JP2006220701A - Photosensitive resin composition, cured material thereof and spacer for display panel comprising the cured material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photosensitive resin composition free of viscosity increase and gelatinization even under room temperature storage conditions, having satisfactory storage stability, and capable of forming a spacer for a display panel having both heat and chemical resistances necessary as a permanent film and excellent in compressive strength, and to provide a cured material of the composition and a spacer for a display panel. <P>SOLUTION: The photosensitive resin composition contains (A) a carboxylic photosensitive resin having both one carboxyl group and at least two ethylenically unsaturated bonds per molecule, (B) a polymerizable compound having one or more ethylenically unsaturated bonds per molecule, (C) a photopolymerization initiator and (D) an oxetane compound having at least two oxcetanyl groups per molecule, wherein the carboxylic photosensitive resin (A) contains a compound having an unsaturated double bond represented by formula (1) as a copolymerized component. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a photosensitive resin composition, a cured product thereof, and a spacer for a display panel made of the cured product. More specifically, a photosensitive resin composition excellent in storage stability and compression strength suitable as a material for forming a display panel spacer such as a liquid crystal panel or a touch panel, and a cured product thereof, and a display panel comprising the cured product Regarding spacers.

  Conventionally, liquid crystal panels have used spacer particles such as glass beads and plastic beads having a predetermined particle size in order to keep the distance between two substrates constant. However, since these spacer particles are randomly distributed on the glass substrate, if the spacer is present in the effective pixel portion, the spacer is reflected or the incident light is scattered and the contrast of the liquid crystal panel is lowered. There was a problem. In order to solve these problems, a method is used in which a spacer is formed by photolithography using a photosensitive resin composition.

  Such a spacer is required to withstand the compressive load when the liquid crystal panel is attached. However, spacers formed using a conventional photosensitive resin composition composed of a photosensitive resin, a polyfunctional monomer, and a photopolymerization initiator are insufficient in hardness, and the color filter and the TFT array substrate are assembled. There was a problem that the amount of plastic deformation under high temperature and high pressure during (cell pressure bonding) was large, which hindered the function as a spacer, and there was still room for improvement.

  Further, since the spacer is used as a permanent film in the liquid crystal panel, heat resistance and chemical resistance are also required. Therefore, a thermosetting resin (see Patent Document 1) having both a carboxyl group and an epoxy group in the same molecule is used for the photosensitive resin composition used for this purpose in order to obtain characteristics as a permanent film. In some cases, a crosslinking agent such as an epoxy resin capable of reacting with the binder resin is added (see Patent Document 2). However, in the case of a photosensitive resin composition using an epoxy-based cross-linking agent, because of the high reactivity of the epoxy group that causes a cross-linking reaction, there are problems such as storage stability becoming a problem and reducing workability. It was difficult to achieve both the properties of the cured product and workability.

JP-A-11-133600 (Claims) JP 2001-324809 A (Claims)

  The present invention has been made on the basis of the circumstances as described above, and the purpose thereof is to prevent the photosensitive resin composition from increasing in viscosity or gelation even under storage conditions at room temperature, and has sufficient storage stability. The present invention also provides a photosensitive resin composition capable of forming a display panel spacer having both heat resistance and chemical resistance necessary for a permanent film and having excellent compressive strength. Another object of the present invention is to provide a cured product obtained by irradiating the photosensitive resin composition with active energy rays and heating and curing, and a display panel spacer formed from the cured product.

The inventors have conducted extensive research to achieve the above object, and as a result, the basic mode is (A) containing a carboxyl group having both a carboxyl group and at least two ethylenically unsaturated bonds in one molecule. Photosensitive resin, (B) a polymerizable compound having one or more ethylenically unsaturated bonds in one molecule, (C) a photopolymerization initiator, and (D) having at least two oxetanyl groups in one molecule. A composition containing an oxetane compound, wherein the carboxyl group-containing photosensitive resin (A) is represented by the following general formula (1):


In the formula, x represents an integer of 0 to 2, R ¹ represents hydrogen or a methyl group, R ² represents a dicyclopentadiene derivative having 10 to 20 carbon atoms, or a tricyclodecane derivative having 10 to 20 carbon atoms. .

A photosensitive resin composition characterized by being a carboxyl group-containing photosensitive resin containing a compound having an unsaturated double bond as a copolymerization component has excellent storage stability, and the photosensitive resin composition is cured. The cured product thus obtained was found to be excellent in hardness, heat resistance, chemical resistance and compressive strength, and the present invention was completed.

Further, according to the present invention, a coating film forming step for applying and drying the photosensitive resin composition, a photocuring treatment step for selectively irradiating the coating film obtained through the coating film forming step with active energy rays, There is provided a cured product obtained through an alkali development step of removing a non-irradiated portion using an alkali developer after the photocuring treatment step, and a step of heating and curing the pattern obtained in the alkali development step.
In the present invention, “active energy rays” mean those including visible light, ultraviolet rays, far ultraviolet rays, electron beams, X-rays and the like.
Furthermore, according to the present invention,

  Furthermore, according to this invention, the spacer for display panels which consists of hardened | cured material which is excellent in the heat resistance and chemical resistance obtained using the said photosensitive resin composition, and also excellent in compressive strength is provided.

  Since the photosensitive resin composition of the present invention is a curing system containing an oxetane compound as a crosslinking component, it has excellent storage stability, and the resulting cured product has sufficient heat resistance and chemical resistance. That is, the photosensitive resin composition of the present invention has no problem of poor storage stability when using an epoxy resin as a conventional crosslinking component, and is a cured product excellent in various properties such as heat resistance and chemical resistance. Can be formed. Furthermore, since the photosensitive resin composition of the present invention gives a cured product having excellent transparency, it is effective for applications such as spacers and planarization films. In addition, since it is excellent in storage stability, it is excellent in workability, and it is very useful in terms of economy, such as reduction of the disposal of the photosensitive resin composition due to the end of life.

