JP4315010B2 - Radiation-sensitive resin composition, display panel spacer and display panel - Google Patents

Description

  The present invention relates to a radiation sensitive resin composition, a display panel spacer, and a display panel. More specifically, the present invention relates to a radiation sensitive material suitable as a material for forming a spacer used in a display panel such as a liquid crystal display panel or a touch panel. The present invention relates to a resin composition, a display panel spacer formed from the composition, and a display panel including the spacer.

Conventionally, liquid crystal display panels use spacer particles such as glass beads and plastic beads having a predetermined particle size in order to keep the distance (cell gap) between two substrates constant. Since particles are randomly distributed on a transparent substrate such as a glass substrate, the presence of spacer particles in the pixel formation region may cause a phenomenon of spacer particle reflection or scattering of incident light, resulting in a contrast of the liquid crystal panel. There was a problem of lowering.
Therefore, in order to solve these problems, a method of forming a spacer by photolithography has been adopted. In this method, a photosensitive resin composition or a radiation-sensitive resin composition (hereinafter, these compositions are collectively referred to as “radiation-sensitive resin composition”) is applied onto a substrate, and a predetermined mask is applied. As described above, the film is exposed to radiation such as ultraviolet rays and then developed to form a dot-like or stripe-like spacer, and the spacer can be formed only in a predetermined place other than the pixel formation region. This problem is basically solved.

  By the way, when a spacer is formed by photolithography on a substrate used in an actual spacer forming process, for example, a color filter, a proximity exposure machine is often used. In the case of this proximity exposure, exposure is performed with a certain cell gap between the mask and the substrate on which a film such as a radiation-sensitive resin composition is formed, and it is ideal that the exposure is performed in a pattern according to the mask. However, the cell gap is filled with air or nitrogen, and the radiation that has passed through the opening (transparent part) of the mask diffuses and spreads in the gap, so that it is exposed wider than the design size of the mask pattern. There was a problem that. Therefore, in order to solve such a problem, the present applicant has already disclosed Patent Document 1, 1,2-octanedione-1- [4- (phenylthio) phenyl] as a photopolymerization initiator of a photosensitive resin composition. It is clear that by using -2- (O-benzoyloxime), the design size of the mask pattern can be faithfully reproduced even by proximity exposure, and a display panel spacer excellent in strength, heat resistance, etc. can be formed. I have to.

JP 2001-261761 A

In addition, with the increase in the size of the display panel, it is necessary to control the cell gap more accurately, but the adhesion of the coating formed from the radiation-sensitive resin composition for the spacer and the like to the substrate is insufficient. The formed spacer is displaced from the substrate, and as a result, it is impossible to accurately maintain the cell gap. In the display panel, the aperture ratio of the pixels is increasing, and as a result, the area of the black matrix region where the spacer can be arranged is gradually decreasing. Therefore, the spacer is required to have higher transparency so that the color tone of the pixel is not impaired even if the spacer enters the pixel region to some extent.
However, conventional radiation-sensitive resin compositions and the like used for the formation of spacers, including those described in Patent Document 1, are still not sufficient in terms of adhesion to substrates and transparency, and these characteristics are also Development of the radiation sensitive resin composition etc. which were equipped together was strongly desired.

Further, in recent years, the mother glass substrate has been increased in size from the viewpoint of increasing the area of the display panel and improving the productivity. With the conventional substrate size (about 680 × 880 mm), the substrate size is smaller than the mask size, so it was possible to cope with the collective exposure method, but for a large substrate (for example, about 1,500 × 1,800 mm) In this case, it is almost impossible to manufacture a mask size comparable to the substrate size, 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 handle a large substrate. However, in the step exposure method, it is necessary to expose several times for each substrate, and it takes time for alignment and step movement at the time of each exposure. Therefore, the throughput may be reduced as compared with the case of the batch exposure method. . In the batch exposure method, an exposure sensitivity of about 3,000 J / m ² is allowed, but in the step exposure method, the exposure sensitivity is required to be 1,500 J / m ² or less. However, it has been difficult to achieve a sufficient spacer shape and film thickness with an exposure dose of 1,500 J / m ² or less in the conventional radiation-sensitive resin composition used for forming the spacer.

Therefore, the problem of the present invention is that the design size of the mask pattern can be faithfully reproduced with high sensitivity, and the adhesion to the substrate is excellent, and a sufficient spacer shape and film thickness can be obtained even with an exposure amount of 1,500 J / m ² or less. Another object of the present invention is to provide a radiation-sensitive resin composition that can be achieved and can form a display panel spacer excellent in compressive strength, rubbing resistance, and the like.

The present invention, first,
[A] Copolymerization of (a1) ethylenically unsaturated carboxylic acid and / or ethylenically unsaturated carboxylic acid anhydride, (a2) epoxy group-containing ethylenically unsaturated compound, and (a3) other ethylenically unsaturated compound Coalescence,
[B] A polymerizable compound having an ethylenically unsaturated bond, and [C] a radiation-sensitive polymerization initiator containing a compound represented by the following formula (1) or (2) as an essential component. The radiation-sensitive resin composition (hereinafter referred to as “radiation-sensitive resin composition (A)”).

[In the formulas (1) and (2), each R ¹ independently represents a linear, branched or cyclic alkyl group having 1 to 12 carbon atoms or a phenyl group, and each R ² is independent from each other. Represents a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 12 carbon atoms or a phenyl group, and each R ³ is independently a hydrogen atom or a linear or branched chain having 1 to 12 carbon atoms. Alternatively, it represents a cyclic alkyl group, and each R ⁴ , each R ⁵ and each R ⁶ independently represents a hydrogen atom or a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms. However, the alkyl groups of R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ are each a group of straight, branched or cyclic alkoxyl groups having 1 to 6 carbon atoms, phenyl groups and halogen atoms. And the phenyl groups of R ¹ and R ² are each a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms, or a linear group having 1 to 6 carbon atoms. Further, it may be substituted with a substituent selected from the group consisting of a branched or cyclic alkoxyl group, a phenyl group and a halogen atom. ]

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

  Thirdly, the present invention comprises a display panel provided with the display panel spacer.

Hereinafter, the present invention will be described in detail.
Radiation sensitive resin composition (I)
-Copolymer [A]-
The component [A] in the radiation-sensitive resin composition (I) is (a1) an ethylenically unsaturated carboxylic acid and / or an ethylenically unsaturated carboxylic acid anhydride (hereinafter referred to as “unsaturated carboxylic acid compound (a1)”). And (a2) an epoxy group-containing ethylenically unsaturated compound (hereinafter referred to as “epoxy group-containing unsaturated compound (a2)”) and (a3) another ethylenically unsaturated compound (hereinafter referred to as “other unsaturated compounds”). And a copolymer (hereinafter referred to as “copolymer [A]”).

