JP4419736B2 - Photosensitive resin composition, display panel spacer and display panel - Google Patents

Description

  The present invention relates to a photosensitive resin composition, a display panel spacer, and a display panel, and more particularly, a photosensitive resin composition suitable as a material for forming a spacer used in a display panel such as a liquid crystal display panel or a touch panel. And a display panel spacer formed from the composition, and a display panel comprising 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.
In order to solve these problems, a method of forming a spacer by photolithography has been adopted. In this method, a photosensitive resin composition is applied onto a substrate, exposed to ultraviolet rays through a predetermined mask, and then developed to form dot-like or stripe-like spacers. Since the spacer can be formed only at a predetermined place, the above-described 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 by providing a certain gap between the mask and the substrate coated with the photosensitive resin composition, and it is ideal that the exposure is performed in a pattern according to the mask. However, the gap is filled with air or nitrogen, and light that has passed through the opening (transparent portion) of the mask diffuses and spreads in the gap, so that the exposure is performed wider than the design size of the mask pattern. was there.
Therefore, in order to solve such a problem, the present applicant has already disclosed in Patent Document 1 1,2-octanedione-1- [4- (phenylthio) phenyl]-as a photopolymerization initiator of a photosensitive composition. By using 2- (O-benzoyloxime), it has been clarified that the design size of the mask pattern can be faithfully reproduced by proximity exposure, and a display panel spacer having excellent strength and heat resistance can be formed. ing.

JP 2001-261761 A

Furthermore, as the liquid crystal display panel becomes larger, it is necessary to control the cell gap more accurately, but it is formed when the adhesion of the coating formed from the photosensitive composition for the spacer to the substrate is insufficient. As a result, it becomes impossible to maintain the cell gap accurately. In the liquid crystal 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 photosensitive resin compositions used for the formation of spacers, including those described in Patent Document 1, are still not sufficient in terms of adhesion to the substrate and transparency, and these characteristics are also provided. Development of a photosensitive resin composition has been strongly desired.
In recent years, the mother glass substrate has been increased in size due to an increase in the area of liquid crystal display devices and an improvement in productivity. With the conventional substrate size (about 680 × 880 mm), since the substrate size is smaller than the mask size, it was possible to cope with the batch exposure method.
However, with a large substrate (for example, about 1500 × 1800 mm), it is almost impossible to create a mask size comparable to this 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 for large substrates. However, in the step exposure method, exposure is performed several times on one substrate, and time required for alignment and step movement occurs each time. In the step exposure method, there is a concern about a reduction in throughput as compared with the batch exposure method. In the batch exposure method, an exposure sensitivity of about 300 mJ / cm ² is allowed, but in the step exposure method, the exposure sensitivity is required to be 150 mJ / cm ² or less. However, with existing materials, it is difficult to obtain a sufficient spacer shape and film thickness with an exposure dose of 150 mJ / cm ² or less.
In addition, the required values for the controllability of the spacer shape and film thickness have become increasingly strict in recent years. The shape due to process variations when forming the spacer, the film thickness fluctuation, and the shape that accompanies changes over time in the composition solution. The problem regarding the stability of the film thickness remained.

Therefore, the object of the present invention is to obtain a sufficient spacer shape and film thickness with an exposure amount of 150 mJ / cm ² or less, with high sensitivity, capable of faithfully reproducing the design size of the mask pattern, excellent in adhesion to the substrate. Providing a photosensitive resin composition that can form display panel spacers that are excellent in strength, heat resistance, etc., and that can control spacer shape, film thickness, process stability, and elapsed time stability. There is to do.

According to the present invention, the problem is firstly
[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 photopolymerization initiator comprising a compound represented by the following formula (1)

〔式（１）において、Ｒ_1、Ｒ_２は、各々、水素原子、炭素数１〜２０のアルキル基、炭素数３〜８のシクロアルキル基、フェニル基（但し、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基、フェニル基、およびハロゲン原子で少なくとも１個以上で置換されてもよい。）、炭素数７〜２０のアリサイクリック基（前記シクロアルキル基をのぞく）、炭素数４〜２０の含酸素複素環基、炭素数４〜２０の含窒素複素環基、炭素数４〜２０の含酸素複素環基、炭素数４〜２０の含硫黄複素環基から選ばれた官能基。ただし、Ｒ_1、Ｒ_２の何れかが、炭素数１３〜２０のアルキル基、炭素数炭素数７〜２０のアリサイクリック基（前記シクロアルキル基をのぞく）、炭素数４〜２０の含酸素複素環基、炭素数４〜２０の含窒素複素環基、炭素数４〜２０の含酸素複素環基、炭素数４〜２０の含硫黄複素環基である。Ｒ_３は水素原子または炭素数１〜１２の直鎖状、分岐状もしくは環状のアルキル基を示し、Ｒ_４、Ｒ_５およびＲ_６は水素原子または炭素数１〜６の直鎖状、分岐状もしくは環状のアルキル基を示す。〕
を含有することを特徴とする感光性樹脂組成物（以下、「感光性樹脂組成物（イ）」という。）、
によって達成される。

[In Formula (1), R <1> _, R < ₂ > is respectively a hydrogen atom, a C1-C20 alkyl group, a C3-C8 cycloalkyl group, a phenyl group (however, a C1-C6 alkyl). A group, an alkoxy group having 1 to 6 carbon atoms, a phenyl group, and a halogen atom may be substituted with at least one group), an alicyclic group having 7 to 20 carbon atoms (excluding the cycloalkyl group), It is selected from an oxygen-containing heterocyclic group having 4 to 20 carbon atoms, a nitrogen-containing heterocyclic group having 4 to 20 carbon atoms, an oxygen-containing heterocyclic group having 4 to 20 carbon atoms, and a sulfur-containing heterocyclic group having 4 to 20 carbon atoms. Functional group. However, any _one of R _{1 and} R ₂ is an alkyl group having 13 to 20 carbon atoms, an alicyclic group having 7 to 20 carbon atoms (excluding the cycloalkyl group), and an oxygen-containing group having 4 to 20 carbon atoms. A heterocyclic group, a nitrogen-containing heterocyclic group having 4 to 20 carbon atoms, an oxygen-containing heterocyclic group having 4 to 20 carbon atoms, and a sulfur-containing heterocyclic group having 4 to 20 carbon atoms. R ₃ represents a hydrogen atom or a linear, branched or cyclic alkyl group having 1 to 12 carbon atoms, and R ₄ , R ₅ and R ₆ are a hydrogen atom or a linear or branched chain having 1 to 6 carbon atoms. Or a cyclic alkyl group is shown. ]
A photosensitive resin composition (hereinafter referred to as “photosensitive resin composition (a)”),
Achieved by:

  According to the present invention, secondly, the above object is achieved by a display panel spacer formed from the photosensitive resin composition (a).

