JP7809652B2 - Photosensitive resin composition and organic EL element partition wall - Google Patents

Description

The present invention relates to a photosensitive resin composition containing a black agent, and an organic EL element partition wall, an organic EL element insulating film, and an organic EL element using the same.

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 around the edges 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, and volatile components are removed by heating or other means. The composition is then exposed to light through a mask. Development is then performed by removing the unexposed portions in the case of a negative-tone pattern or 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 using an inkjet method or other methods to form the pixels of the OLED display.

In recent years, the miniaturization of display devices and the diversification of displayed content have led to demands for higher pixel performance and higher resolution in this field. 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 given light-blocking properties, the photosensitive resin composition tends to have low sensitivity, which can 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.

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.

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

Patent Document 3 (JP 2010-237310 A) describes a radiation-sensitive resin composition that exhibits light-blocking properties through 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.

Patent Document 4 (WO 2017/069172) describes a positive-tone 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.

Japanese Patent Application Laid-Open No. 2001-281440 Japanese Patent Application Laid-Open No. 2002-116536 JP 2010-237310 A International Publication No. 2017/069172

The photosensitive resin composition used to form colored partition wall materials requires the use of a considerable amount of colorant to sufficiently enhance the light-blocking properties of the cured film. When such a large amount of colorant is used, the radiation irradiated onto the photosensitive resin composition coating 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.

In particular, when attempting to form a thick coating, for example, a coating 2 to 3 μm thick, using a photosensitive resin composition containing a black agent, the amount of radiation reaching the bottom of the coating in the exposed area is significantly reduced due to the absorption of radiation by the radiation-sensitive compound in addition to the black agent. As a result, in positive-tone films, the bottom of the coating in the exposed area may not be sufficiently alkaline-soluble, resulting in the generation of resin residue during development, or a large amount of photosensitive resin composition may be consumed to obtain a coating of the desired thickness, resulting in a low film retention rate. On the other hand, in negative-tone films, the bottom of the coating in the exposed area may not be sufficiently insolubilized, resulting in film peeling during development. Therefore, there is a strong demand for photosensitive resin compositions containing black agents that can impart a high optical density (OD value) to the cured coating while increasing the thickness of the cured coating.

If microscopically uneven resin dissolution occurs during the development process, the surface area of the resin in that area, i.e., the area of contact with the developer, increases, and the resin dissolution rate increases locally. As a result, the coating dissolves unevenly during the development process, which can cause the coating surface to become rough after development and deterioration of the pattern shape. This is particularly noticeable in thick film development processes, which generally require long development times or the use of highly concentrated developers.

The object of the present invention is to provide a highly sensitive photosensitive resin composition containing a black agent that can form thick film patterns with high optical density (OD value) and reduced surface roughness.

The inventors have discovered that by combining at least two resins having phenolic hydroxyl groups and setting the ratio of the phenolic hydroxyl group equivalents of these resins within a specified range, it is possible to form thick film patterns with reduced surface roughness, even when using a photosensitive resin composition containing a black agent.

That is, the present invention includes the following aspects.
[1]
(A) a first resin;
(B) a second resin having a phenolic hydroxyl group, which is different from the first resin;
(C) a third resin having a phenolic hydroxyl group, which is different from both the first resin and the second resin;
A photosensitive resin composition comprising: (D) a radiation-sensitive compound; and (E) a black agent, wherein the optical density (OD value) of a cured coating film of the photosensitive resin composition is 0.5 or more per 1 μm of film thickness; and the phenolic hydroxyl group equivalent of the second resin is 1.1 to 5.0 times the phenolic hydroxyl group equivalent of the third resin.
[2]
The photosensitive resin composition according to [1], wherein the second resin contains a structural unit identical to at least one of the structural units of the third resin and other structural units, and contains 30 mol % to 95 mol % of structural units common to the third resin in total, and the alkali dissolution rate of the second resin is lower than the alkali dissolution rate of the third resin.
[3]
The photosensitive resin composition according to [1] or [2], wherein the second resin is a copolymer of a polymerizable monomer having a phenolic hydroxyl group and another polymerizable monomer.
[4]
The photosensitive resin composition according to any one of [1] to [3], wherein the third resin is a copolymer of a polymerizable monomer having a phenolic hydroxyl group and another polymerizable monomer.
[5]
The second resin is represented by formula (17):
(In formula (17), R ³⁸ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and R ³⁹ is a group selected from the group consisting of a linear alkyl group having 1 to 20 carbon atoms, a branched alkyl group having 3 to 20 carbon atoms, a cyclic alkyl group having 3 to 12 carbon atoms, an aryl group having 6 to 20 carbon atoms, a linear alkyl group having 1 to 20 carbon atoms substituted with a group other than an acidic functional group, a branched alkyl group having 3 to 20 carbon atoms substituted with a group other than an acidic functional group, a cyclic alkyl group having 3 to 12 carbon atoms substituted with a group other than an acidic functional group, and an aryl group having 6 to 20 carbon atoms substituted with a group other than an acidic functional group.)
The photosensitive resin composition according to any one of [1] to [4], having a structural unit represented by the following formula:
[6]
The second resin is represented by formula (10):
(In formula (10), R ¹⁵ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and e is an integer of 1 to 5.)
The photosensitive resin composition according to any one of [1] to [5], having a structural unit represented by the following formula:
[7]
The second resin is represented by formula (11):
(In formula (11), R ¹⁶ and R ¹⁷ are each independently a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, a completely or partially fluorinated fluoroalkyl group having 1 to 3 carbon atoms, or a halogen atom; and R ¹⁸ 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 any one of [1] to [6], having a structural unit represented by the following formula:
[8]
The photosensitive resin composition according to any one of [1] to [7], wherein the first resin is a resin having an epoxy group and a phenolic hydroxyl group.
[9]
The first resin 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 (9):
(In formula (9), d 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 any one of [1] to [8], wherein the compound has a structure represented by the formula:
[10]
The photosensitive resin composition according to [9], wherein the compound having at least two epoxy groups in one molecule is a novolac epoxy resin.
[11]
The photosensitive resin composition according to any one of [1] to [10], wherein the black agent is a dye defined by a color index (CI) of Solvent Black 27 to 47.
[12]
The photosensitive resin composition according to any one of [1] to [11], wherein the radiation-sensitive compound is a photoacid generator.
[13]
[13] The photosensitive resin composition according to any one of [1] to [12], wherein the first resin is contained in an amount of 20% by mass to 90% by mass based on the total mass of the resin components.
[14]
[14] The photosensitive resin composition according to any one of [1] to [13], wherein the second resin is contained in an amount of 5% by mass to 50% by mass based on the total mass of the resin components.
[15]
[15] The photosensitive resin composition according to any one of [1] to [14], wherein the third resin is contained in an amount of 5% by mass to 50% by mass based on the total mass of the resin components.
[16]
The photosensitive resin composition according to any one of [1] to [15], comprising 1 to 40 parts by mass of the radiation-sensitive compound based on 100 parts by mass of the total of the resin components.
[17]
[17] The photosensitive resin composition according to any one of [1] to [16], comprising 10 parts by mass to 150 parts by mass of the blackening agent based on 100 parts by mass of the total of the resin components.
[18]
A partition wall for an organic EL device, comprising a cured product of the photosensitive resin composition according to any one of [1] to [17].
[19]
An insulating film for an organic EL device, comprising a cured product of the photosensitive resin composition according to any one of [1] to [17].
[20]
An organic EL device comprising a cured product of the photosensitive resin composition according to any one of [1] to [17].

The present invention provides a highly sensitive photosensitive resin composition containing a blackening agent that can form thick film patterns with high optical density (OD value) and reduced surface roughness.

The present invention is described in detail below.

In this disclosure, "alkali-soluble" means 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. "Alkali-soluble functional group" means 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.

In this disclosure, "radically polymerizable functional group" means an ethylenically unsaturated group, and "radically polymerizable compound" means a compound having one or more ethylenically unsaturated groups.

In the present disclosure, the term "structural unit" refers to an atomic group constituting a 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 (C ₆ H ₅ OH) and one molecule of formaldehyde (HCHO). With regard to structural units having pendant groups (side groups), structural units having pendant groups or groups derived therefrom used to form crosslinked sites are considered to be different from structural units having free pendant groups not involved in the formation of crosslinked sites. With regard to polymers having branched molecular chains (branched chains), structural units including branch points (branch units) are considered to be different from structural units contained in linear molecular chains.

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

In this disclosure, the number average molecular weight (Mn) and weight average molecular weight (Mw) of a resin or polymer refer to values measured by gel permeation chromatography (GPC) in terms of standard polystyrene.

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

In the case of the resin (c) having an epoxy group and a phenolic hydroxyl group, which will be described later, the phenolic hydroxyl group equivalent is calculated by the following formula:
Phenolic hydroxyl group equivalent =
(epoxy equivalent of raw material + molecular weight of carboxylic acid to be added) / (number of phenolic hydroxyl groups of carboxylic acid)
The value calculated by

In this disclosure, "resin components" means the first resin (A), the second resin (B), and the third resin (C).

In this disclosure, "solid content" means the total mass of components, including optional components such as the resin component, radiation-sensitive compound (D), blackening agent (E), and dissolution promoter (F), excluding the liquid basic compound (G) and solvent (H).

In one embodiment, the photosensitive resin composition includes a first resin (A), a second resin (B) having a phenolic hydroxyl group and different from the first resin (A), a third resin (C) having a phenolic hydroxyl group and different from both the first resin (A) and the second resin (B), a radiation-sensitive compound (D), and a black agent (E).

[First resin (A)]
The first resin (A) is not particularly limited, but preferably has an alkali-soluble functional group and is alkali-soluble. Examples of the alkali-soluble functional group include, but are not limited to, a carboxy group, a phenolic hydroxyl group, a sulfo group, a phosphate group, and a mercapto group. The first resin (A) may be a resin having two or more types of alkali-soluble functional groups. In the present disclosure, the first resin (A) is a resin different from the second resin (B) and the third resin (C) described below in terms of the resin skeleton, the alkali-soluble functional group, or both. In one embodiment, the first resin (A) is a resin that is the main component of the resin component, i.e., it is contained in the resin component in an amount greater by mass than each of the second resin (B) and the third resin (C).

Examples of the first resin (A) include acrylic resins, polystyrene resins, epoxy 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 have been bonded. The first resin (A) may also be a homopolymer or copolymer of a polymerizable monomer having an alkali-soluble functional group. The first resin (A) may be any of these resins alone or in combination of two or more of these resins. The first resin (A) may have a radically polymerizable functional group. In one embodiment, the first resin (A) has a (meth)acryloyloxy group, an allyl group, or a methallyl group as the radically polymerizable functional group.

In one embodiment, the first resin (A) includes at least one resin selected from the following resins (a) to (l):
(a) Polyalkenylphenol resins of specific structures (b) Hydroxypolystyrene resin derivatives of specific structures (c) Resins having epoxy groups and phenolic hydroxyl groups (d) Copolymers of polymerizable monomers having alkali-soluble functional groups and other polymerizable monomers (e) Polyimide resins (f) Polyamic acid resins (g) Polybenzoxazole resins (h) Polybenzoxazole resin precursors (i) Silicone resins (j) Cyclic olefin polymers (k) Cardo resins (l) Phenol resins

(a) Polyalkenylphenol Resin The polyalkenylphenol resin (a) can be obtained by converting the hydroxyl groups of a known phenolic resin into alkenyl ethers and then subjecting the alkenyl ether groups to Claisen rearrangement.
Preferably, the polyalkenylphenol resin has the following structural unit: By including such a resin, the development properties of the resulting photosensitive resin composition can be improved and outgassing can be reduced.

In formula (1), R ¹ , R ² and R ³ each independently represent a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a group represented by formula (2):
(In formula (2), R ⁶ , R ⁷ , R ⁸ , R ⁹ and R ¹⁰ are each independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a cyclic alkyl group having 5 to 10 carbon atoms, or an aryl group having 6 to 12 carbon atoms; * in formula (2) represents a bond to a carbon atom constituting an aromatic ring), an alkoxy group having 1 to 2 carbon atoms, or a hydroxyl group; and at least one of R ¹ , R ² and R ³ is an alkenyl group represented by formula (2); Q is an alkylene group represented by formula -CR ⁴ R ⁵ -, a cycloalkylene group having 5 to 10 carbon atoms, a divalent organic group having an aromatic ring, a divalent organic group having an alicyclic fused ring, or a ^divalent group formed by combining these; Each ⁵ is independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, a cyclic alkyl group having 5 to 10 carbon atoms, or an aryl group having 6 to 12 carbon atoms. When two or more structural units of formula (1) are present in one molecule, the structural units of formula (1) may be the same or different.

R ¹ , R ² and R ³ in formula (1) are a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkenyl group represented by formula (2), an alkoxy group having 1 to 2 carbon atoms or a hydroxyl group, and at least one of R ¹ , R ² and R ³ is an alkenyl group represented by formula (2). In R ¹ , R ² and R ³ in formula (1), specific examples of the alkyl group having 1 to 5 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, etc. Specific examples of the alkoxy group having 1 to 2 carbon atoms include a methoxy group and an ethoxy group.

In the alkenyl group represented by formula (2), R ⁶ , R ⁷ , R ⁸ , R ⁹ , and R ¹⁰ are each independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a cyclic alkyl group having 5 to 10 carbon atoms, or an aryl group having 6 to 12 carbon atoms. Specific examples of the alkyl group having 1 to 5 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, and an n-pentyl group. Specific examples of the cyclic alkyl group having 5 to 10 carbon atoms include a cyclopentyl group, a cyclohexyl group, a methylcyclohexyl group, and a cycloheptyl group. Specific examples of the aryl group having 6 to 12 carbon atoms include a phenyl group, a methylphenyl group, an ethylphenyl group, a biphenyl group, and a naphthyl group. It is preferred that R ⁶ , R ⁷ , R ⁸ , R ⁹ , and R ¹⁰ are each independently a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. In terms of reactivity, preferred alkenyl groups represented by formula (2) include allyl and methallyl groups, with allyl being more preferred.

It is most preferable that one of R ¹ , R ² and R ³ is an allyl group or a methallyl group, and the other two are hydrogen atoms.

In formula (1), Q is an alkylene group represented by the formula ^-CR4R5- , a ^{cycloalkylene} group having 5 to 10 carbon atoms, a divalent organic group having an aromatic ring, a divalent organic group having a fused alicyclic ring, or a divalent group formed by combining these. ^R4 and ^R5 are each independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, a cyclic alkyl group having 5 to 10 carbon atoms, or an aryl group having 6 to 12 carbon atoms. Specific examples of alkyl groups having 1 to 5 carbon atoms include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, and n-pentyl. Specific examples of alkenyl groups having 2 to 6 carbon atoms include vinyl, allyl, butenyl, pentenyl, and hexenyl. Examples of cyclic alkyl groups having 5 to 10 carbon atoms include a cyclopentyl group, a cyclohexyl group, a methylcyclohexyl group, and a cycloheptyl group. Specific examples of aryl groups having 6 to 12 carbon atoms include a phenyl group, a methylphenyl group, an ethylphenyl group, a biphenyl group, and a naphthyl group. ^R4 and ^R5 are preferably each independently a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and most preferably both are hydrogen atoms.

Specific examples of the cycloalkylene group having 5 to 10 carbon atoms include a cyclopentylene group, a cyclohexylene group, a methylcyclohexylene group, a cycloheptylene group, etc. Specific examples of the divalent organic group having an aromatic ring include a phenylene group, a tolylene group, a naphthylene group, a biphenylene group, a fluorenylene group, an anthracenylene group, a xylylene group, a 4,4-methylenediphenyl group, and a group represented by the formula (3):
A specific example of the divalent organic group having a fused alicyclic ring is a dicyclopentadienylene group.

When a polyalkenylphenol resin (a) is used as the first resin (A), a particularly preferred polyalkenylphenol resin (a) in terms of alkali developability, outgassing, etc. is one in which Q in formula (1) is —CH ₂ —, that is, a polyalkenylphenol resin (a) represented by formula (4):
In formula (4), R ¹ , R ² and R ³ are the same as those in formula (1). Preferred R ^{1 ,} R ² and R ³ are the same as ^{those in} formula (1).

The structural unit represented by formula (1) or formula (4) preferably accounts for 50 to 100 mol % of the polyalkenyl phenol resin (a), more preferably 70 to 100 mol %, and even more preferably 80 to 100 mol %. It is preferable that the structural unit represented by formula (1) or formula (4) accounts for 50 mol % or more of the polyalkenyl phenol resin (a) in order to improve heat resistance. Since the phenolic hydroxyl groups in the polyalkenyl phenol resin (a) ionize in the presence of a basic compound and become soluble in water, it is necessary for the phenolic hydroxyl groups to be present in a certain amount or more from the viewpoint of alkaline developability. Therefore, the polyalkenyl phenol resin (a) containing the structural unit of formula (4) contains the structural unit represented by formula (4) and the structural unit represented by formula (5)
In formula (5), R ^1a , R ^2a , and R ^3a each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. Preferred R 1a , R 2a , and R ^3a are the same as preferred R ¹ , R ² , and R ³ in formula ( ^{1 )} .

