Next, using the colored spacer (1), a liquid crystal display panel was manufactured by the following method. As shown in FIG. 3, first, an electrode (for example, a transparent electrode) 5 and a polyimide alignment film 4 were formed on a lower glass substrate 111, and rubbing was performed to obtain a lower electrode substrate 110. The colored spacers (1) (in this case, in-plane spacers) 8 for the liquid crystal display panel of the present invention are uniformly spread on the lower electrode substrate 110 at a density of 100 pieces / mm ² without agglomerates by a wet spraying method. Sprayed. In addition, as a wet spray liquid, water / isopropyl alcohol (IPA) (volume ratio:
7/3), water / IPA was mixed at a ratio of 2.5 parts of the colored spacer (1) to 100 parts, and the mixture was ultrasonically dispersed and used. At this time, the wet spraying solvent was transparent without coloring (there was no discoloration from the colored spacer).

On the other hand, after an electrode (for example, a transparent electrode) 5 and a polyimide alignment film 4 were formed on the upper glass substrate 12, rubbing was performed to obtain an upper electrode substrate 120. Next, a silica spacer (in this case, a sealing portion spacer) 3 dispersed in the epoxy resin adhesive sealing material 2 so as to have a volume ratio of 30% by volume is placed on the upper electrode substrate 120.
Was screen printed on the adhesive seal.

Finally, the upper and lower electrode substrates 110 and 120
Are bonded via the spacer (1) 8 of the present invention so that the electrode 5 and the alignment film 4 face each other.
The adhesive sealing material 2 was heated and cured at a temperature of 150 ° C. for 30 minutes while applying a pressure of ² cm ² . Thereafter, the gap between the two electrode substrates 110 and 120 was evacuated and returned to the atmospheric pressure, whereby the STN liquid crystal 7 was injected and the injection portion was sealed. Then, a PVA (polyvinyl alcohol) -based polarizing film 6 was adhered to the outside of the upper and lower glass substrates 12 and 111 to obtain a 13-inch liquid crystal display panel (1).

The liquid crystal display panel (1) thus obtained
Has a uniform display distance between the upper and lower substrates, eliminates light leakage from the spacer itself, and suppresses light leakage around the spacer, resulting in good display quality.
In addition, it was possible to drive for a long time at a predetermined voltage application. [Example 2] In Example 1, except that the polymer (2) was used instead of the polymer (1) and ethyl cellosolve acetate was used instead of isopropyl alcohol.
In the same manner as in Example 1, a black colored spacer (2) was obtained.

Table 1 shows the physical properties of the obtained colored spacer (2). Next, a 13-inch liquid crystal display panel (2) was produced in the same manner as in Example 1 except that the colored spacer (2) was used. Table 2 shows the physical properties of the obtained liquid crystal display panel (2).

[0080]

[Table 1]

In Table 1, the colored spacers indicate the numbers, and the hardness indicates a 10% compression modulus (kgf / mm ² ).

[0082]

[Table 2]

Comparative Example 1 A comparative liquid crystal display panel (1) was prepared in the same manner as in Example 1 except that the organic-inorganic composite particles obtained in Synthesis Example 1 were used as comparative spacers (11).
1) was obtained. The evaluation results are shown in Tables 3 and 4. [Comparative Example 2] A comparative example was prepared in the same manner as in Example 1 except that the polymer (3) obtained in Synthetic Example 3 and Kayasil Sky Blue R were used instead of the polymer (1). A liquid crystal display panel (12) was obtained.

Tables 3 and 4 show the evaluation results. Comparative Example 3 A liquid crystal display panel for comparison was prepared in the same manner as in Example 1 except that the polymer (4) obtained in Synthesis Example 4 and carbon black were used instead of the polymer (2). (13) was obtained.

Tables 3 and 4 show the evaluation results. [Comparative Example 4] 60 g of the crosslinked particles obtained in Synthesis Example 6 was added to water 1
Dispersed in 1 liter, a solution of 120 g of "Kayasil Sky Blue R" dissolved in 1 liter of water as a dye was mixed and dyed in an autoclave at 170 ° C. to obtain dark blue vinyl-based crosslinked particles. The spacer (14) was used. A comparative liquid crystal display panel (14) was obtained in the same manner as in Example 1 using the comparative spacer (14).

Tables 3 and 4 show the evaluation results. [Comparative Example 5] A comparative spacer (15) and a comparative liquid crystal display panel (15) were prepared in the same manner as in Synthetic Example 6, except that suspension polymerization was performed by adding 5% of carbon black to the monomer. Obtained.

Tables 3 and 4 show the evaluation results.

[0088]

[Table 3]

[0089]

[Table 4]

[0090]

According to the present invention, the particle body surface is coated with a polymer containing a colorant, and the colorant is chemically bonded to the coating polymer. Since the characteristic characteristics are maintained, when the liquid crystal display panel is used, no gap unevenness occurs, and a spacer having strength and hardness that facilitates gap control and excellent reliability can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram showing a typical example of a chemical bond between a colorant and a coating polymer.

FIG. 2 is a diagram illustrating a typical example of a chemical bond between a particle main body surface and a coating polymer.

FIG. 3 is a partial cross-sectional view illustrating one embodiment of a liquid crystal display panel according to the present invention.

[Explanation of symbols]

 3 Spacer 7 Liquid crystal 8 Spacer 11 Glass substrate 12 Glass substrate

Claims (7)

[Claims] 1. A colored spacer for a liquid crystal display panel, which is a particle having a particle body surface coated with a polymer containing a coloring agent, wherein the coloring agent is chemically bonded to the coating polymer. 2. The colored spacer according to claim 1, wherein said coating polymer is cross-linked. 3. The colored spacer according to claim 1, wherein the surface of the particle body and the coating polymer are also chemically bonded. 4. A method for producing a colored spacer for a liquid crystal display panel, comprising a step of coating a surface of a particle main body with a colorant graft polymer obtained by chemically bonding a colorant to a polymer. 5. The method for producing a colored spacer according to claim 4, further comprising a step of crosslinking the colorant graft polymer. 6. The method according to claim 4, further comprising the step of reacting the surface of the particle body with the colorant graft polymer.
3. The method for producing a colored spacer according to item 1. 7. A liquid crystal display panel comprising the colored spacer according to claim 1.