  According to the present invention, thirdly, the above object is achieved by a display panel comprising the display panel spacer.

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

Among the components constituting the copolymer [A], (a1) an ethylenically unsaturated carboxylic acid and / or an ethylenically unsaturated carboxylic acid anhydride (hereinafter referred to as “unsaturated carboxylic acid monomer”) Examples of (a1) "include monocarboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, 2-methacryloyloxyethyl succinic acid, 2-methacryloyloxyethyl hexahydrophthalic acid; maleic acid, fumaric acid Examples thereof include dicarboxylic acids such as acid, citraconic acid, mesaconic acid, and itaconic acid; and anhydrides of the dicarboxylic acid.
Among these unsaturated carboxylic acid monomers (a1), acrylic acid, methacrylic acid, maleic anhydride are available from the viewpoints of copolymerization reactivity, solubility of the resulting copolymer in an alkaline aqueous solution and easy availability. Etc. are preferred.
In the photosensitive resin composition (a), the unsaturated carboxylic acid monomer (a1) can be used alone or in admixture of two or more.

  In the copolymer [A], the content of the repeating unit derived from the unsaturated carboxylic acid monomer (a1) is preferably 5 to 50% by weight, more preferably 10 to 40% by weight, and particularly preferably 15%. -30% by weight. In this case, when the content of the repeating unit derived from the unsaturated carboxylic acid monomer (a1) is less than 5% by weight, the solubility in an alkaline aqueous solution tends to decrease, whereas when it exceeds 40% by weight. There is a possibility that the solubility in an alkaline aqueous solution becomes too large.

  Examples of the (a2) epoxy group-containing ethylenically unsaturated compound (hereinafter referred to as “epoxy group-containing monomer (a2)”) include, for example, glycidyl acrylate, 2-methylglycidyl acrylate, 3, Epoxy alkyl esters of acrylic acid such as 4-epoxybutyl, acrylic acid 6,7-epoxyheptyl, 3,4-epoxycyclohexyl acrylate; glycidyl methacrylate, 2-methylglycidyl methacrylate, 3,4-epoxybutyl methacrylate Methacrylic acid epoxy alkyl esters such as 6,7-epoxyheptyl methacrylate, 3,4-epoxycyclohexyl methacrylate; α-ethyl acrylate glycidyl, α-n-propyl acrylate acrylate, α-n-butyl acrylate Glycidyl, α-ethylacrylic acid , 7-epoxy α- alkyl acrylate epoxy alkyl esters heptyl; can be exemplified o- vinylbenzyl glycidyl ether, m- vinylbenzyl glycidyl ether, glycidyl ethers such as p- vinylbenzyl glycidyl ether.

Among these epoxy group-containing monomers (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 photosensitive resin composition (I), the epoxy group-containing monomer (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 monomer (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, when the content of the repeating unit derived from the epoxy group-containing monomer (a2) is less than 10% by weight, the strength of the obtained spacer tends to be reduced, while when it exceeds 70% by weight, There is a tendency for the storage stability of the copolymer to be reduced.

Furthermore, (a3) other ethylenically unsaturated compounds (hereinafter simply referred to as “other monomers (a3)”) include, for example, acrylic acid alkyl esters such as methyl acrylate and i-propyl acrylate. Alkyl methacrylates such as methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, sec-butyl methacrylate, t-butyl methacrylate; cyclohexyl acrylate, 2-methylcyclohexyl acrylate, tricycloacrylate [5 2.1.
02,6] decan-8-yl, acrylic acid alicyclic esters such as 2- (tricyclo [5.2.1.02,6] decan-8-yloxy) ethyl, isobornyl acrylate; methacrylic acid Cyclohexyl, 2-methylcyclohexyl methacrylate, tricyclo [5.2.1.02,6] decane-8-yl methacrylate, 2- (tricyclo [5.2.1.02,6] decane-8-methacrylate Yloxy) methacrylic acid alicyclic esters such as ethyl and isobornyl methacrylate; aryl acrylates or aralkyl esters such as phenyl acrylate and benzyl acrylate; aryl esters of methacrylic acid such as phenyl methacrylate and benzyl methacrylate Or aralkyl esters; diethyl maleate, fumarate Dicarboxylic acid dialkyl esters such as diethyl and diethyl itaconate; Methacrylic acid hydroxyalkyl esters such as 2-hydroxyethyl methacrylate and 2-hydroxypropyl methacrylate; Tetrahydrofurfuryl methacrylate, Tetrahydrofuryl methacrylate, Tetrahydrofupyran-2- Unsaturated hetero 5- and 6-membered methacrylic acid esters containing one oxygen atom such as methyl methacrylate; vinyl aromatic compounds such as styrene, α-methyl styrene, m-methyl styrene, p-methyl styrene, p-methoxy styrene; In addition to conjugated diene compounds such as 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, acrylonitrile, methacrylonitrile, acrylamide, methacrylamide, vinyl chloride, vinyl chloride Nylidene, vinyl acetate and the like can be mentioned.

