Positive photosensitive resin composition and organic EL element partition wall

Abstract

Provided is a highly photosensitive resin composition which is capable of forming a pattern having a high resolution and contains a black colorant. A positive photosensitive resin composition according to an embodiment contains (A) an acrylic resin having a plurality of phenolic hydroxyl groups at least a portion of which is protected by an acid-labile group, (B) at least one black colorant selected from the group consisting of black dyes and black pigments, and (C) a quinonediazide compound as a photoacid generator.

Description

[Technical Field]

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

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

[0003] In recent years, in this field, due to the miniaturization of display devices and the diversification of displayed content, there has been a demand for higher pixel performance and higher resolution. Attempts have been made to impart light-blocking properties to partition wall materials using colorants in order to increase the contrast and improve visibility in display devices. However, when partition wall materials are imparted with light-blocking properties, the photosensitive resin composition tends to have low sensitivity, which may result in longer exposure times and reduced productivity. Therefore, photosensitive resin compositions used to form partition wall materials containing colorants are required to have higher sensitivity.

[0004] Patent Document 1 (JP 2001-281440 A) describes a radiation-sensitive resin composition that exhibits high light-blocking properties through heat treatment after exposure, in which titanium black is added to a positive-tone radiation-sensitive resin composition containing an alkali-soluble resin and a quinone diazide compound.

[0005] Patent Document 2 (JP 2002-116536 A) describes a method for blackening a partition wall material by using carbon black in a radiation-sensitive resin composition containing [A] an alkali-soluble resin, [B] a 1,2-quinonediazide compound, and [C] a colorant.

[0006] Patent Document 3 (JP 2010-237310 A) describes a radiation-sensitive resin composition that exhibits light-blocking properties by heat treatment after exposure, in which a heat-sensitive dye is added to a positive-tone radiation-sensitive resin composition containing an alkali-soluble resin and a quinone diazide compound.

[0007] Patent Document 4 (WO 2017 / 069172) describes a positive photosensitive resin composition containing (A) a binder resin, (B) a quinone diazide compound, and (C) at least one black dye selected from black dyes defined by the color index of Solvent Black 27 to 47. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-281440 [Patent Document 2] Japanese Patent Application Laid-Open No. 2002-116536 [Patent Document 3] Japanese Patent Application Laid-Open No. 2010-237310 [Patent Document 4] International Publication No. 2017 / 069172 Summary of the Invention [Problem to be solved by the invention]

[0009] In the photosensitive resin composition used to form a colored partition wall material, a considerable amount of colorant must be used to sufficiently enhance the light-shielding properties of the cured film. When such a large amount of colorant is used, radiation such as light irradiated onto the coating of the photosensitive resin composition is absorbed by the colorant, reducing the effective intensity of radiation in the coating and resulting in insufficient exposure of the photosensitive resin composition, resulting in poor pattern formability.

[0010] Quinone diazide compounds are widely used as radiation-sensitive compounds in positive-tone photosensitive resin compositions containing common binder resins. When quinone diazide compounds are irradiated with radiation such as visible light, ultraviolet light, gamma rays, or electron beams, they generate carboxyl groups via the reaction shown in Reaction Scheme 1 below. The generation of carboxyl groups makes the exposed portion (coating) soluble in alkaline solutions, thereby exhibiting alkaline developability. When a positive-tone photosensitive resin composition containing a colorant is formed into a thick film, the quinone diazide compound does not react sufficiently at the bottom of the coating, resulting in insufficient alkaline solubility at the bottom of the coating, which can result in the generation of resin residues and reduced pattern resolution during development.

[0011] [ka]

[0012] There is a demand for further increasing the optical density (OD value) of the cured coating of positive-type photosensitive resin compositions containing large amounts of colorants, but the trade-off is an undesirable decrease in pattern resolution.

[0013] An object of the present invention is to provide a highly sensitive photosensitive resin composition containing a black colorant, which is capable of forming a pattern with high resolution. [Means for solving the problem]

[0014] The present inventors have discovered that when a positive-working photosensitive resin composition is formed into a chemically amplified system containing an acrylic resin having multiple phenolic hydroxyl groups, at least some of which are protected with acid-decomposable groups, in combination with a quinone diazide compound as a photoacid generator, the carboxylic acid compound generated when the quinone diazide compound is irradiated with radiation can deprotect the acid-decomposable groups. Based on this finding, the present inventors have realized a positive-working photosensitive composition that is capable of forming high-resolution patterns despite containing a black colorant.

[0015] That is, the present invention includes the following aspects. [1] an acrylic resin (A) having a plurality of phenolic hydroxyl groups, at least a portion of which are protected with acid-decomposable groups; at least one black colorant (B) selected from the group consisting of black dyes and black pigments; A quinone diazide compound (C) as a photoacid generator A positive photosensitive resin composition comprising: [2] The acrylic resin (A) is represented by the formula (3) [ka] In formula (3), R 1 is an alkyl group having 1 to 5 carbon atoms, and R 5 is the acid-decomposable group, r is an integer of 0 to 5, s is an integer of 0 to 5, provided that r+s is an integer of 1 to 5, and the acrylic resin (A) has at least one structural unit in which s is an integer of 1 or more. [3] The acrylic resin (A) is represented by the formula (2) [ka] In formula (2), R 2 and R 3are each independently a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, a fully or partially fluorinated alkyl group having 1 to 3 carbon atoms, or a halogen atom; R 4 is a hydrogen atom, a linear alkyl group having 1 to 6 carbon atoms or a cyclic alkyl group having 4 to 12 carbon atoms, or a phenyl group which may be substituted with at least one selected from the group consisting of a hydroxy group, an alkyl group having 1 to 6 carbon atoms, and an alkoxy group having 1 to 6 carbon atoms. [4] The positive photosensitive resin composition according to either [2] or [3], wherein the acrylic resin (A) contains the structural unit represented by formula (3) in an amount of 60 mol % to 100 mol %. [5] The positive photosensitive resin composition according to any one of [1] to [4], comprising 20 to 50 parts by mass of the quinone diazide compound (C) based on 100 parts by mass in total of the resin components. [6] The positive photosensitive resin composition according to any one of [1] to [5], wherein the content of the photoacid generator other than the quinone diazide compound (C) is 0.5 parts by mass or less based on 100 parts by mass of the total of the resin components. [7] The acid-decomposable group of the acrylic resin (A) is represented by the formula (6) -CR 6 R 7 -OR 8 (6) In formula (6), R 6 and R 7 are each independently a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms, and R 8 is a linear, branched or cyclic alkyl group having 1 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, or an alkenyl group having 2 to 12 carbon atoms, and R 6 or R 7 One of the two and R 8 may be bonded to form a ring structure having 3 to 10 ring members, and R 6 , R 7 and R 8may be substituted with a halogen atom selected from the group consisting of fluorine, chlorine, bromine and iodine. [8] The positive photosensitive resin composition according to any one of [1] to [7], wherein 10 mol % to 95 mol % of the phenolic hydroxyl groups of the acrylic resin (A) are protected with the acid-decomposable group. [9] The positive photosensitive resin composition according to any one of [1] to [8], which contains 30% by mass to 90% by mass of the acrylic resin (A) based on the total mass of the resin components.

[10] The positive photosensitive resin composition according to any one of [1] to [9], comprising 10 to 150 parts by mass of the black colorant (B) based on 100 parts by mass of the total of the resin components.

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

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

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

[11] , further comprising a resin (D) having an epoxy group and a phenolic hydroxyl group.

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

[14] The positive photosensitive resin composition according to

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

[15] The positive photosensitive resin composition according to either

[13] or

[14] , wherein the hydroxybenzoic acid compound is a dihydroxybenzoic acid compound.

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

[15] .

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

[15] .

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

[15] . [Effects of the Invention]

[0016] According to the present invention, it is possible to provide a highly sensitive photosensitive resin composition containing a black colorant, which is capable of forming a pattern with high resolution. DETAILED DESCRIPTION OF THE INVENTION

[0017] The present invention will be described in detail below.

[0018] In this disclosure, "alkali-soluble" and "alkali aqueous solution soluble" mean that a positive photosensitive resin composition or a component thereof, or a coating or cured coating of the positive photosensitive resin composition, is soluble in an alkaline aqueous solution, for example, a 2.38% by mass aqueous solution of tetramethylammonium hydroxide. An "alkali-soluble functional group" refers to a group that imparts such alkali-solubility to a positive photosensitive resin composition or a component thereof, or a coating or cured coating of the positive photosensitive resin composition. Examples of alkali-soluble functional groups include a phenolic hydroxyl group, a carboxyl group, a sulfo group, a phosphate group, an acid anhydride group, and a mercapto group.

[0019] In the present disclosure, the term "acid-decomposable group" refers to a group that is decomposed (deprotected) in the presence of an acid, optionally with heating, to generate an alkali-soluble functional group.

[0020] In the present disclosure, the term "radically polymerizable functional group" refers to one or more ethylenically unsaturated groups.

[0021] In this disclosure, "(meth)acrylic" means acrylic or methacrylic, "(meth)acrylate" means acrylate or methacrylate, and "(meth)acryloyl" means acryloyl or methacryloyl.

[0022] In the present disclosure, the number average molecular weight (Mn) and weight average molecular weight (Mw) of a resin or polymer refer to values ​​calculated as standard polystyrene, measured by gel permeation chromatography (GPC).

[0023] The positive photosensitive resin composition of one embodiment comprises: an acrylic resin (A) having a plurality of phenolic hydroxyl groups, at least a portion of which are protected with acid-decomposable groups; at least one black colorant (B) selected from the group consisting of black dyes and black pigments; and a quinone diazide compound (C) as a photoacid generator.

[0024] [Acrylic resin (A)] The acrylic resin (A) is not particularly limited as long as it is a (co)polymer of an α-alkyl acrylic acid ester and has multiple phenolic hydroxyl groups, at least some of which are protected with acid-decomposable groups. The phenolic hydroxyl groups are alkali-soluble functional groups, and by protecting some of them with acid-decomposable groups, the alkali solubility of the acrylic resin (A) before exposure is suppressed. The acrylic resin (A) has phenolic hydroxyl groups on benzene rings pendant to the polymer backbone. Due to this structure, the acrylic resin (A) has higher alkali solubility than novolak resins with a comparable hydroxyl value, as alkali compounds in the developer are more likely to access the phenolic hydroxyl groups. Therefore, the acrylic resin (A) exhibits a larger change in alkali solubility before and after exposure (before and after decomposition of the acid-decomposable groups), resulting in improved pattern resolution. The acrylic resin (A) 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 way as the phenolic hydroxyl groups. The acid generated during exposure catalytically promotes the decomposition (deprotection) of the acid-decomposable group, regenerating the phenolic hydroxyl group. If necessary, post-exposure baking (PEB) may be performed after exposure. This promotes alkaline dissolution of the acrylic resin (A) in the exposed area during development. The acrylic resin (A) may have an alkali-soluble functional group other than the phenolic hydroxyl group, such as a carboxyl group, a sulfo group, a phosphate group, an acid anhydride group, or a mercapto group. The acrylic resin (A) may be used alone or in combination of two or more types. For example, the acrylic resin (A) may be a combination of two or more resins that differ in polymer structural units, acid-decomposable groups, protection rates of phenolic hydroxyl groups, or combinations thereof.

