Radical polymerizable polymer and photosensitive composition thereof

Abstract

To provide a radical-polymerizable polymer from which a cured product having good handleability and excellent coating workability, and excellent transparency and adhesion can be imparted, and a photosensitive resin composition containing the radical-polymerizable polymer.SOLUTION: A radical-polymerizable polymer has an acid group and an ethylenically unsaturated double bond in a side chain, wherein the radical-polymerizable polymer has a structural unit having a ring structure in a main chain and a structural unit represented by general formula (1), has a double bond equivalent of 330-1,600 (g / eq.) and a weight average molecular weight of 14,000 or less, a content ratio of the structural unit represented by general formula (2) is 5 mass% or less with respect to 100 mass% of the total structural units of the radical-polymerizable polymer, and the acid group has an interval between the main chain and the acid group of 6 or less atoms. A photosensitive resin composition contains the radical-polymerizable polymer, a polyfunctional monomer, a polymerization initiator, inorganic fine particles, and a solvent.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a radical polymerizable polymer and a photosensitive composition thereof. More specifically, the present invention relates to a radical polymerizable polymer and a photosensitive resin composition containing the radical polymerizable polymer, a polyfunctional monomer, a photopolymerization initiator, inorganic fine particles, and a solvent. [Background technology]

[0002] Curable resin compositions that can be cured by heat or active energy rays have been studied for various applications, such as color filters used in liquid crystal displays and solid-state imaging devices, inks, printing plates, printed wiring boards, semiconductor elements, photoresists, and other optical components and electrical and electronic devices, and curable resin compositions with excellent properties required for each application have been developed. Patent Document 1, for example, describes a photosensitive resin composition for color filters that has excellent heat resistance and adhesion, and the copolymer contains a carboxyl group-containing radically polymerizable copolymer. The copolymer contains monomer units derived from an N-substituted maleimide compound, has a carboxyl group, and an ethylenically unsaturated double bond, and has a Tg (glass transition temperature) of 20°C or lower. Furthermore, as a polymer capable of giving a cured product with excellent solvent resistance, for example, Patent Document 2 describes a radically polymerizable copolymer having a structural unit derived from an N-substituted maleimide compound and a structural unit having a hydrocarbon group with a carbon number within a specific range, a double bond equivalent of 330 to 2000 g / equivalent, a glass transition temperature of less than 50°C, a content of structural units having an aromatic group of 5 mass% or less relative to 100 mass% of all structural units, and an acid group in a side chain spaced from the main chain by 6 atoms or less.

[0003] As described above, the level of various required properties for optical materials is increasing, and there is a demand for polymers and photosensitive resin compositions thereof that are excellent in transparency and ease of handling. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-32772 [Patent Document 2] Japanese Patent Application Publication No. 2019-163359 Summary of the Invention [Problem to be solved by the invention]

[0005] In view of the above-mentioned current situation, an object of the present invention is to provide a radical polymerizable polymer that has good handleability and excellent coating workability and can give a cured product that is excellent in transparency and adhesion, and a photosensitive resin composition containing the radical polymer. [Means for solving the problem]

[0006] In order to solve the above problems, the present inventors have conducted extensive research into polymers that can be used in optical components and electrical and electronic equipment applications, and have found that by using a copolymer containing a radically polymerizable polymer having an acid group and an ethylenically unsaturated double bond (carbon-carbon double bond) in its side chain, the radically polymerizable polymer having a structural unit having a ring structure in its main chain and a specific structural unit, and having a double bond equivalent and weight-average molecular weight within a specific range, a content of other specific structural units within a specific range, and the position of the acid group within a specific range, it is possible to obtain a cured product that is excellent in coatability, transparency, and adhesion.The present inventors have also found that a photosensitive resin composition containing such a radically polymerizable polymer is particularly suitable as a resin composition for forming optical components such as color filters, and have completed the present invention. That is, the present invention relates to a radical polymerizable polymer having an acid group and an ethylenically unsaturated double bond in a side chain, the radical polymerizable polymer having a structural unit having a ring structure in the main chain and a structural unit represented by the following general formula (1), the double bond equivalent being 330 to 1600 (g / equivalent), the weight average molecular weight being 14000 or less, the content of the structural unit represented by the following general formula (2) being 5 mass% or less relative to 100 mass% of all structural units of the radical polymerizable polymer, and the distance between the acid group and the main chain being 6 atoms or less.

[0007] [ka] (In the formula, R 1 represents a hydrogen atom or a methyl group. 2 represents a linear or branched hydrocarbon group having 6 to 20 carbon atoms.

[0008] [ka] (In the formula, R 3 represents a hydrogen atom or a methyl group. The radically polymerizable polymer preferably has an acid value of 50 to 150 (mgKOH / g). The radical polymerizable polymer preferably contains the structural unit represented by the general formula (1) in an amount of 10% by mass or more relative to 100% by mass of all structural units in the radical polymerizable polymer. The acid group is preferably a carboxyl group derived from (meth)acrylic acid. The radically polymerizable polymer preferably has a glass transition temperature of 50° C. or lower. The present invention also provides a photosensitive resin composition comprising the above-mentioned radical polymerizable polymer and a polyfunctional monomer. The photosensitive resin composition preferably further contains a photopolymerization initiator, inorganic fine particles, and a solvent. [Effects of the Invention]

[0009] The radical polymerizable polymer and photosensitive resin composition of the present invention have good handleability and excellent coating workability, and can give cured products with excellent transparency and adhesion. Such radical polymerizable polymer and photosensitive resin composition of the present invention can be suitably used in various applications such as optical components such as color filters, inks, printing plates, printed wiring boards, semiconductor elements, and photoresists used in liquid crystal displays and solid-state imaging devices, as well as electric and electronic devices. DETAILED DESCRIPTION OF THE INVENTION

[0010] The present invention will be described in detail below. In addition, a combination of two or more of the individual preferred embodiments of the present invention described below is also a preferred embodiment of the present invention. In addition, in this specification, "(meth)acrylic acid" means "acrylic acid and / or methacrylic acid", and "(meth)acrylate" means "acrylate and / or methacrylate". In this specification, the numerical range "Min to Max" means a range equal to or greater than the minimum value Min and equal to or less than the maximum value Max. Furthermore, when preferred numerical values ​​are given in stages for the upper and lower limit values, a numerical range obtained by appropriately combining the separately given upper and lower limit values ​​is also a preferred numerical range. 1. Radical polymerizable polymers The radical polymerizable polymer of the present invention is a radical polymer having an acid group and an ethylenically unsaturated double bond in a side chain, and the radical polymerizable polymer has a structural unit having a ring structure in the main chain and a structural unit represented by the following general formula (1), and is characterized in that the double bond equivalent is 330 to 1600 (g / equivalent), the weight average molecular weight is 14000 or less, the content of the structural unit represented by the following general formula (2) is 5 mass% or less relative to 100 mass% of all structural units of the radical polymer, and the distance between the acid group and the main chain is 6 atoms or less.

[0011] [ka] (In the formula, R 1represents a hydrogen atom or a methyl group. 2 represents a linear or branched hydrocarbon group having 6 to 20 carbon atoms.

[0012] [ka] (In the formula, R 3 represents a hydrogen atom or a methyl group. The radically polymerizable polymer of the present invention has the above-mentioned constitution, and therefore has good handleability and coating workability, and can give a cured product having excellent transparency and adhesion. The above-described superiority of the radical polymerizable polymer of the present invention is presumably due to the fact that it satisfies specific ranges of physical property parameters, has a structural unit having a ring structure in the main chain, contains a structural unit represented by the above general formula (1), and has acid groups located in specific ranges. The radically polymerizable polymer of the present invention has an acid group and an ethylenically unsaturated double bond in the side chain. The radical polymerizable polymer having an acid group on the side chain thereof is alkali-soluble and exhibits developability, and the cured product of the radical polymerizable polymer exhibits adhesion. The acid group is spaced from the main chain by 6 or less atoms. The acid group is located within a specific range of positions, which improves the developability of the radical polymerizable polymer. In addition, the hydrocarbon group of the structural unit of general formula (1) contained in the radical polymerizable polymer has 6 to 20 carbon atoms, which can improve the dispersibility of inorganic fine particles, which will be described later. Typically, when producing a radically polymerizable polymer having an acid group relatively far from the main chain, a vinyl monomer is reacted with a compound or acid anhydride having an acid group to synthesize a monomer having an acid group far from the vinyl group, and this monomer is then copolymerized. For example, a monomer having an acid group far from the vinyl group can be obtained by reacting hydroxyethyl (meth)acrylate with maleic anhydride. However, when a radically polymerizable polymer produced by copolymerizing this monomer is used in the production of a color filter, water is added during the post-curing process (heating step), causing the maleic acid moiety to detach, resulting in a foreign substance that can reduce the heat resistance and transparency of the resulting cured product. In contrast, when the distance between the acid group and the main chain is six atoms or less, there is no need to use a monomer obtained by reacting a vinyl monomer with a compound or acid anhydride having an acid group. This prevents the acid group moiety from detaching during the color filter production process, and therefore prevents a reduction in the heat resistance and transparency of the radically polymerizable polymer. Here, in the present invention, the phrase "the distance from the main chain is 6 atoms or less" means that the number of atoms between the atom in the main chain to which the side chain is bonded and the atom on the side chain to which the acid group is bonded is 6 atoms or less. For example, in the structural unit represented by (a1) below, the distance between the acid group X and the main chain is 4 atoms, and in the structural unit represented by (a2) below, the distance between the acid group X and the main chain is 6 atoms. Furthermore, when the acid group is directly bonded to the main chain, the distance between the acid group X and the main chain is 0 atoms.