Among these other monomers (a3), from the viewpoint of copolymerization reactivity and solubility of the resulting copolymer in an alkaline aqueous solution, 2-methylcyclohexyl acrylate, t-butyl methacrylate, tricyclomethacrylate [ 5.2.1.02,6] Decan-8-yl, styrene, p-methoxystyrene, tetrahydrofurfuryl methacrylate, 1,3-butadiene and the like are preferable.
In the photosensitive resin composition (A), the other monomer (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 monomer (a3) is preferably 10 to 70% by weight, more preferably 20 to 50% by weight, particularly preferably 30 to 50% by weight. %. In this case, if the content of the repeating unit derived from the other monomer (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 photosensitive resin composition (a) containing the copolymer can easily form a spacer with a predetermined pattern without developing residue and film loss during development. Can be formed.

For example, the copolymer [A] is obtained by starting radical polymerization of an unsaturated carboxylic acid monomer (a1), an epoxy group-containing monomer (a2), and another monomer (a3) in an appropriate solvent. It can manufacture by superposing | polymerizing in presence of an agent.
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;

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 for example, 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-methylpro) Azo compounds such as pionate), 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile); benzoyl peroxide, lauroyl peroxide, t-butylperoxypivalate, 1,1-bis (t-butyl) Peroxy) organic peroxides such as cyclohexane; hydrogen peroxide and the like. Moreover, when using a peroxide as a radical polymerization initiator, it is good also as a redox type initiator combining it and a reducing agent.
These radical polymerization initiators can be used alone or in admixture of two or more.
The copolymer [A] thus obtained may be used for the preparation of the radiation-sensitive resin composition in the form of a solution, or may be separated from the solution and used for the preparation of the radiation-sensitive resin composition. .

  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 is less than 2,000, the developability and the remaining film rate of the resulting film may be reduced, and the pattern shape, heat resistance, and the like may be impaired. , There is a possibility that the resolution is lowered or the pattern shape is damaged.

-Polymerizable compound [B]-
[B] component in the photosensitive 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, 3 -Methoxybutyl acrylate, 3-methoxybutyl methacrylate, 2-acryloyloxyethyl-2-hydroxypropyl phthalate, 2-methacryloyloxyethyl-2-hydroxypropyl phthalate, etc. can be mentioned, and commercially available products include, for example, Aronix M -101, M-111, M-114 (manufactured by Toa Gosei Co., Ltd.); KAYARAD TC-110S, TC-120S (manufactured by Nippon Kayaku Co., Ltd.) ; Viscoat 158, mention may be made of the 2311 (manufactured by Osaka Organic Chemical Industry Ltd.) and the like.

  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, 1,6 -Hexanediol diacrylate, 1,6-hexanediol dimethacrylate, 1,9-nonanediol diacrylate, 1,9-nonanediol dimethacrylate, bisphenoxyethanol full orange acrylate, bisphenoxyethanol full orange methacrylate, etc. As commercial products, for example, Aronix M-210, M-240, M-6200 (manufactured by Toa Gosei Co., Ltd.) , KAYARAD HDDA, the HX-220, (manufactured by Nippon Kayaku Co.) Same R-604, Viscoat 260, the 312, the 335HP (manufactured by Osaka Organic Chemical Industry Ltd.) and the like.

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, etc. Can do.
In particular, a (meth) acrylate having 9 or more functional groups has an alkylene straight chain and an alicyclic structure, a compound containing two or more isocyanate groups, and a trifunctional, tetrafunctional and 5 functional group containing one or more hydroxyl groups in the molecule. The urethane acrylate compound obtained by making a functional (meth) acrylate compound react is mentioned.
As said commercial item, for example, Aronix M-309, M-400, M-405, M-450, M-7100, M-8030, M-8060, M-8060, TO-1450 (Toa Gosei ( KAYARAD TMPTA, DPHA, DPCA-20, DPCA-30, DPCA-60, DPCA-60, DPCA-120 (manufactured by Nippon Kayaku Co., Ltd.), Biscote 295, 300, 360, GPT, 3PA, 400 (produced by Osaka Organic Chemical Industry Co., Ltd.) and the like. Commercially available products of polyfunctional urethane acrylates having 9 or more functional groups include, for example, New Frontier R-1150 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), KAYARAD DPHA-40H (manufactured by Nippon Kayaku Co., Ltd.), etc. Is mentioned.

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.
The monofunctional, bifunctional, or trifunctional or higher (meth) acrylic acid esters can be used alone or in combination of two or more.

  In the photosensitive 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, based on 100 parts by weight of the copolymer [A]. It is. In this case, if the amount of the polymerizable compound [B] used is less than 50 parts by weight, there may be a residual image during development, while if it exceeds 140 parts by weight, the hardness of the resulting spacer tends to decrease.

