JP2008070471A - Curable resin composition for column spacer, column spacer and liquid crystal display element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a curable resin composition for a column spacer from which a column spacer having sufficient flexibility and excellent compressive buckling strength is formed, and also to provide a column spacer formed by using the curable resin composition for the column spacer, and a liquid crystal display element formed by using the column spacer. <P>SOLUTION: The curable resin composition for the column spacer contains a compound (A) having two or more polymerizable unsaturated bonds in a molecule, an epoxy (meth)acrylate compound (B), an alkali soluble polymer compound (C), and a photoreaction initiator (D), wherein the compound (B) is a phenol novolak type (acid) modified epoxyacrylate based compound. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a curable resin composition for a column spacer capable of forming a column spacer excellent in buckling strength, a column spacer using the curable resin composition, and a liquid crystal display element.

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, Patent Document 3, 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.

In recent years, liquid crystal display elements are widely used in personal computers, portable electronic devices, and the like. Among these, particularly when used in portable electronic devices such as mobile phones, pressure may be locally applied to the liquid crystal display element during normal use. At this time, since the column spacer formed in the liquid crystal display element has elasticity, it is compressed according to the applied pressure, and is restored to its original state when the pressure is removed. However, when the pressure reaches a certain level, the column spacer may be deformed rapidly without being compressed. In addition, such a rapidly deformed portion does not recover to the original state. This phenomenon is called “buckling”. Thus, when the column spacer is bent, the cell gap of the liquid crystal cell is varied, which causes a problem that the liquid crystal alignment of the liquid crystal display element is disturbed and the displayed image quality is deteriorated.
Therefore, in liquid crystal display elements such as portable electronic devices, there has been a demand for a curable resin composition for column spacer that can provide a column spacer having sufficient buckling strength.
JP 2001-91954 A JP 2002-251007 A Japanese Patent Laid-Open No. 11-133600

In view of the present situation, the present invention provides a curable resin composition for a column spacer that can form a column spacer having sufficient flexibility and excellent buckling strength, and the column spacer curable resin composition. It is an object to provide a column spacer and a liquid crystal display element to be used.

The present invention contains a compound (A) having two or more polymerizable unsaturated bonds in the molecule, an epoxy (meth) acrylate compound (B), an alkali-soluble polymer compound (C) and a photoinitiator (D). A curable resin composition for column spacers, wherein the epoxy (meth) acrylate compound (B) is a curable resin composition for column spacers, which is a compound having a structure represented by the following chemical formula (1). .

In the formula, R ¹ and R ² represent hydrogen or a methyl group, R ³ represents an atomic group derived from a polybasic acid anhydride and having a carboxyl group, and m and n represent 0 or a positive integer.
The present invention is described in detail below.

As a result of intensive studies, the present inventors have improved the flexibility of the obtained column spacer by producing a curable resin composition for a column spacer using an epoxy (meth) acrylate compound having a specific structure. Thus, the inventors have found that it is possible to produce a column spacer having excellent buckling strength, and have completed the present invention.

The curable resin composition for column spacers of this invention contains the epoxy (meth) acrylate compound (B) which is a compound which has a structure represented by the said Chemical formula (1).
By containing such an epoxy (meth) acrylate compound, the flexibility of the obtained column spacer is improved, and it becomes possible to produce a column spacer excellent in buckling strength.

The epoxy (meth) acrylate compound (B) is not particularly limited as long as it is a compound having a structure represented by the chemical formula (1). For example, an epoxy compound having two or more epoxy groups in one molecule And compounds obtained by reacting (meth) acrylic acid and the like.

The epoxy compound having two or more epoxy groups in one molecule is not particularly limited, and examples thereof include phenol novolac type, cresol novolac type, and halogenated epoxy resins thereof.

In the present specification, the (meth) acrylic acid means acrylic acid or methacrylic acid. In the compound obtained by reacting an epoxy compound having two or more epoxy groups in one molecule and (meth) acrylic acid, the (meth) acrylic group derived from the (meth) acrylic acid is a role of a photosensitive group. Fulfill.

As said epoxy (meth) acrylate compound (B), what is marketed can be used, for example, EA-6320, EA-7120, EA-7420 (above, Shin-Nakamura Chemical Co., Ltd. make), EAM- 2160, EAM-2300, R-205 (manufactured by Nippon Kayaku Co., Ltd.) Ebecryl 3603 (manufactured by Daicel Chemical Industries) and the like.

The epoxy (meth) acrylate compound (B) is preferably an acid-modified epoxy (meth) acrylate compound. Examples of the acid-modified epoxy (meth) acrylate compound include compounds in which n is a positive integer in the chemical formula (1).

By using such an acid-modified epoxy (meth) acrylate compound, it is possible to obtain a curable resin composition for column spacer that can obtain a column spacer having excellent buckling strength. Further, since the acid-modified epoxy (meth) acrylate compound has an acid group, the solubility of the curable resin composition for a column spacer of the present invention in an alkaline developer is increased, and the development residue is left in the alkali development at the time of manufacturing the column spacer. In addition, the adhesion of the obtained column spacer to the base material can be improved.

By reacting the polybasic acid anhydride with a hydroxyl group of a compound obtained by reacting an epoxy compound having two or more epoxy groups in one molecule with (meth) acrylic acid, the compound is reacted with a carboxyl group. Into an acid-modified epoxy (meth) acrylate compound.

The polybasic acid anhydride is not particularly limited, and examples thereof include dibasic acid anhydrides such as maleic anhydride, succinic anhydride, itaconic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, and chlorendic anhydride. Products, trimellitic anhydride, pyromellitic anhydride, benzophenonetetracarboxylic anhydride, biphenyltetracarboxylic anhydride, and the like. Of these, tetrahydrophthalic anhydride or succinic anhydride is preferred. The polybasic acid anhydride may be a saturated polybasic acid anhydride or an unsaturated polybasic acid anhydride.

As said acid-modified epoxy (meth) acrylate compound, what is marketed can be used, for example, PCR-1069, K-48C, CCR-1105, CCR-1115, CCR-1159H, PCR-1157H, TCR-1025, TCR-1064, TCR-1286, ZFR-1122, ZFR-1124, ZFR-1185 (above, manufactured by Nippon Kayaku Co., Ltd.), EA-6340, EA-7140, EA-7440 (above, Shin-Nakamura Chemical) Etc.).

As for the compounding quantity of the said epoxy (meth) acrylate compound (B), a preferable minimum is 0.1 weight% and a preferable upper limit is 50 weight with respect to the compound (A) which has a 2 or more polymerizable unsaturated bond in a molecule | numerator. %. When the content is less than 0.1% by weight, sufficient breaking strength may not be obtained in the obtained column spacer. If it exceeds 50% by weight, the flexibility of the obtained column spacer may be impaired. A more preferred lower limit is 0.5% by weight, and a more preferred upper limit is 30% by weight.

The curable resin composition for column spacers of the present invention contains a compound (A) having two or more polymerizable unsaturated bonds in the molecule.
In the curable resin composition for a column spacer of the present invention, the compound (A) having two or more polymerizable unsaturated bonds in the molecule is contained in the molecule modified with caprolactone, ethylene oxide and / or propylene oxide. A compound having two or more polymerizable unsaturated bonds (hereinafter also referred to as a polymerizable compound according to the present invention) is preferable.
The curable resin composition for a column spacer of the present invention containing the polymerizable compound according to the present invention is such that the column spacer to be produced has excellent flexibility and high compression recovery characteristics. In the liquid crystal display element manufactured using the spacer, it is possible to simultaneously suppress “gravity failure” due to liquid crystal expansion during heating and “low temperature foaming” due to liquid crystal shrinkage at low temperatures.
The above-mentioned “gravity failure” means that the column spacer is lifted from the substrate when the liquid crystal in the liquid crystal cell is heated and expands to expand the cell gap while the display device is in use, and is held by the column spacer. This is a phenomenon in which color unevenness occurs on the upper half and the lower half of the display panel due to the downward flow of the liquid crystal of the volume that has been lost. The “low-temperature foaming” refers to a phenomenon in which when the volume contraction of the liquid crystal in the liquid crystal cell occurs at a low temperature, the internal pressure in the liquid crystal cell rapidly decreases to generate bubbles.

The polymerizable compound according to the present invention is not particularly limited. For example, a polyfunctional (meth) acrylate compound modified with caprolactone, ethylene oxide and / or propylene oxide (hereinafter referred to as polyfunctional (meth) according to the present invention). (Also referred to as acrylate).
In the present specification, caprolactone modification means that a caprolactone ring-opening polymer or ring-opening polymer is introduced between the alcohol-derived site of the (meth) acrylate compound and the (meth) acryloyl group. . The ethylene oxide modification and / or propylene oxide modification means that an ethylene oxide segment and / or a propylene oxide segment is introduced between the alcohol-derived portion of the (meth) acrylate compound and the (meth) acryloyl group. To do.

When the polyfunctional (meth) acrylate according to the present invention is a caprolactone-modified polyfunctional (meth) acrylate compound, the polyfunctional (meth) acrylate compound is not particularly limited. For example, trimethylolpropane di (meta) ) Caprolactone-modified bifunctional (meth) acrylate compounds such as acrylate, trimethylolethane di (meth) acrylate, pentaerythritol di (meth) acrylate, ditrimethylolpropane di (meth) acrylate, dipentaerythritol di (meth) acrylate, etc. Compound: pentaerythritol tri (meth) acrylate, pentaerythritol tri (meth) acrylate, ditrimethylolpropane tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, di Pentaerythritol penta (meth) compound was caprolactone modified trifunctional or more (meth) acrylate compounds such as acrylate. Among them, a compound obtained by modifying a trifunctional or higher (meth) acrylate compound with caprolactone is particularly preferable because the polymerization reaction proceeds rapidly and the exposure sensitivity is easily improved.
These polyfunctional (meth) acrylates according to the present invention may be used alone or in combination of two or more.

