KR20230096058A - Copolymer and method for producing the copolymer - Google Patents

Abstract

Air containing a structural unit (a) having a block isocyanato group blocked with a pyrazole compound, a structural unit (b) having a hydroxy group, and a structural unit (c) having an acid group, and having a glass transition temperature of 30 ° C. or less make it synthetic

Description

Copolymer and method for producing the copolymer

The present invention relates to a copolymer, a resin composition, a color filter, an image display device, and a method for producing the copolymer.

This application claims priority based on Japanese Patent Application No. 2020-215474 for which it applied to Japan on December 24, 2020, and uses the content here.

In general, image display elements such as organic electroluminescence (EL) display devices (particularly, WRGB method combining white light-emitting organic EL and color filters), liquid crystal display elements, integrated circuit elements, and solid-state imaging elements include color filters , Films and fine patterns, such as a black matrix, a color filter protective film, a photo spacer, a projection for liquid crystal alignment, or a microlens, and an insulating film for a touch panel, are provided.

BACKGROUND OF THE INVENTION [0002] In recent years, with the development of flexibility and wearable displays, a switch from glass to organic materials such as resin is progressing as a substrate material. Organic materials are inferior in heat resistance compared to glass. For this reason, in a member formed by thermally curing a resin composition on a substrate, it is desired to lower the temperature at which the resin composition is thermally cured according to the heat resistance of the substrate containing an organic material.

For example, a color filter was conventionally formed by thermally curing a resin composition on a substrate at a temperature of 210 to 230°C. However, in the case of forming a color filter on a flexible substrate containing a resin, since the heat resistance of the substrate is poor, it is required to form the resin composition by thermally curing it at a temperature of 80 to 150°C.

In particular, in color filters used in organic EL display devices, the content of the colorant contained in the resin composition tends to be increased in order to improve color reproducibility. In general, it is difficult to photocur a resin composition containing many colorants. For this reason, in the resin composition used for the color filter of an organic EL display device, it is more important to cure by crosslinking by heat. From this, in the resin composition used for the color filter of an organic electroluminescent display device, the need to improve the thermosetting property especially at low temperature is growing.

Conventionally, as a resin composition used as a material of a color filter, there are those described in Patent Literature 1 and Patent Literature 2, for example.

In Patent Document 1, (a) a polymerization initiator having an extinction coefficient at 365 nm in methanol of 1.0 × 10 ³ mL/gcm or more, (b) an extinction coefficient at 365 nm in methanol of 1.0 × 10 ² mL/gcm or less, A photosensitive coloring composition containing a polymerization initiator having an extinction coefficient of 254 nm of 1.0×10 ³ mL/gcm or more, (c) a compound having an unsaturated double bond, (d) an alkali-soluble resin, and (e) a colorant is disclosed.

Patent Document 2 discloses a photosensitive composition for color filters containing a compound (A) containing a furyl group, a compound (B) containing a photopolymerizable functional group, a photopolymerization initiator (C), and a colorant.

Japanese Unexamined Patent Publication No. 2015-041058 Japanese Unexamined Patent Publication No. 2017-194662

However, conventional resin compositions have good developability and storage stability when used as photosensitive materials, and have not yielded cured products having excellent solvent resistance when cured at low temperatures.

The present invention has been made in view of the above circumstances, and a resin composition capable of obtaining a cured product having good developability when used as a photosensitive material, excellent storage stability, and excellent solvent resistance even when cured at a low temperature, and this resin It is an object to provide a copolymer useful for preparing a composition and a method for preparing the copolymer.

In addition, the present invention provides a color filter having a color pattern containing a cured product of a resin composition that has good developability and excellent solvent resistance even when cured at a low temperature, and an image display element provided with the color filter. aims to do

The first aspect of the present invention provides the following copolymer. [1] a structural unit (a) having a block isocyanato group blocked with a pyrazole compound;

A structural unit (b) having a hydroxyl group;

Containing a structural unit (c) having an acid group,

A copolymer characterized by having a glass transition temperature of 30°C or less.

The copolymer of the first aspect of the present invention preferably has the characteristics described in [2] to [6] below. It is also preferable to arbitrarily combine two or more of the characteristics described in [2] to [6] below. [2] The copolymer according to [1], wherein the structural unit (b) is a structural unit derived from hydroxyalkyl (meth)acrylate.

[3] The copolymer according to [1] or [2], wherein the structural unit (c) is a structural unit derived from an unsaturated carboxylic acid.

[4] The copolymer according to any one of [1] to [3], wherein the structural unit (a) is a structural unit derived from a compound having the block isocyanato group and a (meth)acryloyloxy group.

[5] Containing 1 to 45 mol% of the structural unit (a), 1 to 50 mol% of the structural unit (b), and 1 to 60 mol% of the structural unit (c), [1] to [4] ] The copolymer described in any one of.

[6] The copolymer according to any one of [1] to [5], wherein the weight average molecular weight is 1000 to 50000.

A second aspect of the present invention provides the following resin composition.

[7] A resin composition comprising the copolymer (A) according to any one of [1] to [6] and a solvent (B), wherein the solvent (B) contains a hydroxy group-containing solvent.

The second aspect of the present invention preferably has the following characteristics [8] to [10]. It is also preferable that these features are used in combination.

[8] The resin composition according to [7], further comprising a reactive diluent (C) and a photopolymerization initiator (D).

[9] The resin composition according to [8], further containing a colorant (E).

[10] With respect to 100 parts by mass of the total amount of the copolymer (A) and the reactive diluent (C),

10 to 90 parts by mass of the copolymer (A);

30 to 1000 parts by mass of the solvent (B);

10 to 90 parts by mass of the reactive diluent (C);

0.1 to 30 parts by mass of the photopolymerization initiator (D);

The resin composition according to [9], wherein the coloring agent (E) is contained in an amount of 3 to 80 parts by mass.

A third aspect of the present invention provides the following color filters.

[11] A color filter characterized by having a color pattern comprising a cured product of the resin composition according to [9] or [10].

A fourth aspect of the present invention provides the following image display device.

[12] An image display element characterized by comprising the color filter according to [11].

A fifth aspect of the present invention provides a method for producing the following copolymer.

[13] a solvent heating step (I) in which the temperature of the solvent (B-1) is raised to 60 to 90 ° C;

The monomer (m-a) having a blocked isocyanato group blocked with a pyrazole compound, the hydroxy group-containing monomer (m-b), and the acid group-containing monomer (m-c) are added dropwise to the solvent (B-1) heated up,

A dropwise polymerization step (II) of adding a polymerization initiator solution obtained by dissolving a polymerization initiator in a solvent (B-2) dropwise to the solvent (B-1) to obtain a mixed solution;

A post-polymerization step (III) of reacting the mixed solution at 60 to 90 ° C. for 1 to 5 hours while stirring,

A method for producing a copolymer characterized in that one or both of the solvent (B-1) and the solvent (B-2) contain a hydroxy group-containing solvent.

The fifth aspect of the present invention also preferably has the following [14] and [15] characteristics.

[14] The method for producing a copolymer according to [13], wherein in the solvent heating step (I), the temperature is raised after adding the chain transfer agent to the solvent (B-1).

[15] In the postpolymerization step (III), a structural unit (a) having a block isocyanato group blocked with a pyrazole compound, a structural unit (b) having a hydroxyl group, and a structural unit (c) having an acid group The method for producing a copolymer according to [13], wherein a copolymer containing ) and having a glass transition temperature of 30°C or less can be obtained.

According to the present invention, when used as a photosensitive material, a resin composition having good alkali developability, excellent storage stability, and excellent solvent resistance even when cured at a low temperature is obtained, and air useful for preparing the resin composition. Methods for producing polymers and copolymers can be provided.

Further, according to the present invention, a color filter having a color pattern containing a cured product of a resin composition having good alkali developability and excellent solvent resistance even when cured at a low temperature is obtained, and an image display element provided with the color filter can provide.

Hereinafter, the copolymer of the present invention, a method for producing the copolymer, a resin composition, a color filter, and an image display element will be described in detail. However, this invention is not limited to embodiment shown below. For example, the present invention is not limited only to the following examples, and additions, omissions, and substitutions in numbers, amounts, ratios, compositions, types, positions, materials, configurations, etc., are made within the scope of the present invention. or can be changed.

In addition, what was described as (meth)acrylate in this specification means that either of an acrylate and a methacrylate may be sufficient. In addition, what was written as (meth)acrylic acid means that either of acrylic acid and methacrylic acid may be sufficient.

<Copolymer (A)>

The copolymer (A) of the present embodiment has a structural unit (a) having a block isocyanato group blocked with a pyrazole compound (hereinafter, simply referred to as "structural unit (a)") and a hydroxyl group. It contains a unit (b) (hereinafter, simply referred to as "structural unit (b)") and a structural unit (c) having an acid group (hereinafter, simply referred to as "structural unit (c)").

<Constituent Unit (a)>

The structural unit (a) is a structural unit derived from a monomer (m-a) having a block isocyanato group blocked with a pyrazole compound (hereinafter, simply referred to as “monomer (m-a)”). The block isocyanato group of the structural unit (a) contained in the copolymer (A) is deblocked by thermally curing the resin composition containing the copolymer (A) to generate an isocyanato group, and the structural unit It reacts with the hydroxyl group of (b) to generate a cross-linked structure. Therefore, even if the resin composition containing the copolymer (A) is cured at a low temperature of 50°C to 150°C, a cured film excellent in solvent resistance can be obtained.

As a pyrazole compound which is a blocking agent of a block isocyanato group, Pyrazole; Alkylpyrazoles, such as 3-methylpyrazole and 5-ethylpyrazole; dialkylpyrazoles such as 3,5-dimethylpyrazole and 3,5-diethylpyrazole; 3-acetylaminopyrazole, pyrazole-3,5-dicarboxylic acid diethyl ester, etc. are mentioned. Among these, from the viewpoint of low-temperature curability as a resin composition and easy availability of raw materials, dialkylpyrazole is preferred, and 3,5-dimethylpyrazole is more preferred.

The monomer (m-a) giving the structural unit (a) may be a compound copolymerizable with the hydroxy group-containing monomer (m-b) and acid group-containing monomer (m-c) described later, and is not particularly limited. As a monomer (m-a), the monomer which has a block isocyanato group and an ethylenically unsaturated bond can be used, for example from a reactive viewpoint at the time of synthesize|combining a copolymer (A). As a group which has an ethylenically unsaturated bond, a vinyl group and a (meth)acryloyloxy group are mentioned specifically,.

As an example of the monomer (m-a) which has a block isocyanato group and an ethylenically unsaturated bond, the reaction material of an isocyanate compound containing an ethylenically unsaturated group and a pyrazole compound is mentioned.

These monomers (m-a) may be used alone or in combination of two or more.

It is preferable that the isocyanate compound containing an ethylenically unsaturated group used for formation of the monomer (m-a) or which the monomer (m-a) has is a compound represented by the following formula (1).

(In formula (1), R ⁴ represents a hydrogen atom or a methyl group; R ⁵ is -CO-, -COOR ⁶ - (wherein R ⁶ is an alkylene group having 1 to 6 carbon atoms) or - COO-R ⁷ O-CONH-R ⁸ - (Wherein, R ⁷ is an alkylene group having 2 to 6 carbon atoms; R ⁸ is an alkylene group having 2 to 12 carbon atoms or 6 carbon atoms which may have a substituent It is an arylene group of 12 to 12).)

As described above, R ⁴ in formula (1) represents a hydrogen atom or a methyl group.

R ⁵ in Formula (1) represents -CO-, -COOR ⁶ - or -COO-R ⁷ O-CONH-R ⁸ -. Here, R ⁶ is an alkylene group having 1 to 6 carbon atoms. For example, the number of carbon atoms may be 2 to 5 or 3 to 4. R ⁷ is an alkylene group having 2 to 6 carbon atoms. For example, the number of carbon atoms may be 2 to 5 or 3 to 4. Moreover, ^R8 is a C2-C12 alkylene group or C6-C12 arylene group which may have a substituent. For example, the number of carbon atoms in the alkylene group may be 3 to 10 or 4 to 8. The number of carbon atoms in the arylene group may be 7 to 10 or 8 to 9. Among these, R ⁵ in Formula (1) is preferably -COOR ⁶ -. When R ⁵ is -COOR ⁶ -, R ⁶ is preferably an alkylene group having 1 to 4 carbon atoms.

