JP4862998B2 - Side chain unsaturated polymer, radiation sensitive resin composition, and spacer for liquid crystal display device - Google Patents

Description

  The present invention relates to a side-chain unsaturated polymer particularly suitable for forming a spacer in a liquid crystal display device, a radiation-sensitive resin composition containing the polymer, a spacer, a method for forming the spacer, 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 between two substrates, that is, the cell gap, constant. Since it is randomly scattered on a transparent substrate such as a glass substrate, if there is a spacer in the pixel formation region, the reflection of the spacer occurs, or incident light is scattered and the contrast as a liquid crystal display element decreases. There was a problem.
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, from the viewpoint of increasing the area of liquid crystal display elements and improving productivity, the size of mother glass substrates has been increased, for example, about 1,500 × 1,800 mm, and further about 1,870 × 2,200 mm. 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 the photosensitive resin composition is constituted. It is said that by using a copolymer resin as a unit, it is possible to improve performance as a spacer and a 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 adhesion to a substrate and chemical resistance, for example, alignment film peeling solution resistance, but storage stability and developer There is concern about solubility in
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 capable of forming a spacer for a liquid crystal display element that sufficiently exhibits the resistance to a peeling solution upon peeling of an alignment film.

  The other subject of this invention is providing the side chain unsaturated polymer useful as a resin component of the said radiation sensitive resin composition.

  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) 5 to 50% by weight of unsaturated carboxylic acid and / or unsaturated carboxylic acid anhydride, (a2) compounds 1 to 50 containing two or more hydroxyl groups in one molecule represented by the following formula (1) It is achieved by a polymer obtained by reacting an isocyanate compound represented by the following formula (2) with a copolymer comprising 10% by weight and 10 % by weight of (a3) another unsaturated compound.

(In the formula, R ₁ represents a hydrogen atom or a methyl group, p is an integer of 0 to 3, and q is 1. )

(In the formula, R ₂ represents a hydrogen atom or a methyl group, and n is an integer of 1 to 12.)

According to the present invention, the problem is secondly,
[A] 100 parts by weight of the above polymer, [B] 1 to 150 parts by weight of the polymerizable unsaturated compound, and preferably [C] 15 to 17.5 parts by weight of a radiation sensitive polymerization initiator, This is achieved by a radiation-sensitive resin composition (hereinafter referred to as “a radiation-sensitive resin composition for spacers for liquid crystal display elements”) used for forming a spacer for a liquid crystal display.

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

According to the present invention, the problem is fourthly,
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, fifthly, the problem is as follows:
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. Elastic recovery, rubbing resistance, adhesion to a transparent substrate It is possible to form spacers for liquid crystal display elements with excellent heat resistance, etc., and at the time of spacer formation, the post-baking temperature after development can be lowered, which can cause yellowing or deformation of the resin substrate. Absent.
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-
The polymer of the present invention comprises (a1) an unsaturated carboxylic acid and / or an unsaturated carboxylic acid anhydride, and (a2) an unsaturated compound containing two or more hydroxyl groups in one molecule represented by the formula (1). A compound of a compound (hereinafter referred to as “two or more hydroxyl group-containing compounds”) and (a3) another unsaturated compound (hereinafter referred to as “copolymer [α]”) is represented by the formula (2). ) (Hereinafter referred to as “unsaturated isocyanate compound (1)”), and a polymer (hereinafter referred to as “[A] 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], (a1) content of the repeating unit derived from an unsaturated carboxylic acid compound is preferably 5 to 50 wt%, good Mashiku 10 to 40 wt%, particularly preferably 15 to 30 weight %. (A1) If the content of the repeating unit derived from the 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 an alkaline developer is lowered. On the other hand, if it exceeds 50% by weight, the solubility of the polymer in an alkaline developer may be too high.

