JP4888640B2 - Radiation sensitive resin composition and spacer for liquid crystal display element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radiosensitive resin composition which can acquire a sufficient spacer configuration with high sensitivity and high resolution even in &le;1,200 J/m<SP>2</SP>amount of exposure and excellent in solubility in a developing liquid and can form a spacer for a liquid crystal display element excellent in elastic recovery, rubbing resistance, adhesiveness with a transparent substrate, heat resistance and the like. <P>SOLUTION: The radiosensitive resin composition comprises a polymer and a polymerizable unsaturated compound. The polymer is prepared by reacting a (meth)acryloyloxyalkyl isocyanate compound with a copolymer prepared by copolymerizing an unsaturated carboxylic acid and/or an unsaturated carboxylic acid anhydride, an unsaturated compound having &ge;1 hydroxyl groups in one molecule, an unsaturated compound having a lactone structure and another unsaturated compound except the unsaturated compounds. <P>COPYRIGHT: (C)2007,JPO&amp;INPIT

Description

The present invention relates to a radiation-sensitive resin composition containing a side-chain unsaturated polymer, particularly suitable for forming a spacer in a liquid crystal display device, a spacer, a method for forming the same, and a liquid crystal display device.

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

In recent years, the mother glass substrate has been increased in size (for example, about 1500 × 1800 mm and further about 1870 × 2200 mm) from the viewpoint of increasing the area of the liquid crystal display element and improving productivity. However, with the conventional substrate size, the substrate size is smaller than the mask size, so it was possible to cope with the batch exposure method. However, with a large substrate, it is almost impossible to produce a mask size comparable to this substrate size. It is possible, and it is difficult to cope with the batch exposure method.
Therefore, a step exposure method has been proposed as an exposure method that can be applied to a large substrate. However, in the step exposure method, since a single substrate is exposed several times, and each exposure requires time for alignment and step movement, reduction of throughput is regarded as a problem compared to the batch exposure method. .

Further, in the batch exposure method, an exposure amount of about 3,000 J / m ² is possible, but in the step exposure method, it is necessary to lower the exposure amount at each time, which is a conventional method used for forming a spacer. In the radiation sensitive resin composition, it has been difficult to achieve a sufficient spacer shape and film thickness with an exposure amount of 1,200 J / m ² or less.
Further, when a defect occurs in the process as the substrate becomes larger, the alignment film formed on the color filter must be peeled off and reused. An alkaline aqueous stripping solution is used for stripping the alignment film, but the spacer needs to be resistant to the stripping solution. That is, it is desirable that the lower spacer does not change in thickness due to swelling or dissolution when the alignment film is peeled off, and physical properties such as elastic properties are required to exhibit the same properties as before peeling.

In Patent Document 1, Patent Document 2 and Patent Document 3, a photopolymerizable functional group obtained by reacting a copolymer resin having a hydroxyl group with a (meth) acryloyloxyalkyl isocyanate compound in a photosensitive resin composition is a constituent unit. It is said that the use of the copolymerizable resin can improve the performance as a spacer and protective film such as high sensitivity and chemical resistance. An epoxy resin having two or more epoxy groups in the molecule for the purpose of improving the heat resistance of the spacer and the protective film, adhesion to the substrate, chemical resistance, in particular, the resistance to the alignment film peeling solution and the aqueous alkali solution. Used. However, there is a concern about the storage stability of the photosensitive resin composition and the solubility in a developer by adding this epoxy resin.
As described above, in the conventional radiation-sensitive resin composition, the addition of an epoxy compound can improve the adhesion to the substrate and the chemical resistance (alignment film peeling solution resistance), but the storage stability and development can be improved. There is concern about solubility in the liquid.
JP 2000-105456 A JP 2000-171804 A JP 2000-298339 A

Therefore, the object of the present invention is high sensitivity, a sufficient spacer shape can be obtained even with an exposure amount of 1,200 J / m ² or less, and excellent in elastic recovery, rubbing resistance, adhesion to a transparent substrate, heat resistance, etc. Another object of the present invention is to provide a radiation-sensitive resin composition that can sufficiently form a spacer for a liquid crystal display element that exhibits sufficient resistance to a peeling solution at the time of peeling an alignment film and has excellent solubility in a developing solution.

  Still another object of the present invention is to provide a liquid crystal display spacer formed from the above radiation sensitive resin composition and a liquid crystal display element including the same.

  Still another object of the present invention is to provide a method for forming the above-mentioned liquid crystal display spacer.

According to the present invention, the problem is firstly
(A1) unsaturated carboxylic acid and / or unsaturated carboxylic acid anhydride, (a2) unsaturated compound containing one or more hydroxyl groups in one molecule, (a3) represented by the following formula (1) An isocyanate compound represented by the following formula (2) is added to a copolymer of an unsaturated compound having a lactone structure and (a4) an unsaturated compound other than (a1), (a2) and (a3). 100 parts by weight of the polymer that is obtained by reacting, as well as
[B] 1 to 120 parts by weight of polymerizable unsaturated compound
And a radiation-sensitive resin composition (hereinafter referred to as “a radiation-sensitive resin composition for a spacer for a liquid crystal display device”), which is not used in combination with an epoxy resin having two or more epoxy groups in the molecule. ) .

  Here, L is a group represented by the following formula (L-1), (L-2) or (L-3),

R ₁ is a hydrogen atom or a methyl group, R _{2 to} R ₁₂ are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and n is an integer of 0 to 6.

Here, R ₁₃ is a hydrogen atom or a methyl group, and m is an integer of 0-6.

According to the present invention, the problem is secondly ,
This is achieved by a spacer for a liquid crystal display element formed from each of the radiation sensitive resin compositions.

According to the present invention, the problem is thirdly ,
This is achieved by a method for forming a spacer for a liquid crystal display element, comprising at least the following steps in the order described below.
(A) forming a coating of the radiation-sensitive resin composition for a spacer for a liquid crystal display element on a substrate;
(B) exposing at least a part of the coating;
(C) a step of developing the coated film after exposure, and (d) a step of heating the coated film after development.

According to the present invention, the problem is, the fourth,
This is achieved by a liquid crystal display element comprising the liquid crystal display element spacer.

The radiation-sensitive resin composition of the present invention has high sensitivity and high resolution, and a sufficient pattern shape can be obtained even with an exposure amount of 1,200 J / m ² or less, excellent solubility in a developer, elastic recovery, rubbing A spacer for a liquid crystal display element having excellent resistance, adhesion to a transparent substrate, heat resistance and the like can be formed.
The liquid crystal display element of the present invention comprises a spacer having excellent performance such as pattern shape, elastic recovery, rubbing resistance, adhesion to a transparent substrate, heat resistance, etc., and expresses high reliability over a long period of time. be able to.

  Hereinafter, the present invention will be described in detail.

-[A] polymer-
Polymer in the present invention, (a1) an unsaturated carboxylic acid and / or unsaturated carboxylic acid anhydride, an unsaturated compound containing one or more hydroxyl groups in the (a2) 1 molecule, (a3) the formula A copolymer of an unsaturated compound having a lactone structure represented by (1) and an unsaturated compound other than (a4), (a1), (a2) and (a3) (hereinafter referred to as “copolymer [ α] ”) and a polymer (hereinafter referred to as“ [A] ”) obtained by reacting the isocyanate compound represented by the above formula (2) (hereinafter referred to as“ unsaturated isocyanate compound (1) ”). Polymer ”)).
Among the components constituting the copolymer [α], (a1) unsaturated carboxylic acid and / or unsaturated carboxylic acid anhydride (hereinafter these are collectively referred to as “(a1) unsaturated carboxylic acid compound”. ), For example,
Monocarboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, 2-acryloyloxyethyl succinic acid, 2-methacryloyloxyethyl succinic acid, 2-acryloyloxyethyl hexahydrophthalic acid, 2-methacryloyloxyethyl hexahydrophthalic acid;
Dicarboxylic acids such as maleic acid, fumaric acid, citraconic acid, mesaconic acid, itaconic acid;
The acid anhydride of the said dicarboxylic acid etc. can be mentioned.
Among these (a1) unsaturated carboxylic acid-based compounds, acrylic acid, methacrylic acid, maleic anhydride are available from the viewpoints of copolymerization reactivity, solubility of the resulting [A] polymer in an alkaline developer and easy availability. An acid or the like is preferable.

In the copolymer [α], the (a1) unsaturated carboxylic acid compound can be used alone or in admixture of two or more.
In the copolymer [α], the content of the repeating unit derived from the (a1) unsaturated carboxylic acid compound is preferably 5 to 50% by weight, more preferably 10 to 40% by weight, and particularly preferably 15 to 30%. % By weight. In this case, when the content of the repeating unit derived from the (a1) unsaturated carboxylic acid compound is less than 5% by weight, the solubility of the polymer obtained by the reaction with the unsaturated isocyanate compound (1) in the alkaline developer On the other hand, if it exceeds 50% by weight, the solubility of the polymer in an alkaline developer may become too high.