The degree of modification of the caprolactone modification of the polyfunctional (meth) acrylate according to the present invention is such that when the number of functional groups of the polyfunctional (meth) acrylate compound as a base is n, two or more polymerizable unsaturated bonds in the molecule The preferable lower limit is 0.5 nmol and the preferable upper limit is 5 nmol with respect to 1 mol of the compound having azobenzene. When it is less than 0.5 nmol, when the curable resin composition of the present invention is used for a column spacer, the flexibility of the column spacer to be produced may be insufficient. The reactivity at the time of exposure at the time of manufacturing may be reduced, and patterning of the column spacer to be manufactured may be difficult. A more preferable lower limit is 1 nmol, and a more preferable upper limit is 3 nmol.

A specific method for modifying the above-mentioned polyfunctional (meth) acrylate compound with caprolactone is not particularly limited. For example, a polyhydric alcohol and caprolactone are reacted to synthesize caprolactone-modified alcohol, and then (meth) acrylic acid is esterified. A method in which (meth) acrylic acid and caprolactone are reacted to synthesize caprolactone-modified (meth) acrylic acid, followed by an esterification reaction with alcohol; (meth) acrylic acid, caprolactone, and polyhydric alcohol The method of reacting all together is mentioned.

Moreover, when the polymerizable compound according to the present invention is a polyfunctional (meth) acrylate compound modified with ethylene oxide and / or propylene oxide, the polyfunctional (meth) acrylate compound is not particularly limited. And compounds obtained by modifying the above-described trifunctional or higher functional (meth) acrylate compound with ethylene oxide and / or propylene oxide. Among them, pentaerythritol tri (meth) acrylate, ditrimethylolpropane tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, or dipentaerythritol penta (meth) acrylate is carboxylated. It is preferable that the compound to which the group is added is one obtained by modifying ethylene oxide and / or propylene oxide.

As the degree of modification of the polyfunctional (meth) acrylate with ethylene oxide modification and / or propylene oxide modification, when the number of functional groups of the base polyfunctional (meth) acrylate compound is n, the polyfunctional (meth) acrylate compound 1 A preferable lower limit with respect to mol is 0.5 nmol, and a preferable upper limit is 15 nmol. If it is less than 0.5 nmol, the flexibility of the column spacer to be produced may be insufficient. If it exceeds 15 nmol, the affinity for an alkaline developer will be high, and the resolution will be lowered due to swelling. It tends to happen. A more preferable lower limit is 3 nmol, and a more preferable upper limit is 10 nmol.

The specific method for modifying the polyfunctional (meth) acrylate compound with ethylene oxide and / or propylene oxide is not particularly limited. For example, a polyhydric alcohol and ethylene oxide and / or propylene oxide are reacted to produce ethylene oxide. A method in which an ethylene oxide-modified and / or propylene oxide-modified alcohol is esterified with a (meth) acrylic acid after synthesizing a modified and / or propylene oxide-modified alcohol; (meth) acrylic acid and ethylene oxide and / or propylene A method in which an oxide is reacted to synthesize ethylene oxide-modified and / or propylene oxide-modified (meth) acrylic acid, followed by an esterification reaction with alcohol; (meth) acrylic acid, ethylene oxide Beauty / or propylene oxide, and a method such as to collectively reacting polyhydric alcohols.

In the curable resin composition for a column spacer of the present invention, the content of the polymerizable compound according to the present invention described above is not particularly limited, but is preferable for the solid content of the curable resin composition for a column spacer of the present invention. The lower limit is 20% by weight, and the preferred upper limit is 90% by weight. If it is less than 20% by weight, the curable resin composition for a column spacer of the present invention may not be sufficiently photocured and a column spacer pattern may not be formed by a photolithographic technique. If it exceeds 90% by weight, the solubility in an alkaline developer used when producing a column spacer using the curable resin composition for a column spacer of the present invention is insufficient, and the developability of the pattern of the column spacer to be produced is insufficient. May be insufficient. A more preferred lower limit is 40% by weight, and a more preferred upper limit is 80% by weight.

Further, the curable resin composition for a column spacer of the present invention includes caprolactone-modified, ethylene oxide-modified, and / or propylene in order to adjust reactivity, developability and the like in addition to the above-described polymerizable compound according to the present invention. A compound having a polymerizable unsaturated bond having no oxide-modified site (hereinafter, also simply referred to as a polymerizable unsaturated bond-containing compound) is produced using, for example, the curable resin composition for column spacers of the present invention. You may use together in the range which does not impair the softness | flexibility and developability of the column spacer to do.

The polymerizable unsaturated bond-containing compound is not particularly limited, and examples thereof include neopentyl glycol di (meth) acrylate, 3-methyl-1,5-pentanediol di (meth) acrylate, and 2 -Butyl-2-ethyl-1,3-propanediol di (meth) acrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, hydroxypivalic acid neopentyl glycol ester diacrylate, diethylene glycol (meta ) Acrylate, triethylene glycol (meth) acrylate, tetraethylene glycol (meth) acrylate, hexaethylene glycol (meth) acrylate, polyethylene glycol (meth) acrylate such as nonaethylene glycol (meth) acrylate Diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, hexaethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, etc. (Meth) acrylate etc. are mentioned.

Examples of the tri- or higher functional group include trimethylolethane tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, and pentaerythritol tetra. Examples thereof include polyfunctional (meth) acrylate compounds such as (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, and dipentaerythritol hexa (meth) acrylate.

When the curable resin composition for column spacers of the present invention contains the polymerizable unsaturated bond-containing compound, the amount of the compound is not particularly limited, but it is 40% of the total amount with the polymerizable compound according to the present invention. It is preferable that it is less than%. If it exceeds 40% by weight, the flexibility of the column spacer obtained by using the curable resin composition for column spacers of the present invention may be impaired, and the effect of suppressing poor gravity and low-temperature foaming may be reduced. A more preferred upper limit is 30% by weight.

The compound (A) having two or more polymerizable unsaturated bonds in the molecule has two or more polymerizable unsaturated bonds in the above-mentioned caprolactone-modified, ethylene oxide-modified and / or propylene oxide-modified molecule. Furthermore, it may be a polyfunctional (meth) acrylate compound having one or more carboxyl groups in the molecule modified with caprolactone, ethylene oxide and / or propylene oxide.
A column spacer formed using the curable resin composition for a column spacer of the present invention containing such a compound (hereinafter also referred to as another polyfunctional (meth) acrylate according to the present invention) has excellent recoverability from compression deformation. In the liquid crystal display device manufactured using such a column spacer, it is possible to simultaneously suppress “gravity failure” due to liquid crystal expansion during heating and “low temperature foaming” due to liquid crystal shrinkage at low temperatures. Furthermore, when forming a pattern to be a column spacer by a photolithographic technique, a sharp resolution can be obtained without generating a development residue. Further, since the solubility in the developer is high, when the developer is recycled and used, it is difficult to clog the collection filter of the developer, and high process suitability can be produced.

Other polyfunctional (meth) acrylates according to the present invention are not particularly limited. For example, trimethylolpropane di (meth) acrylate, trimethylolethanedi (meth) acrylate, pentaerythritol di (meth) acrylate, ditrimethylol. Compounds having bifunctional (meth) acrylate compounds such as propanedi (meth) acrylate and dipentaerythritol di (meth) acrylate modified with caprolactone; pentaerythritol tri (meth) acrylate, pentaerythritol tri (meth) acrylate, ditrimethylolpropane Capola is a trifunctional or higher functional (meth) acrylate compound such as tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, etc. Ton modified such the compounds and the like. Among them, a compound obtained by modifying a trifunctional or higher functional (meth) acrylate compound with caprolactone is particularly suitable because the polymerization reaction proceeds rapidly and the exposure sensitivity is easily improved.
These other polyfunctional (meth) acrylates according to the present invention may be used alone or in combination of two or more.

Such a polyfunctional (meth) acrylate according to the present invention may be modified by caprolactone modification and ethylene oxide modification and / or propylene oxide modification by the above-described multifunctional (meta) (meta) ) The same as described for acrylate.

As another polyfunctional (meth) acrylate according to the present invention, for example, a carboxylic acid can be prepared by adding a compound having a carboxyl group to a part of the (meth) acryl group of a tri- or higher-functional (meth) acrylate compound. A (meth) acrylate compound into which is introduced is preferable. By including such a polyfunctional (meth) acrylate compound having a carboxyl group, the curable resin composition for a column spacer of the present invention is necessary for obtaining exposure sensitivity during pattern formation by a photolithographic technique. It has excellent affinity with an alkaline developer necessary for obtaining rapid polymerization reactivity and resolution during development.

The method for obtaining the polyfunctional (meth) acrylate compound having a carboxyl group is not particularly limited. For example, I) succinic anhydride or tetrahydrophthalic anhydride is added to the hydroxyl group of a tri- or higher functional (meth) acrylate compound having a hydroxyl group. II) Addition of a compound having a thiol group such as thiosalicylic acid and a carboxyl group to the (meth) acryl group of a tri- or more functional (meth) acrylate compound by an ene-thiol reaction And the like.

In the curable resin composition for column spacers of the present invention, since the polymerization reaction proceeds rapidly and the exposure sensitivity is easily improved, the preferred lower limit of the number of (meth) acryl groups in the molecule is 3.
In the polyfunctional (meth) acrylate compound having a carboxyl group, the preferable upper limit of the carboxyl group in the molecule is 2. When it is 3 or more, the solubility / swellability in a developer is increased, and for example, the curable resin composition for a column spacer of the present invention is liable to cause peeling of a development pattern or a decrease in resolution due to swelling.

In the curable resin composition for a column spacer of the present invention, the content of the other polyfunctional (meth) acrylate according to the present invention is not particularly limited, but the solid content of the curable resin composition for a column spacer of the present invention is not particularly limited. On the other hand, the preferred lower limit is 20% by weight and the preferred upper limit is 90% by weight. If it is less than 20% by weight, the curable resin composition for a column spacer of the present invention may not be sufficiently photocured and a column spacer pattern may not be formed by a photolithographic technique. If it exceeds 90% by weight, the solubility in an alkali developer used when producing a column spacer using the curable resin composition for a column spacer of the present invention is insufficient, and the developability of the pattern of the column spacer to be produced is insufficient. It may be insufficient. A more preferred lower limit is 40% by weight, and a more preferred upper limit is 80% by weight.

