JP2006091196A - Column spacer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a column spacer in which occurrence of color irregularities caused by the failure of flowing down of liquid crystal by gravity is effectively suppressed, and a liquid crystal display element formed by using the column spacer. <P>SOLUTION: The column spacer is used for the liquid crystal display element, and has an elastic coefficient of 0.13 to 0.65 GPa when compressed with the volume reduction by 15% at 60°C. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a column spacer that can effectively suppress the occurrence of color unevenness due to poor gravity without causing low-temperature foaming, and a liquid crystal display device using the column spacer.

In general, a liquid crystal display element includes a spacer for maintaining a constant gap between two glass substrates, and includes a transparent electrode, a polarizing plate, an alignment layer for aligning a liquid crystal substance, and the like. At present, fine particle spacers having a particle diameter of about several μm are mainly used as spacers. However, in the conventional method for manufacturing a liquid crystal display element, since the fine particle spacers are randomly distributed on the glass substrate, the fine particle spacers may be disposed in the pixel portion. If there is a fine particle spacer in the pixel portion, there is a problem that image quality may be deteriorated, for example, light leaks from disturbance of liquid crystal alignment around the spacer and image contrast is lowered. On the other hand, various arrangement methods of the fine particle spacer in which the fine particle spacer is not arranged in the pixel portion have been studied. However, all of them are complicated and impractical.

In recent years, one drop fill technology (ODF method) has been proposed in order to increase the productivity of liquid crystal display elements. In this method, a predetermined amount of liquid crystal is dropped on the liquid crystal sealing surface of a glass substrate, and the other liquid crystal panel substrate is held in a state where a predetermined cell gap can be maintained under vacuum, and bonded together to display a liquid crystal display. This is a method of manufacturing an element. According to this method, even when the liquid crystal display element has a larger area than the conventional method and the cell gap is narrowed, it is easy to enclose the liquid crystal. It will be mainstream.
However, when fine particle spacers are used in the ODF method, the fine particle spacers scattered when the liquid crystal is dropped or bonded to the counter substrate are flowed along with the flow of the liquid crystal, resulting in a non-uniform distribution of the fine particle spacers on the substrate. Occurs. If the distribution of the fine particle spacers is non-uniform, there is a problem that the cell gap of the liquid crystal cell varies and color unevenness occurs in the liquid crystal display.

On the other hand, instead of the conventional fine particle spacer, a column spacer in which a convex pattern for holding the cell gap uniformly on a liquid crystal substrate by a photolithographic technique is proposed and put into practical use. (For example, Patent Document 1, Patent Document 2, etc.). If the column spacer is used, the problem that the spacer is arranged in the pixel portion and the problem that the spacer unevenness occurs in the ODF method can be solved.

However, in a large-sized liquid crystal display device manufactured by the ODF method using column spacers, the liquid crystal in the liquid crystal cell flows downward during use of the display device, thereby causing color unevenness on the upper half surface and the lower half surface of the display panel. A defect called “gravity failure” may occur, which is a big problem. The phenomenon of “gravity failure” is that the liquid crystal in the liquid crystal cell expands due to the heat generated from the backlight and widens the cell gap. At that time, the substrate rises from the column spacer and is not held by this spacer. It is considered that a volume of liquid crystal is generated by flowing downward due to gravity.

In order to eliminate such “gravity failure”, when the liquid crystal in the liquid crystal cell expands due to the heat generated from the backlight and expands the cell gap, the column spacer once compressed is removed from the compression deformation. It is considered that the problem can be solved by making it possible to follow the change of the cell gap by elastic recovery so that no gap is generated between the substrate and the column spacer.
However, in the conventional method, in order to give the column spacer a high deformation recovery force, it is necessary to highly crosslink the resin forming the column spacer to make it difficult to cause plastic deformation during compression. Resins having a crosslinked structure generally have a high compression modulus and tend to be hard. When the column spacer is formed of such a hard resin, a large pressure is required in the process of compressing and deforming the column spacer. In the obtained liquid crystal display element, the liquid crystal cell by the compressed column spacer is pushed. It contains a great force to spread. When the column spacer has a large force to push the liquid crystal cell, if the volume shrinkage of the liquid crystal in the liquid crystal cell occurs at a low temperature, the internal pressure in the liquid crystal cell rapidly decreases and bubbles are generated. ”Has occurred.

