JP2006091197A - Column spacer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a column spacer of which the compressional characteristic (elastic coefficient) hardly varies even when stress is repeatedly applied to a liquid crystal display element in daily use, which is free from occurrence of color irregularities caused by the failure of flowing down of liquid crystal by gravity or the foaming at a low temperature, and with which a liquid crystal display element excellent in durability is formed, and the 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 a rate of change of the elastic coefficient measured in the fifth compression to that measured in the first compression is 5% or less when a compression test to compress the liquid crystal display element with volume reduction by 15% at 25°C is conducted in repetition. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

In the present invention, even when stress is repeatedly applied to the liquid crystal display element due to daily use, the compression characteristics (elastic coefficient) hardly change, and color unevenness, low-temperature foaming, etc. due to poor gravity occur. The present invention relates to a column spacer that can be used as a liquid crystal display element having excellent durability and a liquid crystal display element 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.).
By using such a column spacer, 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 thought 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, by adjusting the force to expand the liquid crystal cell of the column spacer, that is, the compression characteristic (elastic coefficient) of the column spacer to such an extent that “cold foaming” does not occur at low temperatures, It is considered that a liquid crystal display element in which no “cold foaming” occurs can be obtained.
However, even if the compression characteristics of the column spacer are adjusted in this way, in the conventional column spacer, the compression characteristics are greatly changed by applying stress to the column spacer repeatedly due to daily use of the liquid crystal display element. Therefore, there has been a problem that the above-mentioned “gravity failure” and “low-temperature foaming” may occur.

JP 2001-91954 A JP 2001-159707 A

In view of the present situation, the present invention has little change in compression characteristics (elastic coefficient) even when stress is repeatedly applied to a liquid crystal display element through daily use, and color unevenness or low temperature foaming due to poor gravity. It is an object of the present invention to provide a column spacer capable of providing a liquid crystal display element having excellent durability and a liquid crystal display element using the column spacer.

The present invention relates to a column spacer used in a liquid crystal display device, and when a compression test of 15% compression at 25 ° C. is repeated, the elastic modulus at the time of the fifth compression relative to the elastic modulus at the time of the first compression. The column spacer has a change rate of 5% or less.
The present invention is described in detail below.

In the column spacer of the present invention, when the compression test of compressing 15% at 25 ° C. is repeated, the change rate of the elastic modulus at the time of the fifth compression relative to the elastic modulus at the time of the first compression is 5% or less. . If it exceeds 5%, when a stress is repeatedly applied to the column spacer due to daily use of a liquid crystal display element, the elastic coefficient changes greatly, resulting in color unevenness and low temperature foaming due to gravity failure. More preferably, it is 4% or less.

In this specification, “15% compression” means that the column spacer is compressed so that the deformation ratio of the height of the column spacer is 15%.
The elastic modulus of the column spacer is measured by a compression test according to 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, the load F is held for 5 seconds, and after being deformed at a constant load, the load is removed at a load application speed of 10 mN / sec, and the elastic modulus E is calculated by the following equation (1).

Elastic modulus 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.

In the column spacer of the present invention, when the above compression test is repeated, the rate of change of the elastic modulus during the fifth compression relative to the elastic modulus during the first compression is 5% or less. That is, the column spacer of the present invention has a rate of change calculated by the following equation (2) when the elastic coefficient at the first compression is E ₁ and the elastic coefficient at the fifth compression is E _5. C is in the range of 0 to 5%.

Rate of change C = {(E ₅ −E ₁ ) / E ₁ } × 100 (2)

A column spacer of the present invention as described above, a preferable lower limit of the elastic modulus _{E 5} at the fifth compression 0.2 GPa, the upper limit is preferably 1.0 GPa. If it is less than 0.2 GPa, it may be too soft and it may be difficult to maintain the cell gap. If it exceeds 1.0 GPa, it may be too hard to enter the color filter layer when bonding the substrates, or necessary for recovery. Sufficient elastic deformation may not be obtained. A more preferred lower limit is 0.3 GPa, a more preferred upper limit is 0.9 GPa, a still more preferred lower limit is 0.5 GPa, and a still more preferred upper limit is 0.7 GPa.

The column spacer of the present invention, it is preferable the lower limit of the recovery rate of the elastic coefficient E ₅ at the fifth compression is 70%. If it is less than 70%, the column spacer between the substrates of the obtained liquid crystal display element is too weak to recover, and a sufficient gravity defect suppressing effect may not be obtained. A more preferred lower limit is 80%. The upper limit of the recovery rate is not particularly limited.
In addition, the recovery rate of the column spacer of this invention can be measured with the following method.