  The oxetane compound added as a crosslinking component to the photosensitive composition of the present invention has a four-membered oxetanyl group, which reacts with the carboxyl group of the alkali-soluble photosensitive resin during heat curing, and is mainly a primary hydroxyl group. Therefore, a cured product having excellent adhesion can be obtained as compared with the case of using an epoxy resin that mainly generates a secondary hydroxyl group. In addition, since the oxetane compound has a slower reaction at a low temperature than the epoxy resin, the photosensitive composition containing the oxetane compound has a long shelf life, which is advantageous in terms of workability and economy.

Hereinafter, each component of the photosensitive composition of this invention is demonstrated in detail.
The carboxyl group-containing photosensitive resin (A) having both a carboxyl group and at least two ethylenically unsaturated bonds in the molecule of the present invention is represented by the following general formula (1).



In the formula, x represents an integer of 0 to 2, R ¹ represents hydrogen or a methyl group, R ² represents a dicyclopentadiene derivative having 10 to 20 carbon atoms, or a tricyclodecane derivative having 10 to 20 carbon atoms. .

A carboxyl group-containing photosensitive resin containing a compound having an unsaturated double bond as a copolymerization component.
Such a carboxyl group-containing photosensitive resin (A) contains a compound having an unsaturated double bond represented by the general formula (1) as a constituent component, whereby the glass transition temperature can be improved, and transparency. Therefore, the hardness, compression strength, heat resistance, and chemical resistance of a cured product obtained from the photosensitive resin composition using the same can be remarkably improved.

  Such a carboxyl group-containing photosensitive resin (A) is not limited to a specific one, but is particularly preferably a photosensitive resin synthesized by copolymerization of unsaturated monomers as listed below. it can.

(1) Co-weight containing (a) an unsaturated carboxylic acid and (b) a compound having an unsaturated double bond represented by the general formula (1) or (c) another compound having an unsaturated double bond A carboxyl group-containing photosensitive resin obtained by adding an ethylenically unsaturated group as a pendant to the coalescence,
(2) (d) a compound having an epoxy group and an unsaturated double bond, and (b) a compound having an unsaturated double bond represented by the general formula (1), or (c) another unsaturated double bond A carboxyl group-containing photosensitivity obtained by reacting a copolymer containing a compound having (a) an unsaturated carboxylic acid and reacting the resulting secondary hydroxyl group with (e) a saturated or unsaturated polybasic acid anhydride. Resin,
(3) (f) an acid anhydride having an unsaturated double bond and (b) a compound having an unsaturated double bond represented by the general formula (1) or (c) another unsaturated double bond. Examples thereof include (g) a carboxyl group-containing photosensitive resin obtained by reacting a compound having a compound with a compound having a hydroxyl group and an unsaturated double bond.

Examples of the unsaturated carboxylic acid (a) used in the synthesis of the carboxyl group-containing photosensitive resins (1) and (2) include acrylic acid, methacrylic acid, itaconic acid, β-carboxylethyl acrylate, and β-carboxylethyl methacrylate. And a compound obtained by adding a polybasic acid anhydride to a hydroxyl group-containing (meth) acrylate. Among these, acrylic acid or methacrylic acid is particularly preferable from the viewpoints of photosensitivity, reactivity, and storage stability. These unsaturated monocarboxylic acids (a) may be used alone or in admixture of two or more.
In this specification, (meth) acrylate is a general term for acrylate and methacrylate, and the same applies to other similar expressions.

  Specific examples of the compound (b) having an unsaturated double bond represented by the general formula (1), which is a feature of the carboxyl group-containing photosensitive resin of the present invention, include dicyclopentenyl (meth) acrylate and di Examples thereof include cyclopentenyloxyethyl (meth) acrylate and dicyclopentanyl (meth) acrylate. Examples of commercially available products include FANCLIL FA-511A, FA-512A, FA-513A, FA-512M, and FA-513M manufactured by Hitachi Chemical Co., Ltd.

  As the compound (c) having another unsaturated double bond used for the synthesis of the carboxyl group-containing photosensitive resins (1), (2) and (3), known and commonly used monofunctional monomers can be used. For example, styrene, chlorostyrene, α-methylstyrene; methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, t-butyl, amyl, 2-ethylhexyl, octyl, capryl, nonyl, dodecyl, hexadecyl, octadecyl as substituents Acrylate, methacrylate or fumarate having a substituent such as cyclohexyl, isobornyl, methoxyethyl, butoxyethyl, 2-hydroxyethyl, 2-hydroxypropyl, 3-chloro-2-hydroxypropyl; polyethylene glycol monoacrylate or monomethacrylate, Or polypropylene glycol monoacrylate, monomethacrylate; vinyl acetate, vinyl butyrate or vinyl benzoate; olefins such as ethylene and propylene; acryloni Like Lil, etc.

  As the compound (d) having an epoxy group and an unsaturated double bond used for the synthesis of the carboxyl group-containing photosensitive resin (2), glycidyl (meth) acrylate, β-methylglycidyl (meth) acrylate, β-ethyl Glycidyl (meth) acrylate, N- [4- (2,3-epoxypropoxy) -3,5-dimethylbenzyl] acrylamide, N- [4- (2,3-epoxypropoxy) -3,5-dimethylbenzyl] Examples include methacrylamide, glycidyl crotonate, and 3,4-epoxycyclohexylmethyl (meth) acrylate. Among these, glycidyl (meth) acrylate is preferable from the viewpoint of reactivity.

