JP2023080993A - Photosensitive resin composition and organic el element barrier - Google Patents

Abstract

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

Description

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

2. Description of the Related Art In a display device such as an organic EL display (OLED), in order to improve display characteristics, a partition wall material is used at intervals between colored patterns in a display area or at edges around the display area. In the manufacture of an organic EL display device, partition walls are first formed, and organic pixels are formed between the partition walls in order to prevent organic substance pixels from coming into contact with each other. This partition is generally formed by photolithography using a photosensitive resin composition and has insulating properties. Specifically, a photosensitive resin composition is applied onto a substrate using a coating device, volatile components are removed by means of heating or the like, and then exposed through a mask. In the case of the positive type, the exposed portion is developed by removing it with a developing solution such as an alkaline aqueous solution, and the obtained pattern is heat-treated to form a partition wall (insulating film). Next, by an ink jet method or the like, an organic substance emitting three colors of red, green, and blue is deposited between the barrier ribs to form the pixels of the organic EL display device.

When forming the light-emitting layer, vapor deposition is performed by bringing a vapor deposition mask into contact with the pixel division layer. At this time, if the contact area between the pixel dividing layer and the vapor deposition mask is large, there is a risk that the yield of the panel will decrease due to the generation of particles. In addition, the pixel division layer may be damaged by deposits on the vapor deposition mask, and moisture may enter through the damaged portion, thereby degrading the light emitting element. As a method for solving these problems, there is a method in which the pixel division layer is divided into two layers and the width of the second layer is reduced so that the contact area of the pixel division layer becomes small. However, this method complicates the process and may inevitably increase the process time or reduce the panel yield. Furthermore, as a method for solving these problems, there is a method of forming patterns using a halftone photomask. According to this method, by forming a pixel dividing layer having a step shape by forming a single layer, it is possible to reduce the contact area with the vapor deposition mask without increasing the process time. A positive photosensitive resin composition containing a naphthoquinone diazide compound is generally used for forming a single pixel dividing layer having a stepped shape.

On the other hand, in this field, due to the recent miniaturization of display devices and the diversification of contents to be displayed, there is a demand for higher performance and higher definition of pixels. Attempts have been made to impart a light-shielding property to the partition wall material by using a coloring agent for the purpose of increasing the contrast in the display device and improving the visibility. However, when the partition wall material is provided with a light-shielding property, the sensitivity of the photosensitive resin composition tends to be low, and as a result, the exposure time becomes long, which may reduce productivity. Therefore, the photosensitive resin composition used for forming the partition wall material containing the colorant is required to have higher sensitivity.

Patent Document 1 (Japanese Unexamined Patent Application Publication No. 2001-281440) discloses a positive radiation-sensitive resin composition containing an alkali-soluble resin and a quinonediazide compound as a radiation-sensitive resin composition exhibiting high light-shielding properties by heat treatment after exposure. describes a composition to which titanium black is added.

Patent Document 2 (Japanese Patent Application Laid-Open No. 2002-116536) describes a radiation-sensitive resin composition containing [A] an alkali-soluble resin, [B] a 1,2-quinonediazide compound, and [C] a colorant, wherein carbon black describes a method of blackening a barrier rib material using

Patent Document 3 (Japanese Patent Application Laid-Open No. 2010-237310) describes a positive radiation-sensitive resin composition containing an alkali-soluble resin and a quinonediazide compound as a radiation-sensitive resin composition that exhibits light-shielding properties by heat treatment after exposure. Compositions with added thermal dyes are described.

Patent Document 4 (International Publication No. 2017/069172) discloses (A) a binder resin, (B) a quinonediazide compound, and (C) at least one black dye selected from solvent black color indexes 27 to 47. A positive-acting photosensitive resin composition containing a black dye is described.

Japanese Patent Application Laid-Open No. 2001-281440 JP-A-2002-116536 Japanese Patent Application Laid-Open No. 2010-237310 WO2017/069172

A photosensitive resin composition used for forming a colored barrier rib material requires the use of a considerable amount of a coloring agent in order to sufficiently enhance the light-shielding properties of the cured film. When such a large amount of colorant is used, the radiation irradiated to the film of the photosensitive resin composition is absorbed by the colorant, so that the effective intensity of the radiation in the film is reduced, and the photosensitive resin composition is not sufficiently exposed, resulting in poor patternability.

In the formation of partition walls in an organic EL element, it is important from the viewpoint of productivity that the material forming the partition walls has high sensitivity. However, when a black photosensitive resin composition containing a colorant is used, exposure failure occurs under the exposure conditions normally used, so it is necessary, for example, to lengthen the exposure time, which reduces productivity. It was a factor that made Therefore, it is strongly desired to reduce the exposure amount of the photosensitive resin composition, reduce the energy cost, and increase the throughput.

Addition of a phenolic low-molecular-weight compound having a low hydroxyl equivalent to a photosensitive resin composition may improve its sensitivity. However, in a photosensitive resin composition that exhibits curability in heat treatment after exposure and development, an increase in the blending amount of such a phenolic low-molecular-weight compound lowers the cross-linking density of the resin, causing the coating film to form during heat curing. The step shape may disappear due to flow.

Thus, there is a need for a photosensitive resin composition that has high sensitivity despite having a light-shielding property, and is capable of forming a pattern having a stepped shape using a one-shot exposure process using a halftone photomask. ing.

An object of the present invention is to make it possible to form a stepped pattern in exposure using a halftone photomask (hereinafter also referred to as "halftone exposure"), and to maintain the stepped shape even after heat curing. An object of the present invention is to provide a highly sensitive photosensitive resin composition containing a black colorant.

The present inventors have proposed a resin having a plurality of phenolic hydroxyl groups, at least a portion of which is protected with an acid-decomposable group, a resin having an epoxy group, and a quinonediazide adduct to a phenolic compound. , a dissolution accelerator, and a black colorant, the total number of moles of carboxy groups and phenolic hydroxyl groups contained in the quinonediazide adduct and the dissolution accelerator is It was found that by setting the amount to 150 mmol or less per 100 g of solid content, it is possible to form a stepped pattern in halftone exposure, and to maintain the stepped shape even after thermal curing.

（式（４）において、Ｒ^９は水素原子又は炭素原子数１～５のアルキル基であり、Ｒ^１０は酸分解性基であり、ｒは０～５の整数であり、ｓは０～５の整数であり、但しｒ＋ｓは１～５の整数である。）
で表される構造単位を有し、ｓが１以上の整数である式（４）で表される構造単位を少なくとも１つ有する、［１］～［６］のいずれかに記載の感光性樹脂組成物。
［８］
前記樹脂（Ａ１）が、式（２）

（式（２）において、Ｒ^２及びＲ^３は、それぞれ独立して水素原子、炭素原子数１～３のアルキル基、完全若しくは部分的にフッ素化された炭素原子数１～３のフルオロアルキル基、又はハロゲン原子であり、Ｒ^４は、水素原子、炭素原子数１～６の直鎖アルキル基、炭素原子数３～１２の環状アルキル基、フェニル基、又はヒドロキシ基、炭素原子数１～６のアルキル基及び炭素原子数１～６のアルコキシ基からなる群より選ばれる少なくとも１種で置換されたフェニル基である。）
で表される構造単位を有する、［７］に記載の感光性樹脂組成物。
［９］
前記樹脂（Ａ１）においてフェノール性水酸基の水素原子と置換されている前記酸分解性基が、式（３）
－ＣＲ^６Ｒ^７－Ｏ－Ｒ^８ （３）
（式（３）中、Ｒ^６及びＲ^７は、それぞれ独立して水素原子、炭素原子数１～４の直鎖アルキル基、又は炭素原子数３～４の分岐アルキル基であり、Ｒ^８は、炭素原子数１～１２の直鎖アルキル基、炭素原子数３～１２の分岐アルキル基、炭素原子数３～１２の環状アルキル基、炭素原子数７～１２のアラルキル基、又は炭素原子数２～１２のアルケニル基であり、Ｒ^６又はＲ^７の一方とＲ^８とが結合して環員数３～１０の環構造を形成してもよく、Ｒ^６、Ｒ^７及びＲ^８は、フッ素、塩素、臭素及びヨウ素からなる群より選ばれるハロゲン原子で置換されていてもよい。）
で表される基である、［１］～［８］のいずれかに記載の感光性樹脂組成物。
［１０］
前記樹脂（Ａ２）が、エポキシ基及びフェノール性水酸基を有する樹脂である、［１］～［９］のいずれかに記載の感光性樹脂組成物。
［１１］
前記エポキシ基及びフェノール性水酸基を有する樹脂が、１分子中に少なくとも２個のエポキシ基を有する化合物とヒドロキシ安息香酸化合物との反応物であって、式（６）

（式（６）において、ｂは１～５の整数であり、＊は、１分子中に少なくとも２個のエポキシ基を有する化合物の、反応にかかるエポキシ基を除く残基との結合部を表す。）
の構造を有する化合物である、［１０］に記載の感光性樹脂組成物。
［１２］
前記１分子中に少なくとも２個のエポキシ基を有する化合物がノボラック型エポキシ樹脂である、［１１］に記載の感光性樹脂組成物。
［１３］
樹脂成分の合計１００質量部を基準として、前記黒色着色剤（Ｄ）を１０質量部～１５０質量部含む、［１］～［１２］のいずれかに記載の感光性樹脂組成物。
［１４］
前記感光性樹脂組成物の硬化被膜の光学濃度（ＯＤ値）が膜厚１μｍあたり０．５以上である、［１］～［１３］のいずれかに記載の感光性樹脂組成物。
［１５］
［１］～［１４］のいずれかに記載の感光性樹脂組成物の硬化物を含む有機ＥＬ素子隔壁。
［１６］
［１］～［１４］のいずれかに記載の感光性樹脂組成物の硬化物を含む有機ＥＬ素子絶縁膜。
［１７］
［１］～［１４］のいずれかに記載の感光性樹脂組成物の硬化物を含む有機ＥＬ素子。 That is, the present invention includes the following aspects.
[1]
a resin (A1) having a plurality of phenolic hydroxyl groups, at least a portion of the plurality of phenolic hydroxyl groups being protected with an acid-decomposable group;
a resin (A2) having an epoxy group;
A quinonediazide adduct (B) to a phenol compound;
at least one dissolution accelerator (C) selected from the group consisting of compounds having a carboxyl group and compounds having a phenolic hydroxyl group;
a black coloring agent (D);
wherein the total number of moles of carboxy groups and phenolic hydroxyl groups contained in the quinonediazide adduct (B) and the dissolution accelerator (C) is the solid contained in the photosensitive resin composition A photosensitive resin composition having a content of 150 mmol or less per 100 g per minute.
[2]
The photosensitive resin according to [1], wherein the quinonediazide adduct (B) is 1,2-naphthoquinonediazide-4-sulfonate or 1,2-naphthoquinonediazide-5-sulfonate of the phenol compound. Composition.
[3]
The photosensitive resin composition according to [1] or [2], wherein the quinonediazide adduct (B) has a quinonediazide group equivalent of 500 or less.
[4]
The photosensitive resin composition according to any one of [1] to [3], wherein the dissolution accelerator (C) is an organic low-molecular-weight compound having a molecular weight of 1,000 or less.
[5]
The photosensitive resin composition according to any one of [1] to [4], wherein the dissolution accelerator (C) has a total equivalent weight of carboxy groups and phenolic hydroxyl groups of 60 or less.
[6]
The total number of moles of carboxy groups and phenolic hydroxyl groups contained in the quinonediazide adduct (B) and the dissolution accelerator (C) is 90 mmol or more per 100 g of solid content contained in the photosensitive resin composition [1] The photosensitive resin composition according to any one of [5].
[7]
The resin (A1) has the formula (4)

