JP7415014B2 - Copolymer, copolymer solution, photosensitive resin composition, cured product, method for producing copolymer, and method for producing copolymer solution - Google Patents

Description

The present invention relates to copolymers. More specifically, a copolymer, a copolymer solution, a photosensitive resin composition, a cured product, a method for producing a copolymer, and a method for producing a copolymer that can provide a cured product with excellent solvent resistance even under low temperature curing conditions. The present invention relates to a method for producing a combined solution.

Compositions containing curable resins can be used, for example, in color filters, inks, printing plates, printed wiring boards, semiconductor elements, photoresists, organic insulating films, organic protective films, etc. used in liquid crystal display devices, solid-state imaging devices, etc. Applications to various uses such as various optical members and electric/electronic devices have been studied, and resins and resin compositions with excellent properties required for each use have been developed.
In recent years, optical components, electrical machinery, electronic devices, and the like have become smaller, thinner, and more energy-saving, and as a result, the various components used are required to have higher quality performance. In order to meet such demands, research is being conducted on curable resins that can be used as materials for various parts and the like.

To date, curable resins have been developed that meet various demands.
For example, Patent Document 1 describes an oligomer that has a carboxyl group and a photoreactive unsaturated group in its side chain and is soluble in an alkaline aqueous solution, a compound that has an epoxy group, a sensitizer, and a dicyandiamide modified product. A photosensitive resin composition is described.
For example, Patent Document 2 describes a photosensitive composition containing an alkali-soluble polymer obtained by polymerizing a radically polymerizable monomer having an epoxy group or an oxetanyl group, a radically polymerizable monomer having a carboxyl group, etc. There is.
For example, Patent Document 3 discloses that addition copolymers such as (meth)acrylate monomers having a glass transition temperature of 10°C or less when made into homopolymers, and (meth)acrylate monomers having epoxy groups or carboxyl groups, , a curable polymer having an acid group, a hydroxyl group, and a polymerizable unsaturated bond in the side chain obtained by performing a specific modification reaction, and a photosensitive polymer composition containing the above-mentioned curable polymer are described.

Japanese Patent Application Publication No. 4-25846 Japanese Patent Application Publication No. 2006-251009 Japanese Patent Application Publication No. 2014-210892

As mentioned above, various studies have been conducted on curable resins, but when conventional curable resins are used together with coloring materials as raw materials for color filters, cleaning solvents are removed from the raw materials during the production of color filters. There was a problem with the coloring material eluting inside. Therefore, there has been a demand for further improvement in the solvent resistance of curable resins.

In addition, in recent years, especially in the use of color filters, as the quality of color liquid crystal display devices and the like has increased and applications have expanded, there has been a strong demand for higher performance such as higher brightness and higher contrast of display panels. However, in the production of color filters, if the baking treatment step (post-curing step) after exposure and development is performed at a high temperature of over 200°C, discoloration such as yellowing occurs in the resulting cured product, resulting in the desired color. There was a problem that high coloring could not be achieved sufficiently. Furthermore, when the firing process is performed at high temperatures, unnecessary reactions proceed and by-products are produced, which causes a problem of deterioration of the properties of the base material and cured film. In order to suppress such unnecessary reactions and efficiently obtain a color filter having desired characteristics, it is desirable that the curing reaction proceed sufficiently even under heating conditions at a relatively low temperature of 200° C. or lower. Moreover, if the curable resin composition can be cured at a relatively low temperature, the production efficiency of color filters can also be improved.
The conventional photosensitive resin composition described in Patent Document 1 requires high temperatures in resin synthesis. Furthermore, there was room for improvement in the curability of the resin.

The present invention was made in view of the above-mentioned current situation, and can provide a cured product with excellent solvent resistance even under low-temperature curing conditions, making it suitable as a thermosetting resin for various uses such as color filters. The object is to provide a copolymer that can be used.

The present inventor conducted various studies on curable resins, and found that by creating a copolymer that has an epoxy group-containing group and a long-chain acid group in one molecule and has an epoxy equivalent within a specific range, it is possible to It was discovered that the crosslinking reaction progresses well even under the following low-temperature curing conditions, and a cured product with excellent solvent resistance can be obtained, leading to the completion of the present invention.

That is, the present invention has an epoxy group-containing structural unit (A) represented by the following general formula (1) and an acid group-containing structural unit (B) represented by the following general formula (2), It is a copolymer characterized by having an equivalent weight of 20,000 or less.

（式（１）中、Ｒ^１は、水素原子又はメチル基を表す。Ｒ^２は、直接結合、又は、２価の有機基を表す。Ｘは、エポキシ基含有基を表す。）

(In formula (1), R ¹ represents a hydrogen atom or a methyl group. R ² represents a direct bond or a divalent organic group. X represents an epoxy group-containing group.)

(In formula (2), R ³ represents a hydrogen atom or a methyl group. ^{R 4} represents a direct bond or an organic group. R ⁵ represents a bond chain having a length of 2 atoms or more. Y represents an acid group. a represents 0 or 1.)

In the copolymer, the structural unit (A) preferably includes a structural unit represented by the following general formula (1-1).

（式（１－１）中、Ｒ^１は、水素原子又はメチル基を表す。Ｒ^６は、直接結合、又は、２価の有機基を表す。）

(In formula (1-1), R ¹ represents a hydrogen atom or a methyl group. R ⁶ represents a direct bond or a divalent organic group.)

In the copolymer, the structural unit (B) preferably includes a structural unit represented by the following general formula (2-1).

（式（２－１）中、Ｒ^３は、水素原子又はメチル基を表す。Ｒ^７及びＲ^８は、同一又は異なって、直接結合、又は、有機基を表す。ｂは、０又は１を表す。）

(In formula (2-1), R ³ represents a hydrogen atom or a methyl group. ^{R 7} and R ⁸ are the same or different and represent a direct bond or an organic group. b represents 0 or 1. represent.)

Preferably, the copolymer further has a ring structure in its main chain.

The copolymer preferably further contains a structural unit derived from a monomer whose longest side chain has 5 to 20 atoms or a monomer whose side chain has a ring structure.

The present invention is also a copolymer solution characterized by containing the above-mentioned copolymer and a protic polar solvent.

Preferably, the copolymer solution further contains an acid compound having a pKa of 4.2 or less.

Preferably, the copolymer solution further contains a phosphoric acid derivative.

Preferably, the copolymer solution further contains a basic compound.

The present invention is also a photosensitive resin composition characterized by containing the above-mentioned copolymer or copolymer solution, a polymerizable compound, and a photopolymerization initiator.

It is preferable that the photosensitive resin composition further contains a coloring material.

It is preferable that the photosensitive resin composition is for negative type.

The present invention also relates to a cured product of the above-mentioned copolymer, the above-mentioned copolymer solution, or the above-mentioned photosensitive resin composition.

The present invention also includes a step of polymerizing a monomer component containing an epoxy group-containing monomer represented by the following formula (a) and a hydroxyl group-containing monomer represented by the following formula (b1), It is also a method for producing a copolymer, comprising a step of reacting the polymer obtained in the polymerization step with an acid group-containing compound represented by the following formula (b2) or formula (b3).

（式（ａ）中、Ｒ^１は、水素原子又はメチル基を表す。Ｒ^２は、直接結合、又は、２価の有機基を表す。Ｘは、エポキシ基含有基を表す。）

(In formula (a), R ¹ represents a hydrogen atom or a methyl group. ^{R 2} represents a direct bond or a divalent organic group. X represents an epoxy group-containing group.)

（式（ｂ１）中、Ｒ^３は、水素原子又はメチル基を表す。Ｒ^４は、直接結合、又は、有機基を表す。）

(In formula (b1), R ³ represents a hydrogen atom or a methyl group. R ⁴ represents a direct bond or an organic group.)

（式（ｂ２）中、Ｒ^５は、長さが２原子以上の結合鎖を表す。Ｙは、酸基を表す。）

(In formula (b2), R ⁵ represents a bonded chain with a length of 2 or more atoms. Y represents an acid group.)

（式（ｂ３）中、Ｒ^５は、長さが２原子以上の結合鎖を表す。）

(In formula (b3), R ⁵ represents a bond chain having a length of 2 atoms or more.)

The present invention also includes a step of polymerizing a monomer component containing an epoxy group-containing monomer represented by the following formula (a) and a hydroxyl group-containing monomer represented by the following formula (b1), A step of reacting the polymer obtained in the polymerization step with an acid group-containing compound represented by the following formula (b2) or formula (b3) in the presence of a basic compound, and the pKa is 4.2 or less. It is also a method for producing a copolymer solution characterized by including a step of adding an acid compound and a protic polar solvent.

（式（ａ）中、Ｒ^１は、水素原子又はメチル基を表す。Ｒ^２は、直接結合、又は、２価の有機基を表す。Ｘは、エポキシ基含有基を表す。）

(In formula (a), R ¹ represents a hydrogen atom or a methyl group. ^{R 2} represents a direct bond or a divalent organic group. X represents an epoxy group-containing group.)

（式（ｂ１）中、Ｒ^３は、水素原子又はメチル基を表す。Ｒ^４は、直接結合、又は、有機基を表す。）

(In formula (b1), R ³ represents a hydrogen atom or a methyl group. R ⁴ represents a direct bond or an organic group.)

（式（ｂ２）中、Ｒ^５は、長さが２原子以上の結合鎖を表す。Ｙは、酸基を表す。）

(In formula (b2), R ⁵ represents a bonded chain with a length of 2 or more atoms. Y represents an acid group.)

（式（ｂ３）中、Ｒ^５は、長さが２原子以上の結合鎖を表す。）

(In formula (b3), R ⁵ represents a bond chain with a length of 2 or more atoms.)

The copolymer of the present invention can provide a cured product with excellent solvent resistance even under relatively low curing conditions of 160° C. or lower. The copolymer of the present invention can be used in various optical components used in liquid crystal, organic EL, quantum dot, micro-LED liquid crystal display devices, solid-state image sensors, touch panel display devices, etc., and structural members of electrical and electronic devices. Suitable for use in various applications.

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".

1. Copolymer The copolymer of the present invention comprises an epoxy group-containing structural unit (A) represented by the following general formula (1) and an acid group-containing structural unit (B) represented by the following general formula (2). and has an epoxy equivalent of 20,000 or less.

（式（１）中、Ｒ^１は、水素原子又はメチル基を表す。Ｒ^２は、直接結合、又は、２価の有機基を表す。Ｘは、エポキシ基含有基を表す。）

(In formula (1), R ¹ represents a hydrogen atom or a methyl group. R ² represents a direct bond or a divalent organic group. X represents an epoxy group-containing group.)

（式（２）中、Ｒ^３は、水素原子又はメチル基を表す。Ｒ^４は、直接結合、又は、有機基を表す。Ｒ^５は、長さが２原子以上の結合鎖を表す。Ｙは、酸基を表す。ａは、０又は１を表す。）

(In formula (2), R ³ represents a hydrogen atom or a methyl group. ^{R 4} represents a direct bond or an organic group. R ⁵ represents a bond chain having a length of 2 or more atoms. Y represents an acid group.a represents 0 or 1)

The reason why the copolymer of the present invention can provide a cured product with excellent solvent resistance even under relatively low curing conditions of 160°C or less (preferably about 90°C) is due to the epoxy group and acid In addition, because the acid group is a long-chain acid located relatively far from the main chain, the acid group reacts very easily with the epoxy group, and the crosslinking reaction proceeds even at relatively low temperatures. , it is possible to form a strong cured film, and when the side chain of the acid group-containing structural unit is long, the glass transition temperature is lower than that of the structural unit of acrylic acid or methacrylic acid, and the polymer side chain becomes more flexible. This is presumably because the above-mentioned crosslinking reaction proceeds more easily at low temperatures.

The copolymer of the present invention has the above-mentioned epoxy group-containing structural unit (A) and acid group-containing structural unit (B), and has an epoxy equivalent (g/equivalent) of 20,000 or less. If the epoxy equivalent exceeds 20,000, curing may be insufficient and solvent resistance may decrease. The epoxy equivalent of the copolymer of the present invention is preferably 10,000 or less, more preferably 8,000 or less, even more preferably 5,000 or less, even more preferably 4,000 or less, and even more preferably 3,000 or less. It is particularly preferable that the number is 2000 or less, and most preferably 2000 or less. Further, from the viewpoint of storage stability, the epoxy equivalent is preferably 100 or more, more preferably 150 or more, and even more preferably 200 or more.
The epoxy equivalent can be determined by dividing the copolymer solid content by the number of moles of epoxy groups contained in the copolymer. Moreover, the above-mentioned epoxy equivalent can also be determined by a method based on JIS K7236:2001.

<Structural unit (A)>
The copolymer of the present invention has an epoxy group-containing structural unit (A) represented by the above general formula (1).
In the above general formula (1), R ¹ represents a hydrogen atom or a methyl group.
R ² represents a direct bond or a divalent organic group. The above organic groups include chain or cyclic saturated or unsaturated hydrocarbon groups, -O-, -CO-, -COO-, -NH-, -S-, -SO-, -SO ₂ -, and , a divalent group consisting of a combination thereof, and the like.
Examples of the hydrocarbon group include a divalent aliphatic hydrocarbon group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group.
The aliphatic hydrocarbon group may be linear or branched, and includes alkylene groups such as methylene group, ethylene group, trimethylene group, propylene group, ethylidene group, propylidene group, and isopropylidene group, and vinylene group. group, propenylene group, vinylidene group, etc.
Examples of the alicyclic hydrocarbon group include cycloalkylene groups such as 1,2-cyclopentylene group, 1,2-cyclohexylene group, cyclopentylidene group, and cyclohexylidene group.
Examples of the aromatic hydrocarbon group include 1,2-phenylene group, 1,2-naphthylene group, 2,3-naphthylene group, benzylidene group, cinnamylidene group, and biphenylylene group.

At least one atom constituting the hydrocarbon group may be substituted with an oxygen atom, nitrogen atom, or sulfur atom. Further, the hydrocarbon group may have a substituent. Examples of the above-mentioned substituents include a hydroxyl group, an alkoxy group, an alkyl group, an allyl group, an aryl group, and a halogen atom. The above substituent may further have a substituent.

Specifically, the above divalent organic group includes, for example, -R-, -CO-, -CO-R-, -R-CO-R'-, -COO-, -COO-R-, - R-COO-R'-, -O-R-, -R-O-R'- (wherein R and R' are the same or different and represent the above divalent hydrocarbon group), etc. Can be mentioned.

The number of atoms in the divalent organic group is preferably 0 to 10, more preferably 1 to 5, and even more preferably 2 to 4.

Among these, R ² is preferably -R-, -COO-, -COO-R-, -COO-, -COO-R- (R is a carbon number 1 which may have a substituent) -4 hydrocarbon group, preferably an alkylene group having 1 to 2 carbon atoms).

X represents an epoxy group-containing group. In the present specification, the epoxy group-containing group is a group containing an oxirane ring (epoxy group), and includes a group in which an oxirane ring is bonded to carbon, such as a glycidyl group, and a glycidyl ether group and a glycidyl ester group. Included are groups containing an ether bond or ester bond, alicyclic epoxy groups containing an epoxycyclohexane ring, and the like.
Preferred examples of the epoxy group-containing group include groups represented by the following formulas (x1) to (x4).

In the formula, n is an integer of 0 to 10, preferably an integer of 0 to 4, more preferably an integer of 0 to 2.
m is an integer of 1 to 10, preferably an integer of 2 to 8, more preferably an integer of 3 to 6.
Among them, from the viewpoint of reactivity, (x1) is preferable as X, and (x1) where n=1 is more preferable.

The structural unit (A) is preferably a structural unit (A-1) represented by the following general formula (1-1), since it can further improve solvent resistance.

（式（１－１）中、Ｒ^１は、水素原子又はメチル基を表す。Ｒ^６は、直接結合、又は、２価の有機基を表す。）

(In formula (1-1), R ¹ represents a hydrogen atom or a methyl group. R ⁶ represents a direct bond or a divalent organic group.)

In the above general formula (1-1), R ¹ represents a hydrogen atom or a methyl group. Among these, R ¹ is preferably a methyl group.
Examples of the divalent organic group represented by R ⁶ include the same groups as the divalent organic group represented by R ² described above.
The divalent organic group represented by R ⁶ preferably has 0 to 10 carbon atoms, more preferably 1 to 4 carbon atoms, and still more preferably 1 to 2 carbon atoms.

Among these, the divalent organic group represented by R ⁶ is preferably a divalent aliphatic hydrocarbon group, more preferably a divalent aliphatic hydrocarbon group without a substituent, and a methylene group is preferable. preferable.

The copolymer having the above-mentioned structural unit (A) can be obtained by polymerizing a monomer component containing a monomer into which the above-mentioned structural unit (A) can be introduced.
Examples of monomers into which the structural unit (A) can be introduced include compounds represented by the following formula (a).

（式中、Ｒ^１、Ｒ^２、及びＸは、上記一般式（１）中のＲ^１、Ｒ^２、及びＸとそれぞれ同じである。）

(In the formula, R ¹ , R ² , and X are the same as R ¹ , R ² , and X in the above general formula (1), respectively.)

Specific examples of monomers into which the above structural unit (A) can be introduced include glycidyl (meth)acrylate, β-methylglycidyl (meth)acrylate, β-ethylglycidyl (meth)acrylate, vinylbenzyl Examples include glycidyl ether, allyl glycidyl ether, (3,4-epoxycyclohexyl)methyl (meth)acrylate, and vinylcyclohexene oxide. Among them, glycidyl (meth)acrylate and (3,4-epoxycyclohexyl)methyl (meth)acrylate are preferred, and glycidyl (meth)acrylate is more preferred, as it can suppress side reactions and is expected to improve storage stability. Glycidyl methacrylate is more preferred in that it can be used.

The copolymer of the present invention may have one or more of the above structural units (A).

In the copolymer of the present invention, the content of the structural unit (A) is preferably 0.1 to 50% by mass, more preferably 0.5% by mass or more based on 100% by mass of all structural units. , more preferably 1% by mass or more, more preferably 45% by mass or less, even more preferably 40% by mass or less.

<Structural unit (B)>
The copolymer of the present invention further has an acid group-containing structural unit (B) represented by the above general formula (2).

In the above general formula (2), R ³ represents a hydrogen atom or a methyl group.
R ⁴ represents a direct bond or an organic group. Examples of the organic group represented by R ⁴ include the same groups as the organic group represented by R ² described above.
The number of atoms in the organic group represented by R ⁴ is preferably 1 to 10, more preferably 1 to 8, and even more preferably 2 to 5.
The organic group represented by R ⁴ is preferably a divalent organic group which may have a substituent, preferably a divalent organic group containing an ester bond, -CO-O-R-(R is represents a divalent aliphatic hydrocarbon group having 1 to 3 carbon atoms), -CO-OR(-O-CO-R')-(R is a linear or branched group having 1 to 3 carbon atoms) It represents a chain-like divalent aliphatic hydrocarbon group.R' represents a monovalent aliphatic hydrocarbon group having 1 to 3 carbon atoms.) is more preferable, and -CO-O-R- (R is , representing a divalent aliphatic hydrocarbon group having 1 to 3 carbon atoms) is more preferred.

