Alkali-soluble resin, photosensitive resin composition, method for producing the same, and its uses

Abstract

The present invention provides: an alkali-soluble resin having excellent photocurability and capable of providing a cured product having a high refractive index; and a light-sensitive resin composition. The present invention is an alkali-soluble resin having an aromatic-ring-containing structure represented by formula (1) and a polymerizable unsaturated-bond-containing structure represented by formula (2), in which the polymerizable unsaturated bond equivalent is 700 to 8000 g / equivalent. (In formula (1), R1 represents an ester bond, an oxygen atom, a sulfur atom, or a nitrogen atom that may have a substituent; R2 represents an aromatic group that may have a substituent; and R3 represents a hydrogen atom, or a group represented by formula (3). In formula (2), R4, R5 and R6 are the same as or different from one another and each independently represent a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms; R7 and R8 are the same as or different from each other and each independently represent a direct bond or a bivalent organic group; R9 represents a hydrogen atom or a group represented by formula (3); and at least one of R3 and R9 represents a group represented by formula (3). In formula (3), R10 represents a bivalent hydrocarbon group that may have a substituent.)

Description

[Technical Field]

[0001] This invention relates to alkali-soluble resins, photosensitive resin compositions, methods for producing the same, and applications thereof. More specifically, it relates to alkali-soluble resins, photosensitive resin compositions, methods for producing the same, cured products, components for display devices using the same, and display devices, all of which exhibit excellent photocurability and yield cured products with a high refractive index. [Background technology]

[0002] Alkali-soluble resins and photosensitive resin compositions are being explored for various applications in optical components and electrical / electronic equipment, such as color filters used in liquid crystal display devices and solid-state image sensors, inks, printing plates, printed circuit boards, semiconductor elements, photoresists, organic insulating films, and organic protective films. Resins and resin compositions with superior properties required for each application are being developed.

[0003] In recent years, there has been a growing trend towards miniaturization, thinning, and energy efficiency in optical components, electrical and electronic equipment, and consequently, higher performance is required for the various components used. To meet these demands, research is being conducted on alkali-soluble resins, which are used as materials for various components.

[0004] To date, alkali-soluble resins have been developed to meet a variety of needs. For example, Patent Document 1 describes a modified epoxy resin having excellent heat resistance, moisture resistance, and flexibility, obtained by reacting an epoxy resin having two or more epoxy groups in one molecule (a), a phenol having a substituent containing an aryl group (b), and an unsaturated monobasic acid (c).

[0005] Furthermore, for example, Patent Document 2 describes an alkali-developable photocurable / thermosetting composition that can provide a solder resist film with excellent heat resistance, adhesion, resolution, electroless plating resistance, electrical properties, and moisture resistance, and includes a photosensitive prepolymer obtained by reacting a polybasic acid anhydride with the alcoholic hydroxyl group of the reaction product of an epoxy compound having two or more epoxy groups in one molecule, a predetermined phenol compound and / or naphthol compound, and an unsaturated group-containing monocarboxylic acid. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 11-49840 [Patent Document 2] Japanese Patent Application Publication No. 11-315107 [Overview of the project] [Problems that the invention aims to solve]

[0007] However, these conventional alkali-soluble resins have low refractive indices, and while a high refractive index of around 1.60 is required for optical applications where such a high refractive index is needed, such requirements have not yet been adequately met.

[0008] Furthermore, in recent years, when alkali-soluble resins are used in optical applications such as color filters, there is a strong demand for higher performance, such as increased brightness and contrast in display panels. To better exhibit the physical properties of the cured film, it is desirable for the curing reaction to proceed sufficiently.

[0009] This invention has been made in view of the above-mentioned circumstances, and aims to provide an alkali-soluble resin and a photosensitive resin composition that can provide a cured product with excellent photocurability and a high refractive index. [Means for solving the problem]

[0010] As a result of conducting various studies on alkali-soluble resins, the present inventors have found that a cured product having excellent photocurability and a high refractive index can be obtained when the resin has a specific aromatic ring-containing structure and a polymerizable unsaturated bond-containing structure, with the polymerizable unsaturated bond equivalent falling within a specific range, and thus completed the present invention.

[0011] That is, the present invention provides the invention according to the following aspects. [1] An alkali-soluble resin characterized by having an aromatic ring-containing structure represented by the following formula (1) and a polymerizable unsaturated bond-containing structure represented by the following formula (2), wherein the polymerizable unsaturated bond equivalent is 700 to 8000 g / equivalent.

[0012] Chemical formula

[0013] (In formula (1), R 1 represents an ester bond, an oxygen atom, a sulfur atom, or a nitrogen atom which may have a substituent. R 2 represents an aromatic group which may have a substituent. R 3 is a hydrogen atom or a group represented by formula (3). In formula (2), R 4 , R 5 and R 6 are the same or different and each represents a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms. R 7 and R 8 are the same or different and each represents a direct bond or a divalent organic group. R 9 is a hydrogen atom or a group represented by formula (3). At least one of R 3 and R 9 is a group represented by formula (3). In formula (3), R 10 represents a divalent hydrocarbon group which may have a substituent.) [2] The alkali-soluble resin according to [1] above, characterized in that the acid value is 30 to 150 mgKOH / g. [3] The alkali-soluble resin according to [1] or [2] above, characterized in that the epoxy equivalent is more than 10000 g / equivalent. [4] The alkali-soluble resin according to any one of [1] to [3] above, characterized in that the main chain structure has a novolac structure. [5] A photosensitive resin composition characterized by comprising an alkali-soluble resin, a polymerizable compound, and a photopolymerization initiator as described in any of [1] to [4] above. [6] A cured product characterized by being obtained by curing an alkali-soluble resin described in any of [1] to [4] above, or a photosensitive resin composition described in [5] above. [7] A component for a display device, characterized by containing the cured product described in [6] above. [8] A display device characterized by including the display device component described in [7] above. [9] A method for producing an alkali-soluble resin, the method comprising: a first step of reacting an epoxy resin (a) having two or more epoxy groups in one molecule with an aromatic group-containing compound (b) and an unsaturated monocarboxylic acid (c); and a second step of reacting the reaction product obtained in the first step with a polybasic acid anhydride (d), A method for producing an alkali-soluble resin, characterized by adjusting the amounts of aromatic group-containing compound (b) and unsaturated monocarboxylic acid (c) used in the first step so that the polymerizable unsaturated bond equivalent of the resulting alkali-soluble resin is 700 to 8000 g / equivalent.

[10] A method for producing a photosensitive resin composition, the method comprising the steps of: producing an alkali-soluble resin having a polymerizable unsaturated bond equivalent of 700 to 8000 g / equivalent by the method for producing an alkali-soluble resin described in [9] above; and mixing the obtained alkali-soluble resin, a polymerizable compound, and a photopolymerization initiator.

[11] An alkali-soluble resin characterized by having an aromatic ring-containing structure represented by the following formula (4) and a polymerizable unsaturated bond-containing structure represented by the following formula (2).

[0014] [ka]

[0015] (In formula (4), R 23R represents an aromatic group which may have substituents. 24 R is a hydrogen atom or a group represented by formula (3). In formula (2), R 4 , R 5 and R 6 R represents a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms, either identical or different. 7 and R 8 R represents an identical or different directly bonded or divalent organic group. 9 R is a hydrogen atom or a group represented by formula (3). 24 and R 9 At least one of them is a group represented by formula (3). In formula (3), R 10 (This represents a divalent hydrocarbon group which may have substituents.)

[12] A resin having an aromatic ring-containing structure represented by the following formula (1') and a polymerizable unsaturated bond-containing structure represented by the following formula (2'), characterized in that the polymerizable unsaturated double bond equivalent is 600 to 7000 g / equivalent.

[0016] [ka]

[0017] (In formula (1'), R 1 R represents an oxygen atom or a sulfur atom. 2 R represents an aromatic group which may have substituents. In formula (2'), R 4 , R 5 and R 6 R represents a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms, either identical or different. 7 and R 8 (These represent identical or distinct organic groups that are directly bonded or divalent.)

[13] A photosensitive resin composition characterized by comprising the resin described in

[12] above, an alkali-soluble resin, a polymerizable compound, and a photopolymerization initiator.

[14] A cured product characterized by being obtained by curing the photosensitive resin composition described in

[13] above. [Effects of the Invention]

[0018] The alkali-soluble resin and photosensitive resin composition of the present invention can provide a cured product with excellent photocurability and a high refractive index, a display device component containing the cured product, and a display device. Furthermore, the method for producing the alkali-soluble resin of the present invention can easily produce an alkali-soluble resin with excellent photocurability and a high refractive index. [Modes for carrying out the invention]

[0019] Preferred embodiments of the present invention will be described below in detail, but the present invention is not limited to the following descriptions and can be modified and applied as appropriate without changing the gist of the present invention. Furthermore, embodiments combining two or more of the individual preferred embodiments of the present invention described below also constitute preferred embodiments of the present invention. In this specification, "(meth)acrylic acid" means "acrylic acid and / or methacrylic acid," and "(meth)acrylate" means "acrylate and / or methacrylate." Furthermore, in this specification, the numerical range "Min~Max" means a range greater than or equal to the minimum value Min and less than or equal to the maximum value Max. In addition, when specifying suitable numerical values ​​for the upper and lower limits in stages, a numerical range obtained by appropriately combining the upper and lower limits specified separately is also considered a suitable numerical range.

[0020] 1. Alkali-soluble resins <First alkali-soluble resin> The first alkali-soluble resin of the present invention is characterized by having an aromatic ring-containing structure represented by formula (1) and a polymerizable unsaturated bond-containing structure represented by formula (2), wherein the polymerizable unsaturated bond equivalent is 700 to 8000 g / equivalent.

[0021] The first alkali-soluble resin of the present invention exhibits excellent photocurability and a high refractive index for the following reasons. Specifically, the first alkali-soluble resin of the present invention has a specific aromatic ring-containing structure, which allows it to produce a cured product with a high refractive index. Furthermore, it is presumed that the presence of polymerizable unsaturated bonds in a predetermined range of amounts in the side chains provides excellent photocurability, and the high crosslink density during curing results in a cured product with an even higher refractive index.

[0022] In the above equation (1), R 1 R represents an ester bond, an oxygen atom, a sulfur atom, or a nitrogen atom which may have a substituent. Examples of the substituents include alkyl groups, aralkyl groups, aryl groups, thioester groups, thioether groups, disulfide groups, alkoxy groups, amino groups or their salts, halogen atoms, trifluoromethyl groups, benzamino groups, boronic acid groups, hydroxyl groups, mercapto groups, thiocyanate groups, alkylthiocyanate groups, isothiocyanate groups, thiourea groups, sulfonic acid groups, carboxyl groups, aldehyde groups, heterocyclic groups, or groups that combine these. Among these, R is particularly noteworthy in that it results in a higher refractive index. 1 The atom is preferably an oxygen atom or a sulfur atom, and more preferably a sulfur atom. Furthermore, the presence of a sulfur atom allows it to function as an antioxidant, thereby imparting weather resistance to the resin.

[0023] R 2 The symbol represents an aromatic group which may have substituents. The above aromatic group may have an aromatic ring structure and may be monocyclic or polycyclic. It may also contain heteroatoms. The rings constituting a polycyclic aromatic group may be fused together, bonded by single bonds, or linked by sharing one carbon atom. Furthermore, the rings constituting a polycyclic aromatic group only need to include at least an aromatic ring, and may consist solely of aromatic rings, or of an aromatic ring and a non-aromatic ring.

[0024] Examples of the aromatic groups mentioned above include monovalent groups formed by removing one hydrogen atom from benzene-based aromatic compounds, non-benzene-based aromatic compounds, and heteroaromatic compounds.

[0025] Examples of the above-mentioned benzene-based aromatic compounds include hydrocarbon compounds containing a benzene ring, such as monocyclic hydrocarbon compounds like benzene; condensed ring hydrocarbon compounds like naphthalene, anthracene, triphenylene, and pyrene; and polycyclic hydrocarbon compounds like biphenylene and fluorene.

[0026] Examples of the above-mentioned non-benzene aromatic compounds include hydrocarbon compounds containing unsaturated cyclic compounds other than benzene rings, such as annulene and azulene.

[0027] Examples of the above-mentioned heteroaromatic compounds include unsaturated cyclic compounds containing elements other than carbon and hydrogen atoms, such as oxygen, nitrogen, and sulfur atoms. Examples include monocyclic heteroaromatic compounds such as furan, thiophene, pyrrole, pyrazole, imidazole, pyridine, pyridazine, pyrimidine, pyrazine, triazole, thiazole, thiadizol, and tetrazole; and polycyclic heteroaromatic compounds such as carbazole, benzoxazole, purine, azulene, benzofuran, isobenzofuran, benzothiophene, benzotriazole, isobenzothiophene, indole, isoindole, benzimidazole, and benzothiazole.

[0028] In particular, among the above aromatic groups, monovalent groups formed by removing one hydrogen atom from a benzene-based aromatic compound are preferred, phenyl groups, naphthyl groups, and biphenyl groups are more preferred, phenyl groups and biphenyl groups are even more preferred, and phenyl groups are most preferred.

[0029] The number of carbon atoms in the above aromatic group is preferably 1 to 30, more preferably 2 to 20, and even more preferably 6 to 12.

[0030] Examples of substituents that the above aromatic group may have include alkyl groups, aralkyl groups, aryl groups, thioester groups, thioether groups, disulfide groups, alkoxy groups, amino groups or their salts, halogen atoms, trifluoromethyl groups, benzamino groups, boronic acid groups, hydroxyl groups, mercapto groups, thiocyanate groups, alkylthiocyanate groups, isothiocyanate groups, thiourea groups, sulfonic acid groups, carboxyl groups, aldehyde groups, heterocyclic groups, or combinations thereof. Among these, alkyl groups are preferred. The number of carbon atoms in the substituent is preferably 1 to 20, more preferably 1 to 10, and even more preferably 1 to 6. The above aromatic group may have one or more of the above substituents.

[0031] Specific examples of aromatic groups that may have the above substituents include, in addition to the specific aromatic groups mentioned above, aromatic hydrocarbon groups such as tolyl, xylyl, benzyl, phenethyl, benzhydryl, trityl, styryl, and cinnamyl groups.

[0032] Furthermore, specific examples of aromatic groups that may have the above substituents include monovalent groups obtained by removing one hydrogen atom from the following aromatic compounds: Thiocyanate compounds such as benzylthiocyanate; Isothiocyanate compounds such as phenyl isothiocyanate, benzyl isothiocyanate, and 3,4-difluorophenyl isothiocyanate; Mercaptan compounds such as trityl mercaptan, 4-aminothiophenol, 4-fluorothiophenol, 2,4-difluorothiophenol, 2-amino-4-(trifluoromethyl)thiophenol hydrochloride, 3,5-dichlorothiophenol, bis(3,5-dichlorophenyl) disulfide, 4-methoxythiophenol, 3-mercapto-4-methyl-1,2,4-triazole, 4-bromothiophenol, 2-mercaptobenzoxazole, 2,6-dimethylthiophenol, 4,4',4''-(1,3,5,2,4,6-trioxatriborinan-2,4,6-triol)tribenzenethiol, 1,3,5-tris[3-(2-mercaptoethylsulfanyl)propyl]isocyanate, 6-amino-8-mercaptopurine, 4-mercaptobenzamide, 4-mercaptophenylboronic acid, 2-naphthalenchiol, and diphenyl disulfide; Thiocarboxylic acid compounds such as thioacetic acid-S-phenyl ester; Sulfonyl halogen compounds such as 2-mesitylene sulfonyl chloride; Sulfonic acid compounds such as benzenesulfonic acid; Thiourea compounds such as diphenylthiourea; Thiadiazole compounds such as 2,5-dimercapto-1,3,4-thiadiazole, 2-thioacetate-5-mercapto-1,3,4-thiadiazole, and 2,5-dithioacetate-1,3,4-thiadiazole; Azide compounds such as 4-dodecylbenzenesulfonyl azide, 4-acetylaminobenzenesulfonyl azide, and diphenyl phosphate azide; 1H-tetrazol, 5-amino-1H-tetrazol, 5-methyl-1H-tetrazol, 5-phenyl-1H-tetrazol, 1-methyl-5-ethyl-1H-tetrazol, 1-methyl-5-mercapto-1H-tetrazol, 1-phenyl-5-mercapto-1H-tetrazol, 1-(2-dimethylaminoethyl)-5-mercapto-1H-tetrazol, 2-methoxy-5-(5-trifluoromethyl-1H-tetrazol-1-yl) -Tetrazole compounds such as benzaldehyde, 5,5'-bi-1H-tetrazol diammonium salt, 4,5-di(5-tetrazolyl)-[1,2,3]triazole, 5,5'-azobis-1H-tetrazol, 1-methyl-5-benzoyl-1H-tetrazol, (1-methyl-1H-tetrazol-5-yl)phenylmethanone oxime (E+Z), 5-ethylthio-1H-tetrazol, and 1-benzyl-5-phenyl-1H-tetrazol; Thiazolidine compounds such as 2,4-thiazolidinedione, 2-thio-4-thiazolidone, and 2-imino-4-thiazolidinone; 4-thiazole carboxylic acid; Ketone compounds such as 2-hydroxyacetophenone, 4-hydroxyacetophenone, 2-hydroxypropiophenone, and 4-hydroxypropiophenone; Dicarboxyaldehyde compounds such as 2,6-naphthalenedicarboxyaldehyde and 2,7-naphthalenedicarboxyaldehyde; Trityl chloride compounds such as trityl chloride and 4,4'-dimethoxytrityl chloride.

