WO2022138173A1

WO2022138173A1 - Copolymer, and method for producing said copolymer

Info

Publication number: WO2022138173A1
Application number: PCT/JP2021/045180
Authority: WO
Inventors: 英理永井; 健宏木下; 正義柳
Original assignee: 昭和電工株式会社
Priority date: 2020-12-24
Filing date: 2021-12-08
Publication date: 2022-06-30
Also published as: TW202237675A; JPWO2022138173A1; KR20230096058A; CN116529268A

Abstract

This copolymer contains a structural unit (a) having a blocked isocyanate group blocked by a pyrazole compound, a structural unit (b) having a hydroxy group, and a structural unit (c) having an acid group, wherein the copolymer has a glass transition temperature of at most 30 °C.

Description

Copolymer and method for producing the copolymer

The present invention relates to a copolymer, a resin composition, a color filter, an image display element, and a method for producing a copolymer.
This application claims priority based on Japanese Patent Application No. 2020-215474 filed in Japan on December 24, 2020, the contents of which are incorporated herein by reference.

Generally, an organic electroluminescence (EL) display device (particularly, a WRGB method that combines a white light emitting organic EL and a color filter), a liquid crystal display element, an integrated circuit element, a color filter for an image display element such as a solid-state image sensor, A film such as a black matrix, a color filter protective film, a photo spacer, a protrusion for liquid crystal alignment, a microlens, an insulating film for a touch panel, and a fine pattern are provided.

In recent years, with the flexibility and wearability of displays, the switch from glass to organic materials such as resin has been promoted in the substrate material. Organic materials are inferior in heat resistance to glass. Therefore, in a member formed by thermosetting a resin composition on a substrate, it is desired to lower the temperature at which the resin composition is thermoset according to the heat resistance of the substrate made of an organic material.
For example, a color filter has conventionally been formed by thermally curing a resin composition on a substrate at a temperature of 210 to 230 ° C. However, when a color filter is formed on a flexible substrate made of a resin, the heat resistance of the substrate is inferior, so that it is required to thermally cure the resin composition at a temperature of 80 to 150 ° C.

In particular, in a color filter used in an organic EL display device, there is a tendency to increase the content of a colorant contained in the resin composition in order to improve color reproducibility. Generally, a resin composition containing a large amount of a colorant is difficult to be photocured. Therefore, in the resin composition used for the color filter of the organic EL display device, it is more important to cure by cross-linking by heat. For this reason, in the resin composition used for the color filter of the organic EL display device, there is an increasing need to improve the thermosetting property at a low temperature.

Conventionally, as a resin composition used as a material of a color filter, there are those described in Patent Document 1 and Patent Document 2, for example.
Patent Document 1 describes (a) a polymerization initiator having an extinction coefficient of 365 nm in methanol of 1.0 × 10 ³ mL / gcm or more, and (b) an extinction coefficient of 365 nm in methanol of 1.0 ×. A polymerization initiator having an extinction coefficient of 102 mL / g cm or less and an extinction coefficient of 254 nm of 1.0 × ^{10 3} ^mL / g cm or more, (c) a compound having an unsaturated double bond, (d) an alkali-soluble resin, ( e) A photosensitive coloring composition containing a coloring material is disclosed.
Patent Document 2 describes a photosensitive composition for a color filter containing a compound (A) containing a frill group, a compound (B) containing a photopolymerizable functional group, a photopolymerization initiator (C), and a colorant. It has been disclosed.

JP-A-2015-041058 JP-A-2017-194662

However, the conventional resin composition has good developability and storage stability when used as a photosensitive material, and does not provide a cured product having excellent solvent resistance when cured at a low temperature. rice field.
The present invention has been made in view of the above circumstances, has good developability when used as a photosensitive material, has excellent storage stability, and has excellent solvent resistance even when cured at a low temperature. It is an object of the present invention to provide a resin composition for obtaining a cured product, a copolymer useful for preparing the resin composition, and a method for producing the copolymer.
Further, the present invention provides a color filter having a coloring pattern made of a cured product of a resin composition, which has good developability and a cured product having excellent solvent resistance even when cured at a low temperature, and a color filter thereof. It is an object of the present invention to provide an image display element provided.

The first aspect of the present invention provides the following copolymers. [1] A structural unit (a) having a blocked isocyanate group blocked with a pyrazole compound, and
The structural unit (b) having a hydroxy group and
Containing a structural unit (c) having an acid group,
A copolymer characterized by having a glass transition temperature of 30 ° C. or lower.

The copolymer of the first aspect of the present invention preferably has the characteristics described in the following [2] to [6]. It is also preferable to arbitrarily combine two or more of the features described in the following [2] to [6]. [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 isocyanate group and the (meth) acryloyloxy group. Polymer.

[5] [1] to [4] contain the structural unit (a) in an amount of 1 to 45 mol%, the structural unit (b) in an amount of 1 to 50 mol%, and the structural unit (c) in an amount of 1 to 60 mol%. ] The copolymer according to any one of.
[6] The copolymer according to any one of [1] to [5], which has a weight average molecular weight of 1000 to 50,000.

