JP2006003919A - Spacer for liquid crystal display element and liquid crystal display element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a spacer for liquid crystal display element having excellent coloring property and light shielding property, and to provide a liquid crystal display element using the spacer. <P>SOLUTION: The spacer contains a pigment component comprising 5 to 60 wt.% of carbon black and 40 to 95 wt.% of at least one set of organic color pigments of dissimilar colors other than carbon black. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a spacer for a liquid crystal display element having excellent colorability and light shielding properties, and a liquid crystal display element using the same.

Liquid crystal display elements are widely used in personal computers, portable electronic devices and the like, and in order to improve their performance, it is desired to further increase the display contrast of images.
In Patent Document 1, in a liquid crystal display device in which two transparent substrates with electrodes are arranged so that the electrodes face each other and liquid crystal is sealed between both substrates, a colored spacer is formed on the entire surface of the substrate in contact with the liquid crystal. A technique for preventing a reduction in display contrast of an image by interspersing the image is disclosed.

The spacer for a liquid crystal display element used in such a high contrast liquid crystal display element is required to be colored dark. Various methods for manufacturing such a spacer for a liquid crystal display element have been proposed, and a method of coloring polymer polymer fine particles prepared in advance, and a method of coloring in a step of preparing polymer polymer fine particles, It can be divided into two types.

As a method for coloring the polymer polymer fine particles prepared in advance, for example, the following method is disclosed. Patent Document 2 discloses a method of treating polymer polymer fine particles with an acid and then coloring the polymer, and Patent Document 3 discloses a method of treating a polymer polymer fine particle in a temperature range of 200 to 700 ° C. to provide flame resistance. Patent Document 4 discloses a method for forming a calcined product, Patent Document 4 discloses a method for coating polymer polymer fine particles with a conjugated polymer such as polyacetylene, and Patent Document 5 discloses a method for coating the surface of crosslinked polymer polymer fine particles. After providing a metal coating layer, the method of oxidizing and making the surface into an oxide is disclosed, respectively.

Further, Patent Document 6 discloses a method of implanting black metal oxide ultrafine particles on the surface of organic polymer polymer fine particles, and Patent Document 7 discloses that polymer polymer fine particles containing an anionic functional group are oxidized. Patent Document 8 discloses a method of dispersing in an agent solution, adsorbing or impregnating an oxidizing agent, and then adding at least one of a hetero five-membered ring compound and an aromatic hydrocarbon to perform chemical oxidative polymerization. A method for dyeing water-soluble polymer fine particles obtained by polymerizing a water-soluble unsaturated sulfonic acid or a salt thereof with a basic dye is disclosed.

Further, Patent Document 9 discloses a method of coloring high molecular polymer fine particles of an amino resin with an acid dye in the presence of a solvent at a high temperature, and Patent Document 10 discloses an oily solvent solution of an oily dye in an aqueous medium. Methods of coloring by mixing a finely dispersed dye emulsion and a polymer fine particle emulsion are disclosed.
However, such a method of coloring the polymer polymer fine particles prepared in advance has problems such as high production cost and difficulty in controlling the performance and quality of the product.

As a method for coloring in the step of preparing the polymer fine particles, for example, the following methods are disclosed. Patent Document 11, Patent Document 12 and Patent Document 13 disclose a method for producing a spacer for a liquid crystal display element by suspension polymerization of a polymerizable monomer in the presence of a pigment. However, these methods are limited in terms of the type and amount of the polymerizable monomer, and the contained pigment may be exposed on the surface of the spacer. In some cases, the pigment itself may elute or impurities in the pigment may elute.

In Patent Document 14, a liquid crystal display element is prepared by mixing a pigment composed of a polyfunctional vinyl compound and a lipophilic vinyl compound with a pigment imparted with lipophilicity and performing suspension polymerization in an aqueous medium. Disclosed is a method for manufacturing a spacer. However, with this technology, improvements in the dispersibility and solvent resistance of the pigment are recognized. However, in order to prevent the pigment from being substantially present on the surface of the spacer, the vinyl compound is subjected to suspension polymerization in the subsequent step. Alternatively, since emulsion polymerization is performed, there is a problem that the polymerization process becomes two steps and the production cost is high.

