Radical polymerizable polymers and photosensitive resin compositions

Abstract

To provide a radical polymerizable polymer capable of providing a cured product which is good in handleability and excellent in coating workability and has excellent hardness, transparency and adhesion and to provide a photosensitive resin composition comprising the radical polymerizable polymer.SOLUTION: There is provided a radical polymerizable polymer which is a polymer having a constitutional unit derived from an unsaturated monomer having an acid group, a constitutional unit derived from an unsaturated monomer having a hydroxyalkyl group containing a secondary hydroxyl group and a polymerizable double bond in the side chain, wherein the polymer further has a constitutional unit derived from an N-substituted maleimide monomer in the main chain and / or a constitutional unit derived from an unsaturated monomer having a cyclohexyl group in the side chain and the polymer has a weight average molecular weight of 18000 or less.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a radical polymerizable polymer and a photosensitive resin composition containing the radical polymerizable polymer. [Background technology]

[0002] Curable resin compositions that can be cured by heat or active energy rays are being investigated for various applications in optical components and electrical / electronic equipment, such as color filters used in liquid crystal display devices and solid-state image sensors, inks, printing plates, printed circuit boards, semiconductor elements, and photoresists. Excellent curable resin compositions are being developed according to the properties required for each application. For example, Patent Document 1 describes a radiation-sensitive resin composition that can provide an interlayer insulating film with excellent heat dimensional stability, heat discoloration resistance, and adhesion to a substrate with high resolution, and contains an alkali-soluble resin, a 1,2-quinone diazide compound, and a radical scavenger. The alkali-soluble resin disclosed is a copolymer obtained by copolymerizing an unsaturated carboxylic acid, an unsaturated compound containing an epoxy group, a maleimide compound, etc. For example, Patent Document 2 describes an active energy ray-curable photosensitive resin composition that can provide a cured film exhibiting excellent shielding curability, high heat resistance, high adhesion, and high transparency, comprising a (meth)acrylate having a cyclic ether skeleton, an alkyl (meth)acrylate having 1 to 24 carbon atoms in the alkyl group, a (meth)acrylic resin which is a copolymer of at least two radical polymerizable monomers, and a polymerization initiator.

[0003] As described above, with advancements in technology, curable resin compositions used in optical components are required to have even higher levels of properties. For example, there is a demand for resin compositions capable of forming cured products with excellent hardness, transparency, and adhesion, and for polymers that can provide such resin compositions. Furthermore, there is a demand for polymers and resin compositions with excellent handling properties. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] International Publication No. 2011 / 046230 [Patent Document 2] Japanese Patent Publication No. 2013-36024 [Overview of the project] [Problems that the invention aims to solve]

[0005] The present invention has been made in view of the above circumstances, and its object is to provide a radical polymerizable polymer that can provide a cured product with good handling properties, excellent coating workability, and excellent hardness, transparency, and adhesion, and a photosensitive resin composition containing the radical polymerizable polymer. [Means for solving the problem]

[0006] As a result of diligent research to solve the above problems, the inventors have found that a radical polymer comprising a structural unit derived from an unsaturated monomer having an acid group, a structural unit derived from an unsaturated monomer having a hydroxyalkyl group containing a secondary hydroxyl group, and a polymer having a polymerizable double bond in its side chain, wherein the polymer further comprises a structural unit derived from an N-substituted maleimide monomer in its main chain and / or a structural unit derived from an unsaturated monomer having a cyclohexyl group in its side chain, and having a weight-average molecular weight of 18,000 or less, can provide a cured product with good handling properties, excellent coating workability, and excellent hardness, transparency, and adhesion, thus completing the present invention.

[0007] In other words, the present invention is defined by the following constituent elements. [1] A polymer having a polymerizable double bond in its side chain, comprising a structural unit derived from an unsaturated monomer having an acid group, a structural unit derived from an unsaturated monomer having a hydroxyalkyl group containing a secondary hydroxyl group, The polymer further comprises a main chain containing a structural unit derived from an N-substituted maleimide monomer and / or a side chain containing a structural unit derived from an unsaturated monomer having a cyclohexyl group. A radical polymerizable polymer having a weight-average molecular weight of 18,000 or less. [2] The unsaturated monomer having an acid group, the unsaturated monomer having a hydroxyalkyl group containing a secondary hydroxyl group, and the unsaturated monomer having a cyclohexyl group are each either acrylic or methacrylic, The radical polymerizable polymer according to [1], wherein the content of constituent units derived from acrylic monomers is 7% by mass or less of the total constituent units of the polymer by mass. [3] The radical polymerizable polymer according to [1] or [2], wherein the acid value of the polymer is 30 to 200 mg KOH / g. [4] The radical polymerizable polymer according to any one of [1] to [3], wherein the double bond equivalent of the polymer is 330 to 1600 g / mol. [5] The polymer has a main chain comprising constituent units derived from an N-substituted maleimide monomer, The radical polymerizable polymer according to any one of [1] to [4], wherein the content of constituent units derived from the N-substituted maleimide monomer is 5% by mass or more and 30% by mass or less of the total constituent units of the polymer. [6] The polymer further comprises constituent units derived from an unsaturated monomer having a cyclic ether structure of 5 or more members, The radical polymerizable polymer according to any one of [1] to [5], wherein the unsaturated monomer having a cyclic ether structure of 5 or more members is either acrylic or methacrylic. [7] The radical polymerizable polymer according to [6], wherein the content of constituent units derived from the unsaturated monomer having a cyclic ether structure of 5-membered rings or more is 5% by mass or more and 20% by mass or less of the total constituent units of the polymer. A photosensitive resin composition comprising a radical polymerizable polymer, a polyfunctional monomer, a polymerization initiator, inorganic fine particles, and a solvent, as described in any of [8] [1] to [7]. [Effects of the Invention]

[0008] The radically polymerizable polymer and the photosensitive resin composition of the present invention are excellent in coatability, and can form a cured product (e.g., a cured film) excellent in hardness, transparency, and adhesiveness. Therefore, the radically polymerizable polymer and the photosensitive resin composition of the present invention can be suitably used, for example, in applications such as resist materials, various coating agents, and paints. MODE FOR CARRYING OUT THE INVENTION

[0009] The present invention is described in detail below. Note that forms obtained by combining two or more of the individual preferred embodiments of the present invention described below are also preferred embodiments of the present invention. In the present specification, "(meth)acrylic acid" means "acrylic acid and / or methacrylic acid", and "(meth)acrylate" means "acrylate and / or methacrylate". In the present specification, the numerical range "Min to Max" means not less than the minimum value Min and not more than the maximum value Max. Further, when suitable numerical values for the upper limit and the lower limit are described stepwise, numerical ranges obtained by appropriately combining the separately described upper limits and lower limits are also suitable numerical ranges.

[0010] 1. Radical polymerizable monomers The radically polymerizable polymer of the present invention has a structural unit derived from an unsaturated monomer having an acid group, a structural unit derived from an unsaturated monomer having a hydroxyalkyl group containing a secondary hydroxyl group, and further has at least one of a structural unit derived from an N-substituted maleimide monomer and a structural unit derived from an unsaturated monomer having a cyclohexyl group. In the polymer having these structural units, by introducing a polymerizable double bond into a side chain and adjusting the polymer to a predetermined molecular weight, the resulting radically polymerizable polymer is excellent in coatability, and can form a cured product excellent in hardness, transparency, and adhesiveness. The structural unit derived from an unsaturated monomer corresponds to, for example, a structure in which the polymerizable double bond of the unsaturated monomer is opened through a polymerization reaction. The structure in which the polymerizable double bond is opened is, for example, a structure in which a carbon-carbon double bond (C=C) becomes a single bond (-C-C-). Furthermore, each of the following structural units may be used alone, or two or more types thereof may be used in combination.

[0011] The structural unit derived from the unsaturated monomer having an acid group is used for improving the alkali developability of the resin. The acid group is not particularly limited as long as it is a functional group exhibiting acidity in water, and examples thereof include a carboxyl group, a sulfonic acid group, and a phosphoric acid group, with a carboxyl group being preferred.

[0012] The unsaturated monomer is not particularly limited as long as it is a monomer having a polymerizable double bond, and examples thereof include (meth)acrylic monomers and vinyl monomers; (meth)acrylic monomers are preferred, and methacrylic monomers are more preferred. In the present specification, the term "(meth)acrylic monomer" means a monomer having an acryloyl group and / or a methacryloyl group, such as acrylic acid (i.e., vinyl carboxylic acid) or an ester thereof, methacrylic acid (i.e., α-methyl carboxylic acid) or an ester thereof, and the term "vinyl monomer" means a monomer other than (meth)acrylic monomers that has a vinyl group. For example, crotonic acid (i.e., β-methyl carboxylic acid) corresponds to a methyl-substituted vinyl carbonyl group similar to a methacryloyl group, but does not correspond to an acryloyl group or a methacryloyl group, and is therefore classified as a vinyl monomer.

[0013] As the unsaturated monomer having an acid group, a (meth)acrylic monomer having a carboxylic acid group, a vinyl monomer having a carboxylic acid group, and the like are preferred, and a (meth)acrylic monomer having a carboxylic acid group is more preferred. Examples of the vinyl monomer having a carboxylic acid group include: vinyl monocarboxylic acids such as crotonic acid; vinyl dicarboxylic acids such as itaconic acid, maleic acid, and fumaric acid; and the like. Examples of (meth)acrylic monomers having a carboxylic acid group include (meth)acrylic acid, and compounds in which a polycarboxylic acid is further esterified to an ester of (meth)acrylic acid and a polyol. The polyols include mono- or poly-C such as ethylene glycol, diethylene glycol, propanediol, and dipropanediol. 2-4 The polycarboxylic acid contains an alkanediol, and ethylene glycol is preferred. The polycarboxylic acid may be oxalic acid, malonic acid, succinic acid, glutaric acid, etc. 1-10 Alkanedicarboxylic acids; C such as hexahydrophthalic acid 6-10 Cycloalkanedicarboxylic acids; phthalic acids, etc. 6-10 Examples of dicarboxylic acids include aromatic dicarboxylic acids. Compounds in which a polycarboxylic acid is further esterified to an ester of (meth)acrylic acid and a polyol include 2-(meth)acryloyloxyethyl succinic acid, 2-(meth)acryloyloxyethyl hexahydrophthalic acid, and 2-(meth)acryloyloxyethyl phthalic acid. Furthermore, a structural unit obtained by reacting a structural unit derived from an unsaturated monomer having an acidic group with a compound containing a reactive group (such as an epoxy group) and a polymerizable unsaturated double bond, and then reacting the resulting hydroxyl group with a polycarboxylic acid, will also have an acidic group. However, since such a structural unit contains an unsaturated double bond, it will not be included in the structural units derived from unsaturated monomers having an acidic group in this invention.

[0014] As the (meth)acrylic monomer having a carboxylic acid group, (meth)acrylic acid is preferred, and methacrylic acid is particularly preferred.

[0015] The content of constituent units derived from unsaturated monomers having acidic groups is preferably 0.5 to 50% by mass, more preferably 1% or more by mass, even more preferably 2% or more by mass, even more preferably 5% or more by mass, even more preferably 40% or less by mass, even more preferably 35% or less by mass, and even more preferably 30% or less by mass. When the content of constituent units derived from unsaturated monomers having acidic groups (especially carboxyl groups) is within the above range, the viscosity of the resulting polymer does not become too high, resulting in good handling properties. Furthermore, the developability with alkaline substances is improved.

[0016] The constituent units derived from the unsaturated monomer having a hydroxyalkyl group containing the secondary hydroxyl group are useful for producing cured products with good hardness, transparency, and adhesion. "Containing a secondary hydroxyl group" means that the hydroxyl group (alcoholic hydroxyl group) of the hydroxyalkyl group is bonded to a secondary carbon atom bonded to two carbon atoms. Furthermore, if the hydroxyalkyl group is directly bonded to carbon atoms in the polymer's main chain, or to carbon atoms such as carbonyl groups or amide groups, it is sufficient that the hydroxyalkyl group contains a secondary hydroxyl group in the bonded state between these carbon atoms and the hydroxyalkyl group.

[0017] Examples of alkyl groups in hydroxyalkyl groups include linear or branched alkyl groups such as ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, n-pentyl group, isopentyl group, n-hexyl group, isohexyl group, n-heptyl group, isoheptyl group, n-octyl group, and 2-methylhexyl group. C2-C10 alkyl groups are preferred, C2-C10 linear alkyl groups are more preferred, and C3-C6 linear alkyl groups are even more preferred.

[0018] Examples of hydroxyalkyl groups containing secondary hydroxyl groups include 2-hydroxypropyl group, 2-hydroxybutyl group, 3-hydroxybutyl group, 2,3-dihydroxybutyl group, 2-hydroxypentyl group, 3-hydroxypentyl group, 4-hydroxypentyl group, 4-hydroxyhexyl group, and 5-hydroxyhexyl group.

[0019] The unsaturated monomer is not particularly limited as long as it is a monomer having a polymerizable double bond, and examples include (meth)acrylic monomers and vinyl monomers, with (meth)acrylic monomers being preferred and methacrylic monomers being more preferred.

[0020] As an unsaturated monomer having a hydroxyalkyl group containing a secondary hydroxyl group, a (meth)acrylic monomer having a hydroxyalkyl group containing a secondary hydroxyl group is more preferred. Examples of (meth)acrylic monomers having a hydroxyalkyl group containing a secondary hydroxyl group include (meth)acrylic monomers having one hydroxyl group, such as 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, and 3-hydroxybutyl (meth)acrylate; and (meth)acrylic monomers having two or more hydroxyl groups, such as 2,3-dihydroxypropyl (meth)acrylate and 2,3-dihydroxybutyl (meth)acrylate. A (meth)acrylic monomer having one hydroxyl group is preferred, and a methacrylic monomer having one hydroxyl group is more preferred.

