Copolymer, photosensitive composition, cured product, and organic el display device

Abstract

A copolymer (a) includes: a structural unit represented by formula (1) and / or a structural unit represented by formula (2); a structural unit represented by formula (3); and a structural unit represented by formula (4). The copolymer (a) is characterized in that: the total of the structural units represented by any one of formulae (1)-(4) is 70-100 mol% in the total of 100 mol% of all structural units in the copolymer (a); and, in the copolymer (a), when X represents the total mol number of the structural unit represented by formula (1) and the structural unit represented by formula (2), Y represents the mol number of the structural unit represented by formula (3), and Z represents the mol number of the structural unit represented by formula (4), a value A obtained by dividing X by Y is 1.0-10.0, and a value B obtained by dividing X by Z is 1.0-10.0.

Description

Copolymer, photosensitive composition, cured product, and organic EL display device

[0001] The present invention relates to a copolymer, a photosensitive composition, a cured product, and an organic EL display device.

[0002] BACKGROUND ART In recent years, many products using organic electroluminescence (hereinafter, "EL") display devices have been developed for use in thin display devices such as smartphones, tablet PCs, and televisions.

[0003] In general, an organic EL display device has a transparent electrode such as indium tin oxide (hereinafter referred to as "ITO") on the light extraction side of a light emitting element, and a metal electrode such as an alloy of magnesium and silver on the non-light extraction side of the light emitting element. In addition, an insulating layer called a pixel dividing layer is formed between the transparent electrode and the metal electrode to divide the pixels of the light emitting element.

[0004] In recent years, attempts have been made to impart light-shielding properties to pixel division layers to reduce reflection of external light such as sunlight and improve the visibility and contrast of organic EL display devices. Specific examples of such attempts include negative-type photosensitive resin compositions using black pigments (see, for example, Patent Documents 1 and 2).

[0005] Japanese Patent Publication No. 2022-38599 International Publication No. 2022 / 230792

[0006] However, the negative photosensitive resin composition disclosed in Patent Document 1 above has a small absolute value of the difference in pattern formation width relative to the mask design width (hereinafter sometimes referred to as "mask bias"), but has poor reflow properties in the curing process, resulting in a high taper angle after curing, and the thermal crosslinking group results in a lack of margin (tolerance) for pre-bake temperature conditions, resulting in the problem of minute development residues occurring in the openings of the pixel dividing layer, i.e., on the surface of the ITO electrode. Furthermore, the negative photosensitive colored resin composition disclosed in Patent Document 2 has a development mode problem in which, depending on the development method, the film in the unexposed areas is removed from the ITO electrode surface in an alkaline developer solution, peeling off into pieces, and there is a high risk of contamination of the development tank and clogging of the pipes due to the discharge of alkaline developer waste containing countless coarse, amorphous films, leaving room for improvement.

[0007] The present inventors have conducted extensive research and found that the above-mentioned problems can be solved by a copolymer having the following structure, and a photosensitive composition containing said copolymer: [1] A copolymer (a) containing a structural unit represented by formula (1) and / or a structural unit represented by formula (2), a structural unit represented by formula (3), and a structural unit represented by formula (4), wherein the total of the structural units represented by any one of formulas (1) to (4) accounts for 70 to 100 mol % of a total of 100 mol % of all structural units in said copolymer (a), and wherein, in said copolymer (a), when the total number of moles of the structural units represented by formula (1) and the structural units represented by formula (2) is X, the number of moles of the structural units represented by formula (3) is Y, and the number of moles of the structural units represented by formula (4) is Z, the value A obtained by dividing X by Y is 1.0 to 10.0, and the value B obtained by dividing X by Z is 1.0 to 10.0. In formula (1), R 1 represents a hydrogen atom or a methyl group. 2 represents a single bond or an alkylene group having 1 to 3 carbon atoms. 1 is an integer and represents 1 or 2. 3 represents an alkyl group having 1 to 3 carbon atoms or an alkoxy group having 1 to 3 carbon atoms. 2 is an integer from 0 to 2. * represents a bonding site. 4 represents a hydrogen atom or a methyl group. 5 represents an alkylene group having 1 to 3 carbon atoms. 3 is an integer and represents 1 or 2. 6 represents an alkyl group having 1 to 3 carbon atoms or an alkoxy group having 1 to 3 carbon atoms. 4 is an integer from 0 to 2. * represents a bonding site. 7 represents a hydrogen atom or a methyl group. * represents a bonding site. In formula (4), R 8 represents a hydrogen atom or a methyl group. 9 represents an alkyl group having 5 to 18 carbon atoms. * represents a bonding site.

[0008] [2] The copolymer according to [1], which has a weight average molecular weight (Mw) of 10,000 to 50,000. [3] The copolymer according to [1] or [2], wherein the copolymer (a) has a structural unit represented by formula (1). [4] R in formula (4) 9 is a branched alkyl group having 7 to 15 carbon atoms. [5] The copolymer according to any one of [1] to [4], wherein the copolymer (a) has a structural unit represented by formula (8): In formula (8), R 14 and R 15 each independently represents a hydrogen atom or a methyl group, R 16 represents a divalent group having 4 to 12 carbon atoms and a hydroxyl group. [6] The copolymer according to [5], wherein the copolymer (a) contains 5 to 18 mol % of the structural unit represented by formula (8) relative to the total 100 mol % of all structural units in the copolymer (a). [7] A photosensitive composition containing the copolymer (a) according to any one of [1] to [6], a pigment, a photosensitizer, and an organic solvent. [8] The photosensitive composition according to [7], further containing a (meth)acrylate compound having two 9,9-bis(naphthyl)fluorene skeletons and two ethylenically unsaturated double bond groups in the molecule, and having negative photosensitivity. [9] The photosensitive composition according to [7] or [8], further containing a compound represented by formula (9), and having negative photosensitivity. In formula (9), PO represents an oxypropylene group, EO represents an oxyethylene group, and x, y, and z each independently represent an integer of 1 to 50, satisfying the relationship y<x+z.

[10] A cured product obtained by curing the photosensitive composition according to any one of items [7] to [9].

[11] An organic EL display device comprising the cured product according to item

[10] .

[0009] The copolymer of the present invention can ensure a wide margin (tolerance) of the pre-bake temperature condition, thereby making it possible to suppress the generation of development residues on the surface of the ITO electrode, obtain an excellent solubility in a high-concentration organic alkaline developer, and impart high reflowability to the photosensitive composition.

[0010] 1 is a diagram showing the taper angle θ of the cured product (insulating layer 4) of the photosensitive composition. 2 is an image showing an example in which the evaluation of the development form failed in all Examples and Comparative Examples. 3 is a schematic diagram of the fabrication procedure of the organic EL display device in the Examples.

[0011] The present invention will be described in detail below. The copolymer of the present invention is a copolymer (a) containing a structural unit represented by formula (1) and / or a structural unit represented by formula (2), a structural unit represented by formula (3), and a structural unit represented by formula (4). (In formula (1), R 1 represents a hydrogen atom or a methyl group. 2 represents a single bond or an alkylene group having 1 to 3 carbon atoms. 1 is an integer and represents 1 or 2. 3 represents an alkyl group having 1 to 3 carbon atoms or an alkoxy group having 1 to 3 carbon atoms. 2 is an integer from 0 to 2. * represents a bonding site. 4 represents a hydrogen atom or a methyl group. 5 represents an alkylene group having 1 to 3 carbon atoms. 3 is an integer and represents 1 or 2. 6 represents an alkyl group having 1 to 3 carbon atoms or an alkoxy group having 1 to 3 carbon atoms. 4 is an integer from 0 to 2. * represents a bonding site. 7 represents a hydrogen atom or a methyl group. * represents a bonding site. In formula (4), R 8 represents a hydrogen atom or a methyl group. 9 represents an alkyl group having 5 to 18 carbon atoms. * represents a bonding site.)

[0012] The structural unit in copolymer (a) refers to a structural unit derived from a monomer having one unsaturated double bond group in the molecule when obtaining the copolymer. Examples of copolymerization methods for copolymer (a) of the present invention include the method described in JP-A-5-19467, but any known method can also be used.

[0013] Examples of the structural unit represented by formula (1) include 4-hydroxyphenyl methacrylate (hereinafter, PQMA), (4-hydroxyphenyl)methyl methacrylate, (4-hydroxyphenyl)ethyl methacrylate, (4-hydroxyphenyl)propyl methacrylate, 4-hydroxyphenyl acrylate, (4-hydroxyphenyl)methyl acrylate, (4-hydroxyphenyl)ethyl acrylate, and (4-hydroxyphenyl)propyl acrylate.

[0014] Examples of the structural unit represented by formula (2) include 2-allylphenol, 4-allyl-2,6-dimethoxyphenol, 4-allyl-2,6-dimethylphenol, 4-allyl-2,6-diethylphenol, and 4-allyl-2,6-dipropylphenol.

[0015] When copolymer (a) contains a structural unit represented by formula (1) and / or a structural unit represented by formula (2), for example, in a photosensitive composition containing copolymer (a), such as a negative photosensitive composition, the effect of suppressing radical chain reactions is exhibited, mask bias is reduced, and a pattern as intended can be formed. Among these, copolymer (a) preferably has a structural unit represented by formula (1).

[0016] Examples of the structural unit represented by formula (3) include methacrylic acid (hereinafter, referred to as MAA) and acrylic acid. When copolymer (a) contains the structural unit represented by formula (3), alkaline developability can be imparted to the photosensitive composition containing copolymer (a).

[0017] Examples of structural units represented by formula (4) include hexyl methacrylate, hexyl acrylate, 2-ethylhexyl methacrylate (hereinafter, 2-EHMA), 2-ethylhexyl acrylate, n-octyl methacrylate, n-octyl acrylate, decyl methacrylate, decyl acrylate, isodecyl methacrylate, isodecyl acrylate, 2-propylheptyl methacrylate, 2-propylheptyl acrylate, dodecyl methacrylate, dodecyl acrylate, undecyl methacrylate, undecyl acrylate, isostearyl methacrylate, isostearyl acrylate, n-stearyl methacrylate, and n-stearyl acrylate. When copolymer (a) contains a structural unit represented by formula (4), it is possible to impart high reflowability to a photosensitive composition containing copolymer (a) in a heat curing step. Among these, copolymer (a) is particularly preferable when R 9 It is preferable that the alkyl group has a structural unit represented by a branched alkyl group having 7 to 15 carbon atoms.

