KR20100110478A - Photo sensitive resin composition used as spacer structure in liquid crystal display panel - Google Patents

Abstract

PURPOSE: A photoresist resin composition for producing an LCD spacer is provided to obtain the LCD spacer with the excellent physical properties, and to improve the production efficiency. CONSTITUTION: A photoresist resin composition for producing an LCD spacer contains the following: 100 parts of acrylic copolymer by weight formed with acryl group carboxylic acid, cycloalkyl or cycloalkenyl acrylic ester with a polycyclic structure, acrylic alkyl ester, and a vinyl aromatic compound; 10~150 parts of acryl group polyfunctional monomer by weight; 0.1~15 parts of O-acyloxym system photo-initiator by weight; and 1~20 parts of silane coupling agent by weight.

Description

Photosensitive resin composition used as spacer structure in liquid crystal display panel}

The present invention relates to a photosensitive resin composition for producing an LCD spacer.

In the manufacture of the liquid crystal display panel, spacer particles such as glass beads and plastic beads having a predetermined particle diameter were used to initially maintain two substrate gaps. Since these spacer particles are randomly scattered on a transparent substrate such as a glass substrate, when these particles are present in the pixel formation region, these particles may be reflected or incident light may be scattered to reduce the contrast of the liquid crystal panel. As another method, a method of forming a spacer by photolithography has been developed and used. In this method, the photosensitive resin composition is coated on a substrate, exposed to ultraviolet light through a mask, and then developed to form a spacer on a dot, and the spacer can be formed only at a desired place other than the pixel formation region. I can solve it.

Korean Patent Laid-Open Publication No. 1999-88297 discloses a photosensitive composition comprising an acrylic acid base copolymer and an acrylic ester having a double bond in a sock terminal and a photoinitiator. However, in order to obtain a spacer of required physical properties by the photoinitiation polymerization reaction, a long exposure time is required and the heat resistance of the obtained spacer is not satisfactory. Korean Patent Publication No. 2002-73403 discloses a photosensitive resin composition comprising a copolymer of an ethylenically unsaturated hydrocarbon having an acrylic acid + an acrylic ester + an epoxy group, an ethylenic polymerizable compound and a photoinitiator composition of trihalomethyltriazines. . Formation of the pattern by exposure and heat curing can provide a spacer having relatively good heat resistance. However, it is not easy to form a constant and large height spacer after development and curing. Korean Patent Publication No. 2006-35047 discloses a 3- or 4-cyclic cycloalkyl or cycloalkenyl acrylic ester + acrylic cyclic ester + acrylic alkyl ester + vinyl aromatic compound substituted or unsubstituted with acrylic carboxylic acid + lower alkyl group. The photosensitive resin composition which consists of a copolymer, an acryl-type polyfunctional monomer, an acetophenone type, or a benzophenone type photoinitiator, and an additive is shown. The heat resistance is good by formation of the pattern by exposure and heat curing, and it is easy to form a spacer having a constant and large height after development and curing.

Background Art In recent years, the spread and enlargement of liquid crystal display panels have been rapidly progressing, and therefore, in terms of cost reduction and process time, there is a demand for shortening the exposure irradiation time and shortening the development time in cost reduction and photolithography processes. However, when the spacer or the protective film is formed by a radiation exposure process having a low exposure amount using a photosensitive resin composition known in the art, the desired shape thickness becomes thin, the strength of the thin film is insufficient, or the pattern dimension becomes smaller than a desired value. There is a problem that pattern dimensions cannot be obtained and cause panel failure.

The present invention provides a highly sensitive photosensitive resin composition capable of forming a spacer having a sufficient spacer shape even at an exposure amount of 50 mJ / cm ² or less, and having excellent spacer strength, storage stability of the composition, adhesion to the underlying layer, flatness, heat resistance, and the like. To provide.

According to the present invention, i) an acrylic copolymer consisting of cycloalkyl or cycloalkenyl acrylic ester + acrylic alkyl ester + vinyl aromatic compound of acrylic carboxylic acid + polycyclic structure; ii) acrylic polyfunctional monomers; iii) O-acyl oxime photoinitiators; iv) silane coupling agents; And v) a high sensitivity photosensitive resin composition for forming a spacer of the LCD comprising an additive is provided. If necessary, the acrylic copolymer may further include an acrylic cyclic ester. If necessary, an acetophenone-based or benzophenone-based photoinitiator may be added or replaced within a range of 70% by weight or less of the total amount of photoinitiator.