Among the components constituting the copolymer [A], examples of the unsaturated carboxylic acid compound (a1) include acrylic acid, methacrylic acid, crotonic acid, succinic acid mono (2-acryloyloxyethyl), and succinic acid. Monocarboxylic acids such as mono (2-methacryloyloxyethyl) acid, mono (2-acryloyloxyethyl) phthalate, mono (2-methacryloyloxyethyl) phthalate; maleic acid, fumaric acid, citraconic acid, mesacone Examples thereof include dicarboxylic acids such as acid and itaconic acid; anhydrides of the dicarboxylic acid.
Of these unsaturated carboxylic acid compounds (a1), acrylic acid, methacrylic acid, maleic anhydride are obtained from the viewpoints of copolymerization reactivity, solubility of the resulting copolymer [A] in an alkaline aqueous solution and easy availability. An acid or the like is preferable.
In copolymer [A], unsaturated carboxylic acid type compound (a1) can be used individually or in mixture of 2 or more types.

  In the copolymer [A], the content of the repeating unit derived from the unsaturated carboxylic acid compound (a1) 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 unsaturated carboxylic acid compound (a1) is less than 5% by weight, the solubility in an alkaline aqueous solution tends to decrease, and when it exceeds 40% by weight, There exists a possibility that the solubility with respect to the aqueous alkali solution of the copolymer obtained may become large too much.

  Examples of the epoxy group-containing unsaturated compound (a2) include glycidyl acrylate, 2-methylglycidyl acrylate, 3,4-epoxybutyl acrylate, 6,7-epoxyheptyl acrylate, and 3,4 acrylic acid. -Epoxycyclohexyl, glycidyl methacrylate, 2-methylglycidyl methacrylate, 3,4-epoxybutyl methacrylate, 6,7-epoxyheptyl methacrylate, 3,4-epoxycyclohexyl methacrylate, etc. Esters: α-ethyl acrylate glycidyl, α-ethyl acrylate 2-methylglycidyl, α-ethyl acrylate 3,4-epoxybutyl, α-ethyl acrylate 6,7-epoxyheptyl, α-ethyl acrylate 3 , 4-epoxycyclohexyl, α-n Α-alkylacrylic acid epoxyalkyl esters such as glycidyl propyl acrylate and glycidyl α-n-butyl acrylate; unsaturated glycidyl such as o-vinylbenzyl glycidyl ether, m-vinylbenzyl glycidyl ether, p-vinylbenzyl glycidyl ether Examples include ethers.

Among these epoxy group-containing unsaturated compounds (a2), from the viewpoint of copolymerization reactivity and spacer strength, glycidyl methacrylate, 2-methylglycidyl methacrylate, 6,7-epoxyheptyl methacrylate, o-vinylbenzyl Glycidyl ether, m-vinylbenzyl glycidyl ether, p-vinylbenzyl glycidyl ether and the like are preferable.
In the copolymer [A], the epoxy group-containing unsaturated compound (a2) can be used alone or in admixture of two or more.

  In the copolymer [A], the content of the repeating unit derived from the epoxy group-containing unsaturated compound (a2) is preferably 10 to 70% by weight, more preferably 20 to 60% by weight, and particularly preferably 30 to 50%. % By weight. In this case, if the content of the repeating unit derived from the epoxy group-containing unsaturated compound (a2) is less than 10% by weight, the compressive strength of the resulting spacer tends to decrease, whereas if it exceeds 70% by weight, There is a tendency that the storage stability of the obtained copolymer is lowered.

Furthermore, as other unsaturated monomer (a3), for example, methyl acrylate, ethyl acrylate, n-propyl acrylate, i-propyl acrylate, n-butyl acrylate, sec-butyl acrylate, acrylic T-butyl acid, cyclohexyl acrylate, 2-methylcyclohexyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, i-propyl methacrylate, n-butyl methacrylate, sec-butyl methacrylate, methacrylic acid (Meth) acrylic acid alkyl esters such as t-butyl, cyclohexyl methacrylate, 2-methylcyclohexyl methacrylate; tricyclo [5.2.1.0 ^2,6 ] decane-8-yl acrylate, 2-acrylic acid 2- (tricyclo [5.2.1.0 ^2,6] decan-8-yloxy Ethyl, isobornyl acrylate, methacrylic acid tricyclo [5.2.1.0 ^2,6] decan-8-yl methacrylate, 2 (tricyclo [5.2.1.0 ^2,6] decan-8-yloxy ) Other (meth) acrylic acid alicyclic esters such as ethyl and isobornyl methacrylate; aryl or aralkyl esters of (meth) acrylic acid such as phenyl acrylate, benzyl acrylate, phenyl methacrylate and benzyl methacrylate (Meth) acrylic acid hydroxyalkyl esters such as 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate; tetrahydrofuryl acrylate, tetrahydrofurfuryl acrylate, ( Tetrahydrofupi N-2-yl) methyl acrylate, tetrahydrofuryl methacrylate, tetrahydrofurfuryl methacrylate, (tetrahydrofupyran-2-yl) methyl methacrylate and the like, 5-membered heterocyclic esters or 6-membered heterocycles containing oxygen atoms of (meth) acrylic acid Ring esters; unsaturated dicarboxylic acid dialkyl esters such as diethyl maleate, diethyl fumarate and diethyl itaconate; vinyl aromas such as styrene, α-methyl styrene, m-methyl styrene, p-methyl styrene and p-methoxy styrene Group compounds: Conjugated diene compounds such as 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, acrylonitrile, methacrylonitrile, acrylamide, methacrylamide, vinyl chloride, vinylidene chloride, vinyl acetate And the like can be given.

Of these other unsaturated compounds (a3), 2-methylcyclohexyl acrylate, t-butyl methacrylate, methacrylic acid, from the viewpoint of copolymerization reactivity and solubility of the resulting copolymer [A] in an aqueous alkali solution. Acid tricyclo [5.2.1.0 ^2,6 ] decan-8-yl, tetrahydrofurfuryl methacrylate, styrene, p-methoxystyrene, 1,3-butadiene and the like are preferable.
In the copolymer [A], the other unsaturated compounds (a3) can be used alone or in admixture of two or more.

  In the copolymer [A], the content of the repeating unit derived from the other unsaturated compound (a3) 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 the other unsaturated compound (a3) is less than 10% by weight, the storage stability of the resulting copolymer tends to be lowered, whereas it exceeds 70% by weight. And there exists a tendency for the solubility with respect to the aqueous alkali solution of the copolymer obtained to fall.