[0021] The content of constituent units derived from unsaturated monomers having a hydroxyalkyl group containing a secondary hydroxyl group is preferably 0.3 to 35% by mass, more preferably 0.5% by mass or more, even more preferably 1% by mass or more, even more preferably 3% by mass or more, even more preferably 30% by mass or less, even more preferably 25% by mass or less, and even more preferably 20% by mass or less, based on 100% by mass of all constituent units of the radical polymer. When the content of constituent units derived from unsaturated monomers having a hydroxyalkyl group containing a secondary hydroxyl group is within the above range, the radical polymer and the photosensitive resin composition containing the polymer have low viscosity and good handling (coating properties), and it is possible to obtain a cured product with improved hardness, transparency, and adhesion. Even more preferably, when the content is within the above range, it is possible to obtain a radical polymer and a photosensitive resin composition containing the polymer that have excellent heat resistance (especially resistance to thermal decomposition), and it is possible to obtain a cured product with excellent heat resistance.

[0022] The constituent units derived from the N-substituted maleimide monomer are useful for reducing the viscosity of the polymer and can improve the hardness, transparency, and adhesion of the cured product.

[0023] N-substituted maleimide monomers are monomers having a double-bond-containing ring structure within the molecule, such as N-methylmaleimide, N-ethylmaleimide, N-isopropylmaleimide, N-butylmaleimide, N-isobutylmaleimide, Nt-butylmaleimide, N-laurylmaleimide, and other N-alkylmaleimides (preferably NC 1-12 Alkylmaleimide; N-cycloalkylmaleimide such as N-cyclopropylmaleimide, N-cyclobutylmaleimide, N-cyclopentylmaleimide, N-cyclohexylmaleimide (preferably NC 3-20 Cycloalkylmaleimide; N-arylmaleimide such as N-phenylmaleimide (preferably NC 6-12 Arylmaleimide; N-aralkylmaleimide such as N-benzylmaleimide (preferably NC 7-12aralkylmaleimide); and the like. As N-substituted maleimide monomers, N-cycloalkylmaleimide, N-arylmaleimide and N-aralkylmaleimide are preferred from the viewpoint of excellent adhesiveness and dispersibility, and N-C 6-10 cycloalkylmaleimide, N-phenylmaleimide and N-benzylmaleimide are more preferred, and N-phenylmaleimide and N-benzylmaleimide are even more preferred. Also, from the viewpoint of excellent transparency, N-cycloalkylmaleimide, N-arylmaleimide and N-aralkylmaleimide are preferred, and N-C 6-10 cycloalkylmaleimide, N-phenylmaleimide and N-benzylmaleimide are more preferred, and N-cyclohexylmaleimide is even more preferred.

[0024] The N-alkylmaleimide and N-cycloalkylmaleimide may have a substituent, and examples of the substituent include a phenyl group, a benzyl group, a hydroxy group, and the like. The N-arylmaleimide and N-aralkylmaleimide may have a substituent, and examples of the substituent include an alkyl group, a nitro group, a hydroxy group, an alkoxy group, a carboxyl group, a halogeno group, and the like. Specifically, for example, as N-benzylmaleimide having a substituent, alkyl-substituted benzylmaleimides such as p-methylbenzylmaleimide and p-butylbenzylmaleimide; phenolic hydroxyl group-substituted benzylmaleimides such as p-hydroxybenzylmaleimide; halogen-substituted benzylmaleimides such as o-chlorobenzylmaleimide, o-dichlorobenzylmaleimide and p-dichlorobenzylmaleimide; and the like can be mentioned. As N-phenylmaleimide having a substituent, for example, alkyl-substituted phenylmaleimides such as p-methylphenylmaleimide and p-butylphenylmaleimide; phenolic hydroxyl group-substituted phenylmaleimides such as p-hydroxyphenylmaleimide; halogen-substituted phenylmaleimides such as o-chlorophenylmaleimide, o-dichlorophenylmaleimide and p-dichlorophenylmaleimide; and the like can be mentioned.

[0025] The content of constituent units derived from N-substituted maleimide monomers is preferably 1.5 to 40% by mass, more preferably 3% or more by mass, even more preferably 5% or more by mass, even more preferably 7% or more by mass, even more preferably 35% or less by mass, even more preferably 30% or less by mass, and even more preferably 25% or less by mass. When the content of constituent units derived from N-substituted maleimide monomers is within the above range, the viscosity of the radical polymer and the photosensitive resin composition containing the polymer is low, resulting in good handling (coating properties), and it is possible to obtain a cured product with improved hardness, transparency, and adhesion. Even more preferably, when the content of constituent units derived from N-substituted maleimide monomers is within the above range, it is possible to obtain a radical polymer and a photosensitive resin composition containing the polymer with excellent heat resistance, resulting in a cured product with excellent heat resistance, and the dispersibility of inorganic fine particles in the photosensitive resin composition is improved.

[0026] The constituent units derived from the unsaturated monomer having a cyclohexyl group in its side chain are useful for reducing the viscosity of the polymer and can improve the hardness, transparency, and adhesion of the cured product. The unsaturated monomer having a cyclohexyl group is not particularly limited as long as it has at least one cyclohexyl group in its side chain, and the cyclohexyl group is attached to the main chain directly or via a linear linker (e.g., an organic group containing an ester bond).

[0027] The unsaturated monomer is not particularly limited as long as it is a monomer having a polymerizable double bond, and examples include (meth)acrylic monomers and vinyl monomers, with (meth)acrylic monomers being preferred and methacrylic monomers being more preferred. In the case of (meth)acrylic monomers, the carboxylic acid group (-COO-) constituting the (meth)acryloyl group constitutes part of the linker.

[0028] In the case of (meth)acrylic monomers, the chain-like linkers can be, for example, *-COO-** and *-COO-C. 1-6 Alkylene group -**, *-COO-C 1-6Examples of alkylene groups include -COO-**, with *-COO-** and *-COO-CH2-** being preferred. In the case of vinyl monomers, the linker can be, for example, -O- and *-OC 1-6 Alkylene group-**, *-OC 1-6 Examples of alkylene groups include -COO-**, with -O- and *-O-CH2-** being preferred. In the above formula, * indicates the bond position to the main chain, and ** indicates the bond position to the cyclohexyl group.

[0029] As unsaturated monomers having a cyclohexyl group, (meth)acrylic monomers having a cyclohexyl group are preferred, such as cyclohexyl (meth)acrylate and methylcyclohexyl (meth)acrylate, with cyclohexyl (meth)acrylate being preferred and cyclohexyl methacrylate being more preferred.

[0030] The content of constituent units derived from unsaturated monomers having cyclohexyl groups is preferably 1 to 50% by mass, more preferably 3% or more by mass, even more preferably 5% or more by mass, even more preferably 7% or more by mass, even more preferably 45% or less by mass, even more preferably 40% or less by mass, and even more preferably 35% or less by mass. When the content of constituent units derived from unsaturated monomers having cyclohexyl groups is within the above range, the viscosity of the radical polymer and the photosensitive resin composition containing the polymer is low, resulting in good handling (coating properties), and the hardness, transparency, and adhesion of the cured product are further improved. Even more preferably, when the content of constituent units derived from unsaturated monomers having cyclohexyl groups is within the above range, a radical polymer and a photosensitive resin composition containing the polymer with excellent heat resistance are obtained, making it possible to provide a cured product with excellent heat resistance, and the dispersibility of inorganic fine particles in the photosensitive resin composition is improved.

[0031] A radical polymerizable polymer may have at least one of two constituent units: one derived from an N-substituted maleimide monomer and the other from an unsaturated monomer having a cyclohexyl group in its side chain. However, it is preferable to have both constituent units in order to further improve the handling properties of the radical polymerizable polymer and the photosensitive resin composition, as well as the hardness, transparency, and adhesion of the cured product.

[0032] In 100% by mass of all constituent units of the radical polymerizable polymer, the total content of constituent units derived from unsaturated monomers having acid groups, unsaturated monomers having hydroxyalkyl groups containing secondary hydroxyl groups, N-substituted maleimide monomers, and unsaturated monomers having cyclohexyl groups is preferably 15% by mass or more, more preferably 30% by mass or more, even more preferably 50% by mass or more, and even more preferably 80% by mass or more. There is no particular upper limit, and it may be 100% by mass, and is preferably 95% by mass or less.

[0033] The radical polymerizable polymer of the present invention may further have constituent units derived from unsaturated monomers having a cyclic ether structure of five or more members. If it has constituent units derived from unsaturated monomers having a cyclic ether structure of five or more members, viscosity can be further reduced and coatability can be further improved.

[0034] The cyclic ether structure contained in an unsaturated monomer having a cyclic ether structure of 5 or more members is not particularly limited as long as it is a cyclic ring of 5 or more members, and may be monocyclic, polycyclic, or fused ring. Furthermore, an unsaturated monomer having a cyclic ether structure of 5 or more members may have one or two or more cyclic ether structures of 5 or more members. The cyclic ether structure is preferably a 5- to 10-membered ring, more preferably a 5- to 8-membered ring, even more preferably a 5- or 6-membered ring, and even more preferably a furan ring, tetrahydrofuran ring, dioxolane ring, pyran ring, tetrahydropyran ring, or dioxane ring, and even more preferably a tetrahydrofuran ring, dioxolane ring, tetrahydropyran ring, or dioxane ring. As for the dioxolane ring, a 1,3-dioxolane ring is preferred, and as for the dioxane ring, a 1,3-dioxane ring or a 1,4-dioxane ring is preferred, and a 1,3-dioxane ring is more preferred. The cyclic ether structure may have substituents such as alkyl groups (which may be linear, branched, or alicyclic), alkoxy groups, etc., and the number of carbon atoms of the substituent is preferably 1 to 20, and more preferably 1 to 10.

[0035] As an unsaturated monomer having a cyclic ether structure of five or more members, an unsaturated monomer having a cyclic ether structure of five or more members in its side chain is preferred, and the cyclic ether structure of five or more members is attached to the main chain via a chain-like linker (for example, an organic group containing an ester bond) as needed.

[0036] The unsaturated monomer is not particularly limited as long as it is a monomer having a polymerizable double bond, and examples include (meth)acrylic monomers and vinyl monomers, with (meth)acrylic monomers being preferred and methacrylic monomers being more preferred. In the case of (meth)acrylic monomers, the carboxylic acid group (-COO-) constituting the (meth)acryloyl group constitutes part of the linker.

[0037] In the case of (meth)acrylic monomers, the linker can be, for example, *-COO-**, *-COO-C 1-6 Alkylene group -**, *-COO-C1-6 Examples of alkylene groups include -COO-**, with *-COO-** and *-COO-CH2-** being preferred. In the case of vinyl monomers, the linker can be, for example, -O- and *-OC 1-6 Alkylene group-**, *-OC 1-6 Examples include alkylene groups -COO-**, with -O- and *-O-CH2-** being preferred. In the above formula, * indicates the bond position to the main chain, and ** indicates the bond position to the cyclic ether structure.

[0038] As unsaturated monomers having a cyclic ether structure of 5 or more members, (meth)acrylic monomers having a tetrahydrofuran ring, a dioxolane ring, and / or a dioxane ring are preferred, and (meth)acrylic monomers having a tetrahydrofuran ring and / or a dioxolane ring are more preferred.

[0039] Examples of (meth)acrylic monomers having a tetrahydrofuran ring structure include tetrahydrofurfuryl (meth)acrylate and γ-caprolactone-modified tetrahydrofurfuryl (meth)acrylate. Commercially available products such as Light Acrylate THF-A (manufactured by Kyoeisha Chemical Co., Ltd.) may also be used. Examples of (meth)acrylic monomers having a dioxolane ring structure include (2-methyl-2-ethyl-1,3-dioxolane-4-yl)methyl (meth)acrylate and (2,2-cyclohexyl-1,3-dioxolane-4-yl)methyl (meth)acrylate. Commercially available products such as MEDOL10 (manufactured by Osaka Organic Chemical Industry Co., Ltd.) may also be used. Examples of (meth)acrylic monomers having a dioxane ring structure include dioxane glycol di(meth)acrylate and (5-ethyl-1,3-dioxane-5-yl)methyl (meth)acrylate.

[0040] As a (meth)acrylic monomer having a cyclic ether structure of 5 or more members, monomers in which the glass transition temperature of the monomer's homopolymer is -30°C to 100°C are preferred, and monomers in which the glass transition temperature is -20°C to 90°C are more preferred.

[0041] The content of constituent units derived from unsaturated monomers having a cyclic ether structure with 5 or more members is preferably 0 to 35% by mass, more preferably 1% by mass or more, even more preferably 3% by mass or more, even more preferably 5% by mass or more, even more preferably 30% by mass or less, and even more preferably 20% by mass or less, out of 100% by mass of all constituent units of the radical polymerizable polymer. When the content of constituent units derived from unsaturated monomers having a cyclic ether structure with 5 or more members is within the above range, the viscosity of the radical polymerizable polymer and the photosensitive resin composition containing the polymer becomes lower, resulting in better handling (coating) properties. Furthermore, when the above percentage is within the above range, the dispersibility of inorganic fine particles in the photosensitive resin composition becomes good.

