JP2021148891A - Photosensitive resin composition, cured film, display device, and method for producing cured film - Google Patents

Abstract

To provide a photosensitive resin composition capable of forming a pattern with high sensitivity and excellent in alkali developability.SOLUTION: The photosensitive resin composition contains (A) an alkali-soluble resin, (B) a radically polymerizable compound, (C) a photopolymerization initiator, and (D) a chain transfer agent. The alkali-soluble resin (A) contains one or more selected from the group consisting of polyimide precursors, polyimides, polybenzoxazole precursors, polybenzoxazoles, and copolymers thereof. The alkali-soluble resin (A) contains a phenolic hydroxyl group. A compound represented by formula (1) is contained as the chain transfer agent (D). The content ratio of the chain transfer agent (D) is 0.5-7 pts.mass based on 100 pts.mass of the total of the alkali-soluble resin (A) and the radically polymerizable compound (B).SELECTED DRAWING: Figure 1

Description

The present invention relates to a photosensitive resin composition used in an organic EL display device or the like.

In recent years, many products using an organic electroluminescence (hereinafter, "EL") display have been developed in display devices having a thin display such as smartphones, tablet PCs, and televisions.

Generally, an organic EL display has a transparent electrode such as indium tin oxide (hereinafter, "ITO") on the light extraction side of the light emitting element, and an alloy of magnesium and silver or the like is formed on the side opposite to the light extraction side of the light emitting element. It has a metal electrode. Further, in the organic EL display, in order to divide the pixels of the light emitting element, an insulating layer called a pixel dividing layer is formed between the transparent electrode and the metal electrode. Since the pixel dividing layer is formed at a position adjacent to the light emitting element, degassing from the pixel dividing layer and outflow of ionic components can contribute to a decrease in the life of the organic EL display. Therefore, the pixel division layer is required to have high heat resistance.

As a photosensitive resin composition capable of forming a highly heat-resistant pixel division layer, a negative type photosensitive resin composition containing a polyimide resin has been proposed (see, for example, Patent Document 1). In these photosensitive resin compositions, by using a polyimide resin in which alkali developability is imparted by a phenolic hydroxyl group, it is possible to form a pixel division layer pattern by using a photolithography technique.

International Publication No. 2017/051743

In photolithography, it is desired that the pattern can be formed with excellent alkali developability and high sensitivity. However, in resins such as polyimide resins that can be developed with alkali, there is a problem that curing is hindered by the presence of phenolic hydroxyl groups and high sensitivity cannot be obtained.

The present invention is a photosensitive resin composition containing (A) an alkali-soluble resin, (B) a radically polymerizable compound, (C) a photopolymerization initiator, and (D) a chain transfer agent, wherein the (A) alkali. The soluble resin contains one or more selected from the group consisting of polyimide precursors, polyimides, polybenzoxazole precursors, polybenzoxazoles and copolymers thereof, and the alkali-soluble resin (A) is phenolic. It contains a hydroxyl group, and as the (D) chain transfer agent, contains a compound represented by the formula (1), and the content ratio of the (D) chain transfer agent is the (A) alkali-soluble resin and (B). The photosensitive resin composition is 0.5 to 7 parts by mass with respect to 100 parts by mass of the total amount of the radically polymerizable compound.

In the formula (1), R is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and X is an alkylene group having 1 to 10 carbon atoms.
a is an integer of 0 or more and 2 or less, b is an integer of 0 or more and 2 or less, c is an integer of 2 or more and 4 or less, and satisfies a + b + c = 4.

According to the photosensitive resin composition of the present invention, it is possible to form a pattern with excellent alkali developability and high sensitivity.

FIG. 1 is a cross-sectional view illustrating an embodiment of a TFT substrate on which a flattening layer and an insulating layer are formed.

The photosensitive resin composition of the present invention is a photosensitive resin composition containing (A) an alkali-soluble resin, (B) a radically polymerizable compound, (C) a photopolymerization initiator, and (D) a chain transfer agent. The (A) alkali-soluble resin contains one or more selected from the group consisting of a polyimide precursor, a polyimide, a polybenzoxazole precursor, polybenzoxazole and a copolymer thereof, and the (A) alkali. The soluble resin contains a phenolic hydroxyl group, contains a compound represented by the formula (1) as the (D) chain transfer agent, and the content ratio of the (D) chain transfer agent is the (A) alkali. It is characterized in that it is 0.5 to 7 parts by mass with respect to a total of 100 parts by mass of the soluble resin and the (B) radically polymerizable compound.

<(A) Alkali-soluble resin>
The photosensitive resin composition of the present invention comprises at least one selected from the group consisting of a polyimide precursor, a polyimide, a polybenzoxazole precursor, polybenzoxazole and a copolymer thereof as the (A) alkali-soluble resin. The (A) alkali-soluble resin contains a phenolic hydroxyl group.

Alkali-soluble means that a solution of a resin dissolved in γ-butyrolactone is applied onto a silicon wafer and prebaked at 120 ° C. for 4 minutes to form a prebaked film having a film thickness of 10 μm ± 0.5 μm, and the prebaked film is formed by 23. It means that the dissolution rate obtained from the decrease in film thickness when the film is immersed in a 2.38 mass% tetramethylammonium hydroxide aqueous solution at ± 1 ° C. for 1 minute and then rinsed with pure water is 50 nm / min or more.

Examples of the polyimide precursor include tetracarboxylic acid having a phenolic hydroxyl group, the corresponding tetracarboxylic acid dianhydride, tetracarboxylic acid dichloride, tetracarboxylic acid active diester or tetraformyl compound, and / or phenol. Tetracarboxylic acid, corresponding tetracarboxylic acid dianhydride, tetracarboxylic acid dichloride, tetracarboxylic acid active diester or tetraformyl compound with diamine, corresponding diisocyanate compound or trimethylsilylated diamine having a sex hydroxyl group as essential components. And the known ones obtained by reacting diamine, the corresponding diisocyanate compound, trimethylsilylated diamine, etc. with tetracarboxylic acid and / or derivative residues thereof, and diamine and / or derivative residues thereof. Has.
Examples of the polyimide precursor include polyamic acid, polyamic acid ester, polyamic acid amide or polyisoimide having a known phenolic hydroxyl group.