R ⁵ represents a bonding chain having a length of 2 or more atoms. The length of the bonded chain is the number of atoms connected on the main chain of the bonded chain, and does not include the number of atoms forming the side chains of the bonded chain. Specifically, for example, as a bond chain having a length of two atoms, -CH ₂ -CH ₂ -, -C(CH ₃ )-CH ₂ -, -C(CH ₃ )-C(CH ₃ )- , -CH ₂ -O-, -O-CH ₂ -, -CO-O-, -CH=CH-, etc., and as a bond chain with a length of 3 atoms, -CH ₂ -CH ₂ -CH _2- , -CH ₂ -O-CH ₂ -, -CO-O-CH ₂ -, -CH ₂ -O-CO-, -CH=CH-CH ₂ -, and the like. When the length of the bond chain is 0, it is synonymous with "direct bond."

The length of the bonding chain represented by R ⁵ is preferably 10 or less, more preferably 5 or less, and most preferably 2, in terms of better crosslinkability.

Preferably, the bonding chain is a divalent organic group. Examples of the divalent organic group include the same groups as the divalent organic group represented by R ² described above.
Among them, the above organic groups are -R-, -O-R-, -O-R-O-, -CO-R-, -O-R-O-CO-R'- (R and R' are , which are the same or different and represent a divalent hydrocarbon group which may have a substituent.) are preferably -R-, -O-R-, -O-R-O-CO-R '-(R and R' are the same or different and represent a divalent aliphatic hydrocarbon group which may have a substituent.) More preferably, it is an ethylene group.

Y represents an acid group. Examples of the above-mentioned acid groups include functional groups that neutralize with alkaline water, such as carboxyl groups, phenolic hydroxyl groups, carboxylic acid anhydride groups, phosphoric acid groups, and sulfonic acid groups. or two or more types. Among these, a carboxyl group or a carboxylic acid anhydride group is preferred, and a carboxyl group is more preferred.
Moreover, it may have two or more acid groups.

a represents 0 or 1. It is preferable that a is 1 in that the solvent resistance is even more excellent.

As the structural unit (B), a structural unit (B-1) represented by the following general formula (2-1) is preferably mentioned.

（式（２－１）中、Ｒ^３は、水素原子又はメチル基を表す。Ｒ^７及びＲ^８は、同一又は異なって、直接結合、又は、有機基を表す。ｂは、０又は１を表す。）

(In formula (2-1), R ³ represents a hydrogen atom or a methyl group. ^{R 7} and R ⁸ are the same or different and represent a direct bond or an organic group. b represents 0 or 1. represent.)

In the above general formula (2-1), R ³ represents a hydrogen atom or a methyl group. R ³ is preferably a methyl group from the viewpoint of improving the heat resistance and developability of the polymer.
As the organic group represented by R ⁷ and R ⁸ , the above-mentioned divalent organic groups are preferably mentioned, but among them, R ⁷ is a divalent hydrocarbon group which may have a substituent. is preferable, a divalent aliphatic hydrocarbon group which may have a substituent is more preferable, and an alkylene group is even more preferable.
R ⁸ is preferably a divalent hydrocarbon group which may have a substituent, more preferably a divalent aliphatic hydrocarbon group which may have a substituent, and still more preferably an alkylene group.

The organic group represented by R ⁷ and R ⁸ preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and even more preferably 1 to 3 carbon atoms.

b represents 0 or 1, and is preferably 1 since the solvent resistance can be further improved.

The copolymer having the above structural unit (B) can be obtained by polymerizing a monomer component containing a monomer into which the above structural unit (B) can be introduced, or by polymerizing a monomer component containing a hydroxyl group-containing monomer. It can be obtained by reacting a base polymer obtained by polymerizing with an acid group-containing compound.

Examples of the monomer into which the structural unit (B) can be introduced include β-carboxyethyl (meth)acrylate, mono(2-acryloyloxyethyl) succinate, mono(2-methacryloyloxyethyl) succinate, etc. Examples include long-chain unsaturated monocarboxylic acids in which the chain between an unsaturated group and a carboxyl group is extended.

Examples of the hydroxyl group-containing monomer include a compound represented by the following formula (b1).

（式中、Ｒ^３及びＲ^４は、上記一般式（２）中のＲ^３及びＲ^４とそれぞれ同じである。）

(In the formula, R ³ and R ⁴ are the same as R ³ and R ⁴ in the above general formula (2), respectively.)

Specific examples of the hydroxyl group-containing monomers include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, and 2-hydroxy(meth)acrylate. Hydroxyalkyl (meth)acrylates such as butyl, 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 2,3-hydroxypropyl (meth)acrylate; glycerin mono(meth)acrylate, Polyol mono(meth)acrylates such as methylolpropane mono(meth)acrylate, pentaerythritol mono(meth)acrylate, ditrimethylolpropane mono(meth)acrylate, and dipentaerythritol mono(meth)acrylate; N-hydroxyethyl acrylamide, etc. Examples include hydroxyalkyl acrylamides.

Examples of the acid group-containing compound include compounds represented by the following formula (b2) or formula (b3).

（式中、Ｒ^５及びＹは、上記一般式（２）中のＲ^５及びＹとそれぞれ同じである。）

(In the formula, R ⁵ and Y are the same as R ⁵ and Y in the above general formula (2), respectively.)

（式中、Ｒ^５は、上記一般式（２）中のＲ^５と同じである。）

(In the formula, R ⁵ is the same as R ⁵ in the above general formula (2).)

Specific examples of the acid group-containing compounds include carboxylic acids such as succinic acid, maleic acid, phthalic acid, tetrahydrophthalic acid, and trimellitic acid; succinic anhydride, maleic anhydride, phthalic anhydride, tetrahydrophthalic anhydride; Examples include carboxylic acid anhydrides such as hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, itaconic anhydride, and trimellitic anhydride. Among these, carboxylic acid anhydrides are preferred, and succinic anhydride is more preferred, since they have higher addition reactivity.

A specific method for obtaining a copolymer having the above-mentioned structural unit (B) will be explained in detail in the method for producing a polymer described below.

The copolymer of the present invention may have one or more types of structural units (B).

In the copolymer of the present invention, the content of the structural unit (B) is preferably 0.1 to 50% by mass, more preferably 0.2% by mass or more, based on 100% by mass of all structural units. , more preferably 1% by mass or more, more preferably 45% by mass or less, even more preferably 40% by mass or less.

<Structural unit (C)>
The copolymer of the present invention is preferably a copolymer having a ring structure in its main chain. That is, it is preferable that the above-mentioned copolymer further has a structural unit (C) having a ring structure in the main chain. When the above-mentioned copolymer is a polymer having a ring structure in the main chain, a cured product having excellent heat resistance can be provided.
Examples of the ring structure include an imide ring, a tetrahydropyran ring, a tetrahydrofuran ring, a lactone ring, and the like.
A copolymer having the above structural unit (C) can be obtained by polymerizing a monomer component containing a monomer capable of introducing a ring structure into the main chain.

Examples of monomers that can introduce a ring structure into the main chain include monomers that have a double bond-containing ring structure in the molecule, and polymers that undergo cyclopolymerization to form a polymer that has a ring structure in the main chain. Examples include monomers that form a ring structure after polymerization, and monomers that form a ring structure after polymerization. From the viewpoint of good heat resistance, hardness, colorant dispersibility, etc., specifically, N-substituted maleimide monomers, dialkyl-2,2'-(oxydimethylene) diacrylate monomers, and At least one monomer selected from the group consisting of α-(unsaturated alkoxyalkyl) acrylate monomers is preferably used. Among these, N-substituted maleimide monomers are preferred because they have even better solvent resistance.

Examples of the N-substituted maleimide monomer include N-cyclohexylmaleimide, N-phenylmaleimide, N-methylmaleimide, N-ethylmaleimide, N-isopropylmaleimide, Nt-butylmaleimide, N-dodecylmaleimide, Examples include N-benzylmaleimide and N-naphthylmaleimide, and one or more of these can be used. Among them, from the viewpoint of heat resistance, N-phenylmaleimide, N-benzylmaleimide, and N-cyclohexylmaleimide are preferred, and N-benzylmaleimide is more preferred.

Examples of the N-benzylmaleimide include benzylmaleimide; alkyl-substituted benzylmaleimides such as p-methylbenzylmaleimide and p-butylbenzylmaleimide; phenolic hydroxyl-substituted benzylmaleimides such as p-hydroxybenzylmaleimide; o-chlorobenzylmaleimide; , o-dichlorobenzylmaleimide, p-dichlorobenzylmaleimide, and other halogen-substituted benzylmaleimides; and the like.

Examples of the dialkyl-2,2'-(oxydimethylene) diacrylate monomer include dimethyl-2,2'-[oxybis(methylene)]bis-2-propenoate, diethyl-2,2'- [oxybis(methylene)]bis-2-propenoate, di(n-propyl)-2,2'-[oxybis(methylene)]bis-2-propenoate, di(isopropyl)-2,2'-[oxybis(methylene) )] bis-2-propenoate, di(n-butyl)-2,2'-[oxybis(methylene)]bis-2-propenoate, di(isobutyl)-2,2'-[oxybis(methylene)]bis- 2-propenoate, di(t-butyl)-2,2'-[oxybis(methylene)]bis-2-propenoate, di(t-amyl)-2,2'-[oxybis(methylene)]bis-2- Propenoate, di(stearyl)-2,2'-[oxybis(methylene)]bis-2-propenoate, di(lauryl)-2,2'-[oxybis(methylene)]bis-2-propenoate, di(2- Examples include ethylhexyl)-2,2'-[oxybis(methylene)]bis-2-propenoate. Among these, dimethyl-2,2'-[oxybis(methylene)]bis-2-propenoate is more preferred from the viewpoints of transparency, dispersibility, industrial availability, and the like.

Examples of the α-(unsaturated alkoxyalkyl) acrylate monomer include α-(allyloxymethyl) acrylate monomer.
Specific examples of the α-(allyloxymethyl)acrylate monomers include α-allyloxymethylacrylic acid; methyl α-allyloxymethylacrylate, ethyl α-allyloxymethylacrylate, α-allyl n-propyl oxymethylacrylate, i-propyl α-allyloxymethylacrylate, n-butyl α-allyloxymethylacrylate, s-butyl α-allyloxymethylacrylate, t-allyloxymethylacrylate Butyl, n-amyl α-allyloxymethyl acrylate, s-amyl α-allyloxymethyl acrylate, t-amyl α-allyloxymethyl acrylate, n-hexyl α-allyloxymethyl acrylate, α-allyloxy s-hexyl methyl acrylate, n-heptyl α-allyloxymethyl acrylate, n-octyl α-allyloxymethyl acrylate, s-octyl α-allyloxymethyl acrylate, t-octyl α-allyloxymethyl acrylate , 2-ethylhexyl α-allyloxymethylacrylate, caprylic α-allyloxymethylacrylate, nonyl α-allyloxymethylacrylate, decyl α-allyloxymethylacrylate, undecyl α-allyloxymethylacrylate, α- Lauryl allyloxymethyl acrylate, tridecyl α-allyloxymethyl acrylate, myristyl α-allyloxymethyl acrylate, pentadecyl α-allyloxymethyl acrylate, cetyl α-allyloxymethyl acrylate, α-allyloxymethyl acrylate Alkyl such as heptadecyl, stearyl α-allyloxymethyl acrylate, nonadecyl α-allyloxymethyl acrylate, eicosyl α-allyloxymethyl acrylate, seryl α-allyloxymethyl acrylate, mericyl α-allyloxymethyl acrylate, etc. (α-allyloxymethyl) acrylate monomer; α-allyloxymethyl acrylate methoxyethyl, α-allyloxymethyl acrylate methoxyethoxyethyl, α-allyloxymethyl acrylate methoxyethoxyethoxyethyl, α-allyloxy 3-methoxybutyl methyl acrylate, ethoxyethyl α-allyloxymethyl acrylate, ethoxyethoxyethyl α-allyloxymethyl acrylate, phenoxyethyl α-allyloxymethyl acrylate, phenoxyethoxyethyl α-allyloxymethyl acrylate, etc. Alkoxyalkyl-(α-allyloxymethyl)acrylate monomers; hydroxyethyl α-allyloxymethyl acrylate, hydroxypropyl α-allyloxymethyl acrylate, hydroxybutyl α-allyloxymethyl acrylate, α-allyl Fluoroethyl oxymethyl acrylate, difluoroethyl α-allyloxymethyl acrylate, chloroethyl α-allyloxymethyl acrylate, dichloroethyl α-allyloxymethyl acrylate, bromoethyl α-allyloxymethyl acrylate, α-allyloxymethyl dibromoethyl acrylate, vinyl α-allyloxymethyl acrylate, allyl α-allyloxymethyl acrylate, methallyl α-allyloxymethyl acrylate, crotyl α-allyloxymethyl acrylate, propargyl α-allyloxymethyl acrylate, cyclopentyl α-allyloxymethyl acrylate, cyclohexyl α-allyloxymethyl acrylate, 4-methylcyclohexyl α-allyloxymethyl acrylate, 4-t-butylcyclohexyl α-allyloxymethyl acrylate, α-allyloxymethyl acrylate tricyclodecanyl acid, isobornyl α-allyloxymethyl acrylate, adamantyl α-allyloxymethyl acrylate, dicyclopentadienyl α-allyloxymethyl acrylate, phenyl α-allyloxymethyl acrylate, α-allyloxy Methylphenyl methyl acrylate, dimethylphenyl α-allyloxymethyl acrylate, trimethylphenyl α-allyloxymethyl acrylate, 4-t-butylphenyl α-allyloxymethyl acrylate, benzyl α-allyloxymethyl acrylate, α -Diphenylmethyl allyloxymethyl acrylate, diphenylethyl α-allyloxymethyl acrylate, triphenylmethyl α-allyloxymethyl acrylate, cinnamyl α-allyloxymethyl acrylate, naphthyl α-allyloxymethyl acrylate, α- Anthranyl allyloxymethyl acrylate; and the like. Among these, alkyl-(α-allyloxymethyl)acrylate monomers are preferred. As the alkyl-(α-allyloxymethyl) acrylate monomer, methyl α-allyloxymethyl acrylate (methyl-(α-allyl (also referred to as oxymethyl)acrylate) is particularly preferred.

The above α-(unsaturated alkoxyalkyl)acrylate can be produced, for example, by the production method disclosed in International Publication No. 2010/114077 pamphlet.

Preferred examples of the monomer capable of introducing a ring structure into the main chain include 2-(hydroxyalkyl)acrylic acid alkyl esters. The 2-(hydroxyalkyl)acrylic acid alkyl ester can react with (meth)acrylic acid to form a lactone ring structure in the main chain.

Examples of the 2-(hydroxyalkyl)acrylic acid alkyl esters include 2-(1-hydroxyalkyl)acrylic acid alkyl esters and 2-(2-hydroxyalkyl)acrylic acid alkyl esters, and specifically, for example, Methyl 2-(1-hydroxymethyl)acrylate, ethyl 2-(1-hydroxymethyl)acrylate, isopropyl 2-(1-hydroxymethyl)acrylate, n-butyl 2-(1-hydroxymethyl)acrylate, Examples include t-butyl 2-(1-hydroxymethyl)acrylate and 2-ethylhexyl 2-(1-hydroxymethyl)acrylate. Among them, methyl 2-(1-hydroxymethyl)acrylate and ethyl 2-(1-hydroxymethyl)acrylate are preferred. These may be used alone or in combination of two or more.

The copolymer may have one or more types of structural units (C).

In the copolymer, the content of the structural unit (C) is preferably 0.1 to 50% by mass, more preferably 0.2% by mass or more, based on 100% by mass of all structural units, and 1 It is more preferably at least 45% by mass, even more preferably at most 40% by mass.

<Structural unit (D)>
The above-mentioned copolymer may further have another structural unit (D) in addition to the above-mentioned structural units (A), (B) and (C). Examples of the structural unit (D) include, in addition to the above-mentioned hydroxyl group-containing monomers, acid group-containing monomers other than the above-mentioned long-chain unsaturated monocarboxylic acids, (meth)acrylic acid ester monomers, Structural units derived from monomers having groups that generate acid groups, other copolymerizable monomers, and the like can be mentioned.

Examples of the acid group-containing monomer include unsaturated monocarboxylic acids such as (meth)acrylic acid, crotonic acid, cinnamic acid, and vinylbenzoic acid; maleic acid, fumaric acid, itaconic acid, citraconic acid, and mesaconic acid. unsaturated polyhydric carboxylic acids such as; unsaturated acid anhydrides such as maleic anhydride and itaconic anhydride; phosphoric acid group-containing unsaturated compounds such as Light Ester P-1M (manufactured by Kyoeisha Chemical); and the like.

Examples of the (meth)acrylic acid ester monomers include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, i-propyl (meth)acrylate, and ) n-butyl acrylate, s-butyl (meth)acrylate, n-amyl (meth)acrylate, s-amyl (meth)acrylate, n-hexyl (meth)acrylate, 2-(meth)acrylate Ethylhexyl, isodecyl (meth)acrylate, tridecyl (meth)acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, cyclohexyl (meth)acrylate , isobornyl (meth)acrylate, 1-adamantyl (meth)acrylate, (3,4-epoxycyclohexyl)methyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyl (meth)acrylate , benzyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, N,N-diethylaminoethyl (meth)acrylate, 1,4-dioxaspiro[4,5]dec-2-ylmethacrylic acid, (meth)acryloylmorpholine, 4-(meth)acryloyloxymethyl-2-methyl- 2-ethyl-1,3-dioxolane, 4-(meth)acryloyloxymethyl-2-methyl-2-isobutyl-1,3-dioxolane, 4-(meth)acryloyloxymethyl-2-methyl-2-cyclohexyl- Examples include 1,3-dioxolane, 4-(meth)acryloyloxymethyl-2,2-dimethyl-1,3-dioxolane, and the like.

Examples of the monomer having a group that generates an acid group include compounds that have a group that generates an acid group by heat or an acid and a polymerizable double bond. Examples of the polymerizable double bond include a (meth)acryloyl group, a vinyl group, an allyl group, and a methallyl group.
The above-mentioned groups that generate acid groups by heat or acid include tertiary carbon-containing groups, groups whose acid groups are blocked with vinyl ether compounds, and groups whose acid groups are blocked by a t-butyl group or acetyl group, and phenolic hydroxyl groups formed by protective groups such as t-butyl and acetyl groups. Protected groups, etc.

