Resin composition, cured product, and display device

Abstract

The present invention addresses the problem of providing a resin composition with which can be formed a film that has high sensitivity during pattern processing and high reliability when applied to an organic EL display device. Proposed is a resin composition comprising: polyhydroxystyrene and / or a copolymer of hydroxystyrene and a styrene derivative that does not have a phenolic hydroxyl group (component (A)); a photosensitive compound (component (B)); an aromatic compound that in one aromatic ring has at least one aromatic C-H bond and at least phenolic hydroxyl groups (component (C)); and a cross-linkable compound (component (D)).

Description

Resin compositions, cured products, display devices

[0001] The present invention relates to a resin composition, a cured product using the same, and a display device. More specifically, the present invention relates to a cured product suitable for surface protection films for semiconductor elements, interlayer insulating films, pixel dividing layers for organic electroluminescence (EL) elements, planarizing films for thin film transistor (TFT) substrates used to drive display devices using organic EL elements, wiring protection insulating films for circuit boards, on-chip microlenses for solid-state imaging elements, planarizing films for various displays and solid-state imaging elements, and solder resists for circuit boards, and a resin composition for forming the same.

[0002] Many products using organic electroluminescence (hereinafter, "organic EL") display devices have been developed for display devices having thin displays, such as smartphones, tablet PCs, and televisions. Generally, organic EL display devices have a driving circuit, a planarization layer, a first electrode, a pixel division layer, a light-emitting layer, and a second electrode on a substrate, and can emit light by applying a voltage between the opposing first and second electrodes. Among these, photosensitive resin compositions that can be patterned by ultraviolet irradiation are generally used as materials for the planarization layer and the pixel division layer.

[0003] Photosensitive resin compositions used in these applications are required to have high sensitivity in order to impart high reliability to organic EL display devices and semiconductor devices, as well as to shorten exposure times for reasons such as increasing the size of substrates and improving productivity.

[0004] To meet these demands, a photosensitive resin composition using a polyimide resin has been proposed as a technology that can provide high reliability (see, for example, Patent Document 1). Also, as a technology for increasing sensitivity, mixing a polyimide resin or a polybenzoxazole resin with a novolac resin into a photosensitive resin composition has been investigated (see, for example, Patent Document 2).

[0005] JP 2002-91343 A JP 2014-59463 A

[0006] However, these techniques have been insufficient in either sensitivity during pattern formation or reliability of the organic EL display device. Therefore, an object of the present invention is to provide a resin composition that has high sensitivity during pattern processing and can form a film that is highly reliable when applied to an organic EL display device.

[0007] In order to solve the above problems, the present invention has the following configuration. [1] A resin composition containing one or both of polyhydroxystyrene and a copolymer of hydroxystyrene and a styrene derivative having no phenolic hydroxyl groups (hereinafter referred to as "component (A)"), a photosensitive compound (hereinafter referred to as "component (B)"), an aromatic compound having at least one aromatic C-H bond and at least three phenolic hydroxyl groups in one aromatic ring (hereinafter referred to as "component (C)"), and a crosslinkable compound (hereinafter referred to as "component (D)"). [2] The resin composition according to item [1] above, wherein component (A) contains a structural unit represented by formula (1) in its molecular structure.

[0008]

[0009] (In formula (1), n ​​represents an integer of 1 or more and 5 or less.) [3] The resin composition according to [1] or [2] above, wherein the styrene derivative having no phenolic hydroxyl group is styrene. [4] The resin composition according to any of [1] to [3] above, wherein all or a part of the component (A) is a copolymer of hydroxystyrene and a styrene derivative having no phenolic hydroxyl group. [5] The resin composition according to any of [1] to [4] above, wherein the content of structural units derived from the styrene derivative having no phenolic hydroxyl group is 5 mol % or more and 40 mol % or less, relative to 100 mol % of all structural units of the component (A). [6] The resin composition according to any of [1] to [5] above, wherein all or a part of the component (C) is a compound containing hydroxyl groups such that, when two hydroxyl groups bonded to the compound are selected, the substitution positions of the two hydroxyl groups are ortho- or para-positions. [7] The resin composition according to any one of [1] to [6] above, wherein all or part of the component (C) is a compound containing a structure represented by formula (C)' (2).

[0010]

[0011] (In formula (2), n represents an integer of 2 to 4, and * represents a bonding point with the substituent.) [8] The resin composition according to any one of [1] to [7] above, wherein the weight average molecular weight of the component (A) is 3,000 or more and 20,000 or less. [9] The resin composition according to any one of [1] to [8] above, wherein the dispersity of the component (A) is 1.1 or more and 2.0 or less.

[10] The resin composition according to any one of [1] to [9] above, wherein the molecular weight of the component (C) is 126 or more and 300 or less.

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

[10] above, wherein the content of the component (C) is 20 parts by mass or more and 60 parts by mass or less per 100 parts by mass of the component (A).

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

[11] above, wherein all or part of the component (D) is a compound containing five or more methylol groups.

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

[12] above, wherein all or part of the component (D) is a compound containing a triazine structure.

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

[13] above, wherein the content of the component (D) is 20 parts by mass or more and 50 parts by mass or less per 100 parts by mass of the component (A).

[15] The resin composition according to any one of [1] to

[14] above, further containing a colorant (hereinafter referred to as "component (E)").

[16] The resin composition according to

[15] above, wherein all or part of the component (E) is a compound having a xanthene structure.

[17] The resin composition according to any one of [1] to

[16] above, further comprising one or more selected from the group consisting of polyimide, polyimide precursor, polybenzoxazole, polybenzoxazole precursor, polyamideimide, polyamideimide precursor, and copolymers thereof (hereinafter referred to as "component (F)").

[18] A cured product obtained by curing the resin composition according to any one of [1] to

[17] above.

[19] A display device comprising the cured product according to

[18] above.

[0012] The resin composition of the present invention has high sensitivity during pattern formation, and can form a highly reliable film when applied to an organic EL display device.

[0013] 1A to 1C are schematic diagrams illustrating a procedure for manufacturing an organic EL display device.

[0014] The present invention will be described in detail below.

[0015] <Either or both of polyhydroxystyrene and a copolymer of hydroxystyrene and a styrene derivative having no phenolic hydroxyl group (hereinafter referred to as "component (A))"> The resin composition of the present invention contains, as component (A), either or both of polyhydroxystyrene, which is a polymer of hydroxystyrene that may or may not have a substituent on the benzene ring or the vinyl group (hereinafter sometimes referred to as "component (A-1)"), and a copolymer of hydroxystyrene, which is a polymer of hydroxystyrene that may or may not have a substituent on the benzene ring or the vinyl group, and a styrene derivative having no phenolic hydroxyl group (hereinafter sometimes referred to as "component (A-2)").