When the high sensitivity photosensitive resin composition is described in detail according to the components,

[A] acrylic copolymer

As acrylic carboxylic acid among each component which comprises a copolymer, carboxylic acid, such as acrylic acid, methacrylic acid, crotonic acid, itaconic acid, fumaric acid, 2-carboxyethyl acrylate, is mentioned, for example. Among these carboxylic acid monomers, acrylic acid, methacrylic acid, 2-carboxyethyl acrylate, and the like are preferable in view of copolymerization reactivity, solubility in a developing solution, and ease of obtaining. In particular, 2-carboxyethyl acrylate has the advantage of improving the adhesion of the resulting copolymer to the substrate. In the copolymer, the content rate of the monomers belonging to the carboxylic acid monomer is preferably 5 to 50 weights, particularly preferably 15 to 25 weights. When the content rate of the carboxylic acid monomer is 5 or less, the solubility in the aqueous alkali solution tends to be lowered. When the content of the carboxylic acid monomer exceeds 50 weight, the solubility in the aqueous alkali solution becomes too large. The carboxylic acid monomers may be used alone or in combination of two or more thereof.

The polycyclic cycloalkyl or cycloalkenyl acrylic ester may have a 2-ring to 4-ring structure, preferably a 3-ring to 4-ring structure, and may have one or two unsaturated double bonds. Polycyclic cycloalkyl or cycloalkenyl acrylic esters include dicyclopentenyl acrylate, dicyclopentenyl methacrylate, polycyclopentanyl acrylate, dicyclopentanyl methacrylate, adamantyl acrylate and adamantyl methacrylate. Etc. can be mentioned. Adamantyl methacrylate, dicyclopentenyl methacrylate, etc. are especially excellent at the point of copolymerization reactivity, heat resistance, and the strength of a spacer.

If necessary, good results can be obtained by adding acrylic cyclic esters. Acrylic cyclic esters are, for example, glycidyl methacrylate, glycidyl acrylate, isobornyl acrylate and isobornyl methacrylate. The content rate of the polycyclic cycloalkyl or cycloalkenyl acrylic ester is preferably 10 to 70 weights, particularly preferably 30 to 60 weights. In this case, when the content rate is 10 weight or less, the problem that the strength of the spacer is lowered is 70 weight or more. The cycloalkyl or cycloalkenyl acrylic ester and the acrylic cyclic ester-containing monomer may be used alone or in combination of two or more thereof. Particularly excellent spacers having particularly good physical properties when at least 10 parts by weight of adamantyl methacrylate and / or dicyclopentenyl methacrylate which are 3- or 4- cyclic cycloalkyl or cycloalkenyl acrylate esters are included in the copolymer You can get it.

As the acrylic alkyl ester monomer, for example, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, n-butyl acrylate, n-butyl methacrylate, sec-butyl methacrylate, t-butyl methacrylate, octyl methacrylate, lauryl acrylate, lauryl methacrylate, 2-hydroxyethyl methacrylate, etc. are mentioned. Among the acrylic alkyl ester monomers, methyl methacrylate, t-butyl methacrylate, and lauryl methacrylate are preferable in view of copolymerization reactivity and solubility in an aqueous alkali solution. In particular, lauryl methacrylate is excellent for improving the adhesive strength of the copolymer, methyl methacrylate for the strength of the spacer, and t-butyl methacrylate is excellent for improving the residual film ratio of the spacer. Acrylic alkyl ester monomers can be used individually or in combination of 2 or more types. The content rate of the acrylic alkyl ester monomer is preferably 10 to 40 weights, particularly preferably 15 to 35 weights. In this case, when the content rate of the alkyl monomer is 10 weight or less, the problem that the solubility in aqueous alkali solution becomes too high and the residual film rate of a spacer falls is low, and when 40 weight or more, the problem of inferior solubility in aqueous alkali solution arises.

Moreover, as a vinyl aromatic monomer compound, styrene, (alpha) -methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxy styrene, etc. are mentioned, for example. Among these vinyl aromatic monomer compounds, styrene, α-methylstyrene, and p-methoxy styrene are preferable in view of copolymerization reactivity, solubility in aqueous alkali solution, and permeability of spacer. Vinyl aromatic monomers can be used individually or in combination of 2 types of paper. In the copolymer, the content rate of the monomers belonging to the vinyl aromatic monomer is preferably 5 to 25 weights, particularly preferably 5 to 20 weights. In this case, when the content of the aromatic monomer is 5 weights or less, the problem of excessively high solubility in aqueous alkali solution occurs.

The acrylic copolymer used in the present invention preferably has a polystyrene reduced weight average molecular weight (Mw) of 2,000 to 50,000, more preferably 5,000 to 30,000. When the molecular weight is less than 2,000, not only the remaining film ratio of the obtained film is lowered, but also the pattern formation, heat resistance, and the like tend to be inferior, and when the molecular weight exceeds 50,000, the sensitivity tends to be lowered.