[0025] Protection of phenolic hydroxyl groups with acid-labile groups The acrylic resin (A) can be obtained by protecting some of the phenolic hydroxyl groups of the base acrylic resin (a) having multiple phenolic hydroxyl groups with acid-decomposable groups. The acrylic resin (A) having phenolic hydroxyl groups protected with acid-decomposable groups has a partial structure of Ar-OR, where Ar represents an aromatic ring derived from phenol and R represents an acid-decomposable group.

[0026] The acid-decomposable group is a group that is decomposed (deprotected) in the presence of an acid, if necessary by heating, to generate an alkali-soluble functional group. Specific examples include groups having a tertiary alkyl group such as a tert-butyl group, a 1,1-dimethylpropyl group, a 1-methylcyclopentyl group, a 1-ethylcyclopentyl group, a 1-methylcyclohexyl group, a 1-ethylcyclohexyl group, a 1-methyladamantyl group, a 1-ethyladamantyl group, a tert-butoxycarbonyl group, and a 1,1-dimethylpropoxycarbonyl group; silyl groups such as a trimethylsilyl group, a triethylsilyl group, a t-butyldimethylsilyl group, a triisopropylsilyl group, and a t-butyldiphenylsilyl group; and groups represented by the formula (6): -CR 6 R 7 -OR 8 (6) (In formula (6), R 6 and R 7 are each independently a hydrogen atom or an alkyl group (linear or branched) having 1 to 4 carbon atoms, and R 8 is an alkyl group (linear, branched, or cyclic) having 1 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, or an alkenyl group having 2 to 12 carbon atoms, and R 6 or R 7 One of the two and R 8 may be bonded to form a ring structure having 3 to 10 ring members, and R 6 , R 7 and R 8may be substituted with a halogen atom selected from the group consisting of fluorine, chlorine, bromine, and iodine. The group represented by formula (6) forms an acetal structure or a ketal structure together with the oxygen atom derived from the phenolic hydroxyl group. These acid-decomposable groups may be used alone or in combination of two or more.

[0027] The acid-decomposable group is preferably a group represented by formula (6), since a positive-type photosensitive resin composition having high sensitivity can be obtained even with a low exposure dose. 6 and R 7 are each independently a hydrogen atom or an alkyl group (linear or branched) having 1 to 4 carbon atoms, and R 8 is more preferably an alkyl group (linear, branched, or cyclic) having 1 to 12 carbon atoms, optionally substituted with a halogen atom selected from the group consisting of fluorine, chlorine, bromine, and iodine. Examples of such acid-decomposable groups include 1-alkoxyalkyl groups. Examples of 1-alkoxyalkyl groups include methoxymethyl, 1-methoxyethyl, 1-ethoxyethyl, 1-n-propoxyethyl, 1-n-butoxyethyl, 1-isobutoxyethyl, 1-(2-chloroethoxy)ethyl, 1-(2-ethylhexyloxy)ethyl, 1-cyclohexyloxyethyl, and 1-(2-cyclohexylethoxy)ethyl groups, with 1-ethoxyethyl and 1-n-propoxyethyl groups being preferred. Examples of acid-decomposable groups include a group represented by formula (6), where R 6 or R 7 One of the two and R 8 and R bonded to form a ring structure having 3 to 10 ring members can also be suitably used. In this case, R not involved in the formation of the ring structure can be used. 6 or R 7 is preferably a hydrogen atom. Examples of such an acid-decomposable group include a 2-tetrahydrofuranyl group and a 2-tetrahydropyranyl group, with a 2-tetrahydrofuranyl group being preferred.

[0028] The protection reaction of the phenolic hydroxyl group can be carried out using a common protecting agent under known conditions. For example, the acrylic resin (A) can be obtained by reacting the base acrylic resin (a) with the protecting agent in the presence of an acid or a base at a reaction temperature of −20 to 50° C., either without a solvent or in a solvent such as toluene or hexane.

[0029] Known protecting agents capable of protecting phenolic hydroxyl groups can be used as the protecting agent. For example, isobutene can be used when the acid-decomposable group is a tert-butyl group, and di-tert-butyl dicarbonate can be used when the acid-decomposable group is a tert-butoxycarbonyl group. When the acid-decomposable group is a silyl group such as a trimethylsilyl group or a triethylsilyl group, silicon-containing chlorides such as trimethylsilyl chloride or triethylsilyl chloride, or silicon-containing triflate compounds such as trimethylsilyl triflate or triethyl triflate can be used. When the acid-decomposable group is a methoxymethyl group, chloromethyl methyl ether can be used; when the acid-decomposable group is a 1-ethoxyethyl group, ethyl vinyl ether can be used; when the acid-decomposable group is a 1-n-propoxyethyl group, n-propyl vinyl ether can be used; when the acid-decomposable group is a 2-tetrahydrofuranyl group, 2,3-dihydrofuran can be used; and when the acid-decomposable group is a 2-tetrahydropyranyl group, 3,4-dihydro-2H-pyran can be used.

[0030] Examples of acids include inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, and perchloric acid, and organic acids such as methanesulfonic acid, trifluoromethanesulfonic acid, p-toluenesulfonic acid, and benzenesulfonic acid. Salts of organic acids, such as pyridinium salts of p-toluenesulfonic acid, can also be used as acid sources. Examples of bases include inorganic hydroxides such as sodium hydroxide and potassium hydroxide, inorganic carbonates such as sodium carbonate, sodium bicarbonate, potassium carbonate, and cesium carbonate, metal hydrides such as sodium hydride, and amine compounds such as pyridine, N,N-dimethyl-4-aminopyridine, imidazole, triethylamine, and diisopropylethylamine.

[0031] In another embodiment, the acrylic resin (A) can be obtained by protecting the phenolic hydroxyl group of a polymerizable monomer having a phenolic hydroxyl group with an acid-decomposable group, and then polymerizing or copolymerizing the polymerizable monomer having the phenolic hydroxyl group protected with the acid-decomposable group and, if necessary, other polymerizable monomers. The protection of the phenolic hydroxyl group of the polymerizable monomer having a phenolic hydroxyl group can be carried out in the same manner as in the protection of the phenolic hydroxyl group of the base acrylic resin (a).

[0032] <Base acrylic resin (a)> The base acrylic resin (a) of the acrylic resin (A) can be a homopolymer or copolymer of a polymerizable monomer having a phenolic hydroxyl group. At least one of the polymerizable monomer having a phenolic hydroxyl group and the other polymerizable monomer is an α-alkyl acrylic acid ester. These base acrylic resins (a) can be used alone or in combination of two or more. The base acrylic resin (a) may have a radically polymerizable functional group. In one embodiment, the base acrylic resin (a) has a (meth)acryloyloxy group, an allyl group, or a methallyl group as the radically polymerizable functional group.

[0033] <Alkali Aqueous Solution-Soluble Copolymer (a1) of Polymerizable Monomer Having a Phenolic Hydroxyl Group and Other Polymerizable Monomers> In one embodiment, the base acrylic resin (a) of the acrylic resin (A) is an aqueous alkali-soluble copolymer (a1) composed of a polymerizable monomer having a phenolic hydroxyl group and another polymerizable monomer, and the aqueous alkali-soluble copolymer (a1) has multiple phenolic hydroxyl groups. In this embodiment, the acrylic resin (A) is an aqueous alkali-soluble copolymer (a1) in which at least a portion of the multiple phenolic hydroxyl groups are protected with an acid-decomposable group. The aqueous alkali-soluble copolymer (a1) may further have an alkali-soluble functional group other than the phenolic hydroxyl group, such as a carboxy group, a sulfo group, a phosphate group, an acid anhydride group, or a mercapto group. The polymerizable functional group may be, for example, a radically polymerizable functional group such as CH═CH—, CH═C(CH═)—, CH═CHCO—, CH═C(CH═)CO—, or —OC—CH═CH—CO—.

[0034] The aqueous alkali solution-soluble copolymer (a1) can be produced, for example, by radical polymerization of a polymerizable monomer having a phenolic hydroxyl group with another polymerizable monomer. A copolymer not having a phenolic hydroxyl group may be synthesized by radical polymerization, and then the phenolic hydroxyl group may be introduced into the copolymer. Examples of polymerizable monomers having a phenolic hydroxyl group include acrylic monomers such as 4-hydroxyphenyl(meth)acrylate, 3,5-dimethyl-4-hydroxybenzyl acrylamide, and 4-hydroxyphenyl acrylamide, and 4-hydroxyphenyl maleimide. From the viewpoint of improving developability, an α-alkyl acrylic acid ester having a phenolic hydroxyl group is preferred. Other polymerizable monomers include, for example, polymerizable styrene derivatives such as styrene, vinyltoluene, α-methylstyrene, p-methylstyrene, and p-ethylstyrene, acrylamide, acrylonitrile, vinyl alcohol ether compounds such as vinyl-n-butyl ether, alkyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, glycidyl (meth)acrylate, 2,2,2-trifluoroethyl (meth)acrylate, 2,2,3,3-tetrafluoropropyl (meth)acrylate, and isobol Examples of suitable acrylic acid esters include (meth)acrylic acid esters such as methyl (meth)acrylate, N-substituted maleimides such as phenylmaleimide and cyclohexylmaleimide, maleic acid, maleic anhydride, maleic acid monoesters such as monomethyl maleate, monoethyl maleate and monoisopropyl maleate, (meth)acrylic acid, α-bromo(meth)acrylic acid, α-chloro(meth)acrylic acid, β-furyl(meth)acrylic acid, β-styryl(meth)acrylic acid, fumaric acid, cinnamic acid, α-cyanocinnamic acid, itaconic acid, crotonic acid, propiolic acid, 3-maleimidopropionic acid, 4-maleimidobutyric acid, 6-maleimidohexanoic acid, etc. From the viewpoint of heat resistance, etc., the aqueous alkali solution-soluble copolymer (a1) preferably has one or more cyclic structures such as an alicyclic structure, an aromatic structure, a polycyclic structure, an inorganic cyclic structure, and a heterocyclic structure.

[0035] As an α-alkyl acrylate having a phenolic hydroxyl group, the formula (1) [ka] In formula (1), it is preferable to form a structural unit represented by the formula: 1 is an alkyl group having 1 to 5 carbon atoms, and a is an integer of 1 to 5. 1 is preferably a methyl group. a is preferably an integer of 1 to 3, and more preferably 1. As such an α-alkyl acrylic acid ester having a phenolic hydroxyl group, 4-hydroxyphenyl methacrylate is particularly preferred.