A second aspect of the present invention provides the following resin composition.
[7] The copolymer (A) according to any one of [1] to [6] and the solvent (B) are contained, and the solvent (B) contains a hydroxy group-containing solvent. Resin composition to be used.
The second aspect of the present invention preferably has the following features [8] to [10]. It is also preferable that these features are used in combination.
[8] The resin composition according to [7], which further contains a reactive diluent (C) and a photopolymerization initiator (D).
[9] The resin composition according to [8], further containing the colorant (E).

[10] With respect to 100 parts by mass of the total amount of the copolymer (A) and the reactive diluent (C).
The copolymer (A) is 10 to 90 parts by mass,
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], which contains 3 to 80 parts by mass of the colorant (E).

A third aspect of the present invention provides the following color filters.
[11] A color filter having a coloring pattern made of a cured product of the resin composition according to [9] or [10].
A fourth aspect of the present invention provides the following image display element.
[12] An image display element comprising the color filter according to [11].

A fifth aspect of the present invention provides the following method for producing a copolymer.
[13] The solvent heating step (I) for raising the temperature of the solvent (B-1) to 60 to 90 ° C.
The solvent (B) in which the temperature of the monomer (ma) having a blocked isocyanato group blocked by the pyrazole compound, the hydroxy group-containing monomer (mb), and the acid group-containing monomer (mc) was heated. In addition to dropping in -1)
A dropping polymerization step (II) in which a polymerization initiator solution in which a polymerization initiator is dissolved in a solvent (B-2) is added dropwise to the solvent (B-1) to form a mixed solution.
It has a post-polymerization step (III) in which the mixed solution is reacted at 60 to 90 ° C. for 1 to 5 hours while stirring.
A method for producing a copolymer, wherein one or both of the solvent (B-1) and the solvent (B-2) contains a hydroxy group-containing solvent.

It is also preferable that the fifth aspect of the present invention has the following features [14] and [15].
[14] The method for producing a copolymer according to [13], wherein in the solvent heating step (I), a chain transfer agent is added to the solvent (B-1) and then the temperature is raised.
[15] The structural unit (a) having a blocked isocyanato group blocked by the pyrazole compound, the structural unit (b) having a hydroxy group, and the structural unit (c) having an acid group by the post-polymerization step (III). The method for producing a copolymer according to [13], wherein a copolymer containing (1) and having a glass transition temperature of 30 ° C. or lower can be obtained.

According to the present invention, a resin composition capable of obtaining a cured product having good alkali developability when used as a photosensitive material, excellent storage stability, and excellent solvent resistance even when cured at a low temperature. A product, a copolymer useful for preparing the resin composition, and a method for producing the copolymer can be provided.
Further, according to the present invention, a color filter having a coloring pattern made of a cured product of a resin composition having good alkali developability and a cured product having excellent solvent resistance even when cured at a low temperature, and a color filter thereof. An image display element provided with a color filter can be provided.

Hereinafter, the copolymer of the present invention, the method for producing the copolymer, the resin composition, the color filter, and the image display element will be described in detail. However, the present invention is not limited to the embodiments shown below. For example, the present invention is not limited to the following examples, and additions, omissions, and substitutions are added, omitted, and substituted with respect to numbers, quantities, ratios, compositions, types, positions, materials, configurations, etc., without departing from the spirit of the present invention. Or, it can be changed.

In addition, what is described as (meth) acrylate in this specification means that either acrylate or methacrylate may be used. Further, what is described as (meth) acrylic acid means that either acrylic acid or methacrylic acid may be used.

<Copolymer (A)>
The copolymer (A) of the present embodiment has a structural unit (a) having a blocked isocyanato group blocked with a pyrazole compound (hereinafter, also simply referred to as “constituent unit (a)”) and a hydroxy group. It contains a structural unit (b) (hereinafter, also simply referred to as “constituent unit (b)”) and a structural unit (c) having an acid group (hereinafter, also simply referred to as “constituent unit (c)”). ..

<Constituent unit (a)>
The structural unit (a) is a structural unit derived from a monomer (ma) having a blocked isocyanate group blocked with a pyrazole compound (hereinafter, also simply referred to as “monomer (ma)”). The blocked isocyanate 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 isocyanate group. Then, it reacts with the hydroxy group of the structural unit (b) to form a crosslinked structure. Therefore, the resin composition containing the copolymer (A) can be cured at a low temperature of 50 ° C. to 150 ° C. to obtain a cured film having excellent solvent resistance.

Examples of the pyrazole compound that is a blocking agent for the block isocyanato group include pyrazole; alkylpyrazole such as 3-methylpyrazole and 5-ethylpyrazole; and dialkylpyrazole such as 3,5-dimethylpyrazole and 3,5-diethylpyrazole; 3-. Examples thereof include acetylaminopyrazole and pyrazole-3,5-dicarboxylic acid diethyl ester. Among these, dialkylpyrazole is preferable, and 3,5-dimethylpyrazole is more preferable, from the viewpoint of low-temperature curability as a resin composition and availability of raw materials.