[0033] Among them, R 2 Preferably, the group is an aromatic hydrocarbon group which may have substituents, more preferably a phenyl group, naphthyl group, or biphenyl group which may have substituents, and even more preferably a phenyl group or biphenyl group which may have substituents.

[0034] R 3 is a hydrogen atom or a group represented by the above formula (3). In the above equation (3), R 10This represents a divalent hydrocarbon group which may have substituents.

[0035] Examples of the above-mentioned divalent hydrocarbon groups include divalent aliphatic hydrocarbon groups, alicyclic hydrocarbon groups, and aromatic hydrocarbon groups. Examples of divalent aliphatic hydrocarbon groups include alkylene groups such as methylene, ethylene, propylene, isopropylene, butylene, isobutylene, t-butylene, pentylene, neopentylene, hexamethylene, heptylene, octylene, 2-ethylhexylene, nonylene, decylene, undecylene, and dodecylene, as well as alkenylene groups such as vinylene, propenylene, isopropenylene, butenylene, butadienylene, pentenylene, hexenylene, and heptenylene.

[0036] Examples of divalent alicyclic hydrocarbon groups include cycloalkylene groups such as cyclopropylene, cyclobutylene, cyclopentylene, cyclohexylene, norbornylene, and adamantylene, as well as cycloalkylidene groups such as cyclopentylidene and cyclohexylidene.

[0037] Examples of divalent aromatic hydrocarbon groups include arylene groups such as phenylene, torylene, and naphthylene, as well as cinnamyridene and biphenylene groups.

[0038] In particular, the above-mentioned divalent hydrocarbon group is preferably a divalent aliphatic hydrocarbon group or a divalent alicyclic hydrocarbon group, more preferably a divalent aliphatic hydrocarbon group, and even more preferably an alkylene group.

[0039] The number of carbon atoms in the above-mentioned divalent hydrocarbon group is preferably 2 to 20, more preferably 2 to 8, and even more preferably 2.

[0040] Examples of substituents that the above-mentioned divalent hydrocarbon group may have include carboxyl groups, hydroxyl groups, alkoxy groups, halogen atoms, and hydrocarbon groups having 1 to 7 carbon atoms.

[0041] In equation (2) above, R 4 , R 5 and R 6 These represent, either identical or different, a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms. The above-mentioned hydrocarbon group having 1 to 6 carbon atoms is preferably an aliphatic hydrocarbon group having 1 to 6 carbon atoms, and more preferably an alkyl group having 1 to 6 carbon atoms. Among them, R 4 and R 5 It is preferably a hydrogen atom, R 6 It is preferable that this is a hydrogen atom or a methyl group.

[0042] In equation (2) above, R 7 and R 8 R represents an identical or different directly bonded or divalent organic group. 7 and R 8 Examples of divalent organic groups represented by include divalent hydrocarbon groups, or groups formed by combining a divalent hydrocarbon group with bonds such as -O-, -CO-, -COO-, -NH-, -SO-, or -SO2-. Examples of the above-mentioned divalent hydrocarbon groups include those similar to those described above. The above-mentioned divalent hydrocarbon groups may contain two or more types. In particular, among the above-mentioned divalent organic groups, divalent hydrocarbon groups, or groups that combine a divalent hydrocarbon group with at least one bond selected from the group consisting of -O-, -CO-, and -COO-, are preferred. Examples of groups combining the above-mentioned divalent hydrocarbon group with at least one bond selected from the group consisting of -O-, -CO-, and -COO- include -R a -COO-R b -, -R a -O-(CO)-R b -(In the formula, R a and R b This represents a divalent hydrocarbon group having 1 to 20 carbon atoms, either identical or different. Examples include:

[0043] R 7 and R 8The group is preferably a directly bonded, divalent hydrocarbon group, or a combination of a divalent hydrocarbon group and at least one bond selected from the group consisting of -O- and -COO-, more preferably a directly bonded or divalent aliphatic hydrocarbon group, and even more preferably a directly bonded.

[0044] In equation (2) above, R 9 is a hydrogen atom or a group represented by formula (3) above. Also, the above R 3 and R 9 At least one of these groups is represented by formula (3) above. The group represented by formula (3) has a carboxyl group, which is an acidic group. The presence of such a group in the resin makes it alkali soluble. By adjusting the amount of such acidic groups, the alkali soluble resin can also be made into a resin with excellent developability.

[0045] The first alkali-soluble resin described above preferably has a novolac structure in its main chain. The novolac structure refers to a structure in which a benzene ring or naphthalene ring is bonded to a divalent hydrocarbon group, which may have substituents, in the main chain to form repeating units.

[0046] As an alkali-soluble resin having an aromatic ring-containing structure represented by formula (1) and a polymerizable unsaturated bond-containing structure represented by formula (2), a preferred example is an alkali-soluble resin having a constituent unit (A) represented by the following formula (a) and a constituent unit (B) represented by the following formula (b).

[0047] [ka]

[0048] [ka]

[0049] (In the formula, A represents a benzene ring or a naphthalene ring. R 1 ~R 9These are the same as those described above. R 11 and R 14 R represents a divalent hydrocarbon group having 1 to 20 carbon atoms, which may be the same or different. 12 and R 15 represents a substituent that is identical or different and bonds to A. a is R 12 b represents the number of elements and is an integer between 0 and 5. 15 This represents the number of elements and is an integer between 0 and 5. 12 and R 15 If there are two or more of each, they may be identical or different. 13 and R 16 (These represent identical or distinct organic groups that are directly bonded or divalent.)

[0050] In this specification, "constituent unit" means the repeating unit that constitutes the alkali-soluble resin.

[0051] In formulas (a) and (b) above, A represents a benzene ring or a naphthalene ring. From the viewpoint of balancing high refractive index and developability, A is preferably a benzene ring.

[0052] In the above formulas (a) and (b), R 11 and R 14 This represents a divalent hydrocarbon group having 1 to 20 carbon atoms. Examples of the above divalent hydrocarbon group include the same groups as those mentioned above. Among them, R is particularly readily available. 11 and R 14 The above-mentioned divalent hydrocarbon group represented by is preferably a divalent aliphatic hydrocarbon group, and more preferably an alkylene group.

[0053] The number of carbon atoms in the above-mentioned divalent hydrocarbon group is preferably 1 to 14, more preferably 1 to 10, and even more preferably 1.

[0054] The above-mentioned divalent hydrocarbon group may have at least one of its constituent atoms substituted with an oxygen atom, nitrogen atom, sulfur atom, or halogen atom. Furthermore, the above-mentioned divalent hydrocarbon group may have substituents such as an alkoxy group.

[0055] R 12 and R 15 This represents a substituent that is identical or different and bonds to A. Substituents that can be bonded to A include hydroxyl groups or organic groups having 1 to 20 carbon atoms.

[0056] The above-mentioned organic groups having 1 to 20 carbon atoms include those obtained by converting the aforementioned divalent organic groups to monovalent, with a carbon number of 1 to 20. In particular, R is chosen because of its good curability. 12 and R 15 The substituents represented are -OH, -O-CH2-(C2H3O), and -CR c R d -(C6H4)-O-CH2-(C2H3O), -CR c R d -(C6H4)-OH(wherein, R c and R d ) represents a hydrogen atom or a methyl group, either identical or different. ) or preferably an aliphatic hydrocarbon group having 1 to 20 carbon atoms, more preferably an aliphatic hydrocarbon group having 1 to 20 carbon atoms, even more preferably an aliphatic hydrocarbon group having 1 to 10 carbon atoms, and particularly preferably a methyl group.

[0057] In the above formula (a), a is a substituent R 12 This represents the number of elements and is an integer from 0 to 5. a is preferably 0 to 3, more preferably 1 to 3, and even more preferably 1, in terms of good developability. If a is 2 or greater, i.e., R 12 If there are two or more, R 12 These elements may be identical or different from each other.

[0058] In the above formula (b), b is a substituent R 15 This represents the number of elements and is an integer from 0 to 5. b is preferably 0 to 3, more preferably 1 to 3, and even more preferably 1, in terms of good developability. If b is 2 or greater, i.e., R 15 If there are two or more, R 15each may be the same as or different from each other.

[0059] R 13 and R 16 are the same or different and each represents a direct bond or a divalent organic group. Examples of the divalent organic group include the same groups as the above-mentioned divalent organic groups. Among these, R 13 and R 16 is preferably a direct bond.

[0060] The first alkali-soluble resin may have one or two or more of the above structural units (A). The content ratio of the structural unit (A) in the alkali-soluble resin is preferably 51 to 93 mol%, more preferably 55 to 92 mol%, still more preferably 60 to 91 mol%, even more preferably 60 to 90 mol%, particularly preferably 60 to 80 mol%, and most preferably 60 to 75 mol%, relative to 100 mol% of all structural units.

[0061] The first alkali-soluble resin may have one or two or more of the above structural units (B). The content ratio of the structural unit (B) in the alkali-soluble resin is preferably 7 to 49 mol%, more preferably 8 to 45 mol%, still more preferably 9 to 40 mol%, and even more preferably 10 to 40 mol%, relative to 100 mol% of all structural units.

[0062] The first alkali-soluble resin may further have a structural unit (C) other than the above-described structural units (A) and (B). Further, the alkali-soluble resin may have one or two or more structural units (C).

[0063] Examples of the structural unit (C) include a structural unit represented by the following formula (c).

[0064]

Chemical Formula

[0065] (wherein A represents a benzene ring or a naphthalene ring; R 3 is the same as defined above; R 17 represents a divalent hydrocarbon group having 1 to 20 carbon atoms; R 18 represents a substituent bonded to A; c represents the number of R 18 groups, and is an integer of 0 to 5; when there are two or more R 18 groups, they may be the same as or different from each other; R 19 represents a direct bond or a divalent organic group; R 20 represents an organic group.)

[0066] Examples of the divalent hydrocarbon group having 1 to 20 carbon atoms represented by R 17 include the same groups as the divalent hydrocarbon group having 1 to 20 carbon atoms represented by R 11 described above; a divalent aliphatic hydrocarbon group is preferable, and an alkylene group is more preferable.

[0067] Examples of the substituent represented by R 18 include the same groups as the substituent represented by R 12 described above; preferable substituents are -OH, -O-CH2-(C2H3O), -CR c R d -(C6H4)-O-CH2-(C2H3O), -CR c R d -(C6H4)-OH (wherein R c and R d are the same or different and each represent a hydrogen atom or a methyl group), or an aliphatic hydrocarbon group having 1 to 20 carbon atoms; more preferably an aliphatic hydrocarbon group having 1 to 20 carbon atoms, still more preferably an aliphatic hydrocarbon group having 1 to 10 carbon atoms, and particularly preferably a methyl group.

[0068] In the above formula (c), c represents the number of substituents R 18 and is an integer of 0 to 5. From the viewpoint of good developability, c is preferably 0 to 3, more preferably 1 to 3, and still more preferably 1. When c is 2 or more, that is, when R18 If there are two or more, R 18 These elements may be identical or different from each other.

[0069] R 19 R represents a directly bonded or divalent organic group. 19 As a divalent organic group represented by the above, R 13 Examples of groups similar to the divalent organic group represented by include R 19 It is preferable that the bonding is direct.

[0070] R 20 R represents an organic group. 20 Examples of organic groups represented by include the aforementioned divalent organic groups that have been converted to monovalent, but among these, groups having an acidic group are preferred. It is also preferable that they do not have a double bond. 20 By appropriately selecting the organic groups, the developability and reactivity of the double bond can be controlled.

[0071] Examples of the above-mentioned acidic groups include carboxyl groups, phenolic hydroxyl groups, carboxylic acid anhydride groups, phosphoric acid groups, sulfonic acid groups, and other functional groups that react with alkaline water in a neutralization reaction. Among these, carboxyl groups or carboxylic acid anhydride groups are preferred, and carboxyl groups are more preferred, due to their good developability.

[0072] Examples of groups having the above acid group include -R e -R f (In the formula, R e R represents a divalent organic group. f The symbol represents an acid group. Examples include groups represented by ( ). Examples of the divalent organic groups mentioned above include groups similar to those described above. In particular, groups consisting of a combination of a divalent hydrocarbon group and at least one selected from the group consisting of -O- and -COO- are preferred.

[0073] R 20The organic group represented by also preferably has a functional group that has radical scavenging ability or ultraviolet absorption ability. Having such a functional group can improve the weather resistance of the resin. Examples of the above functional groups include hindered phenol group, hindered amine group, benzotriazole group, triazine group, cyanoacrylate group, melamine group, benzoate group, etc.

[0074] R 20 The number of carbon atoms in the organic group represented is preferably 1 to 20, more preferably 1 to 16, and even more preferably 2 to 12. f By positioning the acid group represented by away from the main chain of the alkali-soluble resin, the developability can be improved.

[0075] The first alkali-soluble resin described above may have one or more of the above-mentioned constituent units (C). The content of the above constituent unit (C) is preferably 0 to 20 mol%, more preferably 0.1 to 20 mol%, even more preferably 0.5 to 15 mol%, and even more preferably 1 to 10 mol%, based on 100 mol% of the total constituent units.

[0076] Furthermore, the first alkali-soluble resin described above may have a constituent unit (D) represented by the following formula (d). By introducing the above constituent unit (D) and extending the chain, the resin can be designed to have any molecular weight.

[0077] [ka]

[0078] In the above formula (d), L represents a direct bond or linking group. 21 and R 22 represents identical or different substituents. d is R 21 This represents the number of elements and is an integer between 0 and 4. e is R 22 This represents the number of elements and is an integer between 0 and 4. 21 and R 22If there are multiple instances, they may be identical or different from one another.

[0079] Examples of the above-mentioned linking groups include alkylene groups, arylene groups, heteroarylene groups, and divalent bonds such as -O-, -CO-, -S-, -SO-, -SO2-, -NH-, or combinations thereof.

[0080] The alkylene group is preferably an alkylene group having 1 to 20 carbon atoms, and more preferably an alkylene group having 1 to 10 carbon atoms. It may also be linear, branched, or cyclic.

[0081] The alkylene group and arylene group described above may have substituents. The substituents are not particularly limited and include, for example, halogen atoms such as fluorine, chlorine, and iodine, or alkyl groups.

[0082] The constituent unit (D) represented by the above formula (d) is preferably derived from one compound selected from bisphenol A, bisphenol AP, bisphenol AF, bisphenol B, bisphenol BP, bisphenol C, bisphenol E, bisphenol F, bisphenol G, bisphenol M, bisphenol S, bisphenol P, bisphenol PH, bisphenol TMC, and bisphenol Z, more preferably derived from bisphenol S, bisphenol A, or bisphenol F, and even more preferably derived from bisphenol S.

[0083] Preferably, the above-mentioned constituent unit (D) is a constituent unit represented by the following formulas (d-1), (d-2), or (d-3).