(In formula (4), R ⁹ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, R ¹⁰ is an acid-decomposable group, r is an integer of 0 to 5, s is 0 to 5 is an integer of , where r + s is an integer of 1 to 5.)
The photosensitive resin according to any one of [1] to [6], having at least one structural unit represented by formula (4), wherein s is an integer of 1 or more. Composition.
[8]
The resin (A1) has the formula (2)

(In Formula (2), R ² and R ³ are each independently a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or a fully or partially fluorinated fluoroalkyl group having 1 to 3 carbon atoms. , or a halogen atom, and R ⁴ is a hydrogen atom, a linear alkyl group having 1 to 6 carbon atoms, a cyclic alkyl group having 3 to 12 carbon atoms, a phenyl group, or a hydroxy group, or a 1 to 6 carbon atom is a phenyl group substituted with at least one selected from the group consisting of an alkyl group and an alkoxy group having 1 to 6 carbon atoms.)
The photosensitive resin composition according to [7], which has a structural unit represented by
[9]
The acid-decomposable group substituted with the hydrogen atom of the phenolic hydroxyl group in the resin (A1) has the formula (3)
—CR ⁶ R ⁷ —OR ⁸ (3)
(In formula (3), R ⁶ and R ⁷ are each independently a hydrogen atom, a linear alkyl group having 1 to 4 carbon atoms, or a branched alkyl group having 3 to 4 carbon atoms, and R ⁸ is , a linear alkyl group having 1 to 12 carbon atoms, a branched alkyl group having 3 to 12 carbon atoms, a cyclic alkyl group having 3 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, or 2 carbon atoms 1 to 12 alkenyl groups, one of R ⁶ or R 7 and R ⁸ may combine to form a ring structure with 3 to 10 ring members, where R ⁶ , ^{R 7 and} R ⁸ are fluorine, It may be substituted with a halogen atom selected from the group consisting of chlorine, bromine and iodine.)
The photosensitive resin composition according to any one of [1] to [8], which is a group represented by
[10]
The photosensitive resin composition according to any one of [1] to [9], wherein the resin (A2) is a resin having an epoxy group and a phenolic hydroxyl group.
[11]
The resin having an epoxy group and a phenolic hydroxyl group is a reaction product of a compound having at least two epoxy groups in one molecule and a hydroxybenzoic acid compound, and has the formula (6)

(In the formula (6), b is an integer of 1 to 5, and * represents a bonding portion of a compound having at least two epoxy groups in one molecule with a residue other than the epoxy group involved in the reaction. .)
The photosensitive resin composition according to [10], which is a compound having the structure of
[12]
The photosensitive resin composition according to [11], wherein the compound having at least two epoxy groups in one molecule is a novolac epoxy resin.
[13]
The photosensitive resin composition according to any one of [1] to [12], containing 10 parts by mass to 150 parts by mass of the black colorant (D) based on a total of 100 parts by mass of the resin components.
[14]
The photosensitive resin composition according to any one of [1] to [13], wherein the cured film of the photosensitive resin composition has an optical density (OD value) of 0.5 or more per 1 μm of film thickness.
[15]
[1] An organic EL element partition comprising a cured product of the photosensitive resin composition according to any one of [1] to [14].
[16]
An organic EL element insulating film comprising a cured product of the photosensitive resin composition according to any one of [1] to [14].
[17]
An organic EL device comprising a cured product of the photosensitive resin composition according to any one of [1] to [14].

According to the present invention, there is provided a highly sensitive photosensitive resin composition containing a black colorant, capable of forming a stepped pattern in halftone exposure and maintaining the stepped shape even after thermal curing. be able to.

The present invention will be described in detail below.

In the present disclosure, "alkali soluble" and "alkali aqueous solution soluble" mean that the photosensitive resin composition or its components, or the coating or cured coating of the photosensitive resin composition is a 2.38% by mass tetramethylammonium hydroxide aqueous solution. means that it is soluble in The “alkali-soluble functional group” means a group that imparts such alkali solubility to the photosensitive resin composition or its components, or the coating or cured coating of the photosensitive resin composition. Alkali-soluble functional groups include, for example, phenolic hydroxyl groups, carboxyl groups, sulfo groups, phosphoric acid groups, acid anhydride groups, and mercapto groups.

In the present disclosure, "acid-decomposable group" means a group that is decomposed (deprotected) by heating in the presence of an acid, if necessary, to generate an alkali-soluble functional group.

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

In the present disclosure, "structural unit" means an atomic group that constitutes part of the basic structure of a polymer, and this atomic group may have pendant atoms or pendant atomic groups. For example, in the case of a radical (co)polymer, it means a unit derived from a radically polymerizable compound used as a monomer, and in the case of a phenol novolac resin, one molecule of phenol (C ₆ H ₅ OH) and one means the following units formed from the condensation reaction of molecular formaldehyde (HCHO). Structural units with pendant groups (side groups) include structural units with pendant groups used to form cross-linking sites or groups derived from them, and structural units with free pendant groups that are not involved in the formation of cross-linking sites. are considered to be different from each other. Regarding a polymer having a branched molecular chain (branched chain), the structural unit containing the branch point (branching unit) and the structural unit contained in the linear molecular chain are considered different from each other.

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

In the present disclosure, the number average molecular weight (Mn) and weight average molecular weight (Mw) of resins, polymers, or copolymers are measured at 40° C. by gel permeation chromatography (GPC, gel permeation chromatography) using tetrahydrofuran as a mobile phase. Means the standard polystyrene conversion value measured in

によって算出される値を意味する。式中、単量体ｉ（ｉ＝１～ｎ）の共重合比（モル基準）の合計は１である。 In the present disclosure, the hydroxyl equivalent of a resin, polymer, or copolymer is a theoretical value calculated from the molecular weight and compositional ratio of structural units that constitute the resin, polymer, or copolymer. Specifically, when the resin is a (co)polymer of n kinds of monomers i (where i is a natural number from 1 to n), the hydroxyl equivalent is calculated by the following formula:

means a value calculated by In the formula, the total copolymerization ratio (molar basis) of monomer i (i=1 to n) is 1.

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

In the present disclosure, the “resin component” means a resin (A1) having a plurality of phenolic hydroxyl groups, at least a portion of which is protected with an acid-decomposable group, a resin having an epoxy group (A2 ), and other resins (A3) described later.

In the present disclosure, the term "solid content" includes a resin component, a quinonediazide adduct to a phenolic compound (B), a dissolution accelerator (C), a black colorant (D) and an optional component (E), and a solvent (F) means the total mass of the components excluding

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

<Resin (A1) having a plurality of phenolic hydroxyl groups, at least a portion of which is protected with an acid-decomposable group>
In a resin (A1) having a plurality of phenolic hydroxyl groups and at least a portion of the plurality of phenolic hydroxyl groups being protected with an acid-decomposable group (hereinafter also referred to as "protected resin (A1)"), the phenolic A hydroxyl group is an alkali-soluble functional group, and a part of it is protected with an acid-decomposable group, so that the alkali-solubility of the protective resin (A1) before exposure is suppressed. The quinonediazide adduct (B), which will be described later, forms an alkali-soluble carboxylic acid compound when irradiated with radiation such as visible light, ultraviolet light, γ-rays, and electron beams. The produced carboxylic acid compound accelerates the decomposition of the acid-decomposable group of the protective resin (A1), regenerates the phenolic hydroxyl group, and increases the alkali solubility of the protective resin (A1). As a result, the change in alkali solubility of the protective resin (A1) before and after exposure (before and after decomposition of the acid-decomposable group) is increased, and the pattern resolution can be further enhanced.

The protective resin (A1) may have alkali-soluble functional groups other than phenolic hydroxyl groups, and these alkali-soluble functional groups may be protected with acid-decomposable groups in the same manner as the phenolic hydroxyl groups. Alkali-soluble functional groups other than phenolic hydroxyl groups include, for example, a carboxy group, a sulfo group, a phosphoric acid group, an acid anhydride group, and a mercapto group.

Protective resin (A1) can be used individually or in combination of 2 or more types. For example, the protective resin (A1) may be a combination of two or more resins differing in polymer or copolymer structural units, acid-decomposable groups, phenolic hydroxyl group protection ratios, or combinations thereof.

(Protection of phenolic hydroxyl group by acid-decomposable group)
The protective resin (A1) can be obtained by protecting some of the phenolic hydroxyl groups of the base resin (a) having a plurality of phenolic hydroxyl groups with acid-decomposable groups. The protective resin (A1) having a phenolic hydroxyl group protected with an acid-decomposable group has a partial structure of Ar—O—R ⁵ , Ar represents an aromatic ring derived from phenol, and R ⁵ is an acid-decomposable group. represents

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

The acid-decomposable group is preferably a group represented by formula (3), since a highly sensitive photosensitive resin composition can be obtained even with a low exposure dose. R ⁶ and R ⁷ are each independently a hydrogen atom, a linear alkyl group having 1 to 4 carbon atoms, or a branched alkyl group having 3 to 4 carbon atoms, and R ⁸ is fluorine, chlorine, bromine and A linear alkyl group having 1 to 12 carbon atoms, a branched alkyl group having 3 to 12 carbon atoms, or a cyclic alkyl group having 3 to 12 carbon atoms, which may be substituted with a halogen atom selected from the group consisting of iodine. more preferably a group. Examples of such acid-decomposable groups include 1-alkoxyalkyl groups. 1-alkoxyalkyl groups include, for example, methoxymethyl group, 1-methoxyethyl group, 1-ethoxyethyl group, 1-n-propoxyethyl group, 1-n-butoxyethyl group, 1-isobutoxyethyl group, 1 -(2-chloroethoxy)ethyl group, 1-(2-ethylhexyloxy)ethyl group, 1-cyclohexyloxyethyl group, and 1-(2-cyclohexylethoxy)ethyl group; - n-propoxyethyl groups are preferred. As the acid-decomposable group, a group represented by formula (3) in which one of R ⁶ or R ⁷ and R ⁸ are bonded to form a ring structure having 3 to 10 ring members is also preferably used. can do. At this time, ^R6 or ^R7 that does not participate in the formation of the ring structure is preferably a hydrogen atom. Examples of such acid-decomposable groups include a 2-tetrahydrofuranyl group and a 2-tetrahydropyranyl group, with the 2-tetrahydrofuranyl group being preferred.

A protective reaction of a phenolic hydroxyl group can be carried out under known conditions using a general protective agent. For example, the protective resin (A1) is obtained by reacting the base resin (a) and the protective agent in no solvent or in a solvent such as toluene or hexane at a reaction temperature of -20 to 50°C in the presence of an acid or base. Obtainable.