As an isocyanate compound containing an ethylenically unsaturated group represented by the formula (1), specifically, 2-isocyanatoethyl (meth)acrylate, 2-isocyanatopropyl (meth)acrylate, 3-isocyanato Propyl (meth)acrylate, 2-isocyanato-1-methylethyl (meth)acrylate, 2-isocyanato-1,1-dimethylethyl (meth)acrylate, 4-isocyanatocyclohexyl (meth)acrylate ) Acrylate, (meth)acryloyl isocyanate, etc. are mentioned.

Moreover, as an isocyanate compound containing an ethylenically unsaturated group represented by the said Formula (1), the equimolar (1 mol: 1 mol) reaction product of 2-hydroxyalkyl (meth)acrylate and a diisocyanate compound can also be used. As an alkyl group contained in said 2-hydroxyalkyl (meth)acrylate, an ethyl group or n-propyl group is preferable, and an ethyl group is more preferable. As said diisocyanate compound, for example, hexamethylene diisocyanate, 2,4- (or 2,6-) tolylene diisocyanate (TDI), 4,4'- diphenylmethane diisocyanate (MDI), 3,5 ,5-trimethyl-3-isocyanatomethylcyclohexyl isocyanate (IPDI), m- (or p-) xylene diisocyanate, 1,3- (or 1,4-) bis (isocyanatomethyl) cyclohexane, Lysine diisocyanate etc. are mentioned.

Among these ethylenically unsaturated group-containing isocyanate compounds, 2-isocyanatoethyl (meth)acrylate, 2-isocyanatopropyl (meth)acrylate, 3-isocyanatopropyl (meth)acrylate, 2-isocyanate Nato-1-methylethyl(meth)acrylate, 2-isocyanato-1,1-dimethylethyl(meth)acrylate, 4-isocyanatocyclohexyl(meth)acrylate and (meth)acryloylisocyanate is preferred, and 2-isocyanatoethyl (meth)acrylate and 2-isocyanatopropyl (meth)acrylate are more preferred. These ethylenically unsaturated group-containing isocyanate compounds may be used alone or in combination of two or more.

The reaction between the isocyanate compound containing an ethylenically unsaturated group and the pyrazole compound can be performed regardless of the presence or absence of a solvent. When performing the said reaction using a solvent, the solvent inactive with respect to an isocyanato group is used. In the case of the said reaction, you may use organometallic salts, such as tin, zinc, and lead, tertiary amine, etc. as a catalyst.

The reaction can generally be carried out at a temperature of -20 to 150°C, preferably at a temperature of 25 to 130°C. When the temperature of the reaction is -20°C or higher, a sufficient reaction rate is obtained. In addition, if the temperature of the reaction is 150 ° C. or less, the raw material having C = C (double bond) is polymerized, thereby preventing the monomer (m-a) giving the structural unit (a) formed after the reaction from gelation. .

As an example of a reaction product of an ethylenically unsaturated group-containing isocyanate compound and a pyrazole compound, specifically, 2-[(3,5-dimethylpyrazolyl)carbonylamino]ethyl methacrylate, 2-[(3-methylpyra zolyl) carbonylamino] ethyl methacrylate; and the like. Among these, 2-[(3,5-dimethyl, because it can be easily obtained, the curability of the resin composition containing the copolymer (A) is good, and a cured product excellent in solvent resistance can be obtained by curing it. It is preferable that it is pyrazolyl) carbonylamino] ethyl methacrylate.

<Structural unit (b) having a hydroxyl group>

The structural unit (b) containing a hydroxyl group of the copolymer (A) does not have a block isocyanato group and has a hydroxyl group. The structural unit (b) is a structural unit derived from a monomer (m-b) having a hydroxyl group (hereinafter, simply referred to as "monomer (m-b)") (except for those corresponding to the structural unit (a) above) . The hydroxyl group of the constituent unit (b) contained in the copolymer (A) is formed by deblocking the block isocyanato group of the constituent unit (a) by thermally curing the resin composition containing the copolymer (A) reacted with the isocyanato group to form a cross-linked structure.

The monomer (m-b) which gives the structural unit (b) should just be a monomer which does not have a block isocyanato group and has a polymerizable unsaturated bond and a hydroxyl group, and is not specifically limited. As a monomer (m-b), the (meth)acrylic acid ester derivative which has a hydroxyl group is mentioned, for example. As an example of such a monomer (m-b), specifically, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 2,3-di Hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, etc. are mentioned. These monomers (m-b) may be used alone or in combination of two or more.

As the monomer (m-b), among the above monomers, from the viewpoint of the reactivity at the time of synthesizing the copolymer (A), the low-temperature curability of the resin composition containing the copolymer (A), and the ease of availability, hydroxyalkyl ( Meth)acrylates are preferred. As an example of hydroxyalkyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate are preferable, and it is easy to obtain And from a viewpoint of reducing the glass transition temperature of copolymer (A), 2-hydroxyethyl (meth)acrylate and 4-hydroxybutyl (meth)acrylate are more preferable.

<Structural unit (c) having an acid group>

The structural unit (c) which has an acidic radical which a copolymer (A) contains does not have a block isocyanato group and a hydroxyl group, but has an acidic radical. The structural unit (c) is a structural unit derived from a monomer (m-c) having an acid group (hereinafter, simply referred to as “monomer (m-c)”) (provided that structural units (a) and (b) correspond to the structural unit). except for doing). By containing the structural unit (c) in the copolymer (A), the alkali developability in the case of using the resin composition containing the copolymer (A) as a photosensitive material becomes good.

As an example of the acidic group which structural unit (c) has, a carboxyl group, a sulfo group, a phospho group, etc. are mentioned. Among these acid groups, as the acid group included in the constituent unit (c), a carboxyl group is preferable from the viewpoint of availability.

As a monomer (m-c) which provides structural unit (c), it should just be a monomer which does not have a block isocyanato group and a hydroxyl group, but has a polymerizable unsaturated bond and an acidic radical, and is not specifically limited. Examples of the monomer (m-c) include unsaturated carboxylic acids or anhydrides thereof, unsaturated sulfonic acids, and unsaturated phosphonic acids.

Specific examples of the monomer (m-c) include (meth)acrylic acid, α-bromo(meth)acrylic acid, β-furyl(meth)acrylic acid, crotonic acid, propiolic acid, cinnamic acid, α-cyanocinnamic acid, and maleic acid. unsaturated carboxylic acids or anhydrides thereof such as maleic anhydride, monomethyl maleate, monoethyl maleate, monoisopropyl maleate, fumaric acid, itaconic acid, itaconic anhydride, citraconic acid, and citraconic anhydride; unsaturated sulfonic acids such as 2-acrylamide-2-methylpropanesulfonic acid, tert-butylacrylamidesulfonic acid, and p-styrenesulfonic acid; unsaturated phosphonic acids such as vinylphosphonic acid; etc. can be mentioned. These monomers (m-c) may be used alone or in combination of two or more.

As the monomer (m-c), among these monomers, an unsaturated carboxylic acid is preferably used because it is readily available and the resin composition containing the copolymer (A) has excellent alkali developability, It is more preferable to use (meth)acrylic acid.

Here, the ratio of the structural unit (a), the structural unit (b), and the structural unit (c) contained in a copolymer (A) is demonstrated.

The proportion of the structural unit (a) contained in the copolymer (A) is not particularly limited, but is preferably 1 to 45 mol%, more preferably 5 to 40 mol%, and most preferably 15 to 35 mol%. am. 18-33 mol%, 20-30 mol%, 25-28 mol%, etc. may be sufficient as needed.

The proportion of the structural unit (b) contained in the copolymer (A) is not particularly limited, but is preferably 1 to 50 mol%, more preferably 5 to 45 mol%, and most preferably 10 to 35 mol%. am. 15-40 mol%, 18-33 mol%, 20-30 mol%, 22-25 mol%, etc. may be sufficient as needed.

The proportion of the structural unit (c) contained in the copolymer (A) is not particularly limited, but is preferably 1 to 60 mol%, more preferably 5 to 50 mol%, and most preferably 10 to 40 mol%. am. 13-35 mol%, 15-30 mol%, 20-28 mol%, 22-25 mol%, etc. may be sufficient as needed.

Therefore, the copolymer (A) preferably contains 1 to 45 mol% of the structural unit (a), 1 to 50 mol% of the structural unit (b), and 1 to 60 mol% of the structural unit (c).

In the copolymer (A) of the present embodiment, when the ratio of the structural unit (a) and the structural unit (b) is 1 mol% or more, the resin composition containing the copolymer (A) is thermally cured, and the structural unit ( The hydroxyl group of b) reacts with the isocyanato group produced by deblocking the block isocyanato group of structural unit (a), and a sufficiently crosslinked structure is formed. Therefore, even if the resin composition containing the copolymer (A) containing 1 mol% or more of structural unit (a) and structural unit (b) is thermally cured at low temperature, a hardened|cured material with favorable solvent resistance is obtained.

The storage stability of the resin composition containing a copolymer (A) becomes further favorable as the ratio of the structural unit (a) in a copolymer (A) is 45 mol% or less. Moreover, it becomes easy to ensure content of a structural unit (b) and a structural unit (c) as the ratio of structural unit (a) is 45 mol% or less. For this reason, the effect by including structural unit (b) and structural unit (c) becomes easy to be acquired.

Moreover, gelation at the time of the polymerization reaction for manufacturing a copolymer (A) can be prevented as the ratio of the structural unit (b) in a copolymer (A) is 50 mol% or less. In addition, the cross-linked structure due to the reaction between the isocyanato group formed by deblocking of the block isocyanato group of the structural unit (a) and the structural unit (b) is not excessively formed, thereby forming the copolymer (A). The storage stability of the resin composition to contain becomes more favorable. Moreover, it becomes easy to ensure content of a structural unit (a) and a structural unit (c) as the ratio of structural unit (b) is 50 mol% or less. For this reason, the effect by including structural unit (a) and structural unit (c) becomes easy to be acquired.

When the proportion of the constituent unit (c) in the copolymer (A) is 1 mol% or more, the resin composition containing the copolymer (A) has a sufficient alkali development rate. When the ratio of the structural unit (c) in the copolymer (A) is 60 mol% or less, the alkali developing rate of the resin composition containing the copolymer (A) is moderately suppressed, so that it becomes easy to form a precise and precise pattern. . Moreover, it becomes easy to ensure content of a structural unit (a) and a structural unit (b) as the ratio of the structural unit (c) in a copolymer (A) is 60 mol% or less. For this reason, even when the resin composition containing the copolymer (A) is cured at a low temperature, it becomes easier to obtain a cured product having further excellent solvent resistance.

The total amount of the content of the structural unit (a) and the structural unit (b) contained in the copolymer (A) is preferably 10 to 90 mol%, more preferably 20 to 80 mol%, and 30 to 80 mol%. It is more preferable that it is 70 mol%. 35 to 65 mol%, 40 to 60 mol%, 45 to 55 mol%, etc. may be sufficient as needed. When the total amount of the content of the structural unit (a) and the content of the structural unit (b) is 10 to 90 mol%, the resin composition containing the copolymer (A) is further excellent in storage stability and cured at a low temperature. Even so, a cured product having excellent solvent resistance can be obtained. Moreover, since it becomes easy to ensure content of structural unit (c), it becomes easy to obtain the resin composition with better alkali developability in the case of using as a photosensitive material.

When the resin composition containing the copolymer (A) contains a compound having a hydroxyl group as the reactive diluent (C) in addition to the copolymer (A), the hydroxyl group of the structural unit (b) contained in the copolymer (A) The total amount of is preferably made small according to the amount of hydroxyl groups contained in the reactive diluent (C).

Specifically, the total amount of the block isocyanato groups of the structural unit (a) and the total amount of hydroxyl groups contained in the resin composition (the total amount of hydroxyl groups of the structural unit (b) and the hydroxyl groups contained in the reactive diluent (C) The molar ratio of ) is preferably 10:90 to 90:10, more preferably 30:70 to 70:30, still more preferably 40:60 to 60:40. When the molar ratio is within the above range, by thermally curing the resin composition containing the copolymer (A), the hydroxyl group contained in the resin composition and the block isocyanato group of the structural unit (a) are deblocked. A crosslinked structure due to the reaction of an isocyanato group tends to be formed. For this reason, a cured product with even better solvent resistance can be obtained.

<Other constituent units (d)>

The copolymer (A) of the present embodiment, if necessary, together with the structural units (a) to (c), and other structural units (d) copolymerizable with these (however, the structural units (a) to (c)) Excluding those corresponding to) may contain.

The monomer (m-d) that gives the other structural unit (d) (hereinafter also simply referred to as "monomer (m-d)") does not have a block isocyanato group, a hydroxyl group, or an acid group, and the monomers (m-a) to monomers ( If it is a compound copolymerizable with m-c), it is not specifically limited.