The copolymer may be prepared by mixing an acrylic carboxylic acid monomer, an acrylic cyclic monomer, an acrylic acid alkyl ester monomer and a vinyl aromatic monomer with a suitable solvent to obtain a uniform liquid phase and then polymerizing in the presence of a radical polymerization initiator. . In this case, it is preferable to use a molecular weight modifier in order to adjust the molecular weight of the copolymer to the desired degree.

As a solvent which can be used for the said superposition | polymerization, For example, ethers, such as tetrahydrofuran and a dioxane; Ethylene glycol monoalkyl ethers; Ethylene glycol monoalkyl ether acetates; Ethylene glycol monoalkyl ether propionates; Diethylene glycol alkyl ethers; Propylene glycol monoalkyl ethers; Propylene glycol monoalkyl ether acetates; Propylene glycol monoalkyl ether propionates; Aromatic hydrocarbons such as toluene and xylene; Ketones such as methyl ethyl ketone, 2-pentanone, 3-pentanone, cyclohexanone, and 4-hydroxy-4-methyl-2-pentanone; Alkoxypropionate alkyl, other ester, etc. are mentioned. Among 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.

Moreover, as a radical polymerization initiator used for the said superposition | polymerization, although it does not specifically limit, For example, 2,2'- azobisisobutyronitrile, 2,2'- azobis- (2, 4- dimethylvaleronitrile ), Azo compounds such as 2,2'-azobis- (4-methoxy-2,4-dimethylvaleronitrile); Organic peroxides such as benzoyl peroxide, lauroyl peroxide, t-butylperoxy pivalate and 1,1-bis (t-butylperoxy) cyclohexane; Hydrogen peroxide and the like. In addition, when using a peroxide as a radical polymerization initiator, it can also be made into a redox type in combination with it and a reducing agent. These radical polymerization initiators can be used individually or in mixture of 2 or more types.

Moreover, although it does not specifically limit as a molecular weight modifier used for the said superposition | polymerization, For example, mercaptan compounds, such as butyl mercaptan, octyl mercaptan, lauryl mercaptan; (alpha) -methylstyrene dimer etc. are mentioned.

The acrylic copolymer thus obtained may be used in the production of the photosensitive resin composition as it is, or may be separated from the solution and used in the production of the photosensitive resin composition. The copolymer can be obtained in various ways depending on the type and content of the monomers used, and the molecular weight, each of which is different in physical properties and may have advantages and disadvantages obtained when used in the final photosensitive resin composition. Therefore, when preparing the photosensitive resin composition, it is more advantageous to mix and use two or more copolymers to complement each other's properties.

[B] acrylic Multifunctional  Monomer

Although the acryl-type polyfunctional monomer used for this invention is not specifically limited, Bifunctional or trifunctional or more (meth) acrylic acid esters are preferable at the point from which polymerization property is favorable and the spacer strength obtained is improved, especially trifunctional or more ( Meta) acrylic acid esters are preferable. As said bifunctional (meth) acrylic acid ester, For example, ethylene glycol diacrylate, ethylene glycol dimethacrylate, diethylene glycol diacrylate, diethylene glycol dimethacrylate, tetraethylene glycol diacrylate, Tetraethylene glycol dimethacrylate, 1,6-hexanedioldiacrylate, 1,6-hexanedioldimethacrylate, 1,9-nonanedioldiacrylate, 1,9-nonanedioldimethacrylate, Bisphenoxy ethanol fluorene diacrylate, bisphenoxy ethanol fluorene dimethacrylate, etc. are mentioned. Moreover, as said trifunctional or more (meth) acrylic acid ester, For example, trimethylol propane triacrylate, trimethylol propane trimethacrylate, pentaerythritol triacrylate, pentaerythritol trimethacrylate, penta Erythritol tetraacrylate, pentaerythritol tetramethacrylate, dipentaerythritol pentaacrylate, dipentaerythritol pentamethacrylate, dipentaerythritol hexaacrylate, dipentaerythritol hexamethacrylate, tri ( 2-acryloyloxyethyl) phosphate, tri (2-methacryloyloxyethyl) phosphate, etc. are mentioned. In addition, the monofunctional, bifunctional or trifunctional or more (meth) acrylic acid ester can be used individually or in combination of 2 or more types. At this time, as monofunctional (meth) acrylic acid ester, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, diethylene glycol monoethyl ether acrylate, diethylene glycol monoethyl ether methacryl Latex, isoboroyl acrylate, isoboroyl methacrylate, 3-methoxybutyl acrylate, 3-methoxybutyl methacrylate, 2-acryloyloxyethyl-2-hydroxypropyl phthalate, 2 -Methacryloyloxyethyl-2-hydroxypropylphthalate, poly (oxy-1,2-ethanediyl), alpha-hydro-w-[(1-oxo-2-propenyl) oxy]-, 2 And 2 '-[oxybis (methylene)] bis (2- (hydroxymethyl) -1,3-propanediol].