[0016] Component (A) is synthesized by a known method. For example, component (A-1) can be obtained by addition polymerization of hydroxystyrene, which may or may not have a substituent on the benzene ring or vinyl group. Examples of phenol derivatives having an unsaturated bond include hydroxystyrene, dihydroxystyrene, coumaric acid, 2-hydroxychalcone, resveratrol, and 4-hydroxystilbene. Two or more of these may be used as polyhydroxystyrene. Furthermore, the phenolic hydroxyl groups contained in components (A-1) and (A-2) may be polymerized using a monomer protected with a protecting group, such as an alkoxy group, at the monomer stage, and then the protecting group may be deprotected by the action of an acid or the like after polymerization to return them to phenolic hydroxyl groups.

[0017] The component (A-2) can also be obtained, for example, by addition polymerization of the above-described hydroxystyrene with a styrene derivative having no phenolic hydroxyl group.

[0018] Examples of styrene derivatives having no phenolic hydroxyl groups include styrene, aminostyrene, vinyltoluene, vinylbenzoic acid and its ester compounds, and styrenesulfonic acid. As the styrene derivative having no phenolic hydroxyl groups, styrene is preferably used from the viewpoint of the change in opening size.

[0019] Examples of addition polymerization techniques include radical polymerization and anionic polymerization. Radical polymerization can produce a polymer with a dispersity of more than 2.0, and by purifying the polymer by techniques such as reprecipitation or gel permeation chromatography, a polymer with a dispersity of 2.0 or less can be obtained. On the other hand, anionic polymerization can directly produce a polymer with a dispersity of 1.5 or less.

[0020] Furthermore, from the viewpoint of improving sensitivity, the component (A) preferably contains a structural unit represented by formula (1) in its molecular structure, and since sensitivity can be further increased, the structure represented by formula (1) preferably accounts for 50 mol % to 100 mol %, relative to 100 mol % of all structural units in the component (A).

[0021]

[0022] In formula (1), n ​​represents an integer of 1 or more and 5 or less.

[0023] From the viewpoint of the change in aperture size, it is preferable that all or part of component (A) is component (A-2). When all structural units contained in component (A) are taken as 100 mol%, the content of structural units derived from the styrene derivative having no phenolic hydroxyl group is preferably 5 mol% or more and 40 mol% or less, and more preferably 10 mol% or more and 30 mol% or less.

[0024] From the viewpoint of sensitivity, the weight average molecular weight of the component (A) is preferably 3,000 or more, more preferably 4,000 or more, even more preferably 5,000 or more, and is preferably 20,000 or less, more preferably 16,000 or less, even more preferably 12,000 or less.

[0025] From the viewpoint of sensitivity, the dispersity of the component (A) is preferably from 1.1 to 2.0, more preferably from 1.1 to 1.8, and even more preferably from 1.1 to 1.5.

[0026] The weight-average molecular weight and number-average molecular weight of component (A) can be determined by gel permeation chromatography (GPC) in polystyrene equivalent terms. The dispersity can be calculated as "dispersity = weight-average molecular weight / number-average molecular weight." GPC is performed using a high-performance liquid chromatograph equipped with TSK-GEL α-2500 and TSK-GEL α-4000 columns manufactured by Tosoh Corporation in series, with the column temperature set to 40°C, and tetrahydrofuran as the developing solvent. The dispersity value is calculated by dividing the weight-average molecular weight by the number-average molecular weight, rounding the result to one decimal place.

[0027] <Photosensitive Compound (Hereinafter referred to as "Component (B)")> The resin composition of the present invention contains the component (B). By containing the component (B), pattern processing by photolithography becomes possible. Examples of the component (B) include a photoacid generator and a photopolymerization initiator. From the viewpoint of resolution, it is preferable to use a photoacid generator as the component (B).

[0028] The photoacid generator may contain a quinone diazide compound, a sulfonium salt, a phosphonium salt, a diazonium salt, an iodonium salt, or the like. A quinone diazide compound is preferably used as component (B). Examples of quinone diazide compounds include those in which the sulfonic acid of quinone diazide is ester-bonded to a polyhydroxy compound, those in which the sulfonic acid of quinone diazide is sulfonamide-bonded to a polyamino compound, and those in which the sulfonic acid of quinone diazide is ester-bonded or sulfonamide-bonded to a polyhydroxypolyamino compound. Among these, those in which the sulfonic acid of quinone diazide is ester-bonded to a polyhydroxy compound are preferred. In particular, in the resin composition of the present invention, it is more preferred to use, as component (B), a quinone diazide compound in which the sulfonic acid of quinone diazide is ester-bonded to the hydroxy groups of a polyhydroxy compound, and in which the proportion of hydroxy groups ester-bonded to the sulfonic acid of quinone diazide is 50 mol% or more and 90 mol% or less relative to 100 mol% of all hydroxy groups. By using a quinone diazide compound in which 50 mol % or more of the hydroxy groups are esterified with a sulfonic acid of quinone diazide, the affinity of the quinone diazide compound to an alkaline aqueous solution is reduced, significantly reducing the solubility of the unexposed portions of the resin composition in an alkaline aqueous solution. Furthermore, the quinone diazide sulfonyl groups are converted to indene carboxylic acid upon exposure, resulting in a high dissolution rate of the exposed portions of the resin composition in an alkaline aqueous solution. As a result, the dissolution rate ratio between the exposed and unexposed portions of the composition is increased, allowing for the production of patterns with high resolution. Furthermore, by using a quinone diazide compound in which 90 mol % or less of the hydroxy groups are esterified with a sulfonic acid of quinone diazide, residues at pattern openings can be suppressed. By using such a quinone diazide compound, a positive-tone resin composition sensitive to the i-line (365 nm), h-line (405 nm), and g-line (436 nm) of a typical mercury lamp can be obtained. Furthermore, photoacid generators may be used alone or in combination to obtain highly sensitive resin compositions.

[0029] The quinone diazide compound may have either a 5-naphthoquinone diazide sulfonyl group or a 4-naphthoquinone diazide sulfonyl group. A quinone diazide compound having a 5-naphthoquinone diazide sulfonyl group has absorption extending into the g-line region of a mercury lamp and is suitable for g-line exposure and full-wavelength exposure. A quinone diazide compound having a 4-naphthoquinone diazide sulfonyl group has absorption in the i-line region of a mercury lamp and is suitable for i-line exposure. In the present invention, it is preferable to select a quinone diazide compound having a 4-naphthoquinone diazide sulfonyl group or a quinone diazide compound having a 5-naphthoquinone diazide sulfonyl group depending on the wavelength of exposure. Furthermore, a quinone diazide compound having both a 4-naphthoquinone diazide sulfonyl group and a 5-naphthoquinone diazide sulfonyl group in the same molecule can also be used, or a quinone diazide compound having a 4-naphthoquinone diazide sulfonyl group and a quinone diazide compound having a 5-naphthoquinone diazide sulfonyl group can also be used in combination.