On the other hand, it is also conceivable to prevent the “gravitational failure” and the “low temperature foaming” by adjusting the force with which the column spacer tries to spread the liquid crystal cell at room temperature, that is, the compression elastic coefficient of the column spacer. However, in the conventional column spacer, the compressive elastic modulus changes due to the heat of the backlight generated during normal use or the heat of the sealing agent curing process during the manufacture of the liquid crystal display element, and the above-mentioned "gravity failure" The problem of “cold foaming” sometimes occurred.

JP 2001-91954 A JP 2001-159707 A

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a column spacer that can effectively suppress the occurrence of color unevenness due to poor gravity without causing low-temperature foaming, and a liquid crystal display element using the column spacer. .

The present invention is a column spacer used for a liquid crystal display element, and has a modulus of elasticity of 0.13 to 0.65 GPa when compressed by 15% at 60 ° C.
The present invention is described in detail below.

As a result of intensive studies, the present inventors have found that the use of a column spacer having a compression elastic modulus at 60 ° C. within a certain range for a liquid crystal display element can prevent the occurrence of poor gravity and low-temperature foaming. It came to complete.
This is because, under the normal use conditions of the liquid crystal display element, a temperature of about 60 ° C. is applied to the liquid crystal cell by the heat generated from the backlight, and the liquid crystal expands, generating a force to push the cell gap. Even when the column spacer has a certain elastic characteristic at this temperature, it can sufficiently follow the change of the cell gap, and the substrate does not float away from the column spacer. It is believed that there is.

In the column spacer of the present invention, the lower limit of the elastic modulus when compressed 15% at 60 ° C. is 0.13 GPa, and the upper limit is 0.65 GPa. If it is less than 0.13 GPa, it is too soft to hold the cell gap, and if it exceeds 0.65 GPa, it is too hard to obtain sufficient elastic deformation necessary for recovery. Since the elastic modulus at 15% compression at 60 ° C. is within this range, the temperature inside the liquid crystal cell becomes about 60 ° C. due to heat generated from the backlight, and the liquid crystal expands and tries to widen the cell gap. Even when a force is generated, the substrate is not lifted away from the column spacer, and the occurrence of a gravity defect can be prevented. A preferred lower limit is 0.2 GPa and a preferred upper limit is 0.6 GPa.

When the column spacer of the present invention is manufactured, it is inevitably subjected to thermocompression bonding at a high temperature of about 120 ° C. in the curing process of the liquid crystal display element sealing agent when the liquid crystal is sealed by combining two glass substrates. . Therefore, it is preferable that the column spacer of the present invention can exhibit a certain elastic characteristic even when thermocompression bonded at 120 ° C.
The column spacer of the present invention has a preferable lower limit of the elastic modulus when compressed by 15% at 120 ° C. and a preferable upper limit of 0.5 GPa. If it is less than 0.1 GPa, it may be too soft to hold the cell gap, and if it exceeds 0.5 GPa, it may be too hard to obtain sufficient elastic deformation necessary for recovery. A more preferable lower limit is 0.12 GPa, and a more preferable upper limit is 0.36 GPa.

In the present invention, 15% compression means compression so that the deformation rate of the column spacer height is 15%. The elastic modulus is measured by the following method.
That is, first, the column spacer formed on the substrate is compressed at a load application speed of 10 mN / s until it reaches a height corresponding to 85% of the initial height, and the load at this time is F. Next, after holding the load F for 5 seconds and applying deformation at a constant load, the load is removed at a load application speed of 10 mN / sec, and the elastic modulus E can be calculated by the following equation (1).

E = F / (D × S) (1)
In Formula (1), F represents the load (N), D represents the deformation rate of the column spacer height, and S represents the cross-sectional area (m ² ) of the column spacer.