In polyalkenylphenol resin (a) having structural units represented by formula (4) and structural units represented by formula (5), where x is the number of structural units represented by formula (4) and y is the number of structural units represented by formula (5), 0.5≦x/(x+y)<1 and 0<y/(x+y)≦0.5 are satisfied, and x+y is preferably 2 to 50, more preferably 3 to 40, and even more preferably 5 to 25.

The number average molecular weight of polyalkenylphenol resin (a) is preferably 500 to 5,000, more preferably 800 to 3,000, and even more preferably 900 to 2,000. The weight average molecular weight of polyalkenylphenol resin (a) is preferably 500 to 30,000, more preferably 3,000 to 25,000, and even more preferably 5,000 to 20,000. If the number average molecular weight is 500 or more, or the weight average molecular weight is 500 or more, the alkaline development rate is appropriate and the difference in dissolution rate between exposed and unexposed areas is sufficient, resulting in good pattern resolution. If the number average molecular weight is 5,000 or less, or the weight average molecular weight is 30,000 or less, good coatability and alkaline developability are achieved.

The phenolic hydroxyl group equivalent of polyalkenylphenol resin (a) is preferably 60 to 400, more preferably 80 to 350, and even more preferably 100 to 300. If the phenolic hydroxyl group equivalent of polyalkenylphenol resin (a) is 60 or more, the film thickness of the unexposed areas can be sufficiently maintained during alkaline development. If the phenolic hydroxyl group equivalent of polyalkenylphenol resin (a) is 400 or less, the desired alkaline solubility can be obtained.

(b) Hydroxypolystyrene resin derivative The first resin (A) is a hydroxypolystyrene resin derivative represented by the formula (6):
It is also possible to use a hydroxypolystyrene resin derivative (b) having the structural unit of the following formula: By including such a resin, the development characteristics of the resulting photosensitive resin composition can be improved and also outgassing can be reduced.

In formula (6), R ¹¹ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, a is an integer of 1 to 4, b is an integer of 1 to 4, a+b is within a range of 2 to 5, and R ¹² is at least one selected from the group consisting of a hydrogen atom, a methyl group, an ethyl group, and a propyl group.

When a hydroxypolystyrene resin derivative (b) is used as the first resin (A), it is preferable that the first resin (A) contains a structural unit represented by formula (6) and a structural unit represented by formula (7)
It is preferable that the copolymer has a structural unit represented by the following formula:

In formula (7), R ¹³ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and c is an integer of 1 to 5.

Hydroxypolystyrene resin derivative (b) having a structural unit represented by formula (6), and hydroxypolystyrene resin derivative (b) having a structural unit represented by formula (6) and a structural unit represented by formula (7), can be obtained by reacting a portion of a polymer or copolymer obtained by polymerizing, using a known method, one or more aromatic vinyl compounds having a phenolic hydroxyl group, such as p-hydroxystyrene, m-hydroxystyrene, o-hydroxystyrene, p-isopropenylphenol, m-isopropenylphenol, or o-isopropenylphenol, with formaldehyde or further reacting with an alcohol using a known method, such as the method described in JP 2013-151705 A.

As aromatic vinyl compounds having a phenolic hydroxyl group, p-hydroxystyrene or m-hydroxystyrene is preferably used.

The number average molecular weight of the hydroxypolystyrene resin derivative (b) is preferably 1,000 to 20,000, more preferably 3,000 to 10,000, and even more preferably 4,000 to 9,000. The weight average molecular weight of the hydroxypolystyrene resin derivative (b) is preferably 1,000 to 100,000, more preferably 5,000 to 75,000, and even more preferably 10,000 to 50,000. If the number average molecular weight is 1,000 or more, or the weight average molecular weight is 1,000 or more, the alkaline development rate is appropriate and the difference in dissolution rate between exposed and unexposed areas is sufficient, resulting in good pattern resolution. If the number average molecular weight is 20,000 or less, or the weight average molecular weight is 100,000 or less, the coatability and alkaline developability are good.

The phenolic hydroxyl group equivalent of the hydroxypolystyrene resin derivative (b) is preferably 60 to 400, more preferably 80 to 350, and even more preferably 100 to 300. If the phenolic hydroxyl group equivalent of the hydroxypolystyrene resin derivative (b) is 60 or more, the film thickness of the unexposed areas can be sufficiently maintained during alkaline development. If the phenolic hydroxyl group equivalent of the hydroxypolystyrene resin derivative (b) is 400 or less, the desired alkaline solubility can be obtained.

(c) Resin Having Epoxy Groups and Phenolic Hydroxyl Groups A resin (c) having epoxy groups and phenolic hydroxyl groups can also be used as the first resin (A). Such a resin (c) can be obtained, for example, by reacting the epoxy group of a compound having at least two epoxy groups per molecule (hereinafter sometimes referred to as an "epoxy compound") with the carboxy group of a hydroxybenzoic acid compound. The epoxy group in the resin (c) having epoxy groups and phenolic hydroxyl groups forms crosslinks by reaction with the phenolic hydroxyl groups upon heating, improving the chemical resistance, heat resistance, etc. of the coating. The phenolic hydroxyl groups impart alkali solubility to the resin during development.

The following reaction scheme 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.

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, and the degree of polymerization. An example of the structure of a novolac epoxy resin is shown in Formula (8). In Formula (8), for example, R ¹⁴ represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 2 carbon atoms, or a hydroxyl group, and m represents an integer from 1 to 50.

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

The compound having at least two epoxy groups per molecule is preferably a novolac epoxy resin, and more preferably a cresol novolac epoxy resin. Photosensitive resin compositions containing a resin (c) 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.

Hydroxybenzoic acid compounds are compounds in which at least one of the 2- to 6-positions of benzoic acid is substituted with a hydroxyl group. Examples 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. These hydroxybenzoic acid compounds may be used alone or in combination of two or more.

In one embodiment, the resin (c) 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 (9):
In formula (9), d is an integer of 1 to 5, and * represents a bond to a residue of a compound having at least two epoxy groups in one molecule, excluding the epoxy groups involved in the reaction.

In the method for obtaining resin (c) having epoxy groups and phenolic hydroxyl groups from an epoxy compound and a hydroxybenzoic acid compound, 0.2 to 1.0 equivalents of the hydroxybenzoic acid compound can be used per 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 hydroxybenzoic acid compound is used in an amount of 0.2 or more, sufficient alkali solubility can be achieved, and if it is 1.0 equivalent or less, molecular weight increase due to side reactions can be suppressed.

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.

The number average molecular weight of resin (c) having epoxy groups and phenolic hydroxyl groups 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 of resin (c) having epoxy groups and phenolic hydroxyl groups is preferably 500 to 30,000, more preferably 2,000 to 25,000, and even more preferably 3,000 to 20,000. If the number average molecular weight is 500 or more, or the weight average molecular weight is 500 or more, the alkaline development rate is appropriate and the difference in dissolution rate between exposed and unexposed areas is sufficient, resulting in good pattern resolution. If the number average molecular weight is 8,000 or less, or the weight average molecular weight is 30,000 or less, good coatability and alkaline developability are achieved.

The phenolic hydroxyl group equivalent of resin (c) having epoxy groups and phenolic hydroxyl groups is preferably 60 to 300, more preferably 80 to 250, and even more preferably 100 to 200. If the phenolic hydroxyl group equivalent of resin (c) having epoxy groups and phenolic hydroxyl groups is 60 or more, the film thickness of the unexposed areas can be sufficiently maintained during alkaline development. If the phenolic hydroxyl group equivalent of resin (c) having epoxy groups and phenolic hydroxyl groups is 300 or less, the desired alkaline solubility can be obtained.

(d) Copolymer of polymerizable monomer having alkali-soluble functional group and other polymerizable monomer Copolymer (d) of polymerizable monomer having alkali-soluble functional group and other polymerizable monomer can be used as the first resin (A). Examples of the alkali-soluble functional group include a carboxy group, an alcoholic hydroxyl group, a phenolic hydroxyl group, a sulfo group, a phosphate group, an acid anhydride group, etc. Examples of the polymerizable functional group possessed by the polymerizable monomer include a radically polymerizable functional group, such as CH ₂ ═CH—, CH ₂ ═C(CH ₃ )—, CH ₂ ═CHCO—, CH ₂ ═C(CH ₃ )CO—, —OC—CH═CH—CO—, etc.

Copolymer (d) of a polymerizable monomer having an alkali-soluble functional group and another polymerizable monomer can be produced, for example, by radical polymerization of a polymerizable monomer having an alkali-soluble functional group and another polymerizable monomer. After synthesizing the copolymer by radical polymerization, a derivative to which an alkali-soluble functional group has been added may also be used. Examples of the polymerizable monomer having an alkali-soluble functional group include 4-hydroxystyrene, (meth)acrylic acid, α-bromo(meth)acrylic acid, α-chloro(meth)acrylic acid, β-furyl(meth)acrylic acid, β-styryl(meth)acrylic acid, maleic acid, monomethyl maleate, monoethyl maleate, monoisopropyl maleate, fumaric acid, cinnamic acid, α-cyanocinnamic acid, itaconic acid, crotonic acid, propiolic acid, 4-hydroxyphenyl methacrylate, 3,5-dimethyl-4-hydroxybenzyl acrylamide, 4-hydroxyphenyl acrylamide, 4-hydroxyphenyl maleimide, 3-maleimide propionic acid, 4-maleimide butyric acid, and 6-maleimide hexanoic acid. Other polymerizable monomers include, for example, polymerizable 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, sec-butyl(meth)acrylate, tert-butyl(meth)acrylate, phenyl(meth)acrylate, tetrahydrofurfuryl(meth)acrylate, ... (meth)acrylic acid esters such as acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, glycidyl (meth)acrylate, 2,2,2-trifluoroethyl (meth)acrylate, 2,2,3,3-tetrafluoropropyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentenyl (meth)acrylate, and dicyclopentanyl (meth)acrylate; maleic acid derivatives such as maleic anhydride and maleic acid monoester; and N-substituted maleimides such as phenylmaleimide and cyclohexylmaleimide. From the viewpoint of heat resistance, etc., the copolymer (d) of a polymerizable monomer having an alkali-soluble functional group and another polymerizable monomer 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.

As a polymerizable monomer having an alkali-soluble functional group, a compound represented by the formula (10)
In formula (10), R ¹⁵ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and e is an integer of 1 to 5. As such a polymerizable monomer having an alkali-soluble functional group, 4-hydroxyphenyl methacrylate is particularly preferred.

Other polymerizable monomers include those represented by formula (11):
In formula (11), R ¹⁶ and R ¹⁷ 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, and R ¹⁸ 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 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. ^{R 16} and R ¹⁷ are preferably hydrogen atoms. R ¹⁸ is preferably a cyclic alkyl group having 3 to 12 carbon atoms or a phenyl group. As such other polymerizable monomers, phenylmaleimide and cyclohexylmaleimide are particularly preferred.

It is particularly preferable to use 4-hydroxyphenyl methacrylate as the polymerizable monomer having an alkali-soluble functional group, and at least one selected from the group consisting of phenylmaleimide and 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.

Polymerization initiators used in producing copolymer (d) of a polymerizable monomer having an alkali-soluble functional group and another polymerizable monomer by radical polymerization include, but are 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-di Examples of peroxide polymerization initiators that can be used include those having a 10-hour half-life temperature of 100 to 170°C, such as methyl-2,5-di(tert-butylperoxy)hexane, tert-butylcumyl peroxide, di-tert-butyl peroxide, 1,1,3,3-tetramethylbutyl hydroperoxide, and cumene hydroperoxide, as well as peroxide polymerization initiators such as benzoyl peroxide, lauroyl peroxide, 1,1'-di(tert-butylperoxy)cyclohexane, and tert-butyl peroxypivalate. The amount of the 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 mixture of polymerizable monomers.

A RAFT (Reversible Addition Fragmentation Transfer) agent may be used in combination with the polymerization initiator. RAFT agents include, but are not limited to, thiocarbonylthio compounds such as dithioesters, dithiocarbamates, trithiocarbonates, and xanthates. The RAFT agent can be used in an amount of 0.005 to 20 parts by weight, preferably 0.01 to 10 parts by weight, per 100 parts by weight of the total amount of polymerizable monomers.

In one embodiment, the copolymer (d) of a polymerizable monomer having an alkali-soluble functional group and another polymerizable monomer is represented by the formula (10):
(In formula (10), R ¹⁵ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and e is an integer of 1 to 5.)
and a structural unit represented by formula (11)
(In formula (11), R ¹⁶ and R ¹⁷ are each independently a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, a completely or partially fluorinated fluoroalkyl group having 1 to 3 carbon atoms, or a halogen atom; and R ¹⁸ 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.)
It has a structural unit represented by the following formula:

The number-average molecular weight of the copolymer (d) of a polymerizable monomer having an alkali-soluble functional group and another polymerizable monomer is preferably 1,000 to 30,000, more preferably 1,500 to 25,000, and even more preferably 2,000 to 20,000. The weight-average molecular weight of the copolymer (d) of a polymerizable monomer having an alkali-soluble functional group and another polymerizable monomer is preferably 3,000 to 80,000, more preferably 4,000 to 70,000, and even more preferably 5,000 to 60,000. If the number-average molecular weight is 1,000 or more, or if the weight-average molecular weight is 3,000 or more, the alkali development rate is appropriate and the difference in dissolution rate between exposed and unexposed areas is sufficient, resulting in good pattern resolution. If the number-average molecular weight is 30,000 or less, or if the weight-average molecular weight is 80,000 or less, the coatability and alkali developability are good. The polydispersity (Mw/Mn) of the copolymer (d) of a polymerizable monomer having an alkali-soluble functional group and another polymerizable monomer is preferably 1.0 to 3.5, more preferably 1.1 to 3.0, and even more preferably 1.2 to 2.8. By adjusting the polydispersity to fall within the above range, a photosensitive resin composition having excellent pattern formability and alkali developability can be obtained.

When the alkali-soluble functional group of the copolymer (d) of a polymerizable monomer having an alkali-soluble functional group and another polymerizable monomer is a phenolic hydroxyl group, the phenolic hydroxyl group equivalent of the copolymer (d) of a polymerizable monomer having an alkali-soluble functional group and another polymerizable monomer is preferably 60 to 400, more preferably 80 to 350, and even more preferably 100 to 300. When the phenolic hydroxyl group equivalent of the copolymer (d) of a polymerizable monomer having an alkali-soluble functional group and another polymerizable monomer is 60 or more, the film thickness of the unexposed areas can be sufficiently maintained during alkaline development. When the phenolic hydroxyl group equivalent of the copolymer (d) of a polymerizable monomer having an alkali-soluble functional group and another polymerizable monomer is 400 or less, the desired alkali solubility can be obtained.

In this disclosure, if a copolymer (d) of a polymerizable monomer having an alkali-soluble functional group and another polymerizable monomer also falls under the category of hydroxypolystyrene resin derivative (b), it will be treated as a copolymer (d) of a polymerizable monomer having an alkali-soluble functional group and another polymerizable monomer. If a copolymer (d) of a polymerizable monomer having an alkali-soluble functional group and another polymerizable monomer also falls under the category of resin (c) having an epoxy group and a phenolic hydroxyl group, it will be treated as a copolymer (d) of a polymerizable monomer having an alkali-soluble functional group and another polymerizable monomer. In other words, hydroxypolystyrene resin derivative (b) and resin (c) having an epoxy group and a phenolic hydroxyl group are excluded from those that fall under the category of copolymer (d) of a polymerizable monomer having an alkali-soluble functional group and another polymerizable monomer.

(e) Polyimide resin, (f) Polyamic acid resin, (g) Polybenzoxazole resin, (h) Polybenzoxazole resin precursor In one embodiment, the first resin (A) is at least one selected from the group consisting of polyimide resin (e), polyamic acid resin (f), polybenzoxazole resin (g), and polybenzoxazole resin precursor (h). The polyamic acid resin (f) undergoes dehydration ring closure to become a resin having a polyimide structure. The polybenzoxazole resin precursor (h) undergoes dehydration ring closure to become the polybenzoxazole resin (g).

Polyimide resin (e) has a structural unit represented by formula (12). Polyamic acid resin (f) and polybenzoxazole resin precursor (h) have a structural unit represented by formula (13). Polybenzoxazole resin (g) has a structural unit represented by formula (14). Polyimide resin (e) may have both a structural unit represented by formula (12) and a structural unit represented by formula (13), and polybenzoxazole resin (g) may have both a structural unit represented by formula (14) and a structural unit represented by formula (13).

In formula (12), R ¹⁹ is a tetravalent to decavalent organic group, R ²⁰ is a divalent to octavalent organic group, R ²¹ and R ²² are each independently a hydroxyl group, a carboxyl group, a sulfo group, or a mercapto group, and f and g are each independently an integer of 0 to 6.