[0018] Copolymer (a) of the present invention contains 70 to 100 mol % of structural units represented by any one of formulas (1) to (4) in total, based on 100 mol % of all structural units. Furthermore, in copolymer (a) of the present invention, when the total number of moles of structural units represented by formula (1) and structural units represented by formula (2) is X, the number of moles of structural units represented by formula (3) is Y, and the number of moles of structural units represented by formula (4) is Z, the value A obtained by dividing X by Y (A=X / Y) is 1.0 to 10.0, and the value B obtained by dividing X by Z (B=X / Z) is 1.0 to 10.0. By containing 70 to 100 mol % in total of structural units represented by any one of formulas (1) to (4), setting the value A obtained by dividing X by Y to 1.0 to 10.0, and the value B obtained by dividing X by Z to 1.0 to 10.0, it is possible to maintain a good balance between the mask bias of the photosensitive composition containing copolymer (a), the suppression of residues generated due to pre-bake temperature conditions, and the reflowability in the heat curing step, and further to obtain an excellent dissolution form during alkali development.

[0019] The copolymer (a) of the present invention can further be copolymerized with any (meth)acrylic monomer as a monomer, if necessary. Specifically, monomers having a carboxy group such as itaconic acid, maleic acid, maleic anhydride, phthalic acid, phthalic anhydride, crotonic acid, 2-carboxyethyl acrylate oligomer, 2-carboxyethyl methacrylate oligomer, methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, t-butyl acrylate, cyclohexyl acrylate, isobornyl acrylate, benzyl acrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, methacrylate, methyl acrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl ... methyl acrylate, ethyl methacrylate, propyl methacrylate, propyl methacrylate, methyl methacrylate, propyl methacrylate, propyl methacrylate, methyl methacrylate, propyl methacrylate, propyl methacrylate, methyl methacrylate, propyl methacrylate, propyl methacrylate, methyl methacrylate, propyl methacrylate, propyl methacrylate, methyl methacrylate, propyl methacrylate, propyl methacrylate, propyl methacrylate, methyl methacrylate, propyl methacrylate, propyl methacrylate, propyl methacrylate, methyl The monomer may include an acrylic acid ester or methacrylic acid ester monomer, such as t-butyl methacrylate, cyclohexyl methacrylate, isobornyl methacrylate, or benzyl methacrylate, or a (fluoro)alkyl ester monomer thereof; an unsaturated monomer having an aromatic ring, such as styrene, α-methylstyrene, 4-vinyltoluene and a structural isomer thereof, 4-methoxystyrene and a structural isomer thereof, 4-butoxystyrene and a structural isomer thereof, 4-tert-butoxystyrene and a structural isomer thereof, 4-vinylbiphenyl, 2-vinylnaphthalene and a structural isomer thereof, 9-vinylanthracene, or 9-vinylcarbazole.

[0020] Copolymer (a) of the present invention may further contain a structural unit represented by formula (3), or a structural unit having a carboxy group, such as itaconic acid, maleic acid, maleic anhydride, phthalic acid, phthalic anhydride, crotonic acid, 2-carboxyethyl acrylate oligomer, or 2-carboxyethyl methacrylate oligomer, which is polymerized followed by the introduction of a known structural unit having an ethylenically unsaturated group. For example, a method may be used in which a glycidyl group-containing polymerizable unsaturated monomer is subjected to an addition reaction with copolymer (a) obtained by copolymerizing the structural unit represented by formula (3). In this case, examples of the glycidyl group-containing unsaturated monomer include glycidyl acrylate and glycidyl methacrylate. In particular, when the photosensitive composition of the present invention, described below, has negative photosensitivity, it is preferable to contain a structural unit represented by formula (8) in order to suppress the generation of development residues caused by minute pigments having a major axis of less than 0.1 μm. (In formula (8), R 14 and R 15 each independently represents a hydrogen atom or a methyl group, R 16 represents a divalent group having 4 to 12 carbon atoms and a hydroxyl group. 16 is preferably a divalent group having 4 to 8 carbon atoms and a hydroxyl group, and R 15 is preferably a methyl group. 16 may have an oxygen atom in the main chain, an alicyclic structure, or an aromatic ring.

[0021] Specific examples of the structural unit represented by formula (8) preferably include structural units represented by formulas (10) to (14). The structural unit represented by the formula (8) is preferably contained in an amount of 5 to 18 mol % relative to the total of 100 mol % of all structural units in the copolymer (a), in order to simultaneously achieve the effect of suppressing development residues of less than 0.1 μm on the surface of the ITO electrode and the effect of suppressing residues of 0.1 μm or more at a pre-bake temperature of 130° C., thereby widening the margin (tolerance range) of the pre-bake temperature conditions.

[0022] The weight-average molecular weight (Mw) of the copolymer (a) of the present invention is preferably 10,000 to 50,000. Having a weight-average molecular weight (Mw) of 10,000 or more ensures a suitably long development time even when the pre-bake temperature of the photosensitive composition containing the copolymer (a) is low, and in the case of a negative photosensitive composition, prevents the pattern from becoming inverted tapered. On the other hand, having a weight-average molecular weight (Mw) of 50,000 or less can suppress the generation of residues in the openings even when the pre-bake temperature is high (e.g., 130°C).

[0023] The weight average molecular weight (Mw) is a value obtained by analyzing by gel permeation chromatography (GPC) using tetrahydrofuran as a carrier and converting the value using a calibration curve based on standard polystyrene.

[0024] The copolymer (a) can be suitably used in a photosensitive composition. The content of the copolymer (a) in the photosensitive composition is preferably 5% by mass or more, more preferably 10% by mass or more, based on 100% by mass of the total components other than the solvent in the photosensitive composition, from the viewpoints of high reflowability in the heat curing step and minimizing the cure mask bias. On the other hand, from the viewpoint of improving the sensitivity during exposure, the content is preferably 60% by mass or less, more preferably 50% by mass or less.

[0025] The copolymer (a) of the present invention can exhibit favorable effects when used in a photosensitive composition containing a pigment (b), a photosensitizer (c) and an organic solvent (d).

[0026] The pigment (b) used in the photosensitive composition of the present invention may be an organic pigment or an inorganic pigment commonly used in the field of electronic information materials. Examples of the organic pigment include diketopyrrolopyrrole pigments, azo pigments such as azo, disazo, or polyazo, phthalocyanine pigments such as copper phthalocyanine, halogenated copper phthalocyanine, or metal-free phthalocyanine, anthraquinone pigments such as aminoanthraquinone, diaminodianthraquinone, anthrapyrimidine, flavanthrone, anthanthrone, indanthrone, pyranthrone, or violanthrone, quinacridone pigments, dioxazine pigments, perinone pigments, perylene pigments, thioindigo pigments, isoindoline pigments, isoindolinone pigments, quinophthalone pigments, threne pigments, or metal complex pigments.

[0027] Examples of inorganic pigments include titanium oxide, zinc oxide, zinc sulfide, white lead, calcium carbonate, precipitated barium sulfate, white carbon, alumina white, kaolin clay, talc, bentonite, black iron oxide, cadmium red, red iron oxide, molybdenum red, molybdate orange, chrome vermilion, yellow lead, cadmium yellow, yellow iron oxide, titanium yellow, chromium oxide, viridian, titanium cobalt green, cobalt green, cobalt chrome green, Victoria green, ultramarine, Prussian blue, cobalt blue, cerulean blue, cobalt silica blue, cobalt zinc silica blue, manganese violet, and cobalt violet.

[0028] Examples of red pigments include Pigment Red 9, 48, 97, 122, 123, 144, 149, 166, 168, 177, 179, 180, 192, 209, 215, 216, 217, 220, 223, 224, 226, 227, 228, 240, and 254 (all numbers are Color Index (C.I.) numbers).

[0029] Examples of orange pigments include Pigment Orange 13, 36, 38, 43, 51, 55, 59, 61, 64, 65, and 71 (all numbers are C.I. numbers).

[0030] Examples of yellow pigments include Pigment Yellow 12, 13, 17, 20, 24, 83, 86, 93, 95, 109, 110, 117, 125, 129, 137, 138, 139, 147, 148, 150, 153, 154, 166, 168, and 185 (all numbers are C.I. numbers).

[0031] Examples of purple pigments include Pigment Violet 19, 23, 29, 30, 32, 37, 40, and 50 (all numbers are C.I. numbers).

[0032] Examples of blue pigments include Pigment Blue 15, 15:3, 15:4, 15:6, 22, 60, and 64 (all numbers are C.I. numbers).

[0033] Examples of green pigments include Pigment Green 7, 10, 36, and 58 (all numbers are C.I. numbers).

[0034] Examples of black pigments include black organic pigments, mixed-color organic pigments, inorganic pigments, etc. Examples of black organic pigments include carbon black, perylene black, aniline black, and benzofuranone pigments (described in JP-A No. 2012-515233).

[0035] Although a photosensitive composition having desired optical properties can be obtained by combining these pigments, it is preferable to include a benzofuranone pigment from the viewpoint of visible light blocking properties and insulating properties per unit mass.

[0036] The content of the pigment (b) used in the photosensitive composition of the present invention is preferably 5% by mass or more, more preferably 10% by mass or more, based on 100% by mass of the total of all components of the photosensitive composition other than the solvent, from the viewpoint of light-shielding property per unit film thickness, while it is preferably 50% by mass or less, more preferably 40% by mass or less, from the viewpoint of improving sensitivity during exposure and fine line processability.

[0037] The photosensitizer (c) used in the photosensitive composition of the present invention may contain a photopolymerization initiator (c1), a photoacid generator (c2), etc. The photopolymerization initiator (c1) is a compound that undergoes bond cleavage and / or reaction upon exposure to generate radicals, and the photoacid generator (c2) is a compound that generates an acid upon light irradiation.

[0038] When the photosensitive composition contains a photopolymerization initiator (c1) and a radically polymerizable compound described below, radical polymerization proceeds in the light-irradiated areas, thereby obtaining a negative relief pattern in which the light-irradiated areas are insolubilized. On the other hand, when the photosensitive composition contains a photoacid generator (c2), acid is generated in the light-irradiated areas, increasing the solubility of the light-irradiated areas in an alkaline aqueous solution, thereby obtaining a positive relief pattern in which the light-irradiated areas are dissolved.

[0039] Examples of the photopolymerization initiator (c1) include carbazole-based photopolymerization initiators, acylphosphine oxide-based photopolymerization initiators, oxime ester-based photopolymerization initiators, and α-aminoalkylphenone-based photopolymerization initiators. Two or more of these may be contained. Among these, carbazole-based photopolymerization initiators and oxime ester-based photopolymerization initiators are preferred because they have high sensitivity to a mixed line consisting of i-line (365 nm), h-line (405 nm), and g-line (436 nm) in the exposure step described below.

[0040] The content of the photopolymerization initiator (c1) in the photosensitive composition of the present invention is preferably 1% by mass or more, more preferably 5% by mass or more, relative to 100% by mass of the radically polymerizable compound described below, from the viewpoint of improving sensitivity to exposure, while being preferably 90% by mass or less, more preferably 80% by mass or less, from the viewpoint of fine line processability.

[0041] The photoacid generator (c2) may contain, for example, a quinone diazide compound, such as a compound in which a sulfonic acid of quinone diazide is bonded to a polyhydroxy compound via an ester bond, a compound in which a sulfonic acid of quinone diazide is bonded to a polyamino compound via a sulfonamide bond, or a compound in which a sulfonic acid of quinone diazide is bonded to a polyhydroxypolyamino compound via an ester bond and / or a sulfonamide bond.

