JPH11133435A - Colored spacer for liquid crystal display element and liquid crystal display element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain spacers which have excellent coloring property and light shielding property and prevent the abnormal alignment of liquid crystals by using an org. radical polymn. initiator having specific radical generation chemical bonds at a specific ratio with a compsn. for polymn. prepd. by dispersing coloring agents into a polymerizable monomer contg. a crosslinkable monomer at a specific ratio and subjecting the compsn. to suspension polymn. in an aq. medium. SOLUTION: The colored spacers for the liquid crystal display element are formed by using the compsn. for polymn. prepd. by dispersing and mixing the coloring agents into the polymerizable monomer contg. >=50 wt.% crosslinkable monomer, such as divinyl benzene. The spacers are formed by using 0.25 to 3 pts.wt. org. radical polymn. initiator having >=2 pieces of the radical generation chamical bonds in one molecule per 100 pts.wt. polymerizable monomer component and subjecting the mixture to the suspension polymn. in the aq. medium. The coloring agents to be added to the polymerizable monomer include powdery carbon black, etc. The pH of the carbon black may be preferably specified to 6 to 10 and the compounding ratio thereof is preferably specified to 0.1 to 20 pts.wt. per 100 pts.wt. polymerizable monomer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a colored spacer for a liquid crystal display device and a liquid crystal display device, and more particularly, to a colored spacer for a liquid crystal display device which is excellent in coloring property and light shielding property and rarely causes abnormal liquid crystal alignment. And a liquid crystal display device having improved image visibility.

[0002]

2. Description of the Related Art Liquid crystal display devices are widely used in personal computers, portable electronic devices, and the like, but are liable to cause blurring of images particularly on colored screens. At present, it is desired to further improve the visibility of an image by removing the cause of blurring of the image and increasing the display contrast. JP-A-57-189117 discloses that in a liquid crystal display element in which liquid crystal is sealed in a liquid crystal cell in which two transparent substrates with electrodes are opposed to each other, colored spacers are scattered over the entire surface of the substrate in contact with the liquid crystal. Accordingly, a technique for preventing a reduction in display contrast of an image has been disclosed.

A spacer for a liquid crystal display element used for a liquid crystal display element requiring such a high contrast is required to be colored dark in order to prevent scattering of incident light. It is known that the above-mentioned colored spacer for a liquid crystal display element is produced by a method of coloring previously produced polymer fine particles, a method of coloring in the step of producing the polymer fine particles, and the like.

[0004] As a method for coloring previously prepared high molecular weight polymer particles, for example, Japanese Patent Application Laid-Open No. 1-144429 discloses a method in which high molecular weight polymer particles are treated with an acid and then colored. And JP-A-1-207.
No. 719 discloses high molecular weight polymer particles of 200-700.
There is disclosed a method of producing a fire-resistant baked product by heat treatment in a temperature range of ℃, and Japanese Patent Application Laid-Open No. 5-165033 discloses a method of coating polymer fine particles with a conjugated polymer such as polyacetylene. Have been.

Further, Japanese Patent Application Laid-Open No. 4-15623 discloses a method of driving ultrafine black metal oxide particles on the surface of high molecular weight polymer particles.
In the publication, after dispersing high-molecular polymer fine particles containing an anionic functional group in an oxidizing agent solution and adsorbing or impregnating the oxidizing agent, at least one of a heterocyclic five-membered ring compound and an aromatic hydrocarbon is used. A method for chemical oxidative polymerization by adding a compound is disclosed in Japanese Patent Publication No. 27242/1992, which discloses a water-soluble polymer fine particle obtainable by polymerizing an ethylenically unsaturated sulfonic acid or a salt thereof. A method of dyeing using a basic dye is disclosed.

Further, Japanese Patent Laid-Open Publication No.
A method of coloring high molecular weight polymer particles of an amino resin with an acid dye at a high temperature in the presence of a solvent is disclosed.
No. 3,633,331 discloses a method of coloring by mixing a dye emulsion in which an oil solvent solution of an oil dye is finely dispersed in an aqueous medium, and a high molecular polymer fine particle emulsion.

However, such a method of coloring previously produced high molecular weight polymer particles requires a complicated additional process for coloring newly prepared high molecular weight polymer particles. In addition, the production cost is increased, and the control of the performance and quality of the obtained colored high molecular weight polymer particles is accompanied by difficulties.

As a method of coloring in the step of preparing high molecular weight polymer particles, for example, Japanese Patent Application Laid-Open No. 4-370160
Japanese Patent Application Laid-Open Publication No. H11-157, discloses colored spherical fine particles obtained by dispersing a carbon black graft polymer obtained by reacting a polymer with carbon black in a state where the carbon black graft polymer is localized on the surface side of the polymer particles.

[0009] However, in the method of coloring in the step of preparing the high-molecular polymer fine particles including the colored spherical fine particles disclosed in JP-A-4-370160, the coloring and light-shielding properties are excellent. In addition, it has been difficult to easily and efficiently obtain a liquid crystal display element spacer having necessary physical properties as a spacer.