Specific examples of the monomer (md) giving the other structural unit (d) include styrene, α-methylstyrene, o-vinyltoluene, p-vinyltoluene, o-chlorostyrene, m-chlorostyrene, methoxystyrene, p - Aromatic vinyl compounds, such as nitro styrene, p-cyano styrene, and p-acetylamino styrene; Norbornene (bicyclo[2.2.1]hept-2-ene), 5-methylbicyclo[2.2.1]hept-2-ene, tetracyclo[4.4.0.1 ^{2,5.1 7,10} ]dodecyl C-3-ene, 8-ethyltetracyclo[4.4.0.1 ^{2,5.1 7,10} ]dodeca-3-ene, dicyclopentadiene, tricyclo[5.2.1.0 ^2,6 ]dec-8- N, tricyclo[4.4.0.1 ^2,5 ]undeca-3-ene, tricyclo[6.2.1.0 ^1,8 ]undeca-9-ene, tetracyclo[4.4.0.1 ^2,5 .1 ^7,10 .0 ^1,6 ]dodeca-3-ene, 8-ethylidenetetracyclo[4.4.0.1 ^2,5 .1 ^7,12 ]dodeca-3-ene, pentacyclo[6.5.1.1 ^3,6 .0 Cyclic olefins having a norbornene structure such as ^{2,7.0 9,13} ]pentadec-4-ene; dienes such as butadiene, isoprene, and chloroprene; Methyl (meth)acrylate, ethyl (meth)acrylate, iso-propyl (meth)acrylate, tert-butyl (meth)acrylate, pentyl (meth)acrylate, benzyl (meth)acrylate, isoamyl (meth)acrylate )acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, dodecyl (meth)acrylate, cyclohexyl (meth)acrylate, methylcyclohexyl (meth)acrylate, rosin (meth)acrylate )Acrylate, norbornyl(meth)acrylate, 5-ethylnorbornyl(meth)acrylate, dicyclopentenyl(meth)acrylate, dicyclopentanyl(meth)acrylate, dicyclopentenyloxyethyl Acrylate, isobornyl (meth)acrylate, adamantyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, 1,1,1-trifluoroethyl (meth)acrylate, perfluoro Ethyl (meth)acrylate, perfluoro-n-propyl (meth)acrylate, 3-(N,N-dimethylamino)propyl (meth)acrylate, triphenylmethyl (meth)acrylate, phenyl (meth) Acrylate, cumyl(meth)acrylate, 4-phenoxyphenyl(meth)acrylate, phenoxyethyl(meth)acrylate, phenoxypolyethylene glycol(meth)acrylate, nonylphenoxypolyethylene glycol mono(meth)acrylate (meth)acrylic acid esters such as late, biphenyloxyethyl (meth)acrylate, naphthalene (meth)acrylate, anthracene (meth)acrylate, and ethoxylated phenyl (meth)acrylate; (meth)acrylic acid amides such as (meth)acrylic acid amide, (meth)acrylic acid N,N-dimethylamide, (meth)acrylic acid N,N-di-isopropylamide, and (meth)acrylic acid anthracenylamide; vinyl compounds such as (meth)acrylic acid anilide, (meth)acrylonitrile, acrolein, vinyl chloride, vinylidene chloride, vinyl fluoride, vinylidene fluoride, N-vinylpyrrolidone, vinylpyridine, vinyl acetate, and vinyltoluene; unsaturated dicarboxylic acid diesters such as diethyl citraconic acid, diethyl maleate, diethyl fumarate, and diethyl itaconate; monomaleimides such as N-phenylmaleimide, N-cyclohexylmaleimide, N-laurylmaleimide, and N-(4-hydroxyphenyl)maleimide; Glycidyl (meth)acrylate etc. are mentioned.

Among these, it is preferable to use a (meth)acrylic acid ester as the monomer (m-d), and from the viewpoint of adjusting the glass transition temperature of the copolymer (A) to 30°C or less, the glass transition temperature of the homopolymer is -20°C. The following is preferable, and it is especially preferable to use 2-ethylhexyl (meth)acrylate or 4-hydroxybutyl acrylate. These monomers (m-d) may be used alone or in combination of two or more.

When the copolymer (A) contains the other structural unit (d), the ratio is not particularly limited, but is preferably 1 to 80 mol%, more preferably 5 to 75 mol%, and most preferably It is preferably 10 to 50 mol%. 3-45 mol%, 5-40 mol%, 10-35 mol%, 15-30 mol%, or 12-25 mol% may be sufficient as needed. When the copolymer (A) includes the other structural unit (d), properties such as solvent resistance in a cured product of a resin composition containing the copolymer (A) can be appropriately improved. When the content of the other structural unit (d) is 80 mol% or less, it becomes easy to ensure the content of the structural units (a) to (c), and the structural units (a) to (c) are included. effect becomes remarkable.

(weight average molecular weight (Mw))

The weight average molecular weight of the copolymer (A) in terms of polystyrene is not particularly limited, but is preferably 1,000 to 50,000, more preferably 3,000 to 40,000. 5,000 to 20,000, 7,000 to 15,000, 9,000 to 12,000, etc. may be sufficient as needed. When the weight average molecular weight of the copolymer (A) is 1,000 or more, the alkali developability in the case of using the resin composition containing the copolymer (A) as a photosensitive material becomes good, and it becomes difficult to cause a pattern dropout after alkali development. . On the other hand, if the weight average molecular weight of the copolymer (A) is 50,000 or less, the development time in the case of using the resin composition containing the copolymer (A) as a photosensitive material becomes appropriate, and practicality is ensured.

(Glass transition temperature (Tg))

The glass transition temperature (Tg) of the copolymer (A) is 30°C or less, preferably 20°C or less, and more preferably 0°C or less. If the glass transition temperature of the copolymer (A) is higher than 30°C, curability at low temperatures is adversely affected. For this reason, the glass transition temperature of copolymer (A) is 30 degrees C or less. The glass transition temperature of the copolymer (A) is preferably -50°C or higher, more preferably -40°C or higher, and still more preferably -30°C or higher. When the glass transition temperature of the copolymer (A) is -50°C or higher, a cured film excellent in heat resistance can be obtained from the resin composition containing the copolymer (A). If necessary, the glass transition temperature may be -45°C or more and 25°C or less, -35°C or more and 15°C or less, -25°C or more and 10°C or less, or -15°C or more and 5°C or less.

(acid value)

The acid value (JIS K6901 5.3) of the copolymer (A) can be selected appropriately. The acid value of the copolymer (A) is preferably 20 to 300 KOHmg/g, more preferably 30 to 200 KOHmg/g, when the resin composition containing the copolymer (A) is used as a photosensitive material. 40 to 150 KOHmg/g, 50 to 100 KOHmg/g, etc. may be sufficient as needed. When the acid value of the copolymer (A) is 20 KOHmg/g or more, the alkali developability in the case of using the resin composition containing the copolymer (A) as a photosensitive material becomes good. On the other hand, if the copolymer (A) has an acid value of 300 KOHmg/g or less, when a resin composition containing the copolymer (A) is used as a photosensitive material, the exposed portion (photocured portion) is less likely to dissolve in an alkaline developer. Since it becomes a thing, the pattern shape becomes favorable.

(number of equivalents of block isocyanate group)

The copolymer (A) contains a block isocyanato group blocked with a pyrazole compound in its molecule. What is necessary is just to select the number of equivalents of a block isocyanato group suitably, but it is preferable that it is 300-6000, and it is more preferable that it is 500-3500. 400 to 2000 or 600 to 1000 may be sufficient as needed. When the number of equivalents of the block isocyanato group is 300 or more, when a hydroxyl group is sufficiently present in the resin composition containing the copolymer (A), the hydroxyl group in the resin composition and the structural unit (a) have A cross-linked structure due to the reaction of the isocyanato group generated by deblocking of the block isocyanato group is sufficiently produced. For this reason, a cured product with even better solvent resistance is obtained.

The number of equivalents of the block isocyanato groups in the copolymer (A) is the mass of the copolymer (A) per 1 mole of the block isocyanato groups contained in the copolymer (A). The number of equivalents of the block isocyanato group is obtained by dividing the mass of the copolymer (A) by the number of moles of the block isocyanato group contained in the copolymer (A) (g/mol). The number of equivalents of the said block isocyanato group is a theoretical value calculated from the charged amount of monomer (m-a).

<Method for producing copolymer (A)>

The copolymer (A) of the present embodiment can be produced, for example, using a method of performing the solvent heating step (I), the dropping polymerization step (II), and the post polymerization step (III) shown below in this order. .

(Solvent heating process (I))

A solvent (B-1) is prepared, and the temperature of the solvent (B-1) is raised to 60 to 90°C. In the solvent heating step (I), the temperature may be raised after putting a chain transfer agent described later in the solvent (B-1). The degree of polymerization of the copolymer (A) synthesized in the dropping polymerization step (II) and the post-polymerization step (III) can be controlled by adding the chain transfer agent to the solvent (B-1) and then raising the temperature.

The concentration of the chain transfer agent in the solvent (B-1) can be, for example, 0.1 to 10% by mass, and is not particularly limited.

(Drop polymerization process (II))

While stirring the heated solvent (B-1), the polymerization initiator solution is added dropwise together with the monomer solution to the heated solvent (B-1) to form a mixed solution, and dropwise polymerization is performed.

The monomer solution contains a monomer (m-a) having a block isocyanato group, a hydroxyl group-containing monomer (m-b), an acid group-containing monomer (m-c), and a monomer (m-d) used as necessary in a solvent (B-2) is dissolved in As the solvent (B-2), those exemplified in the solvent (B-1) can be used similarly.

The polymerization initiator solution is obtained by dissolving the polymerization initiator in the solvent (B-2).

In the method for producing the copolymer (A) of the present embodiment, one or both of the solvent (B-1) and the solvent (B-2) contain a hydroxy group-containing solvent.

In the dropping polymerization step (II), a chain transfer agent solution described later may be added dropwise instead of the chain transfer agent that can be added in the solvent heating step (I). A chain transfer agent solution is obtained by dissolving a chain transfer agent in a solvent (B-2). Further, in the solvent heating step (I), a part of the chain transfer agent used for producing the copolymer (A) is put into the solvent (B-1), then the temperature is raised, and in the dropping polymerization step (II), the chain transfer agent to be used is added. You may add dropwise the chain transfer agent solution which melt|dissolved the remainder except a part from the transfer agent in solvent (B-2) to the heated solvent (B-1).

(Post-polymerization step (III))

After completion of the dropping of the monomer solution and the polymerization initiator solution, the mixed solution is further reacted at 60 to 90°C for 1 to 5 hours while stirring.

「Solvent (B-1)」

The solvent (B-1) used in the solvent heating step (I) may be only a hydroxy group-containing solvent or a hydroxy group-free solvent, and includes both a hydroxy group-containing solvent and a hydroxy group-free solvent It could be anything. The solvent (B-1) preferably contains a hydroxyl group-containing solvent containing a hydroxyl group, more preferably only a hydroxyl group-containing solvent.

Examples of the hydroxy group-containing solvent include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol mono-n-butyl ether, triethylene glycol monomethyl ether, propylene glycol monoethyl ether, (poly)alkylene glycol monoalkyl ethers such as dipropylene glycol monomethyl ether, tripropylene glycol monoethyl ether, and 3-methoxy-1-butanol; 2-Hydroxymethylpropionate, 2-hydroxyethylpropionate, 2-hydroxy-2-methylmethylpropionate, 2-hydroxy-2-methylethylpropionate, hydroxyacetate ethyl, 2-hydroxy-3-methylbutyric acid hydroxy group-containing carboxylic acid esters such as methyl; Diethylene glycol etc. are mentioned.

Among these hydroxy group-containing solvents, in the dropping polymerization step (II) and/or post polymerization step (III), the effect of preventing gelation of the reaction solution and the effect of controlling the molecular weight of the copolymer (A) to an appropriate range is high, so 1 Primary and/or secondary alcohol solvents and ether solvents are preferably used, and propylene glycol monomethyl ether, ethylene glycol monomethyl ether and 3-methoxy-1-butanol are more preferably used. These hydroxy group-containing solvents may be used alone or in combination of two or more.