-Photopolymerization initiator [C]-
[C] component in photosensitive resin composition (I) consists of O-acyl oxime type photoinitiator, especially the compound (henceforth "photoinitiator [C]" represented by said Formula (1). Is preferred).
The photopolymerization initiator as used in the present invention means a component that generates an active species capable of initiating polymerization of the polymerizable compound [B] by exposure with visible light, ultraviolet light, far ultraviolet light, charged particle beam, X-ray or the like. To do.
In the “photopolymerization initiator [C]” represented by the formula (1), R _{1 and} R ₂ are each a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or a cycloalkyl having 3 to 8 carbon atoms. Group, phenyl group (however, it may be substituted with at least one or more with an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a phenyl group, and a halogen atom), 7 to 20 carbon atoms An alicyclic group (excluding the cycloalkyl group), an oxygen-containing heterocyclic group having 4 to 20 carbon atoms, a nitrogen-containing heterocyclic group having 4 to 20 carbon atoms, an oxygen-containing heterocyclic group having 4 to 20 carbon atoms, A functional group selected from sulfur-containing heterocyclic groups having 4 to 20 carbon atoms. However, any _one of R _{1 and} R ₂ is an alkyl group having 13 to 20 carbon atoms, an alicyclic group having 7 to 20 carbon atoms (excluding the cycloalkyl group), and an oxygen-containing group having 4 to 20 carbon atoms. A heterocyclic group, a nitrogen-containing heterocyclic group having 4 to 20 carbon atoms, an oxygen-containing heterocyclic group having 4 to 20 carbon atoms, and a sulfur-containing heterocyclic group having 4 to 20 carbon atoms. R ₃ represents a hydrogen atom or a linear, branched or cyclic alkyl group having 1 to 12 carbon atoms, and R ₄ , R ₅ and R ₆ are a hydrogen atom or a linear or branched chain having 1 to 6 carbon atoms. Or a cyclic alkyl group is shown.
Examples of the alicyclic group having 7 to 20 carbon atoms (excluding the cycloalkyl group) include, for example, a bicycloalkyl group, a tricycloalkyl group, a spiroalkyl group, a ter-cycloalkyl group, a terpene skeleton-containing group, and an adamantyl skeleton Group.
Examples of the nitrogen-containing heterocyclic group having 4 to 20 carbon atoms, the oxygen-containing heterocyclic group having 4 to 20 carbon atoms, and the sulfur-containing heterocyclic group having 4 to 20 carbon atoms include thiolanyl, azepinyl,
Dihydroazepinyl, dioxolanyl, triazinyl, oxathianyl, thiazolyl, oxadiazinyl, dioxaindanyl, dihianaphthalenyl, furanyl, thiophenyl, pyrrolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, pyrazolyl, furazanyl, pyranyl, pyridinyl, pyridazinyl, pyrimidyl , Pyrazinyl, pyrrolinyl, morpholinyl, piperazinyl, quinuclidinyl, indolyl, isoindolyl, benzofuranyl, benzothiophenyl, indolizinyl, chromenyl, quinolinyl, isoquinolinyl, purinyl, quinazolinyl, cinnolinyl, phthalazinyl, pteridinyl, carbazolylyl, acridinyl, triacridyl Thioxanthenyl, phenazinyl, phenothiazinyl, phen Kisachiiniru, phenoxazinyl, such as thianthrenyl and the like.

In the formula (1), examples of the linear, branched or cyclic alkyl group having 1 to 12 carbon atoms represented by R ₃ include, for example, a methyl group, an ethyl group, an n-propyl group, an i-propyl group, and an 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-decyl group, n-undecyl group, n-dodecyl group , Cyclopentyl group, cyclohexyl group and the like.

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.

Specific examples of the compound [C] include
1- [9-ethyl-6- (2-methylbenzoyl) -9.H.-carbazol-3-yl] -bicycloheptylmethane-1-one oxime-O-benzoate,
1- [9-ethyl-6- (2-methylbenzoyl) -9.H.-carbazol-3-yl] -bicycloheptyl-1-one oxime-O-acetate,

1- [9-ethyl-6- (2-methylbenzoyl) -9.H.-carbazol-3-yl] -adamantylmethane-1-one oxime-O-benzoate,
1- [9-ethyl-6- (2-methylbenzoyl) -9.H.-carbazol-3-yl] -adamantylmethane-1-one oxime-O-acetate,

1- [9-ethyl-6- (2-methylbenzoyl) -9.H.-carbazol-3-yl] -tetrahydrofuranylmethane-1-one oxime-O-benzoate,
1- [9-ethyl-6- (2-methylbenzoyl) -9.H.-carbazol-3-yl] -tetrahydrofuranylmethane-1-one oxime-O-acetate,

1- [9-ethyl-6- (2-methylbenzoyl) -9.H.-carbazol-3-yl] -thiophenylmethane-1-one oxime-O-benzoate,
1- [9-Ethyl-6- (2-methylbenzoyl) -9.H.-carbazol-3-yl] -thiophenylmethane-1-one oxime-O-acetate

1- [9-ethyl-6- (2-methylbenzoyl) -9.H.-carbazol-3-yl] -morophonylmethane-1-one oxime-O-benzoate,
1- [9-ethyl-6- (2-methylbenzoyl) -9.H.-carbazol-3-yl] -morophonylmethane-1-one oxime-O-acetate,

1- [9-Ethyl-6- (2-methylbenzoyl) -9.H.-carbazol-3-yl] -ethane-1-one oxime-O-bisheptanecarboxylate 1- [9-ethyl-6- (2-Methylbenzoyl) -9.H.-carbazol-3-yl] -ethane-1-one oxime-O-tricyclodecanecarboxy compound 1- [9-ethyl-6- (2-methylbenzoyl) -9 And .H.-carbazol-3-yl] -ethane-1-one oxime-O-adamantane carbochelate.
Two or more of these photopolymerization initiators [C] may be used at the same time.

As the photopolymerization initiator [C], an O-acyloxime photopolymerization initiator other than the formula (1) (hereinafter referred to as “photopolymerization initiator [C-2]”) can be used in combination.
Specific examples of these photopolymerization initiators [C-2] include 1,2-octadion-1- [4- (phenylthio) phenyl] -2- (O-benzoyloxime), 1,2-butanedione-1- [ 4- (phenylthio) phenyl] -2- (O-benzoyloxime), 1,2-butanedione-1- [4- (phenylthio) phenyl] -2- (O-acetyloxime), 1,2-octadione-1 -[4- (methylthio) phenyl] -2- (O-benzoyloxime), 1,2-octadion-1- [4- (phenylthio) phenyl] -2- (O- (4-methylbenzoyloxime)), etc. Can be mentioned. Of these, 1,2-octadion-1- [4- (phenylthio) phenyl] -2- (O-benzoyloxime) is particularly preferable.

By using these photopolymerization initiators [C], it is possible to obtain a spacer having sufficient sensitivity and adhesion even with an exposure amount of 150 mJ / cm ² or less.

  The amount of the photopolymerization initiator [C] used in the photosensitive resin composition (a) is preferably 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]. It is. In this case, if the amount of the photopolymerization initiator [C] used is less than 5 parts by weight, the residual film ratio during development tends to decrease. On the other hand, if it exceeds 30 parts by weight, an alkaline developer in an unexposed part during development. There is a tendency for the solubility to be reduced.