[0042] As the quinone diazide structure, either a 5-naphthoquinone diazide sulfonyl group or a 4-naphthoquinone diazide sulfonyl group is preferably used. A naphthoquinone diazide sulfonyl ester compound having a 4-naphthoquinone diazide sulfonyl group and a 5-naphthoquinone diazide sulfonyl group in the same molecule may be contained, or a 4-naphthoquinone diazide sulfonyl ester compound and a 5-naphthoquinone diazide sulfonyl ester compound may be contained. 4-naphthoquinone diazide sulfonyl ester compounds have absorption in the i-line region of a mercury lamp and are suitable for i-line exposure. 5-naphthoquinone diazide sulfonyl ester compounds have absorption extending to the g-line region of a mercury lamp and are suitable for g-line exposure.

[0043] The quinone diazide compound can be synthesized by any esterification reaction of a compound having a phenolic hydroxyl group and a quinone diazide sulfonic acid compound. The use of such a quinone diazide compound further improves resolution, sensitivity, and film retention.

[0044] From the viewpoint of increasing sensitivity, the content of the photoacid generator (c2) is preferably 0.1% by mass or more, more preferably 10% by mass or more, and even more preferably 25% by mass or more, relative to 100% by mass of the copolymer (a). On the other hand, from the viewpoint of long-term reliability when the cured product of the present invention is used as a planarizing layer and / or an insulating layer of an organic EL display device, the content of the photoacid generator (c1) is preferably 100% by mass or less, relative to 100% by mass of the copolymer (a).

[0045] Examples of the organic solvent (d) used in the photosensitive composition of the present invention include polar aprotic solvents such as γ-butyrolactone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-n-propyl ether, ethylene glycol mono-n-butyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-n-propyl ether, diethylene glycol mono-n-butyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-n-propyl ether, propylene glycol mono-n-butyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol mono-n-propyl ether, dipropylene glycol mono-n-butyl ether, tripropylene glycol monomethyl ether, tripropylene glycol monoethyl ether, tetrahydrofuran ... Ethers such as furan and dioxane; ketones such as acetone, methyl ethyl ketone, diisobutyl ketone, cyclohexanone, 2-heptanone, 3-heptanone and diacetone alcohol; esters such as ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate and ethyl lactate. , ethyl 2-hydroxy-2-methylpropionate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, ethyl ethoxyacetate, ethyl hydroxyacetate, methyl 2-hydroxy-3-methylbutanoate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-methyl-3-methoxybutylpropionate, ethyl acetate, n-propyl acetate, i-propyl acetate, n-butyl acetate, i-butyl acetate, n-pentyl formate, i-pentyl acetate,The solvent may contain other esters such as n-butyl propionate, ethyl butyrate, n-propyl butyrate, i-propyl butyrate, n-butyl butyrate, methyl pyruvate, ethyl pyruvate, n-propyl pyruvate, methyl acetoacetate, ethyl acetoacetate, and ethyl 2-oxobutanoate; aromatic hydrocarbons such as toluene and xylene; amides such as N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, 3-methoxy-N,N-dimethylpropionamide, 3-butoxy-N,N-dimethylpropionamide, N,N-dimethylpropanamide, and N,N-dimethylisobutyramide; and 3-methyl-2-oxazolidinone. The solvent may contain two or more of these.

[0046] The photosensitive composition of the present invention may contain a radical polymerizable compound (e). In particular, when the photosensitive composition contains a photopolymerization initiator (c1), it is essential that the photosensitive composition contains the radical polymerizable compound (e).

[0047] The radically polymerizable group contained in the radically polymerizable compound (e) is preferably an acrylic group or a methacrylic group, from the viewpoint of improving sensitivity during exposure, and may contain two kinds of these groups.

[0048] The radically polymerizable compound (e) is preferably a compound having two or more radically polymerizable groups, and examples thereof include bisphenol A diglycidyl ether (meth)acrylate, poly(meth)acrylate carbamate, modified bisphenol A epoxy (meth)acrylate, 1,6-hexanediol adipic acid (meth)acrylic acid ester, phthalic anhydride propylene oxide (meth)acrylic acid ester, trimellitic acid diethylene glycol (meth)acrylic acid ester, and rosin-modified epoxy di(meth)acrylate. , alkyd-modified (meth)acrylate, fluorene diacrylate oligomer, tripropylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, bisphenol A diglycidyl ether di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, triacrylformal, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, dipentaerythritol Thuritol penta(meth)acrylate, 2,2-bis[4-(3-acryloxy-2-hydroxypropoxy)phenyl]propane, bis[4-(3-acryloxy-2-hydroxypropoxy)phenyl]methane, bis[4-(3-acryloxy-2-hydroxypropoxy)phenyl]sulfone, bis[4-(3-acryloxy-2-hydroxypropoxy)phenyl]ether, 4,4'-bis[4-(3-acryloxy-2-hydroxypropoxy)phenyl]cyclohexane, 9,9-bis[4-(3 Examples of the fluorene include 9,9-bis[3-methyl-4-(3-acryloxy-2-hydroxypropoxy)phenyl]fluorene, 9,9-bis[3-chloro-4-(3-acryloxy-2-hydroxypropoxy)phenyl]fluorene, bisphenoxyethanol fluorene diacrylate, bisphenoxyethanol fluorene dimethacrylate, biscresol fluorene diacrylate, and biscresol fluorene dimethacrylate. Two or more of these may be contained.

[0049] In order to maintain the dissolution form in alkali development and control the taper angle after development to an appropriately low value, the photosensitive composition of the present invention preferably further contains a (meth)acrylate compound having two 9,9-bis(naphthyl)fluorene skeletons and two ethylenically unsaturated double bond groups in the molecule, and has negative photosensitivity.

[0050] The content of the radical polymerizable compound (e) in the photosensitive composition of the present invention is preferably 10% by mass or more, more preferably 15% by mass or more, relative to 100% by mass of the total content of the copolymer (a) and the radical polymerizable compound (e), from the viewpoint of improving sensitivity during exposure, while it is preferably 80% by mass or less, more preferably 60% by mass or less, from the viewpoint of reflowability during a heat curing step.

[0051] The photosensitive composition of the present invention may further contain a dispersing resin (f) having a repeating unit represented by general formula (5) having a tertiary amino group in a side chain, a repeating unit having a carboxy group, and a repeating unit having an ethylenically unsaturated group. In general formula (5), R 10 represents a hydrogen atom or a methyl group, R 11 represents a single bond, an alkylene group having 1 to 5 carbon atoms, or an alkylene ether group having 1 to 5 carbon atoms and 1 oxygen atom. 12 , and R 13 each independently represents an alkyl group or alkoxy group having 1 to 5 carbon atoms, an alicyclic hydrocarbon group having 3 to 6 carbon atoms, or an aromatic hydrocarbon group having 6 to 10 carbon atoms. * represents a bonding site.

[0052] Specific examples of monomers constituting the repeating unit represented by general formula (5) include 2-dimethylaminoethyl acrylate, 2-diethylaminoethyl acrylate, 2-dipropylaminoethyl acrylate, 2-diphenylaminoethyl acrylate, 2-dibenzylaminoethyl acrylate, 2-dimethylaminoethyl methacrylate, 2-diethylaminoethyl methacrylate, 2-dipropylaminoethyl methacrylate, 2-diphenylaminoethyl methacrylate, and 2-benzylaminoethyl methacrylate. These monomers may be used alone or in combination of two or more. By including an alkali-soluble resin having a repeating unit represented by general formula (5), tertiary amino groups are adsorbed to the pigment surface, thereby further improving the storage stability of photosensitive compositions, such as negative-tone photosensitive compositions.

[0053] Specific examples of monomers constituting repeating units having a carboxy group include acrylic acid, methacrylic acid, itaconic acid, maleic acid, maleic anhydride, phthalic acid, phthalic anhydride, crotonic acid, 2-carboxyethyl acrylate oligomer, and 2-carboxyethyl methacrylate oligomer.

[0054] The dispersion resin (f) can be synthesized by polymerizing the structural unit represented by general formula (5) and the carboxyl group-containing unit, and then introducing a known repeating unit having an ethylenically unsaturated group. For example, a method can be used in which a glycidyl group-containing polymerizable unsaturated monomer is subjected to an addition reaction with a (meth)acrylic copolymer obtained by copolymerizing a carboxyl group-containing unsaturated monomer. In this case, examples of the carboxyl group-containing unsaturated monomer to be copolymerized include acrylic acid and methacrylic acid, and examples of the glycidyl group-containing unsaturated monomer include glycidyl acrylate and glycidyl methacrylate. These acrylic monomers can be used alone or in a mixture of two or more.

[0055] The acid value of the dispersing resin (f) is preferably 50 to 120 mgKOH / g, and by setting it within this range, both pigment dispersion stability and solubility in an alkaline developer can be achieved. The base number is also preferably 5 to 70 mmol / 100 g, and by setting it within this range, pigment dispersion stability can be improved while maintaining solubility in an alkaline developer. The base number is defined as the number of moles of perchloric acid required to neutralize 100 g of the dispersing resin (f).

[0056] The content of the dispersing resin (f) is preferably 5% by mass or more relative to 100% by mass of the total of the copolymer (a) and the dispersing resin (f) from the viewpoint of pigment dispersion stability, and on the other hand, is preferably 50% by mass or less from the viewpoint of minimizing mask bias.

[0057] The photosensitive composition of the present invention may further contain a polymeric dispersant (g). The polymeric dispersant (g) refers to a dispersant that has both an affinity group that chemically bonds to or adsorbs to the pigment surface and a polymer chain or group that is solvent-philic, and does not contain an ethylenically unsaturated group. Because the polymeric dispersant (g) does not contain an ethylenically unsaturated group, adding a large amount may deteriorate the target photosensitive performance. Therefore, it is desirable to add an appropriate amount taking into account dispersion stability and photosensitive performance. The polymeric dispersant (g) improves the wettability of the pigment (b) to the dispersion medium in the wet media dispersion process described below, thereby promoting deagglomeration of the light-blocking material, stabilizes particle size and viscosity through steric hindrance and / or electrostatic repulsion effects, and further suppresses color separation during storage or application of the photosensitive composition.

[0058] Examples of the polymer dispersant (g) include polyester-based polymer dispersants, acrylic-based polymer dispersants, polyurethane-based polymer dispersants, polyallylamine-based polymer dispersants, carbodiimide-based dispersants, etc. Among these, polymer dispersants having an amino group are preferred in order to improve the long-term storage stability of the pigment dispersion.

