JP2024044061A - Radical polymerizable polymer and photosensitive resin composition - Google Patents

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

The present invention relates to a radically polymerizable polymer and a photosensitive resin composition containing the radically polymerizable polymer.

Curable resin compositions that can be cured by heat or active energy rays have been studied for various applications, such as color filters, inks, printing plates, printed wiring boards, semiconductor elements, photoresists, and other optical components and electrical and electronic devices used in liquid crystal display devices and solid-state imaging devices, and excellent curable resin compositions have been developed according to the characteristics required for each application. For example, Patent Document 1 describes a radiation-sensitive resin composition that contains an alkali-soluble resin, a 1,2-quinone diazide compound, and a radical scavenger as a radiation-sensitive resin composition that can provide an interlayer insulating film with excellent heat resistance, heat discoloration resistance, and adhesion to a substrate at high resolution, and discloses a copolymer obtained by copolymerizing an unsaturated carboxylic acid, an unsaturated compound containing an epoxy group, a maleimide compound, and the like as the alkali-soluble resin. For example, Patent Document 2 describes an active energy ray-curable photosensitive resin composition that contains a (meth)acrylate having a cyclic ether skeleton, an alkyl (meth)acrylate having an alkyl group with 1 to 24 carbon atoms, a (meth)acrylic resin that is a copolymer of at least two radically polymerizable monomers, and a polymerization initiator, as a photosensitive resin composition that can provide a cured film that exhibits excellent shielding portion curability, high heat resistance, high adhesion, and high transparency.

As described above, with technological advances, higher levels of properties are being demanded for curable resin compositions used in optical components. For example, there is a demand for resin compositions capable of forming cured products with excellent hardness, transparency, and adhesion, and polymers capable of providing such resin compositions. There is also a demand for polymers and resin compositions with excellent handling properties.

International Publication No. 2011/046230 Japanese Patent Application Publication No. 2013-36024

The present invention has been made in view of the above circumstances, and its purpose is to provide a radical polymerization method that can provide a cured product that is easy to handle, has excellent coating workability, and has excellent hardness, transparency, and adhesion. The present invention provides a radically polymerizable polymer and a photosensitive resin composition containing the radically polymerizable polymer.

As a result of intensive research conducted by the present inventors to solve the above problems, the present inventors discovered that a radical polymerizable polymer having a weight average molecular weight of 18,000 or less, which is a polymer having 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 polymerizable double bond in the side chain, and which further has a structural unit derived from an N-substituted maleimide monomer in the main chain and/or a structural unit derived from an unsaturated monomer having a cyclohexyl group in the side chain, can give a cured product that is easy to handle and has excellent coating workability, as well as excellent hardness, transparency, and adhesion, and thus completed the present invention.

That is, the present invention is defined by the following constituent features.
[1] A polymer having 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 polymerizable double bond in a side chain,
the polymer further has 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,
The radical polymerizable polymer has 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 an acrylic or methacrylic monomer,
The radical polymerizable polymer according to [1], wherein a content of structural units derived from acrylic monomers is 7% by mass or less based on 100% by mass of all structural units of the polymer.
[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 constitutional unit derived from an N-substituted maleimide monomer in the main chain,
The radical polymerizable polymer according to any one of [1] to [4], wherein a content ratio of the structural units derived from the N-substituted maleimide monomer in 100% by mass of all structural units of the polymer is 5% by mass or more and 30% by mass or less.
[6] The polymer further has a constitutional unit derived from an unsaturated monomer having a cyclic ether structure of a 5-membered or larger ring,
The radical polymerizable polymer according to any one of [1] to [5], wherein the unsaturated monomer having a cyclic ether structure of a 5- or higher membered ring is either an acrylic or methacrylic unsaturated monomer.
[7] The radical polymerizable polymer according to [6], wherein the content of the structural units derived from the unsaturated monomer having a cyclic ether structure of a 5 or more membered ring is 5% by mass or more and 20% by mass or less, based on 100% by mass of all structural units of the polymer.
[8] A photosensitive resin composition comprising the radical polymerizable polymer according to any one of [1] to [7], a polyfunctional monomer, a polymerization initiator, inorganic fine particles, and a solvent.

The radically polymerizable polymer and photosensitive resin composition of the present invention can form a cured product (for example, a cured film) with excellent coating properties and excellent hardness, transparency, and adhesion. Therefore, the radically polymerizable polymer and photosensitive resin composition of the present invention can be suitably used, for example, in applications such as resist materials, various coating agents, and paints.

The present invention will be explained in detail below.
Note that a combination of two or more of the individual preferred embodiments of the present invention described below is also a preferred embodiment of the present invention.
Moreover, in this specification, "(meth)acrylic acid" means "acrylic acid and/or methacrylic acid", and "(meth)acrylate" means "acrylate and/or methacrylate".
Furthermore, in this specification, the numerical range "Min to Max" means greater than or equal to the minimum value Min and less than or equal to the maximum value Max. Furthermore, when preferable numerical values are described in stages for the upper limit value and the lower limit value, a numerical range that is a combination of the upper limit value and lower limit value separately described is also a suitable numerical range.

1. Radical Polymerizable Monomer The radical 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. By introducing a polymerizable double bond into the side chain of a polymer having these structural units and adjusting the molecular weight to a predetermined value, the obtained radical polymerizable polymer can form a cured product having excellent coatability, hardness, transparency, and adhesion.
The constitutional unit derived from an unsaturated monomer corresponds to, for example, a structure in which a polymerizable double bond of an unsaturated monomer is opened by a polymerization reaction. 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 in combination of two or more kinds.

The structural unit derived from the unsaturated monomer having an acid group is used to improve the alkaline developability of the resin. The acid group is not particularly limited as long as it is a functional group that exhibits 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.

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, with (meth)acrylic monomers being preferred and methacrylic monomers being more preferred. In this specification, the term (meth)acrylic monomer refers to a monomer having an acryloyl group and/or a methacryloyl group, such as acrylic acid (i.e., vinyl carboxylic acid) or its ester, methacrylic acid (i.e., α-methyl carboxylic acid) or its ester, and the like, and the term vinyl monomer refers to a monomer other than a (meth)acrylic monomer having a vinyl group. For example, crotonic acid (i.e., β-methyl carboxylic acid) corresponds to a methyl-substituted vinyl carbonyl group like a methacryloyl group, but does not correspond to an acryloyl group or a methacryloyl group, and is therefore classified as a vinyl monomer.

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, etc. 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 the (meth)acrylic monomer having a carboxylic acid group include (meth)acrylic acid, and compounds in which a polycarboxylic acid is further ester-bonded to an ester of (meth)acrylic acid and a polyol. The polyol includes mono- or poly-C _2-4 alkanediols such as ethylene glycol, diethylene glycol, propanediol, and dipropanediol, and ethylene glycol is preferred. Examples of the polycarboxylic acid include dicarboxylic acids such as oxalic acid; C _1-10 alkanedicarboxylic acids such as malonic acid, succinic acid, and glutaric acid; C _6-10 cycloalkanedicarboxylic acids such as hexahydrophthalic acid; and C _6-10 aromatic dicarboxylic acids such as phthalic acid. Examples of the compound in which a polycarboxylic acid is further ester-bonded 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.
In addition, a structural unit obtained by reacting a structural unit derived from an unsaturated monomer having an acid group with a compound containing a reactive group (such as an epoxy group) and a polymerizable unsaturated double bond, which will be described later, and then reacting the resulting hydroxy group with a polyvalent carboxylic acid also has an acid group. However, since such a structural unit contains an unsaturated double bond, in the present invention, it is not included in the structural unit derived from an unsaturated monomer having an acid group.

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

The content of the structural units derived from unsaturated monomers having an acid group is preferably 0.5 to 50% by mass, more preferably 1% by mass or more, even more preferably 2% by mass or more, even more preferably 5% by mass or more, and more preferably 40% by mass or less, even more preferably 35% by mass or less, and even more preferably 30% by mass or less, out of 100% by mass of all structural units of the radical polymerizable polymer. When the content of the structural units derived from unsaturated monomers having an acid group (particularly a carboxyl group) is within the above range, the viscosity of the resulting polymer does not become too high, and the handleability is good. Furthermore, the developability with an alkaline substance is improved.

The structural unit derived from an unsaturated monomer having a hydroxyalkyl group containing a secondary hydroxyl group is useful for providing a cured product with good hardness, transparency, and adhesion. Note that "containing a secondary hydroxyl group" means that a hydroxyl group (alcoholic hydroxyl group) of a hydroxyalkyl group is bonded to a secondary carbon atom to which two carbon atoms are bonded. In addition, when the hydroxyalkyl group is directly bonded to a carbon atom in the main chain of the polymer, a carbonyl group, an amide group, etc., the state in which these carbon atoms and the hydroxyalkyl group are bonded is secondary. Any material containing a hydroxyl group may be used.

Examples of the alkyl group in the hydroxyalkyl group include linear or branched alkyl groups such as ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, n-pentyl, isopentyl, n-hexyl, isohexyl, n-heptyl, isoheptyl, n-octyl, and 2-methylhexyl groups, and alkyl groups having 2 to 10 carbon atoms are preferred, linear alkyl groups having 2 to 10 carbon atoms are more preferred, and linear alkyl groups having 3 to 6 carbon atoms are even more preferred.

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

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, vinyl monomers, etc. Monomers are preferred, and methacrylic monomers are more preferred.

As the 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 preferable. As the (meth)acrylic monomer having a hydroxyalkyl group containing a secondary hydroxyl group, for example, (meth)acrylic monomers having one hydroxyl group such as 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, and 3-hydroxybutyl (meth)acrylate; (meth)acrylic monomers having two or more hydroxyl groups such as 2,3-dihydroxypropyl (meth)acrylate and 2,3-dihydroxybutyl (meth)acrylate are mentioned, and (meth)acrylic monomers having one hydroxyl group are preferable, and methacrylic monomers having one hydroxyl group are more preferable.

The content of the structural unit derived from the unsaturated monomer 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. When the content of the structural unit derived from the unsaturated monomer having a hydroxyalkyl group containing a secondary hydroxyl group is within the above range, the viscosity of the radical polymerizable polymer and the photosensitive resin composition containing the polymer is low, and the handleability (applicability) is good, and it is possible to give a cured product with improved hardness, transparency, and adhesion. More preferably, when the content is within the above range, it is possible to give a radical polymerizable polymer and a photosensitive resin composition containing the polymer that have excellent heat resistance (particularly, thermal decomposition resistance), and to give a cured product with excellent heat resistance.

The structural 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.

The N-substituted maleimide monomer is a monomer having a double bond-containing ring structure in the molecule, and includes, for example, N-methylmaleimide, N-ethylmaleimide, N-isopropylmaleimide, N-butylmaleimide, N- - N-alkylmaleimide (preferably N-C _1-12 alkylmaleimide) such as isobutylmaleimide, N-t-butylmaleimide, N-laurylmaleimide; N-cyclopropylmaleimide, N-cyclobutylmaleimide, N-cyclopentyl maleimide, N-cycloalkylmaleimide such as N-cyclohexylmaleimide (preferably N-C _3-20 cycloalkylmaleimide); N-arylmaleimide such as N-phenylmaleimide (preferably N-C _6-12 arylmaleimide) ); N-aralkylmaleimide such as N-benzylmaleimide (preferably N-C _7-12 aralkylmaleimide); and the like. As the N-substituted maleimide monomer, N-cycloalkylmaleimide, N-arylmaleimide, and N-aralkylmaleimide are preferred from the viewpoint of excellent adhesion 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. In addition, in terms 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-cycloalkylmaleimide, N-phenylmaleimide, and N-benzylmaleimide are more preferred. - Cyclohexylmaleimide is more preferred.