[0010]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above facts, and has excellent coloring properties and light-shielding properties.
An object of the present invention is to provide a spacer for a liquid crystal display element which does not cause abnormal alignment of liquid crystal and a liquid crystal display element with improved visibility of an image.

[0011]

According to the first aspect of the present invention,
A polymerizable monomer containing 50% by weight or more of a crosslinkable monomer and a colorant are dispersed and mixed. A colored spacer for a liquid crystal display element characterized by being obtained by suspension polymerization in an aqueous medium using 0.25 to 3 parts by weight of an organic radical polymerization initiator having the above radical generating chemical bond. It is.

The polymerizable monomer used in the present invention is not particularly limited, but examples thereof include acrylic acid, methacrylic acid, maleic acid, maleic anhydride, fumaric acid, crotonic acid, and itaconic acid. Saturated carboxylic acids; methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-acrylate
Acrylates such as -butyl, t-butyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate; methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate;
N-butyl methacrylate, t-butyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, stearyl methacrylate, dodecyl methacrylate,
Methacrylic esters such as glycidyl methacrylate, β-hydroxymethyl methacrylate, and β-hydroxyethyl methacrylate; styrenes such as styrene, vinyltoluene, α-methylstyrene, p-methylstyrene, t-butylstyrene, and chlorostyrene Monomer; diene monomer such as butadiene and isoprene; ethylene, vinyl chloride, vinylidene chloride, vinyl acetate, vinyl propionate, vinyl stearate, acrylamide, methacrylamide, acrylonitrile, methylolacrylamide, acrylacetate, diallyl adipate Dimethyl itaconate, diethyl maleate, allyl alcohol, vinylpyridine, N-vinylpyrrolidone, N-hydroxyacrylamide, 2-vinyl-2-oxazoline, 2-isopropenyl-2 Oxazoline, dimethylaminoethyl acrylate, glycidyl methacrylate, allyl glycidyl ether, monomethyl fumarate, and the like. These may be used alone,
More than one species may be used in combination.

[0013] The polymerizable monomer includes 5
0% by weight or more is added. When the content of the crosslinkable monomer is less than 50% by weight, the mechanical strength of the obtained spacer for a liquid crystal display element may be reduced. The polymerizable monomer may be composed entirely of a crosslinkable monomer.

The crosslinkable monomer is not particularly restricted but includes, for example, divinyl compounds such as divinylbenzene, divinylnaphthalene and derivatives thereof; ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate Alkylene-based polybasic unsaturated carboxylic acid esters such as triethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate and 1,3-butanediol di (meth) acrylate; N, N-divinylaniline; Examples thereof include divinyl compounds such as divinyl ether, divinyl sulfide, and divinyl sulfonic acid, and monomers having three or more vinyl groups. These may be used alone or in combination of two or more.

The amount of the polymerizable monomer is preferably 1 to 200 parts by weight based on 100 parts by weight of the aqueous medium. If the amount of the polymerizable monomer is less than 1 part by weight, the polymerization efficiency is lowered. If the amount is more than 200 parts by weight, it is difficult to remove the heat of polymerization.

The coloring agent added to the polymerizable monomer is
The particle size is not particularly limited as long as the particle size is smaller than the particle size of the obtained polymer granules. For example, powdered carbon black, a silane coupling agent, a titanate Powdered carbon black treated with a surface treatment agent such as an aluminum-based coupling agent, an aluminum-based coupling agent, carbon black suspension-polymerized with the above polymerizable monomer, and carbon black grafted to the obtained polymer. No. The pH of these carbon blacks is preferably 6-10, more preferably 7-9.
It is. If the pH of the carbon black is too low, radicals are trapped in the polymerization reaction, which may hinder the polymerization reaction and cause the polymerization composition to gel.

The compounding amount of the above carbon black is preferably 0.1 to 20 parts by weight based on 100 parts by weight of the polymerizable monomer. If the compounding amount of the carbon black is less than 0.1 part by weight, the liquid display element spacer is hardly colored in a deep color, and if it exceeds 20 parts by weight, the mechanical strength of the obtained liquid display element spacer is reduced. There is a possibility that.

The coloring agent is carbon black,
Azo series such as Brilliant Carmine BS, Lake Carmine FB, Brilliant Fast Carlet, Lake Red 4R, Permanent Red R, Fast Red FGR, Toluidine Malon, Bisazo Yellow, First Yellow G, Bisazo Orange, Vulcan Orange, Pyrazolone Red, etc. Condensed azo organic color pigments; phthalocyanine organic color pigments such as phthalocyanine green and phthalocyanine blue; yellow lake, rose lake,
Dye lake-based organic coloring pigments such as violet lake, blue lake, and green lake; oxazine-based organic coloring pigments; and quinophthalone-based organic coloring pigments.

The light transmittance of the spacer for a liquid crystal display device using the above colorant is preferably 400 to 700 nm.
The maximum value of the spectral transmittance in the visible region is less than 3%, and the total light transmittance in all visible region wavelengths is 0.1%.
~ 2.5%, more preferably the maximum value of the spectral transmittance in the visible region from 400 to 700 nm is less than 2.7%,
And the total light transmittance at all wavelengths in the visible region is 0.2 to
2.0%.