[0042] The radical polymerizable polymer of the present invention may have constituent units derived from other copolymerizable monomers other than the constituent units derived from unsaturated monomers having acid groups as described above, constituent units derived from unsaturated monomers having a hydroxyalkyl group containing a secondary hydroxyl group, constituent units derived from N-substituted maleimide monomers, constituent units derived from unsaturated monomers having a cyclohexyl group, and constituent units derived from unsaturated monomers having a cyclic ether structure of 5-membered rings or more.

[0043] Other copolymerizable monomers include, for example, methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, methyl 2-ethylhexyl (meth)acrylate, benzyl (meth)acrylate, isobornyl (meth)acrylate, 1-adamantyl (meth)acrylate, dicyclopentenyl (meth)acrylate, and dicyclopene (meth)acrylate. (meth)acrylic acid esters such as tenyloxyethyl and dicyclopentanyl (meth)acrylate; primary hydroxyl group-containing (meth)acrylic acid esters such as 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate; (meth)acrylamides such as N,N-dimethyl(meth)acrylamide and N-methylol(meth)acrylamide; polystyrene, polymethyl (meth)acrylate, polyethylene oxide, polypropylene oxide, Examples include macromonomers having a (meth)acryloyl group at one end of the polymer molecular chain, such as polysiloxane, polycaprolactone, and polycaprolactam; conjugated dienes such as 1,3-butadiene and isoprene; vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyrate, and vinyl benzoate; vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, 2-ethylhexyl vinyl ether, n-nonyl vinyl ether, lauryl 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-vinylmorpholin, and N-vinylacetamide; and unsaturated isocyanates such as (meth)acrylate isocyanatoethyl and allyl isocyanate.

[0044] Furthermore, radical polymerizable polymers may have constituent units derived from monomers such as aromatic vinyls like styrene, vinyltoluene, and α-methylstyrene; olefins like ethylene and propylene; vinyl halides like vinyl chloride; and vinyl cyanides like acrylonitrile, to the extent that their heat resistance does not deteriorate.

[0045] Furthermore, radical polymerizable polymers may have constituent units derived from monomers that can introduce ring structures other than N-substituted maleimide structures into the main chain. Examples of monomers that can introduce ring structures other than N-substituted maleimide structures into the main chain include dialkyl-2,2'-(oxydimethylene)diacrylate monomers (also called ether dimers) and α-(unsaturated alkoxyalkyl)acrylate monomers (preferably alkyl-(α-allyloxymethyl)acrylate monomers). Ether dimers and α-(unsaturated alkoxyalkyl)acrylate monomers are monomers that undergo cyclization polymerization to form polymers having ring structures in the main chain. In this invention, constituent units derived from ether dimers and α-(unsaturated alkoxyalkyl)acrylate monomers do not fall under the category of constituent units derived from unsaturated monomers having a cyclic ether structure of 5 or more members.

[0046] As the dialkyl-2,2'-(oxydimethylene) diacrylate monomer, it is preferable to use, for example, dimethyl-2,2'-[oxybis(methylene)]bis-2-propenoate, due to its low coloration, dispersibility, and ease of industrial availability.

[0047] As the α-(unsaturated alkoxyalkyl)acrylate monomer, for example, alkyl-(α-allyloxymethyl)acrylate monomers and alkyl-(α-methallyloxymethyl)acrylate monomers are preferred. Specifically, α-allyloxymethylacrylic acid, α-allyloxymethylacrylate 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 t-octyl, α-allyloxymethylacrylate 2-ethyl α-(allyloxymethyl)acrylates containing chain-like saturated hydrocarbon groups such as tylhexyl, 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, and α-allyloxymethylacrylate melicyl are preferred, and α-(allyloxymethyl)acrylate (also referred to as α-(allyloxymethyl)methyl acrylate) is more preferred.

[0048] Furthermore, radical polymerizable polymers may have constituent units derived from monomers having a cyclic ether structure of a three-membered or four-membered ring. Among the monomers having a cyclic ether structure of a three-membered or four-membered ring, monomers having epoxy groups are preferred from the viewpoint of ease of curing by heat and light. Examples of monomers having epoxy groups include glycidyl (meth)acrylate and 3,4-epoxycyclohexyl (meth)acrylate.

[0049] Among other copolymerizable monomers, methyl (meth)acrylate and benzyl (meth)acrylate are preferred in terms of transparency and heat resistance. Primary hydroxyl group-containing (meth)acrylic acid esters such as 2-hydroxyethyl (meth)acrylate and 3-hydroxypropyl (meth)acrylate are preferred in terms of viscosity reduction.

[0050] The content of constituent units derived from other monomers is preferably 0 to 60% by mass, more preferably 0.3% by mass or more, even more preferably 0.5% by mass or more, even more preferably 1% by mass or more, even more preferably 50% by mass or less, even more preferably 40% by mass or less, and even more preferably 30% by mass or less.

[0051] Furthermore, it is preferable that the radical polymer is a polymer that does not lose weight when heated. For this reason, it is preferable that the content of constituent units derived from monomers containing tertiary carbon, such as t-butyl (meth)acrylate and t-amyl (meth)acrylate, be small in the radical polymer. This is because the OC bond between the oxygen atom adjacent to the (meth)acryloyl group and the adjacent tertiary carbon atom is easily broken by heating. The content of the constituent units derived from monomers containing tertiary carbon is not particularly limited depending on the application, but in terms of reducing the thermal weight loss rate and transparency, it is preferably 0 to 5% by mass, more preferably 0 to 3% by mass, even more preferably 0 to 1% by mass, and particularly preferably substantially absent, out of 100% by mass of the total constituent units of the radical polymer.

[0052] In a radical polymerizable polymer, the content of constituent units derived from (meth)acrylic monomers is preferably 40 to 98.5% by mass, more preferably 50% by mass or more, even more preferably 60% by mass or more, even more preferably 97% by mass or less, and even more preferably 95% by mass or less.

[0053] In a radical polymer, the content of constituent units derived from acrylic monomers is preferably 7% by mass or less, more preferably 5% by mass or less, and even more preferably 3% by mass or less, with no particular lower limit, and may even be 0% by mass. When the content of constituent units derived from acrylic monomers is within the above range, it is possible to obtain a cured product with improved hardness, transparency, and adhesion. Even more preferably, when the content is within the above range, it is possible to obtain a radical polymer with excellent heat resistance (especially resistance to thermal decomposition) and a photosensitive resin composition containing the polymer, and to obtain a cured product with excellent heat resistance.

[0054] In a radical polymer, the content of methacrylic monomer-derived constituent units in a total of 100% by mass of constituent units derived from (meth)acrylic monomers is preferably 90% by mass or more, more preferably over 90% by mass, even more preferably 93% by mass or more, even more preferably 95% by mass or more, and even more preferably 97% by mass or more. There is no particular upper limit, and it may be 100% by mass. When the content of methacrylic monomer-derived constituent units is within the above range, it is possible to obtain a cured product with improved hardness, transparency, and adhesion. Even more preferably, when the content is within the above range, it is possible to obtain a radical polymer with excellent heat resistance (especially resistance to thermal decomposition) and a photosensitive resin composition containing the polymer, and to obtain a cured product with excellent heat resistance.

[0055] The radical polymerizable polymer of the present invention has polymerizable double bonds in its side chains. Because the radical polymerizable polymer has polymerizable double bonds in its side chains, it can be cured by heat or light. When included in a photosensitive resin composition, its sensitivity to light is improved, allowing it to be cured with less light, and the mechanical strength of the resulting cured product can also be improved.

[0056] Polymerizable double bonds in side chains can be introduced, for example, by reacting a compound having polymerizable double bonds with a structural unit derived from an unsaturated monomer. Specifically, they can be introduced by adding a compound containing at least one reactive group selected from the group consisting of epoxy groups, oxazoline groups, and hydroxyl groups (i.e., a group that reacts with an acid group) and a polymerizable unsaturated double bond to a base polymer having an acid group (for example, a polymer having structural units derived from an unsaturated monomer having an acid group). Alternatively, they can also be introduced by adding a compound containing an acid group and a polymerizable unsaturated double bond to a base polymer having a group that reacts with an acid group (preferably an epoxy group) (for example, a polymer having structural units derived from an unsaturated monomer having a group that reacts with an acid group, such as an epoxy group). Hereinafter, compounds containing a reactive group and a polymerizable unsaturated double bond, and compounds containing an acid group and a polymerizable unsaturated double bond, will be collectively referred to as "addition compounds." When an addition compound is reacted with a base polymer, a double bond and a hydroxyl group are formed in the side chain. This hydroxyl group may be further esterified with a compound having a carboxylic acid group (preferably an unsaturated polycarboxylic acid such as maleic anhydride; a saturated polycarboxylic acid such as succinic anhydride; etc.).

[0057] Since the radical polymerizable polymer of the present invention has an acid group, a method of introducing a polymerizable double bond by adding a compound containing a reactive group and a polymerizable unsaturated double bond is preferred. Furthermore, as a polymerizable unsaturated double bond, the double bond of the (meth)acryloyl group is preferred from the viewpoint of reactivity during curing.

[0058] Examples of compounds containing the reactive group and polymerizable unsaturated double bond include compounds having a hydroxyl group and a double bond, such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and allyl alcohol; compounds having an epoxy group and a double bond, such as glycidyl (meth)acrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate, and allyl glycidyl ether; and compounds having an oxazoline group and a double bond, such as vinyl oxazoline and isopropenyl oxazoline. As compounds containing the reactive group and polymerizable unsaturated double bond, compounds having an epoxy group and a carbon-carbon double bond are preferred, such as glycidyl (meth)acrylate, allyl glycidyl ether, α-ethylglycidyl (meth)acrylate, 3,4-epoxycyclohexylmethyl acrylate (for example, "Cychromer A400" manufactured by Daicel Chemical Industries, Ltd.), 3,4-epoxycyclohexylmethyl methacrylate (for example, "Cychromer M100" manufactured by Daicel Chemical Industries, Ltd.), o-vinylbenzylglycidyl ether, m-vinylbenzylglycidyl ether, and p-vinylbenzylglycidyl ether. Glycidyl (meth)acrylate and 3,4-epoxycyclohexylmethyl (meth)acrylate are more preferred due to their high reactivity during curing, ease of reaction control, and availability. Examples of compounds containing the aforementioned acid group and polymerizable unsaturated double bond include those similar to the examples given above as unsaturated monomers having an acid group. The adduct may be used alone or in combination of two or more adducts.

[0059] The amount of the adduct compound used is preferably 5 to 120 parts by mass, more preferably 5 to 80 parts by mass, and even more preferably 5 to 60 parts by mass, per 100 parts by mass of the total constituent units of the base polymer (precursor polymer of a radical polymer). The amount of the compound containing a reactive group and a polymerizable unsaturated double bond used is preferably 0.01 to 0.95 moles, more preferably 0.05 to 0.90 moles, and even more preferably 0.1 to 0.80 moles, per mole of constituent units derived from the unsaturated monomer having an acid group contained in the base polymer. The amount of the compound containing an acid group and a polymerizable unsaturated double bond used is preferably 0.01 to 1.2 moles, more preferably 0.1 to 1.0 mole, and even more preferably 0.3 to 0.9 moles, per mole of constituent units derived from the unsaturated monomer having a group that reacts with the acid group contained in the base polymer. By keeping the amount of adduct compound used within the above range, the exposure sensitivity, developability, and storage stability of the resulting photosensitive resin composition can be improved, and furthermore, the adhesion and hardness of the cured product can also be improved.

[0060] Examples of structural units having a double bond in the side chain include structural unit A, which is formed from any combination of a structural unit derived from an unsaturated monomer having an acid group or a structural unit derived from an unsaturated monomer having a group that reacts with an acid group, and an adduct compound, and structural unit B, which is formed from any combination of structural unit A and the compound having the carboxylic acid group. A structural unit formed by the addition of glycidyl (meth)acrylate to a structural unit derived from (meth)acrylic acid (equivalent to a structural unit formed by the addition of (meth)acrylic acid to a structural unit derived from glycidyl (meth)acrylate is preferred as structural unit A, and a structural unit formed by the esterification of maleic anhydride to the hydroxyl group of this preferred structural unit A is preferred as structural unit B.

[0061] The content of structural units having double bonds in their side chains is preferably 10 to 70% by mass, more preferably 15% by mass or more, even more preferably 20% by mass or more, even more preferably 65% ​​by mass or less, and even more preferably 60% by mass or less, out of 100% by mass of all structural units of the radical polymer. When the content of structural units having double bonds in their side chains is within the above range, the exposure sensitivity, developability, and storage stability of the resulting photosensitive resin composition can be improved, and furthermore, the adhesion and hardness of the cured product can also be improved.

[0062] The double bond equivalent of the radical polymerizable polymer is preferably 330 to 1600 g / equivalent (mol). When the double bond equivalent is within this range, the curability (sensitivity to heat and light) of the radical polymerizable polymer is improved, and the adhesion of the cured product is further enhanced. In addition, discoloration during curing can be reduced and transparency can be improved. From the viewpoint of balancing curability and storage stability, the double bond equivalent is preferably 350 g / equivalent or more, more preferably 380 g / equivalent or more, even more preferably 400 g / equivalent or more, and also preferably 1500 g / equivalent or less, more preferably 1400 g / equivalent or less, and even more preferably 1300 g / equivalent or less.