In the present invention, the amount of the acrylic polyfunctional monomer used is 50 to 200 parts by weight, preferably 70 to 140 parts by weight, most preferably 80 to 120 parts by weight per 100 parts by weight of the acrylic copolymer. In the usage-amount of this range, it is easy to control the film thickness of the spacer obtained, and it can be set as the high sensitivity photosensitive resin composition which provides the spacer excellent in strength and adhesiveness.

[C] Photoinitiator

The O-acyl oxime compound which is a photoinitiator used in the present invention is, for example, ethanone-1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl] -1- ( O-acetyloxime), ethanone-1- [9-ethyl-6- [2-methyl-4- (2,2-dimethyl-1,3-dioxolanyl) methoxybenzoyl] -9.H.- Carbazol-3-yl] -1- (O-acetyloxime), 1- [9-ethyl-6-benzoyl-9.H.-carbazol-3-yl] -1,2-nonan-2-oxime -O-benzoate, 1- [9-ethyl-6-benzoyl-9.H.-carbazol-3-yl] -1,2-nonan-2-oxime-O-acetate, 1- [9-ethyl -6-benzoyl-9.H.-carbazol-3-yl] -1,2-pentane-2-oxime-O-acetate, 1- [9-ethyl-6-benzoyl-9.H.-carbazole -3-yl] -octane-1-onoxime-O-acetate, 1- [9-ethyl-6- (2-methylbenzoyl) -9.H.-carbazol-3-yl] -ethane-1- Onoxime-O-benzoate, 1- [9-ethyl-6- (2-methylbenzoyl) -9.H.-carbazol-3-yl] -ethane-1-onoxime-O-acetate, 1- [9-n-butyl-6- (2-ethylbenzoyl) -9.H.-carbazol-3-yl] -ethane-1-one oxime-O-benzoate and the like.

Other photoinitiators, for example, acyloin, acyloin ethers, acetophenones, benzophenones, quinones and halogens in the range of 70% by weight or less of the photoinitiator total weight with respect to the O-acyl oxime compound photoinitiator. Compounds, acylphosphine oxides and peroxides can be added and used. Other photoinitiators specifically include, for example, benzyl, diacetyl, benzoin, o-toluoin, p-toluoin, anisoin, benzoin methyl ether, benzoin ethyl ether, benzoin i-propyl ether, acetophenone , p-dimethylaminoacetophenone, α, α'-dimethoxyacetoxybenzophenone, 4,4-bis- (diethylanino) -benzophenone, 2,2'-dimethoxy-2-phenylacetophenone, p-methoxyacetophenone, 2-methyl- [4- (methylthio) phenyl] -2-morpholino-1-propanone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl Butan-1-one, anthraquinone, 1,4-naphthoquinone, phenacylchloride, tribromomethylphenylsulfone, tris (trichloromethyl) -s-triazine, 2,4,6-trimethylbenzoyldiphenyl Phosphine oxide, bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide, benzoyl peroxide, di-t-butyl peroxide and the like.

The amount of the photoinitiator used in the present invention is preferably 0.1 to 15 parts by weight, more preferably 1.0 to 10 parts by weight based on 100 parts by weight of the acrylic copolymer. By using within this range, the photosensitive resin composition excellent in the balance of the heat resistance of solvent, solvent resistance, and controllability of the pattern shape after image development is provided.

[ Silane Coupling agent ]

In order to improve the adhesiveness with a board | substrate, the silane coupling agent which uses reactive functional groups, such as a carboxyl group, a methacryloyl group, an isocyanate group, and an epoxy group, is mentioned, More specifically, a trimethoxysilyl Benzoic acid, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, vinyltrimethoxysilane, γ-isocyanatepropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, 2- (3 ', 4'-epoxycyclohexyl) ethyltrimethoxysilane and the like can be given. A silane coupling agent can be used individually or in mixture of 2 or more types. The blending amount is preferably 10 parts by weight or less based on 100 parts by weight of the acrylic copolymer].

