JP2007128062A - Radiation-sensitive resin composition, spacer formation method and spacer - Google Patents

Abstract

[Object] To form a spacer having high radiation sensitivity, sufficiently high resolution, excellent adhesion to a substrate, an underlayer or an upper layer, and suppressed generation of sublimation during firing in a film forming process To provide a radiation-sensitive resin composition suitably used for the purpose.
A radiation-sensitive resin composition (A) is polymerized by living radical polymerization in the presence of a specific thiocarbonylthio compound, and has a weight average molecular weight (Mw) in terms of polystyrene measured by gel permeation chromatography. The ratio (Mw / Mn) to the number average molecular weight (Mn) is 1.7 or less and contains a polymer having a carboxyl group, (B) a polymerizable unsaturated compound and (C) a radiation-sensitive polymerization initiator. And used for forming a spacer.
[Selection figure] None

Description

  The present invention relates to a radiation-sensitive resin composition containing a specific resin, a method for forming a spacer using the same, and a 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 between two transparent substrates constant. Since spacer particles are randomly scattered on a transparent substrate such as a glass substrate, if spacer particles are present in the pixel formation region, the phenomenon of spacer particle reflection will occur, or incident light will be scattered, reducing the contrast of the liquid crystal display element. There was a problem.
Therefore, in order to solve these problems, a method of forming a spacer by photolithography has been adopted (see, for example, Patent Document 1). In this method, a radiation-sensitive resin composition is applied on a substrate, irradiated with ultraviolet rays through a predetermined mask, and then developed to form dot-like or stripe-like spacers other than the pixel formation region. Since the spacers can be formed only at predetermined locations, the above-described problems have been basically solved.
However, in the conventional radiation-sensitive resin composition, there is a concern that the sublimate generated during firing for forming the spacer may contaminate the process line or device, and the generation of the sublimate is reduced. A composition is desired.
JP 2001-261761 A Japanese Patent No. 3639859 (Japanese Patent Publication No. 2000-515181) Special Table 2002-2002 JP-T-2004-518773 Special table 2002-508409 gazette Japanese translation of PCT publication No. 2002-512653 Special table 2003-527458 gazette Japanese Patent No. 3634843 (Japanese Patent Publication No. 2003-536105) JP-T-2005-503452 M.M. K. Georges et al. , Macromolecules, 1993, Vol. 26, p. 2987 Matyjaszewski et al. , Macromolecules, 1997, Vol. 30, p. 7348 Hamasaki, S .; et al. , Macromolecules, 2002, Vol. 35, p. 2934

The present invention has been made on the basis of the above circumstances, and its purpose is, firstly, to have high radiation sensitivity, sufficiently high resolution, excellent adhesion to a substrate, and a film forming process. An object of the present invention is to provide a radiation-sensitive resin composition that is suitably used for forming a spacer, in which generation of sublimates during firing is suppressed. The radiation sensitive resin composition provides a spacer having excellent pattern shape, compressive strength and rubbing resistance.
A second object of the present invention is to provide a method for forming a spacer from the above radiation sensitive resin composition.
A third object of the present invention is to provide a spacer formed by the above method, and fourth, to provide a liquid crystal display device comprising the spacer.

  According to the present invention, the object of the present invention is firstly as follows: (A) the following formula (1)

(In the formula (1), there are two Z each independently represent a hydrogen atom, a carboxyl group, group -R, group -OR, group -NR _2, group -COOR, group -C (= O) NR _2, group - P (═O) R ₂ , group —P (═O) (OR) ₂ or group —NRNR—C (═O) R, wherein R is independently a halogen atom, a cyano group, a hydroxyl group, or a carbon number of 1-20. An alkyl group of 2 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, or a monovalent valence having 3 to 20 carbon atoms in total. When R is an alkyl group, an alkenyl group, an aryl group, an aralkyl group or a heterocyclic group, one or more of the hydrogen atoms of R are a halogen atom, (It may be substituted with a cyano group, a hydroxyl group or a carboxyl group.)
The ratio (Mw / Mn) of polystyrene-reduced weight average molecular weight (Mw) and number average molecular weight (Mn) measured by gel permeation chromatography is 1 by living radical polymerization in the presence of the compound represented by formula (1). Radiation sensitive, characterized in that it comprises a polymer having a carboxyl group of .7 or less, (B) a polymerizable unsaturated compound and (C) a radiation sensitive polymerization initiator, and is used for forming a spacer. This is achieved by the conductive resin composition.

Secondly, the above object of the present invention is achieved by a spacer forming method in which at least the following steps (1) to (4) are carried out in the order described below.
(1) The process of forming the film of said radiation sensitive resin composition on a board | substrate.
(2) A step of exposing radiation to at least a part of the coating.
(3) A step of developing the film after exposure.
(4) A step of heating the film after development.
Thirdly, the above object of the present invention is achieved by the spacer formed by the above method, and fourthly, by a liquid crystal display device comprising the spacer.

<Radiation sensitive resin composition>
The radiation sensitive resin composition of the present invention contains (A) a polymer, (B) a polymerizable unsaturated compound, and (C) a radiation sensitive polymerization initiator. Hereinafter, each component which the radiation sensitive resin composition of this invention contains is demonstrated.
<(A) Polymer>
The polymer (A) preferably used in the radiation-sensitive resin composition of the present invention is polymerized by living radical polymerization in the presence of the compound represented by the above formula (1), and measured by gel permeation chromatography. The ratio (Mw / Mn) of polystyrene-equivalent weight average molecular weight (Mw) to number average molecular weight (Mn) is 1.7 or less, and is a polymer having a carboxyl group, preferably oxiranyl in addition to the carboxyl group. Or a polymer having an oxetanyl group.

(A) The polymer is at least one selected from (a1) an unsaturated carboxylic acid and an unsaturated carboxylic acid anhydride (hereinafter collectively referred to as “compound (a1)”), (a2) an oxiranyl group or Contains an unsaturated compound containing an oxetanyl group (hereinafter referred to as “compound (a2)”) and an unsaturated compound other than (a3), (a1) and (a2) (hereinafter referred to as “compound (a3)”). The polymerizable mixture is preferably a polymer obtained by subjecting the polymerizable mixture to living radical polymerization in the presence of the compound represented by the above formula (1).
For example, the polymer (A) comprises a polymerizable mixture containing the compound (a1), the compound (a2) and the compound (a3) in a suitable solvent, a polymerization initiator, and a compound represented by the above formula (1). It is preferable to produce by living radical polymerization in the presence of. The carboxyl group of the polymer (A) thus obtained is derived from the compound (a1), and the oxiranyl group or oxetanyl group is derived from the compound (a2). The compounds (a1) to (a3) are preferably all having radical polymerizability.

Hereinafter, (A) Living radical polymerization for producing a polymer will be described.
Various radical polymerization initiator systems for living radical polymerization of polymerizable unsaturated compounds or mixtures thereof have been proposed. For example, Non-Patent Document 1 includes a so-called TEMPO system; Non-Patent Document 2 contains copper bromide and bromine. A system comprising a combination of ester compounds;
Non-Patent Document 3 includes a system comprising a combination of carbon tetrachloride and a ruthenium (II) complex;
Patent Documents 2 to 9 each disclose a system comprising a combination of a thiocarbonylthio compound having a chain transfer constant greater than 0.1 and a radical initiator.
However, when the present inventors used a radiation-sensitive resin composition containing a polymer having a specific structure obtained by living radical polymerization using a specific thiocarbonylthio compound for forming a spacer, The present inventors have found that the above-described various required characteristics are satisfied and generation of sublimates during firing in the spacer forming step is suppressed, and the present invention has been achieved.