Examples of the solvent not containing a hydroxy group include (poly)alkylene glycol monoalkyl ether acetates such as ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, and propylene glycol monoethyl ether acetate. Ryu; ethers such as diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol diethyl ether, and tetrahydrofuran; ketones such as methyl ethyl ketone, cyclohexanone, 2-heptanone, and 3-heptanone; 3-methoxymethylpropionate, 3-ethoxymethylpropionate, ethyl ethoxyacetate, 3-methyl-3-methoxybutylacetate, 3-methyl-3-methoxybutylpropionate, ethyl acetate, n-butyl acetate , i-propyl acetate, i-butyl acetate, n-amyl acetate, i-amyl acetate, n-butyl propionate, ethyl butyrate, n-propyl butyrate, i-propyl butyrate, ethyl pyruvate, n-propyl pyruvate, methyl acetoacetate esters such as ethyl acetoacetate and ethyl 2-oxobutyrate; Aromatic hydrocarbons, such as toluene and xylene; and carboxylic acid amides such as N-methylpyrrolidone, N,N-dimethylformamide, and N,N-dimethylacetamide.

Among solvents not containing a hydroxyl group, from the viewpoints of ease of availability, cost and quality, it is preferable to use an ether solvent, and it is more preferable to use propylene glycol monomethyl ether acetate or diethylene glycol methyl ethyl ether. . These solvents that do not contain a hydroxyl group may be used alone or in combination of two or more.

When the solvent (B-1) used in the solvent heating step (I) contains a hydroxyl group-containing solvent, the content of the hydroxyl group-containing solvent in the solvent (B-1) is 10 to 100% by mass It is preferable, that it is 20-90 mass % is more preferable, and it is still more preferable that it is 40-80 mass %. When the content of the hydroxy group-containing solvent is 10% by mass or more, in the dropping polymerization step (II) and/or the post-polymerization step (III), the isocyanato group derived from the monomer (m-a) and the isocyanato group derived from the monomer (m-b) The effect of inhibiting the reaction of the hydroxyl group is sufficiently obtained. When the solvent (B-1) contains a solvent not containing a hydroxyl group, the amount of crosslinking reaction between the isocyanato group derived from the monomer (m-a) and the hydroxyl group derived from the monomer (m-b) when curing as a resin composition The effect of improving is obtained.

「Temperature of Solvent and Mixed Solution」

In the manufacturing method of the present embodiment, in the solvent heating step (I), the solvent (B-1) is put into a reaction vessel and the temperature is raised to 60 to 90°C. Further, in the dropping polymerization step (II) and post polymerization step (III), the mixed solution is reacted at 60 to 90°C for 1 to 5 hours while stirring.

The temperature of the solvent (B-1) in the solvent heating step (I) and the temperature of the mixed solution in the dropping polymerization step (II) and the post polymerization step (III) may be the same or different.

In this embodiment, since the temperature of the solvent (B-1) in the solvent heating step (I) and the temperature of the mixed solution in the dropping polymerization step (II) and the post polymerization step (III) are 60 ° C. or higher, In the dropping polymerization step (II) and the post polymerization step (III), the polymerization reaction of the monomers (m-a) to (m-c) and the monomer (m-d) used as necessary proceeds sufficiently.

Since the temperature of the solvent (B-1) in the solvent heating step (I) and the temperature of the mixed solution in the dropping polymerization step (II) and post-polymerization step (III) are 90 ° C or less, as the monomer (m-a), When a reaction product of an ethylenically unsaturated group-containing isocyanate compound and a pyrazole compound is used, the effects shown below are obtained. That is, in the dropping polymerization step (II) and the post polymerization step (III), it is possible to prevent generation of an isocyanato group due to dissociation of the pyrazole compound from the block isocyanato group. Therefore, the isocyanato group generated by deblocking of the above block isocyanato group reacts with the hydroxyl group derived from the monomer (m-b) or the acid group derived from the monomer (m-c), resulting in the copolymer (A) in the middle of production Gelation can be prevented. In addition, since the temperature is 90° C. or less, in the dropping polymerization step (II) and the post-polymerization step (III), even if a part of the block isocyanato group of the monomer (m-a) is deblocked and an isocyanato group is generated. , The reaction between the isocyanato group and the hydroxyl group derived from the monomer (m-b) can be suppressed. In this respect, a copolymer (A) sufficiently containing the structural unit (a) having a block isocyanato group and the structural unit (b) having a hydroxyl group is obtained.

In the dropping polymerization step (II), the polymerization initiator solution and the monomer solution are added dropwise to the solvent (B-1) heated to 60 to 90 ° C. in the solvent heating step (I), and polymerization is performed while forming a mixed solution. In the dropping polymerization step (II), the chain transfer agent solution may be further added dropwise to the heated solvent (B-1) to obtain a mixed solution containing the chain transfer agent.

In the dropping polymerization step (II), it is preferable to simultaneously drop the polymerization initiator solution and the monomer solution into the solvent (B-1) in which the temperature has been raised. In this case, while the molecular weight of the copolymer (A) can be controlled with high precision, the gelation of the copolymer (A) during production can be prevented.

In the dropping polymerization step (II), when the chain transfer agent solution is added dropwise to the heated solvent (B-1), the chain transfer agent solution may be added dropwise simultaneously with the polymerization initiator solution and the monomer solution. You may drip a chain transfer agent solution before or after dripping.

The rate at which the polymerization initiator solution, monomer solution, and chain transfer agent solution are added can be appropriately determined depending on the scale of the reaction, such as the capacity of the reaction vessel and the volumes of the heated solvent (B-1) and the polymerization initiator solution, monomer solution, and chain transfer agent solution. . The dropping rate of the polymerization initiator solution, the monomer solution, and the chain transfer agent solution is preferably 0.1 to 5 mL/min when a 1 L reaction vessel is used, for example.

The dropping time of the polymerization initiator solution, the monomer solution, and the chain transfer agent solution can be, for example, 30 minutes to 1 hour.

The dropping rate and dropping time of the polymerization initiator solution, the monomer solution, and the chain transfer agent solution may be different from each other, or part or all of them may be the same.

In this embodiment, the polymerization initiator solution, the monomer solution, and the chain transfer agent solution used as needed are prepared individually.

(Polymerization Initiator Solution)

The polymerization initiator solution is obtained by dissolving the polymerization initiator in the solvent (B-2).

Examples of the polymerization initiator include, but are not particularly limited to, 2,2'-azobis(2,4-dimethylvaleronitrile), azobisisobutyronitrile, azobisisovaleronitrile, benzoyl peroxide, t- Butylperoxy-2-ethylhexanoate etc. are mentioned. These polymerization initiators may be used alone or in combination of two or more.

The concentration of the polymerization initiator in the polymerization initiator solution is preferably such that a mixed solution having a uniform concentration is easily obtained, and can be, for example, 16 to 50% by mass, and is not particularly limited.

The amount of the polymerization initiator solution used is 0.5 to 20 parts by mass of the polymerization initiator contained in the polymerization initiator solution, based on 100 parts by mass of the total amount of monomers charged (ie, the mass of monomers (m-a) to monomers (m-d) in the monomer solution). It is preferable that it is an amount to become, More preferably, it is an amount used as 1.0-10 mass parts.

(monomer solution)

The monomer solution contains a monomer (m-a) having a block isocyanato group, a hydroxyl group-containing monomer (m-b), an acid group-containing monomer (m-c), and a monomer (m-d) used as necessary in a solvent (B-2) is dissolved in As the monomers (m-a) to (m-d), those exemplified in the section of the copolymer (A) can be used.

The monomer solution may be prepared by a method of dissolving the monomers (m-a) to (m-d) individually in the solvent (B-2) and then mixing them, or after mixing the monomers (m-a) to (m-d), the solvent ( You may manufacture by the method of dissolving in B-2).

The total concentration of the monomers (m-a) to (m-d) in the monomer solution is preferably a concentration at which a mixed solution having a uniform concentration is easily obtained, and can be, for example, 50 to 95% by mass, but is not particularly limited. .

When one or more of the monomers used for production of the copolymer (A) is liquid at normal temperature, the liquid monomer at normal temperature may serve as a solvent in the monomer solution. In this case, the monomer solution does not have to contain the solvent (B-2).

As a monomer which is liquid at normal temperature, 2-[(3,5-dimethylpyrazolyl) carbonylamino] ethyl methacrylate etc. which are monomer (m-a) which have a block isocyanato group are mentioned, for example.

The ratio of each monomer (m-a) to (m-c) used in the production of the copolymer (A) is not particularly limited, but is 1 to 45 mol% of the monomer (m-a), 1 to 50 mol% of the monomer (m-b), and 1 to 50 mol% of the monomer (m-b). (m-c) is preferably 1 to 60 mol%, more preferably 5 to 40 mol% of monomer (m-a), 5 to 45 mol% of monomer (m-b), and 5 to 50 mol% of monomer (m-c), monomer ( It is more preferable that they are 15-35 mol% of m-a), 10-35 mol% of monomers (m-b), and 10-40 mol% of monomers (m-c).

When the copolymer (A) contains the structural unit (d), the ratio of each monomer (m-a) to (m-d) used in the production of the copolymer (A) is not particularly limited, but monomer (m-a) 1 to 45 mol%, 1 to 50 mol% of monomer (m-b), 1 to 60 mol% of monomer (m-c), and 1 to 80 mol% of monomer (m-d), preferably 5 to 40 mol% of monomer (m-a), monomer (m-b) 5 to 45 mol%, monomer (m-c) 5 to 50 mol%, monomer (m-d) 5 to 75 mol% is more preferable, monomer (m-a) 15 to 35 mol%, monomer (m-b) 10 to It is more preferable that they are 35 mol%, 10-40 mol% of monomers (m-c), and 10-50 mol% of monomers (m-d).

(chain transfer agent solution)

A chain transfer agent solution is obtained by dissolving a chain transfer agent in a solvent (B-2).

In the dropping polymerization step (II), the degree of polymerization of the copolymer (A) synthesized in the postpolymerization step (III) can be controlled by adding the chain transfer agent solution dropwise. Accordingly, copolymer (A) having a desired molecular weight range can be easily produced.

Although it does not specifically limit as a chain transfer agent, For example, a polyfunctional thiol can be used preferably. A polyfunctional thiol is a compound having two or more mercapto groups in a molecule.

The polyfunctional thiol is not particularly limited, and examples thereof include thioglycolic acid, 1,2-ethanedithiol, 1,4-bis(3-mercaptobutyryloxy)butane, and tetraethylene glycol bis(3-mer). captopropionate), trimethylolethanetris (3-mercaptobutyrate), trimethylolpropanetris (3-mercaptobutyrate), trimethylolpropanetris (3-mercaptopropionate), pentaerythritol tetrakis ( 3-mercaptobutyrate), pentaerythritol tetrakis (3-mercaptopropionate), 1,3,5-tris (3-mercaptobutyloxyethyl) -1,3,5-triazine-2, 4,6(1H,3H,5H)-trione, tris-[(3-mercaptopropionyloxy)-ethyl]-isocyanurate, dipentaethylthritol hexakis(3-mercaptopropionate ) and the like.

As the chain transfer agent, among the above, pentaerythritol tetrakis (3-mercaptobutyrate) and/or thioglycolic acid, pentaerythritol tetrakis (3-mercaptobutyrate) from the viewpoints of availability, cost and quality propionate) is preferably used.

The concentration of the chain transfer agent in the polymerization initiator solution is preferably a concentration at which a mixed solution of uniform concentration can be easily obtained, and can be, for example, 0.1 to 10% by mass, and is not particularly limited.

The amount of the chain transfer agent solution used is, for example, 0.5 to 20 parts by mass of the chain transfer agent contained in the mixed solution, based on 100 parts by mass of the total amount of monomers (ie, the mass of monomers (m-a) to monomers (m-d) in the monomer solution). It is preferable that it is an amount used as a mass part, and it is an amount used as 1.0-10 mass parts more preferably. By adjusting the amount of the chain transfer agent solution to be within the above range, the copolymer (A) having a desired molecular weight range can be easily produced in the post-polymerization step (III).

「Solvent (B-2)」

As the solvent (B-2) used in the dropping polymerization step (II), the same solvent (B-1) used in the solvent heating step (I) can be used. The solvent (B-2), like the solvent (B-1), may be only a hydroxyl group-containing solvent or a hydroxyl group-free solvent, and may contain both a hydroxyl group-containing solvent and a hydroxyl group-free solvent. It can be done. The solvent (B-2) preferably contains a hydroxyl group-containing solvent containing a hydroxyl group, more preferably only a hydroxyl group-containing solvent.