The column spacer of the present invention that realizes such elastic properties can be obtained by using, for example, a curable resin composition containing a caprolactone-modified trifunctional or higher functional (meth) acrylate compound.
In this specification, to modify a (meth) acrylate compound with caprolactone is to introduce a caprolactone ring-opening polymer or ring-opening polymer between the alcohol-derived site of the (meth) acrylate compound and the (meth) acryloyloxy group. Further, the caprolactone-modified product of the (meth) acrylate compound means a (meth) acrylate compound that has been subjected to such caprolactone modification.

The specific method for modifying the (meth) acrylate compound with caprolactone is not particularly limited. For example, after reacting an alcohol with caprolactone at a high temperature in the presence of a catalyst to synthesize the caprolactone-modified alcohol, the caprolactone-modified alcohol A method in which (meth) acrylic acid is esterified using a dehydrating solvent in the presence of an acidic catalyst; (meth) acrylic acid and caprolactone are reacted to synthesize caprolactone-modified (meth) acrylic acid, and then caprolactone Examples include a method of esterifying a modified (meth) acrylic acid and an alcohol.

The degree of modification of the caprolactone-modified trifunctional or higher functional (meth) acrylate compound is defined as trifunctional or higher functional (meth) acrylate compound 1 where n is the number of functional groups of the trifunctional or higher functional (meth) acrylate compound. It is preferable to modify by introducing 0.5 n to 5 nmole of caprolactone with respect to mol. If the amount of caprolactone introduced is less than 0.5 nmol, the flexibility of the resulting column spacer may be insufficient, and if it exceeds 5 nmol, the reactivity decreases during exposure and spacer patterning is difficult. May be. More preferably, it is 1n-3nmol.

The trifunctional or higher functional (meth) acrylate compound modified with caprolactone is not particularly limited, but for trifunctional, for example, pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolethane (meth) A caprolactone modified product such as acrylate di (meth) acrylate or dipentaerythritol tri (meth) acrylate is suitable. For tetra- or higher functional groups, pentaerythritol tetra (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, dipentaerythritol Caprolactone-modified products such as (meth) tetraacrylate, dipentaerythritol penta (meth) acrylate, and dipentaerythritol hexa (meth) acrylate are preferred. These caprolactone-modified trifunctional or higher functional (meth) acrylate compounds may be used alone or in combination of two or more.
The above-mentioned caprolactone-modified trifunctional or higher functional (meth) acrylate compound may be used by modifying the (meth) acrylate compound by caprolactone by the above-mentioned method, or “KAYARAD DPCA-120” (caprolactone) manufactured by Nippon Kayaku Co., Ltd. Commercially available products such as “modified dipentaerythritol hexaacrylate” and “NK ester AD-TMP-4CL” (caprolactone-modified ditrimethylolpropane tetraacrylate) manufactured by Shin-Nakamura Chemical Co., Ltd. may be used.

The curable resin composition may contain a polyfunctional (meth) acrylate compound that is not caprolactone-modified for the purpose of adjusting reactivity and the like within a range that does not impair flexibility.

The curable resin composition preferably contains an alkali-soluble carboxyl group-containing polymer compound.
The alkali-soluble carboxyl group-containing polymer compound is not particularly limited. For example, a copolymer obtained by copolymerizing a carboxyl group-containing monofunctional unsaturated compound and a monofunctional compound having an unsaturated double bond (hereinafter simply referred to as a copolymer). Also referred to as a polymer).

Examples of the carboxyl group-containing monofunctional unsaturated compound include acrylic acid and methacrylic acid.
Examples of the monofunctional compound having an unsaturated double bond include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, (meth) acrylic acid 2 -(Meth) acrylic acid ester monomers such as ethylhexyl and hydroxyethyl (meth) acrylate; aromatic vinyl monomers such as styrene, α-methylstyrene, p-methylstyrene and p-chlorostyrene; acrylonitrile Vinyl cyanide compounds such as methacrylonitrile; unsaturated dicarboxylic anhydrides such as maleic anhydride; aromatic substituted maleimides such as phenylmaleimide, benzylmaleimide, naphthylmaleimide, o-chlorophenylmaleimide; methylmaleimide, ethylmaleimide, propyl Maleimide, isopropylmaleimide Include alkyl-substituted maleimide of.

