JPH08262453A - Spacer for liquid crystal display element and liquid crystal display element - Google Patents

Abstract

PURPOSE: To provide a spacer for a liq. crystal display element capable of preventing abnormal orientation of a liq. crystal molecule on the interface between the liq. crystal molecule and spacer by orienting the liq. crystal molecule vertically to the surface of a silica grain and to furnish a liq. crystal display element using the spacer. CONSTITUTION: A coating film obtained from any of the following three org. silane compds. 1 to 3 is formed on the surface of a silica grain. Namely, the org. silane compd. 1 is expressed by R<1> SiX3 (where R<1> is 1-21C alkyl, and X is halogen atom or 1-4C alkoxyl), the org. silane compd. 2 is shown by R<2> SiX3 (where R<2> is 1-5C group having a Debye dipole moment, and X is halogen atom or 1-4C alkyl), and the org. silane compd. 3 is the mixture of the compds. 1 and 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spacer for a liquid crystal display device and a liquid crystal display device which can obtain excellent display quality.

[0002]

2. Description of the Related Art A liquid crystal display device is generally manufactured by arranging a transparent electrode substrate having an alignment layer facing a predetermined gap through a spacer to seal the periphery, and injecting liquid crystal into the gap for sealing. It The spacer is necessary to make the gap between the electrode substrates uniform.

In this type of liquid crystal display device, when abnormal alignment of liquid crystal molecules occurs in the vicinity of the spacer, a bright spot or a dark spot on the screen of the liquid crystal display device (these are connected to each other as if they were white lines). May appear to be connected to each other, which is called a disclination line), and the display quality of the screen is deteriorated. In particular, this phenomenon is likely to occur in a super twist (STN) type liquid crystal display element.

At the interface between the liquid crystal molecule and the spacer,
If the vertical alignment of liquid crystal molecules can be sufficiently performed,
The bright or dark spots above can be erased, resulting in
It is possible to dramatically improve the display quality of the liquid crystal display element.

Several methods have been proposed to prevent horizontal alignment of liquid crystal molecules at the interface between liquid crystal molecules and spacers and to promote vertical alignment of liquid crystal molecules. For example, in JP-A-64-59212 and JP-A-2-297523, by treating the surface of an inorganic spacer such as glass fiber, silica or alumina with an organic silane compound (silane coupling agent), A method of vertically aligning liquid crystal molecules has been proposed.
However, the conventional method is insufficient for vertically aligning the liquid crystal molecules.

[0006]

DISCLOSURE OF THE INVENTION The present invention is intended to solve the above problems, and an object of the present invention is to vertically align liquid crystal molecules so that the liquid crystal molecules at the interface between the liquid crystal molecules and the spacer are aligned. An object of the present invention is to provide a spacer for a liquid crystal display element and a liquid crystal display element capable of preventing abnormal alignment and improving display contrast.

[0007]

SUMMARY OF THE INVENTION The above-mentioned object is to achieve the general formula R ¹ SiX ₃ (where R ¹ has ¹ carbon atom) on the surface of silica particles.
To 21 alkyl groups, X is a halogen atom or 1 to 1 carbon atoms.
It can be achieved by using a spacer for a liquid crystal display device, in which a coating film obtained from the organic silane compound (a) represented by (4 is an alkoxy group of 4) is formed.

Further, the above-mentioned object is that the surface of the silica particle is represented by the general formula R ² SiX ₃ (wherein R ² is a group having a dipole moment of 1 to 5 Debye, X is a halogen atom or a group having 1 to 4 carbon atoms). This can be achieved by using a spacer for a liquid crystal display device, which is characterized in that a coating film obtained from the organic silane compound (b) represented by (which is an alkoxy group) is formed.

Further, the above-mentioned object is to provide on the surface of silica particles, R ¹ SiX ₃ (where R ¹ is an alkyl group having ¹ to 21 carbon atoms, X is a halogen atom or an alkoxy group having 1 to 4 carbon atoms). Is represented by the formula (1)
And an organic silane compound represented by the general formula R ² SiX ₃ (wherein R ² is a group having a dipole moment of 1 to 5 Debye, X is a halogen atom or an alkoxy group having 1 to 4 carbon atoms) (b It can be achieved by using a spacer for a liquid crystal display device, which is characterized in that a coating film obtained from a mixture with

Silica particles The silica particles used in the present invention can be obtained by the following method.