  Examples of the saturated or unsaturated polybasic acid anhydride (e) used for the synthesis of the carboxyl group-containing photosensitive resin (2) include methyltetrahydrophthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydro Aliphatic dibasic acid anhydrides such as phthalic anhydride, nadic anhydride, 3,6-endomethylenetetrahydrophthalic anhydride, methylendomethylenetetrahydrophthalic anhydride, tetrabromophthalic anhydride; succinic anhydride, maleic anhydride, Aliphatic or aromatic polybasic acid anhydrides such as itaconic anhydride, octenyl succinic anhydride, pentadodecenyl succinic anhydride, phthalic anhydride, trimellitic anhydride, etc. are used, and one or more of these are used can do. Among these, alicyclic dibasic acid anhydrides are particularly preferable from the viewpoint of developability.

  Examples of the acid anhydride (f) having an unsaturated double bond used for the synthesis of the carboxyl group-containing photosensitive resin (3) include maleic anhydride, itaconic anhydride, and pyromellitic anhydride and 2-hydroxyethyl anhydride. Examples include partial reaction products with unsaturated compounds having a hydroxyl group such as hydroxyalkyl (meth) acrylates such as (meth) acrylate and 2-hydroxypropyl (meth) acrylate, and these may be used alone or in combination of two or more. They can be used in combination. Among these, maleic anhydride capable of stably synthesizing a polymer is preferable.

  Examples of the compound (g) having a hydroxyl group and an unsaturated double bond used for the synthesis of the carboxyl group-containing photosensitive resin (3) include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4 -Hydroxyalkyl (meth) acrylates such as hydroxybutyl (meth) acrylate; diethylene glycol mono (meth) acrylate, dipropylene glycol mono (meth) acrylate, trimethylolpropane di (meth) acrylate, glycerin di (meth) acrylate, Examples include pentaerythritol tri (meth) acrylate and dipentaerythritol penta (meth) acrylate. Furthermore, a compound obtained by adding a cyclic ester such as ε-caprolactone to the hydroxyl group of the above compound can also be used. These can be used alone or in combination of two or more.

  Such a carboxyl group-containing photosensitive resin (A) may be used alone or as a mixture, but in any case, these are in total 5 to 80% by mass, preferably 10 to 60% by mass of the total amount of the composition. It is preferable to mix | blend in the ratio of%. Furthermore, if necessary, a small amount of a carboxyl group-containing photosensitive resin other than the above, for example, a resin obtained by adding a polybasic acid anhydride to epoxy acrylate can be added.

The acid value of the said carboxyl group-containing photosensitive resin (A) is 30-250 mgKOH / g, Preferably it is 50-150 mgKOH / g. When the acid value of the carboxyl group-containing photosensitive resin is less than 30 mg KOH / g, sufficient curing reaction with the oxetane compound (D) is difficult to proceed, and insufficient solubility in an alkaline aqueous solution results in poor development. It tends to occur. On the other hand, if it exceeds 250 mgKOH / g, it is not preferred because deterioration of the adhesion of the film and dissolution of the photocured part (exposed part) occur during development.
Further, the double bond equivalent of the carboxyl group-containing photosensitive resin (A) is suitably 350 to 2,000, preferably 400 to 1,500. When the double bond equivalent of the carboxyl group-containing photosensitive resin (A) is less than 350, it is not preferable because the storage stability is lowered and the strength of the cured product becomes brittle. On the other hand, when the double bond equivalent exceeds 2,000, the work margin during development is narrow, and a high exposure amount is required during photocuring, which is not preferable.

  As the polymerizable compound (B) having one or more ethylenically unsaturated bonds in one molecule used in the present invention, a monofunctional, bifunctional, or trifunctional or higher (meth) acrylate has good polymerizability. In addition, it is preferably used because the strength and heat resistance of the obtained spacer are improved.

  Examples of the monofunctional (meth) acrylate include 2-hydroxyethyl (meth) acrylate, carbitol (meth) acrylate, isobornyl (meth) acrylate, 3-methoxybutyl (meth) acrylate, and 2- (meth) acryloyloxyethyl. And 2-hydroxypropyl phthalate. Examples of the commercially available products include Aronix M-101, M-111, M-114 (above, manufactured by Toagosei Co., Ltd.), KAYARAD TC-110S, TC-120S (above, Nippon Kayaku Co., Ltd.). Product), Biscoat 158, 2311 (manufactured by Osaka Organic Chemical Industry Co., Ltd.).

  Examples of the bifunctional (meth) acrylate include ethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, and polypropylene glycol di (meth) acrylate. , Tetraethylene glycol di (meth) acrylate, bisphenoxyethanol full orange acrylate, and the like. Examples of commercially available products include Aronix M-210, M-240, M-6200 (above, manufactured by Toagosei Co., Ltd.), KAYARAD HDDA, HX-220, R-604 (above, Nippon Kayaku). Manufactured by Co., Ltd.), Viscoat 260, 312 and 335HP (above, manufactured by Osaka Organic Chemical Industry Co., Ltd.).

  Examples of the trifunctional or higher functional (meth) acrylate include trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, tri ((meth) acryloyloxyethyl) phosphate, and pentaerythritol tetra (meth) acrylate. , Dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and the like. Examples of the commercially available products include Aronix M-309, M-400, M-402, M-405, M-450, M-7100, M-8030, M-8060, and M- 1310, same M-1600, same M-1960, same M-8100, same M-8530, same M-8560, same M-9050, same TO-1450 (above, manufactured by Toagosei Co., Ltd.), KAYARAD TMPTA, DPHA, DPCA-20, DPCA-30, DPCA-60, DPCA-120 (above, manufactured by Nippon Kayaku Co., Ltd.), Biscote 295, 300, 360, GPT, 3PA, 400 (manufactured by Osaka Organic Chemical Industry Co., Ltd.). These monofunctional, bifunctional, or trifunctional or higher (meth) acrylates are used alone or in combination.

  As a compounding quantity of these polymeric compounds (B), 5-100 mass parts is preferable with respect to 100 mass parts of said carboxyl group-containing photosensitive resin (A), Most preferably, it is 5-50 mass parts. When the component (B) is less than 5 parts by mass, sufficient curability cannot be obtained. On the other hand, when the amount is 100 parts or more, the dryness to touch becomes poor and the cured product becomes brittle, which is not preferable.

