Photosensitive resin composition, cured product, cured film, microlens, and image display device

Abstract

To provide a photosensitive resin composition capable of forming a cured product which hardly becomes cloudy even in a high-temperature and high-humidity environment and can maintain high transmittance, a cured product obtained by curing the photosensitive resin composition, a cured film or a microlens composed of the cured product, and an image display device including the cured product or the microlens.SOLUTION: The photosensitive resin composition contains (A) an alkali-soluble resin, (B) a photopolymerizable compound and (C) a photopolymerization initiator, wherein the alkali-soluble resin (A) is a reaction product of a bisarene fluorene compound (A1), an ethylenically unsaturated group-containing monomer (A2) and an acid anhydride (A3), and the acid anhydride (A3) contains two or more compounds selected from compounds represented by the following general formulae (A3-1) to (A3-3).SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a photosensitive resin composition, a cured product, a cured film, a microlens, and an image display device. [Background technology]

[0002] In recent years, highly refractive materials such as microlenses and films with high refractive indexes (hereinafter also referred to as "high refractive index films") have been used in display devices for the purposes of improving brightness, preventing reflection, uniforming light, improving the light collection efficiency of solid-state imaging devices, etc. These are intended to control the directionality of light for efficient use, so they require transparency as well as a high refractive index.

[0003] Known methods for forming structures such as microlenses include using a mold with a thermoplastic or photocurable material, and grinding methods such as laser processing. Other known methods include melting a cylindrical resist pattern formed by photolithography with heat to form a lens shape (see, for example, Patent Document 1), and combining this method with dry etching to form a lens shape directly on a substrate (see, for example, Patent Document 2). Furthermore, when a highly refractive structure is formed by photolithography, it is known to use an alkali-soluble fluorene resin (see, for example, Patent Documents 3 to 5). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-34509 [Patent Document 2] Japanese Patent Application Laid-Open No. 2009-152315 [Patent Document 3] Japanese Patent Publication No. 2022-156546 [Patent Document 4] Japanese Patent Application Publication No. 2023-155216 [Patent Document 5] International Publication No. 2009 / 119622 Summary of the Invention [Problem to be solved by the invention]

[0005] However, when structures formed by photolithography using the fluorene resins described in Patent Documents 3 to 5 are stored in a high-temperature, high-humidity environment, such as a temperature of 85°C and a humidity of 85% RH, they become cloudy and lose their transparency, making it difficult to maintain their original optical properties.

[0006] Therefore, an object of the present invention is to provide a photosensitive resin composition that is resistant to clouding even in a high-temperature, high-humidity environment and can form a cured product that can maintain high transmittance. Another object of the present invention is to provide a cured product obtained by curing the photosensitive resin composition of the present invention, a cured film or a microlens made of the cured product, and an image display device equipped with the cured product or the microlens. [Means for solving the problem]

[0007] As a result of intensive research, the inventors have found that the cloudiness of the structure is caused by hydrolysis of the ester bond of the fluorene resin subjected to alkali development in a high-temperature and high-humidity environment, and the biphenyltetracarboxylic acid or its derivative thus isolated crystallizes in the cured product, scattering light. Therefore, they have found that the above-mentioned problem can be solved by using a specific alkali-soluble fluorene resin, and have completed the present invention.

[0008] That is, the present invention has the following aspects. [1] (A) an alkali-soluble resin, (B) a photopolymerizable compound, and (C) a photopolymerization initiator, the alkali-soluble resin (A) is a reaction product of a bisarenefluorene compound (A1), an ethylenically unsaturated group-containing monomer (A2), and an acid anhydride (A3); The photosensitive resin composition, wherein the acid anhydride (A3) comprises two or more compounds selected from the group consisting of a compound represented by the following general formula (A3-1), a compound represented by the following general formula (A3-2), and a compound represented by the following general formula (A3-3):

[0009] [ka]

[0010] In formulas (A3-1) to (A3-3), R 14 each independently represents an alkyl group having 1 to 3 carbon atoms. Each r independently represents an integer of 0 to 2.

[0011] [2] The photosensitive resin composition according to [1] above, wherein the acid anhydride (A3) includes a compound represented by the general formula (A3-1) above and further includes at least one of a compound represented by the general formula (A3-2) above and a compound represented by the general formula (A3-3). [3] The photosensitive resin composition according to [2] above, wherein the content of the compound represented by the general formula (A3-1) is 50 mass % or more relative to the total mass of the acid anhydride (A3). [4] The alkali-soluble resin (A) is an alkali-soluble resin (AA) obtained by reacting the reaction product of the bisarenefluorene compound (A1) and the acid anhydride (A3) with the ethylenically unsaturated group-containing monomer (A2), The photosensitive resin composition according to any one of [1] to [3] above, wherein the ethylenically unsaturated group-containing monomer (A2) is an epoxy group-containing (meth)acrylate (A2-1). [5] The photosensitive resin composition according to any one of [1] to [4], wherein the (C) photopolymerization initiator is a compound having an absorption maximum in a wavelength region of 360 nm or less and not having an absorption maximum in a wavelength region exceeding 360 nm. [6] The photosensitive resin composition according to [5], wherein the (C) photopolymerization initiator includes an oxime ester compound. [7] The photosensitive resin composition according to any one of [1] to [6] above, wherein the (B) photopolymerizable compound is a compound having a refractive index of 1.60 or more at a wavelength of 589 nm. [8] The photosensitive resin composition according to [7], wherein the (B) photopolymerizable compound comprises at least one of a photopolymerizable compound (B1) having a heterocycle containing a sulfur atom and an ethylenic double bond and a photopolymerizable compound (B2) having a bisarylfluorene ring and an ethylenic double bond. [9] The photosensitive resin composition according to any one of the above [1] to [8], further comprising a solvent.

[10] A cured product obtained by curing the photosensitive resin composition according to any one of [1] to [9] above.

[11] A cured film comprising the cured product according to

[10] above.

[12] A microlens made of the cured product according to

[10] above.

[13] An image display device comprising the cured film according to

[11] above.

[14] An image display device comprising the microlens according to

[12] . [Effects of the Invention]

[0012] According to the present invention, there are provided a photosensitive resin composition capable of forming a cured product that is resistant to clouding even in a high-temperature, high-humidity environment and can maintain high transmittance, a cured product obtained by curing the photosensitive resin composition, a cured film or microlens made of the cured product, and an image display device equipped with the cured product or microlens. DETAILED DESCRIPTION OF THE INVENTION

[0013] The present invention will be described in detail below. The following embodiments are merely examples for explaining the present invention, and are not intended to limit the present invention to these embodiments. The present invention can be implemented in various forms without departing from the spirit of the present invention. In the present invention, the following terms have the following meanings: "(Meth)acrylic" means "either one or both of acrylic and methacrylic." "Total solids" refers to the amount of all components in the photosensitive resin composition other than the solvent. Even if a component other than the solvent is liquid at room temperature, that component is not included in the solvent but is included in the total solids. A numerical range expressed using "to" means a range that includes the numerical values ​​before and after "to" as the lower and upper limits. For example, A to B is equivalent to A or more and B or less. The "coating film" refers to a film formed from the photosensitive resin composition of the present invention before curing, and is also referred to as a "photosensitive resin composition layer" in this specification. The term "cured product" refers to a product obtained by curing the photosensitive resin composition of the present invention. The term "weight average molecular weight" refers to the weight average molecular weight (Mw) calculated as polystyrene by GPC (gel permeation chromatography). Unless otherwise specified, the term "acid value" refers to the acid value calculated as the effective solid content, and is calculated by neutralization titration. The numerical ranges of the contents, various physical property values, and property values ​​disclosed in this specification can be arbitrarily combined with the lower and upper limits to form new numerical ranges.

[0014] [1] Photosensitive resin composition The photosensitive resin composition of the present invention contains (A) an alkali-soluble resin, (B) a photopolymerizable compound, and (C) a photopolymerization initiator. The photosensitive resin composition may further contain, in addition to (A) the alkali-soluble resin, (B) the photopolymerizable compound, and (C) the photopolymerization initiator, components other than these (hereinafter also referred to as "optional components"), as necessary, within a range that does not impair the effects of the present invention.

[0015] [1-1] Components and composition of photosensitive resin composition The components constituting the photosensitive resin composition of the present invention and their composition will be described in order.

[0016] [1-1-1] (A) Alkali-soluble resin The photosensitive resin composition of the present invention contains (A) an alkali-soluble resin. (A) The alkali-soluble resin is a resin that can be developed with an alkaline developer. The alkali-soluble resin (A) contained in the photosensitive resin composition of the present invention is a reaction product of a bisarenefluorene compound (A1), an ethylenically unsaturated group-containing monomer (A2), and an acid anhydride (A3).

[0017] <Bisarene fluorene compound (A1)> The alkali-soluble resin (A) contains a structure derived from the bisarenefluorene compound (A1). When the alkali-soluble resin (A) contains a structure derived from the bisarenefluorene compound (A1), the refractive index of the cured product increases. The bisarenefluorene compound (A1) is not particularly limited as long as it has two arene rings and one fluorene ring, but for example, a compound represented by the following general formula (A1-1) (hereinafter also referred to as "compound (A1-1)") is preferred.

[0018] [ka]

[0019] In formula (A1-1), each ring Z independently represents an arene ring. 1 R each independently represents an alkylene group. 11 R each independently represents a substituent. 12 Each independently represents a substituent. 1 each independently represents a hydrogen atom or a glycidyl group. each independently represents an integer of 0 to 4. each independently represents an integer of 0 or greater. each independently represents an integer of 0 or greater. each independently represents an integer of 1 or greater.

[0020] In the general formula (A1-1), examples of the arene ring represented by ring Z include monocyclic arene rings such as a benzene ring; and polycyclic arene rings. Polycyclic arene rings include fused polycyclic arene rings (fused polycyclic hydrocarbon rings) and ring-assembled arene rings (ring-assembled aromatic hydrocarbon rings).

[0021] The fused polycyclic arene ring includes fused bicyclic arene rings (e.g., fused bicyclic C10-16 arenes such as naphthalene) and fused tricyclic arene rings (e.g., anthracene, phenanthrene, etc.) etc. Preferred fused polycyclic arene rings include a naphthalene ring and an anthracene ring, with a naphthalene ring being particularly preferred. Unless otherwise specified in this specification, the number after "C" indicates the number of carbon atoms.

[0022] Examples of the ring-assembled arene ring include a biarene ring and a terarene ring. Examples of the biarene ring include biC6-12 arene rings such as a biphenyl ring, a binaphthyl ring, and a phenylnaphthalene ring (for example, a 1-phenylnaphthalene ring, a 2-phenylnaphthalene ring, etc.). Examples include ter C6-12 arene rings such as terarene rings and terphenylene rings. A preferred ring assembly arene ring is a biC6-12 arene ring, with a biphenyl ring being particularly preferred.

[0023] The two rings Z substituted at the 9-position of fluorene may be different or the same, but are usually the same ring in many cases. Of the rings Z, a benzene ring and a naphthalene ring are preferred. As the naphthalene ring, a benzene ring is preferred from the viewpoint of improving adhesion.

[0024] The substitution position of ring Z at the 9-position of fluorene is not particularly limited. For example, when ring Z is a naphthalene ring, the group corresponding to ring Z at the 9-position of fluorene may be a 1-naphthyl group, a 2-naphthyl group, or the like.

[0025] In general formula (A1-1), A 1 is an alkylene group. A 1 The alkylene group represented by the formula (I) may be linear or branched. Examples of the linear alkylene group include linear alkylene groups having 2 to 6 carbon atoms, such as an ethylene group, a trimethylene group, and a tetramethylene group. Among these, linear alkylene groups having 2 to 4 carbon atoms are particularly preferred, linear alkylene groups having 2 to 3 carbon atoms are more preferred, and an ethylene group is even more preferred. Examples of branched alkylene groups include branched alkylene groups having 3 to 6 carbon atoms, such as a propylene group, a 1,2-butanediyl group, and a 1,3-butanediyl group. Among these, branched alkylene groups having 3 to 4 carbon atoms are particularly preferred, and a propylene group is more preferred.

[0026] Oxyalkylene group (A 1 O), s, which indicates the number of repetitions (average number of moles added), is an integer of 0 or more, and although there is no particular upper limit, it is preferably, for example, 15. That is, s may be 0 to 15, 0 to 10, 0 to 8, 0 to 5, 0 to 4, 0 to 3, or 1 to 3. From the viewpoint of improving the mechanical strength (hardness or rigidity) and heat resistance of the cured product, s is preferably 0 to 2, more preferably 0 to 1, and even more preferably 1. From the viewpoint of improving the developability and flexibility of the cured product, s is preferably 3 to 8, more preferably 4 to 7, and even more preferably 5 or 6. In addition, s may be the same or different in each ring Z. When s is 2 or more, the types of alkylene groups A1 may be the same or different. 1 The types of may be the same or different in the same or different rings Z.

[0027] The group -[O-(A 1 O) s -G 1 t, which indicates the number of ], is an integer of 1 or more, preferably 1 to 3, more preferably 1 or 2, and even more preferably 1. In addition, t may be the same or different in each ring Z.

[0028] Group -[O-(A 1 O) s -G 1 ] can be substituted at an appropriate position on ring Z. For example, when ring Z is a benzene ring, the group -[O-(A 1 O) s -G 1 may be substituted at any one of the 2-, 3- and 4-positions of the phenyl group, and is particularly preferably substituted at at least one of the 3- and 4-positions. When ring Z is a naphthalene ring, the group -[O-(A 1 O) s -G 1 For example, the 9-position of the fluorene may be substituted at the 1- or 2-position of the naphthalene ring (i.e., substituted in a 1-naphthyl or 2-naphthyl relationship), and the -[O-(A 1 O) s -G 1 In particular, when t is 1, the 2,6-positions of the group -[O-(A 1 O) s -G 1 In addition, when t is 2 or more, the substitution position is not particularly limited. When ring Z is a ring-assembled arene ring, the group -[O-(A 1 O) s -G 1 The substitution position of -[O-(A 1 O) s -G 1The substitution position of may be any of the 2-position, 3-position, 2'-position, 3'-position, and 4'-position, but substitution at the 2-position, 3'-position, or 4'-position is preferred, substitution at the 2-position or 4'-position is more preferred, and substitution at the 2-position is even more preferred.

[0029] In general formula (A1-1), R 11 is a substituent. R 11 Examples of the substituent represented by the formula (I) include a cyano group, a halogen atom (e.g., a fluorine atom, a chlorine atom, a bromine atom, etc.), a carboxy group, an alkoxycarbonyl group (e.g., a C1-4 alkoxycarbonyl group such as a methoxycarbonyl group), an alkyl group (e.g., a C1-6 alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a t-butyl group, etc.), and an aryl group (e.g., a C6-10 aryl group such as a phenyl group). Among these, a linear or branched C1-4 alkyl group (particularly a C1-3 alkyl group such as a methyl group), a carboxy group or a C1-2 alkoxycarbonyl group, a cyano group, and a halogen atom are preferred.