As the organic coloring pigment other than carbon black, two or more of the above-mentioned organic coloring pigments are appropriately selected and used as a mixed organic coloring pigment having a color tone substantially close to black, so that the coloring property and the light-shielding property are improved. Can be further enhanced.

The selection of the organic coloring pigment for the light transmittance is not particularly limited, but examples thereof include an organic blue pigment and an organic violet pigment, an organic blue pigment and an organic red pigment, and an organic blue pigment and an organic yellow pigment. And an organic red pigment, an organic blue pigment, an organic green pigment, and an organic purple pigment, and a mixed organic color pigment obtained by combining an organic blue pigment, an organic red pigment, and an organic purple pigment.

The amount of the organic color pigment is preferably 1 to 50 parts by weight based on 100 parts by weight of the polymerizable monomer. When the amount of the organic coloring pigment is less than 1 part by weight, the obtained colored spacer for a liquid crystal display element is hardly colored in a deep color, and when it exceeds 50 parts by weight, the mechanical properties of the obtained colored spacer for a liquid crystal display element are reduced. The strength may be reduced.

The particle size of the colorant is preferably 1 μm or less in order to keep the light transmittance and the uniformity of the surface properties of the spacer for a liquid crystal display element.

Means for uniformly dispersing the colorant in the polymerizable monomer is not particularly limited.
Ball mill, bead mill, sand mill, attritor,
A method of dispersing using a sand grinder nanomizer or the like can be given. In the method for dispersing the colorant, a dispersant may be added to the mixed system of the polymerizable monomer and the colorant.

The dispersing agent is not particularly restricted but includes, for example, inorganic salts of high-molecular-weight polycarboxylic acids, inorganic salts of long-chain polyaminoamidic acids, long-chain polyaminoamidates, and high-molecular-weight unsaturated polycarboxylic acids. Examples include acids, high molecular weight unsaturated acid esters, polyamides, high molecular weight copolymers, higher alcohol esters, and the like. The amount of the dispersant added is preferably about 0.01 to 20% by weight based on the polymerizable monomer.

The aqueous medium is not particularly restricted but includes, for example, water; polyvinyl alcohol, polyacrylic acid, polymethacrylic acid, gelatin, methyl cellulose, polymethacrylamide, polyethylene glycol,
Aqueous solutions such as polyethylene oxide monostearate, sorbitan tetraoleate, glycerin monooleate, dodecylbenzene sulfonic acid, and the like can be given.

The polymerization composition in which carbon black is uniformly dispersed in a polymerizable monomer in the aqueous medium is suspended in fine particles. The particulate suspension means for the composition for polymerization is
Although not particularly limited, for example, a method of dispersing using a homogenizer or the like may be used. In suspending the polymerization composition in an aqueous medium, a suspension stabilizer may be added.

The suspension stabilizer is not particularly restricted but includes, for example, water-soluble polymers such as polyvinyl alcohol, starch, methylcellulose, carboxymethylcellulose, hydroxymethylcellulose and sodium polymethacrylate; barium sulfate, sulfuric acid Examples include calcium, aluminum sulfate, calcium carbonate, calcium phosphate, talc, clay, diatomaceous earth, and other metal oxide powders. The addition amount of the suspension stabilizer is preferably about 0.01 to 20% by weight based on the polymerizable monomer.

By the above dispersion, the polymerization composition containing the polymerizable monomer and the carbon black is finely dispersed, and is uniformly dispersed to primary particles or small particles having a particle size of about 0.05 to 0.5 μm close to the primary particles. When the composition for polymerization is suspended in an aqueous medium, carbon black is surely incorporated into suspension droplets having a small particle diameter and is uniformly dispersed at a high concentration. Will be.

Next, the polymerization composition containing the polymerizable monomer and carbon black suspended in the form of fine particles in the aqueous medium is added to 100 parts by weight of the polymerizable monomer component of the polymerization composition. Using 0.25 to 3 parts by weight of an organic radical polymerization initiator having two or more radical-generating chemical bonds in one molecule, suspension polymerization is carried out in an aqueous medium to produce a fine spherical colored spacer for a liquid crystal display device. .

The organic radical polymerization initiator having two or more radical-generating chemical bonds in one molecule used in the present invention is not particularly limited. For example, dibutyl peroxyhexahydroterephthalate (10. 11%), bis (t-butylperoxy) isophthalate (8.24%), di-t-butylperoxytrimethyladipate (9.62%), n-butyl-
4,4-bis (t-butylperoxy) valerate (9.57%), 4,4-di-t-butylperoxyvalerate-n-butyl ester (13.66%), 2,
2-bis (4,4-di-t-butylperoxycyclohexyl) propane (11.43%), 2,2-bis (t
-Butylperoxy) butane (13.66%), 2.5
-Dimethyl-2,5-bis (t-butylperoxy) hexane (11.02%), 2,5-dimethyl-2,5-
Bis (benzoylperoxy) hexane (8.28
%), 1,6-bis (t-butylperoxycarbonyloxy) hexane (9.14%), 2,5-dimethyl-
2,5-bis (t-butylperoxy) hexyne-3
(11.17%), 1,1-bis (t-butylperoxy) cyclohexane (10.58%), di-t-butylperoxy-2-methylcyclohexane (9.91)
%), 1,1-bis (t-hexylperoxy) -3,
3,5-trimethylcyclohexane (8.92%),
1,1-bis (t-hexylperoxy) cyclohexane (10.11%), 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane (1
0.58%), di-t-butylperoxy-2-methylcyclohexane (8.92%), 1,1-bis (t-butylperoxy) cyclododecane (9.29%), diethylene glycol-bis ( t-butyl percarbonate) (9.46%), 1,3-bis (t-butylperoxyisopropyl) benzene (9.45%), 3,3
4,4-tetra (t-butylperoxycarbonyl) benzophenone (9.90%) and tris (t-butylperoxy) triazine (13.90%).
The number in parentheses after the compound name indicates the theoretical active oxygen amount.