  The copolymer [A] has a carboxyl group and / or a carboxylic anhydride group and an epoxy group, has an appropriate solubility in an alkaline aqueous solution, and does not require the use of a special curing agent. It can be easily cured by heating, and the radiation-sensitive resin composition (a) containing the copolymer does not cause development residue and film loss at the time of development with a developer composed of an alkaline aqueous solution. A spacer having a predetermined pattern can be easily formed.

For example, the copolymer [A] is obtained by mixing an unsaturated carboxylic acid compound (a1), an epoxy group-containing unsaturated compound (a2), and another unsaturated compound (a3) with a radical polymerization initiator in a suitable solvent. It can be produced by polymerizing in the presence.
As the solvent used for the polymerization, for example,
Alcohols such as methanol, ethanol, n-propanol, i-propanol, benzyl alcohol, 2-phenylethanol, 3-phenyl-1-propanol;
Ethers such as tetrahydrofuran and dioxane;
Ethylene glycol monoalkyl ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-n-propyl ether, ethylene glycol mono-n-butyl ether;
Ethylene glycol monoalkyl ether acetates such as ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether, ethylene glycol mono-n-propyl ether acetate, ethylene glycol mono-n-butyl ether acetate;
Diethylene glycol monoalkyl ether acetates such as diethylene glycol monomethyl ether acetate and diethylene glycol monoethyl ether acetate;
Ethylene glycol monoalkyl ether propionates such as ethylene glycol monomethyl ether propionate, ethylene glycol monoethyl ether propionate, ethylene glycol mono-n-propyl ether propionate, ethylene glycol mono-n-butyl ether propionate ;
Diethylene glycol alkyl ethers such as diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol ethyl methyl ether;

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

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

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

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

The radical polymerization initiator used for the polymerization is not particularly limited, and examples thereof include 2,2′-azobisisobutyronitrile, 2,2′-azobis- (2,4-dimethylvalero). Nitrile), 2,2′-azobis- (4-methoxy-2,4-dimethylvaleronitrile), 4,4′-azobis (4-cyanovaleric acid), dimethyl-2,2′-azobis (2-methyl) Azo compounds such as propionate) and 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile); benzoyl peroxide, lauroyl peroxide, t-butylperoxypivalate, 1,1-bis (t- Examples thereof include organic peroxides such as butylperoxy) cyclohexane; hydrogen peroxide and the like. When a peroxide is used as the radical polymerization initiator, a redox initiator may be used in combination with a reducing agent.
These radical polymerization initiators can be used alone or in admixture of two or more.
The copolymer [A] thus obtained can be used in the preparation of the radiation-sensitive resin composition (a) as it is in the solution, or it can be separated from the solution and used in the radiation-sensitive resin composition (a). You may use for preparation.

The polystyrene-converted weight average molecular weight (hereinafter referred to as “Mw”) of the copolymer [A] by gel permeation chromatography (GPC) is usually 2,000 to 100,000, preferably 5,000 to 50,000. It is. In this case, if the Mw of the copolymer [A] is less than 2,000, the developability and remaining film ratio of the resulting film may be reduced, or the pattern shape and heat resistance may be impaired. If it exceeds 100,000, the resolution may be lowered, or the pattern shape may be impaired.
In the present invention, the copolymer [A] can be used alone or in admixture of two or more.

-Polymerizable compound [B]-
The component [B] in the radiation-sensitive resin composition (A) is a polymerizable compound having an ethylenically unsaturated bond (hereinafter referred to as “polymerizable compound [B]”).
Although it does not specifically limit as polymeric compound [B], Monofunctional, bifunctional, or trifunctional or more (meth) acrylic acid ester has favorable polymerizability, and the intensity | strength of the spacer obtained is good. It is preferable from the viewpoint of improvement.

Examples of the monofunctional (meth) acrylic acid esters include 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, diethylene glycol monoethyl ether acrylate, diethylene glycol monoethyl ether methacrylate, isobornyl acrylate, isobornyl methacrylate, and acrylic. 3-methoxybutyl acid, 3-methoxybutyl methacrylate, phthalic acid (2-acryloyloxyethyl) (2-hydroxypropyl) ester, phthalic acid (2-methacryloyloxyethyl) (2-hydroxypropyl) ester, etc. Can be mentioned.
Moreover, as a commercial item of monofunctional (meth) acrylic acid esters, for example, Aronix-101, ibid-111, ibid-114 (above, manufactured by Toagosei Co., Ltd.); KAYARAD TC-110S, ibid-120S As mentioned above, Nippon Kayaku Co., Ltd.); Biscoat 158, 2311 (above, Osaka Organic Chemical Industry Co., Ltd.) and the like can be mentioned.

Examples of the bifunctional (meth) acrylic acid esters include ethylene glycol diacrylate, ethylene glycol dimethacrylate, diethylene glycol diacrylate, diethylene glycol dimethacrylate, tetraethylene glycol diacrylate, tetraethylene glycol dimethacrylate, and 1,6-hexane. Examples include diol diacrylate, 1,6-hexanediol dimethacrylate, 1,9-nonanediol diacrylate, 1,9-nonanediol dimethacrylate, bis (phenoxyethanol) full orange acrylate, bis (phenoxyethanol) full orange methacrylate, and the like. Can do.
Moreover, as a commercial item of bifunctional (meth) acrylic acid esters, for example, Aronix-210, -240, -6200 (above, manufactured by Toa Gosei Co., Ltd.), KAYARAD HDDA, HX-220, R-604 (above, manufactured by Nippon Kayaku Co., Ltd.), Biscoat 260, 312 and 335HP (above, manufactured by Osaka Organic Chemical Industry Co., Ltd.) and the like can be mentioned.

  Further, the trifunctional or higher functional (meth) acrylic acid esters include, 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, Nine or more functional (meth) acrylic acid esters with alkylene chain and alicyclic structure And a urethane acrylate compound obtained by reacting a compound containing two or more isocyanate groups with a trifunctional, tetrafunctional or pentafunctional (meth) acrylate compound having one or more hydroxyl groups in the molecule, etc. Can be mentioned. Moreover, as a commercial item of trifunctional or more (meth) acrylic acid esters, for example, Aronix M-309, -400, -405, -450, -7100, -8030, -8060, Aronix TO-1450 (above, manufactured by Toa Gosei Co., Ltd.), KAYARAD TMPTA, DPHA, DPCA-20, DPCA-30, DPCA-60, DPCA-60, DPCA-120 (above, Nippon Kayaku Co., Ltd.) ), Biscoat 295, 300, 360, GPT, 3PA, 400 (above, manufactured by Osaka Organic Chemical Industry Co., Ltd.) and commercially available products containing urethane acrylate compounds such as New Frontier R-1150 ( Daiichi Kogyo Seiyaku Co., Ltd.), KAYARAD DPHA-40H (Nippon Kayaku Co., Ltd.) and the like.

