JP2009008755A - 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 a pattern width in a desired size can be formed while suppressing pattern thickening without decreasing sensitivity to irradiation light, and to provide a column spacer and a liquid crystal display element using the curable resin composition for a column spacer. <P>SOLUTION: The curable resin composition for a column spacer contains an alkali-soluble polymer compound having a reactive functional group, a compound having at least two polymerizable unsaturated bonds in the molecule, a photo-reaction initiator and a UV absorbent, wherein the UV absorbent has an absorption band at wavelengths of 330 to 400 nm. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention relates to a curable resin composition for a column spacer that can form a column spacer having a pattern width of a desired size without reducing the sensitivity to irradiation light and suppressing pattern thickening, and the column spacer. The present invention relates to a column spacer using a 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, 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.

Such column spacers are conventionally manufactured by a so-called photolithography process in which a curable resin composition is applied onto a substrate to form a coating film, and the coating film is exposed and developed through a mask. .
However, when a column spacer is formed using a conventional curable resin composition, a so-called “pattern thickening” occurs in which a column spacer having a size larger than a desired spacer width is generated depending on an exposure method and exposure conditions. Column spacers of the size could not be manufactured.
JP 2001-91954 A JP 2001-159707 A

The present invention relates to a curable resin composition for a column spacer that can form a column spacer having a pattern width of a desired size without reducing the sensitivity to irradiation light and suppressing pattern thickening, and the column spacer. It aims at providing the column spacer and liquid crystal display element which use a curable resin composition.

The present invention relates to a curable resin for a column spacer containing an alkali-soluble polymer compound having a reactive functional group, a compound having two or more polymerizable unsaturated bonds in the molecule, a photoreaction initiator, and an ultraviolet absorber. It is a composition, Comprising: The said ultraviolet absorber is curable resin composition for column spacers which have an absorption band in wavelength 330-400 nm.
The present invention is described in detail below.

As a result of intensive studies, the inventors of the present invention have determined that “pattern thickening” means that light that has passed through the mask pattern is irradiated when light is applied to the coating film formed on the substrate through the mask on which the predetermined pattern is formed. It was found that diffraction occurred and the curing reaction of the coating film progressed at the location irradiated with diffracted light. Therefore, as a result of further intensive studies, as a curable resin composition for column spacers, by adding an ultraviolet absorber having a specific absorption band, a column spacer having a desired spacer width that suppresses pattern weighting by photolithography processing is obtained. As a result, the present invention has been completed.

The curable resin composition for column spacers of the present invention contains an ultraviolet absorber.
The ultraviolet absorber has an absorption band at a wavelength of 330 to 400 nm. Although the upper limit and lower limit of the wavelength of the absorption band are not particularly limited, the preferable upper limit of the absorbance at a wavelength of 400 nm or more is 0.05.
In addition, when hardening the curable resin composition for column spacers of this invention, it is normally exposed with the light containing an emission line spectrum of 365 nm (i line).
By containing an ultraviolet absorber having an absorption band in the above range, the curable resin for a column spacer of the present invention has a column spacer having a desired pattern width that suppresses pattern weighting by photolithography without reducing exposure sensitivity. Can be formed. This is considered to be due to the following reasons.