As a protecting agent, a known protecting agent capable of protecting a phenolic hydroxyl group can be used. Examples of protective agents that can be used include isobutene when the acid-decomposable group is a tert-butyl group and di-tert-butyl dicarbonate when the acid-decomposable group is a tert-butoxycarbonyl group. When the acid-decomposable group is a silyl group such as trimethylsilyl group and triethylsilyl group, silicon-containing chlorides such as trimethylsilyl chloride and triethylsilyl chloride, or silicon-containing triflate compounds such as trimethylsilyl triflate and triethylsilyl triflate can be used. . Chloromethyl methyl ether when the acid-decomposable group is a methoxymethyl group, ethyl vinyl ether when it is a 1-ethoxyethyl group, n-propyl vinyl ether when it is a 1-n-propoxyethyl group, and 2-tetrahydrofuranyl group when it is a 2-tetrahydrofuranyl group. In the case of 2,3-dihydrofuran and 2-tetrahydropyranyl groups, 3,4-dihydro-2H-pyran and the like can be used.

Examples of acids include inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid and perchloric acid, and organic acids such as methanesulfonic acid, trifluoromethanesulfonic acid, p-toluenesulfonic acid and benzenesulfonic acid. Salts of organic acids, such as the pyridinium salt of p-toluenesulfonic acid, can also be used as acid sources. Examples of the base include inorganic hydroxides such as sodium hydroxide and potassium hydroxide; inorganic carbonates such as sodium carbonate, sodium hydrogen carbonate, potassium carbonate and cesium carbonate; metal hydrides such as sodium hydride; Amine compounds such as N,N-dimethyl-4-aminopyridine, imidazole, triethylamine and diisopropylethylamine are included.

In another embodiment, after protecting the phenolic hydroxyl group of the polymerizable monomer having a phenolic hydroxyl group with an acid-decomposable group, the polymerizable monomer having a phenolic hydroxyl group protected with an acid-decomposable group and the necessary The protective resin (A1) can also be obtained by polymerizing or copolymerizing other polymerizable monomers depending on the conditions. The phenolic hydroxyl group of the polymerizable monomer having a phenolic hydroxyl group can be protected by the same method as the protection of the phenolic hydroxyl group of the base resin (a).

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

The base resin (a) of the protective resin (A1) preferably has a phenolic hydroxyl group on the benzene ring pendant to the polymer main chain. In the base resin (a) of the protective resin (A1) having this structure, a benzene ring having a phenolic hydroxyl group constitutes the polymer main chain, and compared with a novolak resin having an equivalent hydroxyl value, Alkali compounds easily approach phenolic hydroxyl groups and have high alkali solubility.

(Aqueous alkali-soluble copolymer (a1) of a polymerizable monomer having a phenolic hydroxyl group and another polymerizable monomer)
In one embodiment, the base resin (a) of the protective resin (A1) is an alkaline aqueous solution-soluble copolymer (a1) of a polymerizable monomer having a phenolic hydroxyl group and another polymerizable monomer (this disclosure (also simply referred to as "aqueous alkaline solution-soluble copolymer (a1)"), and the aqueous alkaline solution-soluble copolymer (a1) has a plurality of phenolic hydroxyl groups. In this embodiment, the protective resin (A1) is obtained by protecting at least part of the plurality of phenolic hydroxyl groups of the aqueous alkaline solution-soluble copolymer (a1) with an acid-decomposable group. The aqueous alkaline solution-soluble copolymer (a1) may further have an alkali-soluble functional group other than the phenolic hydroxyl group, such as a carboxy group, a sulfo group, a phosphoric acid group, an acid anhydride group, or a mercapto group. Examples of the polymerizable functional group possessed by the polymerizable monomer include radically polymerizable functional groups such as CH ₂ ═CH—, CH ₂ ═C(CH ₃ )—, CH ₂ ═CHCO—, CH ₂ =C(CH ₃ )CO-, -OC-CH=CH-CO- and the like.

The alkaline aqueous solution-soluble copolymer (a1) can be produced, for example, by radically polymerizing a polymerizable monomer having a phenolic hydroxyl group and other polymerizable monomers. After synthesizing a copolymer by radical polymerization, a derivative obtained by adding a phenolic hydroxyl group to the copolymer may be used.

Polymerizable monomers having a phenolic hydroxyl group include, for example, 4-hydroxystyrene, 4-hydroxyphenyl (meth)acrylate, 3,5-dimethyl-4-hydroxybenzylacrylamide, 4-hydroxyphenylacrylamide, 4-hydroxy phenylmaleimide and the like.

Other polymerizable monomers include, for example, styrene derivatives such as styrene, vinyl toluene, α-methylstyrene, p-methylstyrene and p-ethylstyrene; acrylamide; acrylonitrile; vinyl alcohols such as vinyl-n-butyl ether. Ether compounds; 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, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, glycidyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentanyl (meth) acrylate, 2,2,2-trifluoroethyl (meth) acrylate, 2,2,3,3-tetrafluoropropyl (meth) ) (meth)acrylic acid esters such as acrylates; N-substituted maleimides such as phenylmaleimide and cyclohexylmaleimide; maleic acid derivatives such as maleic acid, monomethyl maleate, monoethyl maleate, monoisopropyl maleate, and maleic anhydride; (Meth)acrylic acid derivatives such as meth)acrylic acid, α-bromo(meth)acrylic acid, α-chloro(meth)acrylic acid, β-furyl (meth)acrylic acid, β-styryl (meth)acrylic acid; unsaturated carboxylic acid compounds such as acid, cinnamic acid, α-cyanocinnamic acid, itaconic acid, crotonic acid, propiolic acid, 3-maleimidopropionic acid, 4-maleimidobutyric acid, 6-maleimidohexanoic acid; (meth)allylsulfone acid, 2-(meth)acrylamido-2-methylpropanesulfonic acid, polymerizable monomers having a sulfo group such as styrenesulfonic acid; and polymerizable monomers having an acid anhydride group such as itaconic anhydride and citraconic anhydride.

From the viewpoint of heat resistance and the like, the copolymer (a1) soluble in an alkaline aqueous solution has one or more types of rings such as an alicyclic structure, an aromatic structure, a polycyclic structure, an inorganic cyclic structure, and a heterocyclic structure. It is preferred to have the formula structure.

The polymerizable monomer having a phenolic hydroxyl group preferably has one or more cyclic structures. The polymerizable monomer having a phenolic hydroxyl group is a (meth)acrylic compound having CH ₂ =CHCO- or CH ₂ =C(CH ₃ )CO- as a radically polymerizable functional group, and -OC-CH=CH It is preferably at least one selected from the group consisting of maleimide compounds having —CO—.

（式（１）において、Ｒ^１は水素原子又は炭素原子数１～５のアルキル基であり、ａは１～５の整数である。）で表される構造単位を形成するものがより好ましい。Ｒ^１は水素原子又はメチル基であることが好ましい。ａは１～３の整数であることが好ましく、１であることがより好ましい。そのようなフェノール性水酸基を有する重合性単量体として、４－ヒドロキシフェニルメタクリレートが特に好ましい。 As a polymerizable monomer having a phenolic hydroxyl group, the formula (1) after polymerization

(In Formula (1), R ¹ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and a is an integer of 1 to 5.) is more preferable. R ¹ is preferably a hydrogen atom or a methyl group. a is preferably an integer of 1 to 3, more preferably 1; 4-Hydroxyphenyl methacrylate is particularly preferred as such a polymerizable monomer having a phenolic hydroxyl group.

（式（２）において、Ｒ^２及びＲ^３は、それぞれ独立して水素原子、炭素原子数１～３のアルキル基、完全若しくは部分的にフッ素化された炭素原子数１～３のフルオロアルキル基、又はハロゲン原子であり、Ｒ^４は、水素原子、炭素原子数１～６の直鎖アルキル基、炭素原子数３～１２の環状アルキル基、フェニル基、又はヒドロキシ基、炭素原子数１～６のアルキル基及び炭素原子数１～６のアルコキシ基からなる群より選ばれる少なくとも１種で置換されたフェニル基である。）で表される構造単位を形成するものが好ましい。Ｒ^２及びＲ^３は、それぞれ独立して水素原子又は炭素原子数１～３のアルキル基であることが好ましく、水素原子であることがより好ましい。Ｒ^４は、炭素原子数３～１２の環状アルキル基、フェニル基、又はヒドロキシ基、炭素原子数１～６のアルキル基及び炭素原子数１～６のアルコキシ基からなる群より選ばれる少なくとも１種で置換されたフェニル基であることが好ましく、炭素原子数３～１２の環状アルキル基、又はフェニル基であることがより好ましい。そのようなその他の重合性単量体として、フェニルマレイミド及びＮ－シクロヘキシルマレイミドが特に好ましい。 As other polymerizable monomers, formula (2) after polymerization

(In Formula (2), R ² and R ³ are each independently a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or a fully or partially fluorinated fluoroalkyl group having 1 to 3 carbon atoms. , or a halogen atom, and R ⁴ is a hydrogen atom, a linear alkyl group having 1 to 6 carbon atoms, a cyclic alkyl group having 3 to 12 carbon atoms, a phenyl group, or a hydroxy group, or a 1 to 6 carbon atom is a phenyl group substituted with at least one selected from the group consisting of an alkyl group and an alkoxy group having 1 to 6 carbon atoms.). R ² and R ³ are each independently preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, more preferably a hydrogen atom. R ⁴ is at least one selected from the group consisting of a cyclic alkyl group having 3 to 12 carbon atoms, a phenyl group, or a hydroxy group, an alkyl group having 1 to 6 carbon atoms, and an alkoxy group having 1 to 6 carbon atoms. A phenyl group substituted with is preferable, and a cyclic alkyl group having 3 to 12 carbon atoms or a phenyl group is more preferable. Phenylmaleimide and N-cyclohexylmaleimide are particularly preferred as such other polymerizable monomers.

（式（１）において、Ｒ^１は水素原子又は炭素原子数１～５のアルキル基であり、ａは１～５の整数である。）で表される構造単位を有することが好ましい。 The alkaline aqueous solution-soluble copolymer (a1) has the formula (1)

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

（式（２）において、Ｒ^２及びＲ^３は、それぞれ独立して水素原子、炭素原子数１～３のアルキル基、完全若しくは部分的にフッ素化された炭素原子数１～３のフルオロアルキル基、又はハロゲン原子であり、Ｒ^４は、水素原子、炭素原子数１～６の直鎖アルキル基、炭素原子数３～１２の環状アルキル基、フェニル基、又はヒドロキシ基、炭素原子数１～６のアルキル基及び炭素原子数１～６のアルコキシ基からなる群より選ばれる少なくとも１種で置換されたフェニル基である。）で表される構造単位を有することが好ましい。 The alkaline aqueous solution-soluble copolymer (a1) has the formula (2)

(In Formula (2), R ² and R ³ are each independently a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or a fully or partially fluorinated fluoroalkyl group having 1 to 3 carbon atoms. , or a halogen atom, and R ⁴ is a hydrogen atom, a linear alkyl group having 1 to 6 carbon atoms, a cyclic alkyl group having 3 to 12 carbon atoms, a phenyl group, or a hydroxy group, or a 1 to 6 carbon atom is a phenyl group substituted with at least one selected from the group consisting of an alkyl group and an alkoxy group having 1 to 6 carbon atoms.).

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

It is particularly preferable to use 4-hydroxyphenyl methacrylate as the polymerizable monomer having a phenolic hydroxyl group and phenylmaleimide or N-cyclohexylmaleimide as the other polymerizable monomer. By using a resin obtained by radically polymerizing these polymerizable monomers, it is possible to improve shape retention and developability and reduce outgassing.