[0036] Other polymerizable monomers include those represented by formula (2): [ka] In formula (2), it is preferable to form a structural unit represented by the formula: 2 and R 3 are each independently a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, a fully or partially fluorinated alkyl group having 1 to 3 carbon atoms, or a halogen atom; R 4 R is a hydrogen atom, a linear alkyl group having 1 to 6 carbon atoms or a cyclic alkyl group having 4 to 12 carbon atoms, or a phenyl group which may be substituted with at least one selected from the group consisting of a hydroxy group, an alkyl group having 1 to 6 carbon atoms, and an alkoxy group having 1 to 6 carbon atoms. 2 and R 3 are preferably each independently a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. 4 is preferably a cyclic alkyl group having 4 to 12 carbon atoms, or a phenyl group which may be substituted with at least one selected from the group consisting of a hydroxy group, an alkyl group having 1 to 6 carbon atoms, and an alkoxy group having 1 to 6 carbon atoms, and more preferably a cyclic alkyl group having 4 to 12 carbon atoms or a phenyl group. As such other polymerizable monomers, phenylmaleimide and cyclohexylmaleimide are particularly preferred.

[0037] In one embodiment, the aqueous alkali solution soluble copolymer (a1) is represented by the formula (1): [ka] (In formula (1), R 1 is an alkyl group having 1 to 5 carbon atoms, and a is an integer of 1 to 5. and a structural unit represented by formula (2) [ka] (In formula (2), R 2 and R 3 are each independently a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, a fully or partially fluorinated alkyl group having 1 to 3 carbon atoms, or a halogen atom; R 4 is a hydrogen atom, a linear alkyl group having 1 to 6 carbon atoms or a cyclic alkyl group having 4 to 12 carbon atoms, or a phenyl group which may be substituted with at least one selected from the group consisting of a hydroxy group, an alkyl group having 1 to 6 carbon atoms, and an alkoxy group having 1 to 6 carbon atoms. It has a structural unit represented by the following formula:

[0038] It is particularly preferred to use 4-hydroxyphenyl methacrylate as the α-alkyl acrylate ester having a phenolic hydroxyl group and phenylmaleimide or cyclohexylmaleimide as the other polymerizable monomer. By using a resin obtained by radical polymerization of these, shape retention and developability can be improved and outgassing can be reduced.

[0039] The polymerization initiator used in producing the base acrylic resin (a) by radical polymerization includes, but is not limited to, azo polymerization initiators such as 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), dimethyl 2,2'-azobis(2-methylpropionate), 4,4'-azobis(4-cyanovaleric acid), and 2,2'-azobis(2,4-dimethylvaleronitrile) (AVN); dicumyl peroxide; and 2,5-dimethyl-2,5-di(tert-butyl 2,5-dihydroxybenzoyl)-2,2'-azobis(2,4-dimethylvaleronitrile). Peroxide polymerization initiators having a 10-hour half-life temperature of 100 to 170°C, such as (tert-butylperoxy)hexane, tert-butylcumyl peroxide, di-tert-butyl peroxide, 1,1,3,3-tetramethylbutyl hydroperoxide, and cumene hydroperoxide, as well as peroxide polymerization initiators such as benzoyl peroxide, lauroyl peroxide, 1,1'-di(tert-butylperoxy)cyclohexane, and tert-butyl peroxypivalate, can be used. The amount of polymerization initiator used is generally at least 0.01 parts by mass, at least 0.05 parts by mass, or at least 0.5 parts by mass, and preferably at most 40 parts by mass, at most 20 parts by mass, or at most 15 parts by mass, per 100 parts by mass of the total amount of polymerizable monomers.

[0040] A RAFT (Reversible Addition Fragmentation Transfer) agent may be used in combination with the polymerization initiator. The RAFT agent may be, but is not limited to, a thiocarbonylthio compound such as a dithioester, dithiocarbamate, trithiocarbonate, or xanthate. The RAFT agent may be used in an amount of 0.005 to 20 parts by mass, preferably 0.01 to 10 parts by mass, per 100 parts by mass of the total amount of polymerizable monomers.

[0041] The weight-average molecular weight (Mw) of the base acrylic resin (a) can be 3,000 to 80,000, preferably 4,000 to 70,000, and more preferably 5,000 to 60,000. The number-average molecular weight (Mn) can be 1,000 to 30,000, preferably 1,500 to 25,000, and more preferably 2,000 to 20,000. The polydispersity (Mw / Mn) can be 1.0 to 3.5, preferably 1.1 to 3.0, and more preferably 1.2 to 2.8. By setting the weight-average molecular weight, number-average molecular weight, and polydispersity within the above ranges, a positive-type photosensitive resin composition with excellent alkali solubility and developability can be obtained.

[0042] In one embodiment, 10 mol % to 95 mol %, preferably 20 mol % to 80 mol %, and more preferably 25 mol % to 70 mol % of the phenolic hydroxyl groups in the acrylic resin (A) are protected with acid-decomposable groups. By ensuring that the proportion of phenolic hydroxyl groups protected with acid-decomposable groups in the acrylic resin (A) is 10 mol % or more, a chemical amplification function can be imparted to the photosensitive resin composition, thereby achieving high sensitivity. By ensuring that the proportion of phenolic hydroxyl groups protected with acid-decomposable groups is 95 mol % or less, the amount of remaining acid-decomposable groups that do not react during exposure can be reduced, thereby increasing the solubility of the exposed area and achieving high sensitivity. The proportion of phenolic hydroxyl groups protected with acid-decomposable groups can be calculated from the weight loss rate (%) of the acrylic resin (A) measured using a thermogravimetric differential thermal analyzer (TG / DTA). In the present disclosure, when the acrylic resin (A) is a combination of two or more resins with different protection rates, the protection rate of the phenolic hydroxyl groups in the acrylic resin (A) is a value when the two or more resins are regarded as a single acrylic resin (A) as a whole.

[0043] In one embodiment, the acrylic resin (A) is an aqueous alkali-soluble homopolymer of an α-alkyl acrylic acid ester having a phenolic hydroxyl group, at least some of which are protected with acid-decomposable groups, or an aqueous alkali-soluble copolymer of an α-alkyl acrylic acid ester having a phenolic hydroxyl group and another polymerizable monomer, at least some of which are protected with acid-decomposable groups. The latter acrylic resin (A) has as its base acrylic resin (a) an aqueous alkali-soluble copolymer (a1) of an α-alkyl acrylic acid ester having a phenolic hydroxyl group and another polymerizable monomer, and the aqueous alkali-soluble copolymer (a1) has a plurality of phenolic hydroxyl groups, at least some of which are protected with acid-decomposable groups.

[0044] In this embodiment, the acrylic resin (A) is represented by the formula (3): [ka] (In formula (3), R 1 is an alkyl group having 1 to 5 carbon atoms, and R 5 is an acid-decomposable group, r is an integer of 0 to 5, and s is an integer of 0 to 5, with the proviso that r+s is an integer of 1 to 5.) and the acrylic resin (A) preferably has at least one of the above structural units where s is an integer of 1 or more. 5 The acid-decomposable group is represented by the formula (6): -CR 6 R 7 -OR 8 (6) In formula (6), R 6 and R 7 are each independently a hydrogen atom or an alkyl group (linear or branched) having 1 to 4 carbon atoms, and R 8 is an alkyl group (linear, branched or cyclic) having 1 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, or an alkenyl group having 2 to 12 carbon atoms, or R 6 or R7 One of the two and R 8 It is more preferable that R and R are bonded to each other to form a ring structure having 3 to 10 ring members. 6 , R 7 and R 8 may be substituted with a halogen atom selected from the group consisting of fluorine, chlorine, bromine, and iodine. Examples of such acid-decomposable groups include 1-alkoxyalkyl groups. Examples of 1-alkoxyalkyl groups include methoxymethyl, 1-methoxyethyl, 1-ethoxyethyl, 1-n-propoxyethyl, 1-n-butoxyethyl, 1-isobutoxyethyl, 1-(2-chloroethoxy)ethyl, 1-(2-ethylhexyloxy)ethyl, 1-cyclohexyloxyethyl, and 1-(2-cyclohexylethoxy)ethyl groups, with 1-ethoxyethyl and 1-n-propoxyethyl being preferred. 6 or R 7 One of the two and R 8 Examples of the acid-decomposable group in which the above are bonded to form a ring structure having 3 to 10 ring members include a 2-tetrahydrofuranyl group and a 2-tetrahydropyranyl group, with a 2-tetrahydrofuranyl group being preferred.

[0045] The acrylic resin (A) is a compound represented by the formula (2) [ka] (In formula (2), R 2 and R 3 are each independently a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, a fully or partially fluorinated alkyl group having 1 to 3 carbon atoms, or a halogen atom; R 4 is a hydrogen atom, a linear alkyl group having 1 to 6 carbon atoms or a cyclic alkyl group having 4 to 12 carbon atoms, or a phenyl group which may be substituted with at least one selected from the group consisting of a hydroxy group, an alkyl group having 1 to 6 carbon atoms, and an alkoxy group having 1 to 6 carbon atoms. 2 and R 3 are preferably each independently a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.4 is preferably a cyclic alkyl group having 4 to 12 carbon atoms, or a phenyl group which may be substituted with at least one selected from the group consisting of a hydroxy group, an alkyl group having 1 to 6 carbon atoms, and an alkoxy group having 1 to 6 carbon atoms.

[0046] In one embodiment, the acrylic resin (A) contains 60 mol % to 100 mol %, preferably 65 mol % to 100 mol %, and more preferably 70 mol % to 100 mol % of the unit represented by formula (3). By adjusting the content of the unit represented by formula (3) to 60 mol % or more, the acrylic resin (A) can exhibit sufficient alkali solubility. By adjusting the content of the unit represented by formula (3) to 100 mol % or less, the alkali solubility of the acrylic resin (A) can be adjusted to an appropriate range.

[0047] In one embodiment, the number of structural units represented by formula (3), where s is an integer of 1 or greater, i.e., structural units represented by formula (3) in which at least one phenolic hydroxyl group is protected with an acid-decomposable group, is 5% to 95%, preferably 15% to 70%, and more preferably 20% to 60% of the total number of structural units in the acrylic resin (A). By setting the proportion of these structural units to 5% or greater, it is possible to impart chemical amplification functionality to the photosensitive resin composition and achieve high sensitivity. By setting the proportion of these structural units to 95% or less, it is possible to reduce the amount of unreacted acid-decomposable groups remaining, increase the solubility of exposed areas, and achieve high sensitivity.

