Photosensitive resin composition and organic EL element partition wall

Abstract

To provide a high-sensitivity photosensitive resin composition containing black colorant which is capable of forming a step pattern in halftone exposure, and capable of maintaining a step shape even after thermosetting.SOLUTION: A photosensitive resin composition includes: resin (A1) which has a plurality of phenolic hydroxyl groups, and in which at least a part of the plurality of phenolic hydroxyl groups is protected by acid-decomposable group; resin (A2) having epoxy group; quinonediazide adduct (B) to a phenolic compound; at least one kind of dissolution accelerator (C) selected from the group consisting of a compound having carboxyl group and a compound having phenolic hydroxyl group; and black colorant (D), where the total molar number of the carboxyl group and the phenolic hydroxyl group included in the quinonediazide adduct (B) and the dissolution accelerator (C) is 150 mmol or less per 100 g of solid content included in the photosensitive resin composition.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a photosensitive resin composition, an organic EL device partition wall, an organic EL device insulating film, and an organic EL device each using the same. More specifically, the present invention relates to a photosensitive resin composition containing a black colorant, and an organic EL device partition wall, an organic EL device insulating film, and an organic EL device each using the same. [Background technology]

[0002] In display devices such as organic light-emitting diode (OLED) displays, partition walls are used in the gaps between colored patterns within the display area or at the edges of the periphery of the display area to improve display characteristics. In the manufacture of OLED displays, partition walls are first formed to prevent organic material pixels from contacting each other, and organic material pixels are then formed between the partition walls. These partition walls are generally formed by photolithography using a photosensitive resin composition and have insulating properties. Specifically, a photosensitive resin composition is applied to a substrate using a coating device, volatile components are removed by heating or other means, and the composition is exposed to light through a mask. The resulting pattern is then developed by removing the unexposed portions in the case of a negative-tone pattern and the exposed portions in the case of a positive-tone pattern with a developer such as an alkaline aqueous solution. The resulting pattern is then heat-treated to form partition walls (insulating films). Next, organic materials that emit light in three colors (red, green, and blue) are deposited between the partition walls by inkjet printing or other methods to form the pixels of the OLED display.

[0003] When forming the light-emitting layer, deposition is performed by bringing a deposition mask into contact with the pixel division layer. If the contact area between the pixel division layer and the deposition mask is large, particle generation may result, reducing panel yield. Furthermore, the pixel division layer may be damaged by deposits on the deposition mask, allowing moisture to penetrate through the damaged area and degrade the light-emitting elements. One method to solve these problems is to deposit the pixel division layer in two layers and narrow the width of the second layer to reduce the contact area. However, this method requires complicated processes, which may inevitably increase process time or reduce panel yield. Another method to solve these problems is to form a pattern using a halftone photomask. This method allows the pixel division layer with a stepped shape to be formed in a single layer, thereby reducing the contact area with the deposition mask without increasing process time. A positive-type photosensitive resin composition containing a naphthoquinone diazide compound is generally used to deposit a single layer of the pixel division layer with a stepped shape.

[0004] On the other hand, in recent years, in this field, due to the miniaturization of display devices and the diversification of displayed content, there has been a demand for higher pixel performance and higher resolution. Attempts have been made to impart light-blocking properties to partition wall materials using colorants in order to increase the contrast and improve visibility in display devices. However, when partition wall materials are imparted with light-blocking properties, the photosensitive resin composition tends to have low sensitivity, which may result in longer exposure times and reduced productivity. Therefore, photosensitive resin compositions used to form partition wall materials containing colorants are required to have higher sensitivity.

[0005] Patent Document 1 (JP 2001-281440 A) describes a radiation-sensitive resin composition that exhibits high light-blocking properties through heat treatment after exposure, in which titanium black is added to a positive-tone radiation-sensitive resin composition containing an alkali-soluble resin and a quinone diazide compound.

[0006] Patent Document 2 (JP 2002-116536 A) describes a method for blackening a partition wall material by using carbon black in a radiation-sensitive resin composition containing [A] an alkali-soluble resin, [B] a 1,2-quinonediazide compound, and [C] a colorant.

[0007] Patent Document 3 (JP 2010-237310 A) describes a radiation-sensitive resin composition that exhibits light-blocking properties by heat treatment after exposure, in which a heat-sensitive dye is added to a positive-tone radiation-sensitive resin composition containing an alkali-soluble resin and a quinone diazide compound.

[0008] Patent Document 4 (WO 2017 / 069172) describes a positive photosensitive resin composition containing (A) a binder resin, (B) a quinone diazide compound, and (C) at least one black dye selected from black dyes defined by the color index of Solvent Black 27 to 47. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-281440 [Patent Document 2] Japanese Patent Application Laid-Open No. 2002-116536 [Patent Document 3] Japanese Patent Application Laid-Open No. 2010-237310 [Patent Document 4] International Publication No. 2017 / 069172 Summary of the Invention [Problem to be solved by the invention]

[0010] In the photosensitive resin composition used to form a colored partition wall material, a considerable amount of colorant must be used to sufficiently enhance the light-shielding properties of the cured film. When such a large amount of colorant is used, the radiation irradiated onto the coating of the photosensitive resin composition is absorbed by the colorant, reducing the effective intensity of the radiation in the coating and resulting in insufficient exposure of the photosensitive resin composition, resulting in poor pattern formability.

[0011] In forming partition walls in organic EL devices, it is important that the material forming the partition walls has high sensitivity from the viewpoint of productivity, etc. However, when a black photosensitive resin composition containing a colorant is used, poor exposure occurs under commonly used exposure conditions, and therefore, for example, a long exposure time is required, which reduces productivity. Therefore, there is a strong demand for reducing the exposure dose of the photosensitive resin composition to reduce energy costs and increase throughput.

[0012] The sensitivity of a photosensitive resin composition can be improved by adding a low-molecular-weight phenolic compound having a low hydroxyl equivalent weight to the composition. However, in a photosensitive resin composition that exhibits curability upon heat treatment after exposure and development, increasing the amount of such a low-molecular-weight phenolic compound reduces the crosslink density of the resin, which can cause the coating film to flow during heat curing, resulting in the loss of the stepped shape.

[0013] Thus, there is a demand for a photosensitive resin composition that has high sensitivity despite having light-shielding properties and that can form a pattern having a stepped shape using a batch exposure process using a halftone photomask.

[0014] An object of the present invention is to provide a highly sensitive photosensitive resin composition containing a black colorant, which is capable of forming a step pattern by exposure using a halftone photomask (hereinafter also referred to as "halftone exposure") and is capable of maintaining the step shape even after thermal curing. [Means for solving the problem]

[0015] The present inventors have found that in a photosensitive resin composition containing a resin having a plurality of phenolic hydroxyl groups, at least a portion of which are protected with acid-decomposable groups, a resin having epoxy groups, a quinone diazide adduct of a phenol compound, a dissolution promoter, and a black colorant, by setting the total number of moles of carboxyl groups and phenolic hydroxyl groups contained in the quinone diazide adduct and the dissolution promoter to 150 mmol or less per 100 g of solids contained in the photosensitive resin composition, it is possible to form a step pattern by halftone exposure and to maintain the step shape even after thermal curing.

[0016] That is, the present invention includes the following aspects. [1] a resin (A1) having a plurality of phenolic hydroxyl groups, at least a part of which is protected with an acid-decomposable group; a resin (A2) having an epoxy group; A quinone diazide adduct to a phenolic compound (B), at least one dissolution promoter (C) selected from the group consisting of compounds having a carboxy group and compounds having a phenolic hydroxyl group; a black colorant (D); wherein the total number of moles of carboxy groups and phenolic hydroxyl groups contained in the quinone diazide adduct (B) and the dissolution promoter (C) is 150 mmol or less per 100 g of solid content contained in the photosensitive resin composition. [2] The photosensitive resin composition according to [1], wherein the quinone diazide adduct (B) is a 1,2-naphthoquinone diazide-4-sulfonic acid ester or a 1,2-naphthoquinone diazide-5-sulfonic acid ester of the phenol compound. [3] The photosensitive resin composition according to [1] or [2], wherein the quinonediazide adduct (B) has a quinonediazide group equivalent of 500 or less. [4] The photosensitive resin composition according to any one of [1] to [3], wherein the dissolution promoter (C) is an organic low-molecular-weight compound having a molecular weight of 1,000 or less. [5] The photosensitive resin composition according to any one of [1] to [4], wherein the total equivalent of the carboxyl group and the phenolic hydroxyl group in the dissolution promoter (C) is 60 or less. [6] The photosensitive resin composition according to any one of [1] to [5], wherein the total number of moles of carboxy groups and phenolic hydroxyl groups contained in the quinone diazide adduct (B) and the dissolution promoter (C) is 90 mmol or more per 100 g of solid content contained in the photosensitive resin composition. [7] The resin (A1) is a compound represented by the formula (4) [ka] (In formula (4), R 9 is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and R 10 is an acid-decomposable group, r is an integer of 0 to 5, and s is an integer of 0 to 5, provided that r+s is an integer of 1 to 5. and at least one structural unit represented by formula (4) in which s is an integer of 1 or more. [8] The resin (A1) is a compound represented by the formula (2) [ka] (In formula (2), R 2 and R 3 are each independently a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, a fully or partially fluorinated fluoroalkyl group having 1 to 3 carbon atoms, or a halogen atom; R 4 is a hydrogen atom, a linear alkyl group having 1 to 6 carbon atoms, a cyclic alkyl group having 3 to 12 carbon atoms, a phenyl group, or a phenyl group substituted with at least one group selected from the group consisting of a hydroxy group, an alkyl group having 1 to 6 carbon atoms, and an alkoxy group having 1 to 6 carbon atoms. The photosensitive resin composition according to [7], having a structural unit represented by the following formula: [9] In the resin (A1), the acid-decomposable group substituted for the hydrogen atom of the phenolic hydroxyl group is represented by the formula (3): -CR 6 R 7 -OR 8 (3) (In formula (3), R 6 and R 7 are each independently a hydrogen atom, a linear alkyl group having 1 to 4 carbon atoms, or a branched alkyl group having 3 to 4 carbon atoms, and R 8 is a linear alkyl group having 1 to 12 carbon atoms, a branched alkyl group having 3 to 12 carbon atoms, a cyclic alkyl group having 3 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, or an alkenyl group having 2 to 12 carbon atoms, and R 6 or R 7 One of the two and R 8 may be bonded to form a ring structure having 3 to 10 ring members, and R 6 , R 7 and R 8 may be substituted with a halogen atom selected from the group consisting of fluorine, chlorine, bromine and iodine. The photosensitive resin composition according to any one of [1] to [8], wherein the group is represented by the following formula:

[10] The photosensitive resin composition according to any one of [1] to [9], wherein the resin (A2) is a resin having an epoxy group and a phenolic hydroxyl group.

[11] The resin having an epoxy group and a phenolic hydroxyl group is a reaction product of a compound having at least two epoxy groups in one molecule with a hydroxybenzoic acid compound, and is represented by the formula (6): [ka] (In formula (6), b is an integer of 1 to 5, and * represents a bond to a residue other than the epoxy group involved in the reaction of a compound having at least two epoxy groups in one molecule.) The photosensitive resin composition according to

[10] , wherein the compound has the structure:

[12] The photosensitive resin composition according to

[11] , wherein the compound having at least two epoxy groups in one molecule is a novolac epoxy resin.

[13] The photosensitive resin composition according to any one of [1] to

[12] , comprising 10 to 150 parts by mass of the black colorant (D) based on 100 parts by mass of the total of the resin components.

[14] The photosensitive resin composition according to any one of [1] to

[13] , wherein the optical density (OD value) of a cured film of the photosensitive resin composition is 0.5 or more per 1 μm of film thickness.

[15] A partition wall for an organic EL device, comprising a cured product of the photosensitive resin composition according to any one of [1] to

[14] .

[16] An insulating film for an organic EL device, comprising a cured product of the photosensitive resin composition according to any one of [1] to

[14] .

[17] An organic EL device comprising a cured product of the photosensitive resin composition according to any one of [1] to

[14] . [Effects of the Invention]

[0017] According to the present invention, it is possible to provide a highly sensitive photosensitive resin composition containing a black colorant, which is capable of forming a step pattern by halftone exposure and maintaining the step shape even after thermal curing. DETAILED DESCRIPTION OF THE INVENTION

[0018] The present invention will be described in detail below.

[0019] In this disclosure, "alkali-soluble" and "alkali aqueous solution soluble" mean that the photosensitive resin composition or its components, or a coating or cured coating of the photosensitive resin composition, is soluble in a 2.38% by mass aqueous solution of tetramethylammonium hydroxide. The term "alkali-soluble functional group" refers to a group that imparts such alkali-solubility to the photosensitive resin composition or its components, or a coating or cured coating of the photosensitive resin composition. Examples of alkali-soluble functional groups include phenolic hydroxyl groups, carboxy groups, sulfo groups, phosphate groups, acid anhydride groups, and mercapto groups.

