JP2005234362A - Radiation sensitive resin composition for forming spacer, spacer, method for forming same and liquid crystal display element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radiation sensitive resin composition for spacers capable of suppressing stain of a photomask, etc., due to sublimation of a radiation sensitive polymerization initiator component, producing no in-liquid foreign substance, having high sensitivity and high resolution, and capable of forming spacers excellent in the shape of a cross section, compressive strength, rubbing resistance and adhesiveness to a transparent substrate. <P>SOLUTION: The radiation sensitive resin composition for forming spacers contains (A) a copolymer of an unsaturated carboxylic acid (anhydride), an epoxy-containing unsaturated compound and another unsaturated compound, (B) a polymerizable unsaturated compound, and (C) a radiation sensitive polymerization initiator containing a compound represented by formula (1) as an essential component, wherein R<SP>1</SP>denotes alkyl; R<SP>2</SP>and R<SP>3</SP>each denotes H, alkyl or benzyl; R<SP>4</SP>, R<SP>5</SP>, R<SP>7</SP>and R<SP>8</SP>each denotes H, halogen, alkyl or alkoxyl; and R<SP>6</SP>denotes halogen, alkyl, alkoxyl or the like. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a radiation-sensitive resin composition for forming a spacer, a spacer, a method for forming the spacer, and a liquid crystal display element, and more specifically, used for forming a spacer used in a display panel such as a liquid crystal display panel or a touch panel. The present invention relates to a radiation-sensitive resin composition, a spacer formed from the composition, a method for forming the spacer, and a liquid crystal display device including the spacer.

Conventionally, liquid crystal display elements have been used spacer particles such as glass beads and plastic beads having a predetermined particle diameter in order to keep the distance (cell gap) between two transparent substrates constant. Since the spacer particles are randomly distributed on a transparent substrate such as a glass substrate, if the spacer particles are present in the pixel formation region, the spacer particles may be reflected, or the incident light may be scattered and the liquid crystal display element There was a problem that the contrast of the image was lowered.
In order to solve these problems, a method of forming a spacer by photolithography has been adopted. In this method, a film of a radiation sensitive resin composition is formed on a substrate, exposed to ultraviolet rays through a predetermined mask, and then developed to form dot-like or stripe-like spacers. Since the spacer can be formed only at a predetermined place other than the region, the above-described problem is basically solved.

By the way, when a spacer is formed by photolithography on a transparent substrate used in an actual spacer forming process, for example, a color filter, a proximity exposure machine is often used. In the case of this proximity exposure, a certain gap is provided between the photomask used for exposure and the substrate on which the coating of the radiation-sensitive resin composition is formed, and the exposure is performed in a pattern as in the photomask. Is ideal. However, this gap is filled with air or nitrogen, and light that has passed through the opening (transparent part) of the photomask diffuses and spreads in the gap, so that the exposure is made wider than the design size of the mask pattern. There was a problem.
Therefore, in order to solve such a problem, the present applicant has already disclosed Patent Document 1 as 1,2-octanedione-1- [4- (phenylthiol) as a radiation-sensitive polymerization initiator of a radiation-sensitive resin composition. ) Phenyl] -2- (O-benzoyloxime) can faithfully reproduce the mask pattern design size even by proximity exposure, and form a display panel spacer with excellent strength and heat resistance. It reveals what can be done.

JP 2001-261761 A

In recent years, the size of the mother glass substrate has been increased from about 680 × 880 mm to about 1,500 × 1,800 mm due to the increase in the area of the liquid crystal display device and the improvement of productivity. In the spacer forming step, the spacer-forming radiation-sensitive resin composition is usually applied to a transparent substrate, baked on a hot plate to remove the solvent, and then exposed and developed to form the spacer. However, with the increase in size of the substrate, the radiation sensitive polymerization initiator component in the radiation sensitive resin composition sublimates during the formation of the spacer, which contaminates the baking furnace and photomask. Concern from causing the rise.
Furthermore, the present applicant states in Patent Document 2 that 1- (2-bromo-4-morpholinophenyl) -2-benzyl-2-dimethylaminobutane-1 as a radiation-sensitive polymerization initiator of the radiation-sensitive resin composition. Radiation sensitive polymerization initiator components by using bromine substituted acetophenone compounds such as 1-one and 1- (3-bromo-4-morpholinophenyl) -2-benzyl-2-dimethylaminobutan-1-one This indicates that contamination of the baking furnace and exhaust duct due to sublimation of the filter, clogging of a filter provided in the development line when the developer is repeatedly used, and the like can be reduced.

JP 2001-235617 A

The radiation-sensitive resin composition used for forming the spacer usually contains a polymerizable unsaturated compound such as (meth) acrylic acid ester or a compound having a thermally crosslinkable group such as an epoxy group. In order to prevent polymerization and crosslinking reaction, the composition solution is often stored at a temperature lower than room temperature. However, the bromine-substituted acetophenone compound described in Patent Document 2 often recrystallizes and precipitates during storage at a low temperature, and the temperature of the composition solution in which the bromine-substituted acetophenone compound is recrystallized is room temperature. Even if it is raised above, the recrystallized component is difficult to re-dissolve and remains as a foreign substance in the liquid during the spacer formation process, which may cause unevenness of the stripes on the substrate and decrease in sensitivity. Very expensive.

  However, in the conventional radiation-sensitive resin composition used for forming the spacer, including those described in Patent Document 1 and Patent Document 2, contamination of the baking furnace, photomask, and the like due to sublimation of the radiation-sensitive polymerization initiator component In addition, it is not sufficient in terms of preventing the occurrence of foreign substances in the liquid, and development of a radiation-sensitive resin composition having these characteristics has been strongly desired.

  The object of the present invention is to suppress contamination of the baking furnace, photomask, etc. due to sublimation of the radiation-sensitive polymerization initiator component, without causing foreign matter in the liquid, and with high sensitivity and high resolution, and also with a cross-sectional shape, A radiation-sensitive resin composition for spacers capable of easily forming a spacer excellent in various performances such as compressive strength, rubbing resistance, adhesion to a transparent substrate, the spacer formed therefrom, its formation method, and the spacer It is providing the liquid crystal display element which comprises.

The present invention, first,
[A] a copolymer of (a1) an unsaturated carboxylic acid and / or an unsaturated carboxylic acid anhydride, (a2) an epoxy group-containing unsaturated compound, and (a3) another unsaturated compound,
[B] A radiation-sensitive resin for spacer formation, comprising a polymerizable unsaturated compound and [C] a radiation-sensitive polymerization initiator having a compound represented by the following general formula (1) as essential components Composition,
Consists of.

[In General Formula (1), R ¹ represents a linear, branched or cyclic alkyl group having 1 to 12 carbon atoms, R ² and R ³ are independently a hydrogen atom; A linear, branched or cyclic alkyl group or a benzyl group, wherein R ⁴ , R ⁵ , R ⁷ and R ⁸ are each independently a hydrogen atom; a halogen atom; a linear or branched chain having 1 to 12 carbon atoms A linear or branched alkyl group having 1 to 4 carbon atoms or a linear or branched alkoxyl group having 1 to 4 carbon atoms, wherein R ⁶ is a halogen atom; a linear, branched or cyclic alkyl group having 1 to 12 carbon atoms; a hydroxyl group And a linear, branched or cyclic alkyl group having 1 to 12 carbon atoms substituted with a substituent selected from the group of linear or branched alkoxyl groups having 1 to 4 carbon atoms; A linear or branched alkoxyl group of Other denotes a hydroxyl group and a linear or branched linear or branched alkoxyl group having 2 to 4 carbon atoms which is substituted with a substituent selected from the group of alkoxy group having 1 to 4 carbon atoms. ]
The term “radiation” as used in the present invention means one containing ultraviolet rays, far ultraviolet rays, X-rays, electron beams, molecular beams, γ rays, synchrotron radiation, proton beam rays, and the like.

  Secondly, the present invention comprises a spacer formed from the radiation-sensitive resin composition for forming a spacer.

Thirdly, the present invention comprises a method for forming a spacer, characterized by including at least the following steps (a) to (2).
(A) A step of forming a coating of the radiation-sensitive resin composition for forming a spacer according to claim 1 on a substrate.
(B) A step of exposing radiation to at least a part of the coating.
(C) A step of developing the film after exposure.
(D) A step of heating the coated film after development.

  Fourthly, the present invention comprises a liquid crystal display element comprising the spacer.

Hereinafter, the present invention will be described in detail.
The following spacer radiation sensitive resin composition, the spacer radiation sensitive resin composition of the present invention (hereinafter, simply referred to as. "Radiation-sensitive resin composition") will be described in detail each component of.
-[A] copolymer-
The component [A] in the radiation-sensitive resin composition of the present invention is (a1) an unsaturated carboxylic acid and / or an unsaturated carboxylic acid anhydride (hereinafter collectively referred to as “compound (a1)”), ( a2) a copolymer of an epoxy group-containing unsaturated compound (hereinafter referred to as “compound (a2)”) and (a3) another unsaturated compound (hereinafter referred to as “compound (a3)”) (hereinafter referred to as “[ A] a copolymer ").