[0030] The molecular weight of component (B) is preferably 300 or more, more preferably 350 or more, and is preferably 3000 or less, more preferably 1500 or less, from the viewpoint of the heat resistance, mechanical properties, and adhesiveness of the cured product obtained by heat treatment.

[0031] The content of component (B) is preferably at least 1 part by mass, more preferably at least 3 parts by mass, and is preferably at most 100 parts by mass, more preferably at most 80 parts by mass, per 100 parts by mass of component (A), from the viewpoint of imparting photosensitivity while maintaining the heat resistance, chemical resistance, and mechanical properties of the cured product after heat treatment.

[0032] <Aromatic Compound Having at Least One Aromatic C—H Bond and at Least Three Phenolic Hydroxyl Groups in One Aromatic Ring (Hereinafter, referred to as “Component (C)”)> The resin composition of the present invention contains Component (C). Component (C) is highly reactive with Component (D), which will be described later, and readily forms a crosslinked structure, thereby improving the reliability of organic EL display devices.

[0033] Here, in the meaning of "one aromatic ring," "aromatic ring" refers to a ring structure having aromaticity, and aromaticity refers to having a cyclic conjugated system and having 4n+2 electrons (π electrons) involved in the conjugation (n is a natural number, i.e., according to Hückel's rule). The outer edge of the aromatic ring is defined by the largest conjugated system. Therefore, for example, anthracene, pyrene, and azulene are compounds containing one aromatic ring, and biphenyl, binaphthalene, and perylene are compounds containing two aromatic rings.

[0034] The phenolic hydroxyl group refers to a hydroxyl group that is directly bonded to an aromatic ring.

[0035] Furthermore, having an aromatic C—H bond means that there is a hydrogen atom directly bonded to the aromatic ring.

[0036] Furthermore, the term "one aromatic ring" refers to a single aromatic ring when component (C) contains only one aromatic ring, or to one of the multiple aromatic rings when component (C) contains multiple aromatic rings. In other words, the aromatic compound of component (C) contains one or more aromatic rings having at least one aromatic C-H bond and at least three phenolic hydroxyl groups.

[0037] In component (C), the one aromatic ring is preferably an aromatic hydrocarbon (a monocyclic ring), and the compound preferably contains an aromatic six-membered carbon ring in its molecular structure, and at least three phenolic hydroxyl groups are preferably bonded to one six-membered aromatic carbon ring.

[0038] An example of the component (C) is a compound having a structure represented by formula (3).

[0039]

[0040] In formula (3), R １ are independently a monovalent organic group having 1 to 20 carbon atoms, a is an integer of 0 to 2, b is an integer of 0 to 6, and c is an integer of 3 to 9, provided that {(2a+6)-(b+c)}≧1.

[0041] On the other hand, 1,1,1-tris(4-hydroxyphenyl)ethane does not fall under the category of component (C) in the present invention because the benzene ring is not conjugated. Furthermore, for example, a compound having two phenolic hydroxyl groups on one aromatic ring and one phenolic hydroxyl group on the other aromatic ring, such as 2,4,2'-trihydroxybiphenyl, does not fall under the category of component (C).

[0042] When component (C) has at least one aromatic C-H bond in one aromatic ring, it can form a crosslinked product with component (D), which will be described later, and improve the reliability of the organic EL display device.From the viewpoint of increasing the number of crosslinking points with component (D) and further improving the reliability of the organic EL display device, the number of aromatic C-H bonds contained in component (C) is more preferably two or more, and even more preferably three or more.

[0043] Examples of component (C) include phloroglucinol (1,3,5-trihydroxybenzene), pyrogallol (1,2,3-trihydroxybenzene), 1,2,4-trihydroxybenzene, 2,4,5-trihydroxybenzaldehyde, 2,3,4-trihydroxybenzaldehyde, 3,4,5-trihydroxybenzaldehyde, galacetophenone (2,3,4-trihydroxyphenyl methyl ketone), and 2,3,4-trihydroxybenzoic acid. , gallic acid (3,4,5-trihydroxybenzoic acid), methyl gallate, ethyl gallate, propyl gallate, octyl gallate, 2,3,4-trihydroxybenzophenone, 2,3,4,4'-tetrahydroxybenzophenone, 4,4'-isopropylidenedipyrogallol, 1,2,3,4-tetrahydroxybenzene, 1,2,3,5-tetrahydroxybenzene, 1,2,4,5-tetrahydroxybenzene, and leucoquinizarin. Among these, phloroglucinol (1,3,5-trihydroxybenzene), pyrogallol (1,2,3-trihydroxybenzene), and 1,2,4-trihydroxybenzene are preferred.

[0044] Furthermore, from the viewpoint of the reliability of the organic EL display device, it is preferable to use, as the component (C) used in the present invention, a compound containing hydroxyl groups such that when two hydroxyl groups bonded to the compound are selected, the relationship of the substitution positions of the two hydroxyl groups is ortho- or para-position, and it is more preferable that the two hydroxyl groups are in the para-position. Note that, when the component (C) contains a fused ring, in the aromatic carbon six-membered ring contained in the fused ring, the ortho-position is when the hydroxyl groups are bonded to adjacent carbon atoms (the carbons at the α- and β-positions relative to the carbon to which the hydroxyl groups are bonded), and the para-position is when the hydroxyl groups are bonded to opposite carbon atoms (the carbons at the α- and δ-positions relative to the carbon to which the hydroxyl groups are bonded).

[0045] From the viewpoint of reliability, it is preferable to use a phenol compound having a structure represented by formula (2) (hereinafter referred to as "component (C)'") as component (C).

[0046]

[0047] In formula (2), n represents an integer of 2 to 4, and * represents the point of attachment to the substituent.

[0048] The component (C)' may have a plurality of structures represented by formula (2) in one molecule, and preferably has two or more structures represented by formula (2) in one molecule. There is no particular upper limit to the number of structures represented by formula (2) contained in one molecule, but it is preferably 10 or less, and more preferably 5 or less.

[0049] In the partial structure represented by formula (2), examples of the substituent bonded at the benzyl position include an optionally substituted amino group, an optionally substituted alkyl group, an optionally substituted alkoxy group, an optionally substituted alkenyl group, an optionally substituted alkenyl ether group, an optionally substituted aryl group, an optionally substituted aryloxy group, and an optionally substituted heteroaryl group. When the substituent bonded to the benzyl position contains carbon, it preferably has 1 to 50 carbon atoms, more preferably 1 to 30 carbon atoms, and even more preferably 1 to 18 carbon atoms. Examples of the substituent include a phenolic hydroxyl group, a sulfo group, a carboxy group, an alkoxy group, and a hydrocarbon group having 1 to 10 carbon atoms, and it is preferable that the substituent has a phenolic hydroxyl group. Examples of component (C)' include phenolic compounds having the structure shown below.