In formula (13), ^R23 is a divalent to octavalent organic group, ^R24 is a divalent to octavalent organic group, ^R25 and ^R26 are each independently a hydroxyl group, a sulfo group, a mercapto group, or ^-COOR27 , ^R27 is a hydrogen atom or a monovalent hydrocarbon group having 1 to 20 carbon atoms, and h and i are each independently an integer of 0 to 6, with the proviso that h+i>0. In the case of polyamic acid resin (f), h is an integer of 1 or greater, and at least one occurrence of ^R25 is ^-COOR27 . In the case of polybenzoxazole resin precursor (h), i is an integer of 1 or greater, and at least one occurrence of ^R26 is a phenolic hydroxyl group.

In formula (14), R ²⁸ is a divalent to octavalent organic group, R ²⁹ is a divalent to octavalent organic group, R ³⁰ and R ³¹ are each independently a hydroxyl group, a carboxyl group, a sulfo group, or a mercapto group, and j and k are each independently an integer of 0 to 6.

In formula (12), R ¹⁹ -(R ²¹ ) _f represents a residue of an acid dianhydride. R ¹⁹ is a tetravalent to decavalent organic group, preferably an organic group having 5 to 40 carbon atoms and containing an aromatic ring or a cycloaliphatic group.

Examples of acid dianhydrides include pyromellitic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2,3,3',4'-biphenyltetracarboxylic dianhydride, 2,2',3,3'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 2,2',3,3'-benzophenonetetracarboxylic dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride, 2,2-bis(2,3-dicarboxyphenyl)propane dianhydride, 1,1-bis(3,4-dicarboxyphenyl)ethane dianhydride, 1,1-bis(2,3-dicarboxyphenyl)ethane dianhydride, bis(3,4-dicarboxyphenyl)methane dianhydride, bis(2,3-dicarboxyphenyl)methane dianhydride, bis Aromatic tetracarboxylic acid dianhydrides such as (3,4-dicarboxyphenyl)ether dianhydride, 1,2,5,6-naphthalenetetracarboxylic acid dianhydride, 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride, 9,9-bis[4-(3,4-dicarboxyphenoxy)phenyl]fluorene dianhydride, 2,3,6,7-naphthalenetetracarboxylic acid dianhydride, 2,3,5,6-pyridinetetracarboxylic acid dianhydride, 3,4,9,10-perylenetetracarboxylic acid dianhydride, and 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride; aliphatic tetracarboxylic acid dianhydrides such as butanetetracarboxylic acid dianhydride and 1,2,3,4-cyclopentanetetracarboxylic acid dianhydride, and combinations of two or more thereof.

R ²³ -(R ²⁵ ) _h in formula (13) and R ²⁸ -(R ³⁰ ) _j in formula (14) each represent an acid residue. ^{R 23} and R ²⁸ each independently represent a divalent to octavalent organic group, preferably an organic group containing an aromatic ring or a cycloaliphatic group and having 5 to 40 carbon atoms.

Examples of the acid include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, diphenyl ether dicarboxylic acid, bis(carboxyphenyl)hexafluoropropane, biphenyl dicarboxylic acid, benzophenone dicarboxylic acid, and triphenyl dicarboxylic acid; aromatic tricarboxylic acids such as trimellitic acid, trimesic acid, diphenyl ether tricarboxylic acid, and biphenyl tricarboxylic acid; pyromellitic acid, 3,3',4,4'-biphenyl tetracarboxylic acid, 2,3,3',4'-biphenyl tetracarboxylic acid, 2,2',3,3'-biphenyl tetracarboxylic acid, 3,3',4,4'-benzophenone tetracarboxylic acid, 2,2',3,3'-benzophenone tetracarboxylic acid, and 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane. Examples of the tetracarboxylic acids include aromatic tetracarboxylic acids such as 1,2,5,6-naphthalenetetracarboxylic acid, 2,3,6,7-naphthalenetetracarboxylic acid, 2,3,5,6-pyridinetetracarboxylic acid, and 3,4,9,10-perylenetetracarboxylic acid; and aliphatic tetracarboxylic acids such as butanetetracarboxylic acid and 1,2,3,4-cyclopentanetetracarboxylic acid, as well as combinations of two or more thereof. In the above tricarboxylic acids and tetracarboxylic acids, one or two carboxy groups correspond to R ²⁵ in Formula (13) or R ³⁰ in Formula (14). These acids may be in the form of esters or acid anhydrides.

R ²⁰ -(R ²² ) _g in formula (12), R ²⁴ -(R ²⁶ ) _i in formula (13), and R ²⁹ -(R ³¹ ) _k in formula (14) each represent a residue of a diamine. R ²⁰ , R ²⁴ , and R ²⁹ each independently represent a divalent to octavalent organic group, preferably an organic group containing an aromatic ring or a cycloaliphatic group and having 5 to 40 carbon atoms.

Examples of diamines corresponding to R ²⁰ in formula (12) and R ²⁴ in formula (13) of the polyamic acid resin (f) include 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 1,4-bis(4-aminophenoxy)benzene, benzidine, m-phenylenediamine, p-phenylenediamine, 1,5-naphthalenediamine, 2,6-naphthalenediamine, bis(4-aminophenoxy)biphenyl, bis[4-(4-aminophenoxy)phenyl]ether, 1,4-bis(4-aminophenoxy)benzene, 2,2'-dimethyl-4,4'-diaminobiphenyl, and 2,2'-diethyl-4,4'-diaminobiphenyl. aromatic diamines such as 3,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-diethyl-4,4'-diaminobiphenyl, 2,2',3,3'-tetramethyl-4,4'-diaminobiphenyl, 3,3',4,4'-tetramethyl-4,4'-diaminobiphenyl, 2,2'-di(trifluoromethyl)-4,4'-diaminobiphenyl, and 9,9-bis(4-aminophenyl)fluorene, or compounds in which at least one hydrogen atom on the aromatic ring of these aromatic diamines has been substituted with an alkyl group or a halogen atom; aliphatic diamines such as cyclohexyldiamine and methylenebiscyclohexylamine, and combinations of two or more thereof.

Examples of diamines corresponding to R ²⁴ in formula (13) and R ²⁹ in formula (14) in the polybenzoxazole resin precursor (h) include bisaminophenol compounds having a phenolic hydroxyl group at the ortho position relative to the amino group on the aromatic ring of the aromatic diamine, and combinations of two or more of these.

The polyimide resin (e), polyamic acid resin (f), polybenzoxazole resin (g), and polybenzoxazole resin precursor (h) may have acidic groups at the ends of their main chains by being capped with monoamines, acid anhydrides, acid chlorides, monocarboxylic acids, etc., which have acidic groups.

Polyamic acid resin (f) can be synthesized, for example, by reacting a tetracarboxylic dianhydride with a diamine; by generating a diester from a tetracarboxylic dianhydride with an alcohol and then reacting the diester with a diamine in the presence of a condensing agent; or by generating a diester from a tetracarboxylic dianhydride with an alcohol, converting the remaining dicarboxylic acid into an acid chloride, and then reacting the resulting intermediate with a diamine.

Polybenzoxazole resin precursor (h) can be synthesized, for example, by a condensation reaction between a bisaminophenol compound and a polycarboxylic acid such as a dicarboxylic acid, tricarboxylic acid, or tetracarboxylic acid. Specifically, examples include a method in which a bisaminophenol compound is reacted with an intermediate obtained by reacting a dehydration condensation agent such as dicyclohexylcarbodiimide (DCC) with a polycarboxylic acid, or a method in which a dicarboxylic acid dichloride solution is added dropwise to a solution of a bisaminophenol compound to which a tertiary amine such as pyridine has been added.

Polyimide resin (e) can be synthesized, for example, by dehydrating and cyclizing polyamic acid resin (f) obtained by the method described above by heating or chemical treatment with acid or base.

Polybenzoxazole resin (g) can be synthesized, for example, by dehydrating and cyclizing the polybenzoxazole resin precursor (h) obtained by the method described above by heating or chemical treatment with an acid or base.

The number average molecular weight of polyimide resin (e), polyamic acid resin (f), polybenzoxazole resin (g), and polybenzoxazole resin precursor (h) is preferably 500 to 8,000, more preferably 800 to 6,000, and even more preferably 1,000 to 5,000. A number average molecular weight of 500 or more provides suitable alkali solubility and is therefore suitable as a resin for photosensitive materials. A number average molecular weight of 8,000 or less provides good coatability and developability.

(i) Silicone Resin In one embodiment, the first resin (A) includes a silicone resin (i). The silicone resin (i) can be synthesized by hydrolysis and condensation of at least one compound selected from organosilanes represented by formula (15) and organosilanes represented by formula (16). By using organosilanes represented by formula (15) and formula (16), a photosensitive resin composition with excellent sensitivity and resolution can be obtained.

The organosilane represented by formula (15) is shown below.

In formula (15), R ³² is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, or an aryl group having 6 to 16 carbon atoms, R ³³ is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkanoyl group having 2 to 6 carbon atoms, or an aryl group having 6 to 16 carbon atoms, and p is an integer of 0 to 3. When p is 2 or more, multiple R ^32s may be the same or different. When p is 2 or less, multiple R ^33s may be the same or different.

Organosilanes represented by formula (15) include, for example, tetrafunctional silanes such as tetramethoxysilane, tetraethoxysilane, tetraacetoxysilane, and tetraphenoxysilane; methyltrimethoxysilane, methyltriethoxysilane, methyltriisopropoxysilane, methyltri-n-butoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltriisopropoxysilane, ethyltri-n-butoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, n-butyltrimethoxysilane, n-butyltriethoxysilane, n-hexyltrimethoxysilane, n-hexyltriethoxysilane, decyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, and 3-methacryloxypropyltriethoxysilane. Trimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, p-hydroxyphenyltrimethoxysilane, 1-(p-hydroxyphenyl)ethyltrimethoxysilane, 2-(p-hydroxyphenyl)ethyltrimethoxysilane, 4-hydroxy-5-(p-hydroxyphenylcarbonyloxy)pentyltrimethoxysilane, trifluoromethyltrimethoxysilane, trifluoromethyltriethoxysilane, 3,3,3-trifluoropropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane hydroxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, [(3-ethyl-3-oxetanyl)methoxy]propyltrimethoxysilane, [(3-ethyl-3-oxetanyl)methoxy]propyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-trimethoxysilylpropylsuccinic acid, 1-naphthyltrimethoxysilane, 1-naphthyltriethoxysilane, 1-naphthyltri-n-propoxysilane, 2-naphthyltrimethoxysilane, 1-anthracenyltrimethoxysilane, 9-anthracenyltrimethoxysilane, 9-phenanthrenyltrimethoxysilane, 9-fluorenyltrimethoxysilane, 2-fluorenyltrimethoxysilane trifunctional silanes such as dimethyldimethoxysilane, dimethyldiethoxysilane, dimethyldiacetoxysilane, di-n-butyldimethoxysilane, diphenyldimethoxysilane, (3-glycidoxypropyl)methyldimethoxysilane, (3-glycidoxypropyl)methyldiethoxysilane, di(1-naphthyl)dimethoxysilane, di(1-naphthyl)diethoxysilane; monofunctional silanes such as trimethylmethoxysilane, tri-n-butylethoxysilane, (3-glycidoxypropyl)dimethylmethoxysilane, (3-glycidoxypropyl)dimethylethoxysilane, and combinations of two or more thereof.

The organosilane represented by formula (16) is shown below.

In formula (16), R ³⁴ to R ³⁷ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkanoyl group having 2 to 6 carbon atoms, or an aryl group having 6 to 16 carbon atoms, and n is in the range of 2 to 8. When n is 2 or greater, multiple R ^35s and R ^36s may be the same or different.

Specific examples of organosilanes represented by formula (16) include Methyl Silicate 51 (R ^{to R} are methyl groups, n is 4 on average) manufactured by Fuso Chemical Co., Ltd., M Silicate 51 (R to R are methyl groups, n is ³ to ⁵ on average), Silicate 40 (R to R are ethyl groups, n is ⁴ to ⁶ on average), and Silicate 45 (R to R are ethyl groups, n is ⁶ to ⁸ on average) manufactured by Tama Chemicals Co., Ltd., and Methyl Silicate 51 (R ^{to R} are methyl groups, n is 4 on average), Methyl Silicate 53A ( ^R to ^R are methyl groups, n is 7 on average), and Ethyl Silicate 40 (R ^{to R} are ethyl groups, n is 5 on average) manufactured by Colcoat Co., Ltd. Combinations of two or more of these may also be used.

Silicone resin (i) can be synthesized by hydrolysis and partial condensation of organosilanes represented by formula (15) and formula (16). Due to partial condensation, residual silanol groups remain in silicone resin (i). Hydrolysis and partial condensation can be carried out, for example, by adding a solvent, water, catalyst, etc. to an organosilane mixture as needed, followed by heating and stirring at 50°C to 150°C for approximately 0.5 to 100 hours. If necessary, hydrolysis by-products (alcohols such as methanol) or condensation by-products (water) can be removed by distillation.

An acid catalyst or a base catalyst is preferably used as the catalyst. Examples of acid catalysts include hydrochloric acid, nitric acid, sulfuric acid, hydrofluoric acid, phosphoric acid, acetic acid, trifluoroacetic acid, formic acid, polycarboxylic acids or their anhydrides, and ion exchange resins. Examples of base catalysts include triethylamine, tripropylamine, tributylamine, tripentylamine, trihexylamine, triheptylamine, trioctylamine, diethylamine, triethanolamine, diethanolamine, sodium hydroxide, potassium hydroxide, alkoxysilanes having amino groups, and ion exchange resins. After hydrolysis and partial condensation, the catalyst may be removed, if necessary, by washing with water, treatment with an ion exchange resin, or a combination thereof. Removing the catalyst can improve the storage stability of the photosensitive resin composition.

The weight-average molecular weight of silicone resin (i) is preferably 1,000 to 100,000, and more preferably 1,000 to 50,000. A weight-average molecular weight of 1,000 or more can improve film-forming properties, while a weight-average molecular weight of 100,000 or less provides good alkaline developability.

(j) Cyclic Olefin Polymer In one embodiment, the first resin (A) contains a cyclic olefin polymer (j). The cyclic olefin polymer (j) is a homopolymer or copolymer of a cyclic olefin monomer having an alicyclic structure and an ethylenically unsaturated double bond. The cyclic olefin polymer (j) may have structural units derived from a monomer other than the cyclic olefin monomer.

Examples of monomers constituting cyclic olefin polymer (j) include cyclic olefin monomers having a protic polar group, cyclic olefin monomers having a non-protic polar group, cyclic olefin monomers having no polar group, and monomers other than cyclic olefins. Monomers other than cyclic olefins may have a protic polar group or a polar group other than this, or may not have a polar group.

Examples of cyclic olefin monomers having a protic polar group include 5-hydroxycarbonylbicyclo[2.2.1]hept-2-ene, 5-methyl-5-hydroxycarbonylbicyclo[2.2.1]hept-2-ene, 5-carboxymethyl-5-hydroxycarbonylbicyclo[2.2.1]hept-2-ene, 5-exo-6-endo-dihydroxycarbonylbicyclo[2.2.1]hept-2-ene, 8-hydroxycarbonyltetracyclo[4.4.0.1 ^2,5 . 1 ^7,10 ]dodec-3-ene, 8-methyl-8-hydroxycarbonyltetracyclo[4.4.0.1 ^2,5 . 1 ^7,10 ]dodec-3-ene, 8-exo-9-endo-dihydroxycarbonyltetracyclo[4.4.0.1 ^2,5 . ^hydroxyl group-containing cyclic olefins such as 5-(4-hydroxyphenyl)bicyclo[2.2.1]hept-2-ene, 5-methyl-5-(4-hydroxyphenyl)bicyclo[2.2.1]hept-2-ene, 8-(4-hydroxyphenyl)tetracyclo[4.4.0.1 ^2,5 . 1 ^7,10 ]dodec-3-ene, and 8-methyl-8-(4-hydroxyphenyl)tetracyclo[4.4.0.1 ^2,5 . 1 ^7,10 ]dodec-3-ene, and combinations of two or more thereof.

