JPH08136933A - Colored spacer for liquid crystal display element and liquid crystal display element using the same - Google Patents

Abstract

PURPOSE: To provide the spacer which is prevented from being decolored and has improved powder fluidity and with which the abnormal orientation of liquid crystal molecules is prevented from occurring and also to provide the display element using the spacer. CONSTITUTION: This spacer is obtained by successively forming a first layer 1 treated with a silane compound and a second layer 2 treated with a silylisocyanate compound on the surface of each of colored solid fine particles A in this order and further forming on the surface of the second layer 2, a third layer 3 which consists of silane-treated parts treated with a silane compound that contains a group having a 1 to 5 debye dipole moment and/or an alkyl group having 1 to 20 carbon atoms and titanate-treated parts 4 treated with an organic titanate compound.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a colored spacer for a liquid crystal display device, in which decolorization is extremely reduced, abnormal alignment of liquid crystal molecules is prevented, and powder fluidity is improved, and a liquid crystal display using the same. Regarding the device.

[0002]

2. Description of the Related Art A main characteristic required for a colored spacer for a liquid crystal display device arranged between a pair of substrates is that the removed colorant causes liquid crystal contamination. It may be small, may not cause abnormal alignment of liquid crystal molecules, and may have excellent powder fluidity when the spacer is dispersed between the substrates.

Conventionally, (1) as a method of reducing the discoloration of a spacer, Japanese Patent Application Laid-Open No. 4-57029 discloses that colored fine particles are treated with a silane compound and then with a silyl isocyanate compound.

(2) As a method for preventing the abnormal alignment of liquid crystal molecules at the interface of the spacer, the applicant of the present application, in Japanese Patent Application No. 4-275782, used colored fine particles with silane having a Debye dipole moment of 1 to 5. A treatment method was proposed, and in Japanese Patent Application No. 4-346028, a treatment method with a silane having an alkyl group having 1 to 20 carbon atoms was proposed.

(3) Further, as a method for improving powder fluidity, Japanese Patent Laid-Open No. 3-63629 discloses a method of treating colored fine particles with an organic titanate compound.

[0006]

However, the above method (1) has a problem that although decolorization is prevented, it causes abnormal alignment of liquid crystal molecules.

The above method (2) prevents abnormal alignment of the liquid crystal, but the powder fluidity of the spacer is deteriorated, and when the spacer is sprayed using a dry disperser, the spacer is used by the feeder of the disperser. There was a problem that it was clogged and could not be sprayed.

Although the powder fluidity is improved by the above method (3), this method also has a problem of causing abnormal alignment of liquid crystal molecules.

An object of the present invention is to provide a colored spacer for a liquid crystal display device, which prevents decolorization, prevents abnormal alignment of liquid crystal molecules, and has improved powder fluidity, and a liquid crystal display device using the same. I am trying.

[0010]

A colored spacer for a liquid crystal display device according to the present invention comprises a first layer treated with a silane compound and a second layer treated with a silylisocyanate compound on the surface of colored solid fine particles. And a silane-treated portion treated with a silane compound having a group having a dipole moment of 1 to 5 Debye and / or an alkyl group having 1 to 20 carbon atoms on the surface of the second layer. Forming a third layer comprising a titanate-treated portion treated with an organic titanate compound,
Thereby, the above object is achieved.

The liquid crystal display device of the present invention comprises the above-mentioned colored spacer for a liquid crystal display device, thereby achieving the above object.

The material of the core particles constituting the colored solid fine particles used in the present invention may be an organic material or an inorganic material.

The organic substance is mainly a polymer compound, specifically, a styrene-based or acrylic-based thermoplastic resin, or an epoxy-based or phenol-based thermosetting resin.