Examples of the polyimide include known polyimides obtained by dehydrating and ring-closing the above-mentioned polyamic acid, polyamic acid ester, polyamic acid amide or polyisoimide by heating or a reaction using an acid or a base. It has acid and / or derivative residues thereof and diamine and / or derivative residues thereof.

Examples of the polybenzoxazole precursor include a dicarboxylic acid having a phenolic hydroxyl group, a corresponding dicarboxylic acid dichloride, a dicarboxylic acid active diester or a diformyl compound, and / or a bisaminophenol compound having a phenolic hydroxyl group. Examples of the essential component include known ones obtained by reacting a dicarboxylic acid, a corresponding dicarboxylic acid dichloride, a dicarboxylic acid active diester or a diformyl compound, and a bisaminophenol compound as a diamine, and dicarboxylic acids. And / or a derivative residue thereof and a bisaminophenol compound and / or a derivative residue thereof.
Examples of the polybenzoxazole precursor include polyhydroxyamides having known phenolic hydroxyl groups.

As the polybenzoxazole, for example, a known one obtained by dehydrating and ring-closing a dicarboxylic acid and a bisaminophenol compound as a diamine by a reaction using polyphosphoric acid, or the above-mentioned polyhydroxyamide is heated or heated. Known ones obtained by dehydration and ring closure by a reaction using an anhydrous phosphoric acid, a base, a carbodiimide compound, or the like include dicarboxylic acid and / or a derivative residue thereof, and a bisaminophenol compound and / or a derivative residue thereof. Has a group.

From the viewpoint of improving the storage stability of the coating liquid of the photosensitive resin composition and improving the pattern processability with the alkali developing solution, the alkali-soluble resin (A) has monoamine or dicarboxylic acid at the end of the alkali-soluble resin. It is preferably sealed with an end-capping agent such as acid anhydride, monocarboxylic acid, monocarboxylic acid acidate, or monocarboxylic acid active ester. The end-capping agent may or may not have a phenolic hydroxyl group.

The polyvalent carboxylic acid and its derivative constituting the alkali-soluble resin (A), and the polyvalent carboxylic acid having a phenolic hydroxyl group, which is an essential component in 100 mol% of the total of the diamine and its derivative, and its derivative. The content of the derivative, the diamine having a phenolic hydroxyl group and the derivative thereof is preferably 10 mol% or more and less than 100 mol%.

Examples of the tetracarboxylic acid having a phenolic hydroxyl group used in the synthesis of the alkali-soluble resin (A) include 2,2'-dihydroxy-3,3', 4,4'-biphenyltetracarboxylic acid, 5, 5'-Dihydroxy-3,3', 4,4'-biphenyltetracarboxylic acid, 6,6'-dihydroxy-3,3', 4,4'-biphenyltetracarboxylic acid, 2,2'-dihydroxy-3 , 3', 4,4'-benzophenone tetracarboxylic acid, 5,5'-dihydroxy-3,3', 4,4'-benzophenone tetracarboxylic acid, 6,6'-dihydroxy-3,3', 4, 4'-Benzophenone tetracarboxylic acid, 3,7-dihydroxy-1,2,5,6-naphthalenetetracarboxylic acid, 4,8-dihydroxy-1,2,5,6-naphthalenetetracarboxylic acid, 1,5- Examples thereof include dihydroxy-2,3,6,7-naphthalenetetracarboxylic acid, 1,7-dihydroxy-3,4,9,10-perylenetetracarboxylic acid, and compounds having the structures shown below. Two or more of these may be used.

R ¹ represents an oxygen atom, C (CF ₃ ) ₂ or C (CH ₃ ) ₂ . R ² , R ³ , R ⁴ and R ⁵ represent a hydrogen atom or a hydroxyl group, and at least one is a hydroxyl group. Examples of the dicarboxylic acid having a phenolic hydroxyl acid used in the synthesis of the alkali-soluble resin (A) include 2-hydroxyphthalic acid, 3-hydroxyphthalic acid, 4-hydroxyphthalic acid, 4-hydroxyisophthalic acid, and 5 -Hydroxyisophthalic acid, 2-hydroxyterephthalic acid, 2,5-dihydroxyterephthalic acid, 2,2'-dihydroxy-4,4'-dicarboxybiphenyl, 3,3'-dihydroxy-4,4'-dicarboxybiphenyl , 2,2'-dihydroxy-4,4'-benzophenone dicarboxylic acid, 3,3'-dihydroxy-4,4'-benzophenone dicarboxylic acid, 2,2'-dihydroxy-4,4'-dicarboxydiphenyl ether, 3 , 3'-Dihydroxy-4,4'-dicarboxydiphenyl ether and the like. Two or more of these may be used.

Examples of the diamine having a phenolic hydroxyl group used in the synthesis of the alkali-soluble resin (A) include 2,2-bis (3-amino-4-hydroxyphenyl) hexafluoropropane and 2,2'-bis ( Examples thereof include trifluoromethyl) -3,3'-dihydroxybenzidine, 2,2'-bis (trifluoromethyl) -5,5'-dihydroxybenzidine, and compounds having the structures shown below. Two or more of these may be used.

R ⁶ and R ⁹ represent an oxygen atom, C (CF ₃ ) ₂ or C (CH ₃ ) ₂ . R ⁷ , R ⁸ and R ^{10 to} R ²⁰ each independently represent a hydrogen atom or a hydroxyl group, and at least one is a hydroxyl group.