[0059] The photosensitive composition of the present invention may contain a thermal crosslinking agent (h). The thermal crosslinking agent (h) refers to a compound having at least two thermally reactive functional groups in the molecule, such as an alkoxymethyl group, a methylol group, an epoxy group, or an oxetanyl group. By containing the thermal crosslinking agent (h), crosslinking occurs between the thermal crosslinking agent (h) and the copolymer (a), or between the thermal crosslinking agents (h) themselves, thereby improving the heat resistance, chemical resistance, and bending resistance of the cured product after thermal curing.

[0060] Preferred examples of the compound having at least two alkoxymethyl groups or methylol groups include DML-PC, DML-PEP, DML-OC, DML-OEP, DML-34X, DML-PTBP, DML-PCHP, DML-OCHP, DML-PFP, DML-PSBP, DML-POP, DML-MBOC, DML-MBPC, DML-MTrisPC, DML-BisOC-Z, DML-BisOCHP-Z, DML-BPC, DML-BisOC-P, DMOM-PC, DMOM-PTBP, DMOM-MBPC, TriML-P, TriML-35XL, TML-HQ, It may contain TML-BP, TML-pp-BPF, TML-BPE, TML-BPA, TML-BPAF, TML-BPAP, TMOM-BP, TMOM-BPE, TMOM-BPA, TMOM-BPAF, TMOM-BPAP, HML-TPPHBA, HML-TPHAP, HMOM-TPPHBA, HMOM-TPHAP (all of which are trade names, manufactured by Honshu Chemical Industry Co., Ltd.), "NIKALAC" (registered trademark) MX-290, "NIKALAC" MX-280, "NIKALAC" MX-270, "NIKALAC" MX-279 (all of which are trade names, manufactured by Sanwa Chemical Co., Ltd.), and the like.

[0061] Preferred examples of compounds having at least two epoxy groups include "Epolite" (registered trademark) 40E, "Epolite" 100E, "Epolite" 200E, "Epolite" 400E, "Epolite" 70P, "Epolite" 200P, "Epolite" 400P, "Epolite" 1500NP, "Epolite" 80MF, "Epolite 4000," and "Epolite" 1500NP. "Denacol" (registered trademark) EX-3002 (all manufactured by Kyoeisha Chemical Co., Ltd.), "Denacol" (registered trademark) EX-212L, "Denacol" EX-214L, "Denacol" EX-216L, "Denacol" EX-850L (all manufactured by Nagase ChemteX Corporation), GAN, GOT (all manufactured by Nippon Kayaku Co., Ltd.), "Epicoat" (registered trademark) 828, "Epicoat" 1002, "Epicoat" 1750, "Epicoat" 1007, YX8100-BH30, E1256, E4250, E4275 (all manufactured by Japan Epoxy Resins Co., Ltd.), "Epiclon" (registered trademark) EXA-9583, HP4032 (all manufactured by DIC Corporation), VG3101 (manufactured by Mitsui Chemicals, Inc.), "Tepic" (registered trademark) S, "Tepic" G, "Tepic" P (all manufactured by Nissan Chemical Industries, Ltd.) The present invention may contain, for example, "Denacol" EX-321L (manufactured by Nagase ChemteX Corporation), "Denacol" EX-321L (manufactured by Nagase ChemteX Corporation), NC6000 (manufactured by Nippon Kayaku Co., Ltd.), "Epotohto" (registered trademark) YH-434L (manufactured by Tohto Kasei Co., Ltd.), EPPN502H, NC3000 (manufactured by Nippon Kayaku Co., Ltd.), "Epiclon" (registered trademark) N695, HP7200 (all manufactured by DIC Corporation), and the like.

[0062] Examples of the compound having at least two oxetanyl groups include Ethanacol EHO, Ethanacol OXBP, Ethanacol OXTP, Ethanacol OXMA (all manufactured by Ube Industries, Ltd.), oxetanized phenol novolac, etc. Two or more types of thermal crosslinking agent (h) may be used in combination.

[0063] The content of the thermal crosslinking agent (h) is preferably 1% by mass or more and 30% by mass or less based on 100% by mass of the total amount of the photosensitive composition excluding the solvent. If the content of the thermal crosslinking agent (h) is 1% by mass or more based on 100% by mass of the total amount of the photosensitive composition excluding the solvent, the chemical resistance of the cured product can be further improved. Furthermore, if the content of the thermal crosslinking agent (h) is 30% by mass or less based on 100% by mass of the total amount of the photosensitive composition excluding the solvent, the storage stability of the photosensitive composition is excellent.

[0064] The photosensitive composition of the present invention preferably further contains a compound represented by formula (9) as a residue inhibitor (i) and has negative photosensitivity. (In formula (9), PO represents an oxypropylene group, EO represents an oxyethylene group, and x, y, and z each independently represent an integer of 1 to 50, and satisfy the relationship y<x+z.) By containing the compound represented by formula (9), it is possible to suppress the generation of residues of less than 0.1 μm in size in the development step described below.

[0065] The photosensitive composition of the present invention may contain a surfactant to improve wettability with the substrate. Examples of the surfactant include fluorine-based surfactants such as the SH series, SD series, and ST series from Dow Corning Toray Co., Ltd., the BYK series from BYK Japan K.K., the KP series from Shin-Etsu Chemical Co., Ltd., the Disfoam series from NOF Corporation, the Megafac (registered trademark) series from DIC Corporation, the Fluorad series from Sumitomo 3M Limited, the Surflon (registered trademark) series and Asahiguard (registered trademark) series from Asahi Glass Co., Ltd., and the Polyfox series from Omnova Solutions, as well as acrylic and / or methacrylic surfactants such as the Polyflow series from Kyoeisha Chemical Co., Ltd. and the Disparlon (registered trademark) series from Kusumoto Chemical Co., Ltd.

[0066] When a surfactant is contained, the content thereof is preferably 0.001 to 1% by mass relative to 100% by mass of the total amount of the photosensitive composition excluding the solvent.

[0067] The photosensitive composition of the present invention may contain, if necessary, a nonionic surfactant as a leveling agent, or a silane coupling agent as an adhesion improver to the substrate surface.

[0068] The chemical structures of the compounds belonging to the aforementioned copolymer (a), pigment (b), photosensitizer (c), organic solvent (d), radically polymerizable compound (e), dispersion resin (f), polymer dispersant (g), and thermal crosslinker (h) can be analyzed by combining known analytical techniques such as time-of-flight secondary ion mass spectrometry (TOF-SIMS), time-of-flight mass spectrometry (TOF-MS), nuclear magnetic resonance (NMR), liquid chromatography mass spectrometry (LC-MS), gas chromatography mass spectrometry (GC-MS), ICP mass spectrometry, infrared absorption spectrometry, and X-ray diffraction using the photosensitive composition as a sample. In particular, for pigment (b), the photosensitive composition may be centrifuged, and the concentrate obtained as the filtrate may be analyzed as a sample to improve identification accuracy. Meanwhile, for copolymer (a) and photosensitizer (c), the filtrate obtained by filtering the supernatant after centrifugation may be analyzed as a sample to improve identification accuracy.

[0069] The method for preparing the photosensitive composition of the present invention is not particularly limited, but examples thereof include a method in which a pigment dispersion containing the pigment (b), the dispersing resin (f), the organic solvent (d), and, if necessary, the polymer dispersant (g) is prepared in advance by wet dispersion treatment, and then the copolymer (a), the photosensitizer (c), the organic solvent (d), and, if necessary, the radical polymerizable compound (e), and other components are mixed and stirred with the pigment dispersion, and the mixture is filtered as necessary.

[0070] The disperser used for wet dispersion treatment may be a wet media disperser or a wet medialess disperser, but the use of a wet media disperser is desirable due to its excellent dispersion treatment speed and economical advantages. Examples of wet media dispersers include bead mills such as "Levomill" (registered trademark) (manufactured by Asada Iron Works Co., Ltd.), "Nano Getter" (registered trademark) (manufactured by Ashizawa Finetech Co., Ltd.), "DYNO-MILL" (registered trademark) (manufactured by Willy A. Bachofen), "Spike Mill" (registered trademark) (manufactured by Inoue Manufacturing Co., Ltd.), "Sand Grinder" (registered trademark) (manufactured by DuPont), "Ultra Apex Mill" (registered trademark) (manufactured by Hiroshima Metal & Machinery Co., Ltd.), and "NEO-Alpha Mill" (registered trademark) (manufactured by AIMEX Co., Ltd.). The media material is preferably ceramic beads such as zirconia, and their diameter is preferably 0.03 to 0.5 mmφ. An example of a commercially available product is "Treceram" (registered trademark) (manufactured by Toray Industries, Inc.) When the primary particle size of the pigment (b) and the particle size of the secondary particles formed by aggregation of the primary particles are small, minute dispersion beads having a diameter of 0.03 to 0.10 mm are preferred.

[0071] In this case, a bead mill having a centrifugal separator capable of separating fine beads from the dispersion is preferred. On the other hand, when dispersing pigment (b) containing coarse particles of the submicron order, beads with a diameter of 0.10 mm or more are preferred because sufficient crushing power can be obtained. The bead diameter can be calculated by measuring the equivalent circle diameter of 100 beads randomly selected by microscopic observation and calculating the number average value.

[0072] The cured product of the present invention is obtained by curing the photosensitive composition. The cured product here refers to a product obtained by a process of heating the photosensitive composition at a temperature of 200° C. or higher and 400° C. or lower under atmospheric pressure for 10 minutes or longer.

[0073] The organic EL display device of the present invention comprises the cured product. The organic EL display device has at least a substrate, a first electrode, a second electrode, light-emitting pixels, a planarizing layer, and a pixel dividing layer. An active matrix organic EL display device having a plurality of pixels arranged in a matrix is ​​preferred. The active matrix display device has light-emitting pixels on a substrate such as glass, and a planarizing layer provided to cover the light-emitting pixels and the lower portions of the areas other than the light-emitting pixels. Furthermore, the planarizing layer has a first electrode provided to cover at least the lower portions of the light-emitting pixels, and a second electrode provided to cover at least the upper portions of the light-emitting pixels. Furthermore, the active matrix display device has an insulating pixel dividing layer to divide the light-emitting pixels, and the cured product obtained from the photosensitive composition of the present invention can be suitably used for the pixel dividing layer.

[0074] Furthermore, since the photosensitive composition of the present invention can form a high-definition pattern that does not leave residues in the openings, it can also be used for colored partition walls for solid-state imaging devices, micro LEDs, and mini LED display devices, and black matrices and black column spacers used in color filters for liquid crystal display devices.