In Patent Document 15, a pigment is uniformly mixed with a compound having a polyfunctional ethylenically unsaturated group containing (meth) acrylonitrile, and this is suspension-polymerized in an aqueous medium to produce a spacer for a liquid crystal display element. Although this technique improves the dispersibility of the pigment and the mechanical strength and solvent resistance of the spacer for the liquid crystal display element, impurities contained in the used pigment are eluted and diffused into the spacer. However, since the electric resistance of the spacer is lowered, there is a limit even if it is desired to increase the blending amount of the pigment, and it has been difficult to obtain a spacer for a liquid crystal display element colored darkly.
As described above, even in the method of coloring in the step of preparing the polymer fine particles, a spacer for a liquid crystal display element having excellent colorability and light shielding properties and having physical properties necessary as a spacer can be obtained simply and efficiently. It was difficult.
JP-A-57-189117 JP-A-1-144429 JP-A-1-207719 Japanese Patent Laid-Open No. 5-165033 JP-A-1-200227 Japanese Patent Laid-Open No. 4-15623 JP-A-3-101713 Japanese Patent Publication No. 4-27242 Japanese Unexamined Patent Publication No. 3-351539 JP-A-4-363331 Japanese Patent Publication No. 50-33821 Japanese Patent Publication No. 56-50883 Japanese Patent Publication No. 4-89805 Japanese Examined Patent Publication No. 4-59321 Japanese Patent Laid-Open No. 7-2913

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-described problems, and is a liquid crystal display element spacer having excellent colorability and light shielding properties, and having suitable electrical properties, physical properties, chemical properties, and optical properties. And providing a liquid crystal display element using the same.

The second aspect of the present invention is a spacer for a liquid crystal display element containing a pigment component composed of carbon black and at least one set of organic coloring pigments of different colors other than carbon black.
The present invention is described in detail below.

1st this invention is the spacer for liquid crystal display elements containing the carbon black by which the surface was coat | covered.
The carbon black used in the first aspect of the present invention has a surface coated in order to prevent elution and diffusion of impurities. The use of carbon black coated with the surface increases the amount of the carbon black. In addition, the electrical resistance of the liquid crystal display element spacer is prevented from being lowered, and further, the dispersibility of carbon black is improved, and the liquid crystal display element spacer can be colored black with a smaller amount. Examples of the coating include coating with a thermoplastic resin or the like.

In the present specification, the impurity is a trace component that is unavoidable to be contained in normal carbon black. When the carbon black is eluted and diffused into the liquid crystal display element spacer, the electric resistance of the liquid crystal display element spacer is lowered. Examples thereof include sodium ions, potassium ions, chlorine ions, and sulfate ions.

The carbon black used for the carbon black coated on the surface is not particularly limited, and examples thereof include channel black, roll black, furnace black, and thermal black.

The thermoplastic resin is not particularly limited. For example, alkyd resin, modified alkyd resin, phenol resin, natural resin modified phenol resin, maleic acid resin, natural resin modified maleic resin, fumaric acid resin, ester gum, rosin, petroleum Examples thereof include resins, coumarone resins, indene resins, polyester resins, polyamide resins, polycarbonate resins, polyethylene resins, epoxy resins, styrene resins, vinyl resins, acrylic resins, chlorinated rubber, benzoguanamine resins, urea resins, and the like. These may be used alone or in combination of two or more.

The method of coating the surface of carbon black with the thermoplastic resin is not particularly limited. For example, the method of pulverizing carbon black in a hydrophobic medium containing the thermoplastic resin using a grinding device such as a ball mill. A method in which an aqueous dispersion of carbon black is added and mixed in a hydrophobic medium containing the thermoplastic resin and emulsified, and then water is distilled off by heating; the hydrophobic medium containing the thermoplastic resin is heated in advance. Examples thereof include a method in which an aqueous dispersion of carbon black is added and mixed, and water is distilled off at the same time. The surface-coated carbon black obtained by the above method can be precipitated by mixing a lower alcohol such as ethanol or isopropanol that can be mixed with a hydrophobic medium, and can be recovered by filtration, decantation, or the like. it can.

The spacer for a liquid crystal display element according to the first aspect of the present invention can be obtained by uniformly mixing and dispersing the above-described surface-coated carbon black in a polymerizable monomer. The polymerization method is not particularly limited, and examples thereof include suspension polymerization and emulsion polymerization. Of these, suspension polymerization is preferred in order to obtain a uniformly colored spacer for a liquid crystal display element.
The suspension polymerization is performed in an aqueous medium in the presence of a polymerization initiator after uniformly dispersing carbon black having the surface coated on the polymerizable monomer.

The polymerizable monomer is not particularly limited, and examples thereof include unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, maleic anhydride, fumaric acid, crotonic acid, and itaconic acid; methyl acrylate, ethyl acrylate Acrylates such as n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, t-butyl acrylate, 2-ethylhexyl acrylate and stearyl acrylate; methyl methacrylate, ethyl methacrylate, propyl methacrylate , Such as n-butyl methacrylate, t-butyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, stearyl methacrylate, dodecyl methacrylate, glycidyl methacrylate, β-hydroxyethyl methacrylate, hydroxymethyl methacrylate, etc. Sulfuric acid esters; Styrene monomers such as styrene, vinyltoluene, α-methylstyrene, p-methoxystyrene, t-butylstyrene, chlorostyrene; Diene monomers such as butadiene and isoprene; Ethylene, vinyl chloride , Vinyl acetate, vinyl propionate, acrylamide, methacrylamide, acrylonitrile, methylol acrylamide, vinyl stearate, acrylic acetate, diallyl adipate, dimethyl itaconate, diethyl maleate, allyl alcohol, vinylidene chloride, vinyl pyridine, N-vinyl pyrrolidone , N-hydroxyacrylamide, 2-vinyl-2-oxazoline, 2-isopropenyl-2-oxazoline, dimethylaminoethyl acrylate, glycidyl methacrylate, allyl glycidyl acetate Le, can be mentioned monomethyl fumarate and the like. These may be used alone or in combination of two or more. These types, combinations, etc. are not particularly limited.