Polymerization initiators for producing the base resin (a) or the copolymer (a1) soluble in an alkaline aqueous solution by radical polymerization include, but are not limited to, 2,2′-azobisisobutyronitrile, 2,2 '-azobis (2-methylbutyronitrile), dimethyl 2,2'-azobis (2-methylpropionate), 4,4'-azobis (4-cyanovaleric acid), 2,2'-azobis (2 ,4-dimethylvaleronitrile) (AVN) and other azo initiators; dicumyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, tert-butylcumyl peroxide, di - A peroxide polymerization initiator having a 10-hour half-life temperature of 100 to 170°C, such as tert-butyl peroxide, 1,1,3,3-tetramethylbutyl hydroperoxide, or cumene hydroperoxide; or benzoyl peroxide , lauroyl peroxide, 1,1′-di(tert-butylperoxy)cyclohexane, tert-butylperoxypivalate, and other peroxide polymerization initiators can be used. The amount of the polymerization initiator used is generally 0.01 parts by mass or more, 0.05 parts by mass or more, or 0.5 parts by mass or more and 40 parts by mass or less, or 20 parts by mass or more with respect to a total of 100 parts by mass of the polymerizable monomers. It is preferably 15 parts by mass or less or 15 parts by mass or less.

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

The weight average molecular weight (Mw) of the base resin (a) or the aqueous alkaline solution-soluble copolymer (a1) can be 3000 to 80000, preferably 4000 to 70000, more preferably 5000 to 60000. preferable. The number average molecular weight (Mn) can be from 1,000 to 30,000, preferably from 1,500 to 25,000, more preferably from 2,000 to 20,000. The polydispersity (Mw/Mn) can be from 1.0 to 3.5, preferably from 1.1 to 3.0, more preferably from 1.2 to 2.8. By setting the weight-average molecular weight, number-average molecular weight and polydispersity within the above ranges, a photosensitive resin composition having excellent alkali solubility and developability can be obtained.

In one embodiment, 10 mol% to 95 mol%, preferably 20 mol% to 80 mol%, more preferably 25 mol% to 70 mol% of the phenolic hydroxyl groups of the protective resin (A1) are protected with acid-decomposable groups. It is In the protective resin (A1), by setting the ratio of the phenolic hydroxyl group protected by the acid-decomposable group to 10 mol% or more, the dissolution of the exposed area is promoted and the solubility of the unexposed area and the exposed area is different. can be applied, high sensitivity can be achieved, and the stability and durability of the coating after thermosetting can be ensured. By keeping the ratio of phenolic hydroxyl groups protected by acid-decomposable groups to 95 mol% or less, the amount of unreacted acid-decomposable groups is reduced, the solubility of exposed areas is increased, and high sensitivity is achieved. can do. The proportion of phenolic hydroxyl groups protected with acid-decomposable groups is calculated from ¹ H NMR spectrum integral values obtained by a nuclear magnetic resonance spectrometer (NMR). In the present disclosure, when the protective resin (A1) is a combination of two or more resins with different protection rates, the protective ratio of the phenolic hydroxyl group of the protective resin (A1) is such that the two or more resins are protected as a whole. It is a numerical value when regarded as resin (A1).

In one embodiment, 5 mol% to 65 mol%, preferably 10 mol% to 55 mol%, more preferably 10 mol% to 55 mol% of the phenolic hydroxyl groups in the protective resin (A1), based on the total alkali-soluble functional groups contained in the resin component. is protected with an acid-labile group at 15 mol % to 50 mol %. By setting the protection rate of the phenolic hydroxyl group of the protective resin (A1) to 5 mol% or more based on the total alkali-soluble functional groups contained in the resin component, the dissolution of the exposed area is promoted and the unexposed area and the exposed area are separated. Since it is possible to make a difference in the solubility of the parts, high sensitivity can be achieved, and the stability and durability of the coating after thermosetting can be ensured. By setting the protection rate of the phenolic hydroxyl group of the protective resin (A1) to 65 mol% or less based on the total alkali-soluble functional groups contained in the resin component, the solubility of the exposed area can be ensured. Alkali-soluble functional groups that serve as criteria for the above protection rate include, in addition to phenolic hydroxyl groups, arbitrary carboxy groups, sulfo groups, phosphoric acid groups, acid anhydride groups, and mercapto groups.

In one embodiment, the protective resin (A1) is a base resin (a) comprising a copolymer (a1) soluble in an alkaline aqueous solution having a plurality of phenolic hydroxyl groups, and at least a portion of the plurality of phenolic hydroxyl groups are acid-decomposable. It is a group-protected resin.

（式（４）において、Ｒ^９は水素原子又は炭素原子数１～５のアルキル基であり、Ｒ^１０は酸分解性基であり、ｒは０～５の整数であり、ｓは０～５の整数であり、但しｒ＋ｓは１～５の整数である。）で表される構造単位を有し、ｓが１以上の整数である式（４）で表される構造単位を少なくとも１つ有することが好ましい。Ｒ^１０の酸分解性基は、上記式（３）で表される基であることが好ましい。 In an embodiment in which the copolymer (a1) soluble in an alkaline aqueous solution is used as the base resin (a), the protective resin (A1) has the formula (4)

(In formula (4), R ⁹ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, R ¹⁰ is an acid-decomposable group, r is an integer of 0 to 5, s is 0 to 5 where r + s is an integer of 1 to 5.) and has at least one structural unit represented by formula (4), wherein s is an integer of 1 or more is preferred. The acid-decomposable group for R ¹⁰ is preferably a group represented by formula (3) above.

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

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

In one embodiment, a structural unit represented by formula (4) and s is an integer of 1 or more, i.e., represented by formula (4) in which at least one phenolic hydroxyl group is protected with an acid-decomposable group The number of structural units is 5% to 95%, preferably 15% to 70%, more preferably 25% to 60% of the total number of structural units in the protective resin (A1). By setting the ratio of the structural unit to 5% or more, the dissolution of the exposed area can be promoted and a difference in solubility between the unexposed area and the exposed area can be made, so that high sensitivity can be realized, and It is possible to ensure the stability and durability of the film after thermosetting. By setting the ratio of the structural unit to 95% or less, the residual amount of unreacted acid-decomposable groups can be reduced, the solubility of the exposed area can be improved, and high sensitivity can be achieved.

In one embodiment, the photosensitive resin composition contains 5% by mass to 50% by mass, preferably 7% to 40% by mass, more preferably 10% by mass of the protective resin (A1) based on 100% by mass of solid content. % to 30% by mass. If the content of the protective resin (A1) is 5% by mass or more based on the solid content of 100% by mass, it is possible to promote the dissolution of the exposed area and differentiate the solubility between the unexposed area and the exposed area. Therefore, high sensitivity can be achieved, and the stability and durability of the coating after thermosetting can be ensured. If the content of the protective resin (A1) is 50% by mass or less based on 100% by mass of the solid content, the residual amount of unreacted acid-decomposable groups is reduced, the solubility of the exposed area is increased, and the sensitivity is increased. can be realized.

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

<Resin (A2) having an epoxy group>
The epoxy group-containing resin (A2) is not particularly limited. Examples of resins having an epoxy group include novolac epoxy resins such as phenol novolac epoxy resins and cresol novolac epoxy resins, bisphenol epoxy resins, biphenol epoxy resins, naphthalene skeleton-containing epoxy resins, alicyclic epoxy resins, and heterocyclic epoxy resins.

In the present disclosure, when the epoxy group-containing resin (A2) also corresponds to the protective resin (A1), it is treated as the epoxy group-containing resin (A2). That is, the protective resin (A1) does not include resins (A2) having an epoxy group.

(Resin having an epoxy group and a phenolic hydroxyl group)
In one embodiment, the resin (A2) having an epoxy group is a resin having an epoxy group and a phenolic hydroxyl group. A resin having an epoxy group and a phenolic hydroxyl group is an alkaline aqueous solution-soluble resin. A resin having an epoxy group and a phenolic hydroxyl group may have an alkali-soluble functional group other than the phenolic hydroxyl group. Phenolic hydroxyl groups and other alkali-soluble functional groups may be protected with the acid-decomposable groups described above for the protective resin (A1). A resin having an epoxy group and a phenolic hydroxyl group is, for example, a compound having at least two epoxy groups in one molecule (hereinafter sometimes referred to as an "epoxy compound"), a part of the epoxy group and a hydroxyl It can be obtained by reacting the carboxy group of a benzoic acid compound. Epoxy groups of resins containing epoxy groups and phenolic hydroxyl groups form crosslinks by reacting with phenolic hydroxyl groups during heat treatment (post-baking) after development, thereby improving the chemical resistance and heat resistance of the film. be able to. Since the phenolic hydroxyl group contributes to the solubility in an alkaline aqueous solution during development, a resin having an epoxy group and a phenolic hydroxyl group also functions as a dissolution accelerator for other resins when exposed at a low exposure dose. The photosensitive resin composition can be made highly sensitive.

Reaction formula 1 below shows an example of the reaction in which one of the epoxy groups of the epoxy compound reacts with the carboxyl group of the hydroxybenzoic acid compound to form a compound having a phenolic hydroxyl group.

Compounds having at least two epoxy groups in one molecule include, for example, novolac epoxy resins such as phenol novolak epoxy resins and cresol novolak epoxy resins, bisphenol epoxy resins, biphenol epoxy resins, and naphthalene skeleton-containing epoxy resins. Mention may be made of resins, cycloaliphatic epoxy resins, and heterocyclic epoxy resins. These epoxy compounds may have two or more epoxy groups in one molecule, and may be used alone or in combination of two or more. Since these compounds are thermosetting compounds, it is common knowledge for those skilled in the art that their structures cannot be uniquely described due to differences in the presence or absence of epoxy groups, types of functional groups, degrees of polymerization, and the like.

An example of the structure of the novolak type epoxy resin is shown in Formula (5). In formula (5), R ¹¹ is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 2 carbon atoms or a hydroxyl group, and m is an integer of 1-50.

Examples of phenolic novolak-type epoxy resins include EPICLON (registered trademark) N-770 (DIC Corporation) and jER (registered trademark)-152 (Mitsubishi Chemical Corporation). Cresol novolac type epoxy resins include, for example, EPICLON (registered trademark) N-695 (DIC Corporation) and EOCN (registered trademark)-102S (Nippon Kayaku Co., Ltd.). Bisphenol-type epoxy resins include, for example, jER (registered trademark) 828, jER (registered trademark) 1001 (Mitsubishi Chemical Corporation), YD-128 (trade name, Nippon Steel Chemical & Materials Co., Ltd.), and other bisphenol A-type epoxies. resins, and bisphenol F-type epoxy resins such as jER (registered trademark) 806 (Mitsubishi Chemical Co., Ltd.) and YDF-170 (trade name, Nippon Steel Chemical & Materials Co., Ltd.). Biphenol-type epoxy resins include, for example, jER (registered trademark) YX-4000 and jER (registered trademark) YL-6121H (Mitsubishi Chemical Corporation). Examples of naphthalene skeleton-containing epoxy resins include NC-7000 (trade name, Nippon Kayaku Co., Ltd.) and EXA-4750 (trade name, DIC Corporation). Alicyclic epoxy resins include, for example, EHPE (registered trademark)-3150 (Daicel Chemical Industries, Ltd.). Heterocyclic epoxy resins include, for example, TEPIC®, TEPIC-L, TEPIC-H, and TEPIC-S (Nissan Chemical Industries, Ltd.).