[0084] [ka]

[0085] When the first alkali-soluble resin described above contains the above-mentioned constituent unit (D), the content of the above-mentioned constituent unit (D) is preferably 0.1 to 10 mol%, more preferably 0.2 to 5 mol%, and even more preferably 0.5 to 2 mol%, based on 100 mol% of the total constituent units.

[0086] The polymerizable unsaturated bond equivalent of the first alkali-soluble resin described above is 700 to 8000 g / equivalent. By having the polymerizable unsaturated bond equivalent within this range, the photocurability of the alkali-soluble resin can be improved. From the viewpoint of reducing the brittleness of the cured product, the polymerizable unsaturated bond equivalent of the alkali-soluble resin is preferably 750 to 6000 g / equivalent, more preferably 800 to 5000 g / equivalent, even more preferably 900 to 4000 g / equivalent, and even more preferably 900 to 2000 g / equivalent.

[0087] The above polymerizable unsaturated bond equivalent is the mass of solids in the alkali-soluble resin solution per mole of polymerizable unsaturated bonds in the alkali-soluble resin. In this specification, the above polymerizable unsaturated bond means a polymerizable double bond. The mass of solids in the above alkali-soluble resin solution is the mass of monomer components constituting the alkali-soluble resin. The above polymerizable unsaturated bond equivalent can be determined by dividing the mass (g) of alkali-soluble resin solids in the alkali-soluble resin solution by the amount (mol) of polymerizable unsaturated bonds in the alkali-soluble resin. Alternatively, it may be calculated by measuring the number of ethylenic double bonds contained in 1 g of alkali-soluble resin in accordance with the iodine value test method described in JIS K 0070:1992.

[0088] The acid value of the first alkali-soluble resin described above is preferably 30 to 150 mg KOH / g. More preferably, the acid value is 40 to 120 mg KOH / g, and even more preferably 45 to 90 mg KOH / g, in that it further improves developability. The above acid value is the acid value per gram of resin solids, obtained by a neutralization titration method using potassium hydroxide (KOH) solution, and can be determined by the method described in the examples below.

[0089] The epoxy equivalent of the first alkali-soluble resin described above is preferably greater than 10,000 g / equivalent. When the epoxy equivalent is within the above range, the alkali-soluble resin of the present invention has almost no epoxy groups. Therefore, it has good storage stability. The epoxy equivalent of the alkali-soluble resin described above is more preferably greater than 13,000 g / equivalent. The above epoxy equivalent can be determined by a method in accordance with JIS K7236:2001, or by dividing the mass (g) of the resin solids by the number of moles (mol) of epoxy groups contained in the resin.

[0090] The weight-average molecular weight of the first alkali-soluble resin described above is preferably 1,000 to 100,000. The weight-average molecular weight of the alkali-soluble resin described above is more preferably 2,000 to 50,000, even more preferably 3,000 to 20,000, even more preferably 3,500 to 15,000, and particularly preferably 4,000 to 10,000, in terms of good curability. The above weight-average molecular weight can be determined by gel permeation chromatography (GPC).

[0091] The glass transition temperature (Tg) of the first alkali-soluble resin described above is preferably 40°C or higher, more preferably 60°C or higher, and even more preferably 80°C or higher, in terms of improving film strength, and preferably 300°C or lower, more preferably 250°C or lower, and even more preferably 200°C or lower, in terms of good developability. The glass transition temperature (Tg) of the first alkali-soluble resin described above is preferably 40 to 300°C, more preferably 60 to 250°C, and even more preferably 80 to 200°C. The above glass transition temperature can be determined by a method in accordance with JIS-K7121.

[0092] <Second alkali-soluble resin> The second alkali-soluble resin of the present invention is characterized by having an aromatic ring-containing structure represented by the following formula (4) and a polymerizable unsaturated bond-containing structure represented by the following formula (2).

[0093] [ka]

[0094] (In formula (4), R 23 R represents an aromatic group which may have substituents. 24 R is a hydrogen atom or a group represented by formula (3). In formula (2), R 4 , R 5 and R 6 R represents a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms, either identical or different. 7 and R 8 R represents an identical or different directly bonded or divalent organic group. 9 R is a hydrogen atom or a group represented by formula (3). 24 and R 9 At least one of them is a group represented by formula (3). In formula (3), R 10 (This represents a divalent hydrocarbon group which may have substituents.)

[0095] The second alkali-soluble resin of the present invention can yield a cured product with excellent photocurability and a high refractive index because it has a structure of formula (4) containing a sulfur atom and an aromatic group, which allows for a high refractive index of the cured product, and it has a structure of formula (2), which allows for good photocurability.

[0096] In the above equation (4), R 23 R represents an aromatic group which may have substituents. 23 An aromatic group which may have substituents represented by the above formula (1) is R 2 Examples of similar groups to aromatic groups that may have substituents represented by include those similar to aromatic groups.

[0097] In the above equation (4), R 24 is a hydrogen atom or a group represented by formula (3). The group represented by formula (3) above is the same group as the group represented by formula (3) described in the section on <First alkali-soluble resin> above.

[0098] The polymerizable unsaturated bond-containing structure represented by formula (2) above is the same structure as the polymerizable unsaturated bond-containing structure represented by formula (2) described in the section on <First alkali-soluble resin> above.

[0099] The second alkali-soluble resin described above preferably has a novolac structure in its main chain, similar to the first alkali-soluble resin described above.

[0100] As an alkali-soluble resin having an aromatic ring-containing structure represented by formula (4) and a polymerizable unsaturated bond-containing structure represented by formula (2), an alkali-soluble resin having a constituent unit (E) represented by the following formula (e) and a constituent unit (B) described in the section <First alkali-soluble resin> above is preferred.

[0101] [ka]

[0102] (In the formula, A represents a benzene ring or a naphthalene ring. R 23 and R 24 These are the same as those described above. R 25 R represents a divalent hydrocarbon group with 1 to 20 carbon atoms. 26 represents a substituent that bonds to A. f is R 26 This represents the number of elements and is an integer between 0 and 5. 26 If there are two or more of them, they may be identical or different. 27 (This represents a directly bonded or divalent organic group.)

[0103] In the formula, A represents a benzene ring or a naphthalene ring, preferably a benzene ring. R 25As a divalent hydrocarbon group having 1 to 20 carbon atoms, the R in formula (a) described in the section <First Alkali-Soluble Resin> above is 11 Examples include divalent hydrocarbon groups with 1 to 20 carbon atoms represented by .

[0104] R 26 The substituent represented by is R in formula (a) above. 12 Examples of substituents similar to those represented by include groups similar to those shown.

[0105] f is R 26 This represents the number of elements and is an integer between 0 and 5. f is preferably between 0 and 3, more preferably between 1 and 3, and most preferably 1, in terms of good developability.

[0106] The second alkali-soluble resin described above may have one or more of the above-mentioned constituent units (E). The content of the above-mentioned constituent unit (E) in the second alkali-soluble resin described above is preferably 1 to 99 mol%, more preferably 20 to 95 mol%, even more preferably 40 to 93 mol%, even more preferably 50 to 90 mol%, particularly preferably 60 to 85 mol%, and most preferably 60 to 80 mol% based on 100 mol% of the total constituent units.

[0107] The content of the above-mentioned constituent unit (B) in the second alkali-soluble resin described above is preferably 1 to 80 mol%, more preferably 2 to 70 mol%, even more preferably 3 to 50 mol%, even more preferably 5 to 40 mol%, particularly preferably 10 to 40 mol%, and most preferably 15 to 40 mol%, based on 100 mol% of the total constituent units.

[0108] Furthermore, the second alkali-soluble resin may have other constituent units in addition to the constituent units (E) and (B) described above. Examples of these other constituent units include constituent unit (C) or constituent unit (D) described in the section on the first alkali-soluble resin described above. If the second alkali-soluble resin described above has the constituent unit (C) and / or constituent unit (D), it is preferable that their content ratios are the same as those in the first alkali-soluble resin described above.

[0109] The polymerizable unsaturated bond equivalent of the second alkali-soluble resin described above is preferably 300 to 8000 g / equivalent, more preferably 500 to 6000 g / equivalent, even more preferably 700 to 5000 g / equivalent, even more preferably 800 to 4000 g / equivalent, and particularly preferably 800 to 2000 g / equivalent.

[0110] Preferably, the acid value, epoxy group equivalent, weight-average molecular weight, and glass transition temperature of the second alkali-soluble resin described above are the same as those of the first alkali-soluble resin described above.

[0111] 2. Method for producing alkali-soluble resin <Method for producing the first alkali-soluble resin> The method for producing the first alkali-soluble resin of the present invention is not particularly limited as long as the first alkali-soluble resin described above can be obtained, but a method including the following steps is preferred in that it can efficiently produce the first alkali-soluble resin of the present invention. (1) First step: Reacting an epoxy resin (a) having two or more epoxy groups in one molecule with an aromatic group-containing compound (b) and an unsaturated monocarboxylic acid (c). (2) Second step: Reacting the reaction product obtained in the first step with polybasic acid anhydride (d) Furthermore, in the above manufacturing method, the first alkali-soluble resin of the present invention can be produced by adjusting the amounts of aromatic group-containing compound (b) and unsaturated monocarboxylic acid (c) used in the first step so that the polymerizable unsaturated bond equivalent of the resulting alkali-soluble resin is 700 to 8000 g / equivalent.

[0112] The present invention also includes a method for producing such a first alkali-soluble resin, that is, a method for producing an alkali-soluble resin, the method comprising a first step of reacting an epoxy resin (a) having two or more epoxy groups in one molecule with an aromatic group-containing compound (b) and an unsaturated monocarboxylic acid (c), and a second step of reacting the reaction product obtained in the first step with a polybasic acid anhydride (d), wherein the amount of aromatic group-containing compound (b) and unsaturated monocarboxylic acid (c) used in the first step is adjusted so that the polymerizable unsaturated bond equivalent of the resulting alkali-soluble resin is 700 to 8000 g / equivalent. The following describes each step.

[0113] In the first method for producing an alkali-soluble resin of the present invention, the epoxy resin (a) having two or more epoxy groups in one molecule as a starting material is not particularly limited, and any known epoxy resin having two or more epoxy groups in one molecule can be used, such as bisphenol-type epoxy resins; biphenyl-type epoxy resins; alicyclic epoxy resins; polyfunctional glycidylamine resins such as tetraglycidylaminodiphenylmethane; polyfunctional glycidyl ether resins such as tetraphenylglycidyl etherethane; phenol novolac-type epoxy resins and cresol novolac-type epoxy resins. Examples include: lipids; polyphenol compounds obtained by the condensation reaction of phenolic compounds such as phenol, o-cresol, m-cresol, and naphthol with aromatic aldehydes having a phenolic hydroxyl group, and reaction products with epichlorohydrin; polyphenol compounds obtained by the addition reaction of phenolic compounds with diolefin compounds such as divinylbenzene and dicyclopentadiene, and reaction products with epichlorohydrin; ring-opened polymers of 4-vinylcyclohexene-1-oxide epoxidized with peracid; and epoxy resins having heterocyclic rings such as triglycidyl isocyanurate. Furthermore, epoxy resins obtained by chain extension by linking two or more molecules of these epoxy resins with a chain extender such as a polybasic acid, polyphenol compound, polyfunctional amino compound, or polyvalent thiol can also be used. Alternatively, homopolymers or copolymers of monomers having epoxy groups, such as glycidyl (meth)acrylate or 3,4-epoxycyclohexylmethyl (meth)acrylate, may also be used. In particular, it is preferable to use novolac-type epoxy resin as a raw material in order to increase the number of ethylenically unsaturated bonds (polymerizable unsaturated double bonds) in each molecule of alkali-soluble resin and improve photocurability.

[0114] The epoxy resin (a) used as the starting material, which has two or more epoxy groups in one molecule, is preferably one with an epoxy equivalent of 500 g / equivalent or less, in order to obtain an alkali-soluble resin with superior developability and photocurability. More preferably, it is one with an epoxy equivalent of 400 g / equivalent or less, and even more preferably, it is one with an epoxy equivalent of 300 g / equivalent or less.

[0115] The aromatic group-containing compound (b) is not particularly limited as long as it has an aromatic group and a group that can react with an epoxy group, and examples include the aromatic compounds mentioned above. Examples of the above-mentioned aromatic groups include groups having the aromatic ring structure described above. Groups that can react with the epoxy group mentioned above include acidic groups, amino groups, and hydroxyl groups. Examples of the above-mentioned acidic groups include carboxyl groups, phenolic hydroxyl groups, and mercapto groups, with phenolic hydroxyl groups and mercapto groups being preferred. The above aromatic group-containing compound is preferably an aromatic group-containing acid compound having the above aromatic group and an acidic group.

[0116] The aromatic group-containing compound is not particularly limited as long as it can impart the aromatic ring-containing structure described above to the resulting resin, but preferred examples include phenol derivatives such as phenylphenol, thiophenol derivatives such as toluenethiol and benzenethiol, and alcohol derivatives such as hydroxyphenethyl alcohol. Among these, thiophenol derivatives are preferred because the resulting thioether bond can achieve both a high refractive index and fast developability, and benzenethiol is the most preferred. These may be used individually or in combination of two or more.

[0117] Furthermore, by using or combining hydroxyphenethyl alcohol, chain-extended acid groups can be introduced into the alkali-soluble resin by reacting it with a polybasic acid anhydride in step (2) described later. Since such acid groups are positioned away from the main chain, the developability and reactivity during curing are improved.

[0118] The above unsaturated monocarboxylic acid (c) is not particularly limited as long as it has an unsaturated bond and a carboxyl group, but those having 3 to 20 carbon atoms are preferred. More preferably, those having 3 to 10 carbon atoms are preferred, and even more preferably, those having 3 to 4 carbon atoms.

[0119] Examples of the above unsaturated monocarboxylic acid (c) include acrylic acid, methacrylic acid, crotonic acid, cinnamic acid, β-acryloxypropionic acid, reaction products of a hydroxyalkyl (meth)acrylate having one hydroxyl group and one (meth)acryloyl group with a dibasic acid anhydride, and reaction products of a polyfunctional (meth)acrylate having one hydroxyl group and two or more (meth)acryloyl groups with a dibasic acid anhydride. Among these, those having a (meth)acryloyl group, such as acrylic acid and methacrylic acid, are preferred. Methacrylic acid is particularly preferred in terms of providing a cured product with particularly excellent solvent resistance for the resulting alkali-soluble resin. One or more of these can be used.

[0120] The aromatic group-containing compound (b) and the unsaturated monocarboxylic acid (c) may be added all at once, in separate portions, or sequentially, but adding them in separate portions or sequentially is preferred in that it can suppress side reactions.

[0121] In the method for producing an alkali-soluble resin of the present invention, in the first step of reacting an epoxy resin (a) having two or more epoxy groups in one molecule with an aromatic group-containing compound (b) and an unsaturated monocarboxylic acid (c), the epoxy resin (a) may be reacted with the unsaturated monocarboxylic acid (c) and then with the aromatic group-containing compound (b), or the epoxy resin (a) may be reacted with the unsaturated monocarboxylic acid (c) and the aromatic group-containing compound (b) all at once, or the epoxy resin (a) may be reacted with the aromatic group-containing compound (b) and then with the unsaturated monocarboxylic acid (c).

[0122] In the first step described above, when reacting the epoxy resin (a) with the aromatic group-containing compound (b), it is preferable to add the aromatic group-containing compound (b) in such a way that the amount of acid groups in the aromatic group-containing compound (b) is 0.51 to 0.93 moles per chemical equivalent (molar equivalent) of epoxy groups in the epoxy resin (a), more preferably 0.55 to 0.92 moles, even more preferably 0.6 to 0.91 moles, even more preferably 0.6 to 0.9 moles, particularly preferably 0.6 to 0.8 moles, and most preferably 0.6 to 0.75 moles.

[0123] The reaction between epoxy resin (a) and aromatic group-containing compound (b) can be accelerated by replacing the reaction vessel with an inert gas such as nitrogen to lower the oxygen concentration. The oxygen concentration in the reaction vessel is preferably 1% by volume or less, more preferably 0.5% by volume or less, and even more preferably 0.3% by volume or less. To lower the oxygen concentration in the reaction solution, it is also preferable to bubble the solution with an inert gas such as nitrogen.