[0075] A preferred embodiment of the cured product of the present invention when used as a pixel division layer in an organic EL display device is described below. The optical density per 1.0 μm of film thickness of the pixel division layer is preferably 0.8 or more, more preferably 1.0 or more, in order to suppress external light reflection and enhance the value of the display device. From the viewpoint of pattern processing, it is preferably 1.5 or less, more preferably 1.3 or less. The optical density refers to the value obtained by measuring the incident light intensity and transmitted light intensity of a pixel division layer formed to a film thickness of 1.5 μm on a transparent substrate using an optical densitometer X-Rite 361T (manufactured by X-Rite), and dividing the optical density value (OD value) calculated from the following formula by the film thickness value of 1.5. A higher optical density indicates a higher light-blocking property. As the transparent substrate, a transparent glass substrate "Tempax (manufactured by AGC Technoglass Co., Ltd.)" can be preferably used. Optical density = log 10 (I 0 / I) In the above formula, I 0 is the incident light intensity, and I is the transmitted light intensity.

[0076] The cross-sectional taper angle of the inclined portion located at the end of the pixel division layer is preferably 50° or less, more preferably 45° or less, in order to prevent disconnection of the electrode and avoid the occurrence of non-illuminated pixels. The cross-sectional taper angle is preferably 20° or more, more preferably 25° or more, in order to prevent a decrease in light-blocking properties at the end of the thin film portion. Here, the taper angle of the pixel division layer is the inclination angle θ of the end of the insulating layer 4 shown in FIG. 1 .

[0077] A preferred method for forming the pixel dividing layer includes a coating step of coating a photosensitive composition to obtain a coating film, a pre-baking step of heating the coating film to obtain a pre-baked film, an exposure step of exposing the coating film to actinic rays in a pattern through an exposure mask to obtain an exposed film, a development step of developing the coating using an alkaline developer to obtain a developed film, and a curing step of thermally curing the coating by heating to obtain a cured product.

[0078] As a coating device used in the coating step, a spin coater or a slit coater can be preferably used because of its excellent thin film coating ability. After coating, pin gap pre-baking or contact pre-baking may be performed.

[0079] In the pre-baking step, the pre-baking temperature is preferably 50 to 150° C., and the pre-baking time is preferably 30 seconds to 5 minutes.

[0080] Examples of exposure devices used in the exposure process include steppers, mirror projection mask aligners (MPA), and parallel light mask aligners (PLA). The active actinic rays irradiated during exposure include j-line (wavelength 313 nm), i-line (wavelength 365 nm), h-line (wavelength 405 nm), or g-line (wavelength 436 nm) from an ultra-high pressure mercury lamp. Mixed rays containing at least i-line are preferred, and mixed rays containing g-line, h-line, and i-line are more preferred. The desired negative or positive exposure mask can be used, and if it has negative photosensitivity, the exposed portion will harden and become insoluble in the developer. If it has positive photosensitivity, the exposed portion will dissolve in the developer.

[0081] Examples of development methods used in the development step include showering, dipping, and puddling, and include a method in which the exposed film is immersed for 10 seconds to 3 minutes. The puddling method is preferred because it reduces the amount of alkaline developer used and provides an economically advantageous manufacturing process. A 0.4 to 2.5 wt% aqueous solution of tetramethylammonium hydroxide (hereinafter referred to as "TMAH") is preferred as the alkaline developer, and a commercially available example is 2.38 wt% TMAH (manufactured by Tama Chemicals Co., Ltd.). After the development step, a washing treatment using a shower of deionized water and / or a water-removing treatment using air spray may be performed. In the case of negative photosensitivity, the development time is preferably set to 1.1 to 1.5 times the development time required for the film thickness to become 0 μm in the unexposed areas in order to eliminate development unevenness in the unexposed areas. When the film has positive photosensitivity, in order to improve the in-plane uniformity of the film thickness of the developed film, it is preferable to set the film thickness (μm) obtained by subtracting the film thickness of the unexposed portion from the film thickness of the prebaked film to 1.0 μm or less. In order to improve the exposure sensitivity, it is preferable to set the film thickness to 0.5 μm or more. Furthermore, the developed film obtained may be irradiated with exposure light again as a second exposure step to control the fluidity of the film in the curing step.

[0082] In the curing step, the developed film is thermally cured by heating, and the developer and moisture remaining in the film are evaporated to obtain a cured product. Examples of heating devices include a hot air oven and an IR oven, and the heating atmosphere can be nitrogen or air. The heating temperature is preferably 200 to 350°C under atmospheric pressure, more preferably 220 to 280°C.

[0083] The present invention will be described in detail below with reference to examples and comparative examples of negative-type photosensitive compositions, but the aspects of the present invention are not limited to these. <Evaluation Methods> (1) Weight-average molecular weight (Mw) The weight-average molecular weight (Mw) is measured using a gel permeation chromatography (GPC) "HLC-8220GPC" (a test device manufactured by Tosoh Corporation) using tetrahydrofuran as a carrier and polystyrene as a molecular weight standard.

[0084] (2) Preparation of Cured Products for Evaluation The photosensitive compositions obtained in each Example and Comparative Example were applied to three ITO substrates using a spinner (MS-A150) manufactured by Mikasa Co., Ltd., so that the film thickness after curing was 1.5 μm. The three coated films were then prebaked on a hot plate at 110°C, 120°C, and 130°C for 2 minutes each to obtain 110°C prebaked films, 120°C prebaked films, and 130°C prebaked films. Each prebaked film was irradiated with 200 mJ / cm using a high-pressure mercury lamp as a light source using a mask aligner (PEM-6M) manufactured by Union Optical Co., Ltd., and a negative mask (stripe design line width 10 μm) manufactured by HOYA Corporation. 2 is the maximum exposure dose, and 10 mJ / cm 2 The exposure dose was reduced stepwise for each exposure. Each exposed film was then developed using a small developing device (AD-1200; manufactured by Takizawa Sangyo Co., Ltd.) and an alkaline developer (2.38% by weight TMAH aqueous solution) by paddle development. After rinsing with ultrapure water for 60 seconds by showering, the substrate was dried by idle rotation at 1000 rpm for 30 seconds, yielding a developed film with a stripe pattern. The paddle development method used here refers to a method in which the alkaline developer is shower-applied to the surface of the exposed film for 10 seconds, and then the film is left to develop until a predetermined development time is reached. The development time was 1.3 times the time required for the film thickness of the unexposed area to reach 0 μm. Each developed film was then heated in air at 250°C for 1 hour using a high-temperature inert gas oven (INH-9CD-S; manufactured by Koyo Thermo Systems Co., Ltd.) to obtain a cured product with a stripe pattern.

[0085] (3) Evaluation of development form The exposed films obtained in each Example and Comparative Example were subjected to alkaline development using a paddle method, and then rinsed using a shower method. The state of dissolution was visually observed, and the development form was evaluated according to the following criteria, with ◯ representing pass and × representing fail. Development form ◯: No film-like peeling was observed, and the film was dissolved uniformly. Development form ×: Black film-like peeling was observed as shown in Figure 2.

[0086] (4) Evaluation of Pre-bake Temperature Margin For three levels of developed films with different pre-bake temperatures obtained in each Example and Comparative Example, the minimum exposure dose (mJ / cm) that could be formed without peeling was evaluated. 2) The presence or absence of granular residues of 0.1 μm or more in the openings of a stripe pattern mask opening width of 10 μm was observed using an optical microscope and evaluated according to the following criteria. The fewer levels of residue observed, the wider the pre-bake temperature margin and the better it was judged to be, with A and B being passed and C being rejected. A: Of three levels of developed films with different pre-bake temperatures, no residue was observed in any of the three levels. B: Of three levels of developed films with different pre-bake temperatures, residue was observed in one level. C: Of three levels of developed films with different pre-bake temperatures, residue was observed in two or more levels.

[0087] (5) Evaluation of Mask Bias The cured products obtained in each Example and Comparative Example were observed under an optical microscope to determine the minimum exposure dose (mJ / cm) at which the cured product could be formed without peeling. 2 The opening width of a stripe pattern with a mask opening width of 10 μm in the above test was measured using an optical microscope and evaluated according to the following criteria. The smaller the absolute value of the difference between the mask design value and the opening width of the cured film, the smaller the mask bias and the better the result was judged to be. A: Mask bias less than 1.0 μm. B: Mask bias 1.0 μm or more and less than 2.0 μm. C: Mask bias 2.0 μm or more and less than 3.0 μm. D: Mask bias 3.0 μm or more.

[0088] (6) Evaluation of Cross-Sectional Shape The minimum exposure dose (mJ / cm) at which the cured product obtained in each Example and Comparative Example could be formed without peeling 2 The cross-sectional shape of the mask opening with a stripe pattern of 10 μm width was observed with a scanning electron microscope (SEM). A pattern with a taper angle of 20° to 50° was judged to have a good cross-sectional shape, and a pattern with a taper angle of less than 20° or more than 50° was judged to have a poor cross-sectional shape.

[0089] (7) Evaluation of Light-Shielding Property The OD value of the cured product of the photosensitive composition obtained in each Example and Comparative Example at the minimum exposure dose at which a pattern could be formed was measured using an X-rite 361T (visual) densitometer to measure the intensity of incident light and transmitted light, and calculated using the following formula: OD value = log 10(I / I) I: incident light intensity I: transmitted light intensity Furthermore, the film thickness (μm) of each cured product was measured using a contact-type film thickness meter DEKTAK150 (manufactured by ULVAC, Inc.), and the light-blocking ability per μm of each cured product was evaluated by calculating the OD value / film thickness.

[0090] (8) Light Emission Evaluation of Organic EL Display Devices Figure 3 shows a schematic diagram of the fabrication procedure for organic EL display devices using the photosensitive compositions obtained in each Example and Comparative Example. First, a 10 nm ITO transparent conductive film was formed over the entire surface of a 38 mm x 46 mm alkali-free glass substrate 1 by sputtering, and then etched to form a first electrode (transparent electrode) 2. Simultaneously, an auxiliary electrode 3 for connecting the second electrode was also formed. The resulting substrate 1 was ultrasonically cleaned with Semicoclean 56 (trade name, manufactured by Furuuchi Chemical Co., Ltd.) for 10 minutes and then washed with ultrapure water. Next, a photosensitive composition (NB-1) was applied to the entire surface of this substrate 1 by spin coating and prebaked on a hot plate at 110 °C for 2 minutes. This prebaked film was exposed to the minimum exposure dose of each photosensitive composition using a high-pressure mercury lamp as a light source through a photomask, and then developed with a 2.38 wt% TMAH aqueous solution to dissolve unnecessary portions, followed by rinsing with pure water. The resulting resin pattern was heat-treated in a hot air oven at 230°C for 60 minutes. In this way, an insulating layer 4 was formed in the effective area of ​​the substrate 1, with openings 70 μm wide and 260 μm long arranged at a widthwise pitch of 155 μm and a lengthwise pitch of 465 μm, each opening exposing a first electrode 2. In this way, an insulating layer 4 with an insulating layer aperture ratio of 25% was formed in the effective substrate area, which was a rectangle with sides of 16 mm. The thickness of the insulating layer 4 was approximately 1.0 μm.