In the living radical polymerization for synthesizing the polymer used in the present invention, the compound represented by the above formula (1) is used.
Examples of the halogen atom of Z in the above formula (1) include a chlorine atom, a bromine atom, and a fluorine atom;
Examples of the alkyl group having 1 to 20 carbon atoms include 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, 1,1-dimethylpropyl group, neopentyl group, n-hexyl group, n-heptyl group, n-octyl group, 1,1-dimethyl-3,3-dimethylbutyl group, n-nonyl group, n- Decyl group, n-dodecyl group, n-tetradecyl group, n-hexadecyl group, n-octadecyl group, n-eicosyl group and the like;
Examples of the alkenyl group having 2 to 20 carbon atoms include a vinyl group, an allyl group, a 1-propenyl group, a 2-propenyl group, an isopropenyl group, a 1-butenyl group, and a 2-butenyl group;

Examples of the aryl group having 6 to 20 carbon atoms include a phenyl group, a 1-naphthyl group, a 2-naphthyl group, a 1-anthracenyl group, and a 9-anthracenyl group;
Examples of the aralkyl group having 7 to 20 carbon atoms include benzyl group, α-methylbenzyl group, α, α-dimethylbenzyl group, phenethyl group and the like;
Examples of the monovalent heterocyclic group having 3 to 20 total atoms of carbon atoms and hetero atoms include oxiranyl group, aziridinyl group, 2-furanyl group, 3-furanyl group, 2-tetrahydrofuranyl group, 3 -Tetrahydrofuranyl group, pyrrol-1-yl group, pyrrol-2-yl group, pyrrol-3-yl group, 1-pyrrolidinyl group, 2-pyrrolidinyl group, 3-pyrrolidinyl group, pyrazol-1-yl group, pyrazole- 3-yl group, 2-tetrahydropyranyl group, 3-tetrahydropyranyl group, 4-tetrahydropyranyl group, 2-thianyl group, 3-thianyl group, 4-thianyl group, 2-pyridinyl group, 3-pyridinyl group 4-pyridinyl group, 2-piperidinyl group, 3-piperidinyl group, 4-piperidinyl group, 2-morpholinyl group, 3-morpholinyl group, 2-imida Lil group, 4-imidazolyl group, indol-1-yl group and the like, can be exemplified respectively.

Preferred specific examples of Z in the above formula (1) include, for example, a hydrogen atom, a cyano group, a chlorine atom, a carboxyl group, a dodecyl group, an octadecyl group, an ethoxy group, a butoxycarbonyl group, a phenyl group, a phenoxy group, a dimethylamino group, and diethylamino. Group, dimethylaminocarbonyl group, diethylaminocarbonyl group, 2-imidazolyl group, pyrrol-1-yl group, pyrazol-1-yl group, 3-methyl-pyrazol-1-yl group, 4-methyl-pyrazol-1-yl group, indol-1-yl group, group _{-P (= O) (OC 2} H 5) 2, group _{-P (= O) (C 6} H 5) 2, group _{-P (= O) (OC 6} H _{5) 2,} group _{-N (C 2 H 5) N} (CH 3) C (= O) CH 2 F, group _{-N (C 6} H _{5) 2,} group _{-N (C 6 H 5) CH} 3 , etc. Raise be able to.
Preferable specific examples of the compound represented by the above formula (1) include, for example, tetraethylthiuram disulfide, bis (pyrazol-1-yl thiocarbonyl) disulfide, bis (3-methyl-pyrazol-1-yl thiocarbonyl) disulfide, bis (4-Methyl-pyrazol-1-yl thiocarbonyl) disulfide, bispyrrol-1-ylthiocarbonyl disulfide, bisthiobenzoyl disulfide and the like can be mentioned.
These compounds can be used alone or in admixture of two or more.

The radical polymerization initiator used in the living radical polymerization is not particularly limited, and those generally known as radical polymerization initiators can be used, for example, 2,2′-azobisisobutyrate. Azo compounds such as rhonitrile, 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile); benzoyl peroxide, lauroyl peroxide, 1 , 1'-bis (t-butylperoxy) cyclohexane, organic peroxides such as t-butylperoxypivalate; hydrogen peroxide; redox initiators composed of these peroxides and reducing agents. it can.
These radical initiators can be used alone or in admixture of two or more.

The solvent used in the living radical polymerization is not particularly limited as long as the active radicals are not deactivated, but for example, propylene glycol monoalkyl ether compounds such as propylene glycol monomethyl ether and propylene glycol monoethyl ether;
Ethylene glycol methyl ether acetate, ethylene glycol ethyl ether acetate, diethylene glycol methyl ether acetate, diethylene glycol ethyl ether acetate, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, dipropylene glycol methyl ether acetate, dipropylene glycol ethyl ether acetate, etc. Poly) alkylene glycol alkyl ether acetate compounds;
(Poly) alkylene glycol dialkyl ether compounds such as diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol diethyl ether, dipropylene glycol dimethyl ether, dipropylene glycol methyl ethyl ether, dipropylene glycol diethyl ether;
Other ether compounds such as tetrahydrofuran;

Ketone compounds such as methyl ethyl ketone, cyclohexanone, 2-heptanone, 3-heptanone;
Ketoalcohol compounds such as diacetone alcohol (ie 4-hydroxy-4-methylpentan-2-one), 4-hydroxy-4-methylhexane-2-one;
Lactic acid alkyl ester compounds such as methyl lactate and ethyl lactate;
Ethyl 2-hydroxy-2-methylpropionate, ethyl hydroxyacetate, methyl 2-hydroxy-3-methylbutanoate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, 3-ethoxypropion Ethyl acetate, ethyl ethoxyacetate, 3-methyl-3-methoxybutyl acetate, 3-methyl-3-methoxybutylpropionate, ethyl acetate, n-propyl acetate, i-propyl acetate, n-butyl acetate, i-acetate Butyl, n-pentyl formate, i-pentyl acetate, n-butyl propionate, ethyl butyrate, n-propyl butyrate, i-propyl butyrate, n-butyl butyrate, methyl pyruvate, ethyl pyruvate, n-propyl pyruvate , Methyl acetoacetate, ethyl acetoacetate, 2-oxobutanoic acid Other ester compounds such as Le;
Aromatic hydrocarbon compounds such as toluene and xylene;
Examples thereof include amide compounds such as N-methylpyrrolidone, N, N-dimethylformamide, and N, N-dimethylacetamide.

Among these solvents, from the viewpoint of solubility of each component and film-forming property when a radiation sensitive resin composition is used, propylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol mono Ethyl ether acetate, dipropylene glycol methyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, dipropylene glycol dimethyl ether, cyclohexanone, 2-heptanone, 3-heptanone, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, 3- Ethyl ethoxypropionate, 3-methyl-3-methoxybutylpropionate, n-butyl acetate, i-acetate Chill, formic acid n- pentyl acetate, i- pentyl, n- butyl propionate, ethyl butyrate, i- propyl butyrate n- butyl, ethyl pyruvate are preferred.
The said solvent can be used individually or in mixture of 2 or more types.
It is preferable that the usage-amount of a solvent is 50-1,000 weight part with respect to 100 weight part of all the unsaturated compounds, More preferably, it is 100-500 weight part.

  In the living radical polymerization, the amount of the compound represented by the formula (1) is preferably 0.1 to 50 parts by weight, more preferably 0.2 to 100 parts by weight of all unsaturated compounds. ˜16 parts by weight, more preferably 0.4 to 8 parts by weight. If this value is less than 0.1 parts by weight, the molecular weight and molecular weight distribution control effects may be insufficient. On the other hand, if this value exceeds 50 parts by weight, low molecular weight components may be preferentially generated. There is. It is preferable that the usage-amount of a radical polymerization initiator is 0.1-50 weight part with respect to 100 weight part of all unsaturated compounds, More preferably, it is 0.1-20 weight part. The polymerization temperature is preferably 0 to 150 ° C., more preferably 50 to 120 ° C., and the polymerization time is preferably 10 minutes to 20 hours, more preferably 30 minutes to 6 hours.

(A) The compound (a1) preferably used for synthesizing the polymer is at least one selected from unsaturated carboxylic acids and unsaturated carboxylic acid anhydrides having radical polymerizability.
Examples of the compound (a1) include monocarboxylic acids, dicarboxylic acids, dicarboxylic acid anhydrides, mono [(meth) acryloyloxyalkyl] esters of polyvalent carboxylic acids, and carboxyl groups and hydroxyl groups at both ends. Examples thereof include mono (meth) acrylates of polymers, polycyclic compounds having a carboxyl group, and anhydrides thereof. In the present specification, “(meth) acrylate” is a concept that combines acrylate and methacrylate. Other similar terms such as “(meth) acryloyloxy group” should be understood as well.
Specific examples thereof include monocarboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid;
Examples of dicarboxylic acids include maleic acid, fumaric acid, citraconic acid, mesaconic acid, itaconic acid and the like;
Examples of dicarboxylic acid anhydrides include, for example, acid anhydrides of the above compounds exemplified as the dicarboxylic acid;

Examples of mono [(meth) acryloyloxyalkyl] esters of polyvalent carboxylic acids such as succinic acid mono [2- (meth) acryloyloxyethyl] and phthalic acid mono [2- (meth) acryloyloxyethyl];
Examples of mono (meth) acrylate of a polymer having a carboxyl group and a hydroxyl group at each of both ends, such as ω-carboxypolycaprolactone mono (meth) acrylate;
Examples of the polycyclic compound having a carboxyl group and anhydrides thereof include 5-carboxybicyclo [2.2.1] hept-2-ene and 5,6-dicarboxybicyclo [2.2.1] hept-2-ene. Ene, 5-carboxy-5-methylbicyclo [2.2.1] hept-2-ene, 5-carboxy-5-ethylbicyclo [2.2.1] hept-2-ene, 5-carboxy-6- Methylbicyclo [2.2.1] hept-2-ene, 5-carboxy-6-ethylbicyclo [2.2.1] hept-2-ene, 5,6-dicarboxybicyclo [2.2.1] And hept-2-ene anhydride.
Of these, monocarboxylic acid and dicarboxylic acid anhydrides are preferably used, and acrylic acid, methacrylic acid, and maleic anhydride are particularly preferably used from the viewpoints of copolymerization reactivity, solubility in alkaline aqueous solutions, and availability. . These may be used alone or in combination.
In the living radical polymerization, the carboxyl group or acid anhydride group of the compound (a1) may be protected with an appropriate protective group and then deprotected.