That is, in a method for producing silica particles by hydrolyzing an alkoxysilane in an alkaline solution containing water and alcohol, first, by reacting at 0 to 10 ° C. for 0.5 to 3 hours, By generating silica seed particles and then raising the temperature to 15 to 20 ° C. at a heating rate of 5 to 8 ° C. per hour, silica is generated on the surface of the seed particles and the seed particles are grown. can get. Examples of the alkoxysilane include tetraalkoxysilane represented by general Si (OR ³ ) ₄ , trialkoxysilane represented by Si (OR ³ ) ₃ R ⁴ and partial hydrolysis of these alkoxysilanes. The low condensation product etc. which are obtained are mentioned. Here, R ³ and R ⁴ are preferably a methyl group, an ethyl group, an isopropyl group, a butyl group or the like. As the alkoxysilane, for example,
Examples thereof include tetramethoxysilane, tetraethoxysilane, trimethoxysilane and triethoxysilane. These alkoxysilanes may be used alone or in combination of two or more.

Examples of the alcohol include methanol, ethanol, isopropanol, butanol, ethylene glycol, propylene glycol and the like.
Ethanol is preferred. These alcohols may be used alone or in combination of two or more.

The alkaline solution containing water and alcohol is prepared by adding a mixed solution of water and alcohol to aqueous ammonia,
Ammonia gas, sodium hydroxide, potassium hydroxide,
It can be obtained by dissolving an alkali such as a quaternary ammonium salt and amines, and ammonia water is particularly preferable. These alkalis may be used alone or in combination of two or more.

(A) Organosilane Compound In the invention described in claim 1, on the surface of the silica particles obtained by the above method, R ¹ SiX _{3 of the} general formula (wherein R ¹ is an alkyl group having ¹ to 21 carbon atoms) , X is a halogen atom or an alkoxy group having 1 to 4 carbon atoms) to form a coating film obtained from the organosilane compound (a). Here, X is bonded to the surface of the silica particles by hydrolysis, and those having an alkoxy group having more than 4 carbon atoms have poor reactivity and are difficult to industrially manufacture. Particularly, X is preferably any one of chlorine atom, bromine atom, methoxy group and ethoxymethoxy group, and more preferably methoxy group or ethoxymethoxy group.

The alkyl group R ¹ having ¹ to 21 carbon atoms promotes the liquid crystal molecules to be aligned vertically to the surface of the silica particles, and the alkyl group having more than 21 carbon atoms is an alkyl group. The part is easily bent and its effect is small, and it is difficult to manufacture industrially. In particular, when the alkyl group R ¹ is a straight-chain alkyl group having 2 to 11 carbon atoms and having no branching, its effect is greatest.

Examples of the organic silane compound (a) include methyltrimethoxysilane, methyltriethoxysilane, methyltripropoxysilane, methyltributoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltripropoxysilane, Ethyltributoxysilane, propyltrimethoxysilane, propyltriethoxysilane, propyltripropoxysilane, propyltributoxysilane, butyltrimethoxysilane, butyltriethoxysilane, butyltripropoxysilane, butyltributoxysilane, pentyltrimethoxysilane, Pentyltriethoxysilane, Hexyltrimethoxysilane, Hexyltriethoxysilane,
Heptyltrimethoxysilane, heptyltriethoxysilane, octyltrimethoxysilane, octyltriethoxysilane, nonyltrimethoxysilane, nonyltriethoxysilane, decyltrimethoxysilane, decyltriethoxysilane, dodecyltrimethoxysilane, dodecyltriethoxysilane, Examples include trialkoxylated alkoxysilanes such as octadecyltrimethoxysilane and octadecyltriethoxysilane.

Further, methyltrichlorosilane, ethyltrichlorosilane, propyltrichlorosilane, butyltrichlorosilane, pentyltrichlorosilane, heptyltrichlorosilane, hexyltrichlorosilane, octyltrichlorosilane, nonyltrichlorosilane, decyltrichlorosilane, dodecyltrichlorosilane, octadecylsilane. Trichlorosilane, methyltribromosilane, ethyltribromosilane, propyltribromosilane, butyltribromosilane, pentyltribromosilane, heptyltribromosilane, hexyltribromosilane,
Octyltribromosilane, Nonyltribromosilane,
Decyl tribromosilane, dodecyl tribromosilane,
Examples include trihalogenated alkylsilanes such as octadecyltribromosilane.