The monomer (ma) that gives the structural unit (a) is not particularly limited as long as it is a compound that can be copolymerized with the hydroxy group-containing monomer (mb) and the acid group-containing monomer (mc) described later. .. As the monomer (ma), for example, a monomer having a blocked isocyanato group and an ethylenically unsaturated bond can be used from the viewpoint of reactivity when synthesizing the copolymer (A). Specific examples of the group having an ethylenically unsaturated bond include a vinyl group and a (meth) acryloyloxy group.

Examples of the monomer (ma) having a block isocyanato group and an ethylenically unsaturated bond include a reaction product of an ethylenically unsaturated group-containing isocyanate compound and a pyrazole compound.
These monomers (ma) may be used alone or in combination of two or more.

The ethylenically unsaturated group-containing isocyanate compound used for forming the monomer (ma) or possessed by the monomer (ma) is preferably a compound represented by the following formula (1).

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

As described above, ^R4 in the formula (1) represents a hydrogen atom or a methyl group.
R ⁵ in the 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. Further, R ⁸ is an alkylene group having 2 to 12 carbon atoms or an arylene group having 6 to 12 carbon atoms which may have a substituent. For example, the number of carbon atoms of the alkylene group may be 3 to 10 or 4 to 8. The number of carbon atoms of the arylene group may be 7 to 10 or 8 to 9. Among these, R ⁵ in the 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.

Specific examples of the ethylenically unsaturated group-containing isocyanate compound represented by the above formula (1) include 2-isocyanatoethyl (meth) acrylate, 2-isocyanatopropyl (meth) acrylate, and 3-isocyanatopropyl. (Meta) acrylate, 2-isocyanato-1-methylethyl (meth) acrylate, 2-isocyanato-1,1-dimethylethyl (meth) acrylate, 4-isocyanatocyclohexyl (meth) acrylate, (meth) acryloyl isocyanate, etc. Can be mentioned.

Further, as the ethylenically unsaturated group-containing isocyanate compound represented by the above formula (1), an equimolar (1 mol: 1 mol) reaction product of a 2-hydroxyalkyl (meth) acrylate and a diisocyanate compound can also be used. .. As the alkyl group contained in the above-mentioned 2-hydroxyalkyl (meth) acrylate, an ethyl group or an n-propyl group is preferable, and an ethyl group is more preferable. Examples of the above-mentioned diisocyanate compound include hexamethylene diisocyanate, 2,4- (or 2,6-) toluene diisocyanate (TDI), 4,4'-diphenylmethane diisocyanate (MDI), and 3,5,5-trimethyl-. Examples thereof include 3-isocyanatomethylcyclohexylisocyanate (IPDI), m- (or p-) xylenediisocyanate, 1,3- (or 1,4-) bis (isocyanatomethyl) cyclohexane, and lysine diisocyanate.

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

The reaction between the ethylenically unsaturated group-containing isocyanate compound and the pyrazole compound can be carried out with or without the presence of a solvent. When the above reaction is carried out using a solvent, a solvent that is inert to the isocyanato group is used. In the above reaction, an organometallic salt such as tin, zinc, lead or the like, a tertiary amine or the like may be used 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 above reaction is −20 ° C. or higher, a sufficient reaction rate can be obtained. Further, when the temperature of the reaction is 150 ° C. or lower, the monomer (ma) that gives the structural unit (a) generated after the reaction is produced by polymerizing the raw material having C = C (double bond). It is possible to prevent gelation.

Specific examples of the reaction product of the ethylenically unsaturated group-containing isocyanate compound and the pyrazole compound include 2-[(3,5-dimethylpyrazolyl) carbonylamino] ethyl methacrylate and 2-[(3-methyl). Pyrazolyl) carbonylamino] ethyl methacrylate and the like. Among these, a easily available resin composition containing the copolymer (A) has good curability, and by curing the resin composition, a cured product having excellent solvent resistance can be obtained. Therefore, 2-[((A) 3,5-Dimethylpyrazolyl) carbonylamino] ethyl methacrylate is preferred.

<Constituent unit having a hydroxy group (b)>
The structural unit (b) having a hydroxy group contained in the copolymer (A) does not have a block isocyanate group but has a hydroxy group. The structural unit (b) is a structural unit derived from a monomer (mb) having a hydroxy group (hereinafter, also simply referred to as “monomer (mb)”) (however, in the structural unit (a)). Applicable ones are excluded). The hydroxy group of the structural unit (b) contained in the copolymer (A) is a block isocyanate contained in the structural unit (a) by thermally curing the resin composition containing the copolymer (A). The group reacts with the isocyanato group produced by deblocking to form a crosslinked structure.

The monomer (mb) that gives the structural unit (b) is not particularly limited as long as it does not have a block isocyanato group and has a polymerizable unsaturated bond and a hydroxy group. Examples of the monomer (mb) include (meth) acrylic acid ester derivatives having a hydroxy group. Specific examples of such a monomer (mb) include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, and 2,3-. Examples thereof include dihydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and 2-hydroxy-3-phenoxypropyl (meth) acrylate. These monomers (mb) may be used alone or in combination of two or more.