[0091] Next, a nitrogen plasma treatment was performed as a pretreatment, and then an organic EL layer 5 including a light-emitting layer was formed by vacuum deposition. The degree of vacuum during deposition was 1×10 -3The pressure was below 1 Pa, and the substrate 1 was rotated relative to the evaporation source during evaporation. First, compound (HT-1) was evaporated to a thickness of 10 nm as a hole injection layer, and compound (HT-2) was evaporated to a thickness of 50 nm as a hole transport layer. Next, compound (GH-1) as a host material and compound (GD-1) as a dopant material were evaporated to a thickness of 40 nm in the light-emitting layer so that the doping concentration was 10%. Next, compound (ET-1) and compound (LiQ) were laminated to a thickness of 40 nm at a volume ratio of 1:1 as electron transport materials. The structures of the compounds used in the organic EL layer are shown below.

[0092] Next, a compound (LiQ) was vapor-deposited to a thickness of 2 nm, followed by vapor deposition of 10 nm of Mg and Ag at a volume ratio of 10:1 to form a second electrode (non-transparent electrode) 6. Finally, a cap-shaped glass plate was sealed by bonding it with an epoxy resin adhesive in a low-humidity nitrogen atmosphere, and four top-emission organic EL display devices, each 5 mm square, were fabricated on one substrate. Note that the film thickness referred to here is the value displayed on a quartz crystal oscillator film thickness monitor.

[0093] The four produced organic EL display devices were allowed to emit light, and the light-emitting surfaces were observed under an optical microscope to evaluate the presence or absence of unlit cells according to the following criteria: A: None of the four organic EL display devices had unlit cells. B: One of the four organic EL display devices had unlit cells. C: Two of the four organic EL display devices had unlit cells. D: Three of the four organic EL display devices had unlit cells.

[0094] (9) Evaluation of Microresidues The minimum exposure dose (mJ / cm) at which the developed films obtained in each Example and Comparative Example at a pre-bake temperature of 120°C could be formed without peeling was evaluated. 2The presence or absence of minute residues in 20 openings randomly selected from the 10 μm stripe pattern openings in the sample was observed using a scanning electron microscope (SEM). The number of minute residues smaller than 0.1 μm in the openings was measured, and the average of the 20 locations was taken as the number of minute residues and evaluated based on the following criteria: A to C were rated as pass, and D and E were rated as fail. A: 0 or more but less than 1 minute residue B: 1 or more but less than 10 minute residues C: 10 or more but less than 20 minute residues D: 20 or more but less than 30 minute residues E: 30 or more minute residues

[0095] <Production Examples> (Synthesis Example 1: Copolymer (a-1)) 17.13 g of 4-hydroxyphenyl methacrylate ("PQMA" manufactured by Showa Denko K.K.; hereinafter, referred to as PQMA), 3.31 g of methacrylic acid (hereinafter, referred to as MAA), and 19.56 g of n-stearyl methacrylate were completely dissolved in 100.0 g of propylene glycol monomethyl ether acetate (hereinafter, referred to as PGMEA), and 3.66 g of V-601 (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) as a polymerization initiator was completely dissolved in 15.0 g of PGMEA. The two resulting solutions were simultaneously added dropwise over 2 hours to 45.0 g of PGMEA heated to 85°C under a nitrogen gas atmosphere in a 300 mL three-neck flask, and after completion of the addition, the mixture was allowed to react at 85°C, thereby obtaining a 20% by mass solids solution of a PQMA / MAA / n-stearyl methacrylate copolymer of 50 / 20 / 30 (mol%). Multiple solutions of this copolymer were prepared by varying the reaction time, and a copolymer having a weight-average molecular weight of 8,400 was used as a 20% by mass solids solution of copolymer (a-1).

[0096] Synthesis Example 2: Copolymer (a-2) Using the same method as in Synthesis Example 1, 2-allylphenol was used instead of PQMA as the type of monomer added, and the amounts of 2-allylphenol, MAA, and n-stearyl methacrylate were changed to 14.43 g, 3.70 g, and 21.87 g, respectively, to obtain a 20% by mass solids solution of a 50 / 20 / 30 (mol%) copolymer of 2-allylphenol, MAA, and n-stearyl methacrylate. A plurality of such copolymers were prepared by varying the reaction time, and a copolymer having a weight-average molecular weight of 8,500 was used as a 20% by mass solids solution of copolymer (a-2).

[0097] Synthesis Example 3: Copolymer (a-3) Using the same method as in Synthesis Example 1, 10.73 g of PQMA, 5.39 g of 2-allylphenol, 3.45 g of MAA, and 20.42 g of n-stearyl methacrylate were added to obtain a 20% by mass solids solution of a copolymer with a PQMA / 2-allylphenol / MAA / n-stearyl methacrylate ratio of 30 / 20 / 20 / 30 (mol %). Multiple solutions of this copolymer were prepared by varying the reaction time, and a copolymer with a weight average molecular weight of 8,500 was used as a 20% by mass solids solution of copolymer (a-3).

[0098] Synthesis Example 4: Copolymer (a-4) A 20% by mass solids solution of a copolymer with a PQMA / MAA / n-stearyl methacrylate ratio of 40 / 30 / 30 (mol %) was obtained by adding 14.34 g of PQMA, 5.19 g of MAA, and 20.46 g of n-stearyl methacrylate in the same manner as in Synthesis Example 1. A plurality of such copolymers were prepared by varying the reaction time, and a copolymer with a weight average molecular weight of 8,300 was used as a 20% by mass solids solution of copolymer (a-4).

[0099] Synthesis Example 5: Copolymer (a-5) A 20% by mass solids solution of a copolymer with a PQMA / MAA / n-stearyl methacrylate ratio of 55 / 39 / 6 (mol %) was obtained by adding 25.81 g of PQMA, 8.83 g of MAA, and 5.36 g of n-stearyl methacrylate in the same manner as in Synthesis Example 1. A plurality of such copolymers were prepared by varying the reaction time, and a copolymer with a weight average molecular weight of 8,700 was used as a 20% by mass solids solution of copolymer (a-5).

[0100] Synthesis Example 6: Copolymer (a-6) A 20% by mass solids solution of a copolymer with a PQMA / MAA / n-stearyl methacrylate ratio of 55 / 6 / 39 (mol %) was obtained by adding 16.66 g of PQMA, 0.88 g of MAA, and 22.47 g of n-stearyl methacrylate in the same manner as in Synthesis Example 1. A plurality of such copolymers were prepared by varying the reaction time, and a copolymer with a weight average molecular weight of 8,400 was used as a 20% by mass solids solution of copolymer (a-6).

[0101] Synthesis Example 7: Copolymer (a-7) A 20% by mass solids solution of a copolymer with a PQMA / MAA / n-stearyl methacrylate ratio of 82 / 9 / 9 (mol %) was obtained by adding 31.70 g of PQMA, 1.68 g of MAA, and 6.62 g of n-stearyl methacrylate in the same manner as in Synthesis Example 1. A plurality of such copolymers were prepared by varying the reaction time, and a copolymer with a weight average molecular weight of 8,200 was used as a 20% by mass solids solution of copolymer (a-7).

[0102] Synthesis Example 8: Copolymer (a-8) 13.29 g of PQMA, 5.61 g of MAA, and 15.8 g of n-stearyl methacrylate were dissolved completely in 100.0 g of PGMEA, and 3.66 g of V-601 as a polymerization initiator was dissolved completely in 15.0 g of PGMEA. The two resulting solutions were simultaneously added dropwise over 2 hours to 45.0 g of PGMEA heated to 85°C under a nitrogen gas atmosphere in a 300 mL three-neck flask, to carry out copolymerization. Thereafter, the atmosphere in the reaction vessel was purged with air, and 5.30 g of glycidyl methacrylate (hereinafter, GMA) was added dropwise over 1 hour using a dropping pump to carry out an addition reaction. The contents of the vessel were further stirred to obtain a 20% by mass solids solution of a copolymer of PQMA / MAA / n-stearyl methacrylate / GMA-added MAA = 40 / 15 / 25 / 20 (mol%). A plurality of copolymers were prepared by varying the reaction time, and a copolymer having a weight average molecular weight of 8,500 was prepared as a 20% by mass solids solution of copolymer (a-8).

[0103] Synthesis Example 9: Copolymer (a-9) A 20% by mass solids solution of a copolymer with a PQMA / MAA / n-stearyl methacrylate ratio of 50 / 20 / 30 (mol %) was obtained by adding 17.13 g of PQMA, 3.31 g of MAA, and 19.56 g of n-stearyl methacrylate in the same manner as in Synthesis Example 1. A plurality of such copolymers were prepared by varying the reaction time, and a copolymer with a weight average molecular weight of 21,000 was used as a 20% by mass solids solution of copolymer (a-9).

[0104] Synthesis Example 10: Copolymer (a-10) A 20% by mass solids solution of a copolymer with a PQMA / MAA / n-stearyl methacrylate ratio of 50 / 20 / 30 (mol %) was obtained by adding 17.13 g of PQMA, 3.31 g of MAA, and 19.56 g of n-stearyl methacrylate in the same manner as in Synthesis Example 1. A plurality of such copolymers were prepared by varying the reaction time, and a copolymer with a weight average molecular weight of 63,000 was used as a 20% by mass solids solution of copolymer (a-10).

[0105] Synthesis Example 11: Copolymer (a-11) A 20% by mass solids solution of a copolymer with a PQMA / MAA / n-stearyl methacrylate ratio of 56 / 13 / 31 (mol %) was obtained by adding 18.47 g of PQMA, 2.07 g of MAA, and 19.46 g of n-stearyl methacrylate in the same manner as in Synthesis Example 1. A plurality of such copolymers were prepared by varying the reaction time, and a copolymer with a weight average molecular weight of 14,300 was used as a 20% by mass solids solution of copolymer (a-11).

[0106] Synthesis Example 12: Copolymer (a-12) Using the same method as in Synthesis Example 1, isodecyl methacrylate was used instead of n-stearyl methacrylate as the type of monomer added, and the amounts of PQMA added were 22.03 g, MAA added 2.47 g, and isodecyl methacrylate added 15.50 g, thereby obtaining a 20% by mass solids solution of a copolymer with a PQMA / MAA / isodecyl methacrylate ratio of 56 / 13 / 31 (mol %). A plurality of such copolymers were prepared by varying the reaction time, and a copolymer with a weight average molecular weight of 14,500 was used as a 20% by mass solids solution of copolymer (a-12).

[0107] Synthesis Example 13: Copolymer (a-13) Using the same method as in Synthesis Example 1, 2-EHMA was used instead of n-stearyl methacrylate as the type of monomer added, and the amounts of PQMA added were 23.15 g, MAA added 2.59 g, and 2-EHMA added 14.26 g, thereby obtaining a 20% by mass solids solution of a copolymer with a PQMA / MAA / 2-EHMA ratio of 56 / 13 / 31 (mol %). A plurality of such copolymers were prepared by varying the reaction time, and a copolymer with a weight average molecular weight of 14,800 was used as a 20% by mass solids solution of copolymer (a-13).