Furthermore, any crosslinkable compound together with the above polymerizable monomer, for example, aromatic divinyl compounds such as divinylbenzene, divinylnaphthalene and derivatives thereof; ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol Diethylenic or triethylenically unsaturated carboxylic acid esters such as di (meth) acrylate, trimethylolpropane tri (meth) acrylate, 1,3-butanediol di (meth) acrylate; N, N-divinylaniline, divinyl ether, One or two or more divinyl compounds such as divinyl sulfide and divinyl sulfonic acid and compounds having three or more vinyl groups can be used. The amount of the crosslinkable compound used is preferably 0.005 to 100% by weight based on the total amount of the crosslinkable compound and the polymerizable monomer.

The compounding amount of the polymerizable monomer is preferably 1 to 200 parts by weight with respect to 100 parts by weight of the aqueous medium. When it is less than 1 part by weight, it is industrially disadvantageous, and when it exceeds 200 parts by weight, it is difficult to remove the polymerization heat.

The amount of carbon black coated on the surface is preferably 0.1 to 200 parts by weight with respect to 100 parts by weight of the polymerizable monomer. If it is less than 0.1 part by weight, it is difficult to be colored deeply, and if it exceeds 200 parts by weight, the mechanical strength of the obtained spacer for liquid crystal display element may be lowered.

In order to uniformly disperse the carbon black whose surface is coated in the polymerizable monomer, for example, a ball mill, a bead mill, a sand mill, an attritor, a sand grinder, a nanomizer, or the like can be used. In this case, a dispersant may be added in order to improve the dispersibility of the carbon black coated on the surface.

The dispersant is not particularly limited, and examples thereof include water-soluble polymers such as polyvinyl alcohol, starch, methylcellulose, carboxymethylcellulose, hydroxyethylcellulose, and sodium polymethacrylate; barium sulfate, calcium sulfate, aluminum sulfate, calcium carbonate, calcium phosphate, Examples include talc, clay, diatomaceous earth, and metal oxide powder.

The amount of the dispersing agent is preferably 0.01 to 20% by weight with respect to the polymerizable monomer component.
The aqueous medium is not particularly limited, for example, polyvinyl alcohol, polyacrylic acid, polymethacrylic acid, gelatin, methylcellulose, polymethacrylamide, polyethylene glycol, polyethylene oxide monostearate, sorbitan tetraoleate, glycerin monooleate, An aqueous solution of a water-soluble organic compound such as dodecylbenzenesulfonic acid; water and the like can be mentioned.

In the aqueous medium, a dispersion in which the surface-coated carbon black is uniformly dispersed in the polymerizable monomer is suspended in the form of fine particles. For example, a homogenizer can be used for the suspension.

The polymerization temperature of the suspension polymerization is preferably 20 to 100 ° C. When it is less than 20 ° C., the polymerization rate becomes low, and when it exceeds 100 ° C., it becomes difficult to control the polymerization reaction.
The polymerization time for the suspension polymerization is preferably 1 to 50 hours. If it is less than 1 hour, the polymerization rate is low, and a time exceeding 50 hours is unnecessary.

The liquid crystal display element spacer obtained by the suspension polymerization can be separated by means such as filtration and centrifugation. The separated spacer for liquid crystal display element is washed with water or the like, and then dried by heating or decompression.

The polymerization initiator used for the suspension polymerization is not particularly limited. For example, 2,2′-azobisisobutyronitrile, 2,2′-azobis-2,4′-dimethylvaleronitrile, 2,2 '-Azobis-methylbutyronitrile, 2,2'-azobis-methylheptonitrile, 2,2'-azobis-2,3-dimethylbutyronitrile, 2,2'-azobis-2,3,3- Azo compounds such as trimethylbutyronitrile, 2,2'-azobis-2-isopropylbutyronitrile, 4,4-azobis-4-cyanovaleric acid, dimethyl-2,2'-azobisisobutyrate; Acetyl, decanoyl peroxide, lauroyl peroxide, benzoyl peroxide, octanoyl peroxide, orthomethoxybenzoyl peroxide, p-chlorobenzoyl peroxide, 2,4 peroxide Dichlorobenzoyl, diisopropyl peroxide, diethyl peroxide-2-ethylhexyl peroxide, acetylcyclohexylsulfonyl peroxide, t-butyl perisobutyrate, t-butyl perbivalate, t-butyl peroxide 2-ethylhexanoate, peroxide Examples thereof include organic peroxides such as di-t-butyl, t-butyl cumyl peroxide, dicumyl peroxide, methyl ethyl ketone peroxide, cumene hydroperoxide, and t-butyl hydroperoxide.