[0020] In the present disclosure, the term "acid-decomposable group" refers to a group that is decomposed (deprotected) in the presence of an acid, optionally with heating, to generate an alkali-soluble functional group.

[0021] In the present disclosure, the term "radically polymerizable functional group" refers to an ethylenically unsaturated group, and the term "radically polymerizable compound" refers to a compound having one or more ethylenically unsaturated groups.

[0022] In this disclosure, the term "structural unit" refers to an atomic group that constitutes part of the basic structure of a polymer, and this atomic group may have a pendant atom or pendant atomic group. For example, in the case of a radical (co)polymer, it refers to a unit derived from a radically polymerizable compound used as a monomer, and in the case of a phenol novolac resin, it refers to the following unit formed by the condensation reaction of one molecule of phenol (C6H5OH) and one molecule of formaldehyde (HCHO). Regarding structural units having pendant groups (side groups), structural units having pendant groups or groups derived therefrom that are used to form crosslinked sites are considered to be different from structural units having free pendant groups that are not involved in the formation of crosslinked sites. Regarding polymers having branched molecular chains (branched chains), structural units containing branch points (branch units) are considered to be different from structural units contained in linear molecular chains. [ka]

[0023] In this disclosure, "(meth)acrylic" means acrylic or methacrylic, "(meth)acrylate" means acrylate or methacrylate, and "(meth)acryloyl" means acryloyl or methacryloyl.

[0024] In the present disclosure, the number average molecular weight (Mn) and weight average molecular weight (Mw) of a resin, polymer, or copolymer refer to values ​​calculated as standard polystyrene, measured at 40°C by gel permeation chromatography (GPC) using tetrahydrofuran as the mobile phase.

[0025] In the present disclosure, the hydroxyl group equivalent of a resin, polymer, or copolymer is a theoretical value calculated from the molecular weight and composition ratio of the structural units constituting the resin, polymer, or copolymer. Specifically, when the resin is a (co)polymer of n types of monomers i (i = a natural number from 1 to n), the hydroxyl group equivalent is calculated by the following formula:

number

[0026] In the case of a resin having an epoxy group and a phenolic hydroxyl group, which will be described later, the hydroxyl group equivalent is calculated by the following formula: Hydroxyl equivalent = [(epoxy equivalent of raw material / equivalent of carboxylic acid to be added to 1 equivalent of epoxy group of raw material) + molecular weight of carboxylic acid to be added] / (number of phenolic hydroxyl groups of carboxylic acid + number of carboxyl groups that react with epoxy group of carboxylic acid) The value calculated by

[0027] In the present disclosure, the term "resin component" refers to a resin (A1) having a plurality of phenolic hydroxyl groups, at least a portion of which is protected with an acid-decomposable group, a resin (A2) having an epoxy group, and other resins (A3) described below.

[0028] In the present disclosure, the term "solid content" refers to the total mass of components including the resin component, the quinone diazide adduct of a phenolic compound (B), the solubility promoter (C), the black colorant (D), and the optional component (E), excluding the solvent (F).

[0029] [Photosensitive resin composition] The photosensitive resin composition of one embodiment includes a resin (A1) having a plurality of phenolic hydroxyl groups, at least a portion of which is protected with an acid-decomposable group, a resin (A2) having an epoxy group, a quinone diazide adduct (B) of a phenolic compound, a dissolution promoter (C), and a black colorant (D). The total number of moles of carboxyl groups and phenolic hydroxyl groups contained in the quinone diazide adduct (B) and the dissolution promoter (C) is 150 mmol or less per 100 g of solids contained in the photosensitive resin composition.

[0030] <Resin (A1) Having a Plurality of Phenolic Hydroxyl Groups, at Least Some of Which are Protected with Acid-Decomposable Groups> In the resin (A1) (hereinafter also referred to as "protected resin (A1)") having multiple phenolic hydroxyl groups, at least some of which are protected with acid-decomposable groups, the phenolic hydroxyl groups are alkali-soluble functional groups, and because some of these groups are protected with acid-decomposable groups, the alkali solubility of the protected resin (A1) before exposure is suppressed. The quinone diazide adduct (B), described below, generates an alkali-soluble carboxylic acid compound when irradiated with radiation such as visible light, ultraviolet light, gamma rays, or electron beams. The generated carboxylic acid compound promotes decomposition of the acid-decomposable groups in the protected resin (A1), regenerating the phenolic hydroxyl groups and increasing the alkali solubility of the protected resin (A1). As a result, the change in alkali solubility of the protected resin (A1) before and after exposure (before and after decomposition of the acid-decomposable groups) is large, thereby enabling further improvement in pattern resolution.

[0031] The protected resin (A1) may have an alkali-soluble functional group other than a phenolic hydroxyl group, and the alkali-soluble functional group may be protected with an acid-decomposable group in the same manner as the phenolic hydroxyl group. Examples of the alkali-soluble functional group other than a phenolic hydroxyl group include a carboxy group, a sulfo group, a phosphate group, an acid anhydride group, and a mercapto group.

[0032] The protective resin (A1) may be used alone or in combination of two or more kinds. For example, the protective resin (A1) may be a combination of two or more kinds of resins that differ in the structural unit of the polymer or copolymer, the protection rate of the acid-decomposable group, the phenolic hydroxyl group, or a combination thereof.

[0033] (Protection of phenolic hydroxyl groups with acid-labile groups) The protected resin (A1) can be obtained by protecting some of the phenolic hydroxyl groups of the base resin (a) having a plurality of phenolic hydroxyl groups with an acid-decomposable group. The protected resin (A1) having phenolic hydroxyl groups protected with an acid-decomposable group can be obtained by the reaction of Ar-OR 5 Ar represents an aromatic ring derived from phenol, and R 5 represents an acid-decomposable group.

[0034] The acid-decomposable group is a group that is decomposed (deprotected) in the presence of an acid, if necessary by heating, to generate an alkali-soluble functional group. Specific examples include groups having a tertiary alkyl group such as a tert-butyl group, a 1,1-dimethylpropyl group, a 1-methylcyclopentyl group, a 1-ethylcyclopentyl group, a 1-methylcyclohexyl group, a 1-ethylcyclohexyl group, a 1-methyladamantyl group, a 1-ethyladamantyl group, a tert-butoxycarbonyl group, and a 1,1-dimethylpropoxycarbonyl group; silyl groups such as a trimethylsilyl group, a triethylsilyl group, a t-butyldimethylsilyl group, a triisopropylsilyl group, and a t-butyldiphenylsilyl group; and groups represented by the formula (3): -CR 6 R 7 -OR 8 (3) (In formula (3), R6 and R 7 are each independently a hydrogen atom, a linear alkyl group having 1 to 4 carbon atoms, or a branched alkyl group having 3 to 4 carbon atoms, and R 8 is a linear alkyl group having 1 to 12 carbon atoms, a branched alkyl group having 3 to 12 carbon atoms, a cyclic alkyl group having 3 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, or an alkenyl group having 2 to 12 carbon atoms, and R 6 or R 7 One of the two and R 8 may be bonded to form a ring structure having 3 to 10 ring members, and R 6 , R 7 and R 8 may be substituted with a halogen atom selected from the group consisting of fluorine, chlorine, bromine, and iodine. The group represented by formula (3) forms an acetal structure or a ketal structure together with the oxygen atom derived from the phenolic hydroxyl group. These acid-decomposable groups may be used alone or in combination of two or more.

[0035] The acid-decomposable group is preferably a group represented by formula (3), since this allows a photosensitive resin composition with high sensitivity to be obtained even at a low exposure dose. 6 and R 7 are each independently a hydrogen atom, a linear alkyl group having 1 to 4 carbon atoms, or a branched alkyl group having 3 to 4 carbon atoms, and R 8is more preferably a linear alkyl group having 1 to 12 carbon atoms, a branched alkyl group having 3 to 12 carbon atoms, or a cyclic alkyl group having 3 to 12 carbon atoms, each of which may be substituted with a halogen atom selected from the group consisting of fluorine, chlorine, bromine, and iodine. Examples of such acid-decomposable groups include 1-alkoxyalkyl groups. Examples of 1-alkoxyalkyl groups include methoxymethyl, 1-methoxyethyl, 1-ethoxyethyl, 1-n-propoxyethyl, 1-n-butoxyethyl, 1-isobutoxyethyl, 1-(2-chloroethoxy)ethyl, 1-(2-ethylhexyloxy)ethyl, 1-cyclohexyloxyethyl, and 1-(2-cyclohexylethoxy)ethyl groups, with 1-ethoxyethyl and 1-n-propoxyethyl groups being preferred. Examples of acid-decomposable groups include a group represented by formula (3), in which R 6 or R 7 One of the two and R 8 and R bonded to form a ring structure having 3 to 10 ring members can also be suitably used. In this case, R not involved in the formation of the ring structure can be used. 6 or R 7 is preferably a hydrogen atom. Examples of such an acid-decomposable group include a 2-tetrahydrofuranyl group and a 2-tetrahydropyranyl group, with a 2-tetrahydrofuranyl group being preferred.

[0036] The protection reaction of the phenolic hydroxyl group can be carried out using a common protecting agent under known conditions. For example, the base resin (a) can be reacted with the protecting agent in the presence of an acid or a base at a reaction temperature of −20 to 50° C. without a solvent or in a solvent such as toluene or hexane to obtain the protected resin (A1).

[0037] Known protecting agents capable of protecting phenolic hydroxyl groups can be used as the protecting agent. For example, isobutene can be used when the acid-decomposable group is a tert-butyl group, and di-tert-butyl dicarbonate can be used when the acid-decomposable group is a tert-butoxycarbonyl group. When the acid-decomposable group is a silyl group such as a trimethylsilyl group or a triethylsilyl group, silicon-containing chlorides such as trimethylsilyl chloride or triethylsilyl chloride, or silicon-containing triflate compounds such as trimethylsilyl triflate or triethylsilyl triflate can be used. When the acid-decomposable group is a methoxymethyl group, chloromethyl methyl ether can be used; when the acid-decomposable group is a 1-ethoxyethyl group, ethyl vinyl ether can be used; when the acid-decomposable group is a 1-n-propoxyethyl group, n-propyl vinyl ether can be used; when the acid-decomposable group is a 2-tetrahydrofuranyl group, 2,3-dihydrofuran can be used; and when the acid-decomposable group is a 2-tetrahydropyranyl group, 3,4-dihydro-2H-pyran can be used.

[0038] Examples of acids include inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, and perchloric acid, and organic acids such as methanesulfonic acid, trifluoromethanesulfonic acid, p-toluenesulfonic acid, and benzenesulfonic acid. Salts of organic acids, such as pyridinium salts of p-toluenesulfonic acid, can also be used as acid sources. Examples of bases include inorganic hydroxides such as sodium hydroxide and potassium hydroxide, inorganic carbonates such as sodium carbonate, sodium bicarbonate, potassium carbonate, and cesium carbonate, metal hydrides such as sodium hydride, and amine compounds such as pyridine, N,N-dimethyl-4-aminopyridine, imidazole, triethylamine, and diisopropylethylamine.

[0039] In another embodiment, the protected resin (A1) can be obtained by protecting the phenolic hydroxyl group of a polymerizable monomer having a phenolic hydroxyl group with an acid-decomposable group, and then polymerizing or copolymerizing the polymerizable monomer having the phenolic hydroxyl group protected with the acid-decomposable group and, if necessary, other polymerizable monomers. The protection of the phenolic hydroxyl group of the polymerizable monomer having a phenolic hydroxyl group can be carried out in the same manner as in the protection of the phenolic hydroxyl group of the base resin (a).

[0040] (Base resin (a)) Examples of the base resin (a) of the protective resin (A1) include acrylic resins, polystyrene resins, polyamide resins, phenolic resins, polyimide resins, polyamic acid resins, polybenzoxazole resins, polybenzoxazole resin precursors, silicone resins, cyclic olefin polymers, cardo resins, and derivatives of these resins, all of which have multiple phenolic hydroxyl groups. For example, derivatives of phenolic resins include polyalkenylphenolic resins in which an alkenyl group is bonded to a benzene ring, and derivatives of polystyrene resins include hydroxypolystyrene resin derivatives in which a phenolic hydroxyl group and a hydroxyalkyl group or an alkoxy group are bonded to a benzene ring. Homopolymers or copolymers of polymerizable monomers having phenolic hydroxyl groups can also be used as the base resin (a). These base resins (a) can be used alone or in combination of two or more. The base resin (a) may have a radically polymerizable functional group. In one embodiment, the base resin (a) has a (meth)acryloyloxy group, an allyl group, or a methallyl group as the radically polymerizable functional group.