That is, when the column spacer is manufactured by photolithography, it is difficult to avoid that the light passing through the mask pattern is diffracted. However, the direct light that has passed through the mask pattern without being diffracted and the diffracted light have different irradiation amounts on the coating film, and the direct light generally has a larger irradiation amount than the diffracted light. Even when the coating film formed using the curable resin composition for a column spacer of the present invention is irradiated with light (ultraviolet rays) through a mask, the irradiation region of the direct light passing through the mask pattern is diffracted. The amount of light irradiation is greater than the light irradiation region.
Usually, in proximity exposure, which is a method of performing exposure at an equal magnification with the mask close to the resist surface (with the mask slightly floated on the resist), in order to suppress pattern thickening with respect to the mask diameter, A method of suppressing the spread of diffracted light by reducing the distance (proximity gap) between the mask and the coating film of the curable resin composition is taken, but if the gap between the mask and the coating film becomes small, the mask is soiled. There is a problem that the risk of being increased.
In addition, there is a method of reducing the amount of photopolymerization initiator added and suppressing the cross-linking reaction with diffracted light that reduces the amount of irradiation to make pattern thickening difficult. However, this method generally decreases the sensitivity. End up.
On the other hand, high-pressure mercury lamps used in general exposure equipment are designed to increase the efficiency of the reaction by combining photopolymerization initiators that have absorption in each emission line based on the emission line spectra of 365 nm, 405 nm, and 436 nm. Is done.
Among these, since the bright line (i-line) having a wavelength of 365 nm has high energy, it has a great influence on the pattern thickness due to diffraction. Therefore, in the curable resin composition for a column spacer of the present invention containing the ultraviolet absorber, By controlling the reactivity due to i-line, pattern thickening can be suppressed without reducing the amount of photopolymerization initiator added.
That is, in the coating film of the curable resin composition for column spacers of the present invention, since the absorption of light having a wavelength of 365 nm by the UV absorber is small on the surface, the crosslinking reaction by the photopolymerization initiator sufficiently proceeds and high sensitivity is obtained. can get. On the other hand, in the deep part of the coating film of the curable resin composition for column spacers of the present invention, the intensity of the 365 nm light that reaches is weakened by absorption of the ultraviolet absorber, and as a result, the cross-linking reaction due to diffracted light is suppressed, resulting in pattern thickening. Is considered to be difficult to occur.
Therefore, the curable resin for column spacers of the present invention can sufficiently cure only the direct light irradiation region (that is, the region corresponding to the mask pattern) at the time of exposure of the photolithography process, and suppresses pattern fatness. It is considered that column spacers having a desired pattern width can be formed.

If the absorption band of the ultraviolet absorber is out of the above range, the light irradiated for curing the curable resin composition for a column spacer of the present invention cannot be absorbed, and the suppression of the photocuring reaction by the diffracted light described above is not possible. It will be enough.

The ultraviolet absorber is not particularly limited as long as it has an absorption band in the above-mentioned range, and among them, a benzotriazole compound and / or a benzophenone series having an absorption band in the above-mentioned range as an easily available ultraviolet absorber. A compound is preferably used.

Examples of the benzotriazole-based compound include a compound having a structure represented by the following general formula (1) and / or 2- (2H-benzotriazol-2-yl) -4-methyl-6- (3,4) , 5,6-tetrahydrophthalimidylmethyl) phenol is preferably used.

In the general formula (1), R ^{1 to} R ⁵ each independently represent hydrogen, an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or 1 to 20 carbon atoms. Represents a benzoyloxy group or a hydroxyl group.

Specific examples of such benzotriazole compounds include 2- (2-hydroxy-5-methylphenyl) -2H-benzotriazole, 2- (3-t-butyl-2-hydroxy-5- Methylphenyl) -5-chloro-2H-benzotriazole, 2- (3,5-di-t-pentyl-2-hydroxyphenyl) -2H-benzotriazole, 2- (2-hydroxy-4-octyloxyphenyl) -2H-benzotriazole, 2- (2-hydroxy-5-t-octylphenyl) -2H-benzotriazole, and the like. These benzotriazole compounds may be used alone or in combination of two or more.

As the benzophenone compound, for example, a compound having a structure represented by the following general formula (2) and / or 1,4-bis (4-benzoyl-3-hydroxyphenoxy) -butane is preferably used.

In the general formula (2), R ^{6 to} R ¹⁵ each independently represent hydrogen, an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or 1 to 20 carbon atoms. Represents a benzoyloxy group or a hydroxyl group.