The compound having at least two epoxy groups in one molecule is preferably a novolak type epoxy resin, and is at least one selected from the group consisting of phenol novolak type epoxy resins and cresol novolak type epoxy resins. More preferably, it is a cresol novolac type epoxy resin. A photosensitive resin composition containing a novolak-type epoxy resin, particularly a resin having an epoxy group and a phenolic hydroxyl group derived from a cresol novolac-type epoxy resin, has excellent pattern formability, and is easy to control alkali solubility. Less outgassing.

A hydroxybenzoic acid compound is a compound in which at least one of the 2-6 positions of benzoic acid is substituted with a hydroxyl group, such as salicylic acid, 4-hydroxybenzoic acid, 2,3-dihydroxybenzoic acid, and 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-nitro Examples include benzoic acid and 4-hydroxy-3-nitrobenzoic acid, and dihydroxybenzoic acid compounds are preferred from the viewpoint of enhancing alkali developability. A hydroxybenzoic acid compound can be used individually or in combination of 2 or more types.

（式（６）において、ｂは１～５の整数であり、＊は、１分子中に少なくとも２個のエポキシ基を有する化合物の、反応にかかるエポキシ基を除く残基との結合部を表す。）
の構造を有する。 In one embodiment, the resin having an epoxy group and a phenolic hydroxyl group is a reaction product of a compound having at least two epoxy groups in one molecule and a hydroxybenzoic acid compound, represented by formula (6)

(In the formula (6), b is an integer of 1 to 5, and * represents a bonding portion of a compound having at least two epoxy groups in one molecule with a residue other than the epoxy group involved in the reaction. .)
has the structure

In the method of obtaining a resin having an epoxy group and a phenolic hydroxyl group from an epoxy compound and a hydroxybenzoic acid compound, it is possible to use 0.2 to 0.95 equivalents of the hydroxybenzoic acid compound with respect to 1 equivalent of the epoxy group of the epoxy compound. preferably 0.3 to 0.9 equivalents, more preferably 0.4 to 0.8 equivalents. If the amount of the hydroxybenzoic acid compound is 0.2 equivalents or more, sufficient alkali solubility can be obtained, and if the amount is 0.95 equivalents or less, an increase in molecular weight 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 the catalyst used can be 0.1 to 10 parts by mass based on 100 parts by mass of the reaction raw material mixture comprising the epoxy compound and the hydroxybenzoic acid compound. The reaction temperature can be 60-150° C., and the reaction time can be 3-30 hours. Catalysts used in this reaction include, for example, triethylamine, benzyldimethylamine, triethylammonium chloride, benzyltrimethylammonium bromide, benzyltrimethylammonium iodide, triphenylphosphine, chromium octanoate, and zirconium octanoate.

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

In one embodiment, the resin (A2) having an epoxy group has an epoxy equivalent weight of 300 to 7,000, preferably 400 to 6,000, and more preferably 500 to 5,000. If the epoxy equivalent of the resin (A2) having an epoxy group is 300 or more, sufficient alkali solubility can be imparted to the resin having an epoxy group and a phenolic hydroxyl group. If the epoxy equivalent of the resin (A2) having an epoxy group is 7000 or less, the strength and heat resistance of the cured film can be enhanced. Epoxy equivalent is determined by JIS K 7236:2009.

In one embodiment, the hydroxyl equivalent weight of the resin having epoxy groups and phenolic hydroxyl groups is 160-500, preferably 170-400, more preferably 180-300. If the hydroxyl equivalent of the resin having an epoxy group and a phenolic hydroxyl group is 160 or more, the strength and heat resistance of the cured film can be enhanced. If the hydroxyl equivalent of the resin having epoxy groups and phenolic hydroxyl groups is 500 or less, sufficient alkali solubility can be imparted to the resin having epoxy groups and phenolic hydroxyl groups.

In one embodiment, the photosensitive resin composition contains 10% by mass to 50% by mass, preferably 12% by mass to 40% by mass, more preferably 12% by mass to 40% by mass, based on the solid content of 100% by mass, the epoxy group-containing resin (A2). contains 15% by mass to 30% by mass. When the content of the epoxy group-containing resin (A2) is 10% by mass or more based on the solid content of 100% by mass, it is possible to accelerate the dissolution of the exposed area and achieve high sensitivity, and during heat curing. The flow of the coating can be suppressed, and the stability and durability of the coating after thermosetting can be ensured. When the content of the epoxy group-containing resin (A2) is 50% by mass or less based on 100% by mass of the solid content, the solubility of the unexposed areas can be kept low and a high residual film rate can be maintained.

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

<Other resin (A3)>
The photosensitive resin composition may further contain other resins (A3) in addition to the protective resin (A1) and the epoxy group-containing resin (A2). Although the other resin (A3) is not particularly limited, it is preferably a resin having an alkali-soluble functional group. Alkali-soluble functional groups include, for example, phenolic hydroxyl groups, carboxyl groups, sulfo groups, phosphoric acid groups, acid anhydride groups, and mercapto groups. Other resins (A3) having two or more alkali-soluble functional groups may be used.

Other resins (A3) include, for example, homopolymers or copolymers of polymerizable monomers having alkali-soluble functional groups. Other resins (A3) include, for example, acrylic resins, polystyrene resins, polyamide resins, phenol resins, polyimide resins, polyamic acid resins, polybenzoxazole resins, polybenzoxazole resin precursors, silicone resins, cyclic olefin polymers, cardo Resins, derivatives of these resins, and those obtained by bonding alkali-soluble functional groups to these resins can be mentioned. For example, phenol resin derivatives include polyalkenylphenol resins in which alkenyl groups are bonded to benzene rings, and polystyrene resin derivatives include hydroxypolystyrene resin derivatives in which phenolic hydroxyl groups and hydroxyalkyl groups or alkoxy groups are bonded to benzene rings. be done. Other resins (A3) can be used alone or in combination of two or more.

Other resins (A3) may have a radically polymerizable functional group. In one embodiment, the other resin (A3) has a (meth)acryloyloxy group, allyl group or methallyl group as a radically polymerizable functional group.

From the viewpoint of miscibility with the protective resin (A1), the other resin (A3) is preferably the resin described as the base resin (a) of the protective resin (A1). (a1) is more preferable. Preferred aspects of the aqueous alkaline solution-soluble copolymer (a1) are as described for the base resin (a).

In one embodiment, the photosensitive resin composition contains 2% by mass to 40% by mass, preferably 5% to 35% by mass, more preferably 10% by mass of the other resin (A3) based on 100% by mass of solid content. Contains from mass % to 30 mass %. When the content of the other resin (A3) is 2% by mass or more based on the solid content of 100% by mass, it is possible to suppress the flow of the coating during heat curing, and the stability and durability of the coating after heat curing. can ensure the integrity of the When the content of the other resin (A3) is 40% by mass or less based on 100% by mass of the solid content, the dissolution of the exposed area can be promoted and high sensitivity can be achieved.

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

In one embodiment, the total number of moles of hydroxyl groups contained in the resin component of the photosensitive resin composition is preferably 170 to 300 mmol, preferably 180 to 290 mmol, per 100 g of solid content contained in the photosensitive resin composition. is more preferred, and 190 to 280 mmol is even more preferred. When the total number of moles of hydroxyl groups contained in the resin component is 170 mmol or more per 100 g of the solid content contained in the photosensitive resin composition, it is possible to suppress the flow of the coating during heat curing, and the stability of the coating after heat curing. performance and durability can be ensured. Desired alkali solubility can be obtained when the total number of moles of hydroxyl groups contained in the resin component is 300 mmol or less per 100 g of the solid content contained in the photosensitive resin composition.

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

In the present disclosure, the quinonediazide adduct (B) means a compound in which some or all of the phenolic hydroxyl groups of a phenol compound are substituted with groups having a quinonediazide structure.

For example, the quinonediazide adduct (B) having a skeleton of a trivalent phenolic compound represented by the following formula (7) is a group in which at least one of the three phenolic hydroxyl groups of the phenolic compound has a quinonediazide structure, such as It means a compound represented by the following formula (8) substituted with a naphthoquinonediazide sulfonate group shown below. Substitution with a naphthoquinonediazide sulfonate group can be carried out by esterifying (sulfonating) the phenolic hydroxyl group of the phenol compound with a quinonediazide sulfonic acid halide.

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

When the quinonediazide adduct (B) is irradiated with ultraviolet light or the like, it undergoes the reaction shown in Reaction Formula 2 below to form a carboxyl group. The formation of carboxyl groups makes the exposed portion (coating) soluble in an alkaline aqueous solution, resulting in alkaline developability in that portion.

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

The phenol compound preferably has two or more phenolic hydroxyl groups, more preferably three or more phenolic hydroxyl groups. The quinonediazide adduct (B) obtained from a phenolic compound having three or more phenolic hydroxyl groups has a high level of balance between photosensitivity and solubility, and therefore improves the sensitivity of the photosensitive resin composition. can be done.

Suitable phenolic compounds include, for example, those having the following structural formulas (b-1) to (b-6).

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

In formulas (10-1) and (10-2), R ^a to R ^d each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms, X represents a halogen atom or OH.

R ^a to R ^d are each independently preferably a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or an alkoxy group having 1 to 3 carbon atoms, more preferably a hydrogen atom, a methyl group, or a methoxy group. and more preferably a hydrogen atom. X is preferably a chlorine atom. Examples of the compounds represented by formulas (10-1) and (10-2) include 1,2-naphthoquinonediazide-4-sulfonyl chloride and 1,2-naphthoquinonediazide-5-sulfonyl chloride. 1,2-naphthoquinonediazide-5-sulfonyl chloride is preferred.

In one embodiment, the quinonediazide adduct (B) is a group having a quinonediazide structure in which the phenolic hydroxyl group of the phenol compound is represented by formula (11-1) or formula (11-2) (hereinafter simply referred to as "quinonediazide group" Also called.) is replaced by

In formulas (11-1) and (11-2), R ^a to R ^d each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms, * indicates the bonding portion with the oxygen atom of the phenolic hydroxyl group of the phenol compound. R ^a to R ^d are each independently preferably a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or an alkoxy group having 1 to 3 carbon atoms, more preferably a hydrogen atom, a methyl group, or a methoxy group. and more preferably a hydrogen atom.

More specifically, the quinonediazide adduct (B) is preferably at least one represented by the following formulas (B-1) to (B-6).

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

The quinonediazide adduct (B) preferably contains 1,2-naphthoquinonediazide-4-sulfonic acid ester or 1,2-naphthoquinonediazide-5-sulfonic acid ester of a phenol compound, and 1,2-naphthoquinonediazide of a phenol compound. More preferred is quinonediazide-4-sulfonate or 1,2-naphthoquinonediazide-5-sulfonate. The quinonediazide adduct (B) may have both a 1,2-naphthoquinonediazide-4-sulfonate ester bond and a 1,2-naphthoquinonediazide-5-sulfonate ester bond in one molecule. In one embodiment, the quinonediazide adduct (B) is 1,2-naphthoquinonediazide-4-sulfonate. In another embodiment, the quinonediazide adduct (B) is 1,2-naphthoquinonediazide-5-sulfonate.

The degree of substitution in the quinonediazide adduct (B) (percentage of the phenolic hydroxyl group of the phenolic compound substituted with a group having a quinonediazide structure based on all molecules of the quinonediazide adduct (B)) is preferably 20 mol% or more. , more preferably 30 mol % or more, still more preferably 40 mol % or more. By setting the degree of substitution to 20 mol % or more, the difference in solubility between the unexposed area and the exposed area can be increased. The degree of substitution may be 100 mol % or less, 95 mol % or less, or 93 mol % or less.