As the monomer (mb), among the above-mentioned monomers, the reactivity at the time of synthesizing the copolymer (A) and the low-temperature curability of the resin composition containing the copolymer (A) are available. From the viewpoint of ease, hydroxyalkyl (meth) acrylate is preferable. Examples of hydroxyalkyl (meth) acrylates are 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and 4-hydroxybutyl (meth) acrylate, which are easily available and have a copolymer (A). ), 2-Hydroxyethyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate are more preferable from the viewpoint of reducing the glass transition temperature.

<Constituent unit having an acid group (c)>
The structural unit (c) having an acid group contained in the copolymer (A) does not have a block isocyanato group and a hydroxy group, but has an acid group. The structural unit (c) is a structural unit derived from a monomer (mc) having an acid group (hereinafter, also simply referred to as “monomer (mc)”) (however, the structural unit (a) and the constitutional unit (c)). Excluding those corresponding to unit (b)). Since the copolymer (A) contains the structural unit (c), the alkali developability becomes good when the resin composition containing the copolymer (A) is used as a photosensitive material.

Examples of the acid group contained in the structural unit (c) include a carboxy group, a sulfo group, a phospho group and the like. Among these acid groups, a carboxy group is preferable as the acid group of the structural unit (c) from the viewpoint of easy availability.
The monomer (mc) that gives the structural unit (c) is not particularly limited as long as it is a monomer that does not have a blocked isocyanato group or a hydroxy group and has a polymerizable unsaturated bond and an acid group. Examples of the monomer (mc) include unsaturated carboxylic acid or an anhydride thereof, unsaturated sulfonic acid, unsaturated phosphonic acid and the like.

Specific examples of the monomer (mc) include (meth) acrylic acid, α-bromo (meth) acrylic acid, β-frill (meth) acrylic acid, crotonic acid, propiole acid, and silicic acid. Unsaturated carboxylic acids such as α-cyanosilicate skin acid, maleic acid, maleic anhydride, monomethyl maleate, monoethyl maleate, monoisopropyl maleate, fumaric acid, itaconic acid, itaconic anhydride, citraconic acid, and citraconic anhydride thereof. Anhydrous; unsaturated sulfonic acid such as 2-acrylamide-2-methylpropanesulfonic acid, tert-butylacrylamide sulfonic acid, p-styrenesulfonic acid; unsaturated phosphonic acid such as vinylphosphonic acid; and the like. These monomers (mc) may be used alone or in combination of two or more.

As the monomer (mc), among these monomers, an unsaturated carboxylic acid is easily available and the resin composition containing the copolymer (A) has excellent alkaline developability. It is preferable to use, and 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 the copolymer (A) will be described.
The ratio 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%. Is. If necessary, it may be 18 to 33 mol%, 20 to 30 mol%, 25 to 28 mol%, or the like.
The ratio 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%. Is. If necessary, it may be 15 to 40 mol%, 18 to 33 mol%, 20 to 30 mol%, 22 to 25 mol%, or the like.
The ratio 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%. Is. If necessary, it may be 13 to 35 mol%, 15 to 30 mol%, 20 to 28 mol%, 22 to 25 mol%, or the like.

Therefore, it is preferable that the copolymer (A) contains 1 to 45 mol% of the constituent unit (a), 1 to 50 mol% of the constituent unit (b), and 1 to 60 mol% of the constituent 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. As a result, the hydroxy group of the structural unit (b) and the isocyanate group generated by deblocking the blocked isocyanato group of the structural unit (a) react with each other to sufficiently form a crosslinked structure. Therefore, the resin composition containing the copolymer (A) containing 1 mol% or more of the structural unit (a) and the structural unit (b), respectively, is a cured product having good solvent resistance even when thermally cured at a low temperature. Is obtained.

When the proportion of the structural unit (a) in the copolymer (A) is 45 mol% or less, the storage stability of the resin composition containing the copolymer (A) becomes better. Further, when the ratio of the constituent unit (a) is 45 mol% or less, it becomes easy to secure the contents of the constituent unit (b) and the constituent unit (c). Therefore, the effect of including the constituent unit (b) and the constituent unit (c) can be easily obtained.

Further, when the ratio of the constituent unit (b) in the copolymer (A) is 50 mol% or less, gelation during the polymerization reaction for producing the copolymer (A) can be prevented. Further, the crosslinked structure formed by the reaction between the isocyanato group generated by deblocking the blocked isocyanato group of the structural unit (a) and the structural unit (b) is not excessively generated, and the copolymer (A) is produced. The storage stability of the contained resin composition becomes better. Further, when the ratio of the constituent unit (b) is 50 mol% or less, it becomes easy to secure the contents of the constituent unit (a) and the constituent unit (c). Therefore, it becomes easy to obtain the effect of including the constituent unit (a) and the constituent unit (c).

When the proportion of the structural unit (c) in the copolymer (A) is 1 mol% or more, the resin composition containing the copolymer (A) has a sufficiently high alkaline development rate. .. When the ratio of the constituent unit (c) in the copolymer (A) is 60 mol% or less, the alkaline development speed of the resin composition containing the copolymer (A) is appropriately suppressed, so that it is precise. It becomes easier to form a pattern. Further, when the ratio of the structural unit (c) in the copolymer (A) is 60 mol% or less, it becomes easy to secure the contents of the structural unit (a) and the structural unit (b). Therefore, even when the resin composition containing the copolymer (A) is cured at a low temperature, it becomes easy to obtain a cured product having better solvent resistance.