Examples of cyclic olefin monomers having a polar group other than a protic group include 5-acetoxybicyclo[2.2.1]hept-2-ene, 5-methoxycarbonylbicyclo[2.2.1]hept-2-ene, 5-methyl-5-methoxycarbonylbicyclo[2.2.1]hept-2-ene, 8-acetoxytetracyclo[4.4.0.1 ^2,5 . 1 ^7,10 ]dodec-3-ene, 8-methoxycarbonyltetracyclo[4.4.0.1 ^2,5 . 1 ^7,10 ]dodec-3-ene, 8-ethoxycarbonyltetracyclo[4.4.0.1 ^2,5 . 1 ^7,10 ]dodec-3-ene, 8-n-propoxycarbonyltetracyclo[4.4.0.1 ^2,5 . 1 ^7,10 ] dodec-3-ene, 8-isopropoxycarbonyltetracyclo[4.4.0.1 ^2,5 . ^{1 7,10} ] dodec-3-ene, 8-n-butoxycarbonyltetracyclo[4.4.0.1 ^2,5 . 1 ^7,10 ] dodec-3-ene, 8-methyl-8-methoxycarbonyltetracyclo[4.4.0.1 ^2,5 . 1 ^7,10 ] dodec-3-ene, 8-methyl-8-ethoxycarbonyltetracyclo[4.4.0.1 ^2,5 . 1 ^7,10 ] dodec-3-ene, 8-methyl-8-n-propoxycarbonyltetracyclo[4.4.0.1 ^2,5 . 1 ^7,10 ] dodec-3-ene, 8-methyl-8-isopropoxycarbonyltetracyclo[4.4.0.1 ^2,5 . ^{1 7,10} ] dodec-3-ene, 8-methyl-8-n-butoxycarbonyltetracyclo[4.4.0.1 ^2,5 . 1 ^7,10 ] dodec-3-ene, 8-(2,2,2-trifluoroethoxycarbonyl)tetracyclo[4.4.0.1 ^2,5 . 1 ^7,10 ] dodec-3-ene, 8-methyl-8-(2,2,2-trifluoroethoxycarbonyl)tetracyclo[4.4.0.1 ^2,5 . cyclic olefins having an ester group such as 8-cyanotetracyclo[4.4.0.1 ^2,5 . 1 ^7,10 ]dodec-3-ene; cyclic olefins having an N-substituted imide group such as N-phenyl-(5-norbornene-2,3-dicarboximide); cyclic olefins having a cyano group such as 8-cyanotetracyclo[4.4.0.1 ^2,5 . 1 ^7,10 ]dodec-3-ene, 8-methyl-8-cyanotetracyclo[4.4.0.1 ^2,5 . 1 ^7,10 ]dodec-3-ene, 5-cyanobicyclo[2.2.1]hept-2-ene; cyclic olefins having a halogen atom such as 8-chlorotetracyclo[4.4.0.1 2,5 . 1 ^7,10 ]dodec-3-ene, 8-methyl-8-chlorotetracyclo[4.4.0.1 ^2,5 . 1 ^7,10 ]dodec-3-ene, and combinations of two or more thereof.

Examples of cyclic olefin monomers having no polar group include bicyclo[2.2.1]hept-2-ene, 5-ethyl-bicyclo[2.2.1]hept-2-ene, 5-butyl-bicyclo[2.2.1]hept-2-ene, 5-ethylidene-bicyclo[2.2.1]hept-2-ene, 5-methylidene-bicyclo[2.2.1]hept-2-ene, 5-vinyl-bicyclo[2.2.1]hept-2-ene, tricyclo[4.3.0.1 ^2,5 ]deca-3,7-diene, tetracyclo[8.4.0.1 ^11,14 . 0 ^3,7 ]pentadeca-3,5,7,12,11-pentaene, tetracyclo[4.4.0.1 ^2,5 . 1 ^7,10 ] dec-3-ene, 8-methyl-tetracyclo[4.4.0.1 ^{2,5 .} 1 7,10 ] dodec-3-ene, 8-ethyl-tetracyclo[4.4.0.1 2,5 . ^{1 7,10} ] dodec-3-ene, 8-methylidene-tetracyclo[4.4.0.1 ^2,5 . 1 ^7,10 ] dodec-3-ene, 8-ethylidene-tetracyclo[4.4.0.1 ^2,5 . 1 ^7,10 ] dodec-3-ene, 8-vinyl-tetracyclo[4.4.0.1 2,5 . ^{1 7,10} ] dodec-3-ene, 8-propenyl-tetracyclo[4.4.0.1 ^2,5 . 1 ^7,10 ] dodec-3-ene, pentacyclo[6.5.1.1 ^3,6 . 0 ^2,7 . 0 ^9,13 ] pentadeca-3,10-diene, cyclopentene, cyclopentadiene, 1,4-methano-1,4,4a,5,10,10a-hexahydroanthracene, 8-phenyl-tetracyclo[4.4.0.1 ^2,5 . 1 ^7,10 ] dodec-3-ene, tetracyclo[9.2.1.0 ^2,10 . 0 ^3,8 ] tetradeca-3,5,7,12-tetraene, pentacyclo[7.4.0.1 ^3,6 . 1 ^10,13 . 0 ^2,7 ]pentadeca-4,11-diene, pentacyclo[9.2.1.14,7.0 ^2,10 . 0 ^3,8 ]pentadeca-5,12-diene, and the like, and combinations of two or more thereof.

Specific examples of monomers other than cyclic olefins include α-olefins having 2 to 20 carbon atoms, such as ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 3-methyl-1-butene, 3-methyl-1-pentene, 3-ethyl-1-pentene, 4-methyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-hexene, 4,4-dimethyl-1-pentene, 4-ethyl-1-hexene, 3-ethyl-1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, and 1-eicosene; linear olefins such as non-conjugated dienes, such as 1,4-hexadiene, 4-methyl-1,4-hexadiene, 5-methyl-1,4-hexadiene, and 1,7-octadiene; and combinations of two or more of these.

The cyclic olefin polymer (j) can be synthesized by polymerizing the above-mentioned monomers by ring-opening polymerization or addition polymerization. Preferred polymerization catalysts include, for example, metal complexes of molybdenum, ruthenium, osmium, etc., or combinations of two or more of these. The cyclic olefin polymer may be subjected to a hydrogenation treatment. Hydrogenation catalysts commonly used for the hydrogenation of olefin compounds can be used, including, for example, Ziegler-type homogeneous catalysts, noble metal complex catalysts, and supported noble metal catalysts.

The weight-average molecular weight of the cyclic olefin polymer (j) is preferably 1,000 to 100,000, and more preferably 1,000 to 50,000. A weight-average molecular weight of 1,000 or more can improve film-forming properties, while a weight-average molecular weight of 100,000 or less can provide good alkaline developability.

(k) Cardo Resin In one embodiment, the first resin (A) includes a cardo resin (k). The cardo resin (k) has a cardo structure, i.e., a skeletal structure in which two other cyclic structures are bonded to a quaternary carbon atom constituting a cyclic structure. Examples of skeletal structures in which two other cyclic structures are bonded to a quaternary carbon atom constituting a cyclic structure include a fluorene skeleton, a bisphenolfluorene skeleton, a bisaminophenylfluorene skeleton, a fluorene skeleton having an epoxy group, and a fluorene skeleton having an acrylic group. An example of a cardo structure is one in which a benzene ring is bonded to a fluorene ring.

Cardo resin (k) can be synthesized by polymerizing monomers having a cardo structure through a reaction between the functional groups of the monomers. Polymerization methods for monomers having a cardo structure include, for example, ring-opening polymerization and addition polymerization. Examples of monomers having a cardo structure include bis(glycidyloxyphenyl)fluorene epoxy resins, cardo structure-containing bisphenol compounds such as 9,9-bis(4-hydroxyphenyl)fluorene and 9,9-bis(4-hydroxy-3-methylphenyl)fluorene; 9,9-bis(cyanoalkyl)fluorene compounds such as 9,9-bis(cyanomethyl)fluorene; 9,9-bis(aminoalkyl)fluorene compounds such as 9,9-bis(3-aminopropyl)fluorene; and combinations of two or more of these. Cardo resin (k) may also be a copolymer of a monomer having a cardo structure and other copolymerizable monomers.

The weight-average molecular weight of the cardo resin (k) is preferably 1,000 to 100,000, and more preferably 1,000 to 50,000. A weight-average molecular weight of 1,000 or more can improve film-forming properties, while a weight-average molecular weight of 100,000 or less provides good alkaline developability.

(l) Phenolic Resin In one embodiment, the first resin (A) comprises a phenolic resin (l) such as a phenol novolac resin, a cresol novolac resin, a triphenylmethane-type phenolic resin, a phenol aralkyl resin, a biphenyl aralkyl phenolic resin, a phenol-dicyclopentadiene copolymer resin, or a derivative thereof. The number average molecular weight of the phenolic resin (l) varies depending on the resin structure, but is preferably 100 to 50,000, more preferably 500 to 30,000, and even more preferably 800 to 10,000. If the number average molecular weight is 100 or more, the alkaline development rate is appropriate and the difference in dissolution rate between the exposed and unexposed areas is sufficient, resulting in good pattern resolution. If the number average molecular weight is 50,000 or less, alkaline developability is good.

The content of the first resin (A) in the photosensitive resin composition is preferably 5 to 60% by mass, more preferably 10 to 55% by mass, and even more preferably 10 to 50% by mass, based on the total mass of the resin components, radiation-sensitive compound (D), and black agent (E). When the content of the first resin (A) is 5% by mass or more based on the above total mass, the film remaining rate, heat resistance, sensitivity, etc. are appropriate. When the content of the first resin (A) is 60% by mass or less based on the above total mass, the optical density (OD value) of the cured coating can be 0.5 or more per μm of film thickness, and light-blocking properties can be maintained even after curing.

The photosensitive resin composition preferably contains 20% to 90% by mass of the first resin (A), more preferably 25% to 70% by mass, and even more preferably 30% to 55% by mass, based on the total mass of the resin components. When the content of the first resin (A) is 20% 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 first resin (A) is 90% by mass or less based on the total mass of the resin components, high sensitivity can be imparted to the photosensitive resin composition.

The first resin (A) is preferably at least one selected from resins (a) to (l), and from the viewpoint of the heat resistance of the resin composition, is more preferably at least one selected from resins (a) to (d), and even more preferably resin (c), i.e., resin (c) having an epoxy group and a phenolic hydroxyl group.

[Second resin (B)]
The second resin (B) can be a resin having a phenolic hydroxyl group different from the first resin (A). The second resin (B) is not particularly limited as long as it has a phenolic hydroxyl group. Among the resins described for the first resin (A), it is preferable to use (a) to (d) or (l) as the second resin (B). However, the second resin (B) is a resin different from the first resin (A). Here, "different" refers to the structure of the structural units of a resin and another resin being different from each other, or, when a resin contains one or more common structural units with another resin, the common structural units are contained in a total of less than 70 mol%. Resins that differ only in molecular weight are considered to be the same resin.

The phenolic hydroxyl group equivalent of the second resin (B) is 1.1 to 5.0 times the phenolic hydroxyl group equivalent of the third resin (C), described below. The phenolic hydroxyl group equivalent of the second resin (B) is preferably 1.2 to 4.0 times, and more preferably 1.3 to 2.5 times, the phenolic hydroxyl group equivalent of the third resin (C). During development, the second resin (B) suppresses excessive dissolution of unexposed areas as a resin component with low alkali solubility, while being released from the coating into the developer in exposed areas along with the dissolution of other highly alkali-soluble resin components and optional dissolution promoters, thereby enhancing the sensitivity and film retention rate of the photosensitive resin composition. This allows the content of the radiation-sensitive compound (D) in the photosensitive resin composition to be reduced depending on the application, thereby making the photosensitive resin composition suitable for thick film formation. Furthermore, by combining a second resin (B) having low alkali solubility with a third resin (C) having higher alkali solubility than the second resin (B) in such a range that the phenolic hydroxyl group equivalents of these resins satisfy the above ratio, the dissolution of the coating during development can be made microscopically uniform, and as a result, roughness of the coating surface can be suppressed.

When the alkali-soluble functional group of the first resin (A) is a phenolic hydroxyl group, the phenolic hydroxyl group equivalent of the second resin (B) is preferably 1.3 to 4.5 times, more preferably 1.4 to 4.0 times, and even more preferably 1.5 to 3.5 times the phenolic hydroxyl group equivalent of the first resin (A). By setting the phenolic hydroxyl group equivalent of the first resin (A) to the phenolic hydroxyl group equivalent of the low alkali-solubility second resin (B) to be in the above ratio, the dissolution of the coating during development can be made microscopically more uniform, and as a result, roughness of the coating surface can be effectively suppressed.

In the present disclosure, the phenolic hydroxyl group equivalent of the first resin (A), the second resin (B), and the third resin (C) refers to the value at the time point after exposure of the photosensitive resin composition but before development. The presence or absence of a change in the phenolic hydroxyl group equivalent value of these resins and the phenolic hydroxyl group equivalent value at the time point after exposure of the photosensitive resin composition but before development can be determined by the following procedure using NMR. A test composition is prepared by adding 30 parts by mass of the radiation-sensitive compound used in the photosensitive resin composition and 1 part by mass of methyltriphenylsilane as an internal standard to 100 parts by mass of the resin to be measured in DMSO-d6 and mixing them. ^1H -NMR of the obtained test composition is measured, and the integral value S1 of the phenolic hydroxyl group is calculated when the integral value of the internal standard is set to 1.00. Furthermore, the test composition is irradiated with 1000 mJ/ ^cm2 of ultraviolet light using an exposure device equipped with an ultra-high pressure mercury lamp, and heated in an oil bath at 120°C for 5 minutes. ^1H -NMR of the test composition is then measured, and the integral value S2 of the phenolic hydroxyl group is calculated when the integral value of the internal standard is set to 1.00. Resins for which the rate of change in these integral values (absolute value of (S2-S1)/S1) is less than 10% are considered to have no change in the value of the phenolic hydroxyl group equivalent.

The phenolic hydroxyl group equivalent of the second resin (B) is preferably 250 to 700, more preferably 260 to 600, and even more preferably 270 to 550. If the phenolic hydroxyl group equivalent of the second resin (B) is 250 or more, the film thickness of the unexposed areas can be sufficiently maintained during alkaline development. If the phenolic hydroxyl group equivalent of the second resin (B) is 700 or less, the desired alkaline solubility can be obtained.

The second resin (B) preferably contains a structural unit identical to at least one of the structural units of the third resin (C) described below, as well as other structural units. Preferably, the second resin (B) contains a total of 30 mol% to 95 mol% of structural units common to the third resin (C), and the alkaline dissolution rate of the second resin (B) is lower than that of the third resin (C). In this embodiment, the second resin (B) and the third resin (C) share some of their structural units in common, resulting in high compatibility between the second resin (B) and the third resin (C). This allows for more microscopically uniform dissolution of the coating during development, thereby effectively suppressing roughness of the coating surface. In this embodiment, the second resin (B) more preferably contains a total of 40 mol% to 90 mol%, and even more preferably 50 mol% to 85 mol%, of structural units common to the third resin (C). When the second resin (B) and the third resin (C) share multiple structural units, the above-mentioned mol% value refers to the sum of the mol% of these multiple structural units. In the present disclosure, the alkaline dissolution rate of a resin or photosensitive resin composition is determined by the following procedure. To a 20% by mass propylene glycol monomethyl ether acetate (PGMEA) solution of the resin or photosensitive resin composition, Megafac (registered trademark) F-559 (a fluorosurfactant manufactured by DIC Corporation) is added as a leveling agent in an amount of 0.1 parts by mass per 100 parts by mass of resin solids. The resulting mixture is applied to a glass substrate (70 mm x 70 mm x 0.7 mm) so that the dry film thickness is 5.0 μm. After vacuum drying for 30 seconds, the coating is dried at a temperature of 120°C for 120 seconds. After drying, alkaline development is performed using a 2.38% by mass aqueous solution of tetramethylammonium hydroxide (TMAH). The development time is adjusted within the range of 8 to 400 seconds so that the coating does not completely dissolve. The alkaline dissolution rate (nm/sec) is defined as the value obtained by dividing the amount of film loss (nm) after development by the development time (seconds). The alkali dissolution rate of the second resin (B) is lower than the alkali dissolution rate of the third resin (C), which ensures that the second resin (B) is less soluble in alkali than the third resin (C).

The second resin (B) is preferably a copolymer of a polymerizable monomer having a phenolic hydroxyl group and another polymerizable monomer. The copolymer of a polymerizable monomer having a phenolic hydroxyl group and another polymerizable monomer is a copolymer (d) of a polymerizable monomer having an alkali-soluble functional group and another polymerizable monomer described for the first resin (A), in which at least some, preferably all, of the alkali-soluble functional groups are phenolic hydroxyl groups. At least some of the structural units derived from the other polymerizable monomer impart lower alkali solubility to the second resin (B) than to the third resin (C). In this embodiment, the second resin (B) can be produced by radical polymerization of a polymerizable monomer having a phenolic hydroxyl group and another polymerizable monomer, similar to the copolymer (d) of a polymerizable monomer having an alkali-soluble functional group and another polymerizable monomer described for the first resin (A).