(A2) Examples of unsaturated compounds containing one or more hydroxyl groups in one molecule include acrylic acid 2-hydroxyethyl ester, acrylic acid 3-hydroxypropyl ester, acrylic acid 4-hydroxybutyl ester, acrylic Acid 5-hydroxypentyl ester, acrylic acid 6-hydroxyhexyl ester, acrylic acid 7-hydroxyheptyl ester, acrylic acid 8-hydroxyoctyl ester, acrylic acid 9-hydroxynonyl ester, acrylic acid 10-hydroxydecyl ester, acrylic acid 11 -Hydroxy undecyl esters, hydroxyalkyl acrylates such as 12-hydroxydodecyl acrylate;
Methacrylic acid 2-hydroxyethyl ester, Methacrylic acid 3-hydroxypropyl ester, Methacrylic acid 4-hydroxybutyl ester, Methacrylic acid 5-hydroxypentyl ester, Methacrylic acid 6-Hydroxyhexyl ester, Methacrylic acid 7-Hydroxyheptyl ester, Methacrylic acid Methacrylic acid hydroxyalkyl esters such as 8-hydroxyoctyl ester, methacrylic acid 9-hydroxynonyl ester, methacrylic acid 10-hydroxydecyl ester, methacrylic acid 11-hydroxyundecyl ester, methacrylic acid 12-hydroxydodecyl ester;

  Acrylic acid 2- (6-hydroxyhexanoyloxy) ethyl ester, acrylic acid 3- (6-hydroxyhexanoyloxy) propyl ester, acrylic acid 4- (6-hydroxyhexanoyloxy) butyl ester, acrylic acid 5- ( 6-hydroxyhexanoyloxy) pentyl ester, acrylic acid (6-hydroxyhexanoyloxy) alkyl ester such as acrylic acid 6- (6-hydroxyhexanoyloxy) hexyl ester;

  Methacrylic acid 2- (6-hydroxyhexanoyloxy) ethyl ester, methacrylic acid 3- (6-hydroxyhexanoyloxy) propyl ester, methacrylic acid 4- (6-hydroxyhexanoyloxy) butyl ester, methacrylic acid 5- ( Methacrylic acid (6-hydroxyhexanoyloxy) alkyl esters such as 6-hydroxyethylhexanoyloxy) pentyl ester, methacrylic acid 6- (6-hydroxyhexanoyloxy) hexyl ester;

  Acrylic acid 2- (3-hydroxy-2,2-dimethyl-propoxycarbonyloxy) -ethyl ester, acrylic acid 3- (3-hydroxy-2,2-dimethyl-propoxycarbonyloxy) -propyl ester, acrylic acid 4- (3-hydroxy-2,2-dimethyl-propoxycarbonyloxy) -butyl ester, acrylic acid 5- (3-hydroxy-2,2-dimethyl-propoxycarbonyloxy) -pentyl ester, acrylic acid 6- (3-hydroxy Acrylic acid (3-hydroxy-2,2-dimethyl-propoxycarbonyloxy) -alkyl esters such as -2,2-dimethyl-propoxycarbonyloxy) -hexyl ester;

  Methacrylic acid 2- (3-hydroxy-2,2-dimethyl-propoxycarbonyloxy) -ethyl ester, methacrylic acid 3- (3-hydroxy-2,2-dimethyl-propoxycarbonyloxy) -propyl ester, methacrylic acid 4- (3-hydroxy-2,2-dimethyl-propoxycarbonyloxy) -butyl ester, methacrylic acid 5- (3-hydroxy-2,2-dimethyl-propoxycarbonyloxy) -pentyl ester, methacrylic acid 6- (3-hydroxy Methacrylic acid (3-hydroxy-2,2-dimethyl-propoxycarbonyloxy) -alkyl ester such as -2,2-dimethyl-propoxycarbonyloxy) -hexyl ester;

Acrylic acid 4-hydroxy-cyclohexyl ester, Acrylic acid 4-hydroxymethyl-cyclohexyl methyl ester, Acrylic acid 4-hydroxyethyl-cyclohexyl ethyl ester, Acrylic acid 3-hydroxy-bicyclo [2.2.1] hept-5-ene 2-yl ester, acrylic acid 3-hydroxymethyl-bicyclo [2.2.1] hept-5-en-2-ylmethyl ester, acrylic acid 3-hydroxyethyl-bicyclo [2.2.1] hept- 5-En-2-ylethyl ester, acrylic acid 8-hydroxy-bicyclo [2.2.1] hept-5-en-2-yl ester, acrylic acid 2-hydroxy-octahydro-4,7-methano-indene -5-yl ester, 2-hydroxymethyl-octahydro-4,7-metaacrylate -Inden-5-ylmethyl ester, acrylic acid 2-hydroxyethyl-octahydro-4,7-methano-inden-5-ylethyl ester, acrylic acid 3-hydroxy-adamantan-1-yl ester, acrylic acid 3-hydroxy Acrylic acid hydroxyalkyl esters having an alicyclic structure such as methyl-adamantan-1-ylmethyl ester, acrylic acid 3-hydroxyethyl-adamantan-1-ylethyl ester;
Methacrylic acid 4-hydroxy-cyclohexyl ester, Methacrylic acid 4-hydroxymethyl-cyclohexyl methyl ester, Methacrylic acid 4-hydroxyethyl-cyclohexyl ethyl ester, Methacrylic acid 3-hydroxy-bicyclo [2.2.1] Hept-5-ene 2-yl ester, methacrylic acid 3-hydroxymethyl-bicyclo [2.2.1] hept-5-en-2-ylmethyl ester, methacrylic acid 3-hydroxyethyl-bicyclo [2.2.1] hept- 5-En-2-ylethyl ester, methacrylic acid 8-hydroxy-bicyclo [2.2.1] hept-5-en-2-yl ester, methacrylic acid 2-hydroxy-octahydro-4,7-methano-indene -5-yl ester, 2-hydroxymethyl methacrylate-octahi B, 7-Methano-inden-5-ylmethyl ester, 2-hydroxyethyl methacrylate-octahydro-4,7-methano-inden-5-ylethyl ester, 3-hydroxy-adamantan-1-yl methacrylate Methacrylic acid hydroxyalkyl esters having an alicyclic structure such as esters, methacrylic acid 3-hydroxymethyl-adamantan-1-ylmethyl ester, methacrylic acid 3-hydroxyethyl-adamantan-1-ylethyl ester;

  Acrylic acid 1,2-dihydroxyethyl ester, acrylic acid 2,3-dihydroxypropyl ester, acrylic acid 1,3-dihydroxypropyl ester, acrylic acid 3,4-dihydroxybutyl ester, acrylic acid 3- [3- (2, Dihydroxyalkyl esters of acrylic acid such as 3-dihydroxypropoxy) -2-hydroxypropoxy] -2-hydroxypropyl ester;

  Methacrylic acid 1,2-dihydroxyethyl ester, methacrylic acid 2,3-dihydroxypropyl ester, methacrylic acid 1,3-dihydroxypropyl ester, methacrylic acid 3,4-dihydroxybutyl ester, methacrylic acid 3- [3- (2, And methacrylic acid dihydroxyalkyl esters such as 3-dihydroxypropoxy) -2-hydroxypropoxy] -2-hydroxypropyl ester.

  Among these unsaturated compounds containing one or more hydroxyl groups in one molecule, acrylic acid 2-hydroxyethyl ester, acrylic acid 3-hydroxypropyl ester, from the viewpoint of copolymerization reactivity and reactivity with isocyanate compounds Acrylic acid 4-hydroxybutyl ester, methacrylic acid 2-hydroxyethyl ester, methacrylic acid 3-hydroxypropyl ester, methacrylic acid 4-hydroxybutyl ester, acrylic acid 2- (6-hydroxyhexanoyloxy) ethyl ester, methacrylic acid 2- (6-hydroxyhexanoyloxy) ethyl ester, acrylic acid 2- (3-hydroxy-2,2-dimethyl-propoxycarbonyloxy) -ethyl ester, methacrylic acid 2- (3-hydroxy-2,2-dimethyl) -Propoxyca Bonyloxy) -ethyl ester, acrylic acid 4-hydroxymethyl-cyclohexyl methyl ester, methacrylic acid 4-hydroxymethyl-cyclohexyl methyl ester, acrylic acid 3-hydroxymethyl-adamantan-1-ylmethyl ester, methacrylic acid 3-hydroxymethyl- Adamantan-1-ylmethyl ester, acrylic acid 2,3-dihydroxypropyl ester, methacrylic acid 2,3-dihydroxypropyl ester and the like are preferable.