The total amount of the content of the structural unit (a) and the content of the structural unit (b) contained in the copolymer (A) is preferably 10 to 90 mol%, preferably 20 to 80 mol%. It is more preferably present, and even more preferably 30 to 70 mol%. If necessary, it may be 35 to 65 mol%, 40 to 60 mol%, 45 to 55 mol%, or the like. 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) has more storage stability. It is possible to obtain a cured product having excellent solvent resistance even when cured at a low temperature. Further, since the content of the structural unit (c) can be easily secured, it becomes easy to obtain a resin composition having better alkaline developability when used as a photosensitive material.

When the resin composition containing the copolymer (A) contains a compound having a hydroxy group as the reactive diluent (C) in addition to the copolymer (A), it is contained in the copolymer (A). The total amount of hydroxy groups contained in the structural unit (b) is preferably reduced according to the amount of hydroxy groups contained in the reactive diluent (C).
Specifically, the total amount of the blocked isocyanato group contained in the constituent unit (a) and the total amount of the hydroxy groups contained in the resin composition (the hydroxy group possessed by the constituent unit (b) and the reactive diluent (C)). The molar ratio with the hydroxy group contained in the above is preferably 10:90 to 90:10, more preferably 30:70 to 70:30, and 40:60 to 60:40. It is more preferable to have. When the molar ratio is in the above range, the resin composition containing the copolymer (A) is thermally cured to contain the hydroxy group contained in the resin composition and the block isocyanato having the structural unit (a). A crosslinked structure is easily generated by the reaction with the isocyanato group generated by the deblocking of the group. Therefore, a cured product having even better solvent resistance can be obtained.

<Other structural units (d)>
The copolymer (A) of the present embodiment includes the structural units (a) to (c) as well as other structural units (d) that can be copolymerized with the structural units (a) to (c) (provided that the structural units (a) to (a) to the same. (Excluding those corresponding to (c)) may be contained.

The monomer (md) that gives the other structural unit (d) (hereinafter, also simply referred to as “monomer (md)”) does not have a block isocyanato group, a hydroxy group, or an acid group, and is a monomer (hereinafter, also referred to as “monomer (md)”). The compound is not particularly limited as long as it is a compound copolymerizable with the mA) to the monomer (mc).

Specific examples of the monomer (md) that gives the other structural unit (d) include styrene, α-methylstyrene, o-vinyltoluene, p-vinyltoluene, o-chlorostyrene, m-chlorostyrene, and methoxystyrene. , P-nitrostyrene, p-cyanostyrene, p-acetylaminostyrene and other aromatic vinyl compounds; norbornene (bicyclo [2.2.1] hept-2-ene), 5-methylbicyclo [2.2.1] ] Hept-2-ene, tetracyclo [4.4.0.1 ^2,5 . 17 and ¹⁰ ] Dodeca-3-ene, 8-ethyltetracyclo [4.4.0.1 ^2,5 . 1 ⁷ , 10] Dodeca-3-en, Dicyclopentadiene, Tricyclo [5.2.1.0 ^2,6 ] Deca-8-en, Tricyclo [4.4.0.1 ^2,5 ] Undeca-3 -En, tricyclo [6.2.1.0 ^1,8 ] Undeca-9-en, tetracyclo [4.4.0.1 ^2,5 . ^{17 and 10} . 0 ^1,6 ] Dodeca-3-en, 8-ethylidenetetracyclo [4.4.0.1 ^2,5 . 17 and ¹² ] Dodeca-3-ene, pentacyclo [6.5.1.1 ^3,6 . 0 ^2,7 . ^09,13 ] Cyclic olefins having a norbornene structure such as pentadeca-4-ene; dienes such as butadiene, isoprene and chloroprene; methyl (meth) acrylates, ethyl (meth) acrylates, iso-propyl (meth) acrylates, tert- Butyl (meth) acrylic rate, pentyl (meth) acrylate, benzyl (meth) acrylate, isoamyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, dodecyl (meth) acrylate, cyclohexyl (meth) acrylate , Methylcyclohexyl (meth) acrylate, rosin (meth) acrylate, norbornyl (meth) acrylate, 5-ethylnorbornyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclo Penthenyloxyethyl acrylate, isobornyl (meth) acrylate, adamantyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, 1,1,1-trifluoroethyl (meth) acrylate, perfluoroethyl (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, biphenyloxyethyl (meth) acrylate, naphthalene (meth) acrylate, anthracene (meth) acrylate, ethoxylated (Meta) acrylic acid esters such as phenyl (meth) acrylate; (meth) acrylic acid amide, (meth) acrylic acid N, N-dimethylamide, (meth) acrylic acid N, N-di-isopropylamide, (meth) (Meta) Acrylate Amides such as Acrylate Anthracenylamide; (Meta) Acrylate Anilide, (Meta) Acrylonitrile, Achlorine, Vinyl Chloride, Vinylidene Chloride, Vinyl Fluoride, Vinylidene Fluoride, N-Vinylpyrrolidone, Vinylpyridine , Vinyl acetate, vinyl compounds such as vinyl toluene; diethyl citratenate, diethyl maleate, fu Unsaturated dicarboxylic acid diesters such as diethyl maleate, diethyl itaconic acid; monomaleimides such as N-phenylmaleimide, N-cyclohexylmaleimide, N-laurylmaleimide, N- (4-hydroxyphenyl) maleimide; glycidyl (meth) acrylate, And so on.