That is, in the compression test of the fifth, to compress the column spacer formed on the substrate is compressed at a load application rate of 10 mN / s, until the height corresponding to 85% of the initial height H _0. Here, the column spacer height when a load of 10 mN is applied is H ₁ , and the column spacer height corresponding to 85% of H ₀ is H ₂ , and the load when the load reaches H ₂ is F. Next, the load F is held for 5 seconds, and after deformation at a constant load, the load is removed at a load application speed of 10 mN / sec, and the recovery deformation of the column spacer height due to elastic recovery is measured. The column spacer height at the time when the compression deformation during this period becomes maximum is H _3, and the column spacer height when a load of 10 mN is applied in the process of recovering the deformation of the column spacer is H ₄ . The recovery rate can be calculated by the following formula (3).

Recovery rate R = (H ₄ −H ₃ ) / (H ₁ −H ₃ ) × 100 (3)

Such a column spacer of the present invention comprises a curable resin composition containing a caprolactone-modified trifunctional or higher functional (meth) acrylate compound, an alkali-soluble carboxyl group-containing polymer compound, and a photoreaction initiator. It is preferable. By comprising such a curable resin composition, the column spacer of the present invention has the compression characteristics described above. In this specification, caprolactone modification means that a ring-opening product or ring-opening polymer of caprolactone is introduced between the alcohol-derived site of the (meth) acrylate compound and the (meth) acryloyloxy group. The caprolactone-modified product means a compound that has been subjected to such caprolactone modification.

A specific method for modifying caprolactone with a trifunctional or higher functional (meth) acrylate compound is not particularly limited. Caprolactone-modified alcohol and (meth) acrylic acid are esterified using a dehydrating solvent in the presence of an acidic catalyst, or (meth) acrylic acid and caprolactone are reacted to synthesize caprolactone-modified (meth) acrylic acid. Then, an esterification reaction method with alcohol and the like can be mentioned. In the present specification, the (meth) acrylate compound means an acrylate compound and a methacrylate compound.

Further, the degree of modification when the above-mentioned trifunctional or higher functional (meth) acrylate compound is modified with caprolactone is not particularly limited, but when the number of functional groups of the trifunctional or higher functional (meth) acrylate compound is n, the trifunctionality It is preferable to introduce and modify caprolactone at a preferred lower limit of 0.5 nmol, a preferred upper limit of 5 nmol, a more preferred lower limit of nmol, and a more preferred upper limit of 3 nmol with respect to 1 mol of the above (meth) acrylate compound. . If the modified amount of caprolactone is less than 0.5 nmol, the flexibility of the column spacer may be insufficient. If it exceeds 5 nmol, the reactivity at the time of exposure decreases and spacer patterning becomes difficult. Sometimes.
Further, in addition to the above-mentioned caprolactone-modified trifunctional or higher functional (meth) acrylate compound, a trifunctional or higher functional (meth) acrylate compound not modified with caprolactone in order to adjust the reactivity, etc. You may use together.

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) Preferred are caprolactone-modified products such as acrylate di (meth) acrylate and dipentaerythritol tri (meth) acrylate. For tetra- or higher functional groups, pentaerythritol tetra (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, and 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 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 “polymeric carboxyl group-containing polymer”). Also referred to as a copolymer).

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 -Ethylhexyl, hydroxyethyl (meth) acrylate and the like (
(Meth) acrylic acid ester monomers, aromatic vinyl monomers such as styrene, α-methylstyrene, p-methylstyrene, p-chlorostyrene; vinyl cyanide compounds such as acrylonitrile and methacrylonitrile; Unsaturated dicarboxylic anhydrides such as acids; aromatic substituted maleimides such as phenylmaleimide, benzylmaleimide, naphthylmaleimide, o-chlorophenylmaleimide; alkyl-substituted maleimides such as methylmaleimide, ethylmaleimide, propylmaleimide, isopropylmaleimide, etc. .

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 for producing the copolymer by the solution polymerization method is not particularly limited, and examples thereof include aliphatic alcohols such as methanol, ethanol, isopropanol and glycol; cellosolvs such as cellosolve and butylcellosolve; carbitol and butylcarbi Carbitols such as Toll; esters such as cellosolve acetate, carbitol acetate, propylene glycol monomethyl ether acetate; ethers such as diethylene glycol dimethyl ether; cyclic ethers such as tetrahydrofuran; ketones such as cyclohexanone, methyl ethyl ketone, methyl isobutyl ketone; A polar organic solvent such as 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. The preferable lower limit of the compounding amount of the trifunctional or higher functional (meth) acrylate compound modified with caprolactone with respect to 100 parts by weight of the molecular compound is 25 parts by weight, and the 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 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 acts 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 blocked isocyanate groups include Duranate 17B-60PX, Duranate E-402-B80T (above, manufactured by Asahi Kasei Chemicals Corporation).