Examples of (a2) two or more hydroxyl group-containing unsaturated compounds include:
1,2-dihydroxy-ethyl acrylate, 2,3-dihydroxypropyl, acrylic acid hydroxyalkyl esters such as acrylic acid 3,4-dihydroxy-butyl le;
Methacrylic acid 1,2-dihydroxy ethyl, methacrylate 2,3-dihydroxypropyl methacrylate hydroxyalkyl esters such as methacrylic acid 3,4-dihydroxy-butyl Le and the like.
Among these (a2) two or more hydroxyl-containing unsaturated compounds, from the viewpoint of copolymerization reactivity and reactivity with isocyanate compounds, 1,2-dihydroxyethyl acrylate, 2,3-dihydroxypropyl acrylate, Preference is given to 1,2-dihydroxyethyl methacrylate, 2,3-dihydroxypropyl methacrylate and the like.

In the copolymer [α], (a2) two or more hydroxyl group-containing unsaturated compounds can be used alone or in admixture of two or more.
In the copolymer [α], (a2) content of the repeating units derived from two or more hydroxyl-containing unsaturated compounds, 1 to 50 wt%, good Mashiku 3 to 40% by weight, particularly preferably 5 ~ 30% by weight. (A2) If the content of the repeating unit derived from the hydroxyl group-containing unsaturated compound is less than 1% by weight, the introduction rate of the unsaturated isocyanate compound (1) into the polymer tends to decrease, and the sensitivity tends to decrease. On the other hand, when it exceeds 50% by weight, the storage stability of the polymer obtained by the reaction with the unsaturated isocyanate compound (1) tends to be lowered.

Moreover, as (a3) 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 (a3) 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 alkaline aqueous 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], (a3) other unsaturated compounds can be used alone or in admixture of two or more.
In the copolymer [α], (a3) the content of the recurring units derived from other unsaturated compounds, 1 0-70% by weight, good Mashiku 20-50% by weight, particularly preferably 30 to 50 weight %. (A3) If the content of the repeating unit derived from 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, If it exceeds 70% by weight, the solubility of the polymer in an alkaline developer tends to be lowered. Further, when (meth) acrylic acid epoxy (cyclo) alkyl esters are used, the content is preferably 20% by weight or less, and if it exceeds 20% by weight, the storage stability tends to be lowered.
The copolymer [α] is obtained by radical polymerization of, for example, (a1) an unsaturated carboxylic acid compound, (a2) two or more hydroxyl group-containing unsaturated compounds and (a3) other unsaturated compounds in a suitable solvent. It can be produced by polymerizing in the presence of an 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, n-propyl methoxyacetate Pill, n-butyl methoxyacetate, methyl ethoxy acetate, ethyl ethoxy acetate, n-propyl ethoxy acetate, n-butyl ethoxy acetate, methyl n-propoxyacetate, ethyl n-propoxyacetate, n-propyloxyacetate n-propyl Other esters such as n-butyl propoxyacetate, methyl n-butoxyacetate, ethyl n-butoxyacetate, n-butoxyacetate, n-butyloxybutoxyacetate and the like can be mentioned.

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 once separated from the solution and used for the production of the polymer [A], or the solvent used for the polymerization of the copolymer [α] may be an alcohol. Otherwise, it may be used in the production of the polymer [A] as it is. As the solvent when the copolymer [α] is once separated from the solution and used for the production of the polymer [A], the above-mentioned solvents (however, alcohols may be used as solvents that can be used for the polymerization of the copolymer [α]). Can be used).

  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. If the Mw is less than 2,000, the resulting film may be deteriorated in alkali developability, residual film ratio, or the like, or may be damaged in pattern shape, heat resistance, or the like. , There is a possibility that the resolution is lowered or the pattern shape is damaged.

The [A] polymer in the present invention can be obtained by reacting the unsaturated isocyanate compound (1) with the copolymer [α].
Examples of the unsaturated isocyanate compound (1) include:
Acrylic acid derivatives such as 2-acryloyloxyethyl isocyanate, 3-acryloyloxypropyl isocyanate, 4-acryloyloxybutyl isocyanate, 6-acryloyloxyhexyl isocyanate, 8-acryloyloxyoctyl isocyanate, 10-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 the unsaturated isocyanate compound (1) used in the production of the polymer is preferably 0 with respect to (a2) two or more hydroxyl group-containing unsaturated compounds in the copolymer [α]. 0.1 to 90% by weight, more preferably 10 to 80% by weight, and particularly preferably 25 to 75% by weight. 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) Remain 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 and a polymerizable unsaturated bond, has an appropriate solubility in an alkali developer, and is used in combination with a special curing agent. The radiation-sensitive resin composition containing the polymer [A] is a spacer having a predetermined shape without developing residue and film loss during development. Can be easily formed.