The organosilane compound (a) is used alone or in combination of two or more. The amount of the organic silane compound (a) used is generally 0.001 to 10 parts by weight, preferably 0.
005 to 1 part by weight.

The spacer for a liquid crystal display element according to the first aspect of the invention can be obtained, for example, as follows.

The organosilane compound (a) is dissolved in a suitable solvent, and the silica particles are immersed in the solution and heated. Then, the treated silica particles are collected by filtration, and the collected silica particles are heated and dried to form a film of the organosilane compound (a) on the surface of the silica particles.

As the solvent for the organic silane compound (a),
A solvent that can dissolve the organosilane compound (a) and does not have active hydrogen that reacts with the organosilane compound (a) is preferable. For example, aromatic solvents such as benzene, toluene and xylene, aliphatic solvents such as hexane, heptane, octane, nonane and decane, alcohols and mixed solvents of alcohol and water can be used.

In particular, when a trialkoxylated alkylsilane is used as the organosilane compound (a), it has a lower reactivity than the trihalogenated alkylsilane, and therefore, for example, an alcohol such as methanol, ethanol, propanol or butanol, and water are used. A mixed solvent of is preferable. In this case, the mixing ratio of alcohol and water is 1: 0.0 by weight.
1 to 1: 0.5 is preferable, and more preferably 1: 0.
It is 05 to 1: 0.3. The amount of the solvent used for the silica particles is 1 to 100 parts by weight with respect to 1 part by weight of the silica particles.
It is preferably part by weight, more preferably 3 to 20 parts by weight.

The heating temperature during heating and drying is usually 60 to 2
The temperature is 50 ° C., preferably 80 to 180 ° C., and the heating time is usually 30 minutes to 10 hours, preferably 1 to 3 hours.

In order to improve the adhesion between the silica particles and the film formed on the surface of the silica particles, and to form a relatively thin film uniformly on the surface of the silica particles, titanium is used between the silica particles and the film. An oxide layer may be provided. This titanium oxide layer can be formed using, for example, an organic titanate compound.

As the organic titanate compound, for example,
Tetraethoxy titanium, tetrapropoxy titanium, tetrobutoxy titanium, tetrapentoxy titanium, tetrahexoxy titanium, tetrakis (2-ethylhexoxy)
Titanium, tetradecoxyalkoxy titanium, tetrastearoxy titanium, dipropoxy-bis (triethanolaminato) titanium, dihydroxy-bis (lactato) titanium, titanium (acetylacetonato) titanium, dibutoxy-bis (triethanolaminato) titanium, etc. Is used.

To form a titanium oxide layer using an organic titanate compound, first, this organic titanate compound is dissolved in a solvent, and the resulting solution is applied to the surface of silica particles. After that, the organic titanate compound reacts with water in the air to be hydrolyzed to form a titanium oxide layer. Examples of the solvent include n-hexane, cyclohexane, benzene, toluene, trichlene, freon (trade name) and the like.

As a method of applying the organic titanate compound to the silica particles, a method of immersing the silica particles in a solution of the organic titanate compound and thoroughly evaporating the solvent while mixing is preferable. After evaporating the solvent, 60
It is preferable to heat at 150 ° C.

The amount of titanium oxide on the surface of the silica particles is, in terms of titanium, 0.0 per 1 m ² of the surface area of the silica particles.
The range of 1 to 500 mg is preferable, and 0.1 to 100 mg
Is more preferable. When the amount of titanium oxide is small, the effect of improving the adhesiveness is not so great, and when the amount is large, the electrical resistance of the spacer decreases.

On the surface of the silica particles, the organic silane compound (a) (for example, trialkoxylated alkylsilane)
FIG. 1 shows a schematic diagram of a reaction in forming a coating film by. First, the alkoxy group of the organosilane compound 1 is hydrolyzed to generate the substituted silanol 2.