As the tetracarboxylic acid used in the synthesis of the alkali-soluble resin (A), those having no phenolic hydroxyl group may be used. For example, pyromellitic acid, 3,3', 4,4'-biphenyltetracarboxylic acid, 2,3,3', 4'-biphenyltetracarboxylic acid, 2,2', 3,3'-biphenyltetracarboxylic acid. , 3,3', 4,4'-benzophenone tetracarboxylic acid, 2,2', 3,3'-benzophenone tetracarboxylic acid, 1,1-bis (3,4-dicarboxyphenyl) ethane, 1,1 -Bis (2,3-dicarboxyphenyl) ethane, bis (3,4-dicarboxyphenyl) methane, bis (2,3-dicarboxyphenyl) methane, bis (3,4-dicarboxyphenyl) ether, 1 , 2,5,6-naphthalenetetracarboxylic acid, 2,3,6,7-naphthalenetetracarboxylic acid, 2,3,5,6-pyridinetetracarboxylic acid, 3,4,9,10-perylenetetracarboxylic acid , 4,4 '- (hexafluoro isopropylidene) diphthalic acid, and among the compounds represented by the above formula ^(2), R ^2, R 3, aromatic tetracarboxylic such ^{R 4} and ^{R 5} is not a hydroxyl group compound Known examples include acids and aliphatic tetracarboxylic acids such as butanetetracarboxylic acid and 1,2,3,4-cyclopentanetetracarboxylic acid. Two or more of these may be used.

As the dicarboxylic acid used in the synthesis of the alkali-soluble resin (A), those having no phenolic hydroxyl group may be used. For example, terephthalic acid, isophthalic acid, diphenyl ether dicarboxylic acid, bis (carboxyphenyl) ethane, bis (carboxyphenyl) hexafluoropropane, biphenyldicarboxylic acid, benzophenone dicarboxylic acid, triphenyldicarboxylic acid, 5- [2,2,2- Known examples include trifluoro-1-hydroxy-1- (trifluoromethyl) ethyl] -1,3-benzenedicarboxylic acid. Two or more of these may be used.

As the diamine used for the synthesis of the alkali-soluble resin (A), a diamine having no phenolic hydroxyl group may be used. For example, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 1,4-bis (4-aminophenoxy) benzene, benzidine, m. -Phenylenediamine, p-Phenylenediamine, 1,5-naphthalenediamine, 2,6-naphthalenediamine, bis (4-aminophenoxy) biphenyl, bis {4- (4-aminophenoxy) phenyl} ether, 1,4- Bis (4-aminophenoxy) benzene, 2,2'-dimethyl-4,4'-diaminobiphenyl, 2,2'-diethyl-4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4' -Diaminobiphenyl, 3,3'-diethyl-4,4'-diaminobiphenyl, 2,2', 3,3'-tetramethyl-4,4'-diaminobiphenyl, 3,3', 4,4'- Tetramethyl-4,4'-diaminobiphenyl, 2,2'-di (trifluoromethyl) -4,4'-diaminobiphenyl, 9,9-bis (4-aminophenyl) fluorene, 2,2-bis ( 3-Aminophenyl) Hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane, 2,2-bis (3-amino-4-methylphenyl) hexafluoropropane, 2,2-bis [4 -(4-Aminophenoxy) phenyl] hexafluoropropane, 2,2'-bis (trifluoromethyl) benzidine, or compounds in which at least some of the hydrogen atoms of these aromatic rings are replaced with alkyl or halogen atoms. , aliphatic cyclohexyl diamine, methylene bis cyclohexylamine, diamines having an alkylene oxide group, a diamine having a silyl group or a siloxane bond, and among the diamine represented by the formula (3), R ^{7, R 8,} and R Known examples include diamines in which ^{10 to} R ^{20 are not hydroxyl groups.} Two or more of these may be used.

Examples of the terminal encapsulant having a phenolic hydroxyl group used in the synthesis of the alkali-soluble resin (A) include amine compounds such as 2-aminophenol, 3-aminophenol, and 4-aminophenol, and 3-hydroxyl. Dicarboxylic acids such as phthalic acid, 4-hydroxyphthalic acid, corresponding carboxylic acid anhydrides or dicarboxylic acid dichlorides and the like can be mentioned. Examples of the terminal encapsulant having no phenolic hydroxyl group include dicarboxylic acids such as maleic acid and phthalic acid, and corresponding carboxylic acid anhydrides or dicarboxylic acid dichlorides.

The alkali-soluble resin (A) described above can be synthesized by a known method. For example, in the case of a polyimide precursor, in a polar solvent such as N-methyl-2-pyrrolidone, tetracarboxylic acid dianhydride and diamine (part of which may be replaced with monoamine as an end-capping agent) may be replaced with 80. A method of reacting at ~ 200 ° C., or tetracarboxylic acid dianhydride (partially replaced with dicarboxylic acid anhydride, monocarboxylic acid, monocarboxylic acid acidate or monocarboxylic acid active ester which is an end-capping agent) Good) and diamine are reacted at 80 to 200 ° C., and the like can be mentioned. Further, in the case of polyimide, a method of synthesizing a polyimide precursor by performing the same method at 0 to 80 ° C. and completely imidizing the obtained polyimide precursor using a known imidization reaction method, in the middle of the process. Examples thereof include a method of stopping the imidization reaction and introducing a partial imide bond, or a method of introducing a partial imide bond by mixing the completely imidized polyimide and the polyimide precursor.

On the other hand, in the case of a polybenzoxazole precursor, a dicarboxylic acid active diester and a bisaminophenol compound (some of which may be replaced with monoamine as an end-capping agent) may be used in a polar solvent such as N-methyl-2-pyrrolidone. ) And the reaction at 80 to 250 ° C., or to a dicarboxylic acid active diester (partly to a dicarboxylic acid anhydride, a monocarboxylic acid, a monocarboxylic acid compound, or a monocarboxylic acid active ester which is an end-capping agent). It may be replaced) and the bisaminophenol compound, and the like, a method of reacting at 80 to 250 ° C. and the like can be mentioned. In the case of polybenzoxazole, the same method is carried out at 0 to 80 ° C. to synthesize a polybenzoxazole precursor, and the obtained polybenzoxazole precursor is completely used by a known oxazole reaction method. A method of oxazole formation, a method of stopping the oxazole formation reaction in the middle to introduce a partial oxazole structure, or a method of mixing a completely oxazoled polybenzoxazole with a polybenzoxazole precursor to introduce a partial oxazole structure. The method etc. can be mentioned.