The N-alkylmaleimide and N-cycloalkylmaleimide may have a substituent, and examples of the substituent include a phenyl group, a benzyl group, and a hydroxy group.
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, and a halogeno group. .
Specifically, for example, N-benzylmaleimide having a substituent includes alkyl-substituted benzylmaleimide such as p-methylbenzylmaleimide and p-butylbenzylmaleimide; phenolic hydroxyl-substituted benzylmaleimide such as p-hydroxybenzylmaleimide; Examples include halogen-substituted benzylmaleimides such as o-chlorobenzylmaleimide, o-dichlorobenzylmaleimide, and p-dichlorobenzylmaleimide; and the like. Examples of N-phenylmaleimides having substituents include alkyl-substituted phenylmaleimides such as p-methylphenylmaleimide and p-butylphenylmaleimide; phenolic hydroxyl-substituted phenylmaleimides such as p-hydroxyphenylmaleimide; o-chlorophenylmaleimide; , o-dichlorophenylmaleimide, p-dichlorophenylmaleimide, and other halogen-substituted phenylmaleimides; and the like.

The content of the structural units derived from the N-substituted maleimide monomer is preferably 1.5 to 40% by mass, and 3% by mass or more based on 100% by mass of the total structural units of the radically polymerizable polymer. It is more preferably 5% by mass or more, even more preferably 7% by mass or more, more preferably 35% by mass or less, even more preferably 30% by mass or less, even more preferably 25% by mass or less. When the content of the structural unit derived from the N-substituted maleimide monomer is within the above range, the viscosity of the radically polymerizable polymer and the photosensitive resin composition containing the polymer is low. It is possible to provide a cured product that has good handling properties (applicability) and further improved hardness, transparency, and adhesion. More preferably, when the content of the structural units derived from the N-substituted maleimide monomer is within the above range, a radically polymerizable polymer with excellent heat resistance and a photosensitive material containing the polymer can be obtained. It becomes possible to obtain a cured product with excellent heat resistance, and the dispersibility of inorganic fine particles in the photosensitive resin composition is improved.

The structural unit derived from an unsaturated monomer having a cyclohexyl group in the side chain is useful for reducing the viscosity of the polymer, and can also 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 a direct or chain linker (for example, an organic group containing an ester bond). It is attached to the main chain via.

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, vinyl monomers, etc. Monomers are preferred, and methacrylic monomers are more preferred. In the case of a (meth)acrylic monomer, the carboxylic acid group (-COO-) constituting the (meth)acryloyl group constitutes a part of the linker.

In the case of a (meth)acrylic monomer, examples of the chain linker include *-COO-**, *-COO-C _1-6 alkylene group-**, *-COO-C _1-6 alkylene group-COO-**, etc., with *-COO-** and *-COO-CH ₂ -** being preferred. In the case of a vinyl monomer, examples of the linker include -O-, *-O-C _1-6 alkylene group-**, *-O-C _1-6 alkylene group-COO-**, etc., with -O- and *-O-CH ₂ -** being preferred. In the above formula, * indicates the bonding position with the main chain, and ** indicates the bonding position with the cyclohexyl group.

As the unsaturated monomer having a cyclohexyl group, a (meth)acrylic monomer having a cyclohexyl group is preferable, such as cyclohexyl (meth)acrylate, methylcyclohexyl (meth)acrylate, etc., with cyclohexyl (meth)acrylate being preferable and cyclohexyl methacrylate being more preferable.

The content of the structural unit derived from an unsaturated monomer having a cyclohexyl group is preferably 1 to 50% by mass, more preferably 3% by mass or more based on 100% by mass of the total structural units of the radically polymerizable polymer. It is preferably 5% by mass or more, more preferably 7% by mass or more, even more preferably 45% by mass or less, even more preferably 40% by mass or less, even more preferably 35% by mass or less. When the content ratio of the structural unit derived from the unsaturated monomer having a cyclohexyl group is within the above range, the viscosity of the radically polymerizable polymer and the photosensitive resin composition containing the polymer is low and easy to handle (coating). The hardness, transparency, and adhesion of the cured product are improved. More preferably, the content of the structural unit derived from an unsaturated monomer having a cyclohexyl group is within the above range, and the radically polymerizable polymer having excellent heat resistance and the photosensitive resin composition containing the polymer Therefore, it becomes possible to provide a cured product with excellent heat resistance, and the dispersibility of inorganic fine particles in the photosensitive resin composition is improved.

The radical polymerizable polymer may have 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 side chain, but it is preferable for the polymer to have both structural units in order to improve the handleability of the radical polymerizable polymer and the photosensitive resin composition, as well as the hardness, transparency, and adhesion of the cured product.

Of the total 100% by mass of all structural units in the radically polymerizable polymer, the total content of structural units derived from unsaturated monomers having an acid group, unsaturated monomers having a hydroxyalkyl group containing a secondary hydroxyl group, N-substituted maleimide monomers, and unsaturated monomers having a cyclohexyl group 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, and there is no particular upper limit, and it may be 100% by mass, but is preferably 95% by mass or less.

The radical polymerizable polymer of the present invention may further have a structural unit derived from an unsaturated monomer having a cyclic ether structure of 5 or more members. If the polymer has a structural unit derived from an unsaturated monomer having a cyclic ether structure of 5 or more members, the viscosity can be further reduced and the coatability can be further improved.

The cyclic ether structure contained in the unsaturated monomer having a cyclic ether structure of 5 or more members is not particularly limited as long as it is 5 or more members, and may be a monocyclic ring, a polycyclic ring, or a condensed ring. The unsaturated monomer having a cyclic ether structure of 5 or more members may have one cyclic ether structure of 5 or more members, 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, a tetrahydrofuran ring, a dioxolane ring, a pyran ring, a tetrahydropyran ring, or a dioxane ring, and even more preferably a tetrahydrofuran ring, a dioxolane ring, a tetrahydropyran ring, or a dioxane ring, and even more preferably a tetrahydrofuran ring or a dioxolane ring. The dioxolane ring is preferably a 1,3-dioxolane ring, and the dioxane ring is preferably a 1,3-dioxolane ring or a 1,4-dioxane ring, and more preferably a 1,3-dioxane ring. The cyclic ether structure may have a substituent such as an alkyl group (which may be linear, branched, or alicyclic) or an alkoxy group, and the carbon number of the substituent is preferably 1 to 20, and more preferably 1 to 10.

As the unsaturated monomer having a cyclic ether structure of 5 or more members, an unsaturated monomer having a cyclic ether structure of 5 or more members in a side chain is preferable, and the cyclic ether structure of 5 or more members is bonded to the main chain via a chain-like linker (e.g., an organic group containing an ester bond) as necessary.

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, 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.

In the case of a (meth)acrylic monomer, examples of the linker include *-COO-**, *-COO-C _1-6 alkylene group-**, *-COO-C _1-6 alkylene group- Examples include COO-**, and *-COO-** and *-COO-CH ₂ -** are preferred. In the case of vinyl monomers, examples of the linker include -O-, *-O-C _1-6 alkylene group -**, *-O-C _1-6 alkylene group -COO-**, etc. -O-, *-O-CH ₂ -** are preferred. In the above formula, * indicates the bonding position to the main chain, and ** indicates the bonding position to the cyclic ether structure.

As the unsaturated monomer having a cyclic ether structure having 5 or more members, a (meth)acrylic monomer having a tetrahydrofuran ring, a dioxolane ring, and/or a dioxane ring is preferable, and a (meth)acrylic monomer having a tetrahydrofuran ring and/or a dioxolane ring is more preferable.

Examples of the (meth)acrylic monomer having a tetrahydrofuran ring structure include tetrahydrofurfuryl (meth)acrylate, γ-caprolactone-modified tetrahydrofurfuryl (meth)acrylate, and commercially available products include, for example, light acrylate. THF-A (manufactured by Kyoeisha Kagaku Co., Ltd.) or the like may be used. Examples of the (meth)acrylic monomer having a dioxolane ring structure include (2-methyl-2-ethyl-1,3-dioxolan-4-yl)methyl (meth)acrylate, (2,2-cyclohexyl) Examples include -1,3-dioxolan-4-yl)methyl (meth)acrylate, and commercially available products such as MEDOL10 (manufactured by Osaka Organic Chemical Industry Co., Ltd.) may be used. Examples of the (meth)acrylic monomer having a dioxane ring structure include dioxane glycol di(meth)acrylate, (5-ethyl-1,3-dioxan-5-yl)methyl(meth)acrylate, and the like.

As for the (meth)acrylic monomer having a cyclic ether structure with 5 or more members, a monomer having a glass transition temperature of a homopolymer of the monomer of -30°C or more and 100°C or less is preferable, and a monomer having a glass transition temperature of -20°C or more and 90°C or less is more preferable.

The content of the structural unit derived from an unsaturated monomer having a 5-membered ring or more cyclic ether structure is preferably 0 to 35% by mass based on 100% by mass of all the structural units of the radically polymerizable polymer, The content is more preferably 1% by mass or more, further preferably 3% by mass or more, even more preferably 5% by mass or more, more preferably 30% by mass or less, and even more preferably 20% by mass or less. When the content of the structural unit derived from an unsaturated monomer having a 5-membered ring or more cyclic ether structure is within the above range, the radically polymerizable polymer and the photosensitive resin composition containing the polymer are The viscosity is lower and the handling (applicability) is better. Further, when the proportion is within the above range, the dispersibility of the inorganic fine particles in the photosensitive resin composition will be good.

The radically polymerizable polymer of the present invention may have structural units derived from copolymerizable monomers other than the structural units derived from the unsaturated monomer having an acid group described above, the structural units derived from the unsaturated monomer having a hydroxyalkyl group containing a secondary hydroxyl group, the structural units derived from the N-substituted maleimide monomer, the structural units derived from the unsaturated monomer having a cyclohexyl group, and the structural units derived from the unsaturated monomer having a cyclic ether structure having five or more members.

Examples of other copolymerizable monomers include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, and n-(meth)acrylate. -Butyl, isobutyl (meth)acrylate, t-butyl (meth)acrylate, methyl 2-ethylhexyl (meth)acrylate, benzyl (meth)acrylate, isobornyl (meth)acrylate, 1- (meth)acrylate (Meth)acrylic acid esters such as adamantyl, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, dicyclopentanyl (meth)acrylate; 2-hydroxyethyl (meth)acrylate , (meth)acrylic acid esters containing primary hydroxyl groups such as 3-hydroxypropyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate; N,N-dimethyl (meth)acrylamide, N-methylol (meth) (Meth)acrylamides such as acrylamide; macromonomers having a (meth)acryloyl group at one end of the polymer molecular chain such as polystyrene, polymethyl (meth)acrylate, polyethylene oxide, polypropylene oxide, polysiloxane, polycaprolactone, polycaprolactam, etc. Conjugated dienes such as 1,3-butadiene and isoprene; Vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyrate, and vinyl benzoate; Methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, 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, 4-hydroxybutyl vinyl ether, and other vinyl ethers; N-vinylpyrrolidone, N- N-vinyl compounds such as vinylcaprolactam, N-vinylimidazole, N-vinylmorpholine, and N-vinylacetamide; unsaturated isocyanates such as isocyanatoethyl (meth)acrylate and allyl isocyanate; and the like.