The curable resin composition for column spacers of the present invention contains an alkali-soluble polymer compound (C).
The alkali-soluble polymer compound (C) used in the curable resin composition for column spacers of the present invention is soluble in an alkali developer in alkali development, which is general for resist development. Although it does not specifically limit as an alkali-soluble high molecular compound (C) used for the curable resin composition for column spacers of this invention, It contains carboxylic acid, dicarboxylic anhydride, or carboxylate in a molecular chain. Therefore, a polymer compound having solubility in an aqueous solution such as potassium hydroxide, sodium hydroxide, sodium carbonate, and tetramethylammonium hydroxide is preferable.
As such an alkali-soluble polymer compound (C), for example, an alkali-soluble carboxyl group-containing copolymer such as a copolymer obtained by copolymerizing a carboxyl group-containing monofunctional unsaturated compound and a monofunctional compound having an unsaturated double bond A high molecular compound is mentioned.

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, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, (meth) acrylic acid 2 -Ethylhexyl, hydroxyethyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-methylcyclohexyl (meth) acrylate, dicyclopentanyloxyethyl (meth) acrylate, isobornyl (meth) acrylate, (meth) And (meth) acrylic acid ester monomers such as dicyclopentanyl acrylate and benzyl (meth) acrylate.

The alkali-soluble carboxyl group-containing polymer compound includes aromatic vinyl monomers such as styrene, α-methylstyrene, p-methylstyrene, and p-chlorostyrene; vinyl cyanide compounds such as acrylonitrile and methacrylonitrile. Unsaturated maleic anhydrides such as maleic anhydride; aromatic substituted maleimides such as phenylmaleimide, benzylmaleimide, naphthylmaleimide, o-chlorophenylmaleimide; alkyl-substituted maleimides such as methylmaleimide, ethylmaleimide, propylmaleimide, isopropylmaleimide, etc. You may contain the component which consists of.

Furthermore, the alkali-soluble carboxyl group-containing polymer compound may contain a monofunctional unsaturated compound having a hydroxyl group for the purpose of controlling solubility during development. The monofunctional unsaturated compound having a hydroxyl group is not particularly limited, and examples of the monomer having one hydroxyl group in the molecule include 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2 -Hydroxypropyl methacrylate, 4-hydroxybutyl acrylate, 4-hydroxybutyl methacrylate and the like.

In the alkali-soluble carboxyl group-containing polymer compound, the preferred lower limit of the ratio of 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.

Solvents for producing the alkali-soluble carboxyl group-containing polymer compound by solution polymerization include, for example, aliphatic alcohols such as methanol, ethanol, isopropanol and glycol; cellosolvs such as cellosolve and butylcellosolve; carbitol and butyl Carbitols such as carbitol; 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; A polar organic solvent such as dimethyl sulfoxide or dimethylformamide 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 alkali-soluble carboxyl group containing high molecular compound, 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.

As the alkali-soluble polymer compound (C), an alkali-soluble (meth) acrylic copolymer (C1) having a (meth) acryl group and a carboxyl group in the side chain is particularly suitable.
As the alkali-soluble (meth) acrylic copolymer (C1) having a (meth) acryl group and a carboxyl group in the side chain, for example, a main chain comprising at least a structural unit having an acidic functional group and a structural unit having a hydroxyl group. And the radical polymerizable group-containing isocyanate compound is amide-bonded to at least a part of the acidic functional group and / or urethane-bonded to at least a part of the hydroxyl group through the isocyanate group of the isocyanate compound. The polymer (C1-1) is preferred.

The polymer (C1-1) is prepared by adjusting the amount of the radical polymerizable group-containing isocyanate compound so that the equivalent ratio (NCO / OH) is 1.0 or more. It becomes possible to introduce into the alkali-soluble polymer compound having a reactive functional group at a high ratio, and the sensitivity of the alkali-soluble polymer compound having a reactive functional group can be improved. Moreover, since content of the structural unit which has an acidic functional group can be adjusted to a suitable ratio, alkali solubility (developability) can be adjusted freely.

In the polymer (C1-1), the equivalent ratio of isocyanate groups (NCO / OH) is adjusted to 1.0 or more, and the content ratio of the structural unit having a hydroxyl group is set to 14 mol% or more in the charged amount. Is preferred. By adjusting the equivalent ratio (NCO / OH) of the isocyanate group to 1.0 or more, the introduction rate of the isocyanate group can be increased, and at the same time, the charge amount of the structural unit having a hydroxyl group is 14 mol% or more. Since the number of isocyanate group-reacting parts increases, it becomes possible to introduce a very large amount of the side chain of the radical polymerizable group into the alkali-soluble polymer compound (C) having a reactive functional group, and particularly high sensitivity can be obtained. .

A preferable upper limit of the charged amount of the radical polymerizable group-containing isocyanate compound is an isocyanate group equivalent ratio (NCO / OH) of 2.0. When the equivalent ratio (NCO / OH) exceeds 2.0, a large amount of unreacted radical polymerizable group-containing isocyanate compound remains in the alkali-soluble polymer compound having a reactive functional group, and the reactive functional group The physical property of the alkali-soluble polymer compound (C) having a group is lowered.

The structural unit having an acidic functional group is a component that contributes to alkali developability, and the content ratio thereof is not particularly limited, and the alkali-soluble polymer compound (C) having a reactive function is required to be alkali-soluble. It is adjusted appropriately depending on the degree. Examples of the monomer used for introducing the structural unit having an acidic functional group into the main chain of the polymer include compounds having a double bond-containing group and an acidic functional group.
The acidic functional group is not particularly limited and is usually a carboxyl group, but may be other than a carboxyl group as long as it can contribute to alkali developability.

Especially, as a structural unit which has the said acidic functional group, the structural unit represented by following Chemical formula (2) is preferable.

R contained in the above chemical formula (2) and other formulas described later represents hydrogen or an alkyl group having 1 to 5 carbon atoms.
The alkyl group is not particularly limited, and examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, and an n-pentyl group. Can be mentioned.

It does not specifically limit as a monomer used in order to introduce | transduce the structural unit of the said Chemical formula (2), For example, acrylic acid, methacrylic acid, 2-carboxy-1-butene, 2-carboxy-1-pentene, Examples include 2-carboxy-1-hexene and 2-carboxy-1-heptene.

Although it does not specifically limit as a structural unit which has the said hydroxyl group, The structural unit represented by following Chemical formula (3) is preferable.

In the chemical formula (3), R is the same as R in the chemical formula (2), and R ⁴ represents an alkylene group having 2 to 4 carbon atoms. Examples of R ⁴ include an ethylene group, a propylene group, and a butylene group.

Moreover, it does not specifically limit as a monomer used in order to introduce | transduce the structural unit of the said Chemical formula (3), For example, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxy Examples thereof include hydroxypropyl methacrylate, 4-hydroxybutyl acrylate, 4-hydroxybutyl methacrylate and the like.

The main chain of the polymer (C1-1) contains a structural unit such as chemical formula (2) having an acidic functional group and a structural unit such as chemical formula (3) having a hydroxyl group as essential copolymerization components. Other copolymer components may be included. For example, the main chain of the polymer may contain a structural unit having an aromatic carbocycle and / or a structural unit having an ester group.

The structural unit having the aromatic carbocyclic ring is not particularly limited, and for example, a structural unit represented by the following chemical formula (4) is preferable.

In the chemical formula (4), R is the same as R in the chemical formula (2), and R ⁵ represents an aromatic carbocycle. Examples of such R ⁵ include a phenyl group and a naphthyl group.

The monomer used for introducing the structural unit of the chemical formula (4) is not particularly limited, and examples thereof include styrene, α-methylstyrene, and the aromatic ring includes chlorine, bromine, and the like. Or a halogen group such as a methyl group or an ethyl group, an amino group such as an amino group or a dialkylamino group, a cyano group, a carboxyl group, a sulfonic acid group, or a phosphoric acid group.

The monomer used for introducing the structural unit having an ester group into the main chain of the polymer is not particularly limited, and examples thereof include a compound having a double bond-containing group and an ester group. The structural unit represented by the following chemical formula (5) is preferred.

In the chemical formula (5), R is the same as R in the chemical formula (2), and R ⁶ represents an alkyl group or an aralkyl group. Examples of such R ⁶ include aralkyl groups such as an alkyl group having 1 to 12 carbon atoms, a benzyl group, and a phenylethyl group.

The monomer used for introducing the structural unit represented by the chemical formula (5) is not particularly limited. For example, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, ( 2-ethylhexyl (meth) acrylate, phenyl (meth) acrylate, cyclohexyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentanyloxyethyl (meth) acrylate, (meth) acrylic acid Examples include esters of (meth) acrylic acid such as isobonyl, benzyl (meth) acrylate, and phenylethyl (meth) acrylate.

In the main chain composed of each of the structural units, a radical polymerizable group-containing isocyanate compound is amide-bonded to at least a part of the acidic functional group via the isocyanate group of the isocyanate compound and / or the hydroxyl group. Are bonded to urethane at least partially, and a side chain of a radical polymerizable group is formed.

It does not specifically limit as said radically polymerizable group containing isocyanate compound, For example, the (meth) acryloyloxyalkyl isocyanate shown to following Chemical formula (6) is suitable.

In the above chemical formula (6), R ⁷ represents an alkylene group, and R ⁸ represents hydrogen or methyl. Of the (meth) acryloyloxyalkyl isocyanates represented by chemical formula (6), those in which a (meth) acryloyl group is bonded to an isocyanate group (—NCO) via an alkylene group having 2 to 6 carbon atoms are preferred. Specific examples include 2-acryloyloxyethyl isocyanate and 2-methacryloylethyl isocyanate. Moreover, as a commercial item of the said 2-methacryloyl ethyl isocyanate, "Karenz MOI" by Showa Denko KK etc. are mentioned, for example.