Specific examples of such benzophenone compounds include 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid trihydrate, 2-hydroxy-4-octyloxybenzophenone, 4-dodecyloxy-2-hydroxybenzophenone, 4-benzyloxy-2-hydroxybenzophenone, 2,2'4,4'-tetrahydroxybenzophenone, 2,2'-dihydroxy- 4,4′-dimethoxybenzophenone and the like can be mentioned. These benzophenone compounds may be used alone or in combination of two or more.

In the curable resin composition for a column spacer of the present invention, the blending amount of the ultraviolet absorber is not particularly limited, but a preferable lower limit is 0.5% by weight and a preferable upper limit is 10.0% by weight. If it is less than 0.5% by weight, the above-described “pattern thickening” suppressing effect of the curable resin composition for a column spacer of the present invention cannot be obtained, and if it exceeds 10.0% by weight, curability at the time of exposure is increased. May decrease. A more preferred lower limit is 1.0% by weight, and a more preferred upper limit is 7.0% by weight.

The curable resin composition for column spacers of the present invention contains an alkali-soluble polymer compound having a reactive functional group.
The alkali-soluble polymer compound having a reactive functional group 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 which has a reactive functional group used for the curable resin composition for column spacers of this invention, Carboxylic acid or dicarboxylic acid anhydride or carboxylate in a molecular chain By containing, a polymer compound having solubility in an aqueous solution such as potassium hydroxide, sodium hydroxide, sodium carbonate, tetramethylammonium hydroxide is preferable.
As such an alkali-soluble polymer compound, for example, an alkali-soluble carboxyl group-containing polymer compound such as a copolymer obtained by copolymerizing a carboxyl group-containing monofunctional unsaturated compound and a monofunctional compound having an unsaturated double bond 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. In the present specification, (meth) acrylic acid means acrylic acid or methacrylic acid.

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.

The alkali-soluble polymer compound is particularly preferably an alkali-soluble (meth) acrylic copolymer (A1) having a (meth) acryl group and a carboxyl group in the side chain.
As the alkali-soluble (meth) acrylic copolymer (A1) 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 (A1-1) is preferred.

The polymer (A1-1) is prepared by adjusting the amount of radical polymerizable group-containing isocyanate compound so that the equivalent ratio (NCO / OH) is 1.0 or more, whereby the side chain of the radical polymerizable group is changed. 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 (A1-1), 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 having a reactive functional group, and particularly high sensitivity is 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 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 is not particularly limited, and is appropriately determined depending on the degree of alkali solubility required for the alkali-soluble polymer compound having a reactive function. Adjusted. 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 (3) is preferable.

R ¹⁶ contained in the chemical formula (3) 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 (3), 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 (4) is preferable.

In the chemical formula (4), R ¹⁶ is the same as R ^{16 in the} chemical formula (3), and R ¹⁷ represents an alkylene group having 2 to 4 carbon atoms. Examples of R ¹⁷ 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 (4), 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 (A1-1) contains a structural unit such as chemical formula (3) having an acidic functional group and a structural unit such as chemical formula (4) 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 carbocycle is not particularly limited, and for example, a structural unit represented by the following chemical formula (5) is preferable.

In the chemical formula (5), R ¹⁶ is the same as R ^{16 in the} chemical formula (3), and R ¹⁸ represents an aromatic carbocycle. Examples of R ¹⁸ include a phenyl group and a naphthyl group.

The monomer used for introducing the structural unit of the chemical formula (5) 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. A structural unit represented by the following chemical formula (6) is preferred.

In the chemical formula (6), R ¹⁶ is the same as R ^{16 in the} chemical formula (3), and R ¹⁹ represents an alkyl group or an aralkyl group. Examples of such R ¹⁹ 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 (6) 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, (meth) acryloyloxyalkyl isocyanate shown to following Chemical formula (7) is suitable.