The radical polymerizable polymer may also have structural units derived from monomers such as aromatic vinyls such as styrene, vinyl toluene, and α-methyl styrene; olefins such as ethylene and propylene; vinyl halides such as vinyl chloride; and vinyl cyanides such as acrylonitrile, to the extent that heat resistance is not impaired.

The radical polymerizable polymer may also have a constituent unit derived from a monomer capable of introducing a ring structure other than an N-substituted maleimide structure into the main chain. Examples of monomers capable of introducing a ring structure other than an N-substituted maleimide structure 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 cyclic polymerization to form a polymer having a ring structure in the main chain. In the present invention, the 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 with a 5-membered ring or more.

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

Examples of the α-(unsaturated alkoxyalkyl) acrylate monomer include alkyl-(α-allyloxymethyl) acrylate monomer, alkyl-(α-methallyloxymethyl) acrylate monomer, etc. is preferred. Specifically, α-allyloxymethyl acrylate, methyl α-allyloxymethyl acrylate, ethyl α-allyloxymethyl acrylate, n-propyl α-allyloxymethyl acrylate, α-allyloxymethyl acrylate i -Propyl, n-butyl α-allyloxymethyl acrylate, s-butyl α-allyloxymethyl acrylate, t-butyl α-allyloxymethyl acrylate, n-amyl α-allyloxymethyl acrylate, α-allyl s-amyl oxymethyl acrylate, t-amyl α-allyloxymethyl acrylate, neopentyl α-allyloxymethyl acrylate, n-hexyl α-allyloxymethyl acrylate, s-hexyl α-allyloxymethyl acrylate, n-heptyl α-allyloxymethyl acrylate, n-octyl α-allyloxymethyl acrylate, s-octyl α-allyloxymethyl acrylate, t-octyl α-allyloxymethyl acrylate, α-allyloxymethyl acrylate 2-ethylhexyl acid, caprylic α-allyloxymethyl acrylate, nonyl α-allyloxymethyl acrylate, decyl α-allyloxymethyl acrylate, undecyl α-allyloxymethyl acrylate, lauryl α-allyloxymethyl acrylate, Tridecyl α-allyloxymethyl acrylate, myristyl α-allyloxymethyl acrylate, pentadecyl α-allyloxymethyl acrylate, cetyl α-allyloxymethyl acrylate, heptadecyl α-allyloxymethyl acrylate, α-allyloxymethyl α- containing linear saturated hydrocarbon groups such as stearyl acrylate, nonadecyl α-allyloxymethyl acrylate, eicosyl α-allyloxymethyl acrylate, seryl α-allyloxymethyl acrylate, mericyl α-allyloxymethyl acrylate, etc. (allyloxymethyl)acrylate is preferred, and methyl α-allyloxymethyl acrylate (also referred to as α-(allyloxymethyl)methyl acrylate) is more preferred.

Further, the radically polymerizable polymer may have a structural unit derived from a monomer having a 3-membered or 4-membered cyclic ether structure. As the monomer having a 3-membered ring or 4-membered ring cyclic ether structure, a monomer having an epoxy group is preferable from the viewpoint of ease of curing by heat or light. Examples of the monomer having an epoxy group include glycidyl (meth)acrylate and 3,4-epoxycyclohexyl (meth)acrylate.

Among these other copolymerizable monomers, methyl (meth)acrylate and benzyl (meth)acrylate are preferred from the viewpoint of transparency and heat resistance. Furthermore, primary hydroxyl group-containing (meth)acrylic esters such as 2-hydroxyethyl (meth)acrylate and 3-hydroxypropyl (meth)acrylate are preferred from the viewpoint of reducing viscosity.

The content ratio of structural units derived from other monomers is preferably 0 to 60% by mass, more preferably 0.3% by mass or more, and The content is more preferably .5% by mass or more, even more preferably 1% by mass or more, more preferably 50% by mass or less, even more preferably 40% by mass or less, even more preferably 30% by mass or less.

The radical polymerizable polymer is preferably a polymer that does not lose weight even when heated. For this reason, it is preferable that the radical polymerizable polymer contains a small proportion of structural units derived from monomers containing tertiary carbon, such as t-butyl (meth)acrylate and t-amyl (meth)acrylate. This is because the O-C bond between the oxygen atom adjacent to the (meth)acryloyl group and the tertiary carbon atom adjacent thereto is easily broken by heating. The content of the structural units derived from monomers containing tertiary carbon is not particularly limited depending on the application, but from the viewpoint of reducing the thermal weight loss rate and transparency, it is preferably 0 to 5 mass%, more preferably 0 to 3 mass%, even more preferably 0 to 1 mass%, of the total structural units of the radical polymerizable polymer (100 mass%), and particularly preferably substantially free.

Of the total 100% by mass of the radically polymerizable polymer, the content of structural 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, more preferably 97% by mass or less, and even more preferably 95% by mass or less.

The content of structural units derived from acrylic monomers in 100% by mass of all structural units of the radically polymerizable polymer is preferably 7% by mass or less, more preferably 5% by mass or less, and 3% by mass. The following is more preferable, and there is no particular lower limit, and it may be 0% by mass. When the content of the structural units derived from the acrylic monomer is within the above range, it is possible to provide a cured product with improved hardness, transparency, and adhesion. More preferably, when the content ratio is within the above range, a radically polymerizable polymer with excellent heat resistance (especially heat decomposition resistance) and a photosensitive resin composition containing the polymer are obtained, and the composition has excellent heat resistance. It becomes possible to provide a cured product.

In the radical polymerizable polymer, the content of the structural units derived from the methacrylic monomer is preferably 90% by mass or more, more preferably more than 90% by mass, even more preferably 93% by mass or more, even more preferably 95% by mass or more, even more preferably 97% by mass or more, and there is no particular upper limit, and it may be 100% by mass. When the content of the structural units derived from the methacrylic monomer is within the above range, it is possible to obtain a cured product with improved hardness, transparency, and adhesion. More preferably, when the content is within the above range, it is possible to obtain a radical polymerizable polymer with excellent heat resistance (particularly, thermal decomposition resistance) and a photosensitive resin composition containing the polymer, and to obtain a cured product with excellent heat resistance.

The radically polymerizable polymer of the present invention has a polymerizable double bond in the side chain. Radically polymerizable polymers have polymerizable double bonds in their side chains, so they can be cured by heat or light, and if they are included in a photosensitive resin composition, the sensitivity to light improves and they can be cured with a smaller amount of light. The mechanical strength of the resulting cured product can also be improved.

The polymerizable double bond in the side chain can be introduced, for example, by reacting a structural unit derived from an unsaturated monomer with a compound having a polymerizable double bond. Specifically, a base polymer having an acid group (e.g., a polymer having a structural unit derived from an unsaturated monomer having an acid group) is added with a base polymer having an epoxy group, an oxazoline group, and a hydroxyl group. It can be introduced by adding a compound containing at least one selected reactive group (that is, a group that reacts with an acid group) and a polymerizable unsaturated double bond. In addition, a base polymer having a group that reacts with an acid group (preferably an epoxy group) (for example, a polymer having a structural unit derived from an unsaturated monomer having a group that reacts with an acid group such as an epoxy group) It can also be introduced by adding a compound containing an acid group and a polymerizable unsaturated double bond to the polymer. Hereinafter, compounds containing a reactive group and a polymerizable unsaturated double bond, and compounds containing an acid group and a polymerizable unsaturated double bond are also collectively referred to as "addition compounds." When the base polymer is reacted with an addition compound, a double bond and a hydroxyl group are generated in the side chain. 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.) may be further ester bonded to this hydroxy group.

Since the radically 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.
Further, as the polymerizable unsaturated double bond, a double bond possessed by a (meth)acryloyl group is preferably mentioned from the viewpoint of reactivity during curing.

Examples of the compound containing a reactive group and a 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 vinyloxazoline and isopropenyloxazoline. As the compound containing a reactive group and a polymerizable unsaturated double bond, a compound having an epoxy group and a carbon-carbon double bond, such as glycidyl (meth)acrylate, allyl glycidyl ether, α-ethyl glycidyl (meth)acrylate, 3,4-epoxycyclohexylmethyl acrylate (for example, "Cyclomer A400" manufactured by Daicel Chemical Industries, Ltd.), 3,4-epoxycyclohexylmethyl methacrylate (for example, "Cyclomer M100" manufactured by Daicel Chemical Industries, Ltd.), o-vinylbenzyl glycidyl ether, m-vinylbenzyl glycidyl ether, p-vinylbenzyl glycidyl ether, etc., is preferred, and glycidyl (meth)acrylate and 3,4-epoxycyclohexylmethyl (meth)acrylate are more preferred from the viewpoints of high reactivity during curing, ease of reaction control, and ease of availability.
Examples of the compound containing an acid group and a polymerizable unsaturated double bond include the same examples as those given above as the unsaturated monomer having an acid group.
The addition compound may be used alone or in combination of two or more kinds.

The amount of the additive 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 structural units of the base polymer (precursor polymer of the radical polymerizable polymer). The amount of the compound containing a reactive group and a polymerizable unsaturated double bond used is preferably 0.01 to 0.95 mol, more preferably 0.05 to 0.90 mol, and even more preferably 0.1 to 0.80 mol, per 1 mol of structural units derived from an 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 mol, more preferably 0.1 to 1.0 mol, and even more preferably 0.3 to 0.9 mol, per 1 mol of structural units derived from an unsaturated monomer having a group that reacts with an acid group contained in the base polymer. By using the addition compound in an amount within the above range, the exposure sensitivity, developability, and storage stability of the resulting photosensitive resin composition can be improved, and the adhesion and hardness of the cured product can also be improved.

Examples of structural units having a double bond in the side chain include structural unit A 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 reactive with an acid group and an addition compound, and structural unit B formed from any combination of structural unit A and a compound having a carboxylic acid group. A structural unit formed by adding glycidyl (meth)acrylate to a structural unit derived from (meth)acrylic acid (equivalent to a structural unit formed by adding (meth)acrylic acid to a structural unit derived from glycidyl (meth)acrylate) is preferred as structural unit A, and a structural unit formed by ester-bonding maleic anhydride to a hydroxyl group of this preferred structural unit A is preferred as structural unit B.

The content of the structural unit having a double bond in the side chain is preferably 10 to 70% by mass, more preferably 15% by mass or more, and 20% by mass based on 100% by mass of all the structural units of the radically polymerizable polymer. % or more, more preferably 65% by mass or less, even more preferably 60% by mass or less. When the content ratio of the structural unit having a double bond in the side chain is within the above range, the exposure sensitivity, developability, and storage stability of the resulting photosensitive resin composition can be improved, and furthermore, the cured product can be improved. It is also possible to improve the adhesion and hardness of

The double bond equivalent of the radically polymerizable polymer is preferably 330 to 1600 g/equivalent (mol). When the double bond equivalent is within the above range, the radically polymerizable polymer has good curability (sensitivity to heat and light), and the adhesiveness of the cured product is further improved. Further, coloring during curing can be reduced and transparency can be improved. The double bond equivalent is preferably 350 g/equivalent or more, more preferably 380 g/equivalent or more, still more preferably 400 g/equivalent or more, and preferably 1500 g/equivalent or less, from the viewpoint of achieving both curability and storage stability. , more preferably 1400 g/equivalent or less, still more preferably 1300 g/equivalent or less.