The polymer comprising such a constitutional unit comprises at least a constitutional unit such as the chemical formula (2) having an acidic functional group and a constitutional unit such as the chemical formula (3) having a hydroxyl group, and if necessary, an aromatic group. A polymer (raw polymer) having a main chain containing a structural unit such as chemical formula (4) having a carbon ring, a structural unit such as chemical formula (5) having an ester group, or other structural units, Subsequently, it can obtain by making a radically polymerizable group containing isocyanate compound react.

The polymerization solvent used for producing the raw material polymer is preferably a solvent having no active hydrogen such as a hydroxyl group or an amino group. For example, ethers such as tetrahydrofuran; diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl Examples include glycol ethers such as ether, cellosolv esters such as methyl cellosolve acetate, propylene glycol monomethyl ether acetate, and 3-methoxybutyl acetate. Aromatic hydrocarbons, ketones, esters, and the like can also be used. .

As the polymerization initiator used for producing the raw material polymer, a conventionally known radical polymerization initiator can be used. Specifically, 2,2′-azobisisobutyronitrile, 2,2 Nitrile azo compounds (nitrile azo polymerization initiators) such as' -azobis- (2,4-dimethylvaleronitrile), 2,2'-azobis- (4-methoxy-2,4-dimethylvaleronitrile); Non-nitrile azo compounds (non-nitrile azo polymerization initiators) such as dimethyl 2,2′-azobis (2-methylpropionate), 2,2′-azobis (2,4,4-trimethylpentane); t-hexylperoxypivalate, tert-butylperoxypivalate, 3,5,5-trimethylhexanoyl peroxide, octanoyl peroxide, lauroylperoxide Xoxide, stearoyl peroxide, 1,1,3,3-tetramethylbutylperoxy 2-ethylhexanoate, succinic peroxide, 2,5-dimethyl-2,5-di (2-ethylhexanoylperoxy) hexane, 1 -Cyclohexyl-1-methylethylperoxy 2-ethylhexanoate, t-hexylperoxy 2-ethylhexanoate, 4-methylbenzoyl peroxide, benzoyl peroxide, 1,1'-bis- (tert-butylperoxy) cyclohexane, etc. Organic peroxide (peroxide-based polymerization initiator); and hydrogen peroxide. When a peroxide is used as the radical polymerization initiator, it may be used as a redox polymerization initiator in combination with a reducing agent.

In the production of the raw material polymer, a molecular weight modifier can be used to adjust the weight average molecular weight. Examples of the molecular weight regulator include halogenated hydrocarbons such as chloroform and carbon tetrabromide; mercaptans such as n-hexyl mercaptan, n-octyl mercaptan, n-dodecyl mercaptan, tert-dodecyl mercaptan, and thioglycolic acid. Xanthogens such as dimethylxanthogen disulfide and diisopropylxanthogen disulfide; terpinolene, α-methylstyrene dimer and the like.

The raw material polymer may be either a random copolymer or a block copolymer.
In the case of producing a random copolymer, for example, each of the monomers represented by the above chemical formulas (2) to (5) and a composition composed of a catalyst are mixed in a polymerization tank containing a solvent in a polymerization tank of 80 to It can be made to polymerize by dripping at 110 degreeC temperature conditions over 2 to 5 hours, and making it age | cure | ripen.

The preferable lower limit of the polystyrene-converted weight average molecular weight (hereinafter simply referred to as “weight average molecular weight” or “Mw”) of the raw material polymer having the structural units of the chemical formulas (2) to (5) is 10,000, and the preferable upper limit is 100. The preferred lower limit of the acid value is 5 mg KOH / g, the preferred upper limit is 400 mg KOH / g, the preferred lower limit of the hydroxyl value is 5 mg KOH / g, and the preferred upper limit is 400 mg KOH / g.

The reaction between the raw material polymerization holiday and the radical polymerizable group-containing isocyanate compound is carried out for a certain period of time after the radical polymerizable group-containing isocyanate compound is charged all at once into the raw polymer solution in the presence of a small amount of catalyst. The reaction can be continued or it can be carried out by dropwise addition.
Examples of the catalyst include, but are not limited to, dibutyltin laurate and the like, and p-methoxyphenol, hydroquinone, naphthylamine, tert-butylcatechol, 2,3-di-tert-butyl p-cresol, and the like. A polymerization inhibitor is used as needed.

The radical polymerizable group-containing isocyanate compound is amide-bonded with an acidic functional group in the raw material polymer via an isocyanate. For example, a part of the structural unit of the chemical formula (2) releases a carbon dioxide gas and is bonded by an amide bond to form a structural unit represented by the following chemical formula (7).
On the other hand, the radical polymerizable group-containing isocyanate compound is urethane-bonded to the hydroxyl group in the raw material polymer via the isocyanate. For example, the structural unit represented by the chemical formula (3) is subjected to an addition reaction and bonded by a urethane bond to form a structural unit represented by the structural unit represented by the following chemical formula (8).

The polymer thus obtained has a radical polymerizable group in a structural unit such as chemical formula (2) having an acidic functional group, a structural unit such as chemical formula (3) having a hydroxyl group, and a structural unit having an acidic functional group. The structural unit such as chemical formula (7) in which is introduced and the structural unit such as chemical formula (8) in which a radical polymerizable group is introduced into the structural unit of chemical formula (3) having a hydroxyl group are linked in an arbitrary order. Has a molecular structure.

Examples of the alkali-soluble (meth) acrylic copolymer (C1) include copolymers (C1) composed of structural units represented by the following formulas (1a), (1b), (1c), (1d) and (1e). -2) is also suitable.

In formulas (1a), (1b), (1c), (1d) and (1e), A ¹ and A ² represent hydrogen, the following formulas (2a), (2b), (2c) or (2d) , A ¹ or A ² is hydrogen, the other is any of the following formulas (2a), (2b), (2c) or (2d). R ⁹ represents hydrogen and / or a methyl group, R ¹⁰ represents a phenyl group including an alkyl group, a phenyl group, an alkyl group or an alkoxy group, a hydroxyalkyl group or an alicyclic hydrocarbon, and R ¹¹ represents a nitrile. R ¹² represents an alkyl group, a hydroxyalkyl group, or a radically polymerizable group-containing aliphatic hydrocarbon. Moreover, a, b, c, d, and e represent the molar ratio (%) of each component, and when a + b + c + d + e = 100, a, b and d are 0 to 90, c is 5 to 50, and e is 5 ~ 60.

By including such a copolymer (C1-2), the column spacer formed by curing the curable resin composition for column spacers of the present invention has high recoverability from compression deformation and is flexible and has low elasticity. Rate. Moreover, since the said copolymer (C1-2) has the low polarity of a segment, it is excellent in the compatibility in a composition. Thereby, problems such as development unevenness do not occur in the development processing at the time of manufacturing the column spacer.

Among them, because of having a highly flexible urethane bond in the structure, flexibility can be imparted while maintaining high crosslinkability, and because the urethane bond has an appropriate polarity, the compatibility in the composition is excellent. In the copolymer (C1-2), A ¹ and / or A ² are preferably represented by the above formula (2b).

In addition, when having a radical polymerizable group in a structural unit bonded by a urethane bond, it is possible to simultaneously give higher crosslinking and flexibility, and the radical polymerizable group is photocrosslinked with other components. Therefore, for reasons such as further improving the compatibility, A ¹ and / or A ² in the copolymer (C1-2) is represented by the above formula (2b) and the above formula (2b). R ¹² therein is preferably a radical polymerizable group-containing aliphatic hydrocarbon.

In addition, it has excellent alkali developability and adhesion to a substrate by having a hydroxyl group, and can have compatibility with other components by having both a highly polar hydroxyl group and a low polarity R ^12. From the above, it is preferable that A ¹ and A ² in the copolymer (C1-2) are represented by the above formula (2c) or (2d).

Although it does not specifically limit as a weight average molecular weight of the said copolymer (C1-2), A preferable minimum is 3000 and a preferable upper limit is 100,000. If it is less than 3000, the developability of the column spacer may be lowered, and if it is 100,000 or more, the resolution may be lowered. A more preferred lower limit is 5000, and a more preferred upper limit is 50,000.

Although it does not specifically limit as a manufacturing method of the said copolymer (C1-2), For example, ring-opening addition of an alicyclic epoxy-group-containing unsaturated compound is added to the (meth) acryl copolymer which has a carboxyl group in a side chain. Examples include a method in which a part of the carboxyl group is modified by polymerization, and further, an isocyanate compound, an epoxy compound, a lactone compound, an alcohol compound, or the like is reacted with a hydroxyl group generated by modification and / or a part of the remaining carboxyl group. It is done.

Specifically, for example, cyclomer P (manufactured by Daicel Chemical Industries) is commercially available, and further, an isocyanate compound, an epoxy compound, and a lactone are included in part of the hydroxyl group and carboxyl group contained in cyclomer P. The said copolymer (C1-2) can also be obtained by making a compound, an alcohol compound, etc. react.

The method for producing the (meth) acrylic copolymer having a carboxyl group in the side chain is not particularly limited. For example, a carboxyl group-containing monofunctional unsaturated compound and a (meth) acrylic acid ester monomer are used as radicals. Examples thereof include a method of copolymerization by a conventionally known method such as bulk polymerization, solution polymerization, suspension polymerization, dispersion polymerization or emulsion polymerization using a polymerization initiator and, if necessary, a molecular weight adjusting agent.

Although it does not specifically limit as said alicyclic epoxy group containing unsaturated compound, For example, 3, 4- epoxy cyclohexyl (meth) acrylate etc. are used suitably.