[0050]

[0051] There is no particular upper limit to the molecular weight of component (C), but from the viewpoint of sensitivity, it is preferably not more than 300, more preferably not more than 200. The lower limit of the molecular weight of component (C) is preferably 126 or more.

[0052] From the viewpoint of sensitivity and reliability of the organic EL display device, the content of the component (C) in the resin composition of the present invention is preferably 20 parts by mass or more, more preferably 30 parts by mass or more, and preferably 60 parts by mass or less, more preferably 50 parts by mass or less, per 100 parts by mass of the component (A).

[0053] <Crosslinkable Compound (Hereinafter referred to as "Component (D)")> The resin composition of the present invention contains Component (D). Component (D) bonds with Component (C) to form a crosslinked structure, thereby improving the reliability of organic EL display devices. Examples of Component (D) include compounds containing a methylol group, an alkoxymethyl group, an epoxy group, and an oxetane group. From the viewpoint of reactivity with Component (C), a compound containing a methylol group is preferred as Component (D).

[0054] From the viewpoint of reliability of the organic EL display device, it is preferable to use a compound containing five or more methylol groups as the component (D), and it is more preferable to use a compound containing six or more methylol groups.

[0055] From the viewpoint of the reliability of the organic EL display device, it is preferable to use a compound containing a triazine structure as the component (D). Examples of compounds having a triazine structure include compounds represented by formula (4).

[0056]

[0057] In formula (4), R ２ ~R ７ each independently represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an alkenyl ether group having 2 to 10 carbon atoms, a methylol group, or an alkoxymethyl group. ２ ~R ７ At least one of these is a methylol group or an alkoxymethyl group.

[0058] The component (D) is a compound represented by formula (4), in which R ２ ~R ７ Among these, compounds in which five or more are methylol groups are more preferred.

[0059] There is no particular upper limit to the molecular weight of component (D), but it is preferably 1,000 or less, more preferably 800 or less, and even more preferably 600 or less.

[0060] From the viewpoints of sensitivity and reliability of the organic EL display device, the content of the component (D) is preferably 20 parts by mass or more, more preferably 30 parts by mass or more, and preferably 50 parts by mass or less, more preferably 40 parts by mass or less, per 100 parts by mass of the component (A).

[0061] <Colorant (hereinafter referred to as "component (E)")> The resin composition of the present invention may further contain component (E). By containing component (E), the reliability of the organic EL display device can be improved. Examples of component (E) include dyes, organic pigments, and inorganic pigments, and the component (E) can be used according to the purpose. From the viewpoint of the reliability of the organic EL display device, a dye is preferred as component (E).

[0062] From the viewpoint of reliability of the organic EL display device, it is preferable to use a compound containing a xanthene structure as the component (E). Examples of the compound containing a xanthene structure include a compound represented by formula (5). Examples of the compound represented by formula (5) include known xanthene acid dyes, compounds comprising an ion pair of the anion moiety of a xanthene acid dye and an ammonium cation, known xanthene basic dyes, and xanthene compounds described in WO 2023 / 013549.

[0063]

[0064] In formula (5), R ８ ~R １１ R each independently represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms which may have a substituent. １２ ~R １７ R each independently represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. １８ ~R ２２ are each independently a hydrogen atom, a halogen atom, or —SO ３ H, -SO ３ － , -SO ３ NR ２３ R ２４ , -COOH, -COO － , -COOR ２５ , -CONR ２６ R ２７ , -OR ２８ , -NR ２９ R ３０ or a monovalent hydrocarbon group having 1 to 20 carbon atoms which may have a substituent. ２３ ~R ３０each independently represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 20 carbon atoms which may have a substituent; Z is a counter ion; ８ ~R ３０ Included in -SO ３ － and-COO － When the total number of is f (f is an integer of 0 or more), if f=0, then g=-1 and h=1; if f=1, then h=0 (i.e., no counter ion is required); and if f≧2, then g=1 and h=f−1.

[0065] Here, examples of the substituent that the monovalent hydrocarbon group having 1 to 10 carbon atoms which may have a substituent or the monovalent hydrocarbon group having 1 to 20 carbon atoms which may have a substituent include a halogen atom, a hydroxyl group, an alkoxy group, a phenoxy group, a carboxyl group, a sulfo group, an acyl group, an amino group, an imino group, an amido group, an imido group, a nitro group, a cyano group, -SO ３ － , -COO － Examples of known substituents include:

[0066] <Polyimide, polyimide precursor, polybenzoxazole, polybenzoxazole precursor, polyamideimide, polyamideimide precursor, and copolymer thereof> The resin composition of the present invention may contain one or more members selected from the group consisting of polyimide, polyimide precursor, polybenzoxazole, polybenzoxazole precursor, polyamideimide, polyamideimide precursor, and copolymers thereof (hereinafter referred to as "component (F)").

[0067] In the case of polyimide, any polymer having an imide ring is acceptable, and in the case of polybenzoxazole, any polymer having a benzoxazole ring is acceptable. The polyimide precursor is not particularly limited as long as it is a polymer having a structure that forms an imide ring by dehydration ring closure, and the polybenzoxazole precursor is not particularly limited as long as it is a polymer having a structure that forms a benzoxazole ring by dehydration ring closure.

[0068] Component (F) is synthesized by a known method. In the case of a polyimide precursor such as a polyamic acid or a polyamic acid ester, examples of production methods include reacting a tetracarboxylic dianhydride with a diamine compound at low temperature, obtaining a diester from a tetracarboxylic dianhydride with an alcohol and then reacting it with an amine in the presence of a condensing agent, or obtaining a diester from a tetracarboxylic dianhydride with an alcohol and then converting the remaining dicarboxylic acid into an acid chloride and reacting it with an amine.

[0069] In the case of polyimide, for example, it can be obtained by dehydrating and ring-closing the polyamic acid or polyamic acid ester obtained by the above-mentioned method by heating or chemical treatment with an acid or base.

[0070] Polybenzoxazole precursors such as polyhydroxyamides can be produced by condensation reaction of a bisaminophenol compound with a dicarboxylic acid. Specifically, a method of reacting a dehydration condensing agent such as dicyclohexylcarbodiimide (DCC) with an acid and then adding the bisaminophenol compound thereto, or a method of adding a dicarboxylic acid dichloride solution dropwise to a solution of a bisaminophenol compound to which a tertiary amine such as pyridine has been added, can be used.

[0071] Polybenzoxazole can be obtained, for example, by dehydrating and cyclizing polyhydroxyamide obtained by the above-mentioned method using heat or a chemical treatment with an acid or base.