In this specification, the double bond equivalent is the mass (g) of the solid content of the polymer solution per 1 mol of double bonds in the polymer. The mass of the solid content of the polymer solution may be, for example, the total mass of each monomer component constituting the polymer. The double bond equivalent can be determined by dividing the mass (g) of the solid content of the polymer solution by the amount of double bonds (mol) of the polymer. Specifically, the double bond equivalent can be determined by confirming the structure of the monomer constituting the base polymer, such as the unsaturated monomer having an acid group used in the polymerization, and the structure of the additional compound used as necessary, and from the masses thereof. It can also be measured using various analyses such as titration, elemental analysis, NMR, and IR, or a differential scanning calorimeter method. For example, it may be calculated by measuring the number of ethylenic double bonds contained per 1 g of polymer in accordance with the iodine value test method described in JIS K 0070:1992.

Double bond equivalent is a value that is a measure of the amount of double bonds contained in a molecule.For compounds (polymers) with the same molecular weight, the larger the value of double bond equivalent, the greater the amount of double bonds introduced. It can be said that there are few

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, even more preferably 12,000 or less, and the lower limit is 3,000 or more. It is preferably 4,000 or more, more preferably 5,000 or more. When the weight average molecular weight is within the above range, the viscosity is low and the handleability (applicability) is good, and the hardness and adhesion of the cured product are further improved.

The number average molecular weight (Mn) of the radically polymerizable polymer is preferably 1000 to 7000, more preferably 1500 or more, even more preferably 2000 or more, even more preferably 2500 or more, and more preferably 5500 or less, and 4500 or more. The following is more preferable, and 4000 or less is even more preferable.

The dispersity (Mw/Mn) of the radical polymerizable polymer is preferably 1.2 to 4.6, more preferably 1.5 or more, even more preferably 1.8 or more, and more preferably 4.2 or less, even more preferably 3.8 or less.

The weight average molecular weight and number average molecular weight can be determined, for example, by gel permeation chromatography (GPC) in terms of polystyrene. Specifically, it can be determined by the GPC method using polystyrene as a standard substance and tetrahydrofuran (THF) as an eluent, using HLC-8220GPC (manufactured by Tosoh Corporation) and column TSKgel SuperHZM-N (manufactured by Tosoh Corporation). .

The acid value of the radical polymerizable polymer is preferably 30 to 200 mgKOH/g, more preferably 35 mgKOH/g or more, even more preferably 40 mgKOH/g or more, even more preferably 45 mgKOH/g or more, and more preferably 180 mgKOH/g or less, even more preferably 170 mgKOH/g or less, and even more preferably 160 mgKOH/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, the viscosity is suppressed, the coating property is excellent, and the adhesion of the obtained cured product is also better. In addition, the alkali solubility is improved, so the developability is also improved.

The acid value of the radical polymerizable polymer can be determined, for example, by measuring the acid value of the polymer solution using an automatic titrator (e.g., Hiranuma Sangyo Co., Ltd., product name "COM-555") using a 0.1N KOH aqueous solution as the titrant, and calculating the acid value per solid content from the acid value of the polymer solution and the solid content of the polymer solution. The solid content of the polymer solution can be determined, for example, as follows. First, about 0.3 g of the polymer solution is weighed out into an aluminum cup, about 1 g of acetone is added to dissolve it, and then it is naturally dried at room temperature. Then, it is dried at 140°C for 3 hours using a hot air dryer (e.g., Espec Corporation, product name "PHH-101"), and then it is allowed to cool in a desiccator and the mass is measured. The solid content concentration (non-volatile content) of the polymer solution is calculated from the amount of mass loss.

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 2.8% by mass or less. is even more preferable, and there is no particular lower limit, and it may be 0% by mass. When the thermogravimetric reduction rate is within the above range, heat resistance (especially heat decomposition resistance) will be high.

The thermal weight loss rate of a radically polymerizable polymer is determined, for example, by dropping a solution of 2 g of the polymer solution and 4 g of tetrahydrofuran into 60 g of hexane, separating and taking out the precipitated resin (polymer), and heating at 40°C. 10 mg of the obtained resin powder is weighed, and the weight loss rate is determined in a nitrogen atmosphere at 230°C for 30 minutes using a thermogravimeter TGA-50 (manufactured by SHIMADZU). be able to.

The use of the radically polymerizable polymer of the present invention is not particularly limited, but it can be suitably used in various uses such as printing plate making, protective films for color filters, color filters, liquid crystal display panels such as black matrices, and the like. In particular, the obtained cured film has high hardness and high transparency, so it is very useful as a protective film or insulating film in various display devices. Although the display device is not particularly limited, for example, a liquid crystal display device, a solid-state image sensor, a touch panel type display device, etc. are preferable. As the touch panel type display device, a capacitive type display device is particularly preferable.

2. Method for producing a radically polymerizable polymer A radically polymerizable polymer is obtained by subjecting monomer components serving as structural units to a polymerization reaction. As the polymerization method, commonly used methods such as bulk polymerization, solution polymerization, emulsion polymerization, etc. can be used, and the method may be appropriately selected depending on the purpose and use. Among these, solution polymerization is preferred because it is industrially advantageous and the molecular weight etc. can be easily adjusted. Furthermore, as the polymerization mechanism of the monomer component, polymerization methods based on mechanisms such as radical polymerization, anionic polymerization, cationic polymerization, coordination polymerization, etc. can be used, but polymerization methods based on radical polymerization mechanisms are also used industrially. It is preferred because it is advantageous.

The polymerization reaction can be initiated by supplying the energy required to initiate polymerization to the monomer components from an active energy source such as heat, electromagnetic waves (infrared rays, ultraviolet rays, X-rays, etc.), or electron beams. If a polymerization initiator is used in combination, the energy required to initiate polymerization can be significantly reduced and reaction control becomes easier, which is preferable. 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.

In the case of polymerization by solution polymerization, the solvent used for polymerization is not particularly limited as long as it is inert to the polymerization reaction, and it takes into account the polymerization mechanism, type and amount of monomers used, polymerization temperature, polymerization concentration, etc. However, if a solvent is used as a diluent or the like when forming a photosensitive resin composition later, it is more efficient to use the solvent in the solution polymerization of the monomer component. desirable and desirable.

Preferred examples of the solvent include the following compounds, and one or more of these can be used.
Monoalcohols such as methanol, ethanol, isopropanol, n-butanol, s-butanol; glycols such as ethylene glycol and propylene glycol; cyclic ethers such as tetrahydrofuran and dioxane; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene Glycol monoethers such as 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, 3-methoxybutanol; ethylene glycol dimethyl ether, ethylene glycol Glycol ethers such as diethyl ether, ethylene glycol ethyl methyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol ethyl methyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether; 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 mono Glycol monoether esters such as ethyl ether acetate, dipropylene glycol monobutyl ether acetate, 3-methoxybutyl acetate; methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, methyl propionate, ethyl propionate, propionic acid Alkyl esters such as butyl, methyl lactate, ethyl lactate, butyl lactate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, methyl acetoacetate, ethyl acetoacetate, etc. 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; Dimethylformamide, dimethylacetamide, Amides such as N-methylpyrrolidone; etc.

Among the above-mentioned solvents, monoalcohols and glycol monoether esters are more preferred, and glycol monoether esters are even more preferred. In particular, as the solvent, propylene glycol monomethyl ether acetate and isopropanol are preferred from the viewpoint of solubility, transparency, and action as a chain transfer agent, and propylene glycol monomethyl ether acetate is particularly preferred.

The amount of the solvent used in the polymerization reaction is preferably 50 to 1000 parts by weight, more preferably 100 to 500 parts by weight, based on 100 parts by weight of the total monomer components. Further, during the polymerization reaction, it is preferable to set the amounts of the solvent and each monomer component so that the final solid content concentration (nonvolatile content concentration) of the polymer solution is 10 to 70% by mass. In terms of productivity and polymerizability, the final solid content concentration is more preferably 20 to 65% by mass, and even more preferably 25 to 60% by mass.

The polymerization initiator is not particularly limited as long as it is a commonly used one, and examples thereof include organic peroxides such as cumene hydroperoxide, diisopropylbenzene hydroperoxide, di-t-butyl peroxide, lauroyl peroxide, benzoyl peroxide, t-butylperoxyisopropylcarbonate, t-amylperoxy-2-ethylhexanoate, and t-butylperoxy-2-ethylhexanoate; azo compounds such as 2,2'-azobis(isobutyronitrile), 1,1'-azobis(cyclohexanecarbonitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), and dimethyl 2,2'-azobis(2-methylpropionate); and the like. These polymerization initiators may be used alone or in combination of two or more. The amount of initiator used may be appropriately set depending on 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 several tens of thousands without gelation, the amount is preferably 0.1 to 18 parts by mass relative to 100 parts by mass of the total mass of the monomer components, 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, 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.

When polymerizing the monomer components, a commonly used chain transfer agent may be added as necessary to adjust the molecular weight. Examples of the chain transfer agent include mercaptan chain transfer agents such as n-dodecylmercaptan, mercaptopropionic acid, mercaptoacetic acid, and methyl mercaptoacetate; 2-mercaptoethanol, thioglycolic acid, 3-mercaptopropionic acid, thiosalicylic acid, 1 - Thiol-based chain transfer agents such as thioglycerol and 4-aminothiophenol; α-methylstyrene dimer; and the like. As the chain transfer agent, n-dodecyl mercaptan and mercaptopropionic acid are preferred because they have a high chain transfer effect, can reduce residual monomers, and are easily available. When using a chain transfer agent, the amount to be used may be determined as appropriate depending on the combination of monomers used, reaction conditions, molecular weight of the target polymer, etc., and is not particularly limited. It is preferable that the amount is 0.1 to 15 parts by mass, and 0.5 parts by mass, based on 100 parts by mass of the total mass of monomer components, since it is possible to obtain a polymer with a weight average molecular weight of several thousand to several tens of thousands. ~10 parts by mass is more preferred. In addition, in order to improve the transparency of the radically polymerizable polymer of the present invention, the amount of the thiol chain transfer agent is preferably 1 part by mass or less, and 0.1 part by mass or less, based on 100 parts by mass of the total monomer components. It is more preferably 1 part by mass or less, and particularly preferably substantially free. In the radically polymerizable polymer of the present invention, it is preferable that the above-mentioned monomer components are radically polymerized using the above-mentioned polymerization initiator and without using a thiol-based chain transfer agent.

The order of addition of the monomer components and polymerization initiator in the polymerization is not particularly limited, but possible methods include a method in which all the monomer components are charged at once in a solvent and polymerized, or a method in which the remaining monomer components are continuously or gradually added to a reaction vessel in which the solvent and some of the monomer components have already been charged, and polymerized.