  As the photopolymerization initiator (C), known compounds that generate radicals upon irradiation with active energy rays can be used, for example, acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy. 2-phenylacetophenone, p-dimethylaminopropiophenone, dichloroacetophenone, trichloroacetophenone, p-tert-butyltrichloroacetophenone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1- [4- (methylthio) phenyl]- Acetophenones such as 2-morpholino-propan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1, N, N-dimethylaminoacetophenone; benzophenone, methylbenzophenone Benzophenones such as 2-chlorobenzophenone, 4,4′-dichlorobenzophenone, 4,4′-bisdimethylaminobenzophenone, 4,4′-bisdiethylaminobenzophenone, Michler's ketone, 4-benzoyl-4′-methyldiphenyl sulfide; benzyl Benzoin ethers such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzoin isobutyl ether; ketals such as acetophenone dimethyl ketal and benzyl dimethyl ketal; thioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, Thioxanthones such as 2,4-diethylthioxanthone and 2,4-diisopropylthioxanthone; 2-methylanthraquinone, 2- Anthraquinones such as tilanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone, 2-aminoanthraquinone and 2,3-diphenylanthraquinone; organic peroxides such as benzoyl peroxide and cumene peroxide; 2,4,5 -Thiol compounds such as triarylimidazole dimer, riboflavin tetrabutyrate, 2-mercaptobenzoimidazole, 2-mercaptobenzoxazole, 2-mercaptobenzothiazole; 2,4,6-tris-s-triazine, 2,2 , 2-tribromoethanol, tribromomethylphenylsulfone, and the like; 2,4,6-trimethylbenzoyldiphenylphosphine oxide and the like. Other examples include acridine compounds and oxime esters. These compounds can be used alone or in combination of two or more.

  Further, the photopolymerization initiator (C) as described above includes N, N-dimethylaminobenzoic acid ethyl ester, N, N-dimethylaminobenzoic acid isoamyl ester, pentyl-4-dimethylaminobenzoate, triethylamine, triethanolamine. Tertiary amines such as; thioethers such as β-thiodiglycol; sensitizing dyes such as (keto) coumarin and thioxanthene; alkylborates such as cyanine, rhodamine, safranine, malachite green, and methylene blue It can be used in combination with one or more of photosensitizers or accelerators.

  A preferable combination of the photopolymerization initiator (C) is 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one (for example, Irgacure 907 manufactured by Ciba Specialty Chemicals). ), 2-chlorothioxanthone (eg Nippon Kayaku Co., Ltd. Kayacure CTX) or 2,4-diethylthioxanthone (eg Nippon Kayaku Co., Ltd. Kayacure DETX), 2-isopropylthioxanthone, 4-benzoyl-4 ′ -Combination with methyldiphenyl sulfide and the like. Moreover, the suitable range of the usage-amount of the above photoinitiators (C) is 0.01-30 mass parts with respect to 100 mass parts of said carboxyl group-containing photosensitive resin (A), Preferably it is 0.00. It is the ratio which becomes 1-15 mass parts. When the blending ratio of the photopolymerization initiator is less than 0.01 parts by mass, the photocurability is deteriorated. On the other hand, when it is more than 30 parts by mass, the characteristics of the cured coating film are deteriorated, and the storage stability is improved. Since it gets worse, it is not preferable.

  As the oxetane compound (D), any compound can be used as long as it is an oxetane compound having two or more oxetanyl groups in one molecule, and is not limited to a specific compound. In view of the properties, those soluble in the organic solvent (E) described later are preferably used.

  Examples of the bifunctional oxetane compound include bisoxetanes represented by the following general formula (2).

In the general formula (2), R ³ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and R ⁴ represents an oxygen atom, a sulfur atom, or a linear or branched saturated hydrocarbon having 1 to 12 carbon atoms. , Linear or branched unsaturated hydrocarbons having 1 to 12 carbon atoms, aromatic hydrocarbons represented by the following formulas (I), (II), (III), (IV) and (V): Two atoms selected from linear or cyclic alkylenes containing carbonyl groups represented by (VI) and (VII), and aromatic hydrocarbons containing carbonyl groups represented by formulas (VIII) and (IX) It is a group with a valence. Examples of other bifunctional oxetane compounds include cardo type and naphthalene type.

In the formula, R ⁵ represents a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, an aryl group, or an aralkyl group, and R ⁶ represents —O—, —S—, —CH ₂ —, —NH—, — SO ₂ —, —CH (CH ₃ ) —, —C (CH ₃ ) ₂ —, or —C (CF ₃ ) ₂ — is represented, and R ⁷ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. .

In the formula, n represents an integer of 1 to 12.

As the polyfunctional oxetane compound, in addition to the compound represented by the following general formula (3), silicone resins such as oxetane alcohol and novolac resin, poly (hydroxystyrene), calixarene, or silsesquioxane are used. And etherified products with a hydroxyl group-containing resin. In addition, a copolymer of an unsaturated monomer having an oxetane ring and an alkyl (meth) acrylate is also included.

In the general formula (3), R ³ has the same meaning as described above, and R ⁸ represents a hydroxyl group-containing residue of the etherified product, the number of carbon atoms as shown by the following formulas (X), (XI), and (XII) 1 to 12 branched alkylene groups, aromatic hydrocarbons represented by the formulas (XIII), (XIV) and (XV). M represents the number of functional groups to which the residue R ⁸ is bonded, and is an integer of 3 or more, preferably an integer of 3 to 100.

In the formula, R ⁹ represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an aryl group having a substituent.