[0048] In one embodiment, the positive photosensitive resin composition contains 10% to 80% by mass, preferably 15% to 60% by mass, and more preferably 20% to 40% by mass of acrylic resin (A) based on 100% by mass of solids. When the content of acrylic resin (A) is 10% by mass or more based on 100% by mass of solids, chemical amplification function can be imparted to the photosensitive resin composition, thereby achieving high sensitivity. When the content of acrylic resin (A) is 80% by mass or less based on 100% by mass of solids, the amount of unreacted acid-decomposable groups remaining can be reduced, increasing the solubility of exposed areas and achieving high sensitivity. In the present disclosure, the term "solid content" refers to the total mass of components including the acrylic resin (A), the black colorant (B), the quinone diazide compound (C), and any resin having an epoxy group and a phenolic hydroxyl group (D), the third resin (E), the dissolution promoter (F), the optional component (G), and any photoacid generator other than the quinone diazide compound (C), excluding the solvent (H).

[0049] In one embodiment, the positive photosensitive resin composition contains 15% to 90% by mass of acrylic resin (A), preferably 20% to 80% by mass or 30% to 90% by mass, and more preferably 25% to 65% by mass, based on the total mass of the resin components. By setting the content of acrylic resin (A) to 15% by mass or more, chemical amplification function can be imparted to the photosensitive resin composition, thereby achieving high sensitivity. By setting the content of acrylic resin (A) to 90% by mass or less, solubility of the exposed area can be increased, thereby achieving high sensitivity. In the present disclosure, the term "resin component" refers to the acrylic resin (A), an optional resin (D) having an epoxy group and a phenolic hydroxyl group, and an optional third resin (E).

[0050] [Black colorant (B)] The black colorant (B) is at least one selected from the group consisting of black dyes and black pigments. A black dye and a black pigment may be used in combination. For example, by forming black partition walls in an organic EL element using a positive photosensitive resin composition containing the black colorant (B), the visibility of a display device such as an organic EL display can be improved.

[0051] In one embodiment, the black colorant (B) comprises a black dye. A dye defined by a color index (CI) of Solvent Black 27 to 47 can be used as the black dye. The black dye is preferably defined by a CI of Solvent Black 27, 29, or 34. When at least one of the dyes defined by a CI of Solvent Black 27 to 47 is used as the black dye, the light-shielding properties of the film of the positive photosensitive resin composition after baking can be maintained. A positive photosensitive resin composition containing a black dye leaves less residue of the black colorant (B) during development compared to a positive photosensitive resin composition containing a black pigment, and a high-resolution pattern can be formed in the film.

[0052] A black pigment may be used as the black colorant (B). Examples of black pigments include carbon black, carbon nanotubes, acetylene black, graphite, iron black, aniline black, titanium black, perylene pigments, and lactam pigments. Surface-treated versions of these black pigments can also be used. Examples of commercially available perylene pigments include K0084, K0086, and Pigment Black 21, 30, 31, 32, 33, and 34 manufactured by BASF. Examples of commercially available lactam pigments include Irgaphor® Black S0100CF manufactured by BASF. Due to its high light-blocking properties, the black pigment is preferably at least one selected from the group consisting of carbon black, titanium black, perylene pigments, and lactam pigments.

[0053] In one embodiment, the positive photosensitive resin composition contains 10 to 150 parts by mass, preferably 30 to 100 parts by mass, and more preferably 40 to 70 parts by mass of the black colorant (B) based on 100 parts by mass of the total resin components. When the content of the black colorant (B) is 10 parts by mass or more based on the total 100 parts by mass, the light-blocking properties of the coating film after baking can be maintained. When the content of the black colorant (B) is 150 parts by mass or less based on the total 100 parts by mass, the coating film can be colored without impairing alkaline developability.

[0054] [Quinone diazide compounds (C)] The positive-type photosensitive resin composition contains a quinone diazide compound (C) as a photoacid generator. When irradiated with radiation such as visible light, ultraviolet light, gamma rays, or electron beams, the quinone diazide compound (C) generates an alkali-soluble carboxylic acid compound via the reaction shown in Reaction Scheme 1 below. The generated carboxylic acid compound promotes the decomposition of the acid-labile groups in the acrylic resin (A), regenerating phenolic hydroxyl groups and increasing the alkali solubility of the acrylic resin (A). Before exposure, the quinone diazide compound interacts (e.g., forms hydrogen bonds) with functional groups in binder resins such as novolac resins, rendering the binder resin insoluble in alkaline aqueous solutions. Meanwhile, the presence of the alkali-soluble carboxylic acid compound in the irradiated area facilitates the dissolution of the resin in that area together with the carboxylic acid compound in alkaline aqueous solutions. Furthermore, the carboxylic acid compound has a relatively larger molecular structure than acids generated by photoacid generators commonly used in chemically amplified resists, such as p-toluenesulfonic acid and 1-propanesulfonic acid, and is therefore less likely to diffuse in the coating. As a result of these synergistic effects, the difference in alkali solubility between the unexposed and exposed areas can be increased, thereby enabling the formation of a high-resolution pattern with high sensitivity even at a low exposure dose.The quinone diazide compound (C) can be used alone or in combination of two or more types.

[0055] [ka]

[0056] In one embodiment, high-resolution patterns can be formed without the post-exposure bake (PEB) required for typical chemically amplified resists. The quinone diazide compound has a relatively high quantum yield, efficiently generating a carboxylic acid compound in the exposed area. When an acid-labile group capable of being decomposed by a carboxylic acid compound is present in the vicinity, the generated carboxylic acid compound decomposes the acid-labile group even at room temperature, regenerating a phenolic hydroxyl group, thereby increasing the difference in alkali solubility between the unexposed and exposed areas. By omitting PEB, deterioration of pattern formability due to excessive diffusion of the acid generated from the photoacid generator to the unexposed area in the high-temperature environment during PEB can be suppressed. Furthermore, when using the optional resin (D) having epoxy groups and phenolic hydroxyl groups described below, omitting PEB prevents ring-opening polymerization of the epoxy groups in the resin (D) having epoxy groups and phenolic hydroxyl groups, thereby maintaining the alkali solubility of the resin (D) having epoxy groups and phenolic hydroxyl groups during development.

[0057] Examples of the quinone diazide compound (C) include a polyhydroxy compound to which a sulfonic acid of quinone diazide is bonded via an ester bond, a polyamino compound to which a sulfonic acid of quinone diazide is bonded via a sulfonamide bond, and a polyhydroxypolyamino compound to which a sulfonic acid of quinone diazide is bonded via an ester bond or a sulfonamide bond. From the viewpoint of contrast between exposed and unexposed areas, it is preferred that 20 mol % or more of the total functional groups of the polyhydroxy compound or polyamino compound be substituted with quinone diazide.

[0058] Examples of the polyhydroxy compounds include Bis-Z, BisP-EZ, TekP-4HBPA, TrisP-HAP, TrisP-PA, TrisP-SA, TrisOCR-PA, BisOCHP-Z, BisP-MZ, BisP-PZ, BisP-IPZ, BisOCP-IPZ, BisP-CP, BisRS-2P, BisRS-3P, BisP-OCHP, and methylenetrieth-FR-CR , BisRS-26X, DML-MBPC, DML-MBOC, DML-OCHP, DML-PCHP, DML-PC, DML-PTBP, DML-34X, DML-EP, DML-POP, Tyrol-BisOC-P, DML-PFP, DML-PSBP, DML-MTrisPC, TriML-P, TriML-35XL, TML-BP, TML-HQ, TML-pp-BPF, TML Examples of suitable tert-butylphenols include, but are not limited to, 4-tert-butylphenol, 2,6-dimethoxymethyl-p-cresol, 2,6-diacetoxymethyl-p-cresol, naphthol, tetrahydroxybenzophenone, methyl gallate, bisphenol A, bisphenol E, methylene bisphenol, and BisP-AP (trade name, manufactured by Honshu Chemical Industry Co., Ltd.).

[0059] Examples of the polyamino compound include, but are not limited to, 1,4-phenylenediamine, 1,3-phenylenediamine, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfone, and 4,4'-diaminodiphenyl sulfide.

[0060] Examples of the polyhydroxypolyamino compound include, but are not limited to, 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane, 3,3'-dihydroxybenzidine, and the like.

[0061] The quinone diazide compound (C) is preferably a 1,2-naphthoquinone diazide-4-sulfonic acid ester or a 1,2-naphthoquinone diazide-5-sulfonic acid ester of a polyhydroxy compound.

[0062] In one embodiment, the positive photosensitive resin composition contains 5 to 50 parts by mass of the quinone diazide compound (C), preferably 10 to 45 parts by mass or 20 to 50 parts by mass, and more preferably 13 to 40 parts by mass, based on 100 parts by mass of the total resin components. When the content of the quinone diazide compound (C) is 5 parts by mass or more based on the total 100 parts by mass, high sensitivity can be achieved. When the content of the quinone diazide compound (C) is 50 parts by mass or less based on the total 100 parts by mass, alkaline developability is good.

[0063] The positive photosensitive resin composition may contain, as a photoacid generator other than the quinone diazide compound (C), for example, a trichloromethyl-s-triazine compound, an onium salt such as a sulfonium salt, a phosphonium salt, a diazonium salt, or an iodonium salt, a quaternary ammonium salt, a diazomethane compound, an imide sulfonate compound, or an oxime sulfonate compound. In one embodiment, the content of the photoacid generator other than the quinone diazide compound (C) in the positive photosensitive resin composition is 0.5 parts by mass or less, preferably 0.3 parts by mass or less, and more preferably 0.1 parts by mass or less, based on 100 parts by mass of the total resin components. The positive photosensitive resin composition preferably does not contain a photoacid generator other than the quinone diazide compound (C).

[0064] [Resin (D) having epoxy groups and phenolic hydroxyl groups] The positive photosensitive resin composition may further contain a resin (D) having an epoxy group and a phenolic hydroxyl group. The resin (D) having an epoxy group and a phenolic hydroxyl group is an alkaline aqueous solution-soluble resin. The resin (D) having an epoxy group and a phenolic hydroxyl group may have an alkali-soluble functional group other than the phenolic hydroxyl group. The phenolic hydroxyl group and other alkali-soluble functional groups may be protected with an acid-decomposable group. The resin (D) having an epoxy group and a phenolic hydroxyl group can be obtained, for example, by reacting some of the epoxy groups of a compound having at least two epoxy groups per molecule (hereinafter sometimes referred to as an "epoxy compound") with the carboxyl group of a hydroxybenzoic acid compound. The epoxy groups of the resin (D) having an epoxy group and a phenolic hydroxyl group react with the phenolic hydroxyl groups to form crosslinks during heat treatment (post-baking) after development, thereby improving the chemical resistance, heat resistance, etc. of the coating. Since the phenolic hydroxyl group contributes to solubility in an alkaline aqueous solution during development, the resin (D) having an epoxy group and a phenolic hydroxyl group also functions as a dissolution promoter for the acrylic resin (A) whose acid-decomposable group is not sufficiently decomposed (deprotected) when exposed to light at a low exposure dose, thereby making it possible to impart high sensitivity to the photosensitive resin composition.