[0013] [ka] The acid group is preferably spaced from the main chain by 6 or less atoms, more preferably 5 or less atoms, and even more preferably 0 atoms. The acid group is preferably directly bonded to the main chain. Examples of the acid group include functional groups that undergo a neutralization reaction with alkaline water, such as a carboxyl group, a phenolic hydroxyl group, a carboxylic anhydride group, a phosphoric acid group, and a sulfonic acid group. Among these, a carboxyl group or a carboxylic anhydride group is preferred, a carboxyl group is more preferred, and a (meth)acrylic acid group is even more preferred. From the viewpoint of further increasing the development rate, an acrylic acid group is more preferred. The radical polymerizable copolymer also has an ethylenically unsaturated double bond in the side chain, which enables thermal and photocrosslinking reactions, improving curability, development adhesion, solvent resistance, etc. Furthermore, the copolymer has improved sensitivity to light, allowing it to be cured with less light, and the mechanical strength of the cured product can also be improved. In the present invention, the above-mentioned ethylenically unsaturated double bond means a polymerizable double bond, that is, a carbon-carbon double bond. Examples of the ethylenically unsaturated double bond include a (meth)acryloyl group, a vinyl group, an allyl group, and a methallyl group. The radical polymerizable polymer of the present invention may have one or more of these groups. Among these, a (meth)acryloyl group is preferred in terms of reactivity. The ethylenically unsaturated double bond can be introduced into the radical polymerizable polymer by, for example, using an epoxy group-containing monomer (X) during the production of the radical polymerizable polymer. The epoxy group-containing monomer (X) may be a compound containing an epoxy group and a polymerizable double bond. The polymerizable double bond may be, for example, the same as the ethylenically unsaturated double bond described above, such as a (meth)acryloyl group, a vinyl group, an allyl group, or a methallyl group, and is preferably one or more of these. Among these, a (meth)acryloyl group is preferred in terms of reactivity. In this specification, the term "epoxy group" refers not only to an epoxy group in the narrow sense, but also to a group in which an oxirane ring is bonded to a carbon atom, such as a glycidyl group, a group containing an ether bond or an ester bond, such as a glycidyl ether group and a glycidyl ester group, an epoxycyclohexane ring, and the like. Examples of the epoxy group-containing monomer (X) include glycidyl (meth)acrylate, β-methylglycidyl (meth)acrylate, β-ethylglycidyl (meth)acrylate, vinylbenzyl glycidyl ether, allyl glycidyl ether, (3,4-epoxycyclohexyl)methyl (meth)acrylate, and vinylcyclohexene oxide. Among these, glycidyl (meth)acrylate and / or 3,4-epoxycyclohexylmethyl (meth)acrylate are more preferred because of their high reactivity, ease of reaction control, ease of availability, and ability to introduce not only radically polymerizable double bonds but also hydroxyl groups. Glycidyl (meth)acrylate (also known as glycidyl (meth)acrylate) is even more preferred, and glycidyl methacrylate is particularly preferred. The radically polymerizable polymer of the present invention has a structural unit having a ring structure in the main chain and a structural unit represented by the above general formula (1). Each structural unit will be explained below. (Structural unit having a ring structure in the main chain) The radically polymerizable polymer has a structural unit (hereinafter also referred to as "structural unit (A)") having a ring structure in the main chain. By including a structural unit having a ring structure in the main chain skeleton, the heat resistance of the radically polymerizable polymer of the present invention can be improved, and the adhesiveness and solvent resistance of the cured product can also be improved. The monomer that provides the structural unit (A) is preferably one or more of a monomer having a double-bond-containing ring structure in the molecule or a monomer that undergoes cyclopolymerization to form a polymer having a ring structure in the main chain. As such a monomer, it is preferable to use at least one selected from the group consisting of N-substituted maleimide monomers, dialkyl-2,2'-(oxydimethylene)diacrylate monomers, and α-(unsaturated alkoxyalkyl)acrylates. As such a structural unit having a ring structure in the main chain, N-substituted maleimide monomer units, dialkyl-2,2'-(oxydimethylene)diacrylate monomer units, and / or α-(unsaturated alkoxyalkyl)acrylate monomer units are preferred. In particular, polymers containing N-substituted maleimide monomer units and / or dialkyl-2,2'-(oxydimethylene)diacrylate monomer units can give cured products with improved heat resistance, dispersibility (e.g., dispersibility of colorants and inorganic fine particles), hardness, etc. The polymer containing the above-mentioned monomer unit means a polymer containing a structural unit derived from the monomer through, for example, a polymerization reaction or crosslinking reaction of the monomer. In the above-mentioned monomer component, examples of the N-substituted maleimide monomer include N-cyclohexylmaleimide, N-phenylmaleimide, N-methylmaleimide, N-ethylmaleimide, N-isopropylmaleimide, Nt-butylmaleimide, N-dodecylmaleimide, N-benzylmaleimide, and N-naphthylmaleimide, and one or more of these can be used. Among them, N-cyclohexylmaleimide, N-phenylmaleimide, and N-benzylmaleimide are preferred in terms of low coloration and excellent dispersibility, and N-benzylmaleimide and N-phenylmaleimide are particularly suitable. Examples of the N-benzylmaleimide include benzylmaleimide; alkyl-substituted benzylmaleimides such as p-methylbenzylmaleimide and p-butylbenzylmaleimide; phenolic hydroxyl group-substituted benzylmaleimides such as p-hydroxybenzylmaleimide; and halogen-substituted benzylmaleimides such as o-chlorobenzylmaleimide, o-dichlorobenzylmaleimide and p-dichlorobenzylmaleimide. Examples of the N-phenylmaleimide include phenylmaleimide; alkyl-substituted phenylmaleimides such as p-methylphenylmaleimide and p-butylphenylmaleimide; phenolic hydroxyl group-substituted phenylmaleimides such as p-hydroxyphenylmaleimide; and halogen-substituted phenylmaleimides such as o-chlorophenylmaleimide, o-dichlorophenylmaleimide and p-dichlorophenylmaleimide. As the dialkyl-2,2'-(oxydimethylene)diacrylate monomer, it is preferable to use, for example, dimethyl-2,2'-[oxybis(methylene)]bis-2-propenoate, etc., from the viewpoints of low coloration, dispersibility, ease of industrial availability, etc. Examples of the α-(unsaturated alkoxyalkyl)acrylate include α-allyloxymethylacrylic acid, methyl α-allyloxymethylacrylate, ethyl α-allyloxymethylacrylate, n-propyl α-allyloxymethylacrylate, i-propyl α-allyloxymethylacrylate, n-butyl α-allyloxymethylacrylate, s-butyl α-allyloxymethylacrylate, t-butyl α-allyloxymethylacrylate, n-amyl α-allyloxymethylacrylate, s-amyl α-allyloxymethylacrylate, t-amyl α-allyloxymethylacrylate, neopentyl α-allyloxymethylacrylate, n-hexyl α-allyloxymethylacrylate, s-hexyl α-allyloxymethylacrylate, n-heptyl α-allyloxymethylacrylate, n-octyl α-allyloxymethylacrylate, s-octyl α-allyloxymethylacrylate, Preferred are α-(allyloxymethyl)acrylates containing a chain saturated hydrocarbon group, such as t-octyl α-allyloxymethylacrylate, 2-ethylhexyl α-allyloxymethylacrylate, capryl α-allyloxymethylacrylate, nonyl α-allyloxymethylacrylate, decyl α-allyloxymethylacrylate, undecyl α-allyloxymethylacrylate, lauryl α-allyloxymethylacrylate, tridecyl α-allyloxymethylacrylate, myristyl α-allyloxymethylacrylate, pentadecyl α-allyloxymethylacrylate, cetyl α-allyloxymethylacrylate, heptadecyl α-allyloxymethylacrylate, stearyl α-allyloxymethylacrylate, nonadecyl α-allyloxymethylacrylate, eicosyl α-allyloxymethylacrylate, ceryl α-allyloxymethylacrylate, and melissyl α-allyloxymethylacrylate. Additionally, alkyl-(α-methallyloxymethyl)acrylate monomers are also preferred, and among these, methyl α-allyloxymethylacrylate (also referred to as α-(allyloxymethyl)methyl acrylate) is particularly preferred. The above-mentioned α-(unsaturated alkoxyalkyl)acrylate can be produced, for example, by the production method disclosed in WO 2010 / 114077. The radically polymerizable polymer may have only one type of the structural unit (A), or may have two or more types. In consideration of achieving both the developability, transparency, and adhesion of the radically polymerizable polymer, the content of the structural unit (A) is preferably 0.5 to 50% by mass relative to 100% by mass of all structural units in the radically polymerizable polymer. The content of the structural unit (A) is more preferably 1% by mass or more, even more preferably 2% by mass or more, and more preferably 30% by mass or less, even more preferably 25% by mass or less, relative to 100% by mass of all structural units in the radically polymerizable polymer. (Structural unit represented by general formula (1)) The radically polymerizable polymer of the present invention also has a structural unit represented by the following general formula (1) (hereinafter also referred to as "structural unit (B)").

[0014] [ka] (In the formula, R 1 represents a hydrogen atom or a methyl group. 2 represents a linear or branched hydrocarbon group having 6 to 20 carbon atoms. The radical polymerizable polymer of the present invention has the structural unit (B), which can reduce the viscosity of the radical polymerizable polymer solution. It also improves developability and can provide a cured product with excellent solvent resistance and adhesion. Furthermore, the combination of the structural unit (B) with an acid group having a distance of 6 or less atoms from the main chain improves the dispersibility of inorganic fine particles. In the above general formula (1), R 1 represents a hydrogen atom or a methyl group. From the viewpoint of development speed, R 1 is preferably a hydrogen atom. In the above general formula (1), R 2 represents a linear or branched hydrocarbon group having 6 to 20 carbon atoms. Examples of the linear or branched hydrocarbon group having 6 to 20 carbon atoms include a 1-methylpentyl group, a 2-methylpentyl group, a 3-methylpentyl group, a 4-methylpentyl group, a 1,1-dimethylbutyl group, a 1,2-dimethylbutyl group, a 1,3-dimethylbutyl group, a 2,2-dimethylbutyl group, a 2,3-dimethylbutyl group, a 3,3-dimethylbutyl group, a 1-ethylbutyl group, a 2-ethylbutyl group, a 1,2,2-trimethylpropyl group, Examples of the alkyl group include an n-ethyl group, a 1-ethyl-1-methylpropyl group, a 1-ethyl-2-methylpropyl group, an n-heptyl group, an n-octyl group, a 2-ethylhexyl group, an n-nonyl group, an n-decyl group, an n-undecyl group, an n-dodecyl group, an n-tridecyl group, an n-tetradecyl group, an n-pentadecyl group, an n-hexadecyl group, an n-heptadecyl group, an n-octadecyl group, an n-nonadecyl group, and an n-eicosyl group. The linear or branched hydrocarbon group having 6 to 20 carbon atoms is preferably a linear or branched hydrocarbon group having 6 to 18 carbon atoms, more preferably a linear or branched hydrocarbon group having 6 to 14 carbon atoms, and particularly preferably a linear hydrocarbon group having 6 to 12 carbon atoms. Above R 2 Specific examples of the alkyl group include preferably an n-octyl group, an n-dodecyl group, and a 2-ethylhexyl group, more preferably an n-octyl group and an n-dodecyl group, and even more preferably an n-dodecyl group. Preferred examples of the monomer that provides the structural unit (B) include compounds represented by the following general formula (1-1). CH2=CR 1 -C(O)-OR 2 (1-1) (In the formula, R 1 represents a hydrogen atom or a methyl group. 2 represents a linear or branched hydrocarbon group having 6 to 20 carbon atoms. By polymerizing a monomer component containing such a monomer compound, a polymer having the structural unit (B) can be obtained. R in the above general formula (1-1) 1 and R 2 are R in the above general formula (1),1 and R 2 The same can be mentioned. Specific examples of the monomer that provides the structural unit (B) include preferably n-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-dodecyl (meth)acrylate, etc., and more preferably n-octyl (meth)acrylate and n-dodecyl (meth)acrylate. The radically polymerizable polymer may have only one type of the structural unit (B), or may have two or more types. Considering the compatibility of the handleability and adhesiveness of the radical polymerizable polymer and the dispersibility of inorganic fine particles, the content of the structural unit (B) is preferably 10% by mass or more relative to 100% by mass of all structural units of the radical polymerizable polymer. The content of the structural unit (B) is more preferably 30% by mass or more, even more preferably 50% by mass or more, and is preferably 90% by mass or less, more preferably 80% by mass or less, even more preferably 70% by mass or less relative to 100% by mass of all structural units of the radical polymerizable polymer.