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 and dipentaerythritol hexaacrylate are preferred.
In this invention, polymeric compound [B] can be used individually or in mixture of 2 or more types.

  In the radiation sensitive resin composition (A), the amount of the polymerizable compound [B] used is preferably 50 to 140 parts by weight, more preferably 60 to 120 parts by weight, relative to 100 parts by weight of the copolymer [A]. Part. In this case, if the amount of the polymerizable compound [B] used is less than 50 parts by weight, there is a risk of developing residue during development with a developer composed of an alkaline aqueous solution, whereas if it exceeds 140 parts by weight, the hardness of the resulting spacer Tends to decrease.

-Polymerization initiator [C]-
The component [C] in the radiation-sensitive resin composition (A) is an O-acyloxime-type carbazole compound (hereinafter referred to as “carbazole compound (C1)” represented by the above formula (1) or formula (2). .) Is an essential component, and radiation-sensitive polymerization initiation that generates active species capable of initiating polymerization of the polymerizable compound [B] upon exposure to radiation such as visible light, ultraviolet light, far ultraviolet light, charged particle beam, and X-ray (Hereinafter referred to as “polymerization initiator [C]”).

In formula (1) and formula (2), examples of the linear, branched or cyclic alkyl group having 1 to 12 carbon atoms of R ¹ , R ² and R ³ include, for example, a methyl group, an ethyl group, n- Propyl group, i-propyl group, n-butyl group, sec-butyl group, t-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, n- A decyl group, n-undecyl group, n-dodecyl group, cyclopentyl group, cyclohexyl group, etc. can be mentioned.

Examples of the linear, branched or cyclic alkyl group having 1 to ⁶ carbon atoms of R ⁴ , R ⁵ and R ⁶ include, for example, methyl group, ethyl group, n-propyl group, i-propyl group, n -Butyl group, sec-butyl group, t-butyl group, n-pentyl group, n-hexyl group, cyclopentyl group, cyclohexyl group and the like can be mentioned.

Of the substituents for the alkyl groups of R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ , and the substituents for the phenyl groups of R ¹ and R ² , a straight chain having 1 to 6 carbon atoms Examples of the branched or cyclic alkoxyl group include a methoxy group, an ethoxy group, an n-propoxy group, an i-propoxy group, an n-butoxy group, and a t-butoxy group. As the halogen atom, For example, a fluorine atom, a chlorine atom, etc. can be mentioned.
Among the substituents for each phenyl group of R ¹ and R ² , examples of the linear, branched or cyclic alkyl group having 1 to 6 carbon atoms include a methyl group, an ethyl group, an n-propyl group, An i-propyl group, an n-butyl group, a t-butyl group, etc. can be mentioned.
One or more of these substituents may be present in each alkyl group and each phenyl group.

In Formula (1) and Formula (2), R ¹ is preferably a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, a phenyl group or the like, and R ² is a hydrogen atom , methyl group, ethyl group, n- propyl group, i- propyl, n- butyl, n- pentyl, n- hexyl, n- heptyl, preferably such as n- octyl group, a R ³ is A hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group and the like are preferable. Further, as R ⁴ , R ⁵ and R ⁶ , a hydrogen atom, a methyl group, an ethyl group, n- A propyl group, i-propyl group, n-butyl group and the like are preferable.

  Preferred carbazole compounds (C1) include, 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-n-butyl-6- (2-ethylbenzoyl) -9. H. -Carbazol-3-yl] -ethane-1-one oxime-O-benzoate and the like.

Of these carbazole compounds (C1), 1- [9-ethyl-6- (2-methylbenzoyl) -9. H. -Carbazol-3-yl] -ethane-1-one oxime-O-acetate is preferred.
In the present invention, the carbazole compound (C1) can be used alone or in admixture of two or more.

In the photosensitive resin composition (a), other radiation-sensitive polymerization initiator (hereinafter simply referred to as “other polymerization initiator”) can be used in combination with the carbazole compound (C1).
Other polymerization initiators are preferably O-acyloxime compounds (hereinafter referred to as “other O-acyloxime polymerization initiators”).
Examples of other O-acyloxime type polymerization initiators include 1,2-octadione-1- [4- (phenylthio) phenyl] -2- (O-benzoyloxime), 1,2-butanedione-1- [ 4- (phenylthio) phenyl] -2- (O-benzoyloxime), 1,2-butanedione-1- [4- (phenylthio) phenyl] -2- (O-acetyloxime), 1,2-octadione-1 -[4- (methylthio) phenyl] -2- (O-benzoyloxime), 1,2-octadion-1- [4- (phenylthio) phenyl] -2- (O- (4-methylbenzoyloxime)), etc. Can be mentioned.
Of these other O-acyloxime type polymerization initiators, 1,2-octadion-1- [4- (phenylthio) phenyl] -2- (O-benzoyloxime) is particularly preferable.
The other O-acyloxime type polymerization initiators can be used alone or in admixture of two or more.

In the present invention, the exposure amount of 1,500 J / m ² or less is obtained by using the carbazole compound (C1) or this and another O-acyloxime type polymerization initiator as the polymerization initiator [C] component. However, a display panel spacer having high sensitivity and excellent adhesion to the substrate can be formed.

In the radiation sensitive resin composition (I), the total amount of the carbazole compound (C1) and the other O-acyloxime type polymerization initiator used is preferably 5 with respect to 100 parts by weight of the polymerizable compound [B]. -30 parts by weight, more preferably 5-20 parts by weight. In this case, if the total amount used is less than 5 parts by weight, the residual film ratio during development with a developer comprising an alkaline aqueous solution tends to decrease, whereas if it exceeds 30 parts by weight, the unexposed part with respect to the developer There is a tendency for solubility to decrease.
In addition, when the carbazole compound (C1) is used in combination with another O-acyloxime polymerization initiator, the proportion of the other O-acyloxime polymerization initiator used is the same as that of the carbazole compound (C1) and the other O-acyloxime polymerization initiator. -Preferably it is 50 weight% or less with respect to the total amount with an acyl oxime type polymerization initiator, More preferably, it is 1 to 30 weight%. In this case, if the proportion of other O-acyloxime polymerization initiator used exceeds 50% by weight, the pattern shape of the resulting spacer may be impaired.

  Furthermore, as other polymerization initiators other than O-acyloxime type polymerization initiators, for example, biimidazole compounds, benzoin compounds, acetophenone compounds, benzophenone compounds, α-diketone compounds, polynuclear quinone compounds A compound, a xanthone compound, a phosphine compound, a triazine compound and the like can be mentioned, and among these, an acetophenone compound and a biimidazole compound are preferable.