The amount of the polymerization initiator used is 0.25 to 3 parts by weight based on 100 parts by weight of the polymerizable monomer component. When the amount of the polymerization initiator used is less than 0.25 parts by weight, the polymerization rate becomes low, and an amount exceeding 3 parts by weight is unnecessary.

The average particle diameter of the spacer for a liquid crystal display element of the present invention is 0.5 to 50 μm, and its variation coefficient is preferably 20% or less, more preferably 10% or less, and further preferably 5% or less. is there. If the average particle size is less than 0.5 μm, the particles are likely to aggregate, and it may be difficult to accurately secure a desired space. If the average particle size exceeds 50 μm, the particles are rarely used. The coefficient of variation is 2
If it exceeds 0%, the particle size distribution becomes too wide, and the performance as a spacer for a liquid crystal display element may be reduced.

The spacer for a liquid crystal display element of the present invention is characterized in that cations such as sodium ions and potassium ions and anions such as chloride ions and sulfate ions contaminating the coloring agent and the like are eluted, and In order to prevent the liquid crystal from being abnormally aligned in the vicinity of the spacer surface or to improve the surface chemistry of the surface, if necessary, it may be treated with a surface treatment agent such as a silane coupling agent. Good.

The above-mentioned surface treatment agent is not particularly limited, but as a silane coupling agent, for example, γ
-Aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane,
3- [N-allyl-N- (2-aminoethyl)] aminopropyltrimethoxysilane, 3- (N-allyl-N-
Glycidyl) aminopropyltriethoxysilane, 3-
Amino-based silane coupling agents such as (N-allyl-N-methacryl) aminopropyltrimethoxysilane and 3- (N, N-diglycidyl) aminopropyltrimethoxysilane; N, N-bis [3- (methyldimethoxy) Silyl) propyl] amine, N, N-bis [3- (trimethoxysilyl) propyl] amine, N, N-bis [3-
(Methyldimethoxysilyl) propyl] ethylenediamine, N, N-bis [3- (trimethoxysilyl) propyl] ethylenediamine, N-glycidyl-N, N-bis [3- (methyldimethoxysilyl) propyl] amine,
Amide-based coupling agents such as N-glycidyl-N, N-bis [3- (trimethoxysilyl) propyl] amine; vinyl-based silanes such as vinyltriethoxysilane and vinyl-tris (2-methoxyethoxy) silane Methacrylic silane coupling agents such as γ-methacryloxypropyltrimethoxysilane;
glycidyl-based coupling agents such as γ-glycidoxypropyltrimethoxysilane; and mercapto-based coupling agents such as γ-mercaptopropyltrimethoxysilane.

The means for coating the surface of the liquid crystal display element spacer with the surface treatment agent is not particularly limited. For example, the surface treatment agent and the liquid crystal display element spacer may be coated with an inorganic material such as water. After mixing in a solvent or an organic solvent such as ethyl alcohol or isopropanol and heating under stirring, an excess surface treatment agent is separated together with an inorganic solvent or an organic solvent by a solid-liquid separation method such as a decantation method, and dried under reduced pressure. A method for coating the surface treatment agent on the surface of the liquid crystal display element spacer by mixing the surface treatment agent and the liquid crystal display element spacer and heating the mixture under stirring to directly apply the surface treatment agent to the liquid crystal display element spacer. A method of coating the surface and the like can be mentioned.

According to a second aspect of the present invention, there is provided a colored spacer for a liquid crystal display device according to the first aspect, wherein the colorant comprises carbon black and an organic color pigment.

The colorant used in the present invention is a mixed colorant obtained by adding an organic color pigment to carbon black. The carbon black and the organic coloring pigment are not particularly limited.
Examples include the carbon blacks and organic color pigments shown in the described invention.

The carbon black generally contains impurities such as cations such as sodium ion, potassium ion and ammonium ion and anions such as chloride ion and sulfate ion. When contained in the polymerization composition in a large amount in a state where the surface is not coated, the cations and anions migrate to the surface of the obtained liquid crystal display element spacer, or partially eluted into the liquid crystal. The liquid crystal may be abnormally aligned near the surface of the liquid crystal display element spacer.