[0030] Substituent R 11 k, which indicates the number of the groups, is an integer of 0 to 4, and may be an integer of 0 to 3, an integer of 0 to 2, an integer of 0 to 1, or 0. The k's may be the same or different from each other, and when k is 2 or more, the substituent R 1 The types of substituents R substituted on the two benzene rings of the fluorene ring may be the same or different. 1 The types of the substituents R may be the same or different. 1 The substitution position of the substituent R 1 may be substituted at any one of the 2- to 7-positions (specifically, the 2-, 3- and / or 7-positions, etc.) of the fluorene ring.

[0031] In general formula (A1-1), R 12 is a substituent. R 12Examples of the substituent represented by the formula (I) include a halogen atom (for example, a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom), an alkyl group (for example, a linear or branched C1-10 alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a s-butyl group, or a t-butyl group, preferably a linear or branched C1-6 alkyl group, more preferably a linear or branched C1-4 alkyl group), a cycloalkyl group (for example, a C5-10 cycloalkyl group such as a cyclopentyl group or a cyclohexyl group), an aryl group (for example, a phenyl group, alkylphenyl groups (C6-12 aryl groups such as methylphenyl (tolyl) group, dimethylphenyl (xylyl) group, etc.), biphenyl group, naphthyl group, etc.), aralkyl groups (C6-10 aryl-C1-4 alkyl groups such as benzyl group, phenethyl group, etc.), alkoxy groups (straight-chain or branched-chain C1-10 alkoxy groups such as methoxy group, ethoxy group, propoxy group, n-butoxy group, isobutoxy group, t-butoxy group, etc.), cycloalkoxy groups (C5-10 cycloalkyloxy groups such as cyclohexyloxy group, etc.) , aryloxy groups (for example, C6-10 aryloxy groups such as phenoxy group, etc.), aralkyloxy groups (for example, C6-10 aryl-C1-4 alkyloxy groups such as benzyloxy group, etc.), alkylthio groups (for example, C1-10 alkylthio groups such as methylthio group, ethylthio group, propylthio group, n-butylthio group, t-butylthio group, etc.), cycloalkylthio groups (for example, C5-10 cycloalkylthio groups such as cyclohexylthio group, etc.), arylthio groups (for example, C6-10 arylthio groups such as thiophenoxy group, etc.) , aralkylthio groups (for example, C6-10 aryl-C1-4 alkylthio groups such as benzylthio groups), acyl groups (for example, C1-6 acyl groups such as acetyl groups), carboxy groups, alkoxycarbonyl groups (for example, C1-4 alkoxy-carbonyl groups such as methoxycarbonyl groups), nitro groups, cyano groups, dialkylamino groups (for example, di-C1-4 alkylamino groups such as dimethylamino groups), and dialkylcarbonylamino groups (for example, di-C1-4 alkyl-carbonylamino groups such as diacetylamino groups). These substituents R 12 Representative examples of the substituent R include a halogen atom, a hydrocarbon group (an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group), an alkoxy group, an acyl group, a nitro group, a cyano group, and a substituted amino group. 12 The alkyl group is preferably an alkoxy group (such as a linear or branched C1-4 alkoxy group, such as a methoxy group), and more preferably an alkyl group, such as a linear or branched C1-4 alkyl group, such as a methyl group. In addition, the substituent R 12 is an aryl group, the substituent R 12 may form the ring assembly arene ring together with the ring Z. 12 The types of may be the same or different in the same or different rings Z.

[0032] Substituent R 12 p, which indicates the number of rings, is an integer of 0 or more. p can be appropriately selected depending on the type of ring Z, and may be, for example, an integer of 0 to 8, an integer of 0 to 4, an integer of 0 to 3, an integer of 0 to 2, or an integer of 0 to 1. In particular, when p is 1, ring Z is a benzene ring, a naphthalene ring, or a biphenyl ring, and the substituent R 2 may be a methyl group.

[0033] Examples of the compound (A1-1) include 9,9-bis(hydroxyC6-10 aryl)fluorenes such as 9,9-bis(4-hydroxyphenyl)fluorene and 9,9-bis(6-hydroxy-2-naphthyl)fluorene; 9,9-bis(dihydroxyC6-10 aryl)fluorenes such as 9,9-bis(3,4-dihydroxyphenyl)fluorene; 9,9-bis(C1-4 alkyl-hydroxyC6-10 aryl)fluorenes such as 9,9-bis(3-methyl-4-hydroxyphenyl)fluorene; 9,9-bis(C6-10 aryl-hydroxyC6-10 aryl)fluorenes such as 9,9-bis(3-phenyl-4-hydroxyphenyl)fluorene; Examples of such 9,9-bis(hydroxy(poly)C2-4alkoxy-C6-10aryl)fluorenes include 9,9-bis[4-(2-hydroxyethoxy)phenyl]fluorene and 9,9-bis[6-(2-hydroxyethoxy)-2-naphthyl]fluorene; 9,9-bis(C1-4alkyl-hydroxy(poly)C2-4alkoxy-C6-10aryl)fluorenes such as 9,9-bis[3-methyl-4-(2-hydroxyethoxy)phenyl]fluorene; and 9,9-bis(C6-10aryl-hydroxy(poly)C2-4alkoxy-C6-10aryl)fluorenes such as 9,9-bis[3-phenyl-4-(2-hydroxyethoxy)phenyl]fluorene. Among these, from the viewpoint of improving adhesion, compounds in which ring Z is a benzene ring, for example, 9,9-bis[hydroxy(mono- to hexa)C2-3alkoxy-phenyl]fluorene such as 9,9-bis[4-(2-hydroxyethoxy)phenyl]fluorene, are preferred. These compounds (A1-1) may be used alone or in combination of two or more.

[0034] <Monomer (A2) containing an ethylenically unsaturated group> The alkali-soluble resin (A) contains an ethylenically unsaturated group derived from the ethylenically unsaturated group-containing monomer (A2). The inclusion of an ethylenically unsaturated group in the alkali-soluble resin (A) provides suitability for development patterning. This means that the exposed areas have high developer resistance, allowing the exposed areas to form a sufficient coating film without dissolving in the developer, while allowing only the unexposed areas to dissolve. Examples of the ethylenically unsaturated group-containing monomer (A2) include epoxy group-containing (meth)acrylates (A2-1) and unsaturated group-containing monocarboxylic acids (A2-2).

[0035] (Epoxy group-containing (meth)acrylate (A2-1)) The epoxy group-containing (meth)acrylate (A2-1) is preferably a compound represented by the following general formula (A2-1).

[0036] [ka]

[0037] In formula (A2-1), A 2 represents an alkylene group. 13 represents a hydrogen atom or a methyl group, and q represents an integer of 0 or greater.

[0038] In general formula (A2-1), A 2 is an alkylene group. A 2 The alkylene group represented by the formula (I) may be linear or branched. Examples of the straight-chain alkylene group include straight-chain alkylene groups having 2 to 6 carbon atoms, such as an ethylene group, a trimethylene group, and a tetramethylene group. Examples of branched alkylene groups include branched alkylene groups having 3 to 6 carbon atoms, such as a propylene group, a 1,2-butanediyl group, and a 1,3-butanediyl group. Alkylene Group A 2 As the alkylene group, a linear alkylene group having 2 to 4 carbon atoms is preferred, a linear alkylene group having 3 to 4 carbon atoms is more preferred, and a butylene group is even more preferred.

[0039] Oxyalkylene group (A 2 q, which indicates the number of repetitions (average number of moles added) of O), is an integer of 0 or more, and although there is no particular upper limit, it is preferably, for example, 10. That is, q may be 0 to 10, 0 to 5, 1 to 3, 1 to 2, or 1. When q is 2 or more, the alkylene group A 2 The types may be the same or different.

[0040] In general formula (A2-1), R 13 is a hydrogen atom or a methyl group. In terms of excellent photosensitivity, the group R 13 is preferably a hydrogen atom.

[0041] Examples of the epoxy group-containing (meth)acrylate (A2-1) include glycidyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate glycidyl ether, 3-hydroxypropyl (meth)acrylate glycidyl ether, 4-hydroxybutyl (meth)acrylate glycidyl ether, polyethylene glycol (meth)acrylate glycol ether, and polypropylene glycol (meth)acrylate. These epoxy group-containing (meth)acrylates (A2-1) may be used alone or in combination of two or more.

[0042] (Unsaturated Monocarboxylic Acid (A2-2)) Examples of the unsaturated monocarboxylic acid (A2-2) include (meth)acrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, pentaerythritol tri(meth)acrylate succinic anhydride adduct, pentaerythritol tri(meth)acrylate tetrahydrophthalic anhydride adduct, dipentaerythritol penta(meth)acrylate succinic anhydride adduct, dipentaerythritol penta(meth)acrylate phthalic anhydride adduct, dipentaerythritol penta(meth)acrylate tetrahydrophthalic anhydride adduct, and the reaction product of (meth)acrylic acid and ε-caprolactone.Among these, (meth)acrylic acid is preferred from the viewpoint of excellent sensitivity. These unsaturation-containing monocarboxylic acids (A2-2) may be used alone or in combination of two or more.

[0043] <Acid anhydride (A3)> The alkali-soluble resin (A) contains a structure derived from the acid anhydride (A3). When the alkali-soluble resin (A) contains a structure derived from the acid anhydride (A3) in addition to the structure derived from the bisarenefluorene compound (A1), the alkali-soluble resin (A) can have a high molecular weight without impairing the refractive index. Acid anhydride (A3) includes two or more compounds selected from the group consisting of a compound represented by the following general formula (A3-1) (hereinafter also referred to as "compound (A3-1)"), a compound represented by the following general formula (A3-2) (hereinafter also referred to as "compound (A3-2)"), and a compound represented by the following general formula (A3-3) (hereinafter also referred to as "compound (A3-3)").

[0044] [ka]

[0045] In formulas (A3-1) to (A3-3), R 14 each independently represents an alkyl group having 1 to 3 carbon atoms. Each r independently represents an integer of 0 to 2.

[0046] In general formulae (A3-1) to (A3-3), R14 is an alkyl group having 1 to 3 carbon atoms. R 14 Examples of the alkyl group represented by the formula (I) include a methyl group, an ethyl group, a propyl group, and an isopropyl group. Among these, a methyl group is preferred in terms of obtaining a high refractive index. base R 14 The number r is an integer of 0 to 2. From the viewpoint of obtaining a high refractive index, r is preferably 0. When r is 0, compound (A3-1) is 3,3',4,4'-biphenyltetracarboxylic dianhydride, compound (A3-2) is 2,3,3',4'-biphenyltetracarboxylic dianhydride, and compound (A3-3) is 2,2',3,3'-biphenyltetracarboxylic dianhydride.

[0047] The compounds (A3-1), (A3-2) and (A3-3) are positional isomers, that is, the acid anhydride (A3) is a mixture of two or more positional isomers. When the acid anhydride (A3) contains one compound selected from the group consisting of compounds (A3-1), (A3-2), and (A3-3) (hereinafter also referred to as the "first compound") and a positional isomer of this first compound (hereinafter also referred to as the "second compound"), a cured product is obtained that is resistant to clouding and maintains high transmittance even in high-temperature, high-humidity environments, for example, environments with a temperature of 85°C or higher and a humidity of 85% RH or higher. The reasons for this are thought to be as follows.

[0048] As mentioned above, one of the reasons for the cloudiness of the structure is that the ester bonds of the fluorene resin that has been subjected to alkaline development treatment are hydrolyzed in a high-temperature, high-humidity environment, and the biphenyltetracarboxylic acid or its derivatives thus isolated crystallize within the cured product, scattering light. The acid anhydride (A3) constituting the alkali-soluble resin (A) contained in the photosensitive resin composition of the present invention includes the first compound and its positional isomer. Therefore, even if the ester moiety of the alkali-soluble resin (A), which is the reaction product of the bisarenefluorene compound (A1), the ethylenically unsaturated group-containing monomer (A2), and the acid anhydride (A3), is hydrolyzed under high-temperature and high-humidity conditions to isolate the first compound or its derivatives, the second compound, which is a positional isomer of the first compound, can prevent crystal formation. This is believed to suppress light scattering and maintain high transmittance. According to the above-described embodiment of the photosensitive resin composition, for example, the transmittance of the cured product can be maintained at 98% or more or 99% or more under high-temperature and high-humidity conditions, as measured by the method described in the Examples below.

[0049] When the first compound is compound (A3-1), compound (A3-2) and compound (A3-3) are positional isomers of the first compound, compound (A3-1). When the first compound is compound (A3-2), compound (A3-1) and compound (A3-3) are positional isomers of the first compound, compound (A3-2). When the first compound is compound (A3-3), compound (A3-1) and compound (A3-2) are positional isomers of the first compound, compound (A3-3).

[0050] The content of the first compound in the acid anhydride (A3) is preferably 30% by mass or more, more preferably 40% by mass or more, even more preferably 50% by mass or more, and particularly preferably 70% by mass or more, based on the total mass of the acid anhydride (A3). It is also preferably 99% by mass or less, more preferably 98% by mass or less, even more preferably 95% by mass or less, and particularly preferably 90% by mass or less. The above upper and lower limits can be arbitrarily combined. For example, the content of the first compound in the acid anhydride (A3) is preferably 30 to 99% by mass, more preferably 40 to 98% by mass, even more preferably 50 to 95% by mass, and particularly preferably 70 to 90% by mass. When the first compound is compound (A3-1), setting the content of the first compound to be equal to or greater than the lower limit tends to increase the yield when producing the alkali-soluble resin (A), while setting the content of the first compound to be equal to or less than the upper limit tends to increase resistance in high-temperature, high-humidity environments.

[0051] The content of the second compound in the acid anhydride (A3) is preferably 1% by mass or more, more preferably 2% by mass or more, even more preferably 3% by mass or more, and particularly preferably 4% by mass or more, based on the total mass of the acid anhydride (A3). It is also preferably 60% by mass or less, more preferably 55% by mass or less, even more preferably 50% by mass or less, and particularly preferably 40% by mass or less. The above upper and lower limits can be arbitrarily combined. For example, the content of the second compound in the acid anhydride (A3) is preferably 1 to 60% by mass, more preferably 2 to 55% by mass, even more preferably 3 to 50% by mass, and particularly preferably 4 to 40% by mass. When the first compound is compound (A3-1), setting the content of the second compound, which is its positional isomer, to the above-mentioned lower limit or more tends to improve resistance in high-temperature and high-humidity environments, while setting the content of the second compound to the above-mentioned upper limit or less tends to improve the yield when producing the alkali-soluble resin (A).