[ Leveling agent , Such as heat-resistant alloys  Other additives]

The photosensitive resin composition of this invention can contain 0.1-15 weight part of additives other than the said component as needed in the range which does not impair the desired effect of this invention. As said additive, the leveling agent for improving applicability | paintability is mentioned. As a commercial item of the said leveling agent, for example, R-08, R-475, R-30 (made by DIC Corporation), BM-1000, BM-1100 (made by BM CHEMIE company), Flolide FC-135, and copper FC- 170C, East FC-430, East FC-431 (manufactured by Sumitomo 3M Co., Ltd.), Supron S-112, East S-113, East S-131, East S-141, East S-145, East S- 382, East SC-101, East SC-102, East SC-103, East SC-104, East SC-105, East SC-106 (manufactured by Asahi Glass Co., Ltd.), SH-28 PA, SH-190, SH And fluorine-based or silicon-based surfactants such as -193, SZ-6032, SF-8428, DC-57, and DC-190 (manufactured by Toray Silicone Co., Ltd.). These leveling agents can be used individually or in mixture of 2 or more types. The leveling agent compounding amount is preferably in the range of 5 parts by weight or less based on 100 parts by weight of the copolymer [A].

In addition to the above additives, a photosensitizer, a thermal polymerization inhibitor, an antifoaming agent, and the like may be used as necessary.

When the highly sensitive photosensitive resin composition which concerns on this invention is used, the pattern excellent in intensity | strength and heat resistance can be formed to a uniform height even with a small irradiation amount. Therefore, when the composition of the present invention is used, the spacer of the large-screen liquid crystal display panel can be formed in a short photosensitive time, and thus there is an advantage in that the production efficiency can be significantly increased.

Hereinafter, the present invention will be described in detail with reference to Examples. However, embodiments according to the present invention may be modified in many different forms, and the scope of the present invention should not be construed as being limited to the embodiments described below.

Synthesis Example 1

2 parts by weight of octyl mercaptan, 2 parts by weight of 2,2'-azobis (2,4-dimethylvaleronitrile), 200 parts by weight of propylene glycol monomethyl ether acetate Part, 25 parts by weight of 2-carboxyethyl acrylate, 20 parts by weight of N-phenylmaleimide, 25 parts by weight of adamantyl methacrylate, and 10 parts by weight of styrene were added, the air in the flask was replaced with nitrogen, and the solution was gradually stirred. The temperature was raised to 60 ° C. and maintained at this temperature for 5 hours to polymerize to obtain a solution of copolymer [A-1]. Mw of the copolymer [A-1] was 15,000.

Synthesis Example 2

2 parts by weight of octyl mercaptan, 1.5 parts by weight of 2,2'-azobis (2,4-dimethylvaleronitrile), 200 parts by weight of propylene glycol monomethyl ether acetate 20 parts by weight of methacrylic acid, 25 parts by weight of N-phenylmaleimide, 20 parts by weight of adamantyl methacrylate, 30 parts by weight of 2-hydroxyethyl methacrylate, 10 parts by weight of styrene, and air in the flask After substituting with nitrogen, the temperature of the solution was raised to 60 DEG C while slowly stirring, and the polymerization was carried out while maintaining the temperature for 5 hours to obtain a solution of copolymer [A-2]. Mw of the copolymer [A-2] was 10,000.

Synthesis Example 3

2 parts by weight of octyl mercaptan, 1 part by weight of 2,2'-azobis (2,4-dimethylvaleronitrile), 200 parts by weight of propylene glycol monomethyl ether acetate 10 parts by weight of 25 parts by weight of 2-carboxyethyl acrylate, 20 parts by weight of N-phenylmaleimide, 15 parts by weight of adamantyl methacrylate, 2-hydroxyethyl methacrylate, 10 parts by weight of styrene and a flask After replacing the air with nitrogen, the temperature of the solution was raised to 60 DEG C while slowly stirring, and the polymerization was carried out while maintaining the temperature for 5 hours to obtain a solution of copolymer [A-3]. Mw of the copolymer [A-3] was 6,000.

Synthesis Example 4

2 parts by weight of octyl mercaptan, 2 parts by weight of 2,2'-azobis (2,4-dimethylvaleronitrile), 200 parts by weight of propylene glycol monomethyl ether acetate 20 parts by weight of 25 parts by weight of methacrylic acid, 15 parts by weight of N-phenylmaleimide, 20 parts by weight of adamantyl methacrylate, 2-hydroxyethyl methacrylate, 5 parts by weight of styrene, and air in the flask After substituting with nitrogen, the temperature of the solution was raised to 80 DEG C while stirring slowly, and the polymerization was carried out while maintaining the temperature for 3 hours to obtain a solution of copolymer [A-4]. Mw of the copolymer [A-4] was 21,000.

Synthesis Example 5

2 parts by weight of octyl mercaptan, 2.5 parts by weight of 2,2'-azobis (2,4-dimethylvaleronitrile), 200 parts by weight of propylene glycol monomethyl ether acetate Part, 25 parts by weight of 2-carboxyethyl acrylate, 20 parts by weight of N-phenylmaleimide, 25 parts by weight of adamantyl methacrylate, 5 parts by weight of styrene were added, the air in the flask was replaced with nitrogen, and the solution was gradually stirred. The temperature of was raised to 80 ° C and polymerization was carried out while maintaining this temperature for 3 hours to obtain a solution of copolymer [A-5]. Mw of the copolymer [A-5] was 31,000.