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-hydroxycyclohexyl phenyl ketone and the like. Examples of the α-aminoketone compound include 2- And methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one, and the like. it can.
Examples of acetophenone compounds other than α-hydroxyketone compounds and α-aminoketone compounds include 2,2-dimethoxyacetophenone, 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, and the like. Can be mentioned.
These acetophenone compounds can be used alone or in admixture of two or more.
In the present invention, by using an acetophenone compound as another polymerization initiator, it is possible to further improve the sensitivity, the shape of the obtained spacer, the compressive strength, and the like.

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) -4,4 ', 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 2,2′-bis (2,4-dichlorophenyl) -4,4 ′, 5,5′-tetraphenyl-1, 2'-biimidazole.
The biimidazole compounds can be used alone or in admixture of two or more.
In the present invention, by using a biimidazole compound as another polymerization initiator, it is possible to further improve sensitivity, resolution, adhesion of the resulting spacer to the substrate, and the like.

Further, when a biimidazole compound is used as another polymerization initiator, an aromatic compound having a dialkylamino group (hereinafter referred to as “dialkylamino group-containing sensitizer”) is used in combination in order to sensitize it. be able to.
Examples of the dialkylamino group-containing sensitizer include 4,4′-bis (dimethylamino) benzophenone, 4,4′-bis (diethylamino) benzophenone, ethyl p-dimethylaminobenzoate, ethyl p-diethylaminobenzoate, Examples include i-amyl p-dimethylaminobenzoate and i-amyl p-diethylaminobenzoate.
Of these dialkylamino group-containing sensitizers, 4,4′-bis (diethylamino) benzophenone is preferred.
The dialkylamino group-containing sensitizer can be used alone or in admixture of two or more.
The amount of the dialkylamino group-containing sensitizer used is preferably 0.1 to 50 parts by weight, more preferably 1 to 20 parts by weight with respect to 100 parts by weight of the copolymer [A]. In this case, if the amount of dialkylamino group-containing sensitizer used is less than 0.1 parts by weight, the resulting spacer may be slipped or the pattern shape may be impaired. The pattern shape of the spacer may be damaged.

  Furthermore, when a biimidazole compound and a dialkylamino group-containing sensitizer are used in combination as other polymerization initiators, a thiol compound can be added as a hydrogen donor compound. Biimidazole compounds are sensitized with a dialkylamino group-containing sensitizer and cleaved to generate imidazole radicals, but at this time, high polymerization initiating ability is not necessarily expressed, and the resulting spacer has a reverse taper shape. In many cases, such an unfavorable shape is obtained. This problem can be alleviated by adding a thiol compound to a system in which a biimidazole compound and a dialkylamino group-containing sensitizer coexist. That is, when a hydrogen radical is donated to the imidazole radical from a thiol compound, the imidazole radical is converted to a neutral imidazole, and as a result, a component having a sulfur radical having a high polymerization initiation ability is generated. It becomes a 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: 3-mercaptopropionic acid, methyl 3-mercaptopropionate, ethyl 3-mercaptopropionate, n-octyl 3-mercaptopropionate and 3,6-dioxa-1,8-octane as a bifunctional or higher compound Examples include aliphatic compounds such as dithiol, pentaerythritol tetra (mercaptoacetate), pentaerythritol tetra (3-mercaptopropionate), and the like.
These thiol compounds can be used alone or in admixture of two or more.

  The amount of the thiol compound used is preferably 0.1 to 50 parts by weight, more preferably 1 to 20 parts by weight with respect to 100 parts by weight of the carbazole compound (C1). In this case, if the amount of the thiol compound used is less than 0.1 parts by weight, the resulting spacer may be slipped or the pattern shape may be impaired. The shape may be damaged.

  In the radiation-sensitive resin composition (a), the use ratio of the other polymerization initiator is preferably 100 parts by weight or less, more preferably 80 parts by weight or less, particularly preferably 100 parts by weight of the total polymerization initiator. 60 parts by weight or less. In this case, when the proportion of other polymerization initiator used exceeds 100 parts by weight, the intended effect of the present invention may be impaired.

-Additives-
In the radiation-sensitive resin composition (A), additives other than the above-mentioned components, for example, surfactants, adhesion assistants, storage stability, as long as they do not impair the intended effects of the present invention. An agent, a heat resistance improver, etc. can also be blended.
The said surfactant is a component used in order to improve applicability | paintability, As a preferable surfactant, a fluorochemical surfactant and a silicone type surfactant can be mentioned.

  The fluorine-based surfactant is preferably a compound having a fluoroalkyl group and / or a fluoroalkylene group in at least one of the terminal, main chain and side chain, and examples thereof include 1,1,2,2 -Tetrafluoro-n-octyl (1,1,2,2-tetrafluoro-n-propyl) ether, 1,1,2,2-tetrafluoro-n-octyl (n-hexyl) ether, 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-pen L) Ether, sodium perfluoro-n-dodecanesulfonate, 1,1,2,2,8,8,9,9,10,10-decafluoro-n-dodecane, 1,1,2,2,3,3 -Hexafluoro-n-decane, sodium fluoroalkylbenzenesulfonates, sodium fluoroalkylphosphonates, sodium fluoroalkylcarboxylates, fluoroalkylpolyoxyethylene ethers, diglycerin tetrakis (fluoroalkylpolyoxyethylene ethers), Fluoroalkylammonium iodides, fluoroalkylbetaines, fluoroalkylpolyoxyethylene ethers, perfluoroalkylpolyoxyethanols, perfluoroalkylalkoxylates, fluorinated alkyl esters, etc. Can.

  Examples of commercially available fluorosurfactants include BM-1000, -1100 (above, manufactured by BM CHEMIE), MegaFuck F142D, 172, 173, 183, 178, 191, 471, 476 (above, manufactured by Dainippon Ink & Chemicals, Inc.), Florard FC-170C, -171, -430, -431 (above, manufactured by Sumitomo 3M), Surflon S-112 -113, -131, -141, -145, -382, Surflon SC-101, -102, -103, -104, -105, -106 (above, Asahi Glass ( Ftop EF301, 303, 352 (above, Shin-Akita Kasei Co., Ltd.), Footent FT-100, -110, -140A, -150, 250, the -251, Futargent FTX-251, the same -218, the -300, the -310, the -400S (or, Co. NEOS), and the like.