[0072] The resin composition of the present invention may contain various known additives such as an adhesion improver and a surfactant as components other than the above-described components (A), (B), (C), (D), (E), and (F).

[0073] <Solvent> The resin composition of the present invention may contain a solvent. Examples of the solvent include polar aprotic solvents such as N-methyl-2-pyrrolidone, γ-butyrolactone, γ-valerolactone, δ-valerolactone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, 1,3-dimethyl-2-imidazolidinone, N,N'-dimethylpropyleneurea, N,N-dimethylisobutyric acid amide, and methoxy-N,N-dimethylpropionamide; ethers such as tetrahydrofuran, dioxane, propylene glycol monomethyl ether, and propylene glycol monoethyl ether; ketones such as acetone, methyl ethyl ketone, and diisobutyl ketone; esters such as ethyl acetate, butyl acetate, isobutyl acetate, propyl acetate, propylene glycol monomethyl ether acetate, and 3-methyl-3-methoxybutyl acetate; alcohols such as ethyl lactate, methyl lactate, diacetone alcohol, and 3-methyl-3-methoxybutanol; and aromatic hydrocarbons such as toluene and xylene. Two or more of these may be used. The content of the solvent is preferably 100 parts by mass or more per 100 parts by mass of the component (A) in order to dissolve the composition.

[0074] The resin composition of the present invention can be used to form insulating films, protective films, planarizing films, etc. for semiconductor elements and display devices. In particular, the resin composition of the present invention is suitable for forming planarizing layers and pixel dividing layers of organic EL display devices because it has high heat resistance and low outgassing properties for planarizing layers and pixel dividing layers, and is particularly suitable for forming pixel dividing layers of organic EL display devices because it can improve the reliability of the organic EL display devices.

[0075] <Method for Producing Resin Composition> Next, an example of a method for producing the resin composition of the present invention will be described.

[0076] A resin composition can be obtained by mixing the components constituting the resin composition of the present invention, namely, components (A), (B), (C), and (D), as well as optional components (E) and (F), and various known additives such as adhesion improvers and surfactants, and solvents. The resin composition of the present invention preferably contains a solvent to dissolve the components. In such cases, methods for promoting dissolution include heating and stirring. When heating, the heating temperature is preferably set within a range that does not impair the performance of the resin composition, typically room temperature to 80°C. Note that, in this specification, room temperature refers to 25°C. The order in which the components are dissolved is not particularly limited, and examples include a method in which compounds with low solubility in the solvent are dissolved sequentially. When stirring, the rotation speed is preferably set within a range that does not impair the performance of the resin composition, typically 200 rpm to 2000 rpm. When stirring, heating may be performed as needed, typically room temperature to 80°C. Furthermore, for components that are prone to generating bubbles when dissolved by stirring, such as surfactants and some adhesion improvers, adding them last after dissolving the other components can prevent incomplete dissolution of the other components due to the generation of bubbles.

[0077] The obtained resin composition is preferably filtered using a filter to remove dust and particles. The filter pore size may be, for example, 0.5 μm, 0.2 μm, 0.1 μm, 0.05 μm, or 0.02 μm, but is not limited to these. Filter materials include polypropylene (PP), polyethylene (PE), nylon (NY), and polytetrafluoroethylene (PTFE), with polyethylene and nylon being preferred. Furthermore, when the resin composition contains organic pigments, it is preferable to use a filter with a pore size larger than the particle size of these pigments.

[0078] <Cured Product Obtained by Curing Resin Composition> The cured product of the present invention can be obtained by curing the above-described resin composition.

[0079] The cured product of the present invention can be obtained, for example, by applying the resin composition described above to a substrate or the like and curing it by heat treatment. The heat treatment conditions are preferably 200°C or higher, more preferably 250°C or higher. The heat treatment conditions are preferably 400°C or lower, more preferably 350°C or lower.

[0080] <Method for Producing a Cured Product Pattern Using Resin Composition> A method for producing a cured product pattern using the resin composition of the present invention will be described below by way of an example.

[0081] The method for producing a cured product includes, in this order: (Step 1) applying the resin composition described above to a substrate to form a coating film; (Step 2) exposing the coating film to actinic rays to obtain an exposed coating film; (Step 3) developing the exposed coating film using an alkaline solution to obtain a developed coating film; and (Step 4) heating the developed coating film to obtain a cured product pattern.

[0082] In step 1, the resin composition of the present invention is applied to a substrate to form a coating film. Applicable coating methods include spin coating, slit coating, dip coating, spray coating, and printing, and a coating film of the resin composition of the present invention is obtained. Prior to coating, the substrate to which the resin composition is to be applied may be pretreated with the adhesion promoter described above. For example, the substrate surface may be treated with a solution prepared by dissolving 0.5 to 20% by mass of an adhesion promoter in a solvent such as isopropanol, ethanol, methanol, water, tetrahydrofuran, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, ethyl lactate, or diethyl adipate. Examples of substrate surface treatment methods include spin coating, slit die coating, bar coating, dip coating, spray coating, and steam treatment. In the coating film drying step, the formed coating film is subjected to a vacuum drying treatment as necessary, followed by heat treatment at 50°C to 180°C for 1 minute to several hours using a hot plate, oven, infrared radiation, or the like to obtain a coating film.

[0083] Next, step 2 will be described.

[0084] The coating film is irradiated with actinic rays (hereinafter, sometimes referred to as "exposure"). At this time, the exposure may be performed through a photomask having a desired pattern, if necessary, or the coating film may be directly exposed with a laser or the like. Actinic rays used for exposure include ultraviolet rays, visible light, electron beams, and X-rays, but in the present invention, it is preferable to use i-rays (365 nm), h-rays (405 nm), and g-rays (436 nm) from a mercury lamp.

[0085] Next, step 3 will be described.

[0086] The exposed coating film is developed using an alkaline solution to remove either the exposed or unexposed portions of the coating film, thereby forming a pattern. The developer used here is preferably an aqueous solution of an alkaline compound such as tetramethylammonium hydroxide, diethanolamine, diethylaminoethanol, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, triethylamine, diethylamine, methylamine, dimethylamine, dimethylaminoethyl acetate, dimethylaminoethanol, dimethylaminoethyl methacrylate, cyclohexylamine, ethylenediamine, or hexamethylenediamine. In some cases, these alkaline aqueous solutions may contain one or more polar solvents such as N-methyl-2-pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethylsulfoxide, γ-butyrolactone, or dimethylacrylamide; alcohols such as methanol, ethanol, or isopropanol; esters such as ethyl lactate or propylene glycol monomethyl ether acetate; or ketones such as cyclopentanone, cyclohexanone, isobutyl ketone, or methyl isobutyl ketone. The development method may be spray, puddle, immersion, ultrasonic, or the like.