In the chemical formula (7), R ²⁰ represents an alkylene group, and R ²¹ represents hydrogen or methyl. Of the (meth) acryloyloxyalkyl isocyanates represented by the chemical formula (7), 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 chemical formula (3) having an acidic functional group and a constitutional unit such as chemical formula (4) having a hydroxyl group, and if necessary, aromatics. A polymer (raw polymer) having a main chain containing a structural unit such as chemical formula (5) having a carbon ring, a structural unit such as chemical formula (6) 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 (3) to (6) and a composition composed of a catalyst are mixed in a polymerization tank containing a solvent in an amount 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 weight average molecular weight in terms of polystyrene (hereinafter simply referred to as “weight average molecular weight” or “Mw”) of the raw material polymer having the structural units of the above chemical formulas (3) to (6) 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 to the acidic functional group in the raw material polymer via an isocyanate. For example, a part of the structural unit represented by the chemical formula (3) releases carbon dioxide and is bonded by an amide bond to form a structural unit represented by the following chemical formula (8).
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 of the above chemical formula (4) is subjected to an addition reaction and bonded by a urethane bond to form a structural unit represented by the structural unit of the following chemical formula (9).

The polymer thus obtained has a radically polymerizable group in a structural unit such as chemical formula (3) having an acidic functional group, a structural unit such as chemical formula (4) having a hydroxyl group, and a structural unit having an acidic functional group. And a structural unit such as chemical formula (9) in which a radical polymerizable group is introduced into a structural unit of chemical formula (4) having a hydroxyl group and a structural unit such as chemical formula (8) in which is introduced are linked in an arbitrary order. Has a molecular structure.

As said alkali-soluble (meth) acrylic copolymer (A1), the copolymer (A1) which consists of a structural unit represented by following formula (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 ²² represents hydrogen and / or a methyl group, R ²³ 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 ²⁴ represents a nitrile. R ²⁵ 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 containing such a copolymer (A1-2), 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 (A1-2) 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 (A1-2), 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 (A1-2) is represented by the above formula (2b) and the above formula (2b). R ²⁵ 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 ^25. From the above, it is preferable that A ¹ and A ² in the copolymer (A1-2) 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 (A1-2), 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 (A1-2), 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 (A1-2) 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 having a reactive functional group, a copolymer (A2) containing an unsaturated carboxylic acid and / or an unsaturated carboxylic acid anhydride and a blocked isocyanate group-containing unsaturated compound is also suitable. is there. The column spacer produced using the curable resin composition for a column spacer of the present invention containing the copolymer (A2) 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. In other words, in the post-baking process when manufacturing the column spacer, the blocked isocyanate group and carboxyl group (and hydroxyl group) in the alkali-soluble polymer compound react to suppress the plasticizer-like behavior of the alkali-soluble polymer compound. This is considered to be because plastic deformation in compression deformation of the column spacer to be manufactured is suppressed.

The unsaturated carboxylic acid and / or unsaturated carboxylic acid anhydride in the copolymer (A2) 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 (A2), 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 (A2) 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 (A2), 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 (A2) is further preferably a copolymer 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 (A2) include (meth) acrylic acid hydroxyalkyl esters such as (meth) acrylic acid 2-hydroxyethyl and (meth) acrylic acid 2-hydroxypropyl. Can be mentioned.

Although it does not specifically limit as a structural ratio of the said hydroxyl-containing unsaturated compound in the said copolymer (A2), 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. A more preferred upper limit is 30% by weight.

Furthermore, the copolymer (A2) 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 (A2), 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 (A2) 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 (A2) is produced by the solution polymerization method, examples of the solvent used include aliphatic alcohols such as methanol, ethanol, isopropanol and glycol; cellosolves 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 (A2) 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 (A2), 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 with respect to 100 weight part of all the monomer components of the said copolymer (A2), for example, and a preferable upper limit is 5.0 weight part. 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 having a reactive functional group, an alkali-soluble (meth) acrylic copolymer (A3) having an epoxy group in the side chain is also suitable. Examples of such a copolymer (A3) include copolymers of unsaturated carboxylic acids and / or unsaturated carboxylic acid anhydrides, epoxy group-containing unsaturated compounds, and other unsaturated compounds other than these ( A3-1).