Next, the substituted silanol 2 is condensed to form a condensate 3
To form. The hydroxyl groups of the condensate 3 form hydrogen bonds with the hydroxyl groups present on the surface of the silica particles 4 or the hydroxyl groups on the surface of the titanium oxide layer formed on the surfaces of the silica particles 4.

Finally, by heat-treating the hydrogen bond 5, the hydrogen bond 5 becomes a Si—O bond and is strongly bonded to form a bond 6. Thus, a coating film of the organic silane compound (a) is formed on the surface of the silica particles 4,
The spacer for a liquid crystal display device of the present invention can be obtained.

(B) Organosilane Compound In the invention according to claim 2, the surface of the silica particles is represented by the general formula R ² SiX ₃ (where R ² is a group having a dipole moment of 1 to 5 Debye, X is A film obtained from the organosilane compound (b) represented by a halogen atom or an alkoxy group having 1 to 4 carbon atoms is formed.

The group R ² having a dipole moment of 1 to 5 debyes promotes the liquid crystal molecules to be aligned perpendicularly to the surface of the silica particles. If the dipole moment is less than 1 debye, the dipole moment is dipole. The moment is not strong enough to prevent vertical alignment of the liquid crystal molecules at the interface between the liquid crystal display element spacer and the liquid crystal molecules, and conversely, for those with more than 5 Debye, a weak electric field is generated around the liquid crystal display element spacer. When the voltage is applied to the liquid crystal display element, normal alignment of the liquid crystal molecules is disturbed.

Further, X is bonded to the surface of silica particles by hydrolysis, and when the alkoxy group has more than 4 carbon atoms, the reactivity is poor and it is difficult to manufacture industrially.
Particularly, it is preferably any one of chlorine atom, bromine atom, methoxy group and ethoxymethoxy group, and more preferably methoxy group or ethoxymethoxy group.

Examples of the group R ² having a dipole moment value of 1 to 5 debye include acetoxy group, amide group, aldehyde group, epoxy group, cyano group, sulfone group, sulfonyl group, halogenoalkyl group, pyridine group and nitro group. ,
Examples thereof include lactone group.

Examples of such an organic silane compound (b) include 2-acetoxyethyltrimethoxysilane, 2-acetoxyethyltrichlorosilane, 2-acetoxyethylmethyldichlorosilane, 3-acetoxypropylmethyldichlorosilane, 3- Acetoxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) -ethyltrimethoxysilane, N-glycidyl-
N, N-bis [3- (methyldimethoxysilyl) propyl] amine, N-glycidyl-N, N-bis [3- (trimethoxysilyl) propyl] amine, β- (3,4-epoxycyclohexyl) ethyltri Methoxysilane, γ
-Glycidoxypropyltrimethoxysilane, 3-cyanobutyltrichlorosilane, 2-cyanoethylmethyldiglorosilane, 2-cyanoethyltriethoxysilane,
2-cyanoethyltrimethoxysilane, cyanomethylphenethyltriethoxysilane, 3-cyanopropylmethyldichlorosilane, 3-cyanopropyltrichlorosilane, 3-cyanopropyltriethoxysilane, trifluoropropyltrimethoxysilane, trifluoropropyltrichlorosilane, Nonafluorohexyltrichlorosilane, tridecafluorooctyltrimethoxysilane, tridecafluorooctyltrichlorosilane, heptadecafluorodecylmethyldichlorosilane, heptadecafluorodecylmethyldimethoxysilane, heptadecafluorodecyltrichlorosilane, heptadecafluorodecyltrimethoxysilane Silane, tridecafluorooctylmethyldichlorosilane, tridecafluorotrichlorosilane, tridecaful B octyltriethoxysilane,
Triethoxysilylpropyl-p-nitrobenzamide, N- [3- (triethoxysilyl) propyl] -2,
4-dinitrophenylamine, β-trimethoxysilylethyl-2-pyridine, 2- [2- (trichlorosilyl) ethyl] pyridine, 4- [2- (trichlorosilyl)
Ethyl] pyridine, N- (3-triethoxysilylpropyl) -p-nitrobenzamide and the like can be mentioned.

In the third aspect of the invention, a coating film obtained from the mixture of the organic silane compound (a) and the organic silane compound (b) is formed on the surface of the silica particles obtained by the above method.