-Radiosensitive resin composition-
The radiation-sensitive resin composition of the present invention contains [A] a polymer, [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- Examples thereof include methoxybutyl acrylate, 3-methoxybutyl methacrylate, (2-acryloyloxyethyl) (2-hydroxypropyl) phthalate, (2-methacryloyloxyethyl) (2-hydroxypropyl) phthalate, and the like. As commercial products, for example, Aronix M-101, M-111, M-114 (above, manufactured by Toa Gosei Co., Ltd.); KAYARAD TC-110S, TC-120S (above, Nippon Kayaku) Biscoat 158, 2311 (above, manufactured by Osaka Organic Chemical Industry Co., Ltd.) and the like.

  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 (above, Nippon Kayaku Co., Ltd.), Biscoat 260, 312 and 335HP (Osaka Organic Chemical Co., Ltd.) and the like.

  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, [B] the amount of the polymerizable unsaturated compound, relative to 100 parts by weight of the polymer (A), 1 to 150 parts by weight, good Mashiku 30 to 140 wt Part. [B] When the amount of the polymerizable unsaturated compound used is less than 1 part by weight, there is a possibility that a development residue may be generated during development.

-[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, 1- [9-ethyl-6- (2-methyl-4-tetrahydropyranylmethoxybenzoyl) -9. H. -Carbazol-3-yl] -ethane-1-one oxime-O-acetate, 1- [9-ethyl-6- (2-methyl-4-tetrahydrofuranylmethoxybenzoyl) -9. H. -Carbazol-3-yl] -ethane-1-one oxime-O-acetate 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, 1- [9-ethyl-6- (2-methyl-4-tetrahydropyranylmethoxybenzoyl) -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 1,200 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 -One, 4- (2-hydroxyethoxy) phenyl- (2-hydroxy-2-propyl) ketone, 1-hydroxycyclohexylphenylketone and the like. Examples of the α-aminoketone compound include 2 -Methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one, 2- (4- And methylbenzoyl) -2- (dimethylamino) -1- (4-morpholinophenyl) -butan-1-one. wear. 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. When the usage-amount of another radiation sensitive polymerization initiator exceeds 100 weight part, there exists a possibility that the desired effect of this 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. 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. On the other hand, if it exceeds 50 parts by weight, the shape of the resulting spacer tends to be impaired. There is.
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. If the amount of the thiol compound added is less than 0.1 parts by weight, the effect of improving the spacer shape tends to be reduced or the film tends to be reduced. There is a tendency to be damaged.

-Additives-
In the radiation-sensitive resin composition of the present invention, a surfactant, an adhesion assistant, a storage stabilizer, a heat resistance, in addition to the above components, if necessary, within a range that does not impair the intended effect of the present invention. Additives such as property improvers can also be blended.
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]. When the compounding amount of the surfactant exceeds 5 parts by weight, there is a tendency that film roughening tends 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. When the blending amount of the adhesion assistant exceeds 20 parts by weight, there is a tendency that a development residue tends 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. When the amount of the storage stabilizer exceeds 3 parts by weight, the sensitivity may be lowered 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 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 particularly 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 and the like.
Among these N- (alkoxymethyl) melamine compounds, N, N, N ′, N ′, N ″, N ″ -hexa (methoxymethyl) melamine is particularly preferable. For example, Nicalac N-2702, MW-30M (manufactured by Sanwa Chemical Co., Ltd.) and the like can be mentioned.

