JP2005227395A - Photothermosetting resin composition for column spacer, and method for manufacturing column spacer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photothermosetting resin composition for a column spacer with which the column spacer effectively suppressing occurrence of color unevenness due to a gravitational defect is manufactured and a method for manufacturing the column spacer using the photothermosetting resin composition for the column spacer. <P>SOLUTION: The photothermosetting resin composition for the column spacer is used for manufacturing the column spacer of a liquid crystal display element and contains an unsaturated compound having two or more functional groups, an alkali soluble polymer compound with a reactive functional group, a thermo-crosslinking agent having a functional group cross-linkable to the alkali soluble polymer compound with the reactive functional group, and a photoreaction initiator. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

The present invention uses a photothermosetting resin composition for a column spacer capable of producing a column spacer capable of effectively suppressing the occurrence of color unevenness due to poor gravity, and the photothermosetting resin composition for a column spacer. The present invention relates to a method for manufacturing a 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 if the liquid crystal display element is larger 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 dispersed when the liquid crystal is dropped or bonded to the opposite substrate are flowed along with the flow of the liquid crystal, and the distribution of the fine particle spacers on the substrate becomes non-uniform. 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.

JP 2001-91954 A JP 2001-159707 A

The present invention uses a photothermosetting resin composition for a column spacer capable of producing a column spacer capable of effectively suppressing the occurrence of color unevenness due to poor gravity, and the photothermosetting resin composition for a column spacer. An object of the present invention is to provide a method for manufacturing a column spacer.

The present invention relates to a photothermosetting resin composition for column spacers used for producing a column spacer of a liquid crystal display element, a compound having a bifunctional or higher unsaturated bond, and an alkali-soluble polymer having a reactive functional group It is a photothermosetting resin composition for column spacers containing a compound, a thermal crosslinking agent having a functional group capable of crosslinking with the alkali-soluble polymer compound having a reactive functional group, and a photoreaction initiator.
The present invention is described in detail below.

Gravity failure occurs when 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 on which the column spacer is not directly bonded is lifted away from the column spacer. It is considered that the volume of liquid crystal that is no longer held by the column spacer flows due to gravity flowing downward. As a result of intensive studies, the present inventors have used a column spacer that is excellent in elasticity and excellent in a recovery rate from compression deformation, and a liquid crystal display element designed so that the height of the column spacer is slightly higher than the cell gap Then, it discovered that the gravity defect phenomenon did not occur. In the liquid crystal display element thus designed, the column spacers between the substrates are always in a state of being elastically recovered from the compressed state, so that the liquid crystal in the liquid crystal cell expands and the cell gap is increased. This is considered to be because the substrate does not float away from the column spacer even when trying to spread.

However, with the conventional curable resin composition, it is difficult to achieve sufficient elasticity and a recovery rate from compressive deformation when subjected to relatively gentle crosslinking that allows photolithography. When the crosslink is strong enough to provide sufficient elasticity and a recovery rate from compressive deformation, it does not dissolve even when alkali-treated, making photolithography impossible and forming a column spacer having a predetermined pattern. I couldn't.
As a result of further intensive studies, the present inventors have made it possible to perform photolithography by using a curable resin composition having a specific configuration, and to obtain a cured product having sufficient elasticity and a recovery rate from compression deformation. As a result, the present invention was completed.

The photothermosetting resin composition for column spacers of the present invention comprises a compound having a bifunctional or higher unsaturated bond, an alkali-soluble polymer compound having a reactive functional group, an alkali-soluble polymer compound having the reactive functional group, and It contains a thermal crosslinking agent having a functional group capable of crosslinking reaction (hereinafter, also simply referred to as a thermal crosslinking agent) and a photoreaction initiator. In the photothermosetting resin composition for a column spacer of the present invention having such a structure, the photo-initiator activated by irradiation with light is crosslinked by the compound having an unsaturated bond of two or more functional groups. A pattern can be easily formed by lithography. Further, when heated after pattern formation, the alkali-soluble polymer compound having the reactive functional group reacts with the thermal cross-linking agent to give stronger cross-linking, and has excellent elasticity and recovery from compression deformation. A cured product is obtained.

Although it does not specifically limit as said compound which has a bifunctional or more unsaturated bond, For example, the bifunctional or more (meth) acrylate compound is suitable.
In the present specification, the (meth) acrylate compound means an acrylate compound and a methacrylate compound.