According to the present invention, the liquid crystal of the obtained liquid crystal display element is formed by adding an organic coloring pigment which is less likely to elute cations and anions to carbon black when coloring the spacer for the liquid crystal display element. An object of the present invention is to provide a spacer for a liquid crystal display element that can avoid the risk of alignment.

The content of the coloring agent is 0.1 to 20 parts by weight of carbon black and 1 to 50 parts by weight of an organic coloring pigment based on 100 parts by weight of the polymerizable monomer in the composition for polymerization. It is appropriately determined according to the types and amounts of the carbon black and the organic coloring pigment. The reason why the contents of the carbon black and the organic coloring pigment are indicated is based on the same reason as described in the first aspect of the present invention.

The content ratio of carbon black in the mixed colorant is preferably 5 to 60% by weight, more preferably 10 to 40% by weight. When the content ratio of carbon black in the mixed colorant is less than 5% by weight, the content ratio of the remaining organic color pigment increases, the absolute amount of the organic color pigment increases, and the mechanical strength of the obtained spacer for a liquid crystal display element increases. When the content exceeds 60% by weight, the content ratio of carbon black is increased, and the absolute amount of carbon black is increased. Contaminants such as cations and anions eluted in the liquid crystal may lower the electric resistance of the liquid crystal and cause abnormal liquid crystal alignment near the surface of the liquid crystal display element spacer.

According to a third aspect of the present invention, there is provided a colored spacer for a liquid crystal display device according to the first or second aspect, wherein the colorant is surface-treated carbon black. .

The carbon black is not particularly restricted but includes, for example, the carbon black described in the first aspect of the present invention.

In the surface-treated carbon black, the above-mentioned contaminants such as cations and anions migrate to the surface of the colored spacer for the liquid crystal display element or partially contact the colored spacer for the liquid crystal display element. It refers to carbon black that has been surface-treated in order to prevent it from being eluted in the liquid crystal and causing abnormal alignment in the liquid crystal of the liquid crystal display element, thereby inhibiting the visibility of an image.

The surface treating agent is not particularly limited as long as it has the above-mentioned properties. For example, polyester-based resins, polyamide-based resins, polycarbonate-based resins, polyethylene-based resins, epoxy-based resins,
Thermoplastic resins such as polystyrene resin, vinyl chloride resin, acrylic resin, chloride rubber, benzoguanamine resin, and urea resin are exemplified.

The means for surface-treating carbon black using the above-mentioned thermoplastic resin is not particularly limited. For example, a means for grinding carbon black in a hydrophobic medium containing such a thermoplastic resin, such as a ball mill, may be used. A method of forming a film of the thermoplastic resin on the surface while pulverizing with the use of ethanol, then mixing and precipitating a lower alcohol such as ethanol and isopropanol, and separating from the medium, a hydrophobic medium containing the thermoplastic resin A method of adding a water dispersion of carbon black in the mixture, mixing and emulsifying, forming a coating of the thermoplastic resin on the surface of the carbon black while heating, separating the mixture from the medium by filtration, decantation, and the like, and the like. Can be

As the surface treating agent, in addition to the thermoplastic resin, the silane coupling agent used in the surface treatment of the colored spacer for a liquid crystal display element itself in the colored spacer for a liquid crystal display element according to the first aspect of the present invention. And the like can be similarly used as the surface treatment agent for carbon black. Means for surface-treating carbon black using a surface-treating agent such as the silane coupling agent is not particularly limited. For example, in the colored spacer for a liquid crystal display element of the invention according to claim 1, The surface treatment method used for the surface treatment of the element colored spacer itself is exemplified. The carbon black surface-coated with a surface treating agent such as the silane coupling agent may be further subjected to a surface treatment of the carbon black using the thermoplastic resin.

According to a fourth aspect of the present invention, there is provided a liquid crystal display wherein the colored spacer for a liquid crystal display element according to the first, second or third aspect is interposed between two opposing transparent substrates with electrodes. The gist is an element.

The transparent substrate used in the present invention is not particularly limited. For example, a soda lime glass substrate, an alkali-free glass substrate, a borosilicate glass substrate, a quartz A glass substrate, a silicon substrate, and the like can be given. The thickness of these transparent substrates is generally 1.1 mm, 0.7 mm,
0.5 mm, 0.4 mm or the like is used, but is not limited to this. The external dimensions of the transparent substrate are
It is cut into various dimensions depending on the use of the liquid crystal display element.

The surface of the transparent substrate is smooth, and when the colored spacer for a liquid crystal display element according to claim 1 is interposed between two substrates, a liquid crystal filling space having the same thickness can be formed. It maintains parallelism and has substantially no surface scratches, bubbles and foreign substances, has a surface roughness expressed by JIS standards, has no waviness or warpage, and has a liquid crystal orientation. , Which do not affect the cutting of the pattern edge. In addition, the transparent substrate is required to have thermal properties such as heat resistance, thermal shock resistance, thermal expansion and contraction, thermal expansion coefficient, cleanliness, and the like.

The electrode is made of a transparent conductive film, and includes, for example, an indium oxide film and a tin oxide film doped with tin oxide.
It can be widely used as an electrode for liquid crystal display from a high resistance region (200 Ω / □ or more) to a low resistance region (10 Ω / □) as a crystalline transparent film by a thermal spray method or the like.