In the above copolymer, the preferred lower limit of the ratio of the components attributable to the carboxyl group-containing monofunctional unsaturated compound is 10% by weight, and the preferred upper limit is 40% by weight. If it is less than 10% by weight, it is difficult to impart alkali solubility, and if it exceeds 40% by weight, swelling during development may be remarkably difficult to form a pattern. A more preferred lower limit is 15% by weight, and a more preferred upper limit is 30% by weight.

The weight average molecular weight of the copolymer is not particularly limited as long as it can be alkali-developed, but the preferable lower limit is 5000, the preferable upper limit is 100,000, the more preferable lower limit is 8000, and the more preferable upper limit is 30,000.

The method for copolymerizing the carboxyl group-containing monofunctional unsaturated compound and the monofunctional compound having an unsaturated double bond is not particularly limited. For example, using a radical polymerization initiator and, if necessary, a molecular weight regulator. And polymerizing by a conventionally known method such as bulk polymerization, solution polymerization, suspension polymerization, dispersion polymerization, and emulsion polymerization. Of these, solution polymerization is preferred.

The solvent in the case of producing the copolymer by the solution polymerization method is not particularly limited, for example,
Aliphatic alcohols such as methanol, ethanol, isopropanol and glycol; cellosolves such as cellosolve and butylcellosolve; carbitols such as carbitol and butylcarbitol; esters such as cellosolve acetate, carbitol acetate and propylene glycol monomethyl ether acetate Ethers such as diethylene glycol dimethyl ether; cyclic ethers such as tetrahydrofuran; ketones such as cyclohexanone, methyl ethyl ketone, and methyl isobutyl ketone; polar organic solvents such as dimethyl sulfoxide and dimethylformamide can be used.
Further, the medium for producing the copolymer by non-aqueous dispersion polymerization such as suspension polymerization, dispersion polymerization, emulsion polymerization and the like is not particularly limited. For example, liquid carbonization such as benzene, toluene, hexane, cyclohexane, etc. Hydrogen, other nonpolar organic solvents, or the like can be used.

It does not specifically limit as a radical polymerization initiator used when manufacturing the said copolymer, For example, conventionally well-known radical polymerization initiators, such as a peroxide and an azo initiator, can be used. As a usage-amount of a polymerization initiator, a preferable minimum is 0.001 weight part with respect to 100 weight part of all the monomer components, for example, a preferable upper limit is 5.0 weight part, A more preferable minimum is 0.5 weight. Parts, more preferred upper limit is 3.0 parts by weight.

Examples of the molecular weight modifier include α-methylstyrene dimer, mercaptan chain transfer agent, and the like. Of these, a long-chain alkyl mercaptan having 8 or more carbon atoms is preferable in terms of odor and little coloring.

The blending ratio of the caprolactone-modified tri- or higher functional (meth) acrylate compound and the alkali-soluble carboxyl group-containing polymer compound in the curable resin composition is not particularly limited, but the alkali-soluble carboxyl group-containing polymer compound is not limited. A preferable lower limit of the amount of the trifunctional or higher functional (meth) acrylate compound modified with caprolactone based on 100 parts by weight is 25 parts by weight, and a preferable upper limit is 900 parts by weight. If the amount is less than 25 parts by weight, the pattern may not be formed by photolithography without sufficient photocuring. If the amount exceeds 900 parts by weight, the solubility in an alkaline developer is insufficient, and the developability is low. It may be insufficient. A preferred lower limit is 50 parts by weight and a preferred upper limit is 500 parts by weight.

The curable resin composition preferably contains a photoreaction initiator.
The photoinitiator is not particularly limited, and conventionally known photoinitiators such as benzoin, benzophenone, benzyl, thioxanthone, and derivatives thereof can be used. Specifically, for example, benzoin methyl ether, benzoin ethyl ether, benzoin isobutyl ether, Michler ketone, (4- (methylphenylthio) phenyl) failmethanone, 2,2-dimethoxy-1,2-diphenylethane-1- ON, 1-hydroxy-cyclohexyl-phenyl-ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 1- (4- (2-hydroxyethoxy) -phenyl) -2-hydroxy-2 -Methyl-1-propan-1-one, 2-methyl-1 (4-methylthio) phenyl) -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholino Phenyl) -butanone-1, bis (2,4,6-trimethylbenzoyl) -phenylphospho Oxide, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethyl-pentylphosphine oxide, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, 2,4-diethylthioxanthone, 2-chloro Examples include thioxanthone. These photoinitiators may be used independently and may use 2 or more types together.