In the photosensitive resin composition (A), at least one other photopolymerization initiator can be used in combination with the photopolymerization initiator [C].
Examples of the other photopolymerization initiator include biimidazole compounds, benzoin compounds, acetophenone compounds, benzophenone compounds, α-diketone compounds, polynuclear quinone compounds, xanthone compounds, phosphine compounds, and triazine compounds. A compound etc. can be mentioned. Of these, acetophenone compounds (hereinafter sometimes referred to as “component (D)”) and biimidazole compounds (hereinafter sometimes referred to as “component (E)”) are preferred.

Component (D): Acetophenone compound In addition, examples of the acetophenone compound include an α-hydroxyketone compound, an α-aminoketone compound, and other compounds.
Specific examples of the α-hydroxyketone compound include 1-phenyl-2-hydroxy-2-methylpropan-1-one, 1- (4-i-propylphenyl) -2-hydroxy-2-methylpropane- 1-one, 4- (2-hydroxyethoxy) phenyl- (2-hydroxy-2-propyl) ketone, 1-hydroxycyclohexyl phenyl ketone and the like can be mentioned, and specific examples of the α-aminoketone compound include: Examples include 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1, and the like. Specific examples of compounds other than these include 2,2-dimethoxyacetophenone, 2,2-diethoxyacetophenone, 2, - it can be given dimethoxy-2-phenyl acetophenone and the like.
These acetophenone compounds can be used alone or in admixture of two or more.

  By using these acetophenone compounds, the sensitivity, spacer shape and compressive strength can be further improved.

(E) component: biimidazole compound As a specific example of the biimidazole compound,
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,
Examples include 2,2′-bis (2,4,6-tribromophenyl) -4,4 ′, 5,5′-tetraphenyl-1,2′-biimidazole.

Among the 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, is particularly preferable. 2'-biimidazole.
The biimidazole compounds can be used alone or in admixture of two or more.
By using these biimidazole compounds, sensitivity, resolution, and adhesion can be further improved.

In order to sensitize the biimidazole compound, an aliphatic or aromatic compound having a dialkylamino group (hereinafter sometimes referred to as “sensitizer [E-2]”) can be used.
Specific examples of the sensitizer [E-2] include, for example, N-methyldiethanolamine, 4,4′-bis (dimethylamino) benzophenone, 4,4′-bis (diethylamino) benzophenone, p-dimethylaminobenzoic acid. Examples include ethyl acrylate, i-amyl p-dimethylaminobenzoate, and the like. Of these sensitizers, 4,4′-bis (diethylamino) benzophenone is preferred.
Two or more of these sensitizers [E-2] may be used at the same time.
The amount of the sensitizer [E-2] 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 [A].
When the amount of the compound [E-2] is less than 0.1 parts by weight, the resulting spacer tends to cause film slippage or poor pattern shape. When the amount exceeds 50 parts by weight, the pattern shape defect similarly occurs. Tend to occur.

When a biimidazole compound is used, a thiol compound (hereinafter sometimes referred to as “thiol compound [E-3]”) may be used as the hydrogen donor compound. The biimidazole compound is sensitized by a benzophenone compound having a dialkylamino group, and the biimidazole compound is cleaved to generate an imidazole radical. In this case, a high radical polymerization initiating ability is not expressed, and an unfavorable shape such as a reverse taper shape is often obtained. This problem is alleviated by adding the thiol compound [E-3] to a system in which a biimidazole compound and a benzophenone compound having a dialkylamino group coexist. A hydrogen radical is donated from the thiol compound to the imidazole radical, thereby generating a compound having a neutral imidazole and a sulfur radical having a high polymerization initiating ability. Thereby, it becomes a more preferable forward taper shape from a reverse taper shape.
The use ratio of the thiol-based compound [E-3] 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 compound [C]. . When the amount of the thiol-based compound [E-3] is less than 0.1 parts by weight, the resulting spacer tends to cause film slippage or poor pattern shape. Defects tend to occur.
Specific examples thereof include aromatic thiols such as 2-mercaptobenzothiazole, 2-mercaptobenzoxazole, 2-mercaptobenzimidazole, 2-mercapto-5-methoxybenzothiazole, 2-mercapto-5-methoxybenzimidazole, 3 -Aliphatic monothiols such as mercaptopropionic acid, methyl 3-mercaptopropionate, ethyl 3-mercaptopropionate and octyl 3-mercaptopropionate. Examples of the bifunctional or higher aliphatic thiol include 3,6-dioxa-1,8-octanedithiol, pentaerythritol tetra (mercaptoacetate), pentaerythritol tetra (3-mercaptopropionate), and the like.

  The use ratio of the other photopolymerization initiator is preferably 100 parts by weight or less, more preferably 80 parts by weight or less, and particularly preferably 60 parts by weight or less with respect to 100 parts by weight of the total photopolymerization initiator. In this case, if the use ratio of the other photopolymerization initiator exceeds 100 parts by weight, the intended effect of the present invention may be impaired.

-Additives-
In the photosensitive resin composition (A), additives other than the above components can be blended as necessary within the range not impairing the intended effect of the present invention.
For example, in order to improve applicability, a surfactant can be blended. As the surfactant, a fluorine-based surfactant and a silicone-based surfactant can be suitably used.
As the fluorosurfactant, a compound having a fluoroalkyl or fluoroalkylene group in at least one of the terminal, main chain and side chain can be suitably used. Specific examples thereof include 1,1,2 , 2-tetrafluorooctyl (1,1,2,2-tetrafluoropropyl) ether, 1,1,2,2-tetrafluorooctyl hexyl ether, octaethylene glycol di (1,1,2,2-tetrafluoro) Butyl) ether, hexaethylene glycol (1,1,2,2,3,3-hexafluoropentyl) ether, octapropylene glycol di (1,1,2,2-tetrafluorobutyl) ether, hexapropylene glycol di ( 1,1,2,2,3,3-hexafluoropentyl) ether, sodium perfluorododecyl sulfonate, 1,1,2,2,8,8,9,9,1 , 10-decafluorododecane, 1,1,2,2,3,3-hexafluorodecane, sodium fluoroalkylbenzenesulfonate, sodium fluoroalkylphosphonate, sodium fluoroalkylcarboxylate, fluoroalkylpolyoxyethylene ether, diglycerin Examples thereof include tetrakis (fluoroalkyl polyoxyethylene ether), fluoroalkyl ammonium iodide, fluoroalkyl betaine, fluoroalkyl polyoxyethylene ether, perfluoroalkyl polyoxyethanol, perfluoroalkyl alkoxylate, and fluorine-based alkyl ester. .