<(B) Radical polymerizable compound>
The photosensitive resin composition of the present invention contains (B) a radically polymerizable compound. (B) The radically polymerizable compound has an unsaturated bond in the molecule. Examples of the unsaturated bond include an unsaturated double bond such as a vinyl group, an allyl group, an acryloyl group and a methacryloyl group, and an unsaturated triple bond such as a propargyl group. Among these, acryloyl group and methacryloyl group are preferable in terms of polymerizability. As the radically polymerizable compound (B), a polyfunctional monomer containing an acryloyl group or a methacryloyl group is suitable.

(B) Examples of the polyfunctional monomer containing an acryloyl group or a methacryloyl group preferably used as a radically polymerizable compound include bisphenol A diglycidyl ether (meth) acrylate, poly (meth) acrylate carbamate, and modified bisphenol A epoxy ( Meta) acrylate, adipanoic acid 1,6-hexanediol (meth) acrylic acid ester, phthalic anhydride propylene oxide (meth) acrylic acid ester, trimellitic acid diethylene glycol (meth) acrylic acid ester, rosin-modified epoxy di (meth) acrylate, Alkid-modified (meth) acrylate, full orange acrylate-based oligomer, tripropylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, bisphenol A diglycidyl ether di (meth) acrylate, trimethyl propantri ( Meta) acrylate, pentaerythritol tri (meth) acrylate, triacrylic formal, pentaerythritol tetra (meth) acrylate or its acid modified product, dipentaerythritol hexa (meth) acrylate or its acid modified product, dipentaerythritol penta (meth) Acrylate and its acid modified product, 2,2-bis [4- (3-acryloxy-2-hydroxypropoxy) phenyl] propane, bis [4- (3-acryloxy-2-hydroxypropoxy) phenyl] methane, bis [4 -(3-Acryloxy-2-hydroxypropoxy) phenyl] sulfone, bis [4- (3-acryloxy-2-hydroxypropoxy) phenyl] ether, 4,4'-bis [4- (3-acryloxy-2-hydroxy) Propoxy) phenyl] cyclohexane, 9,9-bis [4- (3-acryloxy-2-hydroxypropoxy) phenyl] fluorene, 9,9-bis [3-methyl-4- (3-acryloxy-2-hydroxypropoxy)) Phenyl] fluorene, 9,9-bis [3-chloro-4- (3-acryloxy-2-hydroxypropoxy) phenyl] fluorene, bisphenoxyethanol full orange acrylate, bisphenoxyethanol full orange methacrylate, biscresol full orange acrylate or bis Known examples include cresol full orange methacrylate. Two or more of these may be contained.

The content of the radically polymerizable compound is preferably 10 parts by mass or more, more preferably 20 parts by mass or more, based on 100 parts by mass of the (A) alkali-soluble resin, from the viewpoint of reducing film loss in the exposed portion during development. It is by mass or more, more preferably 30 parts by mass or more. On the other hand, the content of the (B) radically polymerizable compound is preferably 300 parts by mass or less, more preferably 200 parts by mass, based on 100 parts by mass of the (A) alkali-soluble resin, from the viewpoint of improving the heat resistance of the cured film. Parts or less, more preferably 150 parts by mass or less.

<(C) Photopolymerization Initiator>
The photosensitive resin composition of the present invention contains (C) a photopolymerization initiator. Examples of the (C) photopolymerization initiator include benzophenones such as benzophenone, Michler's ketone, 4,4-bis (diethylamino) benzophenone, and 3,3,4,5,4-tetra (t-butylperoxycarbonyl) benzophenone. , Benzylidenes such as 3,5-bis (diethylaminobenzylidene) -N-methyl-4-piperidone, 3,5-bis (diethylaminobenzylidene) -N-ethyl-4-piperidone, 7-diethylamino-3-tenonylcmarin , 4,6-Dimethyl-3-ethylaminokumarin, 3,3-carbonylbis (7-diethylaminocoumarin), 7-diethylamino-3- (1-methylmethylbenzoimidazolyl) kumarin, 3- (2-benzothiazolyl) -7 Cmarines such as -diethylaminocoumarin, anthraquinones such as 2-t-butylanthraquinone, 2-ethylanthraquinone and 1,2-benzanthraquinone, benzoins such as benzoin methyl ether, benzoin ethyl ether and benzoin isopropyl ether, N-phenyl Glycines such as glycine, N-methyl-N-phenylglycine, N-ethyl-N- (p-chlorophenyl) glycine, N- (4-cyanophenyl) glycine, 1-phenyl-1,2-butandion-2- (O-methoxycarbonyl) oxime, 1-phenyl-1,2-propanedione-2- (o-methoxycarbonyl) oxime, 1-phenyl-1,2-propanedione-2- (o-ethoxycarbonyl) oxime, 1-Phenyl-1,2-propanedione-2- (o-benzoyl) oxime, bis (α-isonitrosopropiophenone oxime) isophthal, 1,2-octanedione-1- [4- (phenylthio) phenyl] -2- (o-benzoyloxime)], IRGACURE (registered trademark, the same applies hereinafter) OXE01, IRGACURE OXE02, IRGACURE OXE03 (trade name, manufactured by BASF Co., Ltd.), N-1818, N-1919, NCI-831. Oxyme esters such as (trade name, manufactured by ADEKA Co., Ltd.), 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butane-2-methyl-1- [4- (Methylthio) Phenyl] -2-Moliphorinopropan-1-one and other α-aminoalkylphenones, 2,2'-bis (o-chlorophenyl) -4,4', 5,5'-tetra Known examples include phenylbiimidazole. Of these, the above-mentioned oxime esters are preferable because they can process patterns with higher sensitivity. Two or more of these may be contained.

The content of the (C) photopolymerization initiator is preferably 0.5 parts by mass or more, more preferably 0.5 parts by mass or more, based on 100 parts by mass of the (A) alkali-soluble resin, from the viewpoint of reducing film loss in the exposed portion during development. Is 1 part by mass or more, more preferably 2 parts by mass or more. On the other hand, the content of the (C) photopolymerization initiator is preferably 50 parts by mass or less, more preferably 30 parts by mass or less, still more preferably 20 parts by mass or less, from the viewpoint of improving the heat resistance of the cured film.