In the copolymer [α], (a2) unsaturated compounds containing one or more hydroxyl groups in one molecule can be used alone or in admixture of two or more.
In the copolymer [α], (a2) the content of repeating units derived from an unsaturated compound containing one or more hydroxyl groups in one molecule is preferably 1 to 50% by weight, more preferably 3 to 40%. % By weight, particularly preferably 5 to 30% by weight. (A2) When the content of the repeating unit derived from the unsaturated compound containing one or more hydroxyl groups in one molecule is less than 1% by weight, the introduction rate of the unsaturated isocyanate compound (1) into the polymer is decreased. Thus, the sensitivity tends to decrease. On the other hand, if it exceeds 50% by weight, the storage stability of the polymer obtained by the reaction with the unsaturated isocyanate compound (1) tends to decrease.
Moreover, the unsaturated compound which has (a3) lactone structure is represented by the said Formula (1).

In Formula (1), R ₁ is a hydrogen atom or a methyl group,
R _{2 to} R ₁₂ are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.
Examples of the alkyl group having 1 to 4 carbon atoms of R _{2 to} R ₁₂ in the formula (1) include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a t-butyl group. A butyl group can be mentioned.
The following specific examples can be shown as unsaturated compounds represented by the above formula (1).

When the unsaturated carboxylic acid content in the polymer is increased, the developability with respect to an alkaline aqueous developer can be improved. However, in that case, the storage stability of the radiation-sensitive resin composition is reduced and the solution viscosity is increased. However, these unsaturated compounds (a3) can improve the developability with respect to an aqueous alkaline developer and can shorten the development time required for the conventional radiation-sensitive resin composition without impairing other performances. As the unsaturated compound (a3), in particular, (A-1), (A-2), (A-9), (A-10), (B-1), (B-2), (B- 9), (B-10) and the like are preferable.
[A] In the polymer, the unsaturated compound (a3) can be used alone or in admixture of two or more.

Moreover, as (a4) other unsaturated compounds, for example,
Alkyl acrylates such as methyl acrylate, n-propyl acrylate, i-propyl acrylate, n-butyl acrylate, sec-butyl acrylate, t-butyl acrylate;
Alkyl methacrylates such as methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, i-propyl methacrylate, n-butyl methacrylate, sec-butyl methacrylate, t-butyl methacrylate;
Acrylic acid epoxy such as glycidyl acrylate, 2-methylglycidyl acrylate, 4-hydroxybutyl acrylate glycidyl ether, 3,4-epoxybutyl acrylate, 6,7-epoxyheptyl acrylate, 3,4-epoxycyclohexyl acrylate (Cyclo) alkyl esters;
Methacrylic acid epoxy (cyclo) alkyl esters such as glycidyl methacrylate, 2-methylglycidyl methacrylate, 3,4-epoxybutyl methacrylate, 6,7-epoxyheptyl methacrylate, 3,4-epoxycyclohexyl methacrylate;
α-ethyl acrylate glycidyl, α-n-propyl acrylate glycidyl, α-n-butyl acrylate glycidyl, α-ethyl acrylate 6,7-epoxyheptyl, α-ethyl acrylate 3,4-epoxycyclohexyl, etc. Other α-alkyl acrylic acid epoxy (cyclo) alkyl esters;
glycidyl ethers such as o-vinylbenzyl glycidyl ether, m-vinylbenzyl glycidyl ether, p-vinylbenzyl glycidyl ether;

Cyclohexyl acrylate, 2-methylcyclohexyl acrylate, tricyclo [5.2.1.0 ^2,6 ] decane-8-yl acrylate, 2- (tricyclo [5.2.1.0 ^2,6 ] acrylate Acrylic alicyclic esters such as decan-8-yloxy) ethyl, isobornyl acrylate;
Cyclohexyl methacrylate, 2-methylcyclohexyl methacrylate, tricyclo [5.2.1.0 ^2,6 ] decanoyl methacrylate, 2- (tricyclo [5.2.1.0 ^2,6 ] methacrylate) Decane-8-yloxy) ethyl, methacrylic acid alicyclic esters such as isobornyl methacrylate;

Aryl esters or aralkyl esters of acrylic acid such as phenyl acrylate and benzyl acrylate;
Aryl esters or aralkyl esters of methacrylic acid such as phenyl methacrylate and benzyl methacrylate;
Unsaturated dicarboxylic acid dialkyl esters such as diethyl maleate, diethyl fumarate, diethyl itaconate;

Acrylic acid ester having an oxygen-containing hetero 5-membered ring or an oxygen-containing hetero 6-membered ring such as tetrahydrofuran-2-yl acrylate, tetrahydropyran-2-yl acrylate, 2-methyltetrahydropyran-2-yl acrylate;
Methacrylic acid ester having an oxygen-containing hetero 5-membered ring or an oxygen-containing hetero 6-membered ring such as tetrahydrofuran-2-yl methacrylate, tetrahydropyran-2-yl methacrylate, 2-methyltetrahydropyran-2-yl methacrylate;

Vinyl aromatic compounds such as styrene, α-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene;
In addition to conjugated diene compounds such as 1,3-butadiene, isoprene and 2,3-dimethyl-1,3-butadiene,
Examples include acrylonitrile, methacrylonitrile, acrylamide, methacrylamide, vinyl chloride, vinylidene chloride, and vinyl acetate.
Among these (a4) other unsaturated compounds, n-butyl methacrylate, 2-methylglycidyl methacrylate, methacrylic acid, from the viewpoint of copolymerization reactivity and solubility of the obtained [A] polymer in an aqueous alkali solution Preferred are benzyl, tricyclo [5.2.1.0 ^2,6 ] decan-8-yl methacrylate, styrene, p-methoxystyrene, tetrahydrofuran-2-yl methacrylate, 1,3-butadiene and the like.

In the copolymer [α], (a4) other unsaturated compounds can be used alone or in admixture of two or more.
In the copolymer [α], the content of the repeating unit derived from (a4) another unsaturated compound is preferably 10 to 70% by weight, more preferably 20 to 50% by weight, and particularly preferably 30 to 50% by weight. %. In this case, if the content of the repeating unit derived from (a4) another unsaturated compound is less than 10% by weight, the storage stability of the polymer obtained by the reaction with the unsaturated isocyanate compound (1) tends to decrease. On the other hand, if it exceeds 70% by weight, the solubility of the polymer in an alkaline developer tends to decrease. Further, when (meth) acrylic acid epoxy (cyclo) alkyl esters are used, the content is preferably 10% by weight or less. When it exceeds 10% by weight, the storage stability tends to decrease.
The copolymer [α] includes, for example, (a1) an unsaturated carboxylic acid compound, (a2) a hydroxyl group-containing unsaturated compound, (a3) an unsaturated compound having a lactone structure represented by the formula (1), and ( a4) It can be produced by polymerizing another unsaturated compound in a suitable solvent in the presence of a radical polymerization initiator.

As the solvent used for the polymerization, for example,
Alcohols such as methanol, ethanol, n-propanol, i-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;

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 methyl ethyl 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;
Dipropylene glycol alkyl ethers such as dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, dipropylene glycol methyl ethyl 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 such as propylene glycol monomethyl ether propionate, propylene glycol monoethyl ether propionate, propylene glycol mono-n-propyl ether propionate, 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, 4-methoxybutyl acetate, 3-methoxybutyl acetate, acetic acid 2 -Methoxybutyl, 3-ethoxybutyl acetate, 3-proxybutyl acetate, methyl lactate, ethyl lactate, n-propyl lactate, n-butyl lactate, methyl 2-hydroxy-2-methylpropionate, 2-hydroxy-2-methyl Ethyl propionate, methyl 3-hydroxypropionate, ethyl 3-hydroxypropionate, n-propyl 3-hydroxypropionate, n-butyl 3-hydroxypropionate, methyl 2-hydroxy-3-methylbutanoate, methyl methoxyacetate, Ethoxy methoxyacetate, methoxyacetic acid -Propyl, n-butyl methoxyacetate, methyl ethoxyacetate, ethyl ethoxyacetate, n-propyl ethoxyacetate, n-butyl ethoxyacetate, methyl n-propoxyacetate, ethyl n-propoxyacetate, n-propyloxyacetate n-propyl, n -Other esters such as n-butyl propoxyacetate, methyl n-butoxyacetate, ethyl n-butoxyacetate, n-butoxyacetate, n-butyloxybutoxyacetate, and the like.
Of these solvents, diethylene glycol alkyl ether, propylene glycol monoalkyl ether acetate, alkyl alkoxypropionate, acetate, and the like are preferable.

The said solvent can be used individually or in mixture of 2 or more types.
In addition, the radical polymerization initiator is not particularly limited. 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), Azo compounds such as 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile); benzoyl peroxide, lauroyl peroxide, t-butylperoxypivalate, 1,1-bis (t-butylperoxy) cyclohexane, etc. And organic peroxides such as hydrogen peroxide.