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 (A2) is mentioned.
The amount of the unsaturated carboxylic acid and / or unsaturated carboxylic acid anhydride in the copolymer (A3-1) 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 (A3-1) 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 (A3-1) 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 (A3-1) 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, and 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 (A3-1), 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 (A3-1) tends to be lowered. When the amount exceeds 70% by weight, the copolymer (A3-1) 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 (A3-1) 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 having a reactive functional group is not particularly limited, but the solid content of the curable resin composition for column spacers of the present invention is not limited. On the other hand, the preferred lower limit is 10% by weight and the preferred 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 column spacers of the present invention. If it exceeds 90% by weight, the curable resin composition for column spacers of the present invention Curability may be insufficient, and pattern thickening may not be sufficiently suppressed. 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 compound 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 having two or more polymerizable unsaturated bonds in the molecule contains two or more compounds in the caprolactone-modified, ethylene oxide-modified and / or propylene oxide-modified molecule. A compound having a polymerizable unsaturated bond (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. . Further, 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.

In addition, 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. Examples thereof include compounds obtained by modifying the above-described trifunctional or higher functional (meth) acrylate compounds 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 EBR suitability and flexibility of the column spacer obtained using the curable resin composition for a column spacer 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 having two or more polymerizable unsaturated bonds in the molecule has two or more polymerizable unsaturated bonds in the aforementioned caprolactone-modified, ethylene oxide-modified and / or propylene oxide-modified molecule, 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, trimethylolethane di (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 preferable 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 a photoreaction initiator.
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 having two or more blocked isocyanate groups. The compound having two or more blocked isocyanate groups functions as a thermal cross-linking agent. By containing such a compound having two or more blocked isocyanate groups, the curable resin composition for column spacers of the present invention is thermally cured. Sex can be imparted.

The compound having two or more blocked isocyanate groups is not particularly limited. For example, tolylene diisocyanate, 4,4-diphenylmethane diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, methylene bis (4-cyclohexyl isocyanate), trimethyl. Examples thereof include those obtained by blocking hexamethylene diisocyanate and polyfunctional isocyanates composed of these oligomers with blocking agents such as active methylene, oxime, lactam, and alcohol. These compounds having two or more blocked isocyanate groups may be used alone or in combination of two or more.

Moreover, as what is marketed among the compounds which have such a 2 or more block isocyanate group, Duranate 17B-60PX, Duranate E-402-B80T (above, Asahi Kasei Chemicals make) etc. are mentioned, for example.

When the curable resin composition for column spacers of the present invention contains a compound having two or more blocked isocyanate groups, the blending amount thereof is based on 100 parts by weight of the alkali-soluble polymer compound (A). A preferred lower limit is 0.01 parts by weight and a 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 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 a column spacer of the invention is applied using a spin coater or a 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 a column spacer of the present invention contains the above-described ultraviolet absorber, the column has a pattern width of a desired size without reducing the sensitivity to irradiation light and suppressing pattern weighting. Spacers can be formed.
Further, when the curable resin composition for a column spacer of the present invention contains the above-mentioned compound modified with caprolactone as a compound having two or more polymerizable unsaturated bonds in the molecule, the curing for the column spacer of the present invention is performed. Can produce column spacers that are both highly recoverable from compression deformation and flexible and have a low elastic modulus. If such column spacers are used, low-temperature foaming can occur. In addition, a liquid crystal display element that effectively suppresses the occurrence of color unevenness due to poor gravity can be obtained.

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. When the compound having two or more polymerizable unsaturated bonds in the molecule contains the above-described compound modified with caprolactone, the elastic modulus of the cured product can be in the above range.