[0124] In the first step described above, it is preferable that the total amount of aromatic group-containing compound (b) and unsaturated monocarboxylic acid (c) used is 0.8 to 1.2 moles per mole of epoxy groups in epoxy resin (a). Using these proportions makes it easier to obtain good curability of the final alkali-soluble resin and good physical properties of the cured product. Preferably, the ratio is 0.85 to 1.15 moles, more preferably 0.9 to 1.1 moles.

[0125] By adjusting the amounts of aromatic group-containing compound (b) and unsaturated monocarboxylic acid (c) used in the first step described above, an alkali-soluble resin with a polymerizable unsaturated bond equivalent of 700 to 8000 g / equivalent can be obtained.

[0126] As described above, in the first step of the method for producing the first alkali-soluble resin of the present invention, the reaction of the epoxy resin (a) with the aromatic group-containing compound (b) and the unsaturated monocarboxylic acid (c) may be carried out either in order or simultaneously. These reactions can typically be carried out at 60-140°C in the presence or absence of polymerizable compounds or diluents such as solvents, as described later, along with polymerization inhibitors such as hydroquinone and oxygen, and reaction catalysts such as tertiary amines, trimethylphosphine, tributylphosphine, triphenylphosphine, lithium chloride, quaternary ammonium salts, and quaternary phosphonium salts. As a reaction catalyst, tertiary phosphines are preferred from the viewpoint of reaction efficiency, stability during the reaction, and storage stability of the alkali-soluble resin, and triphenylphosphine is particularly preferred.

[0127] The amount of the above reaction catalyst is not particularly limited, but is preferably 0.05 to 5 parts by mass per 100 parts by mass of epoxy resin (a) having two or more epoxy groups in one molecule. More preferably, it is 0.1 to 3 parts by mass, and even more preferably, 0.2 to 2 parts by mass.

[0128] Furthermore, a polymerization inhibitor may be used in the first step. The polymerization inhibitor is not particularly limited and known ones can be used, for example, benzoquinone, hydroquinones (e.g., hydroquinone, hydroquinone monomethyl ether, p-tert-butylhydroquinone, p-benzoquinone, etc.), phenols (e.g., 2,6-di-t-butyl-4-methylphenol, 6-t-butyl-2,4-dimethylphenol, 2,2'-methylenebis(4-methyl-6-t-butylphenol), etc.), catechols (e.g., p-tert-butylcatechol, etc.), amines (e.g., N,N-diethylhydroxylamine, etc.), 1,1-diphenyl-2-picrylhydrazyl, tri-p-nitrophenylmethyl, phenothiazine, piperidine 1-oxyls (e.g., 2,2,6,6-tetramethylpiperidine 1-oxyl, etc.), oxygen, etc. can be used.

[0129] When the polymerization inhibitor is used in the first step, the amount of polymerization inhibitor used is preferably 0.001 to 1% by mass, based on 100% by mass of epoxy resin (a) having two or more epoxy groups in one molecule. More preferably, it is 0.01 to 0.5% by mass.

[0130] The above reaction may be carried out in a solvent, and examples of reaction solvents include hydrocarbons such as toluene and xylene; cellosolves such as cellosolve and butyl cellosolve; carbitols such as carbitol and butyl carbitol; esters such as cellosolve acetate, carbitol acetate, (di)propylene glycol monomethyl ether acetate, (di)methyl glutarate, (di)methyl succinate, and (di)methyl adipate; ketones such as methyl isobutyl ketone and methyl ethyl ketone; and ethers such as (di)ethylene glycol dimethyl ether.

[0131] The reaction temperature in the first step described above is not particularly limited as long as the reaction proceeds, but 40 to 140°C is preferred. This temperature allows the reaction to proceed efficiently. More preferably, the reaction temperature is 50 to 135°C, and even more preferably 60 to 130°C.

[0132] Furthermore, in the first step described above, the epoxy resin (a) may be reacted with an aromatic group-containing compound (b) or an unsaturated monocarboxylic acid (c) along with a carboxylic acid that does not contain a double bond. By reacting the carboxylic acid without a double bond together, the double bond equivalent, epoxy equivalent, glass transition temperature, etc., of the alkali-soluble resin can be adjusted. Examples of carboxylic acids that do not have the double bond mentioned above include propionic acid, acetic acid, butyric acid, decanoic acid, and 2-ethylhexylcarboxylic acid.

[0133] In the first step described above, the epoxy resin (a) may also be reacted with an acid compound having a functional group that possesses radical scavenging ability or ultraviolet absorption ability, together with an aromatic group-containing compound (b) or an unsaturated monocarboxylic acid (c). By reacting with such an acid compound, weather resistance can be imparted to the resin.

[0134] Examples of functional groups having radical scavenging ability or ultraviolet absorption ability include the functional groups having radical scavenging ability or ultraviolet absorption ability as described above. The acidic groups possessed by the above-mentioned acidic compounds include the acidic groups described above, but among them, carboxyl groups are preferred.

[0135] Specific examples of acid compounds having a functional group with the above-mentioned radical scavenging ability or ultraviolet absorption ability include, for example, 3,5-di-tert-butyl 4-hydroxybenzoic acid, 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid, 3-methylsalicylic acid, trimethylhydroquinone, 3-phenylsalicylic acid, 4-hydroxy-3,5-dimethylbenzoic acid, 3,5-di-tert-butylsalicylic acid, mycophenolic acid, xanthohumol, monoethyl 3,5-di-tert-butyl 4-hydroxybenzylphosphonate, and among these, 3,5-di-tert-butyl 4-hydroxybenzoic acid and 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid are preferred.

[0136] In the second step of the above-described method for producing the alkali-soluble resin, the reaction product (intermediate) obtained in the first step is reacted with a polybasic acid anhydride (d). The polybasic acid anhydride (d) reacts with the hydroxyl groups present in the reaction product to obtain the alkali-soluble resin of the present invention, into which carboxyl groups have been introduced. The resulting alkali-soluble resin can be alkali-developed and can therefore be used as an alkali-developable curable resin for applications such as image formation.

[0137] The polybasic acid anhydride (d) used in the second step described above is not particularly limited, but those having 3 to 30 carbon atoms are preferred. More preferably, those having 4 to 20 carbon atoms are preferred, and even more preferably, those having 4 to 10 carbon atoms are preferred.

[0138] Examples of the polybasic acid anhydride (d) above include dibasic acid anhydrides such as phthalic anhydride, succinic anhydride, octenyl succinic anhydride, pentadodecenyl succinic anhydride, maleic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, 3,6-endomethylenetetrahydrophthalic anhydride, methylendomethylenetetrahydrophthalic anhydride, tetrabromophthalic anhydride, trimellitic acid; and aliphatic or aromatic tetrabasic acid dianhydrides such as biphenyltetracarboxylic acid dianhydride, diphenyl ethertetracarboxylic acid dianhydride, butanetetracarboxylic acid dianhydride, cyclopentanetetracarboxylic acid dianhydride, pyromellitic anhydride, and benzophenonetetracarboxylic acid dianhydride. One or more of these polybasic acid anhydrides can be used. Among these, the use of dibasic acid anhydrides is preferred. Furthermore, in order to obtain a cured product with particularly excellent solvent resistance, polybasic acid anhydrides such as phthalic anhydride, which result in an alkali-soluble resin having a cyclic structure in its structure, are particularly preferred.

[0139] In the second step described above, it is preferable to react the polybasic acid anhydride (d) in a ratio of 0.1 moles to 1.1 moles per chemical equivalent of hydroxyl groups in the reaction product obtained in the first step. By reacting the polybasic acid anhydride (d) in this way, the addition reaction of the polybasic acid anhydride (d) can be carried out efficiently, and carboxyl groups can be suitably introduced into the resulting alkali-soluble resin.

[0140] The reaction between the reaction product obtained in the first step and the polybasic acid anhydride (d) in the second step described above can be carried out in the presence or absence of a diluent such as a polymerizable compound or solvent, as described later, and, if necessary, in the presence of the polymerization inhibitor or reaction catalyst mentioned above, similar to the reaction in the first step. In the second step described above, a reaction catalyst may be used, preferably a tertiary phosphine, and more preferably triphenylphosphine.

[0141] The reaction temperature in the second step described above is not particularly limited as long as the reaction proceeds, but 45 to 130°C is preferred. This temperature allows the reaction to proceed efficiently. More preferably, the reaction temperature is 50 to 120°C, and even more preferably 55 to 110°C.

[0142] Furthermore, if the alkali-soluble resin has the constituent unit (D), for example, before the first step, the epoxy resin (a) can be reacted with a compound that can introduce the constituent unit (D) in advance to extend the chain of the epoxy resin (a), and then the extended epoxy resin (a) can be subjected to the first step to produce the alkali-soluble resin having the constituent unit (D).

[0143] Examples of compounds into which the above-mentioned structural unit (D) can be introduced include bisphenol compounds from which the aforementioned structural unit (D) originates.

[0144] A reaction catalyst may be used in the above reaction. Examples of reaction catalysts used in this reaction include those similar to those used in the first and second steps described above.

[0145] The above-described first method for producing alkali-soluble resin may include other steps, as long as it includes the above-described first and second steps.

[0146] <Second method for manufacturing alkali-soluble resin> The second method for producing the alkali-soluble resin described above includes a first and second step similar to the first method for producing the alkali-soluble resin described above, except that the aromatic group-containing compound used contains a sulfur atom and the polymerizable unsaturated bond equivalent of the alkali-soluble resin is not limited to 700-8000 g / equivalent.

[0147] The aromatic group-containing compound (b') used in the second method for producing the alkali-soluble resin described above preferably contains a sulfur atom. The aromatic group-containing compound (b') is preferably one of the aromatic group-containing compound (b) used in the first method for producing the alkali-soluble resin described above, in which the group that can react with the epoxy group contains a sulfur atom. The aromatic group-containing compound (b') is preferably a compound containing the aromatic group and the mercapto group described above.

[0148] Furthermore, in the first step of the second method for producing the alkali-soluble resin described above, the amount of aromatic group-containing compound (b') added is preferably such that the amount of acid groups in the aromatic group-containing compound (b') is 0.01 to 0.99 moles per chemical equivalent (molar equivalent) of epoxy groups in the epoxy resin (a), more preferably 0.2 to 0.95 moles, even more preferably 0.4 to 0.93 moles, even more preferably 0.6 to 0.9 moles, particularly preferably 0.6 to 0.85 moles, and most preferably 0.6 to 0.80 moles.

[0149] In the second alkali-soluble resin described above, the polymerizable unsaturated bond equivalent is not limited, but by adjusting the amounts of the aromatic group-containing compound (b') and the unsaturated monocarboxylic acid (c) used in the first step, an alkali-soluble resin with a polymerizable unsaturated bond equivalent of 300 to 8000 g / equivalent can be obtained.

[0150] The method for producing the alkali-soluble resin of the present invention described above includes the first and second steps described above. The reaction product (intermediate) obtained in the first step preferably has an aromatic ring-containing structure represented by the following formula (1') and a polymerizable unsaturated bond-containing structure represented by the following formula (2'), and the polymerizable unsaturated double bond equivalent is 600 to 7000 g / equivalent.

[0151] [ka]

[0152] (In formula (1'), R 1R represents an oxygen atom or a sulfur atom. 2 R represents an aromatic group which may have substituents. In formula (2'), R 4 , R 5 and R 6 R represents a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms, either identical or different. 7 and R 8 (These represent identical or distinct organic groups that are directly bonded or divalent.) Such resins are also part of the present invention, and they exhibit excellent photocurability and can produce cured products with a high refractive index.

[0153] R in equation (1') above 1 and R 2 This is the same as equation (1) above, and R in equation (2') above 4 ~R 8 This is the same as equation (2) above.

[0154] The polymerizable unsaturated bond equivalent of the above resin is not particularly limited, but is preferably 650 to 6000 g / equivalent, more preferably 700 to 5000 g / equivalent, and even more preferably 750 to 4000 g / equivalent.

[0155] As a resin having an aromatic ring-containing structure represented by the above formula (1'), in the above formula (a), "-CH-OR 3 A resin having a constituent unit (A') that is "-CH-OH" is preferred. The content ratio of the constituent unit (A') in the above resin is preferably within the same range as the content ratio of the constituent unit (A) described above.

[0156] As a resin having a polymerizable unsaturated bond-containing structure represented by the above formula (2'), in the above formula (b), "-CH-OR 9 A resin having a constituent unit (B') that is "-CH-OH" is preferred. The content ratio of the constituent unit (B') in the above resin is preferably within the same range as the content ratio of the constituent unit (B) described above.

[0157] The above resin may further have the constituent units (C) and (D) described above.

[0158] 3. Photosensitive resin composition A photosensitive resin composition comprising the first and / or second alkali-soluble resin of the present invention, a polymerizable compound, and a photopolymerization initiator is also part of the present invention. Since the photosensitive resin composition of the present invention contains the alkali-soluble resin described above, it can provide a cured product with excellent photocurability and a high refractive index. Hereafter, the first alkali-soluble resin of the present invention and the second alkali-soluble resin described above will be collectively referred to as the alkali-soluble resin of the present invention.

[0159] The content of the first and / or second alkali-soluble resins described above is not particularly limited and can be set appropriately depending on the application and the blending of other components. For example, it is preferably 5 to 90% by mass, more preferably 10 to 80% by mass, even more preferably 15 to 75% by mass, and particularly preferably 15 to 70% by mass, based on 100% by mass of the total solid content of the photosensitive resin composition. In this specification, "total solid content" means the total amount of components that form the cured product (excluding solvents and curing catalysts that volatilize during the formation of the cured product).

[0160] (polymerizable compound) The polymerizable compounds described above are low-molecular-weight compounds having polymerizable unsaturated bonds (also called polymerizable unsaturated groups) that can be polymerized by irradiation with free radicals, electromagnetic waves (e.g., infrared rays, ultraviolet rays, X-rays, etc.), electron beams, or other active energy rays. Examples include monofunctional compounds having one polymerizable unsaturated group in the molecule and polyfunctional compounds having two or more polymerizable unsaturated groups.

[0161] Examples of the monofunctional compounds mentioned above include N-substituted maleimide monomers; (meth)acrylic acid esters; (meth)acrylamides; unsaturated monocarboxylic acids; unsaturated polycarboxylic acids; unsaturated monocarboxylic acids in which the chain between the unsaturated group and the carboxyl group is extended; unsaturated acid anhydrides; aromatic vinyls; conjugated dienes; vinyl esters; vinyl ethers; N-vinyl compounds; unsaturated isocyanates; and so on. Monomers having active methylene groups or active methine groups can also be used.