Although it does not specifically limit as said isocyanate compound, For example, C2-C18 alkyl isocyanate and polymeric group containing isocyanate are used suitably.
Alkyl isocyanates having 19 or more carbon atoms are less polar, so that compatibility with a (meth) acrylic copolymer having a carboxyl group in the side chain is not obtained, and the reaction may not proceed smoothly.
When the polymerizable group-containing isocyanate is used, the sensitivity during photocuring is increased, and various physical properties such as heat resistance, chemical resistance, and tack-free property are further improved.
Although it does not specifically limit as said polymerizable group containing isocyanate, For example, it is preferable to use what the (meth) acryloyl group couple | bonded with the isocyanate group through the C2-C6 alkylene group. Specifically, for example, 2-acryloyloxyethyl isocyanate, 2-methacryloylethyl isocyanate, 2-acryloylethyl isocyanate and the like can be mentioned, and 2-methacryloylethyl isocyanate and 2-acryloylethyl isocyanate are respectively Karenz MOI, And it is marketed as Karenz AOI (all are made by Showa Denko KK).

The method of reacting the isocyanate compound with a (meth) acrylic copolymer having a hydroxyl group and a carboxyl group in the side chain generated by the modification is not particularly limited, and the isocyanate compound is reacted with the modification in the presence of a small amount of catalyst. The method of dripping or mixing in the solution of the (meth) acryl copolymer which has a hydroxyl group and a carboxyl group in the produced side chain is mentioned. The catalyst used in this case is not particularly limited, and examples thereof include lauric acid and dibutyltin.

If necessary, a polymerization inhibitor such as p-methoxyphenol, hydroquinone, naphthylamine, tert-butylcatechol, 2,3-di-tert-butyl-p-cresol may be used.

Moreover, you may perform the process by alcohol, such as methanol, ethanol, a propanol, a butanol, a pentanol, a hexanol, a heptanol, an octanol, a decanol, in order to suppress a thickening etc.

When an isocyanate compound is reacted with a (meth) acrylic copolymer having a hydroxyl group and a carboxyl group in the side chain generated by the modification according to the above production method, a structural unit represented by the formula (2b) is formed. .

It does not specifically limit as said epoxy resin compound, For example, a C2-C18 alkyl epoxy compound, a C2-C18 alkoxy epoxy compound, and a polymeric group containing epoxy compound are mentioned. When the number of carbon atoms of the epoxy compound is 19 or more, the polarity is lowered, so compatibility with the (meth) acrylic copolymer having a carboxyl group in the side chain cannot be obtained, and the reaction does not proceed smoothly. There is.
When the above-mentioned polymerizable group-containing epoxy compound is used, an increase in sensitivity during photocuring and further improvements in various physical properties such as heat resistance, chemical resistance and tack-free property are realized.
Although it does not specifically limit as said polymerizable group containing epoxy compound, For example, it is preferable to use what the (meth) acryloyl group couple | bonded with the epoxy group through the C2-C6 alkylene group. Specifically, glycidyl (meth) acrylate etc. are mentioned, for example.

The method of reacting the epoxy compound with a (meth) acrylic copolymer having a hydroxyl group and a carboxyl group in the side chain generated by the modification is not particularly limited, and the epoxy compound is modified by the modification in the presence of a small amount of catalyst. The method of dripping or mixing in the solution of the (meth) acryl copolymer which has a hydroxyl group and a carboxyl group in the produced side chain is mentioned.
The catalyst used in this case is not particularly limited. For example, triethylamine, tripromylamine, tetramethylethylenediamine, dimethyllaurylamine, triethylbenzylammonium chloride, trimethylcetylammonium bromide, tetrabutylammonium bromide, trimethylbutylphosphonium bromide, tetra And butylphosphonium bromide. If necessary, a polymerization inhibitor such as p-methoxyphenol, hydroquinone, naphthylamine, tert-butylcatechol, 2,3-di-tert-butyl-p-cresol may be used.

When the epoxy compound is reacted with the (meth) acrylic copolymer having a hydroxyl group and a carboxyl group in the side chain generated by the modification according to the above production method, the structural units represented by the formulas (2c) and (2d) Is formed.

When the above-mentioned isocyanate compound, epoxy compound, lactone compound, alcohol compound, or the like is reacted with a (meth) acrylic copolymer having a hydroxyl group and a carboxyl group in the side chain, the hydroxyl group contained in the (meth) acrylic copolymer Among them, an amount corresponding to 0 to 100 mol% can be reacted, but a preferable lower limit is 10 mol%. If the amount is less than 10 mol%, a large amount of hydroxyl groups remain, so that the polarity of the resin becomes high. In particular, when a compound containing a trifunctional or higher functional (meth) acrylate compound modified with caprolactone is used as a crosslinking monomer. Solubility may not be obtained.

In addition, when the above-mentioned isocyanate compound, epoxy compound, lactone compound, alcohol compound or the like is reacted with a (meth) acrylic copolymer having a hydroxyl group and a carboxyl group in the side chain, it is included in the (meth) acrylic copolymer. Among the carboxyl groups, an amount corresponding to 0 to 90 mol% can be reacted. If it exceeds 90 mol%, the amount of the remaining carboxyl groups becomes too small, so that alkali solubility is impaired and developability may be lowered.

In the above formulas (1a), (1b), (1c), (1d) and (1e), a, b, c, d and e represent the molar ratio (%) of each component, and when a + b + c + d + e = 100 , A, b and d have a lower limit of 0% and an upper limit of 90%. The lower limit of c is 5%, and the upper limit is 50%. The lower limit of e is 5%, and the upper limit is 60%. The lower limit of c is 5%, and the upper limit is 50%. However, when the molar ratio of the carboxyl group-containing structural unit is less than 5%, it is difficult to impart alkali solubility. If it exceeds 50%, the swelling during development is remarkable and it becomes difficult to form a pattern. Further, the preferable lower limit of e is 5%, and the preferable upper limit is 60%. However, if it is less than 5%, the incorporation of the alkali-soluble resin into the crosslinked structure becomes insufficient, and the effect of improving the recovery rate from compression deformation is obtained. However, if it exceeds 60%, the crosslinking density of the crosslinked structure increases, and the flexible properties are impaired.

As the alkali-soluble polymer compound (C) having a reactive functional group, a copolymer (C2) containing an unsaturated carboxylic acid and / or an unsaturated carboxylic acid anhydride and a blocked isocyanate group-containing unsaturated compound. Is also suitable. The column spacer produced using the curable resin composition for a column spacer of the present invention containing the copolymer (C2) having such a structure is excellent in elasticity and excellent in recovery rate from compression deformation. In the manufactured display element, no gravity defect occurs. The reason for this is not clear, but is thought to be as follows. That is, in the post-baking step when producing the column spacer, the blocked isocyanate group and carboxyl group (and hydroxyl group) in the alkali-soluble polymer compound (C) react with each other, so that the alkali-soluble polymer compound (C) is plasticized. This is considered to be because the chemical behavior is suppressed and plastic deformation in the compression deformation of the column spacer to be manufactured is suppressed.

The unsaturated carboxylic acid and / or unsaturated carboxylic acid anhydride in the copolymer (C2) is not particularly limited, and examples thereof include monocarboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid; maleic acid and fumaric acid Dicarboxylic acids such as citraconic acid, mesaconic acid and itaconic acid; methacrylic acid derivatives having a carboxyl group and an ester bond such as 2-succinyloxyethyl methacrylate, 2-maleoyloxyethyl methacrylate and 2-hexahydrophthaloyloxyethyl methacrylate , And anhydrides thereof. These may be used alone or in combination of two or more. Of these, acrylic acid, methacrylic acid, and 2-hexahydrophthaloyloxyethyl methacrylate are preferable.

Although it does not specifically limit as a structural ratio of the said unsaturated carboxylic acid and / or unsaturated carboxylic anhydride in the said copolymer (C2), A preferable minimum is 10 weight% and a preferable upper limit is 40 weight%. If it is less than 10% by weight, it becomes difficult to impart alkali solubility to the curable resin composition for column spacers of the present invention. If it exceeds 40% by weight, swelling during development when producing the column spacers is remarkable. It may be difficult to form a column spacer pattern. A more preferred lower limit is 15% by weight, and a more preferred upper limit is 30% by weight.

The blocked isocyanate group-containing unsaturated compound in the copolymer (C2) is not particularly limited. For example, the isocyanate is blocked with a blocking agent compound such as active methylene, oxime, lactam, or alcohol. What can be obtained by making it into. Specifically, for example, (meth) acrylic acid 2- (O- [1′-methylpropylideneamino] carboxyamino) ethyl and the like can be mentioned. As a commercially available product of this blocked isocyanate group-containing unsaturated compound, Showa An example is “Karenz MOI-BM” manufactured by Denko.

Although it does not specifically limit as a structural ratio of the said block isocyanate group containing unsaturated compound in the said copolymer (C2), A preferable minimum is 2 weight% and a preferable upper limit is 90 weight%. If it is less than 2% by weight, the alkali-soluble polymer compound is insufficiently cross-linked, the plastic deformation of the column spacer is large, and the liquid crystal display element to be produced is liable to cause a gravity failure. If it exceeds 90% by weight, the content of the unsaturated carboxylic acid and / or the unsaturated carboxylic acid anhydride is relatively lowered, so that it becomes difficult to impart alkali solubility. A more preferred lower limit is 5% by weight, and a more preferred upper limit is 85% by weight.

The copolymer (C2) is preferably a copolymer further containing a hydroxyl group-containing unsaturated compound. By introducing a hydroxyl group, the efficiency of the crosslinking reaction with the blocked isocyanate group is improved, and the solubility during alkali development can be adjusted.

Examples of the hydroxyl group-containing unsaturated compound in the copolymer (C2) include (meth) acrylic acid hydroxyalkyl esters such as 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate. Can be mentioned.

Although it does not specifically limit as a structural ratio of the said hydroxyl-containing unsaturated compound in the said copolymer (C2), A preferable upper limit is 40 weight%. When it exceeds 40% by weight, the pattern is sufficiently protected in alkali development, the resolution of the pattern is lowered, and defects such as pattern loss are likely to occur. More preferred is 30% by weight.