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

When the copolymer (A) contains the other structural unit (d), the ratio thereof is not particularly limited, but is preferably 1 to 80 mol%, more preferably 5 to 75 mol%. Most preferably, it is 10 to 50 mol%. If necessary, it may be 3 to 45 mol%, 5 to 40 mol%, 10 to 35 mol%, 15 to 30 mol%, or 12 to 25 mol%. When the copolymer (A) contains the other structural unit (d), the properties such as solvent resistance of the cured product of the 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 secure the content of the structural unit (a) to the structural unit (c), and the structural unit (a) to the structural unit (c). ) Is included, and the effect is remarkable.

(Weight average molecular weight (Mw))
The polystyrene-equivalent weight average molecular weight of the copolymer (A) is not particularly limited, but is preferably 1,000 to 50,000, more preferably 3,000 to 40,000. If necessary, it may be 5,000 to 20,000, 7,000 to 15,000, 9,000 to 12,000, or the like. When the weight average molecular weight of the copolymer (A) is 1,000 or more, the alkali developability when the resin composition containing the copolymer (A) is used as a photosensitive material becomes good, and the pattern is obtained after the alkali development. It becomes difficult for the chip to occur. On the other hand, when the weight average molecular weight of the copolymer (A) is 50,000 or less, the development time when the resin composition containing the copolymer (A) is used as a photosensitive material becomes appropriate and practical. Is secured.

(Glass transition temperature (Tg))
The glass transition temperature (Tg) of the copolymer (A) is 30 ° C. or lower, preferably 20 ° C. or lower, and more preferably 0 ° C. or lower. If the glass transition temperature of the copolymer (A) is more than 30 ° C., the curability at a low temperature is adversely affected. Therefore, the glass transition temperature of the copolymer (A) is set to 30 ° C. or lower. The glass transition temperature of the copolymer (A) is preferably −50 ° C. or higher, more preferably −40 ° C. or higher, and even more preferably −30 ° C. or higher. When the glass transition temperature of the copolymer (A) is −50 ° C. or higher, the resin composition containing the copolymer (A) can obtain a cured film having excellent heat resistance. If necessary, the glass transition temperature is −45 ° C. or higher and 25 ° C. or lower, −35 ° C. or higher and 15 ° C. or lower, -25 ° C. or higher and 10 ° C. or lower, or −15 ° C. or higher and 5 ° C. or lower. It may be as follows.

(Acid value)
The acid value of the copolymer (A) (JIS K6901 5.3) can be appropriately selected. The acid value of the copolymer (A) is preferably 20 to 300 KOH mg / g, more preferably 30 to 200 KOH mg / g when the resin composition containing the copolymer (A) is used as a photosensitive material. g. If necessary, it may be 40 to 150 KOH mg / g, 50 to 100 KOH mg / g, or the like. When the acid value of the copolymer (A) is 20 KOHmg / g or more, the alkali developability becomes good when the resin composition containing the copolymer (A) is used as a photosensitive material. On the other hand, when the acid value of the copolymer (A) is 300 KOHmg / g or less, when the resin composition containing the copolymer (A) is used as a photosensitive material, the exposed portion (exposed portion to the alkaline developer). Since the photocured portion) is difficult to dissolve, the pattern shape becomes good.

(Equivalent number of block isocyanate groups)
The copolymer (A) contains a blocked isocyanate group blocked by a pyrazole compound in the molecule. The equivalent number of the block isocyanate group may be appropriately selected, but is preferably 300 to 6000, and more preferably 500 to 3500. If necessary, it may be 400 to 2000 or 600 to 1000. When the equivalent number of the block isocyanato group is 300 or more, if a hydroxy group is sufficiently present in the resin composition containing the copolymer (A), the hydroxy group is thermally cured to form a resin composition. A crosslinked structure is sufficiently produced by the reaction between the hydroxy group in the substance and the isocyanato group generated by deblocking the blocked isocyanato group having the structural unit (a). Therefore, a cured product having even better solvent resistance can be obtained.

The equivalent number of blocked isocyanato groups in the copolymer (A) is the mass of the copolymer (A) per mole of the blocked isocyanato groups contained in the copolymer (A). The number of equivalents of the blocked isocyanato groups is determined by dividing the mass of the copolymer (A) by the number of moles of the blocked isocyanato groups contained in the copolymer (A) (g / mol). The equivalent number of the block isocyanate groups is a theoretical value calculated from the amount of the monomer (ma) charged.