The addition amount of the polymerization initiator is 0.01 to 30 parts by weight with respect to 100 parts by weight of the polymerizable monomer. When the amount is less than 0.01 part by weight, the polymerization rate decreases, and an amount exceeding 30 parts by weight is unnecessary. More preferably, it is 0.1 to 10 parts by weight.

The spacer for a liquid crystal display element according to the first aspect of the present invention preferably has an average particle size of 0.5 to 500 μm. If it is less than 0.5 μm, it tends to aggregate and lacks practicality, and if it exceeds 500 μm, it is rarely used. More preferably, it is 1-300 micrometers.

The liquid crystal display element spacer of the first aspect of the present invention preferably has a coefficient of variation in particle size of 20% or less. If it exceeds 20%, the particle size distribution becomes too wide, and the performance as a spacer for a liquid crystal display element may deteriorate. More preferably, it is 10% or less, More preferably, it is 5% or less.

The spacer for a liquid crystal display element according to the first aspect of the present invention is for preventing elution and diffusion of impurities and the like (including the pigment itself), and for giving a surface chemical change to the surface state of the spacer for a liquid crystal display element. If necessary, the surface may be coated with a coating agent such as a silane coupling agent. The coating agent is preferably coated as a monomolecular thin film or a polymer thin film.
The silane coupling agent is not particularly limited. For example, γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, 3- [N-allyl-N- (2 -Aminoethyl)] aminopropyltrimethoxysilane, 3- (N-allyl-N-glycidyl) aminopropyltriethoxysilane, 3- (N-allyl-N-methacryl) aminopropyltrimethoxysilane, 3- (N, Amino-based silane coupling agents such as N-diglycidyl) aminopropyltrimethoxysilane; N, N-bis [3- (methyldimethoxysilyl) propyl] amine, N, N-bis [3- (trimethoxysilyl) propyl] Amine, N, N-bis [3- (methyldimethoxysilyl) propyl] ethylenediamine, N, N-bi [3- (Trimethoxysilyl) propyl] ethylenediamine, N-glycidyl-N, N-bis [3- (methyldimethoxysilyl) propyl] amine, N-glycidyl-N, N-bis [3- (trimethoxysilyl) Propyl] amine and other amide silane coupling agents; vinyltriethoxysilane, vinyltris (2-methoxyethoxy) silane and other vinyl silane coupling agents; γ-methacryloxypropyltrimethoxysilane and other methacrylic silane cups Examples thereof include a ring agent; a glycidyl silane coupling agent such as γ-glycidoxypropyltrimethoxysilane; and a mercapto silane coupling agent such as γ-mercaptopropyltrimethoxysilane.

The method for coating the surface of the spacer for liquid crystal display element using the coating agent is not particularly limited. For example, the coating agent and the spacer for liquid crystal display element are coated in an inorganic solvent such as water or an organic solvent such as alcohol. Mixing, heating under stirring, separating the liquid crystal display element spacer by decantation after heating, removing the solvent by drying under reduced pressure, etc., directly mixing the coating agent and the liquid crystal display element spacer, and heating And the like.

Since the liquid crystal display element spacer of the first aspect of the present invention uses carbon black coated on the surface, the carbon black impurities are not diffused and diffused into the liquid crystal display element spacer. It shows excellent solvent resistance. In addition, the use of the coated carbon black suppresses the decrease in the electrical resistance of the spacer for the liquid crystal display element. Furthermore, since the coated carbon black has better dispersibility than the uncoated carbon black, the liquid crystal is uniformly dispersed. The blackness of the display element spacer is improved.

The second aspect of the present invention is a spacer for a liquid crystal display element containing a pigment component composed of carbon black and at least one set of organic coloring pigments of different colors other than carbon black.
The carbon black is not particularly limited, and examples thereof include acetylene black, channel black, and furnace black. In the second aspect of the present invention, carbon black that has been subjected to a surface treatment such as microlith (manufactured by Ciba Geigy) can also be used in order to improve the dispersibility of the carbon black.

As a set of organic coloring pigments other than the above-mentioned carbon black and having different colors, those having relatively good transparency and excellent heat resistance, weather resistance and solvent resistance are preferable. A set of organic colored pigments that exhibit a substantially black color is preferred. In the second invention, at least one set of such a set of organic coloring pigments is used.

Color pigments that constitute a set of organic colored pigments other than the carbon black are particularly limited, for example, Brilliant Carmine BS, Lake Carmine FB, Brilliant First Scarlet, Lake Red 4R, Permanent Red R, First red FGR, toluidine malon, bisazo yellow, first yellow G, bisazo orange, Vulcan orange, pyrazolone red and other azo and condensed azo organic color pigments; phthalocyanine organics such as phthalocyanine blue, first sky blue and phthalocyanine green Colored pigments: dyed lake organic color pigments such as yellow lake, rose lake, violet lake, blue lake, and green lake; oxazine organic color pigments; quinophthalone organic color pigments, etc. It can be mentioned.
As a set of organic coloring pigments other than the carbon black and having different colors, two or more of them can be appropriately selected and used.