[0162] Examples of the polyfunctional compounds mentioned above include the following compounds. Difunctional (meth)acrylate compounds such as ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, butylene glycol di(meth)acrylate, hexanediol di(meth)acrylate, cyclohexanedimethanol di(meth)acrylate, bisphenol A alkylene oxide di(meth)acrylate, and bisphenol F alkylene oxide di(meth)acrylate;

[0163] Trimethylolpropane tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, glycerin tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, tripentaerythritol hepta(meth)acrylate, tripentaerythritol octa(meth)acrylate, ethylene oxide-added trimethylolpropane tri(meth)acrylate, ethylene oxide-added ditrimethylolpropane tetra(meth)acrylate, ethylene oxide-added pentaerythritol tetra(meth)acrylate, ethylene oxide-added dipentaerythritol hexa(meth)acrylate, propylene oxide-added trimethylolpropane Dimethylolpropane tetra(meth)acrylate, propylene oxide-added ditrimethylolpropane tetra(meth)acrylate, propylene oxide-added pentaerythritol tetra(meth)acrylate, propylene oxide-added dipentaerythritol hexa(meth)acrylate, ε-caprolactone-added trimethylolpropane tri(meth)acrylate, ε-caprolactone-added ditrimethylolpropane tetra(meth)acrylate, ε-caprolactone-added pentaerythritol tetra(meth)acrylate, ε-caprolactone-added dipentaerythritol hexa(meth)acrylate, dipentaerythritol pentaacrylate succinate modified, pentaerythritol triacrylate succinate modified, dipentaerythritol pentaacrylate phthalate modified, pentaerythritol triacrylate phthalate modified, the following formula:

[0164] [ka]

[0165] Polyfunctional (meth)acrylate compounds with three or more functions, such as modified dipentaerythritol hexaacrylate represented by [formula];

[0166] Polyfunctional vinyl ethers such as ethylene glycol divinyl ether, diethylene glycol divinyl ether, polyethylene glycol divinyl ether, propylene glycol divinyl ether, butylene glycol divinyl ether, hexanediol divinyl ether, bisphenol A alkylene oxide divinyl ether, bisphenol F alkylene oxide divinyl ether, trimethylolpropane trivinyl ether, ditrimethylolpropane tetravinyl ether, glycerin trivinyl ether, pentaerythritol tetravinyl ether, dipentaerythritol pentavinyl ether, dipentaerythritol hexanyl ether, ethylene oxide-added trimethylolpropane trivinyl ether, ethylene oxide-added ditrimethylolpropane tetravinyl ether, ethylene oxide-added pentaerythritol tetravinyl ether, and ethylene oxide-added dipentaerythritol hexanyl ether;

[0167] Vinyl ether group-containing (meth)acrylic acid esters such as (meth)acrylate 2-vinyloxyethyl, (meth)acrylate 3-vinyloxypropyl, (meth)acrylate 1-methyl-2-vinyloxyethyl, (meth)acrylate 2-vinyloxypropyl, (meth)acrylate 4-vinyloxybutyl, (meth)acrylate 4-vinyloxycyclohexyl, (meth)acrylate 5-vinyloxypentyl, (meth)acrylate 6-vinyloxyhexyl, (meth)acrylate 4-vinyloxymethylcyclohexylmethyl, (meth)acrylate p-vinyloxymethylphenylmethyl, (meth)acrylate 2-(vinyloxyethoxy)ethyl, (meth)acrylate 2-(vinyloxyethoxyethoxyethoxy)ethyl;

[0168] Polyfunctional allyl ethers such as ethylene glycol diallyl ether, diethylene glycol diallyl ether, polyethylene glycol diallyl ether, propylene glycol diallyl ether, butylene glycol diallyl ether, hexanediol diallyl ether, bisphenol A alkylene oxide diallyl ether, bisphenol F alkylene oxide diallyl ether, trimethylolpropane triallyl ether, ditrimethylolpropane tetraallyl ether, glycerin triallyl ether, pentaerythritol tetraallyl ether, dipentaerythritol pentaallyl ether, dipentaerythritol hexaallyl ether, ethylene oxide-added trimethylolpropane triallyl ether, ethylene oxide-added ditrimethylolpropane tetraallyl ether, ethylene oxide-added pentaerythritol tetraallyl ether, and ethylene oxide-added dipentaerythritol hexaallyl ether;

[0169] Allyl group-containing (meth)acrylic acid esters such as (meth)acrylate; polyfunctional (meth)acryloyl group-containing isocyanurates such as tri(acryloyloxyethyl)isocyanurate, tri(methacryloyloxyethyl)isocyanurate, alkylene oxide-added tri(acryloyloxyethyl)isocyanurate, alkylene oxide-added tri(methacryloyloxyethyl)isocyanurate; polyfunctional allyl group-containing isocyanurates such as triallyl isocyanurate; polyfunctional urethane (meth)acrylates obtained by the reaction of polyfunctional isocyanates such as tolylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate with hydroxyl group-containing (meth)acrylic acid esters such as 2-hydroxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate; polyfunctional aromatic vinyls such as divinylbenzene; etc. These polymerizable compounds may be used individually or in combination of two or more.

[0170] Among the polymerizable compounds mentioned above, it is preferable to use a polyfunctional polymerizable compound from the viewpoint of further improving the curability of the photosensitive resin composition. The number of functionalities in the polyfunctional polymerizable compound is preferably 3 or more, and more preferably 4 or more. Furthermore, the number of functionalities is preferably 10 or less, and more preferably 8 or less. The number of functional groups is preferably 3 to 10, more preferably 4 to 8. The molecular weight of the polymerizable compound is not particularly limited, but from the viewpoint of handling, it is preferably 2000 or less.

[0171] Among the polyfunctional polymerizable compounds mentioned above, from the viewpoint of reactivity, economy, and availability, preferred are compounds having a (meth)acryloyl group, such as polyfunctional (meth)acrylate compounds, polyfunctional urethane (meth)acrylate compounds, and (meth)acryloyl group-containing isocyanurate compounds, and more preferably polyfunctional (meth)acrylate compounds. By including a compound having a (meth)acryloyl group, the above photosensitive resin composition becomes superior in photosensitivity and curability, and a cured product with even higher hardness and transparency can be obtained. It is even more preferable to use a polyfunctional (meth)acrylate compound with three or more functions as the polyfunctional polymerizable compound.

[0172] The content of the polymerizable compound is preferably 5 to 60% by mass, more preferably 10 to 50% by mass, and even more preferably 15 to 40% by mass, based on 100% by mass of the total solid content of the photosensitive resin composition.

[0173] (Photopolymerization initiator) Specific examples of the above photopolymerization initiators include, for example, aminoketone compounds such as 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one ("IRGACURE® 907", manufactured by BASF), 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1 ("IRGACURE 369", manufactured by BASF), and 2-dimethylamino-2-(4-methyl-benzyl)-1-(4-morpholin-4-yl-phenyl)-butan-1-one ("IRGACURE 379", manufactured by BASF); 2,2-dimethoxy-1,2-diphenylethane-1-one ("IRGACURE 651", manufactured by BASF), and phenylglyoxylic acid methyl ester ("DAROCURE® 907"). Benzyl ketal compounds such as "MBF" (manufactured by BASF); 1-hydroxy-cyclohexyl-phenyl-ketone ("IRGACURE184", manufactured by BASF), 2-hydroxy-2-methyl-1-phenyl-propan-1-one ("DAROCUR1173", manufactured by BASF), 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one ("IRGACURE2959", manufactured by BASF), 2-hydroxy Hydroketone compounds such as C-1-{4-[4-(2-hydroxy-2-methylpropionyl)-benzyl]-phenyl}-2-methylpropan-1-one ("IRGACURE 127", manufactured by BASF), 1-hydroxycyclohexylphenyl-ketone + benzophenone ("IRGACURE 500", manufactured by BASF); and other alkylphenone compounds exemplified in paragraphs

[0084] to

[0086] of Japanese Patent Application Publication No. 2013-227485;1,2-Octanedione, 1-[4-(phenylthio)phenyl]-,2-(O-benzoyl oxime) ("OXE01", manufactured by BASF), Ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-,1-(O-acetyl oxime) ("OXE02", manufactured by BASF), 1,2-Octanedione, 1-[4-(phenylthio)-,2-,(O-benzoyl oxime)], Ethanone ("OXE03", manufactured by BASF), 1-[9-ethyl Examples include oxime ester compounds such as -6-(2-methylbenzoyl)-9H-carbazole-3-yl]-,1-(O-acetyloxime) ("OXE04", manufactured by BASF); benzophenone compounds; benzoin compounds; thioxanthone compounds; halomethylated triazine compounds; halomethylated oxadiazole compounds; biimidazole compounds; titanocene compounds; benzoic acid ester compounds; acridine compounds, etc.; phosphine oxide compounds; etc. Among these, aminoketone compounds and oxime ester compounds are preferred. The above photopolymerization initiators may be used individually or in combination of two or more.

[0174] The content of the above-mentioned photopolymerization initiator is preferably 0.3 to 20% by mass, more preferably 0.5 to 10% by mass, and even more preferably 1 to 8% by mass, based on 100% by mass of the total solid content of the photosensitive resin composition.

[0175] The photosensitive resin composition of the present invention contains at least the alkali-soluble resin, polymerizable compound, and photopolymerization initiator described above, but may also contain one or more other components as needed. Furthermore, each component can be used individually or in pairs or more. The other ingredients are described below.

[0176] (Polyfunctional thiol compounds) The above photosensitive resin composition may further contain a polyfunctional thiol compound. When the alkali-soluble resin containing polymerizable unsaturated bonds in its side chains is combined with a polyfunctional thiol compound, an enthiol reaction may occur concurrently during exposure or heating, potentially improving the crosslinking density. In particular, the enthiol reaction proceeds well when acrylate-like polymerizable unsaturated bonds are present in the resin.

[0177] The above polyfunctional thiol compound is preferably a compound having two or more mercapto groups in one molecule and a molecular weight of 200 to 1000, with trifunctional to pentafunctional secondary thiols being particularly preferred. Adding such a polyfunctional thiol compound to the above photosensitive resin composition can further improve its curability and storage stability.

[0178] Examples of the polyfunctional thiol compounds mentioned above include mercaptopropionic acid derivatives such as butanediol bisthiopropionate, ethylene glycol bisthiopropionate, trimethylolpropane tristhiopropionate, pentaerythritol tetrakisthiopropionate, pentaerythritol tetrakis(3-mercaptobutyrate) (Karenz® PE-1), 1,4-bis(3-mercaptobutyryloxy)butane (Karenz BD-1), and 1,3,5-tris(3-mercaptobutyryloxyethyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione (Karenz NR-1). Furthermore, as the polyfunctional thiol compound mentioned above, compounds that do not have a hydroxyl group and / or an aromatic ring in their molecule are preferred.

[0179] Commercially available polyfunctional thiol compounds can also be used, such as "Thiocalcol 20" from Kao Corporation, "Kalenz MT(registered trademark) PE1", "Kalenz MT BD1", "Kalenz MT NR1", "TPMB", and "TEMB" from Showa Denko K.K., and "TMMP", "TEMPIC", "PEMP", "EGMP-4", "DPMP", "TMMP II-20P", and "PEMP II-20P" from SC Organic Chemicals Co., Ltd.

[0180] The content of the above polyfunctional thiol compound is preferably 0.3 to 15% by mass, more preferably 0.5 to 10% by mass, and even more preferably 1 to 8% by mass, based on 100% by mass of the total solid content of the photosensitive resin composition.

[0181] (metal oxide particles) The above photosensitive resin composition preferably also contains metal oxide particles. The inclusion of metal oxide particles in the photosensitive resin composition allows for the production of a cured product with a high refractive index. Furthermore, it results in improved photosensitivity and dielectric properties. While the exact reason is unclear, it is presumed that a smaller difference in refractive index between the resin and the metal oxide particles reduces light loss due to Rayleigh scattering and other factors during exposure. High-density filling of metal oxide particles in the photosensitive resin composition does not impair resolution, thus improving dielectric properties.

[0182] Examples of the above-mentioned metal oxide particles include light-transmitting metal oxide particles with a high refractive index containing atoms such as Be, Mg, Ca, Sr, Ba, Sc, Y, La, Ce, Gd, Tb, Dy, Yb, Lu, Ti, Zr, Hf, Nb, Mo, W, Zn, B, Al, Si, Ge, Sn, Pb, Sb, Bi, and Te. In particular, the above-mentioned metal oxide particles are more preferably composed of at least one metal element selected from the group consisting of Ti, Al, Zr, Zn, Sn, Ce, and Si, in order to provide a cured product with a higher refractive index. Furthermore, it is more preferable to include Zr from the viewpoint of providing a cured film with a high dielectric constant, and it is more preferable to include Si from the viewpoint of providing a cured film with high hardness.

[0183] The above metal oxides may be oxides of a single metal, solid solutions of two or more oxides, or complex oxides. Examples of single metal oxides include aluminum oxide (Al2O3), titanium oxide (TiO2), zirconium oxide (ZrO2), indium oxide (In2O3), zinc oxide (ZnO), tin oxide (SnO2), lanthanum oxide (La2O3), yttrium oxide (Y2O3), cerium oxide (CeO2), magnesium oxide (MgO), and silicon oxide (SiO2). Examples of solid solutions of two or more oxides include ITO and ATO. Examples of complex oxides include barium titanate (BaTiO3), titanite (CaTiO3), and spinel (MgAl2O4). In particular, zirconium dioxide particles (ZrO2 particles) and / or silicon dioxide particles (SiO2 particles) are preferred because they can provide a hardened product with a high refractive index and high dielectric constant or high hardness.

[0184] The metal oxide particles described above are preferably surface-modified metal oxide particles, as this enhances their dispersibility in the photosensitive resin composition. Surface modification of the metal oxide particles can be achieved by known methods such as mixing the metal oxide particles and a surface modifier in a solvent or performing a hydrothermal reaction in the presence of water.

[0185] The surface modifiers mentioned above are not particularly limited and include known coupling agents, surfactants, carboxylic acid compounds, etc. Only one surface modifier may be used, or two or more may be used.

[0186] In particular, carboxylic acid compounds are preferred as the surface modifier in order to further improve the dispersibility of the metal oxide particles. Examples of the above carboxylic acid compounds include optionally substituted carboxylic acids and (meth)acrylic acid. Examples of the above substituents include an ester group, an ether group, an amide group, a thioester group, a thioether group, a carbonate group, a urethane group, and a urea group. Also, examples of the above carboxylic acid compounds include aliphatic carboxylic acids such as acetic acid, butyric acid, valeric acid, hexanoic acid, heptanoic acid, 2-ethylhexanoic acid, 2-methylheptanoic acid, 4-methyloctanoic acid, salicylic acid, naphthenic acid, decanoic acid, and lauric acid, and cyclic carboxylic acids.

[0187] As the above metal oxide particles, the metal oxide particles described in Japanese Unexamined Patent Publication No. 2013-216858 are preferable.

[0188] The crystallite diameter of the above metal oxide particles is preferably 1 to 20 nm, more preferably 1 to 15 nm, and still more preferably 1 to 10 nm. The above crystallite diameter can be determined by X-ray diffraction analysis.

[0189] The number-average primary particle diameter of the above metal oxide particles is preferably less than 30 nm, more preferably 1 to 25 nm, still more preferably 3 to 20 nm, even more preferably 5 to 20 nm, and particularly preferably 5 to 15 nm. The above number-average primary particle diameter can be determined by magnifying and observing the metal oxide particles with a transmission electron microscope (TEM), a field emission transmission electron microscope (FE-TEM), a field emission scanning electron microscope (FE-SEM), or the like, randomly selecting 100 particles, measuring the length in the major axis direction thereof, and calculating the arithmetic average thereof.

[0190] The refractive index of the above metal oxide particles is preferably 1.70 to 2.70, more preferably 1.90 to 2.70.

[0191] The specific surface area of the above metal oxide particles is preferably 10 to 400 m 2 / g, more preferably 20 to 200 m 2 / g, and still more preferably 30 to 150 m 2 / g.

[0192] The content of the above metal oxide particles is preferably 5 to 95% by mass, more preferably 10 to 90% by mass, and even more preferably 20 to 80% by mass, based on 100% by mass of the total solid content of the alkali-soluble resin composition.

[0193] The above photosensitive resin composition may also contain other components besides those described above, as needed. Examples of these other components include solvents; colorants (pigments, dyes); dispersants; heat resistance improvers; leveling agents; developing aids; coupling agents such as silanes, aluminum, and titanium; fillers; thermosetting resins such as phenolic resins, polyvinylphenols, epoxy compounds, and epoxy resins; plasticizers; polymerization inhibitors; ultraviolet absorbers; antioxidants; matting agents; defoamers; antistatic agents; slip agents; surface modifiers; thixotropes; thixotrope aids; quinone diazide compounds; polyvalent phenolic compounds; cationic polymerizable compounds; and thermoacid generators. These may be used individually or in combination of two or more. These other components can be appropriately selected from known components, and their amounts can also be appropriately set.

[0194] Furthermore, a photosensitive resin composition (also referred to as photosensitive resin composition (x)) containing the resin, alkali-soluble resin, polymerizable compound, and photopolymerization initiator of the reaction product (intermediate) of the first step described above is also one of the present inventions.

[0195] The alkali-soluble resin contained in the above photosensitive resin composition (x) is not particularly limited, and any known alkali-soluble resin may be used, or the alkali-soluble resin of the present invention described above may be used.

[0196] The polymerizable compound and photopolymerization initiator contained in the above-mentioned photosensitive resin composition (x) are the same as those described above. The content of each of these components may be the same as described above.