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 completely curing the curable resin composition for column spacers of the present invention include, for example, irradiation with at least 50 mJ / cm ² of ultraviolet rays, and heat treatment at a temperature of 200 to 250 ° C. for about 20 to 60 minutes. The condition to add is mentioned.
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 recovery rate are measured by the following methods.
That is, first, a column spacer formed on the substrate is compressed at a load application rate of 10 mN / s, is compressed to 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 , the column spacer height corresponding to 85% of H ₀ is H ₂ , and the load when F ₂ reaches H ₂ is F. Next, the load F is held for 5 seconds, and after deformation at a constant load, the load is removed at a load application speed of 10 mN / sec, and the recovery deformation of the column spacer height due to elastic recovery is measured. The 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 is applied in the process of recovering the deformation of the column spacer is H ₄ . The elastic count and the recovery rate can be calculated by the following formula (1) and the following formula (2).

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

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

The method for producing the curable resin composition for column spacers of the present invention is not particularly limited. For example, the alkali-soluble polymer compound described above, a compound having two or more polymerizable unsaturated bonds in the molecule, photoreactivity Examples thereof include a method in which an initiator, an ultraviolet absorber, a compound having two or more blocked isocyanate groups added as necessary, a diluent and the like are mixed 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 the direct light irradiation part which passed through the mask without diffracting, the alkali-soluble polymer compound contained in the curable resin composition for a column spacer of the present invention and the photoreaction initiator react to react with light. Harden. On the other hand, in the irradiation part of the diffracted light which diffracted the mask, the photocuring reaction is suppressed by the action of the ultraviolet absorbent contained in the curable resin composition for column spacers of the present invention.
The irradiation amount of the actinic ray is not particularly limited, but is preferably 50 mJ / cm ² or more in terms of i-line using a high-pressure mercury lamp as a light source. 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 ultraviolet absorber having the specific absorption band described above, it can suppress the curing reaction caused by the diffracted light that has passed through the mask during exposure by photolithography, and the mask pattern. Exposure can be performed according to the above, and pattern thickening can be prevented from occurring in the column spacer to be manufactured.
Further, the compound having two or more polymerizable unsaturated bonds in the molecule is a compound having two or more polymerizable unsaturated bonds in the molecule modified with caprolactone, ethylene oxide and / or propylene oxide. In this case, the curable resin composition for a column spacer of the present invention has a high recovery from compression deformation, a soft and low elastic modulus, and almost no residue is formed when a predetermined pattern is formed. It is possible to form a column spacer with a sharp pattern that is excellent in resolution and excellent in resolution.

When the curable resin composition for column spacers of the present invention contains a compound having two or more blocked isocyanate groups, it is further contained by heating the patterned photocured product after the development treatment. An alkali-soluble polymer compound reacts with a compound 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 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.

The column spacer of the present invention is designed so that its height is slightly higher than the cell gap, and is manufactured by a conventionally known method such as the ODF method, thereby generating color unevenness due to poor gravity without causing low-temperature foaming. It is possible to obtain a liquid crystal display element that can effectively suppress the above.
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 a column spacer of the present invention is for a column spacer that can form a column spacer having a pattern width of a desired size that does not reduce sensitivity to irradiation light and suppresses pattern weighting. A curable resin composition, a column spacer using the column spacer curable resin composition, and a liquid crystal display element can be provided.

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

Example 1
(1) Polymerization of alkali-soluble carboxyl group-containing polymer compound A 3 L separable flask was charged with 60 parts by weight of diethylene glycol methyl ethyl ether as a solvent, heated to 90 ° C. in a nitrogen atmosphere, and then methyl methacrylate 10 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 carboxyl group containing polymer compound solution was obtained.
The obtained alkali-soluble carboxyl group-containing polymer compound was sampled and the molecular weight was measured by gel permeation chromatography (GPC). The weight average molecular weight (Mw) was about 20,000.