  Examples of the silicone-based surfactant include Torre Silicone DC3PA, 7PA, Torre Silicone SH11PA, 21PA, 28PA, 29PA, 30PA, Torresilicone SH-190, 193, Torresilicone SZ-6032, Torre Silicone SF-8428, Torre Silicone DC-57, Same -190 (above, manufactured by Toray Dow Corning Silicone Co., Ltd.), TSF-4300, Same 4440, Same 4445, Same 4446, Same 4442, Examples thereof include those commercially available under the trade name such as -4460 (manufactured by GE Toshiba Silicone Co., Ltd.).

  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 commercially available products such as KP341 (Shin-Etsu) Chemical Industry Co., Ltd.), Polyflow No. 57, no. 95 (manufactured by Kyoeisha Chemical Co., Ltd.).

These surfactants can be used alone or in admixture of two or more.
The blending amount of the surfactant is preferably 5 parts by weight or less, and more preferably 2 parts by weight or less with respect to 100 parts by weight of the copolymer [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 aid is a component used for further improving the adhesion to the substrate, and a preferable adhesion aid may include a functional silane coupling agent.
Examples of the functional silane coupling agent include a silane coupling agent having a reactive functional group such as a carboxyl group, a methacryloyl group, a vinyl group, an isocyanate group, and an epoxy group, and more specifically, trimethoxysilylbenzoic acid. , Γ-methacryloyloxypropyltrimethoxysilane, vinyltriacetoxysilane, vinyltrimethoxysilane, γ-isocyanatopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyl A trimethoxysilane etc. can be mentioned.

These adhesion assistants can be used alone or in admixture of two or more.
The compounding amount of the adhesion assistant is preferably 20 parts by weight or less, more preferably 10 parts by weight or less with respect to 100 parts by weight of the copolymer [A]. In this case, when the blending amount of the adhesion assistant exceeds 20 parts by weight, there is a tendency that undeveloped development tends to occur during development with a developer composed of an alkaline aqueous solution.

Examples of the storage stabilizer include sulfur, quinones, hydroquinones, polyoxy compounds, amines, nitronitroso compounds, and more specifically, 4-methoxyphenol, N-nitroso-N-phenylhydroxylamine aluminum, and the like. Can be mentioned.
These storage stabilizers can be used alone or in admixture of two or more.
The amount of storage stability is preferably 3.0 parts by weight or less, more preferably 0.5 parts by weight or less with respect to 100 parts by weight of the copolymer [A]. In this case, when the storage stability compounding amount exceeds 3.0 parts by weight, the sensitivity is lowered, and the pattern shape of the obtained spacer may be impaired.

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

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 can be mentioned. Among these, N, N, N N, N, N-hexa (methoxymethyl) melamine is preferred.
Examples of commercially available N- (alkoxymethyl) melamine compounds include Nicarac N-2702, Nicalac MW-30M (manufactured by Sanwa Chemical Co., Ltd.), and the like.

Examples of the compound having two or more epoxy groups include ethylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, and polypropylene glycol diglycidyl ether. And neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin diglycidyl ether, trimethylolpropane triglycidyl ether, hydrogenated bisphenol A diglycidyl ether, bisphenol A diglycidyl ether, and the like.
Examples of commercially available compounds having two or more epoxy groups include Epolite 40E, 100E, 200E, 70P, 200P, 400P, 1500NP, 80MF, 100MF, 1600, 3,002, 4000 (made by Kyoeisha Chemical Co., Ltd.) and the like.
These heat resistance improvers can be used alone or in admixture of two or more.

Composition solution Radiation-sensitive resin composition (A) is usually dissolved in a suitable solvent in the constituent components such as copolymer [A], polymerizable compound [B], polymerization initiator [C]. Then, it is prepared as a composition solution.
Solvents used for the preparation of the composition solution include those that uniformly dissolve each component constituting the radiation-sensitive resin composition (A), do not react with each component, and have appropriate volatility. Examples thereof include the same solvents as those exemplified for the polymerization for producing the copolymer [A].
Among these solvents, alcohols, ethylene glycol monoalkyl ether acetates, diethylene glycol monoalkyl ether acetates, diethylene glycol alkyl ethers from the viewpoint of solubility of each component, reactivity with each component, and ease of film formation. , Propylene glycol monoalkyl ether acetates, alkyl alkoxypropionates and the like are preferable, and in particular, benzyl alcohol, 2-phenylethanol, 3-phenyl-1-propanol, ethylene glycol mono-n-butyl ether acetate, diethylene glycol monoethyl ether acetate , Diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol ethyl methyl ether, propylene glycol Monomethyl ether acetate, propylene glycol monoethyl ether acetate are preferred.
The said solvent can be used individually or in mixture of 2 or more types.

In preparing the composition solution, 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 acetate, ethyl benzoate, diethyl oxalate, diethyl maleate, γ-butyrolactone, ethylene carbonate, Examples include propylene carbonate and ethylene glycol monophenyl ether acetate.
These high boiling point solvents can be used alone or in admixture of two or more.
The composition solution prepared in this way can be used for use after filtration through a Millipore filter having a pore size of, for example, about 0.2 to 0.5 μm, if necessary.

Here, when the composition of the preferable radiation sensitive resin composition (I) in this invention is illustrated more concretely, it is as following (i)-(v).
(I) The component constituting the copolymer [A] is an epoxy group-containing compound in which the unsaturated carboxylic acid compound (a1) is composed of a single group of acrylic acid, methacrylic acid and maleic anhydride or a mixture of two or more thereof. The unsaturated compound (a2) is glycidyl methacrylate, 6,7-epoxyheptyl methacrylate, o-vinylbenzyl glycidyl ether, m-vinylbenzyl glycidyl ether and p-vinylbenzyl glycidyl ether, or a mixture of two or more thereof The other unsaturated compound (a3) is 2-methylcyclohexyl acrylate, t-butyl methacrylate, tricyclo [5.2.1.0 ^2,6 ] decane-8-yl methacrylate, tetrahydrofurfuryl methacrylate. , Styrene, p-methoxystyrene and 1,3-butadiene alone Composition comprising a mixture of two or more thereof.

(Ii) In the copolymer [A], the content of the repeating unit derived from the unsaturated carboxylic acid compound (a1) is 5 to 40% by weight, more preferably 10 to 30% by weight. The content of the repeating unit derived from the saturated compound (a2) is 10 to 70% by weight, more preferably 20 to 60% by weight, and the content of the repeating unit derived from the other unsaturated compound (a3) is 10 to 70% by weight. The composition according to the above (i), which is 70% by weight, more preferably 20 to 50% by weight.

(Iii) The polymerizable compound [B] is monofunctional, bifunctional or trifunctional or higher (meth) acrylic acid ester, more preferably trifunctional or higher functional (meth) acrylic acid ester, particularly preferably trimethylolpropane tri The composition according to the above (i) or (ii), which is a single group or a mixture of two or more of the group of acrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate.