  The action of the oxetane compound (D) is to form a hardened material having improved chemical resistance and heat resistance by reacting with a carboxyl group in the carboxyl group-containing photosensitive resin to form a crosslinked structure. . The amount of the oxetane compound (D) is appropriately 5 to 100 parts by mass, preferably 15 to 60 parts by mass with respect to 100 parts by mass of the carboxyl group-containing photosensitive resin (A).

  In order to promote the reaction between the oxetane compound (D) and the carboxyl group in the carboxyl group-containing photosensitive resin (A), a reaction accelerator shown below can be added.

  The reaction accelerator can be arbitrarily selected from tertiary amines, imidazoles, quaternary onium salts, tertiary phosphines, phosphonium ylides, acetylacetone metal complexes, or crown ether complexes, You may use these individually or in combination of 2 or more types.

  The tertiary amine includes triethylamine, tributylamine, DBU (1,8-diazabicyclo [5.4.0] undec-7-ene), DBN (1,5-diazabicyclo [4.3.0] non-5- En), DABCO (1,4-diazabicyclo [2.2.2] octane), pyridine, N, N-dimethyl-4-aminopyridine and the like.

  Examples of imidazoles include imidazole, 2-methylimidazole, 2-undecylimidazole, 2-ethyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 2-phenylimidazole, Examples include isocyanuric acid adducts.

  Examples of the quaternary onium salt include ammonium salts, phosphonium salts, arsonium salts, stibonium salts, oxonium salts, sulfonium salts, selenonium salts, stannonium salts, iodonium salts, and the like. Particularly preferred are ammonium salts and phosphonium salts. Specific examples of the ammonium salt include tetra n-butylammonium chloride (TBAC), tetra n-butylammonium bromide (TBAB), tetra n-butylammonium iodide (TBAI), and the like. -Butyl ammonium acetate (TBAAc) etc. are mentioned. Specific examples of the phosphonium salt include tetra n-butylphosphonium halide (TBPC), tetra n-butylphosphonium bromide (TBPB), tetra n-butylphosphonium iodide (TBBI), tetraphenylphosphonium Examples include tetraphenylphosphonium halides such as chloride (TPPC), tetraphenylphosphonium bromide (TPPB), and tetraphenylphosphonium iodide (TPPI), ethyltriphenylphosphonium bromide (ETPPB), and ethyltriphenylphosphonium acetate (ETPPAc). .

  The tertiary phosphine may be a trivalent organic phosphorus compound having an alkyl group having 1 to 12 carbon atoms or an aryl group. Specific examples include triethylphosphine, tributylphosphine, triphenylphosphine and the like.

  Furthermore, a quaternary onium salt formed by an addition reaction between a tertiary amine or tertiary phosphine and a carboxylic acid or a strongly acidic phenol can also be used as a reaction accelerator. These may be any method in which a quaternary salt is formed before addition to the reaction system, or each is added separately to form a quaternary salt in the reaction system. Specific examples include tributylamine acetate obtained from tributylamine and acetic acid, and triphenylphosphine acetate formed from triphenylphosphine and acetic acid.

  As the phosphonium ylide, known compounds can be used as long as they are compounds obtained by the reaction of a phosphonium salt and a base, but a highly stable compound is preferred from the viewpoint of ease of handling. Specific examples include (formylmethylene) triphenylphosphine, (acetylmethylene) triphenylphosphine, (pivaloylmethylene) triphenylphosphine, (benzoylmethylene) triphenylphosphine, (p-methoxybenzoylmethylene) triphenyl. Phosphine, (p-methylbenzoylmethylene) triphenylphosphine, (p-nitrobenzoylmethylene) triphenylphosphine, (naphthoyl) triphenylphosphine, (methoxycarbonyl) triphenylphosphine, (diacetylmethylene) triphenylphosphine, (acetylcyano) ) Triphenylphosphine, (dicyanomethylene) triphenylphosphine, and the like.

  Examples of acetylacetone metal complexes include acetylacetone vanadium complex, acetylacetone chromium complex, acetylacetone manganese complex, acetylacetone iron complex, acetylacetone cobalt complex, acetylacetone nickel complex, and acetylacetone aluminum complex.

  The amount of these reaction accelerators used is desirably 0.1 to 25 mol%, more preferably 0.5 to 20 mol%, more preferably 1 to 1 mol of oxetanyl group. It is a ratio of ˜15 mol%. When the amount of the reaction accelerator used is less than 0.1 mol% with respect to the oxetanyl group, the reaction does not proceed easily at a practical rate. This is not preferable from the viewpoint of economy because no significant reaction promoting effect is observed.

  The photosensitive resin composition of this invention can use the (E) organic solvent in order to melt | dissolve the said photosensitive resin composition uniformly and to adjust a viscosity as needed. Particularly, the carboxyl group-containing photosensitive resin (A), a polymerizable compound (B) having one or more ethylenically unsaturated bonds in one molecule, a photopolymerization initiator (C), and an oxetane compound (D). Those that dissolve each component uniformly and do not react with each component are preferred. If the solubility of each component in the organic solvent (E) is low, it is difficult to uniformly dissolve, and it is difficult to ensure the transparency required for the spacer, which is not preferable.

  Specific examples of these organic solvents (E) include alcohols such as methanol and ethanol; ethers such as tetrahydrofuran; glycol ethers such as ethylene glycol monomethyl ether and ethylene glycol monoethyl ether; methyl cellosolve acetate, ethyl cellosolve acetate and the like. Ethylene glycol alkyl ether acetates; diethylene glycols such as diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol dimethyl ether; propylene glycol monoalkyl ethers such as propylene glycol methyl ether, propylene glycol ethyl ether, propylene glycol propyl ether, propylene glycol butyl ether Propylene glycol alkyl ether acetates such as propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, propylene glycol propyl ether acetate, propylene glycol butyl ether acetate; propylene glycol methyl ether propionate, propylene glycol ethyl ether propionate, propylene glycol Propylene glycol alkyl ether acetates such as propyl ether propionate and propylene glycol butyl ether propionate; aromatic hydrocarbons such as toluene and xylene; ketones such as methyl ethyl ketone and 4-hydroxy-4-methyl-2-pentanone; And methyl acetate, ethyl acetate, propyl acetate, vinegar Butyl, ethyl 2-hydroxypropionate, methyl 2-hydroxy-2-methylpropionate, ethyl 2-hydroxy-2-methylpropionate, methyl hydroxyacetate, ethyl hydroxyacetate, butyl hydroxyacetate, methyl lactate, ethyl lactate, lactic acid Propyl, butyl lactate, methyl 3-hydroxypropionate, ethyl 3-hydroxypropionate, propyl 3-hydroxypropionate, methyl 3-hydroxypropionate, ethyl 3-butoxypropionate, propyl 3-butoxypropionate, 3-butoxy Examples include esters such as butyl propionate.