In the method for producing the copolymer (A) of the present embodiment, one or both of the solvent (B-1) and the solvent (B-2) contain a hydroxy group-containing solvent. Therefore, when the solvent (B-1) used in the solvent heating step (I) does not contain a hydroxyl group-containing solvent, the solvent (B-2) used in the dropping polymerization step (II) is a hydroxyl group-containing solvent includes

The content ratio of the hydroxy group-containing solvent contained in the total amount of the solvent (B-1) used in the solvent heating step (I) and the solvent (B-2) used in the dropping polymerization step (II) is 10 to 100 mass It is preferably %, more preferably 20 to 90% by mass, and still more preferably 40 to 80% by mass. When the content of the hydroxy group-containing solvent is 10% by mass or more, in the dropping polymerization step (II) and/or the post-polymerization step (III), the isocyanato group derived from the monomer (m-a) and the isocyanato group derived from the monomer (m-b) The effect of inhibiting the reaction of the hydroxyl group is sufficiently obtained. When one or both of the solvent (B-1) and the solvent (B-2) contain a solvent that does not contain a hydroxyl group, if the content ratio of the hydroxyl group-containing solvent is 90% by mass or less, for example, as a polymerization initiator 2 , When 2'-azobis(2,4-dimethylvaleronitrile) is used, the polymerization initiator is easily dissolved and the workability is good.

In the production method of the present embodiment, the solvent (B-1) used in the solvent heating step (I) and/or the solvent (B-2) used in the dropping polymerization step (II) include a hydroxy group-containing solvent Therefore, the effects shown below are obtained.

That is, in the dropping polymerization step (II) and/or the post-polymerization step (III), the hydroxyl group of the hydroxyl group-containing solvent reacts with a part of the isocyanato group generated from the block isocyanato group of the monomer (m-a) do.

Thus, in the present embodiment, the reaction between the isocyanato group derived from the monomer (m-a) and the hydroxyl group derived from the monomer (m-b) in the dropping polymerization step (II) and/or the post-polymerization step (III) is , are moderately inhibited. Therefore, in the post-polymerization step (III), gelation of the copolymer (A) during production can be prevented. Moreover, the storage stability of the resin composition containing a copolymer (A) becomes favorable.

In addition, in this embodiment, the reaction in the drop polymerization step (II) and/or the post polymerization step (III) is appropriately inhibited, so that the resin composition containing the copolymer (A) is thermally cured, before the monomer is cured. The reduction of the isocyanato group derived from (m-a) and the hydroxyl group derived from monomer (m-b) can be prevented. For this reason, the copolymer (A) in which the isocyanato group derived from monomer (m-a) and the hydroxyl group derived from monomer (m-b) remain appropriately is obtained. Therefore, by thermally curing the resin composition containing the copolymer (A), a crosslinked structure is sufficiently formed, and a cured product having good solvent resistance is obtained.

Although the amounts of the solvent (B-1) used in the solvent heating step (I) and the solvent (B-2) used in the dropping polymerization step (II) are not particularly limited, the total amount of monomers charged (ie, monomers For example, the total amount of the solvent (B-1) and the solvent (B-2) is preferably 30 to 1,000 parts by mass relative to 100 parts by mass of the monomers (m-a) to (m-d) in the solution, and more Preferably it is 50-800 mass parts. When the total amount of the solvent (B-1) and the solvent (B-2) is 1,000 parts by mass or less with respect to 100 parts by mass of the total amount of monomers charged, the reaction including the copolymer (A) obtained in the postpolymerization step (III) The viscosity of the liquid becomes appropriate. Further, when the chain transfer agent solution is added dropwise in the dropping polymerization step (II) by setting the total amount of the solvent (B-1) and the solvent (B-2) to 1,000 parts by mass or less, the copolymer by chain transfer action ( The decrease in molecular weight of A) can be suppressed. In addition, by setting the total amount of the solvent (B-1) and the solvent (B-2) to 30 parts by mass or more with respect to 100 parts by mass of the total amount of monomers charged, an abnormal polymerization reaction in the post-polymerization step (III) is prevented. , the polymerization reaction can be stably performed. As a result, a copolymer (A) without coloration is obtained while being able to prevent gelation of the copolymer (A) during production.

In the production method of the present embodiment, in the postpolymerization step (III), the mixed solution obtained in the dropping polymerization step (II) is reacted at 60 to 90°C for 1 to 5 hours while stirring. The reaction time in the post polymerization step (III) can be 1 to 5 hours, preferably 1 to 4 hours, more preferably 2 to 3 hours. If the reaction time is 1 to 5 hours, a copolymer (A) having an appropriate molecular weight can be produced in good yield.

The copolymer (A) of the present embodiment comprises a structural unit (a) having a block isocyanato group blocked with a pyrazole compound, a structural unit (b) having a hydroxyl group, and a structural unit (c) having an acid group. It contains, and the glass transition temperature is 30 degrees C or less. Therefore, the resin composition containing the copolymer (A) of the present embodiment has good alkali developability when used as a photosensitive material, excellent storage stability, and excellent solvent resistance even when cured at low temperatures. cargo is obtained.

In the method for producing the copolymer (A) of the present embodiment, the solvent (B-1) used in the solvent heating step (I) and/or the solvent (B-2) used in the dropping polymerization step (II) , A solvent containing a hydroxy group-containing solvent, in the solvent heating step (I), the solvent (B-1) is heated to 60 to 90 ° C., and in the postpolymerization step (III), the mixed solution is reacted at 60 to 90 ° C. let it For this reason, in the dropping polymerization step (II) and/or the post polymerization step (III), the reaction between the isocyanato group derived from the monomer (m-a) and the hydroxyl group derived from the monomer (m-b) is appropriately inhibited. As a result, the copolymer (A) of this embodiment which fully contains the structural unit (a) which has a block isocyanato group, and the structural unit (b) which has a hydroxyl group is obtained.

In contrast, conventionally, when a solvent is used for polymerization of a copolymer, a solvent that does not react with the monomer is selected and used. Therefore, in the prior art, when polymerization of a copolymer is performed using a solvent, there is no case where the monomer reacts with the solvent. For this reason, in the prior art, it is not assumed to use the reaction between the monomer and the solvent, and there is no method for controlling the properties of the copolymer using the reaction between the monomer and the solvent.

<Resin composition>

Next, the resin composition of this embodiment is demonstrated.

The resin composition of this embodiment contains the copolymer (A) of this embodiment and a solvent (B).

The resin composition of the present embodiment may further contain not only the copolymer (A) and the solvent (B), but also a reactive diluent (C) and a photopolymerization initiator (D). Such a resin composition can be suitably used as a photosensitive resin composition.

The resin composition of this embodiment may further contain a coloring agent (E) in addition to the said copolymer (A) - photoinitiator (D). Such a resin composition can be suitably used as a material for forming colored patterns such as color filters, black matrices and black column spacers.

(Solvent (B))

In the resin composition of the present embodiment, the solvent (B) contains a hydroxy group-containing solvent. The solvent (B) may be only a hydroxy group-containing solvent. In the resin composition of this embodiment, since the solvent (B) contains a hydroxy group-containing solvent, storage stability improves.

The hydroxyl group-containing solvent used as the solvent (B) is not particularly limited as long as it is a hydroxyl group-containing solvent, and can be used as the solvent (B-1) and the solvent (B-2) in the process of producing the copolymer (A). What can be used, the same can be used. Examples of the solvent containing no hydroxyl group that can be used as the solvent (B) include those that can be used as the solvent (B-1) and the solvent (B-2) in the step of producing the copolymer (A), and the same ones. can

The content ratio of the hydroxyl group-containing solvent in the solvent (B) can be set in the same manner as the content ratio of the hydroxyl group-containing solvent in the solvent (B-1) used in the step of producing the copolymer (A).

The solvent (B) may be the same as or different from the solvent (B-1) and/or the solvent (B-2) used in the step of producing the copolymer (A).

The resin composition of the present embodiment includes, for example, the copolymer (A) isolated from the reaction solution containing the copolymer (A) obtained in the postpolymerization step (III) for producing the copolymer (A), and a solvent (B) can be manufactured by the method of mixing suitably.

As the resin composition of this embodiment, you may use the reaction liquid containing the copolymer (A) obtained when manufacturing copolymer (A) as it is. In this case, it is not necessary to isolate the copolymer (A) from the reaction solution. Further, when the solvent (B-1) and/or the solvent (B-2) used in the production of the copolymer (A) is contained in the reaction solution, the solvent (B-1) and/or the solvent in the reaction solution ( B-2) can be used as a solvent (B) as it is. In the reaction liquid, you may add a solvent (B) as needed.

In the resin composition of the present embodiment, the blending amounts of the copolymer (A) and the solvent (B) may be appropriately adjusted according to the purpose of use of the resin composition. In the resin composition of this embodiment, it is preferable to contain 30-1,000 mass parts of solvents (B) with respect to 100 mass parts of copolymers (A), for example, and it is more preferable to contain 50-800 mass parts. When the content of the solvent (B) is 30 parts by mass or more, the viscosity of the resin composition becomes appropriate. When the content of the solvent (B) is 1,000 parts by mass or less, the viscosity of the resin composition can be controlled within an appropriate range, and appropriate film thickness adjustment is possible.

(Reactive Diluent (C))

A reactive diluent (C) is contained together with a photoinitiator (D) as needed. The reactive diluent (C) is a compound having at least one polymerizable ethylenically unsaturated group as a polymerizable functional group in the molecule. The reactive diluent (C) may be a monofunctional monomer or a polyfunctional monomer, and is preferably a polyfunctional monomer having a plurality of polymerizable functional groups. By setting it as a resin composition containing a reactive diluent (C), adjustment of a viscosity becomes easy. Moreover, by setting it as a resin composition containing a reactive diluent (C), the adhesiveness with respect to the base material of the hardened|cured material of a resin composition can be improved, or the intensity|strength in the hardened|cured material of a resin composition can be adjusted.

Examples of monofunctional monomers used as the reactive diluent (C) include (meth)acrylamide, methylol (meth)acrylamide, methoxymethyl (meth)acrylamide, ethoxymethyl (meth)acrylamide, and propoxymethyl (meth)acrylamide. )acrylamide, butoxymethoxymethyl (meth)acrylamide, methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, 2-hydroxy Ethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 2-phenoxy-2-hydroxypropyl (meth)acrylate, 2-(meth)acrylate Acryloyloxy-2-hydroxypropylphthalate, glycerin mono(meth)acrylate, tetrahydrofurfuryl(meth)acrylate, glycidyl(meth)acrylate, 2,2,2-trifluoroethyl ( (meth)acrylates such as meth)acrylate, 2,2,3,3-tetrafluoropropyl (meth)acrylate, and half (meth)acrylate of phthalic acid derivatives; aromatic vinyl compounds such as styrene, α-methylstyrene, α-chloromethylstyrene, and vinyltoluene; and carboxylic acid esters such as vinyl acetate and vinyl propionate. These monofunctional monomers may be used alone or in combination of two or more.

Examples of the polyfunctional monomer used as the reactive diluent (C) include ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, and propylene glycol di(meth)acrylate. , Polypropylene glycol di (meth) acrylate, butylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1,6-hexane glycol di (meth) acrylate, trimethylolpropane tri (meth) )Acrylate, glycerin di(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate )Acrylate, 2,2-bis(4-(meth)acryloxydiethoxyphenyl)propane, 2,2-bis(4-(meth)acryloxypolyethoxyphenyl)propane, 2-hydroxy-3- (meth)acryloyloxypropyl (meth)acrylate, ethylene glycol diglycidyl ether di(meth)acrylate, diethylene glycol diglycidyl ether di(meth)acrylate, phthalic acid diglycidyl ester di (meth)acrylate, glycerin triacrylate, glycerin polyglycidyl ether poly(meth)acrylate, urethane (meth)acrylate (i.e., tolylene diisocyanate), trimethylhexamethylene diisocyanate and hexamethylene diisocyanate, and the like; - (meth)acrylates such as a reactant of hydroxyethyl (meth)acrylate and tri(meth)acrylate of tris(hydroxyethyl)isocyanurate; aromatic vinyl compounds such as divinylbenzene, diallylphthalate, and diarylbenzenephosphonate; dicarboxylic acid esters such as divinyl adipate; triallyl cyanurate, methylene bis(meth)acrylamide, (meth)acrylamide methylene ether, a condensate of a polyhydric alcohol and N-methylol(meth)acrylamide, and the like. These polyfunctional monomers may be used alone or in combination of two or more.

Among these monomers, it is preferable to use a polyfunctional (meth)acrylate as the reactive diluent (C) from the viewpoint of improving the development form and curability of the resin composition, and trimethylolpropane tri(meth)acrylate and dipentaerythate. It is more preferable to use 1 type(s) or 2 or more types chosen from ritol penta(meth)acrylate and dipentaerythritol hexa(meth)acrylate.