[0041] The base resin (a) of the protective resin (A1) preferably has a phenolic hydroxyl group on a benzene ring pendant on the polymer main chain. In the base resin (a) of the protective resin (A1) having this structure, the benzene ring having the phenolic hydroxyl group constitutes the polymer main chain, and compared to a novolak resin having a comparable hydroxyl value, the alkali compounds in the developer can easily access the phenolic hydroxyl group, resulting in high alkali solubility.

[0042] (Alkali aqueous solution soluble copolymer (a1) of polymerizable monomer having phenolic hydroxyl group and other polymerizable monomer) In one embodiment, the base resin (a) of the protective resin (A1) is an aqueous alkali-soluble copolymer (a1) (also referred to simply as "aqueous alkali-soluble copolymer (a1)" in the present disclosure) composed of a polymerizable monomer having a phenolic hydroxyl group and another polymerizable monomer, and the aqueous alkali-soluble copolymer (a1) has multiple phenolic hydroxyl groups. In this embodiment, the protective resin (A1) is an aqueous alkali-soluble copolymer (a1) in which at least a portion of the multiple phenolic hydroxyl groups are protected with an acid-decomposable group. The aqueous alkali-soluble copolymer (a1) may further have an alkali-soluble functional group other than the phenolic hydroxyl group, such as a carboxy group, a sulfo group, a phosphate group, an acid anhydride group, or a mercapto group. Examples of the polymerizable functional group possessed by the polymerizable monomer include radically polymerizable functional groups, such as CH2=CH-, CH2=C(CH3)-, CH2=CHCO-, CH2=C(CH3)CO-, -OC-CH=CH-CO-, etc.

[0043] The aqueous alkali-soluble copolymer (a1) can be produced, for example, by radical polymerization of a polymerizable monomer having a phenolic hydroxyl group with another polymerizable monomer. After synthesizing the copolymer by radical polymerization, a derivative in which a phenolic hydroxyl group is added to the copolymer may be used.

[0044] Examples of the polymerizable monomer having a phenolic hydroxyl group include 4-hydroxystyrene, 4-hydroxyphenyl(meth)acrylate, 3,5-dimethyl-4-hydroxybenzyl acrylamide, 4-hydroxyphenyl acrylamide, and 4-hydroxyphenyl maleimide.

[0045] Examples of other polymerizable monomers include styrene derivatives such as styrene, vinyltoluene, α-methylstyrene, p-methylstyrene, and p-ethylstyrene; acrylamide; acrylonitrile; vinyl alcohol ether compounds such as vinyl-n-butyl ether; methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, and sec-butyl (meth)acrylate. acrylate, tert-butyl (meth)acrylate, phenyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, glycidyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentanyl (meth)acrylate, 2,2,2-trifluoroethyl (meth)acrylate, 2,2,3,3-tetrafluoroethylene (Meth)acrylic acid esters such as trifluoropropyl (meth)acrylate; N-substituted maleimides such as phenylmaleimide and cyclohexylmaleimide; maleic acid, maleic acid derivatives such as monomethyl maleate, monoethyl maleate, monoisopropyl maleate, and maleic anhydride; (meth)acrylic acid derivatives such as (meth)acrylic acid, α-bromo(meth)acrylic acid, α-chloro(meth)acrylic acid, β-furyl(meth)acrylic acid, and β-styryl(meth)acrylic acid; fumaric acid, cinnamic acid, α-cinnamic acid, Examples thereof include unsaturated carboxylic acid compounds such as anocinnamic acid, itaconic acid, crotonic acid, propiolic acid, 3-maleimidopropionic acid, 4-maleimidobutyric acid, and 6-maleimidohexanoic acid; polymerizable monomers having a sulfo group such as (meth)allylsulfonic acid, 2-(meth)acrylamido-2-methylpropanesulfonic acid and styrenesulfonic acid; polymerizable monomers having a phosphate group such as mono(2-(meth)acryloyloxyethyl)phosphate; and polymerizable monomers having an acid anhydride group such as itaconic anhydride and citraconic anhydride.

[0046] From the viewpoint of heat resistance, etc., the aqueous alkali solution-soluble copolymer (a1) preferably has one or more cyclic structures such as an alicyclic structure, an aromatic structure, a polycyclic structure, an inorganic cyclic structure, and a heterocyclic structure.

[0047] The polymerizable monomer having a phenolic hydroxyl group preferably has one or more cyclic structures and is preferably at least one selected from the group consisting of (meth)acrylic compounds having CH═CHCO— or CH═C(CH)CO— as a radical polymerizable functional group, and maleimide compounds having —OC—CH═CH—CO—.

[0048] As a polymerizable monomer having a phenolic hydroxyl group, after polymerization, [ka] (In formula (1), R 1 is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and a is an integer of 1 to 5. 1 is preferably a hydrogen atom or a methyl group. a is preferably an integer of 1 to 3, and more preferably 1. As such a polymerizable monomer having a phenolic hydroxyl group, 4-hydroxyphenyl methacrylate is particularly preferred.

[0049] Other polymerizable monomers include those represented by the formula (2) after polymerization. [ka] (In formula (2), R 2 and R 3 are each independently a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, a fully or partially fluorinated fluoroalkyl group having 1 to 3 carbon atoms, or a halogen atom; R 4is a hydrogen atom, a linear alkyl group having 1 to 6 carbon atoms, a cyclic alkyl group having 3 to 12 carbon atoms, a phenyl group, or a phenyl group substituted with at least one group selected from the group consisting of a hydroxy group, an alkyl group having 1 to 6 carbon atoms, and an alkoxy group having 1 to 6 carbon atoms. 2 and R 3 are each preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and more preferably a hydrogen atom. 4 is preferably a cyclic alkyl group having 3 to 12 carbon atoms, a phenyl group, or a phenyl group substituted with at least one selected from the group consisting of a hydroxy group, an alkyl group having 1 to 6 carbon atoms, and an alkoxy group having 1 to 6 carbon atoms, and is more preferably a cyclic alkyl group having 3 to 12 carbon atoms or a phenyl group. As such other polymerizable monomers, phenylmaleimide and N-cyclohexylmaleimide are particularly preferred.

[0050] The aqueous alkali solution-soluble copolymer (a1) is a copolymer represented by the formula (1): [ka] (In formula (1), R 1 is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and a is an integer of 1 to 5.

[0051] The aqueous alkali solution-soluble copolymer (a1) is represented by the formula (2): [ka] (In formula (2), R 2 and R 3 are each independently a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, a fully or partially fluorinated fluoroalkyl group having 1 to 3 carbon atoms, or a halogen atom; R 4is a hydrogen atom, a linear alkyl group having 1 to 6 carbon atoms, a cyclic alkyl group having 3 to 12 carbon atoms, a phenyl group, or a phenyl group substituted with at least one selected from the group consisting of a hydroxy group, an alkyl group having 1 to 6 carbon atoms, and an alkoxy group having 1 to 6 carbon atoms.

[0052] In one embodiment, the aqueous alkali solution-soluble copolymer (a1) has a structural unit represented by the above formula (1) and a structural unit represented by the above formula (2).

[0053] It is particularly preferred to use 4-hydroxyphenyl methacrylate as the polymerizable monomer having a phenolic hydroxyl group and phenylmaleimide or N-cyclohexylmaleimide as the other polymerizable monomer. By using a resin obtained by radical polymerization of these polymerizable monomers, shape retention and developability can be improved, and outgassing can be reduced.

[0054] The polymerization initiator used in producing the base resin (a) or the aqueous alkali solution-soluble copolymer (a1) by radical polymerization includes, but is not limited to, azo polymerization initiators such as 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), dimethyl 2,2'-azobis(2-methylpropionate), 4,4'-azobis(4-cyanovaleric acid), and 2,2'-azobis(2,4-dimethylvaleronitrile) (AVN); dicumyl peroxide, 2,5-dimethyl-2 Peroxide polymerization initiators having a 10-hour half-life temperature of 100 to 170°C, such as 1,5-di(tert-butylperoxy)hexane, tert-butylcumyl peroxide, di-tert-butyl peroxide, 1,1,3,3-tetramethylbutyl hydroperoxide, and cumene hydroperoxide, or peroxide polymerization initiators such as benzoyl peroxide, lauroyl peroxide, 1,1'-di(tert-butylperoxy)cyclohexane, and tert-butyl peroxypivalate, can be used. The amount of polymerization initiator used is generally at least 0.01 parts by mass, at least 0.05 parts by mass, or at least 0.5 parts by mass, and preferably at most 40 parts by mass, at most 20 parts by mass, or at most 15 parts by mass, per 100 parts by mass of the total polymerizable monomers.

[0055] A RAFT (Reversible Addition Fragmentation Transfer) agent may be used in combination with the polymerization initiator. The RAFT agent may be, but is not limited to, a thiocarbonylthio compound such as a dithioester, dithiocarbamate, trithiocarbonate, or xanthate. The RAFT agent may be used in an amount of 0.005 to 20 parts by mass, preferably 0.01 to 10 parts by mass, per 100 parts by mass of the total of the polymerizable monomers.

[0056] The weight-average molecular weight (Mw) of the base resin (a) or the aqueous alkali-soluble copolymer (a1) can be 3,000 to 80,000, preferably 4,000 to 70,000, and more preferably 5,000 to 60,000. The number-average molecular weight (Mn) can be 1,000 to 30,000, preferably 1,500 to 25,000, and more preferably 2,000 to 20,000. The polydispersity (Mw / Mn) can be 1.0 to 3.5, preferably 1.1 to 3.0, and more preferably 1.2 to 2.8. By setting the weight-average molecular weight, number-average molecular weight, and polydispersity within the above ranges, a photosensitive resin composition with excellent alkali solubility and developability can be obtained.

[0057] In one embodiment, 10 mol % to 95 mol %, preferably 20 mol % to 80 mol %, and more preferably 25 mol % to 70 mol % of the phenolic hydroxyl groups in the protective resin (A1) are protected with acid-decomposable groups. By setting the proportion of phenolic hydroxyl groups protected with acid-decomposable groups to 10 mol % or more in the protective resin (A1), it is possible to promote dissolution of the exposed area and create a difference in solubility between the unexposed area and the exposed area, thereby achieving high sensitivity and ensuring the stability and durability of the coating film after thermal curing. By setting the proportion of phenolic hydroxyl groups protected with acid-decomposable groups to 95 mol % or less, it is possible to reduce the amount of unreacted acid-decomposable groups remaining, increase the solubility of the exposed area, and achieve high sensitivity. The proportion of phenolic hydroxyl groups protected with acid-decomposable groups can be determined by nuclear magnetic resonance (NMR) analysis. 1 It is calculated from the integrated value of the H NMR spectrum. In the present disclosure, when the protected resin (A1) is a combination of two or more resins with different protection rates, the protection rate of the phenolic hydroxyl groups in the protected resin (A1) is a value when the two or more resins are regarded as a single protected resin (A1) as a whole.

[0058] In one embodiment, 5 mol % to 65 mol %, preferably 10 mol % to 55 mol %, and more preferably 15 mol % to 50 mol % of the phenolic hydroxyl groups in the protected resin (A1) are protected with acid-decomposable groups, based on the total alkali-soluble functional groups in the resin components. By setting the protection rate of the phenolic hydroxyl groups in the protected resin (A1) to 5 mol % or more, based on the total alkali-soluble functional groups in the resin components, it is possible to promote dissolution of the exposed area and differentiate the solubility of the unexposed area from the exposed area, thereby achieving high sensitivity and ensuring the stability and durability of the coating film after thermal curing. By setting the protection rate of the phenolic hydroxyl groups in the protected resin (A1) to 65 mol % or less, based on the total alkali-soluble functional groups in the resin components, it is possible to ensure the solubility of the exposed area. The alkali-soluble functional groups that serve as the basis for the protection rate include, in addition to phenolic hydroxyl groups, any carboxy group, sulfo group, phosphate group, acid anhydride group, and mercapto group.

[0059] In one embodiment, the protective resin (A1) is a resin in which an aqueous alkali solution-soluble copolymer (a1) having a plurality of phenolic hydroxyl groups is used as the base resin (a), and at least some of the phenolic hydroxyl groups are protected with acid-decomposable groups.

[0060] In an embodiment in which the aqueous alkali solution-soluble copolymer (a1) is the base resin (a), the protective resin (A1) is a compound represented by the formula (4): [ka] (In formula (4), R 9 is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and R 10 is an acid-decomposable group, r is an integer of 0 to 5, and s is an integer of 0 to 5, with the proviso that r+s is an integer of 1 to 5. It is preferable that the compound has a structural unit represented by formula (4), and has at least one structural unit represented by formula (4) in which s is an integer of 1 or more. 10 The acid-decomposable group is preferably a group represented by the above formula (3).

[0061] In an embodiment in which the aqueous alkali solution-soluble copolymer (a1) is used as the base resin (a), the protective resin (A1) preferably has a structural unit represented by the above formula (2).