(2) Preparation of curable resin composition for column spacers 100 parts by weight (solid content rate 40 wt%) of the obtained alkali-soluble carboxyl group-containing polymer compound solution, caprolactone-modified dipentaerythritol hexaacrylate (dipentaerythritol in 1 mol) 60 parts by weight of a compound obtained by reacting 6 moles of acrylic acid by esterification with 1 mole of a compound obtained by reacting 12 moles of caprolactone, 10 parts by weight of Irgacure 907 (manufactured by Ciba Specialty Chemicals) as a photoreaction initiator, Kayacure DETX-S "(Nippon Kayaku Co., Ltd.) 10 parts by weight, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone" SEESORB107 "(Cipro Kasei Co., Ltd.) 5 parts by weight as a UV absorber, and solvent As propylene glycol monomethyl ether It was prepared curable resin composition for column spacers by mixing Seteto 120 parts by weight.

(Example 2)
100 parts by weight of the alkali-soluble carboxyl group-containing polymer compound solution obtained in Example 1, propylene oxide-modified trimethylolpropane triacrylate (1 mol of a compound obtained by reacting 20 mol of propylene oxide with 1 mol of trimethylolpropane, acrylic 120 parts by weight of a compound obtained by reacting 3 moles of acid by esterification), 15 parts by weight of “Irgacure 369” (manufactured by Ciba Specialty Chemicals) as a photoinitiator, and 2- (3-tert-butyl-) as an ultraviolet absorber 2-hydroxy-5-methylphenyl) -5-chlorobenzotriazole "Tinvin 326" (manufactured by Ciba Specialty Chemicals) 4 parts by weight, "Duranate E-402-B80T" (manufactured by Asahi Kasei Chemicals) as a thermal crosslinking agent And as a solvent It was prepared curable resin composition for column spacers by mixing 220 parts by weight of ethylene glycol dimethyl ether.

(Example 3)
As a polymer compound containing an alkali-soluble carboxyl group, “Cyclomer P ACA-230AA” (manufactured by Daicel Chemical Industries) 100 parts by weight (solid content: 40 wt%), carboxylic acid-added caprolactone-modified tetramethylolmethane triacrylate (1 mole of tetramethylolmethane) 1 mol of a compound obtained by reacting 8 mol of caprolactone with 1 mol of tetrahydrocarboxylic anhydride added to the hydroxyl group of a compound obtained by reacting 3 mol of acrylic acid by esterification) 2 parts as an ultraviolet absorber -(2-hydroxy-5-t-octylphenyl) benzotriazole "Sumisorb 340" (manufactured by Sumitomo Chemical Co., Ltd.), 4 parts by weight, "Irgacure 379" (manufactured by Ciba Specialty Chemicals) as a photoinitiator, And as a solvent It was prepared curable resin composition for column spacers by mixing 150 parts by weight glycol dimethyl ether.

Example 4
Instead of 2,2′-dihydroxy-4,4′-dimethoxybenzophenone “SEESORB107” (manufactured by Cypro Kasei Co., Ltd.) as a UV absorber, 2- (2H-benzotriazol-2-yl) -4-methyl-6 A curable resin composition for a column spacer was prepared in the same manner as in Example 1 except that (3,4,5,6-tetrahydrophthalimidylmethyl) phenol “SEESORB706” (manufactured by Cypro Kasei Co., Ltd.) was used. .

(Example 5)
In place of 2,2′-dihydroxy-4,4′-dimethoxybenzophenone “SEESORB107” (manufactured by Cypro Kasei Co., Ltd.) as a UV absorber, 1,4-bis (4-benzoyl-3-hydroxyphenoxy) -butane “SEESORB151” A curable resin composition for a column spacer was prepared in the same manner as in Example 1 except that “Cipro Kasei Co., Ltd.” was used.

(Comparative Example 1)
A curable resin composition for a column spacer was prepared in the same manner as in Example 1 except that no ultraviolet absorber was added.