Synthesis Example 6

2 parts by weight of octyl mercaptan, 2 parts by weight of 2,2'-azobis (2,4-dimethylvaleronitrile), 200 parts by weight of propylene glycol monomethyl ether acetate Part, 25 parts by weight of 2-carboxyethyl acrylate, 25 parts by weight of N-phenylmaleimide, 15 parts by weight of adamantyl methacrylate, 5 parts by weight of styrene were added, the air in the flask was replaced with nitrogen, and the solution was gradually stirred. The temperature was raised to 60 ° C. and maintained at that temperature for 2 hours to polymerize to obtain a solution of copolymer [A-6]. Mw of the copolymer [A-6] was 12,000.

Synthesis Example 7

2 parts by weight of octyl mercaptan, 1 part by weight of 2,2'-azobis (2,4-dimethylvaleronitrile), 200 parts by weight of propylene glycol monomethyl ether acetate Part, 25 parts by weight of 2-carboxyethyl acrylate, 15 parts by weight of N-phenylmaleimide, 20 parts by weight of adamantyl methacrylate, 30 parts by weight of 2-hydroxyethyl methacrylate, 10 parts by weight of styrene and a flask After replacing the air with nitrogen, the temperature of the solution was raised to 80 DEG C while stirring slowly, and the polymerization was carried out while maintaining the temperature for 5 hours to obtain a solution of copolymer [A-7]. Mw of the copolymer [A-7] was 14,000.

Synthesis Example 8

2 parts by weight of octyl mercaptan, 1.5 parts by weight of 2,2'-azobis (2,4-dimethylvaleronitrile), 200 parts by weight of propylene glycol monomethyl ether acetate 20 parts by weight of methacrylic acid, 20 parts by weight of N-phenylmaleimide, 10 parts by weight of adamantyl methacrylate, 30 parts by weight of 2-hydroxyethyl methacrylate, 5 parts by weight of styrene, and air in the flask After substituting with nitrogen, the temperature of the solution was raised to 80 DEG C while stirring slowly, and the polymerization was carried out while maintaining the temperature for 5 hours to obtain a solution of copolymer [A-8]. Mw of the copolymer [A-8] was 16,000.

(Example 1)

Preparation of Photosensitive Resin Composition

100 parts by weight (solid content) of the copolymer [A-1] solution obtained in Synthesis Example 1, 70 parts by weight of the polyfunctional monomer [B], 7 parts by weight of the photoinitiator [C] and other additives in a mixing vessel equipped with a sunscreen and a stirrer. 0.1 parts by weight of γ-glycidoxypropyltrimethoxysilane and 0.1 parts by weight of BM-1100 were added, followed by addition of propylene glycol monomethyl ether acetate as a solvent. The amount of solvent was adjusted so that the viscosity of the composition was 15 cPs. Subsequently, it filtered with the Millipore filter of 0.2 micrometer of pore diameters, and produced the photosensitive resin composition. Specific composition components and composition ratios are summarized in Table 1.

Spacer  formation

After spin-coating or slit-coating the said photosensitive resin composition solution on one surface of a transparent substrate, a thin film is formed by heating (prebaking) an application surface.

As the transparent substrate used for forming the spacer, a glass substrate was used, and after the composition was applied, prebaking was performed at 100 ° C. for 90 seconds, and then the thin film formed was exposed through a photomask having a pattern of 10 μm. . After exposure, after developing at 25 degreeC for 60 second with 0.042 weight% of potassium hydroxide aqueous solution, it wash | cleaned for 1 minute with pure water, and heated for 30 minutes in 230 degreeC oven, and formed the spacer.

(Example 2)

The solution of the copolymer [A-2] obtained in Synthesis Example 2 and the other composition components were carried out as in Example 1 with different composition ratios. Specific composition components and their composition ratios are summarized in Table 1.

(Example 3)

The solution of the copolymer [A-3] obtained in Synthesis Example 3 and the other composition components were carried out as in Example 1 with different composition ratios. Specific composition components and their composition ratios are summarized in Table 1.

(Example 4)

The solution of the copolymer [A-4] obtained in Synthesis Example 4 and the other composition components were carried out as in Example 1 with different composition ratios. Specific composition components and their composition ratios are summarized in Table 1.

(Example 5)

The solution of the copolymer [A-5] obtained in Synthesis Example 5 and the other composition components were carried out as in Example 1 with different composition ratios. Specific composition components and their composition ratios are summarized in Table 1.