Moreover, when using a peroxide as a radical polymerization initiator, it is good also as a redox type initiator using it together with a reducing agent.
These radical polymerization initiators can be used alone or in admixture of two or more.
The copolymer [α] thus obtained may be used as it is in the production of the [A] polymer, or once separated from the solution and used in the production of the [A] polymer.
The polystyrene equivalent weight average molecular weight (hereinafter referred to as “Mw”) of the copolymer [α] by gel permeation chromatography (GPC) is preferably 2,000 to 100,000, more preferably 5,000 to 50, 000. In this case, if the Mw is less than 2,000, there is a risk that the alkali developability, the remaining film ratio, etc. of the resulting film may be reduced, and the pattern shape, heat resistance, etc. may be impaired. If it exceeds 1, the resolution may be reduced, or the pattern shape may be impaired.
The [A] polymer in the present invention is obtained by reacting the unsaturated isocyanate compound (1) with the copolymer [α].

Examples of the unsaturated isocyanate compound (1) include 2-acryloyloxyethyl isocyanate, 3-acryloyloxypropyl isocyanate, 4-acryloyloxybutyl isocyanate, 6-acryloyloxyhexyl isocyanate, 8-acryloyloxyoctyl isocyanate, 10- Acrylic acid derivatives such as acryloyloxydecyl isocyanate;
Mention may be made of methacrylic acid derivatives such as 2-methacryloyloxyethyl isocyanate, 3-methacryloyloxypropyl isocyanate, 4-methacryloyloxybutyl isocyanate, 6-methacryloyloxyhexyl isocyanate, 8-methacryloyloxyoctyl isocyanate, 10-methacryloyloxydecyl isocyanate. it can.

Moreover, as a commercial item of 2-acryloyloxyethyl isocyanate, it is a trade name, Karenz AOI (made by Showa Denko KK), and as a commercial item of 2-methacryloyloxyethyl isocyanate, it is a brand name, Karenz MOI (Showa Denko). (Made by Co., Ltd.).
Of these unsaturated isocyanate compounds (1), 2-acryloyloxyethyl isocyanate, 2-methacryloyloxyethyl isocyanate, and the like are preferable from the viewpoint of reactivity with the copolymer [α].
[A] In the polymer, the unsaturated isocyanate compound (1) can be used alone or in admixture of two or more.

In the present invention, the reaction between the copolymer [α] and the unsaturated isocyanate compound (1) is performed by, for example, a catalyst such as di-n-butyltin (IV) dilaurate or a polymerization inhibitor such as p-methoxyphenol. The unsaturated isocyanate compound (1) can be added dropwise to the copolymer [α] solution containing the above while stirring at room temperature or under heating.
[A] The amount of unsaturated isocyanate compound (1) used in the production of the polymer is such that (a2) in the copolymer [α] is an unsaturated compound containing one or more hydroxyl groups in one molecule. On the other hand, it is preferably 0.1 to 90% by weight, more preferably 10 to 80% by weight, and particularly preferably 25 to 75% by weight. In this case, if the amount of the unsaturated isocyanate compound (1) used is less than 0.1% by weight, the effect of improving the sensitivity and the elastic properties is small, whereas if it exceeds 90% by weight, the unreacted unsaturated isocyanate compound (1) remains, and the storage stability of the resulting polymer solution and radiation-sensitive resin composition tends to decrease.
[A] The polymer has a carboxyl group and / or a carboxylic anhydride group, an epoxy group, and a polymerizable unsaturated bond, and has an appropriate solubility in an alkali developer and a special curing agent. Even if it is not used together, it can be easily cured by heating. [A] From a radiation-sensitive resin composition containing a polymer, a spacer having a predetermined shape can be easily formed without developing residue and film loss during development.

-Radiosensitive resin composition-
The radiation-sensitive resin composition of the present invention contains [A] a polymer and [B] a polymerizable unsaturated compound, and preferably [C] a radiation-sensitive polymerization initiator.

-[B] polymerizable unsaturated compound-
[B] The polymerizable unsaturated compound comprises an unsaturated compound that is polymerized by exposure to radiation in the presence of a radiation-sensitive polymerization initiator.
Such a [B] polymerizable unsaturated compound is not particularly limited. For example, a monofunctional, bifunctional, or trifunctional or higher (meth) acrylic acid ester has good copolymerizability. From the viewpoint of improving the strength of the obtained spacer.
Examples of the monofunctional (meth) acrylic acid ester include 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, diethylene glycol monoethyl ether acrylate, diethylene glycol monoethyl ether methacrylate, isobornyl acrylate, isobornyl methacrylate, 3- Mention of methoxybutyl acrylate, 3-methoxybutyl methacrylate, 2-acryloyloxyethyl) (2-hydroxypropyl) phthalate, 2-methacryloyloxyethyl) (2-hydroxypropyl) phthalate, ω-carboxy-polycaprolactone monoacrylate, etc. Can do. As a commercial product, for example, Aronix M-101, M-111, M-114, M-5300 (above, manufactured by Toa Gosei Co., Ltd.); KAYARAD TC-110S, TC-120S (above) , Nippon Kayaku Co., Ltd.); Biscoat 158, 2311 (above, Osaka Organic Chemical Industry Co., Ltd.).

  Examples of the bifunctional (meth) acrylic acid ester include ethylene glycol diacrylate, ethylene glycol dimethacrylate, diethylene glycol diacrylate, diethylene glycol dimethacrylate, tetraethylene glycol diacrylate, tetraethylene glycol dimethacrylate, 1,6- Examples include hexanediol diacrylate, 1,6-hexanediol dimethacrylate, 1,9-nonanediol diacrylate, 1,9-nonanediol dimethacrylate, bisphenoxyethanol full orange acrylate, and bisphenoxyethanol full orange methacrylate. As commercial products, for example, Aronix M-210, M-240, M-6200 (above, manufactured by Toa Gosei Co., Ltd.), KAYARAD HDDA, HX-220, R-604, KAYARAD UX -2201, UX-2301, UX-3204, UX-3301, UX-4101, UX-6101, UX-7101, UX-8101, UX-0937 (above, Nippon Kayaku Co., Ltd.), Biscoat 260, 312 and 335HP (above, manufactured by Osaka Organic Chemical Industry Co., Ltd.), light acrylate 1,9-NDA (manufactured by Kyoeisha Co., Ltd.), and the like can be mentioned.

  Furthermore, as the tri- or higher functional (meth) acrylic acid ester, for example, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol triacrylate, pentaerythritol trimethacrylate, pentaerythritol tetraacrylate, pentaerythritol tetramethacrylate, Dipentaerythritol pentaacrylate, dipentaerythritol pentamethacrylate, dipentaerythritol hexaacrylate, dipentaerythritol hexamethacrylate, tri (2-acryloyloxyethyl) phosphate, tri (2-methacryloyloxyethyl) phosphate, 9 or more functionalities As (meth) acrylic acid esters, linear alkylene groups and alicyclic structures And a compound having two or more isocyanate groups and a compound having one or more hydroxyl groups in the molecule and having three, four or five acryloyloxy groups and / or methacryloyloxy groups The polyfunctional urethane acrylate type compound etc. which are obtained by making it react with can be mentioned.

  Commercially available products of trifunctional or higher functional (meth) acrylic acid esters are trade names, for example, Aronix M-309, M-400, M-405, M-450, M-7100, M- 8030, M-8060, TO-1450 (above, manufactured by Toa Gosei Co., Ltd.), KAYARAD TMPTA, DPHA, DPCA-20, DPCA-30, DPCA-60, DPCA-60, (above, Nippon Kayaku Co., Ltd.), Biscoat 295, 300, 360, GPT, 3PA, 400 (above, Osaka Organic Chemical Industry Co., Ltd.) and commercial products containing polyfunctional urethane acrylate compounds Examples of the products include New Frontier R-1150 (Daiichi Kogyo Seiyaku Co., Ltd.), KAYARAD DPHA-40H (Nippon Kayaku Co., Ltd.), and the like. wear.

  Among these monofunctional, bifunctional, or trifunctional or higher (meth) acrylic acid esters, trifunctional or higher functional (meth) acrylic acid esters are more preferable, and in particular, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol. Tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, and commercial products containing polyfunctional urethane acrylate compounds are preferred.

The monofunctional, bifunctional, or trifunctional or higher (meth) acrylic acid esters can be used alone or in admixture of two or more.
In the radiation sensitive resin composition of the present invention, the amount of the [B] polymerizable unsaturated compound used is preferably 1 to 120 parts by weight, more preferably 3 to 100 parts per 100 parts by weight of the [A] polymer. Parts by weight. In this case, if the amount of the [B] polymerizable unsaturated compound used is less than 1 part by weight, there is a risk of developing residue during development, whereas if it exceeds 120 parts by weight, the adhesion of the resulting spacer tends to decrease. There is.