[0063] In this specification, double bond equivalent is the mass (g) of solids in the polymer solution per mole of double bonds in the polymer. The mass of solids in the polymer solution may be, for example, the sum of the masses of each monomer component constituting the polymer. The double bond equivalent can be determined by dividing the mass (g) of solids in the polymer solution by the amount (mol) of double bonds in the polymer. Specifically, the double bond equivalent can be determined by confirming the structure of the monomers constituting the base polymer, such as unsaturated monomers having acid groups used in polymerization, and the addition compounds used as needed, and then determining their masses. It can also be measured using various analyses such as titration and elemental analysis, NMR, and IR, as well as differential scanning calorimetering. For example, it may 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.

[0064] Double bond equivalent is a value that measures the amount of double bonds contained in a molecule. For compounds (polymers) of the same molecular weight, a larger double bond equivalent value indicates a smaller amount of double bonds.

[0065] The weight-average molecular weight (Mw) of the radical polymerizable polymer is 18,000 or less, preferably 17,000 or less, more preferably 15,000 or less, even more preferably 13,000 or less, and even more preferably 12,000 or less. The lower limit is preferably 3,000 or more, more preferably 4,000 or more, and even more preferably 5,000 or more. When the weight-average molecular weight is within the above range, the viscosity is low, the handling (coating) is good, and the hardness and adhesion of the cured product are further improved.

[0066] The number-average molecular weight (Mn) of the radical polymerizable polymer is preferably 1000 to 7000, more preferably 1500 or more, even more preferably 2000 or more, even more preferably 2500 or more, even more preferably 5500 or less, even more preferably 4500 or less, and even more preferably 4000 or less.

[0067] The degree of dispersion (Mw / Mn) of the radical polymerizable polymer is preferably 1.2 to 4.6, more preferably 1.5 or higher, even more preferably 1.8 or higher, even more preferably 4.2 or lower, and even more preferably 3.8 or lower.

[0068] Weight-average molecular weight and number-average molecular weight can be determined, for example, by gel permeation chromatography (GPC) using polystyrene equivalents. Specifically, using polystyrene as the standard substance and tetrahydrofuran (THF) as the eluent, the GPC method can be performed using an HLC-8220GPC (manufactured by Tosoh Corporation) and a TSKgel SuperHZM-N column (manufactured by Tosoh Corporation).

[0069] The acid value of the radical polymerizable polymer is preferably 30 to 200 mg KOH / g, more preferably 35 mg KOH / g or more, even more preferably 40 mg KOH / g or more, even more preferably 45 mg KOH / g or more, even more preferably 180 mg KOH / g or less, even more preferably 170 mg KOH / g or less, and even more preferably 160 mg KOH / g or less. When the acid value is within the above range, the dispersibility of the radical polymerizable polymer and inorganic fine particles in the photosensitive resin composition is improved, viscosity is suppressed, resulting in excellent coatability, and the adhesion of the resulting cured product is also improved. Furthermore, alkali solubility is improved, which also improves developability.

[0070] The acid value of a radical polymerizable polymer can be determined by measuring the acid value of the polymer solution using an automatic titrator (e.g., a product name "COM-555" manufactured by Hiranuma Sangyo Co., Ltd.) with a 0.1 N aqueous KOH solution as the titrant, and then calculating the acid value per unit of solids from the acid value of the polymer solution and the solids content of the polymer solution. The solids content of the polymer solution can be determined, for example, as follows: First, weigh out about 0.3 g of the polymer solution into an aluminum cup, add about 1 g of acetone and dissolve it, then allow it to air dry at room temperature. Then, using a hot air dryer (e.g., a product name "PHH-101" manufactured by ESPEC Corporation), dry it at 140°C for 3 hours, allow it to cool in a desiccator, and measure the mass. From the amount of mass loss, calculate the solids content concentration (non-volatile content) of the polymer solution.

[0071] The thermal weight loss rate of the radical polymerizable polymer is preferably 5.0% by mass or less, more preferably 3.2% by mass or less, even more preferably 3.0% by mass or less, and even more preferably 2.8% by mass or less. There is no particular lower limit, and it may be 0% by mass. When the thermal weight loss rate is within the above range, the heat resistance (especially the resistance to thermal decomposition) is high.

[0072] The thermal weight loss rate of a radical polymerizable polymer can be determined by, for example, adding 4 g of tetrahydrofuran to 2 g of polymer solution, dropping the solution onto 60 g of hexane, separating and removing the precipitated resin (polymer), vacuum drying it overnight at 40°C, weighing 10 mg of the resulting resin powder, and measuring the weight loss rate at 230°C for 30 minutes under a nitrogen atmosphere using a thermogravimetric analyzer TGA-50 (manufactured by SHIMADZU).

[0073] The applications of the radical polymerizable polymer of the present invention are not particularly limited, but it can be suitably used in various applications such as printing plates, protective films for color filters, color filters, black matrices, and other liquid crystal display panel manufacturing applications. In particular, the resulting cured film has high hardness and high transparency, making it very useful as a protective film or insulating film in various display devices. The display device is not particularly limited, but examples include liquid crystal display devices, solid-state image sensors, and touch panel display devices. Among touch panel display devices, capacitive types are particularly preferred.

[0074] 2. Method for producing radical polymerizable polymers Radical polymerizable polymers are obtained by polymerizing monomer components that form the constituent units. Commonly used polymerization methods such as bulk polymerization, solution polymerization, and emulsion polymerization can be employed, and the appropriate method should be selected according to the purpose and application. Among these, solution polymerization is preferred because it is industrially advantageous and allows for easy adjustment of molecular weight, etc. Furthermore, polymerization methods based on mechanisms such as radical polymerization, anionic polymerization, cationic polymerization, and coordination polymerization can be used as the polymerization mechanism for the monomer components, but polymerization methods based on the radical polymerization mechanism are preferred because they are industrially advantageous.

[0075] The polymerization initiation method in the aforementioned polymerization reaction is to supply the necessary energy to the monomer components from an active energy source such as heat, electromagnetic waves (infrared rays, ultraviolet rays, X-rays, etc.), or electron beams. Furthermore, the use of a polymerization initiator is preferable because it can significantly reduce the energy required to initiate polymerization and facilitate reaction control. A chain transfer agent may also be used in combination. The molecular weight of the polymer obtained by polymerization can be controlled by adjusting the amount and type of polymerization initiator, the polymerization temperature, and the type and amount of chain transfer agent.

[0076] When polymerization is carried out by solution polymerization, the solvent used for polymerization is not particularly limited as long as it is inert to the polymerization reaction, and can be appropriately set according to the polymerization conditions such as the polymerization mechanism, the type and amount of monomers used, the polymerization temperature, and the polymerization concentration. However, when the solvent is used as a diluent or the like when it is later made into a photosensitive resin composition, it is efficient and preferable to use the solvent for the solution polymerization of the monomer components.

[0077] Suitable solvents include, for example, the following compounds, and one or more of these can be used. Monoalcohols such as methanol, ethanol, isopropanol, n-butanol, and s-butanol; glycols such as ethylene glycol and propylene glycol; cyclic ethers such as tetrahydrofuran and dioxane; glycol monoethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monobutyl ether, and 3-methoxybutanol; glycol ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol ethyl methyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol ethyl methyl ether, propylene glycol dimethyl ether, and propylene glycol diethyl ether; ethylene glycol monomethyl ether ethyl ether Esters of glycol monoethers such as tate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monobutyl ether acetate, dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether acetate, dipropylene glycol monobutyl ether acetate, 3-methoxybutyl acetate; alkyl esters such as methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, methyl propionate, ethyl propionate, butyl propionate, methyl lactate, ethyl lactate, butyl lactate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, methyl acetoacetate, ethyl acetoacetate;Ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; aromatic hydrocarbons such as benzene, toluene, xylene, and ethylbenzene; aliphatic hydrocarbons such as hexane, cyclohexane, and octane; amides such as dimethylformamide, dimethylacetamide, and N-methylpyrrolidone; etc.

[0078] Among the solvents mentioned above, monoalcohols and glycol monoether esters are more preferred, and glycol monoether esters are even more preferred. In particular, as solvents, propylene glycol monomethyl ether acetate and isopropanol are preferred in terms of solubility, transparency, and chain transfer agent function, with propylene glycol monomethyl ether acetate being particularly preferred.

[0079] The amount of solvent used in the polymerization reaction is preferably 50 to 1000 parts by mass, and more preferably 100 to 500 parts by mass, per 100 parts by mass of the total mass of monomer components. Furthermore, during the polymerization reaction, it is preferable to set the amounts of solvent and each monomer component so that the final solid content concentration (non-volatile content concentration) of the polymer solution is 10 to 70% by mass. In terms of productivity and polymerizability, a more preferable final solid content concentration is 20 to 65% by mass, and even more preferably 25 to 60% by mass.

[0080] The polymerization initiator is not particularly limited as long as it is commonly used, but examples include organic peroxides such as cumene hydroperoxide, diisopropylbenzene hydroperoxide, di-t-butyl peroxide, lauroyl peroxide, benzoyl peroxide, t-butyl peroxyisopropyl carbonate, t-amyl peroxy-2-ethylhexanoate, and t-butyl peroxy-2-ethylhexanoate; and azo compounds such as 2,2'-azobis(isobutyronitrile), 1,1'-azobis(cyclohexanecarbonile), 2,2'-azobis(2,4-dimethylvaleronitrile), and dimethyl-2,2'-azobis(2-methylpropionate). These polymerization initiators may be used individually or in combination of two or more. The amount of initiator used is not particularly limited and can be appropriately set according to the combination of monomers used, reaction conditions, and the molecular weight of the target polymer. However, in order to obtain a polymer with a weight-average molecular weight of several thousand to tens of thousands without gelation, it is preferably 0.1 to 18 parts by mass, more preferably 0.5 parts by mass or more, even more preferably 1.5 parts by mass or more, even more preferably 2.2 parts by mass or more, even more preferably 15 parts by mass or less, even more preferably 12 parts by mass or less, and even more preferably 10 parts by mass or less.

[0081] When polymerizing monomer components, a commonly used chain transfer agent may be added as needed to adjust the molecular weight. Examples of chain transfer agents include mercaptan-based chain transfer agents such as n-dodecyl mercaptan, mercaptopropionic acid, mercaptoacetic acid, and methyl mercaptoacetate; thiol-based chain transfer agents such as 2-mercaptoethanol, thioglycolic acid, 3-mercaptopropionic acid, thiosalicylic acid, 1-thioglycerol, and 4-aminothiophenol; and α-methylstyrene dimer. Among the chain transfer agents, n-dodecyl mercaptan and mercaptopropionic acid are preferred because they have a high chain transfer effect, can reduce residual monomers, and are readily available. When using a chain transfer agent, the amount used can be appropriately set according to the combination of monomers used, reaction conditions, the molecular weight of the target polymer, etc., and is not particularly limited. However, in order to obtain a polymer with a weight-average molecular weight of several thousand to tens of thousands without gelation, it is preferable that the amount is 0.1 to 15 parts by mass, and more preferably 0.5 to 10 parts by mass, per 100 parts by mass of the total mass of monomer components. In the radical polymerizable polymer of the present invention, in order to achieve high transparency, the thiol-based chain transfer agent is preferably 1 part by mass or less, more preferably 0.1 parts by mass or less, and particularly preferably substantially absent, per 100 parts by mass of the total mass of monomer components. The radical polymerizable polymer of the present invention is preferably obtained by radical polymerization of the above-mentioned monomer components using the above-mentioned polymerization initiator and without using a thiol-based chain transfer agent.

[0082] While there are no particular limitations on the order in which monomer components and polymerization initiators are added during polymerization, methods such as adding all monomer components at once to the solvent, or adding the remaining monomer components continuously or sequentially to a reaction vessel that has already been charged with the solvent and some of the monomer components, can be employed.

[0083] There are no particular limitations on the pressure during the polymerization reaction; it can be carried out under either atmospheric pressure or pressurized conditions. The temperature during the polymerization reaction depends on the type and composition ratio of monomers used and the type of solvent used, but it is generally preferable to carry it out in the range of 20 to 150°C, and more preferably in the range of 40 to 125°C.

[0084] When a polymer is obtained by a polymerization step and then the addition compound is reacted to contain polymerizable double bonds in the side chains, the method of the addition reaction of the addition compound is not particularly limited. Any known method may be used as appropriate for the addition reaction, but for example, it is preferable to add the addition compound to the reaction solution obtained in the polymerization step and react it at 60 to 140°C (more preferably 70 to 130°C). Furthermore, it is preferable to use catalysts such as amine compounds such as triethylamine and dimethylbenzylamine; ammonium salts such as tetraethylammonium chloride; phosphonium salts such as tetraphenylphosphonium bromide; amide compounds such as dimethylformamide; and phosphines such as tri-n-propylphosphine, tri-n-butylphosphine, diphenylmethylphosphine, and triphenylphosphine. In addition, it is also preferable to use polymerization inhibitors such as methylhydroquinone and oxygen in the addition reaction.

[0085] When reacting a compound having a carboxylic acid group after the addition reaction, the amount of compound having a carboxylic acid group used is not particularly limited, but it is preferable to set it so that the acid value of the resulting radical polymerizable polymer falls within the range described above.

[0086] 3. Photosensitive resin composition The present invention also relates to a photosensitive resin composition comprising the above-mentioned radical polymerizable polymer, polyfunctional monomer, polymerization initiator, inorganic fine particles, and solvent, and is particularly preferably a negative-type photosensitive resin composition. The applications of the photosensitive resin composition of the present invention are not particularly limited, but it is suitably used as a material for forming protective films for color filters, liquid crystal display elements, integrated circuit elements, solid-state image sensors, etc.