(Example 6)

The solution of the copolymer [A-6] obtained in Synthesis Example 6 and the other composition components were carried out as in Example 1 with different composition ratios. The composition ratio is summarized in Table 1.

(Example 7)

The solution of the copolymer [A-7] obtained in Synthesis Example 7 and the other composition components were carried out as in Example 1 with different composition ratios. Specific composition components and their composition ratios are summarized in Table 1.

(Example 8)

The solution of the copolymer [A-8] obtained in Synthesis Example 8 and the other composition components were carried out as in Example 1 with different composition ratios. Specific composition components and their composition ratios are summarized in Table 1.

(Comparative Example 1)

2-dimethylamino-2- (4-methyl-benzyl) -1- (4-morpholin-4-yl-phenyl) -butan-1-one as an acetophenone photoinitiator in place of an oxime photoinitiator as a photoinitiator. : 3 parts by weight of Iga Guru I-369, Ciba Special Chemicals) and 4 parts by weight of 4,4-bis- (diethylanino) -benzophenone (product name: Hycure EMK, Kemax), a benzophenone-based photoinitiator Except that it was carried out as in Example 1. Specific composition components and their composition ratios are summarized in Table 1.

(Comparative Example 2)

 2-dimethylamino-2- (4-methyl-benzyl) -1- (4-morpholin-4-yl-phenyl) -butan-1-one as an acetophenone photoinitiator instead of an oxime photoinitiator Using 4 parts by weight of Guar I-369, Ciba Special Chemicals) and 3 parts by weight of 4,4-bis- (diethylanino) -benzophenone (product name: Haicure EMK, Kemax), a benzophenone-based photoinitiator Except that was carried out as in Example 2. Specific composition components and their composition ratios are summarized in Table 1.

<Table 1>

Copolymer A Polyfunctional Monomer [B] Photoinitiator [C] Copolymer Parts by weight Kinds Parts by weight Kinds Parts by weight Example 1 A-1 100 [B-1] + [B-2] 20 + 50 [C-1] + [C-2] + [C-3] 5 + 1 + 1 Example 2 A-2 100 [B-1] + [B-2] 40 + 30 [C-1] + [C-2] + [C-3] 6 + 0.5 + 0.5 Example 3 A-3 100 [B-1] + [B-2] 20 + 50 [C-1] + [C-2] + [C-3] 6 + 0 + 1 Example 4 A-4 100 [B-1] + [B-2] 30 + 40 [C-1] + [C-2] + [C-3] 4 + 2 + 1 Example 5 A-5 100 [B-1] + [B-2] 0 + 100 [C-1] + [C-2] + [C-3] 6 + 0 + 1 Example 6 A-6 100 [B-1] + [B-2] 20 + 50 [C-1] + [C-2] + [C-3] 7 + 0 + 0 Example 7 A-7 100 [B-1] + [B-2] 10 + 60 [C-1] + [C-2] + [C-3] 5 + 1 + 1 Example 8 A-8 100 [B-1] + [B-2] 20 + 50 [C-1] + [C-2] + [C-3] 6 + 1 + 0 Comparative Example 1 A-1 100 [B-1] + [B-2] 20 + 50 [C-1] + [C-2] + [C-3] 0 + 3 + 4 Comparative Example 2 A-2 100 [B-1] + [B-2] 40 + 30 [C-1] + [C-2] + [C-3] 0 + 4 + 3

Components [B] and [C] used in the preparation of the photosensitive compositions of Examples 1 to 8 and Comparative Examples 1 to 2 are as follows.

[B-1]: Poly (oxy-1,2-ethananeyl) (Product Name: Kayarard DPEA-12, Nippon Kayaku Co., Ltd.),

[B-2]: dipentaerythritol hexaacrylate (product name: Aronix M402, Toa Kosei Co., Ltd.)

[C-1]: Ethanone-1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl] -1- (O-acetyloxime) (product name: Igagyu OXE- 02, Shiba Special Chemicals)

[C-2]: 2-Dimethylamino-2- (4-methyl-benzyl) -1- (4-morpholin-4-yl-phenyl) -butan-1-one (Product Name: Igaguar I-369, Shiba Special Chemicals)

[C-3]: 4,4-bis- (diethylanino) -benzophenone (Product Name: Haicure EMK, Kemax)

Evaluation

Subsequently, various evaluation was performed in the following way. The evaluation results are shown in Table 2.