The combination of the color pigments constituting a set of organic color pigments other than the carbon black and different colors includes at least one set of organic color pigments other than the carbon black and different colors together with the carbon black. When used, the maximum value of the spectral transmittance at all wavelengths in the visible region in the range of about 400 to 700 nm of the spacer for the liquid crystal display element of the second invention is less than 3%, and the total at all wavelengths in the visible region is less than 3%. A combination in which the light transmittance is 0.1 to 2.5% is preferable. More preferably, the combination is such that the maximum value of the spectral transmittance is less than 2.7% and the total light transmittance is 0.2 to 2.0%.
Such a combination is not particularly limited. For example, a blue pigment and a purple pigment, a red pigment and a blue pigment, a yellow pigment and a blue pigment and a purple pigment, a green pigment and a blue pigment and a purple pigment, and a red pigment and a blue pigment and a purple pigment. The combination of a pigment etc. can be mentioned.

The color pigment preferably has a particle size of 1 μm or less from the viewpoints of light transmittance, film surface uniformity, and the like.

In the pigment component, the blending ratio of the carbon black is 5 to 60% by weight, and the blending ratio of at least one set of organic coloring pigments of different colors other than the carbon black is 95 to 40% by weight. Preferably there is. When the blending ratio of the carbon black is less than 5% by weight and the blending ratio of at least one set of organic coloring pigments of different colors other than the carbon black exceeds 95% by weight, the different colors other than the carbon black The blending amount of at least one set of organic coloring pigments may increase the mechanical strength of the spacer for a liquid crystal display element of the second invention.
Further, when the blending ratio of the carbon black exceeds 60% by weight and the blending ratio of at least one set of organic coloring pigments of different colors other than the carbon black is less than 40% by weight, the blending amount of the carbon black is As a result, the influence of impurities eluted and diffused from the carbon black increases, and the electrical resistance of the liquid crystal display element spacer of the second aspect of the present invention may decrease. More preferably, the blending ratio of the carbon black is 10 to 40% by weight, and the blending ratio of at least one set of organic coloring pigments of different colors other than the carbon black is 90 to 60% by weight.

When the pigment component is composed only of at least one set of organic coloring pigments of different colors other than the carbon black, even if the combination is optimal for producing a sufficient black color, the set of organic coloring The mechanical strength of the spacer for a liquid crystal display element may decrease due to an increase in the amount of the pigment.

The spacer for a liquid crystal display element according to the second aspect of the present invention uses, as a pigment component, at least one set of organic coloring pigments of a different color other than carbon black together with carbon black, so that the amount of carbon black is reduced. It is possible to reduce the elution and diffusion of impurities, prevent a decrease in electrical resistance, and ensure sufficient black color and good physical properties.

The spacer for a liquid crystal display element according to the second aspect of the present invention is the above pigment component composed of at least one set of organic coloring pigments other than the above carbon black and different colors other than the above carbon black. Can be obtained by uniformly mixing and dispersing. The polymerization method is not particularly limited, and examples thereof include suspension polymerization and emulsion polymerization. Of these, suspension polymerization is preferred in order to obtain a uniformly colored spacer for a liquid crystal display element.

The suspension polymerization is carried out in an aqueous medium in the presence of a polymerization initiator after the pigment component is uniformly dispersed in the polymerizable monomer.
As said polymerizable monomer, the thing similar to what was demonstrated in 1st this invention can be mentioned.
An appropriate crosslinkable compound can be used together with the polymerizable monomer. Examples of the crosslinkable compound and the amount thereof include those described in the first aspect of the present invention.

As for the compounding quantity of the said pigment component, 1-180 weight part is preferable with respect to 100 weight part of polymerizable monomers. If it is less than 1 part by weight, it will be difficult to be colored deeply, and if it exceeds 180 parts by weight, the mechanical strength of the resulting spacer for liquid crystal display element may be lowered. More preferably, it is 3 to 160 parts by weight.

In order to uniformly disperse the pigment component in the polymerizable monomer, a method using an apparatus similar to that described in the first aspect of the present invention can be exemplified.
In order to improve the dispersibility of the pigment component, a dispersant may be added. Examples of the dispersant and the blending amount thereof are the same as those described in the first invention.
As said aqueous medium, the thing similar to what was demonstrated in 1st this invention can be mentioned.

In the aqueous medium, a dispersion in which the pigment component is uniformly dispersed in the polymerizable monomer is suspended in the form of fine particles. For example, a homogenizer can be used for the suspension.