<(D) Chain transfer agent>
The photosensitive resin composition of the present invention contains (D) a chain transfer agent. The chain transfer agent refers to a compound capable of receiving radicals from the polymer growing end of a polymer chain obtained by radical polymerization during exposure and mediating radical transfer to another polymer chain.

The photosensitive resin composition of the present invention contains a compound represented by the following formula (1) as the chain transfer agent (D).

In the formula (1), R is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and X is an alkylene group having 1 to 10 carbon atoms. a is an integer of 0 or more and 2 or less, b is an integer of 0 or more and 2 or less, c is 2 or more and 4 or less, and a + b + c = 4 is satisfied.

By containing the compound represented by the above formula (1) as the chain transfer agent (D), it is possible to improve the sensitivity at the time of exposure while maintaining good alkali developability.

Examples of the compound represented by the above formula (1) include trimethylolethane ethanetris (propane-3-thiol), trimethylolethane ethanetris (butane-3-thiol), and trimethylolethane propanetris (propane-3-thiol). , Trimethylolethane propanetris (butane-3-thiol), pentaerythritol tris (propane-3-thiol), pentaerythritol tris (butane-3-thiol), pentaerythritol tetrakis (propane-3-thiol), pentaerythritol tetrakis ( Butan-3-thiol), and the like.
Among these, pentaerythritol tris (propane-3-thiol) is preferable.

The content of the chain transfer agent is preferably 0.5% by mass with respect to 100 parts by mass in total of the (A) alkali-soluble resin and (B) radically polymerizable compound from the viewpoint of improving the sensitivity during exposure. Parts or more, more preferably 1 part by mass or more. On the other hand, the content of (D) the chain transfer agent is preferably based on 100 parts by mass of the total of (A) alkali-soluble resin and (B) radically polymerizable compound from the viewpoint of obtaining an appropriate developing time. It is 7 parts by mass or less, more preferably 3 parts by mass or less. Here, the appropriate development time means a case where the removal time of the unexposed portion at the time of development is 30 seconds or more and less than 60 seconds, and more preferably 40 seconds or more and less than 50 seconds.

<Organic solvent>
The photosensitive resin composition of the present invention preferably contains an organic solvent. Examples of the organic solvent include known compounds such as ethers, acetates, esters, ketones, aromatic hydrocarbons, amides and alcohols.

More specifically, for example, ethers such as ethylene glycol monomethyl ether, propylene glycol monomethyl ether or tetrahydrofuran, butyl acetate, ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate or acetate such as 3-methoxy-n-butyl acetate. , Ketones such as methyl ethyl ketone or cyclohexanone, esters such as ethyl propionate, ethyl butyrate, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate or γ-butyrolactone, aromatic hydrocarbons such as toluene or xylene, Amides such as N-methylpyrrolidone, N, N-dimethylformamide or N, N-dimethylacetamide, or butanol, pentanol, 4-methyl-2-pentanol, 3-methyl-2-butanol, 3- Known examples include alcohols such as methyl-3-methoxybutanol or diacetone alcohol. Two or more of these may be contained.

The ratio of the organic solvent to the total solid content of the photosensitive resin composition of the present invention is preferably 50 parts by mass or more, more preferably 100 parts by mass or more, based on 100 parts by mass of the total solid content. Further, 2000 parts by mass or less is preferable, and 1000 parts by mass or less is more preferable. Here, the solid content refers to the entire component of the photosensitive resin composition excluding the organic solvent.

<Manufacturing method of photosensitive resin composition>
The method for producing the photosensitive resin composition of the present invention will be described.
For example, a photosensitive resin composition can be obtained by mixing the above components (A) to (D) with an organic solvent or the like, if necessary. Examples of the mixing method include stirring and heating. When heating, the heating temperature is preferably set within a range that does not impair the performance of the resin composition, and is usually room temperature to 80 ° C. Further, the mixing order of each component is not particularly limited.
<Cured film obtained by curing the photosensitive resin composition>
A cured film obtained by curing the photosensitive resin composition of the present invention will be described.
The cured film obtained by curing the photosensitive resin composition is a film obtained by applying the above-mentioned photosensitive resin composition to a substrate or the like and heat-treating the cured film. The heat treatment conditions are preferably 200 ° C. or higher, more preferably 250 ° C. or higher. The heat treatment conditions are preferably 400 ° C. or lower, more preferably 350 ° C. or lower.

<Manufacturing method of cured film using photosensitive resin composition>
A method for producing a cured film using the photosensitive resin composition of the present invention will be described.
The method for producing the cured film is (1) a step of applying the above-mentioned photosensitive resin composition to a substrate to form a coating film, and (2) exposing the above-mentioned coating film with an active chemical line and exposing the coating film. (3) The step of developing the exposed coating film with an alkaline solution to obtain the developed coating film, and (4) the step of heating the developed coating film to obtain a cured film. Have in order.

(1) In the step of forming a coating film of the photosensitive resin composition, the photosensitive resin composition of the present invention is applied by a spin coating method, a slit coating method, a dip coating method, a spray coating method, a printing method, or the like, and is photosensitive. A coating film of the sex resin composition is obtained. Prior to coating, the base material to which the photosensitive resin composition is applied may be pretreated with the above-mentioned adhesion improving agent in advance. For example, a solution in which the adhesion improver is dissolved in a solvent such as isopropanol, ethanol, methanol, water, tetrahydrofuran, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, ethyl lactate, and diethyl adipate in an amount of 0.5 to 20% by mass is used. Then, a method of treating the surface of the base material can be mentioned. Examples of the method for treating the surface of the base material include methods such as spin coating, slit die coating, bar coating, dip coating, spray coating, and steam treatment. In the step of drying the coating film, the formed coating film is subjected to a vacuum drying treatment as necessary, and then using a hot plate, an oven, infrared rays, etc., in the range of 50 ° C. to 180 ° C. for 1 minute to several hours. A coating film is obtained by performing the heat treatment of.