(A) The compound (a2) preferably used for synthesizing the polymer is an unsaturated compound having radical polymerizability and containing an oxiranyl group or an oxetanyl group.
As the compound (a2) having an oxiranyl group, for example, glycidyl acrylate, glycidyl methacrylate, glycidyl α-ethyl acrylate, glycidyl α-n-propyl acrylate, glycidyl α-n-butyl acrylate, 3,4 acrylate -Oxiranyl butyl, 3,4-oxiranyl butyl methacrylate, 3,4-oxiranyl butyl α-ethyl acrylate, 6,7-oxiranyl heptyl acrylate, 6,7-oxira methacrylate Nylheptyl, α-ethyl acrylate 6,7-oxiranyl heptyl, β-methylglycidyl acrylate, β-methylglycidyl methacrylate, β-ethylglycidyl acrylate, β-ethylglycidyl methacrylate, β-n acrylic acid -Propyl glycidyl, β-n-propyl glycidyl methacrylate, Carboxylic acid ester compounds having an oxiranyl group such as 3,4-oxiranylcyclohexyl chlorate and 3,4-oxiranylcyclohexyl methacrylate;
Examples include ether compounds having an oxiranyl group such as o-vinylbenzyl glycidyl ether, m-vinylbenzyl glycidyl ether, and p-vinylbenzyl glycidyl ether.

Examples of the compound (a2) having an oxetanyl group include 3-ethyl-3-oxetanyl acrylate and 3-ethyl-3-oxetanyl methacrylate.
Among these compounds (a2), glycidyl methacrylate, 6,7-oxiranyl heptyl methacrylate, 3,4-oxiranyl cyclohexyl methacrylate, β-methyl glycidyl methacrylate, o-vinylbenzyl glycidyl ether, m -Vinyl benzyl glycidyl ether, p-vinyl benzyl glycidyl ether, 3-ethyl-3-oxetanyl methacrylate and the like are preferable from the viewpoint of increasing the copolymerization reactivity and the strength of the resulting spacer.
The said compound (a2) can be used individually or in mixture of 2 or more types.

(A) The compound (a3) preferably used for synthesizing the polymer is an unsaturated compound having radical polymerizability other than (a1) and (a2).
As the compound (a3), for example, methacrylic acid alkyl ester, acrylic acid alkyl ester, methacrylic acid cyclic alkyl ester, methacrylic acid ester having a hydroxyl group, acrylic acid cyclic alkyl ester, methacrylic acid aryl ester, acrylic acid aryl ester, unsaturated Examples thereof include dicarboxylic acid diesters, bicyclounsaturated compounds, maleimide compounds, unsaturated aromatic compounds, and conjugated dienes.

Specific examples thereof include methacrylic acid alkyl esters such as methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, sec-butyl methacrylate, t-butyl methacrylate, 2-ethylhexyl methacrylate, isodecyl methacrylate, n-lauryl methacrylate, Decyl methacrylate, n-stearyl methacrylate, etc .;
Examples of acrylic acid alkyl esters such as methyl acrylate and isopropyl acrylate;
Examples of cyclic alkyl esters of methacrylic acid include cyclohexyl methacrylate, 2-methylcyclohexyl methacrylate, tricyclo [5.2.1.0 ^2,6 ] decan-8-yl methacrylate, tricyclo [5.2.1.0 ^2,6 ]. Decane-8-yloxyethyl methacrylate, isobornyl methacrylate, etc .;
Examples of the methacrylic acid ester having a hydroxyl group include hydroxymethyl methacrylate, 2-hydroxyethyl methacrylate, 3-hydroxypropyl methacrylate, 4-hydroxybutyl methacrylate, diethylene glycol monomethacrylate, 2,3-dihydroxypropyl methacrylate, and 2-methacryloxyethylglycol. Side, 4-hydroxyphenyl methacrylate, polyethylene glycol monomethacrylate, polypropylene glycol monomethacrylate, etc .;

Examples of acrylic acid cyclic alkyl esters include cyclohexyl acrylate, 2-methylcyclohexyl acrylate, tricyclo [5.2.1.0 ^2,6 ] decan-8-yl acrylate, tricyclo [5.2.1.0 ^2,6 ]. Decane-8-yloxyethyl acrylate, isobornyl acrylate and the like;
Methacrylic acid aryl esters such as phenyl methacrylate and benzyl methacrylate;
Examples of acrylic acid aryl esters such as phenyl acrylate and benzyl acrylate;
Unsaturated dicarboxylic acid diesters such as diethyl maleate, diethyl fumarate, diethyl itaconate and the like;
Examples of the bicyclo unsaturated compound include bicyclo [2.2.1] hept-2-ene, 5-methylbicyclo [2.2.1] hept-2-ene, and 5-ethylbicyclo [2.2.1] hept. 2-ene, 5-methoxybicyclo [2.2.1] hept-2-ene, 5-ethoxybicyclo [2.2.1] hept-2-ene, 5,6-dimethoxybicyclo [2.2. 1] hept-2-ene, 5,6-diethoxybicyclo [2.2.1] hept-2-ene, 5-t-butoxycarbonylbicyclo [2.2.1] hept-2-ene, 5- Cyclohexyloxycarbonylbicyclo [2.2.1] hept-2-ene, 5-phenoxycarbonylbicyclo [2.2.1] hept-2-ene, 5,6-di (t-butoxycarbonyl) bicyclo [2. 2.1] Hept-2 Ene, 5,6-di (cyclohexyloxycarbonyl) bicyclo [2.2.1] hept-2-ene, 5- (2′-hydroxyethyl) bicyclo [2.2.1] hept-2-ene, 5 , 6-Dihydroxybicyclo [2.2.1] hept-2-ene, 5,6-di (hydroxymethyl) bicyclo [2.2.1] hept-2-ene, 5,6-di (2′- Hydroxyethyl) bicyclo [2.2.1] hept-2-ene, 5-hydroxy-5-methylbicyclo [2.2.1] hept-2-ene, 5-hydroxy-5-ethylbicyclo [2.2 .1] hept-2-ene, 5-hydroxymethyl-5-methylbicyclo [2.2.1] hept-2-ene and the like;

Examples of maleimide compounds include N-phenylmaleimide, N-cyclohexylmaleimide, 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;
Examples of unsaturated aromatic compounds include styrene, α-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, and the like;
Examples of conjugated dienes include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, and the like;
Examples of other unsaturated compounds include acrylonitrile, methacrylonitrile, vinyl chloride, vinylidene chloride, acrylamide, methacrylamide, vinyl acetate, and tetrahydrofurfuryl methacrylate.

Of these, methacrylic acid alkyl esters, methacrylic acid cyclic alkyl esters, bicyclounsaturated compounds, unsaturated aromatic compounds, methacrylic acid esters having hydroxyl groups, conjugated dienes, and the like are preferably used, especially styrene, t-butyl methacrylate, Tricyclo [5.2.1.0 ^2,6 ] decan-8-yl methacrylate, p-methoxystyrene, 2-methylcyclohexyl acrylate, 1,3-butadiene, polyethylene glycol monomethacrylate, polypropylene glycol monomethacrylate, bicyclo [2 2.1] Hept-2-ene or tetrahydrofurfuryl methacrylate is particularly preferable from the viewpoint of copolymerization reactivity and solubility in an aqueous alkali solution. These may be used alone or in combination.