Examples of the compound (a1) include acrylic acid, methacrylic acid, crotonic acid, succinic acid mono (2-acryloyloxyethyl), succinic acid mono (2-methacryloyloxyethyl), hexahydrophthalic acid mono (2- Monocarboxylic acids such as acryloyloxyethyl) and hexahydrophthalic acid mono (2-methacryloyloxyethyl); dicarboxylic acids such as maleic acid, fumaric acid, citraconic acid, mesaconic acid and itaconic acid; and anhydrides of these dicarboxylic acids Examples can be given.
Of these compounds (a1), acrylic acid, methacrylic acid, maleic anhydride and the like are preferable from the viewpoint of copolymerization reactivity and availability.
The said compound (a1) can be used individually or in mixture of 2 or more types.

  [A] In the copolymer, the content of the structural unit derived from the compound (a1) is preferably 5 to 50% by weight, more preferably 10 to 40% by weight. In this case, if the content of the structural unit is less than 5% by weight, the compressive strength, heat resistance and chemical resistance of the resulting spacer tend to decrease, while if it exceeds 50% by weight, the radiation sensitive resin The storage stability of the composition may be reduced.

Examples of the compound (a2) include glycidyl acrylate, glycidyl methacrylate, glycidyl α-ethyl acrylate, glycidyl α-n-propyl acrylate, glycidyl α-n-butyl acrylate, and 3,4-acrylic acid. Epoxy butyl, 3,4-epoxy butyl methacrylate, 3,4-epoxy butyl α-ethyl acrylate, 6,7-epoxy heptyl acrylate, 6,7-epoxy heptyl methacrylate, α-ethyl acrylate 6,7 -Epoxyheptyl, β-methylglycidyl acrylate, β-methylglycidyl methacrylate, β-ethylglycidyl acrylate, β-ethylglycidyl methacrylate, β-n-propyl glycidyl acrylate, β-n-propyl glycidyl methacrylate, 3,4-epoxycyclohexyl acrylate And carboxylic acid esters such as 3,4-epoxycyclohexyl methacrylate; ethers such as o-vinylbenzyl glycidyl ether, m-vinylbenzyl glycidyl ether, and p-vinylbenzyl glycidyl ether.
Among these compounds (a2), glycidyl methacrylate, 6,7-epoxyheptyl methacrylate, β-methylglycidyl methacrylate, 3,4-epoxycyclohexyl methacrylate, o-vinylbenzyl glycidyl ether, m-vinylbenzyl glycidyl Ether, p-vinylbenzylglycidyl ether and the like are preferable from the viewpoint of increasing the copolymerization reactivity and the strength of the obtained spacer.
The said compound (a2) can be used individually or in mixture of 2 or more types.

  [A] In the copolymer, the content of the structural unit derived from the compound (a2) is preferably 10 to 70% by weight, more preferably 20 to 60% by weight. In this case, if the content of the structural unit is less than 10% by weight, the compressive strength, heat resistance and chemical resistance of the resulting spacer tend to decrease, whereas if it exceeds 70% by weight, the radiation-sensitive resin. The storage stability of the composition tends to decrease.

Moreover, as a compound (a3), for example,
Acrylic acid alkyl esters such as methyl acrylate, ethyl acrylate, n-propyl acrylate, i-propyl acrylate, n-butyl acrylate, i-butyl acrylate, sec-butyl acrylate, t-butyl acrylate; methyl methacrylate, ethyl methacrylate, n Methacrylic acid alkyl esters such as propyl methacrylate, i-propyl methacrylate, n-butyl methacrylate, i-butyl methacrylate, sec-butyl methacrylate, t-butyl methacrylate; cyclohexyl acrylate, 2-methylcyclohexyl acrylate, tricyclo [5.2 .1.0 ^2,6] decan-8-yl acrylate (hereinafter, the "tricyclo [5.2.1.0 ^2,6] decan-8-yl,""Jishikuropen Tanyl "), alicyclic esters of acrylic acid such as 2-dicyclopentanyloxyethyl acrylate, isobornyl acrylate, tetrahydrofuryl acrylate; cyclohexyl methacrylate, 2-methylcyclohexyl methacrylate, dicyclopentanyl methacrylate, Alicyclic esters of methacrylic acid such as 2-dicyclopentanyloxyethyl methacrylate, isobornyl methacrylate, and tetrahydrofuryl methacrylate; Aryl esters such as phenyl acrylate and benzyl acrylate; Methacryl such as phenyl methacrylate and benzyl methacrylate Acid aryl esters;

Dicarboxylic acid diesters such as diethyl maleate, diethyl fumarate and diethyl itaconate; hydroxyalkyl esters of acrylic acid such as 2-hydroxyethyl acrylate and 2-hydroxypropyl acrylate; 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate and the like Methacrylic acid hydroxyalkyl esters; aromatic vinyl compounds such as styrene, α-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, acrylonitrile, methacrylonitrile, vinyl chloride, vinylidene chloride, acrylamide , Methacrylamide, vinyl acetate, 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, N-cyclohexylmaleimide, N-phenylmaleimide N-benzylmaleimide, N-succinimidyl-3-maleimidobenzoate, N-succinimidyl-4-maleimidobutyrate, N-succinimidyl-6-maleimidocaproate, N-succinimidyl-3-maleimidopropionate, N- (9 -Acridinyl) maleimide and the like.

Among these compounds (a3), 2-methylcyclohexyl acrylate, t-butyl methacrylate, dicyclopentanyl methacrylate, tetrahydrofuryl methacrylate, styrene, p-methoxystyrene, 1,3-butadiene and the like are copolymerizable. It is preferable from the point.
The said compound (a3) can be used individually or in mixture of 2 or more types.
[A] In the copolymer, the content of the structural unit derived from the compound (a3) is preferably 10 to 80% by weight, more preferably 20 to 60% by weight. In this case, if the content of the structural unit is less than 10% by weight, the storage stability of the radiation-sensitive resin composition may be lowered, whereas if it exceeds 80% by weight, the developability may be lowered. is there.

[A] The polystyrene-reduced weight average molecular weight (hereinafter referred to as “Mw”) by gel permeation chromatography (GPC) of the copolymer is usually 2 × 10 ^{3 to} 5 × 10 ⁵ , preferably 5 × 10 ³ to 1 × 10 ⁵ . In this case, the Mw of the [A] copolymer is 2 ×
If it is less than 10 ³ , the compressive strength and heat resistance of the resulting spacer tend to decrease, while if it exceeds 5 × 10 ⁵ , developability tends to decrease.
In the present invention, the [A] copolymer can be used alone or in admixture of two or more.

[A] The copolymer can be produced by radical polymerization of the compound (a1), the compound (a2) and the compound (a3) in a solvent in the presence of a polymerization initiator, for example. [A] As a solvent used in the production of the copolymer, for example,
Alcohols such as methanol, ethanol, n-propanol, i-propanol, benzyl alcohol, 2-phenylethanol, 3-phenyl-1-propanol;
Ethers such as tetrahydrofuran and dioxane;
Ethylene glycol monoalkyl ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-n-propyl ether, ethylene glycol mono-n-butyl ether;
Ethylene glycol monoalkyl ether acetates such as ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether, ethylene glycol mono-n-propyl ether acetate, ethylene glycol mono-n-butyl ether acetate;
Diethylene glycol monoalkyl ether acetates such as diethylene glycol monomethyl ether acetate and diethylene glycol monoethyl ether acetate;
Ethylene glycol monoalkyl ether propionates such as ethylene glycol monomethyl ether propionate, ethylene glycol monoethyl ether propionate, ethylene glycol mono-n-propyl ether propionate, ethylene glycol mono-n-butyl ether propionate ;
Diethylene glycol alkyl ethers such as diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol ethyl methyl ether;

Propylene glycol monoalkyl ethers such as propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-n-propyl ether, propylene glycol mono-n-butyl ether;
Propylene glycol monoalkyl ether acetates such as propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol mono-n-propyl ether acetate, propylene glycol mono-n-butyl ether acetate;
Propylene glycol monoalkyl ether propionate, propylene glycol monoethyl ether propionate, propylene glycol mono-n-propyl ether propionate, propylene glycol monoalkyl ether propionate such as propylene glycol mono-n-butyl ether propionate ;
Aromatic hydrocarbons such as toluene and xylene;
Ketones such as methyl ethyl ketone, 2-pentanone, 3-pentanone, cyclohexanone, 4-hydroxy-4-methyl-2-pentanone;