[0052] Acid anhydride (A3) may contain compound (A3-1) and compound (A3-2), may contain compound (A3-1) and compound (A3-3), may contain compound (A3-2) and compound (A3-3), or may contain compound (A3-1), compound (A3-2), and compound (A3-3). In particular, from the viewpoint of enhancing reactivity in producing the alkali-soluble resin (A), it is preferred that the acid anhydride (A3) contains the compound (A3-1) and further contains at least one of the compounds (A3-2) and (A3-3). In this case, it is preferred that the compound (A3-1) is the first compound and at least one of the compounds (A3-2) and (A3-3) is the second compound.

[0053] <Structure of reaction product> The alkali-soluble resin (A) is preferably the alkali-soluble resin (AA) or alkali-soluble resin (AB) shown below. The alkali-soluble resin (A) may be one or more alkali-soluble resins (AA), one or more alkali-soluble resins (AB), or a combination of one or more alkali-soluble resins (AA) and one or more alkali-soluble resins (AB). In particular, from the viewpoint of improving the suitability for development patterning, the alkali-soluble resin (A) is preferably one or more alkali-soluble resins (AA).

[0054] (Alkali-soluble resin (AA)) The alkali-soluble resin (AA) is obtained by reacting a reaction product of a bisarenefluorene compound (A1) and an acid anhydride (A3) with an ethylenically unsaturated group-containing monomer (A2). The bisarenefluorene compound (A1) is a compound represented by the general formula (A-1) in which G 1 is a hydrogen atom is preferred. The ethylenically unsaturated group-containing monomer (A2) is preferably the above-mentioned epoxy group-containing (meth)acrylate (A2-1). The acid anhydride (A3) preferably contains the compound (A3-1) and further contains at least one of the compound (A3-2) and the compound (A3-3).

[0055] The alkali-soluble resin (AA) preferably has a structural unit represented by the following general formula (AA-1).

[0056] [ka]

[0057] In formula (AA-1), each ring Z independently represents an arene ring. 1 A each independently represents an alkylene group. 2 represents an alkylene group. 11 R each independently represents a substituent. 12 R each independently represents a substituent. 13 represents a hydrogen atom or a methyl group. 14 each independently represents an alkyl group having 1 to 3 carbon atoms. each k independently represents an integer of 0 to 4. each p independently represents an integer of 0 or greater. each s independently represents an integer of 0 or greater. each q independently represents an integer of 0 or greater. each r independently represents an integer of 0 to 2.

[0058] The alkali-soluble resin (AA) more preferably has a structural unit represented by the following general formula (AA-2).

[0059] [ka]

[0060] In formula (AA-2), R 13 represents a hydrogen atom or a methyl group. 14 each independently represents an alkyl group having 1 to 3 carbon atoms. Each r independently represents an integer of 0 to 2.

[0061] The alkali-soluble resin (AA) can be obtained by reacting a bisarenefluorene compound (A1) with an acid anhydride (A3) and then reacting the resulting reaction product with an ethylenically unsaturated group-containing monomer (A2). The alkali-soluble resin (AA) can be produced by a known method, for example, the method described in JP-A-2017-219838.

[0062] The proportion of the acid anhydride (A3) is preferably 0.5 mol or more, more preferably 0.7 mol or more, and even more preferably 0.8 mol or more, relative to 1 mol of the bisarenefluorene compound (A1), and is preferably 1.5 mol or less, more preferably 1.3 mol or less, and even more preferably 1.2 mol or less. The above upper and lower limits can be arbitrarily combined. For example, the proportion of the acid anhydride (A3) is preferably 0.5 to 1.5 mol, more preferably 0.7 to 1.3 mol, and even more preferably 0.8 to 1.2 mol, relative to 1 mol of the bisarenefluorene compound (A1).

[0063] The proportion of the ethylenically unsaturated group-containing monomer (A2) is preferably 0.1 mol or more, more preferably 0.3 mol or more, and even more preferably 0.4 mol or more, per mol of the acid anhydride (A3), and is preferably 1.0 mol or less, more preferably 0.8 mol or less, and even more preferably 0.6 mol or less. The above upper and lower limits can be arbitrarily combined. For example, the proportion of the ethylenically unsaturated group-containing monomer (A2) is preferably 0.1 to 1.0 mol, more preferably 0.3 to 0.8 mol, and even more preferably 0.4 to 0.6 mol, per mol of the acid anhydride (A3). By setting the proportion of the ethylenically unsaturated group-containing monomer (A2) at or above the lower limit, sensitivity and development patterning suitability tend to be improved. By setting the proportion of the ethylenically unsaturated group-containing monomer (A2) at or below the upper limit, developability tends to be improved.

[0064] After the reaction of the bisarenefluorene compound (A1) with the acid anhydride (A3), the terminals of the reaction product may be capped with a capping agent, followed by reaction with the ethylenically unsaturated group-containing monomer (A2), thereby obtaining an alkali-soluble resin (AA) whose terminals are capped with the capping agent (the terminal acid anhydride groups are capped by a ring-opening reaction). If the alkali-soluble resin (AA) is end-blocked, the developability, sensitivity, and suitability for development patterning are improved, and an increase in the molecular weight of the photosensitive resin composition can be suppressed.

[0065] The blocking agent is not particularly limited as long as it can block the terminals of the reaction product of the bisarenefluorene compound (A1) and the acid anhydride (A3), but from the viewpoint of easily introducing a polymerizable group to block the terminals, a monofunctional or polyfunctional (meth)acrylate having a group reactive with an acid anhydride group is preferred. Among them, it is particularly preferred to include at least one blocking agent selected from monofunctional (meth)acrylates having a hydroxyl group (e.g., hydroxyalkyl (meth)acrylates) and polyfunctional (meth)acrylates having a hydroxyl group.

[0066] Examples of hydroxyalkyl (meth)acrylates include 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, polyethylene glycol (meth)acrylate, and polypropylene glycol (meth)acrylate. These hydroxyalkyl (meth)acrylates may be used alone or in combination of two or more.

[0067] Examples of polyfunctional (meth)acrylates having a hydroxy group include poly(meth)acrylates of polyols such as trimethylolpropane di(meth)acrylate, pentaerythritol tri(meth)acrylate, and dipentaerythritol penta(meth)acrylate. These polyfunctional (meth)acrylates having a hydroxy group may be used alone or in combination of two or more.

[0068] These blocking agents can be used alone or in combination of two or more. Among the above-mentioned hydroxyalkyl (meth)acrylates, monofunctional (meth)acrylates having a hydroxy group (particularly one hydroxy group), such as hydroxy C2-4 alkyl (meth)acrylates such as hydroxyethyl (meth)acrylate, are commonly used from the viewpoint of being less likely to gel and facilitating the production of a photosensitive resin composition. In particular, from the viewpoint of improving suitability for development patterning, 2-hydroxyethyl (meth)acrylate and 4-hydroxybutyl (meth)acrylate are preferred, and 4-hydroxybutyl (meth)acrylate is more preferred. Furthermore, from the viewpoint of improving the curability of the photosensitive resin composition and the mechanical strength of the cured product, polyfunctional (meth)acrylates having a hydroxy group (particularly one hydroxy group), such as di- or tetra(meth)acrylates of polyols such as pentaerythritol tri(meth)acrylate, are commonly used. When a polyfunctional (meth)acrylate having two or more hydroxy groups is contained, gelation may occur during the production of the photosensitive resin composition.

[0069] The proportion of the blocking agent is, for example, preferably 0.05 to 0.8 mol, more preferably 0.1 to 0.5 mol, even more preferably 0.2 to 0.4 mol, and particularly preferably 0.3 to 0.35 mol, relative to 1 mol of the acid anhydride (A3). By setting the proportion of the blocking agent to the lower limit or more, the developability, sensitivity, and development patterning suitability tend to be good. By setting the proportion of the blocking agent to the upper limit or less, the developability tends to be good.

[0070] The weight-average molecular weight of the alkali-soluble resin (AA) is preferably 1,000 or more, more preferably 2,000 or more, and even more preferably 3,000 or more, and is preferably 10,000 or less, more preferably 8,000 or less, and even more preferably 6,000 or less. The above upper and lower limits can be combined arbitrarily. For example, the weight-average molecular weight of the alkali-soluble resin (AA) is preferably 1,000 to 10,000, more preferably 2,000 to 8,000, and even more preferably 3,000 to 6,000. By setting the weight-average molecular weight of the alkali-soluble resin (AA) to the above lower limit or more, the suitability for development patterning tends to be improved. By setting the weight-average molecular weight of the alkali-soluble resin (AA) to the above upper limit or less, the developability tends to be improved.

[0071] The acid value of the alkali-soluble resin (AA) is preferably 20 mgKOH / g or more, more preferably 50 mgKOH / g or more, even more preferably 80 mgKOH / g or more, particularly preferably 100 mgKOH / g or more, and preferably 200 mgKOH / g or less, more preferably 150 mgKOH / g or less, and even more preferably 130 mgKOH / g or less. The above upper and lower limits can be arbitrarily combined. For example, the acid value of the alkali-soluble resin (AA) is preferably 20 to 200 mgKOH / g, more preferably 50 to 150 mgKOH / g, even more preferably 80 to 130 mgKOH / g, and particularly preferably 100 to 130 mgKOH / g. By setting the acid value of the alkali-soluble resin (AA) to the above lower limit or more, developability tends to be improved. By setting the acid value of the alkali-soluble resin (AA) to the above upper limit or less, suitability for development patterning tends to be improved.

[0072] (Alkali-soluble resin (AB)) The alkali-soluble resin (AB) is obtained by reacting a reaction product of a bisarenefluorene compound (A1) and an ethylenically unsaturated group-containing monomer (A2) with an acid anhydride (A3). The bisarenefluorene compound (A1) is a compound represented by the general formula (A-1) in which G 1 is a glycidyl group (A1-1). The ethylenically unsaturated group-containing monomer (A2) is preferably the unsaturated group-containing monocarboxylic acid (A2-2) described above. The acid anhydride (A3) preferably contains the compound (A3-1) and further contains at least one of the compound (A3-2) and the compound (A3-3).

[0073] The alkali-soluble resin (AB) preferably has a structural unit represented by the following general formula (AB-1).

[0074] [ka]

[0075] In formula (AB-1), each ring Z independently represents an arene ring. 1 R each independently represents an alkylene group. 11 R each independently represents a substituent. 12 R each independently represents a substituent. 14 Each of G independently represents an alkyl group having 1 to 3 carbon atoms. 2 represents a (meth)acryloyl group. Each k independently represents an integer of 0 to 4. Each p independently represents an integer of 0 or more. Each s independently represents an integer of 0 or more. Each r independently represents an integer of 0 to 2.

[0076] The alkali-soluble resin (AB) more preferably has a structural unit represented by the following general formula (AB-2).

[0077] [ka]

[0078] In formula (AB-2), each ring Z independently represents an arene ring. 1 R each independently represents an alkylene group. 14 Each of G independently represents an alkyl group having 1 to 3 carbon atoms. 2represents a (meth)acryloyl group. Each s independently represents an integer of 0 or more. Each r independently represents an integer of 0 to 2.

[0079] The alkali-soluble resin (AB) can be obtained by reacting a bisarenefluorene compound (A1) with an ethylenically unsaturated group-containing monomer (A2), and then reacting the resulting reaction product with an acid anhydride (A3). The alkali-soluble resin (AB) can be produced by a known method, for example, the method described in JP-A-2022-173086.

[0080] After the reaction of the bisarenefluorene compound (A1) with the ethylenically unsaturated group-containing monomer (A2), the terminals of the reaction product may be blocked with a blocking agent, followed by reaction with an acid anhydride (A3), thereby obtaining an alkali-soluble resin (AB) whose terminals are blocked with the blocking agent (the terminal acid anhydride groups are blocked by a ring-opening reaction). If the alkali-soluble resin (AB) is end-blocked, the developability (or sensitivity to ultraviolet light, photosensitivity) is improved, and an increase in the molecular weight of the photosensitive resin composition can be suppressed.

[0081] The blocking agent is not particularly limited as long as it can block the terminals of the reaction product of the bisarenefluorene compound (A1) and the ethylenically unsaturated group-containing monomer (A2). However, polybasic acid anhydrides other than the acid anhydride (A3) (hereinafter also referred to as "other polybasic acid anhydrides") are preferred. As the other polybasic acid anhydride, polybasic acid monoanhydrides are preferred, and examples thereof include succinic anhydride, maleic anhydride, itaconic anhydride, adipic anhydride, cyclobutanedicarboxylic anhydride, cyclopentanedicarboxylic anhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, norbornanedicarboxylic anhydride, trimellitic anhydride, phthalic anhydride, and naphthalenedicarboxylic anhydride. Among these, from the viewpoint of ease of reaction, tetrahydrophthalic anhydride, hexahydrophthalic acid, and phthalic anhydride are preferred, and tetrahydrophthalic anhydride is more preferred.

[0082] The weight-average molecular weight of the alkali-soluble resin (AB) is preferably 1,000 or more, more preferably 2,000 or more, and even more preferably 3,000 or more, and is preferably 10,000 or less, more preferably 8,000 or less, and even more preferably 5,000 or less. The above upper and lower limits can be combined arbitrarily. For example, the weight-average molecular weight of the alkali-soluble resin (AB) is preferably 1,000 to 10,000, more preferably 2,000 to 8,000, and even more preferably 3,000 to 5,000. By setting the weight-average molecular weight of the alkali-soluble resin (AB) to the above lower limit or more, resistance to the developer tends to be improved. By setting the weight-average molecular weight of the alkali-soluble resin (AB) to the above upper limit or less, developability tends to be improved.

[0083] The acid value of the alkali-soluble resin (AB) is preferably 20 mgKOH / g or more, more preferably 50 mgKOH / g or more, even more preferably 80 mgKOH / g or more, particularly preferably 100 mgKOH / g or more, and preferably 200 mgKOH / g or less, more preferably 150 mgKOH / g or less, and even more preferably 130 mgKOH / g or less. The above upper and lower limits can be arbitrarily combined. For example, the acid value of the alkali-soluble resin (AB) is preferably 20 to 200 mgKOH / g, more preferably 50 to 150 mgKOH / g, even more preferably 80 to 130 mgKOH / g, and particularly preferably 100 to 130 mgKOH / g. By setting the acid value of the alkali-soluble resin (AB) to the above lower limit or more, developability tends to be improved. By setting the acid value of the alkali-soluble resin (AB) to the above upper limit or less, resistance to the developer tends to be improved.