The liquid crystal display element cell is formed by interposing the colored spacer for a liquid crystal display element according to claim 1 between the two opposing transparent substrates with electrodes thus obtained. Liquid crystal is filled in the parallel space formed by the display element colored spacers, and other necessary components such as a polarizer, a backlight, and a driving IC are mounted.
A liquid crystal display device is manufactured.

The colored spacer for a liquid crystal display device according to the first aspect of the present invention comprises, as described above, an organic radical polymerization initiator having two or more radical-generating chemical bonds in one molecule.
The polymer is obtained by suspension polymerization in an aqueous medium in an amount of 0.25 to 3 parts by weight based on 100 parts by weight of the polymerizable monomer. Theoretical study of a typical organic radical polymerization initiator having one radical-generating chemical bond in one molecule, for example, dibenzoyl peroxide (6.61%) About 1.
Since it is 25 to 2 times or more, the organic radical polymerization initiator can be effectively reduced to a very small amount as described above.

The use of a very small amount of the organic radical polymerization initiator reduces the risk that a large amount of unreacted organic radical polymerization initiator remains in the colored spacer for a liquid crystal display element,
In addition, the risk that a large amount of the decomposition product of the organic radical polymerization initiator is bonded to the terminal of the polymer chain constituting the colored spacer for a liquid crystal display element is reduced. Particle size uniformity required for
The surface smoothness and the chemical inertness of the surface can be imparted extremely favorably.

In addition, as described above, the colored spacer for a liquid crystal display element of the present invention is obtained by suspension polymerizing a polymerizable monomer containing 50% by weight or more of a crosslinkable monomer as described above. Therefore, the mechanical strength required for the colored spacer for a liquid crystal display element can be provided extremely favorably.

The colored spacer for a liquid crystal display device according to the second aspect of the present invention uses, as described above, carbon black having excellent hiding power and an organic colored pigment having a low content of impurities such as highly ionizable ions. By doing so, it is possible to effectively reduce the amount of the coloring agent to a very small amount, whereby the impurities such as the highly ionizable ions migrate to the surface of the coloring spacer for a liquid crystal display element, or Partially eluted therein, the risk of abnormal alignment of the liquid crystal near the surface of the colored spacer for the liquid crystal display element is reduced, and the visibility of the liquid crystal display element can be extremely excellent.

The colored spacer for a liquid crystal display element according to the third aspect of the present invention is characterized in that the surface of carbon black having excellent hiding power is subjected to a surface treatment as described above, whereby highly ionizable ions existing in carbon black are present. By effectively shielding impurities such as ions from the liquid crystal of the liquid crystal display element, the impurities such as the highly ionizable ions migrate to the surface of the colored spacer for the liquid crystal display element or partially elute in the liquid crystal. As a result, the risk of abnormal alignment of the liquid crystal near the surface of the colored spacer for a liquid crystal display element is reduced, and the visibility of the liquid crystal display element can be extremely excellent.

Since the liquid crystal display element according to the fourth aspect uses the colored spacer for a liquid crystal display element according to the first, second or third aspect of the invention, scattering of incident light or the like is prevented. Since the image is not blurred and the refraction of light that causes distortion of the image is small, a multicolored image can be projected on a screen with high fidelity with high fidelity.

[0060]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. FIG. 1 shows an example of the liquid crystal display device of the present invention. The liquid crystal display element includes a pair of substrates 1 and 1, colored spacers for liquid crystal display elements 2, 2,..., A sealing member 3, a nematic liquid crystal 4, and polarizing sheets 5 and 5. The colored spacer 2 for a liquid crystal display element is disposed between the pair of substrates 1 and 1 in order to keep the gap between the pair of substrates 1 and 1 constant. The seal member 3 is filled around the pair of substrates 1 and 1. Nematic liquid crystal 4
Is sealed between the pair of substrates 1. The polarizing sheets 5, 5 are attached to the surfaces of the substrates 1, 1, respectively.

The pair of substrates 1 and 1 are a glass transparent substrate 1
Transparent electrodes 12 and 12 are patterned on one surface of the transparent electrodes 1 and 11, and the orientation control films 13 and 12 are formed on the surfaces of the transparent electrodes 12 and 12.
13 (for example, a polyimide film or the like).

Example 1 60 parts by weight of tetramethylolmethane triacrylate, 20 parts by weight of divinylbenzene and 20 parts by weight of acrylonitrile were uniformly mixed, and the mixture was mixed with polyethylene having a thickness of about 0.1 to 0.5 μm. Add 12 parts by weight of the surface-coated carbon black,
Using a bead mill, uniformly mix and disperse for 48 hours,
A composition for polymerization containing carbon black was obtained.

To the polymerization composition containing carbon black thus obtained, 2 parts by weight of bis (t-butylperoxy) isophthalate was added and uniformly mixed. The mixture was charged into 850 parts by weight of an aqueous polyvinyl alcohol solution containing 3% by weight, stirred sufficiently, and then stirred using a homogenizer until the particle diameter of the composition droplets for polymerization became fine particles in the range of 3 to 10 μm. A composition suspension for polymerization was prepared.