The tertiary carbon-containing group is preferably a -COO ^* R ^a (R ^a represents a monovalent organic group, and the carbon atom bonded to O ^* is a tertiary carbon atom) group. The groups represented are exemplified. By heating, the O--C bond between -COO ^* and R ^a is cleaved and a carboxyl group is generated.

R ^a in the above -COO ^* R ^a represents a monovalent organic group, and the carbon atom bonded to O ^* is a tertiary carbon atom. A tertiary carbon atom means a carbon atom that has three other carbon atoms bonded to it.

The monovalent organic group preferably includes a monovalent chain, branched or cyclic saturated or unsaturated hydrocarbon group having 1 to 91 carbon atoms. The above organic group may have a substituent.
The number of carbon atoms in R ^a is more preferably 1 to 50 carbon atoms, still more preferably 1 to 35 carbon atoms, even more preferably 1 to 20 carbon atoms, and particularly preferably 1 to 12 carbon atoms. The number of carbon atoms is most preferably 1 to 9.

R ^a can preferably be represented by -C(R ^b )(R ^c )(R ^d ). In this case, R ^b , R ^c , and R ^d are preferably the same or different and are hydrocarbon groups having 1 to 30 carbon atoms. The hydrocarbon group may be a saturated hydrocarbon group, an unsaturated hydrocarbon group, a cyclic structure, or a substituent. Furthermore, R ^b , R ^c , and R ^d may be connected to each other at their terminal portions to form a cyclic structure.

Here, in the above-mentioned tertiary carbon-containing group, it is preferable that at least one adjacent carbon atom of the tertiary carbon atom is bonded to a hydrogen atom. For example, when R ^a is a group represented by -C(R ^b )(R ^c )(R ^d ), at least one of R ^b , R ^c and R ^d has one or more hydrogen atoms. Preferably, it contains a carbon atom and the carbon atom is bonded to a tertiary carbon atom.
The above R ^b , R ^c and R ^d are the same or different and are preferably saturated hydrocarbon groups having 1 to 15 carbon atoms, more preferably saturated hydrocarbon groups having 1 to 10 carbon atoms, and even more preferably carbon A saturated hydrocarbon group having 1 to 5 carbon atoms, particularly preferably a saturated hydrocarbon group having 1 to 3 carbon atoms.
The above R ^a is preferably a t-butyl group or a t-amyl group.

Preferable examples of the tertiary carbon-containing monomer include t-butyl (meth)acrylate and t-amyl (meth)acrylate.

Examples of the group in which an acid group is blocked by the vinyl ether compound include a group in which a vinyl ether compound is bonded to the above-mentioned acid group such as a carboxyl group.
Examples of the vinyl ether compounds include aliphatic compounds such as methyl vinyl ether, ethyl vinyl ether, i-propyl vinyl ether, n-propyl vinyl ether, n-butyl vinyl ether, i-butyl vinyl ether, t-butyl vinyl ether, 2-ethylhexyl vinyl ether, and cyclohexyl vinyl ether. Examples include vinyl ether compounds and cyclic ether compounds such as dihydropyran that can be ring-opened to produce vinyl ether.
Among the above-mentioned vinyl ether compounds, dihydropyran is preferred since the protecting group is easily removed at lower temperatures.

Preferably, the group whose acid group is blocked by dihydropyran is a group represented by the following formula.

Preferably, the group whose phenolic hydroxyl group is protected by a protecting group such as a t-butyl group or an acetyl group includes a group represented by the following formula.

（式中ｎは、置換基の数を表し、１～５の整数である。）

(In the formula, n represents the number of substituents and is an integer from 1 to 5.)

For example, the group represented by the above formula can be reacted in a solvent with an acid catalyst such as hydrochloric acid or sulfuric acid at a temperature of 50 to 150°C for 1 to 30 hours to remove the protective group and generate an acid group. be done.

Specifically, examples of the monomer having a group represented by the above formula include p-hydroxystyrene, m-hydroxystyrene, o-hydroxystyrene, p-isopropenylphenol, m-isopropenylphenol, o-hydroxystyrene, Examples include monomers in which the hydroxyl group of an aromatic vinyl compound having a phenolic hydroxyl group, such as -isopropenylphenol, is protected by a t-butyl group or an acetyl group.

Among them, monomers having a group whose acid groups are blocked by dihydropyran are preferred as monomers having a group that generates acid groups, since they can generate acid groups at lower temperatures. preferable.

Examples of the other copolymerizable monomers include one or more of the following compounds.
(Meth)acrylamides such as N,N-dimethyl(meth)acrylamide, N-methylol(meth)acrylamide, and N-isopropylacrylamide; polystyrene, polymethyl(meth)acrylate, polyethylene oxide, polypropylene oxide, polysiloxane, polycaprolactone, Macromonomers having a (meth)acryloyl group at one end of the polymer chain such as polycaprolactam; Conjugated dienes such as 1,3-butadiene, isoprene, and chloroprene; Vinyl acetate, vinyl propionate, vinyl butyrate, benzoic acid Vinyl esters such as vinyl; aromatic vinyls such as styrene, vinyltoluene, α-methylstyrene, xylene, methoxystyrene, and ethoxystyrene; methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, 2-ethylhexyl vinyl ether, n- Vinyl ethers such as nonyl vinyl ether, lauryl vinyl ether, cyclohexyl vinyl ether, methoxyethyl vinyl ether, ethoxyethyl vinyl ether, methoxyethoxyethyl vinyl ether, methoxypolyethylene glycol vinyl ether, 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether; 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.

In particular, by copolymerizing a monomer having an amide group such as the above-mentioned (meth)acrylamides as a monomer that provides the structural unit (D), addition can be achieved without using a basic catalyst such as an amine. The reaction can be carried out and the storage stability of the copolymer can be improved.
Additionally, when using monomers with amine groups such as N,N-dimethylaminoethyl (meth)acrylate and N,N-diethylaminoethyl (meth)acrylate, the addition reaction can be carried out without using a catalyst. The storage stability of the copolymer can be improved.

In addition, as the monomer providing the structural unit (D), a monomer with a long side chain or a monomer with large steric hindrance is used, since gelation is suppressed and storage stability is good. It is preferable.
The monomer with a long side chain is preferably one in which the longest side chain has 5 to 20 atoms, more preferably 6 to 20 atoms, and still more preferably 7 to 10 atoms. preferable. The side chain may be linear or branched. A preferred example of the monomer with a long side chain is 2-ethylhexyl (meth)acrylate.

The monomers with large steric hindrance are preferably those having a ring structure in the side chain, such as those having structures such as cyclohexyl, bicyclo, phenyl, biphenyl, dicyclopentanyl, furan, pyran, and piperidine. can be mentioned. Specific examples of the monomers with large steric hindrance include vinyltoluene, benzyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, 1-adamantyl (meth)acrylate, ( Phenoxyethyl (meth)acrylate (meth)acrylate, (meth)acrylic acid, dicyclopentanyl (meth)acrylate, dicyclopentenyl (meth)acrylate, tricyclodecanyl (meth)acrylate, (meth)acrylate Examples include isobornyl acid and pentamethylpiperidinyl (meth)acrylate. Among these, dicyclopentanyl (meth)acrylate, vinyltoluene, benzyl (meth)acrylate, and cyclohexyl (meth)acrylate are preferred.

Among these, the copolymer is selected from the group consisting of vinyltoluene, 2-ethylhexyl (meth)acrylate, and dicyclopentanyl (meth)acrylate in that the storage stability can be further improved. It is preferable to have a structural unit derived from at least one type of monomer. Further, when the copolymer has a structural unit derived from 2-ethylhexyl (meth)acrylate, the glass transition temperature of the copolymer is lowered, and the developability can be improved.

The above copolymer may have one or more types of structural units (D).

In the copolymer, the content of the structural unit (D) is preferably 0.1 to 50% by mass, more preferably 0.2% by mass or more, based on 100% by mass of all structural units, and 1 It is more preferably at least 45% by mass, even more preferably at most 40% by mass.

The acid value of the copolymer is preferably 10 mgKOH/g or more, more preferably 20 mgKOH/g or more, and even more preferably 30 mgKOH/g or more. Further, it is preferably 300 mgKOH/g or less, more preferably 250 mgKOH/g or less, even more preferably 200 mgKOH/g or less, and even more preferably 100 mgKOH/g or less.
The above acid value is a value obtained by measurement by a neutralization titration method using a potassium hydroxide (KOH) solution, and is an acid value per 1 g of polymer solid content.

The weight average molecular weight of the copolymer is preferably 2,000 or more, more preferably 3,000 or more, and even more preferably 4,000 or more. Further, it is preferably 250,000 or less, more preferably 100,000 or less, even more preferably 50,000 or less, and even more preferably 20,000 or less.
The weight average molecular weight of the above copolymer can be measured by gel permeation chromatography (GPC), and specifically by the method described in Examples.

The copolymer may have a polymerizable double bond (carbon-carbon double bond) in the side chain. By having a polymerizable double bond in the side chain, the photocurability of the copolymer can be improved. Examples of the polymerizable double bond include those mentioned above, and among them, a (meth)acryloyl group is preferable.

When the copolymer has a polymerizable double bond in its side chain, the double bond equivalent of the copolymer is preferably 200 to 20,000 g/equivalent. The double bond equivalent is more preferably 250 to 15,000 g/equivalent, still more preferably 300 to 10,000 g/equivalent, and even more preferably 300 to 4,000 g/equivalent, since curability can be improved. more preferred.

The double bond equivalent is the mass of the solid content of the polymer solution per 1 mol of double bonds in the copolymer. The mass of the solid content of the polymer solution is the sum of the mass of the monomer components constituting the copolymer and the mass of the polymerization inhibitor. The double bond equivalent can be determined by dividing the mass (g) of the polymer solid content of the polymer solution by the amount (mol) of double bonds in the copolymer. The amount of double bonds in the copolymer can be determined from the amount of the acid group-containing monomer used during polymerization and the compound having a polymerizable double bond. Moreover, it can also be measured using various analyzes such as titration, elemental analysis, NMR, and IR, and differential scanning calorimetry. For example, it may be calculated by measuring the number of ethylenic double bonds contained per gram of copolymer in accordance with the iodine number test method described in JIS K 0070:1992.

<Method for producing copolymer>
The method for producing the copolymer of the present invention may be any method capable of obtaining a copolymer having at least the above-mentioned structural unit (A) and structural unit (B) and having an epoxy equivalent within a predetermined range. Examples include, but are not particularly limited to, a method of polymerizing a monomer component containing a monomer into which each of the above-mentioned structural units can be introduced, a method of polymerizing a monomer component to obtain a base polymer, and a method of polymerizing the above-mentioned base polymer. For example, a method for obtaining a polymer having a predetermined structural unit by subjecting the group possessed by another compound to an addition reaction.

The method of polymerizing the monomer components is not particularly limited, and commonly used methods such as bulk polymerization, solution polymerization, and emulsion polymerization can be used. Among these, solution polymerization is preferred because it is industrially advantageous and allows easy structural adjustment such as molecular weight. Furthermore, as the polymerization mechanism of the above monomer components, polymerization methods based on mechanisms such as radical polymerization, anionic polymerization, cationic polymerization, and coordination polymerization can be used; Polymerization methods based on are preferred.
Further, the molecular weight of the polymer obtained by polymerizing the above monomer components can be controlled by appropriately adjusting the amount and type of polymerization initiator, the polymerization temperature, and the type and amount of chain transfer agent.

Examples of the polymerization initiator include peroxides and azo compounds that are commonly used as polymerization initiators. Examples of the chain transfer agent include compounds having a mercapto group, such as alkylmercaptans, mercaptocarboxylic acids, and mercaptocarboxylic acid esters, which are commonly used as chain transfer agents. These may be used alone or in combination of two or more. Moreover, the amount of these additions can be appropriately set using a known method.

Examples of the solvent used in the above polymerization include ethers such as tetrahydrofuran, dioxane, ethylene glycol dimethyl ether, and diethylene glycol dimethyl ether; ketones such as acetone and methyl ethyl ketone; ethyl acetate, butyl acetate, propylene glycol monomethyl ether acetate, and 3-methoxybutyl Examples include esters such as acetate; aromatic hydrocarbons such as toluene, xylene, and ethylbenzene; chloroform; dimethyl sulfoxide; and dimethyl carbonate. These solvents may be used alone or in combination of two or more.

The polymerization concentration when polymerizing the monomer composition (reaction solution) containing the above monomer component is preferably 5 to 90% by mass, more preferably 5 to 70% by mass, and even more preferably 10% by mass. ~60% by mass. The above polymerization concentration is the mass % of the monomer used relative to 100 mass % of the reaction solution.

Regarding the above polymerization conditions, the polymerization temperature may be appropriately set depending on the type and amount of the monomer used, the type and amount of the polymerization initiator, etc., but for example, 50 to 130°C is preferable, and 60 to 60°C. 120°C is more preferred. Further, the polymerization time can be similarly set appropriately, and for example, 1 to 5 hours is preferable, and 2 to 4 hours is more preferable.

The method for producing the copolymer includes, for example, a monomer containing an epoxy group-containing monomer represented by the above formula (a) and a hydroxyl group-containing monomer represented by the above formula (b1). A step (1) of polymerizing the components, and a step (2) of reacting the polymer obtained in the polymerization step (1) with the acid group-containing compound represented by the above formula (b2) or formula (b3). Preferred examples include methods including:
By producing the above-mentioned copolymer by such a method, gelation can be suppressed during production of the copolymer, and the copolymer having the above-mentioned structural unit (A) and structural unit (B) can be produced. can be obtained efficiently.
That is, the present invention also provides a step (1) of polymerizing a monomer component containing an epoxy group-containing monomer represented by formula (a) and a hydroxyl group-containing monomer represented by formula (b1). and a step (2) of reacting the polymer obtained in the above polymerization step (1) with an acid group-containing compound represented by the above formula (b2) or formula (b3). This is a method of manufacturing a combination.

Each step in the above manufacturing method will be explained.
Process (1)
In the method for producing a copolymer of the present invention, a monomer component containing an epoxy group-containing monomer represented by the above formula (a) and a hydroxyl group-containing monomer represented by the above formula (b1) is used. Polymerize.
Examples of the epoxy group-containing monomer represented by the above formula (a) include the monomers described above as monomers into which the structural unit (A) of the copolymer can be introduced. Examples of the hydroxyl group-containing monomer represented by the formula (b1) include those mentioned above.

The content ratio of the above-mentioned epoxy group-containing monomer and hydroxyl group-containing monomer is not particularly limited, and in the resulting copolymer, the content ratio of the above-mentioned structural unit (A) and structural unit (B) is maintained. You can set it as appropriate.

The above-mentioned monomer component may contain other monomer components other than the acid group-containing compound used in step (2) described below. Examples of the other monomer components include the monomer components described above.

The method of polymerizing the above monomer components is not particularly limited, and the above-mentioned known methods may be used. The polymerization temperature and time are also as described above.

Further, the above polymerization may use commonly used polymerization initiators, chain transfer agents, catalysts, solvents, and the like.

Process (2)
Next, the method includes a step of reacting the polymer obtained in step (1) with an acid group-containing compound represented by formula (b2) or formula (b3).
The polymer obtained in step (1) is produced by reacting the polymer (base polymer) obtained in step (1) above with the acid group-containing compound represented by formula (b2) or formula (b3). The above-mentioned acid group-containing compound can be added to the hydroxyl group of the aggregate (base polymer) to form a long chain acid group.

The reaction method is not particularly limited, and any known method can be used.
The reaction temperature is, for example, preferably 25 to 100°C, more preferably 30 to 90°C.
The reaction time is not particularly limited, but includes, for example, 1 to 20 hours.

Further, the step of reacting the acid group-containing compound may be performed in the presence of a basic compound. By performing the reaction in the presence of a basic compound, the reaction between the hydroxyl group and the acid group can be performed under lower temperature conditions such as 70° C. or lower. In addition, since the reaction is carried out under the above-mentioned low temperature conditions, the reaction between the epoxy group and the acid group can be suppressed and only the reaction between the hydroxyl group and the acid group can proceed. A copolymer having the structural unit (B) can be produced more efficiently.

For example, in step (2), the polymer (base polymer) obtained in step (1) and the acid group-containing compound may be reacted at 70° C. or lower in the presence of a basic compound. In this case, if the temperature exceeds 70°C, the reaction between the epoxy group and the acid group will proceed more easily, and there is a possibility that the resin will gel.

Examples of the acid group-containing compound represented by the above formula (b2) or formula (b3) include the above-mentioned acid group-containing compounds.
Examples of the basic compounds include ammonia; primary amines such as methylamine; secondary amines such as dimethylamine; tertiary amines such as triethylamine and diethylmethylamine; aliphatic compounds such as dimethylethanolamine, n-butylamine, and diethylamine. Amines; Cycloaliphatic amines such as cyclohexylamine; Heterocyclic amines such as piperidine, morpholine, N-ethylpiperidine, N-ethylmorpholine, and pyridine; Aromatics such as benzylamine, N-methylaniline, N,N-dimethylaniline, etc. Amines; Tetraalkylammonium halides such as tetramethylammonium chloride and tetraethylammonium chloride; Tetraalkylammonium organic acid salts such as tetramethylammonium acetate; Tetraalkylammonium inorganic acid salts such as tetramethylammonium hydrogen sulfate and tetraethylammonium hydrogen sulfate; Tetra (Hydroxy)alkylammonium hydroxides such as methylammonium hydroxide, tetraethylammonium hydroxide, monohydroxyethyltrimethylammonium hydroxide; hydroxides of alkali metals such as sodium and potassium; transition metals such as barium, strontium, calcium, and lanthanum hydroxides; free salts of complex salts such as [Pt(NH ₃ ) ₆ ](OH) ₄ ; and phosphorus compounds such as triphenylphosphine, tricyclohexylphosphine, and trimethylphosphine. Among these, secondary amines, tertiary amines, heterocyclic amines, and phosphorus compounds are preferred in terms of ease of transpiration and ease of handling, as they can suppress side reactions and reduce the molecular weight of the polymer after addition. Tertiary amines and triphenylphosphine are more preferable in that they can suppress the increase in the concentration.

The amount of the basic compound used is not particularly limited, but from the viewpoint of reaction efficiency, it is preferably 0 to 5 mol%, and 0 to 4 mol%, based on 100 mol% of the acid group-containing compound used. %, and even more preferably 0 to 3 mol%.

The amount of the acid group-containing compound to be used is determined so that the content ratio of the structural unit (B) falls within a desired range, depending on the purpose and use of the copolymer to be obtained, or It is preferable to set the acid value appropriately so that it falls within a desired range.

The total monomer component concentration in the total amount of the polymerization solution during the addition reaction of the acid group-containing compound is preferably 40% by mass or more, more preferably 50% by mass or more. When the total monomer component concentration is within the above range, the acid group-containing compound can be added to the base polymer without using the basic compound as a catalyst, and the resulting copolymer is stable in storage. can improve sex. As described above, when the monomer concentration relative to the total amount of the copolymer solution is high, the acid group-containing compound can be added without a catalyst, and the storage stability of the copolymer can be improved.