[0087] Next, the pattern formed by development is preferably rinsed with distilled water. Here, the rinsing treatment may also be carried out by adding alcohols such as ethanol and isopropyl alcohol, or esters such as ethyl lactate and propylene glycol monomethyl ether acetate to distilled water.

[0088] Next, step 4 will be described.

[0089] Heat treatment of the developed coating film can remove residual solvents and components with low heat resistance, thereby improving the heat resistance and chemical resistance of the cured pattern. This heat treatment is carried out by selecting a certain temperature and gradually increasing the temperature, or by selecting a certain temperature range and continuously increasing the temperature for 5 minutes to 5 hours. For example, a method of heat treatment at 230°C for 60 minutes can be mentioned. In the present invention, the heat treatment conditions are preferably 200°C or higher, more preferably 230°C or higher. Furthermore, the heat treatment conditions are preferably 400°C or lower, more preferably 350°C or lower.

[0090] <Display Device> The display device of the present invention includes a cured product obtained by curing the above-described resin composition.

[0091] The cured product obtained by curing the resin composition of the present invention is contained in the planarization layer or pixel division layer of a display device having, in this order, a substrate on which TFTs are formed, a planarization layer on a drive circuit, a pixel division layer and display element on a first electrode, and a second electrode. Examples of displays having such a configuration include liquid crystal displays and organic EL display devices. Among these, the cured product is particularly suitable for use in organic EL display devices, which require high heat resistance and low outgassing properties for the planarization layer or pixel division layer, and is particularly suitable for use in pixel division layers because it can improve the contrast of organic EL display devices.

[0092] The cured product of the resin composition of the present invention may be used for either the planarization layer or the pixel dividing layer, or for both. An active matrix display device has TFTs and wiring located on the sides of the TFTs and connected to the TFTs on a substrate such as glass, and a planarization layer thereon to cover the irregularities, with display elements further provided on the planarization layer. The display elements and the wiring are connected via contact holes formed in the planarization layer.

[0093] The present invention will be explained below with reference to examples, but the present invention is not limited to these examples.

[0094] (1) Evaluation of Sensitivity A sample resin composition (hereinafter sometimes referred to as "varnish") was applied to an 8-inch silicon wafer by spin coating so that the film thickness after heat treatment (curing) would be 3.0 μm, and the wafer was prebaked at 120°C for 2 minutes to form a prebaked film. The obtained prebaked film was exposed to light at an exposure dose of 50 to 300 mJ / cm through a mask having a 20 μm line and space pattern. ２ in the range of 5 mJ / cm ２ After exposure, the film was developed for 30 seconds with a 2.38% by mass aqueous solution of tetramethylammonium hydroxide, then rinsed with pure water and shaken off to dry, obtaining a pattern. A coater / developer (ACT-8 manufactured by Tokyo Electron Limited) was used for coating, pre-baking, and development, and an i-line stepper (NSR-2005i9C manufactured by Nikon Corporation) was used for exposure.

[0095] The pattern of the film after development obtained by the above method was observed at a magnification of 100 times using an FPD microscope MX61 (manufactured by Olympus Corporation), and the exposure amount at which the line and space width of the line and space pattern could be formed with 20 μm each (for convenience, referred to as the "optimum exposure amount") was determined, and this was taken as the sensitivity. The sensitivity was judged as follows, and was determined as E or higher (sensitivity of 150 mJ / cm ２ S: Sensitivity is 100 mJ / cm or less. ２ A: Sensitivity is less than 100 mJ / cm ２ 110mJ / cm or more ２ B: Sensitivity is less than 110 mJ / cm ２ 120mJ / cm or more ２ C: Sensitivity is less than 120 mJ / cm ２ 130mJ / cm or more ２ D: Sensitivity is less than 130 mJ / cm ２ 140mJ / cm or more ２ E: Sensitivity is less than 140 mJ / cm ２ 150mJ / cm or more ２ F: Sensitivity is less than 150 mJ / cm ２ 160mJ / cm or more ２ G: Sensitivity is less than 160 mJ / cm ２ That's all.

[0096] (2) Evaluation of Aperture Dimension Change Using the method in (1) above, a 20 μm line and space pattern was obtained with the optimum exposure dose, and the aperture dimension (aperture dimension after development, 20 μm) was measured. The obtained pattern was then cured for 60 minutes in an oven at 250°C under a nitrogen atmosphere, and the aperture dimension (μm) after curing was measured. From these measurements, the aperture dimension change was calculated using the following formula and evaluated as follows: Aperture dimension change [μm] = (aperture dimension after development) - (aperture dimension after curing) A: Aperture dimension change was 0.0 μm or more and 0.1 μm or less B: Aperture dimension change was more than 0.1 μm and 0.2 μm or less C: Aperture dimension change was more than 0.2 μm or less than 0.0 μm.

[0097] (3) Evaluation of Reliability Reliability was evaluated based on the light-emitting area ratio of an organic EL display device having a pixel dividing layer made of a cured product obtained from the sample resin composition.

[0098] Schematic diagrams of each process are shown in Figures 1(a) to 1(d). First, a 10 nm thick ITO transparent conductive film was formed over the entire surface of a 38 mm x 46 mm alkali-free glass substrate 1 by sputtering, followed by etching to form a first electrode 2. An auxiliary electrode 3 was also formed at the same time to extract the second electrode (Figure 1(a)). The resulting substrate was ultrasonically cleaned for 10 minutes using "Semicoclean" (registered trademark) 56 (trade name, manufactured by Furuuchi Chemical Co., Ltd.) and then rinsed with ultrapure water. Next, the sample resin composition was applied to the entire substrate by spin coating and prebaked on a hot plate at 100°C for 2 minutes. The film was exposed to ultraviolet light through a photomask, developed with a 2.38% by weight aqueous solution of tetramethylammonium hydroxide, and then rinsed with pure water to obtain a pattern. The resulting pattern was cured for 60 minutes in an oven at 230°C under a nitrogen atmosphere. In this way, a pixel dividing layer 4 (the openings and the exposed first electrodes 2 are not shown) was formed in the effective substrate area (FIG. 1(b)). The pixel dividing layer 4 had openings with a width of 70 μm and a length of 260 μm, arranged at a pitch of 155 μm in the width direction and a pitch of 465 μm in the length direction, and each opening exposed the first electrodes 2 (the openings and the exposed first electrodes 2 are not shown). These openings ultimately became light-emitting pixels. The effective substrate area was 16 mm square, and the pixel dividing layer was approximately 1.0 μm thick.

[0099] Next, an organic EL display device was fabricated using the substrate on which the first electrode 2, auxiliary electrode 3, and pixel dividing layer 4 were formed. After nitrogen plasma treatment as pretreatment, an organic EL layer 5 including a light-emitting layer was formed by vacuum deposition (FIG. 1(c)). The degree of vacuum during deposition was 1×10 －３ The pressure was below 1 Pa, and the substrate 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 emitting layer so that the doping concentration was 10%. Next, compounds (ET-1) and (LiQ) were laminated to a thickness of 40 nm as electron transport materials at a volume ratio of 1:1. The structures of the compounds used in organic EL layer 5 are shown below.