As described above, the polymer (A) is preferably prepared by combining a polymerizable mixture containing the compound (a1), the compound (a2) and the compound (a3) with a polymerization initiator and the above formula (1) in a suitable solvent. It is preferably a polymer obtained by living radical polymerization in the presence of the compound represented.
Preferable specific examples of the polymer (A) used in the radiation-sensitive resin composition of the present invention include, for example, styrene / methacrylic acid / tricyclo [5.2.1.0 ^2,6 ] decan-8-yl methacrylate / Glycidyl methacrylate copolymer, styrene / methacrylic acid / tricyclo [5.2.1.0 ^2,6 ] decan-8-yl methacrylate / glycidyl methacrylate / 1,3-butadiene copolymer, styrene / methacrylic acid / Acrylic acid / benzyl methacrylate / n-butyl methacrylate / 3-ethyl-3-oxetanyl methacrylate copolymer, styrene / methacrylic acid / benzyl methacrylate / tetrahydrofurfuryl methacrylate / methyl glycidyl methacrylate copolymer, etc. Can be mentioned.

In the polymer (A), the content of the structural unit derived from the compound (a1) is preferably 5 to 5 based on the total of the structural units derived from the compounds (a1), (a2) and (a3). It is 50% by weight, more preferably 10 to 40% by weight, and further preferably 10 to 30% by weight. In this case, if the content of the structural unit is less than 5% by weight, the strength, heat resistance, and chemical resistance of the resulting spacer tend to be reduced, whereas if it exceeds 50% by weight, the radiation-sensitive resin composition The storage stability of the product may be reduced.
The polymer (A) used in the present invention preferably has a structural unit derived from the compound (a2) based on the total of structural units derived from the compounds (a1), (a2) and (a3). It contains 10 to 70% by weight, particularly preferably 20 to 60% by weight. When this structural unit is less than 10% by weight, the heat resistance and surface hardness of the resulting spacer tend to decrease, while when the amount of this structural unit exceeds 70% by weight, the storage stability of the radiation-sensitive resin composition is stabilized. Tend to decrease.
The polymer (A) used in the present invention preferably has a structural unit derived from the compound (a3) based on the total of structural units derived from the compounds (a1), (a2) and (a3). 5 to 70% by weight, more preferably 10 to 60% by weight, still more preferably 20 to 50% by weight. When this structural unit is less than 5% by weight, the storage stability of the radiation-sensitive resin composition tends to be lowered. On the other hand, when it exceeds 70% by weight, it is dissolved in an alkaline aqueous solution in the development step in forming the spacer. It may be difficult.

  As described above, the polymer (A) used in the present invention can be obtained by living radical polymerization of an unsaturated compound, and the molecular weight of the compound represented by the above formula (1) is controlled during living radical polymerization. Used as an agent. For this reason, the polymer (A) is represented by the following formula (i) derived from the compound represented by the formula (1) in the polymer.

(In formula (i), Z is the same as in formula (1) above.)
It has group represented by these. The group represented by the above formula (i) is preferably located at the end of the polymer (A).
The polymer (A) used in the present invention is a ratio of polystyrene-equivalent weight average molecular weight (hereinafter referred to as “Mw”) and polystyrene-equivalent number average molecular weight (hereinafter referred to as “Mn”) measured by gel permeation chromatography ( Mw / Mn) is 1.7 or less, preferably 1.5 or less. When Mw / Mn exceeds 1.7, the heat resistance of the obtained spacer may be insufficient. Mw is preferably 2 × 10 ³ to 1 × 10 ⁵ , more preferably 5 × 10 ^{3 to} 5 × 10 ⁴ . If the Mw is less than 2 × 10 ³ , the coating property of the composition becomes insufficient, or the remaining film ratio of the obtained film is reduced, or the pattern shape of the obtained spacer is inferior or the heat resistance is insufficient. There is a case. On the other hand, if Mw exceeds 1 × 10 ⁵ , the sensitivity may be insufficient or the resulting spacer pattern shape may be inferior. Mn is preferably 1.2 × 10 ³ to 1 × 10 ⁵ , and more preferably 2.9 × 10 ^{3 to} 5 × 10 ⁴ . The above ratio Mw / Mn should be evaluated with an accuracy of two significant digits (one decimal place).
Further, the residual monomer amount measured by gel permeation chromatography of the (A) polymer used in the present invention is preferably less than 5.0%, more preferably less than 3.0%, and particularly preferably 2.0%. Is less than. By using such a copolymer having a residual monomer content, a radiation-sensitive resin composition with reduced sublimation during firing can be obtained, and by using a spacer formed from such a composition. Burn-in of the liquid crystal display element can be effectively prevented.

  The radiation sensitive resin composition of the present invention contains the polymer (A) as described above. In the radiation-sensitive resin composition of the present invention, a part of the polymer (A) may be replaced with another polymer as long as the effects of the present invention are not impaired. In this case, other polymers synthesized separately may be used in the preparation of the composition, or (A) the compound represented by the above formula (1) and other molecular weight control in the synthesis of the polymer. By using one or more agents such as α-methylstyrene dimer and t-dodecyl mercaptan in combination, another polymer may be synthesized and used together with the polymer (A). In the latter method, the amount of the other molecular weight control agent used is preferably 200 parts by weight or less, more preferably 40 parts by weight or less, with respect to 100 parts by weight of the compound represented by the above formula (1). . When the usage-amount of another molecular weight control agent exceeds 200 weight part, the effect of this invention may be impaired.

<(B) polymerizable unsaturated compound>
The (B) polymerizable unsaturated compound preferably used in the radiation sensitive resin composition of the present invention is preferably a bifunctional or higher functional (meth) acrylate.
Examples of the bifunctional (meth) acrylate include ethylene glycol diacrylate, ethylene glycol dimethacrylate, 1,6-hexanediol diacrylate, 1,6-hexanediol dimethacrylate, 1,9-nonanediol diacrylate, 1, Examples thereof include 9-nonanediol dimethacrylate, tetraethylene glycol diacrylate, tetraethylene glycol dimethacrylate, polypropylene glycol diacrylate, polypropylene glycol dimethacrylate, bisphenoxyethanol full orange acrylate, bisphenoxyethanol full orange methacrylate, and the like.
Examples of such commercially available bifunctional (meth) acrylates include Aronix M-210, M-240, M-6200 (above, manufactured by Toagosei Co., Ltd.), KAYARAD HDDA, KAYARAD HX-220, R-604, UX-2201, UX-2301, UX-3204, UX-3301, UX-4101, UX-6101, UX-7101, UX-8101, MU-2100, MU-4001 (above, Nippon Kayaku Manufactured by Co., Ltd.), Viscoat 260, 312 and 335HP (above, manufactured by Osaka Organic Chemical Industry Co., Ltd.).

Examples of the tri- or higher functional (meth) acrylate include trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol triacrylate, pentaerythritol trimethacrylate, pentaerythritol tetraacrylate, pentaerythritol tetramethacrylate, dipentaerythritol pentaacrylate, In addition to dipentaerythritol pentamethacrylate, dipentaerythritol hexaacrylate, dipentaerythritol hexamethacrylate, tri (2-acryloyloxyethyl) phosphate, tri (2-methacryloyloxyethyl) phosphate, linear alkylene groups and A compound having an alicyclic structure and having two or more isocyanate groups; And 3 do not have one or more hydroxyl groups can be exemplified such as five (meth) acryloyloxy compound is reacted urethane acrylate compound obtained having a group.
Examples of commercially available trifunctional or higher functional (meth) acrylates include Aronix M-309, -400, -402, -405, -450, -1310, -1600, -1960, and- 7100, -8030, -8060, -8100, -8530, -8560, -8560, -9050, Aronix TO-1450 (manufactured by Toagosei Co., Ltd.), KAYARAD TMPTA, DPHA, DPCA- 20, DPCA-30, DPCA-60, DPCA-120, MAX-3510 (above, manufactured by Nippon Kayaku Co., Ltd.), Biscote 295, 300, 360, GPT, 3PA, 400 (Osaka Organic Chemical Co., Ltd.) and urethane acrylate compounds such as New Frontier R-1150 (Daiichi Kogyo Seiyaku) Co., Ltd.)), manufactured by KAYARAD DPHA-40H (manufactured by Nippon Kayaku Co., Ltd.), and the like.

In this invention, (B) polymeric unsaturated compound can be used individually or in mixture of 2 or more types.
The use amount of the polymerizable unsaturated compound (B) in the radiation sensitive resin composition of the present invention is preferably 10 to 150 parts by weight, more preferably 20 to 100 parts by weight with respect to 100 parts by weight of the polymer (A). 120 parts by weight. (B) If the amount of the polymerizable unsaturated compound used is less than 10 parts by weight, it tends to be difficult to form a film having a uniform film thickness. There is a tendency to decrease.