[0084] <Content> The content of the alkali-soluble resin (A) in the photosensitive resin composition is not particularly limited, but is preferably 10% by mass or more, more preferably 20% by mass or more, even more preferably 30% by mass or more, and particularly preferably 40% by mass or more, based on the total mass of all solids in the photosensitive resin composition. It is also preferably 90% by mass or less, more preferably 85% by mass or less, even more preferably 80% by mass or less, and particularly preferably 75% by mass or less. The above upper and lower limits can be arbitrarily combined. For example, the content of the alkali-soluble resin (A) in the photosensitive resin composition is preferably 10 to 90% by mass, more preferably 20 to 85% by mass, even more preferably 30 to 80% by mass, and particularly preferably 40 to 75% by mass. In another aspect, the content of the alkali-soluble resin (A) in the photosensitive resin composition is preferably 10 to 90% by mass, more preferably 20 to 85% by mass, even more preferably 20 to 80% by mass, and particularly preferably 20 to 75% by mass. By setting the content of (A) alkali-soluble resin to the above lower limit or more, the adhesion of the cured product to the substrate tends to be improved, and by setting the content of (A) alkali-soluble resin to the above upper limit or less, the curability tends to be improved.

[0085] [1-1-2](B) Photopolymerizable compound The photosensitive resin composition of the present invention contains a photopolymerizable compound (B). When the photosensitive resin composition contains a photopolymerizable compound (B), the curability of the coating film tends to increase and the strength of the coating film tends to improve. The photopolymerizable compound (B) may be a compound having one or more ethylenically unsaturated bonds in the molecule. From the viewpoint of enhancing the polymerizability, crosslinkability, and the associated difference in developer solubility between exposed and unexposed areas, the photopolymerizable compound (B) is preferably a compound having two or more ethylenically unsaturated bonds in the molecule (hereinafter also referred to as a "polyfunctional ethylenic monomer"). The ethylenically unsaturated bond is preferably derived from a (meth)acryloyloxy group, and the photopolymerizable compound (B) is more preferably a (meth)acrylate compound.

[0086] Specific examples of the (B) photopolymerizable compound include esters of aliphatic polyhydroxy compounds and unsaturated carboxylic acids, esters of aromatic polyhydroxy compounds and unsaturated carboxylic acids, and esters obtained by esterification of polyhydric hydroxy compounds such as aliphatic polyhydroxy compounds and aromatic polyhydroxy compounds with unsaturated carboxylic acids and polybasic carboxylic acids. Furthermore, the (B) photopolymerizable compound may also be a compound (B1) or a compound (B2) described below. These (B) photopolymerizable compounds may be used alone or in combination of two or more.

[0087] Examples of esters of aliphatic polyhydroxy compounds and unsaturated carboxylic acids include acrylic acid esters of aliphatic polyhydroxy compounds such as ethylene glycol diacrylate, triethylene glycol diacrylate, trimethylolpropane triacrylate, trimethylolethane triacrylate, pentaerythritol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, and glycerol acrylate; methacrylic acid esters in which the acrylate of these exemplary compounds is replaced with methacrylate; itaconic acid esters in which the acrylate of these exemplary compounds is replaced with itaconate; crotonate esters in which the acrylate of these exemplary compounds is replaced with crotonate; and maleic acid esters in which the acrylate of these exemplary compounds is replaced with maleate.

[0088] Examples of esters of aromatic polyhydroxy compounds and unsaturated carboxylic acids include acrylic acid esters and methacrylic acid esters of aromatic polyhydroxy compounds such as hydroquinone diacrylate, hydroquinone dimethacrylate, resorcinol diacrylate, resorcinol dimethacrylate, and pyrogallol triacrylate.

[0089] Esters obtained by the esterification reaction of polyvalent hydroxy compounds such as aliphatic polyhydroxy compounds and aromatic polyhydroxy compounds with unsaturated carboxylic acids and polybasic carboxylic acids are not necessarily single compounds, but examples thereof include condensates of acrylic acid, phthalic acid, and ethylene glycol, condensates of acrylic acid, maleic acid, and diethylene glycol, condensates of methacrylic acid, terephthalic acid, and pentaerythritol, and condensates of acrylic acid, adipic acid, butanediol, and glycerin.

[0090] Other examples of polyfunctional ethylenic monomers include urethane (meth)acrylates obtained by reacting a polyisocyanate compound with a hydroxyl group-containing (meth)acrylic acid ester or a polyisocyanate compound with a polyol and a hydroxyl group-containing (meth)acrylic acid ester; epoxy acrylates such as the addition reaction product of a polyfunctional epoxy compound with a hydroxyl (meth)acrylate or (meth)acrylic acid; acrylamides such as ethylene bisacrylamide; allyl esters such as diallyl phthalate; and vinyl group-containing compounds such as divinyl phthalate.

[0091] From the viewpoint of adhesion of the cured product to the substrate, the (B) photopolymerizable compound is preferably an ester of an aliphatic polyhydroxy compound and an unsaturated carboxylic acid or a urethane (meth)acrylate, and more preferably dipentaerythritol hexa(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol tetra(meth)acrylate, 2-tris(meth)acryloyloxymethylethyl phthalate, pentaerythritol tetra(meth)acrylate, pentaerythritol tri(meth)acrylate, a dibasic acid anhydride adduct of dipentaerythritol penta(meth)acrylate, or a dibasic acid anhydride adduct of pentaerythritol tri(meth)acrylate.

[0092] From the viewpoint of increasing the refractive index of the cured product, the photopolymerizable compound (B) is preferably a compound having a refractive index of 1.60 or more at a wavelength of 589 nm. Examples of such compounds include a photopolymerizable compound (B1) having a heterocycle containing a sulfur atom and an ethylenic double bond (hereinafter also referred to as "compound (B1)"), and a photopolymerizable compound (B2) having a bisarylfluorene ring and an ethylenic double bond (hereinafter also referred to as "compound (B2)").

[0093] The compound (B1) is a photopolymerizable compound having a heterocycle containing a sulfur atom and an ethylenic double bond. In the compound (B1), the number of ethylenic double bonds is not limited, but from the viewpoint of curability, 2 to 3 is preferred. The heterocycle containing a sulfur atom is preferably an aromatic heterocycle containing a sulfur atom (hereinafter also referred to as a "sulfur-containing aromatic heterocycle"). The number of sulfur-containing aromatic heterocycles is not limited, but from the viewpoints of achieving a high refractive index and ensuring solubility, it is preferably 2. From the viewpoints of curability, achieving a high refractive index, and ensuring solubility, it is more preferable that compound (B1) has two sulfur-containing aromatic heterocycles and two ethylenically unsaturated bonds.

[0094] The sulfur-containing aromatic heterocycle has at least one sulfur atom as a heteroatom constituting the aromatic heterocycle, and may have an oxygen atom, a nitrogen atom, or both an oxygen atom and a nitrogen atom as the heteroatom in addition to the sulfur atom. The sulfur-containing aromatic heterocycle may be a single ring or a fused ring. A fused ring is preferred in terms of increasing the refractive index. The number of rings constituting the fused ring is preferably 2 to 5, more preferably 2 to 4, and particularly preferably 2 to 3 in terms of facilitating raw material availability and synthesis. Examples of sulfur-containing aromatic heterocycles include aromatic heterocycles containing one sulfur atom, such as a thiophene ring, a benzothiophene ring, a dibenzothiophene ring, a thiopyran ring, a naphthothiophene ring, a dinaphthothiophene ring, and a dibenzothiopyran ring; aromatic heterocycles containing two or more sulfur atoms, such as a thianthrene ring; and aromatic heterocycles containing two or more heteroatoms, such as a thiazole ring, an isothiazole ring, a benzothiazole ring, a naphthothiazole ring, a phenothiazine ring, a thiazoloimidazole ring, a thiazolopyridine ring, a thiazolopyridazine ring, a thiazolopyrimidine ring, a dioxazolopyrazine ring, a thiazolopyrazine ring, a thiazolooxazole ring, a dibenzobenzothiophene ring, a thienoxazole ring, a thienothiadiazole ring, and a thiazolothiadiazole ring. As the sulfur-containing aromatic heterocycle, from the viewpoints of a high refractive index, low coloring property, and solubility, a benzothiazole ring, a dibenzothiophene ring, and a benzothiophene ring are preferred, and a benzothiazole ring is more preferred.

[0095] Examples of the compound (B1) include the compounds described in JP 2018-104696 A and the compound represented by the following general formula (B1-1) (hereinafter also referred to as "compound (B1-1)"). Among these, compound (B1-1) is preferred from the viewpoints of refractive index and solubility in solvents.

[0096] [ka]

[0097] In formula (B1-1), R 1 represents a hydrogen atom or a methyl group. Cy represents a sulfur-containing aromatic heterocycle. Q 1 and Q 2 Each of X independently represents an alkylene group having 1 to 6 carbon atoms. 1 and X 2 are each independently -O-, -S-, or -NR 2 -, -NR 2 -(C=O)- or -NR 2 -(C=O)-O-. R 2 represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.1 and Z 2 each independently represents a divalent hydrocarbon group. m and n each independently represent an integer of 1 to 3. i and j each independently represent an integer of 0 to 3.

[0098] In the general formula (B1-1), Cy is a sulfur-containing aromatic heterocycle, which contributes to a high refractive index. The sulfur-containing aromatic heterocycle may or may not have a substituent. The sulfur-containing aromatic heterocycle has at least one sulfur atom as a heteroatom constituting the aromatic heterocycle, and may have an oxygen atom, a nitrogen atom, or both an oxygen atom and a nitrogen atom as the heteroatom in addition to the sulfur atom. The number of sulfur atoms constituting the sulfur-containing aromatic heterocycle is preferably 1 to 3, more preferably 1 to 2, and even more preferably 1, from the viewpoint of avoiding coloration, and ensuring solubility. The number of heteroatoms constituting the sulfur-containing aromatic heterocycle is preferably 1 to 3, more preferably 1 to 2, from the viewpoint of avoiding coloration and ensuring solubility. The sulfur-containing aromatic heterocycle may be a single ring or a fused ring. A fused ring is preferred in terms of increasing the refractive index. The number of rings constituting the fused ring is preferably 2 to 5, more preferably 2 to 4, and particularly preferably 2 to 3 in terms of facilitating raw material availability and synthesis.

[0099] Examples of sulfur-containing aromatic heterocycles include aromatic heterocycles containing one sulfur atom, such as a thiophene ring, a benzothiophene ring, a dibenzothiophene ring, a thiopyran ring, a naphthothiophene ring, a dinaphthothiophene ring, and a dibenzothiopyran ring; aromatic heterocycles containing two or more sulfur atoms, such as a thianthrene ring; and aromatic heterocycles containing two or more heteroatoms, such as a thiazole ring, an isothiazole ring, a benzothiazole ring, a naphthothiazole ring, a phenothiazine ring, a thiazoloimidazole ring, a thiazolopyridine ring, a thiazolopyridazine ring, a thiazolopyrimidine ring, a dioxazolopyrazine ring, a thiazolopyrazine ring, a thiazolooxazole ring, a dibenzobenzothiophene ring, a thienoxazole ring, a thienothiadiazole ring, and a thiazolothiadiazole ring. As the sulfur-containing aromatic heterocycle, from the viewpoints of a high refractive index, low coloring property, and solubility, a benzothiazole ring, a dibenzothiophene ring, and a benzothiophene ring are preferred, and a benzothiazole ring is more preferred.

[0100] In general formula (B1-1), Q 1 and Q 2 are independently an alkylene group having 1 to 6 carbon atoms. The alkylene group having 1 to 6 carbon atoms may be linear or branched. The number of carbon atoms in the alkylene group is preferably 1 to 4. Specifically, the alkylene group is more preferably a methylene group, an ethylene group, a methylmethylene group, or an ethylmethylene group, further preferably a methylene group or an ethylene group, and particularly preferably a methylene group. Q in one molecule 1 , Q 2 may be the same or different. Q is preferred in terms of ease of obtaining raw materials and ease of controlling the stereoisomers of the product. 1 , Q 2 are preferably the same as each other.

[0101] In general formula (B1-1), X 1 and X 2 are independently -O-, -S-, and -NR 2 -, -NR 2 -(C=O)- or -NR 2 -(C=O)-O-. R 2 represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Examples of the alkyl group having 1 to 4 carbon atoms include a methyl group, an ethyl group, a propyl group, an isopropyl group, and a butyl group. X 1 , X 2 In terms of facilitating synthesis and reducing viscosity, -O- or -S- is preferred. In terms of availability of raw materials, -O- is more preferred, and in terms of refractive index, -S- is more preferred.

[0102] In general formula (B1-1), Z 1 and Z 2are independently a divalent hydrocarbon group. The divalent hydrocarbon group may or may not have a substituent. The number of carbon atoms in the divalent hydrocarbon group (however, if the divalent hydrocarbon group has a substituent, the number of carbon atoms in the substituent is not included) is preferably 1 to 8. When the number of carbon atoms is 8 or less, the refractive index is less likely to decrease, the viscosity is more likely to decrease due to the small molecular weight, and processability is more likely to improve. Specific examples of the divalent hydrocarbon group include a methylene group, an ethylene group, a 1,3-propylene group, a 1,2-propylene group, and a butylene group. Examples of the substituent include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a hydroxyl group, and a fluoroalkyl group.

[0103] In the general formula (B1-1), m and n are independently an integer of 1 to 3. From the viewpoint of curability, m is preferably 2 to 3, and more preferably 2. In terms of refractive index, n is preferably 2 to 3, and more preferably 2. It is particularly preferred that m and n each be 2.

[0104] In the general formula (B1-1), i and j are independently an integer of 0 to 3. The smaller i and j tend to be, the higher the refractive index becomes. It is particularly preferred that i and j are each 0.

[0105] Specific examples of the compound (B1) are shown below.

[0106] [ka]

[0107] In terms of refractive index, compounds (B1) represented by formulas (b11), (b12) and (b13) are preferred, and compound (B1) represented by formula (b11) is more preferred.

[0108] The compound (B2) is a photopolymerizable compound having a bisarylfluorene ring and an ethylenic double bond. As the compound (B2), compounds described in JP 2018-104696 A, JP 10-2023-0030467 A, JP 2023-155216 A, etc. are preferably used.

[0109] The content of the (B) photopolymerizable compound in the photosensitive resin composition is not particularly limited, but is preferably 1% by mass or more, more preferably 5% by mass or more, even more preferably 10% by mass or more, and particularly preferably 15% by mass or more, based on the total mass of all solids in the photosensitive resin composition. It is also preferably 90% by mass or less, more preferably 80% by mass or less, even more preferably 70% by mass or less, and particularly preferably 60% by mass or less. The above upper and lower limits can be arbitrarily combined. For example, the content of the (B) photopolymerizable compound in the photosensitive resin composition is preferably 1 to 90% by mass, more preferably 5 to 80% by mass, even more preferably 10 to 70% by mass, and particularly preferably 15 to 60% by mass. By setting the content of the (B) photopolymerizable compound at or above the lower limit, the refractive index and curability of the coating film tend to be improved. By setting the content of the (B) photopolymerizable compound at or below the upper limit, the developability tends to be improved.