The obtained composition suspension for polymerization was added to a thermometer,
Transfer to a 2-liter separable flask equipped with a stirrer and a reflux condenser, heat to 85 ° C while stirring in a nitrogen atmosphere, heat at the same temperature for 7 hours, and further heat to 90 ° C to the same temperature. For 3 hours to carry out a polymerization reaction. afterwards,
Cooling the polymerization reaction solution, filtering the resulting colored fine particles,
Subsequent to the washing and drying steps, only coarse particles are classified and removed, and the average particle size is 5.55 μm and the variation coefficient of the particle size is 2.48%.
Of a colored spacer for a liquid crystal display element was obtained.

On a glass plate having a thickness of 0.7 mm, a transparent conductive film of indium oxide-tin oxide having a thickness of 500 ° was formed by a low-temperature sputtering method, and then a predetermined electrode pattern was formed by photolithography. Next, from above the electrode pattern, an alignment agent is applied to a glass plate, heated to form an alignment control film, and then cut, and 5 cm × 12.5 cm
Of a transparent substrate with electrodes,
An epoxy-based adhesive mixed with a glass fiber spacer was printed along the periphery by screen printing with a width of 1 mm, and the obtained colored spacer for a liquid crystal display element was applied on a glass plate surrounded by the epoxy-based adhesive. Spraying was performed uniformly using a pressurized nitrogen gas to about 150 particles / mm ² by a spraying method.

A new transparent substrate with electrodes is superimposed on the transparent substrate with electrodes on which the colored spacers for liquid crystal display elements are dispersed, and a load of 1 kg / cm ² is uniformly applied to the entire surface of the transparent substrate with electrodes by a press. At the same time at 160 ° C
The above-mentioned epoxy-based adhesive was cured by heating for 0 minutes to produce a cell for a liquid crystal display device.

The liquid crystal display cell thus obtained is evacuated with a vacuum pump from an injection hole provided in a part of the epoxy-based adhesive sealing portion to evacuate the inside, and then filled with liquid crystal. Sealing the seal portion in a state where the pressure in the liquid crystal display element cell is 0.6 atm lower than the atmospheric pressure,
The injected liquid crystal was heated to a predetermined temperature, and the liquid crystal was realigned to produce a TN type liquid crystal display element in a normal black display mode.

(Examples 2 to 4) A liquid crystal display device was prepared in the same manner as in Example 1 except that the composition of the polymerizable monomer and the content of carbon black in Example 1 were changed as shown in Table 1. A colored spacer and a liquid crystal display element were manufactured.

Comparative Example 1 A colored spacer for a liquid crystal display element and a liquid crystal display were produced in the same manner as in Example 1 except that carbon black having no polyethylene coating on the surface was used instead of the carbon black of Example 1. An element was manufactured.

Comparative Example 2 A colored spacer for a liquid crystal display element and a liquid crystal display element were produced in the same manner as in Example 1 except that the carbon black of Example 1 was not used.

Example 5 Instead of the carbon black of Example 1, 12 parts by weight of carbon black whose surface is not coated with polyethylene, 6 parts by weight of phthalocyanine blue (organic blue pigment) and dioxane violet (organic purple pigment) A colored spacer for a liquid crystal display element and a liquid crystal display element were produced in the same manner as in Example 1, except that the mixed colorant was changed to 6 parts by weight.

(Examples 6 to 8, Comparative Examples 3 and 4) Example 5
Except that the composition of the polymerizable monomer and the contents of carbon black and the organic coloring pigment were changed as shown in Table 2,
In the same manner as in Example 5, a colored spacer for a liquid crystal display element and a liquid crystal display element were produced.

Examples 9 and 10 In the same manner as in Example 1, except that the composition of the polymerizable monomer and the contents of carbon black and organic coloring pigment in Example 1 were changed as shown in Table 3. A colored spacer for a liquid crystal display element and a liquid crystal display element were produced.

In order to evaluate the performance of the colored spacers for liquid crystal display elements and the liquid crystal display elements obtained in Examples 1 to 10 and Comparative Examples 1 to 4, [1] the average particle diameter and the particle size of the colored spacers for liquid crystal display elements were evaluated. Diameter variation coefficient, blackness (light transmittance), electrical resistance and impurity concentration (a) sodium ion, (b) potassium ion, (c) chloride ion,
(D) Sulfate ions, [2] average cell gap of liquid crystal display element, presence / absence of color unevenness, and light-shielding property were tested by the following methods. The test results are shown in Tables 1 to 3.

[1] Quality of colored spacer for liquid crystal display element: Average particle size: Coulter counter BZ / C-1000
The particle size was measured using a mold (manufactured by Coulter), and the average particle size was calculated.

Coefficient of variation of particle diameter: The value obtained by dividing the standard deviation of the particle diameter by the average particle diameter from the result of the particle diameter measurement described in the preceding section was expressed in%.