Examples of these commercially available products include BM-1000, BM-1100 (manufactured by BM CHEMIE), MegaFuck F142D, F172, F173, F183, F178, F191, F191, F471, and F476. (Above, manufactured by Dainippon Ink & Chemicals, Inc.), Florard FC 170C, FC-171, FC-430, FC-431 (above, manufactured by Sumitomo 3M), Surflon S-112, S-113, S-131, S-141, S-145, S-382, SC-101, SC-102, SC-103, SC-104, SC-105, SC-106 ( Asahi Glass Co., Ltd.), Ftop EF301, 303, 352 (above, Shin-Akita Kasei Co., Ltd.), Footent FT-100, FT-11 FT-140A, FT-150, FT-250, FT-251, FTX-251, FTX-218, FT-300, FT-310, FT-400S ) Manufactured by Neos).
Examples of the silicone-based surfactant include Torre Silicone DC3PA, DC7PA, SH11PA, SH21PA, SH28PA, SH29PA, SH30PA, SH-190, SH-193, SZ-6032, SF -8428, DC-57, DC-190 (above, manufactured by Toray Dow Corning Silicone Co., Ltd.), TSF-4440, TSF-4300, TSF-4445, TSF-4446, TSF-4460, TSF-4442 (The above-mentioned, GE Toshiba Silicone Co., Ltd. product) etc. can be mentioned what is marketed.

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

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.

Moreover, in order to further improve the adhesion to the substrate, an adhesion assistant can be blended.
As the adhesion assistant, a functional silane coupling agent is preferable, and examples thereof include a silane coupling agent having a reactive functional group such as a carboxyl group, a methacryloyl group, an isocyanate group, an epoxy group, More specifically, trimethoxysilylbenzoic acid, γ-methacryloyloxypropyltrimethoxysilane, vinyltriacetoxysilane, vinyltrimethoxysilane, γ-isocyanatopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane and the like 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 a development residue is likely to occur.

Other additives can be added. It is added for the purpose of improving storage stability. Specific examples include sulfur, quinones, hydroquinones, polyoxy compounds, amines, and nitronitroso compounds. Examples thereof include 4-methoxyphenol and N-nitroso-N-phenylhydroxylamine aluminum. These are preferably used in an amount of 3.0 parts by weight or less, more preferably 0.001 to 0.5 parts by weight with respect to 100 parts by weight of the copolymer [A]. When the amount exceeds 3.0 parts by weight, sufficient sensitivity cannot be obtained, and the pattern shape deteriorates.
In order to improve heat resistance, an N- (alkoxymethyl) glycoluril compound, an N- (alkoxymethyl) melamine compound, and a compound having a bifunctional or higher functional epoxy group in one molecule can be added. Specific 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) glycol Examples include uril, N, N, N, N-tetra (t-butoxymethyl) glycoluril and the like. Of these, N, N, N, N-tetra (methoxymethyl) glycoluril is particularly preferable. Specific 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. Of these, N, N, N, N, N, N-hexa (methoxymethyl) melamine is particularly preferable. Examples of these commercially available products include Nicalac N-2702, MW-30M (manufactured by Sanwa Chemical Co., Ltd.) and the like.
Examples of compounds having two or more functional epoxy groups in one molecule 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. Examples include ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin diglycidyl ether, trimethylolpropane triglycidyl ether, hydrogenated bisphenol A diglycidyl ether, and bisphenol A diglycidyl ether. Specific examples of these commercially available products include Epolite 40E, Epolite 100E, Epolite 200E, Epolite 70P, Epolite 200P, Epolite 400P, Epolite 40E, Epolite 1500NP, Epolite 1600, Epolite 80MF, Epolite 100MF, Epolite 4000, Epolite 3,002 ( As mentioned above, Kyoeisha Chemical Co., Ltd.) can be mentioned. These can be used alone or in combination of two or more.

Composition solution The photosensitive resin composition (A) is usually dissolved in a suitable solvent with constituent components such as a copolymer [A], a polymerizable compound [B], and a photopolymerization initiator [C]. Then, it is prepared as a composition solution.
As the solvent used for the preparation of the composition solution, a solvent that uniformly dissolves each component constituting the photosensitive resin composition (A) and does not react with each component is used. The thing similar to the solvent illustrated about the superposition | polymerization which manufactures a polymer [A] can be mentioned.
Among these solvents, ethylene glycol monoalkyl ethers, ethylene glycol monoalkyl ether acetates, diethylene glycol alkyl ethers, and propylene in terms of solubility of each component, reactivity with each component, and ease of film formation. Glycol monoalkyl ether acetates, alkyl alkoxypropionates and the like 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 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.
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.

  The photosensitive resin composition (A) is particularly suitable as a material for forming spacers for display panels such as liquid crystal panels and touch panels.

When forming a display panel spacer using the display panel spacer photosensitive resin composition (a), after applying the composition solution to the surface of the substrate, pre-baking to remove the solvent, the coating film Form.
As a method for applying the composition solution, for example, an appropriate method such as a spray method, a roll coating method, or a spin coating method can be employed.
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 coating 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, visible light, ultraviolet light, far ultraviolet light, charged particle beam, X-ray and the like can be appropriately selected, but radiation having a wavelength in the range of 190 to 450 nm is preferable.
As the 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 30 to 180 seconds.