[0110] The content of the (B) photopolymerizable compound relative to 100 parts by weight of the (A) alkali-soluble resin is not particularly limited, but is preferably at least 1 part by weight, more preferably at least 5 parts by weight, even more preferably at least 10 parts by weight, even more preferably at least 15 parts by weight, particularly preferably at least 20 parts by weight, and most preferably at least 25 parts by weight. It is also preferably at most 500 parts by weight, more preferably at most 450 parts by weight, even more preferably at most 400 parts by weight, even more preferably at most 350 parts by weight, particularly preferably at most 300 parts by weight, and most preferably at most 250 parts by weight. The above upper and lower limits can be arbitrarily combined. For example, the content of the (B) photopolymerizable compound relative to 100 parts by weight of the (A) alkali-soluble resin is preferably 1 to 500 parts by weight, more preferably at most 5 to 450 parts by weight, even more preferably at most 10 to 400 parts by weight, even more preferably at most 15 to 350 parts by weight, even more preferably at most 20 to 300 parts by weight, and most preferably at most 25 to 250 parts by weight. By setting the content of the (B) photopolymerizable compound to the above lower limit or more, the refractive index and curability of the coating film tend to be improved, and by setting the content of the (B) photopolymerizable compound to the above upper limit or less, the developability tends to be good.

[0111] The sum of the content of the (A) alkali-soluble resin and the content of the (B) photopolymerizable compound in the photosensitive resin composition is not particularly limited, but is preferably 11% by mass or more, more preferably 30% by mass or more, even more preferably 40% by mass or more, and particularly preferably 50% by mass or more, based on the total mass of all solids in the photosensitive resin composition. It is also preferably 95% by mass or less, more preferably 92% by mass or less, and even more preferably 90% by mass or less. The above upper and lower limits can be arbitrarily combined. For example, the sum of the content of the (A) alkali-soluble resin and the content of the (B) photopolymerizable compound is preferably 11 to 95% by mass, more preferably 30 to 95% by mass, even more preferably 40 to 92% by mass, and particularly preferably 50 to 90% by mass. By setting the sum of the content of the (A) alkali-soluble resin and the content of the (B) photopolymerizable compound to be equal to or greater than the above lower limit, the refractive index of the cured product tends to be improved. By setting the total content of the alkali-soluble resin (A) and the photopolymerizable compound (B) to the above upper limit or less, the curability of the coating film tends to be improved.

[0112] [1-1-3] (C) Photopolymerization initiator The photosensitive resin composition of the present invention contains (C) a photopolymerization initiator. The (C) photopolymerization initiator is not particularly limited as long as it is a compound that polymerizes the (B) photopolymerizable compound by actinic rays, for example, a compound that polymerizes an ethylenically unsaturated bond contained in the (B) photopolymerizable compound.

[0113] The photosensitive resin composition can use a photopolymerization initiator (C) that is commonly used in this field. Examples of such photopolymerization initiators include metallocene compounds including titanocene compounds described in JP-A-59-152396 and JP-A-61-151197; hexaarylbiimidazole derivatives described in JP-A-2000-56118; halomethyl-s-triazine derivatives described in JP-A-10-39503; halomethylated oxadiazole derivatives; halomethyl-s-triazine derivatives; N-aryl-α-amino acids such as N-phenylglycine; N-aryl-α-amino acid salts; radical activators such as N-aryl-α-amino acid esters; α-aminoalkylphenone derivatives; and oxime ester compounds. These (C) photopolymerization initiators may be used alone or in combination of two or more.

[0114] Examples of the metallocene compound include dicyclopentadienyltitanium dichloride, dicyclopentadienyltitanium bisphenyl, dicyclopentadienyltitanium bis(2,3,4,5,6-pentafluorophenyl), dicyclopentadienyltitanium bis(2,3,5,6-tetrafluorophenyl), dicyclopentadienyltitanium bis(2,4,6-trifluorophenyl), dicyclopentadienyltitanium di(2,6-difluorophenyl), dicyclopentadienyltitanium di(2,4-difluorophenyl), di(methylcyclopentadienyl)titanium bis(2,3,4,5,6-pentafluorophenyl), di(methylcyclopentadienyl)titanium bis(2,6-difluorophenyl), and dicyclopentadienyltitanium[2,6-difluoro-3-(pyrro-1-yl)-phenyl].

[0115] Examples of hexaarylbiimidazole derivatives include 2-(2'-chlorophenyl)-4,5-diphenylimidazole dimer, 2-(2'-chlorophenyl)-4,5-bis(3'-methoxyphenyl)imidazole dimer, 2-(2'-fluorophenyl)-4,5-diphenylimidazole dimer, 2-(2'-methoxyphenyl)-4,5-diphenylimidazole dimer, and (4'-methoxyphenyl)-4,5-diphenylimidazole dimer.

[0116] Examples of halomethylated oxadiazole derivatives include 2-trichloromethyl-5-(2'-benzofuryl)-1,3,4-oxadiazole, 2-trichloromethyl-5-[β-(2'-benzofuryl)vinyl]-1,3,4-oxadiazole, 2-trichloromethyl-5-[β-(2'-(6''-benzofuryl)vinyl)]-1,3,4-oxadiazole, and 2-trichloromethyl-5-furyl-1,3,4-oxadiazole.

[0117] Examples of halomethyl-s-triazine derivatives include 2-(4-methoxyphenyl)-4,6-bis(trichloromethyl)-s-triazine, 2-(4-methoxynaphthyl)-4,6-bis(trichloromethyl)-s-triazine, 2-(4-ethoxynaphthyl)-4,6-bis(trichloromethyl)-s-triazine, and 2-(4-ethoxycarbonylnaphthyl)-4,6-bis(trichloromethyl)-s-triazine.

[0118] Examples of α-aminoalkylphenone derivatives include 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butan-1-one, 2-dimethylamino-2-(4-methylbenzyl)-1-(4-morpholinophenyl)butan-1-one, and 3,6-bis(2-methyl-2-morpholinopropionyl)-9-octylcarbazole.

[0119] Examples of oxime ester compounds include those described in Japanese Patent No. 4454067, WO 2002 / 100903, WO 2012 / 45736, WO 2015 / 36910, WO 2006 / 18973, WO 2008 / 78678, Japanese Patent No. 4818458, and WO 2005 / 80338. Photopolymerization initiators described in International Publication No. WO 2008 / 75564, International Publication No. WO 2009 / 131189, International Publication No. WO 2010 / 133077, International Publication No. WO 2010 / 102502, International Publication No. WO 2012 / 68879, International Publication No. WO 2021 / 175855, and JP 2016-133574 can be used. In particular, the oxime ester compound is preferably a compound represented by the following general formula (C1) (hereinafter also referred to as "compound (C1)").

[0120] [ka]

[0121] In formula (C1), Rc21a represents a hydrogen atom, an alkyl group, or an aromatic ring group. c21b represents an aromatic ring or a heterocyclic ring. c22a represents an alkanoyl group or an aroyl group, and u represents an integer of 0 to 1.

[0122] In general formula (C1), R c21a is a hydrogen atom, an alkyl group or an aromatic ring group. The alkyl group and the aromatic ring group may or may not have a substituent. From a sensitivity perspective, R c21a is preferably an alkyl group which may have a substituent, or an aromatic ring group which may have a substituent.

[0123] R c21a In the formula, the number of carbon atoms in the alkyl group is not particularly limited, but from the viewpoint of solubility in a solvent and sensitivity, it is preferably 1 or more, more preferably 2 or more, and preferably 20 or less, more preferably 15 or less, and even more preferably 10 or less. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a cyclopentylmethyl group, a cyclopentylethyl group, and a cyclohexylmethyl group. Examples of the substituent that the alkyl group may have include an aromatic ring group, a hydroxyl group, a carboxy group, a halogen atom, an amino group, an amide group, a 4-(2-methoxy-1-methyl)ethoxy-2-methylphenyl group, an N-acetyl-N-acetoxyamino group, a methoxycarbonyl group, and an ethoxycarbonyl group. From the viewpoint of ease of synthesis, unsubstituted groups are preferred, and from the viewpoints of sensitivity and adhesion, methoxycarbonyl groups and ethoxycarbonyl groups are preferred.

[0124] R c21aExamples of the aromatic ring group in include an aromatic hydrocarbon ring group and an aromatic heterocyclic group. The number of carbon atoms in the aromatic ring group is not particularly limited, but is preferably 5 or more from the viewpoint of solubility in the photosensitive resin composition. Furthermore, from the viewpoint of developability, the number of carbon atoms is preferably 30 or less, more preferably 20 or less, and even more preferably 12 or less. For example, 5 to 30 is preferred, 5 to 20 is more preferred, and 5 to 12 is even more preferred. Examples of the aromatic ring group include a phenyl group, a naphthyl group, a pyridyl group, and a furyl group. From the viewpoint of developability, the phenyl group and the naphthyl group are preferred, and the phenyl group is more preferred. Examples of the substituent that the aromatic ring group may have include a hydroxyl group, a carboxy group, a halogen atom, an amino group, an amide group, an alkyl group, an alkoxy group, and a group in which these substituents are linked together. From the viewpoint of developability, an alkyl group, an alkoxy group, or a group in which these substituents are linked together is preferred, and a linked alkoxy group is more preferred.

[0125] In general formula (C1), R c21b is an aromatic ring or a heterocyclic ring. The aromatic ring and the heterocyclic ring may or may not have a substituent. R c21b is preferably an optionally substituted or unsubstituted carbazolyl group, an optionally substituted or unsubstituted thioxanthonyl group, an optionally substituted or unsubstituted diphenyl sulfide group, an optionally substituted or unsubstituted fluorenyl group, or an optionally substituted or unsubstituted or substituted indolyl group. From the viewpoint of sensitivity, an optionally substituted carbazolyl group is more preferred, and from the viewpoint of developability, an optionally substituted or unsubstituted diphenyl sulfide group is preferred.

[0126] In general formula (C1), R c22a is an alkanoyl group or an aroyl group. The alkanoyl group and the aroyl group may or may not have a substituent. From a sensitivity perspective, R c22aAs the alkanoyl group, an alkanoyl group which may have a substituent is preferable, an unsubstituted alkanoyl group is more preferable, and an acetyl group is even more preferable.

[0127] R c22a The number of carbon atoms in the alkanoyl group is not particularly limited, but from the viewpoint of solubility in a solvent and sensitivity, it is preferably 2 or more, and preferably 20 or less, more preferably 15 or less, even more preferably 10 or less, and particularly preferably 5 or less. For example, 2 to 20 is preferred, 2 to 15 is more preferred, 2 to 10 is even more preferred, and 2 to 5 is particularly preferred. Examples of the alkanoyl group include an acetyl group, a propanoyl group, and a butanoyl group. Examples of the substituent that the alkanoyl group may have include an aromatic ring group, a hydroxyl group, a carboxyl group, a halogen atom, an amino group, and an amide group. From the viewpoint of ease of synthesis, it is preferable that the alkanoyl group is unsubstituted.

[0128] R c22a The number of carbon atoms in the aroyl group is not particularly limited, but from the viewpoint of solubility in a solvent and sensitivity, it is preferably 7 or more, and preferably 20 or less, more preferably 15 or less, and even more preferably 10 or less. For example, it is preferably 7 to 20, more preferably 7 to 15, and even more preferably 7 to 10. Examples of the aroyl group include a benzoyl group and a naphthoyl group. Examples of the substituent that the aroyl group may have include a hydroxyl group, a carboxyl group, a halogen atom, an amino group, an amide group, and an alkyl group. From the viewpoint of ease of synthesis, it is preferable that the aroyl group is unsubstituted.

[0129] Specific examples of the compound (C1) are shown below.

[0130] [ka]

[0131] [ka]

[0132] From the viewpoint of increasing transmittance, the compounds (C1) represented by formulas (c11) to (c23) are preferred, the compounds (C1) represented by formulas (c15), (c17) and (c18) are more preferred, and the compounds (C1) represented by formulas (c15) and (c18) are even more preferred.

[0133] As the (C) photopolymerization initiator, an oxime ester compound is particularly effective in terms of sensitivity, plate-making properties, and refractive index. Oxime ester compounds have a high quantum yield of photoreaction and the radicals they generate are highly active, so they are highly sensitive even in small amounts and stable against thermal reactions, making it possible to obtain a highly sensitive photosensitive resin composition with a small amount.

[0134] From the viewpoint of optical properties, the photopolymerization initiator (C) is preferably a compound having an absorption maximum in a wavelength region of 360 nm or less and not having an absorption maximum in a wavelength region of more than 360 nm. Preferred examples of such compounds include α-aminoalkylphenone derivatives, hexaarylbiimidazole derivatives, and oxime ester compounds, with oxime ester compounds being more preferred.

[0135] The content of the (C) photopolymerization initiator in the photosensitive resin composition is not particularly limited, but is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, even more preferably 1% by mass or more, particularly preferably 1.5% by mass or more, and most preferably 2% by mass or more, based on the total mass of all solids in the photosensitive resin composition. It is also preferably 25% by mass or less, more preferably 20% by mass or less, even more preferably 15% by mass or less, particularly preferably 10% by mass or less, and most preferably 5% by mass or less. The above upper and lower limits can be arbitrarily combined. For example, the content of the (C) photopolymerization initiator in the photosensitive resin composition is preferably 0.01 to 25% by mass, more preferably 0.1 to 20% by mass, more preferably 1 to 15% by mass, even more preferably 1 to 10% by mass, particularly preferably 1.5 to 5% by mass, and most preferably 2 to 5% by mass. By setting the content of the (C) photopolymerization initiator to be equal to or greater than the above lower limit, adhesion tends to be improved. By setting the content of the (C) photopolymerization initiator to the above upper limit or less, residues tend to be reduced.

[0136] The content ratio of the (C) photopolymerization initiator relative to 100 parts by mass of the (B) photopolymerizable compound is not particularly limited, but is preferably 1 part by mass or more, more preferably 2 parts by mass or more, even more preferably 4 parts by mass or more, particularly preferably 6 parts by mass or more, and most preferably 10 parts by mass or more. It is also preferably 200 parts by mass or less, more preferably 100 parts by mass or less, even more preferably 50 parts by mass or less, and particularly preferably 30 parts by mass or less. The above upper and lower limits can be arbitrarily combined. For example, the content ratio of the (C) photopolymerization initiator relative to 100 parts by mass of the (B) photopolymerizable compound is preferably 1 to 200 parts by mass, more preferably 2 to 200 parts by mass, even more preferably 4 to 100 parts by mass, particularly preferably 6 to 50 parts by mass, and most preferably 10 to 30 parts by mass. In another aspect, the content ratio of the (C) photopolymerization initiator relative to 100 parts by mass of the (B) photopolymerizable compound is preferably 1 to 200 parts by mass, more preferably 2 to 200 parts by mass, even more preferably 2 to 100 parts by mass, particularly preferably 2 to 50 parts by mass, and most preferably 2 to 30 parts by mass. By setting the content ratio of the (C) photopolymerization initiator to the aforementioned lower limit or more, the optical properties tend to be improved, and by setting the content ratio of the (C) photopolymerization initiator to the aforementioned upper limit or less, the residue tends to be reduced.