In one embodiment, the second resin (B) is represented by formula (17):
(In formula (17), R ³⁸ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and R ³⁹ is a group selected from the group consisting of a linear alkyl group having 1 to 20 carbon atoms, a branched alkyl group having 3 to 20 carbon atoms, a cyclic alkyl group having 3 to 12 carbon atoms, an aryl group having 6 to 20 carbon atoms, a linear alkyl group having 1 to 20 carbon atoms substituted with a group other than an acidic functional group, a branched alkyl group having 3 to 20 carbon atoms substituted with a group other than an acidic functional group, a cyclic alkyl group having 3 to 12 carbon atoms substituted with a group other than an acidic functional group, and an aryl group having 6 to 20 carbon atoms substituted with a group other than an acidic functional group.)
In the present disclosure, the acidic functional group refers to a group that exhibits an acid-base reaction with a 2.38% by mass aqueous solution of tetramethylammonium hydroxide, and specific examples thereof include a phenolic hydroxyl group, a carboxyl group, a sulfo group, a phosphate group, an acid anhydride group, and a mercapto group.

In R ³⁸ of formula (17), specific examples of the alkyl group having 1 to 5 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, etc. R ³⁸ is preferably a methyl group.

In R ³⁹ of formula (17), examples of the linear alkyl group having 1 to 20 carbon atoms and the branched alkyl group having 3 to 20 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group, a 2-ethylhexyl group, an n-decyl group, an n-dodecyl group, an n-hexadecyl group, etc. Examples of the cyclic alkyl group having 3 to 12 carbon atoms include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a norbornyl group, an isobornyl group, an adamantyl group, a dicyclopentanyl group, etc. Examples of the aryl group having 6 to 20 carbon atoms include a phenyl group, a 4-(benzyloxymethoxy)phenyl group, a biphenyl group, a naphthyl group, a fluorenyl group, an anthracenyl group, a phenanthrenyl group, etc. R ³⁹ is preferably a tert-butyl group, a cyclohexyl group, an isobornyl group, a dicyclopentanyl group, a phenyl group, or a 4-(benzyloxymethoxy)phenyl group.

In one embodiment, the second resin (B) is represented by formula (10):
(In formula (10), R ¹⁵ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and e is an integer of 1 to 5.)
It has a structural unit represented by the following formula: ^{R 15} is preferably a methyl group. e is preferably 1. When e is 1, the OH group is preferably at the 4-position.

In one embodiment, the second resin (B) is represented by formula (11):
(In formula (11), R ¹⁶ and R ¹⁷ are each independently a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, a completely or partially fluorinated fluoroalkyl group having 1 to 3 carbon atoms, or a halogen atom; and R ¹⁸ 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.)
It has a structural unit represented by the following formula: ^{R 16} and R ¹⁷ are preferably hydrogen atoms. R ¹⁸ is preferably a phenyl group or a cyclohexyl group.

The second resin (B) is preferably a copolymer containing a structural unit represented by the above formula (17), a structural unit represented by formula (10), and a structural unit represented by formula (11).

The number-average molecular weight of the second resin (B) is preferably 1,000 to 30,000, more preferably 1,500 to 25,000, and even more preferably 2,000 to 20,000. The weight-average molecular weight of the second resin (B) is preferably 3,000 to 80,000, more preferably 4,000 to 70,000, and even more preferably 5,000 to 60,000. A number-average molecular weight of 1,000 or more or a weight-average molecular weight of 3,000 or more provides an appropriate alkaline development rate and a sufficient difference in dissolution rate between exposed and unexposed areas, resulting in good pattern resolution. A number-average molecular weight of 30,000 or less or a weight-average molecular weight of 80,000 or less provides good coatability and alkaline developability. The polydispersity (Mw/Mn) of the second resin (B) is preferably 1.0 to 3.5, more preferably 1.1 to 3.0, and even more preferably 1.2 to 2.8. By setting the polydispersity within the above range, a photosensitive resin composition having excellent pattern formability and alkaline developability can be obtained.

The photosensitive resin composition preferably contains 5% to 50% by weight of the second resin (B), more preferably 8% to 45% by weight, and even more preferably 10% to 40% by weight, based on the total weight of the resin components. If the content of the second resin (B) is 5% by weight or more based on the total weight of the resin components, sufficient contrast can be obtained due to the difference in dissolution rate with the first resin (A). If the content of the second resin (B) is 50% by weight or less based on the total weight of the resin components, dissolution of the coating during development can be made microscopically more uniform, and as a result, roughness of the coating surface can be effectively suppressed.

[Third resin (C)]
As the third resin (C), among the resins described in the first resin (A), a resin having a phenolic hydroxyl group different from both the first resin (A) and the second resin (B) can be used.

The phenolic hydroxyl group equivalent of the third resin (C) is preferably 107 to 240, more preferably 140 to 235, and even more preferably 170 to 230. If the phenolic hydroxyl group equivalent of the third resin (C) is 107 or more, the film thickness of the unexposed areas can be sufficiently maintained during alkaline development. If the phenolic hydroxyl group equivalent of the third resin (C) is 240 or less, the desired alkaline solubility can be obtained.

The third resin (C) is preferably a copolymer of a polymerizable monomer having a phenolic hydroxyl group and another polymerizable monomer. The copolymer of a polymerizable monomer having a phenolic hydroxyl group and another polymerizable monomer is a copolymer (d) of a polymerizable monomer having an alkali-soluble functional group and another polymerizable monomer described for the first resin (A), in which at least some, preferably all, of the alkali-soluble functional groups are phenolic hydroxyl groups.

The number-average molecular weight of the third resin (C) is preferably 1,000 to 30,000, more preferably 1,500 to 25,000, and even more preferably 2,000 to 20,000. The weight-average molecular weight of the third resin (C) is preferably 3,000 to 80,000, more preferably 4,000 to 70,000, and even more preferably 5,000 to 60,000. A number-average molecular weight of 1,000 or more or a weight-average molecular weight of 3,000 or more provides an appropriate alkaline development rate and a sufficient difference in dissolution rate between exposed and unexposed areas, resulting in good pattern resolution. A number-average molecular weight of 30,000 or less or a weight-average molecular weight of 80,000 or less provides good coatability and alkaline developability. The polydispersity (Mw/Mn) of the third resin (C) is preferably 1.0 to 3.5, more preferably 1.1 to 3.0, and even more preferably 1.2 to 2.8. By setting the polydispersity within the above range, a photosensitive resin composition having excellent pattern formability and alkaline developability can be obtained.

The photosensitive resin composition preferably contains 5% to 50% by weight of the third resin (C), more preferably 8% to 45% by weight, and even more preferably 10% to 40% by weight, based on the total weight of the resin components. If the content of the third resin (C) is 5% by weight or more based on the total weight of the resin components, the dissolution of the coating during development can be made microscopically more uniform, thereby effectively suppressing roughness of the coating surface. If the content of the third resin (C) is 50% by weight or less based on the total weight of the resin components, a pattern can be formed that maintains the contrast due to the difference in dissolution rate between the first resin (A) and the second resin (B).

[Radiation-sensitive compound (D)]
The radiation-sensitive compound (D) can be a photoacid generator, a photobase generator, or a photopolymerization initiator. A photoacid generator is a compound that generates an acid upon irradiation with radiation such as visible light, ultraviolet light, gamma rays, or electron beams. A photoacid generator increases the solubility of the irradiated portion in an alkaline aqueous solution, and can therefore be used in positive-type photosensitive resin compositions in which the irradiated portion dissolves. A photobase generator is a compound that generates a base upon irradiation with radiation. A photobase generator decreases the solubility of the irradiated portion in an alkaline aqueous solution, and can therefore be used in negative-type photosensitive resin compositions in which the irradiated portion becomes insoluble. A photopolymerization initiator is a compound that generates radicals upon irradiation with radiation. When a photosensitive resin composition contains a binder resin or a radical-polymerizable compound having a radical-polymerizable functional group, the photopolymerization initiator can be used in negative-type photosensitive resin compositions in which radical polymerization of the radical-polymerizable functional group of the binder resin or the radical-polymerizable compound in the irradiated portion proceeds, forming a polymer insoluble in alkaline aqueous solution in the irradiated portion.

<Photoacid generator>
The radiation-sensitive compound (D) is preferably a photoacid generator, since this allows for the formation of a highly sensitive and high-resolution pattern. The photoacid generator may be at least one selected from the group consisting of quinone diazide compounds, sulfonium salts, phosphonium salts, diazonium salts, and iodonium salts. In one embodiment, the photoacid generator is a compound or salt highly sensitive to i-line (365 nm).

It is preferable to use a quinone diazide compound as the photoacid generator. Examples of quinone diazide compounds include those in which the sulfonic acid of quinone diazide is bonded to a polyhydroxy compound via an ester bond, those in which the sulfonic acid of quinone diazide is bonded to a polyamino compound via a sulfonamide bond, and those in which the sulfonic acid of quinone diazide is bonded to a polyhydroxy polyamino compound via an ester bond or sulfonamide bond. From the perspective of contrast between exposed and unexposed areas, it is preferable that 20 mol % or more of the total functional groups of the polyhydroxy compound or polyamino compound be substituted with quinone diazide.

Polyhydroxy 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, and B isRS-26X, DML-MBPC, DML-MBOC, DML-OCHP, DML-PCHP, DML-PC, DML-PTBP, DML-34X, DML-EP, DML-POP, Dimethylo Rules - BisOC-P, DML-PFP, DML-PSBP, DML-MTrisPC, TriML-P, TriML-35XL, TML-BP, TML-HQ, TML-pp-BPF, TML- Examples of the phenolic compounds include, but are not limited to, BPA, TMOM-BP, HML-TPPHBA, HML-TPHAP (trade names, manufactured by Honshu Chemical Industry Co., Ltd.), BIR-OC, BIP-PC, BIR-PC, BIR-PTBP, BIR-PCHP, BIP-BIOC-F, 4PC, BIR-BIPC-F, TEP-BIP-A, 46DMOC, 46DMOEP, TM-BIP-A (trade names, manufactured by Asahi Organic Chemicals Co., Ltd.), 2,6-dimethoxymethyl-4-tert-butylphenol, 2,6-dimethoxymethyl-p-cresol, 2,6-diacetoxymethyl-p-cresol, naphthol, tetrahydroxybenzophenone, methyl gallate, bisphenol A, bisphenol E, methylene bisphenol, and BisP-AP (trade name, manufactured by Honshu Chemical Industry Co., Ltd.).

Examples of polyamino compounds include, but are not limited to, 1,4-phenylenediamine, 1,3-phenylenediamine, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfone, and 4,4'-diaminodiphenyl sulfide.

Examples of polyhydroxypolyamino compounds include, but are not limited to, 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane, 3,3'-dihydroxybenzidine, etc.

The quinone diazide compound is preferably a 1,2-naphthoquinone diazide-4-sulfonic acid ester or a 1,2-naphthoquinone diazide-5-sulfonic acid ester of a polyhydroxy compound.

When quinone diazide compounds are irradiated with ultraviolet light or other light, they generate carboxyl groups via the reaction shown in Reaction Scheme 2 below. The generation of carboxyl groups makes the exposed areas (coating) soluble in alkaline aqueous solutions, making those areas alkaline developable.

When the radiation-sensitive compound (D) is a photoacid generator, the content of the photoacid generator in the photosensitive resin composition can be 1 to 40 parts by weight, preferably 5 to 35 parts by weight, and more preferably 10 to 30 parts by weight, based on 100 parts by weight of the total resin components. When the content of the photoacid generator is 1 part by weight or more, based on the total 100 parts by weight, alkaline developability is good, and when it is 40 parts by weight or less, reduction in the coating film due to heating at 300°C or higher can be suppressed.

<Photobase Generator>
A photobase generator may be used as the radiation-sensitive compound (D). As the photobase generator, at least one selected from the group consisting of an amide compound and an ammonium salt can be used. In one embodiment, the photobase generator is a compound or salt highly sensitive to i-line (365 nm).

Examples of amide compounds include 2-nitrophenylmethyl-4-methacryloyloxypiperidine-1-carboxylate, 9-anthrylmethyl-N,N-dimethylcarbamate, 1-(anthraquinone-2-yl)ethylimidazolecarboxylate, and (E)-1-[3-(2-hydroxyphenyl)-2-propenoyl]piperidine. Examples of ammonium salts include 1,2-diisopropyl-3-(bisdimethylamino)methylene)guanidinium 2-(3-benzoylphenyl)propionate, (Z)-{[bis(dimethylamino)methylidene]amino}-N-cyclohexylamino)methanaminium tetrakis(3-fluorophenyl)borate, and 1,2-dicyclohexyl-4,4,5,5-tetramethylbiguanidinium n-butyltriphenylborate.

When the radiation-sensitive compound (D) is a photobase generator, the content of the photobase generator in the photosensitive resin composition can be 1 to 40 parts by mass, preferably 5 to 35 parts by mass, and more preferably 10 to 30 parts by mass, based on a total of 100 parts by mass of the resin components. When the content of the photobase generator is 1 part by mass or more, based on the total of 100 parts by mass, alkaline developability is good, and when it is 40 parts by mass or less, reduction in the coating film due to heating at 300°C or higher can be suppressed.

<Photopolymerization initiator>
A photopolymerization initiator may be used as the radiation-sensitive compound (D). As the photopolymerization initiator, at least one selected from the group consisting of benzyl ketal compounds, α-hydroxyketone compounds, α-aminoketone compounds, acylphosphine oxide compounds, oxime ester compounds, acridine compounds, benzophenone compounds, acetophenone compounds, aromatic ketoester compounds, and benzoic acid ester compounds can be used. In one embodiment, the photopolymerization initiator is a compound highly sensitive to i-line (365 nm). Due to their high sensitivity upon exposure, the photopolymerization initiator is preferably an α-hydroxyketone compound, α-aminoketone compound, acylphosphine oxide compound, oxime ester compound, acridine compound, or benzophenone compound, and more preferably an α-aminoketone compound, acylphosphine oxide compound, or oxime ester compound.

Examples of benzyl ketal compounds include 2,2-dimethoxy-1,2-diphenylethan-1-one. Examples of α-hydroxy ketone compounds include 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methylpropan-1-one, and 2-hydroxy-1-[4-[4-(2-hydroxy-2-methylpropionyl)benzyl]phenyl]-2-methylpropan-1-one. Examples of the α-aminoketone compound include 2-dimethylamino-2-methyl-1-phenylpropan-1-one, 2-diethylamino-2-methyl-1-phenylpropan-1-one, 2-methyl-2-morpholino-1-phenylpropan-1-one, 2-dimethylamino-2-methyl-1-(4-methylphenyl)propan-1-one, 2-dimethylamino-1-(4-ethylphenyl)-2-methylpropan-1-one, 2-dimethylamino-1-(4-isopropylphenyl)-2-methylpropan-1-one, and 1-(4-butylphenyl)-2-dimethylamino-2-methylpropan-1-one. , 2-dimethylamino-1-(4-methoxyphenyl)-2-methylpropan-1-one, 2-dimethylamino-2-methyl-1-(4-methylthiophenyl)propan-1-one, 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one, 2-benzyl-2-dimethylamino-1-(4-dimethylaminophenyl)-butan-1-one, 2-dimethylamino-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone. Examples of the acylphosphine oxide compound include 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, and bis(2,6-dimethoxybenzoyl)-(2,4,4-trimethylpentyl)phosphine oxide. Examples of the oxime ester compound include 1-phenylpropane-1,2-dione-2-(O-ethoxycarbonyl)oxime, 1-phenylbutane-1,2-dione-2-(O-methoxycarbonyl)oxime, 1,3-diphenylpropane-1,2,3-trione-2-(O-ethoxycarbonyl)oxime, 1-[4-(phenylthio)phenyl]octane-1,2-dione-2-(O-benzoyl)oxime, 1-[4-[4-(carboxymethyl)phenyl]octane-1,2-dione-2-(O-benzoyl)oxime, 1-[4-[4-(carboxymethyl)phenyl]octane-1,2-dione-2-(O-ethoxycarbon ... Examples of the acridine compound include 1,7-bis(acridin-9-yl)-n-heptane. Examples of the acridine compound include 1,7-bis(acridin-9-yl)-n-heptane. Examples of the acridine compound include 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]ethanone-1-(O-acetyl)oxime, ... and 1-[9-ethyl-6-[2-methyl-4-[1-(2,2-dimethyl-1,3-dioxolan-4-yl)methyloxy]benzoyl]-9H-carbazol-3-yl]ethanone-1-(O-acetyl)oxime. Examples of the acridine compound include 1,7-bis(acridin-9-yl)-n-heptane. Examples of benzophenone compounds include benzophenone, 4,4'-bis(dimethylamino)benzophenone, 4,4'-bis(diethylamino)benzophenone, 4-phenylbenzophenone, 4,4-dichlorobenzophenone, 4-hydroxybenzophenone, alkylated benzophenone, 3,3',4,4'-tetrakis(tert-butylperoxycarbonyl)benzophenone, 4-methylbenzophenone, dibenzyl ketone, and fluorenone. Examples of acetophenone compounds include 2,2-diethoxyacetophenone, 2,3-diethoxyacetophenone, 4-tert-butyldichloroacetophenone, benzalacetophenone, and 4-azidobenzalacetophenone. Examples of aromatic ketoester compounds include methyl 2-phenyl-2-oxyacetate. Examples of the benzoate compound include ethyl 4-dimethylaminobenzoate, (2-ethyl)hexyl 4-dimethylaminobenzoate, ethyl 4-diethylaminobenzoate, and methyl 2-benzoylbenzoate.