[0100]

[0101] Next, a compound (LiQ) was vapor-deposited to a thickness of 2 nm, followed by co-deposition of 10 nm of MgAg at a volume ratio of Mg to Ag of 10:1 to form the second electrode 6 (FIG. 1(d)). Finally, a cap-shaped glass plate was attached using an epoxy resin adhesive in a low-humidity nitrogen atmosphere to seal the substrate, and four 5 mm square light-emitting devices were fabricated on one substrate. The film thickness here is the value displayed on a quartz crystal oscillator film thickness monitor.

[0102] The organic EL display device was subjected to a current of 10 mA / cm ２ The device was then placed on a hot plate heated to 80°C with the light-emitting surface facing up, and irradiated with a wavelength of 365 nm and an illuminance of 0.6 mW / cm. ２ After 100 hours, the ultraviolet light was irradiated at 10 mA / cm ２The device was driven by DC current and emitted light at 1000 Hz, and the light-emitting area of ​​the light-emitting pixel (the light-emitting area after UV light irradiation) was measured. From these measured values, the light-emitting area ratio was calculated using the following formula, and the reliability was evaluated from this value as follows, with E or higher (light-emitting area ratio of 70% or higher) being considered acceptable. S is the most excellent. Light-emitting area ratio [%] = (light-emitting area after UV light irradiation) / (light-emitting area before UV light irradiation) x 100 S: light-emitting area ratio is 95% or more and 100% or less A: light-emitting area ratio is 90% or more and less than 95% B: light-emitting area ratio is 85% or more and less than 90% C: light-emitting area ratio is 80% or more and less than 85% D: light-emitting area ratio is 75% or more and less than 80% E: light-emitting area ratio is 70% or more and less than 75% F: light-emitting area ratio is 50% or more and less than 70% G: light-emitting area ratio is less than 50%.

[0103] Synthesis Example 1: 109.4 g (0.62 mol) of 4-tert-butoxystyrene was added to a mixture of 2,400 g of tetrahydrofuran and 16.2 mL (19 mmol) of a 1.2 mol / L hexane solution of sec-butyllithium as an initiator. The mixture was then polymerized with stirring for 3 hours, and 12.82 g (0.4 mol) of methanol was added to terminate the polymerization. The reaction mixture was then poured into 3 L of methanol to purify the polymer, and the precipitated polymer was dried. The resulting polymer was dissolved in 1.6 L of acetone, and 2 g of concentrated hydrochloric acid was added at 60°C and stirred for 7 hours to deprotect the tert-butyl groups, yielding hydroxystyrene. After completion of the reaction, the solution was poured into water to precipitate the polymer. The resulting precipitate was washed three times with water and then dried in a vacuum dryer at 50°C for 24 hours to obtain polyhydroxystyrene a-1, component (A). The weight average molecular weight (polystyrene equivalent) determined by GPC (Waters 2695 manufactured by Waters Corporation, column: TSK-GEL α-2500 and TSK-GEL α-4000 manufactured by Tosoh Corporation in series, column temperature: 40°C, developing solvent: tetrahydrofuran) was 5,500 and the polydispersity was 1.1.

[0104] Synthesis Examples 2 to 5 Polyhydroxystyrenes a-2 to a-5, which are component (A), were obtained in the same manner as in Synthesis Example 1, except that sec-butyllithium and 4-tert-butoxystyrene were used in the amounts shown in Table 1. The weight average molecular weights (polystyrene equivalent) and dispersities determined by GPC are shown in Table 1.

[0105] Copolymers a-6 to a-9 of hydroxystyrene and a styrene derivative having no phenolic hydroxyl group, which is component (A), were obtained in the same manner as in Synthesis Example 1, except that in addition to sec-butyllithium and 4-tert-butoxystyrene, the styrene derivative having no phenolic hydroxyl group shown in Table 1 was used and the amounts of each raw material were changed to those shown in Table 1. The weight average molecular weight (polystyrene equivalent) and dispersity determined by GPC are shown in Table 1.

[0106]

[0107] Synthesis Example 10 To 100 g of ethylene glycol monoethyl ether, 13.1 g (0.080 mol) of azobisisobutyronitrile (AIBN) as a polymerization initiator and 109.4 g (0.62 mol) of 4-tert-butoxystyrene were added, and after purging with nitrogen, the mixture was reacted at 80°C for 16 hours. Thereafter, the same operation as in Synthesis Example 1 was carried out to obtain polyhydroxystyrene a-10, component (A). The weight average molecular weight (polystyrene equivalent) determined by GPC was 5,500, and the dispersity was 2.1.

[0108] Synthesis Example 11 A copolymer a-11 of hydroxystyrene and a styrene derivative having no phenolic hydroxyl group, which is component (A), was obtained in the same manner as in Synthesis Example 10, except that 92.9 g (0.53 mol) of 4-tert-butoxystyrene and 9.7 g (0.093 mol) of styrene were used instead of 109.4 g (0.62 mol) of 4-tert-butoxystyrene. The weight average molecular weight (polystyrene equivalent) determined by GPC was 5,500, and the dispersity was 2.1.

[0109] Synthesis Example 12 Under a dry nitrogen stream, 21.2 g (0.05 mol) of 4,4'-[1-[4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl]ethylidene]bisphenol (TrisP-PA) and 26.8 g (0.1 mol) of 4-naphthoquinone diazide sulfonic acid chloride were dissolved in 450 g of 1,4-dioxane and the solution was allowed to cool to room temperature. 12.7 g of triethylamine mixed with 50 g of 1,4-dioxane was added thereto so that the temperature in the system did not exceed 35°C, and the mixture was stirred at 40°C for 2 hours. The triethylamine salt was filtered, and the filtrate was added to water. The precipitate was then collected by filtration and washed with 1 L of 1% aqueous hydrochloric acid. The mixture was then washed twice with 2 L of water. This precipitate was dried in a vacuum dryer to obtain compound b-1, which is component (B).

[0110] Synthesis Example 13 Under a dry nitrogen stream, 31.02 g (0.10 mol) of bis(3,4-dicarboxyphenyl)ether dianhydride, 31.13 g (0.085 mol) of 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane, 1.24 g (0.0050 mol) of 1,3-bis(3-aminopropyl)tetramethyldisiloxane, 2.18 g (0.020 mol) of 3-aminophenol, and 200.00 g of N-methyl-2-pyrrolidone were placed in a three-neck flask and stirred at 20°C for 1 hour, followed by stirring at 50°C for 4 hours. Thereafter, 15 g of xylene was placed in the mixture and stirred at 150°C for 5 hours. After completion of the reaction, the reaction solution was placed in 3 L of water, and the resulting solid precipitate was collected by filtration. The resulting solid was washed three times with water and then dried in a vacuum dryer at 80° C. for 24 hours to obtain polyimide resin f-1, which is component (F).