<Method for producing copolymer (A)>
The copolymer (A) of the present embodiment can be produced, for example, by using a method in which the solvent heating step (I), the dropping polymerization step (II), and the post-polymerization step (III) shown below are performed in this order.
(Solvent heating step (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 the chain transfer agent described later is added to 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.

(Dripping Polymerization Step (II))
While stirring the heated solvent (B-1), the polymerization initiator solution is added dropwise to the heated solvent (B-1) together with the monomer solution to prepare a mixed solution, and the dropping polymerization is performed.
The monomer solution includes a monomer having a blocked isocyanato group (ma), a hydroxy group-containing monomer (mb), an acid group-containing monomer (mc), and a monomer (m-) used as needed. d) is dissolved in a solvent (B-2). As the solvent (B-2), those exemplified for the solvent (B-1) can be used in the same manner.
The polymerization initiator solution is obtained by dissolving the polymerization initiator in a solvent (B-2).
In the method for producing the copolymer (A) of the present embodiment, either one or both of the solvent (B-1) and the solvent (B-2) contains a hydroxy group-containing solvent.

In the under-liquid polymerization step (II), the chain transfer agent solution described later may be added while dropping instead of the chain transfer agent that can be added in the solvent heating step (I). The chain transfer agent solution is a solution of the 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) and then the temperature is raised, and in the subliquid polymerization step (II). A chain transfer agent solution obtained by dissolving a portion of the chain transfer agent to be used in a solvent (B-2) may be added dropwise to the heated solvent (B-1).

(Post-polymerization step (III))
After the addition and drop of the monomer solution and the polymerization initiator solution are completed, 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, may be only a hydroxy group-free solvent, or may be a hydroxy group-containing solvent and a hydroxy group. It may contain both of the solvents which do not contain. The solvent (B-1) preferably contains a hydroxy group-containing solvent containing a hydroxy group, and more preferably only a hydroxy 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, dipropylene glycol monomethyl ether, and tri. (Poly) alkylene glycol monoalkyl ethers such as propylene glycol monoethyl ether and 3-methoxy-1-butanol; methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, methyl 2-hydroxy-2-methylpropionate, 2 Hydroxy group-containing carboxylic acid esters such as ethyl hydroxy-2-methylpropionate, ethyl hydroxyacetate, and methyl 2-hydroxy-3-methylbutyrate; diethylene glycol and the like can be mentioned.

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

Examples of the hydroxy group-free solvent 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; diethylene glycol. Ethers such as dimethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol diethyl ether, tetrahydrofuran; ketones such as methyl ethyl ketone, cyclohexanone, 2-heptanone, 3-heptanone; methyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl ethoxyacetate , 3-Methyl-3-methoxybutyl acetate, 3-methyl-3-methoxybutyl propionate, ethyl acetate, n-butyl acetate, i-propyl acetate, i-butyl acetate, n-amyl acetate, i-amyl acetate , Esters such as n-butyl propionate, ethyl butyrate, n-propyl butyrate, i-propyl butyrate, ethyl pyruvate, n-propyl pyruvate, methyl acetoacetate, ethyl acetoacetate, ethyl 2-oxobutyrate; toluene, Aromatic hydrocarbons such as xylene; carboxylic acid amides such as N-methylpyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide and the like can be mentioned.

Among the solvents containing no hydroxy group, it is preferable to use an ether solvent from the viewpoint of availability, cost and quality, and it is more preferable to use propylene glycol monomethyl ether acetate and diethylene glycol methyl ethyl ether. These hydroxy group-free solvents 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 hydroxy group-containing solvent, the content ratio of the hydroxy group-containing solvent in the solvent (B-1) is 10 to 100% by mass. Is more preferable, 20 to 90% by mass is more preferable, and 40 to 80% by mass is further preferable. When the content ratio of the hydroxy group-containing solvent is 10% by mass or more, the isocyanato group and the monomer (mb) derived from the monomer (ma) in the dropping polymerization step (II) and / or the post-polymerization step (III). ) Sufficiently obtains the effect of inhibiting the reaction with the hydroxy group derived from. When the solvent (B-1) contains a solvent that does not contain a hydroxy group, an isocyanato group derived from the monomer (ma) and a hydroxy group derived from the monomer (mb) when the resin composition is cured. The effect of improving the amount of the cross-linking reaction of the above can be obtained.

"Solvent and mixed solution temperature"
In the production method of the present embodiment, in the solvent heating step (I), the solvent (B-1) is put into the reaction vessel and the temperature is raised to 60 to 90 ° C. Further, in the dropping polymerization step (II) and the 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. good.

In the present 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, the dropping polymerization is performed. In the step (II) and the post-polymerization step (III), the polymerization reaction of the monomers (ma) to (mc) and, if necessary, the monomer (md) used is sufficiently advanced.