In the above reaction, commonly used catalysts, solvents, etc. may be used.

In addition, in order to produce a copolymer having a polymerizable double bond in the side chain, after the above step (1), an acid group-containing monomer or an isocyanate group-containing polymerizable monomer is added to the hydroxyl group. A polymerizable double bond can be introduced into the side chain of the copolymer by adding an acid group-containing monomer to the epoxy group after the above step (1) or (2). .
Examples of the acid group-containing monomer include those mentioned above, preferably (meth)acrylic acid.
The above-mentioned isocyanate group-containing polymerizable monomers include the above-mentioned unsaturated isocyanates, which are preferably (metal ) isocyanatoethyl acrylate.
The above addition reaction is not particularly limited and can be performed by a known method.
Further, in the above addition reaction, commonly used compounds, catalysts, solvents, etc. may be used.

Among these, the above-mentioned basic compounds are preferably used as the catalyst, with secondary amines, tertiary amines, heterocyclic amines, and phosphorus compounds being preferred, and tertiary amines and triphenylphosphine being more preferred. . Additionally, dibutyltin dichloride, dibutyltin oxide, dibutyltin dibromide, dibutyltin dimaleate, dibutyltin dilaurate, dioctyltin dilaurate, dibutyltin diacetate, dibutyltin sulfide, and tributyltin are commonly used as reaction catalysts between isocyanate monomers and hydroxyl groups. Tin-based compounds such as tin acetate, dioctyltin oxide, and tributyltin chloride can also be suitably used.

The method for producing the copolymer may include steps other than the reaction step described above. Examples include an aging step, a neutralization step, a deactivation step of a polymerization initiator or a chain transfer agent, a dilution step, a drying step, a concentration step, a purification step, and the like. These steps can be performed by known methods.

2. Copolymer Solution The present invention is also a copolymer solution characterized by containing the above-mentioned copolymer and a protic polar solvent. The copolymer solution of the present invention has excellent storage stability.
As mentioned above, the above copolymer has acid groups and epoxy groups, and since these groups have high reactivity, the above copolymer can be easily cured at low temperatures, while ensuring storage stability. That was difficult. The present inventors have discovered that by adding a protic polar solvent, the storage stability of the copolymer can be improved, and both high solvent resistance and storage stability can be achieved.
The reason why the storage stability of the above copolymer is improved by the addition of a protic polar solvent is not clear, but the presence of acid groups such as carboxyl groups in the above copolymer at positions separated from the main chain This is presumed to be because the protic polar solvent relatively easily hydrogen bonds with the acid group, reducing the anionic nature of the acid group and suppressing the reactivity between the acid group and the epoxy group.

<Protic polar solvent>
Examples of the protic polar solvent include water, alcohol solvents, amine solvents, and phenol solvents. Among these, the protic polar solvent is preferably an alcohol solvent.

The alcoholic solvent is preferably saturated alcohol, and includes monofunctional alcohols (monoalcohols), polyhydric alcohols, glycol monoethers, and the like.
Specific examples of the alcoholic solvents include methanol, ethanol, 1-propanol, 1-butanol, 1-pentanol, 1-hexanol, ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-n -Propyl ether, ethylene glycol mono-n-butyl ether, ethylene glycol monophenyl ether, diethylene glycol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-n-propyl ether, diethylene glycol mono-n-butyl ether, triethylene glycol, triethylene Primary alcohols such as glycol monomethyl ether, triethylene glycol mono-n-butyl ether, tripropylene glycol, tripropylene glycol mono-n-butyl ether;
Isopropanol, 2-butanol, 2-pentanol, 3-pentanol, 2-hexanol, cyclohexanol, 2-heptanol, 3-heptanol, propylene glycol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-n -Propyl ether, propylene glycol mono-n-butyl ether, propylene glycol monophenyl ether, dipropylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol mono-n-propyl ether, dipropylene glycol mono- Secondary alcohols such as n-butyl ether or tripropylene glycol monomethyl ether;
Examples include tertiary alcohols such as tert-butanol, tert-pentanol, and tert-hexanol.
Among these, the alcoholic solvent is preferably a secondary alcohol or a tertiary alcohol, from the viewpoints of suppressing reactivity with epoxy groups and reducing the viscosity of the copolymer solution.

The number of carbon atoms in the alcoholic solvent is preferably 1 to 10, more preferably 2 to 8, and 3 to 6, since the boiling point is relatively low and removal by heating is easy. is even more preferable.

As the alcoholic solvent, propylene glycol monomethyl ether is particularly preferred.

Examples of the amine solvent include diethyleneamine, dimethylamine, oleylamine, and the like.

Examples of the phenolic solvent include phenol, cresol, o-cresol, m-cresol, p-cresol, xylenol, and the like.

The above protic polar solvents may be used alone or in combination of two or more.

The boiling point of the protic polar solvent is preferably 70 to 170°C, and preferably 100 to 160°C, since it can be easily removed by heating, has a certain boiling point, and can easily form a flat film. The temperature is more preferably 120 to 150°C, even more preferably 120 to 150°C.

The content of the protic polar solvent in the copolymer solution is preferably 10% by mass or more, more preferably 30% by mass, and 40% by mass based on 100% by mass of the solid content of the copolymer. % or more is more preferable. Further, the content of the protic polar solvent is preferably 1000% by mass or less, based on 100% by mass of the solid content of the copolymer, from the viewpoint of facilitating concentration adjustment in the curable resin composition, and 300% by mass or less. It is more preferably at most 200% by mass, even more preferably at most 200% by mass.

In terms of stability, it is preferable that the copolymer solution further contains, in addition to the protic polar solvent, another solvent capable of hydrogen bonding. Examples of the other solvents include N,N-dimethylformamide and the like.
In addition, as a solvent for adjusting the concentration, for example, ethers such as tetrahydrofuran, dioxane, ethylene glycol dimethyl ether, and diethylene glycol dimethyl ether; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ethyl acetate, butyl acetate, and propylene glycol monomethyl ether acetate. , esters such as 3-methoxybutyl acetate; aromatic hydrocarbons such as toluene, xylene, and ethylbenzene; chloroform; dimethyl sulfoxide; and the like.

When the copolymer solution contains a solvent other than the protic polar solvent, the content of the protic polar solvent is 100% by mass of the total amount of the protic polar solvent and the other solvent. It is preferably 5 parts by mass or more, more preferably 10 mass% or more, even more preferably 20 mass% or more, preferably 99 mass% or less, and preferably 90 mass% or less. The content is more preferably 80% by mass or less.

The above copolymer solution may be prepared by mixing the copolymer purified from the polymerization solution containing the above copolymer obtained during polymerization with the above protic polar solvent, or the above copolymer solution may be prepared by mixing the above protic polar solvent. The protic polar solvent may be added to the polymerization solution containing the polymer. When prepared by adding the protic polar solvent to a polymerization solution containing the copolymer, the copolymer solution may contain the polymerization solvent.

The copolymer solution may further contain other components. Other components include components that improve the storage stability of the copolymer and components that improve curability. Examples of components that improve the storage stability of the copolymer include acid compounds and phosphoric acid derivatives. Examples of the component that improves the curability of the copolymer include basic compounds. These components may be used appropriately depending on the purpose, and may be used in combination.

<Acid compound>
The copolymer solution may further contain an acid compound having a pKa of 4.2 or less.
Since the copolymer solution contains an acid compound having a pKa of 4.2 or less, the reaction between the acid groups and epoxy groups of the copolymer is suppressed, further improving the storage stability of the copolymer. can be done. By including an acid compound having a pKa of 4.2 or less, the storage stability of the copolymer can be improved because the acid groups that can form the acid group-containing structural unit (B) of the copolymer are This is thought to be because the presence of an acid compound with strong acid strength reduces the anionic nature of the acid groups in the copolymer and suppresses the reactivity between the acid groups and the epoxy groups. In addition, if a basic compound is present in the copolymer solution, the basic compound that has formed a salt with the carboxyl group is supplemented by an acid compound with a pKa of 4.2 or less, and the carboxyl group in the copolymer is It is thought that the nucleophilic force of the group is reduced, and the reactivity between the acid group and the epoxy group can be suppressed.

The reason why the pKa was set to 4.2 or less is that the pKa value of the monomer or acid group-containing monomer into which the structural unit (B) can be introduced was used as the threshold value. The pKa values of the above monomers include, for example, acrylic acid (pKa4.35), methacrylic acid (pKa4.26), mono(2-acryloyloxyethyl) succinate (pKa4.35), and mono(2-acryloyloxyethyl) succinate (pKa4.35). -Methachloroyloxyethyl) (pKa4.35).
The pKa of the acid compound is preferably 3 or less, more preferably 2 or less. The lower limit of pKa of the above acid compound is not particularly limited, but is preferably -3 or more, more preferably 0 or more.

pKa (acid dissociation constant) means the negative common logarithm (logarithm of the reciprocal) of the equilibrium constant Ka in a dissociation reaction in which hydrogen ions are released from an acid, and particularly means a value in water at 25°C.
For the value of pKa, for example, references such as Chemical Handbook, Basic Edition II (revised 5th edition, Maruzen Co., Ltd.) can be referred to, and values not listed in the references can be calculated using the method described in the references. can do.

Specific examples of acid compounds having a pKa of 4.2 or less include, for example, hydrochloric acid, hydrobromic acid, hydroiodic acid, phosphoric acid, phosphorous acid, hypophosphorous acid, phosphonic acid, phosphinic acid, and pyrophosphoric acid. , polyphosphoric acid, sulfuric acid, sulfite, thiosulfate, dimethyl sulfite, diethyl sulfite, dipropyl sulfite, dibutyl sulfite, diphenyl sulfite, dimethyl sulfate, diethyl sulfate, dipropyl sulfate, dibutyl sulfate, diphenyl sulfate, benzenesulfinic acid, toluenesulfinic acid, naphthalene Aromatic sulfonic acids such as sulfinic acid, benzenesulfonic acid, toluenesulfonic acid, trifluoromethanesulfonic acid, dodecylbenzenesulfonic acid, naphthalenesulfonic acid, diisopropylnaphthalenesulfonic acid, diisobutylnaphthalenesulfonic acid, methylsulfonic acid, ethylsulfonic acid, propyl Examples include alkyl sulfonic acids such as sulfonic acid, α-olefin sulfonic acids, sulfonated polystyrenes, methyl acrylate-sulfonated styrene copolymers, and derivatives thereof.

The molecular weight of the acid compound is preferably 400 or less, more preferably 350 or less. The molecular weight of the acid compound is preferably 150 or more, more preferably 250 or more.

<Phosphoric acid derivative>
The copolymer solution may contain a phosphoric acid derivative. When the copolymer solution further contains a phosphoric acid derivative, the storage stability of the copolymer can be improved.

As the above-mentioned phosphoric acid derivative, phosphoric acid ester, phosphorous acid ester, phosphorous acid, hypophosphorous acid, phosphonic acid, and phosphinic acid are preferably mentioned, and phosphoric acid ester, phosphonic acid, and phosphinic acid are more preferably mentioned.
Examples of the ester group of the phosphoric acid ester or phosphite include an alkyl ester group, an aryl ester group, an aralkyl ester group, an ester group having a polymerizable double bond, and the like. Examples of the alkyl in the alkyl ester group include methyl, ethyl, octyl, 2-ethylhexyl, and the like. Examples of the aryl in the aryl ester group include phenyl, tolyl, naphthyl, and the like. Examples of the aralkyl of the aralkyl ester group include benzyl and the like. Examples of the ester group having a polymerizable double bond include a 2-acryloyloxyethyl ester group and a 2-methacryloyloxyethyl ester group.

Specific examples of the above-mentioned phosphate esters include monoalkyl phosphates such as methyl phosphate; dialkyl phosphates such as dibutyl phosphate; trimethyl phosphate, triethyl phosphate, tributyl phosphate, trioctyl phosphate, tridecyl phosphate, triotadecyl phosphate, and distearyl phosphate. Trialkyl phosphates such as pentaerythrityl diphosphate, tris (2-chloroethyl) phosphate, tris (2,3-dichloropropyl) phosphate; tricycloalkyl phosphates such as tricyclohexyl phosphate; monoaryl phosphate; diaryl phosphate; triphenyl phosphate , tricresyl phosphate, tris(nonylphenyl) phosphate, triaryl phosphate such as 2-ethyl phenyl diphenyl phosphate; 2-methacryloyloxyethyl acid phosphate, 2-acryloyloxyethyl acid phosphate, 3-methacryloyloxypropyl acid Examples include phosphoric acid esters containing an ester group having a polymerizable double bond, such as phosphate, methacryloyloxypolyoxyethylene glycol acid phosphate, and methacryloyloxypolyoxypropylene glycol acid phosphate.
Specific examples of the phosphonic acid include alkylphosphonic acids such as methylphosphonic acid, arylphosphonic acids such as phenylphosphonic acid, and the like.
Specific examples of the phosphinic acids include alkyl phosphinic acids such as methylphosphinic acid, arylphosphinic acids such as phenylphosphinic acid, and the like.

Among these, as the phosphoric ester, a phosphoric ester containing an ester group having the above-mentioned polymerizable double bond is preferable. When a phosphoric acid ester containing an ester group having a polymerizable double bond is used, a crosslinked structure is formed together with the copolymer and the polymerizable compound during curing of the curable resin composition containing the copolymer solution, The volatilization and elution of the contained components is suppressed, and problems such as contamination of the reaction system and deterioration of electrical insulation can be significantly suppressed.
The phosphoric acid ester preferably contains two or three or more polymerizable double bonds.

In the present invention, commercial products can be used as the phosphoric acid ester containing an ester group having a polymerizable double bond, such as Light Ester P-1M and Light Ester P-2M (both manufactured by Kyoeisha Chemical Co., Ltd.). ), Phosmer M (manufactured by Unichemical Co., Ltd.), etc. can be used. Among them, light ester P-2M is preferred.

The molecular weight of the phosphoric acid derivative is preferably 400 or less, more preferably 350 or less. When the molecular weight of the phosphoric acid derivative is 400 or less, the solid content of the resin when added can be lowered, and the storage stability can be further improved. Further, the effect of improving the anionic property of the acid group and reducing the nucleophilic force becomes greater. The molecular weight of the phosphoric acid derivative is preferably 150 or more, more preferably 250 or more. When the molecular weight of the phosphoric acid derivative is 150 or more, the compatibility with the resin composition can be further improved.

The above-mentioned phosphoric acid derivative may be an acid compound having the above-mentioned pKa of 4.2 or less. That is, from the viewpoint of storage stability and compatibility, the copolymer solution of the present invention preferably contains an acid compound or a phosphoric acid derivative having a pKa of 4.2 or less, and a phosphoric acid derivative having a pKa of 4.2 or less. More preferably, it contains an acid derivative.

The content of the above acid compound and phosphoric acid derivative is not particularly limited and may be set as appropriate depending on the use and the combination of other components, but preferably based on 100% by mass of the total solid content of the copolymer solution. Generally, it is preferably 0.01 to 5% by weight, more preferably 0.01 to 3% by weight, and even more preferably 0.02 to 2% by weight. In addition, the said content is the total amount of the said acid compound and phosphoric acid derivative, when using the said acid compound and a phosphoric acid derivative together. Further, in this specification, the "total solid content" means the total amount of components forming the cured product (excluding solvents etc. that volatilize during formation of the cured product).

The content of the above acid compound and phosphoric acid derivative is preferably 0.01 to 10 parts by mass, and preferably 0.05 to 5 parts by mass, based on 100 parts by mass of the copolymer in the copolymer solution. The amount is more preferably 0.1 to 3 parts by mass. In addition, the said content is the total amount of the said acid compound and phosphoric acid derivative, when using the said acid compound and a phosphoric acid derivative together.

When the above-mentioned copolymer solution further contains a basic compound described below, the content of the above-mentioned acid compound and phosphoric acid derivative is 50 to 200 mol% with respect to 100 mol% of the basic compound used. It is preferably from 70 to 150 mol%, even more preferably from 80 to 120 mol%. By setting the content of the acid compound and phosphoric acid derivative in the range of 0.5 to 2.0 molar equivalents relative to the basic compound, the storage stability of the copolymer is further improved, and the cured product is coloring can be further suppressed. In addition, the said content is the total amount of the said acid compound and phosphoric acid derivative, when using the said acid compound and a phosphoric acid derivative together.

<Basic compound>
The copolymer solution may further contain a basic compound. By including the basic compound, the crosslinking reaction proceeds favorably even under low temperature curing conditions of 160° C. or lower during curing of the copolymer, and a cured product with even better solvent resistance can be obtained.

Examples of the basic compound include the basic compounds mentioned above. Among them, amine compounds are preferred. In addition, as the above-mentioned basic compound, secondary amines, tertiary amines, heterocyclic amines, and phosphorus compounds are more preferable in terms of ease of evaporation and ease of handling, as they can suppress side reactions and Tertiary amines and triphenylphosphine are more preferred in that they can suppress an increase in the molecular weight of the coalescence.

The content of the above-mentioned basic compound is not particularly limited, and may be set as appropriate depending on the use and the combination of other components, etc., but it is 0.01% by mass based on 100% by mass of the total solid content of the copolymer solution. It is preferably from 10% by weight to 10% by weight, more preferably from 0.01 to 6% by weight, even more preferably from 0.02 to 4% by weight.

Further, the content of the basic compound is preferably 0.01 to 20 parts by weight, more preferably 0.1 to 10 parts by weight, based on 100 parts by weight of the copolymer. More preferably, the amount is .1 to 6 parts by mass.

In addition, if the above-mentioned basic compound used as a catalyst during the synthesis of the above-mentioned copolymer (during the addition reaction) remains in the copolymer solution after the synthesis of the copolymer, depending on the remaining amount. The content in the copolymer solution may be adjusted by adding a basic compound.

<Method for producing copolymer solution>
The method for producing the copolymer solution includes, for example, a monomer containing an epoxy group-containing monomer represented by the above formula (a) and a hydroxyl group-containing monomer represented by the above formula (b1). A step of polymerizing the components (polymerization step), and a step of reacting the polymer obtained in the above polymerization step with the acid group-containing compound represented by the above formula (b2) or formula (b3) in the presence of a basic compound. (reaction step) and a step (addition step) of adding an acid compound having a pKa of 4.2 or less and a protic polar solvent.
That is, a step of polymerizing a monomer component containing an epoxy group-containing monomer represented by formula (a) and a hydroxyl group-containing monomer represented by formula (b1), and a step of reacting the polymer with an acid group-containing compound represented by formula (b2) or formula (b3) in the presence of a basic compound, and adding an acid compound with a pKa of 4.2 or less and a protic polar solvent. Another aspect of the present invention is a method for producing a copolymer solution, which comprises the steps of:

Examples of the polymerization step include the same steps as step (1) in the method for producing a copolymer described above.