Furthermore, the copolymer (C2) is derived from a polymerizable unsaturated compound other than the unsaturated carboxylic acid and / or unsaturated carboxylic acid anhydride, the blocked isocyanate group-containing unsaturated compound, and the hydroxyl group-containing unsaturated compound. It may be a copolymer containing a structural unit.
Examples of the polymerizable unsaturated compound include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (meth ) (Meth) acrylic acid alkyl esters such as hydroxyethyl acrylate; (meth) acrylic acid cyclohexyl, (meth) acrylic acid 2-methylcyclohexyl, (meth) acrylic acid dicyclopentanyl, (meth) acrylic acid isobornyl (Meth) acrylic acid cyclic alkyl ester; (meth) acrylic acid aryl ester such as phenyl (meth) acrylate and benzyl (meth) acrylate; styrene, α-methylstyrene, p-methylstyrene, p-chlorostyrene, etc. Aromatic vinyl monomers; acrylonitrile, methacryloni Vinyl cyanide compound Lil and the like; phenylmaleimide, benzyl maleimide, naphthyl maleimide, aromatic-substituted maleimides such as o- chlorophenyl maleimide; methyl maleimide, ethyl maleimide, propyl maleimide, alkyl-substituted maleimides such as isopropyl maleimide.

Although it does not specifically limit as a weight average molecular weight of the said copolymer (C2), A preferable minimum is 3000 and a preferable upper limit is 100,000. If it is less than 3000, the developability when producing the column spacer using the curable resin composition for a column spacer of the present invention may be deteriorated. If it exceeds 100,000, the curability for the column spacer of the present invention may be reduced. The resolution at the time of manufacturing a column spacer using a resin composition may fall. A more preferred lower limit is 5000, and a more preferred upper limit is 50,000.

The method for producing the copolymer (C2) is not particularly limited. For example, bulk polymerization, solution polymerization, suspension polymerization, dispersion polymerization, emulsification using a radical polymerization initiator and a molecular weight regulator as necessary. The method of superposing | polymerizing by conventionally well-known methods, such as superposition | polymerization, is mentioned. Of these, solution polymerization is preferred.

When the copolymer (C2) is produced by the solution polymerization method, examples of the solvent used include aliphatic alcohols such as methanol, ethanol, isopropanol and glycol; cellosolvs such as cellosolve and butylcellosolve; carbitol and butyl Carbitols such as carbitol; 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; A polar organic solvent such as dimethyl sulfoxide or dimethylformamide can be used.

Further, when the copolymer (C2) is produced by non-aqueous dispersion polymerization such as suspension polymerization, dispersion polymerization, emulsion polymerization, etc., as a medium to be used, for example, liquid such as benzene, toluene, hexane, cyclohexane, etc. Hydrocarbons and other nonpolar organic solvents can be used.

It does not specifically limit as a radical polymerization initiator used when manufacturing the said copolymer (C2), For example, conventionally well-known radical polymerization initiators, such as a peroxide and an azo initiator, can be used.
As the usage-amount of the said radical polymerization initiator, a preferable minimum is 0.001 weight part and a preferable upper limit is 5.0 weight part with respect to 100 weight part of all the monomer components of the said copolymer (C2), for example. Yes, a more preferred lower limit is 0.5 parts by weight, and a more preferred upper limit is 3.0 parts by weight.

Examples of the molecular weight regulator 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.

As the alkali-soluble polymer compound (C) having a reactive functional group, an alkali-soluble (meth) acrylic copolymer (C3) having an epoxy group in the side chain is also suitable. Examples of such a copolymer (C3) include copolymers of unsaturated carboxylic acids and / or unsaturated carboxylic acid anhydrides, epoxy group-containing unsaturated compounds, and other unsaturated compounds other than these ( C3-1).

It does not specifically limit as said unsaturated carboxylic acid and / or unsaturated carboxylic acid anhydride, For example, the thing similar to what is used with a copolymer (C2) is mentioned.
The amount of the unsaturated carboxylic acid and / or unsaturated carboxylic anhydride in the copolymer (C3-1) is not particularly limited, but a preferred lower limit is 5% by weight and a preferred upper limit is 40% by weight. When it is less than 5% by weight, it is difficult to dissolve in an alkaline aqueous solution, and when it exceeds 40% by weight, the solubility in an alkaline aqueous solution tends to be too large. A more preferred lower limit is 10% by weight, and a more preferred upper limit is 30% by weight.

The epoxy-containing unsaturated compound is not particularly limited. For example, glycidyl acrylate, glycidyl methacrylate, glycidyl α-ethyl acrylate, glycidyl α-n-propyl acrylate, glycidyl α-n-butyl acrylate, acrylic Acid-3,4-epoxybutyl, methacrylic acid-3,4-epoxybutyl, acrylic acid-6,7-epoxyheptyl, methacrylic acid-6,7-epoxyheptyl, α-ethylacrylic acid-6,7-epoxy Examples include heptyl, o-vinyl benzyl glycidyl ether, m-vinyl benzyl glycidyl ether, p-vinyl benzyl glycidyl ether and the like. Among them, glycidyl methacrylate, methacrylic acid-6,7-epoxyheptyl, o-vinylbenzyl glycidyl ether, m-vinylbenzyl glycidyl ether and p-vinylbenzyl glycidyl ether are copolymerization reactivity and strength of the obtained column spacer. It is preferably used from the standpoint of increasing. These may be used independently and 2 or more types may be used together.

The amount of the epoxy group-containing unsaturated compound in the copolymer (C3-1) is not particularly limited, but a preferred lower limit is 10% by weight and a preferred upper limit is 70% by weight. If it is less than 10% by weight, the strength of the obtained column spacer tends to be reduced, and if it exceeds 70% by weight, the storage stability of the copolymer (C3-1) tends to be lowered. A more preferred lower limit is 20% by weight, and a more preferred upper limit is 60% by weight.

The other unsaturated compound in the copolymer (C3-1) is not particularly limited, and examples thereof include methacrylic acid alkyl esters such as methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, sec-butyl methacrylate, and t-butyl methacrylate. Acrylic alkyl esters such as methyl acrylate and isopropyl acrylate; cyclic alkyl esters of methacrylic acid such as cyclohexyl methacrylate, 2-methylcyclohexyl methacrylate, dicyclopentanyl methacrylate, dicyclopentanyloxyethyl methacrylate, isobornyl methacrylate; cyclohexyl acrylate 2-methylcyclohexyl acrylate, dicyclopentanyl acrylate, dicyclopentaoxyethyl acrylate, Acrylic acid cyclic alkyl esters such as soboronyl acrylate; Methacrylic acid aryl esters such as phenyl methacrylate and benzyl methacrylate; Acrylic acid aryl esters such as phenyl acrylate and benzyl acrylate; Dicarboxylic acids such as diethyl maleate, diethyl fumarate and diethyl itaconate Diesters; hydroxyalkyl esters such as 2-hydroxyethyl methacrylate and 2-hydroxypropyl methacrylate; styrene, α-methylstyrene, m-methylstyrene, p-methylstyrene, vinyltoluene, p-methoxystyrene, acrylonitrile, methacrylonitrile, Vinyl chloride, vinylidene chloride, acrylamide, methacrylamide, vinyl acetate, 1,3-butadiene, isoprene, 2,3-dimethyl And 1,3-butadiene. Of these, styrene, t-butyl methacrylate, dicyclopentanyl methacrylate, p-methoxystyrene, 2-methylcyclohexyl acrylate, 1,3-butadiene and the like are preferable from the viewpoint of copolymerization reactivity and solubility in an aqueous alkali solution. . These may be used independently and 2 or more types may be used together.

Although it does not specifically limit as quantity of the said other unsaturated compound which occupies for the said copolymer (C3-1), A preferable minimum is 10 weight% and a preferable upper limit is 70 weight%. When the amount is less than 10% by weight, the storage stability of the copolymer (C3-1) tends to be lowered. When the amount exceeds 70% by weight, the copolymer (C3-1) is hardly dissolved in the alkaline aqueous solution. . A more preferred lower limit is 20% by weight, and a more preferred upper limit is 50% by weight.

The copolymer (C3-1) is a conventionally known radical polymerization of the unsaturated carboxylic acid and / or unsaturated carboxylic acid anhydride, an epoxy group-containing unsaturated compound, and other unsaturated compounds. It can be obtained by copolymerization in a solvent together with an initiator.

In the curable resin composition for column spacers of the present invention, the blending amount of the alkali-soluble polymer compound (C) is not particularly limited, but the preferred lower limit is 10 wt% in the solid content of the curable resin composition for column spacers. %, And a preferable upper limit is 90% by weight. If it is less than 10% by weight, it is difficult to impart alkali solubility to the curable resin composition for a column spacer of the present invention. If it exceeds 90% by weight, the flexibility that is a feature of the column spacer of the present invention is reduced. It becomes difficult to express. A more preferred lower limit is 20% by weight, and a more preferred upper limit is 60% by weight.

The curable resin composition for column spacers of the present invention contains a photoreaction initiator (D).
The photoreaction initiator is not particularly limited, and examples thereof include conventionally known photoreaction initiators such as benzoin, benzophenone, benzyl, thioxanthone, and derivatives thereof. 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 2 or more types may be used together.

In the curable resin composition for a column spacer of the present invention, the content of the photoreaction initiator is not particularly limited, but a preferable lower limit is 1% by weight and a preferable upper limit is 20% by weight. If it is less than 1% by weight, the curable resin composition for column spacers of the present invention may not be photocured, and if it exceeds 20% by weight, alkali development may not be possible in photolithography. A more preferred lower limit is 5% by weight, and a more preferred upper limit is 15% by weight.

The curable resin composition for column spacers of the present invention 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.

It is preferable that the curable resin composition for column spacers of the present invention further contains a compound (E) having two or more blocked isocyanate groups. The compound (E) having two or more blocked isocyanate groups functions as a thermal cross-linking agent. By containing such a compound (E) having two or more blocked isocyanate groups, the curability for a column spacer of the present invention is obtained. Thermosetting can be imparted to the resin composition.

The compound (E) 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 those obtained by blocking polyfunctional isocyanates comprising these oligomers with blocking agents such as active methylene, oxime, lactam, and alcohol. It is done. These compounds (E) having two or more blocked isocyanate groups may be used alone or in combination of two or more.