[0062] In one embodiment, the protective resin (A1) has a structural unit represented by the above formula (4) and a structural unit represented by the above formula (2).

[0063] In one embodiment, the number of structural units represented by formula (4) where s is an integer of 1 or greater, i.e., structural units represented by formula (4) in which at least one phenolic hydroxyl group is protected with an acid-decomposable group, is 5% to 95%, preferably 15% to 70%, and more preferably 25% to 60% of the total number of structural units in the protected resin (A1). By setting the proportion of these structural units to 5% or greater, it is possible to promote dissolution of the exposed area and create a difference in solubility between the unexposed and exposed areas, thereby achieving high sensitivity and ensuring the stability and durability of the coating after thermal curing. By setting the proportion of these structural units to 95% or less, it is possible to reduce the amount of unreacted acid-decomposable groups remaining, increase the solubility of the exposed area, and achieve high sensitivity.

[0064] In one embodiment, the photosensitive resin composition contains 5% to 50% by mass, preferably 7% to 40% by mass, and more preferably 10% to 30% by mass of the protective resin (A1) based on 100% by mass of the solids content. If the content of the protective resin (A1) is 5% by mass or more based on 100% by mass of the solids content, the dissolution of the exposed area can be promoted, thereby creating a difference in solubility between the unexposed area and the exposed area, thereby achieving high sensitivity and ensuring the stability and durability of the coating after thermal curing. If the content of the protective resin (A1) is 50% by mass or less based on 100% by mass of the solids content, the amount of unreacted acid-decomposable groups remaining can be reduced, increasing the solubility of the exposed area, and achieving high sensitivity.

[0065] In one embodiment, the photosensitive resin composition contains 10% by mass to 60% by mass, preferably 15% by mass to 55% by mass, and more preferably 20% by mass to 50% by mass of the protective resin (A1) based on the total mass of the resin components. When the content of the protective resin (A1) is 10% by mass or more based on the total mass of the resin components, dissolution of the exposed area can be promoted, thereby achieving high sensitivity. When the content of the protective resin (A1) is 60% by mass or less based on the total mass of the resin components, the desired alkali solubility can be obtained.

[0066] <Resin (A2) Having Epoxy Groups> The resin (A2) having an epoxy group is not particularly limited, and examples of the resin having an epoxy group include novolac epoxy resins such as phenol novolac epoxy resins and cresol novolac epoxy resins, bisphenol epoxy resins, biphenol epoxy resins, naphthalene skeleton-containing epoxy resins, alicyclic epoxy resins, and heterocyclic epoxy resins.

[0067] In the present disclosure, when a resin (A2) having an epoxy group also falls under the category of the protective resin (A1), it is treated as the resin (A2) having an epoxy group. In other words, the protective resin (A1) does not include those that fall under the category of the resin (A2) having an epoxy group.

[0068] (Resin containing epoxy groups and phenolic hydroxyl groups) In one embodiment, the resin (A2) having an epoxy group is a resin having an epoxy group and a phenolic hydroxyl group. The resin having an epoxy group and a phenolic hydroxyl group is an aqueous alkali-soluble resin. The resin having an epoxy group and a phenolic hydroxyl group may have an alkali-soluble functional group other than a phenolic hydroxyl group. The phenolic hydroxyl group and other alkali-soluble functional groups may be protected with the acid-decomposable group described above for the protective resin (A1). The resin having an epoxy group and a phenolic hydroxyl group can be obtained, for example, by reacting a portion of the epoxy groups of a compound having at least two epoxy groups per molecule (hereinafter sometimes referred to as an "epoxy compound") with the carboxyl group of a hydroxybenzoic acid compound. The epoxy groups of the resin having an epoxy group and a phenolic hydroxyl group react with the phenolic hydroxyl groups to form crosslinks during heat treatment (post-baking) after development, thereby improving the chemical resistance, heat resistance, etc. of the coating. Since the phenolic hydroxyl group contributes to solubility in an alkaline aqueous solution during development, a resin having an epoxy group and a phenolic hydroxyl group also functions as a dissolution promoter for other resins when exposed to light at a low exposure dose, thereby making it possible to impart high sensitivity to the photosensitive resin composition.

[0069] The following reaction formula 1 shows an example of a reaction in which one of the epoxy groups of an epoxy compound reacts with a carboxy group of a hydroxybenzoic acid compound to form a compound having a phenolic hydroxyl group. [ka]

[0070] Examples of compounds having at least two epoxy groups per molecule include novolac epoxy resins such as phenol novolac epoxy resins and cresol novolac epoxy resins, bisphenol epoxy resins, biphenol epoxy resins, naphthalene skeleton-containing epoxy resins, alicyclic epoxy resins, and heterocyclic epoxy resins. These epoxy compounds may contain two or more epoxy groups per molecule, and may be used alone or in combination of two or more. Because these compounds are thermosetting, it is common knowledge among those skilled in the art that their structures cannot be unambiguously described due to differences in the presence or absence of epoxy groups, the type of functional group, the degree of polymerization, and other factors.

[0071] An example of the structure of a novolac epoxy resin is shown in formula (5). In formula (5), R 11 is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 or 2 carbon atoms, or a hydroxyl group; and m is an integer of 1 to 50. [ka]

[0072] Examples of phenol novolac epoxy resins include EPICLON® N-770 (DIC Corporation) and jER®-152 (Mitsubishi Chemical Corporation). Examples of cresol novolac epoxy resins include EPICLON® N-695 (DIC Corporation) and EOCN®-102S (Nippon Kayaku Co., Ltd.). Examples of bisphenol epoxy resins include bisphenol A epoxy resins such as jER® 828, jER® 1001 (Mitsubishi Chemical Corporation), and YD-128 (trade name, Nippon Steel Chemical & Material Co., Ltd.), and bisphenol F epoxy resins such as jER® 806 (Mitsubishi Chemical Corporation) and YDF-170 (trade name, Nippon Steel Chemical & Material Co., Ltd.). Examples of biphenol-type epoxy resins include jER (registered trademark) YX-4000 and jER (registered trademark) YL-6121H (Mitsubishi Chemical Corporation). Examples of naphthalene skeleton-containing epoxy resins include NC-7000 (trade name, Nippon Kayaku Co., Ltd.) and EXA-4750 (trade name, DIC Corporation). Examples of alicyclic epoxy resins include EHPE (registered trademark)-3150 (Daicel Chemical Industries, Ltd.). Examples of heterocyclic epoxy resins include TEPIC (registered trademark), TEPIC-L, TEPIC-H, and TEPIC-S (Nissan Chemical Industries, Ltd.).

[0073] The compound having at least two epoxy groups per molecule is preferably a novolac epoxy resin, more preferably at least one selected from the group consisting of phenol novolac epoxy resins and cresol novolac epoxy resins, and even more preferably a cresol novolac epoxy resin. Photosensitive resin compositions containing a resin having epoxy groups and phenolic hydroxyl groups derived from a novolac epoxy resin, particularly a cresol novolac epoxy resin, have excellent pattern formability, easy adjustment of alkali solubility, and little outgassing.

[0074] The hydroxybenzoic acid compound is a compound in which at least one of the 2- to 6-positions of benzoic acid is substituted with a hydroxyl group, and examples thereof include salicylic acid, 4-hydroxybenzoic acid, 2,3-dihydroxybenzoic acid, 2,4-dihydroxybenzoic acid, 2,5-dihydroxybenzoic acid, 2,6-dihydroxybenzoic acid, 3,4-dihydroxybenzoic acid, 3,5-dihydroxybenzoic acid, 2-hydroxy-5-nitrobenzoic acid, 3-hydroxy-4-nitrobenzoic acid, and 4-hydroxy-3-nitrobenzoic acid. Dihydroxybenzoic acid compounds are preferred in terms of enhancing alkaline developability. The hydroxybenzoic acid compounds can be used alone or in combination of two or more.

[0075] In one embodiment, the resin having an epoxy group and a phenolic hydroxyl group is a reaction product of a compound having at least two epoxy groups in one molecule with a hydroxybenzoic acid compound, and is represented by the formula (6): [ka] (In formula (6), b is an integer of 1 to 5, and * represents a bond to a residue other than the epoxy group involved in the reaction of a compound having at least two epoxy groups in one molecule.) It has the following structure.

[0076] In a method for obtaining a resin having an epoxy group and a phenolic hydroxyl group from an epoxy compound and a hydroxybenzoic acid compound, 0.2 to 0.95 equivalents of the hydroxybenzoic acid compound can be used relative to 1 equivalent of the epoxy group of the epoxy compound, preferably 0.3 to 0.9 equivalents, and more preferably 0.4 to 0.8 equivalents. If the amount of the hydroxybenzoic acid compound is 0.2 equivalents or more, sufficient alkali solubility can be obtained, and if it is 0.95 equivalents or less, an increase in molecular weight due to side reactions can be suppressed.

[0077] A catalyst may be used to promote the reaction between the epoxy compound and the hydroxybenzoic acid compound. The amount of catalyst used may be 0.1 to 10 parts by mass based on 100 parts by mass of the reaction raw material mixture consisting of the epoxy compound and the hydroxybenzoic acid compound. The reaction temperature may be 60 to 150°C, and the reaction time may be 3 to 30 hours. Examples of catalysts used in this reaction include triethylamine, benzyldimethylamine, triethylammonium chloride, benzyltrimethylammonium bromide, benzyltrimethylammonium iodide, triphenylphosphine, chromium octanoate, and zirconium octanoate.

[0078] The number average molecular weight (Mn) of the epoxy group-containing resin (A2) is preferably 500 to 8,000, more preferably 800 to 6,000, and even more preferably 1,000 to 5,000. The weight average molecular weight (Mw) of the epoxy group-containing resin (A2) is preferably 500 to 30,000, more preferably 2,000 to 25,000, and even more preferably 3,000 to 20,000. When the number average molecular weight is 500 or more, or when the weight average molecular weight is 500 or more, the alkali development rate is appropriate and the difference in dissolution rate between the exposed and unexposed areas is sufficient, resulting in good pattern resolution. When the number average molecular weight is 8,000 or less, or when the weight average molecular weight is 30,000 or less, the coatability and alkali developability are good.

[0079] In one embodiment, the epoxy equivalent of the epoxy group-containing resin (A2) is 300 to 7000, preferably 400 to 6000, and more preferably 500 to 5000. When the epoxy equivalent of the epoxy group-containing resin (A2) is 300 or more, sufficient alkali solubility can be imparted to the resin having an epoxy group and a phenolic hydroxyl group. When the epoxy equivalent of the epoxy group-containing resin (A2) is 7000 or less, the strength and heat resistance of the cured coating can be improved. The epoxy equivalent is determined according to JIS K 7236:2009.

[0080] In one embodiment, the hydroxyl equivalent of the resin having an epoxy group and a phenolic hydroxyl group is 160 to 500, preferably 170 to 400, and more preferably 180 to 300. When the hydroxyl equivalent of the resin having an epoxy group and a phenolic hydroxyl group is 160 or more, the strength and heat resistance of the coating film after curing can be increased. When the hydroxyl equivalent of the resin having an epoxy group and a phenolic hydroxyl group is 500 or less, sufficient alkali solubility can be imparted to the resin having an epoxy group and a phenolic hydroxyl group.

[0081] In one embodiment, the photosensitive resin composition contains 10% by mass to 50% by mass, preferably 12% by mass to 40% by mass, and more preferably 15% by mass to 30% by mass of the epoxy group-containing resin (A2) based on 100% by mass of the solid content. When the content of the epoxy group-containing resin (A2) is 10% by mass or more based on 100% by mass of the solid content, dissolution of the exposed area can be promoted, thereby achieving high sensitivity, and flow of the coating during thermal curing can be suppressed, ensuring the stability and durability of the coating after thermal curing. When the content of the epoxy group-containing resin (A2) is 50% by mass or less based on 100% by mass of the solid content, solubility of the unexposed area can be kept low, thereby maintaining a high residual film rate.

[0082] In one embodiment, the photosensitive resin composition contains 15% by mass to 60% by mass, preferably 20% by mass to 55% by mass, and more preferably 25% by mass to 50% by mass of the epoxy group-containing resin (A2) based on the total mass of the resin components. When the content of the epoxy group-containing resin (A2) is 15% by mass or more based on the total mass of the resin components, the flow of the coating during heat curing can be suppressed, and the stability and durability of the coating after heat curing can be ensured. When the content of the epoxy group-containing resin (A2) is 60% by mass or less based on the total mass of the resin components, the desired alkali solubility can be obtained.

[0083] <Other Resins (A3)> The photosensitive resin composition may further contain another resin (A3) in addition to the protective resin (A1) and the resin (A2) having an epoxy group. The other resin (A3) is not particularly limited, but is preferably a resin having an alkali-soluble functional group. Examples of the alkali-soluble functional group include a phenolic hydroxyl group, a carboxyl group, a sulfo group, a phosphate group, an acid anhydride group, and a mercapto group. Two or more types of other resins (A3) having alkali-soluble functional groups may be used.