(1) Evaluation of elastic recovery rate

With respect to the obtained spacer, using a micro-compression tester (trade name DUH-W201, manufactured by Shimadzu Seisakusho Co., Ltd.), a load of up to 20 mN was loaded and held for 5 seconds by a flat indenter having a diameter of 50 µm, and then removed. The load deflection curve at the time of loading and the load deflection curve at the time of unloading were prepared. At this time, as shown in Table 3, the elastic recovery rate was calculated by the following equation, with the deformation amount at load 20 mN under load as L1 and the deformation amount during unloading as L2.

[Elastic recovery rate (%) = L2 × 100 / L1]

The elastic recovery rate (%) and the deformation amount L1 (µm) are shown in Table 2.

When deformation amount L1 is 0.4 micrometer or less, it can be said that rigid elasticity is favorable.

(2) evaluation of heat resistance

Except not using a photomask, after forming a cured film similarly to the formation of the said spacer, it heats further for 30 minutes in 230 degreeC oven, measures the film thickness before and behind further heating, and measures the remaining film ratio (film after further heating) Thickness x 100 / film thickness before additional heating). When the residual film ratio is 90% or more, it can be said to be good.

(3) Evaluation of storage stability

The change rate of the viscosity when the photosensitive resin composition was left to stand in 40 degreeC thermostat for 1 week was measured. When the increase rate of a viscosity is less than 5%, storage stability is favorable, and when 5% or more, it can be said that storage stability is poor.

(4) evaluation of sensitivity

When a spacer was formed by the photolithography process, the exposure amount which the spacer thickness after postbaking becomes uniform was made into the sensitivity. This exposure amount 80mJ / cm ² When it is below, it can be said that a sensitivity is favorable. In the comparative example, since the exposure amount for obtaining a spacer having similar physical properties is up to 4 times or more, the photosensitive resin composition of the present invention can significantly reduce the photosensitive time while obtaining a spacer having excellent physical properties.

<Table 2>

Sensitivity Elastic recovery rate evaluation Heat resistance Storage stability mJ / cm2 Elastic recovery rate (%) Displacement amount [L1] [μm μm] (%) (%) Example 1 60 72 0.3 95 0.8 Example 2 50 70 0.32 96 0.9 Example 3 150 42 0.58 84 1.1 Example 4 100 52 0.51 91 0.7 Example 5 50 68 0.33 96 1.2 Example 6 40 74 0.3 97 1.1 Example 7 60 72 0.33 96 0.9 Example 8 50 72 0.31 96 0.9 Comparative Example 1 240 38 0.52 91 0.7 Comparative Example 2 210 40 0.54 91 0.9

<Table 3>

Claims (7)

i) an acryl-based copolymer consisting of cycloalkyl or cycloalkenyl acrylic ester of acrylic carboxylic acid + polycyclic structure + acrylic alkyl ester + vinyl aromatic compound; ii) acrylic polyfunctional monomers; iii) O-acyl oxime photoinitiators; And iv) a photosensitive resin composition for producing an LCD spacer comprising a silane coupling agent. The photosensitive resin composition according to claim 1, comprising 10 to 150 parts by weight of the acrylic polyfunctional monomer, 0.1 to 15 parts by weight of the photoinitiator, and 1 to 20 parts by weight of the silane coupling agent, based on 100 parts by weight of the acrylic copolymer. The photosensitive resin composition of claim 1, wherein the acrylic copolymer further comprises an acrylic cyclic ester monomer. The photosensitive resin composition according to claim 3, further comprising acetophenones or benzophenone photoinitiators other than O-acyl oxime compounds in the range of 70% by weight or less of the photoinitiator total weight. The photosensitive resin composition for manufacturing an LCD spacer according to claim 3, further comprising 0.1 to 5 parts by weight of a leveling agent based on 100 parts by weight of the acrylic copolymer. According to claim 3, wherein the content of the acrylic carboxylic acid monomer in the acrylic copolymer is 5 to 50 by weight and the content of the polycyclic cycloalkyl or cycloalkenyl acrylic ester and the acrylic cyclic ester monomer in total 10 to 70 The photosensitive resin composition for manufacturing an LCD spacer having a weight, the content of the acrylic alkyl ester monomer is 10 to 40 weight, and the content of the monomer belonging to the vinyl aromatic monomer is 5 to 25 weight. 4. The method of claim 3 wherein the acrylic carboxylic acid monomer in the copolymer is acrylic acid, methacrylic acid or 2-carboxyethyl acrylate and the acrylic cyclic ester monomer is glycidyl methacrylate and the polycyclic cycloalkyl or Cycloalkenyl acrylate ester is adamantyl methacrylate or dicyclopentenyl methacrylate and the acrylic alkyl ester monomer is methyl methacrylate, t-butyl methacrylate or lauryl methacrylate and the vinyl aromatic monomer is styrene photosensitive resin composition for manufacturing an LCD spacer which is α-methylstyrene or p-methoxystyrene