[0137] [1-1-4]Optional component The photosensitive resin composition of the present invention may contain optional components. Examples of optional components include alkali-soluble resins other than the (A) alkali-soluble resin (hereinafter also referred to as "other alkali-soluble resins"), surfactants, metal oxide particles, thiols, silane coupling agents, phosphoric acid compounds, ultraviolet absorbers, polymerization inhibitors, thermal polymerization initiators, amino compounds, and solvents. These optional components may be used alone or in combination of two or more.

[0138] <Other alkali-soluble resins> The photosensitive resin composition may contain other alkali-soluble resins. Other alkali-soluble resins include, for example, epoxy (meth)acrylate resins, acrylic copolymer resins, epoxy resins, polyurethane resins, novolac resins, polyimide resins, and polyvinylphenol resins. These other alkali-soluble resins may be used alone or in combination of two or more. In this specification, the alkali-soluble resin (A) and other alkali-soluble resins are collectively referred to as "total alkali-soluble resins."

[0139] The sum of the content of the alkali-soluble resin (A) and the content of other alkali-soluble resins in the photosensitive resin composition (i.e., the total content of all alkali-soluble resins) is not particularly limited, but is preferably 40% by mass or more, more preferably 50% by mass or more, even more preferably 60% by mass or more, and particularly preferably 70% by mass or more, based on the total mass of all solids in the photosensitive resin composition. It is also preferably 90% by mass or less, more preferably 85% by mass or less, even more preferably 80% by mass or less, and particularly preferably 75% by mass or less. The above upper and lower limits can be arbitrarily combined. For example, the total content of all alkali-soluble resins in the photosensitive resin composition is preferably 40 to 90% by mass, more preferably 50 to 85% by mass, even more preferably 60 to 80% by mass, and particularly preferably 70 to 75% by mass. In another aspect, the content of all alkali-soluble resins in the photosensitive resin composition is preferably 40 to 90 mass%, more preferably 40 to 85 mass%, further preferably 40 to 80 mass%, and particularly preferably 40 to 75 mass%. By making the total alkali-soluble resin content equal to or greater than the lower limit, the adhesion of the cured product to the substrate tends to be improved, and by making the total alkali-soluble resin content equal to or less than the upper limit, the curability tends to be improved.

[0140] The content ratio of the (B) photopolymerizable compound relative to 100 parts by mass of the total of the (A) alkali-soluble resin and other alkali-soluble resins (i.e., 100 parts by mass of all alkali-soluble resins) is not particularly limited, but is preferably 1 part by mass or more, more preferably 5 parts by mass or more, even more preferably 10 parts by mass or more, even more preferably 15 parts by mass or more, particularly preferably 20 parts by mass or more, and most preferably 25 parts by mass or more, and is preferably 500 parts by mass or less, more preferably 450 parts by mass or less, more preferably 400 parts by mass or less, even more preferably 350 parts by mass or less, particularly preferably 300 parts by mass or less, and most preferably 250 parts by mass or less. The above upper and lower limits can be combined arbitrarily. For example, the content of the (B) photopolymerizable compound relative to 100 parts by mass of the total alkali-soluble resin is preferably 1 to 500 parts by mass, more preferably 5 to 450 parts by mass, even more preferably 10 to 400 parts by mass, even more preferably 15 to 350 parts by mass, even more preferably 20 to 300 parts by mass, and most preferably 25 to 250 parts by mass. By setting the content of the (B) photopolymerizable compound to be equal to or greater than the lower limit, the refractive index and curability of the coating film tend to be improved. By setting the content of the (B) photopolymerizable compound to be equal to or less than the upper limit, the developability tends to be improved.

[0141] The sum of the content of the (A) alkali-soluble resin, the content of other alkali-soluble resins, and the content of the (B) photopolymerizable compound in the photosensitive resin composition (i.e., the sum of the content of all alkali-soluble resins and the content of the (B) photopolymerizable compound) is not particularly limited, but is preferably 60% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, and particularly preferably 90% by mass or more, and is preferably 99% by mass or less, more preferably 98% by mass or less, and even more preferably 97% by mass or less, based on the total mass of all solids in the photosensitive resin composition. The above upper and lower limits can be arbitrarily combined. For example, the sum of the content of all alkali-soluble resins and the content of the (B) photopolymerizable compound is preferably 60 to 99% by mass, more preferably 70 to 99% by mass, even more preferably 80 to 98% by mass, and particularly preferably 90 to 97% by mass. By setting the sum of the content of all alkali-soluble resins and the content of (B) photopolymerizable compound to the above lower limit or more, the refractive index of the cured product tends to be improved. By setting the sum of the content of all alkali-soluble resins and the content of (B) photopolymerizable compound to the above upper limit or less, the curability of the coating film tends to be improved.

[0142] <Surfactant> The photosensitive resin composition may contain a surfactant. The surfactant can be used for the purpose of improving the coatability of the photosensitive resin composition as a coating liquid and the developability of the coating film. Examples of surfactants include silicone surfactants and fluorine surfactants. Among these, silicone surfactants are preferred, and polyether-modified silicone surfactants are more preferred, because they have the effect of removing residues of the photosensitive resin composition from unexposed areas during development and also have the function of exhibiting wettability.

[0143] As the fluorine-based surfactant, a compound having a fluoroalkyl or fluoroalkylene group at least at any one of the terminal, main chain, and side chain is suitable. Commercially available fluorine-based surfactants include, for example, BM Chemie products under the trade names "BM-1000" and "BM-1100"; DIC products under the trade names "Megafac F142D," "Megafac F172," "Megafac F173," "Megafac F183," "Megafac F470," "Megafac F475," "Megafac F554," and "Megafac F559"; 3M Japan products under the trade name "FC430"; and Neos products under the trade name "DFX-18."

[0144] Examples of commercially available silicone surfactants include those manufactured by Dow-Toray under the trade names "DC3PA," "SH7PA," "DC11PA," "SH21PA," "SH28PA," "SH29PA," "8032Additive," and "SH8400"; and those manufactured by BYK-Chemie under the trade names "BYK (registered trademark, the same applies hereinafter) 323," "BYK330," "BYK307," and "BYK377."

[0145] The surfactant may include surfactants other than fluorine-based surfactants and silicone-based surfactants, and other surfactants include, for example, nonionic, anionic, cationic, and amphoteric surfactants.

[0146] The surfactants may be used in combination of two or more types, for example, a combination of a silicone surfactant / a fluorine-based surfactant, a combination of a silicone surfactant / a special polymer surfactant, or a combination of a fluorine-based surfactant / a special polymer surfactant, and a combination of a silicone surfactant / a fluorine-based surfactant is preferred. Examples of combinations of silicone surfactants and fluorine surfactants include a combination of BYK-Chemie's trade name "BYK-300" or "BYK-330" with Neos's trade name "DFX-18"; a combination of BYK-Chemie's trade name "BYK-300" or "BYK-330" with AGC Seimi Chemical's trade name "S-393"; a combination of BYK-Chemie's trade name "BYK-300" or "BYK-330" with DIC's trade name "F-554" or "F-559"; a combination of Shin-Etsu Silicones' trade name "KP340" with DIC's trade name "F-478" or "F-475"; a combination of Dow-Toray's trade name "SH7PA" with Daikin's trade name "DS-401"; and a combination of NUC's trade name "L-77" with 3M Japan's trade name "FC4430". These surfactants may be used alone or in combination of two or more.

[0147] <Metal oxide particles> The photosensitive resin composition may contain metal oxide particles. When the photosensitive resin composition contains metal oxide particles, the refractive index tends to be high. Examples of metal oxide particles include titanium oxide, zirconium oxide, hafnium oxide, aluminum oxide, iron oxide, copper oxide, zinc oxide, yttrium oxide, niobium oxide, molybdenum oxide, indium oxide, tin oxide, tantalum oxide, tungsten oxide, lead oxide, bismuth oxide, cerium oxide, antimony oxide, and germanium oxide. Also, composite oxide particles composed of two or more metal elements, such as barium titanate, can be used. Among these, titanium oxide particles, zirconium oxide particles, and hafnium oxide particles are preferred from the viewpoints of dispersibility and high refractive index, and titanium oxide particles and zirconium oxide particles are more preferred. These metal oxide particles may be used alone or in combination of two or more kinds.

[0148] <Thiols> The photosensitive resin composition may contain thiols in order to increase sensitivity and improve adhesion to the substrate. Examples of thiols include 2-mercaptobenzothiazole, 2-mercaptobenzimidazole, hexanedithiol, decanedithiol, 1,4-dimethylmercaptobenzene, butanediol bisthiopropionate, butanediol bisthioglycolate, ethylene glycol bisthioglycolate, trimethylolpropane tristhioglycolate, butanediol bisthiopropionate, trimethylolpropane tristhiopropionate, trimethylolpropane tristhioglycolate, pentaerythritol tetrakisthiopropionate, pentaerythritol tetrakisthioglycolate, trishydroxyethyl tristhiopropionate, ethylene glycol bis(3-mercaptobutyrate), propylene glycol bis(3-mercaptobutyrate) (PGMB), butanediol bis(3-mercaptobutyrate), 1,4-bis(3-mercaptobutyryloxy)butane; (trade name: Karenz MT) BD1, manufactured by Showa Denko K.K.), butanediol trimethylolpropane tris(3-mercaptobutyrate), pentaerythritol tetrakis(3-mercaptobutyrate); (trade name: Karenz MT PE1, manufactured by Showa Denko K.K.), pentaerythritol tris(3-mercaptobutyrate), ethylene glycol bis(3-mercaptoisobutyrate), butanediol bis(3-mercaptoisobutyrate), trimethylolpropane tris(3-mercaptoisobutyrate), trimethylolpropane tris(3-mercaptobutyrate) (TPMB), trimethylolpropane tris(2-mercaptoisobutyrate) (TPMIB), 1,3,5-tris(3-mercaptobutyloxyethyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione (trade name: Karenz MT Among these, polyfunctional thiol compounds such as PGMB, TPMB, TPMIB, KarenzMT BD1, KarenzMT PE1, and KarenzMT NR1 are preferred, and among these, KarenzMT BD1, KarenzMT PE1, and KarenzMT NR1 are more preferred, with KarenzMT PE1 being particularly preferred. These thiols may be used alone or in combination of two or more.

[0149] When the photosensitive resin composition contains thiols, the content thereof is, from the viewpoint of adhesion, preferably 0.1% by mass or more, more preferably 0.3% by mass or more, and even more preferably 0.5% by mass or more, and is preferably 10% by mass or less, more preferably 5% by mass or less, based on the total mass of all solids in the photosensitive resin composition. The above upper and lower limits can be arbitrarily combined. For example, the content of thiols is preferably 0.1 to 10% by mass, more preferably 0.3 to 5% by mass, and even more preferably 0.5 to 5% by mass.

[0150] <Silane coupling agent> The photosensitive resin composition may contain a silane coupling agent to improve adhesion to the substrate. Examples of the silane coupling agent include epoxy-based, methacrylic-based, amino-based, and imidazole-based silane coupling agents. From the viewpoint of improving adhesion, epoxy-based silane coupling agents are preferred. These silane coupling agents may be used alone or in combination of two or more.

[0151] When the photosensitive resin composition contains a silane coupling agent, the content thereof is, from the viewpoint of adhesion, preferably 0.1% by mass or more, more preferably 0.3% by mass or more, and preferably 5% by mass or less, more preferably 3% by mass or less, and even more preferably 1% by mass or less, based on the total mass of all solids in the photosensitive resin composition. The above upper and lower limits can be arbitrarily combined. For example, the content of the silane coupling agent is preferably 0.1 to 5% by mass, more preferably 0.3 to 3% by mass, and even more preferably 0.3 to 1% by mass.

[0152] <Phosphate compounds> The photosensitive resin composition may contain a phosphoric acid compound for the purpose of imparting adhesion to the substrate. Examples of the phosphoric acid compound include phosphoric acid ethylenic monomers. As the phosphoric acid-based ethylenic monomer, (meth)acryloyloxy group-containing phosphates are preferred, and phosphoric acid-based ethylenic monomers represented by the following general formula (g1), (g2) or (g3) are preferred. These phosphoric acid compounds may be used alone or in combination of two or more.

[0153] [ka]

[0154] In formula (g1), R 51 represents a hydrogen atom or a methyl group. v1 represents an integer of 1 to 10. w1 represents an integer of 1 to 3. In formula (g2), R 52 represents a hydrogen atom or a methyl group. v2 represents an integer of 1 to 10. w2 represents an integer of 1 to 3. In formula (g3), R 53 represents a hydrogen atom or a methyl group. v3 and v4 each independently represent an integer of 1 to 10. w3 represents an integer of 1 to 3.

[0155] <UV absorber> The photosensitive resin composition may contain an ultraviolet absorber. The ultraviolet absorber is added for the purpose of controlling the photocuring distribution by absorbing specific wavelengths of the light source used for exposure. The addition of an ultraviolet absorber has the effect of increasing the taper angle.

[0156] The ultraviolet absorber may be, for example, a compound having a maximum absorption wavelength in the wavelength range of 250 to 400 nm, from the viewpoint of inhibiting light absorption by the (C) photopolymerization initiator. Examples of such compounds include benzotriazole-based compounds, triazine-based compounds, benzophenone compounds, benzoate compounds, cinnamic acid derivatives, naphthalene derivatives, anthracene and its derivatives, dinaphthalene compounds, phenanthroline compounds, and dyes. The ultraviolet absorber preferably contains either or both of a benzotriazole-based compound and a triazine-based compound. These ultraviolet absorbents may be used alone or in combination of two or more.

[0157] <Polymerization inhibitor> The photosensitive resin composition may contain a polymerization inhibitor. When the photosensitive resin composition contains a polymerization inhibitor, it inhibits radical polymerization, and therefore the shape of the resulting cured product tends to be easily controlled.

[0158] Examples of the polymerization inhibitor include hydroquinone, hydroquinone monomethyl ether, methylhydroquinone, methoxyphenol, and 2,6-di-tert-butyl-4-cresol (BHT). Among these, hydroquinone or methoxyphenol is preferred, and methylhydroquinone is more preferred, from the viewpoint of taper angle control. These polymerization inhibitors may be used alone or in combination of two or more.

[0159] In addition, when the alkali-soluble resin (A) is produced, a polymerization inhibitor may be contained in the resin. In that case, the polymerization inhibitor contained in the resin may be used as it is, or a polymerization inhibitor identical to or different from the polymerization inhibitor contained in the resin may be further added during the production of the photosensitive resin composition.