[0111] Synthesis Example 14 33.40 g of 4-hydroxyphenyl methacrylate and 6.66 g of glycidyl methacrylate were completely dissolved in 100.0 g of propylene glycol monomethyl ether acetate (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 dropwise addition, the mixture was allowed to react at 85°C for 3 hours, thereby obtaining a solution with a solids content of 20% by mass of acrylic resin g-1, which was another component.

[0112] Synthesis Example 15: Under a dry nitrogen stream, 1.68 g (0.01 mol) of 2,6-bis(hydroxymethyl)-p-cresol, 12.61 g (0.10 mol) of 1,2,4-trihydroxybenzene, and 0.29 g of p-toluenesulfonic acid monohydrate were dissolved in 40 g of water at room temperature, and the mixture was allowed to react at 65°C for 4 hours. The mixture was then cooled in an ice bath, and the precipitated solid was collected by filtration, washed three times with water, and dried in a vacuum dryer at 50°C for 24 hours to obtain phenol compound (c1-1), which is component (C)'. The molecular weight of (c1-1) is 384.

[0113] Synthesis Example 16: Under a dry nitrogen stream, 16.72 g (0.10 mol) of carbazole and 12.99 g (0.16 mol) of a 37% aqueous formaldehyde solution were dissolved in 120 g of tetrahydrofuran at room temperature, and 0.5 g of a 50% aqueous sodium hydroxide solution was added. The mixture was allowed to react at room temperature for 8 hours. The solution was then poured into 1 L of water to obtain a yellow-white precipitate. This precipitate was collected by filtration, washed three times with water, and then dried in a vacuum dryer at 40°C for 24 hours to obtain an N-methylolated carbazole. Subsequently, the procedure of Synthesis Example 14 was repeated, except that 1.68 g (0.01 mol) of 2,6-bis(hydroxymethyl)-p-cresol was replaced with 3.94 g (0.02 mol) of the obtained N-methylolated carbazole, to obtain a phenol compound (c1-2), component (C)'. The molecular weight of (c1-2) was 305.

[0114] The compounds used in each of the examples and comparative examples are shown below.

[0115]

[0116] Example 1 Under yellow light, polyhydroxystyrene a-5 obtained in Synthesis Example 5 as the component (A), compound b-1 obtained in Synthesis Example 12 as the component (B), compound c-3 as the component (C), compound d-2 as the component (D), and γ-butyrolactone (GBL) and ethyl lactate (EL) as solvents were added in the amounts shown in Table 2, and the mixture was stirred to dissolve, thereby preparing Composition 1.

[0117] Composition 1 was evaluated for sensitivity, change in aperture size, and reliability.

[0118] [Examples 2 to 34, Comparative Examples 1 to 3] Compositions 2 to 37 were prepared in the same manner as in Example 1, with the compositions shown in Table 2 or Table 3.

[0119] Compositions 2 to 37 were evaluated in the same manner as in Example 1.

[0120] The compositions and evaluation results of the resin compositions of the examples and comparative examples are shown in Table 2 or Table 3.

[0121]

[0122]

[0123] From the above results, it was confirmed that the resin composition of the present invention has high sensitivity during pattern processing and can form a highly reliable film when applied to an organic EL display device.

[0124] 1: Glass substrate 2: First electrode 3: Auxiliary electrode 4: Pixel dividing layer 5: Organic EL layer 6: Second electrode

Claims

1. A resin composition containing either or both of polyhydroxystyrene and a copolymer of hydroxystyrene and a styrene derivative having no phenolic hydroxyl groups (hereinafter referred to as "component (A)"), a photosensitive compound (component (B)), an aromatic compound having at least one aromatic C-H bond and at least three phenolic hydroxyl groups in one aromatic ring (hereinafter referred to as "component (C)"), and a crosslinkable compound (hereinafter referred to as "component (D)").

2. The resin composition according to claim 1, wherein component (A) contains a structural unit represented by formula (1) in its molecular structure. (In formula (1), n ​​represents an integer of 1 to 5.) 3. A resin composition according to claim 1 or 2, wherein the styrene derivative having no phenolic hydroxyl group is styrene.

4. A resin composition according to claim 1 or 2, wherein all or a part of component (A) is a copolymer of hydroxystyrene and a styrene derivative having no phenolic hydroxyl group.

5. A resin composition described in claim 4, in which the content of structural units derived from a styrene derivative not having a phenolic hydroxyl group is 5 mol % or more and 40 mol % or less relative to 100 mol % of all structural units of component (A).

6. A resin composition according to claim 1 or 2, wherein all or a part of component (C) is a compound containing hydroxyl groups such that when two hydroxyl groups bonded to the compound are selected, the substitution positions of the two hydroxyl groups are ortho or para.

7. The resin composition according to claim 1 or 2, wherein all or a part of the component (C) is a compound containing a structure represented by formula (C)' (2). (In formula (2), n represents an integer of 2 to 4, and * represents a bonding point to a substituent.) 8. A resin composition according to claim 1 or 2, wherein the weight average molecular weight of component (A) is 3,000 or more and 20,000 or less.

9. A resin composition according to claim 1 or 2, wherein the dispersity of component (A) is 1.1 or more and 2.0 or less.

10. A resin composition according to claim 1 or 2, wherein the molecular weight of component (C) is 126 or more and 300 or less.

11. A resin composition described in claim 1 or 2, in which the content of component (C) per 100 parts by mass of component (A) is 20 parts by mass or more and 60 parts by mass or less.

12. A resin composition according to claim 1 or 2, wherein all or a part of component (D) is a compound containing five or more methylol groups.

13. A resin composition according to claim 1 or 2, wherein all or a part of component (D) is a compound containing a triazine structure.

14. A resin composition described in claim 1 or 2, in which the content of the (D) component per 100 parts by mass of the (A) component is 20 parts by mass or more and 50 parts by mass or less.

15. The resin composition according to claim 1 or 2, further comprising a colorant (hereinafter referred to as "component (E)").

16. A resin composition according to claim 15, wherein all or a part of component (E) is a compound having a xanthene structure.

17. The resin composition according to claim 1 or 2, further comprising one or more members (component (F)) selected from the group consisting of polyimide, polyimide precursor, polybenzoxazole, polybenzoxazole precursor, polyamideimide, polyamideimide precursor, and copolymers thereof.

18. A cured product obtained by curing the resin composition according to claim 1 or 2.

19. A display device comprising the cured product according to claim 18.

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