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. When the blending amount of the heat resistance improver exceeds 30 parts by weight, the storage stability of the radiation sensitive resin composition tends to be lowered.
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 formation of 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 color filter, a protective film, and a transparent conductive film are formed on one surface of the transparent substrate, and a film of the radiation-sensitive resin composition is formed on the transparent conductive film.
Examples of the transparent substrate used for forming the spacer include a glass substrate and a resin substrate. More specifically, a glass substrate such as soda lime glass and alkali-free glass; polyethylene terephthalate, polybutylene terephthalate, Examples thereof include a resin substrate made of a plastic such as polyethersulfone, polycarbonate, and polyimide.
Examples of the transparent conductive film provided on one surface of the transparent substrate include a NESA film (registered trademark of US PPG) made of tin oxide (SnO ₂ ), an ITO film made of indium oxide-tin oxide (In ₂ O ₃ —SnO ₂ ), etc. Can be 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) In the case of the coating method, after coating the photosensitive resin composition of the present invention on the substrate, preferably as a composition solution, the coating surface is heated (prebaked) to form a coating film.
As a coating method of the composition solution, 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 can be employed. In particular, a spin coating method and a slit die coating method are preferable.
Prebaking conditions vary depending on the type of each component, the blending ratio, and the like, but are preferably about 1 to 15 minutes at 70 to 120 ° C.

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 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 using the radiation sensitive resin composition of this invention as a solution, the solid content concentration (ratio with respect to the total composition weight of the weight remove | excluding the solvent from the composition) becomes like this. Preferably it is 15 to 80 weight%. A more preferable solid content concentration varies depending on the method of forming the film. The solid content concentration when the coating method is used for forming the coating is preferably 15 to 30% by weight, and the form concentration when the dry film method is used for forming the coating is preferably 50 to 70% by weight. .

-(B) Process-
Next, at least a part of the formed film is exposed. In this case, when exposing a part of the film, the exposure is usually performed through a photomask having a predetermined pattern.
As the radiation used for the exposure, for example, visible light, ultraviolet light, far ultraviolet light, electron beam, X-ray and the like can be used. However, radiation having a wavelength in the range of 190 to 450 nm is preferable, and particularly radiation containing 365 nm ultraviolet light. Is preferred.
The exposure dose is preferably 100 to 10,000 J / m ² , more preferably 1 as a value measured with an illuminometer (OAI model 356, manufactured by OAI Optical Associates Inc.) at a wavelength of 365 nm of the radiation to be exposed. 2,000 to 2,000 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, and examples thereof include inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and ammonia; ethylamine, n- Aliphatic primary amines such as propylamine; Aliphatic secondary amines such as diethylamine and di-n-propylamine; Aliphatic tertiary amines such as trimethylamine, methyldiethylamine, dimethylethylamine and triethylamine; pyrrole, piperidine and N-methyl Alicyclic tertiary amines such as piperidine, N-methylpyrrolidine, 1,8-diazabicyclo [5.4.0] -7-undecene, 1,5-diazabicyclo [4.3.0] -5-nonene; pyridine , Aromatic tertiary amines such as collidine, lutidine and quinoline; Examples include aqueous solutions of alkaline compounds such as alkanolamines such as methylamine, methyldiethanolamine and triethanolamine; 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.
As a developing method, any of a liquid piling method, a dipping method, a shower method and the like may be used, 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 lower than before, and as a result, even when a resin substrate is used as the transparent substrate, the substrate does not yellow or deform, and the compression strength and liquid crystal alignment It is possible to form a spacer that is excellent in various performances such as rubbing resistance and adhesion to a transparent substrate.

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, but for example, as shown in FIG. 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 diethylene glycol methyl ethyl ether, followed by 18 parts of methacrylic acid and tricyclomethacrylate [5.2.1]. .0 ^2,6] decan-8-yl 25 parts, 5 parts of styrene, 5 parts of butadiene, 25 parts of methacrylic acid 2,3-dihydroxypropyl, were charged methacrylic acid tetrahydrofuran-2-yl 22 parts, after nitrogen substitution While stirring gently, the temperature of the solution was raised to 80 ° C., and this temperature was maintained for 5 hours for polymerization to obtain a copolymer [α-1] solution having a solid content concentration of 28.0%. .
Mw of the obtained copolymer [α-1] was measured using GPC (Gel Permeation Chromatography) HLC-8020 (trade name, manufactured by Tosoh Corporation), and found to be 13,000. .