(Iv) The composition according to any one of (i) to (iii) above, wherein the polymerization initiator [C] further contains another O-acyloxime type polymerization initiator alone or a mixture of two or more thereof.
(V) The amount of the polymerizable compound [B] used is 50 to 140 parts by weight, more preferably 60 to 120 parts by weight, based on 100 parts by weight of the copolymer [A], and the polymerization initiator [C]. Is used in an amount of 5 to 30 parts by weight, more preferably 5 to 20 parts by weight, based on 100 parts by weight of the polymerizable compound [B].

  The radiation sensitive resin composition (A) can be used particularly suitably as a material for forming a spacer for a display panel such as a liquid crystal panel or a touch panel.

When forming a display panel spacer using the display panel spacer radiation-sensitive resin composition (a), the composition solution is applied to the surface of the substrate and then pre-baked to remove the solvent. Form.
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, an ink jet method or the like can be adopted. In particular, a spin coating method and a slit die coating method are preferable.
Moreover, although the conditions of prebaking differ also with the kind of each structural component, a mixture ratio, etc., it is normally about 1 to 15 minutes at 70-90 degreeC.
Next, the pre-baked film is exposed and polymerized through a mask having a predetermined pattern, and then developed with a developing solution, and unnecessary portions are removed to form a pattern.
As radiation used for exposure, radiation such as visible light, ultraviolet light, far ultraviolet light, charged particle beam, and X-ray can be appropriately selected and used, but radiation having a wavelength in the range of 190 to 450 nm can be used. preferable.

As a developing method, for example, any of a liquid filling method, a dipping method, a shower method and the like may be used, and the developing time is usually about 30 to 180 seconds at room temperature.
Examples of the developer include inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and ammonia; primary amines such as ethylamine and n-propylamine; Secondary amines such as n-propylamine; tertiary amines such as trimethylamine, methyldiethylamine, ethyldimethylamine and triethylamine; tertiary alkanolamines such as dimethylethanolamine, methyldiethanolamine and triethanolamine; pyrrole and piperidine , N-methylpiperidine, N-methylpyrrolidine, 1,8-diazabicyclo [5.4.0] -7-undecene, 1,5-diazabicyclo [4.3.0] -5-nonene 3 Secondary amines: pyridine, collidine, ru It can be used tetramethylammonium hydroxide, aqueous solution of an alkaline compound such as quaternary ammonium salts such as tetraethyl ammonium hydroxide (the aqueous alkali solution); Jin, aromatic tertiary amines such as quinoline.
In addition, an appropriate amount of a water-soluble organic solvent such as methanol or ethanol and / or a surfactant can be added to the alkaline aqueous solution.
After development, for example, by washing with running water, for example, for 30 to 90 seconds, unnecessary portions are removed, and then compressed air or compressed nitrogen is blown to dry to form a predetermined pattern.

  Thereafter, the pattern is heated by a heating device such as a hot plate or an oven at a predetermined temperature, for example, 150 to 250 ° C., for a predetermined time, for example, for 5 to 30 minutes on the hot plate, for 30 to 90 minutes in the oven ( Hereinafter, the target spacer can be obtained by performing “post-baking”.

The radiation-sensitive resin composition (a) of the present invention has high sensitivity, can faithfully reproduce the design size of the mask pattern, has excellent adhesion to the substrate, and an exposure amount of 1,500 mJ / m ² or less is sufficient. The spacer shape and film thickness can be obtained, and a display panel spacer excellent in compressive strength, rubbing resistance and the like can be formed.

Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples.
Synthesis example 1
A flask equipped with a condenser and a stirrer was charged with 5 parts by weight of 2,2′-azobis (2,4-dimethylvaleronitrile) and 200 parts by weight of diethylene glycol methyl ethyl ether, followed by 18 parts by weight of methacrylic acid and methacrylic acid. After charging 40 parts by weight of glycidyl, 5 parts by weight of styrene, and 32 parts by weight of tricyclo [5.2.1.0 ^2,6 ] decan-8-yl methacrylate, and substituting with nitrogen, 5 weights of 1,3-butadiene is further added. The temperature of the solution was raised to 70 ° C. while gently stirring, and this temperature was maintained for 5 hours for polymerization to obtain a solution of the copolymer [A] (solid content concentration = 33.0% by weight). ) The Mw of this copolymer [A] was 11,000. This copolymer [A] is referred to as “copolymer [A-1]”.

Synthesis example 2
A flask equipped with a condenser and a stirrer was charged with 7 parts by weight of 2,2′-azobis (2,4-dimethylvaleronitrile) and 200 parts by weight of diethylene glycol methyl ethyl ether, followed by 18 parts by weight of methacrylic acid and methacrylic acid. After charging 20 parts by weight of glycidyl, 5 parts by weight of styrene, 32 parts by weight of tricyclo [5.2.1.0 ^2,6 ] decane-8-yl, and 25 parts by weight of tetrahydrofurfuryl methacrylate, and substituting with nitrogen, While gently stirring, the temperature of the solution was raised to 70 ° C., and this temperature was maintained for 5 hours for polymerization to obtain a solution of the copolymer [A] (solid content concentration = 33.4% by weight). . Mw of this copolymer [A] was 9,000. This copolymer [A] is referred to as “copolymer [A-2]”.

Example 1
Preparation of composition solution The solution of copolymer [A-1] as component [A] is equivalent to 100 parts by weight (solid content) of copolymer (A-1), and dipentaerythritol hexahexa is used as component [B]. 80 parts by weight of acrylate (trade name KAYARAD DPHA, manufactured by Nippon Kayaku Co., Ltd.), 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 Inc.) 8 parts by weight of propylene so that the solid content concentration is 35% by weight After dissolving in glycol monomethyl ether acetate, it was filtered through a Millipore filter having a pore size of 0.2 μm to prepare a composition solution (hereinafter referred to as “composition (S-1)”).

Formation of spacers After applying the composition solution (S-1) on a non-alkali glass substrate using a spinner, pre-baking on a hot plate at 90 ° C. for 3 minutes to form a film with a thickness of 6.0 μm did.
Next, the obtained coating film was exposed to ultraviolet rays having an exposure intensity of 300 W / m ^{2 at} a wavelength of 365 nm through a mask having a 10 μm square left pattern and an exposure gap of 150 μm. Thereafter, development was performed with a 0.05 wt% aqueous potassium hydroxide solution at 25 ° C. for 60 seconds, followed by washing with pure water for 1 minute. Thereafter, post-baking was performed in an oven at 150 ° C. for 120 minutes to form a spacer having a predetermined pattern.
Subsequently, various evaluation was performed about the obtained spacer in the following way. The evaluation results are shown in Table 2-1.