As a compounding quantity of the said photoinitiator in the said curable resin composition, a preferable minimum is 0.01 weight part and a preferable upper limit with respect to 100 weight part of the trifunctional or more than trifunctional (meth) acrylate compound modified | denatured. 50 parts by weight. If it is less than 0.01 part by weight, it may not be photocured. If it exceeds 50 parts by weight, alkali development may not be possible in photolithography. A more preferred lower limit is 0.05 parts by weight, and a more preferred upper limit is 20 parts by weight.

The curable resin composition may contain a reaction aid in order to reduce reaction disturbance due to oxygen. By using such a reaction aid and a hydrogen abstraction type photoreaction initiator in combination, the curing rate when irradiated with light can be improved.
Examples of the reaction aid include amines such as n-butylamine, di-n-butylamine, triethylamine, triethylenetetramine, ethyl p-dimethylaminobenzoate, isoamyl p-dimethylaminobenzoate; tri-n-butylphosphine, etc. Phosphinic compounds such as sulphonic acid such as s-benzylisothiouronium-p-toluenesulfinate can be used. These reaction aids may be used alone or in combination of two or more.

The curable resin composition may further contain a compound having two or more blocked isocyanate groups. The compound having two or more blocked isocyanate groups functions as a thermal crosslinking agent, and can impart thermosetting properties to the curable resin composition.
The compound having two or more blocked isocyanate groups is not particularly limited. For example, tolylene diisocyanate, 4,4-diphenylmethane diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, methylene bis (4-cyclohexyl isocyanate), trimethyl Examples include those obtained by blocking hexamethylene diisocyanate and polyfunctional isocyanates composed of these oligomers with a blocking agent compound such as active methylene, oxime, lactam, and alcohol. These compounds having two or more blocked isocyanate groups may be used alone or in combination of two or more.
Examples of commercially available thermal crosslinking agents having two or more such blocked isocyanate groups include Duranate 17B-60PX, Duranate E-402-B80T (above, manufactured by Asahi Kasei Chemicals) and the like.

As a compounding quantity of the compound having two or more blocked isocyanate groups in the curable resin composition, a preferable lower limit is 0.01 parts by weight and a preferable upper limit is 100 parts by weight of the alkali-soluble carboxyl group-containing polymer compound. 50 parts by weight. If it is less than 0.01 part by weight, it may not be sufficiently cured by heat, and if it exceeds 50 parts by weight, the degree of crosslinking of the resulting cured product may become too high to satisfy the above-mentioned elastic characteristics. A more preferred lower limit is 0.05 parts by weight, and a more preferred upper limit is 20 parts by weight.

The curable resin composition may be diluted with a diluent in order to adjust the viscosity. The diluent is not particularly limited as long as it is selected in consideration of compatibility with the curable resin group, coating method, film uniformity during drying, drying efficiency, and the like. In the case of coating using a coater or a slit coater, for example, organic solvents such as methyl cellosolve, ethyl cellosolve, ethyl cellosolve acetate, diethylene glycol dimethyl ether, propylene glycol monoethyl ether acetate, and isopropyl alcohol are suitable. These diluents may be used independently and may use 2 or more types together.

The said curable resin composition may contain conventionally well-known additives, such as a silane coupling agent for improving adhesiveness with a board | substrate as needed.

It does not specifically limit as a method of manufacturing the column spacer of this invention using the said curable resin composition, For example, the following method is mentioned.
First, the above-mentioned caprolactone-modified trifunctional or higher functional (meth) acrylate compound, alkali-soluble carboxyl group-containing polymer compound, photoinitiator, compound having two or more blocked isocyanate groups, and dilution used if necessary The curable resin composition is prepared by mixing an agent and the like by a conventionally known method.