In the inventions of claims 2 and 3, a method of forming a coating film on the surface of the silica particles, which is obtained from the organic silane compound (b) or the mixture of the organic silane compound (a) and the organic silane compound (b), It can be carried out in the same manner as described in the invention of claim 1 above, except that these are used instead of the organosilane compound (a). The organosilane compound (b) is used alone or in combination of two or more. Similarly, when a mixture of the organic silane compound (a) and the organic silane compound (b) is used, each may be used alone or in combination of two or more.

Manufacture of Liquid Crystal Display Device In order to manufacture a liquid crystal display device using the above-mentioned spacer for a liquid crystal display device, an ordinary known method is adopted. For example, as shown in FIG. 2, first, an insulating film 11 (for example, a SiO ₂ film) is formed on each of the opposing surfaces of a pair of transparent substrates 10.
To form. Then, the insulating film 11 of each transparent substrate
A transparent electrode 12 (for example, an ITO film) is formed on the top by patterning by photolithography.

Then, an alignment film 13 such as a polyimide film is formed on the transparent electrode 12 of each substrate. On the electrode substrate thus formed, that is, the alignment film 1 of the transparent substrate 10.
The spacers 9 for liquid crystal display elements described above are scattered on the surface 3. The dispersion density of the spacers 9 for liquid crystal display elements is 50 to
200 / mm ² is preferable.

A spacer 9 for a liquid crystal display device is provided on the electrode substrate.
As a method for spraying, the spacer 9 for the liquid crystal display element is used.
May be sprayed as it is, but in order to spray more uniformly, it is dispersed in an aqueous dispersion medium (for example, a water dispersion medium containing a water dispersion alcohol or alcohol), a dispersion medium such as a Freon dispersion medium,
It is preferable to spray this dispersion and dry it to evaporate the dispersion medium.

In particular, recently, the regulation of fluorocarbons has become stricter, and an aqueous dispersion medium is being used as an alternative dispersion medium. In particular, a plastic spacer tends to be difficult to disperse in an aqueous dispersion medium. is there. But,
The spacer for a liquid crystal display element of the present invention preferably disperses in an aqueous dispersion medium because it disperses well. As this type of aqueous dispersion medium, an aqueous dispersion medium containing alcohol is usually used.

After that, the electrode substrates are arranged opposite to each other with a spacer interposed therebetween, the periphery thereof is sealed with a sealant 14, and the liquid crystal 8 is injected into the gap to seal the injection port, thereby producing a liquid crystal cell. The liquid crystal display element 15 is manufactured by providing an appropriate wiring to the obtained liquid crystal cell. The liquid crystal 8 is generally a nematic liquid crystal, particularly a nematic liquid crystal having a positive dielectric anisotropy, but a cholesteric liquid crystal or a smectic liquid crystal can also be used.

[0044]

[Action]

On the surface of the invention the silica particles of claim 1 wherein the general formula R ¹ SiX ₃ (Here, R
⁽¹ is an alkyl group having ¹ to 21 carbon atoms, X is a halogen atom or an alkoxy group having 1 to 4 carbon atoms), the organic silane compound (a) is As shown in FIG. 1, it is hydrolyzed by bound water on the surface of the silica particles 4 into a substituted silanol,
The substituted silanol reacts with the above hydroxyl group to easily bond to the surface of the silica particle 4.

Therefore, the above organosilane compound (a)
A large number of alkyl groups R ¹ (indicated by reference numeral 71) of the organosilane compound (a) are present on the surface of the silica particles 4 treated with. These alkyl groups R ¹ (71) stand upright with respect to the surface of the silica particles 4 which are spacers. In the vicinity of the surface of the spacer 9, the alkyl group 71 sandwiches the liquid crystal molecule 8 as shown in FIG.
It is considered to be oriented perpendicular to the surface of.

In particular, when the spacers are dispersed in an ordinary aqueous dispersion medium containing alcohol and dispersed on the electrode substrate, the spacers are more uniformly dispersed on the electrode substrate. The reason is that an affinity acts between the alkyl group R ^{1 of the} film formed on the surface of the spacer and the alkyl group of the alcohol in the aqueous dispersion medium, so that the surface of the spacer is covered with alcohol molecules. This is considered to be because the state is brought about, the affinity is developed, and it becomes easy to disperse in the aqueous dispersion medium.