[0108] Synthesis Example 14: Copolymer (a-14) A 20% by mass solids solution of a copolymer with a PQMA / MAA / n-stearyl methacrylate ratio of 20 / 40 / 40 (mol %) was obtained by adding 6.93 g of PQMA, 6.69 g of MAA, and 26.38 g of n-stearyl methacrylate in the same manner as in Synthesis Example 1. A plurality of such copolymers were prepared by varying the reaction time, and a copolymer with a weight average molecular weight of 8,500 was used as a 20% by mass solids solution of copolymer (a-14).

[0109] Synthesis Example 15: Copolymer (a-15) A 20% by mass solids solution of a copolymer with a PQMA / MAA / n-stearyl methacrylate ratio of 30 / 4 / 66 (mol %) was obtained by adding 7.62 g of PQMA, 0.49 g of MAA, and 31.89 g of n-stearyl methacrylate in the same manner as in Synthesis Example 1. A plurality of such copolymers were prepared by varying the reaction time, and a copolymer with a weight average molecular weight of 8,300 was used as a 20% by mass solids solution of copolymer (a-15).

[0110] Synthesis Example 16: Copolymer (a-16) A 20% by mass solids solution of a copolymer with a PQMA / MAA / n-stearyl methacrylate ratio of 30 / 66 / 4 (mol %) was obtained by adding 17.28 g of PQMA, 18.34 g of MAA, and 4.38 g of n-stearyl methacrylate in the same manner as in Synthesis Example 1. A plurality of such copolymers were prepared by varying the reaction time, and a copolymer with a weight average molecular weight of 8,600 was used as a 20% by mass solids solution of copolymer (a-16).

[0111] Synthesis Example 17: Copolymer (a-17) A 20% by mass solids solution of a copolymer with a PQMA / MAA / n-stearyl methacrylate ratio of 55 / 40 / 5 (mol %) was obtained by adding 26.25 g of PQMA, 9.21 g of MAA, and 4.54 g of n-stearyl methacrylate in the same manner as in Synthesis Example 1. A plurality of such copolymers were prepared by varying the reaction time, and a copolymer with a weight average molecular weight of 8,300 was used as a 20% by mass solids solution of copolymer (a-17).

[0112] Synthesis Example 18: Copolymer (a-18) A 20% by mass solids solution of a copolymer with a PQMA / MAA / n-stearyl methacrylate ratio of 55 / 5 / 40 (mol %) was obtained by adding 16.48 g of PQMA, 0.72 g of MAA, and 22.80 g of n-stearyl methacrylate in the same manner as in Synthesis Example 1. A plurality of such copolymers were prepared by varying the reaction time, and a copolymer with a weight average molecular weight of 8,700 was used as a 20% by mass solids solution of copolymer (a-18).

[0113] Synthesis Example 19: Copolymer (a-19) A 20% by mass solids solution of a copolymer with a PQMA / MAA / n-stearyl methacrylate ratio of 88 / 5 / 7 (mol %) was obtained by adding 33.93 g of PQMA, 0.93 g of MAA, and 5.14 g of n-stearyl methacrylate in the same manner as in Synthesis Example 1. A plurality of such copolymers were prepared by varying the reaction time, and a copolymer with a weight average molecular weight of 8,300 was used as a 20% by mass solids solution of copolymer (a-19).

[0114] Synthesis Example 20: Copolymer (a-20) Using the same method as in Synthesis Example 8, the amounts of PQMA added were 10.26 g, MAA 9.08 g, and n-stearyl methacrylate 9.76 g, and the amount of GMA to be subjected to the addition reaction was 10.91 g, thereby obtaining a 20% by mass solids solution of a copolymer of PQMA / MAA / n-stearyl methacrylate / GMA-added MAA=30 / 15 / 15 / 40 (mol %). Multiple solutions of this copolymer were prepared by varying the reaction time, and a copolymer with a weight average molecular weight of 8,200 was used as a 20% by mass solids solution of copolymer (a-20).

[0115] Synthesis Example 21: Copolymer (a-21) Using the same method as in Synthesis Example 8, the amounts of MAA and n-stearyl methacrylate added were changed to 9.27 g, 24.35 g of n-stearyl methacrylate, and 6.38 g of GMA to be subjected to the addition reaction, thereby obtaining a 20% by mass solids solution of a copolymer with an MAA / n-stearyl methacrylate / GMA-added MAA=35 / 40 / 25 (mol %). A plurality of such copolymers were prepared by varying the reaction time, and a copolymer with a weight average molecular weight of 8,400 was used as a 20% by mass solids solution of copolymer (a-21).

[0116] Synthesis Example 22: Copolymer (a-22) A 20% by mass solids solution of a copolymer with a PQMA / GMA ratio of 60 / 40 (mol %) was obtained by adding 26.12 g of PQMA and 13.88 g of GMA in the same manner as in Synthesis Example 1. A plurality of such copolymers were prepared by varying the reaction time, and a copolymer with a weight average molecular weight of 8,600 was used as a 20% by mass solids solution of copolymer (a-22).

[0117] (Synthesis Example 23: Dispersion resin (f-1) having a tertiary amino group, a carboxy group, and an ethylenically unsaturated group) 400.0 g of PGMEA was charged into a pressure-resistant vessel equipped with a stirrer, a thermometer, a reflux condenser, and a dropping pump. The reaction vessel was filled with nitrogen and then heated to 90 ° C., and 2.0 g of 2-dimethylaminoethyl methacrylate, 31.0 g of methyl methacrylate, 20.0 g of 2-ethylhexyl methacrylate, 30.0 g of styrene, 17.0 g of methacrylic acid, 2.0 g of azobisisobutyronitrile as a polymerization initiator, and a mixture of 3.0 g of normal dodecyl mercaptan was added dropwise using a dropping pump over 3 hours to carry out copolymerization. Thereafter, the atmosphere in the reaction vessel was replaced with air, and 10.0 g of GMA was added dropwise using a dropping pump over 1 hour to carry out an addition reaction, and the vessel was further stirred for 2 hours. As a result, a dispersion resin (f-1) solution having a tertiary amino group, a carboxy group, and an ethylenically unsaturated group and a solids concentration of 20% by mass was obtained, which had characteristic values ​​of a base number of 11 mmol / 100 g, an acid value of 73 mg KOH / g, and a weight average molecular weight of 7,000.

[0118] (Synthesis Example 24: Fluorene acrylate solution (e-1)) A flask was charged with 400.00 g of methyl isobutyl ketone as a solvent, and 350.00 g of 9,9-bis(6-glycidyloxy-2-naphthyl)fluorene, 112.10 g of acrylic acid, 1.50 g of methoquinone as a polymerization inhibitor, and 0.30 g of tetraethylammonium bromide as a catalyst were added thereto. The liquid temperature was maintained at 140 ° C. and stirred for 5 hours to react, after which heating was stopped and the mixture was cooled to room temperature. The reaction product was washed with water by a separation operation and further dried under reduced pressure to obtain fluorene acrylate (mol% ratio of the compound represented by formula (6): the compound represented by formula (7) = 73:27). Next, PGMEA was added so that the solids content was 30% by mass, and the mixture was stirred to obtain a fluorene acrylate solution (e-1).

[0119] Synthesis Example 25: Copolymer (a-23) 13.02 g of PQMA, 4.87 g of MAA, and 17.96 g of n-stearyl methacrylate were dissolved completely in 100.0 g of PGMEA, and 3.66 g of V-601 as a polymerization initiator was dissolved completely in 15.0 g of PGMEA. The two resulting solutions were simultaneously added dropwise over 2 hours to 45.0 g of PGMEA heated to 85°C under a nitrogen gas atmosphere in a 300 mL three-neck flask, to carry out copolymerization. Thereafter, the atmosphere in the reaction vessel was purged with air, and 4.15 g of GMA was added dropwise over 1 hour using a dropping pump to carry out an addition reaction. The contents of the vessel were further stirred to obtain a 20% by mass solids solution of a copolymer of PQMA / MAA / n-stearyl methacrylate / GMA-added MAA = 40 / 15 / 29 / 16 (mol%). A plurality of copolymers were prepared by varying the reaction time, and a copolymer having a weight average molecular weight of 8,500 was prepared as a 20% by mass solids solution of copolymer (a-23).

[0120] Synthesis Example 26: Copolymer (a-24) 13.33 g of PQMA, 3.52 g of MAA, and 21.13 g of n-stearyl methacrylate were dissolved completely in 100.0 g of PGMEA, and 3.66 g of V-601 as a polymerization initiator was dissolved completely in 15.0 g of PGMEA. The two resulting solutions were simultaneously added dropwise over 2 hours to 45.0 g of PGMEA heated to 85°C under a nitrogen gas atmosphere in a 300 mL three-neck flask, to carry out copolymerization. Thereafter, the atmosphere in the reaction vessel was purged with air, and 2.02 g of GMA was added dropwise over 1 hour using a dropping pump to carry out an addition reaction. The contents of the vessel were further stirred to obtain a 20% by mass solids solution of a copolymer of PQMA / MAA / n-stearyl methacrylate / GMA-added MAA = 42 / 15 / 35 / 8 (mol%). A plurality of copolymers were prepared by varying the reaction time, and a copolymer having a weight average molecular weight of 8,500 was prepared as a 20% by mass solids solution of copolymer (a-24).

[0121] Synthesis Example 27: Copolymer (a-25) 13.89 g of PQMA, 2.89 g of MAA, and 22.21 g of n-stearyl methacrylate were dissolved completely in 100.0 g of PGMEA, and 3.66 g of V-601 as a polymerization initiator was dissolved completely in 15.0 g of PGMEA. The two resulting solutions were simultaneously added dropwise over 2 hours to 45.0 g of PGMEA heated to 85°C under a nitrogen gas atmosphere in a 300 mL three-neck flask, to carry out copolymerization. Thereafter, the atmosphere in the reaction vessel was purged with air, and 1.01 g of GMA was added dropwise over 1 hour using a dropping pump to carry out an addition reaction. The contents of the vessel were further stirred to obtain a 20% by mass solids solution of a copolymer of PQMA / MAA / n-stearyl methacrylate / GMA-added MAA = 44 / 15 / 37 / 4 (mol%). A plurality of copolymers were prepared by varying the reaction time, and a copolymer having a weight average molecular weight of 8,500 was prepared as a 20% by mass solids solution of copolymer (a-25).

[0122] (Production Example 1 Production of Pigment Dispersion (B-1)) 525 g of Irgaphor Black S0100CF (manufactured by BASF) as the pigment, 675 g of a 20 mass% PGMEA solution of a dispersion resin (f-1) having a tertiary amino group, a carboxy group, and an ethylenically unsaturated group, and 90 g of a dispersant having an amine value of 20 mg KOH / g described in Synthesis Example 2 of JP-A-2020-070352 as a polymer dispersant, and 1710 g of PGMEA were charged into a tank and stirred with a homomixer for 20 minutes to obtain a preliminary dispersion. The obtained preliminary dispersion was supplied to a disperser Ultra Apex Mill manufactured by Hiroshima Metal & Machinery Co., Ltd., equipped with a centrifugal separator filled with 70% by volume of 0.10 mmφ zirconia beads, and dispersed at a rotation speed of 10 m / s for 3 hours to obtain a pigment dispersion (B-1) with a solids concentration of 25% by mass.