[0065] The following reaction formula 2 shows an example of a reaction in which one of the epoxy groups of an epoxy compound reacts with the carboxy group of a hydroxybenzoic acid compound to form a compound having a phenolic hydroxyl group. [ka]

[0066] Examples of compounds having at least two epoxy groups per molecule include novolac epoxy resins such as phenol novolac epoxy resins and cresol novolac epoxy resins, bisphenol epoxy resins, biphenol epoxy resins, naphthalene skeleton-containing epoxy resins, alicyclic epoxy resins, and heterocyclic epoxy resins. These epoxy compounds may contain two or more epoxy groups per molecule, and may be used alone or in combination of two or more. Because these compounds are thermosetting, it is common knowledge among those skilled in the art that their structures cannot be unambiguously described due to differences in the presence or absence of epoxy groups, the type of functional group, the degree of polymerization, and so on. An example of the structure of a novolac epoxy resin is shown in formula (4). In formula (4), for example, R 9 is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 or 2 carbon atoms, or a hydroxyl group; and m is an integer of 1 to 50. [ka]

[0067] Examples of phenol novolac epoxy resins include EPICLON (registered trademark) N-770 (manufactured by DIC Corporation) and jER (registered trademark)-152 (manufactured by Mitsubishi Chemical Corporation). Examples of cresol novolac epoxy resins include EPICLON (registered trademark) N-695 (manufactured by DIC Corporation) and EOCN (registered trademark)-102S (manufactured by Nippon Kayaku Co., Ltd.). Examples of bisphenol epoxy resins include bisphenol A epoxy resins such as jER (registered trademark) 828, jER (registered trademark) 1001 (manufactured by Mitsubishi Chemical Corporation), and YD-128 (trade name, manufactured by Nippon Steel Chemical & Material Co., Ltd.), and bisphenol F epoxy resins such as jER (registered trademark) 806 (manufactured by Mitsubishi Chemical Corporation) and YDF-170 (trade name, manufactured by Nippon Steel Chemical & Material Co., Ltd.). Examples of biphenol-type epoxy resins include jER (registered trademark) YX-4000 and jER (registered trademark) YL-6121H (manufactured by Mitsubishi Chemical Corporation). Examples of naphthalene skeleton-containing epoxy resins include NC-7000 (trade name, manufactured by Nippon Kayaku Co., Ltd.) and EXA-4750 (trade name, manufactured by DIC Corporation). Examples of alicyclic epoxy resins include EHPE (registered trademark)-3150 (manufactured by Daicel Chemical Industries, Ltd.). Examples of heterocyclic epoxy resins include TEPIC (registered trademark), TEPIC-L, TEPIC-H, and TEPIC-S (manufactured by Nissan Chemical Industries, Ltd.).

[0068] The compound having at least two epoxy groups in one molecule is preferably a novolac epoxy resin, more preferably at least one selected from the group consisting of phenol novolac epoxy resins and cresol novolac epoxy resins. A positive photosensitive resin composition containing a resin (D) having an epoxy group derived from a novolac epoxy resin and a phenolic hydroxyl group has excellent pattern formability, easy adjustment of alkali solubility, and little outgassing.

[0069] The hydroxybenzoic acid compound is a compound in which at least one of the 2- to 6-positions of benzoic acid is substituted with a hydroxyl group, and examples thereof include salicylic acid, 4-hydroxybenzoic acid, 2,3-dihydroxybenzoic acid, 2,4-dihydroxybenzoic acid, 2,5-dihydroxybenzoic acid, 2,6-dihydroxybenzoic acid, 3,4-dihydroxybenzoic acid, 3,5-dihydroxybenzoic acid, 2-hydroxy-5-nitrobenzoic acid, 3-hydroxy-4-nitrobenzoic acid, and 4-hydroxy-3-nitrobenzoic acid. Dihydroxybenzoic acid compounds are preferred in terms of enhancing alkaline developability. The hydroxybenzoic acid compounds can be used alone or in combination of two or more.

[0070] In one embodiment, the resin (D) having an epoxy group and a phenolic hydroxyl group is a reaction product of a compound having at least two epoxy groups in one molecule with a hydroxybenzoic acid compound, and is represented by the formula (5): [ka] In formula (5), b is an integer of 1 to 5, and * represents a bond to a residue other than the epoxy group involved in the reaction of a compound having at least two epoxy groups in one molecule.

[0071] In the method for obtaining resin (D) having an epoxy group and a phenolic hydroxyl group from an epoxy compound and a hydroxybenzoic acid compound, 0.2 to 0.95 equivalents of the hydroxybenzoic acid compound can be used relative to 1 equivalent of the epoxy group of the epoxy compound, preferably 0.3 to 0.9 equivalents, and more preferably 0.4 to 0.8 equivalents. If the amount of the hydroxybenzoic acid compound is 0.2 equivalents or more, sufficient alkali solubility can be obtained, and if it is 0.95 equivalents or less, an increase in molecular weight due to side reactions can be suppressed.

[0072] A catalyst may be used to promote the reaction between the epoxy compound and the hydroxybenzoic acid compound. The amount of catalyst used may be 0.1 to 10 parts by mass based on 100 parts by mass of the reaction raw material mixture consisting of the epoxy compound and the hydroxybenzoic acid compound. The reaction temperature may be 60 to 150°C, and the reaction time may be 3 to 30 hours. Examples of catalysts used in this reaction include triethylamine, benzyldimethylamine, triethylammonium chloride, benzyltrimethylammonium bromide, benzyltrimethylammonium iodide, triphenylphosphine, chromium octanoate, and zirconium octanoate.

[0073] The number average molecular weight (Mn) of the resin (D) having an epoxy group and a phenolic hydroxyl group is preferably 500 to 8000, more preferably 800 to 6000, and even more preferably 1000 to 5000. If the number average molecular weight is 500 or more, the resin has suitable alkali solubility and is therefore suitable as a resin for photosensitive materials, and if it is 8000 or less, the resin has good coatability and developability.

[0074] In one embodiment, the epoxy equivalent of the resin (D) having an epoxy group and a phenolic hydroxyl group is 300 to 7000, preferably 400 to 6000, and more preferably 500 to 5000. When the epoxy equivalent of the resin (D) having an epoxy group and a phenolic hydroxyl group is 300 or more, sufficient alkali solubility can be exhibited in the resin (D) having an epoxy group and a phenolic hydroxyl group. When the epoxy equivalent of the resin (D) having an epoxy group and a phenolic hydroxyl group is 7000 or less, the strength of the coating film after curing can be increased. The epoxy equivalent is determined according to JIS K 7236:2009.

[0075] In one embodiment, the hydroxyl equivalent of the resin (D) having an epoxy group and a phenolic hydroxyl group is 160 to 500, preferably 170 to 400, and more preferably 180 to 300. When the hydroxyl equivalent of the resin (D) having an epoxy group and a phenolic hydroxyl group is 160 or more, the strength of the coating film after curing can be increased. When the hydroxyl equivalent of the resin (D) having an epoxy group and a phenolic hydroxyl group is 500 or less, sufficient alkali solubility can be imparted to the resin (D) having an epoxy group and a phenolic hydroxyl group. The hydroxyl equivalent is determined according to JIS K 0070:1992.

[0076] In one embodiment, the positive photosensitive resin composition contains 5% by mass to 50% by mass, preferably 10% by mass to 40% by mass, and more preferably 15% by mass to 30% by mass of resin (D) having an epoxy group and a phenolic hydroxyl group, based on 100% by mass of solids. When the content of resin (D) having an epoxy group and a phenolic hydroxyl group is 5% by mass or more, based on 100% by mass of solids, dissolution of the exposed area can be promoted, achieving high sensitivity and ensuring the stability and durability of the coating after thermal curing. When the content of resin (D) having an epoxy group and a phenolic hydroxyl group is 50% by mass or less, based on 100% by mass of solids, the solubility of the unexposed area can be kept low, maintaining a high residual film rate.

[0077] [Third Resin (E)] The positive photosensitive resin composition may further contain a third resin (E) other than the acrylic resin (A) and the resin (D) having an epoxy group and a phenolic hydroxyl group. The third resin (E) may be used alone or in combination of two or more kinds.

[0078] Examples of the third resin (E) include acrylic resins other than the acrylic resin (A), polystyrene resins, epoxy resins, polyamide resins, phenolic resins, polyimide resins, polyamic acid resins, polybenzoxazole resins, polybenzoxazole resin precursors, silicone resins, cyclic olefin polymers, cardo resins, and derivatives of these resins. For example, derivatives of phenolic resins include polyalkenylphenolic resins in which an alkenyl group is bonded to a benzene ring, and derivatives of polystyrene resins include hydroxypolystyrene resin derivatives in which a phenolic hydroxyl group and a hydroxyalkyl group or an alkoxy group are bonded to a benzene ring. These resins may or may not have alkali-soluble functional groups.

[0079] In one embodiment, the third resin (E) is an acrylic resin having a plurality of phenolic hydroxyl groups, wherein the plurality of phenolic hydroxyl groups are not protected with acid-decomposable groups, i.e., the acrylic resin (A) from which all of the acid-decomposable groups have been deprotected. Such an acrylic resin has excellent compatibility with the acrylic resin (A) and high alkali solubility, and therefore can be suitably used to adjust the alkali solubility of the coating film.

[0080] The content of the third resin (E) can be determined appropriately within a range that does not impair the properties required for the intended use of the positive photosensitive resin composition.

[0081] [Solubility enhancer (F)] The positive photosensitive resin composition may further contain a dissolution promoter (F) for improving the solubility of the alkali-soluble portion in the developer during development. Examples of the dissolution promoter (F) include organic low-molecular-weight compounds selected from the group consisting of compounds having a carboxy group and compounds having a phenolic hydroxyl group. The dissolution promoter (F) may be used alone or in combination of two or more types.

[0082] In the present disclosure, the term "low molecular weight compound" refers to a compound having a molecular weight of not more than 1000. The above organic low molecular weight compound has a carboxy group or multiple phenolic hydroxyl groups and is alkali-soluble.

[0083] Examples of such organic low molecular weight compounds include aliphatic monocarboxylic acids such as formic acid, acetic acid, propionic acid, butyric acid, valeric acid, pivalic acid, caproic acid, diethylacetic acid, enanthic acid, and caprylic acid; aliphatic dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, brassylic acid, methylmalonic acid, ethylmalonic acid, dimethylmalonic acid, methylsuccinic acid, tetramethylsuccinic acid, and citraconic acid; aliphatic tricarboxylic acids such as tricarballylic acid, aconitic acid, and camphoronic acid; and aromatic monocarboxylic acids such as benzoic acid, toluic acid, cumic acid, hemimellitic acid, and mesitylene acid. Examples of aromatic polycarboxylic acids include phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, trimesic acid, mellophanic acid, and pyromellitic acid; aromatic hydroxycarboxylic acids such as dihydroxybenzoic acid, trihydroxybenzoic acid, and gallic acid; other carboxylic acids such as phenylacetic acid, hydratropic acid, hydrocinnamic acid, mandelic acid, phenylsuccinic acid, atropic acid, cinnamic acid, methyl cinnamate, benzyl cinnamate, cinnamylideneacetic acid, coumaric acid, and umbellic acid; and aromatic polyols such as catechol, resorcinol, hydroquinone, 1,2,4-benzenetriol, pyrogallol, phloroglucinol, and bisphenol.