Specifically, polyethylene, polypropylene, polymethylpentene, polyvinyl chloride, polytetrafluoroethylene, polystyrene, polymethylmethacrylate, polyethylene terephthalate, polybutylene terephthalate, polyamide, polyimide, polysulfone, polyphenylene oxide, polyacetal, etc. Linear or cross-linked polymer; epoxy resin, phenolic resin,
Network structure of melamine resin, unsaturated polyester resin, divinylbenzene polymer, divinylbenzene-styrene copolymer, divinylbenzene-acrylic acid ester copolymer, diallylphthalate polymer, triallyl isocyanurate polymer, benzoguanamine polymer, etc. And a resin having Of the above solid fine particles, particularly preferable are resins having a network structure such as divinylbenzene copolymer, divinylbenzene-styrene copolymer, divinylbenzene-acrylic acid ester copolymer and diallylphthalate polymer.

As the inorganic substances, silica glass, borosilicate, glass, lead glass, soda-lime glass, alumina,
Alumina silicate or the like can be used. Of these, silicate glass and borosilicate glass are particularly preferable.

Core particles made of these materials are treated with carbon black, a disperse dye, an acid dye, a basic dye, a pigment, a metal oxide or the like to obtain colored solid fine particles. When the core particles are formed of an inorganic substance, a resin coating film may be first formed on the surface of the core particles, and the solid particles may be decomposed or carbonized at a high temperature to be colored solid fine particles. Further, the colored solid fine particles may be those in which the material itself has a color.

Specific examples of the silane compound used in the present invention include γ-aminopropyltrimethoxysilane and N.
-Β- (aminoethyl) -γ-aminopropyl-trimethoxysilane, 3- [N-allyl-N (2-aminoethyl)] aminopropyltrimethoxysilane, 3- (N-
Amino-based compounds such as allyl-N-glycidyl) aminopropyltrimethoxysilane, 3- (N-allyl-N-methacryl) aminopropyltrimethoxysilane and 3- (N, N-diglycidyl) aminopropyltrimethoxysilane; N, N-bis [(methyldimethoxysilyl) 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, and N-glycidyl-N, N-bis [3- (tri Methoxysilyl)
Propyl] amine and other amines; N, N-bis [(methyldimethoxysilyl) propyl] methacrylamide and N, N-bis [3- (trimethoxysilyl) propyl]
Amides such as methacrylamide; vinyls such as vinyltriethoxysilane and vinyl-tris (2-methoxyethoxy) silane; methacrylics such as γ-methacryloxypropyltrimethoxysilane; γ-glycidoxypropyltrimethoxysilane and the like. And mercapto-based ones such as γ-mercaptopyrupryltrimethoxysilane, and amino-based and amide-based ones are particularly preferably used.

Examples of the silyl isocyanate compound used in the present invention include hydrogenated silyl triisocyanate HSi (NCO) ₃ , fluorinated silyl triisocyanate FSi (NCO) ₃ , methylsilyl triisocyanate MeSi (NCO) ₃ , ethyl. Silyl triisocyanate EtSi (NCO) ₃ , isopropyl silyl triisocyanate i-PrSi (NCO) ₃ , n-propyl silyl triisocyanate n-PrSi (NC
O) ₃ , n-butylsilyltriisocyanate n-Bu
Si (NCO) ₃ , methoxysilyltriisocyanate MeOSi (NCO) ₃ , ethoxysilyltriisocyanate EtOSi (NCO) ₃ , phenoxysilyltriisocyanate PhOSi (NCO) ₃ ,

[0019]

Embedded image

Triisocyanates such as difluorosilyldiisocyanate F ₂ Si (NCO) ₂ , dimethylsilyldiisocyanate Me ₂ Si (NCO) ₂ , di-n-butylsilyldiisocyanate (n-Bu) ₂ Si (NC)
O) ₂ , diphenylsilyl diisocyanate Ph ₂ Si
(NCO) ₂ , dimethoxysilyl diisocyanate (M
eO) ₂ Si (NCO) ₂ , diethoxysilyldiisocyanate (EtO) ₂ Si (NCO) _{2 and} other diisocyanates; trimethylsilyl isocyanate Me ₃ SiNC
O, triethylsilyl isocyanate Et ₃ SiNC
O, triphenylsilyl isocyanate Ph ₃ SiNC
O, trifluorosilyl isocyanate F ₃ SiNCO
And monoisocyanates such as tetraisocyanate silane Si (NCO) _{4 and the} like.