There is no particular limitation on the pressure during the polymerization reaction, and the reaction may be carried out under either normal pressure or increased pressure. Regarding the temperature during the polymerization reaction, it depends on the type and composition ratio of the monomers used and the type of solvent used, but it is usually preferably carried out in the range of 20 to 150°C, more preferably 40 to 125°C. be.

When the addition compound is reacted to include a polymerizable double bond in the side chain after the base polymer is obtained by the polymerization process, the method of addition reaction of the addition compound is not particularly limited. For the addition reaction, a known method may be appropriately adopted, but for example, it is preferable to add the addition compound to the reaction liquid obtained in the polymerization process and react at 60 to 140°C (more preferably 70 to 130°C). In addition, 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; phosphines such as tri-n-propylphosphine, tri-n-butylphosphine, diphenylmethylphosphine, and triphenylphosphine. Furthermore, it is also preferable to use a polymerization inhibitor such as methylhydroquinone or oxygen in the addition reaction.

When the compound having a carboxylic acid group is reacted after the addition reaction, the amount of the compound having a carboxylic acid group used is not particularly limited, and it is preferable to set it so that the acid value of the resulting radical polymerizable polymer is in the above-mentioned range.

3. Photosensitive resin composition The present invention also relates to a photosensitive resin composition containing the above-mentioned radically polymerizable polymer, a polyfunctional monomer, a polymerization initiator, inorganic fine particles, and a solvent, and in particular a negative photosensitive resin composition. It is preferable that there be. The use of the photosensitive resin composition of the present invention is not particularly limited, but it is suitably used as a material for forming a protective film for color filters, liquid crystal display elements, integrated circuit elements, solid-state image sensors, etc.

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

The content of the radically polymerizable polymer in the photosensitive resin composition is preferably 5 to 70% by mass, more preferably 10% by mass or more, based on 100% by mass of the total solid content of the photosensitive resin composition, and more preferably 15% by mass or more. It is more preferably at least 65% by mass, even more preferably at most 50% by mass, even more preferably at most 45% by mass, and even more preferably at most 40% by mass. When the content ratio of the radically polymerizable polymer is within the above range, the effects of the present invention can be more pronounced.

3.2 Polyfunctional monomer The polyfunctional monomer contained in the photosensitive resin composition of the present invention can be polymerized by free radicals, electromagnetic waves (e.g., infrared rays, ultraviolet rays, X-rays, etc.), irradiation with active energy rays such as electron beams, etc. It is a low-molecular compound having a polymerizable unsaturated bond (also referred to as a polymerizable unsaturated group). Examples include polyfunctional compounds having two or more polymerizable unsaturated groups in the molecule. The molecular weight is not particularly limited, but from the viewpoint of ease of handling, it is preferably, for example, 3,000 or less, more preferably 2,000 or less. Among these, polyfunctional (meth)acrylate compounds having two or more functionalities (hereinafter also simply referred to as "polyfunctional (meth)acrylate compounds") are particularly preferred. A polyfunctional (meth)acrylate compound is a compound having two or more (meth)acryloyl groups in one molecule. By containing a polyfunctional monomer (especially a polyfunctional (meth)acrylate compound), the photosensitive resin composition has superior photosensitivity and curability, making it possible to obtain a cured product with extremely high hardness and high transparency. become. The functional number of the polyfunctional (meth)acrylate compound is preferably 3 or more, more preferably 4 or more, and even more preferably 5 or more. Further, from the viewpoint of further suppressing curing shrinkage, the functional number is preferably 10 or less, more preferably 8 or less, and even more preferably 6 or less.

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 and polyfunctional (meth)acrylates such as pentaerythritol 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, tris(hydroxyethyl)isocyanurate tri(meth)acrylate, propylene oxide-added ditrimethylolpropane tetra(meth)acrylate, and ε-caprolactone-added ditrimethylolpropane tetra(meth)acrylate. Among these, trimethylolpropane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, ethylene oxide-added dipentaerythritol hexa(meth)acrylate, propylene oxide-added trimethylolpropane tri(meth)acrylate, propylene oxide-added ditrimethylolpropane tetra(meth)acrylate, propylene oxide-added pentaerythritol tetra(meth)acrylate, propylene oxide-added dipentaerythritol hexa(meth)acrylate, ε-caprolactone-added trimethylolpropane tri(meth)acrylate, ε-caprolactone-added ditrimethylolpropane tetra(meth)acrylate, ε-caprolactone-added pentaerythritol tetra(meth)acrylate, and ε-caprolactone-added dipentaerythritol hexa(meth)acrylate are preferred.

The content ratio of the polyfunctional monomer in the photosensitive resin composition is not particularly limited, and may be set as appropriate depending on the type of polyfunctional monomer and radically polymerizable polymer used, the use and purpose of the photosensitive resin composition, etc. Bye. The content of the polyfunctional monomer in the photosensitive resin composition is preferably 2 to 85% by mass based on 100% by mass of the total solid content of the photosensitive resin composition, for example, from the viewpoint of better developability and plate-making properties. , more preferably 5% by mass or more, further preferably 10% by mass or more, even more preferably 15% by mass or more, more preferably 75% by mass or less, even more preferably 60% by mass or less, even more preferably 50% by mass or less. , more preferably 40% by mass or less.

The content of the polyfunctional monomer is preferably 50 to 500 parts by mass relative to 100 parts by mass of the radical polymerizable polymer, 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. From the viewpoint of further improving the 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 content of the polyfunctional monomer relative to the radical polymerizable polymer is within the above range, a cured product with higher surface hardness is obtained, and in combination with the preferred weight average molecular weight of the radical polymerizable polymer being 3000 or more, the developability is further improved.

3.3 Polymerization Initiator The photosensitive resin composition of the present invention contains a polymerization initiator, and can initiate polymerization and form a cured product by irradiating it with light or applying heat. Although the photosensitive resin composition of the present invention can be thermally cured by using a known thermal polymerization initiator, photopolymerization is preferable because it allows the cured product to be microfabricated and image formed by photolithography. It is preferable to add an initiator and photocure. In this respect, it is preferable to use a photopolymerization initiator as the polymerization initiator.

As the thermal polymerization initiator, known ones can be used, such as methyl ethyl ketone peroxide, benzoyl peroxide, dicumyl peroxide, t-butyl hydroperoxide, cumene hydroperoxide, t-butyl peroxyoctoate, and t-butyl peroxide. - Organic peroxides such as butyl peroxybenzoate and lauroyl peroxide; azo compounds such as azobisisobutyronitrile; and the like. For thermal polymerization applications, a curing accelerator may be mixed into the composition and examples of such curing accelerators include tertiary amines, cobalt naphthenate, cobalt octylate, etc. .

As the photopolymerization initiator, known ones can be used, for example, acetophenone, diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyl dimethyl ketal, 4-(2-hydroxyethoxy)phenyl-(2-hydroxy-2-propyl)ketone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone, 2-dimethylamino-2-(4-methyl-benzyl)-1-(4-morpholin-4-yl-phenyl)-butan-1-one. acetophenones such as oligo{2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone} and 2-hydroxy-1-{4-[4-(2-hydroxy-2-methylpropionyl)benzyl]phenyl}-2-methylpropan-1-one; benzoins such as benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether and benzoin isobutyl ether; benzophenone, o-benzoyl methyl benzoate, 4-phenylbenzophenone, 4-benzoyl-4'-methyl-diphenyl sulfide, 3,3',4,4'-tetra(t-butylperoxycarbonyl)benzof benzophenones such as 4-benzoyl-N,N-dimethyl-N-[2-(1-oxo-2-propenyloxy)ethyl]benzenemethanaminium bromide and (4-benzoylbenzyl)trimethylammonium chloride; thioxanthones such as 2-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; 2,4,6-trimethylbenzoyl -diphenyl-phosphine oxide, acylphosphine oxide such as bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide; oxime esters such as 1,2-octanedione, 1-[4-(phenylthio)-, 2-(O-benzoyloxime)], O-(acetyl)-N-(1-phenyl-2-oxo-2-(4'-methoxy-naphthyl)ethylidene)hydroxylamine; titanocenes such as bis(η5-2,4-cyclopentadiene-1-yl)-bis(2,6-difluoro-3-(1H-pyrrol-1-yl)-phenyl)titanium; phenylglyoxylic methyl esters; and the like. Among these, from the viewpoint of hardness and heat resistance, acetophenones, oxime esters, and titanocenes are preferred, 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.

Particularly preferred specific polymerization initiators include 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one ("IRGACURE907", manufactured by BASF), 2-benzyl-2 -dimethylamino-1-(4-morpholinophenyl)-butanone-1 ("IRGACURE369", manufactured by BASF), 2-dimethylamino-2-(4-methyl-benzyl)-1-(4-morpholine- Aminoacetophenones such as 4-yl-phenyl)-butan-1-one ("IRGACURE379", manufactured by BASF); bis(η5-2,4-cyclopentadien-1-yl)-bis(2,6-difluoro Titanocenes such as -3-(1H-pyrrol-1-yl)-phenyl) titanium ("IRGACURE784", manufactured by BASF); 1,2-octanedione, 1-[4-(phenylthio)-,2-( Examples include oxime ester compounds such as O-benzoyloxime) ("IRGACURE OXE01", manufactured by BASF).

These polymerization initiators may be used alone or in combination of two or more.

The content of the polymerization initiator in the photosensitive resin composition is not particularly limited and may be appropriately set depending on the use or purpose of the photosensitive resin composition. The content of the polymerization initiator in the photosensitive resin composition is preferably 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 the total solid content of the photosensitive resin composition (100% by mass), from the viewpoint of obtaining a cured product with excellent heat resistance. In addition, from the viewpoint of the balance between the influence of decomposition products of the polymerization initiator and economic efficiency, the content is preferably 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.

3.4 Inorganic fine particles Inorganic fine particles refer to fine particles containing an inorganic component, and examples thereof include metals (including metalloids), their salts (carbonates, sulfates, etc.), and their oxides. Among these, metal salts or oxides are preferred, and metal oxides are more preferred. Note that one or two or more metal atoms may be present in one molecule, and when two or more metal atoms are present, one or more types may be present.
Since the photosensitive resin composition of the present invention contains inorganic fine particles, it is possible to form a cured product having superior hardness.

As the metal, for example, silicon (metalloid), titanium, zirconium, calcium, barium, aluminum, etc. are preferable, and silicon, zirconium, titanium, and aluminum are more preferable, and it is even more preferable to contain at least silicon in terms of further increasing the surface hardness. As the metal salt, for example, calcium carbonate, barium sulfate, etc. are preferable, and as the metal oxide, for example, silicon oxide (silica, etc.), titanium oxide, aluminum oxide, zirconium oxide (zirconia, etc.), etc. are preferable. As the inorganic fine particles, it is particularly preferable to contain silicon oxide, and it may be a composite metal oxide further containing a metal atom other than silicon. In addition, as the inorganic fine particles, it is preferable to be metal oxide particles having hydroxyl groups on the surface, and more preferable to be silica fine particles. If the metal oxide particles have hydroxyl groups on the surface, the affinity with the radical polymerizable polymer contained in the photosensitive resin composition is further improved. As the silica fine particles, it is preferable to have a surface modification such as carboxylic acid modification or amino group modification, and for example, it is more preferable to have a (meth)acryloyloxy group bonded to a silicon atom via a divalent linking group by surface modification.