[0084] The content of the dissolution promoter (F) in the positive photosensitive resin composition can be 0.1 to 50 parts by mass, preferably 1 to 35 parts by mass, and more preferably 2 to 20 parts by mass, based on 100 parts by mass of the total resin components. If the content of the dissolution promoter (F) is 0.1 part by mass or more based on the total 100 parts by mass, the dissolution of the resin components can be effectively promoted, and if it is 50 parts by mass or less, excessive dissolution of the resin components can be suppressed, and the pattern formability and surface quality of the coating can be improved.

[0085] [Optional component (G)] The positive photosensitive resin composition may contain, as optional component (G), a heat curing agent, a surfactant, a colorant other than (B), etc. In the present disclosure, optional component (G) is defined as not falling under any of (A) to (F).

[0086] A thermal radical generator can be used as the thermal curing agent. Preferred examples of the thermal radical generator include organic peroxides, specifically organic peroxides having a 10-hour half-life temperature of 100 to 170°C, such as dicumyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, tert-butylcumyl peroxide, di-tert-butyl peroxide, 1,1,3,3-tetramethylbutyl hydroperoxide, and cumene hydroperoxide.

[0087] The content of the heat curing agent is preferably 5 parts by mass or less, more preferably 4 parts by mass or less, and even more preferably 3 parts by mass or less, based on 100 parts by mass of the total solid content excluding the heat curing agent.

[0088] The positive photosensitive resin composition may contain a surfactant, for example, to improve the coatability, the smoothness of the coating, or the developability of the coating. Examples of the surfactant include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, and polyoxyethylene oleyl ether; polyoxyethylene aryl ethers such as polyoxyethylene octylphenyl ether and polyoxyethylene nonylphenyl ether; polyoxyethylene dialkyl esters such as polyoxyethylene dilaurate and polyoxyethylene distearate; and nonionic surfactants such as Megafac (registered trademark) F-2. Fluorine-based surfactants such as Surflon (registered trademark) S-242, S-243, S-386, S-420, and S-611 (all trade names, manufactured by ACG Seimi Chemical Co., Ltd.); organosiloxane polymers KP323, KP326, and KP341 (all trade names, manufactured by Shin-Etsu Chemical Co., Ltd.). These surfactants can be used alone or in combination of two or more.

[0089] The content of the surfactant is preferably 2 parts by mass or less, more preferably 1 part by mass or less, and even more preferably 0.5 parts by mass or less, based on 100 parts by mass of the total solid content excluding the surfactant.

[0090] The positive photosensitive resin composition may contain a second colorant other than the black colorant (B). Examples of the second colorant include dyes, organic pigments, and inorganic pigments, and can be used according to the purpose. The second colorant can be used in an amount that does not impair the effects of the present disclosure.

[0091] Examples of dyes include azo dyes, benzoquinone dyes, naphthoquinone dyes, anthraquinone dyes, cyanine dyes, squarylium dyes, croconium dyes, merocyanine dyes, stilbene dyes, diphenylmethane dyes, triphenylmethane dyes, fluoran dyes, spiropyran dyes, phthalocyanine dyes, indigo dyes, fulgide dyes, nickel complex dyes, and azulene dyes. Among dyes, red dyes are preferred. Examples of red dyes include VALIFAST® RED 3312 (a red dye defined by the CI of Solvent Red 122, manufactured by Orient Chemical Industry Co., Ltd.) and VALIFAST® RED 3311 (a red dye defined by the CI of Solvent Red 8, manufactured by Orient Chemical Industry Co., Ltd.).

[0092] Examples of pigments include CI Pigment Yellow 20, 24, 86, 93, 109, 110, 117, 125, 137, 138, 147, 148, 153, 154, 166, CI Pigment Orange 36, 43, 51, 55, 59, 61, CI Pigment Red 9, 97, 122, 123, 149, 168, 177, 180, 192, 215, 216, 217, 220, 223, 224, 226, 227, 228, 240, CI Pigment Violet 19, 23, 29, 30, 37, 40, 50, CI Pigment Blue 15, 15:1, 15:4, 22, 60, 64, CI Pigment Green 7, CI Pigment Brown 23, 25, 26, and the like.

[0093] [Coating composition] [Solvent (H)] The positive-type photosensitive resin composition can be dissolved in a solvent (H) and used as a coating composition in solution form (however, when a black pigment is included, the pigment is in a dispersed state). For example, a coating composition of the positive-type photosensitive resin composition can be prepared by dissolving an acrylic resin (A), an optional resin (D) having epoxy groups and phenolic hydroxyl groups, and a third resin (E) in a solvent (H) to obtain a solution, and then mixing the solution with a black colorant (B), a quinone diazide compound (C), and, if necessary, optional components (G) such as a solubility promoter (F), a thermosetting agent, and a surfactant in a predetermined ratio. The viscosity of the coating composition can be adjusted to suit the application method used by changing the amount of solvent (H).

[0094] Examples of the solvent (H) include glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol dimethyl ether, ethylene glycol methyl ethyl ether, and ethylene glycol monoethyl ether; ethylene glycol alkyl ether acetates such as methyl cellosolve acetate and ethyl cellosolve acetate; diethylene glycol compounds such as diethylene glycol monomethyl ether, diethylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol ethyl methyl ether, diethylene glycol monoethyl ether, and diethylene glycol monobutyl ether; and propylene glycol alkyl ether acetates such as propylene glycol methyl ether acetate and propylene glycol ethyl ether acetate. Examples of suitable solvents include esters such as ethyl acetate compounds, aromatic hydrocarbons such as toluene and xylene, ketones such as methyl ethyl ketone, methyl amyl ketone, cyclohexanone, 4-hydroxy-4-methyl-2-pentanone and cyclohexanone, esters such as ethyl 2-hydroxypropionate, methyl 2-hydroxy-2-methylpropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxyacetate, ethyl hydroxyacetate, methyl 2-hydroxy-2-methylbutanoate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, ethyl ethyl acetate, butyl acetate, methyl lactate, ethyl lactate and γ-butyrolactone, and amide compounds such as N-methyl-2-pyrrolidone, N,N-dimethylformamide and N,N-dimethylacetamide. These solvents can be used alone or in combination of two or more.

[0095] The coating composition can be prepared by dissolving or dispersing the acrylic resin (A), black colorant (B), quinone diazide compound (C), and optionally the resin (D) having epoxy groups and phenolic hydroxyl groups, third resin (E), dissolution promoter (F), or optional component (G) in a solvent (H) and mixing them together. The solids concentration of the coating composition can be appropriately determined depending on the intended use. For example, the solids concentration of the coating composition may be 1 to 60 mass %, 3 to 50 mass %, or 5 to 40 mass %.

[0096] When a pigment is used, known methods can be used for dispersion and mixing. For example, ball-type mills such as a ball mill, sand mill, bead mill, paint shaker, and rocking mill, blade-type mills such as a kneader, paddle mixer, planetary mixer, and Henschel mixer, and roll-type mills such as a three-roll mixer, as well as Raikai mixers, colloid mills, ultrasonic mixers, homogenizers, and rotation-revolution mixers may be used. From the viewpoints of dispersion efficiency and fine dispersion, it is preferable to use a bead mill.

[0097] The prepared coating composition is usually filtered before use, for example, using a Millipore filter with a pore size of 0.05 to 1.0 μm.

[0098] The coating composition thus prepared also has excellent long-term storage stability.

[0099] [Method of using the positive photosensitive resin composition] When a positive-type photosensitive resin composition is used in radiation lithography, the positive-type photosensitive resin composition is first dissolved or dispersed in a solvent to prepare a coating composition. Next, the coating composition is applied to a substrate surface, and the solvent is removed by heating or other means to form a coating film. The method for applying the coating composition to the substrate surface is not particularly limited, and examples of methods that can be used include spraying, roll coating, slit coating, and spin coating.

[0100] After applying the coating composition to the surface of a substrate, the solvent is usually removed by heating to form a coating (pre-baking). The heating conditions vary depending on the type and blending ratio of each component, but the coating can usually be obtained by heating at 70 to 130°C for 30 seconds to 20 minutes on a hot plate or 1 to 60 minutes in an oven.

[0101] Next, the prebaked coating is irradiated with radiation (e.g., visible light, ultraviolet light, far ultraviolet light, X-rays, electron beams, gamma rays, synchrotron radiation, etc.) through a photomask having a predetermined pattern (exposure step). Preferred radiation is ultraviolet light or visible light having a wavelength of 250 to 450 nm. In one embodiment, the radiation is i-ray. In another embodiment, the radiation is ghi-ray.

[0102] After the exposure step, a post-exposure bake (PEB) may be performed to promote decomposition of the acid-labile groups. PEB can further increase the alkali solubility of the acrylic resin (A) in the exposed areas. The heating conditions vary depending on the type and blending ratio of each component, but PEB can usually be performed at 70 to 140°C, for example, for 30 seconds to 20 minutes on a hot plate or for 1 to 60 minutes in an oven.

[0103] In one embodiment, the PEB after the exposure step can be omitted.

[0104] After the exposure step or PEB step, the coating is developed by contacting it with a developer to remove unnecessary portions and form a pattern in the coating (development step). Examples of the developer include aqueous solutions of alkaline compounds such as inorganic alkalis (e.g., sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and aqueous ammonia); primary amines (e.g., ethylamine and n-propylamine); secondary amines (e.g., diethylamine and di-n-propylamine); tertiary amines (e.g., triethylamine and methyldiethylamine); alcohol amines (e.g., dimethylethanolamine and triethanolamine); quaternary ammonium salts (e.g., tetramethylammonium hydroxide, tetraethylammonium hydroxide, and choline); and cyclic amines (e.g., pyrrole, piperidine, 1,8-diazabicyclo[5.4.0]-7-undecene, 1,5-diazabicyclo[4.3.0]-5-nonane). An aqueous solution containing an appropriate amount of a water-soluble organic solvent (e.g., methanol or ethanol), a surfactant, etc., can also be used as the developer. The development time is typically 30 to 180 seconds. The developing method may be any of a puddle method, a shower method, a dipping method, etc. After development, the film is washed with running water for 30 to 90 seconds to remove unnecessary portions, and then air-dried with compressed air or compressed nitrogen, thereby forming a pattern in the film.

[0105] Thereafter, the coating film on which the pattern has been formed can be heat-treated, for example, at 100 to 350°C for 20 to 200 minutes using a heating device such as a hot plate or oven, to obtain a cured coating film (post-baking, heat treatment step). In the heat treatment, the temperature may be maintained constant, or may be increased continuously or stepwise. The heat treatment is preferably carried out in a nitrogen atmosphere.