<(C) Radiation sensitive polymerization initiator>
The (C) radiation-sensitive polymerization initiator preferably used in the radiation-sensitive resin composition of the present invention is a component that generates an active species that can initiate polymerization of the polymerizable unsaturated compound (B) in response to radiation. is there.
As such (C) radiation sensitive polymerization initiator, for example, a radiation sensitive radical polymerization initiator can be preferably used.
Examples of the radiation-sensitive radical polymerization initiator include α-diketones such as diacetyl;
Acyloin such as benzoin; acyloin ether such as benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether; thioxanthone, 2,4-diethylthioxanthone, thioxanthone-4-sulfonic acid, benzophenone, 4,4′-bis (dimethylamino) Benzophenones such as benzophenone and 4,4′-bis (diethylamino) benzophenone; acetophenone, p-dimethylaminoacetophenone, 4- (α, α′-dimethoxyacetoxy) benzophenone, 2,2′-dimethoxy-2-phenylacetophenone, p-methoxyacetophenone, 2-methyl-2-morpholino-1- (4-methylthiophenyl) -1-propanone, 2-benzyl-2-dimethylamino-1- (4-morpholinopheny ) -Butan-1-one and other acetophenones; anthraquinone, 1,4-naphthoquinone and other quinones; phenacyl chloride, tribromomethylphenyl sulfone, tris (trichloromethyl) -s-triazine and other halogen compounds; 2,4 Acylphosphine oxides such as, 6-trimethylbenzoyldiphenylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide; An organic peroxide such as di-t-butyl peroxide can be used.

Examples of commercially available radiation-sensitive radical polymerization initiators include IRGACURE-124, -149, -184, -369, -500, -651, -819, -907, -1000, and the same. -1700, -1800, -1850, -1959, Darocur-1116, -1173, -1664, -2959, -4093 (above, manufactured by Ciba Specialty Chemicals), KAYACURE-DETX, -MBP, -DMBI, -EPA, -OA (above, manufactured by Nippon Kayaku Co., Ltd.), LUCIRIN TPO (made by BASF), VICURE-10, -55 (above, made by STAUFFER), TRIGONALP1 (manufactured by AKZO), SANDORAY 1000 (manufactured by SANDOZ), DEAP (APJOHN Ltd.), QUANTACURE-PDO, the -ITX, same -EPD (manufactured by WARD BLEKINSOP Co., Ltd.) and the like.
Such (C) radiation sensitive polymerization initiators can be used alone or in admixture of two or more.
The amount of the (C) radiation sensitive polymerization initiator used in the radiation sensitive resin composition of the present invention is preferably 1 to 40 parts by weight, more preferably 3 with respect to 100 parts by weight of the (A) polymer. -35 parts by weight. (C) If the amount of the radiation-sensitive polymerization initiator used is less than 1 part by weight, the heat resistance, surface hardness and chemical resistance of the resulting spacer may decrease, whereas if it exceeds 40 parts by weight, the transparency will be increased. There is a tendency to decrease.

In the radiation-sensitive resin composition of the present invention, (C) a radiation-sensitive polymerization initiator and one or more radiation-sensitive sensitizers are used in combination, so that the deactivation due to oxygen in the air is low and the sensitivity is high. It is also possible to obtain a radiation-sensitive radiation-sensitive resin composition.
Examples of such radiation sensitizers include N-methyldiethanolamine, 4,4′-bis (dimethylamino) benzophenone, 4,4′-bis (diethylamino) benzophenone, ethyl p-dimethylaminobenzoate, p-dimethylamino. Examples include i-amyl benzoate, 2,4-diethylthioxanthone, and thioxanthone-4-sulfonic acid. Of these sensitizers, 4,4′-bis (diethylamino) benzophenone or 2,4-diethylthioxanthone is preferred.
Two or more of these radiation sensitizers may be used at the same time.
The use ratio of the radiation sensitizer is preferably 40 parts by weight or less, and more preferably 20 parts by weight or less with respect to 100 parts by weight of the (C) radiation sensitive polymerization initiator. When the use ratio of the radiation sensitizer exceeds 40 parts by weight, there may be a case where a development residue is likely to occur.

<Optional components>
In addition to the above (A) polymer, (B) polymerizable unsaturated compound and (C) radiation sensitive polymerization initiator, the radiation sensitive resin composition of the present invention is within a range not impairing the effects of the present invention. Optional additives other than the above can be contained as necessary. As such optional additives, for example, an adhesion assistant, a surfactant, a storage stabilizer, a heat resistance improver and the like can be blended.
The said adhesion assistant is a component which can be used in order to improve the adhesiveness of the spacer obtained and a board | substrate.
As such an adhesion assistant, a functional silane coupling agent having a reactive functional group such as a carboxyl group, a methacryloyl group, a vinyl group, an isocyanate group, and an oxiranyl group is preferable. Examples thereof include trimethoxysilylbenzoic acid. , Γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, vinyltrimethoxysilane, γ-isocyanatopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, β- (3,4-oxiranylcyclohexyl) ) Ethyltrimethoxysilane and the like.
These adhesion assistants can be used alone or in admixture of two or more.
The compounding amount of the adhesion assistant is preferably 20 parts by weight or less, more preferably 15 parts by weight or less with respect to 100 parts by weight of the polymer (A). If the blending amount of the adhesion aid exceeds 20 parts by weight, there may be a case where a development residue is likely to occur.

The said surfactant is a component which can be used in order to improve film forming property.
As such a surfactant, for example, a fluorine-based surfactant, a silicone-based surfactant, and the like are preferable.
The fluorine-based surfactant is preferably a compound having a fluoroalkyl group and / or a 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, hexaethylene glycol di (1, 1,2,2,3,3-hexafluoro-n-pentyl) ether, octaethylene glycol di (1,1,2,2-tetrafluoro-n-butyl) ether, hexapropylene glycol di (1,1,2, 2,3,3-hexafluoro-n-pentyl) ether, octapropylene glycol di (1,1,2,2-tetrafluoro-n- Til) ether, sodium perfluoro-n-dodecanesulfonate, 1,1,2,2,3,3-hexafluoro-n-decane, 1,1,2,2,8,8,9,9,10,10 -Decafluoro-n-dodecane, sodium fluoroalkylbenzenesulfonate, sodium fluoroalkylphosphate, sodium fluoroalkylcarboxylate, diglycerin tetrakis (fluoroalkylpolyoxyethylene ether), fluoroalkylammonium iodide, fluoroalkylbetaine, other fluoro Examples thereof include alkyl polyoxyethylene ether, perfluoroalkyl polyoxyethanol, perfluoroalkyl alkoxylate, and carboxylic acid fluoroalkyl ester.

Examples of commercially available fluorosurfactants include BM-1000, BM-1100 (above, manufactured by BM CHEMIE), MegaFuck F142D, F172, F173, F183, F178, F191, F191, and F471. F476 (above, Dainippon Ink & Chemicals, Inc.), Florard FC-170C, -171, -430, -431 (above, Sumitomo 3M Limited), Surflon S-112, -113, -131, -141, -145, -382, Surflon SC-101, -102, -103, -104, -105, -106 (above, Asahi Glass Co., Ltd.) Manufactured), F-top EF301, 303, 352 (above, Shin-Akita Kasei Co., Ltd.), FT-100, -110, -140A, -1 50, the same -250, the same -251, the same -300, the same -310, the same -400S, the tangent FTX-218, the same -251 (above, manufactured by Neos Co., Ltd.) and the like.
Examples of the silicone-based surfactant include Toray 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.

Further, as surfactants other than the above, polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether; polyoxyethylene-n-octylphenyl ether, polyoxyethylene-n -Polyoxyethylene aryl ethers such as nonylphenyl ether; Nonionic surfactants such as polyoxyethylene dialkyl esters such as polyoxyethylene dilaurate and polyoxyethylene distearate; and organosiloxane polymer KP341 (Shin-Etsu Chemical Co., Ltd.) Manufactured), (meth) acrylic acid copolymer polyflow No. 57, no. 95 (above, 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 1.0 part by weight or less, and more preferably 0.5 part by weight or less with respect to 100 parts by weight of the polymer (A). In this case, when the compounding amount of the surfactant exceeds 1.0 part by weight, film unevenness may easily occur.

Examples of the storage stabilizer include sulfur, quinones, hydroquinones, polyoxy compounds, amines, nitronitroso compounds, and more specifically, 4-methoxyphenol, N-nitroso-N-phenyl. Examples include hydroxylamine aluminum.
These storage stabilizers can be used alone or in admixture of two or more.
The blending amount of the storage stabilizer 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 polymer (A). In this case, when the amount of the storage stabilizer exceeds 3.0 parts by weight, the sensitivity may be lowered and the pattern shape may be deteriorated.