Methyl 2-methoxypropionate, ethyl 2-methoxypropionate, n-propyl 2-methoxypropionate, n-butyl 2-methoxypropionate, methyl 2-ethoxypropionate, ethyl 2-ethoxypropionate, 2-ethoxypropion N-propyl acid, n-butyl 2-ethoxypropionate, methyl 2-n-propoxypropionate, ethyl 2-n-propoxypropionate, n-propyl 2-n-propoxypropionate, 2-n-propoxypropionic acid n-butyl, methyl 2-n-butoxypropionate, ethyl 2-n-butoxypropionate, n-propyl 2-n-butoxypropionate, n-butyl 2-n-butoxypropionate, methyl 3-methoxypropionate , Ethyl 3-methoxypropionate, 3-methoxy N-propyl propionate, n-butyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, n-propyl 3-ethoxypropionate, n-butyl 3-ethoxypropionate, 3-n -Methyl propoxypropionate, ethyl 3-n-propoxypropionate, n-propyl 3-n-propoxypropionate, n-butyl 3-n-propoxypropionate, methyl 3-n-butoxypropionate, 3-n- Alkyl alkoxypropionates such as ethyl butoxypropionate, n-propyl 3-n-butoxypropionate, n-butyl 3-n-butoxypropionate;

Methyl acetate, ethyl acetate, n-propyl acetate, n-butyl acetate, methyl hydroxyacetate, ethyl hydroxyacetate, n-propyl hydroxyacetate, n-butyl hydroxyacetate, methyl lactate, ethyl lactate, n-propyl lactate, n-lactic acid Butyl, methyl 2-hydroxy-2-methylpropionate, ethyl 2-hydroxy-2-methylpropionate, methyl 3-hydroxypropionate, ethyl 3-hydroxypropionate, n-propyl 3-hydroxypropionate, 3-hydroxy N-butyl propionate, methyl 2-hydroxy-3-methylbutanoate, methyl methoxyacetate, ethyl methoxyacetate, n-propyl methoxyacetate, n-butyl methoxyacetate, methyl ethoxyacetate, ethyl ethoxyacetate, n-propyl ethoxyacetate, Ethoxyacetic acid n- Chill, n-propoxyacetate methyl, n-propoxyacetate ethyl, n-propoxyacetate n-propyl, n-propoxyacetate n-butyl, n-butoxyacetate methyl, n-butoxyacetate, n-butoxyacetate n-propyl, Other esters such as n-butoxyacetate n-butyl can be mentioned.

Of these solvents, diethylene glycol alkyl ethers, propylene glycol monoalkyl ether acetates, alkyl alkoxypropionates and the like are preferable.
The said solvent can be used individually or in mixture of 2 or more types.

[A] As the polymerization initiator used in the production of the copolymer, those generally known as radical polymerization initiators can be used, for example, 2,2′-azobisisobutyronitrile, 2,2'-azobis- (2,4-dimethylvaleronitrile), 2,2'-azobis- (4-methoxy-2,4-dimethylvaleronitrile), 4,4'-azobis (4-cyanovaleric acid ), Dimethyl-2,2′-azobis (2-methylpropionate), 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile); benzoyl peroxide, lauroyl peroxide, t -Organic peroxides such as butylperoxypivalate and 1,1'-bis- (t-butylperoxy) cyclohexane; hydrogen peroxide and the like. When a peroxide is used as the radical polymerization initiator, a redox initiator may be used in combination with a reducing agent.
These radical polymerization initiators can be used alone or in admixture of two or more.

-[B] polymerizable unsaturated compound-
Examples of the polymerizable unsaturated compound in the radiation-sensitive resin composition of the present invention include bifunctional or higher acrylic esters and methacrylic esters (hereinafter collectively referred to as “(meth) acrylic esters”). Is preferred.
Examples of the bifunctional (meth) acrylic acid esters include ethylene glycol acrylate, ethylene glycol methacrylate, 1,6-hexanediol diacrylate, 1,6-hexanediol dimethacrylate, 1,9-nonanediol diacrylate, Examples include 1,9-nonanediol dimethacrylate, tetraethylene glycol diacrylate, tetraethylene glycol dimethacrylate, polypropylene glycol diacrylate, polypropylene glycol dimethacrylate, bisphenoxyethanol full orange acrylate, and bisphenoxyethanol full orange methacrylate.

  Moreover, as a commercial item of bifunctional (meth) acrylic acid esters, for example, Aronix M-210, M-240, M-6200 (above, manufactured by Toagosei Co., Ltd.), KAYARAD HDDA, KAYARAD HX -220, R-604, same UX-2201, same UX-2301, same UX-3204, same UX-3301, same UX-4101, same UX-6101, same UX-7101, same UX-8101, same MU -2100, MU-4001 (above, manufactured by Nippon Kayaku Co., Ltd.), Biscoat 260, 312 and 335HP (above, manufactured by Osaka Organic Chemical Industry Co., Ltd.).

  Examples of the tri- or more functional (meth) acrylic acid esters include trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol triacrylate, pentaerythritol trimethacrylate, pentaerythritol tetraacrylate, pentaerythritol tetramethacrylate, dipenta Erythritol pentaacrylate, dipentaerythritol pentamethacrylate, dipentaerythritol hexaacrylate, dipentaerythritol hexamethacrylate, tri (2-acryloyloxyethyl) phosphate, tri (2-methacryloyloxyethyl) phosphate, and more than 9 functional groups (Meth) acrylic acid esters having a linear alkylene group and an alicyclic structure, Reacting a compound having two or more isocyanate groups with a compound having one or more hydroxyl groups in the molecule and having three, four or five acryloyloxy groups and / or methacryloyloxy groups; The urethane acrylate type compound obtained etc. can be mentioned.

Moreover, as a commercial item of trifunctional or more (meth) acrylic acid esters, for example, Aronix M-309, M-400, M-402, M-405, M-450, M-1310 M-1600, M-1960, M-7100, M-8030, M-8060, M-8100, M-8100, M-8530, M-8560, M-9050, Aronix TO-1450 (Above, manufactured by Toagosei Co., Ltd.), KAYARAD TMPTA, DPHA, DPCA-20, DPCA-30, DPCA-60, DPCA-120, MAX-3510 (above, Nippon Kayaku Co., Ltd.) Manufactured), Biscoat 295, 300, 360, GPT, 3PA, 400 (above, manufactured by Osaka Organic Chemical Industry Co., Ltd.) and urethane acrylate compounds Examples of commercially available products include New Frontier R-1150 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), KAYARAD DPHA-40H (manufactured by Nippon Kayaku Co., Ltd.), and the like.
In this invention, a polymerizable unsaturated compound can be used individually or in mixture of 2 or more types.

  In the radiation-sensitive resin composition of the present invention, the amount of the polymerizable unsaturated compound used is preferably 30 to 200 parts by weight, more preferably 50 to 140 parts by weight with respect to 100 parts by weight of the [A] copolymer. It is. In this case, if the amount of the polymerizable unsaturated compound used is less than 30 parts by weight, the resulting spacer tends to be thin and the strength tends to decrease. On the other hand, if it exceeds 200 parts by weight, Adhesion may be insufficient.

-[C] Radiation sensitive polymerization initiator-
The radiation-sensitive polymerization initiator in the radiation-sensitive resin composition of the present invention comprises a compound represented by the general formula (1) (hereinafter referred to as “compound (1)”) as an essential component.

In the general formula (1), R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ and R ⁸ having 1 to 12 carbon atoms as a linear, branched or cyclic alkyl group For example, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group, t-butyl group, n-pentyl group, n-hexyl group, n -Heptyl group, n-octyl group, n-nonyl group, n-decyl group, n-undecyl group, n-dodecyl group, cyclopentyl group, cyclohexyl group and the like can be mentioned.

As the halogen atom of ^{R 4, R 5, R 6} , R 7 and R ^8, for example, a fluorine atom, a chlorine atom, may be mentioned bromine atom.
Examples of the linear or branched alkoxyl group having 1 to 4 carbon atoms of R ⁴ , R ⁵ , R ⁶ , R ⁷ and R ⁸ include, for example, a methoxy group, an ethoxy group, an n-propoxy group, i- A propoxy group, n-butoxy group, i-butoxy group, sec-butoxy group, t-butoxy group and the like can be mentioned.

In addition, a linear, branched or cyclic alkyl group having 1 to 12 carbon atoms substituted with a substituent selected from the group consisting of a hydroxyl group of R ⁶ and a linear or branched alkoxyl group having 1 to 4 carbon atoms. In the above, the linear or branched alkoxyl group having 1 to 4 carbon atoms is, for example, a linear or branched chain having 1 to 4 carbon atoms of R ⁴ , R ⁵ , R ⁶ , R ⁷ and R ^8. The thing similar to the group illustrated about the alkoxyl group of can be mentioned.
As the substituent for the substituted, straight-chain, branched or cyclic alkyl group having 1 to 12 carbon atoms of R ⁶ , for example, a hydroxyl group, a methoxy group and the like are preferable.
Examples of the linear, branched or cyclic alkyl group having 1 to 12 carbon atoms to be substituted for R ⁶ include R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ and the like. Examples thereof include the same groups as those exemplified for the linear, branched or cyclic alkyl group having 1 to 12 carbon atoms of R ⁸ .
In the substituted, straight chain, branched or cyclic alkyl group having 1 to 12 carbon atoms of R ⁶ , one or more substituents may be present.