[0015] (Structural units derived from acid group-containing monomers) The radical polymerizable polymer of the present invention preferably further comprises a structural unit derived from an acid group-containing monomer (hereinafter also referred to as "structural unit (C)"). By comprising the structural unit (C), the radical polymerizable polymer has the above-mentioned acid group and can exhibit developability and adhesion. Examples of the monomer that provides the structural unit (C) include an acid group-containing monomer. A polymer having the structural unit (C) can be obtained by polymerizing a monomer component containing the acid group-containing monomer. Examples of the acid group of the acid group-containing monomer include the same acid groups as those mentioned above. Examples of the acid group-containing monomer include unsaturated monocarboxylic acids such as (meth)acrylic acid, crotonic acid, cinnamic acid, and vinylbenzoic acid; unsaturated polycarboxylic acids such as maleic acid, fumaric acid, itaconic acid, citraconic acid, and mesaconic acid; unsaturated acid anhydrides such as maleic anhydride and itaconic anhydride; and phosphate group-containing unsaturated compounds such as Light Ester P-1M (manufactured by Kyoeisha Chemical Co., Ltd.). Among these, from the viewpoints of versatility and availability, it is preferable to use carboxylic acid-based monomers (unsaturated monocarboxylic acids, unsaturated polycarboxylic acids, and unsaturated acid anhydrides). In terms of reactivity, heat discoloration resistance, and the like, unsaturated monocarboxylic acids are more preferred, and (meth)acrylic acid is even more preferred. Thus, in the radically polymerizable polymer, the acid group is preferably a carboxyl group derived from (meth)acrylic acid. The radical polymerizable polymer may have only one type of structural unit (C), or two or more types, but preferably has, as the structural unit (C), at least a structural unit having an acid group spaced apart from the main chain by 6 or less atoms. The acid group spaced apart from the main chain by 6 or less atoms is as described above. In consideration of achieving a balance between the developability, handling, and adhesion of the radically polymerizable polymer, the content of the structural unit (C) is preferably 1 to 50% by mass relative to 100% by mass of all structural units in the radically polymerizable polymer. The content of the structural unit (C) is more preferably 5% by mass or more, even more preferably 10% by mass or more, and more preferably 45% by mass or less, even more preferably 40% by mass or less, and particularly preferably 35% by mass or less, relative to 100% by mass of all structural units. (Structural unit having a ring structure in the side chain) The radical polymerizable polymer of the present invention may also have a ring structure in the side chain. That is, the radical polymerizable polymer may have a structural unit having a ring structure in the side chain (hereinafter also referred to as "structural unit (D)"). By having a ring structure in the side chain, the hydrophobicity of the radical polymerizable polymer can be improved, and the solvent resistance can be improved. Examples of the ring structure include aromatic ring structures such as benzene, and alicyclic structures such as a cyclohexane skeleton, an adamantane skeleton, and a norbornene skeleton. In order for the radical polymerizable polymer to have a ring structure in the side chain, it is advisable to polymerize a monomer component containing a monomer having an aromatic hydrocarbon group or an alicyclic hydrocarbon group and a polymerizable double bond. Examples of the aromatic hydrocarbon group include aryl groups such as benzyl, tolyl, naphthyl, and biphenyl. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 15 carbon atoms. Specific examples of the alicyclic hydrocarbon group include monocyclic hydrocarbon groups such as cyclopropyl, cyclopentyl, cyclohexyl, cyclooctyl, cyclododecyl, cycloheptyl, cyclobutenyl, cyclopentenyl, and cyclohexenyl; and polycyclic hydrocarbon groups such as dicyclopentanyl, dicyclopentenyl, tricyclodecanyl, adamantyl, and isobornyl. These groups may have a substituent. The polymerizable double bond is, for example, similar to the above-mentioned ethylenically unsaturated double bond, and includes a (meth)acryloyl group, a vinyl group, an allyl group, a methallyl group, etc. Among these, a (meth)acryloyl group is preferred in terms of reactivity. Specific examples of the monomer that provides the structural unit (D) include alicyclic hydrocarbon group-containing monomers such as cyclohexyl (meth)acrylate, cyclohexylmethyl (meth)acrylate, isobornyl (meth)acrylate, 1-adamantyl (meth)acrylate, (3,4-epoxycyclohexyl)methyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, tricyclodecanyl (meth)acrylate, dimethylol-tricyclodecane di(meth)acrylate, pentacyclopentadecanedimethanol di(meth)acrylate, cyclohexanedimethanol di(meth)acrylate, and norbornanedimethanol di(meth)acrylate; and aromatic hydrocarbon group-containing monomers such as benzyl (meth)acrylate and 1-mol-ethoxylated phenylphenol acrylate. Among these, alicyclic hydrocarbon group-containing monomers are preferred, and cyclohexyl (meth)acrylate is more preferred, in terms of improving hydrophobicity. The content of the structural unit (D) is preferably 1 to 60 mass %, more preferably 3 to 50 mass %, and even more preferably 5 to 40 mass %, relative to 100 mass % of all structural units in the radically polymerizable polymer. The radically polymerizable polymer may have only one type of the structural unit (D), or may have two or more types. However, when the radical polymerizable polymer has a structural unit represented by the following general formula (2) as the structural unit (D), the content thereof is 5% by mass or less relative to 100% by mass of all structural units in the radical polymerizable polymer. It is particularly preferable that the radical polymer is substantially free of such structural unit. The hydrogen atom at the benzyl position in the following general formula (2) is likely to be cleaved, generating radicals in the main chain, and oxidation of the main chain may reduce the heat discoloration resistance of the cured product of the radically polymerizable polymer. Furthermore, the aromatic ring may absorb light, reducing the transparency of the cured product. Furthermore, in the photosensitive resin composition of the present invention containing inorganic fine particles, the dispersibility of the inorganic fine particles tends to decrease. Therefore, it is desirable that the content of the structural unit represented by the following general formula (2) be within the above-mentioned range. Specifically, the content of the structural unit represented by the following general formula (2) is preferably 3% by mass or less, more preferably 1% by mass or less, and even more preferably 0% by mass, relative to 100% by mass of all structural units in the radically polymerizable polymer.

[0016] [ka] (In the formula, R 3 represents a hydrogen atom or a methyl group. Examples of the monomer that gives the structural unit represented by the above general formula (2) include styrene and vinyltoluene. When the structural unit (D) contains a structural unit represented by the general formula (2) and other structural units, the content of the other structural units is preferably 1 to 60 mass%, more preferably 3 to 50 mass%, relative to 100 mass% of all structural units in the radical polymerizable polymer. The content of the structural unit represented by the general formula (2) is 5 mass% or less, preferably 3 mass% or less, more preferably 1 mass% or less, and even more preferably 0 mass%, relative to 100 mass% of all structural units in the radical polymerizable polymer.

[0017] (other structural units) The radically polymerizable polymer may further contain other structural units (E) as necessary. Examples of the other structural unit (E) include structural units derived from a (meth)acrylic acid ester-based monomer, a hydroxyl group-containing monomer, or another copolymerizable monomer other than the monomer that gives the structural unit (B). Examples of (meth)acrylic acid ester monomers other than the monomer that gives the structural unit (B) include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, i-propyl (meth)acrylate, n-butyl (meth)acrylate, t-butyl (meth)acrylate, 1-methylpropyl (meth)acrylate, 2-methylpropyl (meth)acrylate, 1,1-dimethylethyl (meth)acrylate, n-pentyl (meth)acrylate, 1-methylbutyl (meth)acrylate, 2-methylbutyl (meth)acrylate, 3-methylbutyl (meth)acrylate, 2,2-dimethylpropyl (meth)acrylate, 1-ethylpropyl (meth)acrylate, n-hexyl (meth)acrylate, and 1,1-dimethyl (meth)acrylate. propyl acrylate, 1,2-dimethylpropyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, 1,4-dioxaspiro[4,5]dec-2-yl methacrylic acid, (meth)acryloylmorpholine, 4-(meth)acryloyloxymethyl-2-methyl-2-ethyl-1,3-dioxolane, 4-(meth)acryloyloxymethyl-2-methyl-2-isobutyl-1,3-dioxolane, 4-(meth)acryloyloxymethyl-2-methyl-2-cyclohexyl-1,3-dioxolane, 4-(meth)acryloyloxymethyl-2,2-dimethyl-1,3-dioxolane, and the like. Examples of the hydroxyl group-containing monomer include hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and 2,3-hydroxypropyl (meth)acrylate. Examples of the other copolymerizable monomer include one or more of the following compounds: (Meth)acrylamides such as N,N-dimethyl(meth)acrylamide and N-methylol(meth)acrylamide; macromonomers having a (meth)acryloyl group at one end of the polymer molecular chain such as polystyrene, polymethyl(meth)acrylate, polyethylene oxide, polypropylene oxide, polysiloxane, polycaprolactone, and polycaprolactam; conjugated dienes such as 1,3-butadiene, isoprene, and chloroprene; vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyrate, and vinyl benzoate; methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, and 2-ethylhexyl vinyl ether. vinyl ethers such as methyl vinyl ether, n-nonyl vinyl ether, lauryl vinyl ether, cyclohexyl vinyl ether, methoxyethyl vinyl ether, ethoxyethyl vinyl ether, methoxyethoxyethyl vinyl ether, methoxypolyethylene glycol vinyl ether, 2-hydroxyethyl vinyl ether, and 4-hydroxybutyl vinyl ether; N-vinyl compounds such as N-vinylpyrrolidone, N-vinylcaprolactam, N-vinylimidazole, N-vinylmorpholine, and N-vinylacetamide; and unsaturated isocyanates such as isocyanatoethyl (meth)acrylate and allyl isocyanate. The radically polymerizable polymer may have only one type of the structural unit (E), or may have two or more types. The content of the structural unit (E) is preferably 0 to 60 mass %, more preferably 0.3 to 50 mass %, and even more preferably 0.5 to 40 mass %, relative to 100 mass % of all structural units in the radically polymerizable polymer. The double bond equivalent of the radical polymerizable polymer is 330 to 1600 g / equivalent (mol). When the double bond equivalent is within the above range, the curability (sensitivity to heat and light) of the radical polymerizable polymer is improved, and the adhesiveness of the cured product is improved. Furthermore, coloration during curing can be reduced. From the viewpoint of achieving both curability and storage stability, the double bond equivalent is preferably 400 g / equivalent or more, more preferably 500 g / equivalent or more, and even more preferably 550 g / equivalent or more. From the viewpoint of curability and dispersibility, it is preferably 1500 g / equivalent or less, more preferably 1400 g / equivalent or less, and even more preferably 1300 g / equivalent or less. As used herein, the double bond equivalent refers to the mass (g) of the solid content of a polymer solution per 1 mol of double bonds in the polymer. The mass of the solid content of the polymer solution is the sum of the masses of the monomer components constituting the polymer (e.g., the mass of the base polymer component and the mass of the compound having a functional group capable of bonding to an acid group and a polymerizable double bond group). The double bond equivalent can be determined by dividing the mass (g) of the polymer solid content of the polymer solution by the amount of double bonds (mol) in the polymer. The amount of double bonds in the polymer can be determined by confirming the structures of the acid group-containing monomer and the compound having a polymerizable double bond (a compound having a functional group capable of bonding to an acid group and a polymerizable double bond) used in the polymerization and determining their amounts. It can also be measured by various analyses such as titration, elemental analysis, NMR, and IR, or by differential scanning calorimetry. For example, it can be calculated by measuring the number of ethylenic double bonds contained per gram of polymer in accordance with the iodine value test method described in JIS K 0070:1992. The double bond equivalent is a measure of the amount of double bonds contained in a molecule, and for compounds of the same molecular weight, the larger the double bond equivalent value, the smaller the amount of double bonds introduced. The weight-average molecular weight of the radically polymerizable polymer is 3,000 to 14,000. When the weight-average molecular weight is within the above range, the viscosity can be adjusted within an appropriate range, the handleability is good, and the adhesion is further improved. The weight-average molecular weight is more preferably 4,000 to 13,000, further preferably 5,000 to 12,000, and particularly preferably 7,000 to 12,000. In this specification, the weight average molecular weight can be determined by the method described in the Examples below. The acid value of the radical polymerizable polymer is preferably 50 to 150 mgKOH / g. When the acid value is within the above range, not only is alkali solubility enhanced, but the adhesion of the cured product is further improved and the dispersibility of inorganic fine particles is more appropriate. The dispersibility of the radical polymerizable polymer is also improved. The acid group is more preferably 60 to 150 mgKOH / g, and even more preferably 70 to 150 mgKOH / g. In this specification, the acid value can be determined by the method described in the Examples below. The glass transition temperature (Tg) of the radical polymerizable polymer is preferably 50°C or lower. When the glass transition temperature is within the above range, the viscosity can be adjusted to an appropriate range, improving handleability and resulting in excellent developability and adhesion. The glass transition temperature is preferably 40°C or lower, more preferably 30°C or lower, and even more preferably 0°C or lower. Furthermore, from the viewpoint of heat resistance, the glass transition temperature is preferably -50°C or higher, more preferably -30°C or higher. In this specification, the glass transition temperature can be determined by the method described in the Examples below.