Next, 15 parts of 2-methacryloyloxyethyl isocyanate (trade name Karenz MOI, manufactured by Showa Denko KK) and 0.1 part of 4-methoxyphenol are added to the copolymer [α-1] solution. The reaction was carried out by stirring at 1 ° C. for 1 hour and further at 60 ° C. for 2 hours. 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] after the reaction for 1 hour and the solution after the reaction at 40 ° C. for 1 hour and further at 60 ° C. for 2 hours are shown in FIG. 3, FIG. 4 and FIG. 5, respectively. It was confirmed that the peak near 2270 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 content concentration of 29.3% was obtained. Let this [A] polymer be a polymer (A-1).

Synthesis example 2
After adding 14 parts of 2-acryloyloxyethyl isocyanate (trade name Karenz AOI, Showa Denko KK) and 0.1 part of 4-methoxyphenol to 100 parts of the copolymer [α-1] solution, 40 parts are added. By stirring and reacting at 60 ° C. for 1 hour and further at 60 ° C. for 2 hours, an [A] polymer solution having a solid content concentration of 29.5% was obtained. Let this [A] polymer be a polymer (A-2).

Synthesis example 3
A flask equipped with a condenser and a stirrer was charged with 7 parts by weight of 2,2′-azobis (2,4-dimethylvaleronitrile) and 250 parts of diethylene glycol methyl ethyl ether, followed by 18 parts of methacrylic acid, tricyclomethacrylate [ 5.2.1.0 ^2,6 ] Decan-8-yl 20 parts, styrene 5 parts, butadiene 5 parts, glycidyl methacrylate 5 parts, 2,3-dihydroxypropyl methacrylate 25 parts, tetrahydrofuran-2-methacrylate After charging 22 parts of the oil and purging with nitrogen, the temperature of the solution was raised to 70 ° C. while gently stirring, and polymerization was carried out while maintaining this temperature for 5 hours, so that the solid content concentration was 28.0%. A polymer [α-2] solution was obtained.
For the obtained copolymer [α-2], Mw was 8,000 as measured using GPC (gel permeation chromatography) HLC-8020 (trade name, manufactured by Tosoh Corporation). .

  Next, 15 parts of 2-methacryloyloxyethyl isocyanate and 0.1 part of 4-methoxyphenol are added to 100 parts of the copolymer [α-2] solution, and then 1 hour at 40 ° C. and 2 hours at 60 ° C. By stirring and reacting, a [A] polymer solution having a solid concentration of 29.4% was obtained. Let this [A] polymer be a polymer (A-3).

Synthesis example 4
A flask equipped with a condenser and a stirrer was charged with 5 parts of 2,2′-azobisisobutyronitrile and 250 parts of diethylene glycol methyl ethyl ether, followed by 22 parts of acrylic acid, 26 parts of benzyl methacrylate, and 39 parts of styrene. Then, after adding 23 parts of 2-hydroxyethyl methacrylate and purging with nitrogen, the temperature of the solution was raised to 100 ° C. while gently stirring, and this temperature was maintained for 5 hours to polymerize, thereby solid content concentration A 29.0% copolymer [α-4] solution was obtained.
About the obtained copolymer [α-4], Mw was 25,000 as measured using GPC (gel permeation chromatography) HLC-8020 (trade name, manufactured by Tosoh Corporation). .

  Subsequently, after adding 27 parts of 2-methacryloyloxyethyl isocyanate and 0.1 part of 4-methoxyphenol to 100 parts of the copolymer [α-4] solution, it is 1 hour at 40 ° C., and further 2 hours at 60 ° C. By stirring and reacting, a [A] polymer solution having a solid concentration of 29.4% was obtained. This [A] polymer is referred to as a polymer (A-4).