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 Jin, aromatic tertiary amines such as quinoline; tetramethylammonium hydroxide, the aqueous solution of an alkaline compound such as quaternary ammonium salts such as tetraethyl ammonium hydroxide may be used.
In addition, an appropriate amount of a water-soluble organic solvent such as methanol or ethanol and / or a surfactant can be added to the aqueous solution of the alkaline compound.
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, or for 30 to 90 minutes in the oven. By doing so, the target spacer can be obtained.

Here, specific examples of the composition of the preferred photosensitive resin composition (a) are as follows (i) to (vii).
(I) The component constituting the copolymer [A] is an epoxy resin in which the unsaturated carboxylic acid monomer (a1) is a single group of acrylic acid, methacrylic acid and maleic anhydride or a mixture of two or more types. The group-containing monomer (a2) is glycidyl methacrylate, 6,7-epoxyheptyl methacrylate, o-vinylbenzyl glycidyl ether, m-vinylbenzyl glycidyl ether and p-vinylbenzyl glycidyl ether alone or in combination The other monomer (a3) is 2-methylcyclohexyl acrylate, t-butyl methacrylate, tricyclo [5.2.1.02,6] decane-8-yl methacrylate, styrene, p -Methoxystyrene, tetrahydrofurfuryl methacrylate, and 1,3-butadiene group alone or in combination A composition comprising the above mixture.
(Ii) In the copolymer [A], the content of repeating units derived from the unsaturated carboxylic acid monomer (a1) is 5 to 40% by weight, more preferably 10 to 30% by weight, and an epoxy group The content of the repeating unit derived from the monomer (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 monomer (a3) is The composition according to the above (i), which is 10 to 70% by weight, more preferably 20 to 50% by weight.
(Iii) The polymerizable compound [B] is a monofunctional, bifunctional or trifunctional or higher (meth) acrylic acid ester, particularly preferably a trifunctional or higher functional (meth) acrylic acid ester (i) or ( The composition of ii).
(Iv) The composition according to any one of (i) to (iii), wherein the photopolymerization initiator [C] is an O-acyloxime type photopolymerization initiator.

(Vii) 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 photopolymerization 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 photosensitive 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, has a sufficient spacer shape with an exposure amount of 150 mJ / cm ² or less, and It is an object of the present invention to provide a photosensitive resin composition capable of forming a film thickness and capable of forming a display panel spacer excellent in strength, heat resistance and the like.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples and comparative 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. 40 parts by weight of glycidyl, 5 parts by weight of styrene, tricyclomethacrylate [5.2.1.
[02,6] decane-8-yl (32 parts by weight) was replaced with nitrogen, and further 5 parts by weight of 1,3-butadiene was added, and the temperature of the solution was raised to 70 ° C. while gently stirring. Polymerization was performed while maintaining the temperature for 5 hours to obtain a solution of copolymer [A-1].
The solid content concentration of this solution was 33.0% by weight, and the Mw of the copolymer [A-1] was 11,000.

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. 20 parts by weight of glycidyl, 5 parts by weight of styrene, tricyclomethacrylate [5.2.1.
[02,6] Decan-8-yl 32 parts by weight and tetrahydrofurfuryl methacrylate 25 parts by weight were charged with nitrogen, and then the temperature of the solution was raised to 70 ° C. while gently stirring, and this temperature was increased for 5 hours. The polymer was retained and polymerized to obtain a solution of the copolymer [A-2].
The solid content concentration of this solution was 33.4% by weight, and the Mw of the copolymer [A-2] was 9,000.

Example 1
Preparation of Composition Solution 100 parts by weight (solid content) of the copolymer [A-1] obtained in Synthesis Example 1 as a copolymer [A], and KAYARAD DPHA (Nippon Kayaku) as a polymerizable compound [B] 80 parts by weight, 1- [9-ethyl-6- (2-methylbenzoyl) -9.H.-carbazol-3-yl] -bicycloheptyl-1-one oxime as photopolymerization initiator [C] After dissolving 8 parts by weight of —O-acetate in propylene glycol monomethyl ether acetate so that the solid content concentration is 35% by weight, the solution is filtered through a Millipore filter having a pore size of 0.2 μm to obtain a composition solution (S-1) Was prepared.

(I) Formation of Spacer The above composition solution was applied on an alkali-free glass substrate using a spinner, and then pre-baked on a hot plate at 90 ° C. for 3 minutes to form a coating film having a thickness of 6.0 μm.
The coating film obtained above was exposed to ultraviolet rays having an exposure gap at a wavelength of 365 nm of 300 W / m ² with an exposure gap of 150 μm through a mask having a 10 μm square pattern. Next, development was performed with a 0.05 wt% aqueous solution of potassium hydroxide at 25 ° C. for 60 seconds, and then rinsed with pure water for 1 minute. Furthermore, it heated at 150 degreeC for 120 minute (s) in oven, and the spacer was formed.

(II) Evaluation of resolution In the pattern obtained in the above (I), the evaluation was performed with the minimum pattern size in the sensitivity where the remaining film ratio after development (film thickness after development / initial film thickness × 100) is 90% or more. . The smaller the pattern size, the better the resolution.

(III) Sensitivity Evaluation In the pattern obtained in (I) above, when the sensitivity at which the remaining film ratio after development is 90% or more is 150 mJ / cm ² or less, it can be said that the sensitivity is good.

(IV) Evaluation of pattern cross-sectional shape As a result of observing the cross-sectional shape of the pattern obtained in the above (I) with a scanning electron microscope, it showed which shape of A to C shown in FIG. . When the pattern edge is forward tapered as in A, the pattern shape is good. When the pattern edge is formed in a vertical shape as in B, the pattern shape is slightly good.
In addition, as shown in C, the shape that is inversely tapered (in which the side of the film surface in the cross-sectional shape is longer than the side on the substrate side, the inverted triangle shape) is likely to cause the pattern to peel off during the subsequent rubbing process. Therefore, such a shape was regarded as defective.