[0018] (Method for producing radical polymerizable polymer) The method for producing the radical polymerizable polymer of the present invention will now be described. The method for obtaining the radical polymerizable polymer is not particularly limited, and examples thereof include (1) a method of subjecting a polymer (hereinafter also referred to as "base polymer 1") obtained by polymerizing a monomer component containing at least the monomer (a) that provides the structural unit (A), the monomer (b) that provides the structural unit (B), and the acid group-containing monomer (c) to an addition reaction with the epoxy group-containing monomer (X); and (2) a method of subjecting a polymer (hereinafter also referred to as "base polymer 2") obtained by polymerizing a monomer component containing at least the monomer (a), the monomer (b), and the epoxy group-containing monomer (X) to a reaction with the acid group-containing monomer (c). That is, the radical polymerizable polymer is preferably a reaction product of base polymer 1 and the epoxy group-containing monomer (X) or a reaction product of base polymer 2 and the acid group-containing monomer (c). Among these, from the viewpoint of production efficiency for introducing an acid group, a reaction product of base polymer 1 and epoxy group-containing monomer (X) is preferred. The synthesis method will be described below. Method (1) When a radically polymerizable polymer is obtained by the above method (1), the monomer components that give the base polymer 1 include at least the above monomer (a), the above monomer (b), and the above acid group-containing monomer (c). The proportion of each monomer shown in the above monomer components is not particularly limited as long as a radically polymerizable polymer having excellent handleability (coating workability) and excellent transparency and adhesion of the cured product can be obtained. For example, the content proportions of the above monomers (a), (b), and (c) are preferably 0.5 to 30 mass% of the above monomer (a), 11 to 85 mass% of the above monomer (b), and 5 to 85 mass% of the above monomer (c), relative to 100 mass% of the total amount of the monomer components that give base polymer 1, and more preferably 1 to 25 mass% of the above monomer (a), 15 to 80 mass% of the above monomer (b), and 10 to 70 mass% of the above monomer (c). Furthermore, when the monomer components that give the base polymer 1 include the monomer (a), the monomer (b), the monomer (c), and the monomer (d) that gives the structural unit (D), the content of each monomer, relative to 100% by mass of the total amount of the monomer components that give the base polymer 1, is preferably 0.5 to 30% by mass of the monomer (a), 11 to 85% by mass of the monomer (b), 5 to 85% by mass of the monomer (c), and 1 to 70% by mass of the monomer (d), and more preferably 1 to 25% by mass of the monomer (a), 15 to 80% by mass of the monomer (b), 10 to 70% by mass of the monomer (c), and 5 to 40% by mass of the monomer (d). Furthermore, when the monomer components that give the base polymer 1 include the monomer (a), the monomer (b), the monomer (c), the monomer (d), and the monomer (e) that gives the structural unit (E), the content of each monomer, relative to 100% by mass of the total amount of the monomer components that give the base polymer 1, is preferably 0.5 to 30% by mass of the monomer (a), 11 to 85% by mass of the monomer (b), 5 to 85% by mass of the monomer (c), 1 to 70% by mass of the monomer (d), and 0 to 70% by mass of the monomer (e), and more preferably 1 to 25% by mass of the monomer (a), 15 to 80% by mass of the monomer (b), 10 to 70% by mass of the monomer (c), 5 to 40% by mass of the monomer (d), and 1 to 40% by mass of the monomer (e). In the above method (1), the method for polymerizing the monomer components is not particularly limited, and commonly used techniques such as bulk polymerization, solution polymerization, and emulsion polymerization can be used, and may be appropriately selected depending on the purpose and application. Among these, solution polymerization is preferred because it is industrially advantageous and allows for easy structural adjustment, such as molecular weight. Furthermore, the polymerization mechanism of the monomer components can be based on polymerization methods such as radical polymerization, anionic polymerization, cationic polymerization, and coordination polymerization, but polymerization methods based on radical polymerization mechanisms are preferred because they are industrially advantageous. Preferred forms of the polymerization reaction are as described in

[0062] to

[0072] of JP 2016-29151 A. The polymerization initiation method for the above polymerization reaction can be achieved by supplying the energy required to initiate polymerization to the monomer components from an active energy source such as heat, electromagnetic waves (e.g., infrared rays, ultraviolet rays, X-rays, etc.), or electron beams. The use of a polymerization initiator in combination is advantageous because it significantly reduces the energy required to initiate polymerization and also facilitates reaction control. The molecular weight of the polymer obtained by polymerizing the above monomer components can be controlled by adjusting the amount and type of polymerization initiator, the polymerization temperature, the type and amount of chain transfer agent, etc. In the above method (1), an epoxy group-containing monomer (X) is subjected to an addition reaction with a portion of the acid groups contained in the base polymer 1. The reaction method is not particularly limited, and any known method may be appropriately adopted. For example, the reaction temperature is preferably set to 60 to 140°C. It is also preferable to use known catalysts such as amine compounds such as triethylamine and dimethylbenzylamine; ammonium salts such as tetraethylammonium chloride; phosphonium salts such as tetraphenylphosphonium bromide; and amide compounds such as dimethylformamide. The amount of the epoxy group-containing monomer (X) used is preferably set appropriately so that the acid value and double bond equivalent are within the desired ranges, and is preferably 1 to 90 parts by mass, for example, per 100 parts by mass of the total amount of the monomer components that give base polymer 1. This further improves adhesion, enhances curability, and provides a cured product with even more sufficient strength. The amount is more preferably 3 to 85 parts by mass, and even more preferably 5 to 80 parts by mass. The amount of the epoxy group-containing monomer (X) used is preferably 10 to 95 mol %, more preferably 15 to 90 mol %, and even more preferably 20 to 85 mol %, relative to 100 mol % of the acid group-containing monomer (c) in the monomer components that give the base polymer 1. Method (2) When the radically polymerizable polymer is obtained by the method (2), the monomer components that give the base polymer 2 include at least the monomer (a), the monomer (b), and the epoxy group-containing monomer (X). The proportion of each monomer in the above-mentioned monomer components is not particularly limited, but for example, the content of the above-mentioned monomer (a) is preferably 0.5 to 30 mass%, more preferably 1 to 20 mass%, relative to 100 mass% of the total amount of the monomer components that give base polymer 2, and the content of the above-mentioned monomer (b) is preferably 15 to 90 mass%, more preferably 20 to 80 mass%. The content of the epoxy group-containing monomer (X) is preferably set appropriately so that the acid value and double bond equivalent are within the above-mentioned ranges. For example, the content is preferably 3 to 80 mass %, and more preferably 5 to 75 mass %, relative to 100 mass % of the total amount of the monomer components that give the base polymer 2. Furthermore, when the monomer components that give the base polymer 2 include the monomer (a), the monomer (b), the epoxy group-containing monomer (X), and the monomer (d), the content of each monomer, relative to 100% by mass of the total amount of the monomer components that give the base polymer 2, is preferably 0.5 to 30% by mass of the monomer (a), 15 to 90% by mass of the monomer (b), 3 to 80% by mass of the epoxy group-containing monomer, and 1 to 70% by mass of the monomer (d), and more preferably 1 to 20% by mass of the monomer (a), 19 to 80% by mass of the monomer (b), 5 to 75% by mass of the epoxy group-containing monomer (X), and 5 to 40% by mass of the monomer (d). Furthermore, when the monomer components that give the base polymer 2 include the monomer (a), the monomer (b), the epoxy group-containing monomer (X), the monomer (d), and the monomer (e), the content of each monomer, relative to 100% by mass of the total amount of the monomer components that give the base polymer 2, is preferably 0.5 to 30% by mass of the monomer (a), 15 to 90% by mass of the monomer (b), 3 to 80% by mass of the epoxy group-containing monomer (X), 1 to 70% by mass of the monomer (d), and 0 to 70% by mass of the monomer (e), and more preferably 0.5 to 20% by mass of the monomer (a), 19 to 80% by mass of the monomer (b), 5 to 75% by mass of the epoxy group-containing monomer (X), 5 to 40% by mass of the monomer (d), and 0.5 to 40% by mass of the monomer (e). In the above method (2), the method for polymerizing the monomer components is not particularly limited, and may be the same as the polymerization method described in the above method (1). In the method (2), the acid group-containing monomer (c) is subjected to an addition reaction with a portion of the epoxy groups contained in the base polymer 2. This reaction method is not particularly limited, but it is preferable to set the reaction temperature at 60°C to 140°C, for example. It is also preferable to use known catalysts such as amine compounds such as triethylamine and dimethylbenzylamine; ammonium salts such as tetraethylammonium chloride; phosphonium salts such as tetraphenylphosphonium bromide; and amide compounds such as dimethylformamide. The amount of the acid group-containing monomer (c) used is preferably 1 to 60 parts by mass per 100 parts by mass of the total amount of the monomer components that give the base polymer 2. This further improves adhesion, enhances curability, and ensures sufficient strength of the cured product. The amount is more preferably 2 to 50 parts by mass, and even more preferably 3 to 40 parts by mass. After the addition reaction of the acid group-containing monomer (c), it is also preferable to react a polybasic acid anhydride. In this reaction, the hydroxyl group generated by the reaction of the epoxy group contained in the base polymer 2 with the acid group-containing monomer (c) is reacted with the polybasic acid anhydride to generate a carboxyl group. By carrying out this reaction, the acid value can be adjusted to an appropriate level. The polybasic acid anhydride is not particularly limited, and examples thereof include dibasic acid anhydrides such as succinic anhydride (also known as succinic anhydride), maleic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, endomethylenetetrahydrophthalic anhydride, methylendomethylenetetrahydrophthalic anhydride, and itaconic anhydride; trimellitic anhydride; and the like. The amount of the polybasic acid anhydride used is not particularly limited, but is preferably set so that the acid value of the resulting radically polymerizable polymer falls within the above-mentioned range. During synthesis, the amounts of the solvent and each monomer component are preferably set so that the final solid concentration of the radically polymerizable polymer solution is 10 to 70% by mass. From the viewpoints of productivity and polymerizability, the final solid concentration (non-volatile content) is more preferably 20 to 65% by mass, and even more preferably 25 to 60% by mass. The radical polymerizable polymer of the present invention is excellent in handleability (coating workability) and can give a cured product with excellent transparency. Therefore, it is useful as an alkali-developable negative resist material for producing colored pixels, black matrices, black column spacers, overcoats, photospacers, optical waveguides, etc. of color filters. Furthermore, because it has good inorganic particle dispersibility, colorant dispersibility, and adhesion, it is also useful as a colored photosensitive resin composition for color filters. The above radical polymerizable polymer is particularly preferably used as an alkali-soluble resin for a binder resin for color resists, and the above radical polymerizable polymer is extremely useful as a main component of a photosensitive resin composition.