Example 1
Preparation of Composition Solution As component [A], 100 parts of polymer solution [A] obtained in Synthesis Example 1 was used as polymer (A-1), and dipentaerystol hexaacrylate (trade name as component [B]. KAYARAD DPHA, Nippon Kayaku Co., Ltd.) 100 parts, [C] component, 1- [9-ethyl-6- (2-methyl-4-tetrahydropyranylmethoxybenzoyl) -9. H. -Carbazol-3-yl] -ethane-1-one oxime-O-acetate, 5 parts, 2,2′-bis (2-chlorophenyl) -4,4 ′, 5,5′-tetraphenyl-1,2 ′ -5 parts biimidazole, 5 parts 4,4'-bis (diethylamino) benzophenone and 2.5 parts 2-mercaptobenzothiazole, 5 parts γ-glycidoxypropyltrimethoxysilane, surfactant As a storage stabilizer, 0.5 part of FTX-218 (trade name, manufactured by Neos Co., Ltd.) and 0.5 part of 4-methoxyphenol were mixed, and propylene glycol monomethyl was added so that the solid concentration was 30%. After dissolving in ether acetate, the solution was filtered through a Millipore filter having a pore size of 0.5 μm to prepare a composition solution.

Evaluation of Composition (1) Evaluation of Sensitivity A transparent conductive film is formed on an alkali-free glass substrate, and the composition solution is applied thereon using a spinner, and then prebaked on a hot plate at 90 ° C. for 3 minutes. Thus, a film having a thickness of 4.0 μm was formed.
Next, the obtained coating film was exposed to ultraviolet rays having an intensity at 365 nm of 250 W / m ² through a photomask having a remaining pattern of 10 μm square and varying the exposure amount. 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.
At this time, the minimum exposure amount at which the remaining film ratio after development (film thickness after development × 100 / initial film thickness; the same applies hereinafter) 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 amount that can be resolved when a spacer is formed in the same manner as the sensitivity evaluation, except that the exposure amount is the minimum exposure amount at which the residual film ratio after development is 90% or more. Evaluation was based on the pattern size.

(3) Evaluation of development time A spacer was formed in the same manner as in the above sensitivity evaluation except that the development time was the minimum exposure amount at which the residual film ratio after development was 90% or more and 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. At this time, the shortest development time in which no residue was confirmed in the unexposed area is shown in Table 2. Even when the development time is 40 seconds or less, it can be said that the development time is shortened when it is confirmed that there is no residue in the unexposed portion.

Evaluation of spacer (4) Evaluation of cross-sectional shape The cross-sectional shape of the spacer obtained in the same manner as the sensitivity evaluation described above except that the exposure amount was the minimum exposure amount at which the remaining film ratio after development was 90% or more. Observation was made with a scanning electron microscope, and evaluation was made depending on which of A to D shown in FIG. At this time, when the pattern edge is forward tapered or vertical like A or B, it can be said that the cross-sectional shape is good. On the other hand, as shown in C, when the sensitivity is insufficient, the remaining film rate is low, the cross-sectional dimension is small compared to A and B, and the bottom surface is a semi-convex lens shape with a flat surface, the cross-sectional shape is Also, as shown in D, the pattern may be peeled off during the subsequent rubbing process even in the case of an inversely tapered shape (in the cross-sectional shape, an inverted triangular shape in which the side of the film surface is longer than the side on the substrate side). Since it became very large, the cross-sectional shape was regarded as defective.

(5) Evaluation of elastic recovery rate About the obtained spacer, using a micro-compression tester (trade name DUH-201, manufactured by Shimadzu Corporation), a flat indenter with a diameter of 50 μm was used for both loading speed and unloading speed. A load of up to 50 mN was applied as 2.6 mN / sec, the load was held for 5 seconds, and then unloaded, and a load-deformation curve at load and a load-deformation curve during loading were prepared. At this time, as shown in FIG. 7, 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 evaluation of the cross-sectional shape except that no photomask was used, among the adhesion tests of JIS K-5400 (1900) 8.5, It was evaluated by the 8.5-2 cross-cut tape method. At this time, the number of remaining grids out of 100 grids is shown in Table 2.