[0106] The optical density (OD value) of the cured film of the positive photosensitive resin composition is preferably 0.5 or more per 1 μm of film thickness, more preferably 0.7 or more, and even more preferably 1.0 or more. If the OD value of the cured film is 0.5 or more per 1 μm of film thickness, sufficient light-blocking properties can be obtained.

[0107] In one embodiment, a method for producing an organic EL device partition wall or insulating film includes dissolving or dispersing a positive photosensitive resin composition in a solvent to prepare a coating composition, applying the coating composition to a substrate to form a coating film, removing the solvent contained in the coating and drying the coating, exposing the dried coating to radiation through a photomask to decompose at least a portion of the acid-decomposable groups of the acrylic resin (A), developing the exposed coating by contacting it with a developer to form a pattern in the coating, and heat-treating the patterned coating at a temperature of 100°C to 350°C to form an organic EL device partition wall or insulating film. The PEB described above can also be performed after exposure and before development.

[0108] One embodiment is a partition wall for an organic EL device, which comprises a cured product of a positive-type photosensitive resin composition.

[0109] One embodiment is an insulating film for an organic EL device, which comprises a cured product of a positive photosensitive resin composition.

[0110] One embodiment is an organic EL device containing a cured product of the positive photosensitive resin composition. [Example]

[0111] The present invention will be specifically described below based on examples and comparative examples, but the present invention is not limited to these examples.

[0112] (1) Raw materials The raw materials used in the examples and comparative examples were produced or obtained as follows.

[0113] The weight average molecular weight and number average molecular weight of the acrylic resin (A), the resin (D) having an epoxy group and a phenolic hydroxyl group, and the third resin (E) were calculated using a calibration curve prepared using a polystyrene standard substance under the following measurement conditions. Device name: Shodex (registered trademark) GPC-101 Column: Shodex (registered trademark) LF-804 Mobile phase: tetrahydrofuran Flow rate: 1.0mL / min Detector: Shodex (registered trademark) RI-71 Temperature: 40℃

[0114] [Production Example 1] Production of an aqueous alkali solution-soluble copolymer (PCX-02e) (third resin (E)) of an α-alkyl acrylate ester having a phenolic hydroxyl group and another polymerizable monomer 29.0 g of 4-hydroxyphenyl methacrylate ("PQMA" manufactured by Showa Denko K.K.) and 5.12 g of N-cyclohexylmaleimide (manufactured by Nippon Shokubai Co., Ltd.) were completely dissolved in 96.5 g of 1-methoxy-2-propyl acetate (manufactured by Daicel Corporation) as a solvent, and 3.41 g of V-601 (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) as a polymerization initiator were completely dissolved in 13.7 g of 1-methoxy-2-propyl acetate (manufactured by Daicel Corporation). The two resulting solutions were simultaneously added dropwise over 2 hours to 40.0 g of 1-methoxy-2-propyl acetate (manufactured by Daicel Corporation) heated to 85 °C under a nitrogen gas atmosphere in a 300 mL three-neck flask, and then reacted at 85 °C for 3 hours. The reaction solution was cooled to room temperature and added dropwise to 815 g of toluene to precipitate the copolymer. The precipitated copolymer was collected by filtration and vacuum dried at 90°C for 4 hours, and 32.4g of white powder was collected. The number average molecular weight of the obtained PCX-02e was 3100 and the weight average molecular weight was 6600.

[0115] [Production Example 2] Production of acrylic resin (A) (PCX-02e-POE 58%) in which phenolic hydroxyl groups are protected with 1-n-propoxyethyl groups In a 100 mL three-neck flask, 10.0 g of an aqueous alkali-soluble copolymer (PCX-02e) of an α-alkyl acrylate ester having a phenolic hydroxyl group and other polymerizable monomers and 0.60 g of pyridinium salt of p-toluenesulfonic acid (Tokyo Chemical Industry Co., Ltd.) as an acid catalyst were dissolved in 40.0 g of tetrahydrofuran (Fujifilm Wako Pure Chemical Industries, Ltd.). The mixture was then ice-cooled under a nitrogen gas atmosphere, and 5.33 g of n-propyl vinyl ether (Tokyo Chemical Industry Co., Ltd.) was added dropwise over 1 hour. The mixture was then stirred at room temperature for 4 hours. The acid catalyst was neutralized with saturated aqueous sodium bicarbonate, and the aqueous layer was removed. The organic layer was further washed twice with water. The tetrahydrofuran was then distilled off. The resulting solid was dissolved in 50.0 g of ethyl acetate and added dropwise to 200 g of toluene to precipitate the product. The precipitate was collected by filtration and dried under vacuum at 80°C for 4 hours, yielding 11.0 g of a white powder. The resulting powder was dissolved in propylene glycol monomethyl acetate to obtain a 20% solids solution of acrylic resin (A) (PCX-02e-POE58%) in which the phenolic hydroxyl groups were protected with 1-n-propoxyethyl groups. The resulting PCX-02e-POE58% had a number-average molecular weight of 4500, a weight-average molecular weight of 8400, 58 mol% of the phenolic hydroxyl groups protected with acid-decomposable groups, and 49% of the total number of structural units of acrylic resin (A). The proportion of phenolic hydroxyl groups protected with acid-decomposable groups was calculated from the weight loss (%) of the acrylic resin (A) at 260°C when the temperature was increased from room temperature to 250°C at a rate of 10°C / min in a nitrogen gas flow, held for 10 minutes, and then further increased to 400°C at a rate of 10°C / min using a thermogravimetric differential thermal analyzer (TG / DTA6200, manufactured by Hitachi High-Tech Science Corporation).

[0116] [Production Example 3] Production of acrylic resin (A) (PCX-02e-THF 55%) in which the phenolic hydroxyl group is protected with a 2-tetrahydrofuranyl group A white powder (11.0 g) was recovered in the same manner as in Production Example 2, except that 3.00 g of 2,3-dihydrofuran (Tokyo Chemical Industry Co., Ltd.) was used instead of n-propyl vinyl ether. The resulting powder was dissolved in propylene glycol monomethyl acetate to obtain a 20% solids solution of acrylic resin (A) (PCX-02e-THF55%) in which the phenolic hydroxyl groups were protected with 2-tetrahydrofuranyl groups. The resulting PCX-02e-THF55% had a number-average molecular weight of 3,600 and a weight-average molecular weight of 6,900. The proportion of phenolic hydroxyl groups protected with acid-decomposable groups was 55 mol %, and the number of structural units represented by formula (3) in which at least one phenolic hydroxyl group was protected with an acid-decomposable group accounted for 47% of the total number of structural units of acrylic resin (A).

[0117] [Production Example 4] Production of acrylic resin (A) (PCX-02e-THF 29%) in which the phenolic hydroxyl group is protected with a 2-tetrahydrofuranyl group A white powder (10.0 g) was recovered in the same manner as in Production Example 2, except that 50.0 g of tetrahydrofuran and 2.34 g of 2,3-dihydrofuran were used. The resulting powder was dissolved in propylene glycol monomethyl acetate to obtain a 20% solids solution of acrylic resin (A) (PCX-02e-THF 29%) in which the phenolic hydroxyl groups were protected with 2-tetrahydrofuranyl groups. The resulting PCX-02e-THF 29% had a number-average molecular weight of 3700 and a weight-average molecular weight of 6800. The proportion of phenolic hydroxyl groups protected with acid-decomposable groups was 29 mol %, and the number of structural units represented by formula (3) in which at least one phenolic hydroxyl group was protected with an acid-decomposable group accounted for 25% of the total number of structural units of acrylic resin (A).

[0118] [Production Example 5] Production of Resin (D) (N770OH70) Having Epoxy Groups and Phenolic Hydroxyl Groups A 300 mL three-neck flask was charged with 75.2 g of γ-butyrolactone (Mitsubishi Chemical Corporation) as a solvent and 37.6 g of EPICLON® N-770 (a phenolic novolac epoxy resin manufactured by DIC Corporation, epoxy equivalent weight 188) as a compound having at least two epoxy groups per molecule, and dissolved under a nitrogen gas atmosphere at 60°C. 20.1 g (0.65 equivalents per epoxy equivalent) of 3,5-dihydroxybenzoic acid (Fujifilm Wako Pure Chemical Industries, Ltd.) as a hydroxybenzoic acid compound and 0.173 g (0.660 mmol) of triphenylphosphine (Tokyo Chemical Industry Co., Ltd.) as a reaction catalyst were added, and the mixture was allowed to react at 110°C for 56 hours. The reaction solution was returned to room temperature, diluted with γ-butyrolactone to a solids content of 20% by mass, and filtered to obtain 286.5 g of a solution of a second resin (N770OH70) having epoxy groups and phenolic hydroxyl groups. The resulting reaction product had a number average molecular weight of 2,200, a weight average molecular weight of 6,900, and an epoxy equivalent of 2,000.

[0119] [Production Example 6] Production of Resin (D) (N695OH70) Having Epoxy Groups and Phenolic Hydroxyl Groups A solution of 304.2 g of a second resin (N695OH70) having epoxy groups and phenolic hydroxyl groups was obtained in the same manner as in Production Example 5, except that 42.8 g of EPICLON® N-695 (a cresol novolac epoxy resin manufactured by DIC Corporation, epoxy equivalent weight 214) was used as a compound having at least two epoxy groups per molecule and 0.166 g (0.660 mmol) of triphenylphosphine (manufactured by Tokyo Chemical Industry Co., Ltd.) was used as a reaction catalyst at 110°C for 21 hours. The number-average molecular weight of the resulting reaction product was 3,000, the weight-average molecular weight was 7,500, and the epoxy equivalent weight was 2,200.

[0120] [Production Example 7] Production of an aqueous alkali solution-soluble copolymer (PCX-01) (third resin (E)) of an α-alkyl acrylate ester having a phenolic hydroxyl group and another polymerizable monomer 28.0 g of 4-hydroxyphenyl methacrylate ("PQMA" manufactured by Showa Denko K.K.) and 7.89 g of N-cyclohexylmaleimide (manufactured by Nippon Shokubai Co., Ltd.) were dissolved in 77.1 g of 1-methoxy-2-propyl acetate (manufactured by Daicel Corporation) as a solvent, and 3.66 g of V-601 (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) as a polymerization initiator were completely dissolved in 14.6 g of 1-methoxy-2-propyl acetate (manufactured by Daicel Corporation). The two resulting solutions were simultaneously added dropwise over 2 hours to 61.2 g of 1-methoxy-2-propyl acetate (manufactured by Daicel Corporation) heated to 85 °C under a nitrogen gas atmosphere in a 300 mL three-neck flask, and then reacted at 85 °C for 3 hours. The reaction solution was cooled to room temperature and added dropwise to 815 g of toluene to precipitate the copolymer. The precipitated copolymer was collected by filtration and vacuum dried at 90°C for 4 hours, and 33.4g of white powder was collected. The number average molecular weight of the obtained PCX-01 was 6,600 and the weight average molecular weight was 11,600.