In the silane compound having a group having a dipole moment of 1 to 5 debye used in the present invention, the group having a dipole moment of 1 debye to 5 debye is an acetoxy group, an amide group, an aldehyde group or an epoxy group. , Cyano group, sulfone group, sulfonyl group, halogenoalkyl group, pyridine group, nitro group, lactone group and the like.

The silane compound having a group having a dipole moment of 1 to 5 Debye is, for example, 2
-Acetoxyethyltrimethoxysilane, 2-acetoxyethyltrichlorosilane, 2-acetoxyethylmethyldichlorosilane, 2-acetoxypropylmethyldichlorosilane, acetoxypropyltrimethoxysilane,
3-glycidoxypropyltrimethoxysilane, 2-
(3,4-Epoxycyclohexyl) -ethyltrimethoxysilane, N-glycidyl-N, N-bis [3- (methyldimethoxysilyl) propyl] amine, N-glycidyl-N, N-bis [3- (trimethoxy (Silyl) propyl] amine, beta- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, gamma-glycidoxypropyltrimethoxysilane, 3-cyanobutyltrichlorosilane, 2-cyanoethylmethyldichlorosilane, 2-cyanoethyltriethoxysilane , 2-cyanoethyltrimethoxysilane, cyanomethylphenethyltriethoxysilane, 3-cyanopropylmethyldichlorosilane, 3-cyanopropyltrichlorosilane, 3-cyanopropyltriethoxysilane, trifluoropropyltrimethoxysilane , Trifluoropropyltrichlorosilane, nonafluorohexyltrichlorosilane, tridecafluorooctyltrimethoxysilane, tridecafluorooctyltrichlorosilane, heptadecafluorodecylmethyldichlorosilane, heptadecafluorodecylmethyldimethoxysilane, heptadecafluorodecyltrichlorosilane , Heptadecafluorodecyltrimethoxysilane, tridecafluorooctylmethyldichlorosilane, tridecafluorotrichlorosilane, tridecafluorooctyltriethoxysilane, triethoxypropyl-p-nitrobenzamide, N- [3- (triethoxysilyl) Propyl] -2,4-dinitrophenylamine, beta-trimethoxysilylethyl-2-pyridine, 2- [2- (trichlorosilyl) ) Ethyl] pyridine, 4- [2- (trichlorosilyl) ethyl] pyridine, N-(3- triethoxysilylpropyl)-p-nitro benzamide and the like.

Examples of the silane compound having an alkyl group having 1 to 20 carbon atoms used in the present invention include, for example, methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane and propyltrimethoxysilane. , Propyltriethoxysilane, butyltrimethoxysilane, butyltriethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, octyltrimethoxysilane, octyltriethoxysilane, decyltrimethoxysilane, decyltriethoxysilane, dodecyltrisilane Methoxysilane, dodecyltriethoxysilane, octadecyltrimethoxysilane, octadecyltriethoxysilane, methyltrichlorosilane, ethyltrichlorosilane, propyltrichlorosilane Butyl trichlorosilane, hexyl trichlorosilane, octyl trichlorosilane, decyl trichlorosilane, and the like octadecyl trichlorosilane.