(I) Evaluation of Sensitivity For the obtained pattern, the exposure amount at which the residual 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 the sensitivity is 1,500 mJ / m ² or less, it can be said that the sensitivity is good.
(II) Evaluation of resolution The obtained pattern was evaluated by the minimum pattern size at an exposure amount at which the remaining film ratio after development was 90% or more. The smaller the pattern size, the better the resolution.

(III) Evaluation of pattern shape The cross-sectional shape of the obtained pattern was observed with a scanning electron microscope, and the shape was evaluated according to which of A to C shown in FIG. At this time, when the pattern edge is a forward taper like A, the pattern shape is good, and when the pattern edge is vertical like B, the pattern shape is slightly good. In addition, when the pattern edge is reversely tapered as shown in C (inverted triangular shape with a cross-sectional shape and whose film surface side is longer than the substrate side), the pattern may be peeled off during the subsequent rubbing process. Therefore, it can be said that the pattern shape is defective.

(IV) Evaluation of compressive strength When compressive strength of the obtained pattern was applied using a micro compression tester (trade name MCTM-200, manufactured by Shimadzu Corporation) and a load of 10 mN was applied by a flat indenter having a diameter of 50 μm. The amount of deformation of was measured at a measurement temperature of 23 ° C. When this value is 0.55 μm or less, it can be said that the compressive strength is good.
(V) Evaluation of rubbing resistance AL3046 (trade name, manufactured by JSR Co., Ltd.) as a liquid crystal aligning agent was applied to a substrate on which a spacer was formed by a printing machine for applying a liquid crystal alignment film, and then dried at 180 ° C. for 1 hour. Then, a coating film of an orientation agent having a film thickness of 0.05 μm was formed.
Next, this coating film was rubbed with a rubbing machine having a roll wound with a polyamide cloth under the conditions of a roll rotation speed of 500 rpm and a stage moving speed of 1 cm / sec. At this time, the evaluation was made based on the presence or absence of pattern shaving or peeling.

(VI) Evaluation of adhesion A cured film for evaluation of adhesion was formed in the same manner as in the formation of the spacer except that no pattern mask was used.
Next, of the adhesion test of JIS K-5400 (1900) 8.5, the cross-cut tape method of 8.5 · 2 was performed, and the evaluation was performed based on the number of remaining cross-cuts in 100 cross-cuts.

Examples 2-18
Each composition solution was prepared in the same manner as in Example 1 except that the components [A], [B] and [C] were as shown in Table 1-1. Evaluation was performed. The evaluation results are shown in Table 2-1.

Example 19
The same [A] component, [B] component and [C] component as in Example 3 were dissolved in diethylene glycol ethyl methyl ether so that the solid content concentration was 17.5% by weight, and then the Millipore having a pore size of 0.2 μm was used. It filtered with the filter and the composition solution (henceforth "composition (S-19)") was prepared.
A spacer was formed in the same manner as in Example 1 except that the composition (S-19) was used instead of the composition (S-1), and a slit die coater was used instead of the spinner, and various evaluations were made. Went. The evaluation results are shown in Table 2-1.

Example 20
The same [A] component, [B] component and [C] component as in Example 5 were mixed into a mixture of diethylene glycol ethyl methyl ether / benzyl alcohol = 90/10 (weight ratio) so that the solid content concentration was 15% by weight. After dissolution, the solution was filtered through a Millipore filter having a pore diameter of 0.2 μm to prepare a composition solution (hereinafter referred to as “composition (S-20)”).
A spacer was formed in the same manner as in Example 1 except that the composition (S-20) was used instead of the composition (S-1), and a slit die coater was used instead of the spinner. Went. The evaluation results are shown in Table 2-1.

Comparative Examples 1-10
Each composition solution was prepared in the same manner as in Example 1 except that the components [A], [B], and the polymerization initiator were as shown in Table 1-2. Went. The evaluation results are shown in Table 2-2.

In Table 1-1 and Table 1-2, each component other than [A] component is as follows.
[B] Component B-1: Dipentaerythritol hexaacrylate (trade name KAYARAD DPHA, manufactured by Nippon Kayaku Co., Ltd.)
B-2: Trade name KAYARAD DPHA-40H (manufactured by Nippon Kayaku Co., Ltd.)

Polymerization initiator 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)
γ-1: 1,2-octadion-1- [4- (phenylthio) phenyl] -2- (O-benzoyloxime (trade name CGI-124, manufactured by Ciba Specialty Chemicals)
γ-2: 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one (trade name Irgacure 907, manufactured by Ciba Specialty Chemicals)
γ-3: 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one (trade name Irgacure 369, manufactured by Ciba Specialty Chemicals)
γ-4: 2,2′-bis (2,4-dichlorophenyl) -4,4 ′, 5,5′-tetraphenyl-1,2′-biimidazole γ-5: 4,4′-bis (diethylamino) ) Benzophenone γ-6: 2-mercaptobenzothiazole

It is a figure which illustrates the cross-sectional shape of a pattern.

Claims (3)

[A] Copolymerization of (a1) ethylenically unsaturated carboxylic acid and / or ethylenically unsaturated carboxylic acid anhydride, (a2) epoxy group-containing ethylenically unsaturated compound, and (a3) other ethylenically unsaturated compound Coalescence,
[B] A polymerizable compound having an ethylenically unsaturated bond, and [C] a radiation-sensitive polymerization initiator containing a compound represented by the following formula (1) or (2) as an essential component. A radiation sensitive resin composition.

[In the formulas (1) and (2), each R ¹ independently represents a linear, branched or cyclic alkyl group having 1 to 12 carbon atoms or a phenyl group, and each R ² is independent from each other. Represents a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 12 carbon atoms or a phenyl group, and each R ³ is independently a hydrogen atom or a linear or branched chain having 1 to 12 carbon atoms. Alternatively, it represents a cyclic alkyl group, and each R ⁴ , each R ⁵ and each R ⁶ independently represents a hydrogen atom or a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms. However, the alkyl groups of R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ are each a group of straight, branched or cyclic alkoxyl groups having 1 to 6 carbon atoms, phenyl groups and halogen atoms. And the phenyl groups of R ¹ and R ² are each a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms, or a linear group having 1 to 6 carbon atoms. Further, it may be substituted with a substituent selected from the group consisting of a branched or cyclic alkoxyl group, a phenyl group and a halogen atom. ]   The spacer for display panels formed from the radiation sensitive resin composition of Claim 1.   A display panel comprising the display panel spacer according to claim 2.

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