(Comparative Example 2)
A curable resin composition for a column spacer was prepared in the same manner as in Example 2 except that no ultraviolet absorber was added.

(Comparative Example 3)
A curable resin composition for a column spacer was prepared in the same manner as in Example 3 except that no ultraviolet absorber was added.

(Evaluation)
The curable resin compositions for column spacers obtained in Examples 1 to 5 and Comparative Examples 1 to 3 were evaluated by the following methods.
The results are shown in Table 1.

(Production of column spacer)
On a glass substrate on which a transparent conductive film of 370 mm × 470 mm is formed, the column spacer curable resin composition obtained in each Example and Comparative Example is applied by spin coating, and dried at 100 ° C. for 2 minutes to be applied. A membrane was obtained. The obtained coating film was irradiated with 100 mJ / cm ² ultraviolet rays through a dot pattern mask having a diameter of 10 μm by proximity exposure. At this time, the exposure gap was set to 100 μm. Thereafter, development was performed with a 0.04% KOH solution for 60 seconds, and washing with pure water was performed for 30 seconds to form a column spacer pattern.
Finally, a baking process at 220 ° C. for 30 minutes was performed to obtain a column spacer pattern.

(Evaluation of column spacer)
(Pattern fat)
The shape of the column spacer was measured with a laser microscope (manufactured by Keyence Corporation, VK-9500). The bottom width of the column spacer pattern formed through a dot pattern mask having a diameter of 10 μm was measured, and the spacer bottom width was compared with the mask diameter.

According to the present invention, the curable resin composition for a column spacer that can form a column spacer having a pattern width of a desired size without reducing the sensitivity to irradiation light and suppressing pattern thickening, A column spacer and a liquid crystal display element using the column spacer curable resin composition can be provided.

Claims (8)

A curable resin composition for a column spacer, comprising an alkali-soluble polymer compound having a reactive functional group, a compound having two or more polymerizable unsaturated bonds in the molecule, a photoreaction initiator, and an ultraviolet absorber. And
The said ultraviolet absorber has an absorption band in wavelength 330-400 nm, The curable resin composition for column spacers characterized by the above-mentioned. The curable resin composition for a column spacer according to claim 1, wherein the ultraviolet absorber has an absorption band at a wavelength of 330 to 400 nm, and an absorbance at a wavelength of 400 nm or more is 0.05 or less. The curable resin composition for a column spacer according to claim 1 or 2, wherein the content of the ultraviolet absorber is 5 to 50 parts by weight with respect to 100 parts by weight of the photoinitiator. 4. The curable resin composition for a column spacer according to claim 1, wherein the ultraviolet absorber is a benzotriazole compound and / or a benzophenone compound. The benzotriazole-based compound is a compound having a structure represented by the following general formula (1) and / or 2- (2H-benzotriazol-2-yl) -4-methyl-6- (3,4,5,6) -Tetrahydrophthalimidylmethyl) phenol, and the benzophenone compound is a compound represented by the following general formula (2) and / or 1,4-bis (4-benzoyl-3-hydroxyphenoxy) -butane The curable resin composition for column spacers of Claim 4 characterized by these.

In the general formulas (1) and (2), R ^{1 to} R ¹⁵ are each independently hydrogen, an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, A benzoyloxy group or a hydroxyl group having a carbon atom is represented. The compound having two or more polymerizable unsaturated bonds in the molecule is a compound having two or more polymerizable unsaturated bonds in the molecule modified with caprolactone, ethylene oxide and / or propylene oxide. The curable resin composition for column spacers of Claim 1, 2, 3, 4 or 5. A column spacer comprising the curable resin composition for a column spacer according to claim 1, 2, 3, 4, 5 or 6. A curable resin composition for a column spacer according to claim 1, 2, 3, 4, 5 or 6, or a column spacer according to claim 7, wherein the liquid crystal display element is characterized in that