[0084] Examples of the other resin (A3) include homopolymers or copolymers of polymerizable monomers having alkali-soluble functional groups. Examples of the other resin (A3) include acrylic resins, polystyrene resins, polyamide resins, phenolic resins, polyimide resins, polyamic acid resins, polybenzoxazole resins, polybenzoxazole resin precursors, silicone resins, cyclic olefin polymers, cardo resins, and derivatives of these resins, as well as resins to which alkali-soluble functional groups are bonded. For example, derivatives of phenolic resins include polyalkenylphenolic resins in which an alkenyl group is bonded to a benzene ring, and derivatives of polystyrene resins include hydroxypolystyrene resin derivatives in which a phenolic hydroxyl group and a hydroxyalkyl group or alkoxy group are bonded to a benzene ring. The other resin (A3) can be used alone or in combination of two or more types.

[0085] The other resin (A3) may have a radically polymerizable functional group. In one embodiment, the other resin (A3) has a (meth)acryloyloxy group, an allyl group, or a methallyl group as the radically polymerizable functional group.

[0086] From the viewpoint of miscibility with the protective resin (A1), the other resin (A3) is preferably the resin described as the base resin (a) of the protective resin (A1), and more preferably the above-mentioned aqueous alkali solution-soluble copolymer (a1). Suitable embodiments of the aqueous alkali solution-soluble copolymer (a1) are as described for the base resin (a).

[0087] In one embodiment, the photosensitive resin composition contains 2% by mass to 40% by mass, preferably 5% by mass to 35% by mass, and more preferably 10% by mass to 30% by mass of the other resin (A3) based on 100% by mass of the solid content. When the content of the other resin (A3) is 2% by mass or more based on 100% by mass of the solid content, the flow of the coating during heat curing can be suppressed, and the stability and durability of the coating after heat curing can be ensured. When the content of the other resin (A3) is 40% by mass or less based on 100% by mass of the solid content, dissolution of the exposed area can be promoted, achieving high sensitivity.

[0088] In one embodiment, the photosensitive resin composition contains 5% by mass to 60% by mass, preferably 10% by mass to 55% by mass, and more preferably 15% by mass to 50% by mass of the other resin (A3) based on the total mass of the resin components. When the content of the other resin (A3) is 5% by mass or more based on the total mass of the resin components, the desired alkali solubility can be obtained. When the content of the other resin (A3) is 60% by mass or less based on the total mass of the resin components, a highly sensitive positive photosensitive resin composition can be obtained.

[0089] In one embodiment, the total number of moles of hydroxyl groups contained in the resin components of the photosensitive resin composition is preferably 170 to 300 mmol, more preferably 180 to 290 mmol, and even more preferably 190 to 280 mmol per 100 g of solids contained in the photosensitive resin composition. When the total number of moles of hydroxyl groups contained in the resin components is 170 mmol or more per 100 g of solids contained in the photosensitive resin composition, the flow of the coating during thermal curing can be suppressed, and the stability and durability of the coating after thermal curing can be ensured. When the total number of moles of hydroxyl groups contained in the resin components is 300 mmol or less per 100 g of solids contained in the photosensitive resin composition, the desired alkali solubility can be obtained.

[0090] <Quinone diazide adduct (B)> The photosensitive resin composition contains at least one quinone diazide adduct (B) of a phenol compound as a radiation-sensitive compound.

[0091] In the present disclosure, the quinone diazide adduct (B) means a compound in which some or all of the phenolic hydroxyl groups of a phenol compound have been substituted with a group having a quinone diazide structure.

[0092] For example, the quinone diazide adduct (B) having a skeleton of a trivalent phenol compound represented by the following formula (7) means a compound represented by the following formula (8) in which at least one of the three phenolic hydroxyl groups of the phenol compound is substituted with a group having a quinone diazide structure, for example, the naphthoquinone diazide sulfonate group shown below. The substitution with the naphthoquinone diazide sulfonate group can be achieved by esterifying (sulfonating) the phenolic hydroxyl group of the phenol compound with a quinone diazide sulfonyl halide. [ka] [ka]

[0093] In the above structural formula, each R is independently a hydrogen atom, a group represented by formula (9-1), or a group represented by formula (9-2). [ka] [ka]

[0094] When quinone diazide adduct (B) is irradiated with ultraviolet light or the like, it generates a carboxy group via the reaction shown in the following reaction formula 2. The generation of a carboxy group makes the exposed portion (coating) soluble in an alkaline aqueous solution, and this portion becomes alkaline developable. [ka]

[0095] Examples of phenolic compounds include Bis-Z, BisP-EZ, TekP-4HBPA, TrisP-HAP, TrisP-PA, TrisP-SA, TrisOCR-PA, BisOCHP-Z, BisP-MZ, BisP-PZ, BisP-IPZ, BisOCP-IPZ, BisP-CP, BisRS-2P, BisRS-3P, BisP-OCHP, methylenetris-FR-CR, BisRS-26X, DML-MBPC, DML-MBOC, DML-OCHP, DML-PCHP, DML-PC, DML-PTBP, DML-34X, DML-EP, DML-POP, dimethylol-BisOC-P, DML-PFP, DML-PSBP, and DML-M Examples of suitable phenols include, but are not limited to, TrisPC, TriML-P, TriML-35XL, TML-BP, TML-HQ, TML-pp-BPF, TML-BPA, TMOM-BP, HML-TPPHBA, and HML-TPHAP (all trade names, Honshu Chemical Industry Co., Ltd.), 2,6-bis(methoxymethyl)-4-tert-butylphenol, 2,6-bis(methoxymethyl)-p-cresol, 2,6-bis(acetoxymethyl)-p-cresol, naphthol, trihydroxybenzophenone, tetrahydroxybenzophenone, bisphenol A, bisphenol E, methylene bisphenol, and BisP-AP (trade name, Honshu Chemical Industry Co., Ltd.).

[0096] The phenol compound preferably has two or more phenolic hydroxyl groups, more preferably three or more phenolic hydroxyl groups. The quinone diazide adduct (B) obtained from a phenol compound having three or more phenolic hydroxyl groups has a high level of balance between photosensitivity and solubility, and therefore can improve the sensitivity of the photosensitive resin composition.

[0097] Suitable phenol compounds include, for example, those having the following structural formulas (b-1) to (b-6). [ka] [ka] [ka] [ka] [ka] [ka]

[0098] The quinone diazide adduct (B) can be obtained, for example, by subjecting the phenolic hydroxyl group of a phenol compound to an esterification reaction with a compound represented by formula (10-1) or formula (10-2). [ka] [ka]

[0099] In formula (10-1) and formula (10-2), R a ~R d each independently represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms, and X represents a halogen atom or OH.

[0100] R a ~R d are each independently preferably a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or an alkoxy group having 1 to 3 carbon atoms, more preferably a hydrogen atom, a methyl group, or a methoxy group, and even more preferably a hydrogen atom. X is preferably a chlorine atom. Examples of compounds represented by formula (10-1) and formula (10-2) include 1,2-naphthoquinone diazide-4-sulfonic acid chloride and 1,2-naphthoquinone diazide-5-sulfonic acid chloride, with 1,2-naphthoquinone diazide-5-sulfonic acid chloride being preferred.

[0101] In one embodiment, the quinone diazide adduct (B) has a phenolic compound in which the phenolic hydroxyl group is substituted with a group having a quinone diazide structure represented by formula (11-1) or formula (11-2) (hereinafter, also simply referred to as a "quinone diazide group").

[0102] [ka] [ka]

[0103] In formula (11-1) and formula (11-2), R a ~R d R each independently represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms, and * represents the bond between the phenolic hydroxyl group of the phenol compound and the oxygen atom. a ~R d are each independently preferably a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or an alkoxy group having 1 to 3 carbon atoms, more preferably a hydrogen atom, a methyl group, or a methoxy group, and even more preferably a hydrogen atom.

[0104] More specifically, the quinone diazide adduct (B) is preferably at least one of the compounds represented by the following formulae (B-1) to (B-6). [ka] [ka] [ka] [ka] [ka] [ka]

[0105] In the above formulas (B-1) to (B-6), R is each independently a hydrogen atom, a group represented by formula (9-1), or a group represented by formula (9-2). [ka] [ka]

[0106] The quinone diazide adduct (B) preferably contains a 1,2-naphthoquinone diazide-4-sulfonic acid ester or a 1,2-naphthoquinone diazide-5-sulfonic acid ester of a phenolic compound, and more preferably a 1,2-naphthoquinone diazide-4-sulfonic acid ester or a 1,2-naphthoquinone diazide-5-sulfonic acid ester of a phenolic compound. The quinone diazide adduct (B) may have both a 1,2-naphthoquinone diazide-4-sulfonic acid ester bond and a 1,2-naphthoquinone diazide-5-sulfonic acid ester bond in one molecule. In one embodiment, the quinone diazide adduct (B) is a 1,2-naphthoquinone diazide-4-sulfonic acid ester. In another embodiment, the quinone diazide adduct (B) is a 1,2-naphthoquinone diazide-5-sulfonic acid ester.

[0107] The degree of substitution in the quinone diazide adduct (B) (the proportion of phenolic hydroxyl groups of the phenol compound substituted with groups having a quinone diazide structure, based on the total number of molecules of the quinone diazide adduct (B)) is preferably 20 mol% or more, more preferably 30 mol% or more, and even more preferably 40 mol% or more. By setting the degree of substitution to 20 mol% or more, the difference in solubility between the unexposed area and the exposed area can be increased. The degree of substitution may be 100 mol% or less, 95 mol% or less, or 93 mol% or less.

[0108] The photosensitive resin composition contains the quinone diazide adduct (B) in an amount of preferably 10 to 50 parts by mass, more preferably 12 to 45 parts by mass, and even more preferably 15 to 40 parts by mass, based on 100 parts by mass of the total resin components. When the content of the quinone diazide adduct (B) is 10 parts by mass or more, based on 100 parts by mass of the total resin components, high sensitivity can be achieved. When the content of the quinone diazide adduct (B) is 50 parts by mass or less, based on 100 parts by mass of the total resin components, alkaline developability is good.

[0109] Without being bound by any theory, it is believed that the carboxylic acid compound generated from the quinone diazide adduct (B) promotes the decomposition of the acid-labile groups in the protected resin (A1), regenerating phenolic hydroxyl groups and increasing the alkaline solubility of the protected resin (A1). Before exposure, the quinone diazide adduct (B) interacts (e.g., forms hydrogen bonds) with alkali-soluble functional groups, such as phenolic hydroxyl groups, contained in the resin, rendering it insoluble in alkaline aqueous solutions. Meanwhile, the presence of the alkali-soluble carboxylic acid compound in the irradiated area facilitates the dissolution of the resin in that area in alkaline aqueous solutions, along with the carboxylic acid compound. Furthermore, the carboxylic acid compound has a relatively larger molecular structure than acids generated from photoacid generators commonly used in chemically amplified resists, such as p-toluenesulfonic acid and 1-propanesulfonic acid, and thus is less likely to diffuse within the film. These synergistic effects are believed to increase the difference in alkaline solubility between the unexposed and exposed areas, thereby enabling the formation of high-sensitivity, high-resolution patterns even at low exposure doses.

[0110] In one embodiment, high-resolution patterns can be formed without the post-exposure bake (PEB) required for typical chemically amplified resists. The quinone diazide adduct (B) has a relatively high quantum yield, efficiently generating a carboxylic acid compound in the exposed area. When an acid-labile group capable of being decomposed by a carboxylic acid compound is present in the vicinity, the generated carboxylic acid compound decomposes the acid-labile group even at room temperature, regenerating a phenolic hydroxyl group, thereby increasing the difference in alkaline solubility between the unexposed and exposed areas. By omitting PEB, deterioration of pattern formability due to excessive diffusion of acid generated from the photoacid generator to the unexposed area in the high-temperature environment during PEB can be suppressed. Furthermore, when the epoxy-containing resin (A2) contains a resin having both epoxy and phenolic hydroxyl groups, omitting PEB prevents ring-opening polymerization of the epoxy groups in the resin having both epoxy and phenolic hydroxyl groups, thereby maintaining the alkaline solubility of the resin having both epoxy and phenolic hydroxyl groups during development.

[0111] The total number of moles of quinone diazide groups contained in the quinone diazide adduct (B) is preferably 20 mmol to 60 mmol, more preferably 22 mmol to 55 mmol, and even more preferably 25 mmol to 50 mmol per 100 g of solids contained in the photosensitive resin composition. When the total number of moles of quinone diazide groups is 20 mmol or more, high sensitivity can be obtained and flow of the coating film during thermal curing can be suppressed. When the total number of moles of quinone diazide groups is 60 mmol or less, alkaline developability can be improved.