When the resin composition contains the reactive diluent (C), the compounding amount of each component is 10 to 90 parts by mass of the copolymer (A) based on 100 parts by mass of the total amount of the copolymer (A) and the reactive diluent (C); It is preferable that the solvent (B) is 30 to 1,000 parts by mass and the reactive diluent (C) is 10 to 90 parts by mass, the copolymer (A) is 20 to 80 parts by mass, and the solvent (B) is 50 to 800 parts by mass, the reactivity It is more preferable that the diluent (C) is 20 to 80 parts by mass, the copolymer (A) is 30 to 75 parts by mass, the solvent (B) is 100 to 700 parts by mass, and the reactive diluent (C) is 25 to 70 parts by mass. more preferable When the compounding amount of each component is within the above range, it becomes a resin composition having an appropriate viscosity, and can be suitably used for various coatings, adhesives, binders for printing ink, and the like.

(Photoinitiator (D))

Although it does not specifically limit as a photoinitiator (D), For example, Benzoins, such as benzoin, benzoin methyl ether, benzoin ethyl ether, and benzoin butyl ether; Acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 4-(1-t-butyldioxy-1-methylethyl)acetophenone, 2-methyl-1-[ acetophenones such as 4-(methylthio)phenyl]-2-morpholino-propan-1-one and 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone-1; anthraquinones such as 2-methylanthraquinone, 2-amylanthraquinone, 2-t-butylanthraquinone, and 1-chloroanthraquinone; thioxanthone such as xanthone, thioxanthone, 2,4-dimethylthioxanthone, 2,4-diisopropylthioxanthone, and 2-chlorothioxanthone; ketals such as acetophenone dimethyl ketal and benzyl dimethyl ketal; Benzophenones such as benzophenone, 4-(1-t-butyldioxy-1-methylethyl)benzophenone, and 3,3',4,4'-tetrakis(t-butyldioxycarbonyl)benzophenone ; acyl phosphine oxides; Ethanone 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-1-(O-acetyloxime) etc. are mentioned. These photoinitiators (D) may be used independently or may be used in combination of 2 or more type.

When the resin composition contains the photopolymerization initiator (D), the content thereof is preferably 0.1 to 30 parts by mass, and preferably 0.5 to 20 parts by mass, based on 100 parts by mass of the total amount of the copolymer (A) and the reactive diluent (C). It is more preferable, and it is more preferable that it is 1-15 mass parts.

(colorant (E))

A coloring agent (E) is contained as needed. The colorant (E) is not particularly limited as long as it is dissolved or dispersed in the solvent (B), and examples thereof include dyes and pigments. A coloring agent (E) may be used individually by 1 type or may be used in combination of 2 or more types according to the color of the hardened|cured material of the resin composition made into the objective. As a coloring agent (E), only a dye may be used, only a pigment may be used, or a dye and a pigment may be used in combination.

As the dye, from the viewpoint of solubility in the solvent (B) and alkaline developing solution, interaction with other components in the resin composition, heat resistance, etc., acid dyes having acidic groups such as carboxylic acid and sulfonic acid, nitrogen compounds of acid dyes It is preferable to use salts, sulfonamides of acidic dyes, and the like.

Examples of such dyes include acid alizarin violet N; acid black 1, 2, 24, 48; acid blue1, 7, 9, 25, 29, 40, 45, 62, 70, 74, 80, 83, 90, 92, 112, 113, 120, 129, 147; acid chrome violet K; acid Fuchsin; acid green 1, 3, 5, 25, 27, 50; acid orange6, 7, 8, 10, 12, 50, 51, 52, 56, 63, 74, 95; acid red1, 4, 8, 14, 17, 18, 26, 27, 29, 31, 34, 35, 37, 42, 44, 50, 51, 52, 57, 69, 73, 80, 87, 88, 91 ,92,94,97,103,111,114,129,133,134,138,143,145,150,151,158,176,183,198,211,215,216,217,249,252,25 7 , 260, 266, 274; acid violet 6B, 7, 9, 17, 19; acid yellow1, 3, 9, 11, 17, 23, 25, 29, 34, 36, 42, 54, 72, 73, 76, 79, 98, 99, 111, 112, 114, 116; food yellow3 and derivatives thereof; and the like. Among these dyes, it is preferable to use acidic dyes of azo type, xanthene type, anthraquinone type or phthalocyanine type. These dyes may be used alone or in combination of two or more, depending on the color of the cured product of the intended resin composition.

As an example of the pigment, C.I. Pigment Yellow 1, 3, 12, 13, 14, 15, 16, 17, 20, 24, 31, 53, 83, 86, 93, 94, 109, 110, 117, 125, 128, 137, 138, 139 , 147, 148, 150, 153, 154, 166, 173, 194, yellow pigments such as 214; C.I. orange pigments such as Pigment Orange 13, 31, 36, 38, 40, 42, 43, 51, 55, 59, 61, 64, 65, 71, 73; C.I. Red pigments such as Pigment Red9, 97, 105, 122, 123, 144, 149, 166, 168, 176, 177, 180, 192, 209, 215, 216, 224, 242, 254, 255, 264, 265 ; C.I. blue pigments such as Pigment Blue 15, 15:3, 15:4, 15:6, and 60; C.I. Violet color pigments, such as Pigment Violet 1, 19, 23, 29, 32, 36, 38; C.I. green pigments such as Pigment Green 7, 36, 58, and 59; C.I. brown pigments such as Pigment Brown 23 and 25; C.I. Black pigments, such as Pigment Black 1 and 7, carbon black, titanium black, and iron oxide, etc. are mentioned. These pigments may be used alone or in combination of two or more, depending on the color of the cured product of the intended resin composition.

When using a pigment as a coloring agent (E), you may contain a well-known dispersing agent in a resin composition from a viewpoint of improving the dispersibility of a pigment. As the dispersant, it is preferable to use a polymeric dispersant excellent in dispersion stability over time.

Examples of the polymer dispersant include urethane dispersants, polyethyleneimine dispersants, polyoxyethylene alkyl ether dispersants, polyoxyethylene glycol diester dispersants, sorbitan aliphatic ester dispersants, aliphatic modified ester dispersants, and the like.

As the polymer dispersant, commercially available under trade names such as EFKA (manufactured by EFKA Chemicals Co., Ltd.), Disperbyk-161 (manufactured by Big Chemie Co., Ltd.), Dispalon (manufactured by Kusumoto Kasei Co., Ltd.), SOLSPERSE (manufactured by Zeneca Co., Ltd.) you can use that

What is necessary is just to set the kind and compounding quantity of a dispersing agent suitably according to the kind of pigment to be used, etc.

When the resin composition contains the colorant (E), the content thereof is preferably 3 to 80 parts by mass, more preferably 5 to 70 parts by mass, based on 100 parts by mass of the total amount of the copolymer (A) and the reactive diluent (C). and more preferably 10 to 60 parts by mass. The resin composition containing the copolymer (A) of the present embodiment is excellent in storage stability, and even when cured at a low temperature, a cured product excellent in solvent resistance is obtained. For this reason, content of a coloring agent (E) can be 20 mass parts or more with respect to 100 mass parts of total amounts of a copolymer (A) and a reactive diluent (C), for example. The resin composition containing 20 parts by mass or more of the coloring agent (E) can improve color reproducibility in an image display element provided with a color filter by using it as a material for a color filter.

In addition to the components described above, the resin composition of the present embodiment may contain known additives such as a coupling agent, a leveling agent, and a thermal polymerization inhibitor in order to impart predetermined characteristics. The blending amount of these additives is not particularly limited as long as the effect of the present invention is not impaired.

Since the resin composition of this embodiment contains the copolymer (A) of this embodiment, a crosslinking reaction fully advances also at low temperature. Therefore, the resin composition of this embodiment can be hardened at low temperature.

Specifically, the resin composition of the present embodiment is preferably cured at a temperature of 150°C or lower, more preferably 120°C or lower, still more preferably 100°C or lower, and most preferably 80°C or lower. . When the temperature at which the resin composition is cured is 150°C or lower, the amount of energy required to cure the resin composition is reduced. In addition, when the resin composition contains a colorant (E) having poor heat resistance, deterioration of the colorant (E) accompanying thermal curing can be suppressed, and a cured product exhibiting the original characteristics of the colorant (E) can be easily obtained. . Therefore, as the colorant (E), those containing various materials can be used. Further, when forming a cured product by applying a resin composition onto a substrate and curing it by heat, the cured product can be formed even if the substrate contains a material having poor heat resistance. Therefore, as a board|substrate, what consists of various materials, such as resin for flexible displays, for example can be used.

The resin composition of the present embodiment is preferably cured at a temperature of 50°C or higher, more preferably 60°C or higher, still more preferably 70°C or higher. When the temperature at which the resin composition is cured is 50°C or higher, a crosslinked structure is sufficiently formed in a short time, and a cured product having good solvent resistance can be efficiently formed.

The heating time (curing time) for curing the resin composition of the present embodiment can be appropriately determined depending on the size, thickness, curing temperature, etc. of the cured product, and can be, for example, 10 minutes to 4 hours, or 20 minutes to 20 minutes. It is preferable to set it as 2 hours.

The resin composition of this embodiment can be manufactured by a method of mixing the above components using a known mixing device. The solvent contained in each component used as a raw material when manufacturing the resin composition of this embodiment can be used as a solvent (B).

When the resin composition of the present embodiment contains components other than the copolymer (A) and the solvent (B), for example, the resin composition containing the previously prepared copolymer (A) and the solvent (B) has reactivity. You may manufacture by the method of adding and mixing a diluent (C), a photoinitiator (D), and a coloring agent (E).

Since the resin composition of the present embodiment contains the copolymer (A) of the present embodiment, a cured product having excellent storage stability and excellent solvent resistance even when cured at a low temperature is obtained. Therefore, the resin composition of the present embodiment is, for example, a color filter, a black matrix, a color filter protective film, a photo spacer, a projection for liquid crystal orientation, a micro lens, an insulating film for a touch panel, an adhesive for electronic materials around a flexible printed wiring board, and adhesion. As a material for a sheet or the like, it can be preferably used.

When the resin composition of the present embodiment contains the copolymer (A) of the present embodiment, the solvent (B), the reactive diluent (C), and the photopolymerization initiator (D), it is preferable as a photosensitive material having good alkali developability. can be used In particular, organic electroluminescence (EL) displays (for black pixel defining layers (PDL)), liquid crystal displays, solid-state imaging devices using charge-coupled devices (CCD) and complementary metal oxide semiconductor (CMOS) devices, etc. It is suitable as a resist used for a filter.

Further, when the resin composition of the present embodiment contains the copolymer (A) of the present embodiment, the solvent (B), the reactive diluent (C), the photopolymerization initiator (D), and the colorant (E), It is possible to form a colored pattern including a cured product having excellent solvent resistance at a low temperature. For this reason, deterioration of the coloring agent (E) accompanying thermal curing is suppressed, and a coloring pattern in which the original characteristics of the coloring agent (E) can be exhibited can be formed. Therefore, the resin composition described above can be suitably used as a photosensitive material for color filters.

<Color Filter>

Next, the color filter of the present embodiment will be described.

The color filter of the present embodiment includes a substrate, a plurality of pixels including three color patterns of a red (R) pattern, a green (G) pattern, and a blue (B) pattern formed on the substrate, and boundaries between the respective color patterns. It has a black matrix formed on and a protective film formed on the pixels and the black matrix.

As the substrate, a known substrate can be employed, and examples thereof include a glass substrate, a silicon substrate, a polycarbonate substrate, a polyester substrate, a polyamide substrate, a polyamideimide substrate, a polyimide substrate, an aluminum substrate, a printed wiring board, An array substrate or the like can be used. In the color filter of the present embodiment, an organic substrate having a relatively low heat resistance temperature such as a polycarbonate substrate, a polyester substrate, a polyamide substrate, a polyamideimide substrate, or a polyimide substrate, and suitable as a flexible substrate can be used. there is.

In the color filter of the present embodiment, the three color patterns forming the black matrix and each pixel are the copolymer (A), the solvent (B), the reactive diluent (C), and the photopolymerization initiator of the present embodiment. It is a coloring pattern containing (D) and the hardened|cured material of the resin composition of this embodiment containing a coloring agent (E).

It does not specifically limit as a protective film, A well-known thing can be used.

Next, the manufacturing method of the color filter of this embodiment is demonstrated by giving an example.