When the first resin (A), the second resin (B), or the third resin (C), or two or more of these have a cationically polymerizable group such as an epoxy group, a photocationic polymerization initiator that generates a cationic species or a Lewis acid by light can be used as the photopolymerization initiator. Examples of the photocationic polymerization initiator include onium salts whose cationic moiety is a sulfonium such as triphenylsulfonium or diphenyl-4-(phenylthio)phenylsulfonium, an iodonium such as diphenyliodonium or bis(dodecylphenyl)iodonium, a diazonium such as phenyldiazonium, a pyridinium such as 1-benzyl-2-cyanopyridinium or 1-(naphthylmethyl)-2-cyanopyridinium, or an Fe cation such as (2,4-cyclopentadien-1-yl)[(1-methylethyl)benzene]-Fe, and whose anionic moiety is BF ₄ ⁻ , PF ₆ ⁻ , SbF ₆ ⁻ , [BX ₄ ] ⁻ (X is a phenyl group substituted with at least two or more fluorine atoms or trifluoromethyl groups), etc.

When the radiation-sensitive compound (D) is a photopolymerization initiator, the content of the photopolymerization initiator in the photosensitive resin composition can be 1 to 40 parts by mass, preferably 1.5 to 35 parts by mass, and more preferably 2 to 30 parts by mass, based on 100 parts by mass of the total resin components. When the content of the photopolymerization initiator is 1 part by mass or more, based on the total 100 parts by mass, alkaline developability is good, and when it is 40 parts by mass or less, reduction in the coating film due to heating at 300°C or higher can be suppressed.

When the radiation-sensitive compound (D) is a photopolymerization initiator, the photosensitive resin composition may further contain a radically polymerizable compound. Resins and compounds having multiple ethylenically unsaturated groups as radically polymerizable compounds can crosslink the coating and increase its hardness.

From the viewpoints of reactivity during exposure, hardness and heat resistance of the coating, etc., it is preferable to use a compound having multiple (meth)acrylic groups as the radical polymerizable compound. Examples of such compounds include diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, trimethylolpropane di(meth)acrylate, trimethylolpropane tri(meth)acrylate, ethoxylated trimethylolpropane di(meth)acrylate, ethoxylated trimethylolpropane tri(meth)acrylate, ditrimethylolpropane tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, 1,3- Butanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, dimethylol-tricyclodecane di(meth)acrylate, ethoxylated glycerin tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, ethoxylated pentaerythritol tri(meth)acrylate, ethylenediaminetetraacetic acid dimeth ... ethoxylated pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, tripentaerythritol hepta(meth)acrylate, tripentaerythritol octa(meth)acrylate, tetrapentaerythritol nona(meth)acrylate, tetrapentaerythritol deca(meth)acrylate, pentaerythritol undeca(meth)acrylate, pentaerythritol dodeca(meth)acrylate, ethoxylated bisphenol A di(meth)acrylate, Examples of the acrylic acid-modified copolymer include 2,2-bis[4-(3-(meth)acryloxy-2-hydroxypropoxy)phenyl]propane, 1,3,5-tris((meth)acryloxyethyl)isocyanuric acid, 1,3-bis((meth)acryloxyethyl)isocyanuric acid, 9,9-bis[4-(2-(meth)acryloxyethoxy)phenyl]fluorene, 9,9-bis[4-(3-(meth)acryloxypropoxy)phenyl]fluorene, and 9,9-bis(4-(meth)acryloxyphenyl)fluorene, as well as acid-modified, ethylene oxide-modified, or propylene oxide-modified copolymers thereof.

The content of the radical polymerizable compound in the photosensitive resin composition can be 15 to 65 parts by weight, preferably 20 to 60 parts by weight, and more preferably 25 to 50 parts by weight, per 100 parts by weight of the total resin components. When the content of the radical polymerizable compound is within the above range, alkaline developability is good and the heat resistance of the cured coating can be improved.

[Black agent (E)]
The black agent (E) is selected from the group consisting of a black dye and a black pigment. A black dye and a black pigment may be used in combination. By forming a black partition wall in an organic EL element using a photosensitive resin composition containing the black agent (E), the visibility of a display device such as an organic EL display can be improved.

In one embodiment, the black agent (E) includes a black dye. Dyes defined by the Color Index (C.I.) of Solvent Black 27 to 47 can be used as the black dye. The black dye is preferably defined by the C.I. of Solvent Black 27, 29, or 34. When at least one of the dyes defined by the C.I. of Solvent Black 27 to 47 is used as the black dye, the light-blocking properties of the cured photosensitive resin composition coating can be maintained. Compared to photosensitive resin compositions containing black pigments, photosensitive resin compositions containing a black dye leave less colorant residue during development, allowing for the formation of high-resolution patterns in the coating.

When the black agent (E) is a black dye, the content of the black dye in the photosensitive resin composition is preferably 10 to 150 parts by mass, more preferably 15 to 100 parts by mass, and even more preferably 20 to 80 parts by mass, based on 100 parts by mass of the total resin components. If the content of the black dye is 10 parts by mass or more based on the above total 100 parts by mass, the light-blocking properties of the cured coating can be maintained. If the content of the black dye is 150 parts by mass or less based on the above total 100 parts by mass, the film retention rate, heat resistance, sensitivity, etc. are appropriate.

A black pigment may be used as the black agent (E). 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, and Pigment Black 21, 30, 31, 32, 33, and 34 manufactured by BASF. Examples of commercially available lactam pigments include Irgaphor® Black S0100CF manufactured by BASF. Due to its 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. In negative-tone photosensitive resin compositions in which the radiation-sensitive compound (D) is a photopolymerization initiator, it is advantageous for the black agent (E) to be a black pigment that is less likely to inhibit polymerization.

When the black agent (E) is a black pigment, the content of the black pigment in the photosensitive resin composition is preferably 10 to 150 parts by mass, more preferably 15 to 100 parts by mass, and even more preferably 20 to 80 parts by mass, based on 100 parts by mass of the total resin components. If the content of the black pigment is 10 parts by mass or more based on the total 100 parts by mass, sufficient light-blocking properties can be obtained. If the content of the black pigment is 150 parts by mass or less based on the total 100 parts by mass, the remaining film rate, sensitivity, etc. are appropriate.

When the black agent (E) contains both a black dye and a black pigment, the total amount of the black dye and black pigment in the photosensitive resin composition is preferably 10 to 150 parts by mass, more preferably 15 to 100 parts by mass, and even more preferably 20 to 80 parts by mass, based on 100 parts by mass of the total resin components. If the total amount of the black dye and black pigment is 10 parts by mass or more based on the above 100 parts by mass, sufficient light-blocking properties can be obtained. If the total amount of the black dye and black pigment is 150 parts by mass or less based on the above 100 parts by mass, the remaining film rate, sensitivity, etc. are appropriate.

[Optional ingredients]
The photosensitive resin composition may contain, as optional components, a dissolution promoter (F), a basic compound (G), a solvent (H), a heat curing agent, a surfactant, a second colorant other than the black agent (E), etc. In the present disclosure, optional components are defined as those that do not fall into any of (A) to (E).

[Solubility promoter (F)]
The photosensitive resin composition may contain a dissolution promoter (F) to improve the solubility of the alkali-soluble portion during development, for example. As the dissolution promoter (F), a low-molecular-weight compound having an alkali-soluble functional group is used. Among these, a compound having at least one group selected from a carboxy group and a phenolic hydroxyl group is preferred.

For example, low molecular weight compounds having a carboxy group 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; benzoic acid, aromatic monocarboxylic acids such as toluic acid, cumic acid, hemimellitic acid, and mesitylene acid; aromatic polycarboxylic acids such as 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; and 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.

Examples of low molecular weight compounds having a phenolic hydroxyl group include catechol, resorcinol, hydroquinone, propyl gallate, dihydroxynaphthalene, leucoquinizarin, 1,2,4-benzenetriol, anthracenetriol, pyrogallol, phloroglucinol, tetrahydroxybenzophenone, phenolphthalein, phenolphthaline, tris(4-hydroxyphenyl)methane, 1,1,1-tris(4-hydroxyphenyl)ethane, α,α,α'-tris(4-hydroxyphenyl)-1-ethyl-4-isopropylbenzene, etc.

The content of the dissolution promoter (F) can be 0.1 to 20 parts by mass, preferably 1 to 15 parts by mass, and more preferably 3 to 12 parts by mass, based on a total of 100 parts by mass of the resin components. If the content of the dissolution promoter (F) is 0.1 part by mass or more based on the total of 100 parts by mass, the dissolution of the resin components can be effectively promoted, and if it is 20 parts by mass or less, excessive dissolution of the resin components can be suppressed, improving the pattern formability and surface quality of the coating.

[Basic compound (G)]
The photosensitive resin composition may contain a basic compound (G) to ensure the long-term reliability of the organic EL device. The basic compound (G) acts as a quencher for acidic components or acidic sites, such as carboxylic acids and phenolic hydroxyl groups, contained in the photosensitive resin composition, or acidic gases generated from photoacid generators. When the coating is used as an organic EL device, the use of the basic compound (G) can prevent a decrease in luminance, pixel shrinkage, the occurrence of dark spots, and the like.

Examples of basic compounds (G) include n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine, 3-(2-ethylhexyloxy)propylamine, di-n-butylamine, di-n-pentylamine, di-n-hexylamine, di-n-heptylamine, di-n-octylamine, di-n-nonylamine, di-n-decylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decylamine, tricyclohexylamine, triphenylamine, aniline, N-methylaniline, N,N-dimethylaniline, 2-methyl Aniline, 3-methylaniline, 4-methylaniline, 4-nitroaniline, diphenylamine, triphenylamine, naphthylamine, ethylenediamine, N,N,N',N'-tetramethylethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 4,4'-diaminobenzophenone, 4,4'-diaminodiphenylamine, 2,2-bis(4-aminophenyl)propane, 2-(3-aminophenyl)-2-(4-aminophenyl)propane, 2-(4-aminophenyl)-2-(3-hydroxyphenyl)propane, 2-(4-aminophenyl)-2-(4-hydroxyphenyl)propane, 1,4-bis[1-(4-aminophenyl)-1- [methylethyl]benzene, 1,3-bis[1-(4-aminophenyl)-1-methylethyl]benzene, poly(4-vinylpyridine), poly(2-pyridine), poly(N-2-pyrrolidone), polyethyleneimine, polyallylamine, poly(dimethylaminoethylacrylamide), formamide, N-methylformamide, N,N-dimethylformamide, acetamide, N-methylacetamide, N,N-dimethylacetamide, propionamide, benzamide, pyrrolidone, N-methylpyrrolidone, urea, methylurea, 1,1-dimethylurea, 1,3-dimethylurea, 1,1,3,3-tetramethylurea, 1,3-diphenylurea, tributylthiourea, imidazole, benzimidazole, 4-methylimidazole, 4-methyl Examples of suitable phenyl-2-phenylimidazole include pyridine, 2-methylpyridine, 4-methylpyridine, 2-ethylpyridine, 4-ethylpyridine, 2-phenylpyridine, 4-phenylpyridine, N-methyl-4-phenylpyridine, nicotine, nicotinic acid, nicotinamide, quinoline, 8-oxyquinoline, acridine, pyrazine, pyrazole, pyridazine, quinoxaline, purine, pyrrolidine, piperidine, morpholine, 4-methylmorpholine, piperazine, 1,4-dimethylpiperazine, 1,4-diazabicyclo[2.2.2]octane, 1,5-diazabicyclo[4.3.0]-5-nonene, 1,8-diazabicyclo[5.4.0]-7-undecene, and 2,4,6-tris[bis(methoxymethyl)amino]-1,3,5-triazine.

The content of basic compound (G) is preferably 4 parts by mass or less, more preferably 3 parts by mass or less, and even more preferably 2 parts by mass or less, based on 100 parts by mass of the total solid content excluding basic compound (G).

[Solvent (H)]
The photosensitive resin composition can be dissolved in a solvent and used in a solution state (however, when a black pigment is contained, the pigment is in a dispersed state). For example, a photosensitive resin composition in a solution state can be prepared by dissolving the first resin (A), the second resin (B), and the third resin (C) in a solvent (H) to obtain a solution, and then mixing the solution with a radiation-sensitive compound (D), a black agent (E), and optional components such as a dissolution promoter (F), a basic compound (G), a thermosetting agent, and a surfactant in a predetermined ratio. The viscosity of the photosensitive resin composition can be adjusted to suit the coating method to be used by changing the amount of solvent.

Examples of the solvent (H) 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 the solvent include: 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, γ-butyrolactone, and diethyl carbonate; and amide compounds such as N-methyl-2-pyrrolidone, N,N-dimethylformamide, and N,N-dimethylacetamide. The solvent (H) may be used alone or in combination of two or more.

[Thermal curing agent]
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.

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 solids excluding the heat curing agent.

[Surfactant]
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; polyoxyethylene dialkyl esters such as polyoxyethylene dilaurate and polyoxyethylene distearate; and nonionic surfactants such as Megafac (registered trademark) F-2. Fluorine-based surfactants such as Surflon (registered trademark) S-51, F-281, F-430, F-444, R-40, F-553, F-554, F-555, F-556, F-557, F-558, and F-559 (all trade names, manufactured by DIC Corporation), Surflon (registered trademark) S-242, S-243, S-386, S-420, and S-611 (all trade names, manufactured by AGC Seimi Chemical Co., Ltd.); organosiloxane polymers KP323, KP326, and KP341 (all trade names, manufactured by Shin-Etsu Chemical Co., Ltd.). These may be used alone or in combination of two or more.

The surfactant content 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 solids excluding the surfactant.

[Second Colorant]
The photosensitive resin composition may contain a second colorant other than the black agent (E). Examples of the second colorant include dyes, organic pigments, and inorganic pigments, and 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 invention.

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.

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

[Method for producing photosensitive resin composition]
The photosensitive resin composition can be prepared by dissolving or dispersing the first resin (A), the second resin (B), the third resin (C), the radiation-sensitive compound (D), the blackening agent (E), and, if necessary, the optional components such as the dissolution promoter (F) and the basic compound (G) in a solvent (H) and mixing them. The solids concentration of the photosensitive resin composition can be appropriately determined depending on the intended use. For example, the solids concentration of the photosensitive resin composition may be 1 to 60% by mass, 3 to 50% by mass, or 5 to 40% by mass.

When using pigments, known dispersion and mixing methods can be used. For example, ball-type mills such as ball mills, sand mills, bead mills, paint shakers, and rocking mills; blade-type mills such as kneaders, paddle mixers, planetary mixers, and Henschel mixers; roll-type mills such as three-roll mixers; and other mixers such as Raikai mixers, colloid mills, ultrasonic mixers, homogenizers, and planetary mixers. From the standpoint of dispersion efficiency and fine dispersion, it is preferable to use a bead mill.

The prepared photosensitive resin composition is usually filtered before use. Filtration methods include, for example, a Millipore filter with a pore size of 0.05 to 1.0 μm.

The photosensitive resin composition prepared in this manner also has excellent long-term storage stability.

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

After applying the coating composition to the substrate surface, the solvent is typically removed by heating to form a coating (pre-baking). Heating conditions vary depending on the type and ratio of each component, but a coating can typically be obtained by heating at 70-130°C for 30 seconds to 20 minutes on a hot plate or 1-60 minutes in an oven. In one embodiment, the thickness of the formed coating is 2-3 μm.

Next, the prebaked coating is irradiated with radiation (e.g., visible light, ultraviolet light, far ultraviolet light, X-rays, electron beams, gamma rays, synchrotron radiation, etc.) through a photomask having a predetermined pattern (exposure step). When a quinone diazide compound is used as the radiation-sensitive compound, 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.

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

The patterned coating is then heat-treated using a heating device such as a hot plate or oven at a temperature of, for example, 100 to 350°C for 20 to 200 minutes to obtain a hardened coating (post-baking, heat treatment process). During the heat treatment, the temperature may be maintained constant, or may be increased continuously or in stages.

The optical density (OD value) of the cured film of the photosensitive resin composition is 0.5 or more per 1 μm of film thickness. This ensures sufficient light-blocking properties. The OD value of the cured film of the photosensitive resin composition is preferably 0.7 or more, and more preferably 1.0 or more.

[Method of manufacturing organic EL element partition or organic EL element insulating film]
One embodiment is a method for producing an organic EL element partition wall or an organic EL element insulating film, the method comprising: 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 coating film; removing the solvent contained in the coating and drying the coating; exposing the dried coating to radiation through a photomask; developing the exposed coating by contacting it with a developer to form a pattern in the coating; and heat-treating the patterned coating at a temperature of 100°C to 350°C to form an organic EL element partition wall or an organic EL element insulating film.