Next, the prepared curable resin composition is applied onto a substrate so as to have a predetermined thickness, thereby forming a film. The coating method is not particularly limited, and conventionally known coating methods such as spin coating, slit coating, spray coating, dip coating, and bar coating can be used.

Next, actinic rays such as ultraviolet rays are irradiated on the obtained coating film through a mask on which a predetermined pattern is formed. Thereby, in a light irradiation part, the trifunctional or more than trifunctional (meth) acrylate compound by which the caprolactone modification | denaturation contained in the said curable resin composition reacts with a photoreaction initiator, and photocures. If this is alkali-developed, a column spacer having a predetermined pattern made of a curable resin composition photocured on the substrate can be obtained. In addition, when the said curable resin composition contains the compound which has 2 or more block isocyanate groups, it heats further and has an alkali-soluble carboxyl group-containing high molecular compound and 2 or more blocked isocyanate groups to contain. The compound is reacted.

By designing the column spacer of the present invention so as to be slightly higher than the cell gap and manufacturing the column spacer by a conventionally known method such as the ODF method, a liquid crystal display element free from color unevenness due to gravity failure can be obtained.
A liquid crystal display element using the column spacer of the present invention is also one aspect of the present invention.

ADVANTAGE OF THE INVENTION According to this invention, the curable resin composition for column spacers which can manufacture the column spacer which can suppress effectively the generation | occurrence | production of the color nonuniformity by poor gravity without producing low-temperature foaming, This curable resin for column spacers A column spacer and a liquid crystal display element using the composition can be provided.

Hereinafter, 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
(1) Polymerization of alkali-soluble carboxyl group-containing polymer compound A 3 L separable flask was charged with 60 parts by weight of diethylene glycol dimethyl ether (DMDG) as a solvent, heated to 90 ° C. in a nitrogen atmosphere, and then methyl methacrylate. 10 parts by weight, 8 parts by weight of methacrylic acid, 12 parts by weight of n-butyl methacrylate, 10 parts by weight of hydroxyethyl methacrylate, 0.4 parts by weight of azobisvaleronitrile, and 3 parts by weight of 0.8 parts by weight of n-dodecyl mercaptan It was dripped continuously over time. Then, after hold | maintaining for 30 minutes at 90 degreeC, temperature was heated up to 105 degreeC and superposition | polymerization was continued for 3 hours and the alkali-soluble carboxyl group containing polymer compound solution was obtained.
The obtained alkali-soluble carboxyl group-containing polymer compound was sampled and the molecular weight was measured by gel permeation chromatography (GPC). As a result, the weight average molecular weight (Mw) was about 20,000.

(2) Preparation of curable resin composition for column spacer 100 parts by weight of the obtained alkali-soluble carboxyl group-containing polymer compound solution, 80 parts by weight of caprolactone-modified dipentaerythritol hexaacrylate (manufactured by Nippon Kayaku Co., Ltd., DPCA-120) , Photoreaction initiator (manufactured by Ciba Specialty Chemicals, Irgacure-90
7) 10 parts by weight, 10 parts by weight of a photoreaction initiator (manufactured by Nippon Kayaku Co., Ltd., DETX-S), 8 parts by weight of a thermal crosslinking agent (manufactured by Asahi Kasei Chemicals, Duranate 17B-60PX), and diethylene glycol dimethyl ether 60 as a solvent A curable resin composition for column spacers was prepared by mixing parts by weight.

(3) Preparation of Column Spacer A curable resin composition for column spacer obtained on a glass substrate on which a transparent conductive film was formed was applied by spin coating, and dried at 80 ° C. for 3 minutes to obtain a coating film. The obtained coating film was irradiated with UV light of 200 mJ / cm ² through a 30 μm square dot pattern mask, developed with 0.04% KOH solution for 60 seconds, washed with pure water for 30 seconds, A spacer pattern was formed. After baking at 220 ° C. for 1 hour, the column spacer had a cross-sectional area of 30 μm × 30 μm (900 μm ² ) and a height of 4.5 μm.