-[C] Radiation sensitive polymerization initiator-
[C] Radiation sensitive polymerization initiator generates [B] active species capable of initiating polymerization of polymerizable unsaturated compounds upon exposure to radiation such as visible light, ultraviolet light, far ultraviolet light, charged particle beam, and X-ray. It consists of the component to do.
Examples of such [C] radiation sensitive polymerization initiators include O-acyloxime compounds, acetophenone compounds, biimidazole compounds, benzoin compounds, benzophenone compounds, α-diketone compounds, polynuclear quinone compounds, Examples include xanthone compounds, phosphine compounds, triazine compounds, and the like.

  As the O-acyloxime compound, 9. H. A carbazole-based O-acyloxime polymerization initiator is preferred. For example, 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-butyl-6- (2-ethylbenzoyl) -9. H. -Carbazol-3-yl] -ethane-1-one oxime-O-benzoate and the like.

Of these O-acyloxime compounds, 1- [9-ethyl-6- (2-methylbenzoyl) -9. H. -Carbazol-3-yl] -ethane-1-one oxime-O-acetate is preferred.
The O-acyloxime compounds can be used alone or in admixture of two or more. In the present invention, the use of an O-acyloxime compound makes it possible to obtain a spacer having sufficient sensitivity and adhesion even with an exposure amount of 1,500 J / m ² or less.
Examples of the acetophenone compound include an α-hydroxyketone compound and an α-aminoketone compound.

Examples of the α-hydroxyketone compound include 1-phenyl-2-hydroxy-2-methylpropan-1-one, 1- (4-i-propylphenyl) -2-hydroxy-2-methylpropane-1 -On, 4- (2-hydroxyethoxy) phenyl- (2-hydroxy-2-propyl) ketone, 1-hydroxycyclohexyl phenylketone and the like can be mentioned. Examples of the α-aminoketone compound include 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one and 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl). ) -Butan-1-one, 2- (4-methylbenzoyl) -2- (dimethylamino) -1- (4-morpholinophenyl) -butan-1-one, and the like. Examples of compounds other than these include 2,2-dimethoxyacetophenone, 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, and the like.
Among these acetophenone compounds, in particular, 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one, 2- (4-methylbenzoyl) -2- (dimethylamino) -1- (4-Morpholinophenyl) -butan-1-one is preferred.
In the present invention, the sensitivity, spacer shape and compressive strength can be further improved by using an acetophenone compound in combination.

  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'-biimidazole, 2,2'-bis (2,4,6-trichlorophenyl) -4,4 ', 5,5'-tetraphenyl-1,2'-biimidazole, 2,2 '-Bis (2-bromophenyl)- , 4 ′, 5,5′-tetraphenyl-1,2′-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 can be mentioned. .

  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 are preferable, and in particular, 2,2′-bis (2,4-dichlorophenyl) -4,4 ′, 5,5′-tetraphenyl-1,2 ′. -Biimidazole is preferred.

In the present invention, it is possible to further improve sensitivity, resolution and adhesion by using a biimidazole compound in combination.
When a biimidazole compound is used in combination, an aliphatic or aromatic compound having a dialkylamino group (hereinafter referred to as “amino sensitizer”) may be added to sensitize it. it can.
Examples of amino sensitizers include N-methyldiethanolamine, 4,4′-bis (dimethylamino) benzophenone, 4,4′-bis (diethylamino) benzophenone, ethyl p-dimethylaminobenzoate, p-dimethylamino. Examples include i-amyl benzoate.
Of these amino sensitizers, 4,4′-bis (diethylamino) benzophenone is particularly preferable.

The amino sensitizers can be used alone or in admixture of two or more.
Further, when a biimidazole compound and an amino sensitizer are used in combination, a thiol compound can be added as a hydrogen donor compound. The biimidazole compound is sensitized and cleaved by the amino sensitizer to generate an imidazole radical, but as it is, high polymerization initiating ability is not expressed, and the resulting spacer has an unfavorable shape such as a reverse taper shape. In many cases. However, by adding a thiol compound to a system in which a biimidazole compound and an amino sensitizer coexist, hydrogen radicals are donated from the thiol compound to the imidazole radical, so that the imidazole radical is neutral imidazole. In addition, a component having a sulfur radical having a high polymerization initiating ability is generated, whereby the spacer can have a more preferable forward taper 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, Bifunctional or higher aliphatic thiols such as pentaerythritol tetra (mercaptoacetate) and pentaerythritol tetra (3-mercaptopropionate) can be exemplified.
Of these thiol compounds, 2-mercaptobenzothiazole is particularly preferable.

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.
Further, when the biimidazole compound and the amino sensitizer are used in combination, the addition amount of the amino sensitizer is preferably 0.1 to 50 parts by weight with respect to 100 parts by weight of the biimidazole compound. Preferably it is 1-20 weight part. In this case, if the addition amount of the amino sensitizer is less than 0.1 parts by weight, the effect of improving the sensitivity, resolution and adhesion tends to be reduced. There is a tendency to be damaged.
In addition, when a biimidazole compound and an amino sensitizer are used in combination, the addition amount of the thiol compound is preferably 0.1 to 50 parts by weight, more preferably 100 parts by weight of the biimidazole compound. 1 to 20 parts by weight. In this case, if the addition amount of the thiol compound is less than 0.1 parts by weight, the effect of improving the shape of the spacer tends to be reduced or the film tends to be reduced. On the other hand, if the amount exceeds 50 parts by weight, the resulting spacer There is a tendency that the shape of is damaged.

-Additives-
In the radiation-sensitive resin composition of the present invention, a heat-sensitive acid-generating compound, a surfactant, and an adhesion assistant other than the above components, as necessary, within a range that does not impair the intended effect of the present invention. Additives such as storage stabilizers and heat resistance improvers can also be blended.

  The heat-sensitive acid generating compound can be used to improve heat resistance and hardness. Examples of onium salts include phenyldiazonium tetrafluoroborate, phenyldiazonium hexafluorophosphonate, phenyldiazonium hexafluoroarsenate, phenyldiazonium trifluoromethanesulfonate, phenyldiazonium trifluoroacetate, phenyldiazonium-p-toluenesulfonate, 4-methoxyphenyldiazonium Tetrafluoroborate, 4-methoxyphenyldiazonium hexafluorophosphonate, 4-methoxyphenyldiazonium hexafluoroarsenate, 4-methoxyphenyldiazonium trifluoromethanesulfonate, 4-methoxyphenyldiazonium trifluoroacetate, 4-methoxyphenyldiazonium-p- Toluenesulfonate, 4 ter-butylphenyldiazonium tetrafluoroborate, 4-ter-butylphenyldiazonium hexafluorophosphonate, 4-ter-butylphenyldiazonium hexafluoroarsenate, 4-ter-butylphenyldiazonium trifluoromethanesulfonate, 4-ter-butylphenyl Diazonium salts such as diazonium trifluoroacetate and 4-ter-butylphenyldiazonium-p-toluenesulfonate; triphenylsulfonium tetrafluoroborate, triphenylsulfonium hexafluorophosphonate, triphenylsulfonium hexafluoroarsenate, triphenylsulfonium trifluoromethane Sulfonate, triphenylsulfonium trifluoroacetate , Triphenylsulfonium-p-toluenesulfonate, 4-methoxyphenyldiphenylsulfonium tetrafluoroborate, 4-methoxyphenyldiphenylsulfonium hexafluorophosphonate, 4-methoxyphenyldiphenylsulfonium hexafluoroarsenate, 4-methoxyphenyldiphenylsulfonium trifluoromethane Sulfonate, 4-methoxyphenyldiphenylsulfonium trifluoroacetate, 4-methoxyphenyldiphenylsulfonium-p-toluenesulfonate, 4-phenylthiophenyldiphenyltetrafluoroborate, 4-phenylthiophenyldiphenylhexafluorophosphonate, 4-phenylthio Phenyldiphenyl hexafluoroarsenate, 4-phenyl Oh diphenyl trifluoromethanesulfonate, 4-phenylthiophenyldiphenylsulfonium trifluoroacetate, sulfonium salts such as 4-phenylthiophenyldiphenylsulfonium -p- toluenesulfonate.

Examples of the metallocene compounds include (1-6-η-cumene) (η-cyclopentadienyl) iron (1+) hexafluorophosphate (1-).
Commercially available products of these radiation-sensitive cationic polymerization initiators include, for example, Adeka Ultra Set PP-33 (made by Asahi Denka Kogyo Co., Ltd.) which is a diazonium salt, OPTOMER SP-150 and 170 (both Asahi Denka) which are sulfonium salts. Kogyo Co., Ltd.) and Irgacure 261 (Ciba Specialty Chemicals Co., Ltd.), which is a metallocene compound.
The above heat-sensitive acid generating compounds can be used alone or in admixture of two or more.