Next, (2) a step of exposing the coating film will be described.
The coating film is irradiated with active chemical rays (hereinafter, may be referred to as exposure). At this time, if necessary, the exposure may be performed through a photomask having a desired pattern, or the coating film may be directly exposed with a laser or the like. The active chemical rays used for exposure include ultraviolet rays, visible rays, electron beams, X-rays, etc., but in the present invention, i-rays (365 nm), h-rays (405 nm), and g-rays (436 nm) of mercury lamps can be used. preferable.

Next, (3) a step of developing the exposed coating film with an alkaline solution to obtain the developed coating film will be described.
The exposed coating film is developed with an alkaline solution to remove parts other than the exposed portion of the coating film. At this time, the appropriate development time refers to the case where the removal time of the unexposed portion during development is 30 seconds or more and less than 60 seconds, and more preferably 40 seconds or more and less than 50 seconds.

As alkaline solutions, tetramethylammonium hydroxide, diethanolamine, diethylaminoethanol, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, triethylamine, diethylamine, methylamine, dimethylamine, dimethylaminoethyl acetate, dimethylaminoethanol, dimethyl An aqueous solution of an alkaline compound such as aminoethyl methacrylate, cyclohexylamine, ethylenediamine and hexamethylenediamine is preferable. In some cases, these alkaline aqueous solutions are mixed with polar solvents such as N-methyl-2-pyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, dimethylsulfoxide, γ-butyrolactone and dimethylacrylamide, methanol, ethanol, etc. Alcohols such as isopropanol, esters such as ethyl lactate and propylene glycol monomethyl ether acetate, and ketones such as cyclopentanone, cyclohexanone, isobutyl ketone and methyl isobutyl ketone may be added alone or in combination of several types. good. As the developing method, a spray, paddle, immersion, ultrasonic wave or the like can be used.

Next, it is preferable to rinse the pattern formed by development with distilled water. Here, too, alcohols such as ethanol and isopropyl alcohol, and esters such as ethyl lactate and propylene glycol monomethyl ether acetate may be added to distilled water for rinsing.

Next, (4) a step of heat-treating the developed coating film to obtain a cured film will be described.
By heat-treating the developed coating film, residual solvents and components having low heat resistance can be removed, so that the heat resistance and chemical resistance of the cured film can be improved. This heat treatment is carried out for 5 minutes to 5 hours while selecting a certain temperature and gradually raising the temperature, or selecting a certain temperature range and continuously raising the temperature. As an example, heat treatment is performed at 200 ° C. and 250 ° C. for 30 minutes each. Alternatively, a method such as linearly raising the temperature from room temperature to 300 ° C. over 2 hours can be mentioned. The heat treatment conditions in the present invention are preferably 200 ° C. or higher, more preferably 250 ° C. or higher. The heat treatment conditions are preferably 400 ° C. or lower, more preferably 350 ° C. or lower.

<Display device>
The display device of the present invention includes a cured film obtained by curing the photosensitive resin composition.
The cured film obtained by curing the photosensitive resin composition is a substrate on which a TFT is formed, a flattening layer on a drive circuit, an insulating layer and a display element on the first electrode, and a flattening of a display device having a second electrode in this order. Included in layers and insulating layers. Examples of the display device having such a configuration include a liquid crystal display device and an organic EL display device. Among them, it is particularly preferably used for an organic EL display device that requires high heat resistance and low outgassing properties for a flattening layer and an insulating layer.

The cured film obtained by curing the photosensitive resin composition of the present invention may be used for only one of the flattening layer and the insulating layer, or may be used for both. The active matrix type display device has a TFT and wiring located on the side of the TFT and connected to the TFT on a substrate such as glass, and has a flattening layer on the TFT so as to cover the unevenness. Further, a display element is provided on the flattening layer. The display element and the wiring are connected via a contact hole formed in the flattening layer.

FIG. 1 shows a cross-sectional view of a display device in which a flattening layer and an insulating layer are formed. A bottom gate type or top gate type TFT 1 is provided in a matrix on the substrate 6, and a TFT insulating film 3 is formed so as to cover the TFT 1. Further, a wiring 2 connected to the TFT 1 is provided under the TFT insulating film 3. Further, a contact hole 7 for opening the wiring 2 and a flattening layer 4 are provided on the TFT insulating film 3 in a state of embedding them. The flattening layer 4 is provided with an opening so as to reach the contact hole 7 of the wiring 2. Then, the ITO (transparent electrode) 5 is formed on the flattening layer 4 in a state of being connected to the wiring 2 through the contact hole 7. Here, the ITO (transparent electrode) 5 becomes the first electrode of the display element (for example, an organic EL element). Then, the insulating layer 8 and the light emitting pixel 9 are formed so as to cover the peripheral edge of the ITO (transparent electrode) 5, and the second electrode 10 is formed on the insulating layer 8. The organic EL element may be a top emission type that emits emitted light from the opposite side of the substrate 6, or a bottom emission type that emits light from the substrate 6 side.