[0123] (Production Example 2: Production of Pigment Dispersion (B-2)) 11.49 g of Irgaphor Black S0100CF (manufactured by BASF) as a pigment, 2.77 g of a dispersant (100% solids content) described in <Dispersant-I> of Patent Document 2, 14.37 g of an alkali-soluble resin (PGMEA solution with a 40% solids content) described in <Synthesis Example 1> of Patent Document 2, 55.40 g of PGMEA, and 15.98 g of MB were charged into a tank, and the mixture was subjected to a dispersion treatment for 3 hours at a temperature of 25 to 45°C using a paint shaker. Zirconia beads with a diameter of 0.5 mm were used as beads, and 2.5 times the mass of the dispersion was added. After completion of dispersion, the beads and the dispersion were separated using a filter to obtain a pigment dispersion (B-2) with a solids concentration of 20% by mass.

[0124] (Example 1) 20.60 g of pigment dispersion (B-1), 28.43 g of a 20% by weight PGMEA solution of copolymer (a-1), 0.88 g of ADEKA ARCLES (registered trademark) NCI-831 as a photopolymerization initiator, 3.26 g of KAYARAD HX-220 (manufactured by Nippon Kayaku Co., Ltd.), 0.02 g of silicone surfactant "BYK" (registered trademark) 333 (manufactured by BYK-Chemie Co., Ltd.), and 46.81 g of PGMEA were added to obtain a negative photosensitive composition (NB-1) with a total solids concentration of 15% by weight. Further, a cured product of the obtained negative photosensitive composition, and an organic EL display device comprising the cured product were prepared according to the method described above.

[0125] (Examples 2 to 13) In the same manner as in Example 1, negative-type photosensitive compositions (NB-2) to (NB-13), cured products thereof, and organic EL display devices equipped with the cured products were obtained by using (a-2) to (a-13) as the copolymer (a) to be added, respectively.

[0126] (Example 14) 25.70 g of pigment dispersion (B-1), 22.00 g of 20% by mass PGMEA solution of copolymer (a-13), 1.00 g of ADEKA ARCLES (registered trademark) NCI-831 as a photopolymerization initiator, 3.16 g of KAYARAD HX-220 (manufactured by Nippon Kayaku Co., Ltd.), 0.02 g of silicone surfactant "BYK" (registered trademark) 333 (manufactured by BYK-Chemie Co., Ltd.), and 48.13 g of PGMEA were added, resulting in a total solids concentration of 15% by mass of a negative photosensitive composition (NB-14). Further, a cured product of the obtained negative photosensitive composition, and an organic EL display device comprising the cured product were prepared according to the method described above.

[0127] (Example 15) 25.70 g of pigment dispersion (B-1), 22.00 g of 20% by weight PGMEA solution of copolymer (a-13), 1.00 g of ADEKA ARCLES (registered trademark) NCI-831 as a photopolymerization initiator, 1.58 g of KAYARAD HX-220 (manufactured by Nippon Kayaku Co., Ltd.), and 5.26 g of fluorene acrylate solution (e-1), silicone surfactant "BYK" (registered trademark) 333 (manufactured by BYK-Chemie Co., Ltd.) 0.02 g, PGMEA 48.13 g was added, a total solids concentration of 15% by weight negative photosensitive composition (NB-15) was obtained. Further, a cured product of the obtained negative photosensitive composition, and an organic EL display device comprising the cured product was prepared according to the method described above.

[0128] (Examples 16 to 18) Negative-type photosensitive compositions (NB-26) to (NB-28), cured products thereof, and organic EL display devices comprising the cured products were obtained in the same manner as in Example 1, except that (a-23) to (a-25) were used as the copolymer (a) to be added.

[0129] (Example 19) To 20.60 g of the pigment dispersion (B-1), 27.85 g of a 20 mass% PGMEA solution of copolymer (a-25), 0.87 g of ADEKA ARCLES (registered trademark) NCI-831 (manufactured by ADEKA Corporation) as a photopolymerization initiator, 3.24 g of KAYARAD HX-220 (manufactured by Nippon Kayaku Co., Ltd.) as a radical polymerizable compound, 0.15 g of ADEKA Pluronic (registered trademark) 17R-2 (manufactured by ADEKA Corporation) as a residue inhibitor, 0.02 g of silicone surfactant "BYK" (registered trademark) 333 (manufactured by BYK-Chemie Co., Ltd.), and 46.81 g of PGMEA were added to obtain a negative photosensitive composition (NB-29) having a total solids concentration of 15 mass%. Furthermore, a cured product of the obtained negative photosensitive composition and an organic EL display device equipped with the cured product were produced according to the above-mentioned method.

[0130] Comparative Examples 1 to 9 Negative-type photosensitive compositions (NB-16) to (NB-24), cured products thereof, and organic EL display devices comprising the cured products were obtained in the same manner as in Example 1, except that (a-14) to (a-22) were used as the copolymer (a) to be added.

[0131] (Comparative Example 10) To 49.65 g of pigment dispersion (B-2), 14.93 g of acrylic soluble resin-IV (40% solids PGMEA solution) described in <Synthesis Example 3> of Patent Document 2, 0.76 g of photopolymerization initiator-I described in <Synthesis Example 4> of Patent Document 2, 1.16 g of KAYARAD DPHA-40H (manufactured by Nippon Kayaku Co., Ltd.) as a radical polymerizable compound, 1.16 g of Light Acrylate TMP-A (manufactured by Kyoeisha Chemical Co., Ltd.), 0.02 g of surfactant "BYK" 330 (manufactured by BYK-Chemie), 24.06 g of PGMEA, and 8.25 g of MB were added to obtain a negative photosensitive composition (NB-25) with a total solids concentration of 19% by mass. Further, a cured product of the obtained negative photosensitive composition, and an organic EL display device comprising the cured product were prepared according to the method described above. The compositions of the copolymers (a) used in the examples and comparative examples are shown in Tables 1, 2 and 3, and the evaluation results are shown in Tables 4, 5 and 6.

[0132]

[0133]

[0134]

[0135]

[0136]

[0137]

[0138] From the above results, the negative-tone photosensitive compositions of the Examples, compared to the negative-tone photosensitive compositions of the Comparative Examples, not only exhibited a smaller mask bias during fine pattern processing, but also exhibited excellent dissolution properties in alkaline developers, suppressed the generation of development residues over a wide range of pre-baking temperatures, and exhibited excellent tapered shapes of the cured products, resulting in excellent light-emitting characteristics of organic EL display devices using the cured products. In particular, even in the cases of Examples 14 and 15, which exhibited high light-blocking properties with an OD value of 1.3 per 1.0 μm thickness of the cured product, the use of copolymer (a) resulted in an excellent dissolution property in alkaline developers. In particular, the use of radically polymerizable compound (e-1) in Example 15 enabled a lower taper angle after development, improved the taper angle after curing, and achieved excellent light-emitting characteristics. Furthermore, in Examples 16, 17, and 19, the formation of micro-residues of less than 0.1 μm was suppressed while maintaining a pre-baking temperature margin.

[0139] 1: Non-alkali glass substrate 2: First electrode (transparent electrode) 3: Auxiliary electrode 4: Insulating layer 5: Organic EL layer 6: Second electrode (non-transparent electrode) θ: Taper angle

Claims

1. A copolymer (a) containing a structural unit represented by formula (1) and / or a structural unit represented by formula (2), a structural unit represented by formula (3), and a structural unit represented by formula (4), wherein the total of the structural units represented by any one of formulas (1) to (4) is 70 to 100 mol % out of a total of 100 mol % of all structural units in the copolymer (a), and wherein, in the copolymer (a), the total number of moles of the structural units represented by formula (1) and the structural units represented by formula (2) is X, the number of moles of the structural units represented by formula (3) is Y, and the number of moles of the structural units represented by formula (4) is Z, where A, obtained by dividing X by Y, is 1.0 to 10.0, and B, obtained by dividing X by Z, is 1.0 to 10.

0. (In formula (1), R 1 represents a hydrogen atom or a methyl group. 2 represents a single bond or an alkylene group having 1 to 3 carbon atoms. 1 is an integer and represents 1 or 2. 3 represents an alkyl group having 1 to 3 carbon atoms or an alkoxy group having 1 to 3 carbon atoms. 2 is an integer from 0 to 2. * represents a bonding site. 4 represents a hydrogen atom or a methyl group. 5 represents an alkylene group having 1 to 3 carbon atoms. 3 is an integer and represents 1 or 2. 6 represents an alkyl group having 1 to 3 carbon atoms or an alkoxy group having 1 to 3 carbon atoms. 4 is an integer from 0 to 2. * represents a bonding site. 7 represents a hydrogen atom or a methyl group. * represents a bonding site. In formula (4), R 8 represents a hydrogen atom or a methyl group. 9 represents an alkyl group having 5 to 18 carbon atoms. * represents a bonding site.) 2. The copolymer according to claim 1, having a weight average molecular weight (Mw) of 10,000 to 50,000.

3. The copolymer according to claim 1 or 2, wherein the copolymer (a) has a structural unit represented by the formula (1).

4. R in the above formula (4) 9 The copolymer according to claim 1 or 2, wherein is a branched alkyl group having 7 to 15 carbon atoms.

5. The copolymer according to claim 1 or 2, wherein the copolymer (a) has a structural unit represented by formula (8). (In formula (8), R 14 and R 15 each independently represents a hydrogen atom or a methyl group; R 16 represents a divalent group having 4 to 12 carbon atoms and a hydroxyl group.

6. The copolymer according to claim 5, wherein the copolymer (a) contains the structural unit represented by the formula (8) in an amount of 5 to 18 mol % based on 100 mol % in total of all structural units of the copolymer (a).

7. A photosensitive composition comprising the copolymer (a) according to claim 1 or 2, a pigment, a photosensitizer and an organic solvent.

8. The photosensitive composition according to claim 7, further comprising a (meth)acrylate compound having two 9,9-bis(naphthyl)fluorene skeletons and two ethylenically unsaturated double bond groups in the molecule, and having negative photosensitivity.

9. The photosensitive composition according to claim 7, further comprising a compound represented by formula (9) and having negative photosensitivity. (In formula (9), PO represents an oxypropylene group, EO represents an oxyethylene group, and x, y, and z each independently represent an integer of 1 to 50 and satisfy the relationship y<x+z.) 10. A cured product obtained by curing the photosensitive composition according to claim 7.

11. An organic EL display device comprising the cured product according to claim 10.

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