The polymerization temperature of the suspension polymerization is the same as that described in the first aspect of the present invention.
The polymerization time of the suspension polymerization is the same as that described in the first aspect of the present invention.
The liquid crystal display element spacer obtained by the suspension polymerization can be separated by means such as filtration and centrifugation. The separated spacer for liquid crystal display element is washed with water or the like, and then dried by heating or decompression.
The said polymerization initiator and its compounding quantity can mention the thing similar to what was demonstrated in 1st this invention.
The spacer for a liquid crystal display element according to the second aspect of the invention has the same average particle diameter and variation coefficient of the particle diameter as those described in the first aspect of the invention.

The surface of the spacer for a liquid crystal display element of the second aspect of the present invention may be coated with a coating agent such as a silane coupling agent as necessary. As said silane coupling agent, the thing similar to what was demonstrated in 1st this invention can be mentioned.

The spacer for a liquid crystal display element according to the second aspect of the present invention uses carbon black and at least one set of organic colored pigments of different colors other than carbon black as a pigment component. It becomes black and has excellent electrical resistance. In addition, liquid crystal contamination due to the pigment component can be prevented.

A third aspect of the present invention is a spacer for a liquid crystal display element comprising carbon black having a surface coated and a pigment component composed of at least one set of organic coloring pigments of different colors other than carbon black.

The carbon black used in the third aspect of the present invention is one whose surface is coated to prevent elution and diffusion of impurities. Examples of the carbon black coated on the surface include the same as those described in the first aspect of the present invention.
A set of organic coloring pigments of different colors other than the carbon black and the blending ratio thereof may be the same as those described in the second invention.
The spacer for the liquid crystal display element of the third aspect of the present invention is obtained by using the same method for obtaining the spacer for the liquid crystal display element of the second aspect of the present invention, using the carbon black whose surface is coated as carbon black. be able to.
The spacer for a liquid crystal display element of the third aspect of the present invention has the same average particle diameter and coefficient of variation of the particle diameter as those described in the first aspect of the present invention.
The surface of the spacer for a liquid crystal display element of the third aspect of the present invention may be coated with a coating agent such as a silane coupling agent as necessary. As said silane coupling agent, the thing similar to what was demonstrated in 1st this invention can be mentioned.

Since the liquid crystal display element spacer of the third aspect of the present invention uses carbon black whose surface is coated, impurities of carbon black do not elute and diffuse into the liquid crystal display element spacer, and further, as a pigment component, In addition to carbon black, at least one set of organic color pigments of different colors other than carbon black is used, so these synergistic effects make dark black in a smaller amount than the first invention and the second invention. It is excellent in solvent resistance, electrical resistance and mechanical strength.

The fourth aspect of the present invention is a liquid crystal display element using the liquid crystal display element spacer of the first, second or third aspect of the present invention.
The liquid crystal display element of the fourth aspect of the present invention exhibits excellent display contrast without displaying the spacer as a bright spot in the black display portion of the image when displaying the image.

One mode of the liquid crystal display element of the fourth aspect of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the liquid crystal display element A includes a pair of substrates 7 and 9, a spacer 8, a seal member 10, a nematic liquid crystal 11, and polarizing sheets 12 and 13.
The spacer 8 is disposed between the pair of substrates 7 and 9 in order to keep the gap between the pair of substrates 7 and 9 constant. The seal member 10 is filled around the pair of substrates 7 and 9. The nematic liquid crystal 11 is sealed between the pair of substrates 7 and 9. The polarizing sheets 12 and 13 are affixed to the surfaces of the substrates 7 and 9.
The substrates 7 and 9 are formed by patterning transparent electrodes 2 and 5 on one side of the glass transparent substrates 1 and 4, and orientation control films 3 and 6 (for example, polyimide) on the surfaces of the transparent electrodes 2 and 5 and the transparent substrates 1 and 4. Film). The orientation control films 3 and 6 are subjected to orientation control processing by rubbing.
The spacer 8 is a spacer for a liquid crystal display element according to the first, second or third aspect of the present invention.

ADVANTAGE OF THE INVENTION According to this invention, it is excellent in coloring property and light-shielding property, and has a suitable electrical property, a physical property, a chemical property, and an optical property, The spacer for liquid crystal display devices, and a liquid crystal display device using the same Can be provided.

Hereinafter, embodiments of the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.

Example 1
Preparation of spacers for liquid crystal display elements
60 parts by weight of tetramethylol methane triacrylate, 20 parts by weight of divinylbenzene and 20 parts by weight of acrylonitrile are uniformly mixed. Further, 12 parts by weight of carbon black whose surface is coated with polyethylene is added, and a bead mill is used for 48 hours. Thus, the carbon black whose surface was coated was uniformly dispersed.
2 parts by weight of benzoyl peroxide are uniformly mixed with the colored polymerizable monomer composition in which carbon black coated with the surface is dispersed, and this is added to 850 parts by weight of a 3% by weight aqueous polyvinyl alcohol solution. After thoroughly stirring, the suspension was suspended with a homogenizer so that the particle diameter of the colored polymerizable monomer droplets became fine particles of about 3 to 10 μm.
The obtained suspension was transferred to a 2 liter separable flask equipped with a thermometer, a stirrer and a reflux condenser, heated to 85 ° C. with stirring in a nitrogen atmosphere, and subjected to a polymerization reaction for 7 hours. Further, the temperature was raised to 90 ° C. and maintained for 3 hours to complete the polymerization reaction.