Further, in the linear or branched alkoxyl group having 2 to 4 carbon atoms substituted with a substituent selected from the group consisting of the hydroxyl group of R ⁶ and the linear or branched alkoxyl group having 1 to 4 carbon atoms, Examples of the linear or branched alkoxyl group having 1 to 4 carbon atoms include, for example, the above-mentioned R ⁴ , R ⁵ , R ⁶ , R ⁷ and R ⁸ linear or branched alkoxyl having 1 to 4 carbon atoms. The thing similar to the group illustrated about the group can be mentioned.
As the substituent for the substituted or straight-chain or branched alkoxyl group having 2 to 4 carbon atoms of R ⁶ , for example, a hydroxyl group, a methoxy group and the like are preferable.
Examples of the linear or branched alkoxyl group having 2 to 4 carbon atoms to be substituted for R ⁶ include ethoxy group, n-propoxy group, i-propoxy group, n-butoxy group, i-butoxy group, sec -Butoxy group, t-butoxy group and the like can be mentioned.
In the substituted or straight chain or branched alkoxyl group having 2 to 4 carbon atoms of R ⁶ , one or more substituents can be present.

In the general formula (1), R ¹ is methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group, t-butyl group, n- Pentyl group, n-hexyl group and the like are preferable.
R ² and R ³ are methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group, t-butyl group, n-pentyl group. N-hexyl group, n-heptyl group, n-octyl group and the like are preferable.
R ⁴ , R ⁵ , R ⁷ and R ⁸ are preferably a hydrogen atom, a methyl group, an ethyl group or the like.

Furthermore, as R ⁶ , methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group, t-butyl group, n-pentyl group, n- Hexyl, n-heptyl, n-octyl, n-decyl, n-dodecyl, hydroxymethyl, 2-hydroxyethyl, methoxymethyl, 2-methoxyethyl, methoxy, ethoxy, n -Propoxy group, i-propoxy group, n-butoxy group, hydroxymethoxy group, 2-hydroxyethoxy group, methoxymethoxy group, 2-methoxyethoxy group and the like are preferable.

Specific examples of preferred compound (1) in the present invention include
2- (4-methylbenzyl) -2- (dimethylamino) -1- (4-morpholinophenyl) butan-1-one,
2- (4-ethylbenzyl) -2- (dimethylamino) -1- (4-morpholinophenyl) butan-1-one,
2- (4-i-propylbenzyl) -2- (dimethylamino) -1- (4-morpholinophenyl) butan-1-one,
2- (4-n-butylbenzyl) -2- (dimethylamino) -1- (4-morpholinophenyl) butan-1-one,
2- (4-i-butylbenzyl) -2- (dimethylamino) -1- (4-morpholinophenyl) butan-1-one,
2- (4-n-dodecylbenzyl) -2- (dimethylamino) -1- (4-morpholinophenyl) butan-1-one,
2- (3,4-dimethylbenzyl) -2- (dimethylamino) -1- (4-morpholinophenyl) butan-1-one,

2- (4-methoxybenzyl) -2- (dimethylamino) -1- (4-morpholinophenyl) butan-1-one,
2- (4-ethoxybenzyl) -2- (dimethylamino) -1- (4-morpholinophenyl) butan-1-one,
2- (4-hydroxymethylbenzyl) -2- (dimethylamino) -1- (4-morpholinophenyl) butan-1-one,
2- [4- (2-hydroxyethoxy) benzyl] -2- (dimethylamino) -1- (4-morpholinophenyl) butan-1-one,
2- [4- (2-methoxyethoxy) benzyl] -2- (dimethylamino) -1- (4-morpholinophenyl) butan-1-one,
2- (4-i-propylbenzyl) -2-[(n-butyl) (methyl) amino] -1- (4-morpholinophenyl) butan-1-one,
2- (4-n-butylbenzyl) -2-[(n-butyl) (methyl) amino] -1- (4-morpholinophenyl) butan-1-one,

2- (4-i-propylbenzyl) -2- (dimethylamino) -1- (4-morpholinophenyl) pentan-1-one,
2- (4-i-butylbenzyl) -2-[(n-butyl) (methyl) amino)]-1- (4-morpholinophenyl) pentan-1-one,
2- (4-n-butoxybenzyl) -2-[(n-butyl) (methyl) amino] -1- (4-morpholinophenyl) pentan-1-one,
2- (4-methylbenzyl) -2- [di (n-octyl) amino] -1- (4-morpholinophenyl) hexane-1-one,
2- (4-n-dodecylbenzyl) -2- (dimethylamino) -1- (4-morpholinophenyl) octan-1-one and the like can be mentioned.

Of these compounds (1), in particular, 2- (4-methylbenzyl) -2- (dimethylamino) -1- (4-morpholinophenyl) butan-1-one, 2- (4-ethylbenzyl) 2- (dimethylamino) -1- (4-morpholinophenyl) butan-1-one, 2- (4-i-propylbenzyl) -2- (dimethylamino) -1- (4-morpholinophenyl) Butan-1-one and the like are preferable.
Compound (1) is excellent in solubility in a solvent, does not cause foreign matters such as undissolved matter and precipitates, and does not cause contamination of a baking furnace or a photomask due to sublimation, and lack of pattern and defect. It is a component that can form an excellent spacer.
In this invention, a compound (1) can be used individually or in mixture of 2 or more types.

  In the radiation sensitive resin composition of the present invention, the amount of the compound (1) used is preferably 5 to 50 parts by weight, more preferably 5 to 30 parts by weight with respect to 100 parts by weight of the [A] copolymer. is there. In this case, when the amount of the compound (1) used is less than 5 parts by weight, the residual film ratio tends to decrease. On the other hand, when it exceeds 50 parts by weight, the solubility of the unexposed part in the alkaline developer tends to decrease. is there.

In the radiation sensitive resin composition of the present invention, at least one other radiation sensitive polymerization initiator can be used in combination with the compound (1).
Examples of the other radiation-sensitive polymerization initiator include O-acyloxime type compounds, acetophenone compounds, biimidazole compounds, benzoin compounds, benzophenone compounds, α-diketone compounds, polynuclear quinone compounds, xanthones. Compounds, phosphine compounds, triazine compounds, and the like.
Of these other radiation-sensitive polymerization initiators, O-acyloxime compounds, acetophenone compounds, and biimidazole compounds are preferred.

The O-acyloxime type compound is a component having an effect of further improving sensitivity.
Specific examples of the O-acyloxime type compound include 1- (9-ethyl-6-benzoyl-9.H.-carbazol-3-yl) nonane-1,2-nonane-2-oxime-O-benzoate, 1- (9-ethyl-6-benzoyl-9.H.-carbazol-3-yl) nonane-1,2-nonane-2-oxime-O-acetate, 1- (9-ethyl-6-benzoyl-9 .H.-carbazol-3-yl) pentane-1,2-pentane-2-oxime-O-acetate, 1- (9-ethyl-6-benzoyl-9.H.-carbazol-3-yl) octane- 1-one oxime-O-acetate, 1- [9-ethyl-6- (2-methylbenzoyl) -9. H. -Carbazol-3-yl] ethane-1-one oxime-O-benzoate, 1- [9-ethyl-6- (2-methylbenzoyl) -9. H. -Carbazol-3-yl] ethane-1-one oxime-O-acetate, 1- [9-ethyl-6- (1,3,5-trimethylbenzoyl) -9. H. -Carbazol-3-yl] ethane-1-one oxime-O-benzoate, 1- [9-n-butyl-6- (2-ethylbenzoyl) -9. H. -Carbazol-3-yl] ethane-1-oneoxime-O-benzoate, 1,2-octadion-1- [4- (phenylthio) phenyl] -2- (O-benzoyloxime), 1,2-butanedione-1 -[4- (phenylthio) phenyl] -2- (O-benzoyloxime), 1,2-butanedione-1- [4- (phenylthio) phenyl] -2- (O-acetyloxime), 1,2-octadione -1- [4- (methylthio) phenyl] -2- (O-benzoyloxime), 1,2-octadion-1- [4- (phenylthio) phenyl] -2- [O- (4-methylbenzoyloxime) And the like.

Of these O-acyloxime type compounds, 1- [9-ethyl-6- (2-methylbenzoyl) -9. H. -Carbazol-3-yl] ethane-1-one oxime-O-acetate, 1,2-octadion-1- [4- (phenylthio) phenyl] -2- (O-benzoyloxime) and the like are preferable.
The O-acyloxime type compounds can be used alone or in admixture of two or more.

  The amount of the O-acyloxime compound used is preferably 30 parts by weight or less, more preferably 20 parts by weight or less with respect to 100 parts by weight of the [A] copolymer. In this case, if the amount of the O-acyl oxime type compound used exceeds 30 parts by weight, the solubility of the unexposed part in the alkaline developer tends to decrease, and the sublimation of the O-acyl oxime type compound causes a firing furnace. There is a tendency to increase the risk of contamination of the photomask and the photomask. In addition, there exists a possibility that a remaining film rate may fall that the usage-amount of an O-acyl oxime type compound is less than 5 weight part.