[0112] The quinone diazide adduct (B) preferably has a quinone diazide group equivalent of 500 or less. When the quinone diazide group equivalent is 500 or less, high sensitivity can be obtained and the flow of the coating film during thermal curing can be suppressed. When a plurality of quinone diazide adducts (B) are used in combination, it is more preferable that the quinone diazide group equivalent of each quinone diazide adduct (B) is 500 or less.

[0113] <Solubility enhancer (C)> The photosensitive resin composition contains a dissolution promoter (C) for improving the solubility of the alkali-soluble portion in the developer during development.

[0114] The dissolution promoter (C) may be an organic low molecular weight compound selected from the group consisting of compounds having a carboxy group and compounds having a phenolic hydroxyl group. The dissolution promoter (C) may be used alone or in combination of two or more kinds.

[0115] In the present disclosure, the term "low molecular weight compound" refers to a compound having a molecular weight of 1,000 or less. The organic low molecular weight compound has a carboxy group and / or a phenolic hydroxyl group and is alkali-soluble. The organic low molecular weight compound may have only a carboxy group, only a phenolic hydroxyl group, or both a carboxy group and a phenolic hydroxyl group. The total number of carboxy groups and phenolic hydroxyl groups contained in one molecule of the organic low molecular weight compound is preferably 2 or more.

[0116] Examples of such organic low molecular weight compounds include aliphatic monocarboxylic acids such as formic acid, acetic acid, propionic acid, butyric acid, valeric acid, pivalic acid, caproic acid, diethylacetic acid, enanthic acid, and caprylic acid; aliphatic dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, brassylic acid, methylmalonic acid, ethylmalonic acid, dimethylmalonic acid, methylsuccinic acid, tetramethylsuccinic acid, and citraconic acid; aliphatic tricarboxylic acids such as tricarballylic acid, aconitic acid, and camphoronic acid; and aromatic monocarboxylic acids such as benzoic acid, toluic acid, cumic acid, hemimellitic acid, and mesitylene acid. Examples of aromatic polycarboxylic acids include phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, trimesic acid, mellophanic acid, and pyromellitic acid; aromatic hydroxycarboxylic acids such as dihydroxybenzoic acid, trihydroxybenzoic acid, and gallic acid; other carboxylic acids such as phenylacetic acid, hydratropic acid, hydrocinnamic acid, mandelic acid, phenylsuccinic acid, atropic acid, cinnamic acid, methyl cinnamate, benzyl cinnamate, cinnamylideneacetic acid, coumaric acid, and umbellic acid; and aromatic polyols such as catechol, resorcinol, hydroquinone, 1,2,4-benzenetriol, pyrogallol, phloroglucinol, and bisphenol.

[0117] The total equivalent weight of the carboxyl groups and phenolic hydroxyl groups of the dissolution promoter (C) ((molecular weight) / (number of carboxyl groups and phenolic hydroxyl groups per molecule)) is preferably 60 or less, more preferably 50 or less. When the equivalent weight is 60 or less, the flow of the coating during thermal curing can be suppressed. When multiple dissolution promoters (C) are used in combination, the total equivalent weight of the carboxyl groups and phenolic hydroxyl groups of each dissolution promoter (C) is more preferably 60 or less.

[0118] The content of the dissolution promoter (C) in the photosensitive resin composition can be 0.1 to 50 parts by mass, preferably 1 to 35 parts by mass, and more preferably 2 to 20 parts by mass, based on 100 parts by mass of the total resin components. If the content of the dissolution promoter (C) is 0.1 part by mass or more based on the total 100 parts by mass, the dissolution of the resin components can be effectively promoted, and if it is 50 parts by mass or less, excessive dissolution of the resin components can be suppressed, and the step pattern formability of the coating can be improved.

[0119] <Total number of moles of carboxyl groups and phenolic hydroxyl groups contained in the quinone diazide adduct (B) and the dissolution promoter (C)> In the photosensitive resin composition, the total number of moles of carboxy groups and phenolic hydroxyl groups contained in the quinone diazide adduct (B) and the dissolution promoter (C) is 150 mmol or less per 100 g of solids contained in the photosensitive resin composition.

[0120] Without being bound by any theory, it is presumed that when the total number of moles of carboxy groups and phenolic hydroxyl groups is 150 mmol or less, a photosensitive resin composition capable of forming a step pattern by halftone exposure can be obtained for the following reason.

[0121] A step pattern formed by forming a coating containing a photosensitive resin composition on a substrate, performing halftone exposure, and developing with an alkali is then subjected to a heat treatment to harden the coating. This heat treatment induces a ring-opening polymerization reaction of the epoxy groups in the epoxy-containing resin (A2), or a crosslinking reaction between the epoxy groups in the epoxy-containing resin (A2) and phenolic hydroxyl groups regenerated or originally present in the protective resin (A1), phenolic hydroxyl groups optionally present in the epoxy-containing resin (A2), and epoxy-reactive functional groups such as carboxyl groups present in any other resin (A3). During the temperature rise process of the heat treatment, the coating flows and deforms due to surface tension, reducing the surface area of ​​the coating. This tends to damage the shape of the step pattern (rounding of the edges of the step pattern) or cause the step pattern to disappear. Specifically, during the temperature rise process, when the temperature of the coating reaches or exceeds the glass transition temperature of the resin contained in the coating, the entanglement of the polymer chains of the resin is eliminated, making the coating more likely to flow. On the other hand, during the temperature rise process, the resin polymerizes or crosslinks as the ring-opening polymerization reaction or crosslinking reaction proceeds, reducing the fluidity of the coating. The elimination of entanglement of polymer chains competes with the polymerization or crosslinking of the resin. That is, when the elimination of entanglement of polymer chains predominates, the coating flows and the shape of the step pattern is damaged, whereas when the polymerization or crosslinking of the resin predominates, the flow of the resin is suppressed and the shape of the step pattern is maintained in the cured coating.

[0122] When the phenolic compound in the quinone diazide adduct (B) has multiple phenolic hydroxyl groups, or when the dissolution promoter (C) has multiple carboxyl or phenolic hydroxyl groups, the epoxy groups in the epoxy-containing resin (A2) react with the carboxyl or phenolic hydroxyl groups in the quinone diazide adduct (B) after exposure, or with the carboxyl or phenolic hydroxyl groups in the dissolution promoter (C), consuming two epoxy groups to form one crosslinking point. In contrast, when resins crosslink, one crosslinking point is formed for each epoxy group consumed. On the other hand, when the phenolic compound of the quinone diazide adduct (B) to the phenolic compound has one phenolic hydroxyl group, or when the dissolution promoter (C) has either one carboxyl group or one phenolic hydroxyl group, when the epoxy group of the resin (A2) having an epoxy group reacts with the carboxyl group that may be contained in the quinone diazide adduct (B) after exposure, or the carboxyl group or phenolic hydroxyl group of the dissolution promoter (C), the epoxy group is simply consumed and does not contribute to crosslinking between the resins.

[0123] Therefore, the crosslinkability of the photosensitive resin composition is lowered because the carboxyl or phenolic hydroxyl groups of the dissolution promoter (C) or the carboxyl or phenolic hydroxyl groups that may be contained in the quinone diazide adduct (B) after exposure are more likely to react with epoxy groups. In other words, the greater the total molar number of carboxyl and phenolic hydroxyl groups contained in the quinone diazide adduct (B) and the dissolution promoter (C), both of which generally have lower molecular weights than the resin, the more likely the disentanglement of polymer chains will occur, leading to damage to the shape of the step pattern. Therefore, by setting the total molar number of carboxyl and phenolic hydroxyl groups contained in the quinone diazide adduct (B) and the dissolution promoter (C) to 150 mmol or less per 100 g of solids in the photosensitive resin composition, it is believed that the flow of the coating during heat treatment can be suppressed, enabling the formation of a high-precision pattern, such as a step pattern.

[0124] The total number of moles of carboxy groups and phenolic hydroxyl groups contained in the quinone diazide adduct (B) and the dissolution promoter (C) is preferably 145 mmol or less, more preferably 140 mmol or less, per 100 g of solids contained in the photosensitive resin composition. Since both carboxy groups and phenolic hydroxyl groups can improve alkaline developability, the total number of moles of carboxy groups and phenolic hydroxyl groups contained in the quinone diazide adduct (B) and the dissolution promoter (C) is preferably 90 mmol or more, more preferably 100 mmol or more.

[0125] <Black colorant (D)> As the black colorant (D), at least one selected from the group consisting of black dyes and black pigments can be used. A black dye and a black pigment may be used in combination. For example, by forming black partition walls in an organic EL element using a photosensitive resin composition containing the black colorant (D), the visibility of a display device such as an organic EL display can be improved.

[0126] In one embodiment, the black colorant (D) comprises a black dye. Examples of black dyes include dyes defined by the color index (CI) of Solvent Black 27 to 47. The black dye is preferably defined by the CI of Solvent Black 27, 29, or 34. When at least one of the dyes defined by the CI of Solvent Black 27 to 47 is used as the black dye, the light-blocking properties of the film of the photosensitive resin composition after curing can be maintained. Compared to photosensitive resin compositions containing a black pigment, photosensitive resin compositions containing a black dye leave less residue of the black colorant (D) during development, and can form a high-resolution pattern in the film.

[0127] A black pigment may be used as the black colorant (D). Examples of black pigments include carbon black, carbon nanotubes, acetylene black, graphite, iron black, aniline black, titanium black, perylene pigments, and lactam pigments. Surface-treated versions of these black pigments can also be used. Examples of commercially available perylene pigments include K0084, K0086, Pigment Black 21, 30, 31, 32, 33, and 34 from BASF. Examples of commercially available lactam pigments include Irgaphor® Black S0100CF from BASF. Due to their high light-blocking properties, the black pigment is preferably at least one selected from the group consisting of carbon black, titanium black, perylene pigments, and lactam pigments.

[0128] In one embodiment, the photosensitive resin composition contains 10 to 150 parts by mass, preferably 30 to 100 parts by mass, and more preferably 40 to 70 parts by mass of the black colorant (D) based on 100 parts by mass of the total resin components. When the content of the black colorant (D) is 10 parts by mass or more based on the total 100 parts by mass, the light-blocking properties of the cured coating can be maintained. When the content of the black colorant (D) is 150 parts by mass or less based on the total 100 parts by mass, the coating can be colored without impairing alkaline developability.

[0129] <Optional component (E)> The photosensitive resin composition may contain, as optional component (E), a heat curing agent, a surfactant, a colorant other than the black colorant (D), etc. In the present disclosure, optional component (E) is defined as anything other than (A1), (A2), (A3), (B), (C), and (D).

[0130] A thermal radical generator can be used as the thermal curing agent. Preferred examples of the thermal radical generator include organic peroxides, specifically organic peroxides having a 10-hour half-life temperature of 100 to 170°C, such as dicumyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, tert-butylcumyl peroxide, di-tert-butyl peroxide, 1,1,3,3-tetramethylbutyl hydroperoxide, and cumene hydroperoxide.

[0131] The content of the heat curing agent is preferably 5 parts by mass or less, more preferably 4 parts by mass or less, and even more preferably 3 parts by mass or less, based on 100 parts by mass of the total solid content excluding the heat curing agent.

[0132] The photosensitive resin composition may contain a surfactant, for example, to improve the coatability, the smoothness of the coating, or the developability of the coating. Examples of the surfactant include 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; Fluorine-based surfactants such as SURFLOON (registered trademark) F-251, F-281, F-430, F-444, R-40, F-553, F-554, F-555, F-556, F-557, F-558, and F-559 (trade names, DIC Corporation), and SURFLOON (registered trademark) S-242, S-243, S-386, S-420, and S-611 (trade names, AGC Seimi Chemical Co., Ltd.), as well as organosiloxane polymers KP323, KP326, and KP341 (trade names, Shin-Etsu Chemical Co., Ltd.). These surfactants can be used alone or in combination of two or more.

[0133] The content of the surfactant is preferably 2 parts by mass or less, more preferably 1 part by mass or less, and even more preferably 0.5 parts by mass or less, based on 100 parts by mass of the total solid content excluding the surfactant.

[0134] The photosensitive resin composition may contain a second colorant other than the black colorant (D). Examples of the second colorant include dyes, organic pigments, and inorganic pigments. The second colorant can be used according to the purpose. The second colorant can be used in an amount that does not impair the effects of the present disclosure.

[0135] Examples of dyes include azo dyes, benzoquinone dyes, naphthoquinone dyes, anthraquinone dyes, cyanine dyes, squarylium dyes, croconium dyes, merocyanine dyes, stilbene dyes, diphenylmethane dyes, triphenylmethane dyes, fluoran dyes, spiropyran dyes, phthalocyanine dyes, indigo dyes, fulgide dyes, nickel complex dyes, and azulene dyes. Among dyes, red dyes are preferred. Examples of red dyes include VALIFAST® RED 3312 (a red dye defined by the CI of Solvent Red 122, Orient Chemical Industry Co., Ltd.) and VALIFAST® RED 3311 (a red dye defined by the CI of Solvent Red 8, Orient Chemical Industry Co., Ltd.).