Examples of the organic titanate compound used in the present invention include tetraethoxy titanium Ti (OC ₂
H ₅ ) ₄ , tetrapropoxy titanium Ti (OC ₃ H ₇ ) ₄ ,
Tetrabutoxy titanium Ti (OC ₄ H ₉ ) ₄ , tetrapentoxy titanium Titanium (OC ₅ H ₁₁ ) ₄ , tetrahexoxy titanium Ti (OC ₆ H ₁₃ ) ₄ , tetrakis (2-ethylhexoxy) titanium Ti [OCH ₂ CH (C ₂ H ₅ ) C
₄ H ₉ ] ₄ , tetradodecylalkoxytitanium Ti (OC
₁₂ H ₂₅ ) ₄ , tetrastearoxytitanium Ti (OC ₁₇ H _3
5 ) ₄ , dipropoxy bis (acetylacetonato) titanium Ti (OC ₃ H ₇ ) ₂ [OC. (CH ₃ ) CHCOC
H ₃ ] ₂ , dibutoxy bis (triethanolaminato)
Titanium Ti (OC ₄ H ₉ ) ₂ [OC ₂ H ₄ N (C ₂ H ₄ O
H) ₂ ] ₂ , dihydroxy bis (lactato) titanium Ti
(OH) ₂ [OCH (CH ₃ ) COOH] ₂ , titanium propoxyoctylene glycolate Ti [OCH ₂ C
H (C ₂ H ₅ ) CH (C ₃ H ₇ ) OH] _{4 and the} like are used, and among these, particularly preferable are tetrapropoxy titanium, tetrabutoxy titanium, tetrakis (2-ethylhexoxy) titanium, dipropoxy bis. (Acetylacenato) titanium and dibutoxy bis (triethanolaminato) titanium.

As shown in FIG. 1, the colored spacer for a liquid crystal display device of the present invention comprises the above-mentioned colored solid fine particles A.
A layer 1 treated with a silane compound and a layer 2 treated with a silyl isocyanate compound are laminated in this order on the surface of, and the surface of the layer 2 treated with the silyl isocyanate compound. A group having a dipole moment of 1 to 5 Debye and / or a carbon number of 1
A layer comprising a silane-treated portion 3 treated with a silane compound having ˜20 alkyl groups and a titanate-treated portion 4 treated with an organic titanate compound has been formed.
The silane-treated portion 3 treated with the silane compound and the titanate-treated portion 4 treated with the organic titanate compound are non-uniformly formed on the surface of the layer 2 treated with the silylisocyanate compound, and between the silane-treated portions 3. Is provided with the titanate-treated portion 4.

As an operation method for treating colored solid fine particles (hereinafter referred to as colored fine particles) with each treatment agent, there is, for example, the following method.

(1) The colored fine particles are immersed in a dispersion liquid containing each treatment agent, the dispersion liquid is filtered off, and then the colored fine particles are dried.

(2) A dispersion containing each treatment solution is sprayed or applied on the colored fine particles.

In the above method (1), conditions such as the concentration of the treatment liquid, the treatment temperature and the treatment time are as follows, for example.

1 part by weight of colored fine particles is dispersed in 1 to 1000 parts by weight, preferably 5 to 500 parts by weight of a suitable dispersion medium (described later), and 0.001 to 1 part by weight of each treating agent, preferably 0. After adding 005 to 0.3 parts by weight and stirring at room temperature or under heating for 10 minutes to 12 hours, preferably 30 minutes to 6 hours, the dispersion medium is identified, and the remaining colored fine particles are mixed with 40
15 minutes-at ℃ ~ 500 ℃, preferably 60 ℃ ~ 400 ℃
Heat for 12 hours, preferably 30 minutes to 5 hours.

As the dispersion medium of the silane compound, alcohols such as methanol, ethanol and isopropanol; ketones such as acetone and methyl ethyl ketone;
A mixture of an organic solvent such as esters such as methyl acetate and ethyl acetate; ethers such as dioxane, tetrahydrofuran, methyl cellosolve and ethyl cellosolve; and water is used. The mixing ratio of the organic solvent and water is preferably 0.01 to 1 part by weight of water, and more preferably 0.05 to 0.5 part by weight of water, relative to 1 part by weight of the organic solvent.