[0087] 3.1 Radical polymerizable polymers The photosensitive resin composition of the present invention contains a polymer as a radical polymerizable polymer, comprising a structural unit derived from an unsaturated monomer having an acid group, a structural unit derived from an unsaturated monomer having a hydroxyalkyl group containing a secondary hydroxyl group, and a polymer having a polymerizable double bond in its side chain, further comprising a structural unit derived from an N-substituted maleimide monomer and / or a structural unit derived from an unsaturated monomer having a cyclohexyl group in its side chain, and having a weight-average molecular weight of 18,000 or less.

[0088] The content of the radical polymerizable polymer in the photosensitive resin composition is preferably 5 to 70% by mass, more preferably 10% by mass or more, even more preferably 15% by mass or more, more preferably 65% ​​by mass or less, even more preferably 50% by mass or less, even more preferably 45% by mass or less, and even more preferably 40% by mass or less. When the content of the radical polymerizable polymer is within the above range, the effects of the present invention can be more significantly realized.

[0089] 3.2 Polyfunctional monomers The polyfunctional monomer contained in the photosensitive resin composition of the present invention is a low-molecular-weight compound having polymerizable unsaturated bonds (also referred to as polymerizable unsaturated groups) that can be polymerized by irradiation with free radicals, electromagnetic waves (e.g., infrared rays, ultraviolet rays, X-rays, etc.), electron beams, or other active energy rays. For example, a polyfunctional compound having two or more polymerizable unsaturated groups in the molecule is an example. The molecular weight is not particularly limited, but from the viewpoint of handling, for example, 3000 or less is preferred, and 2000 or less is more preferred. Among these, a polyfunctional (meth)acrylate compound with two or more functions (hereinafter also simply referred to as "polyfunctional (meth)acrylate compound") is particularly preferred. A polyfunctional (meth)acrylate compound is a compound having two or more (meth)acryloyl groups in one molecule. By including a polyfunctional monomer (especially a polyfunctional (meth)acrylate compound), the photosensitive resin composition becomes superior in photosensitivity and curability, making it possible to obtain a cured product with extremely high hardness and high transparency. The number of functionalities in the polyfunctional (meth)acrylate compound is preferably 3 or more, more preferably 4 or more, and even more preferably 5 or more. Furthermore, from the viewpoint of further suppressing curing shrinkage, the number of functionalities is preferably 10 or less, more preferably 8 or less, and even more preferably 6 or less.

[0090] Examples of polyfunctional monomers include (di)ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, trimethylolpropane di(meth)acrylate, trimethylolpropane tri(meth)acrylate, propylene oxide-added trimethylolpropane tri(meth)acrylate, ε-caprolactone-added 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, propylene oxide-added pentaerythritol Examples of polyfunctional (meth)acrylates include tetra(meth)acrylate, ε-caprolactone-added pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, ethylene oxide-added dipentaerythritol hexa(meth)acrylate, propylene oxide-added dipentaerythritol hexa(meth)acrylate, ε-caprolactone-added dipentaerythritol hexa(meth)acrylate, tri(meth)acrylate of tris(hydroxyethyl) isocyanurate, propylene oxide-added ditrimethylolpropanetetra(meth)acrylate, ε-caprolactone-added ditrimethylolpropanetetra(meth)acrylate, and other such meth)acrylates.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.

[0091] The content ratio of polyfunctional monomers in a photosensitive resin composition is not particularly limited and can be set appropriately depending on the type of polyfunctional monomer and radical polymer used, as well as the application and purpose of the photosensitive resin composition. The content ratio of polyfunctional monomers in a photosensitive resin composition is preferably 2 to 85% by mass, more preferably 5% by mass or more, even more preferably 10% by mass or more, even more preferably 15% by mass or more, even more preferably 75% by mass or less, even more preferably 60% by mass or less, even more preferably 50% by mass or less, and even more preferably 40% by mass or less, from the viewpoint of superior developability and platemaking properties.

[0092] Furthermore, the polyfunctional monomer content is preferably 50 to 500 parts by mass, more preferably 80 parts by mass or more, even more preferably 100 parts by mass or more, and even more preferably 120 parts by mass or more, and from the viewpoint of further improving developability, it is more preferably 400 parts by mass or less, even more preferably 300 parts by mass or less, even more preferably 200 parts by mass or less, and even more preferably 150 parts by mass or less. When the polyfunctional monomer content relative to the radical polymer is within the above range, a cured product with higher surface hardness can be obtained, and combined with the preferred weight-average molecular weight of the radical polymer being 3000 or more, developability is further improved.

[0093] 3.3 Polymerization Initiators The photosensitive resin composition of the present invention contains a polymerization initiator and can initiate polymerization and form a cured product by irradiation with light or heat. The photosensitive resin composition of the present invention can also be thermally cured by using a known thermal polymerization initiator, but it is preferable to add a photopolymerization initiator and perform photocuring from the standpoint of enabling microfabrication or image formation of the cured product by photolithography. In this respect, it is preferable to use a photopolymerization initiator as the polymerization initiator.

[0094] Known thermal polymerization initiators can be used, such as organic peroxides including methyl ethyl ketone peroxide, benzoyl peroxide, dicumyl peroxide, t-butyl hydroperoxide, cumene hydroperoxide, t-butyl peroxyoctoate, t-butyl peroxybenzoate, and lauroyl peroxide; and azo compounds such as azobisisobutyronitrile. For thermal polymerization applications, a curing accelerator may be mixed into the composition. Examples of such curing accelerators include tertiary amines, cobalt naphthenate, and cobalt octoate.

[0095] Known photopolymerization initiators can be used, for example, acetophenone, diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyldimethylketal, 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, 2- Acetophenones such as dimethylamino-2-(4-methylbenzyl)-1-(4-morpholin-4-ylphenyl)-butan-1-one, oligo{2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone}, and 2-hydroxy-1-{4-[4-(2-hydroxy-2-methylpionyl)benzyl]phenyl}-2-methylpropan-1-one; benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzoin isobutyl ether. Benzoins such as benzoin; benzophenone, o-methyl benzoylbenzoate, 4-phenylbenzophenone, 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]benzenemethanaminonium bromide, (4-benzoylbenzyl)trimethylammonium chloride, and other benzophenones; 2- Thioxanthones such as isopropylthioxanthone, 4-isopropylthioxanthone, 2,4-diethylthioxanthone, 2,4-dichlorothioxanthone, 1-chloro-4-propoxythioxanthone, and 2-(3-dimethylamino-2-hydroxy)-3,4-dimethyl-9H-thioxanthone-9-one mesochloride; acylphosphine oxides such as 2,4,6-trimethylbenzoyl-diphenylphosphine oxide and bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide;Examples include oxime esters such as 1,2-octanedione, 1-[4-(phenylthio)-,2-(O-benzoyl oxime)], and O-(acetyl)-N-(1-phenyl-2-oxo-2-(4'-methoxynaphthyl)ethylidene)hydroxylamine; titanosenes such as bis(η5-2,4-cyclopentadiene-1-yl)-bis(2,6-difluoro-3-(1H-pyrrole-1-yl)-phenyl)titanium; and phenylglyoxylic methyl esters. Among these, acetophenones, oxime esters, and titanosenes are preferred in terms of hardness and heat resistance, acetophenones are more preferred, aminoacetophenones are even more preferred, and 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one and 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone are even more preferred. ;

[0096] Particularly preferred specific polymerization initiators include 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one ("IRGACURE 907", BASF), 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1 ("IRGACURE 369", BASF), and 2-dimethylamino-2-(4-methyl-benzyl)-1-(4-morpholin-4-yl-phenyl). Examples include aminoacetophenones such as -butan-1-one ("IRGACURE379", manufactured by BASF); titanosenes such as bis(η5-2,4-cyclopentadiene-1-yl)-bis(2,6-difluoro-3-(1H-pyrrole-1-yl)-phenyl)titanium ("IRGACURE784", manufactured by BASF); and oxime ester compounds such as 1,2-octanedione,1-[4-(phenylthio)-,2-(O-benzoyloxime)] ("IRGACURE OXE01", manufactured by BASF).

[0097] These polymerization initiators may be used individually or in combination of two or more.

[0098] The content of polymerization initiators in a photosensitive resin composition can be appropriately set according to the use and purpose of the photosensitive resin composition, and is not particularly limited. As for the content ratio of polymerization initiators in a photosensitive resin composition, for example, from the viewpoint of obtaining a cured product with superior heat resistance, it is preferable to have 0.5% by mass or more, more preferably 1% by mass or more, and even more preferably 1.2% by mass or more, based on 100% by mass of the total solid content of the photosensitive resin composition. Furthermore, from the viewpoint of balancing the effects of decomposition products of the polymerization initiator and economic efficiency, it is preferable to have 30% by mass or less, more preferably 20% by mass or less, even more preferably 10% by mass or less, and even more preferably 5% by mass or less.

[0099] 3.4 Inorganic fine particles Inorganic fine particles refer to fine particles containing inorganic components, such as metals (including metalloids), their salts (carbonates, sulfates, etc.), or their oxides. Among these, metal salts or oxides are preferred, and metal oxides are more preferred. A molecule may contain one or more metal atoms, and if it contains two or more, it may contain one or more types of metal atoms. Because the photosensitive resin composition of the present invention contains inorganic fine particles, it can form a cured product with superior hardness.

[0100] Preferred metals include, for example, silicon (metalloid), titanium, zirconium, calcium, barium, and aluminum, with silicon, zirconium, titanium, and aluminum being more preferred, and even more preferably containing at least silicon to further enhance surface hardness. Preferred metal salts include, for example, calcium carbonate and barium sulfate, and preferred metal oxides include, for example, silicon oxide (silica, etc.), titanium oxide, aluminum oxide, and zirconium oxide (zirconia, etc.). Inorganic fine particles are particularly preferably silicon oxide, and may also be composite metal oxides further containing metal atoms other than silicon. Furthermore, inorganic fine particles are preferably metal oxide particles having hydroxyl groups on their surface, and more preferably silica fine particles. If metal oxide particles have hydroxyl groups on their surface, their affinity with the radical polymerizable polymer contained in the photosensitive resin composition is further improved. Silica fine particles are preferably surface-modified, such as carboxylic acid modification or amino group modification, and more preferably have (meth)acryloyloxy groups bonded to silicon atoms via divalent linking groups through surface modification.

[0101] The number-average primary particle diameter (diameter of primary particles) of inorganic fine particles is preferably 1 to 500 nm, more preferably 1 to 300 nm, even more preferably 1 to 200 nm, even more preferably 1 to 100 nm, and even more preferably 1 to 50 nm. When the number-average primary particle diameter of inorganic fine particles is within the above range, the dispersibility and dispersion stability of the inorganic fine particles in the photosensitive resin composition are improved, and it becomes possible to form a cured product with high transparency. The number-mean primary particle diameter can be measured, for example, using a laser diffraction particle size analyzer. Alternatively, the number-mean primary particle diameter can be determined by observing inorganic fine particles under magnification using a transmission electron microscope (TEM), field emission transmission electron microscope (FE-TEM), or field emission scanning electron microscope (FE-SEM), randomly selecting 100 primary particles, measuring their lengths along their long axes, and calculating their arithmetic mean.

[0102] Inorganic fine particles may be used in the form of a dried powder or as a dispersion in an organic solvent (for example, colloidal silica). However, from the viewpoint of dispersion stability of the photosensitive resin composition, it is preferable to use inorganic fine particles in the form of a dispersion in an organic solvent. In other words, it is preferable that inorganic fine particles be included in the photosensitive resin composition as an organic solvent dispersion.

[0103] Examples of inorganic fine particle shapes include spherical, granular, ellipsoidal, cubic, rectangular, pyramidal, needle-shaped, columnar, rod-shaped, cylindrical, flake-shaped, plate-shaped, and flaky. From the viewpoint of dispersibility in solvents, spherical, granular, and columnar shapes are preferred for inorganic fine particle shapes.

[0104] When inorganic fine particles are used in a dispersed form, the organic solvent (dispersion medium) used can be, for example, one of the solvents contained in the photosensitive resin composition described later, and one type of organic solvent may be used, or two or more types may be used in combination.

[0105] Organic solvent dispersions can be obtained by sufficiently dispersing inorganic fine particles in an organic solvent, but commercially available products may also be used. For example, organosilica sols using methyl ethyl ketone as the dispersion medium, such as MEK-ST, MEK-ST-L, MEK-ST-ZL, MEK-ST-UP, MEK-AC-2140Z; organosilica sols using methyl isobutyl ketone as the dispersion medium, such as MIBK-ST, MIBK-SD-L; organosilica sols using ethyl acetate as the dispersion medium, such as EAC-ST; organosilica sols using methanol as the dispersion medium, such as methanol silica sol and MA-ST-M; organosilica sols using isopropanol as the dispersion medium, such as IPA-ST, IPA-ST-L; organosilica sols using ethylene glycol as the dispersion medium, such as EG-ST; X Examples include organosilica sols using xylene / n-butanol as a dispersion medium, such as BA-ST; organosilica sols using alkylene glycol monoalkyl ethers as a dispersion medium, such as NPC-ST-30 and PGM-ST; organosilica sols using dimethylacetamide as a dispersion medium, such as DMAC-ST; organosilica sols using toluene as a dispersion medium, such as TOL-ST; organosilica sols using propylene glycol monomethyl ether acetate as a dispersion medium, such as PMA-ST; and organosilica sols using propylene glycol monomethyl ether as a dispersion medium, such as PGM-AC-4130Y (all manufactured by Nissan Chemical Corporation).