The photosensitive resin composition preferably contains 10 parts by mass to 50 parts by mass, more preferably 12 parts by mass to 45 parts by mass, still more preferably 15 parts by mass of the quinone diazide adduct (B) based on the total of 100 parts by mass of the resin components. Contains parts by mass to 40 parts by mass. If the content of the quinonediazide adduct (B) is 10 parts by mass or more based on the total of 100 parts by mass of the resin components, high sensitivity can be achieved. If the content of the quinonediazide adduct (B) is 50 parts by mass or less based on the total of 100 parts by mass of the resin components, the alkali developability is good.

Although not bound by any theory, the carboxylic acid compound produced from the quinonediazide adduct (B) accelerates the decomposition of the acid-decomposable group of the protective resin (A1) to regenerate the phenolic hydroxyl group, thereby forming the protective resin. Increases the alkaline solubility of (A1). The quinonediazide adduct (B) interacts (eg, forms hydrogen bonds) with alkali-soluble functional groups contained in the resin, such as phenolic hydroxyl groups, before exposure to light, to render the resin insoluble in an aqueous alkaline solution. On the other hand, the presence of the alkali-soluble carboxylic acid compound in the irradiated portion makes it easier for the resin in that portion to dissolve in the alkaline aqueous solution together with the carboxylic acid compound. Furthermore, the carboxylic acid compound has a relatively larger molecular structure than acids generated from photoacid generators commonly used in chemically amplified resists, such as p-toluenesulfonic acid and 1-propanesulfonic acid, and diffuses in the film. hard to do. As a result of the synergistic action of these, the difference in alkali solubility between the unexposed area and the exposed area can be increased, which is thought to enable the formation of high-sensitivity, high-resolution patterns even at low exposure doses. .

In one embodiment, high resolution patterns can be formed without the post-exposure bake (PEB) required for typical chemically amplified resists. The quinonediazide adduct (B) has a relatively high quantum yield, and a carboxylic acid compound is efficiently produced in the exposed area. If an acid-decomposable group that can be decomposed by a carboxylic acid compound exists in the surroundings, the generated carboxylic acid compound causes decomposition of the acid-decomposable group even at room temperature to regenerate the phenolic hydroxyl group. It is possible to increase the difference in alkali solubility between the parts. By omitting PEB, it is possible to suppress deterioration in pattern formability due to excessive diffusion of acid generated from the photo-acid generator into unexposed areas in a high-temperature environment during PEB. Further, when the resin (A2) having an epoxy group contains a resin having an epoxy group and a phenolic hydroxyl group, if PEB is omitted, the ring-opening polymerization of the epoxy group of the resin having an epoxy group and a phenolic hydroxyl group does not proceed, so development is difficult. In some cases, the alkali solubility of resins having epoxy groups and phenolic hydroxyl groups can be maintained.

The total number of moles of quinonediazide groups contained in the quinonediazide adduct (B) is preferably 20 mmol to 60 mmol, more preferably 22 mmol to 55 mmol, more preferably 25 mmol to 60 mmol per 100 g of the solid content contained in the photosensitive resin composition. More preferably 50 mmol. When the total number of moles of the quinonediazide groups is 20 mmol or more, high sensitivity can be obtained, and flow of the film during thermosetting can be suppressed. When the total number of moles of quinonediazide groups is 60 mmol or less, alkali developability can be enhanced.

The quinonediazide group equivalent of the quinonediazide adduct (B) is preferably 500 or less. When the quinonediazide group equivalent is 500 or less, high sensitivity can be obtained, and flow of the film during thermosetting can be suppressed. When a plurality of quinonediazide adducts (B) are used in combination, the quinonediazide group equivalent of each quinonediazide adduct (B) is more preferably 500 or less.

<Solubilizer (C)>
The photosensitive resin composition contains a dissolution accelerator (C) for improving the solubility of the alkali-soluble portion in the developer during development.

Examples of the dissolution accelerator (C) include organic low-molecular-weight compounds selected from the group consisting of compounds having a carboxyl group and compounds having a phenolic hydroxyl group. The dissolution accelerator (C) can be used alone or in combination of two or more.

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

Examples of such organic low-molecular-weight compounds include aliphatic monocarboxylic acids such as formic acid, acetic acid, propionic acid, butyric acid, valeric acid, pivalic acid, caproic acid, diethylacetic acid, enanthic acid, and caprylic acid; 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, citraconic acid, etc. Aliphatic dicarboxylic acids; aliphatic tricarboxylic acids such as tricarballylic acid, aconitic acid and camphoronic acid; aromatic monocarboxylic acids such as benzoic acid, toluic acid, cumic acid, hemimelitic acid and mesitylene acid; phthalic acid, isophthalic acid, Aromatic polycarboxylic acids such as terephthalic acid, trimellitic acid, trimesic acid, merophanic acid and pyromellitic acid; aromatic hydroxycarboxylic acids such as dihydroxybenzoic acid, trihydroxybenzoic acid and gallic acid; phenylacetic acid, hydroatropic acid, hydrosilicic acid Other carboxylic acids such as mic acid, mandelic acid, phenylsuccinic acid, atropic acid, cinnamic acid, methyl cinnamate, benzyl cinnamate, cinnamylideneacetic acid, coumaric acid, umberic acid; catechol, resorcinol, hydroquinone, 1, Aromatic polyols such as 2,4-benzenetriol, pyrogallol, phloroglucinol, bisphenol and the like are included.

The total equivalent weight of carboxy groups and phenolic hydroxyl groups ((molecular weight)/(number of carboxy groups and phenolic hydroxyl groups per molecule)) of the dissolution accelerator (C) is preferably 60 or less, and 50 or less. is more preferable. When the equivalent weight is 60 or less, it is possible to suppress the flow of the film during thermosetting. When multiple dissolution accelerators (C) are used in combination, the total equivalent weight of carboxy groups and phenolic hydroxyl groups in each solubility enhancer (C) is more preferably 60 or less.

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

<Total number of moles of carboxy groups and phenolic hydroxyl groups contained in quinonediazide adduct (B) and dissolution accelerator (C)>
In the photosensitive resin composition, the total number of moles of the carboxy groups and phenolic hydroxyl groups contained in the quinonediazide adduct (B) and the dissolution accelerator (C) is 150 mmol or less per 100 g of solid content contained in the photosensitive resin composition. be.

Although not bound by any theory, when the total number of moles of the carboxy group and the phenolic hydroxyl group is 150 mmol or less, the photosensitive resin composition is capable of forming a stepped pattern in halftone exposure for the following reasons. presumed to be obtained.

A step pattern formed by forming a film containing a photosensitive resin composition on a substrate, exposing it to halftone exposure, and developing with an alkali is exposed to a heat treatment for curing the film. By this heat treatment, a ring-opening polymerization reaction of the epoxy group of the epoxy group-containing resin (A2), or the epoxy group of the epoxy group-containing resin (A2) and the phenolic hydroxyl group regenerated or originally present in the protective resin (A1) , phenolic hydroxyl groups optionally possessed by the resin (A2) having an epoxy group, phenolic hydroxyl groups optionally possessed by other resins (A3), and epoxy-reactive functional groups such as carboxyl groups proceed. During the heat treatment process, the film flows and deforms so that the surface area of the film becomes smaller due to surface tension, so the shape of the step pattern is damaged (edges of the step pattern become rounded) or the step pattern disappears. tend to Specifically, when the temperature of the film reaches the glass transition temperature or higher of the resin contained in the film during the temperature rising process, the entanglement of the polymer chains of the resin is dissolved, and the film becomes easy to flow. On the other hand, in the process of raising the temperature, the progress of the ring-opening polymerization reaction or cross-linking reaction causes the resin to polymerize or cross-link, thereby reducing the fluidity of the film. The disentanglement of the polymer chains and the polymerization or cross-linking of the resin compete. That is, when disentanglement of polymer chains is dominant, the film flows and the shape of the step pattern is damaged, and when polymerization or cross-linking of the resin is dominant, the flow of the resin is suppressed. The shape of the step pattern is retained even in the cured film.

When the phenol compound of the quinonediazide adduct (B) to the phenol compound has a plurality of phenolic hydroxyl groups, or when the dissolution accelerator (C) has a plurality of carboxy groups or phenolic hydroxyl groups, the epoxy group is When the epoxy group of the resin (A2) having a One epoxy group is consumed to form one cross-linking point. In contrast, when resins are crosslinked, one crosslink point is formed for the consumption of one epoxy group. On the other hand, when the phenol compound of the quinonediazide adduct (B) to the phenol compound has one phenolic hydroxyl group, or the dissolution accelerator (C) has either one carboxy group or one phenolic hydroxyl group, , the epoxy group of the epoxy group-containing resin (A2) reacts with the carboxy group that may be contained in the quinonediazide adduct (B) after exposure, or the carboxy group or phenolic hydroxyl group of the dissolution accelerator (C). Then, the epoxy groups are only consumed, and do not contribute to the cross-linking of the resins.

Therefore, the carboxy group or phenolic hydroxyl group of the dissolution accelerator (C), or the carboxy group or phenolic hydroxyl group that may be contained in the quinonediazide adduct (B) after exposure is likely to participate in the reaction with the epoxy group. The composition becomes less crosslinkable. In other words, the higher the total number of moles of the carboxy groups and phenolic hydroxyl groups contained in the quinonediazide adduct (B) and the dissolution accelerator (C), both of which generally have lower molecular weights than the resin, the more the entanglement of the polymer chains increases. becomes dominant, and the shape of the step pattern is likely to be damaged. Therefore, the total number of moles of the carboxy groups and phenolic hydroxyl groups contained in the quinonediazide adduct (B) and the dissolution accelerator (C) is set to 150 mmol or less per 100 g of the solid content contained in the photosensitive resin composition, whereby the heat treatment is performed. It is thought that high-precision pattern formation, for example, stepped pattern formation, can be achieved by suppressing the flow of the coating film.

The total number of moles of the carboxy groups and phenolic hydroxyl groups contained in the quinonediazide adduct (B) and the dissolution accelerator (C) is preferably 145 mmol or less, preferably 140 mmol or less, per 100 g of the solid content contained in the photosensitive resin composition. is more preferable. Since both carboxy groups and phenolic hydroxyl groups can enhance alkali developability, the total number of moles of the carboxyl groups and phenolic hydroxyl groups contained in the quinonediazide adduct (B) and the dissolution accelerator (C) is 90 mmol. It is preferably 100 mmol or more, more preferably 100 mmol or more.

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

In one embodiment the black colorant (D) comprises a black dye. Examples of black dyes include dyes defined by the color index (C.I.) of Solvent Black 27-47. The black dye is preferably Solvent Black 27, 29 or 34 C.I. I. It is defined by Solvent Black 27-47 C.I. I. When at least one of the dyes defined in (1) is used as the black dye, the light-shielding property of the cured photosensitive resin composition film can be maintained. A photosensitive resin composition containing a black dye has less residual black coloring agent (D) during development than a photosensitive resin composition containing a black pigment, and can form a high-definition pattern on a film. .