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

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

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

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

(1) Evaluation of Physical Properties The physical properties of the resin or photosensitive resin composition were evaluated by the following procedure.

[Alkali dissolution rate]
To a 20% by weight propylene glycol monomethyl ether acetate (PGMEA) solution of a resin or photosensitive resin composition, 0.1 parts by weight of Megafac® F-559 (a fluorosurfactant manufactured by DIC Corporation) was added as a leveling agent per 100 parts by weight of resin solids. The resulting mixture was applied to a glass substrate (70 mm x 70 mm x 0.7 mm) to a dry film thickness of 5.0 μm. The substrate was vacuum dried for 30 seconds and then dried at 120°C for 120 seconds. After drying, the substrate was subjected to alkaline development using a 2.38% by weight aqueous solution of tetramethylammonium hydroxide (TMAH). The development time was adjusted within a range of 8 to 400 seconds so that the coating did not completely dissolve. The alkaline dissolution rate (nm/sec) was determined by dividing the amount of film loss (nm) after development by the development time (seconds).

[Molecular weight]
The weight average molecular weight (Mw) and number average molecular weight (Mn) of the first resin (A), the second resin (B), the third resin (C) and other resins 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: 1.0 mL/min Detector: Shodex (registered trademark) RI-71
Temperature: 40℃

(2) Raw Materials Raw materials used in the Examples and Comparative Examples were produced or obtained as follows.

[Production Example 1] First Resin (A): Production of Resin (N770OH70) Having Epoxy Groups and Phenolic Hydroxyl Groups In a 300 mL three-necked flask, 75.2 g of γ-butyrolactone (manufactured by Mitsubishi Chemical Corporation) as a solvent and 37.6 g of EPICLON (registered trademark) N-770 (a phenol novolac epoxy resin manufactured by DIC Corporation, epoxy equivalent weight 188) as a compound having at least two epoxy groups per molecule were charged and dissolved under a nitrogen gas atmosphere at 60 ° C. To this was added 20.1 g (0.65 equivalents relative to 1 equivalent of epoxy) of 3,5-dihydroxybenzoic acid (manufactured by Fujifilm Wako Pure Chemical Industries Co., Ltd.) as a hydroxybenzoic acid compound, and 0.173 g (0.660 mmol) of triphenylphosphine (manufactured by Tokyo Chemical Industry Co., Ltd.) as a reaction catalyst, and the mixture was allowed to react at 110 ° C. for 24 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 286.5 g of a solution of a resin (N770OH70) having epoxy groups and phenolic hydroxyl groups. The resulting reaction product had a number average molecular weight of 2,400, a weight average molecular weight of 5,400, an epoxy equivalent of 2,000, and a phenolic hydroxyl equivalent of 142.

[Production Example 2] First Resin (A): Production of Resin (N695OH70) Having Epoxy Groups and Phenolic Hydroxyl Groups In a 300 mL three-necked flask, 75.2 g of γ-butyrolactone (manufactured by Mitsubishi Chemical Corporation) as a solvent and 37.8 g of EPICLON (registered trademark) N-695 (a cresol novolac epoxy resin manufactured by DIC Corporation, epoxy equivalent weight 214) as a compound having at least two epoxy groups per molecule were charged and dissolved under a nitrogen gas atmosphere at 60 ° C. To this was added 20.1 g (0.65 equivalents relative to 1 equivalent of epoxy) of 3,5-dihydroxybenzoic acid (manufactured by Fujifilm Wako Pure Chemical Industries Co., Ltd.) as a hydroxybenzoic acid compound, and 0.166 g (0.660 mmol) of triphenylphosphine (manufactured by Tokyo Chemical Industry Co., Ltd.) as a reaction catalyst, 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 274.2 g of a solution of a resin (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 5,100, an epoxy equivalent of 2,200, and a phenolic hydroxyl equivalent of 161.

[Production Example 3] Second Resin (B): Production of Second Resin Having Phenolic Hydroxyl Groups (B-TBMA 42.5%) 17.3 g of 4-hydroxyphenyl methacrylate ("PQMA" manufactured by Showa Denko K.K.), 6.15 g of N-cyclohexylmaleimide (manufactured by Nippon Shokubai Co., Ltd.), and 13.8 g of tert-butyl methacrylate ("Acryester TB" manufactured by Mitsubishi Chemical Corporation) were completely dissolved in 56.0 g of isopropyl acetate (manufactured by Shinko Organic Chemical Industry Co., Ltd.) as a solvent, and 2.69 g of 2,2'-azobis(isobutyrate)dimethyl ("V-601" manufactured by Fujifilm Wako Pure Chemical Industries Co., Ltd.) as a polymerization initiator and 4.05 g of isopropyl acetate (manufactured by Shinko Organic Chemical Industry Co., Ltd.) were completely dissolved. The two resulting solutions were simultaneously added dropwise over two hours to 100 g of isopropyl acetate (Shinko Organic Chemical Industry Co., Ltd.) heated to 89°C under a nitrogen gas atmosphere in a 300 mL three-neck flask, and then the mixture was allowed to react at 89°C under reflux for four hours. The reaction solution was cooled to room temperature and added dropwise to 1000 g of an 80:20 mixture of hexane and toluene to precipitate the copolymer. The precipitated copolymer was recovered by filtration and vacuum dried at 80°C for five hours, yielding 36.5 g of a white powder. The resulting second resin B-TBMA 42.5% having phenolic hydroxyl groups had a number average molecular weight of 4100, a weight average molecular weight of 7600, and a phenolic hydroxyl group equivalent of 384.

[Production Example 4] Second resin (B): Production of second resin (B-PhMA 41%) having phenolic hydroxyl groups 17.0 g of 4-hydroxyphenyl methacrylate ("PQMA" manufactured by Showa Denko K.K.), 5.83 g of N-cyclohexylmaleimide (manufactured by Nippon Shokubai Co., Ltd.), and 14.4 g of phenyl methacrylate ("Acryester PH" manufactured by Mitsubishi Chemical Corporation) were completely dissolved in 60.0 g of isopropyl acetate (manufactured by Shinko Organic Chemical Industry Co., Ltd.) as a solvent, and 2.72 g of 2,2'-azobis(isobutyrate)dimethyl ("V-601" manufactured by Fujifilm Wako Pure Chemical Industries Co., Ltd.) as a polymerization initiator were completely dissolved in 4.08 g of isopropyl acetate (manufactured by Shinko Organic Chemical Industry Co., Ltd.). The two resulting solutions were simultaneously added dropwise over 2 hours to 95.9 g of isopropyl acetate (Shinko Organic Chemical Industry Co., Ltd.) heated to 89 ° C under a nitrogen gas atmosphere in a 300 mL three-neck flask, and then reacted for 4 hours under reflux at 89 ° C. The reaction solution was cooled to room temperature and added dropwise to 1000 g of a 50:50 mixture of hexane and toluene to precipitate the copolymer. The precipitated copolymer was recovered by filtration and vacuum dried at 80 ° C for 5 hours, resulting in the recovery of 36.5 g of a white powder. The resulting second resin B-PhMA 41% having phenolic hydroxyl groups had a number average molecular weight of 4300, a weight average molecular weight of 7800, and a phenolic hydroxyl group equivalent of 390.

[Production Example 5] Second Resin (B): Production of Second Resin Having Phenolic Hydroxyl Groups (B-PhMA 20%) 24.6 g of 4-hydroxyphenyl methacrylate ("PQMA" manufactured by Showa Denko K.K.), 5.71 g of N-cyclohexylmaleimide (manufactured by Nippon Shokubai Co., Ltd.), and 6.89 g of phenyl methacrylate ("Acryester PH" manufactured by Mitsubishi Chemical Corporation) were completely dissolved in 55.8 g of isopropyl acetate (manufactured by Shinko Organic Chemical Industry Co., Ltd.) as a solvent, and 2.83 g of 2,2'-azobis(isobutyrate)dimethyl ("V-601" manufactured by Fujifilm Wako Pure Chemical Industries Co., Ltd.) as a polymerization initiator and 4.23 g of isopropyl acetate (manufactured by Shinko Organic Chemical Industry Co., Ltd.) were completely dissolved. The two resulting solutions were simultaneously added dropwise over 2 hours to 100 g of isopropyl acetate (Shinko Organic Chemical Industry Co., Ltd.) heated to 89 ° C under a nitrogen gas atmosphere in a 300 mL three-neck flask, and then the mixture was allowed to react for 4 hours under reflux at 89 ° C. The reaction solution was cooled to room temperature and added dropwise to 1000 g of a 50:50 mixture of hexane and toluene to precipitate the copolymer. The precipitated copolymer was recovered by filtration and vacuum dried at 80 ° C for 5 hours, resulting in the recovery of 36.4 g of a white powder. The resulting second resin B-PhMA20% having phenolic hydroxyl groups had a number average molecular weight of 3600, a weight average molecular weight of 7200, and a phenolic hydroxyl group equivalent of 270.

[Production Example 6] Third Resin (C): Production of a Copolymer (PCX-02e) of a Polymerizable Monomer Having a Phenolic Hydroxyl Group and Other Polymerizable Monomers 25.5 g of 4-hydroxyphenyl methacrylate ("PQMA" manufactured by Showa Denko K.K.) and 4.50 g of N-cyclohexylmaleimide (manufactured by Nippon Shokubai Co., Ltd.) were completely dissolved in 77.1 g of 1-methoxy-2-propyl acetate (manufactured by Daicel Corporation) as a solvent, 3.66 g of V-601 (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) as a polymerization initiator, and 14.6 g of 1-methoxy-2-propyl acetate (manufactured by Daicel Corporation). The two resulting solutions were simultaneously added dropwise over 2 hours to 61.2 g of 1-methoxy-2-propyl acetate (manufactured by Daicel Corporation) heated to 85 ° C. under a nitrogen gas atmosphere in a 300 mL three-necked flask, and then the mixture was allowed to react at 85 ° C. for 3 hours. The reaction solution cooled to room temperature was added dropwise to 815 g of toluene to precipitate a copolymer. The precipitated copolymer was recovered by filtration and vacuum dried at 90°C for 4 hours, and 32.4 g of a white powder was recovered. The resulting copolymer PCX-02e of a polymerizable monomer having a phenolic hydroxyl group and another polymerizable monomer had a number average molecular weight of 3,100, a weight average molecular weight of 6,700, and a phenolic hydroxyl group equivalent of 210.

[Production Example 7] Production of a copolymer of glycidyl methacrylate and methacrylic acid (GMA-MAA) 99.5 g (0.7 mol) of glycidyl methacrylate (GMA) and 8.6 g (0.1 mol) of methacrylic acid (MAA) were dissolved completely in 72.1 g of propylene glycol monomethyl ether (PGME), and 7.6 g of V-65 (Fujifilm Wako Pure Chemical Industries, Ltd.) as a polymerization initiator was dissolved in 7.6 g of PGME. The two resulting solutions were simultaneously added dropwise over 2 hours to 172.6 g of PGME heated to 80 °C under a nitrogen gas atmosphere in a 500 mL three-necked flask, and then the mixture was stirred for 2 hours to allow the reaction to proceed. In this way, a copolymer of glycidyl methacrylate and methacrylic acid (GMA-MAA) having a molar ratio of glycidyl methacrylate to methacrylic acid of 7:1 was obtained in the form of a PGME solution with a solids content of 30% by mass. The obtained GMA-MAA has a carboxyl group and an epoxy group in the molecule, and therefore is highly self-reactive, i.e., the ring-opening polymerization of the epoxy group easily proceeds. Therefore, when reprecipitation and vacuum drying were performed, the molecular weight increased, and it was not possible to isolate it. The PGME solution of GMA-MAA had low stability, and the molecular weight increased over time, resulting in an increase in the viscosity of the solution.

[Production Example 8] Second resin (B): Production of second resin (B-CHMA 20%) having phenolic hydroxyl groups 24.5 g of 4-hydroxyphenyl methacrylate ("PQMA" manufactured by Showa Denko K.K.), 7.11 g of N-cyclohexylmaleimide (manufactured by Nippon Shokubai Co., Ltd.), and 5.68 g of cyclohexyl methacrylate (manufactured by Tokyo Chemical Industry Co., Ltd.) were completely dissolved in 69.3 g of isopropyl acetate (manufactured by Shinko Organic Chemical Industry Co., Ltd.) as a solvent, and 2.72 g of 2,2'-azobis(isobutyrate)dimethyl ("V-601" manufactured by Fujifilm Wako Pure Chemical Industries Co., Ltd.) as a polymerization initiator were completely dissolved in 10.87 g of isopropyl acetate (manufactured by Shinko Organic Chemical Industry Co., Ltd.). The two resulting solutions were simultaneously added dropwise over two hours to 143 g of isopropyl acetate (Shinko Organic Chemical Industry Co., Ltd.) heated to 89°C under a nitrogen gas atmosphere in a 300 mL three-neck flask, and then the mixture was allowed to react at 89°C under reflux for four hours. The reaction solution was cooled to room temperature and added dropwise to 1000 g of a 50:50 mixture of hexane and toluene to precipitate the copolymer. The precipitated copolymer was recovered by filtration and vacuum dried at 80°C for five hours, resulting in the recovery of 39.1 g of a white powder. The resulting second resin B-CHMA20% having phenolic hydroxyl groups had a number average molecular weight of 3500, a weight average molecular weight of 7200, and a phenolic hydroxyl group equivalent of 271.

[Production Example 9] Second resin (B): Production of second resin (B-CHMA 40%) having phenolic hydroxyl groups 17.14 g of 4-hydroxyphenyl methacrylate ("PQMA" manufactured by Showa Denko K.K.), 14.39 g of N-cyclohexylmaleimide (manufactured by Nippon Shokubai Co., Ltd.), and 5.75 g of cyclohexyl methacrylate (manufactured by Tokyo Chemical Industry Co., Ltd.) were completely dissolved in 69.3 g of isopropyl acetate (manufactured by Shinko Organic Chemical Industry Co., Ltd.) as a solvent, and 2.72 g of 2,2'-azobis(isobutyrate)dimethyl ("V-601" manufactured by Fujifilm Wako Pure Chemical Industries Co., Ltd.) as a polymerization initiator were completely dissolved in 10.87 g of isopropyl acetate (manufactured by Shinko Organic Chemical Industry Co., Ltd.). The two resulting solutions were simultaneously added dropwise over two hours to 143 g of isopropyl acetate (Shinko Organic Chemical Industry Co., Ltd.) heated to 89°C under a nitrogen gas atmosphere in a 300 mL three-neck flask, and then the mixture was allowed to react at 89°C under reflux for four hours. The reaction solution was cooled to room temperature and added dropwise to 1000 g of a 50:50 mixture of hexane and toluene to precipitate the copolymer. The precipitated copolymer was recovered by filtration and vacuum dried at 80°C for five hours, recovering 39.1 g of a white powder. The resulting second resin B-CHMA 40% having phenolic hydroxyl groups had a number average molecular weight of 3900, a weight average molecular weight of 7500, and a phenolic hydroxyl group equivalent of 387.

[Production Example 10] Second Resin (B): Production of Second Resin Having Phenolic Hydroxyl Groups (B-BOM 32%) 17.3 g of 4-hydroxyphenyl methacrylate ("PQMA" manufactured by Showa Denko K.K.), 29.0 g of N,N-diisopropylethylamine (manufactured by Tokyo Chemical Industry Co., Ltd.), and 160 g of tetrahydrofuran (anhydrous) (manufactured by Kanto Chemical Co., Inc.) were stirred in a 500 mL three-neck flask under a nitrogen gas atmosphere until the solids were completely dissolved. The solution was cooled to 0°C, and 26.4 g of benzyl chloromethyl ether (manufactured by Tokyo Chemical Industry Co., Ltd.) was added dropwise to the solution. After the addition was complete, the solution was heated to 70°C and reacted for 5 hours. After the reaction solution was brought to room temperature, insoluble materials were removed by filtration, 200 mL of ethyl acetate (special grade manufactured by Junsei Chemical Co., Ltd.) was added, and THF was distilled off. The organic layer was washed once with 300 mL of saturated aqueous bicarbonate solution and twice with 200 mL of pure water. After drying with sodium sulfate, the solvent was completely distilled off, and the crude product was purified by silica gel column chromatography using a developing solvent of hexane:ethyl acetate=50:1 to obtain 31.2 g of PQMA-BOM.