Examples of the heat resistance improver include N- (alkoxymethyl) glycoluril compounds, N- (alkoxymethyl) melamine compounds, and compounds having two or more oxiranyl groups.
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 can be mentioned.
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 ′, N ′, N ″, N ″ -hexa (n-butoxymethyl) melamine, N, N, N ′, N ′, N ″, N ″ -Hexa (t-butoxymethyl) melamine etc. can be mentioned.
Among these N- (alkoxymethyl) melamine compounds, N, N, N ′, N ′, N ″, N ″ -hexa (methoxymethyl) melamine is preferable, and as a commercially available product, for example, Nicalac N-2702 MW-30M (manufactured by Sanwa Chemical Co., Ltd.).

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

<Method for preparing radiation-sensitive resin composition>
The radiation-sensitive resin composition of the present invention uniformly contains the above-mentioned (A) polymer, (B) polymerizable unsaturated compound and (C) radiation-sensitive polymerization initiator and other components optionally added. Prepared by mixing. The radiation-sensitive resin composition of the present invention is preferably used in a solution state after being dissolved in an appropriate solvent. For example, by mixing (A) a polymer, (B) a polymerizable unsaturated compound and (C) a radiation-sensitive polymerization initiator and other optional components in a suitable solvent in a predetermined ratio. A radiation-sensitive resin composition in a solution state can be prepared.
Solvents used in the preparation of the radiation sensitive resin composition of the present invention include (A) a polymer, (B) a polymerizable unsaturated compound, and (C) a radiation sensitive polymerization initiator, and other optionally blended. Those components are dissolved uniformly and do not react with each component.
As such a solvent, the thing similar to what was illustrated as a solvent which can be used in order to manufacture the polymer (A) mentioned above can be mentioned.

Among such solvents, alcohol, glycol ether, ethylene glycol alkyl ether acetate, ester and diethylene glycol are preferably used from the viewpoints of solubility of each component, reactivity with each component, ease of film formation, and the like. . Among these, for example, benzyl alcohol, 2-phenylethyl alcohol, 3-phenyl-1-propanol, ethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol diethyl ether, diethylene glycol ethyl methyl ether, diethylene glycol dimethyl ether, propylene glycol monomethyl ether Propylene glycol monomethyl ether acetate, methyl methoxypropionate, and ethyl ethoxypropionate can be particularly preferably used.
Furthermore, a high boiling point solvent can be used in combination with the above solvent. By using an appropriate amount of the high boiling point solvent in combination, the effect of increasing the in-plane uniformity of the film thickness can be expected. Examples of the high boiling point solvent that can be used in combination 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. Of these, N-methylpyrrolidone, γ-butyrolactone, and N, N-dimethylacetamide are preferable.

When a high boiling point solvent is used in combination as the solvent of the radiation-sensitive resin composition of the present invention, the amount used is preferably 50% by weight or less, more preferably 40% by weight or less, and still more preferably based on the total amount of the solvent. 30% by weight or less. If the amount of the high-boiling solvent used exceeds this amount, the film thickness uniformity, sensitivity, and residual film rate may be reduced.
When preparing the radiation-sensitive resin composition of the present invention in a solution state, components other than the solvent in the solution, that is, (A) polymer, (B) polymerizable unsaturated compound, and (C) radiation-sensitive polymerization initiation The ratio of the total amount of the agent and other components optionally added can be arbitrarily set according to the purpose of use, the value of the desired film thickness, etc., and can be, for example, 5 to 80% by weight. However, the preferred value varies depending on the method of using the solution of the radiation-sensitive resin composition of the present invention (film forming method). This will be described later.
The composition solution thus prepared can be used after being filtered using a Millipore filter or a membrane filter having a pore size of about 0.5 μm.

<Method for forming spacer>
The method of forming the spacer of a liquid crystal display element using the radiation sensitive resin composition of this invention implements following process (1)-(4) in the order as described below.
(1) The process of forming the film of the radiation sensitive resin composition of this invention on a board | substrate.
(2) A step of exposing radiation to at least a part of the coating.
(3) A step of developing the film after exposure.
(4) A step of heating the film after development.
Hereinafter, each of these steps will be described in order.

(1) The process of forming the film of the radiation sensitive resin composition of this invention on a board | substrate First, the film of the composition of the solution of the radiation sensitive resin composition of this invention is formed on a board | substrate.
As a substrate used in this method, a transparent substrate having a transparent conductive film formed on one side is preferable.
Examples of the material constituting the transparent substrate include glass and resin. Examples of the glass include soda lime glass and alkali-free glass; examples of the resin include polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, and polyimide.
As the transparent conductive film such as tin oxide NESA film made of (SnO ₂₎ (US PPG Inc. registered trademark), indium oxide - and the like ITO film made of tin oxide _{(In 2} O 3 -SnO ₂₎ it can.

As a method of forming a coating film of the composition of the first composition on the substrate, for example, (i) a coating method and (ii) a dry film method can be used.
(I) In the case of the coating method, a coating film can be formed by heating (pre-baking) the coated surface after coating the solution of the first composition on the substrate.
The method for applying the composition solution is not particularly limited, and for example, an appropriate method such as a spray method, a roll coating method, a spin coating method (spin coating method), a slit die coating method, a bar coating method, or an ink jet coating method is adopted. In particular, a spin coating method or a slit die coating method is preferable.
Prebaking conditions vary depending on the type of each component, the blending ratio, etc., but are preferably about 70 to 120 ° C. for about 1 to 15 minutes.

When forming the film of the first composition solution on the substrate, (ii) when the dry film method is adopted, the dry film is formed on the base film, preferably a flexible base film. A layer formed by laminating a photosensitive layer made of a photosensitive resin composition (hereinafter referred to as “photosensitive dry film”).
The photosensitive dry film can be formed by laminating a photosensitive layer on a base film by applying the photosensitive resin composition of the present invention, preferably as a liquid composition, and then removing the solvent. As a base film of the photosensitive dry film, for example, a synthetic resin film such as polyethylene terephthalate (PET), polyethylene, polypropylene, polycarbonate, polyvinyl chloride, or the like can be used. The thickness of the base film is suitably in the range of 15 to 125 μm. As for the thickness of the photosensitive layer obtained, about 1-30 micrometers is preferable. The removal of the solvent can be preferably performed by heating at 80 to 150 ° C. for about 1 to 10 minutes.
Moreover, the photosensitive dry film can also be preserve | saved by laminating | stacking a cover film on the photosensitive layer at the time of unused. This cover film needs to have an appropriate releasability so that it does not peel off when not in use and can be easily peeled off when in use. As a cover film satisfying such conditions, for example, a film obtained by applying or baking a silicone mold release agent on the surface of a synthetic resin film such as a PET film, a polypropylene film, a polyethylene film, or a polyvinyl chloride film may be used. it can. A thickness of about 25 μm is usually sufficient for the cover film.

When the radiation-sensitive resin composition of the present invention is used as a solution, the solid content concentration (ratio of the weight of the composition excluding the solvent to the total composition weight) is preferably 5 to 80% by weight. A more preferable solid content concentration varies depending on the method of forming the film. The solid content concentration when (i) the coating method is used for forming the coating is preferably 15 to 30% by weight, and the solid concentration when (ii) the dry film method is used for forming the coating is 50 ~ 70 wt% is preferred.
In addition, the film thickness of the coating film formed on the substrate is not particularly limited, but is preferably about 0.5 to 10 μm, more preferably about 1.0 to 7.0 μm.

(2) Step of exposing radiation to at least part of the coating film Next, radiation is exposed to at least a part of the formed coating film. When a part of the coating film is exposed, for example, a method of exposing through a photomask having a predetermined pattern can be used.
Visible light, ultraviolet light, deep ultraviolet light, or the like can be used as radiation used for exposure. As the radiation, radiation having a wavelength in the range of 190 to 450 nm is preferable, and radiation including ultraviolet light of 365 nm is particularly preferable.
The exposure dose is preferably 100 to 10,000 J / m ² , more preferably 1, as a value measured by an illuminometer (OAI model 356, manufactured by OAI Optical Associates Inc.) at a wavelength of 365 nm of the radiation to be exposed. 500-3,000 J / m ² .