Invention of Claim 2 As shown in FIG. 4, a group R having the dipole moment of the organosilane compound (b) is formed on the surface of the silica particles 4.
There will be a large number of ² (indicated by reference numeral 72). Then, an electrostatic interaction occurs between the dipole of these groups R ² (72) and the dipole of the liquid crystal molecules 8 existing around the dipole, and as a result, the silica particles 4 serving as spacers
It is considered that at the interface between the liquid crystal molecule 8 and the liquid crystal molecule 8, the liquid crystal molecule 8 is aligned perpendicular to the surface of the spacer.

Invention of Claim 3 A large number of groups R ² (72) derived from the organic silane compound (b) and groups R ¹ (71) derived from the organic silane compound (a) are present on the surface of the silica particles. . The alkyl group R ¹ rises perpendicularly to the surface of the silica particles that are spacers.

Then, in the vicinity of the surface of the spacer, as shown in FIG. 5, the alkyl group R ¹ (71) is a group R ² having a dipole moment of 1 to 5 Debye.
Due to the action of (72), the molecules of the liquid crystal which are vertically aligned are sandwiched, so that at the interface between the liquid crystal molecules 8 and the spacer 9 for liquid crystal display element, the liquid crystal molecules 8 are aligned vertically to the surface of the spacer 9. It is supposed to do.

In particular, when the spacers are dispersed in a normal aqueous dispersion medium containing alcohol and dispersed on the electrode substrate, the spacers are more uniformly dispersed on the electrode substrate. The reason is that the group R ² having a dipole moment of 1 to 5 debye has good affinity with water, and the group R ² or alkyl group R ¹ having the above dipole moment and the alkyl group of alcohol in the aqueous dispersion medium. This is considered to be because the affinity acts between and, as a result, the surface of the spacer is covered with alcohol molecules, the affinity is developed, and the spacer is easily dispersed in the aqueous dispersion medium.

[0051]

The present invention will be described below with reference to examples and comparative examples.

[0052]Example 1 (1) Fabrication of spacer for liquid crystal display device Ethyltrimethoxysilane as an organic silane compound
Use 2g and 0.2g octadecyltrimethoxysilane
This organic silane compound is mixed with ethanol / water
(Volume ratio 9/1) Dissolve in 50 ml and add to this by classification
Silica particles with adjusted particle size (average particle size 3.75 μm, standard particle size)
10 g (semi-deviation of 0.11 μm) was immersed. This mixture
The mixture was heated in a water bath at 55 ° C with stirring for 1 hour and then filtered.
I had The obtained spacer particles are placed in a dryer at 120 ° C.
By heating for 1 hour at
Obtained a spacer for liquid crystal display devices having a coating on the surface
Was. (2) Fabrication of liquid crystal display element As shown in FIG. 2, a pair of transparent glass substrates (300 mm
X 300 mm) on one surface by CVD method
Insulating film (SiO₂Film 11 was deposited. Then one of the
A transparent electrode film (ITO) is formed on the insulating film 11 of the glass substrate 10.
The film 12 was formed on the entire surface by the sputtering method. The other
Of the transparent electrode film (ITO) on the insulating film 11 of the glass substrate 10 of
The film 12 is patterned by ordinary photolithography.
I went out.

Transparent electrode film 1 on both glass substrates 10
2 and the polyimide intermediate LP-6 by the offset method.
4 (manufactured by Toray Industries, Inc.) was printed and baked at 280 ° C. for 2 hours to form a polyimide alignment film 13. After that, when the polyimide alignment film 13 and liquid crystal molecules come into contact with each other,
The alignment film 13 was rubbed in such a direction that the twist angle of the liquid crystal molecules was 240 °.

On the electrode substrate thus obtained, the above spacer for liquid crystal display element was dispersed in an aqueous dispersion medium containing ethanol, and this dispersion was sprayed with a spray type spacer sprayer at 120 pieces / mm ² . After spraying at a density and drying, seal printing was performed on the peripheral portion of this glass substrate. As the sealing agent 14, a one-pack type epoxy resin (Structbond manufactured by Sankyo Toatsu Chemical Co., Ltd.) was used.