Hereinafter, the present invention will be described with reference to Examples and the like, but the present invention is not limited to these examples. The names of the compounds used that use abbreviations are shown below.
4-MOP: 4-methoxyphenol 6FDA: 2,2- (3,4-dicarboxyphenyl) Hexafluoropropane AIBN: 2,2'-azobis (isobutyronitrile)
BAHF: 2,2-bis (3-amino-4-hydroxyphenyl) hexafluoropropane BFE: 1,2-bis (4-formylphenyl) ethane BnMA: benzyl methacrylate DBA: dibenzylamine DHTA: 2,5- Dihydroxyterephthalic acid GMA: Glycidyl methacrylate MAA: MAP methacrylate: 3-Aminophenol; Metaaminophenol MBA: 3-Methoxy-n-butylacetate NA: 5-Norbornene-2,3-dicarboxylic acid anhydride NMP: N- Methyl-2-pyrrolidone ODPA: bis (3,4-dicarboxyphenyl) ether dianhydride; oxydiphthalic acid dianhydride PGMEA: propylene glycol monomethyl ether acetate SiDA: 1,3-bis (3-aminopropyl) tetramethyldi. Siloxane TCDM: Dimethylol-tricyclodecanedimethacrylate [Synthesis Example 1]
Weigh 31.13 g (0.085 mol) of BAHF, 1.24 g (0.0050 mol) of SiDA, 2.18 g (0.020 mol) of MAP, and 150.00 g of NMP as end-capping agent in a three-necked flask under a dry nitrogen stream. And dissolved. A solution prepared by dissolving 31.02 g (0.10 mol) of ODPA in 50.00 g of NMP was added thereto, and the mixture was stirred at 20 ° C. for 1 hour and then at 50 ° C. for 4 hours. Then, 15 g of xylene was added, and the mixture was stirred at 150 ° C. for 5 hours while azeotropically boiling water with xylene. After completion of the reaction, the reaction solution was poured into 3 L of water, and the precipitated solid precipitate was obtained by filtration. The obtained solid was washed with water three times and then dried in a vacuum dryer at 80 ° C. for 24 hours to obtain (A) a polyimide resin a-1 as an alkali-soluble resin.

[Synthesis Example 2]
In a three-necked flask, 18.31 g (0.05 mol) of BAHF, 17.4 g (0.3 mol) of propylene oxide, and 100 mL of acetone were weighed and dissolved. A solution prepared by dissolving 20.41 g (0.11 mol) of 3-nitrobenzoyl chloride in 10 mL of acetone was added dropwise thereto. After completion of the dropping, the reaction was carried out at −15 ° C. for 4 hours, and then the temperature was returned to room temperature. The precipitated white solid was collected by filtration and vacuum dried at 50 ° C. 30 g of the obtained solid was placed in a 300 mL stainless autoclave, dispersed in 250 mL of 2-methoxyethanol, and 2 g of 5% palladium-carbon was added. Hydrogen was introduced into this with a balloon and reacted at room temperature for 2 hours. After 2 hours, it was confirmed that the balloon did not deflate any more. After completion of the reaction, the palladium compound as a catalyst was removed by filtration, distilled off under reduced pressure, and concentrated to obtain a hydroxy group-containing diamine compound (HA) having the following structure.

88.8 g (0.20 mol) of 6FDA was dissolved in 500 g of NMP under a dry nitrogen stream. To this, 96.7 g (0.16 mol) of HA was added together with 100 g of NMP, and the mixture was reacted at 20 ° C. for 1 hour and then at 50 ° C. for 2 hours. Next, 8.7 g (0.08 mol) of MAP as an end-capping agent was added together with 50 g of NMP, and the mixture was reacted at 50 ° C. for 2 hours. Then, a solution of 47.7 g (0.40 mol) of N, N-dimethylformamide dimethyl acetal diluted with 100 g of NMP was added dropwise over 10 minutes. After the dropping, the mixture was stirred at 50 ° C. for 3 hours. After completion of stirring, the solution was cooled to room temperature, and then the solution was poured into 5 L of water to obtain a white precipitate. This precipitate was collected by filtration, washed with water three times, and then dried in a vacuum dryer at 80 ° C. for 24 hours to obtain (A) a polyimide precursor a-2 as an alkali-soluble resin.

[Synthesis Example 3]
34.79 g (0.095 mol) of BAHF, 1.24 g (0.0050 mol) of SiDA, and 75.00 g of NMP are weighed and dissolved in a 500 mL round bottom flask equipped with a Dean-Stark water separator filled with toluene and a cooling tube. rice field. A solution prepared by dissolving 14.29 g (0.060 mol) of BFE, 3.96 g (0.020 mol) of DHTA, and 6.57 g (0.040 mol) of NA as an end-capping agent was added to 25.00 g of NMP. The mixture was stirred at 20 ° C. for 1 hour and then at 50 ° C. for 1 hour. Then, under a nitrogen atmosphere, the mixture was heated and stirred at 200 ° C. or higher for 10 hours to carry out a dehydration reaction. After completion of the reaction, the reaction solution was poured into 3 L of water, and the precipitated solid precipitate was obtained by filtration. The obtained solid was washed with water three times and then dried in a vacuum dryer at 80 ° C. for 24 hours to obtain polybenzoxazole resin a-3 as (A) alkali-soluble resin.

[Synthesis Example 4]
41.3 g (0.16 mol) of diphenyl ether-4,4'-dicarboxylic acid and 43.2 g (0.32 mol) of 1-hydroxy-1,2,3-benzotriazole are reacted under a dry nitrogen stream. 0.16 mol of the mixture of the obtained dicarboxylic acid derivative and 73.3 g (0.20 mol) of BAHF were dissolved in 570 g of NMP, and then reacted at 75 ° C. for 12 hours. Next, 13.1 g (0.08 mol) of NA dissolved in 70 g of NMP was added, and the mixture was further stirred for 12 hours to complete the reaction. After filtering the reaction mixture, the reaction mixture was added to a solution of water / methanol = 3/1 (volume ratio) to obtain a white precipitate. This precipitate was collected by filtration, washed with water three times, and then dried in a vacuum dryer at 80 ° C. for 24 hours to obtain a polybenzoxazole precursor a-4 as an alkali-soluble resin (A).

[Synthesis Example 5]
A three-necked flask was charged with 0.821 g (0.005 mol) of AIBN and 29.29 g of PGMEA. Next, 21.52 g (0.25 mol) of MAA, 22.03 g (0.10 mol) of TCDM, and 26.43 g (0.15 mol) of BnMA were charged, and the inside of the flask was stirred for a while at room temperature. After sufficient nitrogen substitution by bubbling, the mixture was stirred at 70 ° C. for 5 hours. Next, in the obtained solution, 59.47 g of PGMEA, 14.22 g (0.10 mol) of GMA, 0.676 g (0.005 mol) of DBA, and 0.186 g (0.0015) of 4-MOP. (Mole) A dissolved solution was added, and the mixture was stirred at 90 ° C. for 4 hours to obtain a solution of (A) an acrylic resin a-5 as an alkali-soluble resin.