  Of these organic solvents (E), glycol ethers, ethylene glycol alkyl ether acetates, esters and diethylene glycols are preferably used because of their solubility, reactivity with each component, and ease of formation of a coating film. It is done. These organic solvents (E) can be used alone or in admixture of two or more, and the amount used is not particularly limited, but usually 30 to 90% by mass in the photosensitive resin composition of the present invention. , Preferably it is the range used as 40-85 mass%.

The photosensitive resin composition of the present invention may contain other components in addition to the above as necessary, as long as the object of the present invention is not impaired.
For example, a surfactant for improving applicability can be mentioned. 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, the main chain and the side chain can be suitably used. , 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, perfluorododecylsulfonic acid sodium L, 1,1,2,2,8,8,9,9,10,10-decafluorododecane, 1,1,2,2,3,3-hexafluorodecane, sodium fluoroalkylbenzenesulfonate, fluoroalkyl Sodium phosphonate, sodium fluoroalkylcarboxylate, fluoroalkyl polyoxyethylene ether, diglycerin tetrakis (fluoroalkyl polyoxyethylene ether), fluoroalkyl ammonium iodide, fluoroalkyl betaine, fluoroalkyl polyoxyethylene ether, perfluoroalkyl poly Examples include oxyethanol, perfluoroalkyl alkoxylates, and fluorine-based alkyl esters.

  In addition, as these commercially available products, for example, BM-1000, BM-1100 (above, manufactured by BM CHEMIE), MegaFuck F142D, F172, F173, F183, F178, F191, F191, and F471 (above, 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 (above, Asahi Glass Ftop EF301, 303, 352 (above, manufactured by Shin-Akita Kasei Co., Ltd.), Footent FT-100, FT-110, FT- 40A, FT-150, FT-250, FT-251, FTX-251, FTX-218, FT-300, FT-310, FT-400S (above, manufactured by Neos Co., Ltd.) Etc. 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 Silicone Co., Ltd.), TSF-4440, TSF-4300, TSF-4445, TSF-4446, TSF-4460, TSF-4442 (above, Toshiba) Silicone Co., Ltd.), BYK-300, BYK-302, BYK-306, BYK-307, BYK-310, BYK-315, BYK-320, BYK-322, BYK-323, BYK-325, BYK-330 BYK-331, BYK-332, BYK-333, BYK 337, BYK-344, BYK-370, BYK-375 (or more, BYK Chemie Co., Ltd.) can be mentioned those that are commercially available under the trade names such as.

  In addition, polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, and polyoxyethylene oleyl ether; polyoxyethylene aryl ethers such as polyoxyethylene octylphenyl ether and polyoxyethylene nonylphenyl ether Nonionic surfactants such as polyoxyethylene dialkyl esters such as polyoxyethylene dilaurate and polyoxyethylene distearate; Organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.), (meth) acrylic acid copolymer Polymer polyflow No. 57, 95 (manufactured by Kyoeisha Yushi Chemical Co., Ltd.), BYK-352, BYK-354, BYK-355, BYK-356, BYK-357, BYK-35 8, BYK-359, BYK-361, BYK-390, BYK-392 (manufactured by Big Chemie) and the like. These surfactants are used in an amount of 5 parts by mass or less, preferably 2 parts by mass or less, based on 100 parts by mass of the carboxyl group-containing photosensitive resin (A). When the amount of the surfactant exceeds 5 parts by mass, the film is liable to occur during coating.

An adhesion assistant can also be used to improve the adhesion to the substrate. As such an adhesion assistant, a functional silane coupling agent is preferably used, and examples thereof include a silane coupling agent having a reactive substituent such as a carboxyl group, a methacryloyl group, an isocyanate group, and an epoxy group. Are trimethoxysilylbenzoic acid, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, vinyltrimethoxysilane, γ-isocyanatopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, β- (3 , 4-epoxycyclohexyl) ethyltrimethoxysilane and the like. Such an adhesion assistant is used in an amount of 20 parts by mass or less, preferably 10 parts by mass or less with respect to 100 parts by mass of the carboxyl group-containing photosensitive resin (A). When the amount of the adhesion assistant exceeds 20 parts by mass, the development residue tends to occur.
The photosensitive resin composition solution thus prepared can be used after being filtered using a Millipore filter having a pore size of about 0.5 μm.

  As a method for forming a pattern using the photosensitive resin composition of the present invention, specifically, a solid colored photosensitive resin obtained by previously forming the photosensitive resin composition of the present invention on a substrate or a substrate. It is applied onto a composition layer (hereinafter sometimes referred to as a substrate), and volatile components such as a solvent are removed from the applied photosensitive resin composition layer, and the volatile components are removed through a photomask. And a method of developing after exposing the exposed layer.

  Examples of the substrate include flat substrates such as a glass substrate, a silicon substrate, a polycarbonate substrate, a polyester substrate, an aromatic polyamide substrate, a polyamideimide substrate, a polyimide substrate, an Al substrate, and a GaAs substrate. These substrates may be subjected to pretreatment such as chemical treatment with chemicals such as a silane coupling agent, plasma treatment, ion plating treatment, sputtering treatment, gas phase reaction treatment, and vacuum deposition treatment. When a silicon substrate or the like is used as the substrate, a charge coupled device (CCD), a thin film transistor (TFT), or the like may be formed on the surface of the silicon substrate.