[0019] 2. Photosensitive resin composition The above-described radical polymerizable polymer can be further made into a photosensitive resin composition containing a polyfunctional monomer. Furthermore, the photosensitive resin composition can be made into a photosensitive resin composition containing a photopolymerization initiator, inorganic fine particles, and a solvent, as needed. Since the photosensitive resin composition contains the above-described polymer, it is easy to handle, has excellent coating workability, and can provide a cured product with excellent transparency and adhesion. Furthermore, by further containing a polyfunctional monomer, it is possible to provide a cured product with excellent physical properties, such as the curability of the resin composition, adhesion to the substrate, mechanical strength, and heat resistance. Such a photosensitive resin composition containing the above-described radical polymerizable polymer and polyfunctional monomer also constitutes one aspect of the present invention. Applications are not limited, but the composition is suitable for use as a material for forming protective films for color filters, liquid crystal display elements, integrated circuit elements, solid-state imaging elements, and the like. In the photosensitive resin composition, the content of the radical polymerizable polymer is preferably 5% by mass or more, and suitably 70% by mass or less, relative to 100% by mass of the total solid content of the photosensitive resin composition. By being in this range, the effects of the present invention can be more significantly achieved. It is more preferably 10 to 65% by mass, even more preferably 10 to 50% by mass, particularly preferably 10 to 40% by mass, even more preferably 10 to 35% by mass, and most preferably 15 to 35% by mass. The term "total solid content" refers to the total amount of components that form the cured product (excluding solvents and the like that volatilize during the formation of the cured product). In the photosensitive resin composition, the polyfunctional monomer is a low-molecular-weight compound having a polymerizable unsaturated bond (also referred to as a polymerizable unsaturated group) that can be polymerized by irradiation with active energy rays such as free radicals, electromagnetic waves (e.g., infrared rays, ultraviolet rays, X-rays, etc.), and electron beams. Examples include polyfunctional compounds having two or more polymerizable unsaturated groups in the molecule. While the molecular weight is not particularly limited, from the viewpoint of ease of handling, it is preferably 3,000 or less, and more preferably 2,000 or less. Among these, bifunctional or higher polyfunctional (meth)acrylate compounds (hereinafter simply referred to as "polyfunctional (meth)acrylate compounds") are particularly preferred. These compounds have two or more (meth)acryloyl groups in one molecule. The inclusion of such compounds imparts excellent photosensitivity and curability to the photosensitive resin composition, enabling the production of a cured film with extremely high hardness and transparency. The number of functionalities of the polyfunctional (meth)acrylate compound is preferably 3 or more, more preferably 4 or more, and even more preferably 5 or more. In addition, from the viewpoint of further suppressing cure shrinkage, the functionality is preferably 10 or less, more preferably 8 or less, and even more preferably 6 or less. Examples of the polyfunctional monomer include polyfunctional (meth)acrylates such as (di)ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, trimethylolpropane di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol di(meth)acrylate, dipentaerythritol tri(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and tris(hydroxyethyl)isocyanurate tri(meth)acrylate. Among these, trimethylolpropane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, ethylene oxide-added dipentaerythritol hexa(meth)acrylate, propylene oxide-added trimethylolpropane tri(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, and ε-caprolactone-added dipentaerythritol hexa(meth)acrylate are preferred. The content of the polyfunctional monomer may be appropriately set depending on the type of polyfunctional monomer and the radically polymerizable polymer used, as well as the purpose and application, but from the viewpoint of superior developability, curability, and adhesion, it is preferably 2% by mass or more and suitably 85% by mass or less, relative to 100% by mass of the total solid content of the photosensitive resin composition. The lower limit is more preferably 5% by mass or more, even more preferably 10% by mass or more, and particularly preferably 15% by mass or more, and the upper limit is more preferably 75% by mass or less, even more preferably 60% by mass or less, particularly preferably 50% by mass or less, and most preferably 40% by mass or less. The content of the polyfunctional monomer is preferably 50 to 500 parts by mass relative to 100 parts by mass of the radical polymerizable polymer. A polyfunctional monomer content within this range not only provides a cured film with higher surface hardness, but also, combined with the preferred weight-average molecular weight of the radical polymerizable polymer being 5,000 or greater, improves developability. The content is more preferably 80 parts by mass or greater, even more preferably 100 parts by mass or greater, and particularly preferably 120 parts by mass or greater. From the viewpoint of further improving developability, the content is more preferably 400 parts by mass or less. The content is even more preferably 300 parts by mass or less, particularly preferably 200 parts by mass or less, and most preferably 150 parts by mass or less. In the photosensitive resin composition, it is preferable to use a photo or thermal polymerization initiator when curing the photosensitive resin composition. Examples of the photopolymerization initiator include diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyl dimethyl ketal, 4-(2-hydroxyethoxy)phenyl-(2-hydroxy-2-propyl)ketone, 1-hydroxycyclohexylphenyl ketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone, oligo{2- Acetophenones such as 2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methylpropionyl)benzyl]phenyl}-2-methylpropan-1-one; benzoins such as benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzoin isobutyl ether; benzophenone, methyl o-benzoylbenzoate, 4-phenylbenzophenone benzophenones such as 4-benzoyl-4'-methyl-diphenyl sulfide, 3,3',4,4'-tetra(t-butylperoxycarbonyl)benzophenone, 2,4,6-trimethylbenzophenone, 4-benzoyl-N,N-dimethyl-N-[2-(1-oxo-2-propenyloxy)ethyl]benzenemethanaminium bromide, and (4-benzoylbenzyl)trimethylammonium chloride; 2-isopropylthioxanthone, 4-isopropylthioxanthone, Examples of the thioxanthones include 2,4-diethylthioxanthone, 2,4-dichlorothioxanthone, 1-chloro-4-propoxythioxanthone, and 2-(3-dimethylamino-2-hydroxy)-3,4-dimethyl-9H-thioxanthone-9-one mesochloride, as well as phenylglyoxylic methyl ester, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, and bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide.Among these, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one and 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone are preferred.

[0020] Examples of the photopolymerization initiator include organic peroxides such as cumene hydroperoxide, diisopropylbenzene hydroperoxide, di-t-butyl peroxide, lauroyl peroxide, benzoyl peroxide, t-butylperoxyisopropyl carbonate, t-amylperoxy-2-ethylhexanoate, and t-butylperoxy-2-ethylhexanoate; and azo compounds such as 2,2'-azobis(isobutyronitrile), 1,1'-azobis(cyclohexanecarbonitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), and dimethyl 2,2'-azobis(2-methylpropionate). These photopolymerization initiators may be used alone or in combination of two or more.

[0021] Particularly preferred specific polymerization initiators include aminoketone compounds such as 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one ("IRGACURE907", manufactured by BASF), 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1 ("IRGACURE369", manufactured by BASF), and 2-dimethylamino-2-(4-methyl-benzyl)-1-(4-morpholin-4-yl-phenyl)-butan-1-one ("IRGACURE379", manufactured by BASF); titanocene compounds such as bis(η5-2,4-cyclopentadien-1-yl)-bis(2,6-difluoro-3-(1H-pyrrol-1-yl)-phenyl)titanium ("IRGACURE784", manufactured by BASF); oxime ester compounds such as 1,2-octanedione, 1-[4-(phenylthio)-, 2-(O-benzoyloxime)] ("IRGACURE OXE01", manufactured by BASF); and the like. Among the above photopolymerization initiators, it is particularly preferable to use at least an aminoketone compound (also referred to as an aminoketone polymerization initiator). That is, it is preferable that the photosensitive resin composition further contains an aminoketone polymerization initiator. This results in better hardness and heat resistance. The content of the photopolymerization initiator may be appropriately set depending on the purpose, application, etc., and is not particularly limited, but is preferably 0.5 parts by mass or more relative to 100 parts by mass of the total solid content of the photosensitive resin composition. This allows for the production of a cured film with superior heat resistance and adhesion. The content is more preferably 1 part by mass or more, and even more preferably 1.5 parts by mass or more. Furthermore, in consideration of the balance between the effects of decomposition products of the photopolymerization initiator and economic efficiency, the content is preferably 30 parts by mass or less. The content is more preferably 20 parts by mass or less, and even more preferably 10 parts by mass or less. The photosensitive resin composition preferably contains inorganic fine particles in order to increase the hardness of a cured film obtained by curing the photosensitive resin composition. As inorganic fine particles, in addition to silicon oxides such as silica described above, metal oxides such as titanium oxide, aluminum oxide, and zirconium oxide (zirconia, etc.); and metal salts such as calcium carbonate and barium sulfate are preferred. Among these, metal oxides are more preferred. Composite metal oxides containing two or more types of metal atoms are also suitable. Metal oxide particles having hydroxyl groups on the surface are more preferred, and silica particles are particularly preferred. Of these, surface-modified silica fine particles are preferred, and for example, those surface-modified with (meth)acryloyloxy groups bonded to silicon atoms via a divalent linking group are even more preferred. The inorganic fine particles have good affinity with the radical polymerizable polymer having the structural unit (B) of a hydrocarbon group having 6 to 20 carbon atoms and an acid group spaced apart from the main chain by 6 or less atoms, which is contained in the photosensitive resin composition of the present invention, and have good dispersibility. The number average primary particle diameter (diameter of primary particles) of the inorganic fine particles is preferably, for example, 1 to 500 nm. Within this range, the inorganic fine particles have more sufficient dispersibility and dispersion stability, and it is possible to provide a cured film with excellent dispersibility and high transparency. The number average primary particle diameter is more preferably 1 to 300 nm, even more preferably 1 to 200 nm, particularly preferably 1 to 100 nm, and most preferably 1 to 50 nm. The number average primary particle diameter can be measured, for example, using a laser diffraction particle size distribution analyzer. The number average primary particle diameter can be determined directly by magnifying and observing inorganic fine 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 primary particles, measuring their lengths in the major axis direction, and calculating the arithmetic average. The inorganic fine particles may be used in the form of a dried powder or a dispersion (e.g., colloidal silica) dispersed in an organic solvent. However, from the viewpoint of the dispersion stability of the photosensitive resin composition, it is preferable to use a dispersion in an organic solvent. That is, the inorganic fine particles are preferably contained in the photosensitive resin composition as an organic solvent dispersion. Examples of particle shapes include spherical, granular, ellipsoidal, cubic, rectangular, pyramidal, needle-like, columnar, rod-like, cylindrical, scale-like, plate-like, and thin flake-like shapes. Considering dispersibility in the solvent, spherical, granular, and columnar shapes are preferred. Specific examples of organic solvents include the various solvents described in JP 2013-227485 A (Patent Publication No. 2013-227485). The organic solvent dispersion can be obtained by thoroughly dispersing inorganic fine particles in an organic solvent, but commercially available products can also be used. For example, various organosilica sols exemplified in JP 2013-227485 A (

[0026] ) (e.g., NBAC-ST (organosilica sol using butyl acetate as a dispersion medium) and the like) can be mentioned. When the photosensitive resin composition contains inorganic fine particles, the content (solid content) thereof is preferably 5% by mass or more, more preferably 7% by mass or more, and even more preferably 10% by mass or more, based on 100% by mass of the total solid content of the photosensitive resin composition. From the viewpoints of developability, transparency, etc., the content is preferably 50% by mass or less, and more preferably 40% by mass or less. When at least a silicon-containing compound (preferably silica fine particles) is used as the inorganic fine particles, the content (solid content) thereof is preferably 50 parts by mass or more, more preferably 70 parts by mass or more, even more preferably 90 parts by mass or more, and most preferably 100 parts by mass, per 100 parts by mass of the total amount of inorganic fine particles in the photosensitive resin composition. The photosensitive resin composition (preferably a negative-type photosensitive resin composition) of the present invention preferably contains a solvent as a diluent, if necessary. The solvent is not particularly limited as long as it can uniformly dissolve components such as the polymer, polyfunctional monomer, photopolymerization initiator, and inorganic fine particles. Specific examples include ethers such as tetrahydrofuran, dioxane, ethylene glycol dimethyl ether, and diethylene glycol dimethyl ether; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; esters such as ethyl acetate, butyl acetate, propylene glycol monomethyl ether acetate, and 3-methoxybutyl acetate; alcohols such as methanol, ethanol, isopropanol, n-butanol, ethylene glycol monomethyl ether, and propylene glycol monomethyl ether; aromatic hydrocarbons such as toluene, xylene, and ethylbenzene; chloroform, dimethyl sulfoxide, and the like. The content of the solvent may be appropriately determined depending on the optimal viscosity of the photosensitive resin composition when used. For example, the amount is 1,000 parts by mass or less, more preferably 700 parts by mass or less, per 100 parts by mass of the polymer. The lower limit is preferably 30 parts by mass or more, more preferably 60 parts by mass or more, per 100 parts by mass of the polymer. By controlling the amount within the above range, the handleability and storage stability of the composition, as well as the efficiency of the coating operation, are improved. The viscosity of the photosensitive resin composition can be appropriately set depending on the desired thickness of the cured film. The viscosity of the photosensitive resin composition can be adjusted by adding a solvent. The upper limit of the viscosity of a photosensitive resin composition in which the solid content (non-volatile content) is adjusted to 40% by adding a solvent is, for example, preferably 30 mPa·s or less, more preferably 20 mPa·s or less, and particularly preferably 15 mPa·s or less. The lower limit of the viscosity is, for example, preferably 1 mPa·s or more, more preferably 5 mPa·s or more, depending on the desired thickness of the cured film. By setting the viscosity within the above range, handleability and coating workability are improved.