[0160] <Thermal polymerization initiator> The photosensitive resin composition may contain a thermal polymerization initiator. When the photosensitive resin composition contains a thermal polymerization initiator, the degree of crosslinking of the cured product tends to be increased. Examples of the thermal polymerization initiator include azo compounds, organic peroxides, and hydrogen peroxide. These thermal polymerization initiators may be used alone or in combination of two or more.

[0161] <Amino compounds> The photosensitive resin composition may contain an amino compound. Examples of the amino compound include an amino compound having a methylol group as a functional group and at least two alkoxymethyl groups obtained by condensing the methylol group with an alcohol having 1 to 8 carbon atoms. Specific examples include a melamine resin obtained by polycondensing melamine with formaldehyde, a benzoguanamine resin obtained by polycondensing benzoguanamine with formaldehyde, a glycoluril resin obtained by polycondensing glycoluril with formaldehyde, a urea resin obtained by polycondensing urea with formaldehyde, a resin obtained by copolycondensing two or more of melamine, benzoguanamine, glycoluril, urea, etc. with formaldehyde, and a modified resin obtained by condensing the methylol groups of the above-mentioned resins with an alcohol. These amino compounds may be used alone or in combination of two or more.

[0162] <Solvent> The photosensitive resin composition may contain a solvent. When the photosensitive resin composition contains a solvent, the above-mentioned components can be used in a state of being dissolved or dispersed in the solvent. The solvent is not particularly limited, but examples thereof include the following organic solvents:

[0163] glycol monoalkyl ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-n-butyl ether, propylene glycol t-butyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-n-butyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monomethyl ether, 3-methyl-3-methoxybutanol, 3-methoxy-1-butanol, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, and tripropylene glycol methyl ether; glycol dialkyl ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol ethyl methyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether, diethylene glycol dibutyl ether, and dipropylene glycol dimethyl ether; glycol alkyl ether acetates such as ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol mono-n-butyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether acetate, 3-methoxy-1-butyl acetate, methoxypentyl acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol mono-n-butyl ether acetate, dipropylene glycol monomethyl ether acetate, triethylene glycol monomethyl ether acetate, triethylene glycol monoethyl ether acetate, and 3-methyl-3-methoxybutyl acetate; glycol diacetates such as ethylene glycol diacetate, propylene glycol diacetate, 1,3-butylene glycol diacetate, 1,4-butanediol diacetate, and 1,6-hexanol diacetate; alkyl acetates such as cyclohexanol acetate; ethers such as amyl ether, diethyl ether, dipropyl ether, diisopropyl ether, dibutyl ether, diamyl ether, ethyl isobutyl ether, and dihexyl ether; ketones such as acetone, methyl ethyl ketone, methyl isopropyl ketone, methyl amyl ketone, methyl isoamyl ketone, diisopropyl ketone, diisobutyl ketone, methyl isobutyl ketone, cyclohexanone, ethyl amyl ketone, methyl butyl ketone, methyl hexyl ketone, methyl nonyl ketone, and methoxymethyl pentanone; monohydric or polyhydric alcohols such as methanol, ethanol, propanol, butanol, hexanol, cyclohexanol, ethylene glycol, propylene glycol, butanediol, diethylene glycol, dipropylene glycol, triethylene glycol, methoxymethylpentanol, glycerin, and benzyl alcohol; Aliphatic hydrocarbons such as n-pentane, n-octane, diisobutylene, n-hexane, hexene, isoprene, dipentene, and dodecane; Alicyclic hydrocarbons such as cyclohexane, methylcyclohexane, methylcyclohexene, and bicyclohexyl; Aromatic hydrocarbons such as benzene, toluene, xylene, and cumene; Chain or cyclic esters such as amyl formate, ethyl formate, ethyl acetate, propyl acetate, butyl acetate, amyl acetate, methyl isobutyrate, ethyl propionate, propyl propionate, butyl butyrate, isobutyl butyrate, methyl isobutyrate, ethyl caprylate, ethyl benzoate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, propyl 3-methoxypropionate, butyl 3-methoxypropionate, and γ-butyrolactone; Alkoxycarboxylic acids such as 3-methoxypropionic acid and 3-ethoxypropionic acid; Halogenated hydrocarbons such as butyl chloride and amyl chloride; ether ketones such as methoxymethylpentanone; Nitriles such as acetonitrile and benzonitrile; tetrahydrofurans such as tetrahydrofuran, dimethyltetrahydrofuran, and dimethoxytetrahydrofuran;

[0164] Commercially available solvents include, for example, mineral spirits, Balsol #2, Apco #18 Solvent, Apco Thinner, Socal Solvent No. 1 and No. 2, Solvesso #150, Shell TS28 Solvent, Carbitol, ethyl carbitol, butyl carbitol, methyl cellosolve, ethyl cellosolve, ethyl cellosolve acetate, methyl cellosolve acetate, and diglyme (all trade names).

[0165] The solvent may be any solvent capable of dissolving or dispersing each component in the photosensitive resin composition, and is selected depending on the method of use of the photosensitive resin composition of the present invention. From the viewpoint of coatability, solvents having a boiling point under atmospheric pressure of 60 to 280°C are preferred, and solvents having a boiling point of 70 to 260°C are more preferred. Examples of such solvents include propylene glycol monomethyl ether, 3-methoxy-1-butanol, propylene glycol monomethyl ether acetate, and 3-methoxy-1-butyl acetate.

[0166] The solvent may be used alone or in combination of two or more kinds. The solvent is used so that the content of the total solids in the photosensitive resin composition is preferably 2% by mass or more, more preferably 5% by mass or more, even more preferably 10% by mass or more, particularly preferably 12% by mass or more, and preferably 90% by mass or less, more preferably 50% by mass or less, even more preferably 40% by mass or less, and particularly preferably 35% by mass or less, relative to the total mass of the photosensitive resin composition. The above upper and lower limits can be arbitrarily combined. For example, the solvent is used so that the content of the total solids in the photosensitive resin composition is preferably 10 to 90% by mass, more preferably 15 to 50% by mass, even more preferably 20 to 40% by mass, and particularly preferably 25 to 35% by mass. That is, the content of the solvent is preferably 10 to 98% by mass, more preferably 50 to 95% by mass, even more preferably 60 to 90% by mass, and particularly preferably 65 to 88% by mass, relative to the total mass of the photosensitive resin composition. By setting the content ratio of the total solids in the photosensitive resin composition to the above lower limit or more, the occurrence of coating unevenness tends to be suppressed. By setting the content ratio of the total solids in the photosensitive resin composition to the above upper limit or less, the occurrence of foreign matter, repelling, etc. tends to be suppressed.

[0167] The photosensitive resin composition may contain known colorants such as pigments and dyes as long as the effects of the present invention are not impaired. However, from the viewpoint of maintaining high transmittance, it is preferable that the photosensitive resin composition does not substantially contain any colorants. Here, "substantially free of colorants" means that colorants are not intentionally blended into the photosensitive resin composition, except for those that are unintentionally contained. Specifically, the content of the colorant is preferably 1% by mass or less, more preferably 0.5% by mass or less, and even more preferably 0.1% by mass or less, relative to the total mass of all solids in the photosensitive resin composition.

[0168] For example, a photosensitive resin composition having the configuration of the present invention can be produced by using a composition containing 73.5 parts by mass of alkali-soluble resin (AA) as (A) the alkali-soluble resin, 10.5 parts by mass of TMP-A (trimethylolpropane triacrylate) and 10.5 parts by mass of DPHA (a mixture of dipentaerythritol hexaacrylate and dipentaerythritol pentaacrylate) as (B) the photopolymerizable compound, 3 parts by mass of a diphenyl sulfide oxime ester compound as (C) the photopolymerization initiator, and 1 part by mass of a polyfunctional thiol compound, 1 part by mass of a phosphoric acid compound, 0.5 parts by mass of a silane coupling agent, and 0.05 parts by mass of a silicone surfactant as optional components.

[0169] [1-2] Method for producing photosensitive resin composition The photosensitive resin composition of the present invention can be produced by mixing the above-mentioned components with a mixer. In the manufacturing process of the photosensitive resin composition, fine dust particles may be mixed in the liquid, and therefore the obtained photosensitive resin composition is preferably filtered, for example, with a filter.

[0170] [2] Cured product The cured product of the present invention is obtained by curing the photosensitive resin composition of the present invention. The method for forming a cured product using a photosensitive resin composition is not particularly limited, and any conventionally known method can be used. For example, a photolithography method including a coating step of applying a photosensitive resin composition onto a substrate to form a photosensitive resin composition layer (i.e., a coating film), an exposure step of exposing the photosensitive resin composition layer to light, and a development step can be used.

[0171] The material of the substrate on which the cured product is formed is not particularly limited as long as it has an appropriate strength, and can be appropriately selected depending on the type of organic electroluminescent device or the like to be manufactured using the substrate on which the cured product is formed. Examples of materials for the substrate include polyester resins such as polyethylene terephthalate; polyolefin resins such as polypropylene and polyethylene; polycarbonate; thermoplastic resin sheets such as polymethyl methacrylate and polysulfone; epoxy resins; unsaturated polyester resins; thermosetting resin sheets such as poly(meth)acrylic resins; and various types of glass. In addition, a transparent electrode such as ITO or IZO, a metal electrode such as silver, gold, platinum, aluminum, or magnesium, or a silicon nitride (SiN x The cured product may be formed on an inorganic film such as an insulating film, a protective film, a filling layer, or a color filter layer.

[0172] In the photolithography method, a photosensitive resin composition is applied to substantially the entire surface of a substrate to form a photosensitive resin composition layer. The formed photosensitive resin composition layer is exposed to light according to a predetermined pattern, and then the exposed photosensitive resin composition layer is developed to form a cured product on the substrate.

[0173] In the photolithography method, in the coating step of coating a substrate with a photosensitive resin composition, the photosensitive resin composition is coated onto the substrate using a contact transfer type coating device such as a roll coater, reverse coater, or bar coater, or a non-contact type coating device such as a spinner (rotary coating device) or curtain flow coater, and if necessary, the solvent is removed by drying to form a photosensitive resin composition layer.

[0174] Drying is preferably carried out by a drying method using a hot plate, an IR oven, or a convection oven. A reduced pressure drying method in which drying is carried out in a reduced pressure chamber without increasing the temperature may also be used in combination. Drying conditions can be appropriately selected depending on the type of solvent component contained in the photosensitive resin composition, the performance of the dryer used, etc. Drying time is usually selected in the range of 15 seconds to 5 minutes at a temperature of 40 to 130°C, and preferably in the range of 30 seconds to 3 minutes at a temperature of 50 to 110°C, depending on the type of solvent component, the performance of the dryer used, etc. It is preferable to perform drying within a temperature range that does not exceed the baking temperature described below.

[0175] In the exposure step, the photosensitive resin composition layer is exposed to active energy rays such as ultraviolet rays and excimer laser light using a negative mask. For exposure, a light source that emits ultraviolet light, such as a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a xenon lamp, or a carbon arc lamp, can be used. The exposure dose varies depending on the composition of the photosensitive resin composition, but is, for example, 10 to 400 mJ / cm 2 The degree is preferable. Another method is to use a laser to directly draw the pattern without using a mask.

[0176] In the development step, the exposed photosensitive resin composition layer is developed with a developer to form a cured product. Since the cured product thus obtained is in the form of a film, the method for producing a cured product according to the present embodiment can also be said to be a method for producing a cured film. The developing method is not particularly limited, and immersion, spraying, etc. can be used. Examples of the developing solution include organic developers such as tetramethylammonium hydroxide (TMAH), dimethylbenzylamine, monoethanolamine, diethanolamine, and triethanolamine, as well as aqueous solutions of sodium hydroxide, potassium hydroxide, sodium carbonate, ammonia, and quaternary ammonium salts. An antifoaming agent or a surfactant may be added to the developing solution.

[0177] After development and post-baking, a post-exposure step and a post-baking (firing) step may be carried out. The post-baking temperature is preferably 70 to 250° C. The post-baking time is preferably 10 to 60 minutes.

[0178] The photosensitive resin composition of the present invention contains an alkali-soluble resin (A) containing a structure derived from the acid anhydride (A3) in addition to a structure derived from the bisarenefluorene compound (A1). Therefore, a cured product prepared from the photosensitive resin composition of the present invention has a high refractive index. The refractive index of the cured product at a wavelength of 589 nm is preferably 1.600 or higher, more preferably 1.620 or higher, even more preferably 1.630 or higher, and particularly preferably 1.640 or higher. It is also preferably 1.800 or lower, more preferably 1.700 or lower. The above upper and lower limits can be arbitrarily combined. For example, the refractive index of the cured product at a wavelength of 589 nm is preferably 1.600 to 1.800, more preferably 1.620 to 1.800, even more preferably 1.630 to 1.700, and particularly preferably 1.640 to 1.700. A refractive index equal to or higher than the lower limit tends to improve light extraction efficiency. The refractive index of the cured product can be measured, for example, by using a prism coupler. Specifically, as described in the Examples, a refractive index measurement substrate is prepared by forming a cured product on a glass substrate, and the value measured at a wavelength of 589 nm using a prism coupler under the condition of 20°C using a He-Ne laser as a light source can be taken as the refractive index of the cured product.

[0179] The acid anhydride (A3) constituting the alkali-soluble resin (A) contained in the photosensitive resin composition includes two or more selected from the group consisting of the compound (A3-1), the compound (A3-2), and the compound (A3-3). Therefore, a cured product prepared from the photosensitive resin composition of the present invention is less likely to become cloudy and maintain high transmittance even in a high-temperature, high-humidity environment, for example, a temperature of 85°C or higher and a humidity of 85% RH or higher.

[0180] The cured product of the present invention has a high refractive index and is therefore suitable for use as an optical element that is required to have a high refractive index, such as an image display device equipped with a cured film or microlens made of the cured product of the present invention.

[0181] [3] Cured film The cured film of the present invention comprises the cured product of the present invention. The cured film of the present invention is a high refractive index film because it is made of a cured product having a high refractive index. The cured film can be produced, for example, by the same method as the above-mentioned method for producing the cured product.

[0182] The thickness of the cured film is preferably 0.1 μm or more, more preferably 0.5 μm or more, even more preferably 0.8 μm or more, and preferably 20 μm or less, more preferably 15 μm or less, and even more preferably 12 μm or less. The above upper and lower limits can be arbitrarily combined. For example, the thickness of the cured film is preferably 0.1 μm to 20 μm, more preferably 0.5 to 15 μm, and even more preferably 0.8 to 12 μm. By setting the thickness to be equal to or greater than the lower limit, the strength of the cured product tends to be improved, and by setting the thickness to be equal to or less than the upper limit, the hole resolution tends to be improved. The thickness of the cured film is measured using a step / surface roughness / microshape measuring device, a scanning white light interference microscope, an ellipsometer, a reflection spectroscopic film thickness meter, and an electron microscope.