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

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

<Optional component (E)>
The photosensitive resin composition can contain, as an optional component (E), a thermosetting agent, a surfactant, a coloring agent other than the black coloring agent (D), and the like. For purposes of this disclosure, optional component (E) is defined as none of (A1), (A2), (A3), (B), (C) and (D).

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

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

The photosensitive resin composition may contain a surfactant, for example, to improve coatability, to improve the smoothness of the coating, or to improve the developability of the coating. Examples of surfactants include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether and polyoxyethylene oleyl ether; Ethylene aryl ether; Nonionic surfactants such as polyoxyethylene dialkyl esters such as polyoxyethylene dilaurate and polyoxyethylene distearate; Megafac (registered trademark) F-251, F-281, F-430, F- 444, R-40, F-553, F-554, F-555, F-556, F-557, F-558, F-559 (trade name, DIC Corporation), Surflon (registered trademark) S-242 , S-243, S-386, S-420, S-611 (trade name, AGC Seimi Chemical Co., Ltd.) and other fluorine-based surfactants; and organosiloxane polymers KP323, KP326, and KP341 (trade name, Shin-Etsu Chemical Kogyo Co., Ltd.). These surfactants can be used alone or in combination of two or more.

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

The photosensitive resin composition can contain a second colorant other than the black colorant (D). Examples of the second colorant include dyes, organic pigments, and inorganic pigments. The second coloring agent can be used according to the purpose. The second colorant can be used in a content that does not impair the effects of the disclosure 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, and triphenylmethane dyes. Examples include dyes, fluoran dyes, spiropyran dyes, phthalocyanine dyes, indigo dyes, fulgide dyes, nickel complex dyes, and azulene dyes. Among the dyes, red dyes are preferred. As red dyes, for example, VALIFAST (registered trademark) RED 3312 (red dye defined by C.I. of Solvent Red 122, Orient Chemical Industry Co., Ltd.) and VALIFAST (registered trademark) RED 3311 (C of Solvent Red 8 (Orient Chemical Industry Co., Ltd.).

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

[Coating composition]
<Solvent (F)>
The photosensitive resin composition can be dissolved in the solvent (F) and used as a coating composition in a solution state (when a black pigment is contained, the pigment is in a dispersed state). For example, a quinonediazide adduct (B), a dissolution accelerator (C), a black colorant (D), and optionally a heat curing agent, are added to a solution obtained by dissolving a resin component in a solvent (F). A coating composition containing a photosensitive resin composition can be prepared by mixing an optional component (E) such as a surfactant in a predetermined ratio. The coating composition can be adjusted to a viscosity suitable for the application method used by varying the amount of solvent (F).

Examples of the solvent (F) include glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol dimethyl ether, ethylene glycol methyl ethyl ether and ethylene glycol monoethyl ether; ethylene glycol alkyl ether acetates such as methyl cellosolve acetate and ethyl cellosolve acetate; diethylene glycol. Diethylene glycol compounds such as monomethyl ether, diethylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol ethyl methyl ether, diethylene glycol monoethyl ether, and diethylene glycol monobutyl ether; Propylene glycol monoalkyl ether acetate compounds such as propylene glycol monomethyl ether acetate and propylene glycol monoethyl ether acetate; 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; ethyl 2-hydroxypropionate, 2-hydroxy-2-methylpropion methyl acid, ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxyacetate, ethyl hydroxyacetate, methyl 2-hydroxy-2-methylbutanoate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypropionate Esters such as methyl acid, ethyl 3-ethoxypropionate, ethyl acetate, butyl acetate, methyl lactate, ethyl lactate, γ-butyrolactone; and N-methyl-2-pyrrolidone, N,N-dimethylformamide, N,N-dimethyl Amide compounds such as acetamide are included. The solvent (F) can be used alone or in combination of two or more.

The solid content concentration of the coating composition can be appropriately determined depending on the purpose of use. For example, the coating composition may have a solids concentration of 1 to 60% by weight, 3 to 50% by weight, or 5 to 40% by weight.

A known method can be used as a dispersing and mixing method when a pigment is used. For example, ball mills, sand mills, bead mills, paint shakers, rocking mills, etc.; blade types, such as kneaders, paddle mixers, planetary mixers, and Henschel mixers; roll types, such as three-roll mixers; An ultrasonic wave, a homogenizer, a rotation/revolution mixer, etc. may be used. It is preferable to use a bead mill from the viewpoint of dispersion efficiency and fine dispersion.

A prepared coating composition is usually filtered before use. Filtration means include, for example, a Millipore filter with a pore size of 0.05 to 1.0 μm.

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

[How to use the photosensitive resin composition]
When the photosensitive resin composition is used in radiation lithography, first, the photosensitive resin composition is dissolved or dispersed in a solvent to prepare a coating composition. The coating composition can then be applied to the substrate surface and the solvent removed by means such as heating to form a coating. The method of applying the coating composition to the substrate surface is not particularly limited, and for example, a spray method, a roll coating method, a slit method, or a spin coating method can be used.

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

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

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

In one embodiment, no PEB step is included after the exposure step. As a result, it is possible to prevent flow, deformation, etc. of the film due to heating, to form the stepped pattern with high precision, and to reduce the number of processes for forming the partition wall or the insulating film.

After the exposure step or PEB step, the coating is developed by contacting it with a developer to remove unnecessary portions and form a pattern on the coating (development step). Examples of the developer include inorganic alkali compounds such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia; primary amines such as ethylamine and n-propylamine; secondary amines such as n-propylamine; tertiary amines such as triethylamine and methyldiethylamine; alcohol amines such as dimethylethanolamine and triethanolamine; quaternary amines such as tetramethylammonium hydroxide, tetraethylammonium hydroxide and choline. ammonium salts; pyrrole, piperidine, 1,8-diazabicyclo[5.4.0]-7-undecene, cyclic amines such as 1,5-diazabicyclo[4.3.0]-5-nonane, etc. Aqueous solutions can be used. An aqueous solution obtained by adding an appropriate amount of a water-soluble organic solvent such as methanol or ethanol, a surfactant, or the like to an alkaline aqueous solution can also be used as a developer. Development time is usually 30 to 180 seconds. The developing method may be any one of a liquid swell method, a shower method, a dipping method, and the like. After development, the coating can be patterned by washing with running water for 30 to 90 seconds, removing unnecessary portions, and air-drying with compressed air or compressed nitrogen.

Thereafter, the film having the pattern formed thereon is subjected to heat treatment at 100 to 350° C. for 20 to 200 minutes using a heating device such as a hot plate or oven to obtain a cured film (post-baking, heat treatment process). In the heat treatment, the temperature may be maintained constant, may be increased continuously, or may be increased stepwise. Heat treatment is preferably performed in a nitrogen atmosphere.

The optical density (OD value) of the cured film of the photosensitive resin composition is preferably 0.5 or more, more preferably 0.7 or more, and preferably 1.0 or more per 1 μm of film thickness. More preferred. If the cured film has an OD value of 0.5 or more per 1 μm of film thickness, sufficient light shielding properties can be obtained.

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

One embodiment is an organic EL element partition containing a cured product of a photosensitive resin composition.

One embodiment is an organic EL element insulating film containing a cured product of a photosensitive resin composition.

One embodiment is an organic EL device containing a cured product of a photosensitive resin composition.

EXAMPLES The present invention will be specifically described below based on Examples and Comparative Examples, but the present invention is not limited to these Examples.

(1) Raw Materials Raw materials used in Examples and Comparative Examples were manufactured or obtained as follows.

The weight average molecular weight (Mw) and number average molecular weight (Mn) of the resin were calculated under the following measurement conditions using a calibration curve prepared using polystyrene standard substances.
Apparatus name: Shodex (registered trademark) GPC-101
Column: Shodex® LF-804
Mobile phase: Tetrahydrofuran Flow rate: 1.0 mL/min Detector: Shodex (registered trademark) RI-71
Temperature: 40°C

[Production Example 1] Base resin (a) and other resin (A3): Alkaline aqueous solution-soluble copolymer (a1) of a polymerizable monomer having a phenolic hydroxyl group and another polymerizable monomer (PCX- 02e) 4-hydroxyphenyl methacrylate ("PQMA" by Showa Denko Co., Ltd.) 29.0 g and N-cyclohexylmaleimide (Nippon Shokubai Co., Ltd.) 5.12 g were added to the solvent 1-methoxy-2-propyl acetate ( Daicel Co., Ltd.) 96.5 g, V-601 (Fuji Film Wako Pure Chemical Co., Ltd.) 3.41 g as a polymerization initiator, 1-methoxy-2-propyl acetate (Daicel Co., Ltd.) 13.7 g Dissolved. The two solutions thus obtained were simultaneously added dropwise over 2 hours to 40.0 g of 1-methoxy-2-propyl acetate (Daicel Co., Ltd.) heated to 85° C. in a 300 mL three-necked flask under a nitrogen gas atmosphere. and then reacted at 85° C. for 3 hours. The reaction solution cooled to room temperature was dropped into 815 g of toluene to precipitate a copolymer. The precipitated copolymer was collected by filtration and vacuum-dried at 90° C. for 4 hours to collect 32.4 g of white powder. The obtained PCX-02e had a number average molecular weight of 3,100, a weight average molecular weight of 6,600, and a hydroxyl equivalent of 202.

[Production Example 2] Protected resin (A1): Production of resin (PCX-02e-THF55) in which phenolic hydroxyl group is protected with 2-tetrahydrofuranyl group 10.0 g of a copolymer of a polymerizable monomer having a phenolic hydroxyl group and another polymerizable monomer (PCX-02e), and a pyridinium salt of p-toluenesulfonic acid as an acid catalyst (Tokyo Chemical Industry Co., Ltd. ) was dissolved in 50.0 g of tetrahydrofuran (Fuji Film Wako Pure Chemical Industries, Ltd.). After cooling with ice in a nitrogen gas atmosphere, 6.69 g of 2,3-dihydrofuran (Tokyo Chemical Industry Co., Ltd.) was added dropwise over 1 hour. After that, the mixture was stirred at room temperature for 16 hours. After neutralizing the acid catalyst with saturated sodium bicarbonate aqueous solution, the water layer was removed. Furthermore, the organic layer was washed twice with water. The tetrahydrofuran was then distilled off. The resulting solid was dissolved in 50.0 g of ethyl acetate and added dropwise to 200 g of toluene to precipitate the product. The precipitate was recovered by filtration and vacuum dried at 80° C. for 4 hours to recover 11.0 g of white powder. The obtained powder was dissolved in propylene glycol monomethyl ether acetate to obtain a 20 mass % solids solution of a resin (PCX-02e-THF55) in which the phenolic hydroxyl group was protected with a 2-tetrahydrofuranyl group. The obtained PCX-02e-THF55 had a number average molecular weight of 3716, a weight average molecular weight of 6806, a hydroxyl group equivalent of 552, a proportion of phenolic hydroxyl groups protected with acid-decomposable groups of 55 mol%, and at least one phenolic The number of structural units represented by formula (4) in which the hydroxyl group was protected with an acid-decomposable group was 55% of the total number of structural units of PCX-02e-THF55.