Blackness (light transmittance): A polymerizable composition comprising a mixture of a polymerizable monomer and a coloring substance having the same composition as the spacer for a liquid crystal display element is polymerized under the same conditions and has a thickness of 1 mm. A plate-like body was prepared, and the plate-like body was measured for spectral transmittance at all wavelengths in the visible region at a wavelength of 400 to 700 nm using a spectrophotometer, and the maximum value was taken as the blackness of the spacer for a liquid crystal display element. .

Electric resistance: Electric resistance measuring instrument (trade name “ULTRA MEGOHMMETER S” manufactured by Toa Denpasha Co., Ltd.)
M-8210 ”), the liquid sample electrode was filled with a liquid crystal display element spacer 1 g, and the electric resistance of the liquid crystal display element spacer was measured at a voltage of 500 V.

Impurity concentration: 10 g of the obtained liquid crystal display element spacer was mixed with a mixed solvent (water / isopropanol = 7).
(3/3 volume ratio) into 330 ml with stirring.
It was left for a week (while stirring once a day). For the last two days, the liquid crystal display element spacer was settled down. The supernatant was filtered, and the filtrate was concentrated to 30 ml for analysis. For sodium and potassium ions, use SPQ8000 atomic absorption spectrophotometer (Jarrell
(Ash Co.). Chloride ions and sulfate ions were analyzed using a 2010I ion chromatography analyzer (manufactured by Dionex).

[2] Quality of liquid crystal display element: average cell gap: liquid crystal cell gap measuring device TFM
The liquid crystal cell gap was measured using a -120AFT type (manufactured by Oak Manufacturing Co., Ltd.), and the average cell gap was calculated.

Presence or absence of color unevenness: A polarizing sheet is superposed on both sides of the TN type liquid crystal display element so that the color tone of the reflected light of the obtained TN type liquid crystal display element has an olive color.
The presence or absence of color unevenness of the TN-type liquid crystal display element is visually observed. ◎: No color unevenness is observed at all, ：: Some color unevenness is recognized depending on the conditions, but a degree that does not cause a problem in practical use. X: Color unevenness was recognized, which was not practically acceptable.

Light-shielding property: The polarizing sheet to be affixed to the obtained TN-type liquid crystal display device was set to a normal black mode, and the black portion at the center of the liquid crystal display device spacer and the liquid crystal portion without the spacer were set when the driving voltage was turned off. Is compared with 10 observers with a transmission microscope having a magnification of 200 times, and it is determined that the blackness of the central portion of the liquid crystal display element spacer is darker than or equal to the blackness of the liquid crystal portion where no spacer exists. Recognized number of people: ◎: 8 or more, ○: 7
の も の: 5-6 people, ×: 4 or less,
Was evaluated in four steps.

[0083]

[Table 1]

[0084]

[Table 2]

[0085]

[Table 3]

[0086]

As described above, the colored spacer for a liquid crystal display element according to the first aspect of the present invention is provided with excellent uniformity of particle size, surface smoothness and inertness, and is colored at a high concentration. And has a strong mechanical strength required by the colored spacer for a liquid crystal display element.

The colored spacer for a liquid crystal display device according to the second aspect of the present invention is a mixed colored pigment composed of carbon black having excellent hiding power and an organic colored pigment having a low content of impurities such as highly ionizable ions. The use of the agent further enhances the inertness and enhances the visibility of a liquid crystal display device using the colored spacer for a liquid crystal display device.

The colored spacer for a liquid crystal display element according to the third aspect of the present invention is preferably obtained by coating the surface of carbon black having excellent concealing power with a highly ionizable ion or the like contained in the carbon black. Since the object is blocked, the visibility of the liquid crystal display device using the colored spacer for the liquid crystal display device is further improved.

The liquid crystal display element according to the fourth aspect uses the colored spacer for a liquid crystal display element according to the first, second or third aspect of the present invention, so that scattering of incident light is prevented. Since the image is not blurred and the refraction of light that causes image distortion is small, an image that is multicolored can be projected on the screen with high fidelity with high fidelity.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing one example of a liquid crystal display device of the present invention.

[Description of sign]

 DESCRIPTION OF SYMBOLS 1 Substrate 11 Transparent substrate 12 Transparent electrode 13 Alignment control film 2 Colored spacer for liquid crystal display elements 3 Sealing member 4 Nematic liquid crystal 5 Polarizing sheet

Claims (4)

[Claims] 1. A polymerizable monomer containing 50% by weight or more of a crosslinkable monomer and a colorant dispersed and mixed, and 100 parts by weight of a polymerizable monomer component of a polymerizable composition. What is claimed is: 1. A colored spacer for a liquid crystal display element, comprising 0.25 to 3 parts by weight of an organic radical polymerization initiator having two or more radical-generating chemical bonds in a molecule, and suspension polymerization in an aqueous medium. 2. The colored spacer for a liquid crystal display device according to claim 1, wherein the coloring agent comprises carbon black and an organic coloring pigment. 3. The colored spacer for a liquid crystal display device according to claim 1, wherein the colorant is carbon black subjected to a surface treatment. 4. A liquid crystal display device, wherein the colored spacer for a liquid crystal display device according to claim 1, 2 or 3 is interposed between two opposing transparent substrates with electrodes.