(3) Process of developing the film after exposure Next, by developing the film after exposure, an unnecessary part is removed and a predetermined pattern is formed.
Examples of the developer used for development include inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and ammonia; aliphatic primary amines such as ethylamine and n-propylamine; 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-methylpyrrolidine, 1,8 -Alicyclic tertiary amines such as diazabicyclo [5.4.0] -7-undecene and 1,5-diazabicyclo [4.3.0] -5-nonene; aromatics such as pyridine, collidine, lutidine, quinoline Tertiary amine; dimethylethanolamine, methyldi Ethanolamine, alkanolamines such as triethanolamine; tetramethylammonium hydroxide, the aqueous solution of an alkaline compound such as quaternary ammonium salts such as tetraethyl ammonium hydroxide may be used.
An appropriate amount of at least one of a water-soluble organic solvent such as methanol and ethanol and a surfactant may be added to the aqueous solution of the alkaline compound.
The developing method may be any known developing method such as a liquid filling method, a dipping method, or a shower method, and the developing time is preferably 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.

(4) Step of heating the film after development Next, the obtained pattern (film) is heated at a predetermined temperature, for example, 100 to 160 ° C., for a predetermined time, for example, with an appropriate heating device such as a hot plate or an oven. A predetermined spacer can be obtained by heating (post-baking) for 5 to 30 minutes on the plate and for 30 to 180 minutes in the oven.
In addition, the conventional radiation-sensitive resin composition used for the formation of the spacer, when the heat treatment was not performed at a temperature of about 180 to 200 ° C. or more, the obtained spacer could not exhibit sufficient performance, The radiation-sensitive resin composition of the present invention 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, transparent substrate It has an advantage that a spacer having excellent performance such as adhesion can be provided.

  As will be apparent from the examples described later, the spacer formation method described above is to form the spacer under a clean condition without substantially generating sublimation in the heating process (firing process) for forming the spacer. Can do. Further, the obtained spacer is excellent in pattern shape, compressive strength and rubbing resistance.

<Liquid crystal display element>
The spacer of the present invention formed as described above can be suitably used for a liquid crystal display element.
The liquid crystal display element of the present invention comprises the spacer of the present invention formed as described above.
Such a liquid crystal display element is produced, for example, by the following method. First, two substrates on which a protective film and a liquid crystal alignment film are formed are prepared, and the two substrates are placed through a gap (cell gap) so that the liquid crystal alignment directions in the respective alignment films are orthogonal or antiparallel. The two substrate substrates are bonded to each other through the spacer of the present invention, the liquid crystal is filled in the cell gap defined by the substrate surface and the spacer of the present invention, and the filling hole is sealed. A liquid crystal cell is constructed. Then, on the outer surface of the liquid crystal cell, that is, on the other surface side of each substrate constituting the liquid crystal cell, a polarizing plate is aligned or orthogonal to the liquid crystal alignment direction of the protective film formed on one surface of the substrate. By sticking together, a liquid crystal display element can be obtained.

Examples of the liquid crystal include a nematic liquid crystal and a smectic liquid crystal. Among them, nematic liquid crystal is preferable, for example, Schiff base liquid crystal, azoxy liquid crystal, biphenyl liquid crystal, phenyl cyclohexane liquid crystal, ester liquid crystal, terphenyl liquid crystal, biphenyl cyclohexane liquid crystal, pyrimidine liquid crystal, dioxane liquid crystal, bicyclooctane. Type liquid crystal, cubane type liquid crystal, etc. are used. Further, for these liquid crystals, for example, cholesteric liquid crystals such as cholestyl chloride, cholesteryl nonate, cholesteryl carbonate, and chiral agents such as those sold under the trade names “C-15” and “CB-15” (manufactured by Merck). Etc. can also be used. Furthermore, a ferroelectric liquid crystal such as p-decyloxybenzylidene-p-amino-2-methylbutylcinnamate can also be used.
As a polarizing plate used outside the liquid crystal cell, a polarizing plate formed by sandwiching a polarizing film called an H film that absorbs iodine while stretching and aligning polyvinyl alcohol with a cellulose acetate protective film, or a polarizing film made of the H film itself And so on.

The present invention will be described more specifically with reference to synthesis examples and examples. However, the present invention is not limited to the following examples.
About the polymer synthesize | combined in the synthesis example of the following polymer, a gel permeation chromatography was measured on condition of the following, the weight average molecular weight (Mw) and number average molecular weight (Mn) of polystyrene conversion were calculated | required, molecular weight distribution ( Mw / Mn) was calculated.
Apparatus: GPC-101 (made by Showa Denko KK)
Column: GPC-KF-801, GPC-KF-802, GPC-KF-803 and GPC-KF-804 (manufactured by Showa Denko KK) are combined Mobile phase: Tetrahydrofuran containing 0.5% by weight of phosphoric acid

Polymer Synthesis Example 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), 5 parts by weight of tetraethylthiuram disulfide and 200 parts by weight of diethylene glycol diethyl ether as a molecular weight control agent. Twenty parts by weight of styrene, 17 parts by weight of methacrylic acid, 18 parts by weight of tricyclo [5.2.1.0 ^2,6 ] decan-8-yl methacrylate and 45 parts by weight of glycidyl methacrylate were charged, and the gas was gently replaced. The reaction solution was heated to 70 ° C. while stirring and polymerized for 4 hours while maintaining this temperature. Thereafter, 3 parts by weight of 2,2′-azobis (2,4-dimethylvaleronitrile) was added, and the polymerization was further continued for 3 hours to obtain a solution containing a copolymer. This resin had Mw = 12,000 and Mw / Mn = 1.60. This resin is referred to as “resin (A-1)”.

Synthesis example 2
A flask equipped with a condenser and a stirrer was charged with 5 parts by weight of 2,2′-azobis (2,4-dimethylvaleronitrile), 5 parts by weight of tetraethylthiuram disulfide and 200 parts by weight of diethylene glycol diethyl ether as a molecular weight control agent, Subsequently, 5 parts by weight of styrene, 16 parts by weight of methacrylic acid, 34 parts by weight of tricyclo [5.2.1.0 ^2,6 ] decan-8-yl methacrylate, 35 parts by weight of glycidyl methacrylate and 5 parts by weight of methyl glycidyl methacrylate were charged. Then, after substituting with nitrogen, stirring was started gently. The temperature of the solution was raised to 70 ° C., and this temperature was maintained for 8 hours. Then, 3 parts by weight of 2,2′-azobis (2,4-dimethylvaleronitrile) was added, and the mixture was further stirred at 70 ° C. for 4 hours. Then, 200 parts by weight of diethylene glycol ethyl methyl ether was added to obtain a solution containing the copolymer (A-2). Mw of the obtained copolymer (A-2) was 12,000, and molecular weight distribution (Mw / Mn) was 1.40.

Comparative 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 220 parts by weight of diethylene glycol methyl ethyl ether, followed by 20 parts by weight of styrene and 17 parts by weight of methacrylic acid. 1 part, 18 parts by weight of tricyclo [5.2.1.0 ^2,6 ] decan-8-yl methacrylate and 45 parts by weight of glycidyl methacrylate were substituted with nitrogen, and then the temperature of the reaction solution was adjusted while gently stirring. The temperature was raised to 70 ° C., and this temperature was maintained for 4 hours for polymerization to obtain a solution containing a copolymer. The solid content concentration of this solution was 29.5% by weight, Mw of the obtained copolymer was 13,000, the molecular weight distribution (Mw / Mn) was 2.4, and the residual monomer was 7%. . This copolymer is referred to as “copolymer (a-1)”.

Example 1
Preparation of Radiation Sensitive Resin Composition (A) An amount corresponding to 100 parts by weight (solid content) of the polymer (A-1) as a component containing the polymer (A-1) synthesized in the above synthesis example, 100 parts by weight of dipentaerythritol hexaacrylate as component (B) and 8 parts by weight of 2,2′-bis (2,4-dichlorophenyl) -4,4 ′, 5,5′-tetraphenylbiimidazole as component (C) In addition, 5 parts by weight of γ-glycidoxypropyltrimethoxysilane as an adhesion assistant, 0.5 part by weight of FTX-218 (trade name, manufactured by Neos Co., Ltd.) as a surfactant, and 4-methoxyphenol as a storage stabilizer After mixing 5 parts by weight and adding and dissolving propylene glycol monomethyl ether acetate so that the solid content concentration of the composition is 20% by weight, the pore size is reduced to 0. And filtered through a μm Millipore filter, to prepare a composition solution.
The composition solution prepared as described above was evaluated as follows.

<Formation of spacer>
The composition solution was applied onto an alkali-free glass substrate using a spinner and then pre-baked on a hot plate at 90 ° C. for 3 minutes to form a film having a thickness of 6.0 μm.
Next, the obtained film was irradiated with ultraviolet rays having an intensity of 365 W / m ² at 365 nm for 10 seconds through a photomask having a 10 μm square remaining pattern. Thereafter, development was performed with a 0.05 wt% aqueous solution of potassium hydroxide at 25 ° C. for 60 seconds, followed by washing with pure water for 1 minute. Furthermore, the spacer which has a predetermined pattern was formed by post-baking at 150 degreeC for 120 minute (s) in oven.
<Evaluation of resolution>
When the pattern was formed in the “spacer formation” above, the case where the remaining pattern was resolved was evaluated as good (◯), and the case where the pattern was not resolved was evaluated as defective (×). The resolution of the composition prepared above was good.