Examples of the reaction step include a method similar to the method in which step (2) in the above-mentioned method for producing a copolymer is carried out in the presence of a basic compound. Specific examples of the acid group-containing compound and basic compound represented by the above formula (b2) or formula (b3) include those similar to the acid group-containing compound and basic compound described above.

The acid compound having a pKa of 4.2 or less and the protic polar solvent used in the above addition step are as described above.

3. Curable Resin Composition The copolymer and copolymer solution of the present invention can be combined with other components to form a curable resin composition. Since the above-mentioned curable resin composition contains the copolymer of the present invention, it is possible to provide a cured product with excellent solvent resistance even under low temperature curing conditions. Furthermore, when the curable resin composition contains the copolymer solution, it has even better storage stability. Such a curable resin composition containing the above copolymer or copolymer solution is also one of the preferred embodiments of the present invention.

In the curable resin composition, the content of the copolymer is not particularly limited and may be set appropriately depending on the use and the combination of other components. Based on 100% by mass, it is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, and preferably 80% by mass or less. , more preferably 75% by mass or less, and even more preferably 70% by mass or less.
In addition, in this specification, "total solid content" means the total amount of the components (excluding the solvent etc. which volatilize at the time of formation of a cured product) which form a cured product.

The above-mentioned curable resin composition preferably contains the above-mentioned protic polar solvent, since the composition has good stability.
In order to ensure the stability of the curable resin composition, the content of the protic polar solvent in the curable resin composition is 10% by mass or more based on 100% by mass of the solid content of the copolymer. It is preferably at least 30% by mass, even more preferably at least 40% by mass, and preferably at most 3000% by mass, and more preferably at most 1000% by mass.

In order to ensure the stability of the curable resin composition, the content of the protic polar solvent in the curable resin composition is 1% by mass or more based on 100% by mass of the solid content of the curable resin composition. It is preferably 5% by mass or more, more preferably 10% by mass or more, and preferably 400% by mass or less, more preferably 300% by mass or less, More preferably, it is 200% by mass or less.

The curable resin composition can also contain various other components such as a polymerizable compound and a polymerization initiator. Regarding various components such as a polymerizable compound and a polymerization initiator, the same components as those of the photosensitive resin composition described later can be mentioned.
A photosensitive resin composition will be described as an example of a preferable form of the curable resin composition.

3-1. Photosensitive resin composition The copolymer or copolymer solution of the present invention can be made into a photosensitive resin composition by further combining a polymerizable compound and a photopolymerization initiator.
Since the photosensitive resin composition contains the above-mentioned copolymer, it can provide a cured product with excellent solvent resistance even under low temperature curing conditions of 160°C or lower, for example about 90°C. In addition, since it further contains a polymerizable compound, it is possible to provide a cured product that is excellent in various physical properties such as curability, adhesion to a substrate, surface hardness, and heat resistance. A photosensitive resin composition containing the above-mentioned copolymer or copolymer solution, a polymerizable compound, and a photopolymerization initiator is also part of the present invention.

In the photosensitive resin composition of the present invention, the content of the above-mentioned copolymer is not particularly limited and may be set appropriately depending on the use and the combination of other components. It is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, and even more preferably 80% by mass or less, based on the total amount of 100% by mass. The content is preferably 75% by mass or less, more preferably 70% by mass or less.

<Polymerizable compound>
The above polymerizable compound has a polymerizable unsaturated bond (also referred to as a polymerizable unsaturated group) that 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. For example, monofunctional compounds having one polymerizable unsaturated group in the molecule and polyfunctional compounds having two or more polymerizable unsaturated groups can be mentioned.

Examples of the above-mentioned monofunctional compounds include N-substituted maleimide monomers; (meth)acrylic esters; (meth)acrylamides; unsaturated monocarboxylic acids; unsaturated polycarboxylic acids; unsaturated groups and carboxyl Unsaturated monocarboxylic acids with chain extension between groups; unsaturated acid anhydrides; aromatic vinyls; conjugated dienes; vinyl esters; vinyl ethers; N-vinyl compounds; unsaturated isocyanates; etc. can be mentioned. Examples of these include compounds similar to those listed as monomer components of the above copolymer. Furthermore, monomers having an active methylene group or an active methine group can also be used.

Examples of the polyfunctional compound include the following compounds.
Ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, butylene glycol di(meth)acrylate, hexanediol di(meth)acrylate, cyclohexanedimethanol Bifunctional (meth)acrylate compounds such as di(meth)acrylate, bisphenol A alkylene oxide di(meth)acrylate, bisphenol F alkylene oxide di(meth)acrylate;

Trimethylolpropane tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, glycerin tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, Dipentaerythritol hexa(meth)acrylate, tripentaerythritol hepta(meth)acrylate, tripentaerythritol octa(meth)acrylate, ethylene oxide trimethylolpropane tri(meth)acrylate, ethylene oxide ditrimethylolpropane tetra(meth)acrylate, ethylene oxide Added pentaerythritol tetra(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 (meth)acrylate, propylene oxide added dipentaerythritol hexa(meth)acrylate, ε-caprolactone added trimethylolpropane tri(meth)acrylate, ε-caprolactone added ditrimethylolpropane tetra(meth)acrylate, ε-caprolactone added pentaerythritol tetra (meth)acrylate, ε-caprolactone added dipentaerythritol hexa(meth)acrylate, dipentaerythritol pentaacrylate succinic acid modified product, pentaerythritol triacrylate succinic acid modified product, dipentaerythritol pentaacrylate phthalic acid modified product, pentaerythritol triacrylate Acrylate phthalic acid modified product, the following formula:

Trifunctional or higher functional polyfunctional (meth)acrylate compounds such as modified dipentaerythritol hexaacrylate represented by;

Ethylene glycol divinyl ether, diethylene glycol divinyl ether, polyethylene glycol divinyl ether, propylene glycol divinyl ether, butylene glycol divinyl ether, hexanediol divinyl ether, bisphenol A alkylene oxide divinyl ether, bisphenol F alkylene oxide divinyl ether, trimethylolpropane trivinyl ether, ditri Methylolpropane tetravinyl ether, glycerin trivinyl ether, pentaerythritol tetravinyl ether, dipentaerythritol pentavinyl ether, dipentaerythritol hexavinyl ether, ethylene oxide trimethylolpropane trivinyl ether, ethylene oxide ditrimethylolpropane tetravinyl ether, ethylene oxide pentaerythritol tetravinyl ether, ethylene oxide Polyfunctional vinyl ethers such as added dipentaerythritol hexavinyl ether;

2-vinyloxyethyl (meth)acrylate, 3-vinyloxypropyl (meth)acrylate, 1-methyl-2-vinyloxyethyl (meth)acrylate, 2-vinyloxypropyl (meth)acrylate, 4-vinyloxy(meth)acrylate - Vinyloxybutyl, 4-vinyloxycyclohexyl (meth)acrylate, 5-vinyloxypentyl (meth)acrylate, 6-vinyloxyhexyl (meth)acrylate, 4-vinyloxymethylcyclohexylmethyl (meth)acrylate, ( Vinyl ether group-containing (meth)acrylics such as p-vinyloxymethylphenylmethyl meth)acrylate, 2-(vinyloxyethoxy)ethyl (meth)acrylate, and 2-(vinyloxyethoxyethoxyethoxy)ethyl (meth)acrylate. Acid esters;

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

Allyl group-containing (meth)acrylic acid esters such as allyl (meth)acrylate; tri(acryloyloxyethyl)isocyanurate, tri(methacryloyloxyethyl)isocyanurate, alkylene oxide addition tri(acryloyloxyethyl)isocyanurate, alkylene Polyfunctional (meth)acryloyl group-containing isocyanurates such as oxidized tri(methacryloyloxyethyl) isocyanurate; polyfunctional allyl group-containing isocyanurates such as triallyl isocyanurate; tolylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, etc. Polyfunctional urethane (meth)acrylates obtained by the reaction of polyfunctional isocyanate with hydroxyl group-containing (meth)acrylic acid esters such as 2-hydroxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate; Polyfunctional aromatic vinyls such as divinylbenzene; etc. These polymerizable compounds may be used alone or in combination of two or more.
However, although the polymer having a vinyl ether group in the side chain improves the curability of the resin composition, it may reduce the storage stability. It is preferable that the polymer does not contain a polymer having a vinyl ether group in a side chain.

Among the above polymerizable compounds, it is preferable to use polyfunctional polymerizable compounds from the viewpoint of further improving the curability of the photosensitive resin composition. The functional number of the polyfunctional polymerizable compound is preferably 3 or more, more preferably 4 or more. Further, the functional number is preferably 10 or less, more preferably 8 or less.
Further, the molecular weight of the polymerizable compound is not particularly limited, but from the viewpoint of handling, it is preferably, for example, 2000 or less.

Among the above polyfunctional polymerizable compounds, from the viewpoint of reactivity, economy, availability, etc., preferred are polyfunctional (meth)acrylate compounds, polyfunctional urethane (meth)acrylate compounds, and (meth)acryloyl groups. Examples include compounds having a (meth)acryloyl group, such as isocyanurate compounds, and more preferably polyfunctional (meth)acrylate compounds. By including a compound having a (meth)acryloyl group, the photosensitive resin composition becomes more excellent in photosensitivity and curability, and a cured product with even higher hardness and higher transparency can be obtained. As the polyfunctional polymerizable compound, it is more preferable to use a trifunctional or more polyfunctional (meth)acrylate compound.

The above polymerizable compounds may be used alone or in combination of two or more.

In the photosensitive resin composition of the present invention, the content of the polymerizable compound is not particularly limited and may be set as appropriate as long as the effect of the present invention is exhibited. In terms of viscosity, it is preferably 5 to 60% by mass, more preferably 10 to 50% by mass, based on 100% by mass of the total solid content of the photosensitive resin composition.

<Photopolymerization initiator>
As the photopolymerization initiator, preferably a radically polymerizable photopolymerization initiator is mentioned. A radically polymerizable photopolymerization initiator is one that generates polymerization initiation radicals by irradiation with active energy rays such as electromagnetic waves and electron beams.

Specific examples of the photopolymerization initiator 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-morpholinophenyl) Aminoketone compounds such as phosphorus-4-yl-phenyl)-butan-1-one ("IRGACURE379", manufactured by BASF); 2,2-dimethoxy-1,2-diphenylethan-1-one ("IRGACURE651", Benzyl ketal compounds such as phenylglyoxylic acid methyl ester (“DAROCUR MBF”, manufactured by BASF); 1-hydroxy-cyclohexyl-phenyl-ketone (“IRGACURE184”, manufactured by BASF), 2- Hydroxy-2-methyl-1-phenyl-propan-1-one (“DAROCUR1173”, manufactured by BASF), 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1- Propan-1-one ("IRGACURE2959", manufactured by BASF), 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]-phenyl}-2-methyl-propane In addition to hydroketone compounds such as -1-one ("IRGACURE127", manufactured by BASF), [1-hydroxy-cyclohexyl-phenyl-ketone + benzophenone] ("IRGACURE500", manufactured by BASF); etc., JP-A-2013 Other alkylphenone compounds exemplified in paragraphs [0084] to [0086] of Publication No.-227485; 1,2-octanedione, 1-[4-(phenylthio)phenyl]-,2-(O-benzoyloxime) ) ("OXE01", manufactured by BASF), ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-,1-(O-acetyloxime) ("OXE02") ”, manufactured by BASF), 1,2-octanedione, 1-[4-(phenylthio)-,2-,(O-benzoyloxime)], ethanone (“OXE03”, manufactured by BASF), 1-[9 Oxime ester compounds such as -ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-,1-(O-acetyloxime) ("OXE04", manufactured by BASF); benzophenone compounds; Benzoin-based compounds; thioxanthone-based compounds; halomethylated triazine-based compounds; halomethylated oxadiazole-based compounds; biimidazole-based compounds; titanocene-based compounds; benzoic acid ester-based compounds; acridine-based compounds, etc.; phosphine oxide-based compounds; It will be done. Among these, aminoketone compounds and oxime ester compounds are preferred.
The above photopolymerization initiators may be used alone or in combination of two or more.

The content of the photopolymerization initiator is not particularly limited and may be set appropriately as long as the effects of the present invention are exhibited. For example, the total solid content of the photosensitive resin composition of the present invention is 100 It is preferably 0.3 to 20% by mass, more preferably 0.5 to 10% by mass, and even more preferably 1 to 8% by mass.

<Photoacid generator>
It is preferable that the photosensitive resin composition of the present invention further contains a photoacid generator. By further including a photoacid generator, the curability of the photosensitive resin composition can be further improved.
The photoacid generator is a compound that generates an acid when exposed to active energy rays such as radiation, and includes strong acids such as toluenesulfonic acid or boron tetrafluoride, sulfonium salts, ammonium salts, phosphonium salts, Onium salts such as iodonium salts or selenium salts; iron-alene complexes; silanol-metal chelate complexes; disulfones, disulfonyldiazomethanes, disulfonylmethanes, sulfonylbenzoylmethanes, imidosulfonates, benzoinsulfonates, etc. Examples include sulfonic acid derivatives; organic halogen compounds; and the like.

The content of the photoacid generator is preferably 0.3 to 20% by mass, more preferably 0.5 to 10% by mass, based on 100% by mass of the total solid content of the photosensitive resin composition. It is preferably 1 to 8% by mass, and more preferably 1 to 8% by mass.

<Other ingredients>
In addition to the above-mentioned components, the photosensitive resin composition of the present invention may contain other components as necessary. Other components mentioned above include, for example, solvents; coloring materials (pigments, dyes); dispersants; heat resistance improvers; leveling agents; development aids; inorganic particles such as silica particles; silane-based, aluminum-based, titanium-based, etc. Coupling agents; fillers, thermosetting resins such as epoxy resins, phenolic resins, and polyvinylphenols; curing aids such as polyfunctional thiol compounds; plasticizers; polymerization inhibitors; ultraviolet absorbers; antioxidants; matting agents; Antifoaming agents; antistatic agents; slip agents; surface modifiers; thixotropic agents; thixotropic aids; quinone diazide compounds; polyhydric phenol compounds; cationically polymerizable compounds; acid generators; and the like. These may be used alone or in combination of two or more. These other components may be appropriately selected from known components and used, and the amounts used can be set appropriately.
For example, when the photosensitive resin composition is used for a color filter, it is preferable that the photosensitive resin composition contains a coloring material.

<Preparation of photosensitive resin composition>
The method for preparing the photosensitive resin composition of the present invention is not particularly limited and any known method may be used. For example, the above-mentioned components are mixed and dispersed using various mixers and dispersers. There are several methods. The mixing/dispersing process is not particularly limited and may be performed by a known method. Moreover, it may further include other steps that are normally performed. When the photosensitive resin composition contains a coloring material, it is preferably prepared through a known process such as a coloring material dispersion process.

<Cured product>
The cured product obtained by curing the copolymer, copolymer solution, or photosensitive resin composition (curable resin composition) of the present invention has excellent solvent resistance. A cured product of such a copolymer, copolymer solution, or photosensitive resin composition is also part of the present invention.

When the cured product is a cured film, the film thickness is preferably 0.1 μm or more. When the film thickness is 0.1 μm or more, even more excellent solvent resistance can be exhibited. The film thickness is more preferably 0.5 μm or more, and even more preferably 1 μm or more. The upper limit of the film thickness is not particularly limited and may be set appropriately depending on the purpose and use of the cured film, but for example, it is preferably 20 μm or less, more preferably 15 μm or less, and 10 μm or less. It is even more preferable that there be.

The method for obtaining the above-mentioned cured product is not particularly limited, and any known method may be used. For example, the above-mentioned copolymer, copolymer solution, or photosensitive resin composition is coated on a base material, or Examples include a method of obtaining a cured product by curing the molded product by drying, heating, irradiating with energy rays such as ultraviolet rays, or a combination thereof.

By using the copolymer, copolymer solution, or photosensitive resin composition of the present invention, a cured product with excellent solvent resistance can be obtained even under low temperature curing conditions. The method for producing such a cured product includes, for example, a step of coating the photosensitive resin composition on a base material to form a coating film, a step of irradiating the formed coating film with light, and a step of irradiating the formed coating film with light. A method including a step of heating the coated film at 160° C. or lower is preferred.

The above-mentioned base material is not particularly limited and may be appropriately selected depending on the purpose and use, and examples thereof include base materials made of various materials such as glass plates and plastic plates.

The method of applying the photosensitive resin composition to form a coating film is not particularly limited, and can be performed by known methods such as spin coating, slit coating, roll coating, and cast coating.
In the above manufacturing method, it is preferable to apply the photosensitive resin composition onto a substrate and then dry the coated material to form a coating film. The above-mentioned drying can be performed by a known method, and specifically, it can be performed by a method similar to the drying method described in "Arrangement step" of "<Color filter manufacturing method>" described later.

The manufacturing method includes a step of forming a coating film and then irradiating the coating film with light.
The method of irradiating the formed coating film with light is not particularly limited and can be carried out by any known method. Specifically, the "light irradiation step" of "<Method for manufacturing a color filter>" described below is applicable. It can be carried out by a method similar to that described in .

When the coating film is irradiated with light, the irradiation may be performed through a photomask. As the photomask, it is preferable to use a mask in which a light-shielding portion is formed according to the intended pattern. When light irradiation is performed through a photomask, it is preferable to perform a development step after that. By performing the development process, a desired pattern can be formed in the coating film. The developing method is not particularly limited and can be carried out by any known method, specifically the same method as described in "Developing step" in "<Color filter manufacturing method>" below. be able to.

The above manufacturing method also includes a step of heating the light-irradiated coating film at 160° C. or lower. Since the above-mentioned manufacturing method uses the above-described photosensitive resin composition, the heating step (post-curing step) after light irradiation can be performed under relatively low-temperature conditions such as 160° C. or lower.
The heating temperature is preferably 155°C or lower, more preferably 150°C or lower. The lower limit of the heating temperature is preferably 70° C. or higher, more preferably 90° C. or higher in terms of maintaining curability.
The above-mentioned heating method other than temperature is not particularly limited and can be carried out by a known method, for example, by the same method as described in "Heating step" of "<Color filter manufacturing method>" described below. It can be carried out.

<Application>
The copolymer, copolymer solution, and photosensitive resin composition (curable resin composition) containing the same of the present invention allow the curing reaction to proceed sufficiently even under low-temperature curing conditions of 160°C or lower, for example, about 90°C. It is possible to provide a cured product with excellent solvent resistance. Therefore, it can be suitably used in applications that require sufficient curing at low temperatures and applications that require solvent resistance.