The two electrode substrates thus prepared were closely adhered to each other so that the opposite seal-printed portions were in contact with each other, and then the sealant 14 was cured by heating and pressing at 180 ° C. for 1 hour. . Next, the STN liquid crystal cell was prepared by injecting the liquid crystal 8 into the cell gap of the electrode substrate by a conventional method.

(3) Evaluation of Display Quality of Liquid Crystal Display Element The liquid crystal display element 15 using the obtained liquid crystal cell shows abnormal alignment of the liquid crystal molecules at the interface between the liquid crystal molecules and the spacer for the liquid crystal display element during lighting operation. No basal bright and dark spots (disclination lines) were observed. Therefore, it is understood that the liquid crystal molecules are vertically aligned at the interface between the liquid crystal molecules and the spacer for the liquid crystal display element.

Further, when a negative type which shows a dark level in the absence of applied voltage is displayed, the spacer for liquid crystal display element in the liquid crystal layer is not visually recognized as a white dot in the dark part, and the display contrast of the liquid crystal display element is good. It was

The above results are shown in Table 1.

Examples 2 to 4 and Comparative Example 1 In Example 1, the organic silane compound was changed as shown in Table 1, and the same operation as in Example 1 was carried out except that the spacer for liquid crystal display element and the liquid crystal display element were changed. Was produced. Table 1 shows the display performance of these liquid crystal display devices. In addition, in Example 4, a titanium oxide layer was provided as an undercoat by the following method.

That is, tetrabutoxy titanium 0.35
g was dissolved in 50 ml of n-hexane to prepare a solution, to which the silica particles used in Example 1 were added,
After stirring well, n-hexane was evaporated. afterwards,
Heat treatment was carried out at 80 ° C. for 1 hour, and then this was sufficiently crushed using a mortar to prepare silica particles having a titanium oxide layer formed on the surface.

The liquid crystal display elements obtained in Examples 2 to 4 and Comparative Example 1 were bright and dark spots due to abnormal alignment of the liquid crystal molecules at the interface between the liquid crystal molecules and the spacer for the liquid crystal display element during the lighting operation ( No disclination line) was observed. Therefore, it is understood that the liquid crystal molecules are vertically aligned at the interface between the liquid crystal molecules and the spacer for the liquid crystal display element.

The liquid crystal display device obtained in Comparative Example 1 was found to have a bright spot during the lighting operation. In addition, many bright and dark spots (disclination lines) due to the abnormal alignment of the liquid crystal molecules were observed at the interface between the liquid crystal molecules and the spacer for the liquid crystal display element. Therefore, it can be seen that vertical alignment of the liquid crystal molecules at the interface between the liquid crystal molecules and the spacer for the liquid crystal display element hardly occurs.

[0063]

[Table 1]

Examples 5 to 17 and Comparative Examples 2 to 3 In Example 1, the organic silane compound was changed as shown in Tables 2 to 4, and the other operations were performed in the same manner as in Example 1 for liquid crystal display devices. A spacer and a liquid crystal display element were produced.
Tables 2 to 4 show the display performance of these liquid crystal display devices.

In Tables 3 and 4, the organic silane compounds are divided into those represented by the general formula R ² SiX ₃ and those represented by the general formula R ¹ SiX ₃ , and the dipole of the group R ² is divided. Moments are shown in parentheses in units of D (Debye).

In Examples 9 and 15, ethanol / water (volume ratio 9: 1) was used as the solvent for the organic silane compound instead of toluene. In addition, Examples 8 and 9
And 14 to 19, a titanium oxide layer was provided as an undercoat by the following method.

That is, tetrabutoxy titanium 0.35
g was dissolved in 50 ml of n-hexane to prepare a solution, to which the silica particles used in Example 1 were added,
After stirring well, n-hexane was evaporated. afterwards,
Heat treatment was carried out at 80 ° C. for 1 hour, and then this was sufficiently crushed using a mortar to prepare silica particles having a titanium oxide layer formed on the surface.

The liquid crystal display elements obtained in Examples 5 to 17 were displayed by a negative type showing a dark level when no voltage was applied, and the liquid crystal at the interface between the liquid crystal molecules and the spacer for the liquid crystal display element was operated at the time of lighting operation. No bright or dark spots (disclination lines) due to the unusual orientation of the molecules were observed. Therefore, it is understood that the liquid crystal molecules are vertically aligned at the interface between the liquid crystal molecules and the spacer for the liquid crystal display element.