In order to manufacture the color filter of this embodiment, first, the three color patterns which form the color pattern used as a black matrix and each pixel are formed on a board|substrate, respectively. First, a color pattern serving as a black matrix is formed on a substrate, and then a red pattern, a green pattern, and a blue pattern forming each pixel are formed within a range partitioned by the black matrix, respectively. The order of forming the red pattern, the green pattern, and the blue pattern is not particularly limited.

Each color pattern can be formed by a photolithography method using the resin composition of the present embodiment.

Specifically, the resin composition of the present embodiment is applied onto a substrate to form a coating film. Subsequently, the coating film is exposed through a photomask having a predetermined pattern shape, and the exposed portion is photocured. And the unexposed part of the coating film is alkali-developed using aqueous alkali solution, and is removed. After that, by baking, the exposed portion of the coated film is heated and cured. Through the above steps, a colored pattern having a predetermined shape and containing the cured resin composition of the present embodiment is obtained.

A method of applying the resin composition to form a colored pattern is not particularly limited, and examples thereof include a screen printing method, a roll coating method, a curtain coating method, a spray coating method, and a spin coating method.

After applying the resin composition, if necessary, the solvent (B) contained in the coating film may be volatilized and removed by heating the coating film using a heating means such as a circulation oven, an infrared heater, or a hot plate.

Heating for removing the solvent (B) in the coated film can be performed at a temperature of, for example, 50°C to 120°C. In addition, heating for removing the solvent (B) in the coating film can be performed, for example, for 30 seconds to 30 minutes. The heating temperature and heating time for removing the solvent (B) in the coating film can be appropriately set depending on the composition of the resin composition, the thickness of the coating film, and the like.

When exposing a coating film, a well-known negative mask can be used as a photomask, for example.

When exposing the coating film, for example, it is preferable to use active energy rays such as ultraviolet rays and excimer laser light. The light source used for exposure is not particularly limited, and for example, a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, a xenon lamp, a metal halide lamp, or the like can be used. The amount of energy radiation applied to the coating film can be appropriately selected depending on the thickness of the coating film, the composition of the resin composition, and the like, and can be, for example, 30 to 2000 mJ/cm 2 .

The aqueous alkali solution used for alkali development is not particularly limited, and examples thereof include aqueous solutions such as sodium carbonate, potassium carbonate, calcium carbonate, sodium hydroxide, and potassium hydroxide; aqueous solutions of amine compounds such as ethylamine, diethylamine, and dimethylethanolamine; Tetramethylammonium, 3-methyl-4-amino-N,N-diethylaniline, 3-methyl-4-amino-N-ethyl-N-β-hydroxyethylaniline, 3-methyl-4-amino-N -Ethyl-N-β-methanesulfonamide ethylaniline, 3-methyl-4-amino-N-ethyl-N-β-methoxyethylaniline and p-phenyl such as sulfates, hydrochlorides or p-toluenesulfonates thereof An aqueous solution of a rendiamine-based compound or the like can be used, and can be appropriately selected according to the composition of the resin composition.

You may add additives of an antifoamer and surfactant to these aqueous alkali solutions as needed.

In this embodiment, it is preferable to wash the substrate with water to remove the aqueous alkali solution and dry it after alkali development with an aqueous alkali solution and before baking.

In this embodiment, the temperature at which the exposed portion of the coating film is heated and cured by baking can be appropriately selected depending on the thickness of the coating film, the composition of the resin composition, and the like. In this embodiment, since the coating film is formed using the resin composition containing the copolymer (A) of this embodiment, the exposed part of the coating film can be hardened even at low temperature.

The temperature at which the exposed portion of the coating film is heated can be, for example, 210°C or lower, and may be 150°C or lower, 120°C or lower, 100°C or lower, or 80°C or lower as needed. If the temperature at which the exposed portion of the coated film is heated is 210° C. or lower, a material with low heat resistance such as a substrate with low heat resistance can be used as the material of the color filter. When the temperature at which the exposed portion of the coating film is heated is 150° C. or less, the amount of energy required to cure the coating film becomes small, which is preferable. In addition, when the temperature at which the exposed portion of the coating film is heated is 150° C. or lower, a color pattern containing a colorant (E) with poor heat resistance, which has been difficult to use as a material for a color pattern in the past, while suppressing deterioration of the colorant (E) can form Further, when the temperature at which the exposed portion of the coated film is heated is set to 150° C. or lower, a colored pattern can be formed on a substrate having poor heat resistance, which has been difficult to use as a substrate for a color filter in the past.

The temperature at which the exposed portion of the coating film is heated is preferably 50°C or higher, more preferably 60°C or higher, still more preferably 70°C or higher. When the temperature at which the exposed portion of the coating film is heated is 50° C. or higher, the copolymer (A) and the reactive diluent (C) are sufficiently crosslinked, so that the colored pattern has good solvent resistance and a good pattern shape is obtained. In addition, if the temperature at which the exposed portion of the coating film is heated is 50°C or higher, the exposed portion of the coating film can be heated in a short time, and a colored pattern can be efficiently produced.

The time for heating the exposed portion of the coating film can be appropriately selected depending on the temperature at which the exposed portion of the coating film is heated, the thickness of the coating film, the composition of the resin composition, etc., and can be, for example, 10 minutes to 4 hours, preferably. 20 minutes to 2 hours.

Next, a protective film is formed on the color pattern to be the black matrix and the three color patterns forming each pixel by a known method.

Through the above steps, the color filter of the present embodiment is obtained.

In the color filter of the present embodiment, the three color patterns and the black matrix forming each pixel are the copolymer (A) of the present embodiment, the solvent (B), the reactive diluent (C), and the photopolymerization initiator ( It is a coloring pattern containing D) and the hardened|cured material of the resin composition of this embodiment containing a coloring agent (E). The resin composition of the present embodiment has good alkali developability, and even when cured at a low temperature, a cured product having excellent solvent resistance is obtained. Therefore, in the color filter of this embodiment, the pixel and black matrix can be formed using the method of hardening a resin composition at low temperature, and the choice of material usable for a color filter can increase.

For this reason, in the color filter of this embodiment, it can contain the colorant (E) with poor heat resistance, for example, and can have a pixel and/or a black matrix which have a favorable pattern shape. In addition, by forming the pixels and the black matrix using a method of curing the resin composition at a low temperature, a color filter having a substrate made of a material with poor heat resistance can be obtained.

On the other hand, when forming a colored pattern using a conventional resin composition instead of the resin composition of the present embodiment, if the temperature at which the exposed portion of the coating film is heated and cured is less than 210°C, the solvent resistance of the colored pattern as a cured product this is lacking Therefore, in the case of forming a colored pattern using a conventional resin composition, the temperature at which the exposed portion of the coating film is heated cannot be set to 210°C or lower. For this reason, in the prior art, it has been difficult to use a colorant (E) with poor heat resistance as a material for a colored pattern. In addition, it was also difficult to use a substrate having poor heat resistance as a substrate for a color filter.

In the color filter of the present embodiment, the color pattern contains the copolymer (A), the solvent (B), the reactive diluent (C), the photopolymerization initiator (D), and the colorant (E) of the present embodiment. Although the case of having a pixel and a black matrix containing a cured product of a resin composition to be described has been described as an example, a resin composition containing a curing accelerator and a known epoxy resin may be used instead of the photopolymerization initiator (D).

In this case, a coloring pattern can be formed, for example, by the method shown below. First, a resin composition is applied onto a substrate by an inkjet method to form a coated film having a predetermined pattern shape. Then, the coating film is heated to harden. By the above method, it is possible to form a colored pattern having a desired shape and containing a cured product of the resin composition. Even if a resin composition containing a curing accelerator and a known epoxy resin in place of the photopolymerization initiator (D) is cured at a low temperature, a cured product having excellent solvent resistance can be obtained. Therefore, even in this case, it is possible to form pixels and a black matrix using a method of curing the resin composition at a low temperature, and it is possible to increase the choice of materials usable for the color filter.

<Image Display Element>

Next, the image display element of the present embodiment will be described.

As the liquid crystal display element as the image display element of the present embodiment, for example, a first substrate having a color filter and a first electrode formed on the surface thereof, and a second substrate having a second electrode formed on the surface thereof, the first electrode and the second electrode are disposed facing each other via a spacer, and a liquid crystal composition is sandwiched between the first substrate and the second substrate.

In the liquid crystal display element of this embodiment, the color filter of this embodiment is provided as a color filter. In the liquid crystal display element of the present embodiment, a known member can be used for members other than the color filter.

The liquid crystal display element of this embodiment can be manufactured using the manufacturing method shown below, for example.

First, on a first substrate, a color filter and a first electrode are formed in this order. A color filter can be formed using the manufacturing method mentioned above. The first electrode can be formed using a known method.

Subsequently, a second electrode and a spacer are formed on the second substrate by a known method.

Thereafter, the first substrate and the second substrate are bonded by arranging the first electrode and the second electrode to face each other, and a liquid crystal composition is injected between the first substrate and the second substrate to seal.

Through the above process, the liquid crystal display element of this embodiment is obtained.

Since the liquid crystal display element of this embodiment is equipped with the color filter of this embodiment, the pixel of a color filter and a black matrix can be formed using the method of hardening a resin composition at low temperature. Therefore, as a material usable for the liquid crystal display element, it is possible to use a material with poor heat resistance, and it is possible to increase the options of usable materials.

In the above-described embodiment, a liquid crystal display element was described as an example of the image display element of the present embodiment, but the image display element of the present embodiment may be provided with the color filter of the present embodiment, and the liquid crystal display element is not limited to The image display element of this embodiment may be, for example, an organic EL display element or a solid-state imaging device using a CCD element/CMOS element.

Example

Hereinafter, the present invention will be described in more detail by way of Examples and Comparative Examples. In addition, this invention is not limited only to the following example.

[Synthesis Example 1]

207.7 g of propylene glycol monomethyl ether (manufactured by Sankyo Chemical Co., Ltd.) as a solvent (B-1) was placed in a flask equipped with a stirrer, dropping funnel, condenser, thermometer, and gas inlet pipe, and while purging with nitrogen gas It stirred and heated up to 78 degreeC (solvent heating process (I)).

Then, 20.6 g of 2,2'-azobis(2,4-dimethylvaleronitrile) (polymerization initiator) was dissolved in 79.1 g of propylene glycol monomethyl ether as solvent (B-2) to obtain a polymerization initiator solution made it

In addition, 50.2 g (20 mol%) of MOI-BP, 26.0 g (20 mol%) of 2-hydroxyethyl methacrylate, 12.9 g (15 mol%) of methacrylic acid, and 82.8 g (45 mol%) of %) of 2-ethylhexyl acrylate (2EHA) was dissolved in 61.8 g of propylene glycol monomethyl ether as the solvent (B-2) and then mixed to obtain a monomer solution.

Thereafter, into the flask containing the solvent heated to 78°C, while stirring the solvent (B-1) in the flask, the polymerization initiator solution and the monomer solution are added dropwise simultaneously using a dropping funnel, respectively, to form a mixed solution. Polymerization was performed (drop polymerization step (II)). The dripping rate was 1.7 ml/min for both the polymerization initiator solution and the monomer solution.

After completion of the dropwise addition, the mixed solution was reacted at 78°C for 3 hours while stirring to produce a copolymer (A) (postpolymerization step (III)).

The polymer composition of Synthesis Example 1 was obtained by adding propylene glycol monomethyl ether as the solvent (B) so that the components other than the solvent were 35% by mass to the reaction solution containing the copolymer (A) thus obtained.

[Synthesis Examples 2 to 6, Comparative Synthesis Examples 1 to 3]

Polymer compositions of Synthesis Examples 2 to 6 and Comparative Synthesis Examples 1 to 3 were obtained in the same manner as in Synthesis Example 1 except that the materials shown in Tables 1 and 2 were used in the ratios shown in Tables 1 and 2.

In Tables 1 and 2, (m-a) represents a monomer having a block isocyanato group. (m-b) represents a hydroxy group-containing monomer. (m-c) represents an acid group-containing monomer. (d) represents other monomers that do not correspond to (m-a), (m-b) or (m-c).

In Table 1 and Table 2, (number of equivalents of block isocyanato groups) represents the number of equivalents of block isocyanato groups contained in the molecule of the copolymer (A).

Materials used in Table 1 and Table 2 are as follows.

MOI-BP: Karenz (registered trademark) MOI-BP (2-[(3,5-dimethylpyrazolyl)carbonylamino]ethyl methacrylate, Showa Denko Co., Ltd.)

MOI-BM: Karenz (registered trademark) MOI-BM (2-"0-(1'-methylpropylideneamino)carboxyamino]ethyl methacrylate, Showa Denko Co., Ltd.)