The acetophenone compound is a component having an action of adjusting the shape of the formed spacer.
Examples of acetophenone compounds include α-hydroxy ketone compounds and α-amino ketone compounds.
Specific examples of the α-hydroxyketone compound include 1-phenyl-2-hydroxy-2-methylpropan-1-one, 1- (4-i-propylphenyl) -2-hydroxy-2-methylpropane- 1-one, 4- (2-hydroxyethoxy) phenyl- (2-hydroxy-2-propyl) ketone, 1-hydroxycyclohexyl phenyl ketone and the like can be mentioned, and specific examples of the α-aminoketone compound include: 2-Methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, 2-benzyl-2- (dimethylamino) -1- (4-morpholinophenyl) butan-1-one 1- (2-bromo-4-morpholinophenyl) -2-benzyl-2-dimethylaminobutan-1-one, 2- (2-bromoben Dil) -2- (dimethylamino) -1- (4-morpholinophenyl) butan-1-one, 2- (4-bromobenzyl) -2- (dimethylamino) -1- (4-morpholinophenyl) Examples of acetophenone compounds other than these include 2,2-dimethoxyacetophenone, 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, and the like. Can be mentioned.

Among these acetophenone compounds, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, 2-benzyl-2- (dimethylamino) -1- (4-morpho Linophenyl) butan-1-one, 1- (2-bromo-4-morpholinophenyl) -2-benzyl-2-dimethylaminobutan-1-one, 2- (4-bromobenzyl) -2- (dimethyl) Amino) -1- (4-morpholinophenyl) butan-1-one and the like are preferable.
The acetophenone compounds can be used alone or in admixture of two or more.

  The amount of the acetophenone compound used is preferably 30 parts by weight or less, more preferably 20 parts by weight or less, based on 100 parts by weight of the [A] copolymer. In this case, if the amount of the acetophenone compound used exceeds 30 parts by weight, there is a tendency that contamination of the baking furnace, photomask, etc. due to sublimation of the acetophenone compound and generation of foreign matter in the liquid increase. If the amount of the acetophenone compound used is less than 1 part by weight, the remaining film ratio during development may be reduced.

The biimidazole compound is a component that has an effect of adjusting the shape of the formed spacer and can further improve the sensitivity, resolution, and adhesion to the substrate.
Specific examples of the biimidazole compound include 2,2′-bis (2-chlorophenyl) -4,4 ′, 5,5′-tetrakis (4-ethoxycarbonylphenyl) -1,2′-biimidazole, 2 , 2′-bis (2-bromophenyl) -4,4 ′, 5,5′-tetrakis (4-ethoxycarbonylphenyl) -1,2′-biimidazole, 2,2′-bis (2-chlorophenyl) -4,4 ', 5,5'-tetraphenyl-1,2'-biimidazole, 2,2'-bis (2,4-dichlorophenyl) -4,4', 5,5'-tetraphenyl-1 2,2′-biimidazole, 2,2′-bis (2,4,6-trichlorophenyl) -4,4 ′, 5,5′-tetraphenyl-1,2′-biimidazole, 2,2′- Bis (2-bromophenyl) -4,4 ′, 5,5′-tetraphenyl-1, '-Biimidazole, 2,2'-bis (2,4-dibromophenyl) -4,4', 5,5'-tetraphenyl-1,2'-biimidazole, 2,2'-bis (2, 4,6-tribromophenyl) -4,4 ′, 5,5′-tetraphenyl-1,2′-biimidazole and the like.

Among these biimidazole compounds, 2,2′-bis (2-chlorophenyl) -4,4 ′, 5,5′-tetraphenyl-1,2′-biimidazole, 2,2′-bis (2 , 4-dichlorophenyl) -4,4 ′, 5,5′-tetraphenyl-1,2′-biimidazole, 2,2′-bis (2,4,6-trichlorophenyl) -4,4 ′, 5 , 5′-tetraphenyl-1,2′-biimidazole and the like, and particularly 2,2′-bis (2,4-dichlorophenyl) -4,4 ′, 5,5′-tetraphenyl-1,2 ′ -Biimidazole is preferred.
The biimidazole compounds can be used alone or in admixture of two or more.

  The amount of the biimidazole compound used is preferably 50 parts by weight or less, more preferably 35 parts by weight or less with respect to 100 parts by weight of the [A] copolymer. In this case, if the amount of the biimidazole compound used exceeds 50 parts by weight, the amount of eluate in the liquid crystal increases and the voltage holding ratio tends to decrease. There is a tendency to increase the risk of contaminating the mask and the like. In addition, there exists a possibility that a residual film rate may fall that the usage-amount of a biimidazole type compound is less than 0.1 weight part.

In the radiation-sensitive resin composition of the present invention, when a biimidazole compound is used as the radiation-sensitive polymerization initiator component, it is preferable to use a dialkylamino group-containing compound having an action of sensitizing the biimidazole compound.
As such a dialkylamino group-containing compound, for example, a dialkylamino group-containing benzophenone derivative and a dialkylamino group-containing benzoic acid ester are preferable, and more specifically, for example, 4,4′-bis (dimethylamino) benzophenone. 4,4′-bis (diethylamino) benzophenone, ethyl p-dimethylaminobenzoate, ethyl p-diethylaminobenzoate, i-amyl p-dimethylaminobenzoate, i-amyl p-diethylaminobenzoate, and the like. it can.
Of these dialkylamino group-containing compounds, 4,4′-bis (diethylamino) benzophenone is particularly preferable.
The said dialkylamino group containing compound can be used individually or in mixture of 2 or more types.

  When the biimidazole compound and the dialkylamino group-containing compound are used in combination, the amount of the dialkylamino group-containing compound is preferably 0.1 to 50 parts by weight, more preferably 100 to 50 parts by weight of the [A] copolymer. Preferably it is 1-20 weight part. In this case, if the amount of the dialkylamino group-containing compound used is less than 0.1 parts by weight, the resulting spacer tends to cause film slippage or poor shape of the spacer, while if it exceeds 50 parts by weight, the spacer There is a tendency that there is a high possibility that the shape of the above will be damaged or the baking furnace, the photomask or the like is contaminated due to sublimation of the dialkylamino group-containing compound.

  Further, in the radiation-sensitive resin composition of the present invention, when a biimidazole compound and a dialkylamino group-containing compound are used in combination as a radiation-sensitive polymerization initiator component, an action of donating a hydrogen radical to the biimidazole compound It is preferable to add a thiol-based compound having Biimidazole compounds are sensitized by a dialkylamino group-containing compound and cleaved to generate imidazole radicals. In this case, if no thiol compound is present, high radical polymerization initiating ability is not expressed, and In many cases, the shape of the spacer to be formed becomes an unfavorable shape such as a reverse taper shape. However, by adding a thiol compound to a system in which a biimidazole compound and a dialkylamino group-containing compound coexist, a hydrogen radical is donated to the imidazole radical, so that the imidazole radical is converted to neutral imidazole. At the same time, a component having a sulfur radical having a high polymerization initiating ability is generated, whereby the spacer can have a more preferable forward tapered shape.

Examples of the thiol compound include aromatics such as 2-mercaptobenzothiazole, 2-mercaptobenzoxazole, 2-mercaptobenzimidazole, 2-mercapto-5-methoxybenzothiazole, 2-mercapto-5-methoxybenzimidazole. Compounds: aliphatic monothiols such as 3-mercaptopropionic acid, methyl 3-mercaptopropionate, ethyl 3-mercaptopropionate, octyl 3-mercaptopropionate; 3,6-dioxa-1,8-octanedithiol, Aliphatic polythiol compounds such as pentaerythritol tetra (mercaptoacetate) and pentaerythritol tetra (3-mercaptopropionate) can be mentioned.
These thiol compounds can be used alone or in admixture of two or more.

  When a biimidazole compound, a dialkylamino group-containing compound and a thiol compound are used in combination, the amount of the thiol compound used is preferably 0.1 to 50 weights per 100 parts by weight of the [A] copolymer. Parts, more preferably 1 to 20 parts by weight. In this case, if the amount of the thiol-based compound used is less than 0.1 parts by weight, the resulting spacer tends to cause film slippage or poor shape, whereas if it exceeds 50 parts by weight, the shape of the spacer is impaired. Or the sublimation of the thiol compound tends to increase the risk of contaminating the baking furnace, the photomask, and the like.

  In the radiation-sensitive resin composition of the present invention, the use ratio of the other radiation-sensitive polymerization initiator is preferably 100 parts by weight or less, more preferably 80 parts by weight with respect to 100 parts by weight of the total radiation-sensitive polymerization initiator. Part or less, particularly preferably 60 parts by weight or less. In this case, if the use ratio of the other radiation-sensitive polymerization initiator exceeds 100 parts by weight, the intended effect of the present invention may be impaired.