The number average primary particle size (diameter of primary particles) of the 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 size of the inorganic fine particles is within the above range, the inorganic fine particles have excellent dispersibility and dispersion stability in the photosensitive resin composition, and a cured product with high transparency can be formed.
The number average primary particle diameter can be measured, for example, by using a laser diffraction particle size distribution analyzer. The number average primary particle diameter can be determined directly by enlarging and observing inorganic fine particles with a transmission electron microscope (TEM), a field emission transmission electron microscope (FE-TEM), a field emission scanning electron microscope (FE-SEM), or the like, randomly selecting 100 primary particles, measuring the length in the major axis direction, and calculating the arithmetic average.

The inorganic fine particles may be in the form of a dried powder or in the form of a dispersion in an organic solvent (e.g., colloidal silica, etc.). From the viewpoint of the dispersion stability of the photosensitive resin composition, however, it is preferable to use the inorganic fine particles in the form of a dispersion in an organic solvent. In other words, it is preferable that the inorganic fine particles are contained in the photosensitive resin composition as an organic solvent dispersion.

Examples of the particle shape of the inorganic fine particles include spherical, granular, ellipsoidal, cubic, rectangular parallelepiped, pyramidal, needle-like, columnar, rod-like, cylindrical, scale-like, plate-like, and flake-like. The particle shape of the inorganic fine particles is preferably spherical, granular, or columnar from the viewpoint of dispersibility in a solvent.

When inorganic fine particles are used in the form of a dispersion, the organic solvent (dispersion medium) used may be, for example, any of the solvents contained in the photosensitive resin composition described below. Only one type of organic solvent may be used, or two or more types may be used in combination.

The organic solvent dispersion can be obtained by thoroughly 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 a dispersion medium, such as MEK-ST, MEK-ST-L, MEK-ST-ZL, MEK-ST-UP, and MEK-AC-2140Z; organosilica sols using methyl isobutyl ketone as a dispersion medium, such as MIBK-ST and MIBK-SD-L; organosilica sols using ethyl acetate as a dispersion medium, such as EAC-ST; organosilica sols using methanol as a dispersion medium, such as methanol silica sol and MA-ST-M; organosilica sols using isopropanol as a dispersion medium, such as IPA-ST and IPA-ST-L; organosilica sols using ethylene glycol as a dispersion medium, such as EG-ST; X Organosilica sols using xylene/n-butanol as a dispersion medium, such as BA-ST; organosilica sols using alkylene glycol monoalkyl ether 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; organosilica sols using propylene glycol monomethyl ether as a dispersion medium, such as PGM-AC-4130Y; and the like (all manufactured by Nissan Chemical Industries, Ltd.).

The content ratio of inorganic fine particles (solid content ratio) in the photosensitive resin composition is 5 to 70% by mass based on 100% by mass of the total solid content of the photosensitive resin composition from the viewpoint of developability, transparency, etc. It is preferably 10% by mass or more, more preferably 15% by mass or more, and even more preferably 60% by mass or less.
Further, when silicon-containing fine particles (preferably silica fine particles) are used as the inorganic fine particles, the content rate (solid content rate) of the silicon-containing fine particles is 50% by mass out of 100% by mass of the total amount of inorganic fine particles in the photosensitive resin composition. % or more, more preferably 70% by mass or more, even more preferably 90% by mass or more, and there is no particular upper limit, and 100% by mass is preferable.

When inorganic fine particles are used in the form of a dispersion, the amount of organic solvent used should be an amount that can adequately disperse the inorganic fine particles, but for example, it is preferably 50 to 600 parts by mass, more preferably 70 parts by mass or more, even more preferably 100 parts by mass or more, more preferably 550 parts by mass or less, and even more preferably 500 parts by mass or less, per 100 parts by mass of inorganic fine particles.

3.5 Solvent The photosensitive resin composition of the present invention contains a solvent as a diluent. In addition, when the radically polymerizable polymer is obtained by a solution polymerization method, the radically polymerizable polymer is used as a polymer solution without being separated from the solvent, and the solvent contained in the polymer solution is used as a photosensitive resin composition. It is also possible to use a solvent containing it. Furthermore, when the inorganic fine particles are used in the form of a dispersion, 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, the solvent may or may not be further added.

There are no particular limitations on the solvent, so long as it can uniformly dissolve or disperse components such as the radical polymerizable polymer, the polyfunctional monomer, the polymerization initiator, and the inorganic fine particles. Specific examples of the glycols 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; 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 acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ... esters of glycol monoethers such as ethylene 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; methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, methyl propionate, ethyl propionate, and propionate; Examples of the solvent include alkyl esters such as butyl pionate, 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. Examples of the solvent contained in the photosensitive resin composition include monoalcohols and esters of glycol monoethers, more preferably esters of glycol monoethers, and even more preferably propylene glycol monomethyl ether acetate.

The total content of the solvent in the photosensitive resin composition may be appropriately set depending on the optimum viscosity when using the photosensitive resin composition, but for example, based on 100 parts by mass of the radically polymerizable polymer, It is preferably 50 to 1200 parts by weight, more preferably 100 to 900 parts by weight. If the total content of the solvent in the photosensitive resin composition is within the above range, the ease of handling and storage stability of the composition as well as the efficiency during coating work will be improved.

3.6 Other Components The photosensitive resin composition of the present invention may contain components other than the radically polymerizable polymer, polyfunctional monomer, polymerization initiator, inorganic fine particles, and solvent. Other components are not particularly limited as long as they do not impair the effects of the present invention, but examples include fillers such as aluminum hydroxide, talc, clay, and barium sulfate, quantum dot particles, pigments, dyes, and antifoaming agents. , coupling agent, leveling agent, sensitizer, mold release agent, lubricant, plasticizer, antioxidant, ultraviolet absorber, light stabilizer, flame retardant, polymerization inhibitor, polymerization retarder, polymerization accelerator, thickener Known additives such as agents, dispersants, and surfactants can be mentioned. As the pigment, various organic pigments and/or inorganic pigments can be used, and as the dye, various organic dyes and/or inorganic dyes can be used. Further, the pigments and dyes may be natural pigments or synthetic pigments. One type of other components may be used, or two or more types may be used in combination.

Other components may include polymers other than the above-mentioned radically polymerizable polymer. When a polymer other than the radically polymerizable polymer is included, the content of the radically polymerizable polymer is preferably 30% by mass or more, more preferably 50% by mass or more, and 70% by mass based on the total amount of 100% by mass of the polymer. % or more is more preferable, and less than 100% by mass is preferable.

4. Method for preparing photosensitive resin composition The method for preparing the photosensitive resin composition of the present invention is not particularly limited, and may be a known method. 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 necessary, using a known mixer or disperser. The mixing and dispersing step is not particularly limited, and the components used may be mixed and dispersed all at once, or a part of the components may be mixed first, and then the remaining components may be added and mixed and dispersed. Examples of the dispersing machine include a paint conditioner, a bead mill, a roll mill, a ball mill, a jet mill, a homogenizer, a kneader, a blender, and the like. In addition, other steps that are usually performed when preparing a photosensitive resin composition may be further included. It is preferable to filter the obtained photosensitive resin composition using a filter or the like to remove fine dust.

When the photosensitive resin composition contains a colorant such as a pigment or dye, it is preferably prepared through a colorant dispersion process. In the colorant dispersion process, for example, a colorant (preferably an organic pigment), a dispersant, and a solvent are each weighed in predetermined amounts, and a dispersion machine is used to disperse the colorant into fine particles to form a liquid colorant dispersion ( (also referred to as milbase).

The colorant dispersion process preferably involves kneading and dispersing the colorant using a roll mill, kneader, blender, or the like, and then finely dispersing the colorant using a media mill, such as a bead mill filled with beads of 0.01 to 1 mm, to obtain a mill base.

When preparing a photosensitive resin composition using the mill base, the photosensitive resin composition can be prepared by mixing and dispersing the 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 to form a composition (preferably a transparent liquid) and the mill base to form a uniform dispersion solution.

The viscosity of the photosensitive resin composition may be appropriately set depending on the desired thickness of the cured film, but for example, in a photosensitive resin composition whose solid content (nonvolatile content) is adjusted to 40% by mass, the viscosity is 25% by mass. The viscosity at °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 3 mPa·s or more. More preferred. By controlling the viscosity of the photosensitive resin composition within the above range, handling properties and coating workability are improved.

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

Examples of materials used for the substrate include transparent materials such as glass, acrylic resin, polycarbonate resin, polyester resin (e.g., PET, etc.), polystyrene resin, and metal materials such as aluminum, copper, iron, and stainless steel. .

Examples of the coating method on the substrate include methods using a spin coater, a bar coater, a gravure coater, a roll coater, a knife coater, an applicator, and the like.

It may further include a drying step before curing the coating layer, and the drying temperature in this step is preferably 40 to 180°C, more preferably 60 to 120°C, even more preferably 70 to 100°C. The drying time is preferably 0.5 to 30 minutes, more preferably 1 to 10 minutes.

The coating layer can be cured by, for example, irradiating the coating layer with active energy rays using an ultra-high pressure mercury lamp or the like. The active energy dose to be irradiated is not particularly limited and can be set appropriately depending on the purpose and use of the photosensitive resin composition, the amount of polymerization initiator used, etc. ) is preferably 10 to 2000 mJ/cm ² , more preferably 20 to 1500 mJ/cm ² .

Drying after curing is preferably performed by heating (post-baking), and the heating temperature is preferably 90 to 200°C, more preferably 100 to 190°C, and even more preferably 120 to 180°C. The heating time is preferably 10 to 120 minutes, more preferably 20 to 90 minutes. By further heating after curing, the cured film can be further cured, and the hardness and adhesion can be further improved.

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, it is possible to fully meet the demand for low height for components and display devices that use the cured film.

Specifically, the light transmittance of the cured product is preferably 70% or more for light at a wavelength of 410 nm at a thickness of 10 μm, more preferably 75% or more, even more preferably 80% or more, and 90% or more. % or more is even more preferable, 90.5% or more is even more preferable, and 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. Since the cured film formed from the radically polymerizable polymer and/or photosensitive resin composition of the present invention has high transparency, even when a laminate containing the cured film is used for a touch panel, for example, Clear images can be displayed without deteriorating display performance.

It is preferable that the cured product has high surface hardness. Specifically, the pencil hardness of the cured product is preferably H or higher, more preferably 3H or higher. In addition, 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 radically polymerizable polymer and/or photosensitive resin composition of the present invention has excellent surface hardness and can cushion external impacts, so it can be used as a component for protective films, insulating films, etc. suitable.

It is preferable that the cured product has high adhesion. Specifically, it is preferable that the residual ratio in the test results according to JIS K5600-5-6 (1999) "General test methods for coating materials - Part 5: Mechanical properties of coating films - Section 6: Adhesion (cross-cut method)" is 90% or more. The cured film formed from the radical polymerizable polymer and/or photosensitive resin composition of the present invention has excellent adhesion, so that problems such as peeling from the substrate are unlikely to occur.

It is also suitable to form a laminate such as a color filter using a cured product (cured film) formed from the radically polymerizable polymer and/or photosensitive resin composition of the present invention.