(V) Evaluation of compressive strength The compressive strength of the spacer obtained in the above (I) was evaluated using a micro compression tester (MCTM-200, manufactured by Shimadzu Corporation). The amount of deformation when a load of 10 mN was applied was measured with a flat indenter with a diameter of 50 μm (measurement temperature: 23 ° C.). When this value is 0.5 or less, the compressive strength is good. The results are shown in Table 2.
(VI) Evaluation of rubbing resistance On the substrate obtained in (I) above, AL3046 (manufactured by JS R. Co., Ltd.) as a liquid crystal aligning agent was applied by a printing machine for applying a liquid crystal aligning film, It dried for a time and formed the coating film of the orientation agent with a dry film thickness of 0.05 micrometer.
The coating film was rubbed with a rubbing machine having a roll around which a nylon cloth was wound at a roll rotation speed of 500 rpm and a stage moving speed of 1 cm / sec. Table 2 shows the presence or absence of scraping or peeling of the spacer pattern.

(VII) Evaluation of adhesiveness Except not using a pattern mask, it implemented similarly to said (I), formed the cured film for adhesiveness evaluation, and performed the adhesiveness test. The test method followed the cross-cut tape method of 8.5.2 in the adhesion test of JIS K-5400 (1900) 8.5. Table 2 shows the number of the remaining grids.
(VIII) Evaluation of storage stability After preparing the composition, it is stored at -15 ° C, and the change in required exposure over time is traced so that the residual film ratio after development becomes 90% or more in the same manner as in the above (III) sensitivity evaluation. The relative values of the sensitivity after 3 months after storage and the sensitivity immediately after preparation were measured.

Examples 2-18, Comparative Examples 1-10
In Example 1, a composition solution was prepared and a spacer was formed in the same manner as in Example 1 except that the types and amounts shown in Table 1 were used as the [A] component to the [E] component. And evaluated. The addition amount of [B]-[E] is a weight ratio with respect to 100 weight part of copolymer [A].
In Table 1, the abbreviations of the components indicate the following compounds.
(B-1): KAYARAD DPHA (manufactured by Nippon Kayaku Co., Ltd.)
(B-2): KAYARAD DPHA-40H (manufactured by Nippon Kayaku Co., Ltd.)
(C-1): 1- [9-ethyl-6- (2-methylbenzoyl) -9.H.-carbazol-3-yl] -bicycloheptyl-1-one oxime-O-acetate,
(C-2): 1- [9-ethyl-6- (2-methylbenzoyl) -9.H.-carbazol-3-yl] -tetrahydrofuranylmethane-1-one oxime-O-acetate,
(C-3): 1- [9-ethyl-6- (2-methylbenzoyl) -9.H.-carbazol-3-yl] -ethane-1-one oxime-O-bisheptanecarboxylate (C- 4): 1- [9-Ethyl-6- (2-methylbenzoyl) -9.H.-carbazol-3-yl] -ethane-1-one oxime-O-tricyclodecanecarboxy compound (C-5) : 1- [9-Ethyl-6- (2-methylbenzoyl) -9.H.-carbazol-3-yl] -ethane-1-one oxime-O-adamantane carboxylate (C-6): 1- [ 9-Ethyl-6- (2-methylbenzoyl) -9.H.-carbazol-3-yl] -tetrahydrofuranylmethane-1-one oxime-O-bicycloheptanecarboxylate (CR): 1- [9 -Ethyl-6- (2-me Rubenzoiru) -9.H.- carbazol-3-yl] - ethan-1-one oxime -O- acetate (Ciba Specialty Chemicals Inc. CGI-242)
(D-1): 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one (Irgacure 907 manufactured by Ciba Specialty Chemicals)
(D-2): 2-Benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1
(Irgacure 369 manufactured by Ciba Specialty Chemicals)
(E-1): 2,2′-bis (2,4-dichlorophenyl) -4,4 ′, 5,5′-tetraphenyl-1,2′-biimidazole (E-2): 4,4 ′ -Bis (diethylamino) benzophenone (E-3): 2-mercaptobenzothiazole In Table 1,-mark shows that this component is not added.
The evaluation results are shown in Table 2.

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 photopolymerization initiator comprising a compound represented by the following formula (1)

[In Formula (1), R <1> _, R < ₂ > is respectively a hydrogen atom, a C1-C20 alkyl group, a C3-C8 cycloalkyl group, a phenyl group (however, a C1-C6 alkyl). A group, an alkoxy group having 1 to 6 carbon atoms, a phenyl group, and a halogen atom may be substituted with at least one group), an alicyclic group having 7 to 20 carbon atoms (excluding the cycloalkyl group), It is selected from an oxygen-containing heterocyclic group having 4 to 20 carbon atoms, a nitrogen-containing heterocyclic group having 4 to 20 carbon atoms, an oxygen-containing heterocyclic group having 4 to 20 carbon atoms, and a sulfur-containing heterocyclic group having 4 to 20 carbon atoms. Functional group. However, any _one of R _{1 and} R ₂ is an alkyl group having 13 to 20 carbon atoms, an alicyclic group having 7 to 20 carbon atoms (excluding the cycloalkyl group), and an oxygen-containing group having 4 to 20 carbon atoms. A heterocyclic group, a nitrogen-containing heterocyclic group having 4 to 20 carbon atoms, an oxygen-containing heterocyclic group having 4 to 20 carbon atoms, and a sulfur-containing heterocyclic group having 4 to 20 carbon atoms. R ₃ represents a hydrogen atom or a linear, branched or cyclic alkyl group having 1 to 12 carbon atoms, and R ₄ , R ₅ and R ₆ are a hydrogen atom or a linear or branched chain having 1 to 6 carbon atoms. Or a cyclic alkyl group is shown. ]
A photosensitive resin composition comprising:
A display panel spacer formed from the photosensitive resin composition according to claim 1. A display panel comprising the display panel spacer according to claim 2.

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