-Optional additives-
In the radiation-sensitive resin composition of the present invention, optional additives other than the above components, for example, surfactants, adhesion assistants, storage stabilizers, heat resistance, as long as they do not impair the effects of the present invention. A property improver or the like can be blended.
The surfactant is a component blended to improve applicability, and a fluorosurfactant and a silicone surfactant are preferable.
The fluorine-based surfactant is preferably a compound having a fluoroalkyl and / or fluoroalkylene group in at least one of the terminal, main chain and side chain, and examples thereof include 1,1,2,2- Tetrafluoro-n-octyl (1,1,2,2-tetrafluoro-n-propyl) ether, 1,1,2,2-tetrafluoro-n-octyl (n-hexyl) ether, octaethylene glycol di (1,1 , 2,2-tetrafluoro-n-butyl) ether, hexaethylene glycol (1,1,2,2,3,3-hexafluoro-n-pentyl) ether, octapropylene glycol di (1,1,2,2- Tetrafluoro-n-butyl) ether, hexapropylene glycol di (1,1,2,2,3,3-hexafluoro-n-pent ) Ether, 1,1,2,2,3,3-hexafluoro-n-decane, 1,1,2,2,8,8,9,9,10,10-decafluoro-n-dodecane, perfluoro-n -Sodium dodecane sulfonate, sodium fluoroalkylbenzene sulfonates, sodium fluoroalkyl phosphonates, sodium fluoroalkyl carboxylates, fluoroalkyl polyoxyethylene ethers, diglycerin tetrakis (fluoroalkyl polyoxyethylene ethers), fluoro Examples thereof include alkylammonium iodides, fluoroalkylbetaines, fluoroalkylpolyoxyethylene ethers, perfluoroalkylpolyoxyethanols, perfluoroalkylalkoxylates, and fluorine-based alkyl esters.

  Examples of commercially available fluorosurfactants include BM-1000, BM-1100 (manufactured by BM CHEMIE), MegaFack F142D, F172, F173, F178, F183, F191, F191, F471, F476 (above, Dainippon Ink & Chemicals, Inc.), Florard FC 170C, FC-171, FC-430, FC-431 (above, Sumitomo 3M Limited), Surflon S -112, S-113, S-131, S-141, S-145, S-382, SC-101, SC-102, SC-103, SC-104, SC -105, SC-106 (above, manufactured by Asahi Glass Co., Ltd.), F-top EF301, EF303, EF352 (above, manufactured by Shin-Akita Kasei Co., Ltd.), Futagen FT-100, FT-110, FT-140A, FT-150, FT-250, FT-251, FT-300, FT-310, FT-400S, FTX-218, FTX-251 (above, manufactured by Neos Co., Ltd.) and the like.

  Examples of the silicone-based surfactant include Torre Silicone DC3PA, DC7PA, SH11PA, SH21PA, SH28PA, SH29PA, SH30PA, SH-190, SH-193, SZ-6032, SF -8428, DC-57, DC-190 (above, manufactured by Toray Dow Corning Silicone Co., Ltd.), TSF-4440, TSF-4300, TSF-4445, TSF-4446, TSF-4460, TSF-4442 (The above-mentioned, GE Toshiba Silicone Co., Ltd. product) etc. can be mentioned what is marketed.

Examples of surfactants other than the above include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether; polyoxyethylene n-octylphenyl ether, polyoxy Polyoxyethylene aryl ethers such as ethylene n-nonylphenyl ether; nonionic surfactants such as polyoxyethylene dialkyl esters such as polyoxyethylene dilaurate and polyoxyethylene distearate, and commercially available products such as KP341 (Shin-Etsu) Chemical Industry Co., Ltd.), Polyflow No. 57, no. 95 (manufactured by Kyoeisha Chemical Co., Ltd.).
These surfactants can be used alone or in admixture of two or more.

  The compounding amount of the surfactant is preferably 5 parts by weight or less, and more preferably 2 parts by weight or less with respect to 100 parts by weight of the [A] copolymer. In this case, when the compounding amount of the surfactant exceeds 5 parts by weight, the film is liable to be roughened during the coating.

The said adhesion assistant is a component mix | blended in order to improve the adhesiveness with a base | substrate further.
As such an adhesion assistant, a functional silane coupling agent is preferable. Examples thereof include a silane coupling agent having a reactive functional group such as a carboxyl group, a methacryloyl group, a vinyl group, an isocyanate group, and an epoxy group. More specifically, trimethoxysilylbenzoic acid, γ-methacryloyloxypropyltrimethoxysilane, vinyltriacetoxysilane, vinyltrimethoxysilane, γ-isocyanatopropyltriethoxysilane, γ-glycidoxy Examples thereof include propyltrimethoxysilane and 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane.
These adhesion assistants can be used alone or in admixture of two or more.

  The blending amount of the adhesion assistant is preferably 20 parts by weight or less, more preferably 10 parts by weight or less, with respect to 100 parts by weight of the [A] copolymer. In this case, when the blending amount of the adhesion assistant exceeds 20 parts by weight, there is a tendency that a development residue is likely to occur.

Examples of the storage stabilizer include sulfur, quinones, hydroquinones, polyoxy compounds, amines, nitronitroso compounds, etc., and examples thereof include 4-methoxyphenol, N-nitroso-N-phenylhydroxyl. An amine aluminum etc. can be mentioned.
The amount of the storage stabilizer used is preferably 3.0 parts by weight or less, more preferably 0.5 parts by weight or less, with respect to 100 parts by weight of the [A] copolymer. In this case, when the usage-amount of a storage stabilizer exceeds 3.0 weight part, there exists a possibility that a sensitivity may fall and the shape of a spacer may be impaired.

Examples of the heat resistance improver include N- (alkoxymethyl) glycoluril compounds, N- (alkoxymethyl) melamine compounds, compounds having two or more epoxy groups, and the like.
Examples of the N- (alkoxymethyl) glycoluril compound include N, N, N, N-tetra (methoxymethyl) glycoluril, N, N, N, N-tetra (ethoxymethyl) glycoluril, N, N , N, N-tetra (n-propoxymethyl) glycoluril, N, N, N, N-tetra (i-propoxymethyl) glycoluril, N, N, N, N-tetra (n-butoxymethyl) glycoluril , N, N, N, N-tetra (t-butoxymethyl) glycoluril and the like.
Of these N- (alkoxymethyl) glycoluril compounds, N, N, N, N-tetra (methoxymethyl) glycoluril is preferred.

Examples of the N- (alkoxymethyl) melamine compound include N, N, N, N, N, N-hexa (methoxymethyl) melamine, N, N, N, N, N, N-hexa (ethoxymethyl). Melamine, N, N, N, N, N, N-hexa (n-propoxymethyl) melamine, N, N, N, N, N, N-hexa (i-propoxymethyl) melamine, N, N, N, Examples thereof include N, N, N-hexa (n-butoxymethyl) melamine, N, N, N, N, N, N-hexa (t-butoxymethyl) melamine and the like.
Of these N- (alkoxymethyl) melamine compounds, N, N, N, N, N, N-hexa (methoxymethyl) melamine is preferred, and examples of commercially available products thereof include Nicalac N-2702 and MW- 30M (manufactured by Sanwa Chemical Co., Ltd.).

Examples of the compound having two or more epoxy groups include ethylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, and polypropylene glycol diglycidyl ether. And neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin diglycidyl ether, trimethylolpropane triglycidyl ether, hydrogenated bisphenol A diglycidyl ether, bisphenol A diglycidyl ether, and the like.
Examples of commercially available compounds having two or more epoxy groups include Epolite 40E, 100E, 200E, 70P, 200P, 400P, 1500NP, 1600, 80MF, 100MF, 3002 and 4000 (above, manufactured by Kyoeisha Chemical Co., Ltd.).
These heat resistance improvers can be used alone or in admixture of two or more.

The radiation-sensitive resin composition of the present invention is preferably used as a composition solution dissolved in an appropriate solvent.
As the solvent, a solvent that dissolves each component constituting the radiation-sensitive resin composition uniformly, does not react with each component, and has appropriate volatility is used.
Examples of such a solvent include the same solvents as those exemplified for the polymerization for producing the [A] copolymer.
Among these solvents, alcohols, ethylene glycol monoalkyl ether acetates, diethylene glycol monoalkyl ether acetates, diethylene glycol alkyl ethers from the viewpoint of solubility of each component, reactivity with each component, and ease of film formation. , Propylene glycol monoalkyl ether acetates, alkyl alkoxypropionates and the like are preferable, and in particular, benzyl alcohol, 2-phenylethanol, 3-phenyl-1-propanol, ethylene glycol mono-n-butyl ether acetate, diethylene glycol monoethyl ether acetate , Diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol ethyl methyl ether, propylene glycol Monomethyl ether acetate, propylene glycol monoethyl ether acetate are preferred.
The said solvent can be used individually or in mixture of 2 or more types.

In the present invention, a high boiling point solvent may be used in combination with the solvent.
Examples of the high boiling point solvent include N-methylformamide, N, N-dimethylformamide, N-methylformanilide, N-methylacetamide, N, N-dimethylacetamide, N-methylpyrrolidone, dimethylsulfoxide, and benzylethyl ether. , Dihexyl ether, acetonyl acetone, isophorone, caproic acid, caprylic acid, 1-octanol, 1-nonanol, benzyl acetate, ethyl benzoate, diethyl oxalate, diethyl maleate, γ-butyrolactone, ethylene carbonate, propylene carbonate, phenyl Examples include cellosolve acetate.
These high-boiling solvents can be used alone or in admixture of two or more.
In addition, the composition solution prepared as described above can be used after being filtered using a Millipore filter having a pore size of about 0.5 μm.