(4) Manufacture of liquid crystal display element The sealing agent (made by Sekisui Chemical Co., Ltd.) was apply | coated with the dispenser so that the rectangular frame might be drawn on the glass substrate in which the column spacer obtained was formed. Subsequently, fine droplets of liquid crystal (manufactured by Chisso Co., Ltd., JC-5004LA) are dropped on the entire surface of the glass substrate, and the other glass substrate is immediately overlaid, and a high-pressure mercury lamp is used as a seal portion to apply ultraviolet light at 50 mW / Irradiated with cm ² for 60 seconds. Thereafter, liquid crystal annealing was performed at 120 ° C. for 1 hour for thermosetting to produce a liquid crystal display element.

(Example 2)
100 parts by weight of the alkali-soluble carboxyl group-containing polymer compound obtained in Example 1, 80 parts by weight of caprolactone-modified ditrimethylolpropane tetraacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., NK ester AD-TMP-4CL), photoinitiator A column spacer prepared by mixing 15 parts by weight (manufactured by Ciba Specialty Chemicals Co., Ltd., Irgacure 369), 8 parts by weight of a thermal crosslinking agent (manufactured by Asahi Kasei Chemicals Co., Ltd., Duranate E-402-B80T), and 60 parts by weight of diethylene glycol dimethyl ether as a solvent. A curable resin composition was prepared. A column spacer and a liquid crystal display element were obtained in the same manner as in Example 1 except that the obtained curable resin composition for column spacer was used.

(Comparative Example 1)
In preparation of the curable resin composition for column spacers, dipentaerythritol hexaacrylate (manufactured by Kyoeisha Chemical Co., DPE-6A) is used instead of caprolactone-modified dipentaerythritol hexaacrylate (manufactured by Nippon Kayaku Co., Ltd., DPCA-120). A column spacer and a liquid crystal display element were obtained in the same manner as in Example 1 except that.

(Evaluation)
The column spacers and liquid crystal display elements obtained in Examples 1 and 2 were evaluated by the following methods.
The results are shown in Table 1.

(1) Evaluation of column spacers The column spacers were compressed at a load application rate of 10 mN / s under the conditions of 60 ° C. and 120 ° C., and compressed to a height corresponding to 85% of the initial height H ₀ . Here, a load of 10 mN was applied, the column spacer height corresponding to 85% of H ₀ was H ₁ , and the load when the load reached H ₁ was F. Using each obtained value, the compression elastic modulus E at the time of 15% compression was calculated by the above formula (1).

(2) Evaluation of liquid crystal display element The liquid crystal display element was turned on and the uniformity of the cell gap was visually observed on the display screen, and evaluated according to the following criteria.
Further, the liquid crystal display element was left standing at 60 ° C. for 2 days in a vertically standing state. After being allowed to stand, a liquid crystal display element was installed between the crossed Nicols, and the display image was observed with the naked eye to evaluate the occurrence of poor gravity according to the following criteria.
Further, after the liquid crystal display element was allowed to stand for 24 hours at 0 ° C., the liquid crystal display element was placed between crossed Nicols and visually observed to evaluate the occurrence of low temperature foaming according to the following criteria.
Evaluation of cell gap ○: Uniform ×: Color unevenness Evaluation of gravity failure ○: Uniform ×: Color unevenness Evaluation of low-temperature foaming ○: No foaming ×: With foaming

ADVANTAGE OF THE INVENTION According to this invention, the column spacer which can suppress effectively generation | occurrence | production of the color nonuniformity by a gravity defect, and the liquid crystal display element using this column spacer can be provided.

Claims (4)

A column spacer used for a liquid crystal display element, wherein the elastic modulus is 0.13 to 0.65 GPa when compressed by 15% at 60 ° C. The column spacer according to claim 1, wherein the elastic modulus is 0.1 to 0.5 GPa when compressed at 15% at 120 ° C. 3. A curable resin composition comprising a caprolactone-modified tri- or higher functional (meth) acrylate compound, an alkali-soluble carboxyl group-containing polymer compound, and a photoreaction initiator. Column spacer. A liquid crystal display element comprising the column spacer according to claim 1, 2 or 3.