- 4-hydroxybutyl acrylate (manufactured by Mitsubishi Chemical Corporation)

2-Hydroxyethyl methacrylate (manufactured by Kyoesha Chemical Co., Ltd.)

・Methacrylic acid (manufactured by Kuraray)

・Acrylic acid (manufactured by Toagosei Co., Ltd.)

2EHA: 2-ethylhexyl acrylate (manufactured by Toagosei Co., Ltd.)

TCDMA: Tricyclo[5.2.1.0 ^2,6 ]decanyl-8-methacrylate (manufactured by Hitachi Chemical Co., Ltd.)

・GMA: Glycidyl methacrylate (manufactured by Nichiyu Co., Ltd.)

Regarding the polymer compositions of Synthesis Examples 1 to 6 and Comparative Synthesis Examples 1 to 3 shown in Tables 1 and 2, weight average molecular weight (Mw), glass transition temperature (Tg), storage stability, and acid value were obtained by the methods shown below. Each physical property of was measured and evaluated. The results are shown in Table 1 and Table 2, respectively.

<Weight average molecular weight (Mw)>

The weight average molecular weight (Mw) of each of the copolymers (A) included in the polymer compositions of Synthesis Examples 1 to 6 and Comparative Synthesis Examples 1 to 3 was measured.

The weight average molecular weight is a weight average molecular weight in terms of standard polystyrene measured using gel permeation chromatography (GPC) under the following conditions.

Column: Shodex (registered trademark) LF-804+LF-804 (manufactured by Showa Denko Co., Ltd.)

Column temperature: 40°C

Sample: 0.2% by mass tetrahydrofuran solution of the copolymer

Developing solvent: tetrahydrofuran

Detector: Differential refractometer (Shodex (registered trademark) RI-71S) (manufactured by Showa Denko Co., Ltd.)

Flow rate: 1mL/min

<Glass transition temperature (Tg)>

The polymer compositions of Synthesis Examples 1 to 6 and Comparative Synthesis Examples 1 to 3 were applied to glass substrates and dried at 50°C under reduced pressure for 24 hours. After that, it was dissolved again in acetone and dried at 50°C under reduced pressure for 24 hours. The solid content of the copolymer solution from which the volatile components were removed in this way was measured in accordance with JIS-K7121 at a heating rate of 10°C/min under a nitrogen stream using DSC (differential scanning calorimetry, measuring instrument: Seiko DSC6200) (midpoint glass transition point). The obtained result was taken as the glass transition temperature (Tg) of copolymer (A).

<Storage stability>

After adjustment, the polymer compositions of Synthesis Examples 1 to 6 and Comparative Synthesis Examples 1 to 3 containing 35% by mass of components other than the solvent were measured in equal amounts in a glass container, covered with a lid to prevent dust from entering, and used as samples. After measuring the viscosity of each sample, it was allowed to stand for 3 months in an incubator maintained at 12°C. And the viscosity of each sample left still for 3 months was measured. In addition, the measurement of the viscosity was performed at 25 degreeC and rotation speed 10rpm using the E-type viscometer (RE-80L, Toki Sangyo make, cone No.3).

For each sample, the thickening rate {(1-(viscosity after standing for 3 months/viscosity before standing)) × 100 (%)} of the viscosity after standing for 3 months with respect to the viscosity before standing in a thermostat was calculated , evaluated according to the criteria shown below.

◎ (excellent): 10% or less thickening rate

○ (good): thickening rate of 10.1% to 20%

△ (deterioration): 20.1% or more thickening rate

As shown in Tables 1 and 2, the evaluation of storage stability of the polymer compositions of Synthesis Examples 1 to 6 and Comparative Synthesis Example 3 was ◎ (excellent) or ○ (good), and it was confirmed that they had excellent storage stability. It became.

In contrast, as shown in Table 2, the polymer compositions of Comparative Synthesis Examples 1 and 2 had an evaluation of storage stability of Δ (deterioration), and although they were not cured by storage, their viscosity increased compared to the results of Examples, resulting in storage stability. Stability was insufficient.

<acid value>

The acid values of the polymer compositions of Synthesis Examples 1 to 6 and Comparative Synthesis Examples 1 to 3 were respectively measured and set as the acid value of the copolymer (A).

It is the acid value of the curable polymer measured according to JIS K6901 5.3. That is, the acid value means the number of milligrams of potassium hydroxide required to neutralize the acidic component contained in 1 g of the copolymer.

[Examples 1 to 6, Comparative Examples 1 to 3]

Polymer compositions of Synthesis Examples 1 to 6 and Comparative Synthesis Examples 1 to 3 shown in Tables 1 and 2, (B) propylene glycol monomethyl ether acetate as a solvent, and (C) dipentaerythritol pentaacrylate as a reactive diluent and dipentaerythritol hexaacrylate (Kayarad DPHA, manufactured by Nippon Kayaku Co., Ltd.), (D) ethanone as a photopolymerization initiator, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carb Bazol-3-yl] -, 1- (o-acetyloxime) (manufactured by BASF Japan Co., Ltd.) and (E) a dye (VALIFAST BLUE 2620) as a coloring agent were mixed in the ratios shown in Table 3, respectively, and carried out Resin compositions of Examples 1 to 6 and Comparative Examples 1 to 3 were prepared.

In the copolymer (A) shown in Table 3, the amount of the solvent contained in the reaction solution used when preparing the copolymer (A) is not included.

The amount of the solvent (B) shown in Table 3 is the sum of the solvent (propylene glycol monomethyl ether) contained in the polymer composition and the solvent (propylene glycol monomethyl ether acetate) added at the time of production of the resin composition. The content ratio of the hydroxy group-containing solvent in the solvent (B) shown in Table 3 is 79.1% by mass.

About the resin compositions of Examples 1-6 and Comparative Examples 1-3, alkali developability and solvent resistance were evaluated by the method shown below.

(1) alkali developability

The resin compositions of Examples and Comparative Examples were spin-coated so that the thickness after exposure was 2.5 μm on a planar view square glass substrate (alkali-free glass substrate) with a length of 5 cm and a width of 5 cm, respectively, to form a coating film. Subsequently, by heating at 100°C for 3 minutes, the solvent in the coated film was volatilized and removed.

Subsequently, a photomask having a predetermined pattern was placed at a distance of 100 μm from the coating film, and ultraviolet rays having a wavelength of 365 nm were irradiated to the coating film through the photomask at an energy dose of 40 mJ/cm 2 to expose the exposed portion to photocuring. made it

Subsequently, an aqueous solution containing 0.1% by mass of sodium carbonate was sprayed at a temperature of 23°C and a pressure of 0.3 MPa, and the unexposed portion was dissolved and developed. After that, a predetermined pattern was formed by baking at 100°C for 20 minutes.

Then, by observing the pattern after alkali development using an electron microscope S-3400 manufactured by Hitachi High-Technologies Co., Ltd., the residue after alkali development was confirmed and evaluated according to the criteria shown below. The results are shown in Table 4.

○ (Good): No residue in the unexposed part

× (unavailable): Residues in unexposed areas

(2) solvent resistance

The resin compositions of Examples and Comparative Examples were spin-coated so that the thickness after exposure was 2.5 μm on a planar view square glass substrate (alkali-free glass substrate) with a length of 5 cm and a width of 5 cm, respectively, to form a coating film. Subsequently, by heating at 100°C for 3 minutes, the solvent in the coated film was volatilized and removed.

Next, the coated film was exposed to light by irradiating ultraviolet light having a wavelength of 365 nm at an energy dose of 40 mJ/cm 2 , and the exposed portion was photocured. Then, the coated film was cured by baking at 80°C for 30 minutes or at 100°C for 20 minutes to obtain a cured film.

The created cured film was immersed in 20 g of propylene glycol monomethyl ether at 23°C for 15 minutes. The color change (ΔEab) before and after immersion of the cured film was measured with a spectrophotometer UV-1650PC (manufactured by Shimadzu Corporation), and solvent resistance was evaluated based on the result. The results are shown in Table 4. In addition, the smaller the value of the color change before and after immersion, the better.

As shown in Table 4, the cured films obtained by curing the resin compositions of Examples 1 to 6 had good alkali developability evaluation.

The cured films obtained by curing the resin compositions of Examples 1 to 6 were either cured at a temperature of 80°C for 30 minutes or at a temperature of 100°C for 20 minutes. , ΔEab was less than 2, and the solvent resistance was good.

The cured films obtained by curing the resin compositions of Comparative Examples 1 to 3 had good alkali developability evaluation. However, the cured films obtained by curing the resin compositions of Comparative Examples 1 and 2 had ΔEab of 2 or more when the temperature for curing the coating film was 80°C and the time was 30 minutes, and the solvent resistance was insufficient. In addition, the cured film obtained by curing the resin composition of Comparative Example 3 had a ΔEab of 2 even when the temperature for curing the coating film was 80°C and the time was 30 minutes, and the temperature was 100°C and the time was 20 minutes. above, and the solvent resistance was insufficient.

According to the present invention, when used as a photosensitive material, a resin composition having good alkali developability, excellent storage stability, and excellent solvent resistance even when cured at a low temperature is obtained, and air useful for preparing the resin composition. Methods for preparing the polymers and copolymers are provided. Further, according to the present invention, a color pattern comprising a cured product of a resin composition having good alkali developability and excellent solvent resistance even when cured at a low temperature, a color filter having the cured product, and an image display provided with the color filter A device is provided.

The resin composition of the present invention can be suitably used in a wide range of applications as materials such as transparent films, protective films, insulating films, overcoats, photo spacers, black matrices, black column spacers, and resists for color filters.

Claims (15)

A structural unit (a) having a block isocyanato group blocked with a pyrazole compound;
A structural unit (b) having a hydroxyl group;
Containing a structural unit (c) having an acid group,
A copolymer characterized by having a glass transition temperature of 30°C or less. The copolymer according to claim 1, wherein the structural unit (b) is a structural unit derived from hydroxyalkyl (meth)acrylate. The copolymer according to claim 1 or 2, wherein the structural unit (c) is a structural unit derived from an unsaturated carboxylic acid. The copolymer according to any one of claims 1 to 3, wherein the structural unit (a) is a structural unit derived from a compound having the block isocyanato group and a (meth)acryloyloxy group. The structural unit (a) according to any one of claims 1 to 4, wherein the structural unit (a) is 1 to 45 mol%, the structural unit (b) is 1 to 50 mol%, and the structural unit (c) is 1 to 60 A copolymer containing mol%. The copolymer according to any one of claims 1 to 5, which has a weight average molecular weight of 1000 to 50000. Containing the copolymer (A) according to any one of claims 1 to 6 and a solvent (B),
A resin composition characterized in that the solvent (B) contains a hydroxy group-containing solvent. The resin composition according to claim 7, further comprising a reactive diluent (C) and a photopolymerization initiator (D). The resin composition according to claim 8, further comprising a coloring agent (E). The method according to claim 9, based on 100 parts by mass of the total amount of the copolymer (A) and the reactive diluent (C),
10 to 90 parts by mass of the copolymer (A);
30 to 1000 parts by mass of the solvent (B);
10 to 90 parts by mass of the reactive diluent (C);
0.1 to 30 parts by mass of the photopolymerization initiator (D);
A resin composition containing 3 to 80 parts by mass of the coloring agent (E). A color filter characterized by having a color pattern comprising a cured product of the resin composition according to claim 9 or 10. An image display element comprising the color filter according to claim 11. A solvent heating step (I) of raising the temperature of the solvent (B-1) to 60 to 90 ° C;
The monomer (ma) having a block isocyanato group blocked with a pyrazole compound, the hydroxy group-containing monomer (mb), and the acid group-containing monomer (mc) are added dropwise to the solvent (B-1) heated up,
A dropwise polymerization step (II) of adding a polymerization initiator solution obtained by dissolving a polymerization initiator in a solvent (B-2) dropwise to the solvent (B-1) to obtain a mixed solution;
A post-polymerization step (III) of reacting the mixed solution at 60 to 90 ° C. for 1 to 5 hours while stirring,
A method for producing a copolymer characterized in that one or both of the solvent (B-1) and the solvent (B-2) contain a hydroxy group-containing solvent. The method for producing a copolymer according to claim 13, wherein in the solvent heating step (I), the temperature is raised after a chain transfer agent is added to the solvent (B-1). The method of claim 13, by the post-polymerization step (III),
Air containing a structural unit (a) having a block isocyanato group blocked with a pyrazole compound, a structural unit (b) having a hydroxy group, and a structural unit (c) having an acid group, and having a glass transition temperature of 30 ° C. or less A method for producing a copolymer capable of obtaining a copolymer.