Examples of commercially available compounds (E) having two or more blocked isocyanate groups include Duranate 17B-60PX, Duranate E-402-B80T (manufactured by Asahi Kasei Chemicals). Can be mentioned.

When the curable resin composition for column spacers of the present invention contains the compound (E) having two or more blocked isocyanate groups, the blending amount thereof is 100 parts by weight of the alkali-soluble polymer compound (C). The preferred lower limit is 0.01 parts by weight and the preferred upper limit is 50 parts by weight. If it is less than 0.01 part by weight, the curable resin composition for a column spacer of the present invention may not be sufficiently cured by heat, and if it exceeds 50 parts by weight, the degree of crosslinking of the resulting cured product becomes too high. The elastic characteristics described later may not be satisfied. 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 for column spacers of the present invention may contain a fluorine-based surfactant (F) that is a compound having a structure represented by the following chemical formula (9) or (10).

In the chemical formulas (9) and (10), R ¹³ represents hydrogen or an alkyl group having 1 to 6 carbon atoms, and R ¹⁴ and R ¹⁵ each independently represents 1 to 20 linear or branched chain. Wherein at least 50% of the hydrogen atoms of the alkyl group represented by R ¹⁴ and R ¹⁵ are substituted with fluorine atoms, and k independently represents 1 to 6 , L represents 2-40.
The fluorosurfactant (F) is used as a so-called leveling agent, and the leveling agent having the above structure can exhibit a very high leveling effect even when added in a small amount. A column spacer excellent in height uniformity can be obtained from the curable resin composition for a column spacer of the present invention containing such a fluorosurfactant (F).
In addition, such a leveling agent is a compound (A) having two or more polymerizable unsaturated bonds in the molecule having the above-mentioned specific structure, in particular, two or more polymerizable groups in the molecule modified with caprolactone or the like. By using it in combination with the compound (A) having a saturated bond, the spacer height can be formed extremely uniformly for the column spacer having excellent flexibility and high compression recovery.

The fluorine-based surfactant (F) is not particularly limited as long as it is a compound having a structure represented by the chemical formula (9) or (10). For example, the fluorine-based surfactant (F) is represented by the chemical formula (9) or (10). It may be a block copolymer containing the structure as a polyfluorooxetane block.

As said fluorosurfactant (F), for example, it is supplied as a PolyFox series from Omninova Solsons Inc. Especially, in order to avoid the liquid-crystal contamination by ion, it is preferable that it is nonionic, for example, PF-636, PF-6320, PF-651, PF-652, PF-656, PF-6520, PF-151N, AT-1045, AT-1084, AT-1085, AT-1089 and the like are preferable.

Furthermore, it is preferable to have a polymerizable unsaturated bond at one or both ends of the polyether main chain structure of the fluorosurfactant (F). Since the fluorine-based surfactant (F) has a polymerizable unsaturated bond in the molecule, the fluorine-based surfactant (F) molecule also has a polymerization structure at the time of polymerization and curing of the curable resin composition for a column spacer of the present invention. Contamination due to elution into the liquid crystal of the fluorosurfactant (F) can be significantly reduced. Examples of such a fluorosurfactant (F) include AT-1005 and PF-3320 in the PolyFox series.

In the curable resin composition for column spacers of the present invention, the blending amount of the fluorosurfactant (F) is not particularly limited, but in the curable resin composition for column spacers, the preferred lower limit is 0.01% by weight. The preferred upper limit is 1.0% by weight. If it is less than 0.01% by weight, the leveling effect of the curable resin composition for a column spacer of the present invention described above may be insufficient, and if it exceeds 1.0% by weight, the liquid crystal may be contaminated. There is. A more preferred lower limit is 0.05% by weight, and a more preferred upper limit is 1.0% by weight.

The curable 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 curable resin composition for a column spacer of the present invention, coating method, film uniformity during drying, drying efficiency, etc. When the curable resin composition for column spacers of the invention is applied using a spin coater or slit coater, for example, methyl cellosolve, ethyl cellosolve, ethyl cellosolve acetate, diethylene glycol dimethyl ether, propylene glycol monoethyl ether acetate An organic solvent such as isopropyl alcohol is preferred. These diluents may be used alone or in combination of two or more.

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

Since the curable resin composition for column spacers of the present invention contains the epoxy (meth) acrylate compound (B), the curable resin composition for column spacers has sufficient flexibility and is capable of being compressed and deformed. Excellent buckling strength. Furthermore, when the compound (A) having two or more polymerizable unsaturated bonds is contained in the molecule modified with caprolactone, ethylene oxide and / or propylene oxide, the curable resin composition for a column spacer of the present invention is In addition, it is possible to manufacture a column spacer that achieves both high recovery from compression deformation and flexibility and low elastic modulus. By using such a column spacer, low-temperature foaming does not occur, resulting in poor gravity. A liquid crystal display element in which the occurrence of color unevenness is effectively suppressed can be obtained.

The curable resin composition for column spacers of the present invention is cured by light irradiation (and heating), and the preferable lower limit of the buckling strength of the cured product when the bottom area is 100 μm ² and the height is 3.0 μm is 30 mN. It is. When the pressure is less than 30 mN, when a pressure is applied to the obtained liquid crystal display element, the column spacer using the curable resin composition for a column spacer of the present invention is cramped, resulting in disturbance in the liquid crystal alignment. May get worse. A more preferred lower limit is 40 mN, and a still more preferred lower limit is 50 mN.

In the present specification, the cured product means a cured product when the column spacer curable resin composition of the present invention is almost completely cured by light irradiation (and heating). The conditions for almost complete curing are that at least 50 mJ / cm ² of ultraviolet light is irradiated, and when heating, the film can be cured almost completely by applying a heat treatment at a temperature of 200 to 250 ° C. for about 20 minutes. .
Further, in this specification, the buckling strength refers to the magnitude of the load corresponding to the position of the shoulder of the hysteresis curve measured by the following method with respect to the relationship between the load and the deformation (hereinafter referred to as the buckling load). Say). Furthermore, the recovery rate was also measured by the following method.
That is, first, a load is applied to the column spacer formed on the substrate at a speed of 10 mN / s, and the column spacer is compressed until a predetermined load is reached. Here, the column spacer height when a load of 1 mN is applied is H ₁ , and the column spacer height when compressed to reach a predetermined load is H ₂ , and the load when the column spacer height 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 speed of 10 mN / sec, and the recovery deformation of the column spacer height due to elastic recovery is measured. The height of the column spacer at the time when the compression deformation during this time becomes maximum is H _3, and the height of the column spacer when a load of 1 mN in the process of recovering the deformation of the column spacer is applied is H ₄ . The recovery rate can be calculated by the following formula (1).

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

In such a curable resin composition for a column spacer of the present invention, a preferable lower limit of the elastic modulus at 15% compression at 25 ° C. of the cured product when cured by light irradiation (and heating) is preferably 0.2 GPa. The upper limit is 1.0 GPa. If it is less than 0.2 GPa, the column spacer using the curable resin composition for a column spacer of the present invention may be difficult to maintain a cell gap. Thus, the color filter layer may be plunged when the substrates are bonded using the curable resin composition for column spacers of the present invention, or sufficient elastic deformation necessary for recovery 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.

Further, in this specification, 15% compression means compression so that the deformation rate of the height of the column spacer is 15%. Further, the elastic modulus and the 15% compression recovery rate were measured by the following methods.
That is, first, the column spacer formed on the substrate is compressed by applying a load at a speed of 10 mN / s until it reaches a height corresponding to 85% of the initial height H ₀ . Here, the column spacer height when a load of 1 mN is applied is H ₁ , and the column spacer height corresponding to 85% of H ₀ is H ₂ , and the load when F ₂ is reached is H. Next, the load F is held for 5 seconds, and after deformation at a constant load, the load is removed at a speed of 10 mN / sec, and the recovery deformation of the column spacer height due to elastic recovery is measured. The height of the column spacer at the time when the compression deformation during this time becomes maximum is H _3, and the height of the column spacer when a load of 1 mN in the process of recovering the deformation of the column spacer is applied is H ₄ . The elastic coefficient and the 15% compression recovery rate can be calculated by the following formula (2) and the following formula (3).

Elastic modulus E = F / (D × S) (2)
15% compression recovery rate R = (H ₄ −H ₃ ) / (H ₁ −H ₃ ) × 100 (3)

In formula (2), 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 method for producing the curable resin composition for column spacers of the present invention is not particularly limited. For example, the above-described compound (A) having two or more polymerizable unsaturated bonds in the molecule, epoxy (meth) acrylate compound (B), an alkali-soluble polymer compound (C), a photoreaction initiator (D), and a compound (E) having two or more blocked isocyanate groups added as necessary, a fluorine-based surfactant (F ), A method of mixing a diluent or the like by a conventionally known method.

Next, a method for producing a column spacer using the curable resin composition for a column spacer of the present invention will be described.
When producing a column spacer using the curable resin composition for a column spacer of the present invention, first, the curable resin composition for a column spacer of the present invention is applied onto a substrate so as to have a predetermined thickness. To form a film.
The coating method is not particularly limited, and for example, conventionally known coating methods such as spin coating, slit & spin, slit coating, spray coating, dip coating, and bar coating can be used.

Next, actinic rays such as ultraviolet rays are irradiated on the formed film through a mask on which a predetermined pattern is formed. Thereby, in a light irradiation part, the alkali-soluble high molecular compound and photoinitiator which are contained in the curable resin composition for column spacers of this invention react and are photocured.
The irradiation amount of the actinic ray is not particularly limited, but is preferably 50 mJ / cm ² or more in the case of ultraviolet rays. If it is less than 50 mJ / cm ² , the photocuring is insufficient and the subsequent alkali treatment may dissolve the exposed area and a pattern may not be formed.