The liquid crystal display elements obtained in Comparative Examples 2 and 3 were
The existence of a bright spot was recognized during lighting operation. In addition, many bright and dark spots (disclination lines) due to the abnormal alignment of the liquid crystal molecules were observed at the interface between the liquid crystal molecules and the spacer for the liquid crystal display element. Therefore, it can be seen that vertical alignment of the liquid crystal molecules at the interface between the liquid crystal molecules and the spacer for the liquid crystal display element hardly occurs.

[0070]

[Table 2]

[0071]

[Table 3]

[0072]

[Table 4]

[0073]

The spacer for liquid crystal display device of the present invention comprises
The liquid crystal molecules can be vertically aligned, and abnormal alignment of the liquid crystal molecules at the interface between the liquid crystal molecules and the spacer for the liquid crystal display device can be prevented. Therefore, the liquid crystal display element using the spacer for liquid crystal display element has excellent display quality without generating bright points and dark points (disclination lines) at the time of lighting operation.

The spacer for a liquid crystal display device of the present invention can be dispersed in an ordinary aqueous dispersion medium containing alcohol and evenly dispersed on the electrode substrate. Such an aqueous dispersion medium is a Freon-based dispersion medium. Since it is less harmful than the medium, it is advantageous in manufacturing a liquid crystal display element.

[Brief description of drawings]

FIG. 1 is a schematic view showing a process in which a coating film of an organic silane compound is formed on the surface of silica particles.

FIG. 2 is a cross-sectional view of a main part of the liquid crystal display element of the present invention.

FIG. 3 is an explanatory diagram showing a mechanism in which liquid crystal molecules are vertically aligned at an interface between the liquid crystal molecules and the spacer for a liquid crystal display element according to claim 1.

FIG. 4 is an explanatory diagram showing a mechanism in which liquid crystal molecules are vertically aligned at the interface between the liquid crystal molecules and the spacer for a liquid crystal display element of claim 2.

FIG. 5 is an explanatory diagram showing a mechanism in which liquid crystal molecules are vertically aligned at an interface between the liquid crystal molecules and the spacer for a liquid crystal display element according to claim 3.

[Explanation of symbols]

1 Organic Silane Compound 2 Substituted Silanol 3 Condensate 4 Silica Particle 5 Hydrogen Bonder 6 Bonder 8 Liquid Crystal Molecule 9 Liquid Crystal Display Spacer 10 Transparent Substrate 11 Insulating Film 12 Transparent Conductive Film 13 Alignment Film 14 Sealing Agent 15 Liquid Crystal Display Device 71 Alkyl group (R ¹ ) of the coating film of the organic silane compound (a) 72 Group (R ² ) having a dipole moment of 1 to 5 Debye of the coating film of the organic silane compound (b)

Claims (4)

[Claims] 1. The surface of silica particles is represented by the general formula R ¹ SiX ₃
(However, R ¹ is an alkyl group having ¹ to 21 carbon atoms, X is a halogen atom or an alkoxy group having 1 to 4 carbon atoms) and a coating film obtained from the organic silane compound (a) is formed. A spacer for a liquid crystal display device, which is characterized in that 2. The general formula R ² SiX ₃ is formed on the surface of silica particles.
(Wherein R ² is a group having a dipole moment of 1 to 5 Debye, X is a halogen atom or an alkoxy group having 1 to 4 carbon atoms), and a film obtained from the organosilane compound (b) is formed. A spacer for a liquid crystal display element, which is characterized in that 3. The surface of the silica particles has the general formula R ¹ SiX ₃
(Wherein R ¹ is an alkyl group having ¹ to 21 carbon atoms, X is a halogen atom or an alkoxy group having 1 to 4 carbon atoms), and an organic silane compound (a) represented by the general formula R ² SiX
₃ (wherein R ² is a group having a dipole moment of 1 to 5 Debye, X is a halogen atom or an alkoxy group having 1 to 4 carbon atoms) and is obtained from a mixture with an organosilane compound (b). A spacer for a liquid crystal display element, which is characterized in that a coating is formed. 4. A liquid crystal display device, characterized in that the spacer according to any one of claims 1 to 3 is used.