The bifunctional or higher functional (meth) acrylate compound is not particularly limited. For example, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, neopentyl glycol, 3- Methyl-1,5-pentanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 2-butyl-2-ethyl-1,3-propanediol di (meth) acrylate, 1,9- Bifunctional monomers such as nonanediol di (meth) acrylate, dimethylol-tricyclodecane di (meth) acrylate, hydroxypivalic acid neopentyl glycol di (meth) acrylate, and tritetramethylene glycol di (meth) acrylate; pentaerythritol Trifunctional monomers such as tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate di (meth) acrylate, dipentaerythritol tri (meth) acrylate; pentaerythritol tetra (meth) acrylate And tetrafunctional or higher functional monomers such as dipentaerythritol (meth) tetraacrylate, dipentaerythritol penta (meth) acrylate, and dipentaerythritol hexa (meth) acrylate. Moreover, a polyfunctional epoxy (meth) acrylate compound, a urethane (meth) acrylate compound, etc. can be used suitably. Furthermore, what modified these polyfunctional (meth) acrylates can also be used. These (meth) acrylate compounds may be used alone or in combination of two or more.

Although it does not specifically limit as an alkali-soluble high molecular compound which has the said reactive functional group, For example, an alkali-soluble carboxyl group containing high molecular compound is suitable.
Examples of the alkali-soluble carboxyl group-containing polymer compound include a copolymer obtained by copolymerizing a carboxyl group-containing monofunctional unsaturated compound and a monofunctional compound having an unsaturated double bond (hereinafter also simply referred to as a copolymer). ) And the like.

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.
In addition, the copolymer includes aromatic vinyl monomers such as styrene, α-methylstyrene, p-methylstyrene, and p-chlorostyrene; vinyl cyanide compounds such as acrylonitrile and methacrylonitrile; maleic anhydride and the like Unsaturated dicarboxylic acid anhydrides; aromatic substituted maleimides such as phenylmaleimide, benzylmaleimide, naphthylmaleimide, o-chlorophenylmaleimide; components containing alkyl-substituted maleimides such as methylmaleimide, ethylmaleimide, propylmaleimide, isopropylmaleimide May be.

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 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.

Examples of the solvent for producing the copolymer by the solution polymerization method include aliphatic alcohols such as methanol, ethanol, isopropanol and glycol; cellosolves such as cellosolve and butylcellosolve; and carbitols such as carbitol and butylcarbitol. Tolls; 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; dimethyl sulfoxide, dimethylformamide An organic solvent having a polarity such as can be used.
Examples of the medium for producing the copolymer by non-aqueous dispersion polymerization such as suspension polymerization, dispersion polymerization, and emulsion polymerization include, for example, liquid hydrocarbons such as benzene, toluene, hexane, and cyclohexane, and others. These nonpolar organic solvents 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. Moreover, as said molecular weight regulator, (alpha) -methylstyrene dimer, a mercaptan-type chain transfer agent, etc. can be used, for example.

The compounding ratio of the compound having a bifunctional or higher unsaturated bond and the alkali-soluble polymer compound having a reactive functional group in the photothermosetting resin composition for column spacers of the present invention is not particularly limited, but the reactivity described above is not limited. The preferable lower limit of the compounding amount of the compound having a bifunctional or higher unsaturated bond with respect to 100 parts by weight of the alkali-soluble polymer compound having a functional group 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, and if it exceeds 900 parts by weight, the cured product after thermosetting cannot exhibit the above-described elastic characteristics. Sometimes. A preferred lower limit is 50 parts by weight and a preferred upper limit is 500 parts by weight.

The thermal crosslinking agent is appropriately selected according to the type of the alkali-soluble polymer compound having the reactive functional group. The alkali-soluble polymer compound having the reactive functional group is an alkali-soluble carboxyl group-containing polymer. When it is a compound, a thermal crosslinking agent having two or more blocked isocyanate groups is preferred.