[0197] The above-mentioned photosensitive resin composition (x) may also contain other components, such as those similar to those in the above-mentioned photosensitive resin composition. The content of each of these components can be set as appropriate.

[0198] 4. Method for producing a photosensitive resin composition The method for producing the photosensitive resin composition of the present invention is not particularly limited and any known method may be used. For example, one method may be to mix and disperse each of the above-mentioned components using various mixers and dispersers. The mixing and dispersion steps are not particularly limited and may be carried out by known methods. In addition, other commonly performed steps may be included.

[0199] In particular, as a method for producing a photosensitive resin composition, the above-mentioned method for producing alkali-soluble resins yields a polymerizable unsaturated bond equivalent of 700-8000 g / equivalent, or R 1 When the atom is a sulfur atom, a preferred method includes the steps of producing an alkali-soluble resin with a polymerizable unsaturated bond equivalent of 300 to 8000 g / equivalent, and mixing the obtained alkali-soluble resin, a polymerizable compound, and a photopolymerization initiator. Such a method for producing a photosensitive resin composition is also part of the present invention.

[0200] Using the alkali-soluble resin or photosensitive resin composition of the present invention, it is possible to obtain a cured product with a high refractive index and excellent curability. A cured product obtained by curing such an alkali-soluble resin or photosensitive resin composition of the present invention is also one of the present inventions. Furthermore, the photosensitive resin composition (x) described above also has a high refractive index and can yield a cured product with excellent curability. A cured product of such a photosensitive resin composition (x) is also one of the present inventions.

[0201] When the above cured product is a cured film, its film thickness is preferably 0.1 to 50 μm, more preferably 0.5 to 40 μm, and even more preferably 1 to 30 μm.

[0202] The method for obtaining the above-mentioned cured product is not particularly limited, and any known method may be used. For example, a method may be used in which the alkali-soluble resin or photosensitive resin composition described above is applied to or molded onto a substrate, and then cured by heating, irradiation with active energy rays such as ultraviolet light, or a combination thereof. In particular, a method for producing the cured product is preferred that includes the steps of applying the above-mentioned photosensitive resin composition onto a substrate to form a coating film, irradiating the formed coating film with light, and heating the light-irradiated coating film.

[0203] The above-mentioned substrate is not particularly limited and can be appropriately selected according to the purpose and application. Examples include substrates made of various materials such as glass plates and plastic plates.

[0204] The method for applying the above-mentioned photosensitive resin composition onto a substrate to form a coating film is not particularly limited and can be carried out by known methods such as spin coating, slit coating, roll coating, and casting.

[0205] It is preferable to apply the above photosensitive resin composition onto a substrate and then dry the coated material to form a coating film. The drying can be carried out by known methods, such as using a hot plate, IR oven, or convection oven. The drying conditions are appropriately selected according to the boiling point of the solvent components, the type of curing component, the film thickness, the performance of the dryer, etc., but it is generally preferable to dry at a temperature of 50 to 160°C for 10 to 300 seconds.

[0206] The method for irradiating the formed coating with light is not particularly limited and can be carried out by known methods. Examples of light sources for the active light used for light irradiation include lamp light sources such as xenon lamps, halogen lamps, tungsten lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, metal halide lamps, medium-pressure mercury lamps, low-pressure mercury lamps, carbon arcs, and fluorescent lamps, as well as laser light sources such as argon ion lasers, YAG lasers, excimer lasers, nitrogen lasers, helium-cadmium lasers, and semiconductor lasers.

[0207] When irradiating the above coating film with light, the light irradiation may be performed through a photomask. As the photomask, it is preferable to use a mask having a light-shielding portion formed according to a target pattern. After performing light irradiation through a photomask, the method may include a step of performing development treatment with a developer to remove unirradiated portions. By light irradiation, the irradiated portions are cured, and the cured product becomes insoluble or poorly soluble in the developer. On the other hand, unirradiated portions are dissolved in the developer, so they are removed by the development treatment, and a patterned cured film can be obtained. The development treatment can usually be carried out by methods such as immersion development, spray development, brush development, and ultrasonic development at a development temperature of 10 to 50° C.

[0208] The developer is not particularly limited as long as it can dissolve the photosensitive resin composition, but usually an organic solvent or an alkaline aqueous solution is used, and a mixture of these may also be used. When an alkaline aqueous solution is used as the developer, it is preferable to wash with water after development. Examples of the organic solvent and alkaline aqueous solution include those similar to those described in Japanese Unexamined Patent Publication No. 2015-157909.

[0209] After the above light irradiation, it is preferable to heat the coating film at 160° C. or lower. The heating temperature of the coating film is more preferably 150° C. or lower. The lower limit of the heating temperature is preferably 70° C. or higher, and more preferably 80° C. or higher, from the viewpoint that curability can be maintained. The above heating temperature is preferably 70 to 160° C., more preferably 80 to 150° C.

[0210] The heating time is not particularly limited, and for example, it is suitably 5 to 60 minutes. The heating method is also not particularly limited, and for example, the heating can be performed using a known heating device such as a hot plate, a convection oven, or a high-frequency heater.

[0211] 5. Uses The alkali-soluble resin and photosensitive resin composition of the present invention exhibit excellent curability, yielding cured products with a high refractive index. Therefore, the alkali-soluble resin and photosensitive resin composition can be suitably used in applications requiring high curability and a high refractive index.

[0212] The alkali-soluble resin and photosensitive resin composition of the present invention can also be suitably used in applications requiring fast development speed and developability. Therefore, it is suitably used for optical materials and particularly suitably used for resists. The photosensitive resin composition of the present invention can be suitably used for both negative and positive type photoresists.

[0213] The alkali-soluble resin and photosensitive resin composition of the present invention, which have a high refractive index, can be used, for example, in magnetic recording materials, catalyst materials, ultraviolet absorbing materials, dental materials, contact lenses, intraocular lenses, high refractive index lenses for eyeglasses, optical computing, optical memory media, anti-reflective coatings, conformal coatings, microlens arrays, automotive topcoats, paints, coating agents, hair cosmetics, gradient refractive index optical components and dynamic gradient refractive index components, nanoimprint materials, photocurable plastics, polymerizable compounds for hologram recording, glass surface coating materials, transparent coating materials for solar cells, plastic lenses, printing plates, and semiconductor light-emitting elements (light-emitting diodes, organic light-emitting diodes, laser diodes). The present invention can be widely applied to various applications such as optical guides (both planar and "fiber" geometric shapes), semiconductor elements, light diffusion members, prism sheets, hard coat materials, optical wiring members, diffraction gratings, sealing materials for LEDs, pressure-sensitive adhesives, glass used in sensor elements such as CCD / CMOS and display elements such as displays, protective films used on the surface of films and sheets, photocurable resins (OCR) used for bonding image display members such as liquid crystals to plastic cover panels, reflective protective films used for transparent electrodes, index matching for preventing the visibility of ITO electrodes in touch panels, antiblocking layers, anti-reflective films for displays, and interlayer insulating films for semiconductors. In particular, the alkali-soluble resin and photosensitive resin composition of the present invention are suitable as curable resins or resin compositions for forming semiconductor members or optical materials, and are especially suitable as curable resins or resin compositions for optical materials.

[0214] In the present invention, "optical material" refers to a material used as a component of devices in the optical or electrical / electronic fields. For example, it refers to a material used in color filters, light extraction layers, black matrices, photospacers, black column spacers, photoresists, overcoats, planarization layers for TFTs, insulating films for TFTs, and surface coatings for optical lenses used in liquid crystal, organic EL, quantum dot, mini / micro LED display devices, solid-state image sensors, and touch panel display devices. The alkali-soluble resin of the present invention is suitable for use in applications where photolithography is applied due to its alkali solubility, and can become a cured film with high refractive index, high hardness, and high transparency. Therefore, the photosensitive resin composition of the present invention is most preferably a curable resin composition for color filters, light extraction layers, and color conversion layers for organic EL display devices. The alkali-soluble resin of the present invention can be suitably used as a highly refractive member that is photolithographic and highly transparent.

[0215] In particular, the alkali-soluble resin and photosensitive resin composition described above are preferably for use in display devices, and a display device component and a display device containing a cured product of the photosensitive resin composition are also part of the present invention.

[0216] The above-mentioned alkali-soluble resin and photosensitive resin compositions can also be suitably used in various optical components such as inks, printed circuit boards, insulating films, films, and organic protective films, as well as components of electrical and electronic equipment. [Examples]

[0217] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0218] The various evaluation methods used in this embodiment are as follows.

[0219] <Weight average molecular weight> The weight-average molecular weight (Mw) was determined by gel permeation chromatography (GPC) using polystyrene as a standard substance. The measurement conditions were as follows: Equipment: Gel permeation chromatography apparatus HLC-8320GPC (manufactured by Tosoh Corporation) Column: TSKgel SuperHZM-M (manufactured by Tosoh Corporation) Detector: RI detector for liquid chromatogram Measurement temperature: 40℃ Solvent: THF (tetrahydrofuran) Sample concentration: 0.05g / 10cc Sample flow rate: 0.6 ml / min

[0220] <Acid value> 3 g of the resin solution was accurately weighed and dissolved in a mixed solvent of 90 g of acetone and 10 g of water. The solution was then titrated using a 0.1 N KOH aqueous solution as the titrant. The titration was performed using an automatic titrator (product name: COM-555, manufactured by Hiranuma Sangyo Co., Ltd.). The acid value per gram of solid content (mgKOH / g) was determined from the acid value of the resin solution and the solid content of the resin solution. The solid content of the resin solution was determined by the following method. Approximately 1 g of the resin solution was weighed into an aluminum cup, and approximately 3 g of acetone was added to dissolve it. The solution was then allowed to air dry at room temperature. Next, it was dried under vacuum at 140°C for 1.5 hours using a vacuum dryer (EYELA, product name: VOS-301SD), and then allowed to cool in a desiccator. The mass was then measured. The solid content (mass %) of the resin solution was calculated from the mass loss.

[0221] <Polymerizable unsaturated bond equivalent> The amount of resin solids was determined by dividing the mass (g) of the resin's polymerizable unsaturated bonds (mol).

[0222] <Epoxy equivalent> The solid content equivalent value was determined using a method compliant with JIS K7236:2001.

[0223] <Refractive index (resin)> The resin solution shown in Table 1 was uniformly applied onto a 5 cm square glass substrate (soda-lime glass AS-2K, manufactured by Toshin Riko Co., Ltd.) using a spin coater (Mikasa Corporation, 1H-D7). The coated plate was dried at 90°C for 3 minutes to obtain a laminate. After removing the resin composition adhering to the edges of the glass substrate, the obtained laminate was heat-treated at 95°C for 60 minutes using a Perfect Oven constant temperature chamber (ESPEC Corporation), cooled to room temperature, and a laminate with a coating film thickness of 0.5 μm was obtained. The obtained laminate was used as a measurement sample, and the reflectivity of the coating film at a wavelength of 589 nm was calculated by performing a reflectivity simulation of the coating film based on Fresnel's equation from the reflectivity due to coating film interference measured using the apparatus described below. Equipment: Film thickness measurement system F-20 manufactured by Filmetrics. Standard fiber stage SS-1 (spot diameter 1.5mm).

[0224] <Refractive index (photosensitive resin composition)> Photosensitive resin compositions according to the formulations in Tables 2 and 4 were uniformly coated onto a 5 cm square glass substrate (soda-lime glass AS-2K, manufactured by Toshin Riko Co., Ltd.) using a spin coater (Mikasa Corporation, 1H-D7). After drying the coated plate at 90°C for 3 minutes, exposure was performed using a high-pressure mercury lamp at 100 mJ to obtain a laminate with a coating film formed on the glass substrate. After removing the resin composition adhering to the edges of the glass substrate, the obtained laminate was heat-treated using a Perfect Oven constant temperature chamber (ESPEC Corporation) at 95°C for 60 minutes, cooled to room temperature, and a laminate with a coating film thickness of 0.5 μm was obtained. The obtained laminate was used as a measurement sample, and the refractive index value was determined using the same method as for the refractive index of the resin described above.

[0225] <Solvent resistance> The photosensitive resin compositions according to the formulations in Table 3 were spin-coated onto a 5 cm square glass substrate, dried at 100°C for 3 minutes, exposed to 200 mJ using a high-pressure mercury lamp, and then heat-treated (post-cured) at 150°C for 40 minutes each to obtain a cured film with a thickness of 2 μm. The cured film was then immersed in 20 g of propylene glycol monomethyl ether (PGME) at 40°C for 10 minutes and then removed. The absorbance of the immersion solution (PGME) after removal of the cured film was measured using a UV3100 spectrophotometer (Shimadzu Corporation). A higher absorbance value indicated that more colorant had leached into the immersion solution, and the solvent resistance of the photosensitive resin composition was evaluated as low.

[0226] <Development speed> A photosensitive resin composition was applied to a 10 cm square glass substrate by spin coating, and after heat treatment (90°C for 3 minutes), the coated film was exposed to light at an exposure dose of 60 mJ / cm2 (equivalent to 365 nm illuminance) using a UV aligner (manufactured by Dainippon Kaken Co., Ltd., product name "MA-1100") equipped with a 2.0 kW ultra-high pressure mercury lamp through a photomask with a 30 μm line-and-space opening 50 μm away from the coated film. The unexposed areas were dissolved and removed by spraying a 0.05% potassium hydroxide aqueous solution using a spin developer, and the remaining exposed areas were developed by washing with pure water for 10 seconds to evaluate the developability. Specifically, the coated film developed via a photomask as described above was observed using a surface roughness meter (Ryoka Systems Co., Ltd., product name "VertScan2.0"), and the development time was defined as the spraying time of the 0.05% potassium hydroxide aqueous solution required for the unexposed areas to run off. ◎: Development time less than 20 seconds ○: Development time 20 seconds or more but less than 30 seconds △: Development time 30 seconds or more but less than 40 seconds ×: Development time 40 seconds or more

[0227] <Weather resistance> The photosensitive resin composition solutions shown in Table 4 were uniformly applied onto a 5 cm square glass substrate (soda-lime glass AS-2K, manufactured by Toshin Riko Co., Ltd.) using a spin coater (Mikasa Corporation, 1H-D7). The coated substrate was dried at 100°C for 3 minutes to obtain a laminate. After removing the resin composition adhering to the edges of the glass substrate, the obtained laminate was exposed to 100 mJ using a high-pressure mercury lamp. The laminate was then heated at 230°C for 30 minutes using a Perfect Oven constant temperature chamber (ESPEC Corporation), cooled to room temperature, and a laminate with a coating film thickness of 2 μm was obtained. The obtained laminate was used as a measurement sample, and a weather resistance test was performed using the following apparatus, conditions, and evaluation method. Equipment: Xenon weather meter X25 (manufactured by Suga Test Instruments Co., Ltd.) Conditions: Tank temperature 50℃, tank humidity 17%, irradiance 0.45kW / m 2 , 200 hours Evaluation Method: The percentage reduction in film thickness before and after testing was measured using the Filmetrics F-20 film thickness measurement system. A smaller value indicated better weather resistance.

[0228] <Measurement of Mass Loss Rate> Using a TG-DTA (thermogravimetric-differential thermal analysis) apparatus, zirconia particles were heated from room temperature to 800°C at a rate of 10°C / min under an air atmosphere, and the mass loss rate of the particles was measured. Based on this mass loss rate, the proportion of the compound surface-modifying the zirconia particles and the proportion of zirconia particles were determined.