[0106] The content of inorganic fine particles (solid content) in a photosensitive resin composition is preferably 5 to 70% by mass, more preferably 10% by mass or more, even more preferably 15% by mass or more, and most preferably 60% by mass or less, based on the total solid content of the photosensitive resin composition, from the viewpoint of developability and transparency. Furthermore, when silicon-containing fine particles (preferably silica fine particles) are used as inorganic fine particles, the content of silicon-containing fine particles (solid content) is preferably 50% by mass or more, more preferably 70% by mass or more, and even more preferably 90% by mass or more, with no particular upper limit, and 100% by mass being preferred.

[0107] When inorganic fine particles are used in dispersion form, the amount of organic solvent used should be sufficient to adequately disperse the inorganic fine particles. For example, it is preferable to use 50 to 600 parts by mass per 100 parts by mass of inorganic fine particles, more preferably 70 parts by mass or more, even more preferably 100 parts by mass or more, and even more preferably 550 parts by mass or less, and even more preferably 500 parts by mass or less.

[0108] 3.5 Solvents The photosensitive resin composition of the present invention contains a solvent as a diluent. When a radical polymerizable polymer is obtained by solution polymerization, the radical polymerizable polymer may be used as a polymer solution without separating it from the solvent, and the solvent contained in the polymer solution may be the solvent contained in the photosensitive resin composition. Furthermore, when inorganic fine particles are used in dispersion form, the organic solvent contained in the dispersion may be the solvent contained in the photosensitive resin composition. When the photosensitive resin composition contains a solvent derived from the polymer solution or the dispersion of inorganic fine particles, further solvents may or may not be added.

[0109] The solvent is not particularly limited as long as it uniformly dissolves or disperses components such as radical polymerizable polymers, polyfunctional monomers, polymerization initiators, and inorganic fine particles. Specifically, examples include monoalcohols such as methanol, ethanol, isopropanol, n-butanol, and s-butanol; glycols such as ethylene glycol and propylene glycol; cyclic ethers such as tetrahydrofuran and dioxane; glycol monoethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monobutyl ether, and 3-methoxybutanol; ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol ethyl methyl ether, diethylene glycol dimethyl ether, and diethylene glycol diethyl ether. Glycol ethers such as diethylene glycol ethyl methyl ether, propylene glycol dimethyl ether, and propylene glycol diethyl ether; esters of glycol monoethers such as ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monobutyl ether acetate, dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether acetate, dipropylene glycol monobutyl ether acetate, and 3-methoxybutyl acetate;Examples of solvents include alkyl esters such as methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, methyl propionate, ethyl propionate, butyl propionate, methyl lactate, ethyl lactate, butyl lactate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, methyl acetoacetate, and ethyl acetoacetate; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; aromatic hydrocarbons such as benzene, toluene, xylene, and ethylbenzene; aliphatic hydrocarbons such as hexane, cyclohexane, and octane; halogenated hydrocarbons such as methylene chloride, chloroform, and 1,2-dichlorobenzene; and sulfoxide solvents such as dimethyl sulfoxide. Preferred solvents in the photosensitive resin composition are monoalcohols and glycol monoether esters, more preferably glycol monoether esters, and even more preferably propylene glycol monomethyl ether acetate.

[0110] The total solvent content in the photosensitive resin composition can be appropriately set according to the optimal viscosity when using the photosensitive resin composition, but for example, 50 to 1200 parts by mass, and more preferably 100 to 900 parts by mass, per 100 parts by mass of radical polymer. If the total solvent content in the photosensitive resin composition is within the above range, the handling properties, storage stability, and efficiency during coating operations of the composition will be improved.

[0111] 3.6 Other ingredients The photosensitive resin composition of the present invention may contain other components besides a radical polymerizable polymer, a polyfunctional monomer, a polymerization initiator, inorganic fine particles, and a solvent. The other components are not particularly limited as long as they do not impair the effects of the present invention, but include known additives such as fillers like aluminum hydroxide, talc, clay, and barium sulfate, quantum dot particles, pigments, dyes, defoamers, coupling agents, leveling agents, sensitizers, release agents, lubricants, plasticizers, antioxidants, ultraviolet absorbers, light stabilizers, flame retardants, polymerization inhibitors, polymerization retarders, polymerization accelerators, thickeners, dispersants, and surfactants. Various organic pigments and / or inorganic pigments can be used as the pigments, and various organic dyes and / or inorganic dyes can be used as the dyes. Furthermore, the pigments and dyes may be natural pigments or synthetic pigments. The other components may be present alone or in combination of two or more.

[0112] Other components may include polymers other than the radical polymerizable polymers described above. When polymers other than the radical polymerizable polymers are included, the content of the radical polymerizable polymer is preferably 30% by mass or more, more preferably 50% by mass or more, even more preferably 70% by mass or more, and preferably less than 100% by mass, based on 100% by mass of the total amount of polymers.

[0113] 4. Method for preparing a photosensitive resin composition The method for preparing the photosensitive resin composition of the present invention is not particularly limited and any known method may be used. For example, a method of mixing and dispersing a radical polymerizable polymer, a polyfunctional monomer, a polymerization initiator, inorganic fine particles, a solvent, and other components as needed, using a known mixer or disperser is possible. The mixing and dispersion step is not particularly limited; the components may be mixed and dispersed all at once, or some components may be mixed first, and then the remaining components may be added and mixed and dispersed. Examples of dispersers include paint conditioners, bead mills, roll mills, ball mills, jet mills, homogenizers, kneaders, blenders, and the like. The method may also include other steps that are normally performed when preparing a photosensitive resin composition. It is preferable to filter the obtained photosensitive resin composition using a filter or the like to remove fine debris.

[0114] When a photosensitive resin composition contains a coloring agent such as a pigment or dye, it is preferable to prepare it through a coloring agent dispersion process. An example of a coloring agent dispersion process is to weigh predetermined amounts of a coloring agent (preferably an organic pigment), a dispersant, and a solvent, and then use a disperser to disperse the coloring agent into fine particles to obtain a liquid coloring agent dispersion (also called a mill base).

[0115] Preferably, the dispersion process for the coloring agent involves kneading and dispersing it using a roll mill, kneader, blender, etc., and then finely dispersing it in a media mill such as a bead mill filled with 0.01 to 1 mm beads to obtain a mill base.

[0116] When preparing a photosensitive resin composition using the aforementioned mill base, one method is to mix a composition (preferably a transparent liquid) obtained by mixing and dispersing components other than the colorant contained in the mill base, such as a radical polymerizable polymer, a polyfunctional monomer, a polymerization initiator, and inorganic fine particles, using a mixer or disperser, with the mill base to obtain a uniform dispersion solution, thereby obtaining the photosensitive resin composition.

[0117] The viscosity of the photosensitive resin composition can be appropriately set according to the desired thickness of the cured film. For example, in a photosensitive resin composition with a solid content (non-volatile content) adjusted to 40% by mass, the viscosity at 25°C is preferably 100 mPa·s or less, more preferably 50 mPa·s or less, even more preferably 20 mPa·s or less, even more preferably 18 mPa·s or less, and preferably 1 mPa·s or more, and even more preferably 3 mPa·s or more. By setting the viscosity of the photosensitive resin composition within the above range, handling and application workability are improved.

[0118] 5. Cured product A cured product can be obtained by curing the radical polymerizable polymer and / or photosensitive resin composition of the present invention. Specifically, a cured film can be formed by applying the radical polymerizable polymer and / or photosensitive resin composition of the present invention to a substrate to form a coating layer, and then curing and drying the coating layer.

[0119] Examples of materials used as the substrate include transparent materials such as glass, acrylic resin, polycarbonate resin, polyester resin (e.g., PET), and polystyrene resin, as well as metallic materials such as aluminum, copper, iron, and stainless steel.

[0120] Methods for coating the substrate include, for example, using a spin coater, bar coater, gravure coater, roll coater, knife coater, or applicator.

[0121] A drying step may be further included before the coating layer is cured, and the drying temperature in this step is preferably 40 to 180°C, more preferably 60 to 120°C, and even more preferably 70 to 100°C. The drying time is preferably 0.5 to 30 minutes, and more preferably 1 to 10 minutes.

[0122] The curing of the coating layer can be performed, for example, by irradiating the coating layer with active energy rays using an ultra-high pressure mercury lamp or the like. The amount of active energy radiation to be irradiated is not particularly limited and can be set appropriately depending on the purpose and application of the photosensitive resin composition, the amount of polymerization initiator used, etc., but for example, an ultraviolet irradiation intensity (converted to 365 nm illuminance) of 10 to 2000 mJ / cm² is used. 2 Preferably, the concentration is 20-1500 mJ / cm². 2 This is preferable.

[0123] Post-curing drying is preferably performed by heating (post-bake), with a heating temperature of 90-200°C, more preferably 100-190°C, and even more preferably 120-180°C. The heating time is preferably 10-120 minutes, and more preferably 20-90 minutes. Further heating after curing can further harden the cured film, making it possible to further improve hardness and adhesion.

[0124] The thickness of the cured film is preferably 0.1 to 20 μm, more preferably 0.5 to 10 μm, and even more preferably 0.5 to 8 μm. By keeping the thickness of the cured film within the above range, the requirement for lower profile components, display devices, etc., using the cured film can be fully met.

[0125] Specifically, the light transmittance of the cured product is preferably 70% or more for light with a wavelength of 410 nm at a thickness of 10 μm, more preferably 75% or more, even more preferably 80% or more, even more preferably 90% or more, and even more preferably 90.5% or more. There is no particular upper limit, and it may be 100%. If the light transmittance is within the above range, the cured product will have high transmittance. Because the cured film formed from the radical polymerizable polymer and / or photosensitive resin composition of the present invention has high transparency, even if a laminate containing the cured film is used in a touch panel, for example, its display performance will not be reduced, and a clear image can be displayed.

[0126] The cured product preferably has high surface hardness. Specifically, the pencil hardness of the cured product is preferably H or higher, and more preferably 3H or higher. In the evaluation of pencil hardness, the hardness decreases in the order of 5H > 4H > 3H > 2H > H > F > HB > B > 2B > 3B > 4B. If the pencil hardness is within the above range, it can be said that the cured product has excellent surface hardness. The cured film formed from the radical polymerizable polymer and / or photosensitive resin composition of the present invention has excellent surface hardness and can mitigate external impacts, making it suitable as a component of protective films, insulating films, and the like.

[0127] The cured product preferably has high adhesion. Specifically, it is preferable that the residue retention rate in the test results 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)" is 90% or more. Because the cured film formed from the radical polymerizable polymer and / or photosensitive resin composition of the present invention has excellent adhesion, problems such as peeling from the substrate are less likely to occur.

[0128] Furthermore, it is also preferable to form laminates such as color filters using cured products (cured films) formed from the radical polymerizable polymer and / or photosensitive resin composition of the present invention.

[0129] The color filter preferably has a cured product of a radical polymerizable polymer and / or a photosensitive resin composition on a substrate. In the color filter, the cured product is particularly suitable as a segment that requires coloring, such as a black matrix or individual pixels of red, green, blue, and yellow, and is also suitable as a segment that does not require coloring, such as a photospacer, protective layer, or orientation control rib.

[0130] Examples of substrates used in color filters include glass substrates such as white glass, blue glass, alkali-strengthened glass, and silica-coated blue glass; sheets, films, or substrates made of thermoplastic resins such as polyester, polycarbonate, polyolefin, polysulfone, ring-opening polymers of cyclic olefins, and their hydrogenated products; sheets, films, or substrates made of thermosetting resins such as epoxy resin and unsaturated polyester resin; metal substrates such as aluminum plates, copper plates, nickel plates, and stainless steel plates; ceramic substrates; semiconductor substrates having photoelectric conversion elements; and glass substrates with a colorant layer on the surface (e.g., color filters for LCDs). Among these, glass substrates and sheets, films, or substrates made of heat-resistant resins are preferred from the viewpoint of heat resistance. Furthermore, transparent substrates are preferred for color filters. The substrate may be subjected to corona discharge treatment, ozone treatment, chemical treatment with silane coupling agents, etc., as needed.

[0131] The color filter is preferably formed by photolithography. Specifically, it is preferable to employ a manufacturing method that includes, for each pixel color (i.e., for each pixel of each color), a step of placing a photosensitive resin composition on a substrate (also referred to as a placement step), a step of irradiating the photosensitive resin composition placed on the substrate with light (also referred to as a light irradiation step), a step of developing it with a developer (also referred to as a development step), and a step of heating it (also referred to as a heating step), and repeating the same method for each color. The order in which each color pixel is formed is not particularly limited.

[0132] As described above, the radical polymerizable polymer and photosensitive resin composition of the present invention can form cured products with excellent coatability, hardness, transparency, and adhesion. For this reason, the radical polymerizable polymer and photosensitive resin composition of the present invention can be suitably used in applications such as resist materials, various coatings, and paints. Furthermore, since the radical polymerizable polymer has acidic groups such as carboxyl groups, it can be suitably used as an alkali-developable negative resist material for producing colored pixels, black matrices, overcoats, photospacers, and optical waveguides for color filters. [Examples]

[0133] The present invention will be described in more detail below with reference to examples, but the present invention is not limited by the following examples, and it is certainly possible to implement it with appropriate modifications within the scope that is consistent with the spirit of the preceding and following descriptions, and all such modifications are included within the technical scope of the present invention.