[0022] In addition to the above-mentioned components, the photosensitive resin composition of the present invention may contain known additives such as fillers such as aluminum hydroxide, talc, clay, and barium sulfate, quantum dot particles, colorants (pigments, dyes), defoamers, coupling agents, leveling agents, sensitizers, mold release agents, lubricants, plasticizers, antioxidants, UV absorbers, light stabilizers, flame retardants, polymerization inhibitors, polymerization retarders, polymerization accelerators, thickeners, dispersants, and surfactants, provided that the effects of the present invention are not impaired. As the pigment, one or more of various organic or inorganic colorants can be used. As the organic colorant, dyes, organic pigments, natural dyes, and the like can be used. The coloring materials will be described below. Examples of the coloring material include pigments and dyes. Either a pigment or a dye may be used as the coloring material, or a combination of a pigment and a dye may be used. For example, when forming red, blue, and green pixels of a color filter, a known method may be used in which desired color characteristics are exhibited by appropriately combining coloring materials, such as blue and purple, or green and yellow. Furthermore, when forming a black matrix or black column spacer, a black coloring material may be used. Among coloring materials, pigments are preferred in terms of durability, and dyes are preferred in terms of improving the brightness of panels, etc. These can be selected appropriately depending on the desired properties. In the curable resin composition of the present invention, pigments are preferred in that they can further improve the solvent resistance and heat color resistance of the cured product. As the pigment, the same pigments as those described in JP 2015-157909 A can be used. Examples of the dye that can be used include organic dyes described in JP-A Nos. 2010-9033, 2010-211198, 2009-51896, and 2008-50599. Of these, azo dyes, anthraquinone dyes, phthalocyanine dyes, quinoneimine dyes, quinoline dyes, nitro dyes, carbonyl dyes, and methine dyes are preferred. These coloring materials may be used alone or in combination of two or more. The content of the colorant is not particularly limited and can be appropriately determined depending on the purpose and application. Preferably, it is 2 to 80% by mass, more preferably 5 to 70% by mass, and even more preferably 10 to 60% by mass, based on 100% by mass of the total solids content of the photosensitive resin composition. Furthermore, when the photosensitive resin composition of the present invention contains the colorant, it preferably further contains a dispersant. The dispersant has an interactive site with the colorant and an interactive site with the dispersion medium (e.g., a solvent or binder resin) and functions to stabilize the dispersion of the colorant in the dispersion medium. Generally, dispersants are classified into resin-type dispersants (e.g., polymer dispersants), surfactants (e.g., low-molecular-weight dispersants), and dye derivatives. These may be used alone or in combination of two or more. Examples of the resin-type dispersant include polyurethane, polyacrylate and other polycarboxylic acid esters, unsaturated polyamides, polycarboxylic acids, polycarboxylic acid amine salts, polycarboxylic acid ammonium salts, polycarboxylic acid alkylamine salts, polysiloxanes, long-chain polyaminoamide phosphates, hydrogen-containing polycarboxylic acid esters, amides formed by the reaction of poly(lower alkylene imines) with polyesters having free carboxyl groups, and salts thereof, (meth)acrylic acid-styrene copolymers, (meth)acrylic acid-(meth)acrylic acid ester copolymers, styrene-maleic acid copolymers, polyvinyl alcohol, polyvinylpyrrolidone, polyesters, modified polyacrylates, ethylene oxide / polypropylene oxide adducts, etc. Commercially available resin-type dispersants include those similar to those described in JP 2015-157909 A. Examples of the surfactant include anionic surfactants such as polyoxyethylene alkyl ether sulfate, sodium dodecylbenzenesulfonate, sodium alkylnaphthalenesulfonate, sodium alkyldiphenyletherdisulfonate, monoethanolamine lauryl sulfate, triethanolamine lauryl sulfate, ammonium lauryl sulfate, sodium stearate, and sodium lauryl sulfate; nonionic surfactants such as polyoxyethylene oleyl ether, polyoxyethylene lauryl ether, polyoxyethylene nonylphenyl ether, polyoxyethylene sorbitan monostearate, and polyethylene glycol monolaurate; cationic surfactants such as alkyl quaternary ammonium salts and ethylene oxide adducts thereof; and amphoteric surfactants such as alkyl betaines, such as alkyldimethylaminoacetic acid betaine, and alkyl imidazolines. The dye derivative is a compound having a structure in which a functional group has been introduced into a dye, and examples of the functional group include a sulfonic acid group, a sulfonamide group and quaternary salts thereof, a dialkylamino group, a hydroxyl group, a carboxyl group, an amide group, and a phthalimide group. Examples of the structure of the parent dye include azo-based, anthraquinone-based, quinophthalone-based, phthalocyanine-based, quinacridone-based, benzimidazolone-based, isoindoline-based, dioxazine-based, indanthrene-based, perylene-based, and diketopyrrolopyrrole-based structures. The content of the dispersant may be appropriately set depending on the purpose and application, but from the viewpoint of a balance between dispersion stability, durability (heat resistance, light resistance, weather resistance, etc.), and transparency, it is preferably 0.01 to 60 mass%, more preferably 0.1 to 50 mass%, and even more preferably 0.3 to 40 mass%, relative to 100 mass% of the total solid content of the photosensitive resin composition. The method for preparing the photosensitive resin composition is not particularly limited and may be a known method, for example, a method in which the above-mentioned components are mixed and dispersed using various mixers or dispersers. The mixing and dispersion step is not particularly limited and may be performed by a known method. The composition may further include other commonly performed steps. When the photosensitive resin composition contains a colorant, it is preferable to prepare the composition via a colorant dispersion step. The colorant dispersion step may involve, for example, first weighing out predetermined amounts of colorant (preferably an organic pigment), dispersant, and solvent, and then dispersing the colorant into fine particles using a disperser to obtain a liquid colorant dispersion (also referred to as a "mill base"). Examples of such dispersers include paint conditioners, bead mills, roll mills, ball mills, jet mills, homogenizers, kneaders, and blenders. The dispersion step preferably involves kneading and dispersing the mixture using a roll mill, kneader, blender, or the like, followed by fine dispersion using a media mill, such as a bead mill filled with beads of 0.01 to 1 mm. A composition (preferably a transparent liquid) containing the radical polymerizable polymer and inorganic fine particles, which has been separately stirred and mixed, is added to the obtained mill base, and mixed to obtain a uniform dispersion solution, thereby obtaining a photosensitive resin composition. The obtained photosensitive resin composition is preferably filtered using a filter or the like to remove fine particles.

[0023] The present invention also relates to a cured film obtained by curing the radically polymerizable polymer and / or the photosensitive resin composition. Materials used as substrates to which the film is applied include, for example, transparent materials such as glass, acrylic resin, polycarbonate resin, polyester resin such as PET, and polystyrene resin, as well as metal materials such as aluminum, copper, iron, and stainless steel. The cured film preferably has a film thickness of 0.1 to 20 μm. This allows sufficient fulfillment of the demand for low-profile components and display devices using the cured film. The film thickness is more preferably 0.5 to 10 μm, and even more preferably 0.5 to 8 μm. Specifically, the light transmittance of the cured film can be 65% or more, preferably 70% or more, and more preferably 75% or more, at a thickness of 130 μm for light having a wavelength of 410 nm. Thus, the cured film obtained from the photosensitive resin composition of the present invention preferably has high transparency. This allows, for example, a laminate including the cured film to be used in a touch panel, whereby the display performance is not impaired and a clear image can be displayed. The present invention also includes a color filter having a cured product (cured film) of the above-mentioned photosensitive resin composition on a substrate. The color filter will be described below. The color filter of the present invention has a configuration in which a substrate is provided with a cured product of the photosensitive resin composition. In the color filter, the cured product formed from the photosensitive resin composition is particularly suitable for segments that require coloring, such as a black matrix or pixels of red, green, blue, yellow, etc., but is also suitable for segments that do not necessarily require coloring, such as photospacers, protective layers, and alignment control ribs. Substrates used in the color filters include, for example, glass substrates such as white plate glass, blue plate glass, alkali-strengthened glass, and silica-coated blue plate glass; sheets, films, or substrates made of thermoplastic resins such as polyester, polycarbonate, polyolefin, polysulfone, ring-opening polymers of cyclic olefins, and hydrogenated products thereof; sheets, films, or substrates made of thermosetting resins such as epoxy resins and unsaturated polyester resins; metal substrates such as aluminum plates, copper plates, nickel plates, and stainless steel plates; ceramic substrates; semiconductor substrates having photoelectric conversion elements; and components made of various materials such as glass substrates having a colorant layer on their surface (e.g., LCD color filters). Among these, glass substrates and sheets, films, or substrates made of heat-resistant resins are preferred in terms of heat resistance. It is also preferable that the substrate be transparent. The substrate may be subjected to corona discharge treatment, ozone treatment, chemical treatment with a silane coupling agent, or the like, as needed. To obtain the color filter, it is preferable to employ a manufacturing method that includes, for each pixel color (i.e., for each pixel color), a step of disposing the photosensitive resin composition on a substrate (also referred to as a disposing step), a step of irradiating the photosensitive resin composition disposed on the substrate with light (also referred to as a light irradiation step), a step of developing with a developer (also referred to as a developing step), and a step of heating (also referred to as a heating step), and that repeats this same procedure for each color. Note that the order in which the pixels of each color are formed is not particularly limited. The above-mentioned disposing step is preferably carried out by coating. Examples of a method for coating the above-mentioned photosensitive resin composition on a substrate include spin coating, slit coating, roll coating, and cast coating. Since the viscosity of the photosensitive resin composition of the present invention can be adjusted within an appropriate range and is excellent in coating workability, any of these methods can be preferably used. The heating step is a final step (also referred to as a post-curing step) in which the exposed area (cured area) is further cured by baking. For example, a light source such as a high-pressure mercury lamp is used, and the cured area is further cured by baking at a luminous energy of, for example, 0.5 to 5 J / cm. 2 and a step of post-heating at a temperature of, for example, 60 to 260° C. for 10 seconds to 120 minutes. By carrying out such a post-curing step, it is possible to further increase the hardness and adhesion of the patterned cured film. As described above, the radical polymerizable polymer of the present invention has good handleability and excellent coating workability, and can provide a cured product that is excellent in transparency and adhesion. Furthermore, a photosensitive resin composition containing the radical polymer of the present invention has excellent curability and can provide a cured product that is excellent in adhesion to a substrate, transparency, heat resistance, etc. The radical polymerizable polymer and photosensitive resin composition of the present invention can be used in applications such as resist materials, various coating agents, paints, etc., and since the polymer contains acid groups such as carboxyl groups, they can be suitably used as alkaline-developable negative resist materials for producing colored pixels of color filters, black matrices, overcoats, photospacers, optical waveguides, etc. [Example]