Thereafter, the polymerization reaction liquid was cooled, and the produced colored fine particles were filtered, sufficiently washed with water and dried to obtain 120 parts by weight of pigment-dispersed colored fine particles having a particle size of 3 to 10 μm.
The obtained colored fine particles were classified to obtain spacers for liquid crystal display elements having an average particle size of 5.55 μm and a particle size variation coefficient of 2.48%.
The blackness (light transmittance) of the obtained liquid crystal display element spacer, the impurity concentration in the liquid crystal display element spacer, and the electrical resistance of the liquid crystal display element spacer were evaluated by the following methods, and the results are shown in Table 1. Indicated.

Evaluation Method (1) Blackness A flaky product having a thickness of 1 mm was prepared by polymerizing a mixed composition of a polymerizable monomer and a colored substance having the same composition as the spacer for a liquid crystal display element. With respect to this flaky material, the spectral transmittance at all visible wavelengths in the visible range of 400 to 700 nm was measured using a spectrophotometer, and the maximum value was defined as the blackness of the spacer for liquid crystal display elements.

(2) Impurity concentration in spacers for liquid crystal display elements
10 g of the obtained spacer for a liquid crystal display device was added to 330 ml of a mixed solvent (water / isopropanol = 7/3 volume ratio) with stirring, and left for 1 week at room temperature (stirred once a day). The liquid crystal display element spacer was allowed to settle for the last two days.
The supernatant was filtered using filter paper (thickness 0.2 μm). The filtrate was concentrated to 30 ml and analyzed. Sodium ions and potassium ions were analyzed using a SPQ8000 type atomic absorption photometer manufactured by Jarrel Ash. Chlorine ions and sulfate ions were analyzed using a 2010 I-type ion chromatography analyzer manufactured by Dionex.

(3) Electric resistance of spacer for liquid crystal display element ULTRA MEGOHMMETER SM-8210 manufactured by Toa Denpa Co., Ltd. is used, and the liquid sample display element is filled with the spacer for liquid crystal display element, and the liquid crystal is measured according to the measurement method determined for the liquid sample. The electrical resistance of the display element spacer was measured.

Production of TN type liquid crystal display element In evaluating the performance of the liquid crystal display element using the obtained spacer for liquid crystal display element, a TN type liquid crystal display of a normally black display mode in which the light shielding property of the spacer can be easily evaluated. An element was produced. The effect of the spacer evaluated by the prototype liquid crystal display element on the light shielding property or cell gap formation is the same even when the STN liquid crystal display element is used in different modes. It is not limited to a liquid crystal display element.
An indium oxide-tin oxide based transparent conductive film having a thickness of about 500 angstroms was formed on a glass plate having a thickness of 0.7 mm by a low temperature sputtering method, and then a predetermined electrode pattern was formed by photolithography. Next, an orientation agent was applied thereon, and then a heated orientation control film was formed. Next, this glass plate was cut into a size of 5 cm × 12.5 cm to obtain a glass substrate of a liquid crystal display element.
An epoxy adhesive mixed with glass fiber spacers was printed on the periphery of the obtained glass substrate with a width of 1 mm by screen printing.

After arranging this glass substrate horizontally, the spacer for liquid crystal display elements was scattered from above by pressurized nitrogen gas, and was uniformly dropped on the glass substrate. The spraying time was adjusted so that the spraying concentration of the spacers for liquid crystal display elements on the glass substrate was about 150 pieces / mm ² .
After another glass substrate was superposed on the glass substrate on which the spacers for liquid crystal display elements were dispersed, a load of 1 kg / cm ² was applied by a press so that the entire glass substrate was uniformly applied. At the same time, this was heated at a temperature of 160 ° C. for 20 minutes to cure the surrounding epoxy adhesive.
After vacuuming the inside of the cell thus produced, liquid crystal is injected into the inside through a hole provided in a part of the peripheral seal portion, and the pressure inside the cell is 0.6 atm, which is lower than atmospheric pressure. Then, the injection hole was sealed, the temperature was raised to a predetermined temperature, liquid crystal realignment treatment was performed, and a liquid crystal display element was produced.
As a result of measuring the gap value between the upper and lower substrates of the obtained liquid crystal display element, the gap value was 5.38 μm.

Evaluation Method (1) Presence / absence of color unevenness of TN type liquid crystal display element
Polarizing sheets were stacked on both the upper and lower surfaces of the liquid crystal display element so that the color of the reflected light of the light applied to the obtained TN liquid crystal display element exhibited an olive color. At this time, the olive color was uniform and no color unevenness was observed in the density.
In addition, the case where there was no color unevenness at all was rated as ◎, the case where there was some color unevenness depending on the conditions was marked as ◯, and the case where practically unacceptable was marked as x.