The color filter preferably has a cured product of a radically polymerizable polymer and/or a photosensitive resin composition on a substrate. In a color filter, the cured product is particularly suitable as a black matrix or a segment that requires coloring such as each pixel of red, green, blue, yellow, etc., and is also suitable for use as a photo spacer, a protective layer, an alignment control layer, etc. It is also suitable for segments that do not require coloring, such as ribs.

Substrates used for color filters include, for example, glass substrates such as white glass, blue glass, alkali-strengthened glass, and silica-coated blue glass; polyester, polycarbonate, polyolefin, polysulfone, ring-opening polymers of cyclic olefins, and hydrogenated polymers thereof. Sheets, films, or substrates made of thermoplastic resins such as objects; sheets, films, or substrates made of thermosetting resins such as epoxy resins and unsaturated polyester resins; metal substrates such as aluminum plates, copper plates, nickel plates, and stainless steel plates; Ceramic substrates; semiconductor substrates having photoelectric conversion elements; glass substrates having coloring material layers on their surfaces (for example, color filters for LCDs); and the like. Among these, from the viewpoint of heat resistance, glass substrates and sheets, films, or substrates made of heat-resistant resin are preferred. Moreover, as a substrate for a color filter, a transparent substrate is preferable. The substrate may be subjected to corona discharge treatment, ozone treatment, chemical treatment using a silane coupling agent, etc., as necessary.

The color filter is preferably formed by photolithography, and specifically includes a step of arranging a photosensitive resin composition on a substrate for each pixel of one color (that is, for each pixel of one color) (also referred to as an arrangement step); A step of irradiating the photosensitive resin composition disposed on the substrate with light (also referred to as a light irradiation step), a step of developing with a developer (also referred to as a developing step), and a step of heat treatment (also referred to as a heating step) It is preferable to adopt a manufacturing method in which the same method is repeated for each color. Note that the order in which pixels of each color are formed is not particularly limited.

As described above, the radical polymerizable polymer and photosensitive resin composition of the present invention can form a cured product that has excellent coatability, hardness, transparency, and adhesion. Therefore, the radical polymerizable polymer and photosensitive resin composition of the present invention can be suitably used in applications such as resist materials, various coating agents, and paints. In addition, since the radical polymerizable polymer has an acid group such as a carboxyl group, it can be suitably used as an alkaline development type negative resist material for producing color pixels of color filters, black matrices, overcoats, photospacers, optical waveguides, etc.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited by the Examples below, and modifications may be made as appropriate within the scope of the spirit of the preceding and following. Of course, other implementations are also possible, and all of them are included within the technical scope of the present invention.

First, the measurement and evaluation methods employed in the following examples and comparative examples will be described.
(1) Weight average molecular weight (Mw) and number average molecular weight (Mn)
Measurements were performed by gel permeation chromatography (GPC; HLC-8220GPC, manufactured by Tosoh Corporation) using tetrahydrofuran as an eluent and a TSKgel Super HZM-N (manufactured by Tosoh Corporation) column, and calculations were made in terms of standard polystyrene.
(2) Solids (non-volatiles)
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 naturally dried at room temperature. After that, the solution was dried at 140°C for 3 hours using a hot air dryer (product name: PHH-101, manufactured by Espec Corporation), cooled in a desiccator, and weighed. The weight of the solid content (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 each of the Examples and Comparative Examples was precisely weighed out, dissolved in a mixed solvent of 90 g of acetone and 10 g of water, and titrated with a 0.1 N KOH aqueous solution. The titration was performed using an automatic titrator (product name: COM-555, manufactured by Hiranuma Sangyo Co., Ltd.), and the acid value per 1 g of polymer was calculated from the solid content concentration (mg KOH/g).
(4) Thermal Weight Loss Rate A solution of 2 g of the copolymer solution prepared in each of the Examples and Comparative Examples, to which 4 g of tetrahydrofuran was added, was dropped into 60 g of hexane, and the precipitated resin (copolymer) was separated, taken out, and vacuum dried overnight at 40° C. 10 mg of the resulting resin powder was weighed, and the weight loss rate at 230° C. for 30 minutes in a nitrogen atmosphere was measured using a thermogravimetric analyzer TGA-50 (manufactured by Shimadzu Corporation).
(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.). The cone-plate used was a standard rotor (name: 1°34′×R=24).
(6) Adhesion (cross-cut test)
The test was conducted according to JIS K5600-5-6 (1999) "General test methods for paints - Part 5: Mechanical properties of coatings - Section 6: Adhesion (cross-cut method)". The remaining film rate of the test results was rated as "1" if it was 100-90%, "2" if it was 89-80%, "3" if it was 79-70%, "4" if it was 69-60%, and "5" if it was 59% or less.
(7) Pencil hardness The test was conducted according to JIS K5600-5-4 (1999), except that the load was 500 g as in the old JIS version (JIS K5400 (1990)). The hardest pencil that did not cause any scratches was recorded as the hardness (surface hardness).
(8) Transmittance Using a glass substrate as a blank, the transmittance of the formed cured product was measured with a spectrophotometer UV3100 (manufactured by Shimadzu Corporation) to determine the transmittance at 410 nm.

[Example 1]
A separable flask equipped with a cooling tube was prepared as a reaction tank. On the other hand, in the monomer dropping tank, as monomer compositions, 10 g of N-phenylmaleimide (hereinafter also referred to as "PMI"), 37 g of methacrylic acid (hereinafter also referred to as "MAA"), and tetrahydrofurfuryl methacrylate (hereinafter also referred to as "THFMA") were added. ) 10g, cyclohexyl methacrylate (hereinafter also referred to as "CHMA") 33g, 2-hydroxypropyl methacrylate (hereinafter also referred to as "HPMA") 10g, t-butylperoxy-2-ethylhexanoate (trade name: Perbutyl (registered) Trademark) O, manufactured by Nippon Oil & Fats Co., Ltd., hereinafter also referred to as "PBO") (8 g) was added and mixed with stirring.
A reaction tank was charged with 233 g of propylene glycol methyl ether acetate (hereinafter also referred to as "PGMEA"), the atmosphere was replaced with nitrogen, and the temperature of the reaction tank was raised to 90° C. by heating in an oil bath while stirring. After the temperature of the reaction tank was 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 completion of dropping the monomer composition, 0.5 g of PBO was added. After another 30 minutes, the temperature of the reaction tank was raised to 115°C. After maintaining the temperature at 115°C for 1 hour, a gas introduction tube was attached to the separable flask, and bubbling of a mixed gas of oxygen/nitrogen = 7/93 (v/v) 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 triphenylphosphine (hereinafter also referred to as "TPP") as a catalyst were added to the reaction tank. ) and reacted at 115° C. for 14 hours. Thereafter, it was cooled to room temperature to obtain a copolymer solution (A-1) containing 36.2% by mass of resin (copolymer; radically polymerizable polymer). The resin had a number average molecular weight (Mn) of 3010, a weight average molecular weight (Mw) of 8600, a molecular weight distribution (Mw/Mn) of 2.86, and an acid value of 85 mgKOH/g. Table 1 shows the composition, double bond equivalent, Mn, Mw, Mw/Mn, acid value, solid content concentration (nonvolatile content), and thermal weight loss rate of the copolymer solution (A-1).

[Example 2]
A separable flask equipped with a cooling tube was prepared as a reaction tank. On the other hand, 10 g of PMI, 37 g of MAA, 43 g of CHMA, 10 g of HPMA, and 8 g of PBO were added as monomer compositions into a monomer dropping tank and mixed with stirring.
After charging 233 g of PGMEA into a reaction tank and purging with nitrogen, the temperature of the reaction tank was raised to 90° C. by heating in an oil bath while stirring. After the temperature of the reaction tank was 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 completion of dropping the monomer composition, 0.5 g of PBO was added. After another 30 minutes, the temperature of the reaction tank was raised to 115°C. After maintaining the temperature at 115°C for 1 hour, a gas introduction tube was attached to the separable flask, and bubbling of a mixed gas of oxygen/nitrogen = 7/93 (v/v) was started. Next, 33 g of GMA, 0.2 g of Antige W-400 as a polymerization inhibitor, and 0.4 g of TPP as a catalyst were placed in a reaction tank, and the mixture was reacted at 115° C. for 14 hours. Thereafter, it was cooled to room temperature to obtain a copolymer solution (A-2) containing 36.5% by mass of resin. The resin had a number average molecular weight (Mn) of 3100, a weight average molecular weight (Mw) of 9000, a molecular weight distribution (Mw/Mn) of 2.90, and an acid value of 86 mgKOH/g. Table 1 shows the composition, double bond equivalent, Mn, Mw, Mw/Mn, acid value, solid content concentration (nonvolatile content), and thermal weight loss rate of the copolymer solution (A-2).

[Example 3]
A separable flask equipped with a cooling tube was prepared as a reaction tank. On the other hand, 15 g of PMI, 37 g of MAA, 20 g of THFMA, 10 g of HPMA, 18 g of CHMA, and 8 g of PBO were charged as monomer compositions into a monomer dropping tank and mixed with stirring.
After charging 233 g of PGMEA into a reaction tank and purging with nitrogen, the temperature of the reaction tank was raised to 90° C. by heating in an oil bath while stirring. After the temperature of the reaction tank was 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 completion of dropping the monomer composition, 0.5 g of PBO was added. After another 30 minutes, the temperature of the reaction tank was raised to 115°C. After maintaining the temperature at 115°C for 1 hour, a gas introduction tube was attached to the separable flask, and bubbling of a mixed gas of oxygen/nitrogen = 7/93 (v/v) was started. Next, 33 g of GMA, 0.2 g of Antige W-400 as a polymerization inhibitor, and 0.4 g of TPP as a catalyst were placed in a reaction tank, and the mixture was reacted at 115° C. for 14 hours. Thereafter, 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 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 (nonvolatile content), and thermal weight loss rate of the copolymer solution (A-3).

[Example 4]
A separable flask equipped with a cooling tube was prepared as a reaction vessel. On the other hand, 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 charged as a monomer composition in a monomer dropping vessel and mixed with stirring.
233g of PGMEA was charged into the reaction vessel, and after nitrogen substitution, 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 was stabilized at 90°C, the monomer composition was dropped. While maintaining the temperature at 90°C, the monomer composition was dropped over 180 minutes. After the monomer composition was dropped, 0.5g of PBO was added. After another 30 minutes, the reaction vessel was heated to 115°C. After maintaining 115°C for 1 hour, a gas inlet tube was attached to the separable flask, and bubbling of oxygen/nitrogen = 7/93 (v/v) mixed gas was started. Next, 17g of GMA, 0.2g of Antage W-400 as a polymerization inhibitor, and 0.4g of TPP as a catalyst were charged into the reaction vessel, and reacted at 115°C for 7 hours. Thereafter, it was cooled to room temperature to obtain a copolymer solution (A-4) containing 33.8% by mass of resin. The resin had a number average molecular weight (Mn) of 2650, a weight average molecular weight (Mw) of 5400, Mw/Mn of 2.04, and an acid value of 150 mgKOH/g. The composition, double bond equivalent, Mn, Mw, Mw/Mn, acid value, solids concentration (non-volatile content), and thermal weight loss rate of the copolymer solution (A-4) are shown in Table 1.