[0136] Examples of pigments include CI Pigment Yellow 20, 24, 86, 93, 109, 110, 117, 125, 137, 138, 147, 148, 153, 154, 166, CI Pigment Orange 36, 43, 51, 55, 59, 61, CI Pigment Red 9, 97, 122, 123, 149, 168, 177, 180, 192, 215, 216, 217, 220, 223, 224, 226, 227, 228, 240, CI Pigment Violet 19, 23, 29, 30, 37, 40, 50, CI Pigment Blue 15, 15:1, 15:4, 22, 60, 64, CI Pigment Green 7, and CI Pigment Brown 23, 25, 26.

[0137] [Coating composition] <Solvent (F)> The photosensitive resin composition can be dissolved in a solvent (F) and used as a coating composition in solution form (however, when a black pigment is included, the pigment is in a dispersed state). For example, a coating composition containing the photosensitive resin composition can be prepared by mixing the quinone diazide adduct (B), dissolution promoter (C), black colorant (D), and optional components (E) such as a thermosetting agent and surfactant, in predetermined proportions with the solution obtained by dissolving the resin components in the solvent (F). The viscosity of the coating composition can be adjusted to suit the application method used by changing the amount of solvent (F).

[0138] Examples of the solvent (F) include glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol dimethyl ether, ethylene glycol methyl ethyl ether, and ethylene glycol monoethyl ether; ethylene glycol alkyl ether acetates such as methyl cellosolve acetate and ethyl cellosolve acetate; diethylene glycol compounds such as diethylene glycol monomethyl ether, diethylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol ethyl methyl ether, diethylene glycol monoethyl ether, and diethylene glycol monobutyl ether; and propylene glycol monoalkyl ether acetates such as propylene glycol monomethyl ether acetate and propylene glycol monoethyl ether acetate. Examples of suitable solvents include acetates, aromatic hydrocarbons such as toluene and xylene, ketones such as methyl ethyl ketone, methyl amyl ketone, cyclohexanone, 4-hydroxy-4-methyl-2-pentanone, and cyclohexanone, esters such as ethyl 2-hydroxypropionate, methyl 2-hydroxy-2-methylpropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxyacetate, ethyl hydroxyacetate, methyl 2-hydroxy-2-methylbutanoate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, ethyl ethyl acetate, butyl acetate, methyl lactate, ethyl lactate, and γ-butyrolactone, and amides such as N-methyl-2-pyrrolidone, N,N-dimethylformamide, and N,N-dimethylacetamide. The solvent (F) can be used alone or in combination of two or more.

[0139] The solid content of the coating composition can be appropriately determined depending on the purpose of use. For example, the solid content of the coating composition may be 1 to 60 mass %, 3 to 50 mass %, or 5 to 40 mass %.

[0140] When a pigment is used, known methods can be used for dispersion and mixing. For example, ball-type mills such as a ball mill, sand mill, bead mill, paint shaker, and rocking mill, blade-type mills such as a kneader, paddle mixer, planetary mixer, and Henschel mixer, and roll-type mills such as a three-roll mixer, as well as Raikai mixers, colloid mills, ultrasonic mixers, homogenizers, and rotation-revolution mixers may be used. From the viewpoints of dispersion efficiency and fine dispersion, it is preferable to use a bead mill.

[0141] The prepared coating composition is usually filtered before use, for example, using a Millipore filter with a pore size of 0.05 to 1.0 μm.

[0142] The coating composition thus prepared also has excellent long-term storage stability.

[0143] [Method of using the photosensitive resin composition] When using a photosensitive resin composition in radiation lithography, the photosensitive resin composition is first dissolved or dispersed in a solvent to prepare a coating composition. Next, the coating composition is applied to a substrate surface, and the solvent is removed by heating or other means to form a coating. The method for applying the coating composition to the substrate surface is not particularly limited, and for example, spraying, roll coating, slit coating, or spin coating can be used.

[0144] After applying the coating composition to the surface of a substrate, the solvent is usually removed by heating to form a coating (pre-baking). The heating conditions vary depending on the type and blending ratio of each component, but the coating can usually be obtained by heating at 70 to 130°C for 30 seconds to 20 minutes on a hot plate or for 1 to 60 minutes in an oven.

[0145] Next, the prebaked coating is irradiated with radiation (for example, visible light, ultraviolet light, far ultraviolet light, X-rays, electron beams, gamma rays, or synchrotron radiation) through a photomask having a predetermined pattern (exposure step). Preferred radiation is ultraviolet light or visible light having a wavelength of 250 to 450 nm. In one embodiment, the radiation is i-ray. In another embodiment, the radiation is ghi-ray.

[0146] After the exposure step, a post-exposure bake (PEB) may be performed to promote decomposition of the acid-labile groups. PEB can further increase the alkali solubility of the protective resin (A1) in the exposed area. The heating conditions vary depending on the type and blending ratio of each component, but PEB can usually be performed at 70 to 140°C, for example, for 30 seconds to 20 minutes on a hot plate or for 1 to 60 minutes in an oven.

[0147] In one embodiment, the PEB step is not included after the exposure step, which prevents the film from flowing or deforming due to heating, allowing the step pattern to be formed with high precision and reducing the number of steps related to the formation of the partition wall or insulating film.

[0148] After the exposure step or PEB step, the coating is developed by contacting it with a developer to remove unnecessary portions and form a pattern in the coating (development step). Examples of the developer include aqueous solutions of alkaline compounds such as inorganic alkaline compounds (e.g., sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and aqueous ammonia); primary amines (e.g., ethylamine and n-propylamine); secondary amines (e.g., diethylamine and di-n-propylamine); tertiary amines (e.g., triethylamine and methyldiethylamine); alcohol amines (e.g., dimethylethanolamine and triethanolamine); quaternary ammonium salts (e.g., tetramethylammonium hydroxide, tetraethylammonium hydroxide, and choline); and cyclic amines (e.g., pyrrole, piperidine, 1,8-diazabicyclo[5.4.0]-7-undecene, 1,5-diazabicyclo[4.3.0]-5-nonane). An aqueous solution containing an appropriate amount of a water-soluble organic solvent (e.g., methanol or ethanol), a surfactant, etc., can also be used as the developer. The development time is typically 30 to 180 seconds. The developing method may be any of a puddle method, a shower method, a dipping method, etc. After development, the film is washed with running water for 30 to 90 seconds to remove unnecessary portions, and then air-dried with compressed air or compressed nitrogen, thereby forming a pattern in the film.

[0149] Thereafter, the coating film on which the pattern has been formed can be heat-treated, for example, at 100 to 350°C for 20 to 200 minutes using a heating device such as a hot plate or oven, to obtain a cured coating film (post-baking, heat treatment step). In the heat treatment, the temperature may be maintained constant, or may be increased continuously or stepwise. The heat treatment is preferably carried out in a nitrogen atmosphere.

[0150] The optical density (OD value) of the cured film of the photosensitive resin composition is preferably 0.5 or more per 1 μm of film thickness, more preferably 0.7 or more, and even more preferably 1.0 or more. If the OD value of the cured film is 0.5 or more per 1 μm of film thickness, sufficient light-blocking properties can be obtained.

[0151] In one embodiment, a method for producing an organic EL element partition wall or an organic EL element insulating film includes dissolving or dispersing a photosensitive resin composition in a solvent to prepare a coating composition, applying the coating composition to a substrate to form a film, removing the solvent contained in the film and drying the film, exposing the dried film to radiation through a photomask, developing the exposed film by contacting it with a developer to form a pattern in the film, and heat-treating the patterned film at a temperature of 100° C. to 350° C. to form an organic EL element partition wall or an insulating film. The PEB described above can also be performed after exposure and before development.

[0152] One embodiment is a partition wall for an organic EL device, which comprises a cured product of the photosensitive resin composition.

[0153] One embodiment is an insulating film for an organic EL device, which comprises a cured product of a photosensitive resin composition.

[0154] One embodiment is an organic EL device containing a cured product of the photosensitive resin composition. [Example]

[0155] The present invention will be specifically described below based on examples and comparative examples, but the present invention is not limited to these examples.

[0156] (1) Raw materials The raw materials used in the examples and comparative examples were produced or obtained as follows.

[0157] The weight average molecular weight (Mw) and number average molecular weight (Mn) of the resin were calculated using a calibration curve prepared using a polystyrene standard substance under the following measurement conditions. Device name: Shodex (registered trademark) GPC-101 Column: Shodex (registered trademark) LF-804 Mobile phase: tetrahydrofuran Flow rate: 1.0mL / min Detector: Shodex (registered trademark) RI-71 Temperature: 40℃

[0158] [Production Example 1] Base resin (a) and other resins (A3): Production of aqueous alkali solution soluble copolymer (a1) (PCX-02e) of polymerizable monomer having a phenolic hydroxyl group and other polymerizable monomer 29.0 g of 4-hydroxyphenyl methacrylate (Showa Denko K.K. "PQMA") and 5.12 g of N-cyclohexylmaleimide (Nippon Shokubai Co., Ltd.) were completely dissolved in 96.5 g of 1-methoxy-2-propyl acetate (Daicel Corporation) as a solvent, and 3.41 g of V-601 (Fujifilm Wako Pure Chemical Industries, Ltd.) as a polymerization initiator was completely dissolved in 13.7 g of 1-methoxy-2-propyl acetate (Daicel Corporation). The two resulting solutions were simultaneously added dropwise over 2 hours to 40.0 g of 1-methoxy-2-propyl acetate (Daicel Corporation) heated to 85 °C under a nitrogen gas atmosphere in a 300 mL three-neck flask, and then reacted at 85 °C for 3 hours. The reaction solution was cooled to room temperature and added dropwise to 815 g of toluene to precipitate the copolymer. The precipitated copolymer was collected by filtration and vacuum dried at 90°C for 4 hours, yielding 32.4g of white powder. The resulting PCX-02e had a number-average molecular weight of 3100, a weight-average molecular weight of 6600, and a hydroxyl equivalent of 202.

[0159] [Production Example 2] Production of Protected Resin (A1): Resin (PCX-02e-THF55) in Which the Phenolic Hydroxyl Group is Protected with a 2-Tetrahydrofuranyl Group In a 100 mL three-neck flask, 10.0 g of the copolymer (PCX-02e) of the polymerizable monomer having a phenolic hydroxyl group and another polymerizable monomer obtained in Production Example 1 and 0.60 g of pyridinium salt of p-toluenesulfonic acid (Tokyo Chemical Industry Co., Ltd.) as an acid catalyst were dissolved in 50.0 g of tetrahydrofuran (Fujifilm Wako Pure Chemical Industries Co., Ltd.). The mixture was then ice-cooled under a nitrogen gas atmosphere, and 6.69 g of 2,3-dihydrofuran (Tokyo Chemical Industry Co., Ltd.) was added dropwise over 1 hour. The mixture was then stirred at room temperature for 16 hours. The acid catalyst was neutralized with a saturated aqueous solution of sodium bicarbonate, and the aqueous layer was removed. The organic layer was further washed twice with water. The tetrahydrofuran was then distilled off. The resulting solid was dissolved in 50.0 g of ethyl acetate and added dropwise to 200 g of toluene to precipitate the product. The precipitate was collected by filtration and dried in vacuo at 80°C for 4 hours, yielding 11.0 g of a white powder. The resulting powder was dissolved in propylene glycol monomethyl ether acetate to obtain a 20% solids solution of a resin (PCX-02e-THF55) in which the phenolic hydroxyl groups were protected with 2-tetrahydrofuranyl groups. The resulting PCX-02e-THF55 had a number-average molecular weight of 3716, a weight-average molecular weight of 6806, a hydroxyl equivalent weight of 552, 55 mol% of the phenolic hydroxyl groups protected with acid-decomposable groups, and 55% of the total number of structural units of PCX-02e-THF55.

[0160] [Production Example 3] Production of resin (A2) having epoxy groups: resin (N695OH70) having epoxy groups and phenolic hydroxyl groups A 300 mL three-neck flask was charged with 75.2 g of propylene glycol monomethyl ether acetate (Mitsubishi Chemical Corporation) as a solvent and 42.8 g of EPICLON® N-695 (DIC Corporation, cresol novolac epoxy resin, epoxy equivalent weight 214) as a compound having at least two epoxy groups per molecule, and dissolved under a nitrogen gas atmosphere at 60°C. 20.1 g (0.65 equivalents per epoxy equivalent) of 3,5-dihydroxybenzoic acid (Fujifilm Wako Pure Chemical Industries, Ltd.) as a hydroxybenzoic acid compound and 0.166 g (0.633 mmol) of triphenylphosphine (Tokyo Chemical Industry Co., Ltd.) as a reaction catalyst were added, and the mixture was allowed to react at 110°C for 21 hours. The reaction solution was returned to room temperature, diluted with γ-butyrolactone to a solids content of 20% by mass, and filtered to obtain 304.2 g of a resin solution (N695OH70) having epoxy groups and phenolic hydroxyl groups. The resulting reaction product had a number-average molecular weight of 3,000, a weight-average molecular weight of 7,500, and an epoxy equivalent of 1,100.