12.1 g of 4-hydroxyphenyl methacrylate ("PQMA" manufactured by Showa Denko K.K.), 3.45 g of N-cyclohexylmaleimide (manufactured by Nippon Shokubai Co., Ltd.), and 12.3 g of PQMA-BOM were completely dissolved in 41.8 g of isopropyl acetate (manufactured by Shinko Organic Chemical Industry Co., Ltd.) as a solvent, and 2.14 g of 2,2'-azobis(isobutyrate)dimethyl ("V-601" manufactured by Fujifilm Wako Pure Chemical Industries Co., Ltd.) as a polymerization initiator were completely dissolved in 8.54 g of isopropyl acetate (manufactured by Shinko Organic Chemical Industry Co., Ltd.) in a 300 mL three-neck flask. The resulting two solutions were simultaneously added dropwise over two hours to 69.7 g of isopropyl acetate (manufactured by Shinko Organic Chemical Industry Co., Ltd.) heated to 89°C under a nitrogen gas atmosphere in a 300 mL three-neck flask, and then the mixture was allowed to react under reflux at 89°C for four hours. The reaction solution cooled to room temperature was added dropwise to 1000 g of a 50:50 mixture of hexane and toluene to precipitate the copolymer. The precipitated copolymer was recovered by filtration and vacuum dried at 80°C for 5 hours, and 29.3 g of a white powder was recovered. The resulting second resin B-BOM32% having phenolic hydroxyl groups had a number average molecular weight of 3600, a weight average molecular weight of 6900, and a phenolic hydroxyl group equivalent of 431.

[Production Example 11] Second Resin (B): Production of Second Resin Having Phenolic Hydroxyl Groups (B-IBMA 20%) 23.1 g of 4-hydroxyphenyl methacrylate ("PQMA" manufactured by Showa Denko K.K.), 8.86 g of N-cyclohexylmaleimide (manufactured by Nippon Shokubai Co., Ltd.), and 5.35 g of isobornyl methacrylate (manufactured by Tokyo Chemical Industry Co., Ltd.) were completely dissolved in 69.2 g of isopropyl acetate (manufactured by Shinko Organic Chemical Industry Co., Ltd.) as a solvent, and 2.72 g of 2,2'-azobis(isobutyrate)dimethyl ("V-601" manufactured by Fujifilm Wako Pure Chemical Industries Co., Ltd.) as a polymerization initiator were completely dissolved in 10.83 g of isopropyl acetate (manufactured by Shinko Organic Chemical Industry Co., Ltd.). The two resulting solutions were simultaneously added dropwise over two hours to 143 g of isopropyl acetate (Shinko Organic Chemical Industry Co., Ltd.) heated to 89°C under a nitrogen gas atmosphere in a 300 mL three-neck flask, and then the mixture was allowed to react at 89°C under reflux for four hours. The reaction solution was cooled to room temperature and added dropwise to 1000 g of a 50:50 mixture of hexane and toluene to precipitate the copolymer. The precipitated copolymer was recovered by filtration and vacuum dried at 80°C for five hours, yielding 39.1 g of a white powder. The resulting second resin B-IBMA 20% having phenolic hydroxyl groups had a number average molecular weight of 3600, a weight average molecular weight of 7100, and a phenolic hydroxyl group equivalent of 288.

[Production Example 12] Second resin (B): Production of second resin (B-TCDMA 20%) having phenolic hydroxyl groups 23.1 g of 4-hydroxyphenyl methacrylate ("PQMA" manufactured by Showa Denko K.K.), 8.79 g of N-cyclohexylmaleimide (manufactured by Nippon Shokubai Co., Ltd.), and 5.37 g of dicyclopentanyl methacrylate (manufactured by Tokyo Chemical Industry Co., Ltd.) were completely dissolved in 69.2 g of isopropyl acetate (manufactured by Shinko Organic Chemical Industry Co., Ltd.) as a solvent, and 2.72 g of 2,2'-azobis(isobutyrate)dimethyl ("V-601" manufactured by Fujifilm Wako Pure Chemical Industries Co., Ltd.) as a polymerization initiator were completely dissolved in 10.83 g of isopropyl acetate (manufactured by Shinko Organic Chemical Industry Co., Ltd.). The two resulting solutions were simultaneously added dropwise over 2 hours to 143 g of isopropyl acetate (Shinko Organic Chemical Industry Co., Ltd.) heated to 89°C under a nitrogen gas atmosphere in a 300 mL three-neck flask, and then the mixture was allowed to react for 4 hours under reflux at 89°C. The reaction solution was cooled to room temperature and added dropwise to 1000 g of a 50:50 mixture of hexane and toluene to precipitate the copolymer. The precipitated copolymer was recovered by filtration and vacuum dried at 80°C for 5 hours, recovering 39.1 g of a white powder. The resulting second resin B-TCDMA20% having phenolic hydroxyl groups had a number average molecular weight of 3800, a weight average molecular weight of 8000, and a phenolic hydroxyl group equivalent of 287.

[First resin (A)]
As the first resin (A), N770OH70 of Production Example 1 and N695OH70 of Production Example 2 were used.

[Second resin (B)]
As the second resin (B), 42.5% of B-TBMA from Production Example 3, 41% of B-PhMA from Production Example 4, 20% of B-PhMA from Production Example 5, 20% of B-CHMA from Production Example 8, 40% of B-CHMA from Production Example 9, 32% of B-BOM from Production Example 10, 20% of B-IBMA from Production Example 11, and 20% of B-TCDMA from Production Example 12 were used.

[Third resin (C)]
As the third resin (C), PCX-02e of Production Example 6 was used.

[Other resins]
Other resins used were SHONOL (registered trademark) BRG-558 (phenol novolac resin manufactured by AICA Kogyo Co., Ltd., phenolic hydroxyl group equivalent: 107), EPICLON (registered trademark) N-770 (phenol novolac epoxy resin manufactured by DIC Corporation, epoxy equivalent: 188), and GMA-MAA of Production Example 7.

The resin's structural unit ratio, phenolic hydroxyl group equivalent, alkaline dissolution rate, and weight-average molecular weight (Mw) are shown in Table 1. In Table 1, PQMA represents a structural unit derived from 4-hydroxyphenyl methacrylate, and CHMI represents a structural unit derived from N-cyclohexylmaleimide.

[Radiation-sensitive compound (D)]
As the radiation-sensitive compound (D), a quinone diazide compound, TS-150A (ester of 4,4'-[1-[4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl]ethylidene]bisphenol (TrisP-PA) and 6-diazo-5,6-dihydro-5-oxonaphthalene-1-sulfonic acid (1,2-naphthoquinone diazide-5-sulfonic acid), manufactured by Toyo Gosei Co., Ltd.) was used. The structure of TS-150A is shown below.

[Black agent (E)]
As the black agent, a black dye, VALIFAST (registered trademark) BLACK 3820 (a black dye specified by C.I. as Solvent Black 27, manufactured by Orient Chemical Industries Co., Ltd.) was used.

[Solubility promoter (F)]
Phloroglucinol was used as the solubility enhancer (F).

[Basic compound (G)]
Tri-n-octylamine (TOA) was used as the basic compound (G).

[Solvent (H)]
As the solvent (H), a mixed solvent of γ-butyrolactone (GBL), propylene glycol monomethyl ether acetate (PGMEA), and diethyl carbonate (DEC) (GBL:PGMEA:DEC=35:45:20 (mass ratio)), or a mixed solvent of γ-butyrolactone (GBL), propylene glycol monomethyl ether acetate (PGMEA), diethyl carbonate (DEC), and propylene glycol monomethyl ether (PGME) (GBL:PGMEA:DEC:PGME=35:35:20:10 (mass ratio)) was used. The mass ratio values of GBL and PGME also include those used in Production Examples 1, 2, and 7.

(3) Evaluation Methods The evaluation methods used in the examples and comparative examples are as follows.

[Solubility]
<Solubility of exposed areas>
The photosensitive resin composition was bar-coated onto a glass substrate (100 mm x 100 mm x 1 mm) to a dry film thickness of 2.7 μm, and then heated on a hot plate at 120°C for 120 seconds to dry off the solvent (pre-baked). The dry film thickness was measured using an optical film thickness measurement device (F20-NIR, manufactured by Filmetrics Inc.), and then the film was exposed at 100 mJ/cm2 using an exposure device (product name Multilight ML-251A/B, manufactured by Ushio Inc.) equipped with an ultra-high pressure mercury lamp through a mercury exposure bandpass filter (product name HB0365, manufactured by Asahi Spectroscopic Co., Ltd.) and a quartz photomask (having line and space (L/S) patterns of 5 μm, 10 μm, 20 μm, 50 μm, 100 μm, 200 μm, and 500 μm ⁾ . The exposure dose was measured using an ultraviolet integrating actinometer (product name UIT-150, light-receiving part UVD-S365, manufactured by Ushio Inc.). Subsequently, using a spin developer (AD-1200, manufactured by Takizawa Sangyo Co., Ltd.), alkaline development was performed with a 2.38% by mass aqueous solution of tetramethylammonium hydroxide for 20 to 200 seconds until the coating in the exposed area was completely removed. Therefore, in Table 2, the solubility of the exposed area, along with the development time, is all expressed as 2.70 μm (exceeding 2.70 μm in Comparative Example 2 only, where the pattern peeled off).

<Solubility of unexposed areas>
The photosensitive resin composition was bar-coated onto a glass substrate (100 mm x 100 mm x 1 mm) to a dry film thickness of 2.7 μm, and the substrate was heated on a hot plate at 120°C for 120 seconds to dry the solvent (pre-baked). The dry film thickness was measured using an optical film thickness measuring device (F20-NIR, Filmetrics Inc.), and then the substrate was subjected to alkaline development using a spin developing device (AD-1200, Takizawa Sangyo Co., Ltd.) with a 2.38% by mass aqueous solution of tetramethylammonium hydroxide for the same development time as the solubility of the exposed area. The film thickness after alkaline development was again measured using the optical film thickness measuring device (F20-NIR, Filmetrics Inc.), and the film thickness (μm) dissolved before and after development was calculated as the solubility of the unexposed area.

<Solubility difference>
The solubility difference (μm) was calculated by subtracting the solubility (μm) of the unexposed area from the solubility (μm) of the exposed area. A larger solubility difference means higher sensitivity and better pattern formability.

[OD value of cured coating]
The photosensitive resin composition was spin-coated onto a glass substrate (100 mm x 100 mm x 1 mm) to a dry film thickness of approximately 1.5 μm, and the substrate was heated on a hot plate at 120°C for 120 seconds to dry off the solvent. 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, manufactured by Sakata Inx Engineering Corporation), 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 measuring device (F20-NIR, manufactured by Filmetrics Inc.).

[Pattern Formability]
The photosensitive resin composition was bar-coated onto a glass substrate (100 mm x 100 mm x 1 mm) to a dry film thickness of 2.7 μm, and then heated on a hot plate at 120°C for 120 seconds to dry the solvent (pre-baked). The coating was exposed at 100 mJ/cm² or less using an exposure system (product name Multilight ML-251A/B, manufactured by Ushio Inc.) incorporating an ultra-high pressure mercury lamp through a mercury exposure bandpass filter (product name HB0365, manufactured by Asahi Spectroscopy Co., Ltd.) and a quartz photomask (with a φ10 μm pattern). The exposure dose was measured using an ultraviolet integrating actinometer (product name UIT-150, light-receiving part UVD-S365, manufactured by Ushio Inc.). After exposure, the coating was subjected to alkaline development for ⁶⁰ seconds using a 2.38% by weight aqueous solution of tetramethylammonium hydroxide using a spin development system (AD-1200, manufactured by Takizawa Sangyo Co., Ltd.). The coating was then cured by heating at 250°C for 60 minutes in an inert oven (DN411I, manufactured by Yamato Scientific Co., Ltd.). The thickness of the cured coating was measured using an optical film thickness measuring device (F20-NIR, manufactured by Filmetrics Inc.), and the holes formed were observed using a microscope (VHX-6000, manufactured by Keyence Corporation). A film thickness of 3.0 μm or more and a hole diameter of 10 μm or more was judged as good, and a film thickness of 2.9 μm or less or a hole diameter of 9 μm or less was judged as bad.

[Surface roughness]
Visual observation was made using a microscope, and when irregularities of about 0.5 μm were observed over the entire coating surface, it was judged as poor, and when no irregularities were observed over the entire coating surface, it was judged as good.

(4) Preparation and Evaluation of Photosensitive Resin Compositions [Examples 1 to 9, Comparative Examples 1 to 4]
The resin components were mixed and dissolved according to the composition shown in Table 2, and the radiation-sensitive compound (D), blackening agent (E), dissolution promoter (F), basic compound (G), and solvent (H) 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 approximately 12% by mass. The parts by mass of the compositions in Table 2 are values calculated as solids. Table 2 also lists the alkali dissolution rate of the photosensitive resin composition. Table 2 shows the evaluation results of the photosensitive resin compositions of Examples 1 to 9 and Comparative Examples 1 to 4. In Comparative Example 3, pattern peeling occurred during development, making accurate solubility measurement impossible; therefore, the solubility values in Table 2 are enclosed in parentheses. In Comparative Example 4, the stability of the PGME solution of GMA-MAA was low, making evaluation impossible.

The photosensitive resin composition of the present disclosure can be suitably used in radiation lithography to form partition walls or insulating films for organic EL elements. Organic EL elements equipped with partition walls or insulating films formed from the photosensitive resin composition of the present disclosure are suitable for use as electronic components in display devices that exhibit good contrast.

Claims (20)

(A) a first resin;
(B) a second resin having a phenolic hydroxyl group, which is different from the first resin;
(C) a third resin having a phenolic hydroxyl group, which is different from both the first resin and the second resin;
A photosensitive resin composition comprising: (D) a radiation-sensitive compound; and (E) a black agent, wherein the optical density (OD value) of a cured coating film of the photosensitive resin composition is 0.5 or more per 1 μm of film thickness; and the phenolic hydroxyl group equivalent of the second resin is 1.3 to 2.5 times the phenolic hydroxyl group equivalent of the third resin. The photosensitive resin composition according to claim 1, wherein the second resin contains a structural unit identical to at least one of the structural units of the third resin and other structural units, and contains a total of 30 mol % to 95 mol % of structural units common to the third resin, and the alkali dissolution rate of the second resin is lower than the alkali dissolution rate of the third resin. The photosensitive resin composition according to claim 1 or 2, wherein the second resin is a copolymer of a polymerizable monomer having a phenolic hydroxyl group and another polymerizable monomer. The photosensitive resin composition according to any one of claims 1 to 3, wherein the third resin is a copolymer of a polymerizable monomer having a phenolic hydroxyl group and another polymerizable monomer. The second resin is represented by formula (17):
(In formula (17), R ³⁸ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and R ³⁹ is a group selected from the group consisting of a linear alkyl group having 1 to 20 carbon atoms, a branched alkyl group having 3 to 20 carbon atoms, a cyclic alkyl group having 3 to 12 carbon atoms, an aryl group having 6 to 20 carbon atoms, a linear alkyl group having 1 to 20 carbon atoms substituted with a group other than an acidic functional group, a branched alkyl group having 3 to 20 carbon atoms substituted with a group other than an acidic functional group, a cyclic alkyl group having 3 to 12 carbon atoms substituted with a group other than an acidic functional group, and an aryl group having 6 to 20 carbon atoms substituted with a group other than an acidic functional group.)
The photosensitive resin composition according to any one of claims 1 to 4, having a structural unit represented by the following formula: The second resin is represented by formula (10):
(In formula (10), R ¹⁵ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and e 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 the following formula: The second resin is represented by formula (11):
(In formula (11), R ¹⁶ and R ¹⁷ are each independently a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, a completely or partially fluorinated fluoroalkyl group having 1 to 3 carbon atoms, or a halogen atom; and R ¹⁸ 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 any one of claims 1 to 6, having a structural unit represented by the following formula: The photosensitive resin composition according to any one of claims 1 to 7, wherein the first resin is a resin having an epoxy group and a phenolic hydroxyl group. The first resin 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 (9):
(In formula (9), d 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 any one of claims 1 to 8, wherein the compound has a structure represented by the formula: The photosensitive resin composition according to claim 9, wherein the compound having at least two epoxy groups per molecule is a novolac epoxy resin. The photosensitive resin composition according to any one of claims 1 to 10, wherein the black agent is a dye defined by a color index (C.I.) of Solvent Black 27 to 47. The photosensitive resin composition according to any one of claims 1 to 11, wherein the radiation-sensitive compound is a photoacid generator. The photosensitive resin composition according to any one of claims 1 to 12, comprising 20% by mass to 90% by mass of the first resin, based on the total mass of the resin components. The photosensitive resin composition according to any one of claims 1 to 13, comprising 5% by mass to 50% by mass of the second resin, based on the total mass of the resin components. The photosensitive resin composition according to any one of claims 1 to 14, comprising 5% to 50% by mass of the third resin based on the total mass of the resin components. The photosensitive resin composition according to any one of claims 1 to 15, comprising 1 to 40 parts by mass of the radiation-sensitive compound, based on 100 parts by mass of the total resin components. The photosensitive resin composition according to any one of claims 1 to 16, comprising 10 to 150 parts by mass of the blackening agent, based on 100 parts by mass of the total resin components. An organic EL element partition wall comprising a cured product of the photosensitive resin composition described in any one of claims 1 to 17. An insulating film for an organic electroluminescent device comprising a cured product of the photosensitive resin composition described in any one of claims 1 to 17. An organic EL device comprising a cured product of the photosensitive resin composition described in any one of claims 1 to 17.