<Evaluation of sensitivity>
With respect to the pattern obtained in the above “spacer formation”, the remaining film ratio after development (film thickness after development / initial film thickness × 100 (%)) was calculated. When this value was evaluated as good (◯) when the value was 90% or more, and poor (x) when the value was less than 90%, the sensitivity of the composition prepared above was good.
<Evaluation of pattern shape>
The cross-sectional shape of the pattern obtained in the above “formation of the 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 pattern shape as the spacer is good. On the other hand, as shown in C, when the sensitivity is insufficient, the remaining film rate is low, the cross-sectional area is small compared to A or B, and the bottom surface of the cross-sectional shape is a flat semi-convex lens shape, The pattern shape as a spacer is very bad, and even when the cross-sectional shape is a reverse taper shape as shown in D, the pattern shape as a spacer is considered to be bad because the pattern is very likely to peel off during the subsequent rubbing process. .
The cross-sectional shape of the spacer formed from the composition prepared above was B, and the cross-sectional shape was good.

<Evaluation of compressive strength>
Deformation of the pattern obtained in the above “spacer formation” when a load of 10 mN is applied using a flat indenter with a diameter of 50 μm using a micro compression tester (manufactured by Shimadzu Corporation, model “MCTM-200”). The quantity was measured at a measurement temperature of 23 ° C. When this value is 0.5 μm or less, it can be said that the compressive strength is good.
The deformation amount of the spacer formed from the composition prepared above was 0.41 μm, and the compression strength was good.
<Evaluation of rubbing resistance>
A liquid crystal aligning agent (manufactured by JSR Co., Ltd., trade name “AL3046”) was applied to a substrate on which a pattern was formed as in the above “formation of spacer” using a printing machine for applying a liquid crystal alignment film, and then 180 ° C. And heated for 1 hour to form a coating film of an orientation agent having a thickness of 0.05 μm after heating. Thereafter, the coating film was rubbed using a rubbing machine having a roll wound with a polyamide cloth under conditions of 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 examined.
For the substrate having a pattern formed from the composition prepared above, no pattern scraping or peeling was observed.

<Evaluation of adhesion>
A cured film was formed in the same manner as in the above “spacer formation” except that the remaining pattern mask was not used. About the cured film formed here, adhesiveness was evaluated by the cross-cut tape method of 8.5.2 among the adhesion tests of JIS K-5400 (1900) 8.5. The number of remaining grids out of the 100 grids was 100.
<Evaluation of sublimation>
The composition solution was applied onto a silicon substrate using a spinner and then pre-baked on a hot plate at 90 ° C. for 2 minutes to form a coating film having a thickness of 3.0 μm. The obtained coating film was exposed to an integrated irradiation amount of 3,000 J / m ² using an exposure machine (model “PLA-501F”, ultra-high pressure mercury lamp) manufactured by Canon Inc. The substrate was heated at 220 ° C. for 1 hour in a clean oven to obtain a cured film. A bare silicon wafer for cooling was mounted at an interval of 1 cm above the obtained cured film, and a heating process was performed at 230 ° C. for 1 hour on a hot plate. Without replacing the cooling bare silicon wafer, after continuously processing 20 silicon substrates separately formed with a cured film in the same manner as described above, the presence or absence of sublimates attached to the bare silicon was visually observed. Sublimates were not confirmed.

Evaluation of voltage holding ratio Prepared as above using a spinner on a soda glass substrate on which a SiO ₂ film for preventing elution of sodium ions is formed on the surface, and an ITO (indium-tin oxide alloy) electrode is deposited in a predetermined shape. The applied radiation sensitive resin composition was applied and prebaked in a clean oven at 90 ° C. for 10 minutes to form a coating film having a thickness of 2.0 μm. Next, using a high-pressure mercury lamp, the coating film was exposed to radiation containing wavelengths of 365 nm, 405 nm, and 436 nm at an exposure dose of 2,000 J / m ² without using a photomask. Further, post-baking was performed at 230 ° C. for 30 minutes to cure the coating film to form a cured film.
Next, a sealing agent in which the substrate having this cured film is opposed to a soda glass substrate in which an ITO electrode is vapor-deposited in a predetermined shape on the surface, and glass beads of 0.8 mm are mixed on four sides leaving a liquid crystal injection port. The liquid crystal cell was produced by sealing the liquid crystal injection port after injecting and using liquid crystal MLC6608 (trade name) manufactured by Merck.
This liquid crystal cell is put in a constant temperature layer of 60 ° C., and the applied voltage is set to a square wave of 5.5 V with a liquid crystal voltage holding ratio measurement system VHR-1A type (trade name) manufactured by Toyo Technica Co., Ltd., and the measurement frequency is 60 Hz. As a result, the voltage holding ratio of the liquid crystal cell was measured and found to be 97%. Here, the voltage holding ratio is a value represented by the following formula.

Voltage holding ratio (%) = (potential difference of liquid crystal cell after 16.7 milliseconds) / (voltage applied at 0 milliseconds) × 100

If the voltage holding ratio of the liquid crystal cell is 90% or less, it means that the liquid crystal cell cannot hold the applied voltage at a predetermined level for a time of 16.7 milliseconds, and the liquid crystal cannot be sufficiently aligned. Such a liquid crystal cell is likely to cause “burn-in”.

Examples 2 to 10 and Comparative Example 1
In “Preparation of radiation-sensitive resin composition” in Example 1, the same components as (A), (B), and (C) were used, except that the types and amounts shown in Table 1 were used. A composition was prepared and evaluated. The evaluation results are shown in Table 2.
In Table 1, abbreviations indicating each component mean the following. In addition, when the kind and quantity of a component are combined with “/”, it indicates that a plurality of kinds are used together as the ingredient in the amounts shown in the table. In addition, “-” in the table indicates that the component corresponding to that column was not used.
(B) Component B-1: Dipentaerythritol hexaacrylate (C) Component C-1: 2,2′-bis (2,4-dichlorophenyl) -4,4 ′, 5,5′-tetraphenylbiimidazole C -2: 2,2'-bis (2-chlorophenyl) -4,4 ', 5,5'-tetraphenylbiimidazole C-3: 2-methyl [4- (methylthio) phenyl] -2-morpholino-1 -Propanone C-4: 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1
Radiation sensitizer D-1: 4,4′-bis (dimethylamino) benzophenone D-2: 2-mercaptobenzothiazole D-3: pentaerythritol tetra (mercaptoacetate)

It is a schematic diagram which illustrates the cross-sectional shape of a spacer.

Claims (5)

(A) The following formula (1)

(In the formula (1), there are two Z each independently represent a hydrogen atom, a carboxyl group, group -R, group -OR, group -NR _2, group -COOR, group -C (= O) NR _2, group - P (═O) R ₂ , group —P (═O) (OR) ₂ or group —NRNR—C (═O) R, wherein R is independently a halogen atom, a cyano group, a hydroxyl group, or a carbon number of 1-20. An alkyl group of 2 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, or a monovalent valence having 3 to 20 carbon atoms in total. When R is an alkyl group, an alkenyl group, an aryl group, an aralkyl group or a heterocyclic group, one or more of the hydrogen atoms of R are a halogen atom, (It may be substituted with a cyano group, a hydroxyl group or a carboxyl group.)
The ratio (Mw / Mn) of polystyrene-reduced weight average molecular weight (Mw) and number average molecular weight (Mn) measured by gel permeation chromatography is 1 by living radical polymerization in the presence of the compound represented by formula (1). Radiation sensitive, characterized in that it comprises a polymer having a carboxyl group of .7 or less, (B) a polymerizable unsaturated compound and (C) a radiation sensitive polymerization initiator, and is used for forming a spacer. Resin composition. (A) The polymer is represented by the following formula (i)

(In formula (i), Z is the same as in formula (1) above.)
The radiation sensitive resin composition of Claim 1 which has a structure represented by these. A method for forming a spacer, wherein at least the following steps (1) to (4) are carried out in the order described below.
(1) The process of forming the film of the radiation sensitive resin composition of Claim 1 or 2 on a board | substrate.
(2) A step of exposing radiation to at least a part of the coating.
(3) A step of developing the film after exposure.
(4) A step of heating the film after development.   A spacer formed by the method according to claim 3.   A liquid crystal display element comprising the spacer according to claim 4.

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