[0229] (Example of synthesis 1) Production of alkali-soluble resin (A-1) In a reaction vessel equipped with a thermometer, stirrer, gas inlet, condenser, and dropper inlet, 132.1 g of propylene glycol monomethyl ether acetate and 206 g of cresol novolac type epoxy resin (product name "YDCN-704A", manufactured by Nippon Steel Chemical & Material Co., Ltd., epoxy equivalent 206 g / equivalent) (1 mole of epoxy group) were charged, and the mixture was heated to 120°C. After the reaction vessel reached 120°C, the system was purged with nitrogen gas bubbling while maintaining the same temperature until the oxygen concentration was 0.5 volume% or less. Then, 102.1 g (0.6 moles) of o-phenylphenol and 1 g of triphenylphosphine were added to carry out the addition reaction, which was allowed to proceed for 8 hours to complete the reaction. Subsequently, while blowing in a nitrogen-air mixture gas adjusted to an oxygen concentration of 7%, 28.8 g (0.4 mol) of acrylic acid, 0.7 g of triphenylphosphine, 0.3 g of Antige W-400 (manufactured by Kawaguchi Chemical Industry Co., Ltd.) as a polymerization inhibitor, and 12.4 g of propylene glycol monomethyl ether acetate were added to carry out an addition reaction, which was allowed to proceed for 16 hours to complete the reaction. After cooling to room temperature, 41.9 g (0.42 mol) of succinic anhydride and 108.2 g of propylene glycol monomethyl ether acetate were added, and the reaction was allowed to proceed at 100°C for 7 hours to complete the reaction. Finally, 771.7 g of propylene glycol monomethyl ether was added to obtain an alkali-soluble resin solution (A-1). The various physical properties of the obtained alkali-soluble resin (A-1) are shown in Table 1.

[0230] (Example of synthesis 2) Production of alkali-soluble resin (A-2) In a reaction vessel equipped with a thermometer, stirrer, gas inlet, condenser, and dropper inlet, 138.7 g of propylene glycol monomethyl ether acetate and 206 g of the same cresol novolac type epoxy resin "YDCN-704A" used in Example 1 (1 mole of epoxy groups) were charged, and the mixture was heated to 120°C. After the reaction vessel reached 120°C, the system was purged with nitrogen gas bubbling while maintaining the temperature until the oxygen concentration was 0.5% by volume or less. Then, 110.6 g (0.65 moles) of o-phenylphenol, 6.9 g (0.05 moles) of p-hydroxyphenyl-2-ethanol, and 1 g of triphenylphosphine were added to carry out the addition reaction, which was allowed to proceed for 8 hours to complete the reaction. Subsequently, while blowing in a nitrogen-air mixture gas adjusted to an oxygen concentration of 7%, 21.6 g (0.3 mol) of acrylic acid, 0.7 g of triphenylphosphine, 0.3 g of Antige W-400, and 9.3 g of propylene glycol monomethyl ether acetate were added to carry out an addition reaction, which was allowed to proceed for 16 hours to complete the reaction. After cooling to room temperature, 42.9 g (0.43 mol) of succinic anhydride and 110.8 g of propylene glycol monomethyl ether acetate were added, and the reaction was allowed to proceed at 100°C for 7 hours to complete the reaction. Finally, 790.5 g of propylene glycol monomethyl ether was added to obtain an alkali-soluble resin solution (A-2). The various physical properties of the obtained alkali-soluble resin (A-2) are shown in Table 1.

[0231] (Example of synthesis 3) Production of alkali-soluble resin (A-3) In a reaction vessel equipped with a thermometer, stirrer, gas inlet, condenser, and dropper inlet, 142.9 g of propylene glycol monomethyl ether acetate and 206 g of the same cresol novolac type epoxy resin "YDCN-704A" used in Example 1 (1 mole of epoxy group) were charged, and the mixture was heated to 120°C. After the reaction vessel reached 120°C, the system was purged with nitrogen gas bubbling while maintaining the temperature until the oxygen concentration was 0.5% by volume or less. Then, 126.0 g (0.74 moles) of o-phenylphenol, 1.4 g (0.01 mole) of p-hydroxyphenyl-2-ethanol, and 1.1 g of triphenylphosphine were added to carry out the addition reaction, which was allowed to proceed for 8 hours to complete the reaction. Subsequently, while blowing in a nitrogen-air mixture gas adjusted to an oxygen concentration of 7%, 18.0 g (0.25 mol) of acrylic acid, 0.7 g of triphenylphosphine, 0.4 g of Antige W-400, and 7.7 g of propylene glycol monomethyl ether acetate were added to carry out an addition reaction, which was allowed to proceed for 16 hours to complete the reaction. After cooling to room temperature, 43.7 g (0.44 mol) of succinic anhydride and 112.8 g of propylene glycol monomethyl ether acetate were added, and the reaction was allowed to proceed at 100°C for 7 hours to complete the reaction. Finally, 804.7 g of propylene glycol monomethyl ether was added to obtain an alkali-soluble resin solution (A-3). The various physical properties of the obtained alkali-soluble resin (A-3) are shown in Table 1.

[0232] (Example of synthesis 4) Production of alkali-soluble resin (A-4) In a reaction vessel equipped with a thermometer, stirrer, gas inlet, condenser, and dropper inlet, 134.3 g of propylene glycol monomethyl ether acetate and 206 g of the same cresol novolac type epoxy resin "YDCN-704A" used in Example 1 (1 mole of epoxy groups) were charged, and the mixture was heated to 120°C. After the reaction vessel reached 120°C, the system was purged with nitrogen gas bubbling while maintaining the temperature until the oxygen concentration was 0.5% by volume or less. Then, 93.6 g (0.55 moles) of o-phenylphenol, 13.8 g (0.1 mole) of p-hydroxyphenyl-2-ethanol, and 1 g of triphenylphosphine were added to carry out the addition reaction, which was allowed to proceed for 8 hours to complete the reaction. Subsequently, while blowing in a nitrogen-air mixture gas adjusted to an oxygen concentration of 7%, 25.2 g (0.35 mol) of acrylic acid, 0.7 g of triphenylphosphine, 0.3 g of Antige W-400, and 10.8 g of propylene glycol monomethyl ether acetate were added to carry out an addition reaction, which was allowed to proceed for 16 hours to complete the reaction. After cooling to room temperature, 29.6 g (0.3 mol) of succinic anhydride and 100.3 g of propylene glycol monomethyl ether acetate were added, and the reaction was allowed to proceed at 100°C for 7 hours to complete the reaction. Finally, 750.1 g of propylene glycol monomethyl ether was added to obtain an alkali-soluble resin solution (A-4). The various physical properties of the obtained alkali-soluble resin (A-4) are shown in Table 1.

[0233] (Example of synthesis 5) Production of alkali-soluble resin (A-5) In a reaction vessel equipped with a thermometer, stirrer, gas inlet, condenser, and dropper inlet, 116.6 g of propylene glycol monomethyl ether acetate and 206 g of the same cresol novolac type epoxy resin "YDCN-704A" used in Example 1 (1 mole of epoxy groups) were charged, and the mixture was heated to 120°C. After the reaction vessel reached 120°C, the system was purged with nitrogen gas bubbling while maintaining the temperature until the oxygen concentration was 0.5% by volume or less. Then, 66.1 g (0.6 moles) of thiophenol and 0.9 g of triphenylphosphine were added to carry out the addition reaction, which was allowed to proceed for 8 hours to complete the reaction. Subsequently, while blowing in a nitrogen-air mixture gas adjusted to an oxygen concentration of 7%, 28.8 g (0.4 mol) of acrylic acid, 0.6 g of triphenylphosphine, 0.3 g of Antige W-400, and 12.4 g of propylene glycol monomethyl ether acetate were added to carry out an addition reaction, which was allowed to proceed for 16 hours to complete the reaction. After cooling to room temperature, 37.4 g (0.37 mol) of succinic anhydride and 96.6 g of propylene glycol monomethyl ether acetate were added, and the reaction was allowed to proceed at 100°C for 7 hours to complete the reaction. Finally, 689.2 g of propylene glycol monomethyl ether was added to obtain an alkali-soluble resin solution (A-5). The various physical properties of the obtained alkali-soluble resin (A-5) are shown in Table 1.

[0234] (Example of synthesis 6) Production of alkali-soluble resin (A-6) In a reaction vessel equipped with a thermometer, stirrer, gas inlet, condenser, and dropper inlet, 203.6 g of propylene glycol monomethyl ether acetate and 206 g of the same cresol novolac type epoxy resin "YDCN-704A" used in Example 1 (1 mole of epoxy groups) were charged and heated to 100°C. After the temperature of the reaction vessel reached 100°C, it was maintained for 30 minutes to dissolve the resin. The system was purged with nitrogen while the temperature was cooled to 70°C. 99.2 g (0.9 moles) of thiophenol and 0.2 g of triphenylphosphine were added to carry out the addition reaction, and the reaction was allowed to complete for 5 hours. Subsequently, while blowing in a nitrogen-air mixture gas adjusted to an oxygen concentration of 7%, 7.2 g (0.1 mol) of acrylic acid, 1.3 g of triphenylphosphine, and 0.3 g of Antige W-400 were added to carry out an addition reaction, and the reaction was carried out at 120°C for 16 hours to complete the reaction. After cooling to room temperature, 27.5 g (0.275 mol) of succinic anhydride and 23.5 g of propylene glycol monomethyl ether acetate were added, and the reaction was carried out at 110°C for 7 hours to complete the reaction. A further 284.9 g of propylene glycol monomethyl ether acetate was added to obtain an alkali-soluble resin solution (A-6). The various physical properties of the obtained alkali-soluble resin (A-6) are shown in Table 1.

[0235] (Example of synthesis 7) Production of alkali-soluble resin (A-7) In a reaction vessel equipped with a thermometer, stirrer, gas inlet, condenser, and dropper inlet, 215.9 g of propylene glycol monomethyl ether acetate and 231 g of NC-7000-L (naphthalene-containing novolac-type epoxy resin, manufactured by Nippon Kayaku, epoxy equivalent 231.0 g / equivalent) (1 mole of epoxy group) were charged and heated to 100°C. After the temperature of the reaction vessel reached 100°C, it was maintained for 30 minutes to dissolve the resin. The system was purged with nitrogen while the temperature was cooled to 70°C. 92.5 g (0.84 moles) of thiophenol and 0.2 g of triphenylphosphine were added to carry out the addition reaction, and the reaction was carried out for 5 hours to complete the reaction. Subsequently, while blowing in a nitrogen-air mixture gas adjusted to an oxygen concentration of 7%, 11.5 g (0.16 mol) of acrylic acid, 1.3 g of triphenylphosphine, and 0.3 g of Antige W-400 were added to carry out an addition reaction, and the reaction was carried out at 120°C for 16 hours to complete the reaction. After cooling to room temperature, 27.5 g (0.275 mol) of succinic anhydride and 27.2 g of propylene glycol monomethyl ether acetate were added, and the reaction was carried out at 110°C for 7 hours to complete the reaction. A further 303.9 g of propylene glycol monomethyl ether acetate was added to obtain an alkali-soluble resin solution (A-7). The various physical properties of the obtained alkali-soluble resin (A-7) are shown in Table 1.

[0236] (Example of synthesis 8) Production of alkali-soluble resin (A-8) In a reaction vessel equipped with a thermometer, stirrer, gas inlet, condenser, and dropper inlet, 135.6 g of propylene glycol monomethyl ether acetate and 206 g of the same cresol novolac type epoxy resin "YDCN-704A" used in Example 1 (1 mole of epoxy group) were charged, and the mixture was heated to 120°C. After the reaction vessel reached 120°C, the system was purged with nitrogen while maintaining the temperature, and 108.9 g (0.64 moles) of p-phenylphenol, 1.4 g (0.01 mole) of p-hydroxyphenyl-2-ethanol, and 1 g of triphenylphosphine were added to carry out the addition reaction, which was allowed to proceed for 8 hours to complete the reaction. Subsequently, while blowing in a nitrogen-air mixture gas adjusted to an oxygen concentration of 7%, 25.2 g (0.35 mol) of acrylic acid, 0.7 g of triphenylphosphine, 0.3 g of Antige W-400, and 10.8 g of propylene glycol monomethyl ether acetate were added to carry out an addition reaction, which was allowed to proceed for 16 hours to complete the reaction. After cooling to room temperature, 102.3 g (0.67 mol) of tetrahydrophthalic anhydride and 149.5 g of propylene glycol monomethyl ether acetate were added, and the reaction was allowed to proceed at 100°C for 10 hours to complete the reaction. Finally, 904.1 g of propylene glycol monomethyl ether was added to obtain an alkali-soluble resin solution (A-8). The various physical properties of the obtained alkali-soluble resin (A-8) are shown in Table 1.

[0237] (Example of synthesis 9) Production of alkali-soluble resin (A-9) In a reaction vessel equipped with a thermometer, stirrer, gas inlet, condenser, and dropper inlet, 135 g of propylene glycol monomethyl ether acetate and 206 g of the same cresol novolac type epoxy resin "YDCN-704A" used in Example 1 (1 mole of epoxy group) were charged, and the mixture was heated to 120°C. After the reaction vessel reached 120°C, the system was purged with nitrogen while maintaining the temperature, and 102.1 g (0.6 moles) of o-phenylphenol, 6.9 g (0.05 moles) of p-hydroxyphenyl-2-ethanol, and 1 g of triphenylphosphine were added to carry out the addition reaction, which was allowed to proceed for 8 hours to complete the reaction. Subsequently, while blowing in a nitrogen-air mixture gas adjusted to an oxygen concentration of 7%, 30.1 g (0.35 mol) of methacrylic acid, 0.7 g of triphenylphosphine, 0.3 g of Antige W-400, and 12.9 g of propylene glycol monomethyl ether acetate were added to carry out an addition reaction, which was allowed to proceed for 16 hours to complete the reaction. After cooling to room temperature, 57.5 g (0.57 mol) of succinic anhydride and 120.5 g of propylene glycol monomethyl ether acetate were added, and the reaction was allowed to proceed at 100°C for 8 hours to complete the reaction. Finally, 820.2 g of propylene glycol monomethyl ether was added to obtain an alkali-soluble resin solution (A-9). The various physical properties of the obtained alkali-soluble resin (A-9) are shown in Table 1.

[0238] (Example of synthesis 10) Production of alkali-soluble resin (A-10) 310.5 g of propylene glycol monomethyl ether acetate was charged into a reaction vessel equipped with a thermometer, stirrer, gas inlet, condenser, and dropper inlet. After purging with nitrogen, the mixture was heated to 90°C. Meanwhile, for dropper inlet (A), a beaker was prepared containing 70.0 g of methyl methacrylate (MMA), 142.2 g of glycidyl methacrylate (GMA) (1 mole of epoxy group), and 4.2 g of t-butyl peroxy-2-ethylhexanoate ("Perbutyl® O" manufactured by Nippon Oil & Fats Co., Ltd.), which was stirred and mixed. For dropper inlet (B), 2.1 g of n-dodecyl mercaptan (nDM) and 7.8 g of propylene glycol monomethyl ether acetate were stirred and mixed. After the temperature of the reaction vessel reached 90°C, polymerization was carried out by starting the dropper addition from the dropper over a period of 3 hours while maintaining the same temperature. After the dropwise addition was complete, the reaction vessel was kept at 90°C for 1 hour, then the temperature was raised to 115°C and aged for 90 minutes. After that, it was cooled to room temperature, and under nitrogen gas bubbling, 74.9 g (0.68 mol) of thiophenol and 0.9 g of triphenylphosphine were added to carry out an addition reaction, which was carried out for 8 hours to complete the reaction. Subsequently, while blowing in a nitrogen-air mixture gas adjusted to an oxygen concentration of 7%, 23.1 g (0.32 mol) of acrylic acid, 0.5 g of triphenylphosphine, and 0.5 g of Antige W-400 were added to carry out an addition reaction, which was carried out for 16 hours to complete the reaction. After cooling to room temperature, 38.7 g (0.39 mol) of succinic anhydride was added, and the reaction was carried out at 100°C for 7 hours to complete the reaction, obtaining an alkali-soluble resin solution (A-10). The various physical properties of the obtained alkali-soluble resin (A-10) are shown in Table 1.