The use ratio of the heat-sensitive acid-generating compound is preferably 20 parts by weight or less, more preferably 5 parts by weight or less with respect to 100 parts by weight of the copolymer [A]. When the amount used exceeds 20 parts by weight, precipitates may be deposited in the coating film forming step, which may hinder the coating film formation.
The said surfactant is a component which has the effect | action which improves coating property, and a fluorine-type surfactant and a silicone type surfactant are preferable.

  The fluorine-based surfactant is preferably a compound having a fluoroalkyl group or a fluoroalkylene group at at least one of the terminal, main chain and side chain, and specific examples thereof include 1,1,2,2- Tetrafluorooctyl (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- Nethyl) ether, 1,1,2,2,3,3-hexafluoro-n-decane, 1,1,2,2,8,8,9,9,10,10-decafluoro-n-dodecane, Sodium perfluoro-n-dodecyl sulfonate, sodium fluoroalkylbenzene sulfonate, sodium fluoroalkyl phosphonate, sodium fluoroalkyl carboxylate, fluoroalkyl polyoxyethylene ether, diglycerin tetrakis (fluoroalkyl polyoxyethylene ether), fluoroalkyl Ammonium iodide, fluoroalkyl betaine, fluoroalkyl polyoxyethylene ether, perfluoroalkyl polyoxyethanol, perfluoroalkyl alkoxylate, fluorine alkyl ester and the like can be mentioned.

  Moreover, as a commercial item of a fluorine-type surfactant, it is a brand name, for example, BM-1000, the same -1100 (above, the product made from BM CHEMIE), MegaFuck F142D, the same F172, the same F173, the same F183, the same F178. F191, F471, F476 (above, manufactured by Dainippon Ink & Chemicals, Inc.), Florard FC 170C, FC-171, FC-430, FC-431 (above, manufactured by Sumitomo 3M Limited) ), Surflon S-112, S-113, S-131, S-141, S-145, S-382, SC-101, SC-102, SC-103, SC-103 104, SC-105, SC-106 (above, manufactured by Asahi Glass Co., Ltd.), F-top EF301, EF303, EF352 (above, manufactured by Shin-Akita Kasei Co., Ltd.), lid Agent FT-100, FT-110, FT-140A, FT-150, FT-250, FT-251, FTX-251, FTX-218, FT-300, FT-310, FT-400S (above, manufactured by Neos Co., Ltd.) and the like.

  Examples of the silicone-based surfactants are commercially available products, for example, Toray Silicone DC3PA, DC7PA, SH11PA, SH21PA, SH28PA, SH29PA, SH30PA, SH-190, SH-193. SZ-6032, SF-8428, DC-57, DC-190 (manufactured by Toray Dow Corning Silicone Co., Ltd.), TSF-4440, -4300, -4445, -4446 -4460, -4442 (above, manufactured by GE Toshiba Silicone Co., Ltd.), and the like.

  Furthermore, as surfactants other than the above, for example, 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 commercial products, For example, KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.), Polyflow No. 57, no. 95 (manufactured by Kyoeisha Chemical Co., Ltd.).

The surfactants can be used alone or in admixture of two or more.
The blending amount of the surfactant is preferably 5 parts by weight or less, more preferably 2 parts 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 5 parts by weight, there is a tendency that film roughening is likely to occur during coating.
The adhesion assistant is a component having an effect of further improving the adhesion between the spacer and the substrate, and a functional silane coupling agent is preferable.

Examples of the functional silane coupling agent include compounds having a reactive functional group such as a carboxyl group, a methacryloyl group, a vinyl group, an isocyanate group, and an epoxy group, and more specifically, trimethoxysilyl. Benzoic acid, γ-methacryloyloxypropyltrimethoxysilane, vinyltriacetoxysilane, vinyltrimethoxysilane, γ-isocyanatopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ) Ethyltrimethoxysilane and the like.
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] polymer. 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, 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 parts by weight or less, more preferably 0.001 to 0.5 parts by weight, with respect to 100 parts by weight of the [A] polymer. In this case, if the amount of the storage stabilizer exceeds 3 parts by weight, the sensitivity may decrease and the pattern shape may be impaired.

Examples of the heat resistance improver include N- (alkoxymethyl) glycoluril compounds and N- (alkoxymethyl) melamine compounds.
Examples of the N- (alkoxymethyl) glycoluril compound, e.g., 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' - can be given tetra (t-butoxymethyl) glycoluril.
Of these N- (alkoxymethyl) glycoluril compound, particularly 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 particularly preferable. Nicalac N-2702, MW-30M (manufactured by Sanwa Chemical Co., Ltd.) and the like.

The heat resistance improvers can be used alone or in admixture of two or more.
The blending amount of the heat resistance improver 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] polymer. In this case, when the compounding amount of the heat resistance improver exceeds 30 parts by weight, the storage stability of the radiation-sensitive resin composition tends to decrease.
The radiation-sensitive resin composition of the present invention is preferably used as a composition solution dissolved in an appropriate solvent.

  As the solvent, each component constituting the radiation-sensitive resin composition is uniformly dissolved, does not react with each component, and has a suitable volatility, but the solubility of each component, each component and Alcohols, ethylene glycol monoalkyl ether acetate, diethylene glycol monoalkyl ether acetate, diethylene glycol alkyl ether, propylene glycol monoalkyl ether acetate, dipropylene glycol alkyl ether, alkoxypropionic acid Alkyl, acetate ester 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 ester. 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, dipropylene glycol dimethyl ether, 3-methoxybutyl acetate, 2-methoxyethyl acetate and the like are preferable.

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. , Di-n-hexyl ether, acetonyl acetone, isophorone, caproic acid, caprylic acid, 1-octanol, 1-nonanol, benzyl alcohol, benzyl acetate, ethyl benzoate, diethyl oxalate, diethyl maleate, γ-butyrolactone, Examples thereof include ethylene carbonate, propylene carbonate, and ethylene glycol monophenyl ether acetate.

These high boiling point solvents can be used alone or in admixture of two or more.
In addition, the composition solution prepared as described above can be filtered for use with a Millipore filter or the like having a pore diameter of about 0.5 μm.
Especially the radiation sensitive resin composition of this invention can be used very suitably for formation of the spacer for liquid crystal display elements.

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 method of forming the spacer of the present invention includes at least the following steps in the order described below.

(A) forming a film of the radiation sensitive resin composition of the present invention on a substrate;
(B) exposing at least a part of the coating;
(C) a step of developing the coated film after exposure, and (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, and a radiation-sensitive resin composition is applied onto the transparent conductive film, preferably as a composition solution, 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, examples include glass substrates such as soda lime glass and alkali-free glass; resin substrates made of plastics such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, and polyimide.
As the transparent conductive film provided on one surface of the transparent substrate, for example, an 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 used.

As a method of forming a film of the photosensitive resin composition of the present invention, for example, (1) a coating method and (2) a dry film method can be used.
(1) As a coating method, 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, an ink jet coating method, etc. can be adopted. In particular, a spin coating method and a slit die coating method are preferable.
Further, when the film of the photosensitive resin composition of the present invention is formed, (2) when the dry film method is employed, the dry film is formed on the base film, preferably a flexible base film. And a photosensitive layer made of the photosensitive resin composition (hereinafter referred to as “photosensitive dry film”).

  The photosensitive dry film can be formed by laminating a photosensitive layer on the base film by applying the photosensitive resin composition of the present invention, preferably as a liquid composition, and then drying. 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. As a thickness of a base film, the range of 15-125 micrometers is suitable, for example. The thickness of the obtained photosensitive layer is preferably about 1 to 30 μm.

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. For example, about 25 μm is sufficient for the thickness of the cover film.
Moreover, although the conditions of prebaking differ also with the kind of each component, a mixture ratio, etc., Preferably, it is about 1 to 15 minutes at 70-120 degreeC.

-(B) Process-
Next, at least a part of the formed film is exposed. In this case, when a part of the film is exposed, it is preferably exposed through a photomask having a predetermined pattern.
Examples of radiation used for exposure include visible light, ultraviolet light, far ultraviolet light, electron beams, and X-rays. Radiation having a wavelength in the range of 190 to 450 nm is preferable, and radiation containing ultraviolet light of 365 nm is particularly preferable.
The exposure amount is preferably 100 to 10,000 J / m ² , more preferably as a value measured by the illuminometer (OAI model 356, manufactured by OAI Optical Associates Inc.) at a wavelength of 365 nm of the radiation to be exposed. 1,500 to 3,000 J / m ² .