[0121] Acrylic resin (A) As the acrylic resin (A), 58% of PCX-02e-POE, 55% of PCX-02e-THF, and 29% of PCX-02e-THF were used.

[0122] Black colorant (B) As the black colorant (B), a black dye, VALIFAST (registered trademark) BLACK 3820 (a black dye specified by the CI of Solvent Black 27, manufactured by Orient Chemical Industries Co., Ltd.) was used.

[0123] Quinone diazide compounds (C) The quinone diazide compound (C) used was a quinone diazide photoacid generator, TS-150A (ester of 4,4'-[1-[4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl]ethylidene]bisphenol (TrisP-PA) and 6-diazo-5,6-dihydro-5-oxonaphthalene-1-sulfonic acid (1,2-naphthoquinone diazide-5-sulfonic acid), manufactured by Toyo Gosei Co., Ltd.). The structure of TS-150A is shown below.

[0124] [ka]

[0125] Another photoacid generator used was the oxime-based photoacid generator PAG-103 (2-[2-(propylsulfonyloxyimino)thiophen-3(2H)-ylidene]-2-(2-methylphenyl)acetonitrile, manufactured by BASF, CAS No. 852246-55-0). PAG-103 generates 1-propanesulfonic acid (pKa=-2.8) upon exposure to light. The structure of PAG-103 is shown below.

[0126] [ka]

[0127] As the resin (D) having an epoxy group and a phenolic hydroxyl group, N770OH70 and N695OH70 were used.

[0128] As the third resin (E), PCX-02e, PCX-01, and TR4020G (cresol novolac resin, manufactured by Asahi Organic Chemicals Co., Ltd.) were used.

[0129] Phloroglucinol and adipic acid were used as dissolution promoters (F).

[0130] (2) Evaluation method The evaluation methods used in the examples and comparative examples are as follows.

[0131] [Film thickness after pre-baking, development, and hardening] A glass substrate (100 mm × 100 mm × 1 mm) was bar-coated with the positive photosensitive resin composition so that the dry film thickness was 2.4 to 4.5 μm, and pre-baked by heating on a hot plate under the conditions shown in Table 1. The dry film thickness was measured using an optical film thickness measurement device (F20-NIR, manufactured by Filmetrics Inc.) and recorded as the post-pre-baking film thickness (μm). The coating was then exposed to 100 mJ / cm 2 through a quartz photomask (having a φ10 μm opening pattern) using an exposure device (product name Multilight ML-251A / B, manufactured by Ushio Inc.) equipped with an ultra-high pressure mercury lamp. 2 The film was exposed to an i-line irradiance of 1000 nm. The exposure dose was measured using an ultraviolet integrating actinometer (product name UIT-150, light-receiving part UVD-S365, manufactured by Ushio Inc.). After exposure, the film was either not subjected to PEB or heated on a hot plate at 110°C for 240 or 280 seconds for PEB. The film was then subjected to alkaline development for 60 seconds using a spin developer (AD-1200, manufactured by Takizawa Sangyo Co., Ltd.) with a 2.38% by mass aqueous solution of tetramethylammonium hydroxide. The film thickness of the unexposed area after alkaline development was measured again using an optical film thickness measurement device (F20-NIR, manufactured by Filmetrics Inc.) and recorded as the film thickness after development (μm). The film was then cured by heating at 250°C for 60 minutes in an inert oven (DN411I, manufactured by Yamato Scientific Co., Ltd.). The film thickness of the unexposed area after curing was measured again using an optical film thickness measuring device (F20-NIR, manufactured by Filmetrics Inc.) and recorded as the film thickness (μm) after curing.

[0132] [Alkali solubility] The alkali solubility (μm) was calculated by subtracting the film thickness (μm) after development from the film thickness (μm) after pre-baking. The smaller this value, the higher the alkali resistance of the unexposed area.

[0133] [Hole diameter] After curing, the diameter of the holes formed in the coating film was measured using a microscope (VHX-6000, manufactured by Keyence Corporation) and recorded as the hole diameter.

[0134] (3) Preparation and evaluation of positive photosensitive resin compositions [Examples 1 to 7 and Comparative Examples 1 to 7] An acrylic resin (A), a resin (D) having an epoxy group and a phenolic hydroxyl group, and a third resin (E) were mixed and dissolved in the composition shown in Table 1. To the resulting solution, a black colorant (B), a quinone diazide compound (C) or other photoacid generator, and a dissolution promoter (F) shown in Table 1 were added and further mixed. After visually confirming that the components had dissolved, the mixture was filtered through a Millipore filter with a pore size of 0.22 μm to prepare a positive photosensitive resin composition with a solids concentration of 12% by mass. The parts by mass of the compositions in Table 1 are values ​​converted to solids. Table 1 shows the evaluation results of the positive photosensitive resin compositions of Examples 1 to 7 and Comparative Examples 1 to 7. In the hole diameter evaluation results in Table 1, "0" means that no hole was opened. Furthermore, "na" means that no hole was opened or a pattern could not be formed, and measurement was not possible.

[0135] [Table 1-1]

[0136] [Table 1-2]

[0137] Although PEB was not performed in Examples 1 to 5, the hole diameter was 6.4 μm or more, and holes could be formed with high resolution. As shown in Examples 6 and 7, PEB can also be performed.

[0138] In Comparative Examples 1 to 3, which did not contain acrylic resin (A), holes either did not open (Comparative Examples 1 and 3), or the unexposed areas completely dissolved, failing to form a pattern (Comparative Example 2). In Comparative Example 4, in which the photoacid generator in Example 5 was changed from quinone diazide compound (C) to PAG-103, a large amount of the unexposed areas dissolved, failing to form a pattern. In Comparative Example 5, in which the photoacid generator in Example 6 was changed from quinone diazide compound (C) to PAG-103, pattern formability decreased (hole diameter decreased) compared to Example 6. In Comparative Example 6, in which the PEB time in Comparative Example 5 was extended by 40 seconds, a large amount of the unexposed areas dissolved, failing to form a pattern. The results of Comparative Examples 5 and 6 demonstrate that the process window for PEB conditions is narrow in a chemically amplified system using PAG-103. Furthermore, in Comparative Example 7, in which a positive-tone photosensitive resin composition with the same composition as Comparative Examples 5 and 6 was used but PEB was not performed, no holes were opened. [Industrial Applicability]

[0139] The positive photosensitive resin composition according to the present embodiment can be suitably used in radiation lithography for forming partition walls or insulating films of organic EL devices. Organic EL devices having partition walls or insulating films formed from the positive photosensitive resin composition according to the present embodiment are suitably used as electronic components of display devices that exhibit good contrast.

Claims

1. an acrylic resin (A) having a plurality of phenolic hydroxyl groups, at least a portion of which are protected with acid-decomposable groups; at least one black colorant (B) selected from the group consisting of black dyes and black pigments; a quinone diazide compound (C) as a photoacid generator; Including, the acid-decomposable group is at least one selected from the group consisting of a silyl group and a group represented by formula (6), -CR 6 R 7 -O-R 8 (6) In formula (6), R 6 and R 7 each independently represent a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms; R 8 represents a linear, branched or cyclic alkyl group having 1 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, or an alkenyl group having 2 to 12 carbon atoms; one of R 6 or R 7 may be bonded to R 8 to form a ring structure having 3 to 10 ring members; and R 6 , R 7 , and R 8 may be substituted with a halogen atom selected from the group consisting of fluorine, chlorine, bromine, and iodine. A positive photosensitive resin composition.

2. The acrylic resin (A) is represented by the formula (3) 【Chemistry 1】 In formula (3), R １ is an alkyl group having 1 to 5 carbon atoms, and R ５ is the acid-decomposable group, r is an integer of 0 to 5, s is an integer of 0 to 5, provided that r+s is an integer of 1 to 5, and the acrylic resin (A) has at least one structural unit in which s is an integer of 1 or more.

3. The acrylic resin (A) is represented by the formula (2) 【Chemistry 2】 In formula (2), R ２ and R ３ are each independently a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, a fully or partially fluorinated alkyl group having 1 to 3 carbon atoms, or a halogen atom; R ４ is a hydrogen atom, a linear alkyl group having 1 to 6 carbon atoms or a cyclic alkyl group having 4 to 12 carbon atoms, or a phenyl group which may be substituted with at least one selected from the group consisting of a hydroxy group, an alkyl group having 1 to 6 carbon atoms, and an alkoxy group having 1 to 6 carbon atoms.

4. 4. The positive photosensitive resin composition according to claim 2, wherein the acrylic resin (A) contains 60 mol % to 100 mol % of the structural unit represented by formula (3).

5. The positive photosensitive resin composition according to any one of claims 1 to 4, comprising 20 parts by mass to 50 parts by mass of the quinone diazide compound (C) based on 100 parts by mass of the total of the resin components.

6. 6. The positive photosensitive resin composition according to claim 1, wherein the content of the photoacid generator other than the quinone diazide compound (C) is 0.5 parts by mass or less based on 100 parts by mass of the total of the resin components.

7. 7. The positive photosensitive resin composition according to claim 1, wherein 10 mol % to 95 mol % of the phenolic hydroxyl groups of the acrylic resin (A) are protected with the acid-decomposable group.

8. The positive photosensitive resin composition according to any one of claims 1 to 7, comprising 30% by mass to 90% by mass of the acrylic resin (A) based on the total mass of the resin components.

9. The positive photosensitive resin composition according to any one of claims 1 to 8, comprising 10 parts by mass to 150 parts by mass of the black colorant (B) based on 100 parts by mass of the total of the resin components.

10. 10. The positive photosensitive resin composition according to claim 1, wherein the optical density (OD value) of a cured film of the positive photosensitive resin composition is 0.5 or more per 1 μm of film thickness.

11. The positive photosensitive resin composition according to any one of claims 1 to 10, further comprising a resin (D) having an epoxy group and a phenolic hydroxyl group.

12. The resin (D) having an epoxy group and a phenolic hydroxyl group is a reaction product of a compound having at least two epoxy groups in one molecule with a hydroxybenzoic acid compound, and is represented by the formula (5): 【Transformation 3】 wherein in formula (5), b is an integer of 1 to 5, and * represents a bond to a residue excluding the epoxy group involved in the reaction of a compound having at least two epoxy groups in one molecule.

13. 13. The positive photosensitive resin composition according to claim 12, wherein the compound having at least two epoxy groups in one molecule is a novolac epoxy resin.

14. 14. The positive photosensitive resin composition according to claim 12, wherein the hydroxybenzoic acid compound is a dihydroxybenzoic acid compound.

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

16. An insulating film for an organic EL device, comprising a cured product of the positive photosensitive resin composition according to any one of claims 1 to 14.

17. An organic EL device comprising a cured product of the positive photosensitive resin composition according to any one of claims 1 to 14.

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