The thermal crosslinking agent 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). , Trimethylhexamethylene diisocyanate, and polyfunctional isocyanates composed of these oligomers may be obtained by blocking with an active methylene-based, oxime-based, lactam-based, or alcohol-based blocking agent compound. These thermal crosslinking agents 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 the blending amount of the thermal crosslinking agent in the photothermosetting resin composition for column spacers of the present invention, a preferable lower limit is 0.01 parts by weight with respect to 100 parts by weight of the alkali-soluble polymer compound having the reactive functional group, A preferred 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 photoinitiator may be selected as appropriate according to the type of the compound having a bifunctional or higher unsaturated bond, but the compound having a bifunctional or higher unsaturated bond may be a bifunctional or higher (meth). When using an acrylate compound, conventionally well-known photoinitiators, such as a benzoin, a benzophenone, benzyl, a thioxanthone, and these derivatives, can be used, for example. 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 blending amount of the photopolymerization initiator in the photothermosetting resin composition for column spacers of the present invention, a preferable lower limit is 0.01 parts by weight with respect to 100 parts by weight of the compound having a bifunctional or higher unsaturated bond, A preferred upper limit is 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 photothermosetting resin composition for column spacers of the present invention may further 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.
The reaction aid is not particularly limited, and examples thereof include amines such as n-butylamine, di-n-butylamine, triethylamine, triethylenetetramine, ethyl p-dimethylaminobenzoate, isoamyl p-dimethylaminobenzoate, Examples include phosphine series such as -n-butylphosphine; sulfone series such as s-benzylisothiuronium-p-toluenesulfinate. These reaction aids may be used alone or in combination of two or more.

The photothermosetting resin composition for column spacers of the present invention 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 photothermosetting resin group for column spacers of the present invention, coating method, film uniformity during drying, drying efficiency, etc. When the photothermosetting resin group for a column spacer of the invention is applied using a spin coater or a slit coater, for example, methyl cellsolve, ethylcellsolve, ethylcellsolve acetate, diethylene glycol dimethyl ether, propylene glycol monoethyl ether acetate An organic solvent such as isopropyl alcohol is preferred. These diluents may be used independently and may use 2 or more types together.

The photothermosetting resin composition for column spacers of the present invention may contain conventionally known additives such as a silane coupling agent for improving the adhesion to the substrate, if necessary.

The method for producing the photothermosetting resin composition for column spacers of the present invention is not particularly limited. For example, the compound having a bifunctional or higher unsaturated bond, the alkali-soluble polymer compound having a reactive functional group, heat Examples thereof include a method in which a crosslinking agent, a photoreaction initiator, a diluent used as necessary, and the like are mixed by a conventionally known method.

If the photothermosetting resin composition for column spacers of the present invention is used, a cured product having the above-mentioned elastic properties can be obtained by photocuring and thermosetting, and if a column spacer using this is used, it is caused by poor gravity. A liquid crystal display element free from color unevenness can be manufactured.

Although it does not specifically limit as a method of manufacturing a column spacer using the photothermosetting resin composition for column spacers of this invention, For example, the photothermosetting resin composition for column spacers is coated on a glass substrate, and is a coating film. A film for forming a photocured product by irradiating the obtained coating film with actinic rays to cause a crosslinking reaction between the compound having a bifunctional or higher unsaturated bond and a photoinitiator. A curing step; a development step of alkali-developing the photocured product after the photocuring step to form a predetermined pattern; and a heat treatment of the patterned photocured product after the developing step to form the reactive functional group. And a thermosetting step of obtaining a thermoset by cross-linking the alkali-soluble polymer compound having a group and the alkali-soluble polymer compound having a reactive functional group and a thermal cross-linking agent having a functional group capable of cross-linking reaction It is preferred.
Such a column spacer manufacturing method is also one aspect of the present invention.

In the method for producing a column spacer of the present invention, first, a coating film forming step is performed in which a photothermosetting resin composition for column spacers is coated on a glass substrate to form a coating film. The coating method is not particularly limited, and for example, conventionally known coating methods such as spin coating, slit coating, spray coating, dip coating, and bar coating can be used. After coating, a coating film is formed by drying for a certain period of time.

Next, the obtained coating film is irradiated with actinic rays, and a photocuring step is carried out to obtain a photocured product by cross-linking the compound having a bifunctional or higher unsaturated bond and the photoreaction initiator. The light irradiation method is not particularly limited, but usually, the obtained film is irradiated with actinic rays such as ultraviolet rays through a mask on which a predetermined pattern is formed.
The irradiation amount of the active light is preferably at least 100 mJ / cm ^{2 in} the case of ultraviolet rays. If it is less than 100 mJ / cm ² , the photocuring is insufficient, and when exposed to an alkali treatment in the development step, the exposed portion may be dissolved and a pattern may not be formed.