[0134] First, the measurement and evaluation methods used in the following examples and comparative examples will be described. (1) Weight average molecular weight (Mw), number average molecular weight (Mn) Gel permeation chromatography (GPC; HLC-8220GPC, Tosoh Corporation) was used with tetrahydrofuran as the eluent and a TSKgel SuperHZM-N column (Tosoh Corporation) for measurement. The results were calculated on a standard polystyrene basis. (2) Solid content (non-volatile content) Approximately 0.3 g of the copolymer solution prepared in the examples and comparative examples was weighed into an aluminum cup, dissolved in approximately 1 g of acetone, and then air-dried at room temperature. Subsequently, it was dried at 140°C for 3 hours using a hot air dryer (product name: PHH-101, manufactured by ESPEC), then allowed to cool in a desiccator, and its weight was measured. The weight of the solid content (non-volatile content; resin) of the copolymer solution was calculated from the weight loss. (3) Acid value 1.5 g of the copolymer solution prepared in the examples and comparative examples was accurately weighed, dissolved in a mixed solvent of 90 g of acetone and 10 g of water, and titrated with a 0.1 N aqueous KOH solution. The titration was performed using an automatic titrator (product name: COM-555, manufactured by Hiranuma Sangyo Co., Ltd.), and the acid value per gram of polymer was determined from the solid content concentration (mgKOH / g). (4) Thermogravimetric reduction rate 2 g of the copolymer solution prepared in the examples and comparative examples was mixed with 4 g of tetrahydrofuran, and the solution was added dropwise to 60 g of hexane. The precipitated resin (polymer) was separated and removed, and vacuum-dried overnight at 40°C. 10 mg of the obtained resin powder was weighed, and the weight loss rate was measured using a thermogravimetric analyzer TGA-50 (manufactured by SHIMADZU) at 230°C for 30 minutes under a nitrogen atmosphere. (5) Viscosity The viscosity of the resin composition was measured at 25°C using a cone-plate type rotational viscometer (TVE22LT, manufactured by Toki Sangyo Co., Ltd.). A standard rotor (name: 1°34′×R=24) was used for the cone plate. (6) Adhesion (cross-cut test) The test was conducted in accordance with JIS K5600-5-6 (1999) "General test methods for paints - Part 5: Mechanical properties of paint films - Section 6: Adhesion (cross-cut method)". The residual film retention rate was evaluated as follows: "1" for 100-90%, "2" for 89-80%, "3" for 79-70%, "4" for 69-60%, and "5" for 59% or less. (7) Pencil hardness Except for the 500g load specified in the old JIS version (JIS K5400 (1990)), the tests were conducted in accordance with JIS K5600-5-4 (1999). The hardest pencil that did not show any marks was used as the hardness (surface hardness) value. (8) Transmittance Using a glass substrate as a blank, the transmittance of the formed cured material was measured with a UV3100 spectrophotometer (Shimadzu Corporation), and the transmittance at 410 nm was determined.

[0135] [Example 1] A separable flask equipped with a condenser was prepared as a reaction vessel. Meanwhile, 10 g of N-phenylmaleimide (hereinafter also referred to as "PMI"), 37 g of methacrylic acid (hereinafter also referred to as "MAA"), 10 g of tetrahydrofurfuryl methacrylate (hereinafter also referred to as "THFMA"), 33 g of cyclohexyl methacrylate (hereinafter also referred to as "CHMA"), 10 g of 2-hydroxypropyl methacrylate (hereinafter also referred to as "HPMA"), and 8 g of t-butyl peroxy-2-ethylhexanoate (trade name: Perbutyl® O, manufactured by Nippon Oil & Fats Co., Ltd., hereinafter also referred to as "PBO") were added to the monomer dropping vessel and stirred and mixed. 233 g of propylene glycol methyl ether acetate (hereinafter also referred to as "PGMEA") was placed in the reaction vessel, and after purging with nitrogen, the temperature of the reaction vessel was raised to 90°C by heating in an oil bath while stirring. After the temperature of the reaction vessel stabilized at 90°C, the monomer composition was added dropwise. The monomer composition was added dropwise over 180 minutes while maintaining the temperature at 90°C. After the addition of the monomer composition was complete, 0.5 g of PBO was added. After another 30 minutes, the temperature of the reaction vessel was raised to 115°C. After maintaining 115°C for 1 hour, a gas inlet tube was attached to the separable flask and bubbling of an oxygen / nitrogen = 7 / 93 (v / v) mixed gas was started. Next, 33 g of glycidyl methacrylate (hereinafter also referred to as "GMA"), 0.2 g of Antige W-400 (manufactured by Kawaguchi Chemical Industry Co., Ltd.) as a polymerization inhibitor, and 0.4 g of triphenylphosphine (hereinafter also referred to as "TPP") as a catalyst were charged into the reaction vessel, and the reaction was carried out at 115°C for 14 hours. After that, it was cooled to room temperature to obtain copolymer solution (A-1) containing 36.2% by mass of resin (polymer; radical polymerizable polymer). The number average molecular weight (Mn) of the resin was 3010, the weight average molecular weight (Mw) was 8600, the molecular weight distribution (Mw / Mn) was 2.86, and the acid value was 85 mgKOH / g. The composition, double bond equivalent, Mn, Mw, Mw / Mn, acid value, solid content concentration (non-volatile content), and thermal weight loss rate of copolymer solution (A-1) are shown in Table 1.

[0136] [Example 2] A separable flask with a condenser was prepared as the reaction vessel. Meanwhile, 10 g of PMI, 37 g of MAA, 43 g of CHMA, 10 g of HPMA, and 8 g of PBO were added to the monomer dropping vessel and mixed by stirring. 233g of PGMEA was placed in the reaction vessel, and after purging with nitrogen, the vessel was heated in an oil bath while stirring to raise the temperature to 90°C. After the temperature of the reaction vessel stabilized at 90°C, the monomer composition was added dropwise. The monomer composition was added dropwise over 180 minutes while maintaining the temperature at 90°C. After the addition of the monomer composition was complete, 0.5g of PBO was added. After another 30 minutes, the temperature of the reaction vessel was raised to 115°C. After maintaining 115°C for 1 hour, a gas inlet tube was attached to the separable flask and bubbling of an oxygen / nitrogen = 7 / 93 (v / v) mixed gas was started. Next, 33g of GMA, 0.2g of Antige W-400 as a polymerization inhibitor, and 0.4g of TPP as a catalyst were placed in the reaction vessel and reacted at 115°C for 14 hours. After that, it was cooled to room temperature to obtain a copolymer solution (A-2) containing 36.5% by mass of resin. The number-average molecular weight (Mn) of the resin was 3100, the weight-average molecular weight (Mw) was 9000, the molecular weight distribution (Mw / Mn) was 2.90, and the acid value was 86 mgKOH / g. Table 1 shows the composition, double bond equivalent, Mn, Mw, Mw / Mn, acid value, solid content concentration (non-volatile content), and thermal weight loss rate of the copolymer solution (A-2).

[0137] [Example 3] A separable flask with a condenser was prepared as the reaction vessel. Meanwhile, 15g of PMI, 37g of MAA, 20g of THFMA, 10g of HPMA, 18g of CHMA, and 8g of PBO were added to the monomer dropping vessel and mixed by stirring. 233g of PGMEA was placed in the reaction vessel, and after purging with nitrogen, the vessel was heated in an oil bath while stirring to raise the temperature to 90°C. After the temperature of the reaction vessel stabilized at 90°C, the monomer composition was added dropwise. The monomer composition was added dropwise over 180 minutes while maintaining the temperature at 90°C. After the addition of the monomer composition was complete, 0.5g of PBO was added. After another 30 minutes, the temperature of the reaction vessel was raised to 115°C. After maintaining 115°C for 1 hour, a gas inlet tube was attached to the separable flask and bubbling of an oxygen / nitrogen = 7 / 93 (v / v) mixed gas was started. Next, 33g of GMA, 0.2g of Antige W-400 as a polymerization inhibitor, and 0.4g of TPP as a catalyst were placed in the reaction vessel and reacted at 115°C for 14 hours. After that, it was cooled to room temperature to obtain a copolymer solution (A-3) containing 36.3% by mass of resin. The number-average molecular weight (Mn) of the resin was 2670, the weight-average molecular weight (Mw) was 8400, the Mw / Mn ratio was 3.15, and the acid value was 87 mgKOH / g. Table 1 shows the composition, double bond equivalent, Mn, Mw, Mw / Mn, acid value, solid content concentration (non-volatile content), and thermal weight loss rate of the copolymer solution (A-3).

[0138] [Example 4] A separable flask with a condenser was prepared as the reaction vessel. Meanwhile, 15 g of N-cyclohexylmaleimide (hereinafter also referred to as "CHMI"), 37 g of MAA, 10 g of THFMA, 18 g of CHMA, 20 g of HPMA, and 10 g of PBO were added to the monomer dropping vessel and mixed by stirring. 233g of PGMEA was placed in the reaction vessel, and after purging with nitrogen, the vessel was heated in an oil bath while stirring to raise the temperature to 90°C. After the temperature of the reaction vessel stabilized at 90°C, the monomer composition was added dropwise. The monomer composition was added dropwise over 180 minutes while maintaining the temperature at 90°C. After the addition of the monomer composition was complete, 0.5g of PBO was added. After another 30 minutes, the temperature of the reaction vessel was raised to 115°C. After maintaining 115°C for 1 hour, a gas inlet tube was attached to the separable flask and bubbling of an oxygen / nitrogen = 7 / 93 (v / v) mixed gas was started. Next, 17g of GMA, 0.2g of Antige W-400 as a polymerization inhibitor, and 0.4g of TPP as a catalyst were placed in the reaction vessel and reacted at 115°C for 7 hours. After that, it was cooled to room temperature to obtain a copolymer solution (A-4) containing 33.8% by mass of resin. The number-average molecular weight (Mn) of the resin was 2650, the weight-average molecular weight (Mw) was 5400, the Mw / Mn ratio was 2.04, and the acid value was 150 mgKOH / g. Table 1 shows the composition, double bond equivalent, Mn, Mw, Mw / Mn, acid value, solid content concentration (non-volatile content), and thermal weight loss rate of the copolymer solution (A-4).

[0139] [Example 5] A separable flask equipped with a condenser was prepared as the reaction vessel. Meanwhile, 15g of PMI, 33g of MAA, 10g of THFMA, 10g of HPMA, 32g of CHMA, and 8g of PBO were added to the monomer dropping vessel and mixed by stirring. 233g of PGMEA was placed in the reaction vessel, and after purging with nitrogen, the vessel was heated in an oil bath while stirring to raise the temperature to 90°C. After the temperature of the reaction vessel stabilized at 90°C, the monomer composition was added dropwise. The monomer composition was added dropwise over 180 minutes while maintaining the temperature at 90°C. After the addition of the monomer composition was complete, 0.5g of PBO was added. After another 30 minutes, the temperature of the reaction vessel was raised to 115°C. After maintaining 115°C for 1 hour, a gas inlet tube was attached to the separable flask and bubbling of an oxygen / nitrogen = 7 / 93 (v / v) mixed gas was started. Next, 38g of cyclomer M100 (manufactured by Daicel, hereinafter also referred to as "M100"), 0.2g of anti-aging W-400 as a polymerization inhibitor, and 0.4g of TPP as a catalyst were placed in the reaction vessel and reacted at 115°C for 21 hours. Subsequently, the solution was cooled to room temperature to obtain a copolymer solution (A-5) containing 37.0% by mass of resin. The number-average molecular weight (Mn) of the resin was 3460, the weight-average molecular weight (Mw) was 8100, the Mw / Mn ratio was 2.34, and the acid value was 88 mgKOH / g. Table 1 shows the composition, double bond equivalent, Mn, Mw, Mw / Mn, acid value, solid content concentration (non-volatile content), and thermal weight loss rate of the copolymer solution (A-5).

[0140] [Example 6] A separable flask with a condenser was prepared as the reaction vessel. Meanwhile, 15g of PMI, 47g of MAA, 10g of THFMA, 10g of HPMA, 18g of CHMA, and 10g of PBO were added to the monomer dropping vessel and mixed by stirring. 233g of PGMEA was placed in the reaction vessel, and after purging with nitrogen, the vessel was heated in an oil bath while stirring to raise the temperature to 90°C. After the temperature of the reaction vessel stabilized at 90°C, the monomer composition was added dropwise. The monomer composition was added dropwise over 180 minutes while maintaining the temperature at 90°C. After the addition of the monomer composition was complete, 0.5g of PBO was added. After another 30 minutes, the temperature of the reaction vessel was raised to 115°C. After maintaining 115°C for 1 hour, a gas inlet tube was attached to the separable flask and bubbling of an oxygen / nitrogen = 7 / 93 (v / v) mixed gas was started. Next, 58g of GMA, 0.2g of Antige W-400 as a polymerization inhibitor, and 0.4g of TPP as a catalyst were placed in the reaction vessel and reacted at 115°C for 21 hours. After that, it was cooled to room temperature to obtain a copolymer solution (A-6) containing 40.6% by mass of resin. The number-average molecular weight (Mn) of the resin was 3120, the weight-average molecular weight (Mw) was 11100, the Mw / Mn ratio was 3.56, and the acid value was 50 mgKOH / g. Table 1 shows the composition, double bond equivalent, Mn, Mw, Mw / Mn, acid value, solid content concentration (non-volatile content), and thermal weight loss rate of the copolymer solution (A-6).