[0024] The present invention will be described in more detail below with reference to examples. However, the following examples do not limit the present invention, and all modifications and variations within the scope of the present invention are included in the technical scope of the present invention. The present invention will be specifically illustrated by examples, comparative examples, and property evaluations. In the examples and comparative examples, % and wt% mean mass % and parts mean parts by mass, unless otherwise specified. In the following production examples, various physical properties were evaluated as follows. [Evaluation method] (1) Weight average molecular weight (Mw) Measurement was carried out by GPC (HLC-8220GPC, manufactured by Tosoh Corporation) using THF as an eluent and a TSKgel SuperHZM-N (manufactured by Tosoh Corporation) column, and the values ​​were calculated in terms of standard polystyrene. (2) Solids Approximately 0.3 g of the copolymer solution prepared in the Production Example was weighed into an aluminum cup, dissolved in approximately 1 g of acetone, and then air-dried at room temperature. The solution was then dried at 140°C for 3 hours using a hot air dryer (product name: PHH-101, manufactured by Espec Corporation), cooled in a desiccator, and weighed. The weight of the solid content (resin) of the polymer solution was calculated from the weight loss. (3) Acid value 1.5 g of the copolymer solution prepared in the Production Example was precisely weighed out, dissolved in a mixed solvent of 90 g of acetone and 10 g of water, and titrated with a 0.1 N KOH aqueous solution. The titration was carried out using an automatic titrator (product name: COM-555, manufactured by Hiranuma Sangyo Co., Ltd.), and the acid value per 1 g of polymer (mg KOH / g) was calculated from the solid concentration.

[0025] (4) Glass transition temperature (Tg) In this example, the glass transition temperature (Tg) of each polymer was calculated according to the following FOX formula. 1 / (Tg+273)=Σ〔wi / (Tgi+273)〕 (where wi is the mass fraction of monomer i, and Tgi is the glass transition temperature (°C) of a homopolymer of monomer i). The Tg of the homopolymer of the monomer used in the FOX formula can be, for example, the value listed in "POLYMER HANDBOOK THIRD EDITION" (by J. BRANDRUP and EHIMMERGUT, 1989, published by John Wiley & Sons, Inc., pages VI / 209 to VI / 277) (if multiple glass transition temperatures are listed, the lowest value can be used). For monomers not listed in "POLYMER HANDBOOK THIRD EDITION," a value calculated by computer using commercially available glass transition temperature calculation software (for example, "MATERIALS STUDIO" manufactured by Accelrys Software Inc., version 4.0.0.0, module: Synthia, calculation conditions: weight average molecular weight 100,000) can be used. Specifically, the Tg of the copolymer of the present invention is calculated from the following formula. 1 / (Tg+273)=w1 / (Tg1+273)+w2 / (Tg2+273)+... Tg: Copolymer Tg (w 1、 w 2、··· : Weight fraction of monomers 1, 2, ... in the copolymer Tg 1、 Tg 2、··· : homopolymer Tg of monomers 1, 2, ... constituting the copolymer) For actual measurements, the polymer solution is applied to a 5 cm square glass substrate, spin-coated onto the glass substrate, and dried at room temperature under reduced pressure for 4 hours to form a thin film with a film mass of 30 mg or less, thereby removing volatile components and obtaining the solid content. The residual solvent content is confirmed to be 0.1 wt% or less by quantitative gas chromatography. The obtained solid content is measured using a DSC (differential scanning calorimeter, measuring device: Netsch DSC3500) in a nitrogen stream at a heating rate of 10°C / min in accordance with JIS-K7121.

[0026] [Production of radically polymerizable polymer] The following radical polymerizable polymers were used: [Manufacturing Example 1] A separable flask equipped with a condenser was prepared as a reaction vessel. On the other hand, a monomer composition consisting of 20 g of N-phenylmaleimide (PMI), 36 g of methacrylic acid (MAA), 44 g of lauryl methacrylate (LMA), and 8 g of t-butylperoxy-2-ethylhexanoate (trade name "Perbutyl (registered trademark) O", manufactured by NOF Corporation, hereinafter also referred to as PBO) was added to a monomer dropping vessel and mixed with stirring.

[0027] A reaction vessel was charged with 233 g of propylene glycol methyl ether acetate (PGMEA), and the atmosphere was replaced with nitrogen. The reaction vessel was then heated in an oil bath with stirring to a temperature of 90°C. After the temperature of the reaction vessel stabilized at 90°C, the monomer composition was added dropwise. While maintaining the temperature at 90°C, the monomer composition was added dropwise over 180 minutes. After the monomer composition addition was complete, 0.5 g of PBO was added. After an additional 30 minutes, the vessel was heated to 115°C. After maintaining the temperature at 115°C for 1 hour, a gas inlet tube was attached to the separable flask, and bubbling of a 7 / 93 (v / v) oxygen / nitrogen mixed gas began. Next, 20.5 g of Cyclomer M100 (manufactured by Daicel, hereafter referred to as M100), 0.2 g of Antage W-400 (manufactured by Kawaguchi Chemical Industry Co., Ltd.) as a polymerization inhibitor, and 0.4 g of triphenylphosphine (TPP) as a catalyst were charged into the reaction vessel and reacted at 115°C for 14 hours. The mixture was then cooled to room temperature to obtain a copolymer solution (A-1) containing 34.2 wt% of resin. The resin had a weight-average molecular weight (Mw) of 8000 and an acid value of 150 mgKOH / g. The production conditions, solids concentration (non-volatile content), weight-average molecular weight (Mw), and acid value of the copolymer solution are shown in Table 1. [Manufacturing Example 2] A separable flask equipped with a condenser was prepared as a reaction vessel. A monomer composition consisting of 20 g of N-benzylmaleimide (BzMI), 31 g of acrylic acid (AA), 17 g of LMA, 32 g of methyl methacrylate (MMA), and 6 g of PBO was added to a monomer dropping vessel and mixed with stirring.

[0028] 233 g of PGMEA was charged into the reactor, and the atmosphere was replaced with nitrogen. The reactor temperature was then raised to 90°C by stirring in an oil bath. After the temperature of the reactor stabilized at 90°C, the monomer composition was added dropwise. While maintaining the temperature at 90°C, the monomer composition was added dropwise over 180 minutes. After the monomer composition addition was completed, 0.5 g of PBO was added. After an additional 30 minutes, the reactor was heated to 115°C. After maintaining the temperature at 115°C for 1 hour, a gas inlet tube was attached to the separable flask, and bubbling of a 7 / 93 (v / v) oxygen / nitrogen mixed gas began. Next, 33 g of glycidyl methacrylate (GMA), 0.2 g of Antage W-400 as a polymerization inhibitor, and 0.4 g of TPP as a catalyst were charged into the reactor, and the reaction was carried out at 115°C for 14 hours. The mixture was then cooled to room temperature, yielding a copolymer solution (A-2) containing 36.1 wt% resin. The weight-average molecular weight (Mw) of the resin was 12,000 and the acid value was 76 mgKOH / g. The production conditions, solid content (non-volatile content), weight-average molecular weight (Mw) and acid value of the copolymer solution are shown in Table 1. [Manufacturing Example 3] A separable flask equipped with a condenser was prepared as a reaction vessel. On the other hand, 15 g of PMI, 31 g of AA, 54 g of n-octyl acrylate (NOAA), and 10 g of PBO were added to a monomer dropping vessel as a monomer composition and mixed with stirring.

[0029] 233 g of PGMEA was charged into the reactor, and the atmosphere was replaced with nitrogen. The reactor temperature was then raised to 90°C by stirring in an oil bath. After the temperature of the reactor stabilized at 90°C, the monomer composition was added dropwise. While maintaining the temperature at 90°C, the monomer composition was added dropwise over 180 minutes. After the monomer composition addition was completed, 0.5 g of PBO was added. After an additional 30 minutes, the reactor was heated to 115°C. After maintaining the temperature at 115°C for 1 hour, a gas inlet tube was attached to the separable flask, and bubbling of a 7 / 93 (v / v) oxygen / nitrogen mixed gas began. Next, 33 g of GMA, 0.2 g of Antage W-400 as a polymerization inhibitor, and 0.4 g of TPP as a catalyst were charged into the reactor, and the reaction was carried out at 115°C for 14 hours. The mixture was then cooled to room temperature, yielding a copolymer solution (A-3) containing 36.3 wt% resin. The weight average molecular weight (Mw) of the resin was 7000 and the acid value was 77 mgKOH / g. The production conditions, solid content (non-volatile content), weight average molecular weight (Mw) and acid value of the copolymer solution are shown in Table 1. [Manufacturing Example 4] A separable flask equipped with a condenser was prepared as a reaction vessel. On the other hand, 15 g of PMI, 31 g of AA, 54 g of 2-ethylhexyl acrylate (2EHA), and 10 g of PBO were added to a monomer dropping vessel as a monomer composition and mixed with stirring.

[0030] 233 g of PGMEA was charged into the reactor, and the atmosphere was replaced with nitrogen. The reactor temperature was then raised to 90°C by stirring in an oil bath. After the temperature of the reactor stabilized at 90°C, the monomer composition was added dropwise. While maintaining the temperature at 90°C, the monomer composition was added dropwise over 180 minutes. After the monomer composition addition was completed, 0.5 g of PBO was added. After an additional 30 minutes, the reactor was heated to 115°C. After maintaining the temperature at 115°C for 1 hour, a gas inlet tube was attached to the separable flask, and bubbling of a 7 / 93 (v / v) oxygen / nitrogen mixed gas began. Next, 33 g of GMA, 0.2 g of Antage W-400 as a polymerization inhibitor, and 0.4 g of TPP as a catalyst were charged into the reactor, and the reaction was carried out at 115°C for 14 hours. The mixture was then cooled to room temperature, yielding a copolymer solution (A-4) containing 36.1 wt% of resin. The weight average molecular weight (Mw) of the resin was 6500 and the acid value was 78 mgKOH / g. The production conditions, solid content (non-volatile content), weight average molecular weight (Mw) and acid value of the copolymer solution are shown in Table 1. [Manufacturing Example 5] A separable flask equipped with a condenser was prepared as a reaction vessel. On the other hand, 15 g of methyl (α-allyloxymethyl)acrylate (AOMA), 44 g of AA, 41 g of LMA, and 16 g of PBO were added to a monomer dropping vessel as a monomer composition and mixed with stirring.

[0031] 233 g of PGMEA was charged into the reactor, and the atmosphere was replaced with nitrogen. The reactor temperature was then raised to 90°C by stirring in an oil bath. After the temperature of the reactor stabilized at 90°C, the monomer composition was added dropwise. While maintaining the temperature at 90°C, the monomer composition was added dropwise over 180 minutes. After the monomer composition addition was completed, 0.5 g of PBO was added. After an additional 30 minutes, the reactor was heated to 115°C. After maintaining the temperature at 115°C for 1 hour, a gas inlet tube was attached to the separable flask, and bubbling of a 7 / 93 (v / v) oxygen / nitrogen mixed gas began. Next, 69 g of GMA, 0.2 g of Antage W-400 as a polymerization inhibitor, and 0.4 g of TPP as a catalyst were charged into the reactor, and the reaction was carried out at 115°C for 21 hours. The mixture was then cooled to room temperature, yielding a copolymer solution (A-5) containing 41.9 wt% of resin. The weight-average molecular weight (Mw) of the resin was 9000 and the acid value was 50 mgKOH / g. The production conditions, solid content (non-volatile content), weight-average molecular weight (Mw) and acid value of the copolymer solution are shown in Table 1. [Manufacturing Example 6] A separable flask equipped with a condenser was prepared as a reaction vessel. On the other hand, a monomer composition consisting of 37 g of MAA, 50 g of styrene (St), 13 g of MMA, and 10 g of PBO was added to a monomer dropping vessel and mixed with stirring.