Subsequently, the photocured product after the photocuring step is subjected to an alkali development to form a predetermined pattern. The developing method is not particularly limited, and a conventionally known method such as washing with an pure solution after dissolving an unexposed portion with an alkali solution such as calcium hydroxide can be used.
Finally, a heat-curing step for obtaining a thermo-cured product by heat-treating the patterned photo-cured product after the development step to cross-link the alkali-soluble polymer compound having the reactive functional group and the heat-crosslinking agent. As a result, a column spacer having a predetermined pattern and excellent in elastic properties can be obtained. The heating condition may be appropriately determined in consideration of the size and thickness of the pattern, but is preferably at least 200 ° C. for 20 minutes or more. If the temperature is less than 200 ° C. or less than 20 minutes, a column spacer produced by the method for producing a column spacer of the present invention in which thermal curing is insufficient and a sufficiently excellent column spacer may not be obtained. Moreover, it is one of the present inventions.

The column spacer of the present invention has extremely excellent elastic characteristics.
That is, the column spacer of the present invention has a lower limit of the elastic modulus at 15% compression at 25 ° C. of 0.2 GPa and an upper limit of 1.0 GPa. If it is less than 0.2 GPa, it is too soft and it is difficult to maintain the cell gap. If it exceeds 1.0 GPa, it is too hard to enter the color filter layer when the substrates are bonded together, and sufficient for recovery. Elastic deformation may not be obtained. The preferred lower limit is 0.3 GPa, the preferred upper limit is 0.9 GPa, the more preferred lower limit is 0.5 GPa, and the more preferred upper limit is 0.7 GPa.

Further, the lower limit of the recovery rate when the column spacer of the present invention is 15% compressed and deformed at 25 ° C. is 70%. If it is less than 70%, the force to recover the column spacer between the substrates of the obtained liquid crystal display element is too weak, and a sufficient gravity defect suppressing effect cannot be obtained. A preferred lower limit is 80%. The upper limit of the recovery rate is not particularly limited.

In the present invention, 15% compression means compression so that the deformation rate of the column spacer height is 15%. The elastic modulus and recovery rate are measured by the following methods.
That is, first, the column spacer formed on the substrate is compressed at a load application speed of 10 mN / s, and is compressed to a 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 elastic count and the recovery rate can be calculated by the following formula (1) and the following formula (2).

Elastic modulus E = F / (D × S) (1)
Recovery rate R = (H ₄ −H ₃ ) / (H ₁ −H ₃ ) × 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.

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.

According to the present invention, there is provided a photothermosetting resin composition for a column spacer capable of effectively suppressing the occurrence of color unevenness due to poor gravity and a photothermosetting resin composition for the column spacer. The manufacturing method of the used 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) Preparation 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 A mixture consisting of parts by weight, 8 parts by weight of methacrylic acid, 22 parts by weight of n-butyl methacrylate, 0.4 parts by weight of azobisvaleronitrile and 0.1 parts by weight of n-dodecyl mercaptan is continuously added dropwise over 3 hours. Supplied. 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 copolymer solution was obtained. The obtained copolymer solution was sampled and the molecular weight was measured by gel permeation chromatography (GPC) method. The weight average molecular weight (Mw) of the copolymer was 78000. This copolymer solution was used as an alkali-soluble carboxyl group-containing polymer compound solution.

(2) Preparation of photothermosetting 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 polymerizable monomer (Kyoeisha Chemical Co., Ltd., DPE-6A), initiation of photoreaction 5 parts by weight of an agent (manufactured by Ciba Specialty Chemicals, Irgacure 907) and 8 parts by weight of a thermal crosslinking agent (manufactured by Asahi Kasei Chemicals, Duranate 17B-60PX) are added, and 120 parts by weight of diethylene glycol dimethyl ether is added as a diluent. By mixing, a photothermosetting resin composition for column spacers was obtained.

(3) Manufacture of column spacers The obtained photothermosetting resin composition for column spacers was coated on a glass substrate on which a transparent conductive film was formed using a spin coater, and then dried at 80 ° C. for 3 minutes. A coating film was formed. The obtained coating film was irradiated with ultraviolet rays with an intensity of 200 mJ / cm ² through a 30 μm square dot pattern mask. After developing with 0.04% KOH solution for 60 seconds, it was washed with pure water for 30 seconds to form a column spacer pattern. Subsequently, baking was performed at 220 ° C. for 1 hour. As a result, a column spacer having a cross-sectional shape of 30 μm × 30 μm (cross-sectional area 900 μm ² ) and a height of 5.0 μm was obtained.