Next, the photocured product after photocuring is alkali-developed to form a column spacer having a predetermined pattern made of the photocured product of the curable resin composition for column spacers of the present invention on the substrate.
Since the curable resin composition for column spacers of the present invention contains the epoxy (meth) acrylate compound (B) having the specific structure described above, it has sufficient flexibility and excellent buckling strength. Column spacers can be formed. Moreover, when it contains the compound (A) which has a 2 or more polymerizable unsaturated bond in the molecule | numerator modified | denatured by caprolactone modification, ethylene oxide modification, and / or propylene oxide mentioned above, the curable resin composition for column spacers of this invention The product can be such that the cured product has high recovery from compression deformation and is flexible and has a low elastic modulus.

When the curable resin composition for a column spacer of the present invention contains a compound (E) having two or more blocked isocyanate groups, by further heating the patterned photocured product after the development treatment, The alkali-soluble polymer compound to be contained reacts with the compound (E) having two or more blocked isocyanate groups.
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.
A column spacer using the curable resin composition for a column spacer of the present invention is also one aspect of the present invention.

In the column spacer of the present invention, the preferable lower limit of the buckling strength when the bottom area is 100 μm ² and the height is 3.0 μm is 30 mN. When the pressure is less than 30 mN, when pressure is applied to the obtained liquid crystal display element, the column spacer is crooked, so that the liquid crystal alignment is disturbed and the image quality may be deteriorated. A more preferred lower limit is 40 mN, and a still more preferred lower limit is 50 mN.

In the column spacer of the present invention, the preferable lower limit of the elastic modulus at 15% compression at 25 ° C. is 0.2 GPa, and the preferable upper limit is 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.

By using the curable resin composition for a column spacer of the present invention or the column spacer of the present invention, a liquid crystal display element that does not deteriorate image quality even when pressure is applied can be produced.
The curable resin composition for column spacers of the present invention or a liquid crystal display device using the column spacers of the present invention is also one aspect of the present invention.

The curable resin composition for column spacers of the present invention can improve the flexibility of the column spacers obtained and have excellent buckling strength. According to such a curable resin composition for column spacers, it is possible to provide a liquid crystal display element in which image quality does not deteriorate even when pressurized.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.

(Examples 1-7, Comparative Example 1)
(1) Preparation of alkali-soluble polymer compound solution A 3 L separable flask was charged with 60 parts by weight of DEGDME (diethylene glycol dimethyl ether) as a solvent, heated to 90 ° C. in a nitrogen atmosphere, and then 10 mg of methyl methacrylate. 3 parts by weight, 8 parts by weight of methacrylic acid, 12 parts by weight of n-butyl methacrylate, 10 parts by weight of 2-ethylhexyl acrylate, 0.4 parts by weight of azobisvaleronitrile, and 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 high molecular compound solution (solid content rate of 40 weight%) was obtained.
When the alkali-soluble polymer compound was sampled from the obtained alkali-soluble polymer compound solution and the molecular weight was measured by gel permeation chromatography (GPC), the weight average molecular weight (Mw) was about 20,000.

(2) Preparation of Curable Resin Composition for Column Spacer Using the obtained alkali-soluble polymer compound solution, a mixed composition composed of raw materials in the weight ratio shown in Table 1 below was mixed by a conventionally known method. The curable resin compositions for column spacers according to Examples 1 to 7 and Comparative Example 1 were prepared.
In Table 1, “A-SA-TMM” is carboxylic acid-added caprolactone-modified tetramethylolmethane triacrylate (1 mol of a compound obtained by reacting 1 mol of tetramethylolmethane with 8 mol of caprolactone and 3 mol of acrylic acid as an ester. Prototype in which 1 mol of tetrahydrocarboxylic anhydride was added to the hydroxyl group of the compound reacted by chemical conversion), “I-907” is Irgacure 907 (manufactured by Ciba Specialty Chemicals), “DETX-S” is Kayacure DETX-S (Japan) “EDB” is Speedcure EDB (Nihon Shibel Hegner), “PCR-1157H” is a phenol novolac acid-modified epoxy acrylate (Nippon Kayaku), and “EA-7120” is a cresol novolac epoxy acrylate. , "EA-714 ”Is a cresol novolac type carboxylic anhydride modified epoxy acrylate,“ EA-7420 ”is a cresol novolac type epoxy acrylate,“ EA-7440 ”is a cresol novolac type carboxylic anhydride modified epoxy acrylate, and“ EA-6320 ”is a phenol novolak. Type epoxy acrylate, “EA-6340” is a phenol novolac carboxylic anhydride modified epoxy acrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.), and “DEGDME” is diethylene glycol dimethyl ether.

(3) Preparation of column spacers On the glass substrate on which a transparent conductive film of 150 mm × 150 mm was formed, the obtained curable resin compositions for column spacers according to Examples 1 to 7 and Comparative Example 1 were applied by spin coating. And dried at 100 ° C. for 2 minutes to obtain a coating film. The obtained coating film was irradiated with 300 mJ / cm ² ultraviolet rays through an 8 μm square dot pattern mask, developed with 0.04% KOH solution for 80 seconds, washed with pure water for 30 seconds, and then column spacers. Pattern was formed.
Thereafter, a baking process was performed at 220 ° C. for 30 minutes to prepare a column spacer. The obtained column spacer had a bottom area of 100 μm ² and a height of 3 μm.

(Evaluation)
The column spacers obtained in Examples 1 to 7 and Comparative Example 1 were evaluated by the following methods.
The results are shown in Table 2.

(Evaluation of column spacer)
(1) The presence or absence of a development residue was observed with a developable optical microscope and evaluated according to the following criteria.
○: No development residue △: Development residue is slightly seen ×: Development residue is seen

(2) 40 mN load recovery rate (%) measurement temperature In a chamber adjusted to 25 ° C., the column spacer was compressed by applying a load at a speed of 10 mN / s to a load of 40 mN. Here, the column spacer height when a load of 10 mN was applied was H ₁ , and the column spacer height when the load reached 40 mN was H ₂ . Next, a load of 40 mN was held for 5 seconds, and after applying deformation at a constant load, the load was removed at a speed of 10 mN / sec, and recovery deformation of the column spacer height due to elastic recovery was measured. The height of the column spacer at the time when the compressive deformation during this period became 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 each of the obtained values, a 40 mN load recovery rate (%) was calculated by the above formula (1).

(3) Measurement of 500 mN load recovery rate (%) A 500 mN load recovery rate (%) was calculated in the same manner as the measurement of 40 mN load recovery rate (%) except that a load was applied up to 500 mN.

(4) Measurement of buckling load (mN) The buckling load (mN) was obtained from the hysteresis curve related to the relationship between the load obtained in the evaluations (2) and (3) and the deformation of the column spacer. . The hysteresis curve obtained about the column spacer obtained by each Example and the comparative example was shown in FIGS.

According to the present invention, a curable resin composition for a column spacer capable of forming a column spacer having sufficient flexibility and excellent buckling strength, and the column spacer curable resin composition are used. A column spacer and a liquid crystal display element can be provided.

2 is a hysteresis curve obtained by applying a load of 40 mN to the column spacer produced in Example 1. FIG. 2 is a hysteresis curve obtained by applying a load of 500 mN to the column spacer produced in Example 1. FIG. 6 is a hysteresis curve obtained by applying a load of 40 mN to the column spacer produced in Example 2. FIG. 4 is a hysteresis curve obtained by applying a load of 500 mN to the column spacer produced in Example 2. FIG. 6 is a hysteresis curve obtained by applying a load of 40 mN to the column spacer produced in Example 3. FIG. 4 is a hysteresis curve obtained by applying a load of 500 mN to the column spacer produced in Example 3. FIG. 6 is a hysteresis curve obtained by applying a load of 40 mN to the column spacer produced in Example 4. FIG. 6 is a hysteresis curve obtained by applying a load of 500 mN to the column spacer produced in Example 4. FIG. 6 is a hysteresis curve obtained by applying a load of 40 mN to the column spacer produced in Example 5. FIG. 6 is a hysteresis curve obtained by applying a load of 500 mN to the column spacer produced in Example 5. FIG. 6 is a hysteresis curve obtained by applying a load of 40 mN to the column spacer produced in Example 6. FIG. 6 is a hysteresis curve obtained by applying a load of 500 mN to the column spacer produced in Example 6. FIG. 6 is a hysteresis curve obtained by applying a load of 40 mN to the column spacer produced in Example 7. FIG. 6 is a hysteresis curve obtained by applying a load of 500 mN to the column spacer produced in Example 7. FIG. 6 is a hysteresis curve obtained by applying a load of 40 mN to the column spacer produced in Comparative Example 1. FIG. 5 is a hysteresis curve obtained by applying a load of 500 mN to the column spacer produced in Comparative Example 1. FIG.

Claims (6)

For column spacers containing a compound (A) having two or more polymerizable unsaturated bonds in the molecule, an epoxy (meth) acrylate compound (B), an alkali-soluble polymer compound (C) and a photoreaction initiator (D) A curable resin composition comprising:
The said epoxy (meth) acrylate compound (B) is a compound which has a structure represented by following Chemical formula (1), The curable resin composition for column spacers characterized by the above-mentioned.

In the formula, R ¹ and R ² represent hydrogen or a methyl group, R ³ represents an atomic group derived from a polybasic acid anhydride and having a carboxyl group, and m and n represent 0 or a positive integer. The curable resin composition for a column spacer according to claim 1, wherein the epoxy (meth) acrylate compound (B) is an acid-modified epoxy (meth) acrylate compound. The column according to claim 1 or 2, wherein the compound (A) having two or more polymerizable unsaturated bonds in the molecule is a methacrylate compound modified with caprolactone, ethylene oxide and / or propylene oxide. Curable resin composition for spacers. Furthermore, the compound (E) which has a 2 or more block isocyanate group contains, The curable resin composition for column spacers of Claim 1, 2, or 3 characterized by the above-mentioned. A column spacer comprising the curable resin composition for a column spacer according to claim 1, 2, 3 or 4. A curable resin composition for a column spacer according to claim 1, 2, 3, or 4, or a column spacer according to claim 5 is used.

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