Specifically, the copolymer, copolymer solution, and photosensitive resin composition of the present invention can be used, for example, in liquid crystal, organic EL, quantum dot, micro LED liquid crystal display devices, solid-state image sensors, touch panel display devices, etc. Various optical components and electrical/electronic materials such as color filters, black matrices, photo spacers, black column spacers, inks, printing plates, printed wiring boards, semiconductor elements, photoresists, insulating films, films, and organic protective films used in It can be suitably used for constituent members of devices and the like. Among these, it is preferably used for color filter applications.
The photosensitive resin composition of the present invention is suitably used as an optical material, and is also suitably used as a negative type.

3. A color filter having a cured product of the above-mentioned photosensitive resin composition on a color filter substrate is also one of the preferred embodiments of the present invention.
In the above color filter, the cured product formed from the above photosensitive resin composition is particularly suitable for use as a black matrix and segments that require coloring such as red, green, blue, yellow, etc. pixels. However, it is also suitable as segments that do not necessarily require coloring, such as photo spacers, protective layers, and alignment control ribs.

Substrates used in the above color filters include, for example, glass substrates such as white glass, blue glass, alkali-strengthened glass, and silica-coated blue glass; ring-opening polymers of polyester, polycarbonate, polyolefin, polysulfone, and cyclic olefin, and their hydrogen Sheets, films, or substrates made of thermoplastic resins such as additives; 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; Members made of various materials such as glass substrates with 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. Further, it is preferable that the substrate is a transparent substrate.
Further, the substrate may be subjected to corona discharge treatment, ozone treatment, chemical treatment using a silane coupling agent, etc., as necessary.

<Production method of color filter>
In order to obtain the above color filter, for example, a step (also referred to as an arrangement step) of disposing the above-mentioned photosensitive resin composition on a substrate for each pixel of one color (that is, for each pixel of one color), and a step of disposing the photosensitive resin composition on the substrate. A step of irradiating the placed photosensitive resin composition 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.

(1) Placement process (preferably coating process)
The above arrangement step is preferably performed by coating. Examples of the method for applying the photosensitive resin composition onto the substrate include spin coating, slit coating, roll coating, and cast coating, and any of these methods can be preferably used.
In the above arrangement step, it is also preferable to apply the photosensitive resin composition onto the substrate and then dry the coating film. The coating film can be dried using, for example, a hot plate, an IR oven, a convection oven, or the like. The drying conditions are appropriately selected depending on the boiling point of the solvent component contained, the type of curing component, the film thickness, the performance of the dryer, etc., but it is usually carried out at a temperature of 50 to 160°C for 10 seconds to 300 seconds. suitable.

(2) Light irradiation step In the light irradiation step, examples of active light sources used include xenon lamps, halogen lamps, tungsten lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, metal halide lamps, medium-pressure mercury lamps, low-pressure mercury lamps, Lamp light sources such as carbon arc and fluorescent lamps, laser light sources such as argon ion lasers, YAG lasers, excimer lasers, nitrogen lasers, helium cadmium lasers, and semiconductor lasers are used. Further, as the method of the exposure machine, there are a proximity method, a mirror projection method, and a stepper method, and the proximity method is preferably used.
Note that in the active energy ray irradiation step, the active energy ray may be irradiated through a predetermined mask pattern depending on the application. In this case, the exposed area is cured, and the cured area is made insoluble or poorly soluble in the developer.

(3) Development process The development process is a process in which, after the light irradiation process described above, development is performed using a developer to remove unexposed areas and form a pattern. Thereby, a patterned cured film can be obtained. The development treatment can be carried out usually at a development temperature of 10 to 50° C. by methods such as immersion development, spray development, brush development, and ultrasonic development.

The developer used in the development step is not particularly limited as long as it dissolves the photosensitive resin composition, but organic solvents and alkaline aqueous solutions are usually used, and mixtures thereof may also be used. In addition, when using an alkaline aqueous solution as a developer, it is preferable to wash|clean with water after image development. Examples of the organic solvent and alkaline aqueous solution include those described in JP-A-2015-157909.

(4) Heating process The heating process is a process (also referred to as a "post-curing process") of further curing the exposed area (cured area) by baking after the above-described development process. Examples include a process of post-exposure at a light intensity of 0.5 to 5 J/cm ² using a light source such as a high-pressure mercury lamp, and a process of post-heating at a temperature of 60 to 200°C for 10 seconds to 120 minutes. It will be done. By performing such a post-curing step, it is possible to further increase the hardness and adhesion of the patterned cured film.
The above heating step is generally carried out at a temperature of about 200 to 260°C, but if the above photosensitive resin composition is used, it can be carried out at a relatively low temperature of 200°C or lower, preferably 160°C or lower. Sufficient curing can be achieved. Therefore, a product with excellent solvent resistance can be obtained without impairing the properties held by the substrate or cured product.

In the heating step, the heating temperature is preferably 160°C or lower, more preferably 155°C or lower, and even more preferably 150°C or lower. Moreover, the heating temperature is preferably 70°C or higher, more preferably 90°C or higher, and even more preferably 95°C or higher.

The heating time in the heating step is not particularly limited, but is preferably 5 to 60 minutes, for example. Further, the heating method is not particularly limited, but it can be performed using a heating device such as a hot plate, a convection oven, or a high-frequency heater.

The thickness of the cured film obtained by the heating step (ie, the cured coating film obtained by thermally curing the photosensitive resin composition) is preferably 0.1 to 20 μm. The film thickness is more preferably 0.5 to 15 μm, and even more preferably 1 to 10 μm.

4. Display device A display device including the above-mentioned color filter is also one of the preferred embodiments of the present invention.
A member for a display device and a display device having a cured product of the photosensitive resin composition described above are also included in the preferred embodiments of the present invention. The cured product (cured film) formed from the above photosensitive resin composition is stable, has excellent adhesion to substrates, etc., and has high hardness, high smoothness, and high transmittance. Therefore, it is particularly suitable as a transparent member, and is also useful as a protective film or an insulating film in various display devices.

As the display device, for example, a liquid crystal display device, a solid-state image sensor, a touch panel type display device, etc. are suitable.
In addition, when the above-mentioned cured product (cured film) is used as a member for a display device, the member may be a film-like single-layer or multi-layer member composed of the above-mentioned cured film, or the above-mentioned single-layer or multi-layer member. It may be a member in which another layer is combined with the above member, or it may be a member that includes the above-mentioned cured film in its structure.

As described above, the copolymer, copolymer solution, and photosensitive resin composition (curable resin composition) of the present invention give a cured product with excellent solvent resistance even under low temperature curing conditions. be able to. The copolymer, copolymer solution, and photosensitive resin composition of the present invention can be used for various optical members used in liquid crystal, organic EL, quantum dot, micro LED liquid crystal display devices, solid-state image sensors, touch panel display devices, etc. It can be suitably used in various applications such as electrical and electronic equipment, and as a structural member.

The present invention will be explained in more detail with reference to Examples below, but the present invention is not limited to these Examples. In addition, unless otherwise specified, "parts" shall mean "parts by mass" and "%" shall mean "% by mass."

In this example, various physical properties were measured by the following methods.
(1) Weight average molecular weight (Mw)
The weight average molecular weight was measured by GPC (gel permeation chromatography) using HLC-8220GPC (manufactured by Tosoh Corporation) and column: TSKgel SuperHZM-M (manufactured by Tosoh Corporation) using polystyrene as a standard substance and tetrahydrofuran as an eluent.

(2) About 1 g of the solid content copolymer solution was weighed into an aluminum cup, and about 3 g of acetone was added to dissolve it, followed by air drying at room temperature. Then, it was dried under vacuum at 140° C. for 1.5 hours using a hot air dryer (trade name: PHH-101, manufactured by ESPEC), and then allowed to cool in a desiccator, and its mass was measured. The solid content (mass %) of the polymer solution was calculated from the amount of mass loss.

(3) 3 g of the acid value copolymer solution was accurately weighed, dissolved in a mixed solvent of 90 g of acetone and 10 g of water, and titrated using a 0.1N KOH aqueous solution as a titrant. The titration was performed using an automatic titration device (trade name: COM-555, manufactured by Hiranuma Sangyo Co., Ltd.), and the acid value per 1 g of solid content (mgKOH/g) was determined from the acid value of the solution and the solid content of the solution.

(4) Epoxy equivalent (g/equivalent)
It was determined by dividing the mass (g) of the copolymer solid content by the number of moles (mol) of epoxy groups contained in the copolymer.

(5) Double bond equivalent (g/equivalent)
It was determined by dividing the mass (g) of the solid content of the copolymer by the amount of double bonds (mol) of the copolymer.

(6) The solvent-resistant photosensitive resin composition was spin-coated onto a 5 cm square glass substrate, dried at 100°C for 3 minutes, exposed to light at 200 mJ using a high-pressure mercury lamp, and exposed at 90°C or 110°C. Heat treatment (post-curing) was performed for 40 minutes for each to obtain a cured film with a thickness of 2 μm. Then, the cured film was immersed in 20 g of 1-methyl-2-pyrrolidone (NMP) at 40°C for 10 minutes and then taken out. The absorbance was measured using a commercially available product (manufactured by J.D. Co., Ltd.) and evaluated based on the following criteria. The larger the absorbance value, the more the coloring material eluted into the immersion liquid, and the lower the solvent resistance of the photosensitive resin composition is evaluated.
(Evaluation criteria)
◎: Absorbance value is less than 0.2 〇: Absorbance value is 0.2 or more and less than 0.3 △: Absorbance value is 0.3 or more and less than 0.4 ×: Absorbance value is 0.4 or more XX : Film peeling

(7) Solvent resistance (Examples 20 to 23)
The photosensitive resin composition was spin-coated onto a 5 cm square glass substrate, dried at 90°C for 2 minutes, exposed to light at 100 mJ using a high-pressure mercury lamp, and heat-treated (post-cured) at 90°C for 30 minutes to form a film. A cured film with a thickness of 2 μm was obtained. Then, the cured film was immersed in 20 g of the dipping solvent listed in Table 5 at 30°C for 5 minutes, and then taken out. After taking out the cured film, the absorbance of the dipping solvent was measured using a spectrophotometer UV3100 (manufactured by Shimadzu Corporation). did.

(8) Viscosity The viscosity of the copolymer solution was measured at 25° C. using a viscometer (VISCOMETER TV-22, manufactured by Toki Sangyo Co., Ltd.).

(9) Remaining film rate The residual film rate was calculated by measuring the weight of the film before and after the evaluation of solvent resistance in (7) above. Specifically, the film weight before solvent resistance evaluation was calculated by taring the glass substrate. Thereafter, the remaining film rate was calculated by dividing the film weight after solvent resistance evaluation by the film weight before evaluation.

(Manufacturing example 1)
Preparation of copolymer solution A-1 (SAH adduct solution of HEMA-GMA copolymer) Propylene glycol monomethyl ether acetate was placed in a reaction tank equipped with a thermometer, a stirrer, a gas introduction pipe, a cooling pipe, and a dropping tank inlet. After charging 185.3 parts and purging with nitrogen, the temperature was raised to 90°C. On the other hand, as the dropping tank (A), 30.0 parts of 2-hydroxyethyl methacrylate, 70.0 parts of glycidyl methacrylate, 30 parts of propylene glycol monomethyl ether acetate, and t-butylperoxy-2-ethylhexanoate were placed in a beaker. Prepare a stirred mixture of 2.0 parts of "Perbutyl (registered trademark) O" manufactured by NOF Corporation, and add 2.0 parts of n-dodecyl mercaptan and 18.0 parts of propylene glycol monomethyl ether acetate to the dropping tank (B). A mixture of 0 parts was prepared by stirring and mixing. After the temperature of the reaction tank reached 90°C, while maintaining the same temperature, dropping was started from the dropping tank over 3 hours to carry out polymerization. After the dropwise addition was completed, the temperature was maintained at 90°C for 30 minutes, and then the temperature was raised to 115°C, and ripening was performed for 90 minutes. Thereafter, after cooling to room temperature, 11.5 parts of succinic anhydride, 0.33 parts of triethylamine as a catalyst, 189 parts of dimethyl carbonate, and 29.6 parts of propylene glycol monomethyl ether acetate were charged and reacted at 40°C for 10 hours. A polymer solution A-1 was obtained. Table 1 shows various physical properties of the obtained copolymer.

(Manufacturing example 2)
Preparation of copolymer solution A-2 (solution of SAH adduct of BzMI-CHMA-HEMA-GMA copolymer) Propylene was added to a reaction tank equipped with a thermometer, a stirrer, a gas introduction pipe, a cooling pipe, and a dropping tank inlet. After charging 172.0 parts of glycol monomethyl ether acetate and purging with nitrogen, the temperature was raised to 90°C. On the other hand, as the dropping tank (A), 10.0 parts of N-benzylmaleimide, 43.6 parts of cyclohexyl methacrylate, 30.0 parts of 2-hydroxyethyl methacrylate, 16.4 parts of glycidyl methacrylate, and propylene glycol monomethyl were placed in a beaker. Prepare a stirred mixture of 30 parts of ether acetate and 2.0 parts of t-butyl peroxy-2-ethylhexanoate ("Perbutyl (registered trademark) O" manufactured by NOF Corporation), and add it to the dropping tank (B). , 2.0 parts of n-dodecyl mercaptan, and 31.33 parts of propylene glycol monomethyl ether acetate were mixed with stirring. After the temperature of the reaction tank reached 90°C, while maintaining the same temperature, dropping was started from the dropping tank over 3 hours to perform polymerization. After the dropwise addition was completed, the temperature was maintained at 90°C for 30 minutes, and then the temperature was raised to 115°C, and ripening was performed for 90 minutes. Thereafter, after cooling to room temperature, 11.5 parts of succinic anhydride, 0.33 parts of triethylamine as a catalyst, and 29.0 parts of propylene glycol monomethyl ether acetate were reacted at 60°C for 10 hours to form copolymer solution A-2. Obtained. Table 1 shows various physical properties of the obtained copolymer.

(Manufacturing example 3)
Preparation of copolymer solution A-3 (solution of SAH adduct of BzMI-VT-HEMA-GMA copolymer) Propylene was added to a reaction tank equipped with a thermometer, a stirrer, a gas inlet pipe, a cooling pipe, and a dropping tank inlet. After charging 172.0 parts of glycol monomethyl ether acetate and purging with nitrogen, the temperature was raised to 90°C. On the other hand, as the dropping tank (A), 10.0 parts of N-benzylmaleimide, 43.6 parts of vinyltoluene, 30.0 parts of 2-hydroxyethyl methacrylate, 16.4 parts of glycidyl methacrylate, and propylene glycol monomethyl ether were placed in a beaker. Prepare a stirred mixture of 30 parts of acetate and 2.0 parts of t-butyl peroxy-2-ethylhexanoate ("Perbutyl (registered trademark) O" manufactured by NOF Corporation), and put it in a dropping tank (B). A mixture of 2.0 parts of n-dodecyl mercaptan and 31.33 parts of propylene glycol monomethyl ether acetate with stirring was prepared. After the temperature of the reaction tank reached 90°C, while maintaining the same temperature, dropping was started from the dropping tank over 3 hours to carry out polymerization. After the dropwise addition was completed, the temperature was maintained at 90° C. for 30 minutes, and then the temperature was raised to 115° C. and aged for 90 minutes. Thereafter, after cooling to room temperature, 11.5 parts of succinic anhydride, 0.33 parts of triethylamine as a catalyst, and 29.0 parts of propylene glycol monomethyl ether acetate were reacted at 60°C for 10 hours to form copolymer solution A-3. Obtained. Table 1 shows various physical properties of the obtained copolymer.

(Manufacturing example 4)
Preparation of copolymer solution A-4 (solution of SAH adduct of BzMI-2EHA-HEMA-GMA copolymer) Propylene was added to a reaction tank equipped with a thermometer, a stirrer, a gas introduction pipe, a cooling pipe, and a dropping tank inlet. After charging 172.0 parts of glycol monomethyl ether acetate and purging with nitrogen, the temperature was raised to 90°C. On the other hand, as the dropping tank (A), 10.0 parts of N-benzylmaleimide, 43.6 parts of 2-ethylhexyl acrylate, 30.0 parts of 2-hydroxyethyl methacrylate, 16.4 parts of glycidyl methacrylate, and propylene glycol were placed in a beaker. Prepare a stirred mixture of 30 parts of monomethyl ether acetate and 2.0 parts of t-butyl peroxy-2-ethylhexanoate ("Perbutyl (registered trademark) O" manufactured by NOF Corporation), and place it in the dropping tank (B). A mixture of 2.0 parts of n-dodecyl mercaptan and 31.33 parts of propylene glycol monomethyl ether acetate was prepared by stirring. After the temperature of the reaction tank reached 90°C, while maintaining the same temperature, dropping was started from the dropping tank over 3 hours to perform polymerization. After the dropwise addition was completed, the temperature was maintained at 90°C for 30 minutes, and then the temperature was raised to 115°C, and ripening was performed for 90 minutes. Thereafter, after cooling to room temperature, 11.5 parts of succinic anhydride, 0.33 parts of triethylamine as a catalyst, and 29.0 parts of propylene glycol monomethyl ether acetate were reacted at 60°C for 10 hours to form copolymer solution A-4. Obtained. Table 1 shows various physical properties of the obtained copolymer.

(Manufacturing example 5)
Preparation of copolymer solution A-5 (solution of SAH adduct of BzMI-CHMA-HEAA-GMA copolymer) Diethylene glycol After charging 85.6 parts of ethyl methyl ether and purging with nitrogen, the mixture was heated to 90°C. On the other hand, as the dropping tank (A), 10.0 parts of N-benzylmaleimide, 46.65 parts of cyclohexyl methacrylate, 26.8 parts of N-hydroxyethylacrylamide, 16.55 parts of glycidyl methacrylate, and diethylene glycol ethyl methyl ether were placed in a beaker. Prepare a mixture of 49.8 parts of t-butyl peroxy-2-ethylhexanoate ("Perbutyl (registered trademark) O" manufactured by NOF Corporation) by stirring, and add it to the dropping tank (B). , 2.0 parts of n-dodecyl mercaptan, and 98.0 parts of diethylene glycol ethyl methyl ether were mixed with stirring. After the temperature of the reaction tank reached 90°C, while maintaining the same temperature, dropping was started from the dropping tank over 3 hours to perform polymerization. After the dropwise addition was completed, the temperature was maintained at 90°C for 30 minutes, and then the temperature was raised to 115°C, and ripening was performed for 90 minutes. Thereafter, after cooling to room temperature, 13.0 parts of succinic anhydride and 32.5 parts of diethylene glycol ethyl methyl ether were reacted at 60° C. for 10 hours to obtain copolymer solution A-5. Table 1 shows various physical properties of the obtained copolymer.