The dispersion medium of the silyl isocyanate compound, the silane compound having a group having a dipole moment of 1 to 5 Debye and / or the alkyl group having a carbon number of 1 to 20 and the organic titanate compound is an aliphatic n-hexane or the like. Hydrocarbons; Esters such as ethyl acetate;
Aromatic hydrocarbons such as benzene, toluene and xylene are preferably used.

[0033]

The decolorization is reduced by stacking the first layer treated with the silane compound and the second layer treated with the silylisocyanate compound in this order on the surface of the colored fine particles. On the surface of the layer, a group having a dipole moment of 1 to 5 Debye and / or 1 to 20 carbon atoms
By forming a silane-treated portion treated with a silane compound having an alkyl group, abnormal alignment of liquid crystal is prevented, and by forming a titanate-treated portion treated with an organic titanate compound, powder flowability is enhanced. be able to.

[0034]

EXAMPLES The present invention will be specifically described below based on examples.

(Example 1) 1) Preparation of spacer Disperse dye (Sumikaron Black EB manufactured by Sumitomo Chemical Co., Ltd.)
(N)) 50 g was dispersed in 3 liters of water, and the pH was adjusted to 5 with acetic acid.
To prepare a dyebath. Divinylbenzene-dipentaerythritol acrylate (8 μm in particle size)
0 parts by weight: 20 parts by weight) 100 g of crosslinked polymer fine particles
Was added to the above dyeing bath, charged into a 5 liter autoclave, and dyed at 130 ° C. for 5 hours to obtain black fine particles.

The obtained colored fine particles are dispersed in a mixed solution of 200 g of water and 1800 g of ethanol, and 3 g of γ-aminopropyltrimethoxysilane (manufactured by Nippon Unicar Co., Ltd., trade name: A-1100) is added thereto at room temperature. Stir for 2 hours. Then, the colored fine particles obtained by filtering the reaction solution
It heat-processed at 50 degreeC for 2 hours.

Next, 5 g of tetraisocyanate silane (Matsumoto Pharmaceutical Co., Ltd., trade name: Organic SI-400)
The colored fine particles treated in the first step were dispersed in a treatment solution prepared by dissolving in 1 liter of toluene and stirred at room temperature for 1 hour. Then, the colored fine particles obtained by filtering the reaction solution were heat-treated at 150 ° C. for 1 hour.

Next, the colored fine particles were dispersed in a treatment liquid prepared by dissolving 3 g of 2-acetoxyethyltrichlorosilane in 500 g of toluene, and heated in a water bath at 55 ° C. for 1 hour while stirring. Then, the reaction liquid was filtered off, and the obtained colored fine particles were heat-treated at 120 ° C. for 1 hour.

Next, the colored fine particles are dispersed in a treatment liquid prepared by dissolving 1.0 g of tetrabutoxytitanium (B-1 manufactured by Nippon Soda Co., Ltd.) in 400 g of toluene and stirred for 1 hour in a water bath at 55 ° C. with stirring. Heated. Then, the reaction solution was filtered off, and the obtained colored fine particles were heat-treated at 120 ° C. for 1 hour.

2) Fabrication of liquid crystal display element A pair of 300 mm square glass plates were subjected to Si by CVD.
After depositing the O ₂ film, the ITO electrode was patterned by ordinary photolithography on the substrate on which the transparent conductive film ITO was formed by the sputtering method.

Polyimide intermediate LP-64 manufactured by Toray Industries, Inc. was printed on both of the substrates by the offset method, and the temperature was 280 ° C.
And baked for 2 hours to form a polyimide alignment film. Then, this alignment film was rubbed in a direction such that the twist angle of liquid crystal molecules was 240 °.