(8) Evaluation of heat resistance A cured film was formed in the same manner as the evaluation of the cross-sectional shape except that a photomask was not used, and then heated in an oven at 240 ° C for 60 minutes, and the film thickness before and after heating was measured. Then, 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 performed based on the film thickness after heating / initial film thickness × 100 (%). 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) Evaluation of thickening rate Similarly, after preparing a composition solution, the viscosity of the composition solution was measured. 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.
Thickening rate (%) = {(viscosity 10 days after preparation of composition solution) − (viscosity 0 days after preparation of composition solution)} / (viscosity 0 days after preparation of composition solution) × 100
When the thickening rate after 10 days is 2% or less, it can be said that the storage stability is good.

Examples 2-5, Comparative Examples 1-5
In Example 1, each component shown in Table 1 was used as an adhesion assistant, 5 parts of γ-glycidoxypropyltrimethoxysilane, as a surfactant, 0.5 part of FTX-218, and as a storage stabilizer, 4 parts. -It 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, evaluation was performed 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: 1- [9-ethyl-6- (2-methyl-4-tetrahydropyranylmethoxybenzoyl) -9. H. -Carbazol-3-yl] -ethane-1-one oxime-O-acetate C-3: 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one (trade name Irgacure 907, Ciba Specialty Chemicals)
C-4: 2- (4-methylbenzoyl) -2- (dimethylamino) -1- (4-morpholinophenyl) -butan-1-one (trade name Irgacure 379, manufactured by Ciba Specialty Chemicals)
C-5: 2,2′-bis (2-chlorophenyl) -4,4 ′, 5,5′-tetraphenyl-1,2′-biimidazole C-6: 4,4′-bis (diethylamino) benzophenone C-7: 2-mercaptobenzothiazole [D] component D-1: polyfunctional novolac type epoxy resin (trade name, manufactured by Japan Epoxy Resin Co., Ltd., Epicoat 152)

It is a schematic diagram which shows an example of the structure of a liquid crystal display element. It is a schematic diagram which shows the other example of the structure of a liquid crystal display element. 2 is an infrared spectrum diagram of a polymer [α-1] in Synthesis Example 1. FIG. It is an infrared spectrum figure of the solution after 1 hour reaction of the polymer solution [α-1]. It is the infrared spectrum figure of the solution after making the solution after the same reaction for 1 hour react further at 40 degreeC for 1 hour, and 60 degreeC for 2 hours. It is a schematic diagram which illustrates the cross-sectional shape of a spacer. It is a 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 (8)

(A1) an unsaturated carboxylic acid and / or unsaturated carboxylic acid anhydride and from 5 to 50 wt%, (a2) a compound containing two or more hydroxyl groups in one molecule represented by the following formula (1) 1 A polymer obtained by reacting an isocyanate compound represented by the following formula (2) with a copolymer of 50% by weight and (a3) another unsaturated compound of 10 to 70% by weight.

(In the formula, R ₁ represents a hydrogen atom or a methyl group, p is an integer of 0 to 3, and q is 1. )

(In the formula, R ₂ represents a hydrogen atom or a methyl group, and n is an integer of 1 to 12.) (A1) an unsaturated carboxylic acid and and / or unsaturated carboxylic acid anhydride 5 to 50 wt%, (a2) the formula (1) containing two or more hydroxyl groups in one molecule represented by compound 1 The isocyanate compound represented by the above formula (2) is reacted with a copolymer of 50% by weight and (a3) 10 to 70% by weight of another unsaturated compound. A method for producing a polymer. [A] A radiation-sensitive resin composition comprising 100 parts by weight of the polymer according to claim 1 and [B] 1 to 150 parts by weight of a polymerizable unsaturated compound. Furthermore, the radiation sensitive resin composition of Claim 3 which contains 15-17.5 weight part of [C] radiation sensitive polymerization initiators with respect to 100 weight part of [A] polymer. The radiation sensitive resin composition of Claim 3 or 4 used for formation of the spacer for liquid crystal display elements. The spacer for liquid crystal display elements formed from the radiation sensitive resin composition of Claim 5 . 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 or 4 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 6 .

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