The structures of the compounds shown in each Example and Comparative Example are shown below.

[Example 1]
Under yellow light, (A) the polyimide resin a-1 obtained in Synthesis Example 1 as an alkali-soluble resin, (B) b-1 and b-2 as radically polymerizable compounds, and (C) c-1 as a photopolymerization initiator. , (D) d-1 as a chain transfer agent and PGMEA and MBA as a solvent were added at a mass ratio of 80/20, and the mixture was stirred and dissolved to prepare the composition 1.

The composition 1 was evaluated for alkali developability and sensitivity as follows.
(Evaluation of alkali developability)
The composition 1 is spun on a glass substrate (manufactured by Geomatec Co., Ltd .; hereinafter, “ITO substrate”) formed by sputtering ITO using a spin coater (MS-A100; manufactured by Mikasa Co., Ltd.) at an arbitrary rotation speed. After coating by coating, it was prebaked at 110 ° C. for 120 seconds using a buzzer hot plate (HPD-3000BZN; manufactured by AS ONE) to prepare a prebaked film having a film thickness of about 1.8 μm.

The prepared prebake film is spray-developed with a 2.38 mass% TMAH aqueous solution using a small photolithography developing device (AD-2000; manufactured by Takizawa Sangyo Co., Ltd.), and the time required for the prebake film (unexposed portion) to completely dissolve. (Breaking Point; hereinafter, "BP") was measured to determine the alkali developability. B. P. If is 30 seconds or more and less than 60 seconds, it is considered that the development time is appropriate, and the result is passed. P. Was rejected if it was less than 30 seconds or 60 seconds or more. Especially B. P. When is 40 seconds or more and less than 50 seconds, it is a more appropriate development time.

The alkali developability was determined as follows.
A: B. P. Is 40 seconds or more and less than 50 seconds B: B. P. Is 30 seconds or more and less than 40 seconds, or 50 seconds or more and less than 60 seconds C: B. P. Is less than 30 seconds, or 60 seconds or more.

(Sensitivity evaluation)
A prebake film was prepared in the same manner as in the evaluation of alkali developability described above, and the prepared prebake film was subjected to a grayscale mask for sensitivity measurement using a double-sided alignment single-sided exposure apparatus (mask aligner PEM-6M; manufactured by Union Optical Co., Ltd.). (MDRM MODEL 4000-5-FS; manufactured by Opto-Line International) was subjected to patterning exposure with i-line (wavelength 365 nm), h-line (wavelength 405 nm), and g-line (wavelength 436 nm) of an ultrahigh-pressure mercury lamp. After exposure, using a small photolithography developing device (AD-2000; manufactured by Takizawa Sangyo Co., Ltd.), using a 2.38 mass% TMAH aqueous solution, B.I. P. It was developed for +20 seconds and rinsed with water for 30 seconds.

The pattern of the developed film obtained by the above method is observed with an FDP microscope MX61 (manufactured by Olympus Corporation) at a magnification of 100 times to form a line-and-space pattern of 20 μm in a width of 1: 1. The exposure amount (this is called the optimum exposure amount) was obtained, and this was used as the sensitivity.
A case where the sensitivity was less than 35 mJ / cm ² was regarded as a pass, and a case where the sensitivity was 35 mJ / cm ² or more was regarded as a failure.
The sensitivity was determined as follows.
A: sensitivity is 25 mJ / cm ² less B: sensitivity 25 mJ / cm ² or more 35 mJ / cm ² less than C: sensitivity 35 mJ / cm ² or more.

[Examples 2 to 10, Comparative Examples 1 to 7]
Compositions 2 to 17 were prepared with the compositions shown in Table 1 in the same manner as in Example 1.
Compositions 2 to 17 were evaluated in the same manner as in Example 1.

Table 2 shows the composition and evaluation results of the photosensitive resin compositions of each Example and Comparative Example.

From the above results, it was confirmed that the photosensitive resin composition according to the present invention has good alkali developability and sensitivity.

1: TFT
2: Wiring 3: TFT insulating film 4: Flattening layer 5: ITO (transparent electrode)
6: Substrate 7: Contact hole 8: Insulation layer 9: Light emitting pixel 10: Second electrode

Claims (6)

A photosensitive resin composition containing (A) an alkali-soluble resin, (B) a radically polymerizable compound, (C) a photopolymerization initiator, and (D) a chain transfer agent, wherein the (A) alkali-soluble resin is The (A) alkali-soluble resin contains a phenolic hydroxyl group and contains one or more selected from the group consisting of a polyimide precursor, a polyimide, a polybenzoxazole precursor, polybenzoxazole and a copolymer thereof. As the (D) chain transfer agent, the compound represented by the formula (1) is contained, and the content ratio of the (D) chain transfer agent is the (A) alkali-soluble resin and the (B) radically polymerizable compound. The photosensitive resin composition is 0.5 to 7 parts by mass with respect to 100 parts by mass in total.

(In the formula (1), R is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, X is an alkylene group having 1 to 10 carbon atoms. A is an integer of 0 or more and 2 or less, and b is 0 or more and 2 The following integers and c are integers of 2 or more and 4 or less, and satisfy a + b + c = 4.) The first aspect of claim 1, wherein the content ratio of the (D) chain transfer agent is 1 to 3 parts by mass with respect to 100 parts by mass in total of the (A) alkali-soluble resin and (B) radically polymerizable compound. Photosensitive resin composition. The photosensitive resin composition according to claim 1 or 2, wherein the compound represented by the formula (1) contains pentaerythritol tris (propane-3-thiol). A cured film obtained by curing the photosensitive resin composition according to any one of claims 1 to 3. A display device comprising the cured film according to claim 4. (1) A step of applying the photosensitive resin composition according to any one of claims 1 to 3 to a substrate to form a coating film.
(2) A step of exposing the coating film with active chemical rays to obtain an exposed coating film.
(3) A step of developing the exposed coating film with an alkaline solution to obtain a developed coating film, and
(4) A step of heating the developed coating film to obtain a cured film.
A method for producing a cured film having the above in this order.

Images