[0183] The cured film of the present invention has a high refractive index, is resistant to clouding even in high-temperature and high-humidity environments, and can maintain high transmittance, making it useful for image display devices. The cured film of the present invention can be used, for example, as optical components such as microlenses, optical waveguides, antireflection films, and sealing materials; as planarizing films in image display devices described below, insulating films, functional films for improving light extraction efficiency, and protective films for color filters.

[0184] [4] Microlenses The microlens of the present invention is made of the cured product of the present invention. The microlenses can be manufactured by the method for manufacturing the cured film described above. By making the opening pattern of the exposure mask circular, hexagonal, or the like, a dome-shaped lens shape can be obtained after development. Furthermore, if a cylindrical or hexagonal prism shape is obtained after development, the dome-shaped lens shape can be obtained by melting the material during the subsequent post-baking.

[0185] The shape of the microlens is not particularly limited, but examples thereof include a dome shape, a truncated cone shape, and a semi-cylindrical shape, with the dome shape being preferred. The height of the microlenses is preferably 0.5 μm or more, more preferably 1 μm or more, and even more preferably 5 μm or more, and is preferably 20 μm or less, and more preferably 10 μm or less. The above upper and lower limits can be combined arbitrarily. For example, the height of the microlenses is preferably 0.5 to 20 μm, more preferably 1 to 10 μm, and even more preferably 5 to 10 μm. The size (diameter) of the microlenses is preferably 1 μm or more, more preferably 3 μm or more, and preferably 50 μm or less, more preferably 30 μm or less, and even more preferably 15 μm or less. The above upper and lower limits can be combined arbitrarily. For example, the size of the microlenses is preferably 1 to 50 μm, more preferably 3 to 30 μm, and even more preferably 3 to 15 μm.

[0186] The microlens of the present invention has a high refractive index, is resistant to clouding even in a high-temperature, high-humidity environment, and can maintain high transmittance, making it useful for use in image display devices. The microlens of the present invention can be used in the image display devices described below, as well as, for example, a condenser lens provided in an image sensor such as a CCD image sensor or a CMOS image sensor, or a light extraction lens for an organic electroluminescent device. The image sensor is used, for example, in a solid-state imaging device such as a camera or a video camera. An example of an image sensor is one having a stacked structure including a semiconductor substrate, one or more color filters selected from a green color filter, a blue color filter, and a red color filter, a planarizing layer, and a microlens.

[0187] [5] Image display device The image display device of the present invention comprises the cured film or microlens of the present invention, that is, it can also be said that the image display device of the present invention comprises the cured product of the present invention. The type and structure of the image display device are not particularly limited as long as it comprises the cured film or microlenses of the present invention, and it can be assembled in a conventional manner using, for example, an active-drive organic electroluminescent device. For example, the image display device of the present invention can be formed by the method described in "Organic EL Display" (Ohmsha, published August 20, 2004, by Shizuo Tokito, Chinaya Adachi, and Hideyuki Murata). Examples of image display devices include liquid crystal display devices and image display devices including organic electroluminescent devices. [Example]

[0188] The present invention will be described in more detail below with reference to examples. However, the present invention is not limited to the following examples as long as it does not deviate from the gist of the present invention, and various modifications are possible as long as they do not deviate from the gist of the present invention. The components of the photosensitive resin compositions used in the following examples and comparative examples are as follows:

[0189] [Alkali-soluble resin] <Synthesis of alkali-soluble resin-1> A flask equipped with a stirrer and a condenser was charged with 80.8 g of 9,9-bis[4-(2-hydroxyethoxy)phenyl]fluorene as compound (A1-1), 27.1 g of 3,3',4'-biphenyltetracarboxylic dianhydride as compound (A3-1), 27.1 g of 2,3,3',4'-biphenyltetracarboxylic dianhydride as compound (A3-2), 8.8 g of 4-hydroxybutyl acrylate, 160 g of propylene glycol monomethyl ether acetate (PGMEA), 0.1 g of p-methoxyphenol (manufactured by Tokyo Chemical Industry Co., Ltd., trade name "MEHQ"), and 0.1 g of diazabicycloundecene (manufactured by Kanto Chemical Co., Ltd., trade name "DBU"), and the mixture was heated with stirring in a mantle heater at 120°C for 4 hours. Then, 18.4 g of 4-hydroxybutyl acrylate glycidyl ether was added as an epoxy group-containing (meth)acrylate (A2-1), and the mixture was further heated and stirred at 120°C for 84 hours to obtain a pale yellow, transparent, viscous resin solution containing alkali-soluble resin-1. Alkali-soluble resin-1 is (A) alkali-soluble resin. The polystyrene-equivalent weight average molecular weight (Mw) and solid acid value of the obtained resin solution were measured by GPC, and were found to be Mw=3800 and solid acid value=103 mgKOH / g.

[0190] <Synthesis of alkali-soluble resin-2> A resin solution containing alkali-soluble resin-2 was obtained in the same manner as for alkali-soluble resin-1, except that all 2,3,3',4'-biphenyltetracarboxylic dianhydride used in the synthesis of alkali-soluble resin-1 was replaced with 3,3',4,4'-biphenyltetracarboxylic dianhydride, i.e., the amount of 3,3',4,4'-biphenyltetracarboxylic dianhydride added was changed to 54.2 g, and no 2,3,3',4'-biphenyltetracarboxylic dianhydride was added.Alkali-soluble resin-2 is a comparative product of alkali-soluble resin (A). The polystyrene-equivalent weight average molecular weight (Mw) and solid acid value of the obtained resin solution were measured by GPC, and were found to be Mw=3900 and solid acid value=109 mgKOH / g.

[0191] <Synthesis of alkali-soluble resin-3> As the compound (A1-1), an epoxy compound (epoxy equivalent weight: 230) having the structure shown below was used.

[0192] [ka]

[0193] 230 g of an epoxy compound (epoxy equivalent weight 230) having the above structure, 72 g of acrylic acid as an unsaturation-containing monocarboxylic acid (A2-2), 300 g of methoxybutyl acetate, 5 g of triphenylphosphine, and 0.13 g of paramethoxyphenol were placed in a flask equipped with a thermometer, a stirrer, and a condenser, and reacted with stirring at 90°C for 15 hours until the acid value reached 5 mgKOH / g or less. Next, 82.4 g of 3,3'4,4'-biphenyltetracarboxylic dianhydride as compound (A3-1), 30.4 g of tetrahydrophthalic anhydride, and 120 g of methoxybutyl acetate were added, and the mixture was slowly heated to 105°C with stirring to react, yielding a resin solution containing alkali-soluble resin-3. Alkali-soluble resin-3 is a comparative product of (A) alkali-soluble resin. The polystyrene-equivalent weight average molecular weight (Mw) and solid acid value of the obtained resin solution were measured by GPC, and were found to be Mw=5200 and solid acid value=111 mgKOH / g.

[0194] <Alkali-soluble resin-4> A carboxyl group-containing epoxy (meth)acrylate resin (manufactured by Nippon Kayaku Co., Ltd., trade name "ZCR-1642H", weight average molecular weight (Mw) = 6500, acid value = 98 mg KOH / g) was used as alkali-soluble resin-4. Alkali-soluble resin-4 is another alkali-soluble resin.

[0195] [(B) Photopolymerizable compound] <Photopolymerizable compound-1> A compound having the structure shown below was used as photopolymerizable compound-1. Photopolymerizable compound-1 can be produced, for example, by the method described in JP 2021-024842 A.

[0196] [ka]

[0197] [(C) Photopolymerization initiator] <Photopolymerization initiator-1> A compound having the structure shown below (manufactured by BASF, trade name "Irgacure OXE01") was used as photopolymerization initiator-1.

[0198] [ka]

[0199] [Optional ingredients] <Additive-1> A methacryloyloxy group-containing phosphate (manufactured by Nippon Kayaku Co., Ltd., trade name "KAYAMER PM-21") was used as additive-1.

[0200] <Additive-2> 3-Glycidoxypropyltrimethoxysilane (manufactured by Dow-Toray Industries, Inc., trade name "DOWSIL SH 6040") was used as additive-2.

[0201] <Additive-3> Polyether-modified polydimethylsiloxane (manufactured by BYK Chemie, trade name "BYK-307") was used as additive-3.

[0202] <Solvent> PGMEA (propylene glycol monomethyl ether acetate) was used as the solvent.

[0203] [Example 1, Comparative Examples 1 and 2] <Preparation of Photosensitive Resin Compositions 1 to 3> The components were mixed in the blending ratios shown in Table 1, stirred to dissolve thoroughly, and then subjected to vibration stirring using an ultrasonic cleaner for 10 minutes to prepare photosensitive resin compositions 1 to 3. The blending ratios of components other than the solvent in Table 1 are solid content converted values. Also, blank cells in Table 1 mean that the component was not blended (blended amount 0 parts by mass).

[0204] <Sample Preparation> Using a spin coater, any one of the photosensitive resin compositions 1 to 3 was applied onto a glass substrate so that the film thickness after heat drying would be about 7.5 μm, to prepare a coated substrate. The coated substrate was vacuum dried for 1 minute and then heated and dried on a hot plate at 90°C for 120 seconds. The resulting coating film was exposed to light at an exposure dose of 110 mJ / m using a mirror projection type exposure machine (Canon Inc., product name "MPA-600FA"). 2 The entire surface was exposed to light with a light intensity of 500 mW / cm at a wavelength of 365 nm. 2 It was. Next, using a 22°C aqueous solution containing 0.04% by mass of KOH and 0.07% by mass of a surfactant (Kao Corporation, product name "Emulgen A-60") as a developer, the exposed coated substrate was spray-developed for 160 seconds, and then washed with pure water for 20 seconds. This was followed by post-baking for 20 minutes in a 90°C oven to obtain test pieces in which a cured product of the photosensitive resin composition was formed on the glass substrate. The obtained cured products were colorless and transparent in all cases of photosensitive resin compositions 1 to 3. The test pieces thus obtained were used to evaluate the storage stability under high temperature and high humidity conditions as follows. The results are shown in Table 1.

[0205] <Storage evaluation> The test piece was placed upright on a sample stand and stored in a high-temperature, high-humidity chamber (manufactured by Espec Corporation, product name "PR-1KP") at a temperature of 85°C and a humidity of 85% RH for two weeks.

[0206] (Appearance evaluation) After storage, the appearance of the cured test piece was visually observed and evaluated according to the following evaluation criteria. A: It is colorless and transparent. B: It is cloudy.

[0207] (Transmittance measurement) The total light transmittance of the cured product of the test piece was measured before and after storage. Specifically, using a glass substrate without a cured product as the reference plate, the transmittance of the cured product from 400 to 800 nm was measured using a spectrophotometer (Hitachi, product name "U-4100"). The transmittance at a wavelength of 550 nm was defined as the transmittance of the cured product, and the transmittance retention rate after storage was calculated using the following formula. Transmittance retention rate [%] = (Transmittance of cured material after storage / Transmittance of cured material before storage) x 100

[0208] [Table 1]

[0209] The photosensitive resin composition-1 obtained in Example 1, which contained an alkali-soluble resin-1 synthesized using two types of biphenyltetracarboxylic dianhydrides that are positional isomers of each other as the acid anhydride (A3), was able to form a cured product that was resistant to clouding even when stored in a high-temperature, high-humidity environment and could maintain high transmittance. In contrast, the cured products formed from the photosensitive resin compositions 2 and 3 obtained in Comparative Examples 1 and 2 became cloudy when stored in a high-temperature and high-humidity environment. When the cloudy cured products were observed under a microscope at 100x magnification, numerous crystalline substances were observed. From the results of this microscopic observation, it is believed that in the Comparative Example, the alkaline developer used for development penetrated into the cured product, and that the biphenyltetracarboxylic acid hydrolyzed in the hot and humid environment crystallized, which caused the clouding of the cured product. On the other hand, in the Example, it is believed that crystallization was suppressed by using two types of biphenyltetracarboxylic dianhydride that are positional isomers, and that the cured product did not become cloudy even in a hot and humid environment.

Claims

1. (A) an alkali-soluble resin, (B) a photopolymerizable compound, and (C) a photopolymerization initiator, the alkali-soluble resin (A) is a reaction product of a bisarenefluorene compound (A1), an ethylenically unsaturated group-containing monomer (A2), and an acid anhydride (A3), The photosensitive resin composition, wherein the acid anhydride (A3) comprises two or more compounds selected from the group consisting of a compound represented by the following general formula (A3-1), a compound represented by the following general formula (A3-2), and a compound represented by the following general formula (A3-3): 【Chemistry 1】 (In formulas (A3-1) to (A3-3), R １４ each independently represents an alkyl group having 1 to 3 carbon atoms; and each r independently represents an integer of 0 to 2.

2. The photosensitive resin composition according to claim 1, wherein the acid anhydride (A3) includes a compound represented by general formula (A3-1) and further includes at least one of a compound represented by general formula (A3-2) and a compound represented by general formula (A3-3).

3. 3. The photosensitive resin composition according to claim 2, wherein the content of the compound represented by general formula (A3-1) is 50 mass% or more relative to the total mass of the acid anhydride (A3).

4. the alkali-soluble resin (A) is an alkali-soluble resin (AA) obtained by reacting a reaction product of the bisarenefluorene compound (A1) and the acid anhydride (A3) with the ethylenically unsaturated group-containing monomer (A2), 2. The photosensitive resin composition according to claim 1, wherein the ethylenically unsaturated group-containing monomer (A2) is an epoxy group-containing (meth)acrylate (A2-1).

5. 2. The photosensitive resin composition according to claim 1, wherein the (C) photopolymerization initiator is a compound having an absorption maximum in a wavelength region of 360 nm or less and not having an absorption maximum in a wavelength region exceeding 360 nm.

6. The photosensitive resin composition according to claim 5 , wherein the (C) photopolymerization initiator comprises an oxime ester compound.

7. 2. The photosensitive resin composition according to claim 1, wherein the photopolymerizable compound (B) has a refractive index of 1.60 or more at a wavelength of 589 nm.

8. 8. The photosensitive resin composition according to claim 7, wherein the photopolymerizable compound (B) comprises at least one of a photopolymerizable compound (B1) having a heterocycle containing a sulfur atom and an ethylenic double bond and a photopolymerizable compound (B2) having a bisarylfluorene ring and an ethylenic double bond.

9. The photosensitive resin composition according to claim 1 , further comprising a solvent.

10. A cured product obtained by curing the photosensitive resin composition according to any one of claims 1 to 9.

11. A cured film comprising the cured product according to claim 10.

12. A microlens comprising the cured product according to claim 10.

13. An image display device comprising the cured film according to claim 11.

14. An image display device comprising the microlens according to claim 12.