(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)
(1) Preparation 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 A mixture consisting of 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, 0.1 part by weight of n-dodecyl mercaptan, The solution was continuously added dropwise 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 copolymer solution was obtained. The obtained copolymer solution was sampled and the molecular weight was measured by gel permeation chromatography (GPC) method. The weight average molecular weight (Mw) of the copolymer was 81,000. This copolymer solution was used as an alkali-soluble carboxyl group-containing polymer compound solution.

(2) Preparation of photothermosetting resin composition for column spacer 100 parts by weight of the obtained alkali-soluble carboxyl group-containing polymer compound solution, 20 parts by weight of polymerizable monomer (Kyoeisha Chemical Co., Ltd., Light Acrylate DPE-6A), polymerization Monomer (light acrylate 6EG-A manufactured by Kyoeisha Chemical Co., Ltd.) 20 parts by weight, photoinitiator (manufactured by Ciba Specialty Chemicals Co., Ltd., Irgacure 907), thermal crosslinking agent (manufactured by Asahi Kasei Chemicals Co., Ltd., Duranate E-402) -B80T) 4 parts by weight was mixed, and further 60 parts by weight of diethylene glycol dimethyl ether as a diluent was added and mixed to obtain a photothermosetting resin composition for column spacers.

(3) Manufacture of column spacer and liquid crystal display element After coating the obtained photothermosetting resin composition for column spacer on a glass substrate on which a transparent conductive film has been formed using a spin coater, 3 at 80 ° C. Dried for a minute to form a coating. The obtained coating film was irradiated with ultraviolet rays at an intensity of 200 mJ / cm ² through a 30 μm square dot pattern mask. After developing with 0.04% KOH solution for 60 seconds, it was washed with pure water for 30 seconds to form a column spacer pattern. Subsequently, baking was performed at 220 ° C. for 1 hour. As a result, a column spacer having a cross-sectional shape of 30 μm × 30 μm (cross-sectional area 900 μm ² ) and a height of 4.6 μm was obtained.
A liquid crystal display device was produced in the same manner as in Example 1 except that the glass substrate on which the obtained column spacer was formed was used.

(Comparative Example 1)
100 parts by weight of the alkali-soluble carboxyl group-containing polymer compound solution prepared in Example 1, 80 parts by weight of a polymerizable monomer (manufactured by Kyoeisha Chemical Co., Ltd., Light Acrylate DPE-6A), a photoreaction initiator (manufactured by Ciba Specialty Chemicals Co., Ltd., Iruga) Cure 907) 5 parts by weight was mixed, and further 120 parts by weight of diethylene glycol dimethyl ether was added as a diluent and mixed to obtain a curable resin composition.

After apply | coating the obtained curable resin composition using the spin coat on the glass substrate in which the transparent conductive film was formed, it dried at 80 degreeC for 3 minute (s), and formed the coating film. The obtained coating film was irradiated with ultraviolet rays with an intensity of 200 mJ / cm ² through a 30 μm square dot pattern mask. After developing with 0.04% KOH solution for 60 seconds, it was washed with pure water for 30 seconds to form a column spacer pattern. Subsequently, baking was performed at 220 ° C. for 1 hour. As a result, a column spacer having a cross-sectional shape of 30 μm × 30 μm (cross-sectional area 900 μm ² ) and a height of 5.0 μm was obtained.
A liquid crystal display device was produced in the same manner as in Example 1 except that the glass substrate on which the obtained column spacer was formed was used.

(Comparative Example 2)
100 parts by weight of the alkali-soluble carboxyl group-containing polymer compound solution prepared in Example 2, 20 parts by weight of a polymerizable monomer (Kyoeisha Chemical Co., Ltd., Light Acrylate DPE-6A), a polymerizable monomer (Kyoeisha Chemical Co., Ltd., Light Acrylate 6EG) -A) 20 parts by weight, 5 parts by weight of a photoinitiator (manufactured by Ciba Specialty Chemicals, Irgacure 907), and 120 parts by weight of diethylene glycol dimethyl ether as a diluent are added and mixed to obtain a curable resin composition. I got a thing.