  In order to apply the photosensitive resin composition on the substrate, for example, the photosensitive resin composition of the present invention can be applied by spin coating (spin coating), casting coating, roll coating, slit & spin coating. The coating may be performed on a substrate or the like by a known coating method such as coating using a liquid-saving coater such as a spinless coater, and then a volatile component such as a solvent may be volatilized by heating. In this way, a layer made of the solid content of the photosensitive resin composition is formed on the substrate or the like. Subsequently, the layer (henceforth a photosensitive resin composition layer) which consists of solid content of the photosensitive resin composition is exposed. For exposure, for example, active energy rays may be selectively irradiated through a photomask. As the exposure light source, a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a xenon lamp, a metal halide lamp, or the like is usually suitable. A laser beam or the like can also be used as an active energy ray for exposure. In addition, electron beams, α rays, β rays, γ rays, X rays, neutron rays, and the like can also be used. The active energy rays are irradiated through a photomask. Here, for example, the photomask has a light shielding layer that shields the active energy rays on the surface of a glass plate. The portion of the glass plate where the light-shielding layer is not provided is a light-transmitting portion through which the active energy ray is transmitted. The photosensitive resin composition layer is exposed in a pattern according to the pattern of the light-transmitting portion, and active. An unirradiated region that has not been irradiated with energy rays and an irradiated region that has been irradiated with active energy rays are generated. The irradiation amount of the active energy ray in the irradiation region is the weight average molecular weight of the binder polymer, the monomer ratio, the content, the type and content of the photopolymerizable compound, the type and content of the photopolymerization initiator, and the photopolymerization initiation aid. It is appropriately selected depending on the type and content of the agent.

  The substrate exposed as described above is developed with a dilute alkaline aqueous solution. For development, for example, the exposed photosensitive resin composition layer may be brought into contact with a dilute aqueous alkali solution. Specifically, the substrate with the photosensitive resin composition layer formed on the surface thereof is diluted. What is necessary is just to immerse in aqueous alkali solution or to spray dilute aqueous alkali solution in shower shape. Examples of the diluted alkaline aqueous solution include aqueous solutions of alkaline compounds such as sodium carbonate, potassium carbonate, sodium hydroxide, potassium hydroxide, tetramethylammonium hydroxide, and organic amine. By the development, an unirradiated region that has not been irradiated with the active energy ray in the photosensitive resin composition layer is removed. On the other hand, the active energy ray irradiation region remains as it is to form a pattern.

  The substrate thus developed is usually washed with water and dried to obtain a target pattern. You may heat after drying. The pattern can be cured by heating to further improve its mechanical strength. The heating temperature is usually 180 ° C. or higher, preferably 200 ° C. or higher, and usually 250 ° C. or lower. When the heating temperature is 180 to 250 ° C., the mechanical strength of the coating film is improved and the solvent resistance and liquid crystal resistance are improved, which is preferable. The heating time is usually 5 minutes to 120 minutes, preferably 10 minutes to 90 minutes, and more preferably 15 minutes to 60 minutes. When the heating time is 5 minutes to 120 minutes, the mechanical strength of the coating film is improved, which is preferable. In this way, a spacer made of the photosensitive resin composition is formed.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. In the following description, “part” means part by mass unless otherwise specified.

Preparation of carboxyl group-containing photosensitive resin solution (Synthesis Example 1)
In a separable flask equipped with a stirrer, a reflux condenser, and a thermometer, 4.1 parts of azobisisobutyronitrile and 286 g of propylene glycol monomethyl ether acetate are charged and heated in a hot water bath to an internal temperature of 70 ° C. A mixture of 124.5 parts of dicyclopentanyl methacrylate represented by the general formula (1), 10.4 parts of styrene and 58.9 parts of glycidyl methacrylate was added dropwise thereto over 3 hours to carry out a polymerization reaction. Furthermore, it stirred at 70 degreeC for 3 hours, and it confirmed that the unreacted monomer did not exist by GPC. 31.2 parts of acrylic acid and 1 part of triphenylphosphine were added to this polymer and reacted at 80-90 ° C. for 24 hours. After confirming the disappearance of the epoxy group by IR spectrum, 60.9 parts of tetrahydrophthalic anhydride was added and further reacted at 80 ° C. for 12 hours to obtain a carboxyl group-containing photosensitive resin (A-1) varnish. It was. In addition, the solid content acid value of this carboxyl group-containing photosensitive resin (A-1) of this invention was 79 mgKOH / g, and the molecular weight (Mw) in GPC was 18000. The solid content concentration of the carboxyl group-containing photosensitive resin (A-1) varnish was 50% by mass.

(Comparative Synthesis Example 1)
In a separable flask equipped with a stirrer, a reflux condenser, and a thermometer, 4.1 parts of azobisisobutyronitrile and 125 g of propylene glycol monomethyl ether acetate are charged and heated in a hot water bath to an internal temperature of 70 ° C. A mixture of 55 parts of methyl methacrylate, 20.8 parts of styrene and 42.7 parts of glycidyl methacrylate was added dropwise over 3 hours to carry out a polymerization reaction. Furthermore, it stirred at 70 degreeC for 3 hours, and it confirmed that the unreacted monomer did not exist by GPC. To this polymer, 23.4 parts of acrylic acid and 0.8 part of triphenylphosphine were added and reacted at 80 to 90 ° C. for 16 hours. After confirming the disappearance of the epoxy group by IR spectrum, 45.7 parts of tetrahydrophthalic anhydride was added, and further reacted at 80 ° C. for 8 hours, so that the carboxyl group not containing the compound represented by the general formula (1) Containing photosensitive resin (R-1) varnish was obtained. The acid value of the carboxyl group-containing photosensitive resin (R-1) was 90 mgKOH / g, and the molecular weight (Mw) by GPC was 15000. The solid content concentration of the carboxyl group-containing photosensitive resin (R-1) varnish was 60% by mass.