(2) Shielding property of spacer in TN type liquid crystal display element
The polarizing sheet attached to the obtained liquid crystal display element was set to TN type normally black mode, and it observed with the transmission type 200 times magnification microscope.
With the driving voltage OFF, the black at the center of the spacer and the black at the liquid crystal without the spacer were compared by visual observation with 10 people.
If the number of people who observe that the spacer central part is blacker than or equal to the liquid crystal part is 80% or more, ◎, 70-80% ○, 50-70% Δ, less than 50% If it was, it was set as x.
Table 1 shows the average cell gap, the presence or absence of color unevenness, and the evaluation results of the light shielding properties.

(Examples 2 to 4)
A spacer for a liquid crystal display element and a liquid crystal display element were prepared and evaluated in the same manner as in Example 1 except that the blending amounts shown in Table 1 were used. The results are shown in Table 1.

(Comparative Example 1)
A liquid crystal display element spacer and a liquid crystal display element were produced and evaluated in the same manner as in Example 1 except that the surface was not coated and carbon black was used in the amount shown in Table 1. Results Is shown in Table 1.

(Comparative Example 2)
A liquid crystal display element spacer and a liquid crystal display element were prepared and evaluated in the same manner as in Example 1 except that carbon black was not blended and the blending amounts shown in Table 1 were used. The results are shown in Table 1. Indicated.

(Example 5)
Preparation of spacers for liquid crystal display elements
60 parts by weight of tetramethylol methane triacrylate, 20 parts by weight of divinylbenzene and 20 parts by weight of acrylonitrile were uniformly mixed, 12 parts by weight of carbon black as a black pigment component, 6 parts by weight of phthalocyanine blue (blue pigment) and dioxane violet ( 6 parts by weight of a purple pigment) was added, and the black pigment component was uniformly dispersed over 48 hours using a bead mill.
The colored polymerizable monomer composition in which the black pigment component is dispersed is uniformly mixed with 2 parts by weight of benzoyl peroxide, and this is added to 850 parts by weight of a 3% strength by weight aqueous polyvinyl alcohol solution and stirred well. Thereafter, the colored polymerizable monomer droplets were suspended with a homogenizer so that the particle diameter was about 3 to 10 μm, and a suspension was obtained.

The obtained suspension was transferred to a 2 liter separable flask equipped with a thermometer, a stirrer and a reflux condenser, heated to 85 ° C. with stirring in a nitrogen atmosphere, and subjected to a polymerization reaction for 7 hours. Further, the temperature was raised to 90 ° C. and maintained for 3 hours to complete the polymerization reaction.
Thereafter, the polymerization reaction liquid was cooled, and the produced colored fine particles were filtered, sufficiently washed with water and dried to obtain 120 parts by weight of pigment-dispersed colored fine particles having a particle size of 3 to 10 μm.
The obtained colored fine particles were classified to obtain spacers for liquid crystal display elements having an average particle size of 6.45 μm and a particle size variation coefficient of 2.88%.
The obtained spacer for a liquid crystal display element was evaluated in the same manner as in Example 1. Further, a liquid crystal display element was prepared and evaluated in the same manner as in Example 1, and the results are shown in Table 2.

(Examples 6 to 8, Comparative Examples 3 and 4)
A spacer for a liquid crystal display element and a liquid crystal display element were prepared and evaluated in the same manner as in Example 5 except that the blending amounts shown in Table 2 were used. The results are shown in Table 2.

(Examples 9 and 10)
The coated carbon black of Example 1 was used as carbon black, and the liquid crystal display element spacer and the liquid crystal display element were prepared and evaluated in the same manner as in Example 5 except that the blending amounts shown in Table 3 were used. The results are shown in Table 3.

Since the spacer for a liquid crystal display element of the first aspect of the present invention is as described above, it has excellent colorability and light shielding properties, and has suitable electrical properties, physical properties, chemical properties, and optical properties. The liquid crystal display device using the same exhibits excellent display contrast without displaying the spacer as a bright spot in the black display portion of the image when displaying the image.

It is sectional drawing which shows one form of the liquid crystal display element of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Transparent substrate 2 Transparent electrode 3 Orientation control film 4 Transparent substrate 5 Transparent electrode 6 Orientation control film 7 Substrate 8 Spacer 9 Substrate 10 Sealing member 11 Nematic liquid crystal 12 Polarizing sheet 13 Polarizing sheet

Claims (2)

A spacer for a liquid crystal display device comprising 5 to 60% by weight of carbon black and a pigment component composed of 40 to 95% by weight of at least one set of organic coloring pigments of different colors other than carbon black . A liquid crystal display element, wherein the liquid crystal display element spacer according to claim 1 is used.

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