[0239] (Example of synthesis 11) Production of resin intermediate (A-11) In a reaction vessel equipped with a thermometer, stirrer, gas inlet, condenser, and dropper inlet, 116.6 g of propylene glycol monomethyl ether acetate and 206 g of the same cresol novolac type epoxy resin "YDCN-704A" used in Example 1 (1 mole of epoxy groups) were charged, and the mixture was heated to 120°C. After the reaction vessel reached 120°C, the system was purged with nitrogen gas bubbling while maintaining the temperature until the oxygen concentration was 0.5% by volume or less. Then, 66.1 g (0.6 moles) of thiophenol and 0.9 g of triphenylphosphine were added to carry out the addition reaction, which was allowed to proceed for 8 hours to complete the reaction. Subsequently, while blowing in a nitrogen-air mixture gas adjusted to an oxygen concentration of 7%, 28.8 g (0.4 mol) of acrylic acid, 0.6 g of triphenylphosphine, 0.3 g of Antige W-400, and 12.4 g of propylene glycol monomethyl ether acetate were added to carry out an addition reaction. The reaction was allowed to proceed for 16 hours to complete, yielding resin intermediate (A-11). The various physical properties of the obtained resin intermediate (A-11) are shown in Table 1.

[0240] (Example of synthesis 12) Production of alkali-soluble resin (A-12) In a reaction vessel equipped with a thermometer, stirrer, gas inlet, condenser, and dropper inlet, 181.5 g of propylene glycol monomethyl ether acetate and 206 g of the same cresol novolac type epoxy resin "YDCN-704A" used in Example 1 (1 mole of epoxy groups) were charged, and the mixture was heated to 120°C. After the reaction vessel reached 120°C, the system was purged with nitrogen gas bubbling while maintaining the temperature until the oxygen concentration was 0.5% by volume or less. Then, 66.1 g (0.6 moles) of thiophenol and 0.9 g of triphenylphosphine were added to carry out the addition reaction, which was allowed to proceed for 8 hours to complete the reaction. Subsequently, while blowing in a nitrogen-air mixture gas adjusted to an oxygen concentration of 7%, 28.1 g (0.39 mol) of acrylic acid, 2.8 g (0.01 mol) of 3-(3,5-di-t-butyl-4-hydroxyphenyl)propionic acid, 0.6 g of triphenylphosphine, 0.3 g of Antige W-400, and 16.6 g of propylene glycol monomethyl ether acetate were added to carry out an addition reaction, which was allowed to proceed for 16 hours to complete the reaction. After cooling to room temperature, 37.4 g (0.37 mol) of succinic anhydride and 24.3 g of propylene glycol monomethyl ether acetate were added, and the reaction was allowed to proceed at 100°C for 7 hours to complete the reaction. Finally, 290.8 g of propylene glycol monomethyl ether was added to obtain an alkali-soluble resin solution (A-12). The various physical properties of the obtained alkali-soluble resin (A-12) are shown in Table 1.

[0241] (Comparative Synthesis Example 1) Production of comparative alkali-soluble resin (B-1) In a reaction vessel equipped with a thermometer, stirrer, gas inlet, condenser, and dropper inlet, 117.5 g of propylene glycol monomethyl ether acetate and 206 g of the same cresol novolac type epoxy resin "YDCN-704A" used in Example 1 (1 mole of epoxy group) were charged and heated to 120°C. After the reaction vessel reached 120°C, the system was purged with nitrogen while maintaining the temperature, and 68.1 g (0.4 moles) of o-phenylphenol and 1 g of triphenylphosphine were added to carry out an addition reaction, which was allowed to proceed for 8 hours to complete the reaction. Subsequently, while blowing in a nitrogen-air mixture gas adjusted to an oxygen concentration of 7%, 43.2 g (0.6 moles) of acrylic acid, 0.6 g of triphenylphosphine, 0.3 g of Antige W-400, and 18.5 g of propylene glycol monomethyl ether acetate were added to carry out an addition reaction, which was allowed to proceed for 16 hours to complete the reaction. After cooling to room temperature, 39.5 g (0.39 mol) of succinic anhydride and 101.9 g of propylene glycol monomethyl ether acetate were added, and the reaction was carried out at 100°C for 7 hours to complete the reaction. Then, 726.8 g of propylene glycol monomethyl ether was added to obtain comparative alkali-soluble resin solution (B-1). The various physical properties of the obtained alkali-soluble resin (B-1) are shown in Table 1.

[0242] (Comparative Synthesis Example 2) Production of comparative alkali-soluble resin (B-2) In a reaction vessel equipped with a thermometer, stirrer, gas inlet, condenser, and dropper inlet, 157.6 g of propylene glycol monomethyl ether acetate and 206 g of the same cresol novolac type epoxy resin "YDCN-704A" used in Example 1 (1 mole of epoxy groups) were charged, and the mixture was heated to 120°C. After the reaction vessel reached 120°C, the system was purged with nitrogen while maintaining the temperature, and 161.7 g (0.95 moles) of o-phenylphenol and 1.1 g of triphenylphosphine were added to carry out the addition reaction, which was allowed to proceed for 8 hours to complete the reaction. Subsequently, while blowing in a nitrogen-air mixture gas adjusted to an oxygen concentration of 7%, 3.6 g (0.05 mol) of acrylic acid, 0.7 g of triphenylphosphine, 0.4 g of Antige W-400, and 1.5 g of propylene glycol monomethyl ether acetate were added to carry out an addition reaction, which was allowed to proceed for 16 hours to complete the reaction. After cooling to room temperature, 46.2 g (0.46 mol) of succinic anhydride and 119.2 g of propylene glycol monomethyl ether acetate were added, and the reaction was allowed to proceed at 100°C for 10 hours to complete the reaction. Further, 850.4 g of propylene glycol monomethyl ether was added to obtain a comparative alkali-soluble resin solution (B-2). The various physical properties of the obtained alkali-soluble resin (B-2) are shown in Table 1.

[0243] (Examples 1-12, Comparative Examples 1-2) Using the resins from the experimental synthesis examples 1-12 and comparative synthesis examples 1-2, photosensitive resin compositions were prepared with the formulations shown in Table 2, and the refractive index of the resins was measured using the method described above. The results are shown in Table 2.

[0244] (Examples 13-39, Comparative Examples 3-6) Photosensitive resin compositions 1 to 31 were obtained by mixing the resin solutions obtained in the experimental and comparative synthesis examples with the formulations (solid content) shown in Table 3 or Table 4, dipentaerythritol hexaacrylate, a photopolymerization initiator (Irgacure® OXE-02, manufactured by BASF), pigment dispersion 1 or zirconia particle dispersion, and propylene glycol monomethyl ether acetate. Pigment dispersion 1 and zirconia particle dispersion were prepared by the following methods.

[0245] (Preparation of Pigment Dispersion 1) Pigment dispersion 1 was obtained by mixing 12.9 parts of propylene glycol monomethyl ether acetate, 0.4 parts of Disparon DA-7301 as a dispersant, 2.25 parts of CI Pigment Green 58 as a colorant, and 1.5 parts of CI Pigment Yellow 138, and dispersing the mixture in a paint shaker for 3 hours.

[0246] (Preparation of zirconia particle dispersion) Manufacturing Example 1 (Production of coated zirconium oxide nanoparticles coated with 2-ethylhexanoic acid and / or carboxylate derived from 2-ethylhexanoic acid (coated ZrO2 particles 1)) 782 g of zirconium 2-ethylhexanoate mineral spirit solution (44% by mass zirconium 2-ethylhexanoate, manufactured by Daiichi Kigenso Kagaku Kogyo Co., Ltd.) was mixed with pure water (268 g). The resulting mixture was placed in an autoclave equipped with a stirrer, and the atmosphere inside the autoclave was replaced with nitrogen gas. The mixture was then heated to 180°C and maintained at this temperature for 16 hours (autoclave pressure of 0.94 MPa) to allow the reaction to occur and produce zirconium oxide particles. Subsequently, the mixture was removed after the reaction, the precipitate accumulated at the bottom was filtered off and washed with acetone, and then dried. When the dried precipitate (100 g) was dispersed in toluene (800 mL), a cloudy solution was obtained. Next, as a purification step, the solution was filtered again using quantitative filter paper (Advantec Toyo Co., Ltd., No. 5C) to remove coarse particles from the precipitate. Furthermore, white zirconium oxide nanoparticles 1 (coated ZrO2 particles 1) were recovered by concentrating the filtrate under reduced pressure to remove toluene. When the crystal structure of the obtained coated ZrO2 particles 1 was confirmed by XRD diffraction, diffraction lines belonging to tetragonal and monoclinic phases were detected. Based on the intensity of the diffraction lines, the ratio of tetragonal to monoclinic phases was 54 / 46, and the particle size (crystallite size) was 5 nm. The average particle size (number-mean primary particle size) of coated ZrO2 particles 1, measured using an electron microscope (JEOL FE-TEM JEM-2100F TEM, magnification 600,000x), was 12 nm. Furthermore, analysis of the obtained coated ZrO2 particles 1 by infrared absorption spectroscopy revealed absorption originating from CH and absorption originating from COOH. These absorptions are thought to be due to 2-ethylhexanoic acid and / or carboxylates derived from 2-ethylhexanoic acid that coat the surface of coated ZrO2 particles 1. Furthermore, the mass loss rate of coated ZrO2 particles 1, measured according to the above <Measurement of Mass Loss Rate>, was 12% by mass. Therefore, it was found that 2-ethylhexanoic acid and / or carboxylate derived from 2-ethylhexanoic acid, which coats the surface of coated ZrO2 particles 1, account for 12% by mass of the entire coated ZrO2 particle 1.

[0247] Manufacturing Example 2 (Production of zirconium oxide nanoparticles coated with 2-ethylhexanoic acid and / or carboxylate derived from 2-ethylhexanoic acid and 2-acryloyloxyethyl succinate (coated ZrO2 particles 2)) The coated ZrO2 particles 1 (10 g) obtained in the above Production Example 1 and 2-acryloyloxyethyl succinate (1.5 g) were stirred and mixed in propylene glycol monomethyl ether acetate (12 g, hereinafter referred to as "PGMEA") until uniformly dispersed. Next, n-hexane (36 g) was added to agglomerate the dispersed particles and make the solution cloudy, and the agglomerated particles were separated from the cloudy liquid using filter paper. Subsequently, the separated agglomerated particles were added to n-hexane (36 g), stirred for 10 minutes, and the agglomerated particles were separated using filter paper. The resulting particles were vacuum-dried at room temperature to prepare zirconium oxide nanoparticles (coated ZrO2 particles 2) surface-treated with 2-ethylhexanoic acid and / or carboxylate derived from 2-ethylhexanoic acid and 2-acryloyloxyethyl succinate. The obtained coated ZrO2 particles 2 were dispersed in deuterated chloroform to prepare the measurement sample. 1Analysis was performed using 1H-NMR. The results showed that the molar ratio of carboxylate derived from 2-ethylhexanoic acid and / or 2-ethylhexanoic acid to 2-acryloyloxyethyl succinate was 24:76. The mass loss rate of coated ZrO2 particles 2, measured according to the above <Measurement of Mass Loss Rate>, was 18% by mass. Therefore, it was found that 2-ethylhexanoic acid and / or carboxylate derived from 2-ethylhexanoic acid, and 2-acryloyloxyethyl succinate, which coat the coated zirconium oxide particles, account for 18% by mass of the total coated zirconium oxide particles. A zirconia particle dispersion was obtained by mixing the coated ZrO2 particles 2 (7g) obtained above, methyl ethyl ketone (3g), and DISPER BYK-111 (manufactured by Big Chemie Japan, 0.14g) and uniformly stirring the mixture. The number-average primary particle diameter of the coated ZrO2 particles 2, as measured by electron microscopy, was 12 nm.

[0248] The development speed and solvent resistance of the obtained photosensitive resin compositions 1 to 15 were evaluated using the method described above. The results are shown in Table 3. The development speed, refractive index, and weather resistance of the obtained photosensitive resin compositions 16-31 were evaluated using the method described above. The results are shown in Table 4.

[0249] [Table 1]

[0250] The entries in Table 1 represent the following: YDCN-704A: Cresol novolac type epoxy resin (epoxy equivalent 206g / equivalent) NC-7000-L: Naphthalene-containing novolac-type epoxy resin, epoxy equivalent weight 231.0 / equivalent)

[0251] [Table 2]

[0252] [Table 3]

[0253] [Table 4]

[0254] Tables 1-4 show that the cured products of the alkali-soluble resins and photosensitive resin compositions containing them, which have a predetermined aromatic ring-containing structure and a polymerizable unsaturated bond-containing structure, and have a polymerizable unsaturated bond equivalent of 700-8000 g / equivalent, all had a high refractive index of approximately 1.6. In particular, resins with a structure containing a sulfur atom and a benzene ring showed a high refractive index. Although the development speed was slightly worsened by the inclusion of metal oxide particles, the refractive index was further improved. Furthermore, the alkali-soluble resins of the examples also had good solvent resistance and developability. Photosensitive resin compositions using resins with a structure containing a sulfur atom and a benzene ring showed good weather resistance, and the results were even better when resins with functional groups having radical scavenging ability were used. Furthermore, the resin intermediate (A-11) in Synthesis Example 11 is a synthesis intermediate of the resin (A-5) in Synthesis Example 5, and since it does not have alkali solubility, when used alone, this resin does not have developability when used to prepare a photosensitive resin composition. However, it can impart high refractive index and high solvent resistance to the photosensitive resin composition. When used in combination with other alkali-soluble resins, it is possible to prepare a photosensitive resin composition with excellent developability.

Claims

1. An alkali-soluble resin having an aromatic ring-containing structure represented by the following formula (4) and a polymerizable unsaturated bond-containing structure represented by the following formula (2), characterized in that the polymerizable unsaturated bond equivalent is 700 to 8000 g / equivalent. 【Chemistry 1】 In formula (4), R ２３ represents an aromatic group which may have a substituent. R ２４ is a hydrogen atom or a group represented by formula (3). In formula (2), R ４ , R ５ and R ６ are the same or different and each represents a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms. R ７ and R ８ are the same or different and each represents a direct bond or a divalent organic group. R ９ is a hydrogen atom or a group represented by formula (3). At least one of R ２４ and R ９ is a group represented by formula (3). In formula (3), R １０ represents a divalent hydrocarbon group which may have a substituent.)

2. The alkali-soluble resin according to claim 1, characterized in that the acid value is 30 to 150 mg KOH / g.

3. The alkali-soluble resin according to claim 1, characterized in that the epoxy equivalent is greater than 10,000 g / equivalent.

4. The alkali-soluble resin according to claim 1, characterized in that the main chain structure has a novolac structure.

5. A photosensitive resin composition characterized by comprising the alkali-soluble resin, polymerizable compound, and photopolymerization initiator described in claim 1.

6. A cured product characterized by being obtained by curing the alkali-soluble resin described in claim 1, or the photosensitive resin composition described in claim 5.

7. A component for a display device, characterized by including the cured product described in claim 6.

8. A display device characterized by including the display device component described in claim 7.

9. A method for producing alkali-soluble resins, The manufacturing method comprises a first step of reacting an epoxy resin (a) having two or more epoxy groups in one molecule with an aromatic group-containing compound (b') and an unsaturated monocarboxylic acid (c), The process includes a second step of reacting the reaction product obtained in the first step with a polybasic acid anhydride (d), The aromatic group-containing compound (b') is a compound containing an aromatic group and a mercapto group, The polymerizable unsaturated bond equivalent of the alkali-soluble resin is 700 to 8000 g / equivalent. A method for producing an alkali-soluble resin, characterized by the above.

10. A method for producing a photosensitive resin composition, The manufacturing method comprises the steps of manufacturing an alkali-soluble resin by the method for manufacturing an alkali-soluble resin described in claim 9, A method for producing a photosensitive resin composition, characterized by comprising the step of mixing the obtained alkali-soluble resin, polymerizable compound, and photopolymerization initiator.

11. It has an aromatic ring-containing structure represented by the following formula (1') and a polymerizable unsaturated bond-containing structure represented by the following formula (2'), The polymerizable unsaturated double bond equivalent is 600 to 7000 g / equivalent. A resin characterized by the following features. 【Chemistry 2】 (In formula (1'), R １ R represents a sulfur atom. ２ R represents an aromatic group which may have substituents. In formula (2'), R ４ , R ５ and R ６ R represents a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms, either identical or different. ７ and R ８ (These represent identical or different directly bonded or divalent organic groups.)

12. A photosensitive resin composition characterized by comprising the resin described in claim 11, an alkali-soluble resin, a polymerizable compound, and a photopolymerization initiator.

13. A cured product characterized by being obtained by curing the photosensitive resin composition described in claim 12.

Images