(Manufacturing example 6)
Preparation of copolymer solution A-6 (SAH adduct solution of BzMI-CHMA-GLMA-GMA copolymer) Propylene was added to a reaction tank equipped with a thermometer, a stirrer, a gas introduction pipe, a cooling pipe, and a dropping tank inlet. 50.1 parts of glycol monomethyl ether acetate and 50.1 parts of diethylene glycol ethyl methyl ether were charged, the atmosphere was purged with nitrogen, and then the temperature was raised to 90°C. On the other hand, as the dropping tank (A), 10.0 parts of N-benzylmaleimide, 46.65 parts of cyclohexyl methacrylate, 30.0 parts of glycerin monomethacrylate ("Blenmar GL" manufactured by NOF Corporation), and 13 parts of glycidyl methacrylate were placed in a beaker. .35 parts, propylene glycol monomethyl ether acetate 24.1 parts, diethylene glycol ethyl methyl ether 24.1 parts, t-butyl peroxy-2-ethylhexanoate ("Perbutyl (registered trademark) O" manufactured by NOF Corporation) 2 0 parts were prepared by stirring and mixing, and 2.0 parts of n-dodecyl mercaptan, 42.5 parts of propylene glycol monomethyl ether acetate, and 42.5 parts of diethylene glycol ethyl methyl ether were stirred and mixed in the dropping tank (B). I prepared things. After the temperature of the reaction tank reached 90°C, while maintaining the same temperature, dropping was started from the dropping tank over 3 hours to perform polymerization. After the dropwise addition was completed, the temperature was maintained at 90°C for 30 minutes, and then the temperature was raised to 115°C, and ripening was performed for 90 minutes. Thereafter, after cooling to room temperature, 9.4 parts of succinic anhydride, 12.0 parts of propylene glycol monomethyl ether acetate, and 12.0 parts of diethylene glycol ethyl methyl ether were reacted at 60°C for 10 hours to form copolymer solution A-6. Obtained. Table 1 shows various physical properties of the obtained copolymer.

(Manufacturing example 7)
Preparation of copolymer solution A-7 (SAH adduct solution of BzMI-CHMA-HEMA-GMA-NIPAM copolymer) In a reaction tank equipped with a thermometer, a stirrer, a gas inlet pipe, a cooling pipe, and a dropping tank inlet. , 30.9 parts of propylene glycol monomethyl ether acetate were charged, the atmosphere was replaced with nitrogen, and then the temperature was raised to 90°C. On the other hand, as the dropping tank (A), 10.0 parts of N-benzylmaleimide, 23.6 parts of cyclohexyl methacrylate, 30.0 parts of 2-hydroxyethyl methacrylate, 16.4 parts of glycidyl methacrylate, and N-isopropyl were placed in a beaker. 20.0 parts of acrylamide, 10.0 parts of propylene glycol monomethyl ether acetate, and 2.0 parts of t-butyl peroxy-2-ethylhexanoate ("Perbutyl (registered trademark) O" manufactured by NOF Corporation) were mixed with stirring. 4.0 parts of n-dodecyl mercaptan and 67.4 parts of propylene glycol monomethyl ether acetate were mixed with stirring in a dropping tank (B). After the temperature of the reaction tank reached 90°C, while maintaining the same temperature, dropping was started from the dropping tank over 3 hours to perform polymerization. After the dropwise addition was completed, the temperature was maintained at 90°C for 30 minutes, and then the temperature was raised to 115°C, and ripening was performed for 90 minutes. Thereafter, after cooling to room temperature, 11.5 parts of succinic anhydride and 4.7 parts of propylene glycol monomethyl ether acetate were reacted at 60° C. for 10 hours to obtain copolymer solution A-7. Table 1 shows various physical properties of the obtained copolymer.

(Manufacturing example 8)
Preparation of copolymer solution A-8 (solution of SAH adduct of MAA adduct of BzMI-CHMA-HEMA-GMA copolymer) Reaction equipped with a thermometer, a stirrer, a gas introduction pipe, a cooling pipe and a dropping tank inlet A tank was charged with 64.0 parts of propylene glycol monomethyl ether acetate, the tank was purged with nitrogen, and then heated to 90°C. On the other hand, as the dropping tank (A), 10.0 parts of N-benzylmaleimide, 19.0 parts of cyclohexyl methacrylate, 30.0 parts of 2-hydroxyethyl methacrylate, 41.0 parts of glycidyl methacrylate, and propylene glycol monomethyl were placed in a beaker. Prepare a stirring mixture of 10.0 parts of ether acetate and 2.0 parts of t-butyl peroxy-2-ethylhexanoate ("Perbutyl (registered trademark) O" manufactured by NOF Corporation), and place it in a dropping tank (B ), 4.0 parts of n-dodecyl mercaptan, and 54.82 parts of propylene glycol monomethyl ether acetate were mixed with stirring. After the temperature of the reaction tank reached 90°C, while maintaining the same temperature, dropping was started from the dropping tank over 3 hours to perform polymerization. After the dropwise addition was completed, the temperature was maintained at 90°C for 30 minutes, and then the temperature was raised to 115°C, and ripening was performed for 90 minutes. Thereafter, after cooling to room temperature, 13.5 parts of methacrylic acid, 0.34 part of triphenylphosphine as a catalyst, and 0.17 part of Antige W-400 were reacted at 85° C. for 12 hours. Thereafter, after cooling to room temperature, 13.1 parts of succinic anhydride was reacted at 60° C. for 5 hours to obtain copolymer solution A-8. Table 1 shows various physical properties of the obtained copolymer.

(Production example 9)
Preparation of copolymer solution A-9 (SAH adduct solution of Karenz MOI adduct of BzMI-CHMA-HEMA-GMA copolymer) Equipped with a thermometer, a stirrer, a gas introduction pipe, a cooling pipe and a dropping tank inlet. A reaction tank was charged with 208.7 parts of propylene glycol monomethyl ether acetate, purged with nitrogen, and heated to 90°C. On the other hand, as the dropping tank (A), 10.0 parts of N-benzylmaleimide, 14.3 parts of cyclohexyl methacrylate, 55.0 parts of 2-hydroxyethyl methacrylate, 20.7 parts of glycidyl methacrylate, and propylene glycol monomethyl were placed in a beaker. Prepare a stirring mixture of 10.0 parts of ether acetate and 2.0 parts of t-butyl peroxy-2-ethylhexanoate ("Perbutyl (registered trademark) O" manufactured by NOF Corporation), and place it in a dropping tank (B ), 2.0 parts of n-dodecyl mercaptan, and 98.00 parts of propylene glycol monomethyl ether acetate were mixed with stirring. After the temperature of the reaction tank reached 90°C, while maintaining the same temperature, dropping was started from the dropping tank over 3 hours to perform polymerization. After the dropwise addition was completed, the temperature was maintained at 90°C for 30 minutes, and then the temperature was raised to 115°C, and ripening was performed for 90 minutes. Thereafter, after cooling to room temperature, 26.2 parts of 2-isocyanatoethyl methacrylate ("Karens MOI (registered trademark)" manufactured by Showa Denko), 0.13 parts of triethylamine, and 0.19 parts of Antige W-400 were added. , 90°C for 4 hours. Thereafter, after cooling to room temperature, 14.7 parts of succinic anhydride and 0.28 parts of triethylamine as a catalyst were reacted at 60°C for 7 hours, and further 69 parts of propylene glycol monomethyl ether were added and reacted at 60°C for 1 hour. The remaining succinic anhydride was eliminated to obtain copolymer solution A-9. Table 1 shows various physical properties of the obtained copolymer.

(Manufacturing example 10)
Preparation of copolymer solution A-10 (SAH adduct solution of AMA-TBMA-HEMA-GMA copolymer) Propylene was added to a reaction tank equipped with a thermometer, a stirrer, a gas inlet pipe, a cooling pipe, and a dropping tank inlet. After charging 172 parts of glycol monomethyl ether acetate and purging with nitrogen, the temperature was raised to 90°C. On the other hand, as the dropping tank (A), 10.0 parts of methyl α-(allyloxymethyl)acrylate, 43.6 parts of tert-butyl methacrylate, 30.0 parts of 2-hydroxyethyl methacrylate, and glycidyl methacrylate were placed in a beaker. 16.4 parts of propylene glycol monomethyl ether acetate, 30.0 parts of propylene glycol monomethyl ether acetate, and 2.0 parts of t-butyl peroxy-2-ethylhexanoate ("Perbutyl (registered trademark) O" manufactured by NOF Corporation) were mixed with stirring. 2.0 parts of n-dodecyl mercaptan and 31.3 parts of propylene glycol monomethyl ether acetate were stirred and mixed in a dropping tank (B). After the temperature of the reaction tank reached 90°C, while maintaining the same temperature, dropping was started from the dropping tank over 3 hours to perform polymerization. After the dropwise addition was completed, the temperature was maintained at 90°C for 30 minutes, and then the temperature was raised to 115°C, and ripening was performed for 90 minutes. Thereafter, after cooling to room temperature, 11.5 parts of succinic anhydride, 0.33 parts of triethylamine as a catalyst, and 29.04 parts of propylene glycol monomethyl ether acetate were reacted at 60°C for 10 hours to obtain copolymer solution A-10. Ta. Table 1 shows various physical properties of the obtained copolymer.

(Production example 11)
Preparation of copolymer solution A-11 (solution of SAH adduct of AA adduct of MD-CHMA-HEMA-GMA copolymer) Reaction equipped with a thermometer, stirrer, gas inlet tube, cooling tube and dropping tank inlet A tank was charged with 86.5 parts of propylene glycol monomethyl ether acetate, the tank was purged with nitrogen, and then heated to 90°C. On the other hand, as the dropping tank (A), 10.0 parts of dimethyl-2,2'-[oxybis(methylene)]bis-2-propenoate, 43.6 parts of cyclohexyl methacrylate, and 30.0 parts of 2-hydroxyethyl methacrylate were placed in a beaker. 0 parts, glycidyl methacrylate 16.4 parts, propylene glycol monomethyl ether acetate 48.8 parts, t-butyl peroxy-2-ethylhexanoate ("Perbutyl (registered trademark) O" manufactured by NOF Corporation) 2.0 parts A mixture of 2.0 parts of n-dodecyl mercaptan and 98 parts of propylene glycol monomethyl ether acetate was prepared in a dropping tank (B). After the temperature of the reaction tank reached 90°C, while maintaining the same temperature, dropping was started from the dropping tank over 3 hours to perform polymerization. After the dropwise addition was completed, the temperature was maintained at 90°C for 30 minutes, and then the temperature was raised to 115°C, and ripening was performed for 90 minutes. Thereafter, after cooling to room temperature, 5.0 parts of acrylic acid, 0.32 parts of triethylamine as a catalyst, 0.16 parts of Antige W-400, and 20 parts of propylene glycol monomethyl ether acetate were reacted at 115° C. for 7 hours. Thereafter, after cooling to room temperature, 12.6 parts of succinic anhydride and 20 parts of propylene glycol monomethyl ether acetate were reacted at 60° C. for 10 hours to obtain copolymer solution A-11. Table 1 shows various physical properties of the obtained copolymer.

(Production example 12)
Preparation of Copolymer Solution A-12 (SAH adduct solution of CHMI-CHMA-HEMA-GMA copolymer) Propylene was added to a reaction tank equipped with a thermometer, a stirrer, a gas inlet pipe, a cooling pipe, and a dropping tank inlet. After charging 172 parts of glycol monomethyl ether acetate and purging with nitrogen, the temperature was raised to 90°C. On the other hand, as the dropping tank (A), 10.0 parts of N-cyclohexylmaleimide, 43.6 parts of cyclohexyl methacrylate, 30.0 parts of 2-hydroxyethyl methacrylate, 16.4 parts of glycidyl methacrylate, and propylene glycol monomethyl were placed in a beaker. Prepare a stirring mixture of 30.0 parts of ether acetate and 2.0 parts of t-butyl peroxy-2-ethylhexanoate ("Perbutyl (registered trademark) O" manufactured by NOF Corporation), and place it in a dropping tank (B ), 2.0 parts of n-dodecyl mercaptan, and 31.3 parts of propylene glycol monomethyl ether acetate were mixed with stirring. After the temperature of the reaction tank reached 90°C, while maintaining the same temperature, dropping was started from the dropping tank over 3 hours to perform polymerization. After the dropwise addition was completed, the temperature was maintained at 90°C for 30 minutes, and then the temperature was raised to 115°C, and ripening was performed for 90 minutes. Thereafter, after cooling to room temperature, 11.5 parts of succinic anhydride, 0.33 parts of triethylamine as a catalyst, and 29.0 parts of propylene glycol monomethyl ether acetate were reacted at 60°C for 10 hours to obtain copolymer solution A-12. Ta. Table 1 shows various physical properties of the obtained copolymer.

(Manufacturing example 13)
Preparation of copolymer solution A-13 (solution of SAH adduct of BzMI-DCPMA-HEMA-GMA copolymer) Propylene was added to a reaction tank equipped with a thermometer, a stirrer, a gas introduction pipe, a cooling pipe, and a dropping tank inlet. After charging 53.4 parts of glycol monomethyl ether acetate and purging with nitrogen, the mixture was heated to 90°C. On the other hand, as the dropping tank (A), 5.0 parts of N-benzylmaleimide, 25.0 parts of dicyclopentanyl methacrylate, 40.0 parts of 2-hydroxyethyl methacrylate, 30.0 parts of glycidyl methacrylate, Prepare a stirred mixture of 10 parts of propylene glycol monomethyl ether acetate and 2.0 parts of t-butyl peroxy-2-ethylhexanoate ("Perbutyl (registered trademark) O" manufactured by NOF Corporation), and add it to a dropping tank ( B) was prepared by stirring and mixing 6.0 parts of n-dodecyl mercaptan and 54.0 parts of propylene glycol monomethyl ether acetate. After the temperature of the reaction tank reached 90°C, while maintaining the same temperature, dropping was started from the dropping tank over 3 hours to perform polymerization. After the dropwise addition was completed, the temperature was maintained at 90°C for 30 minutes, and then the temperature was raised to 115°C, and ripening was performed for 90 minutes. Thereafter, after cooling to room temperature, 23.1 parts of succinic anhydride and 9.13 parts of propylene glycol monomethyl ether acetate were reacted at 60° C. for 12 hours, followed by dilution with 172 parts of propylene glycol monomethyl ether. A copolymer solution A-13 was obtained. Table 1 shows various physical properties of the obtained copolymer.

(Manufacturing example 14)
Preparation of copolymer solution A-14 (solution of SAH adduct of BzMI-CHMA-HEMA-GMA copolymer) Propylene was added to a reaction tank equipped with a thermometer, a stirrer, a gas introduction pipe, a cooling pipe, and a dropping tank inlet. After charging 165.3 parts of glycol monomethyl ether acetate and purging with nitrogen, the temperature was raised to 90°C. On the other hand, as the dropping tank (A), 10.0 parts of N-benzylmaleimide, 27.5 parts of cyclohexyl methacrylate, 30.0 parts of 2-hydroxyethyl methacrylate, 32.5 parts of glycidyl methacrylate, and propylene glycol monomethyl were placed in a beaker. Prepare a stirred mixture of 30 parts of ether acetate and 2.0 parts of t-butyl peroxy-2-ethylhexanoate ("Perbutyl (registered trademark) O" manufactured by NOF Corporation), and add it to the dropping tank (B). , 2.0 parts of n-dodecyl mercaptan, and 38.0 parts of propylene glycol monomethyl ether acetate were mixed with stirring. After the temperature of the reaction tank reached 90°C, while maintaining the same temperature, dropping was started from the dropping tank over 3 hours to perform polymerization. After the dropwise addition was completed, the temperature was maintained at 90°C for 30 minutes, and then the temperature was raised to 115°C, and ripening was performed for 90 minutes. Thereafter, after cooling to room temperature, 11.5 parts of succinic anhydride, 0.33 parts of triethylamine as a catalyst, 29.0 parts of propylene glycol monomethyl ether acetate, and 76 parts of propylene glycol monomethyl ether were reacted at 60°C for 10 hours. dilution was performed. A copolymer solution A-14 was obtained. Table 1 shows various physical properties of the obtained copolymer.

(Production example 15)
Preparation of copolymer solution A-15 (solution of SAH adduct of BzMI-2EHA-HEMA-GMA copolymer) Propylene was added to a reaction tank equipped with a thermometer, a stirrer, a gas introduction pipe, a cooling pipe, and a dropping tank inlet. After charging 172.0 parts of glycol monomethyl ether acetate and purging with nitrogen, the temperature was raised to 90°C. On the other hand, as the dropping tank (A), 10.0 parts of N-benzylmaleimide, 29.0 parts of 2-ethylhexyl acrylate, 30.0 parts of 2-hydroxyethyl methacrylate, 31.0 parts of glycidyl methacrylate, and propylene glycol were placed in a beaker. Prepare a stirred mixture of 30 parts of monomethyl ether acetate and 2.0 parts of t-butyl peroxy-2-ethylhexanoate ("Perbutyl (registered trademark) O" manufactured by NOF Corporation), and place it in the dropping tank (B). A mixture of 2.0 parts of n-dodecyl mercaptan and 31.33 parts of propylene glycol monomethyl ether acetate was prepared by stirring. After the temperature of the reaction tank reached 90°C, while maintaining the same temperature, dropping was started from the dropping tank over 3 hours to perform polymerization. After the dropwise addition was completed, the temperature was maintained at 90°C for 30 minutes, and then the temperature was raised to 115°C, and ripening was performed for 90 minutes. Thereafter, after cooling to room temperature, 6.2 parts of succinic anhydride, 0.33 parts of triethylamine as a catalyst, 16.5 parts of propylene glycol monomethyl ether acetate, and 16.5 parts of propylene glycol monomethyl ether acetate were reacted at 60°C for 10 hours, followed by 40 parts of propylene glycol monomethyl ether. Copolymer solution A-15 was obtained. Table 1 shows various physical properties of the obtained copolymer.

(Production example 16)
Preparation of copolymer solution A-16 (solution of SAH adduct of BzMI-CHMA-HEMA-GMA copolymer) Propylene was added to a reaction tank equipped with a thermometer, a stirrer, a gas introduction pipe, a cooling pipe, and a dropping tank inlet. After charging 83.6 parts of glycol monomethyl ether acetate and purging with nitrogen, the temperature was raised to 90°C. On the other hand, as the dropping tank (A), 20.0 parts of N-benzylmaleimide, 25.0 parts of cyclohexyl methacrylate, 50.0 parts of 2-hydroxyethyl methacrylate, 5.0 parts of glycidyl methacrylate, and propylene glycol monomethyl were placed in a beaker. Prepare a stirred mixture of 50 parts of ether acetate and 2.0 parts of t-butyl peroxy-2-ethylhexanoate ("Perbutyl (registered trademark) O" manufactured by NOF Corporation), and add it to the dropping tank (B). , 0.3 parts of n-dodecyl mercaptan, and 99.70 parts of propylene glycol monomethyl ether acetate were mixed with stirring. After the temperature of the reaction tank reached 90°C, while maintaining the same temperature, dropping was started from the dropping tank over 3 hours to perform polymerization. After the dropwise addition was completed, the temperature was maintained at 90°C for 30 minutes, and then the temperature was raised to 115°C, and ripening was performed for 90 minutes. Thereafter, after cooling to room temperature, 34.6 parts of succinic anhydride, 0.40 parts of triethylamine as a catalyst, and 78.9 parts of propylene glycol monomethyl ether acetate were reacted at 60°C for 10 hours to form copolymer solution A-16. Obtained. Table 1 shows various physical properties of the obtained copolymer.