[0141] [Example 7] A separable flask with a condenser was prepared as the reaction vessel. Meanwhile, 30g of PMI, 37g of MAA, 10g of THFMA, 10g of HPMA, 13g of CHMA, and 8g of PBO were added to the monomer dropping vessel and mixed by stirring. 233g of PGMEA was placed in the reaction vessel, and after purging with nitrogen, the vessel was heated in an oil bath while stirring to raise the temperature to 90°C. After the temperature of the reaction vessel stabilized at 90°C, the monomer composition was added dropwise. The monomer composition was added dropwise over 180 minutes while maintaining the temperature at 90°C. After the addition of the monomer composition was complete, 0.5g of PBO was added. After another 30 minutes, the temperature of the reaction vessel was raised to 115°C. After maintaining 115°C for 1 hour, a gas inlet tube was attached to the separable flask and bubbling of an oxygen / nitrogen = 7 / 93 (v / v) mixed gas was started. Next, 33g of GMA, 0.2g of Antige W-400 as a polymerization inhibitor, and 0.4g of TPP as a catalyst were placed in the reaction vessel and reacted at 115°C for 14 hours. After that, it was cooled to room temperature to obtain a copolymer solution (A-7) containing 36.7% by mass of resin. The number-average molecular weight (Mn) of the resin was 3030, the weight-average molecular weight (Mw) was 7600, the Mw / Mn ratio was 2.51, and the acid value was 85 mgKOH / g. Table 1 shows the composition, double bond equivalent, Mn, Mw, Mw / Mn, acid value, solid content concentration (non-volatile content), and thermal weight loss rate of the copolymer solution (A-7).

[0142] [Example 8] A separable flask with a condenser was prepared as the reaction vessel. Meanwhile, 30g of CHMI, 37g of MAA, 10g of THFMA, 10g of HPMA, 13g of CHMA, and 8g of PBO were added to the monomer dropping vessel and mixed by stirring. 233g of PGMEA was placed in the reaction vessel, and after purging with nitrogen, the vessel was heated in an oil bath while stirring to raise the temperature to 90°C. After the temperature of the reaction vessel stabilized at 90°C, the monomer composition was added dropwise. The monomer composition was added dropwise over 180 minutes while maintaining the temperature at 90°C. After the addition of the monomer composition was complete, 0.5g of PBO was added. After another 30 minutes, the temperature of the reaction vessel was raised to 115°C. After maintaining 115°C for 1 hour, a gas inlet tube was attached to the separable flask and bubbling of an oxygen / nitrogen = 7 / 93 (v / v) mixed gas was started. Next, 33g of GMA, 0.2g of Antige W-400 as a polymerization inhibitor, and 0.4g of TPP as a catalyst were placed in the reaction vessel and reacted at 115°C for 14 hours. After that, it was cooled to room temperature to obtain a copolymer solution (A-8) containing 36.5% by mass of resin. The number-average molecular weight (Mn) of the resin was 3080, the weight-average molecular weight (Mw) was 8000, the Mw / Mn ratio was 2.60, and the acid value was 84 mgKOH / g. Table 1 shows the composition, double bond equivalent, Mn, Mw, Mw / Mn, acid value, solid content concentration (non-volatile content), and thermal weight loss rate of the copolymer solution (A-8).

[0143] [Comparative Example 1] A separable flask with a condenser was prepared as the reaction vessel. Meanwhile, 10 g of PMI, 37 g of MAA, 10 g of THFMA, 10 g of HPMA, 33 g of CHMA, and 2 g of PBO were added to the monomer dropping vessel and mixed by stirring. 233g of PGMEA was placed in the reaction vessel, and after purging with nitrogen, the vessel was heated in an oil bath while stirring to raise the temperature to 90°C. After the temperature of the reaction vessel stabilized at 90°C, the monomer composition was added dropwise. The monomer composition was added dropwise over 180 minutes while maintaining the temperature at 90°C. After the addition of the monomer composition was complete, 0.5g of PBO was added. After another 30 minutes, the temperature of the reaction vessel was raised to 115°C. After maintaining 115°C for 1 hour, a gas inlet tube was attached to the separable flask and bubbling of an oxygen / nitrogen = 7 / 93 (v / v) mixed gas was started. Next, 33g of GMA, 0.2g of Antige W-400 as a polymerization inhibitor, and 0.4g of TPP as a catalyst were placed in the reaction vessel and reacted at 115°C for 14 hours. After that, it was cooled to room temperature to obtain a copolymer solution (A-9) containing 36.9% by mass of resin. The number-average molecular weight (Mn) of the resin was 5820, the weight-average molecular weight (Mw) was 20100, the Mw / Mn ratio was 3.45, and the acid value was 85 mgKOH / g. Table 1 shows the composition, double bond equivalent, Mn, Mw, Mw / Mn, acid value, solid content concentration (non-volatile content), and thermal weight loss rate of the copolymer solution (A-9).

[0144] [Comparative Example 2] A separable flask with a condenser was prepared as the reaction vessel. Meanwhile, 10 g of PMI, 37 g of MAA, 10 g of tetrafurfuryl acrylate (hereinafter also referred to as "THFA"), 10 g of 2-hydroxyethyl methacrylate (hereinafter also referred to as "HEMA"), 33 g of CHMA, and 8 g of PBO were added to the monomer dropping vessel and stirred. 233g of PGMEA was placed in the reaction vessel, and after purging with nitrogen, the vessel was heated in an oil bath while stirring to raise the temperature to 90°C. After the temperature of the reaction vessel stabilized at 90°C, the monomer composition was added dropwise. The monomer composition was added dropwise over 180 minutes while maintaining the temperature at 90°C. After the addition of the monomer composition was complete, 0.5g of PBO was added. After another 30 minutes, the temperature of the reaction vessel was raised to 115°C. After maintaining 115°C for 1 hour, a gas inlet tube was attached to the separable flask and bubbling of an oxygen / nitrogen = 7 / 93 (v / v) mixed gas was started. Next, 33g of GMA, 0.2g of Antige W-400 as a polymerization inhibitor, and 0.4g of TPP as a catalyst were placed in the reaction vessel and reacted at 115°C for 14 hours. After that, it was cooled to room temperature to obtain a copolymer solution (A-10) containing 36.2% by mass of resin. The number-average molecular weight (Mn) of the resin was 3250, the weight-average molecular weight (Mw) was 8500, the Mw / Mn ratio was 2.62, and the acid value was 86 mgKOH / g. Table 1 shows the composition, double bond equivalent, Mn, Mw, Mw / Mn, acid value, solid content concentration (non-volatile content), and thermal weight loss rate of the copolymer solution (A-10).

[0145] [Comparative Example 3] A separable flask with a condenser was prepared as the reaction vessel. Meanwhile, 10 g of PMI, 15 g of MAA, 10 g of THFMA, 10 g of HPMA, 55 g of CHMA, and 6 g of PBO were added to the monomer dropping vessel and mixed by stirring. 233 g of PGMEA was placed in the reaction vessel, and after purging with nitrogen, the vessel was heated in an oil bath while stirring to raise the temperature to 90°C. After the temperature of the reaction vessel stabilized at 90°C, the monomer composition was added dropwise. The monomer composition was added dropwise over 180 minutes while maintaining the temperature at 90°C. After the addition of the monomer composition was complete, 0.5 g of PBO was added. After another 30 minutes, the temperature of the reaction vessel was raised to 115°C. After maintaining 115°C for 1 hour, it was cooled to room temperature to obtain a copolymer solution (A-11) containing 30.5% by mass of resin. The number average molecular weight (Mn) of the resin was 2900, the weight average molecular weight (Mw) was 6200, the Mw / Mn ratio was 2.14, and the acid value was 100 mg KOH / g. The composition, Mn, Mw, Mw / Mn, acid value, solid content concentration (non-volatile content), and thermal weight loss rate of the copolymer solution (A-11) are shown in Table 1.

[0146] [Comparative Example 4] A separable flask with a condenser was prepared as the reaction vessel. Meanwhile, 37g of MAA, 10g of THFMA, 10g of HPMA, 43g of benzyl methacrylate (hereinafter also referred to as "BzMA"), and 8g of PBO were added to the monomer dropping vessel and stirred and mixed. 233g of PGMEA was placed in the reaction vessel, and after purging with nitrogen, the vessel was heated in an oil bath while stirring to raise the temperature to 90°C. After the temperature of the reaction vessel stabilized at 90°C, the monomer composition was added dropwise. The monomer composition was added dropwise over 180 minutes while maintaining the temperature at 90°C. After the addition of the monomer composition was complete, 0.5g of PBO was added. After another 30 minutes, the temperature of the reaction vessel was raised to 115°C. After maintaining 115°C for 1 hour, a gas inlet tube was attached to the separable flask and bubbling of an oxygen / nitrogen = 7 / 93 (v / v) mixed gas was started. Next, 33g of GMA, 0.2g of Antige W-400 as a polymerization inhibitor, and 0.4g of TPP as a catalyst were placed in the reaction vessel and reacted at 115°C for 14 hours. After that, it was cooled to room temperature to obtain a copolymer solution (A-12) containing 36.0% by mass of resin. The number-average molecular weight (Mn) of the resin was 3600, the weight-average molecular weight (Mw) was 8800, the Mw / Mn ratio was 2.44, and the acid value was 85 mgKOH / g. Table 1 shows the composition, double bond equivalent, Mn, Mw, Mw / Mn, acid value, solid content concentration (non-volatile content), and thermal weight loss rate of the copolymer solution (A-12).

[0147] [Table 1]

[0148] [Example 9] (Preparation of photosensitive resin composition) 3.31 g of the copolymer solution (A-1) described above (i.e., 1.2 g of resin solids) was added as the resin, 4.00 g of PGM-AC-4130Y as inorganic fine particles (30% by mass of surface-treated silica dispersion of propylene glycol monomethyl ether, manufactured by Nissan Chemical, 1.2 g of non-volatile content), 1.54 g of dipentaerythritol hexaacrylate (hereinafter also referred to as "DPHA") as a polyfunctional monomer, and 0.06 g of 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-propan-1-one (trade name: IRGACURE® 907, manufactured by BASF Japan, hereinafter also referred to as "Irg907") as a photopolymerization initiator. The mixture was then diluted with PGMEA to a non-volatile content of 40% by mass to prepare a photosensitive resin composition (B1). The viscosity of the photosensitive resin composition (B1) was 9 mPa·s.

[0149] (Formation of a hardened film) A photosensitive resin composition (B1) was applied to a 5cm square glass substrate using a spin coater and dried in an oven at 80°C for 3 minutes. After drying, a UV aligner (product name: TME-150RNS, manufactured by TOPCON) equipped with a 2.0kW ultra-high pressure mercury lamp was used to measure 1 J / cm². 2 Ultraviolet light was irradiated at an intensity equivalent to 365 nm illuminance. After UV irradiation, the coating was cured at 160°C for 1 hour to completely harden it, obtaining a cured film (coating) with a thickness of 10 μm. Adhesion, pencil hardness, and transmittance tests were performed using the obtained cured film. The results are shown in Table 2.

[0150] [Examples 10-16, Comparative Examples 5-8] Photosensitive resin compositions (B2) to (B12) were prepared in the same manner as in Example 9, except that copolymer solutions (A-2) to (A-12) were used as the resin. A cured film was then formed using the obtained photosensitive resin compositions. The composition and viscosity of the photosensitive resin compositions (B2) to (B12), as well as the test results for adhesion, pencil hardness, and transmittance using the formed cured film, are shown in Table 2.

[0151] [Table 2] [Industrial applicability]

[0152] The radical polymerizable polymer and photosensitive resin composition of the present invention can be applied, for example, to resist materials and can be suitably used in the optical and electrical / electronic fields.

Claims

1. A polymer having polymerizable double bonds in its side chains, comprising: a structural unit derived from an unsaturated monomer having an acid group; a structural unit derived from an unsaturated monomer having a hydroxyalkyl group containing a secondary hydroxyl group; a structural unit derived from an unsaturated monomer having a cyclic ether structure of five or more members; and a polymer having polymerizable double bonds in its side chains. The polymer further comprises a main chain containing a structural unit derived from an N-substituted maleimide monomer and / or a side chain containing a structural unit derived from an unsaturated monomer having a cyclohexyl group. The unsaturated monomer having a cyclic ether structure of five or more members is either acrylic or methacrylic. A radical polymerizable polymer having a weight-average molecular weight of 18,000 or less.

2. The unsaturated monomer having an acid group, the unsaturated monomer having a hydroxyalkyl group containing a secondary hydroxyl group, and the unsaturated monomer having a cyclohexyl group are each either acrylic or methacrylic. The radical polymerizable polymer according to claim 1, wherein the content of constituent units derived from acrylic monomers is 7% by mass or less of the total constituent units of the polymer by mass 100%.

3. The radical polymerizable polymer according to claim 1, wherein the acid value of the polymer is 30 to 200 mg KOH / g.

4. The radical polymerizable polymer according to claim 1, wherein the double bond equivalent of the polymer is 330 to 1600 g / mol.

5. The polymer has a main chain containing constituent units derived from an N-substituted maleimide monomer, The radical polymerizable polymer according to claim 1, wherein the content of constituent units derived from the N-substituted maleimide monomer is 5% by mass or more and 30% by mass or less of the total constituent units of the polymer by mass.

6. The radical polymerizable polymer according to claim 1, wherein the content of constituent units derived from the unsaturated monomer having a cyclic ether structure of 5 member rings or more is 5% by mass or more and 20% by mass or less of the total constituent units of the polymer.

7. A photosensitive resin composition comprising a radical polymerizable polymer according to any one of claims 1 to 6, a polyfunctional monomer, a polymerization initiator, inorganic fine particles, and a solvent.

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