[0161] [Production Example 4] Production of resin (A2) having epoxy groups: resin (N695OH50) having epoxy groups and phenolic hydroxyl groups Except for using 13.9 g of 3,5-dihydroxybenzoic acid, 256.2 g of a solution of a resin (N695OH50) having epoxy groups and phenolic hydroxyl groups was obtained in the same manner as in Production Example 3. The resulting reaction product had a number average molecular weight of 2,900, a weight average molecular weight of 6,400, and an epoxy equivalent of 690.

[0162] <Protective resin (A1)> PCX-02e-THF55 of Production Example 2 was used as the protective resin (A1).

[0163] <Resin (A2) Having Epoxy Groups> As the resin (A2) having an epoxy group, N695OH70 of Production Example 3 and N695OH50 of Production Example 4 were used.

[0164] <Other Resins (A3)> As the other resin (A3), PCX-02e of Production Example 1 was used.

[0165] <Quinone diazide adduct (B)> The compounds used as the quinone diazide adduct (B) are shown in Table 1. The structural formula of the quinone diazide adduct (B) is also shown in Table 1. In the structural formula, R represents a hydrogen atom or a group represented by the formula (9-1): [ka] The molecular weights in Table 1 are calculated values ​​based on the average number of quinone diazide groups per molecule.

[0166] [Table 1]

[0167] <Solubility enhancer (C)> Phloroglucinol was used as the solubility enhancer (C).

[0168] <Black colorant (D)> As the black colorant (D), a black dye, VALIFAST (registered trademark) BLACK 3820 (a black dye specified by the CI of Solvent Black 27, Orient Chemical Industry Co., Ltd.) was used.

[0169] <Solvent (F)> As the solvent (F), a mixed solvent of γ-butyrolactone (GBL) and propylene glycol monomethyl ether acetate (PGMEA) (GBL:PGMEA=25:75 (mass ratio)) was used.

[0170] (2) Evaluation method The evaluation methods used in the examples and comparative examples are as follows.

[0171] [sensitivity] The photosensitive resin composition was bar-coated onto a glass substrate (100 mm × 100 mm × 1 mm) to a dry film thickness of 4.0 μm. After vacuum drying for 90 seconds, the substrate was prebaked by heating on a lidded hot plate at 100°C for 2 minutes. The coating was exposed to light using an exposure system (product name: Multilight ML-251A / B, Ushio Inc.) equipped with an ultra-high pressure mercury lamp through a mercury exposure bandpass filter (product name: HB0365, Asahi Spectroscopy Co., Ltd.) and a quartz photomask (with a φ10 μm opening pattern). The exposure dose was measured using an ultraviolet integrating actinometer (product name: UIT-150, photoreceptor: UVD-S365, Ushio Inc.). After exposure, the substrate was heated on a lidded hot plate at 120°C for 3 minutes to perform PEB. The substrate was then subjected to alkaline development for 60 seconds using a spin-developer (AD-1200, Takizawa Sangyo Co., Ltd.) with a 2.38 wt% tetramethylammonium hydroxide aqueous solution. The coating was then cured by heating at 250°C for 60 minutes in an inert oven (DN411I, Yamato Scientific Co., Ltd.). The above procedure was repeated while changing the exposure dose to determine the minimum exposure dose (mJ / cm) that would allow a pattern with a film thickness of 3 μm and a hole diameter of 10 μm to be formed after curing. 2 The minimum irradiation dose was 400 mJ / cm 2 or less was determined to be highly sensitive.

[0172] [Step width of step pattern of hardened coating] A glass substrate (100 mm × 100 mm × 1 mm) was bar-coated with the photosensitive resin composition to a dry film thickness of 4.0 μm. After vacuum drying for 90 seconds, the substrate was prebaked by heating on a lidded hot plate at 100°C for 2 minutes. The coating was exposed to light using an exposure system (product name: Multilight ML-251A / B, Ushio Inc.) equipped with an ultra-high pressure mercury lamp through a mercury exposure bandpass filter (product name: HB0365, Asahi Spectroscopy Co., Ltd.) and a quartz halftone photomask (patterned with a 10 μm-wide line with 100% transmittance on the inside and a 15 μm-wide intermediate exposure line with slits on both sides with a light transmittance of 31%). The exposure dose was measured using an ultraviolet integrating actinometer (product name: UIT-150, light receiving part: UVD-S365, Ushio Inc.). After exposure, the substrate was heated on a lidded hot plate at 120°C for 3 minutes for PEB. The coating was then subjected to alkaline development using a spin developer (AD-1200, Takizawa Sangyo Co., Ltd.) with a 2.38% by mass aqueous solution of tetramethylammonium hydroxide. The coating was then cured by heating at 250°C for 60 minutes in an inert oven (DN411I, Yamato Scientific Co., Ltd.). The above procedure was repeated while varying the exposure dose and development time. After curing, a pattern with a film thickness of 3 μm and a line width of 10 μm was formed. The step pattern formed in the cured coating was observed with a shape analysis laser microscope (product name VK-X200, Keyence Corporation), and the step width (μm) corresponding to the intermediate exposure area was measured.

[0173] [OD value of cured film] The photosensitive resin composition was spin-coated onto a glass substrate (100 mm × 100 mm × 1 mm) to a dry film thickness of approximately 1.5 μm, and pre-baked by heating on a hot plate at 120°C for 80 seconds. The coating was then cured at 250°C for 60 minutes in a nitrogen gas atmosphere to obtain a coating. The OD value of the cured coating was measured using a transmission densitometer (BMT-1, Sakata Inx Engineering Co., Ltd.), corrected for the OD value of the glass alone, and converted to an OD value per 1 μm of coating thickness. The coating thickness was measured using an optical film thickness measurement device (F20-NIR, Filmetrics Inc.).

[0174] (3) Preparation and evaluation of photosensitive resin compositions [Examples 1 to 7 and Comparative Examples 1 to 3] The protective resin (A1), epoxy group-containing resin (A2), and other resin (A3) were mixed and dissolved in the composition shown in Table 2. The quinone diazide adduct (B), dissolution promoter (C), black colorant (D), and GBL / PGMEA mixed solvent (F) shown in Table 2 were added to the resulting solution and further mixed. After visually confirming that the components had dissolved, the mixture was filtered through a Millipore filter with a pore size of 0.22 μm to prepare a photosensitive resin composition with a solids concentration of 12% by mass. The parts by mass in the composition in Table 2 are values ​​calculated as solids. The evaluation results of the photosensitive resin compositions of Examples 1 to 7 and Comparative Examples 1 to 3 are shown in Table 2.

[0175] [Table 2]

[0176] Comparing Examples 1 to 7, in which the total number of moles of carboxyl groups and phenolic hydroxyl groups contained in the quinone diazide adduct (B) and the dissolution promoter (C) was 150 mmol or less per 100 g of solid content contained in the photosensitive resin composition, with Comparative Examples 1 to 3, in which the total number of moles exceeded 150 mmol, Examples 1 to 7 had a wider step width and less fluidity of the coating during thermal curing. [Industrial Applicability]

[0177] The photosensitive resin composition according to the present disclosure can be suitably used in radiation lithography for forming partition walls or insulating films of organic EL devices. Organic EL devices having partition walls or insulating films formed from the photosensitive resin composition according to the present disclosure are suitably used as electronic components of display devices that exhibit good contrast.

Claims

1. a resin (A1) having a plurality of phenolic hydroxyl groups, at least a part of which is protected with an acid-decomposable group; a resin (A2) having an epoxy group; a quinone diazide adduct (B) of a phenol compound; at least one dissolution promoter (C) selected from the group consisting of compounds having a carboxy group and compounds having a phenolic hydroxyl group; a black colorant (D); a photosensitive resin composition comprising: a quinone diazide adduct (B) and a dissolution promoter (C) each having a total molar number of carboxy groups and phenolic hydroxyl groups of 150 mmol or less per 100 g of a solid content in the photosensitive resin composition; the quinone diazide adduct (B) has a quinone diazide group equivalent of 500 or less; Photosensitive resin composition.

2. 2. The photosensitive resin composition according to claim 1, wherein the quinone diazide adduct (B) is a 1,2-naphthoquinone diazide-4-sulfonic acid ester or a 1,2-naphthoquinone diazide-5-sulfonic acid ester of the phenol compound.

3. 3. The photosensitive resin composition according to claim 1, wherein the dissolution promoter (C) is an organic low-molecular-weight compound having a molecular weight of 1,000 or less.

4. 4. The photosensitive resin composition according to claim 1, wherein the total equivalent of the carboxyl group and the phenolic hydroxyl group of the dissolution promoter (C) is 60 or less.

5. 5. The photosensitive resin composition according to claim 1, wherein the total number of moles of carboxy groups and phenolic hydroxyl groups contained in the quinone diazide adduct (B) and the dissolution promoter (C) is 90 mmol or more per 100 g of solids contained in the photosensitive resin composition.

6. The resin (A1) is a compound represented by the formula (4) 【Chemistry 1】 (In formula (4), R ９ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and R １０ is an acid-decomposable group, r is an integer of 0 to 5, and s is an integer of 0 to 5, provided that r+s is an integer of 1 to 5. The photosensitive resin composition according to any one of claims 1 to 5, having a structural unit represented by formula (4):

7. The resin (A1) is a compound represented by the formula (2) 【Chemistry 2】 (In formula (2), R ２ and R ３ are each independently a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, a fully or partially fluorinated fluoroalkyl group having 1 to 3 carbon atoms, or a halogen atom; R ４ is a hydrogen atom, a linear alkyl group having 1 to 6 carbon atoms, a cyclic alkyl group having 3 to 12 carbon atoms, a phenyl group, or a phenyl group substituted with at least one group selected from the group consisting of a hydroxy group, an alkyl group having 1 to 6 carbon atoms, and an alkoxy group having 1 to 6 carbon atoms. The photosensitive resin composition according to claim 6 , which has a structural unit represented by the following formula:

8. In the resin (A1), the acid-decomposable group substituted for the hydrogen atom of the phenolic hydroxyl group is represented by the formula (3): -CR ６ R ７ -O-R ８ (3) (In formula (3), R ６ and R ７ are each independently a hydrogen atom, a linear alkyl group having 1 to 4 carbon atoms, or a branched alkyl group having 3 to 4 carbon atoms, and R ８ is a linear alkyl group having 1 to 12 carbon atoms, a branched alkyl group having 3 to 12 carbon atoms, a cyclic alkyl group having 3 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, or an alkenyl group having 2 to 12 carbon atoms; R ６ or R ７ One of the two and R ８ may be bonded to form a ring structure having 3 to 10 ring members, and R ６ , R ７ and R ８ may be substituted with a halogen atom selected from the group consisting of fluorine, chlorine, bromine and iodine. The photosensitive resin composition according to any one of claims 1 to 7, wherein the group is represented by:

9. The photosensitive resin composition according to any one of claims 1 to 8, wherein the resin (A2) is a resin having an epoxy group and a phenolic hydroxyl group.

10. The resin having an epoxy group and a phenolic hydroxyl group is a reaction product of a compound having at least two epoxy groups in one molecule with a hydroxybenzoic acid compound, and is represented by the formula (6): 【Transformation 3】 (In formula (6), b is an integer of 1 to 5, and * represents a bond to a residue other than the epoxy group involved in the reaction of a compound having at least two epoxy groups in one molecule.) The photosensitive resin composition according to claim 9, wherein the compound has the structure:

11. 11. The photosensitive resin composition according to claim 10, wherein the compound having at least two epoxy groups in one molecule is a novolac epoxy resin.

12. The photosensitive resin composition according to any one of claims 1 to 11, comprising 10 parts by mass to 150 parts by mass of the black colorant (D) based on a total of 100 parts by mass of the resin components.

13. The photosensitive resin composition according to any one of claims 1 to 12, wherein the optical density (OD value) of a cured film of the photosensitive resin composition is 0.5 or more per 1 µm of film thickness.

14. A partition wall for an organic EL device, comprising a cured product of the photosensitive resin composition according to any one of claims 1 to 13.

15. An insulating film for an organic EL device, comprising a cured product of the photosensitive resin composition according to any one of claims 1 to 13.

16. An organic EL device comprising a cured product of the photosensitive resin composition according to any one of claims 1 to 13.

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