(Manufacturing example 17)
Preparation of copolymer solution A-17 (SAH adduct solution of AA adduct of BzMI-CHMA-HEMA-GMA copolymer) Reaction equipped with a thermometer, stirrer, gas inlet pipe, cooling pipe and dropping tank inlet A tank was charged with 16.6 parts of propylene glycol monomethyl ether acetate, the tank was purged with nitrogen, and then heated to 90°C. On the other hand, as the dropping tank (A), 30.0 parts of N-benzylmaleimide, 10.0 parts of cyclohexyl methacrylate, 10.0 parts of 2-hydroxyethyl methacrylate, 50.0 parts of glycidyl methacrylate, and propylene glycol monomethyl were placed in a beaker. Prepare a stirring mixture of 30.0 parts of ether acetate and 2.0 parts of t-butyl peroxy-2-ethylhexanoate ("Perbutyl (registered trademark) O" manufactured by NOF Corporation), and place it in a dropping tank (B ), 6.0 parts of n-dodecyl mercaptan, and 82.24 parts of propylene glycol monomethyl ether acetate were mixed with stirring. After the temperature of the reaction tank reached 90°C, while maintaining the same temperature, dropping was started from the dropping tank over 3 hours to perform polymerization. After the dropwise addition was completed, the temperature was maintained at 90°C for 30 minutes, and then the temperature was raised to 115°C, and ripening was performed for 90 minutes. Thereafter, after cooling to room temperature, 22.8 parts of acrylic acid, 0.37 parts of triphenylphosphine as a catalyst, and 0.18 parts of Antige W-400 were reacted at 85° C. for 12 hours. Thereafter, after cooling to room temperature, 4.6 parts of succinic anhydride was reacted at 60° C. for 8 hours, and then diluted with 118 parts of propylene glycol monomethyl ether to obtain copolymer solution A-17. Table 1 shows various physical properties of the obtained copolymer.

(Production example 18)
Preparation of copolymer solution A-18 (SAH adduct solution of Karenz MOI adduct of BzMI-CHMA-HEMA-GMA copolymer) Equipped with a thermometer, a stirrer, a gas introduction pipe, a cooling pipe and a dropping tank inlet. A reaction tank was charged with 78.6 parts of propylene glycol monomethyl ether acetate, purged with nitrogen, and heated to 90°C. On the other hand, as the dropping tank (A), 10.0 parts of N-benzylmaleimide, 29.3 parts of cyclohexyl methacrylate, 40.0 parts of 2-hydroxyethyl methacrylate, 20.7 parts of glycidyl methacrylate, and propylene glycol monomethyl were placed in a beaker. Prepare a stirring mixture of 10.0 parts of ether acetate and 6.0 parts of t-butyl peroxy-2-ethylhexanoate ("Perbutyl (registered trademark) O" manufactured by NOF Corporation), and place it in a dropping tank (B ), 2.0 parts of n-dodecyl mercaptan, and 48.00 parts of propylene glycol monomethyl ether acetate were mixed with stirring. After the temperature of the reaction tank reached 90°C, while maintaining the same temperature, dropping was started from the dropping tank over 3 hours to perform polymerization. After the dropwise addition was completed, the temperature was maintained at 90°C for 30 minutes, and then the temperature was raised to 115°C, and ripening was performed for 90 minutes. Thereafter, after cooling to room temperature, 4.8 parts of 2-isocyanatoethyl methacrylate ("Karens MOI (registered trademark)" manufactured by Showa Denko) and 0.16 parts of Antige W-400 were reacted at 90° C. for 8 hours. Thereafter, after cooling to room temperature, 14.6 parts of succinic anhydride and 0.36 parts of triethylamine as a catalyst were reacted at 60° C. for 10 hours to obtain copolymer solution A-18. Table 1 shows various physical properties of the obtained copolymer.

(Manufacturing example 19)
Preparation of copolymer solution B-1 (BzMI-CHMA-HEMA-Cyclomer M100-MAA copolymer) Propylene glycol was added to a reaction tank equipped with a thermometer, a stirrer, a gas introduction pipe, a cooling pipe, and a dropping tank inlet. After charging 145.3 parts of monomethyl ether acetate and purging with nitrogen, the mixture was heated to 90°C. On the other hand, as the dropping tank (A), 10.0 parts of N-benzylmaleimide, 47.4 parts of cyclohexyl methacrylate, 13.45 parts of 2-hydroxyethyl methacrylate, and 3,4-epoxycyclohexylmethyl methacrylate (Daicel) were placed in a beaker. 20.25 parts of ``Cyclomer M100 (registered trademark)''), 8.9 parts of methacrylic acid, 10.0 parts of propylene glycol monomethyl ether acetate, t-butyl peroxypivalate (``Luperox 11'' manufactured by Arkema Yoshitomi). A mixture of 2.7 parts of n-dodecyl mercaptan and 78 parts of propylene glycol monomethyl ether acetate was prepared in a dropping tank (B). . After the temperature of the reaction tank reached 70°C, while maintaining the same temperature, dropping was started from the dropping tank over 3 hours to carry out polymerization. After the dropwise addition was completed, the temperature was maintained at 70°C for 30 minutes, and then the temperature was raised to 80°C and aged for 180 minutes to obtain copolymer solution B-1. Table 1 shows various physical properties of the obtained copolymer.

(Production example 20)
Preparation of copolymer solution B-2 (BzMI-CHMA-HEMA-GMA-MAA copolymer) Propylene glycol monomethyl ether was placed in a reaction tank equipped with a thermometer, a stirrer, a gas introduction pipe, a cooling pipe, and a dropping tank inlet. After charging 145.3 parts of acetate and purging with nitrogen, the temperature was raised to 70°C. On the other hand, as the dropping tank (A), 10.0 parts of N-benzylmaleimide, 52.95 parts of cyclohexyl methacrylate, 13.45 parts of 2-hydroxyethyl methacrylate, 14.7 parts of glycidyl methacrylate, and methacrylic acid were placed in a beaker. A mixture of 8.9 parts of propylene glycol monomethyl ether acetate, 10.0 parts of propylene glycol monomethyl ether acetate, and 2.7 parts of t-butyl peroxypivalate ("Luperox 11 (registered trademark)" manufactured by Arkema Yoshitomi) was prepared and added dropwise. A mixture of 2.0 parts of n-dodecyl mercaptan and 78 parts of propylene glycol monomethyl ether acetate with stirring was prepared in tank (B). After the temperature of the reaction tank reached 70°C, while maintaining the same temperature, dropping was started from the dropping tank over 3 hours to carry out polymerization. After the dropwise addition was completed, the temperature was maintained at 70°C for 30 minutes, and then the temperature was raised to 80°C and aged for 180 minutes to obtain copolymer solution B-2. Table 1 shows various physical properties of the obtained copolymer.

Note that the descriptions in Table 1 are as follows.
BzMI: N-benzylmaleimide AMA: α-(allyloxymethyl)methyl acrylate MD: dimethyl-2,2'-[oxybis(methylene)]bis-2-propenoate CHMI: N-cyclohexylmaleimide CHMA: cyclohexyl methacrylate VT : Vinyltoluene 2EHA: 2-ethylhexyl acrylate DCPMA: dicyclopentanyl methacrylate TBMA: tert-butyl methacrylate HEMA: 2-hydroxyethyl methacrylate HEAA: N-hydroxyethyl acrylamide GLMA: Glycerin monomethacrylate M100: 3, 4-Epoxycyclohexylmethyl methacrylate GMA: Glycidyl methacrylate NIPAM: N-isopropylacrylamide MAA: Methacrylic acid AA: Karenz acrylate MOI: 2-methacryloyloxyethyl isocyanate SAH: Succinic anhydride

(Preparation of pigment dispersion 1)
12.9 parts of propylene glycol monomethyl ether acetate, 0.4 parts of Disparon DA-7301 as a dispersant, C.I. I. 2.25 parts of Pigment Green 58 and C.I. I. Pigment Yellow 138 was mixed with 1.5 parts and dispersed in a paint shaker for 3 hours to obtain Pigment Dispersion 1 (solid content: 22% by mass).

(Example 1)
In terms of solid content, 35.0 parts of copolymer solution A-1, 30.0 parts of dipentaerythritol hexaacrylate as a radically polymerizable compound, and Irgacure OXE-02 (manufactured by BASF Japan) as a radically polymerizable photoinitiator. ), 30.0 parts of Pigment Dispersion 1, and a diluting solvent (propylene glycol monomethyl ether acetate) to give a solid content concentration of 20%, and by stirring, photosensitive resin composition 1 was prepared. I got it.

(Examples 2 to 18, Comparative Examples 1 to 2)
Photosensitive resin compositions 2 to 20 were obtained in the same manner as in Example 1 except that the formulations shown in Table 2 were used.
The solvent resistance of the obtained photosensitive resin compositions 1 to 20 was evaluated. The results are shown in Table 2.

From Table 2, a photosensitive resin composition containing a copolymer having an epoxy group-containing structural unit and a long-chain acid group-containing structural unit and having an epoxy equivalent of 20,000 or less can be cured at a low temperature of 90°C or 110°C. It was found that a cured product with good curability and excellent solvent resistance could be obtained even under these conditions.

Example 19, Comparative Example 3
(Storage stability confirmation)
In order to investigate the effect of diluting solvent on storage stability, the following operation was performed. A copolymer solution in which 20 parts of a diluting solvent (equivalent to 66.7% by mass with respect to 100% by mass of copolymer solid content) was added to 100 parts (in form) of copolymer solution A-2. Changes in the physical properties (weight average molecular weight and viscosity) of the copolymer were confirmed before and after storage at 40° C. for two weeks. Two types of diluting solvents were used: propylene glycol monomethyl ether acetate and propylene glycol monomethyl ether. Table 3 shows changes in physical properties of the obtained copolymer solution.
As for the amount of change, the weight average molecular weight was expressed as the ratio (%) of the difference between the weight average molecular weight before and after storage with respect to the weight average molecular weight before storage. Regarding viscosity, the ratio (%) of the difference between the viscosity before and after storage with respect to the viscosity before storage was expressed.

From Table 3, when the alcoholic solvent propylene glycol monomethyl ether is added, the amount of change in weight average molecular weight and the amount of change in viscosity after storage is smaller than when propylene glycol monomethyl ether acetate is added. It was found that the copolymer has excellent storage stability.

(Manufacturing example 21)
Preparation of copolymer solution A-19 105.3 parts of propylene glycol monomethyl ether acetate was charged into a reaction tank equipped with a thermometer, a stirrer, a gas inlet pipe, a cooling pipe, and a dropping tank inlet, and the mixture was purged with nitrogen and heated. The temperature was raised to 90°C. On the other hand, as the dropping tank (A), 10.0 parts of N-benzylmaleimide, 27.5 parts of cyclohexyl methacrylate, 30.0 parts of 2-hydroxyethyl methacrylate, 32.5 parts of glycidyl methacrylate, and propylene glycol monomethyl were placed in a beaker. Prepare a stirred mixture of 30 parts of ether acetate and 2.0 parts of t-butyl peroxy-2-ethylhexanoate ("Perbutyl (registered trademark) O" manufactured by NOF Corporation), and add it to the dropping tank (B). , 2.0 parts of n-dodecyl mercaptan, and 98.0 parts of propylene glycol monomethyl ether acetate were mixed with stirring. After the temperature of the reaction tank reached 90°C, while maintaining the same temperature, dropping was started from the dropping tank over 3 hours to perform polymerization. After the dropwise addition was completed, the temperature was maintained at 90°C for 30 minutes, and then the temperature was raised to 115°C, and ripening was performed for 90 minutes. Thereafter, after cooling to room temperature, 11.5 parts of succinic anhydride, 0.33 parts of triethylamine as a catalyst, and 29.0 parts of propylene glycol monomethyl ether acetate were added and reacted at 60° C. for 7 hours. Thereafter, 42.0 parts of propylene glycol monomethyl ether was added so that the solid content was 27% to obtain copolymer solution A-19. Table 4 shows various physical properties of the obtained copolymer.

(Production example 22)
Preparation of copolymer solution A-20 Copolymer solution A-20 was obtained in the same manner as copolymer solution A-19, except that propylene glycol monomethyl ether acetate was added instead of propylene glycol monomethyl ether. Ta. Table 4 shows various physical properties of the obtained copolymer.

Note that the descriptions in Table 4 are as follows.
BzMI: N-benzylmaleimide CHMA: cyclohexyl methacrylate HEMA: 2-hydroxyethyl methacrylate GMA: glycidyl methacrylate SAH: succinic anhydride TEA: triethylamine

(Example 20)
In terms of solid content, 35.0 parts of copolymer solution A-19, 30.0 parts of dipentaerythritol hexaacrylate as a radically polymerizable compound, and Irgacure OXE-02 (manufactured by BASF Japan) as a radically polymerizable photoinitiator. ), 30.0 parts of Pigment Dispersion 1, 1.0 part of P-2M (Light Ester P-2M, pKa: 1.29, manufactured by Kyoeisha Chemical Co., Ltd.), and a diluting solvent (propylene glycol monomethyl Ether acetate) was added thereto so that the solid content concentration was 20%, and the mixture was stirred to obtain a photosensitive resin composition 21.

(Examples 21-23)
Photosensitive resin compositions 22 to 24 were obtained in the same manner as in Example 20, except that the formulations shown in Table 5 were used.
The solvent resistance of the obtained photosensitive resin compositions 21 to 24 was evaluated. The results are shown in Table 5.

From Table 5, it can be seen that the photosensitive resin composition containing a copolymer having an epoxy group-containing structural unit and an acid group-containing structural unit and having an epoxy equivalent of 20,000 or less, even under low temperature curing conditions of 90°C, It can be seen that the curability is good and the solvent resistance is excellent.

Examples 24-40
(Storage stability confirmation)
A diluent (propylene glycol monomethyl ether) and P-1M, P-2M, MSA, or ACA are added to 100 parts of the copolymer solution (as present) in the amounts listed in Table 6 or Table 7. A copolymer solution was prepared. In Table 6 (35 parts), the amount of diluent solvent corresponds to 129.6% by mass relative to 100% by mass of copolymer solids, and in Table 7 (8 parts), it corresponds to 129.6% by mass relative to 100% by mass of copolymer solids. This corresponds to 29.6% by mass. Using the obtained copolymer solution, changes in physical properties (viscosity) of the copolymer solution were confirmed before and after storage at 40° C. for 1 to 2 weeks. Tables 6 and 7 show changes in physical properties of the obtained copolymer solutions. The amount of change in viscosity (viscosity increase rate) is expressed as the ratio (%) of the difference in viscosity before and after storage relative to the viscosity before storage. Furthermore, the content of acid compounds (P-1M, P-2M, MSA, ACA) relative to 100 mol% of basic compound (TEA) in the copolymer solution is shown in the table.

Note that the descriptions in Tables 6 and 7 are as follows.
P-1M: Light ester P-1M (manufactured by Kyoeisha Chemical) 2-methacryloyloxyethyl acid phosphate, pKa: 1.78, molecular weight: 210.12
P-2M: Light ester P-2M (manufactured by Kyoeisha Chemical) 2-methacryloyloxyethyl acid phosphate, pKa: 1.29, molecular weight: 322.25
MSA: methanesulfonic acid, pKa: -2.6, molecular weight: 96.1
ACA: acetic acid, pKa: 4.76, molecular weight: 60.05

From Tables 6 and 7, in a copolymer solution containing a copolymer having an epoxy group-containing structural unit and an acid group-containing structural unit and having an epoxy equivalent of 20,000 or less, and a protic polar solvent, further: It was confirmed that by including an acid compound with a pKa of 4.2 or less, the rate of viscosity increase after storage was reduced and the storage stability was excellent.

Claims (10)

Including a copolymer , a polymerizable compound, and a photopolymerization initiator ,
The copolymer has an epoxy group-containing structural unit (A) represented by the following general formula (1) and an acid group-containing structural unit (B) represented by the following general formula (2). A photosensitive resin composition having an equivalent weight of 20,000 or less .

(In formula (1), R ¹ represents a hydrogen atom or a methyl group. R ² represents a direct bond or a divalent organic group. X represents an epoxy group-containing group.)

(In formula (2), R ³ represents a hydrogen atom or a methyl group. R ⁴ represents a direct bond or an organic group. R ⁵ represents a bond chain having a length of 2 or more atoms. Y represents an acid group.a represents 0 or 1) The photosensitive resin composition according to claim 1, wherein the structural unit (A) includes a structural unit represented by the following general formula (1-1).

(In formula (1-1), R ¹ represents a hydrogen atom or a methyl group. R ⁶ represents a direct bond or a divalent organic group.) The photosensitive resin composition according to claim 1 or 2, wherein the structural unit (B) includes a structural unit represented by the following general formula (2-1).

(In formula (2-1), R ³ represents a hydrogen atom or a methyl group. ^{R 7} and R ⁸ are the same or different and represent a direct bond or an organic group. b represents 0 or 1. represent.) The photosensitive resin composition according to any one of claims 1 to 3, further comprising a copolymer having a ring structure in its main chain. The photosensitive resin composition according to any one of claims 1 to 4, further comprising a phosphoric acid derivative. The photosensitive resin composition according to any one of claims 1 to 5, further comprising a coloring material. The photosensitive resin composition according to any one of claims 1 to 6, which is for negative type use. A cured product of the photosensitive resin composition according to any one of claims 1 to 7 . A member for a display device, comprising the cured product according to claim 8. A step of polymerizing a monomer component containing an epoxy group-containing monomer represented by the following formula (a) and a hydroxyl group-containing monomer represented by the following formula (b1),
A step of reacting the polymer obtained in the polymerization step with an acid group-containing compound represented by the following formula (b2) or formula (b3) in the presence of a basic compound;
A method for producing a copolymer solution, comprising the step of adding an acid compound having a pKa of 4.2 or less and a protic polar solvent.

(In formula (a), R ¹ represents a hydrogen atom or a methyl group. ^{R 2} represents a direct bond or a divalent organic group. X represents an epoxy group-containing group.)

(In formula (b1), R ³ represents a hydrogen atom or a methyl group. R ⁴ represents a direct bond or an organic group.)

(In formula (b2), R ⁵ represents a bonded chain with a length of 2 or more atoms. Y represents an acid group.)

(In formula (b3), R ⁵ represents a bond chain with a length of 2 or more atoms.)