Method of forming spacers Next, a method of forming a spacer of the present invention will be described with reference to radiation-sensitive resin composition of the present invention.
The formation of the spacer of the present invention includes at least the following steps (a) to (2).
(A) A step of forming a film of the radiation sensitive resin composition of the present invention on a substrate.
(B) A step of exposing radiation to at least a part of the coating.
(C) A step of developing the film after exposure.
(D) A step of heating the coated film after development.

Hereinafter, each of these steps will be described sequentially.
-(I) Process-
A transparent conductive film is formed on one surface of a transparent substrate, the composition solution of the radiation-sensitive resin composition of the present invention is applied on the transparent conductive film, and then the coated surface is heated (prebaked) to form a coating film. Form.
Examples of the transparent substrate used for forming the spacer include a glass substrate and a resin substrate. More specifically, glass substrates such as soda lime glass and non-alkali glass; polyethylene terephthalate, polybutylene terephthalate, Examples thereof include a resin substrate made of a plastic such as polyethersulfone, polycarbonate, and polyimide.
Examples of the transparent conductive film provided on one surface of the transparent substrate include a NESA film (registered trademark of US PPG) made of tin oxide (SnO ₂ ), an ITO film made of indium oxide-tin oxide (In ₂ O ₃ —SnO ₂ ), etc. Can be mentioned.
As a coating method of the composition solution, for example, an appropriate method such as a spray coating method, a roll coating method, a spin coating method (spin coating method), a slit die coating method, a bar coating method, an ink jet coating method, or the like may be adopted. In particular, a spin coating method and a slit die coating method are preferable.
Moreover, although the conditions of prebaking differ also with the kind of each component, a mixture ratio, etc., it is normally about 1 to 15 minutes at 70-120 degreeC.

-(B) Process-
Next, radiation is exposed to at least a part of the formed film. In this case, when exposing a part of the film, the exposure is usually performed through a photomask having a predetermined pattern.
Visible rays, ultraviolet rays, far ultraviolet rays, electron beams, X-rays, and the like can be used as the radiation used, but radiation having a wavelength in the range of 190 to 450 nm is preferable, and radiation including ultraviolet light having a wavelength of 365 nm is particularly preferable.
The exposure dose is usually 100 to 10,000 J / m ² , preferably 1,500, as a value obtained by measuring the intensity of the exposed radiation at a wavelength of 365 nm with an illuminometer (OAI model 356, manufactured by OAI Optical Associates Inc.). ˜3,000 J / m ² .

-(C) Process-
Subsequently, the exposed film is developed to remove unnecessary portions and form a predetermined pattern.
Examples of the developer used for development include inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and ammonia; and aliphatic primary grades such as ethylamine and n-propylamine. Amines; aliphatic secondary amines such as diethylamine and di-n-propylamine; aliphatic tertiary amines such as trimethylamine, methyldiethylamine, dimethylethylamine and triethylamine; pyrrole, piperidine, N-methylpiperidine, N-methyl Alicyclic tertiary amines such as pyrrolidine, 1,8-diazabicyclo [5.4.0] -7-undecene, 1,5-diazabicyclo [4.3.0] -5-nonene; pyridine, collidine, lutidine , Aromatic tertiary amines such as quinoline; dimethylethanolamine, methyl Ethanolamine, alkanolamines such as triethanolamine; tetramethylammonium hydroxide, may be used an aqueous solution of an alkaline compound such as quaternary ammonium salts such as tetraethyl ammonium hydroxide.
In addition, an appropriate amount of a water-soluble organic solvent such as methanol or ethanol and / or a surfactant can be added to the aqueous solution of the alkaline compound.
As a developing method, any of a liquid filling method, a dipping method, a shower method and the like may be used, and the developing time is usually about 10 to 180 seconds at room temperature.
After development, for example, after washing with running water for 30 to 90 seconds, a desired pattern is formed by, for example, air drying with compressed air or compressed nitrogen.

-(2) Process-
Next, the obtained pattern is heated at a predetermined temperature, for example, 100 to 160 ° C., for a predetermined time, for example, 5 to 30 minutes on the hot plate, for 30 to 180 minutes in the oven, by a heating device such as a hot plate or oven. A predetermined spacer can be obtained by heating (post-baking).
The conventional radiation-sensitive resin composition used for the formation of the spacer cannot exhibit sufficient performance unless the heat treatment is performed at a temperature of about 180 to 200 ° C. or higher. The radiation-sensitive resin composition can be heated at a lower temperature than before, and as a result, without causing yellowing or deformation of the resin substrate, compressive strength, rubbing resistance during liquid crystal alignment, It is possible to provide a spacer having excellent performance such as adhesion.

Liquid crystal display element The liquid crystal display element of the present invention comprises the spacer of the present invention formed as described above.
The structure of the liquid crystal display element is not particularly limited. For example, as shown in FIG. 1, a color filter layer and a spacer of the present invention are formed on a transparent substrate, and the liquid crystal display element 2 is disposed via the liquid crystal layer. A structure having two alignment films, opposing transparent electrodes, opposing transparent substrates, and the like can be given. As shown in FIG. 1, a protective film may be provided on the polarizing plate or the color filter layer as necessary.

  Further, as shown in FIG. 2, a color filter layer and a spacer of the present invention are formed on a transparent substrate, and are made to face a thin film transistor (TFT) array through an alignment film and a liquid crystal layer, thereby allowing a TN-TFT type. It can also be set as a liquid crystal display element. Also in this case, a protective film can be provided on the polarizing plate or the color filter layer as necessary.

The radiation-sensitive resin composition for spacer formation of the present invention can suppress contamination of a baking furnace, a photomask, etc. due to sublimation of the radiation-sensitive polymerization initiator component, does not cause foreign matter in the liquid, and has high sensitivity and high sensitivity. It is easy to form a spacer with excellent resolution and other performance such as cross-sectional shape, compressive strength, rubbing resistance, adhesion to a transparent substrate, and lowering the post-baking temperature when forming the spacer. This is possible and does not cause yellowing or deformation of the resin substrate.
The liquid crystal display element of the present invention includes a spacer having excellent performance such as a cross-sectional shape, compressive strength, rubbing resistance, and adhesion to a transparent substrate, and can ensure high reliability over a long period of time.

Hereinafter, the embodiment of the present invention will be described more specifically with reference to examples.
Synthesis example 1
A flask equipped with a condenser and a stirrer was charged with 5 parts by weight of 2,2′-azobis (2,4-dimethylvaleronitrile) and 250 parts by weight of diethylene glycol ethyl methyl ether, followed by 17 parts by weight of methacrylic acid and methacrylic acid. After 45 parts by weight of glycidyl, 20 parts by weight of styrene and 18 parts by weight of dicyclopentanyl methacrylate were substituted with nitrogen, the temperature of the solution was raised to 70 ° C. while gently stirring, and this temperature was maintained for 4 hours. To obtain a resin solution (solid content concentration = 28.4% by weight) containing the [A] copolymer. Mw of the obtained [A] copolymer was 16,000.
This [A] copolymer is referred to as “copolymer (A-1)”.
Mw of the copolymer (A-1) and the copolymer (A-2) described below was measured using GPC (gel permeation chromatography) HLC-8020 (manufactured by Tosoh Corporation).

Synthesis example 2
A flask equipped with a condenser and a stirrer was charged with 7 parts by weight of 2,2′-azobis (2,4-dimethylvaleronitrile) and 250 parts by weight of diethylene glycol ethyl methyl ether, followed by 18 parts by weight of methacrylic acid and methacrylic acid. After charging 20 parts by weight of glycidyl, 5 parts by weight of styrene, 32 parts by weight of dicyclopentanyl methacrylate, and 25 parts by weight of tetrahydrofurfuryl methacrylate and replacing with nitrogen, the temperature of the solution was raised to 70 ° C. while gently stirring. This temperature was maintained for 4 hours for polymerization to obtain a resin solution containing [A] copolymer (solid content concentration = 28.8% by weight). Mw of the obtained [A] copolymer obtained was 11,000.
This [A] copolymer is referred to as “copolymer (A-2)”.

Example 1
-Preparation of composition solution-
As component [A], 100 parts by weight (solid content) of the resin solution obtained in Synthesis Example 1 as copolymer (A-1), and as component [B], dipentaerystol hexaacrylate (trade name: KAYARAD DPHA, Japan 80 parts by weight of Kayaku Co., Ltd., and 2- (4-methylbenzyl) -2- (dimethylamino) -1- (4-morpholinophenyl) butan-1-one (trade name Irgacure) as the [C] component 379, manufactured by Ciba Specialty Chemicals), 40 parts by weight, 5 parts by weight of γ-glycidoxypropyltrimethoxysilane as an adhesion aid, 0.5 parts by weight of surfactant FTX-218 as a surfactant, storage stabilizer As a solution, 0.5 part by weight of 4-methoxyphenol is mixed and dissolved in propylene glycol methyl ether acetate so that the solid content concentration is 30% by weight. And then, filtered through a Millipore filter having a pore size 0.5 [mu] m, to prepare a composition solution.