-(C) Process-
Subsequently, the exposed film is developed to remove unnecessary portions and form a predetermined pattern.
As the developer used for development, an alkali developer is preferable. Examples thereof 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; diethylamine, di-n- Aliphatic secondary amines such as propylamine; aliphatic tertiary amines such as trimethylamine, methyldiethylamine, dimethylethylamine, and triethylamine; pyrrole, piperidine, N-methylpiperidine, N-methylpyrrolidine, 1,8-diazabicyclo [5.4 0.0] -7-undecene, 1,5-diazabicyclo [4.3.0] -5-nonene and other alicyclic tertiary amines; pyridine, collidine, lutidine, quinoline and other aromatic tertiary amines; ethanol dimethyl Amine, methyldiethanolamine, triethanolamine And aqueous solutions of alkaline compounds such as quaternary ammonium salts such as tetramethylammonium hydroxide and tetraethylammonium hydroxide.
In addition, an appropriate amount of a water-soluble organic solvent such as methanol or ethanol or a surfactant can be added to the aqueous solution of the alkaline compound.

The developing method may be any of a liquid filling method, a dipping method, a shower method, and the like, and the developing time is preferably about 10 to 180 seconds.
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 250 ° 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 an 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 obtain sufficient performance unless the heat treatment is performed at a temperature of about 180 to 200 ° C. or higher. In the radiation-sensitive resin composition, the heating temperature can be made lower than before, and as a result, without causing yellowing or deformation of the resin substrate, compressive strength, rubbing resistance during liquid crystal alignment, adhesion to the transparent substrate It is possible to form a spacer excellent in various properties such as properties.

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 element of the present invention is not particularly limited. For example, as shown in FIG. 1, a color filter layer and a spacer are formed on a transparent substrate, and the liquid crystal 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. Moreover, as shown in FIG. 1, you may form a protective film on a polarizing plate or a color filter layer as needed.
In addition, as shown in FIG. 2, a color filter layer and a spacer are formed on a transparent substrate, and are opposed to a thin film transistor (TFT) array through an alignment film and a liquid crystal layer, whereby a TN-TFT type liquid crystal display. It can also be an element. Also in this case, a protective film may be formed on the polarizing plate or the color filter layer as necessary.

  Hereinafter, the embodiment of the present invention will be described more specifically with reference to examples. Here, parts and% are based on weight.

Synthesis example 1
A flask equipped with a condenser and a stirrer was charged with 5 parts of 2,2′-azobisisobutyronitrile and 250 parts of 3-methoxybutyl acetate, followed by 10 parts of methacrylic acid and tricyclomethacrylate [5.2. 1.0 ^2,6 ] decan-8-yl 25 parts, styrene 5 parts, butadiene 5 parts, methacrylic acid 2-hydroxyethyl ester 25 parts, methacrylic acid 2-oxo-tetrahydrofuran-3-yl ester (formula (1) Specific Example (B-1)) After charging 30 parts and substituting with nitrogen, the temperature of the solution was raised to 80 ° C. while gently stirring, and this temperature was maintained for 5 hours to polymerize. A copolymer [α-1] solution having a partial concentration of 28.5% was obtained.
About the obtained copolymer [(alpha) -1], it was 20,000 when Mw was measured using GPC (gel permeation chromatography) HLC-8020 (brand name, Tosoh Corporation make). .

Subsequently, 14 parts of 2-methacryloyloxyethyl isocyanate (trade name Karenz MOI, manufactured by Showa Denko KK) and 0.08 part of 4-methoxyphenol were added to the copolymer [α-1] solution, and then 60 parts. The reaction was stirred for 2 hours at ° C. The progress of the reaction between the isocyanate group derived from 2-methacryloyloxyethyl isocyanate and the hydroxyl group of the copolymer [α-1] was confirmed by IR (infrared absorption) spectrum. IR spectra of the polymer solution [α-1], the solution after 1 hour of reaction at 60 ° C., and the solution after the reaction for 2 hours are shown in FIGS. 3 (a), (b) and (c), respectively. It was confirmed that the peak near 2,270 cm ⁻¹ derived from the isocyanate group of 2-methacryloyloxyethyl isocyanate decreased with the progress of the reaction. A [A] polymer solution having a solid concentration of 31.5% was obtained. Let this [A] polymer be a polymer (A-1).

Synthesis example 2
A flask equipped with a condenser and a stirrer was charged with 7.5 parts of 2,2′-azobisisobutyronitrile, 100 parts of 3-methoxybutyl acetate and 100 parts of propylene glycol monomethyl ether acetate, followed by 10 parts of methacrylic acid. Parts, 10 parts tricyclo [5.2.1.0 ^2,6 ] decan-8-yl methacrylate, 5 parts styrene, 25 parts 2-hydroxyethyl methacrylate, 4,4-dimethyl-2-oxomethacrylate -30 parts of tetrahydrofuran-3-yl (specific example (B-9) of formula (1)) and 20 parts of tetrahydrofuran-2-yl methacrylate were substituted with nitrogen, and then the temperature of the solution was stirred gently. Is raised to 80 ° C., held at this temperature for 4 hours, then raised to 100 ° C. and held at this temperature for 1 hour to polymerize, Solid content concentration 33.0% of the copolymer [alpha-2] to obtain a solution.
When the obtained copolymer [α-2] was measured using GPC, Mw was 15,000.

  Subsequently, 2-methacryloyloxyethyl isocyanate was reacted with the copolymer [α-2] solution in the same manner as in Synthesis Example 1. In the same manner as in Synthesis Example 1, the reaction between the isocyanate group and the copolymer was confirmed by IR spectrum. An [A] polymer solution having a solid content concentration of 35.0% was obtained. Let this [A] polymer be a polymer (A-2).

Synthesis example 3
In the same manner as in Synthesis Example 1, 100 parts of the copolymer [α-2] solution was reacted with 2-acryloyloxyethyl isocyanate to obtain an [A] polymer solution having a solid content concentration of 35.0%. Let this [A] polymer be a polymer (A-3).

Synthesis example 4
A flask equipped with a condenser and a stirrer was charged with 7.5 parts of 2,2′-azobisisobutyronitrile, 100 parts of 3-methoxybutyl acetate and 100 parts of propylene glycol monomethyl ether acetate, followed by 12 parts of methacrylic acid. Parts, 30 parts of tricyclo [5.2.1.0 ^2,6 ] decan-8-yl methacrylate, 5 parts of styrene, 5 parts of butadiene, 2- (6-hydroxyhexanoyloxy) ethyl methacrylate and methacrylic acid 25 parts of a mixture of 2-hydroxyethyl ester (trade name PLACEL FM1D (manufactured by Daicel Chemical Industries, Ltd.), 4-methyl-2-oxo-tetrahydropyran-4-yl methacrylate (a specific example of formula (1) ( B-14)) After charging 23 parts and substituting with nitrogen, the temperature of the solution was adjusted to 80 ° C. while gently stirring. The temperature is raised for 4 hours, then raised to 100 ° C., and this temperature is held for 1 hour for polymerization to obtain a copolymer [α-3] solution having a solid content concentration of 32.5%. It was.
When the obtained copolymer [α-3] was measured using GPC, Mw was 17,000.

  Subsequently, 2-methacryloyloxyethyl isocyanate was reacted with the copolymer [α-3] solution in the same manner as in Synthesis Example 1. In the same manner as in Synthesis Example 1, the reaction between the isocyanate group and the copolymer was confirmed by IR spectrum. An [A] polymer solution having a solid content concentration of 34.0% was obtained. This [A] polymer is referred to as a polymer (A-4).

Synthesis example 5
A flask equipped with a condenser and a stirrer was charged with 4 parts by weight of 2,2′-azobisisobutyronitrile and 220 parts by weight of diethylene glycol methyl ethyl ether. Subsequently, 5 parts by weight of styrene, 10 parts by weight of methacrylic acid, 4 parts by weight of acrylic acid, 31 parts by weight of benzyl methacrylate, 50 parts by weight of methacrylic acid n-butyl ester were charged, and after nitrogen substitution, the solution was stirred gently. The temperature was raised to 80 ° C., this temperature was maintained for 4 hours, and further maintained at 100 ° C. for 1 hour to obtain a polymer solution containing the copolymer [A-3]. The solid content concentration of the obtained polymer solution was 32.0%, and the weight average molecular weight of the polymer was 15,000 (weight average molecular weight was GPC (gel permeation chromatography) HLC-8020 ( It is a molecular weight in terms of polystyrene measured using Tosoh Corporation). Let this [A] polymer be a polymer (A-5).