As a compounding quantity of the compound which has the said 2 or more block isocyanate group in the said curable resin composition, a preferable minimum is 0.01 weight part with respect to 100 weight part of said alkali-soluble carboxyl group-containing high molecular compounds, and a preferable upper limit Is 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 assembly, coating method, film uniformity during drying, drying efficiency, etc., but the curable resin composition For example, an organic solvent such as methyl cellosolve, ethyl cellosolve, ethyl cellosolve acetate, diethylene glycol dimethyl ether, propylene glycol monoethyl ether acetate, and isopropyl alcohol is suitable. is there. 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 which consists of such a curable resin composition, For example, the method quoted below is mentioned.
That is, 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 as necessary The said curable resin composition is prepared by mixing the diluent etc. to be used by a conventionally well-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, the column spacer of the present invention having a predetermined pattern made of the curable resin composition photocured on the substrate can be produced.
In addition, when the said curable resin composition contains the compound which has a 2 or more block isocyanate group, by further heating, the alkali-soluble carboxyl group containing polymer compound and 2 or more block isocyanate group which are contained are contained. Reacts with compounds having

The column spacer of the present invention is designed to be slightly higher than the cell gap and manufactured by a conventionally known method such as the ODF method, so that there is no color unevenness due to gravity failure and low temperature foaming occurs. A liquid crystal display element free from this is obtained.
A liquid crystal display element using the column spacer of the present invention is also one aspect of the present invention.

According to the present invention, even when stress is repeatedly applied to the liquid crystal display element due to daily use, the compression characteristic (elastic coefficient) hardly changes and color unevenness or low-temperature foaming occurs due to poor gravity. The column spacer which can be used as the liquid crystal display element excellent in durability, and the liquid crystal display element using this column spacer 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 methacrylic acid. 10 parts by weight of methyl, 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 0.8 parts by weight of n-dodecyl mercaptan It was dripped continuously over 3 hours. 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 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 100 parts by weight of the obtained alkali-soluble carboxyl group-containing polymer compound, caprolactone-modified dipentaerythritol hexaacrylate (manufactured by Nippon Kayaku Co., Ltd., KAYARAD DPCA-120), light Reaction initiator 1 (manufactured by Ciba Specialty Chemicals, Irgacure 907), 10 parts by weight of photopolymerization initiator 2 (manufactured by Nippon Kayaku Co., Ltd., DETX-S), thermal crosslinking agent (manufactured by Asahi Kasei Chemicals Corporation, Duranate 17B) -60PX) 8 parts by weight and 60 parts by weight of diethylene glycol dimethyl ether as a solvent were mixed to prepare a curable resin composition for a column spacer.

(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 4.6 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), photoreaction initiation 15 parts by weight of an agent (manufactured by Ciba Specialty Chemicals, Irgacure 369), 8 parts by weight of a thermal crosslinking agent (manufactured by Asahi Kasei Chemicals, Duranate E-402-B80T), and 60 parts by weight of diethylene glycol dimethyl ether as a solvent are cured. A functional 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 was used.

(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) The column spacer is compressed at a load application rate of 10 mN / s in a chamber adjusted to an evaluation temperature of 25 ° C., and compressed to a height corresponding to 85% of the initial height H _0. After holding the load (F) at the time for 5 seconds to give a constant load deformation, a compression test is performed to remove the load at a load application speed of 10 mN / sec. It was calculated elastic modulus _{E 1.} Thereafter, repeating the same compression test on the same column spacer, to calculate the elastic modulus E ₅ which definitive when the fifth compression were calculated rate of change in elastic modulus by the following equation (2).

Elastic modulus E = F / (D × S) (1)
Rate of change C = {(E ₅ / E ₁ ) / E ₁ } × 100 (2)
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.

(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, the display image was observed with the naked eye, and the occurrence of poor gravity was evaluated according to the following criteria.
Further, the liquid crystal display element was allowed to stand at 0 ° C. for 24 hours. After being allowed to stand, a liquid crystal display element was placed between the crossed Nicols and observed visually, and the occurrence of low temperature foaming was evaluated according to the following criteria.
Cell gap evaluation ○: Uniform ×: Color unevenness Gravity failure evaluation ○: Uniform ×: Color unevenness Low-temperature foaming evaluation ○: Uniform ×: Foamed

According to the present invention, even when stress is repeatedly applied to the liquid crystal display element due to daily use, the compression characteristic (elastic coefficient) hardly changes and color unevenness or low-temperature foaming occurs due to poor gravity. The column spacer which can be made into the liquid crystal display element excellent in durability without using this, and the liquid crystal display element using this column spacer can be provided.

Claims (3)

A column spacer used in a liquid crystal display element, and when the compression test of compressing 15% at 25 ° C. is repeated, the rate of change of the elastic coefficient at the time of the fifth compression with respect to the elastic coefficient at the time of the first compression is Column spacer characterized by being 5% or less. 2. The column according to claim 1, comprising a curable resin composition containing a caprolactone-modified tri- or higher functional (meth) acrylate, an alkali-soluble carboxyl group-containing polymer compound, and a photoreaction initiator. Spacer. Claim 1 or 2
A liquid crystal display element comprising the column spacer described above.