-Spacer formation-
The composition solution was applied onto an alkali-free glass substrate using a spinner and then pre-baked on an 80 ° C. hot plate for 3 minutes to form a film having a thickness of 6.0 μm.
Subsequently, the obtained film was exposed to ultraviolet rays having an intensity of 250 W / m ^{2 at} a wavelength of 365 nm for 10 seconds through a photomask having a remaining pattern of 10 μm square. Thereafter, development was performed with a 0.05 wt% aqueous potassium hydroxide solution at 25 ° C. for 60 seconds, followed by washing with pure water for 1 minute. Then, the spacer of the predetermined pattern was formed by post-baking for 120 minutes at 150 degreeC in oven.
Subsequently, evaluation was performed according to the following procedures (I) to (VIII). The evaluation results are shown in Table 2-1.

(I) Evaluation of sensitivity When the spacer was formed, the exposure amount at which the residual film ratio after development (film thickness after development × 100 / initial film thickness; the same applies hereinafter) was 90% was defined as sensitivity. When this exposure amount is 1,500 J / m ² or less, it can be said that the sensitivity is good.
(II) Evaluation of resolution When the spacer was formed, the resolution was evaluated based on the minimum pattern size resolved by the exposure amount at which the remaining film ratio after development was 90% or more.

(III) Evaluation of the cross-sectional shape of the spacer The cross-sectional shape of the obtained spacer was observed with a scanning electron microscope and evaluated according to which of A to D shown in FIG. At this time, when the pattern edge is forward tapered or vertical like A or B, it can be said that the cross-sectional shape is good. On the other hand, as shown in C, when the sensitivity is insufficient, the remaining film rate is low, the cross-sectional dimension is small compared to A and B, and the bottom surface is a semi-convex lens shape with a flat surface, the cross-sectional shape is Also, as shown in D, the pattern may be peeled off during the subsequent rubbing process even in the case of an inversely tapered shape (in the cross-sectional shape, an inverted triangular shape in which the side of the film surface is longer than the side on the substrate side). Since it became very large, the cross-sectional shape was regarded as defective.

(IV) Evaluation of compressive strength About the obtained spacer, using a micro compression tester (MCTM-200, manufactured by Shimadzu Corporation), the amount of deformation when a load of 10 mN was applied by a flat indenter with a diameter of 50 μm was used. The measurement temperature was 23 ° C. When this value is 0.5 μm or less, it can be said that the compressive strength is good. (V) Evaluation of rubbing resistance AL3046 (trade name, manufactured by JSR Co., Ltd.) as a liquid crystal aligning agent was applied to a substrate on which a spacer was formed by a printing machine for applying a liquid crystal alignment film, and then dried at 180 ° C. for 1 hour. A film of a liquid crystal aligning agent having a thickness of 0.05 μm was formed.
Thereafter, the coating film was subjected to a rubbing treatment with a rubbing machine having a roll around which a polyamide cloth was wound, with a roll rotation speed of 500 rpm and a stage moving speed of 1 cm / sec. At this time, the presence or absence of pattern shaving or peeling was evaluated.

(VI) Evaluation of adhesion A cured film was formed in the same manner as in the formation of the spacer except that no photomask was used. Thereafter, the adhesive test of JIS K-5400 (1900) 8.5 was evaluated by the 8.5 / 2 cross-cut tape method. At this time, the number of remaining grids out of 100 grids is shown in Table 2.

(VII) Evaluation of sublimation property The composition solution was applied onto a substrate and then dried to form a film having a thickness of 6.0 μm. Thereafter, for this coating, n-octane (specific gravity = 0.701, injection amount = 0.02 μL) was used as a standard substance, purge conditions were set to 100 ° C./10 minutes, headspace gas chromatography / mass spectrometry (head Space sampler: JHS-100A manufactured by Nihon Analytical Industries, Ltd., gas chromatography / mass spectrometer: JEOL JMS-AX505W type mass spectrometer manufactured by Nihon Analytical Industries, Ltd.), derived from a radiation-sensitive polymerization initiator The peak area A to be obtained was determined, and the volatilization amount in terms of n-octane was calculated by the following formula. It can be said that the greater the volatilization amount, the greater the sublimation property.
Calculation formula for volatilization amount in terms of n-octane Volatilization amount (μg)
= A × (amount of n-octane) (μg) / (peak area of n-octane)

(VIII) Evaluation of foreign matter in liquid The presence or absence of a recrystallized product of the radiation-sensitive polymerization initiator component when the composition solution was stored at −15 ° C. for 7 days was visually observed. Further, when the liquid temperature of the stored composition solution is raised from −15 ° C. to 23 ° C., a solid matter (residual foreign matter) having a size of 0.5 μm or more remaining without being redissolved in 1 ml of the composition solution. ) Was measured using a light scattering liquid particle detector (trade name KS-28B, manufactured by Rion Co., Ltd.).

Examples 2-23
Each composition solution was prepared in the same manner as in Example 1 except that the components shown in Table 1-1 were used as the components [A], [B] and [C], and a spacer was formed. Evaluation was performed. The evaluation results are shown in Table 2-1.

Example 24
The same components as in Example 1 were dissolved in diethylene glycol ethyl methyl ether so that the solid content concentration was 17.5% by weight, and then filtered through a Millipore filter having a pore size of 0.5 μm to prepare a composition solution. Except for the above, a spacer was formed and evaluated in the same manner as in Example 1. The evaluation results are shown in Table 2-1.

Comparative Examples 1-8
Prepare each composition solution in the same manner as in Example 1 except that each of the components shown in Table 1-2 was used as the component [A], the component [B] and the radiation-sensitive polymerization initiator, and a spacer was formed. And evaluated. The evaluation results are shown in Table 2-2.

In Table 1-1 and Table 1-2, each component other than [A] component is as follows.
B-1: Dipentaerystol hexaacrylate B-2: Trade name KAYARAD DPHA-40H (manufactured by Nippon Kayaku Co., Ltd.)
C-1: 2- (4-methylbenzyl) -2- (dimethylamino) -1- (4-morpholinophenyl) butan-1-one D-1: 1- [9-ethyl-6- (2-methyl) Benzoyl) -9. H. -Carbazol-3-yl] ethane-1-one oxime-O-acetate (trade name CGI-242, manufactured by Ciba Specialty Chemicals)
E-1: 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one (trade name Irgacure 907, manufactured by Ciba Specialty Chemicals)
E-2: 2-benzyl-2- (dimethylamino) -1- (4-morpholinophenyl) butan-1-one (trade name Irgacure 369, manufactured by Ciba Specialty Chemicals)
E-3: 1- (2-bromo-4-morpholinophenyl) -2-benzyl-2-dimethylaminobutan-1-one F-1: 2,2′-bis (2,4-dichlorophenyl) -4, 4 ', 5,5'-tetraphenyl-1,2'-biimidazole F-2: 4,4'-bis (diethylamino) benzophenone F-3: 2-mercaptobenzothiazole

It is a schematic diagram which shows an example of the structure of a liquid crystal display element. It is a schematic diagram which shows the other example of the structure of a liquid crystal display element. It is a schematic diagram which illustrates the cross-sectional shape of a spacer.

Claims (4)

[A] a copolymer of (a1) an unsaturated carboxylic acid and / or an unsaturated carboxylic acid anhydride, (a2) an epoxy group-containing unsaturated compound, and (a3) another unsaturated compound,
[B] A radiation-sensitive resin for spacer formation, comprising a polymerizable unsaturated compound and [C] a radiation-sensitive polymerization initiator having a compound represented by the following general formula (1) as essential components Composition.

[In General Formula (1), R ¹ represents a linear, branched or cyclic alkyl group having 1 to 12 carbon atoms, R ² and R ³ are independently a hydrogen atom; A linear, branched or cyclic alkyl group or a benzyl group, wherein R ⁴ , R ⁵ , R ⁷ and R ⁸ are each independently a hydrogen atom; a halogen atom; a linear or branched chain having 1 to 12 carbon atoms A linear or branched alkyl group having 1 to 4 carbon atoms or a linear or branched alkoxyl group having 1 to 4 carbon atoms, wherein R ⁶ is a halogen atom; a linear, branched or cyclic alkyl group having 1 to 12 carbon atoms; a hydroxyl group And a linear, branched or cyclic alkyl group having 1 to 12 carbon atoms substituted with a substituent selected from the group of linear or branched alkoxyl groups having 1 to 4 carbon atoms; A linear or branched alkoxyl group of Other denotes a hydroxyl group and a linear or branched linear or branched alkoxyl group having 2 to 4 carbon atoms which is substituted with a substituent selected from the group of alkoxy group having 1 to 4 carbon atoms. ]   A spacer formed from the radiation-sensitive resin composition for forming a spacer according to claim 1. A method for forming a spacer, comprising at least the following steps (a) to (2). (A) A step of forming a coating of the radiation-sensitive resin composition for forming a spacer according to claim 1 on a substrate.
(B) A step of exposing radiation to at least a part of the coating.
(C) A step of developing the film after exposure.
(D) A step of heating the coated film after development.   A liquid crystal display device comprising the spacer according to claim 2.

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