[Example 5]
A separable flask equipped with a cooling tube was prepared as a reaction vessel. Meanwhile, 15 g of PMI, 33 g of MAA, 10 g of THFMA, 10 g of HPMA, 32 g of CHMA, and 8 g of PBO were charged as a monomer composition into a monomer dropping vessel and mixed with stirring.
233g of PGMEA was charged into the reaction vessel, and after nitrogen replacement, 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 was stabilized at 90°C, the monomer composition was added dropwise. While maintaining the temperature at 90°C, the monomer composition was added dropwise over 180 minutes. After the monomer composition was added dropwise, 0.5g of PBO was added. After another 30 minutes, the reaction vessel was heated to 115°C. After maintaining 115°C for 1 hour, a gas inlet tube was attached to the separable flask, and bubbling of 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 Antage W-400 as a polymerization inhibitor, and 0.4g of TPP as a catalyst were charged into the reaction vessel, and the reaction was carried out at 115°C for 21 hours. The mixture was then cooled to room temperature to obtain a copolymer solution (A-5) containing 37.0% by mass of resin. The resin had a number average molecular weight (Mn) of 3460, a weight average molecular weight (Mw) of 8100, Mw/Mn of 2.34, and an acid value of 88 mgKOH/g. The composition, double bond equivalent, Mn, Mw, Mw/Mn, acid value, solids concentration (non-volatile content), and thermal weight loss rate of the copolymer solution (A-5) are shown in Table 1.

[Example 6]
A separable flask equipped with a cooling tube was prepared as a reaction tank. On the other hand, 15 g of PMI, 47 g of MAA, 10 g of THFMA, 10 g of HPMA, 18 g of CHMA, and 10 g of PBO were added as monomer compositions into a monomer dropping tank and mixed with stirring.
After charging 233 g of PGMEA into a reaction tank and purging with nitrogen, the temperature of the reaction tank was raised to 90° C. by heating in an oil bath while stirring. After the temperature of the reaction tank was 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 completion of dropping the monomer composition, 0.5 g of PBO was added. After another 30 minutes, the temperature of the reaction tank was raised to 115°C. After maintaining the temperature at 115°C for 1 hour, a gas introduction tube was attached to the separable flask, and bubbling of a mixed gas of oxygen/nitrogen = 7/93 (v/v) was started. Next, 58 g of GMA, 0.2 g of Antige W-400 as a polymerization inhibitor, and 0.4 g of TPP as a catalyst were placed in a reaction tank, and the mixture was reacted at 115° C. for 21 hours. Thereafter, 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 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 (nonvolatile content), and thermal weight loss rate of the copolymer solution (A-6).

[Example 7]
A separable flask equipped with a cooling tube was prepared as a reaction tank. On the other hand, 30 g of PMI, 37 g of MAA, 10 g of THFMA, 10 g of HPMA, 13 g of CHMA, and 8 g of PBO were added as monomer compositions into a monomer dropping tank and mixed with stirring.
After charging 233 g of PGMEA into a reaction tank and purging with nitrogen, the temperature of the reaction tank was raised to 90° C. by heating in an oil bath while stirring. After the temperature of the reaction tank was 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 completion of dropping the monomer composition, 0.5 g of PBO was added. After another 30 minutes, the temperature of the reaction tank was raised to 115°C. After maintaining the temperature at 115°C for 1 hour, a gas introduction tube was attached to the separable flask, and bubbling of a mixed gas of oxygen/nitrogen = 7/93 (v/v) was started. Next, 33 g of GMA, 0.2 g of Antige W-400 as a polymerization inhibitor, and 0.4 g of TPP as a catalyst were placed in a reaction tank, and the mixture was reacted at 115° C. for 14 hours. Thereafter, 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 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 (nonvolatile content), and thermal weight loss rate of the copolymer solution (A-7).

[Example 8]
A separable flask equipped with a cooling tube was prepared as a reaction tank. On the other hand, 30 g of CHMI, 37 g of MAA, 10 g of THFMA, 10 g of HPMA, 13 g of CHMA, and 8 g of PBO were added as monomer compositions into a monomer dropping tank and mixed with stirring.
After charging 233 g of PGMEA into a reaction tank and purging with nitrogen, the temperature of the reaction tank was raised to 90° C. by heating in an oil bath while stirring. After the temperature of the reaction tank was 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 completion of dropping the monomer composition, 0.5 g of PBO was added. After another 30 minutes, the temperature of the reaction tank was raised to 115°C. After maintaining the temperature at 115°C for 1 hour, a gas introduction tube was attached to the separable flask, and bubbling of a mixed gas of oxygen/nitrogen = 7/93 (v/v) was started. Next, 33 g of GMA, 0.2 g of Antige W-400 as a polymerization inhibitor, and 0.4 g of TPP as a catalyst were placed in a reaction tank, and the mixture was reacted at 115° C. for 14 hours. Thereafter, 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 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 (nonvolatile content), and thermal weight loss rate of the copolymer solution (A-8).

[Comparative example 1]
A separable flask equipped with a cooling tube was prepared as a reaction tank. On the other hand, 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 as monomer compositions into a monomer dropping tank and mixed with stirring.
After charging 233 g of PGMEA into a reaction tank and purging with nitrogen, the temperature of the reaction tank was raised to 90° C. by heating in an oil bath while stirring. After the temperature of the reaction tank was 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 completion of dropping the monomer composition, 0.5 g of PBO was added. After another 30 minutes, the temperature of the reaction tank was raised to 115°C. After maintaining the temperature at 115°C for 1 hour, a gas introduction tube was attached to the separable flask, and bubbling of a mixed gas of oxygen/nitrogen = 7/93 (v/v) was started. Next, 33 g of GMA, 0.2 g of Antige W-400 as a polymerization inhibitor, and 0.4 g of TPP as a catalyst were placed in a reaction tank, and the mixture was reacted at 115° C. for 14 hours. Thereafter, 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 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 (nonvolatile content), and thermal weight loss rate of the copolymer solution (A-9).

[Comparative example 2]
A separable flask equipped with a cooling tube was prepared as a reaction tank. On the other hand, in a monomer dropping tank, 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 as monomer compositions. and stirred and mixed.
After charging 233 g of PGMEA into a reaction tank and purging with nitrogen, the temperature of the reaction tank was raised to 90° C. by heating in an oil bath while stirring. After the temperature of the reaction tank was 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 completion of dropping the monomer composition, 0.5 g of PBO was added. After another 30 minutes, the temperature of the reaction tank was raised to 115°C. After maintaining the temperature at 115°C for 1 hour, a gas introduction tube was attached to the separable flask, and bubbling of a mixed gas of oxygen/nitrogen = 7/93 (v/v) was started. Next, 33 g of GMA, 0.2 g of Antige W-400 as a polymerization inhibitor, and 0.4 g of TPP as a catalyst were placed in a reaction tank, and the mixture was reacted at 115° C. for 14 hours. Thereafter, 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 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 (nonvolatile content), and thermogravimetric reduction rate of the copolymer solution (A-10).

[Comparative Example 3]
A separable flask equipped with a cooling tube was prepared as a 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 charged as a monomer composition into a monomer dropping vessel and mixed with stirring.
233 g of PGMEA was charged into the reaction vessel, and after replacing 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 was stabilized at 90 ° C., the monomer composition was added dropwise. While maintaining the temperature at 90 ° C., the monomer composition was added dropwise over 180 minutes. After the monomer composition was added dropwise, 0.5 g of PBO was added. After another 30 minutes, the reaction vessel was heated 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 mass % of resin. The number average molecular weight (Mn) of the resin was 2900, the weight average molecular weight (Mw) was 6200, Mw / Mn was 2.14, and the acid value was 100 mg KOH / g. Table 1 shows 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).

[Comparative example 4]
A separable flask equipped with a cooling tube was prepared as a reaction tank. On the other hand, 37 g of MAA, 10 g of THFMA, 10 g of HPMA, 43 g of benzyl methacrylate (hereinafter also referred to as "BzMA"), and 8 g of PBO were charged into a monomer dropping tank and mixed with stirring.
After charging 233 g of PGMEA into a reaction tank and purging with nitrogen, the temperature of the reaction tank was raised to 90° C. by heating in an oil bath while stirring. After the temperature of the reaction tank was 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 completion of dropping the monomer composition, 0.5 g of PBO was added. After another 30 minutes, the temperature of the reaction tank was raised to 115°C. After maintaining the temperature at 115°C for 1 hour, a gas introduction tube was attached to the separable flask, and bubbling of a mixed gas of oxygen/nitrogen = 7/93 (v/v) was started. Next, 33 g of GMA, 0.2 g of Antige W-400 as a polymerization inhibitor, and 0.4 g of TPP as a catalyst were placed in a reaction tank, and the mixture was reacted at 115° C. for 14 hours. Thereafter, 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 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 (nonvolatile content), and thermogravimetric reduction rate of the copolymer solution (A-12).

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

(Formation of cured film)
The photosensitive resin composition (B1) was applied onto a 5 cm square glass substrate using a spin coater and dried in an oven at 80° C. for 3 minutes. After drying, ultraviolet rays were irradiated at an intensity of 1 J/cm ² (converted to 365 nm illuminance) using a UV aligner (trade name: TME-150RNS, manufactured by TOPCON) equipped with a 2.0 kW ultra-high pressure mercury lamp. After irradiation with ultraviolet rays, after-curing was performed at 160° C. for 1 hour to completely cure the coating film to obtain a cured film (coating film) with a thickness of 10 μm. The resulting cured film was tested for adhesion, pencil hardness, and permeability. The results are shown in Table 2.

[Examples 10 to 16, Comparative Examples 5 to 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, and cured films were formed using the resulting photosensitive resin compositions. Table 2 shows the composition and viscosity of the photosensitive resin compositions (B2) to (B12), as well as the test results of adhesion, pencil hardness, and transmittance using the cured films formed.

The radically 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 field and the electrical/electronic field.

Claims (8)

A polymer having 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 polymerizable double bond in a side chain,
the polymer further has 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,
The radical polymerizable polymer has a weight average molecular weight of 18,000 or less. 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. can be,
The radically polymerizable polymer according to claim 1, wherein the content of structural units derived from an acrylic monomer is 7% by mass or less in 100% by mass of all structural units of the polymer. The radically polymerizable polymer according to claim 1, wherein the acid value of the polymer is 30 to 200 mgKOH/g. The radically polymerizable polymer according to claim 1, wherein the double bond equivalent of the polymer is 330 to 1600 g/mol. The polymer has a structural unit derived from an N-substituted maleimide monomer in the main chain,
The radical polymerizable material according to claim 1, wherein the content of the structural unit derived from the N-substituted maleimide monomer is 5% by mass or more and 30% by mass or less in 100% by mass of all the structural units of the polymer. Polymer. The polymer further has a structural unit derived from an unsaturated monomer having a 5-membered ring or more cyclic ether structure,
The radically polymerizable polymer according to claim 1, wherein the unsaturated monomer having a cyclic ether structure of five or more members is either an acrylic type or a methacrylic type. The radical polymerizable polymer according to claim 6, wherein the content of the structural units derived from the unsaturated monomer having a cyclic ether structure of 5 or more members is 5% by mass or more and 20% by mass or less out of 100% by mass of all structural units of the polymer. A photosensitive resin composition comprising the radical polymerizable polymer according to any one of claims 1 to 7, a polyfunctional monomer, a polymerization initiator, inorganic fine particles, and a solvent.