Example 1
Preparation of Composition Solution As component [A], 100 parts of polymer solution [A] obtained in Synthesis Example 1 as polymer (A-1) and dipentaerystol hexaacrylate (trade name) as component [B] KAYARAD DPHA, manufactured by Nippon Kayaku Co., Ltd.) 100 parts, [C] component as 1- [9-ethyl-6- (2-methylbenzoyl) -9. H. -Carbazol-3-yl] -ethane-1-one oxime-O-acetate (trade name CGI-242, manufactured by Ciba Specialty Chemicals), γ-glycidoxypropyltrimethoxysilane as an adhesion aid 5 parts, 0.5 parts FTX-218 (trade name, manufactured by Neos Co., Ltd.) as a surfactant and 0.5 parts 4-methoxyphenol as a storage stabilizer are mixed to a solid content concentration of 30%. After being dissolved in propylene glycol monomethyl ether acetate, it was filtered through a Millipore filter having a pore size of 0.5 μm to prepare a composition solution.

Formation of Spacer The composition solution was applied on a non-alkali 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 4.0 μm.
Subsequently, the obtained coating film was exposed to ultraviolet rays having an intensity of 365 W / m ² at 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 solution of potassium hydroxide at 25 ° C. for 60 seconds, followed by washing with pure water for 1 minute, and further heating in an oven at 220 ° C. for 60 minutes to form a spacer.

  Next, various evaluations were performed in the following manner. The evaluation results are shown in Table 2.

(1) Evaluation of sensitivity When the spacer was formed in the same manner as the spacer except that the exposure amount was changed, the residual film ratio after development (film thickness after development × 100 / initial film thickness. The same applies hereinafter. The exposure amount at which 90) is 90% or more was defined as sensitivity. When this exposure amount is 1,200 J / m ² or less, it can be said that the sensitivity is good.
(2) Evaluation of resolution The minimum resolution that can be resolved by the exposure amount when the remaining film ratio after development is 90% or more when the spacer is formed in the same manner as the formation of the spacer except that the exposure amount is variable. Evaluation was based on the pattern size.
(3) Evaluation of development time A spacer was formed in the same manner as the formation of the spacer except that the development time was variable. At this time, the development time was set to 25, 30, 35, 40, 45, 50, and 60 seconds, and the residue in the unexposed area was observed with an optical microscope at each development time. Even when the development time is 40 seconds or less, if it is confirmed that there is no residue in the unexposed area, it can be said that the development time has been shortened.
(4) Evaluation The resulting spacer of the cross-sectional shape of the cross section was observed by a scanning electron microscope, were evaluated by either corresponds to any of A~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.
(5) Evaluation of elastic recovery rate About the obtained spacer, using a micro compression tester (trade name: FISCHER SCOPE H100C, manufactured by Fisher Instruments Co., Ltd.), a flat indenter with a diameter of 50 μm was used to load and unload. Both were set to 2.6 mN / sec, a load up to 50 mN was applied, the load was held for 5 seconds, and then unloaded, and a load-deformation curve during loading and a load-deformation curve during slow loading were prepared. At this time, as shown in FIG. 4, the difference between the deformation amount at the load of 50 mN and the deformation amount at the load of 5 mN is L1, and the deformation amount at the load of 50 mN and the deformation amount at the load of 5 mN at unloading. The elastic recovery rate was calculated by the following formula, with the difference between L2 and L2.
Elastic recovery rate (%) = L2 × 100 / L1
(6) 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.
(7) Evaluation of adhesion After forming a cured film in the same manner as the formation of the spacer except that no photomask was used, 8 of the adhesion tests of JIS K-5400 (1900) 8.5 Evaluation was performed by the cross-cut tape method of. At this time, the number of remaining grids out of 100 grids is shown in Table 2.
(8) Evaluation of heat resistance A cured film was formed in the same manner as the spacer formation except that no photomask was used, and then heated in an oven at 240 ° C for 60 minutes, and the film thickness before and after heating was measured. The remaining film ratio (film thickness after heating × 100 / initial film thickness) was evaluated.
(9) Evaluation of stripping solution resistance The substrate on which the spacer is formed is immersed in an alignment layer stripping solution (product name: TS-204, manufactured by Sanyo Chemical Co., Ltd.) at 50 ° C. for 30 minutes, and further heated at 210 ° C. for 15 minutes to change the thickness. It was measured. Evaluation was carried out by film thickness after heating × 100 / initial film thickness. If there is no change in the film thickness before and after immersion in the alignment film stripping solution, it can be said that the alignment film stripping solution resistance is good.
(10) In the same manner as in example 1. All evaluation thickening rate, after, prepare composition solution was measured the viscosity of the composition solution. It was stored at 23 ° C. for 10 days, and the viscosity of the composition solution after 10 days was measured. The thickening rate (%) was calculated by the following formula. Viscosity measurement temperature is 20 ° C.
Zonebaritsu (%) = - (viscosity of the composition solution adjustment made after 0 days) {(viscosity of the composition solution adjustment made after 10 days) (composition solution viscosity regulating made after 0 days)} / × 100
When the thickening rate after 10 days is 2% or less, it can be said that the storage stability is good.

Examples 2-11, Comparative Examples 1-5
In Example 1, each component shown in Table 1 was mixed with 5 parts of γ-glycidoxypropyltrimethoxysilane as an adhesion assistant, 0.5 part of FTX-218 as a surfactant, 4- It was mixed with 0.5 parts of methoxyphenol, dissolved in propylene glycol monomethyl ether acetate so that the solid content concentration was 30%, and then filtered through a Millipore filter having a pore size of 0.5 μm to prepare a composition solution. Thereafter, spacers were formed in the same manner as in Example 1 and evaluated in the same manner as in Example 1. The evaluation results are shown in Table 2.

  In Table 1, each component other than the polymer is as follows.

[B] Component B-1: Dipentaerystol hexaacrylate (trade name KAYARAD DPHA)
B-2: Commercial product containing a polyfunctional urethane acrylate compound (trade name KAYARAD DPHA-40H)
[C] component C-1: 1- [9-ethyl-6- (2-methylbenzoyl) -9. H. -Carbazol-3-yl] -ethane-1-one oxime-O-acetate (trade name CGI-242, manufactured by Ciba Specialty Chemicals)
C-2: 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one (trade name Irgacure 907, manufactured by Ciba Specialty Chemicals)
C-3: 2- (4-methylbenzoyl) -2- (dimethylamino) -1- (4-morpholinophenyl) -butan-1-one (trade name Irgacure 379, manufactured by Ciba Specialty Chemicals)
C-4: 2,2′-bis (2-chlorophenyl) -4,4 ′, 5,5′-tetraphenyl-1,2′-biimidazole C-5: 4,4′-bis (diethylamino) benzophenone C-6: 2-mercaptobenzothiazole [D] component D-1: polyfunctional novolak type epoxy resin (trade name, manufactured by Japan Epoxy Resin Co., Ltd., Epicoat 152)
D-2: Triphenylsulfonium trifluoromethanesulfonate

The schematic diagram which shows an example of the structure of a liquid crystal display element. The schematic diagram which shows the other example of the structure of a liquid crystal display element. The schematic diagram which illustrates the cross-sectional shape of a spacer. The figure which illustrates the load-deformation amount curve at the time of the load in evaluation of an elastic recovery factor, and a slow load.

Claims (6)

[A] (a1) unsaturated carboxylic acid and / or unsaturated carboxylic acid anhydride, (a2) unsaturated compound containing one or more hydroxyl groups in one molecule, and (a3) in the following formula (1) A copolymer of an unsaturated compound having a lactone structure represented by (a4) and another unsaturated compound other than (a1), (a2) and (a3) is represented by the following formula (2): 100 parts by weight of the polymer that is obtained by reacting an isocyanate compound, and
[B] 1 to 120 parts by weight of polymerizable unsaturated compound
And a radiation-sensitive resin composition characterized by not being used in combination with an epoxy resin having two or more epoxy groups in the molecule .

Here, L is a group represented by the following formula (L-1), (L-2) or (L-3),

R ₁ is a hydrogen atom or a methyl group, R _{2 to} R ₁₂ are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and n is an integer of 0 to 6.

Here, R ₁₃ is a hydrogen atom or a methyl group, and m is an integer of 0-6. Further contains 5 to 25 parts by weight (C) radiation-sensitive polymerization initiator relative to (A) 100 parts by weight of the polymer, the radiation-sensitive resin composition of claim 1. Claim 1 or 2 consists of the radiation-sensitive resin composition according The radiation-sensitive resin composition used for forming a spacer for a liquid crystal display device. The spacer for liquid crystal display elements formed from the radiation sensitive resin composition of Claim 3 . A method for forming a spacer for a liquid crystal display element, comprising at least the following steps in the order described below.
(A) forming a film of the radiation-sensitive resin composition according to claim 3 on a substrate;
(B) exposing at least a part of the coating;
(C) a step of developing the coated film after exposure, and (d) a step of heating the coated film after development. A liquid crystal display device comprising the spacer according to claim 4 .

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