[Production Example 3] Resin having an epoxy group (A2): Production of a resin having an epoxy group and a phenolic hydroxyl group (N695OH70) Propylene glycol monomethyl ether acetate (Mitsubishi Chemical Corporation) 75 was added as a solvent to a 300 mL three-necked flask. .2 g, 42.8 g of EPICLON (registered trademark) N-695 (DIC Corporation, cresol novolak type epoxy resin, epoxy equivalent 214) as a compound having at least two epoxy groups in one molecule were charged under a nitrogen gas atmosphere. , and dissolved at 60°C. 20.1 g of 3,5-dihydroxybenzoic acid (FUJIFILM Wako Pure Chemical Industries, Ltd.) as a hydroxybenzoic acid compound (0.65 equivalents per equivalent of epoxy), and triphenylphosphine (Tokyo Chemical Industry Co., Ltd.) as a reaction catalyst. 0.166 g (0.633 mmol) was added and reacted at 110° C. for 21 hours. The reaction solution was returned to room temperature, diluted with γ-butyrolactone to a solid content of 20% by mass, and filtered to obtain 304.2 g of a solution of a resin (N695OH70) having epoxy groups and phenolic hydroxyl groups. The obtained reactant had a number average molecular weight of 3,000, a weight average molecular weight of 7,500, and an epoxy equivalent of 1,100.

[Production Example 4] Resin (A2) having an epoxy group: Production of a resin (N695OH50) having an epoxy group and a phenolic hydroxyl group In the same manner as in Production Example 3, except that 13.9 g of 3,5-dihydroxybenzoic acid was used. A solution of 256.2 g of epoxy- and phenolic hydroxyl-containing resin (N695OH50) was obtained. The obtained reactant had a number average molecular weight of 2,900, a weight average molecular weight of 6,400, and an epoxy equivalent of 690.

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

<Resin (A2) having an epoxy group>
N695OH70 of Production Example 3 and N695OH50 of Production Example 4 were used as the epoxy group-containing resin (A2).

<Other resin (A3)>
PCX-02e of Production Example 1 was used as another resin (A3).

で表される基を表す。表１中の分子量は、１分子あたりのキノンジアジド基の平均数に基づく計算値である。 <Quinone diazide adduct (B)>
A compound shown in Table 1 was used as the quinonediazide adduct (B). Table 1 also shows the structural formula of the quinonediazide adduct (B). In the structural formula, R is a hydrogen atom or formula (9-1)

Represents a group represented by The molecular weights in Table 1 are calculated values based on the average number of quinonediazide groups per molecule.

<Solubilizer (C)>
Phloroglucinol was used as a dissolution enhancer (C).

<Black colorant (D)>
As the black colorant (D), a black dye, VALIFAST (registered trademark) BLACK 3820 (black dye defined by C.I. of Solvent Black 27, Orient Chemical Industry Co., Ltd.) was used.

<Solvent (F)>
A mixed solvent of γ-butyrolactone (GBL) and propylene glycol monomethyl ether acetate (PGMEA) (GBL:PGMEA=25:75 (mass ratio)) was used as the solvent (F).

(2) Evaluation methods Evaluation methods used in Examples and Comparative Examples are as follows.

[sensitivity]
A glass substrate (size 100 mm × 100 mm × 1 mm) was bar-coated with a photosensitive resin composition so that the dry film thickness was 4.0 μm, vacuum dried for 90 seconds, and placed on a hot plate with a lid at 100° C. for 2 minutes. It was pre-baked by heating. An exposure apparatus (trade name: Multilight ML-251A/B, Ushio Inc.) incorporating an ultra-high pressure mercury lamp was used. The coating was exposed through the aperture pattern. The amount of exposure was measured using an ultraviolet integrating photometer (trade name: UIT-150, light receiving unit: UVD-S365, USHIO INC.). After exposure, PEB was performed by heating at 120° C. for 3 minutes on a hot plate with a lid. After that, using a spin developing device (AD-1200, Takizawa Sangyo Co., Ltd.), alkali development was carried out for 60 seconds with a 2.38% by mass tetramethylammonium hydroxide aqueous solution. Further, the coating was cured by heating at 250° C. for 60 minutes in an inert oven (DN411I, Yamato Scientific Co., Ltd.). The above procedure was repeated while changing the exposure dose, and the sensitivity was defined as the minimum dose (mJ/cm ² ) at which a pattern with a film thickness of 3 μm and a hole diameter of 10 μm could be formed after curing. The sensitivity was judged to be high when the minimum dose was 400 mJ/cm ² or less.

[Step width of step pattern of cured film]
A glass substrate (size 100 mm × 100 mm × 1 mm) was bar-coated with a photosensitive resin composition so that the dry film thickness was 4.0 μm, vacuum dried for 90 seconds, and placed on a hot plate with a lid at 100° C. for 2 minutes. It was pre-baked by heating. An exposure device (trade name: Multilight ML-251A/B, Ushio Inc.) incorporating an ultra-high pressure mercury lamp was used with a mercury exposure bandpass filter (trade name: HB0365, Asahi Spectrosco Co., Ltd.) and a quartz halftone photomask. The coating was exposed through (having a pattern of 15 μm wide intermediate exposure lines with 10 μm wide lines with 100% transmission inside and slits with 31% light transmission area at both ends). The amount of exposure was measured using an ultraviolet integrating photometer (trade name: UIT-150, light receiving unit: UVD-S365, USHIO INC.). After exposure, PEB was performed by heating at 120° C. for 3 minutes on a hot plate with a lid. After that, alkali development was carried out with a 2.38% by mass tetramethylammonium hydroxide aqueous solution using a spin developing device (AD-1200, Takizawa Sangyo Co., Ltd.). Further, the coating was cured by heating at 250° C. for 60 minutes in an inert oven (DN411I, Yamato Scientific Co., Ltd.). The above procedure was repeated while changing the exposure amount and development time, and the stepped pattern formed on the cured film, which was capable of forming a pattern with a film thickness of 3 μm and a line width of 10 μm after curing, was observed with a shape analysis laser microscope (trade name: VK-X200, Keyence Corporation), and the step width (μm) corresponding to the intermediately exposed portion was measured.

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

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

Examples 1 to 7 in which the total number of moles of carboxy groups and phenolic hydroxyl groups contained in the quinonediazide adduct (B) and the dissolution accelerator (C) is 150 mmol or less per 100 g of the solid content contained in the photosensitive resin composition. , and more than 150 mmol, Examples 1 to 7 had a wider step width and less coating flow during heat curing.

The photosensitive resin composition according to the present disclosure can be suitably used for radiation lithography for forming partition walls or insulating films of organic EL elements. An organic EL element provided with a partition wall or an insulating film formed from the photosensitive resin composition according to the present disclosure is suitably used as an electronic component of a display device exhibiting good contrast.

Claims (17)

a resin (A1) having a plurality of phenolic hydroxyl groups, at least a portion of the plurality of phenolic hydroxyl groups being protected with an acid-decomposable group;
a resin (A2) having an epoxy group;
A quinonediazide adduct (B) to a phenol compound;
at least one dissolution accelerator (C) selected from the group consisting of compounds having a carboxyl group and compounds having a phenolic hydroxyl group;
a black coloring agent (D);
wherein the total number of moles of carboxy groups and phenolic hydroxyl groups contained in the quinonediazide adduct (B) and the dissolution accelerator (C) is the solid contained in the photosensitive resin composition A photosensitive resin composition having a content of 150 mmol or less per 100 g per minute. 2. The photosensitive resin according to claim 1, wherein the quinonediazide adduct (B) is 1,2-naphthoquinonediazide-4-sulfonate or 1,2-naphthoquinonediazide-5-sulfonate of the phenol compound. Composition. 3. The photosensitive resin composition according to claim 1, wherein the quinonediazide adduct (B) has a quinonediazide group equivalent of 500 or less. 4. The photosensitive resin composition according to any one of claims 1 to 3, wherein the dissolution accelerator (C) is an organic low-molecular-weight compound having a molecular weight of 1,000 or less. 5. The photosensitive resin composition according to any one of claims 1 to 4, wherein the dissolution accelerator (C) has a total equivalent weight of carboxy groups and phenolic hydroxyl groups of 60 or less. 2. The total number of moles of carboxy groups and phenolic hydroxyl groups contained in the quinonediazide adduct (B) and the dissolution accelerator (C) is 90 mmol or more per 100 g of solid content contained in the photosensitive resin composition. 6. The photosensitive resin composition according to any one of -5. The resin (A1) has the formula (4)

(In formula (4), R ⁹ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, R ¹⁰ is an acid-decomposable group, r is an integer of 0 to 5, s is 0 to 5 is an integer of , where r + s is an integer of 1 to 5.)
Having at least one structural unit represented by formula (4), wherein s is an integer of 1 or more, photosensitive resin according to any one of claims 1 to 6 Composition. The resin (A1) has the formula (2)

(In Formula (2), R ² and R ³ are each independently a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or a fully or partially fluorinated fluoroalkyl group having 1 to 3 carbon atoms. , or a halogen atom, and R ⁴ is a hydrogen atom, a linear alkyl group having 1 to 6 carbon atoms, a cyclic alkyl group having 3 to 12 carbon atoms, a phenyl group, or a hydroxy group, or a 1 to 6 carbon atom is a phenyl group substituted with at least one selected from the group consisting of an alkyl group and an alkoxy group having 1 to 6 carbon atoms.)
The photosensitive resin composition according to claim 7, which has a structural unit represented by The acid-decomposable group substituted with the hydrogen atom of the phenolic hydroxyl group in the resin (A1) has the formula (3)
—CR ⁶ R ⁷ —OR ⁸ (3)
(In formula (3), R ⁶ and R ⁷ are each independently a hydrogen atom, a linear alkyl group having 1 to 4 carbon atoms, or a branched alkyl group having 3 to 4 carbon atoms, and R ⁸ is , a linear alkyl group having 1 to 12 carbon atoms, a branched alkyl group having 3 to 12 carbon atoms, a cyclic alkyl group having 3 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, or 2 carbon atoms 1 to 12 alkenyl groups, one of R ⁶ or R 7 and R ⁸ may combine to form a ring structure with 3 to 10 ring members, where R ⁶ , ^{R 7 and} R ⁸ are fluorine, It may be substituted with a halogen atom selected from the group consisting of chlorine, bromine and iodine.)
The photosensitive resin composition according to any one of claims 1 to 8, which is a group represented by The photosensitive resin composition according to any one of claims 1 to 9, wherein the resin (A2) is a resin having an epoxy group and a phenolic hydroxyl group. The resin having an epoxy group and a phenolic hydroxyl group is a reaction product of a compound having at least two epoxy groups in one molecule and a hydroxybenzoic acid compound, and has the formula (6)

(In the formula (6), b is an integer of 1 to 5, and * represents a bonding portion of a compound having at least two epoxy groups in one molecule with a residue other than the epoxy group involved in the reaction. .)
The photosensitive resin composition according to claim 10, which is a compound having the structure of 12. The photosensitive resin composition according to claim 11, wherein the compound having at least two epoxy groups in one molecule is a novolak type epoxy resin. The photosensitive resin composition according to any one of claims 1 to 12, comprising 10 parts by mass to 150 parts by mass of the black colorant (D) based on a total of 100 parts by mass of the resin components. 14. The photosensitive resin composition according to any one of claims 1 to 13, wherein the cured film of the photosensitive resin composition has an optical density (OD value) of 0.5 or more per 1 μm of film thickness. An organic EL element partition comprising a cured product of the photosensitive resin composition according to any one of claims 1 to 14. An organic EL element insulating film comprising a cured product of the photosensitive resin composition according to any one of claims 1 to 14. An organic EL device comprising a cured product of the photosensitive resin composition according to any one of claims 1 to 14.