The spacers obtained by the above method were dispersed at a density of 120 per 1 mm ² by using a dispersion prepared by adding 30 g to 1 liter of water / ethanol mixed solvent (9/1 volume ratio), and Entered the sticker printing process. As the sealant, a struct bond manufactured by Mitsui Toatsu Chemical Co., Ltd., which is a one-pack type epoxy resin, was used. The substrates thus prepared were bonded together, and the epoxy resin was heated and pressed at 180 ° C. for 1 hour to be cured. Then, a liquid crystal was injected into the empty cell by a conventional method to prepare an STN liquid crystal cell.

Example 2 Instead of 3 g of 2-acetoxyethyltrichlorosilane used in Example 1, 1.5 g of ethyltrichlorosilane (Toray Silicone TSL822) was used.
A spacer was obtained in the same manner as in Example 1 except that 6) and 1.5 g of octadecyltrichlorosilane (Toray Silicone TSL8083) were used, and a liquid crystal display device was obtained using this spacer.

(Comparative Example 1) A spacer was obtained in the same manner as in Example 1 except that the γ-aminopropyltrimethoxysilane treatment and the tetraisocyanate silane treatment of Example 1 were not carried out, and this spacer was used. A liquid crystal display device was obtained.

(Comparative Example 2) A spacer was obtained in the same manner as in Example 1 except that the treatment with 2-acetoxyethyltrichlorosilane in Example 1 was not carried out, and a liquid crystal display device was obtained using this spacer. .

(Comparative Example 3) A spacer was obtained in the same manner as in Example 1 except that the treatment with tetrabutoxytitanium in Example 1 was not performed, and a liquid crystal display device was obtained using this spacer.

(Evaluation) The above Examples 1 and 2 and Comparative Example 1
The following items were evaluated with respect to the spacer and the liquid crystal display element obtained in each of Examples 3 to 3.

(1) Elution property (decolorization property): 0.1 g of a sample was dispersed in 30 ml of ethanol and immersed in 30 ° C. for 3 hours, and then the sample was filtered to observe the degree of coloring of the filtrate.

(2) Powder fluidity: 5 g of the sample is put into a 4 mmφ glass funnel and the passability of the powder through the tube is observed.

(3) Abnormal orientation of liquid crystal: Light leakage around the spacer after application of DC50V × 10 seconds to the produced liquid crystal display element is observed with an optical microscope (× 500).

The results are shown in Table 1.

[0052]

[Table 1]

[0053]

The spacer according to the present invention has the first layer treated with the silane compound and the second layer treated with the silylisocyanate compound formed on the surface of the colored fine particles. The separation is prevented, and the inconvenience of contaminating the liquid crystal and damaging the displayed image does not occur.

Further, since the third layer having a silane-treated portion treated with a silane compound having a group having a dipole moment of 1 to 5 Debye and / or an alkyl group having 1 to 20 carbon atoms, the liquid crystal is vertically aligned. It is possible to reduce light leakage around the spacer caused by static electricity, vibration, etc., and improve the display quality. Further, since the third layer contains the titanate-treated portion treated with the organic titanate compound, the powder fluidity is improved and the dry sprayability onto the substrate can be improved.

[Brief description of drawings]

FIG. 1 is an enlarged sectional view of an embodiment of a spacer of the present invention.

[Explanation of symbols]

A Colored solid fine particles 1 First layer treated with silane compound 2 Second layer treated with silyl isocyanate compound 3 1-5 A group having a dipole moment of Debye and / or an alkyl group having 1-20 carbon atoms Silane-treated part treated with silane compound having 4 Titanate-treated part treated with organic titanate compound

Claims (2)

[Claims] 1. A first layer treated with a silane compound and a second layer treated with a silylisocyanate compound are formed in this order on the surface of the colored solid fine particles, and the second layer is formed.
On the surface of the layer, a silane-treated portion treated with a silane compound having a group having a dipole moment of 1-5 Debye and / or an alkyl group having 1-20 carbon atoms and a titanate-treated portion treated with an organic titanate compound are provided. A colored spacer for a liquid crystal display device, comprising a third layer containing. 2. A liquid crystal display device comprising the colored spacer for a liquid crystal display device according to claim 1.