After apply | coating the obtained curable resin composition using the spin coat on the glass substrate in which the transparent conductive film was formed, it dried at 80 degreeC for 3 minute (s), and formed the coating film. The obtained coating film was irradiated with ultraviolet rays at an intensity of 200 mJ / cm ² through a 30 μm square dot pattern mask. After developing with 0.04% KOH solution for 60 seconds, it was washed with pure water for 30 seconds to form a column spacer pattern. Subsequently, baking was performed at 220 ° C. for 1 hour. As a result, a column spacer having a cross-sectional shape of 30 μm × 30 μm (cross-sectional area 900 μm ² ) and a height of 4.9 μm was obtained.
A liquid crystal display device was produced in the same manner as in Example 1 except that the glass substrate on which the obtained column spacer was formed was used.

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

(1) The column spacer was compressed at a load application speed of 10 mN / s in a chamber adjusted to an evaluation temperature of 25 ° C., and was compressed to a height corresponding to 85% of the initial height H ₀ . Here, the column spacer height when a load of 10 mN was applied was H ₁ , the column spacer height corresponding to 85% of H ₀ was H ₂ , and the load when the load reached H ₂ was F. Next, the load F was held for 5 seconds and subjected to deformation at a constant load. Then, the load was removed at a load application speed of 10 mN / sec, and the recovery deformation of the column spacer height due to elastic recovery was measured. The height of the column spacer at the time when the compression deformation during this period reached the maximum was H _3, and the height of the column spacer when a load of 10 mN was applied in the process of recovering the deformation of the column spacer was H ₄ . Using the obtained values, the elastic modulus at the time of 15% compression and the recovery rate at the time of 15% compression deformation were calculated by the above formula (1) and the above formula (2).

(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. Next, the liquid crystal display element was allowed to stand for 2 days at 60 ° C. in a state where the liquid crystal display element was set up vertically. After standing, the display image was visually observed, and the occurrence of poor gravity was evaluated according to the following criteria.
Cell gap evaluation ○: Uniform ×: Color unevenness Gravity failure evaluation ○: Uniform ×: Color unevenness

According to the present invention, there is provided a photothermosetting resin composition for a column spacer capable of effectively suppressing the occurrence of color unevenness due to poor gravity and a photothermosetting resin composition for the column spacer. The manufacturing method of the used column spacer can be provided.

Claims (6)

A photothermosetting resin composition for a column spacer used for producing a column spacer of a liquid crystal display element, a compound having a bifunctional or higher unsaturated bond, an alkali-soluble polymer compound having a reactive functional group, the reaction A photothermosetting resin composition for column spacers, comprising a thermal crosslinking agent having a functional group capable of crosslinking with an alkali-soluble polymer compound having a functional functional group, and a photoreaction initiator. The photothermosetting resin composition for column spacers according to claim 1, wherein the compound having a bifunctional or higher unsaturated bond is a bifunctional or higher (meth) acrylate compound. The alkali-soluble polymer compound having a reactive functional group is an alkali-soluble carboxyl group-containing polymer compound, and the thermal cross-linking agent having a functional group capable of crosslinking with an alkali-soluble polymer compound having a reactive functional group is 2 The photothermosetting resin composition for column spacers according to claim 1 or 2, wherein the photocrosslinking resin composition is a thermal crosslinking agent having the above-mentioned blocked isocyanate group. A compound having a bifunctional or higher unsaturated bond, an alkali-soluble polymer compound having a reactive functional group, a thermal crosslinking agent having a functional group capable of undergoing a crosslinking reaction with the alkali-soluble polymer compound having the reactive functional group, and A method for producing a column spacer using a photothermosetting resin composition for a column spacer containing a photoreaction initiator,
A coating film forming step of coating the column spacer photothermosetting resin composition on a glass substrate to form a coating film; and
A photocuring step of irradiating the coating film with an actinic ray to crosslink the compound having a bifunctional or higher unsaturated bond and a photoinitiator to obtain a photocured product;
A development step of forming a predetermined pattern by alkali development of the photocured product after the photocuring step;
A functional group capable of undergoing a crosslinking reaction with the alkali-soluble polymer compound having the reactive functional group and the alkali-soluble polymer compound having the reactive functional group by heat-treating the patterned photocured product after the development step And a thermosetting step of obtaining a thermoset by cross-linking reaction with a thermal cross-linking agent containing A column spacer manufactured by the method for manufacturing a column spacer according to claim 4. A liquid crystal display element comprising the column spacer according to claim 5.