The raw materials used in the examples and comparative examples are shown in Table 1 below.


Remarks:
1) Bifunctional oxetane compound manufactured by Toagosei Co., Ltd. (trade name: OXT-121)
2) Bifunctional oxetane compound (trade name: Eternacoll OXBP) manufactured by Ube Industries, Ltd.
3) Polyfunctional oxetane compound manufactured by Toagosei Co., Ltd. (trade name: PNOX-1009)
4) Bifunctional epoxy resin manufactured by Japan Epoxy Resin Co., Ltd. 5) Multifunctional epoxy resin manufactured by Nippon Kayaku Co., Ltd.

Examples 1-3 and Comparative Examples 1-4
Preparation of photosensitive resin composition Each component was blended at the blending ratio shown in Table 2 and stirred for 1 hour at room temperature to dissolve each component, followed by filtration with a Millipore filter having a pore size of 0.45 μm to obtain a photosensitive resin composition. It was.

(1) Evaluation of resolution Using a spin coater on a glass substrate, the photosensitive resin composition solution was applied for 20 seconds at a rotation speed of 1000 rpm, and then pre-baked on a hot plate at 90 ° C. for 3 minutes. A dry coating was formed. The coating film obtained above was irradiated with 100 mJ / cm ^{2 of} ultraviolet light having an intensity of 12 mW / cm ² at 365 nm through a mask having a dot pattern of φ10 μm. The ultraviolet irradiation at this time was performed in an oxygen atmosphere (in air), and the exposure gap was 100 μm. Next, after developing for 120 seconds at 25 ° C. using a 0.4 mass% aqueous solution of tetramethylammonium hydroxide, it was washed with running pure water for 30 seconds. The spacer pattern formed above was cured by heating at 230 ° C. for 60 minutes in an oven.
The case where the pattern having a dot diameter of 10 μm can be resolved with the spacer pattern obtained above is marked with ◯, and the case where the pattern is not resolved is marked with ×. The results are shown in Table 3.

(2) Evaluation of NMP resistance Using a spin coater on a glass substrate, the photosensitive resin composition solution was applied for 20 seconds at a rotation speed of 1000 rpm, and then pre-baked on a hot plate at 90 ° C. for 3 minutes. A dry coating was formed. The entire surface of the coating film obtained above was irradiated with 100 mJ / cm ^{2 of} ultraviolet light having an intensity at 365 nm of 12 mW / cm ² with an integrated light amount. The ultraviolet irradiation at this time was performed in an oxygen atmosphere (in air), and the exposure gap was 100 μm. Thereafter, it was cured by heating in an oven at 230 ° C. for 60 minutes.
The cured coating film was rubbed with a waste impregnated with N-methyl-2-pyrrolidone (NMP) to observe the surface state. The case where there was no change at all was marked as ◯, and the case where the surface was dissolved or softened and scratched, was marked as x.

(3) γ-Butyrolactone Resistance A cured coating film prepared in the same manner as in (2) above was rubbed with a waste impregnated with γ-butyrolactone to observe the surface condition. The case where there was no change at all was marked as ◯, and the case where the surface was dissolved or softened and scratched, was marked as x.

(4) Evaluation of transparency The cured coating film produced similarly to said (2) was observed visually, and transparency was evaluated. The case where the film was completely transparent was marked with ◯, and the film with a slight turbidity and opaque was marked with x.

(5) Compressive strength A pattern having a film thickness of 5 μm and a dot diameter of 30 μm was formed, and a spacer pattern thermally cured at 230 ° C. for 60 minutes was evaluated using a microhardness meter. The amount of deformation when a load of 50 mN was applied was measured with a flat indenter having a diameter of 50 μm. The case where this numerical value was 0.6 or less was marked with ◯, and the case where it was larger than 0.6 was marked with ×.

(6) Storage stability The above photosensitive resin composition was stored in an oven at 40 ° C. for 14 days, and when the gelation or marked increase in viscosity was observed x, the viscosity increase was slight and not gelled. ○.

The test results are summarized in Table 3.

As is apparent from the results shown in Table 3, Examples 1 to 3 which are the photosensitive resin compositions of the present invention show excellent storage stability, and the cured product has excellent chemical resistance and compressive strength. It was revealed that the film had transparency and transparency.

Claims (3)

(A) a carboxyl group-containing photosensitive resin having both a carboxyl group and at least two ethylenically unsaturated bonds in one molecule; (B) a polymerizable compound having one or more ethylenically unsaturated bonds in one molecule; (C) a photopolymerization initiator, and (D) a composition containing an oxetane compound having at least two oxetanyl groups in one molecule, wherein the carboxyl group-containing photosensitive resin (A) has the following general formula: Represented by (1)


In the formula, x represents an integer of 0 to 2, R ¹ represents hydrogen or a methyl group, R ² represents a dicyclopentadiene derivative having 10 to 20 carbon atoms, or a tricyclodecane derivative having 10 to 20 carbon atoms. .

A photosensitive resin composition, which is a carboxyl group-containing photosensitive resin containing a compound having an unsaturated double bond as a copolymerization component. A coating film forming step for applying and drying the photosensitive resin composition according to claim 1, a photocuring treatment step for selectively irradiating the coating film obtained through the coating film forming step with active energy rays, light Hardened | cured material obtained through the process of heating and hardening the pattern obtained by the alkali image development process which removes an unirradiated part using an alkali developing solution after a hardening process process, and obtains a pattern, and the said alkali image development process. The spacer for display panels obtained using the photosensitive resin composition of the said Claim 1.