[0032] 233 g of PGMEA was charged into the reactor, and the atmosphere was replaced with nitrogen. The reactor temperature was then raised to 90°C by stirring in an oil bath. After the reactor temperature stabilized at 90°C, the monomer composition was added dropwise. While maintaining the temperature at 90°C, the monomer composition was added dropwise over 180 minutes. After the monomer composition addition was complete, 0.5 g of PBO was added. After an additional 30 minutes, the reactor was heated to 115°C. After maintaining the temperature at 115°C for 1 hour, a gas inlet tube was attached to the separable flask, and bubbling of a 7 / 93 (v / v) oxygen / nitrogen mixed gas began. Next, 54.4 g of M100, 0.2 g of Antage W-400 as a polymerization inhibitor, and 0.4 g of TPP as a catalyst were charged into the reactor, and the reaction was carried out at 115°C for 21 hours. The mixture was then cooled to room temperature, yielding a copolymer solution (A-6) containing 39.5 wt% resin. The weight average molecular weight (Mw) of the resin was 7000 and the acid value was 90 mgKOH / g. The production conditions, solid content (non-volatile content), weight average molecular weight (Mw) and acid value of the copolymer solution are shown in Table 1. [Manufacturing Example 7] A separable flask equipped with a condenser was prepared as a reaction vessel. A monomer composition of 20 g of BzMI, 31 g of AA, 17 g of St, 32 g of MMA, and 6 g of PBO was added to a monomer dropping vessel and mixed with stirring.

[0033] 233 g of PGMEA was charged into the reactor, and the atmosphere was replaced with nitrogen. The reactor temperature was then raised to 90°C by stirring in an oil bath. After the temperature of the reactor stabilized at 90°C, the monomer composition was added dropwise. While maintaining the temperature at 90°C, the monomer composition was added dropwise over 180 minutes. After the monomer composition addition was completed, 0.5 g of PBO was added. After an additional 30 minutes, the reactor was heated to 115°C. After maintaining the temperature at 115°C for 1 hour, a gas inlet tube was attached to the separable flask, and bubbling of a 7 / 93 (v / v) oxygen / nitrogen mixed gas began. Next, 33 g of GMA, 0.2 g of Antage W-400 as a polymerization inhibitor, and 0.4 g of TPP as a catalyst were charged into the reactor, and the reaction was carried out at 115°C for 14 hours. The mixture was then cooled to room temperature, yielding a copolymer solution (A-7) containing 36.6 wt% resin. The weight-average molecular weight (Mw) of the resin was 15,000 and the acid value was 76 mgKOH / g. The production conditions, solid content (non-volatile content), weight-average molecular weight (Mw) and acid value of the copolymer solution are shown in Table 1. [Manufacturing Example 8] A separable flask equipped with a condenser was prepared as a reaction vessel. On the other hand, a monomer composition consisting of 15 g of AOMA, 15 g of MAA, 47 g of 2EHA, 23 g of MMA, and 8 g of PBO was added to a monomer dropping vessel and mixed with stirring.

[0034] A reactor was charged with 233 g of PGMEA and purged with nitrogen. The reactor was then heated in an oil bath with stirring until the temperature reached 90°C. After the reactor temperature stabilized at 90°C, the monomer composition was added dropwise. While maintaining the temperature at 90°C, the monomer composition was added dropwise over 180 minutes. After the monomer composition addition was complete, 0.5 g of PBO was added. After an additional 30 minutes, the reactor was heated to 115°C. After maintaining the temperature at 115°C for 1 hour, the mixture was cooled to room temperature, yielding a copolymer solution (A-8) containing 30.3 wt% of resin. The resin had a weight-average molecular weight (Mw) of 6500 and an acid value of 100 mgKOH / g. The production conditions, solids concentration (non-volatile content), weight-average molecular weight (Mw), and acid value of the copolymer solution are shown in Table 1. Table 1 shows the compositions and physical properties of the above radical polymerizable polymers A-1 to A-5 (Examples 1 to 5) and A-6 to A-8 (Comparative Examples 1 to 3).

[0035] [Table 1] [Preparation of Photosensitive Resin Composition] 3.51 g of the copolymer solution (A-1) (i.e., 1.2 g of resin) was used as the binder resin, 4.00 g of PGM-AC-4130Y (1.2 g of nonvolatile content: manufactured by Nissan Chemical Industries, Ltd.) as inorganic fine particles (silica fine particles), 1.54 g of DPHA as a polyfunctional monomer, and 0.06 g of 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-propan-1-one (trade name "IRGACURE (registered trademark) 907", manufactured by BASF Japan Ltd., hereinafter referred to as Irg907) as a photopolymerization initiator were added, and the mixture was diluted with PGMEA to a nonvolatile content concentration of 40 wt %, to prepare photosensitive resin composition B1. Similarly, photosensitive resin compositions B2 to B8 were prepared using the copolymer solutions (A-2 to A-8) as binder resins. The compositions and evaluation results of photosensitive resin compositions B1 to B5 (Examples 6 to 10) and photosensitive resin compositions B6 to B8 (Comparative Examples 4 to 6) are shown in Table 2. The viscosity of Resin Composition B at 25° C. was measured using a cone-plate type rotational viscometer (TVE22LT, manufactured by Toki Sangyo Co., Ltd.). The cone-plate used was a standard rotor (name: 1°34'×R24). (Curing method) The photosensitive resin compositions B1 to B10 were applied to a 5 cm square glass substrate using a spin coater and dried in an oven at 80°C for 3 minutes. After drying, the coating was applied at 1 J / cm using a UV aligner (trade name "TME-150RNS", manufactured by TOPCON) equipped with a 2.0 kW ultra-high pressure mercury lamp. 2 (equivalent to 365 nm illuminance) was applied. After UV irradiation, the coating was post-cured at 160°C for 1 hour to completely cure the coating. The resulting coating was subjected to the following evaluations (5) and (6). The results are shown in Table 2. (5) Adhesion (cross-cut test) According to JIS K5600-5-6:1999 "General test methods for paints - Part 5: Mechanical properties of coating films - Section 6: Adhesion (cross-cut method)", the remaining film rate was rated as 1 if it was 100-90%, 2 if it was 89-80%, 3 if it was 79-70%, 4 if it was 69-60%, and 5 if it was less than 59%. The evaluation results are shown in Table 2. (6) Transmittance Using a glass substrate as a blank, the light transmittance of the coating film was measured with a spectrophotometer UV3100 (manufactured by Shimadzu Corporation) to determine the transmittance at 410 nm.

[0036] [Table 2] The abbreviations are as follows: Irg907: IRGACURE® 907, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one DPHA: Dipentaerythritol hexaacrylate From Tables 1 and 2, the following points were confirmed. Copolymers A-1 to A-5 obtained in Production Examples 1 to 5 correspond to the radical polymerizable polymer of the present invention. On the other hand, copolymer A-6 obtained in Production Example 6 does not contain a structural unit having a ring structure in the main chain or a structural unit represented by general formula (1) and contains more than 5 mass% of structural units represented by general formula (2). Copolymer A-7 obtained in Production Example 7 does not contain a structural unit represented by general formula (1), has a weight-average molecular weight of more than 14,000, and contains more than 5 mass% of structural units represented by general formula (2). Copolymer A-8 obtained in Production Example 8 does not have a polymerizable double bond (carbon-carbon double bond). These copolymers differ from copolymers A-1 to A-5. Comparing the viscosity, transparency (light transmittance), and adhesion of photosensitive resin compositions used in combination with inorganic fine particles under these differences, it was found that Examples 6 to 10, which used copolymers A-1 to A-5, had lower viscosity and higher light transmittance than Comparative Examples 4 to 6, which used copolymers A-6 to A-8. Resin composition B6, which contained A-6, in which styrene was copolymerized at a high ratio, had lower 410 nm transmittance and lower transparency of the cured film than B1 to B5, confirming the effect of a low content of structural units represented by general formula (2). (See Table 2.) Furthermore, Examples 6 to 10, which used copolymers A-1 to A-5, were found to have better adhesion than Comparative Examples 4 and 6 (See Table 2.) It is believed that the development of adhesion is due to the inclusion of a polymer with a main chain ring structure and a specific range of the amount of ethylenically unsaturated double bonds in the side chain. Furthermore, side chain double bonds due to the addition of GMA were more preferable than M100. In addition, Examples 6 to 8, which contain A-1 to A-3 copolymerized with linear NOAA or LMA, tended to have slightly lower viscosity, better coating workability, and higher 410 nm transmittance than Example 9, which contains A-4 copolymerized with branched 2EHA as the hydrocarbon group of the structural unit represented by general formula (1). From the above, the superiority of the radical polymerizable polymer and the photosensitive resin composition of the present invention was confirmed. [Industrial Applicability]

[0037] The radical polymerizable polymer and photosensitive resin composition of the present invention can be applied to, for example, resist materials, and can be suitably used in the fields of optics and electric / electronics.

Claims

1. A photosensitive resin composition comprising a radical polymerizable polymer having an acid group and an ethylenically unsaturated double bond in a side chain, a polyfunctional monomer, a photopolymerization initiator, inorganic fine particles having a number average primary particle size of 1 to 300 nm, and a solvent, The radical polymerizable polymer has a structural unit having a ring structure in the main chain and a structural unit represented by the following general formula (1): The double bond equivalent weight is 360 to 1600 (g / equivalent), The weight average molecular weight is 3,000 to 14,000, an acid value of 50 to 150 (mgKOH / g); the structural unit having a ring structure in the main chain includes an α-(unsaturated alkoxyalkyl)acrylate monomer unit, the content of the structural unit represented by the following general formula (2) is 3% by mass or less, based on 100% by mass of all structural units of the radical polymerizable polymer: The acid group is spaced from the main chain by 6 or less atoms. A photosensitive resin composition comprising: 【Chemistry 1】 (In the formula, R １ represents a hydrogen atom or a methyl group. ２ represents a linear or branched hydrocarbon group having 6 to 20 carbon atoms. 【Chemistry 2】 (In the formula, R ３ represents a hydrogen atom or a methyl group.

2. R in the general formula (1) ２ 2. The photosensitive resin composition according to claim 1, wherein represents a linear or branched hydrocarbon group having 6 to 14 carbon atoms.

3. 3. The photosensitive resin composition according to claim 1, wherein the content of the structural unit represented by the general formula (1) is 10% by mass or more relative to 100% by mass of all structural units of the radical polymerizable polymer.

4. The photosensitive resin composition according to any one of claims 1 to 3, wherein a content ratio of the α-(unsaturated alkoxyalkyl)acrylate monomer units is 1% by mass or more and 30% by mass or less, based on 100% by mass of all structural units of the radical polymerizable polymer.

5. 5. The photosensitive resin composition according to claim 1, wherein the acid group is a carboxyl group derived from acrylic acid.

6. A photosensitive resin composition described in any one of claims 1 to 5, characterized in that the glass transition temperature of the radical polymerizable polymer is 50°C or less.

7. 7. The photosensitive resin composition according to claim 1, which is a colored photosensitive resin composition for use in a color filter.

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