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 90 ° C. or lower, the monomer (ma) is used. When a reaction product of an ethylenically unsaturated group-containing isocyanate compound and a pyrazole compound is used, the following effects can be obtained. That is, in the drop polymerization step (II) and the post-polymerization step (III), it is possible to prevent the pyrazole compound from being dissociated from the blocked isocyanate group to generate an isocyanate group. Therefore, the isocyanate group generated by the deblocking of the blocked isocyanate group reacts with the hydroxy group derived from the monomer (mb) or the acid group derived from the monomer (mc), and is in the process of production. It is possible to prevent the copolymer (A) from gelling. Further, since the temperature is 90 ° C. or lower, in the dropping polymerization step (II) and the post-polymerization step (III), a part of the blocked isocyanato group contained in the monomer (ma) is deblocked to form the isocyanato group. Even if it is produced, the reaction between the isocyanate group and the hydroxy group derived from the monomer (mb) can be suppressed. From these, a copolymer (A) sufficiently containing the structural unit (a) having a block isocyanate group and the structural unit (b) having a hydroxy group can be obtained.

In the dropping polymerization step (II), the polymerization initiator solution and the monomer solution are dropped onto the solvent (B-1) heated to 60 to 90 ° C. in the solvent heating step (I) to polymerize while forming a mixed solution. I do. In the dropping polymerization step (II), the chain transfer agent solution may be further added dropwise to the heated solvent (B-1) to prepare 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 heated solvent (B-1). In this case, the molecular weight of the copolymer (A) can be controlled accurately, and the copolymer (A) in the process of production can be prevented from gelling.
In the dropping polymerization step (II), when the chain transfer agent solution is dropped onto the heated solvent (B-1), the chain transfer agent solution may be dropped at the same time as the polymerization initiator solution and the monomer solution, or the polymerization may be carried out. The chain transfer agent solution may be added dropwise before or after the initiator solution and the monomer solution are added dropwise.

The dropping rate of the polymerization initiator solution, monomer solution, and chain transfer agent solution depends on the reaction scale such as the volume of the reaction vessel, the volume of the heated solvent (B-1) and the polymerization initiator solution, the monomer solution, and the chain transfer agent solution. It can be decided as appropriate. 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, for example, when a 1 L reaction vessel is used.
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 may be partially or wholly the same.

In the present embodiment, the polymerization initiator solution, the monomer solution, and the chain transfer agent solution used as needed are prepared individually.
(Polymer initiator solution)
The polymerization initiator solution is obtained by dissolving the polymerization initiator in a solvent (B-2).
The polymerization initiator is not particularly limited, but is, for example, 2,2'-azobis (2,4-dimethylvaleronitrile), azobisisobutyronitrile, azobisisobutyronitrile, benzoyl peroxide, t-butylper. Examples thereof include oxy-2-ethylhexanoate. 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 a concentration at which a mixed solution having a uniform concentration can be easily obtained, and is, for example, 16 to 50% by mass, and is not particularly limited.
The amount of the polymerization initiator solution used is such that the polymerization initiator contained in the polymerization initiator solution is the total amount of the monomers charged (that is, the mass of the monomers (ma) to the monomers (md) in the monomer solution). The amount is preferably 0.5 to 20 parts by mass, more preferably 1.0 to 10 parts by mass with respect to 100 parts by mass.

(Monomer solution)
The monomer solution includes a monomer having a blocked isocyanato group (ma), a hydroxy group-containing monomer (mb), an acid group-containing monomer (mc), and a monomer (m-) used as needed. d) is dissolved in a solvent (B-2). As the monomer (ma) to the monomer (md), those exemplified in the item of the copolymer (A) can be used.

The monomer solution may be produced by a method in which the monomers (ma) to (md) are individually dissolved in a solvent (B-2) and then mixed, or the monomers (ma) to the monomer solution may be produced. (Md) may be mixed and then dissolved in a solvent (B-2).
The total concentration of the monomers (ma) to (md) in the monomer solution is preferably a concentration at which a mixed solution having a uniform concentration can be easily obtained, and can be, for example, 50 to 95% by mass. However, it is not particularly limited.

When one or more of the monomers used for producing the copolymer (A) is liquid at room temperature, the monomer that is liquid at room temperature may also serve as a solvent in the monomer solution. In this case, the monomer solution may not contain the solvent (B-2).
Examples of the monomer that is liquid at room temperature include 2-[(3,5-dimethylpyrazolyl) carbonylamino] ethyl methacrylate, which is a monomer (ma) having a blocked isocyanate group.

The ratio of each of the monomers (ma) to (mc) used in the production of the copolymer (A) is not particularly limited, but the monomer (ma) is 1 to 45 mol% and the monomer (m). -B) 1 to 50 mol%, preferably 1 to 60 mol% of the monomer (mc), 5 to 40 mol% of the monomer (ma), 5 to 45 mol% of the monomer (mb), It is more preferably 5 to 50 mol% of the monomer (mc), 15 to 35 mol% of the monomer (ma), 10 to 35 mol% of the monomer (mb), and 10 to 35 mol% of the monomer (mc). It is more preferably 40 mol%.

When the copolymer (A) contains the structural unit (d), the ratio of each of the monomers (ma) to (md) used in the production of the copolymer (A) is not particularly limited. However, the content is 1 to 45 mol% of the monomer (ma), 1 to 50 mol% of the monomer (mb), 1 to 60 mol% of the monomer (mc), and 1 to 80 mol% of the monomer (md). It is preferably 5 to 40 mol% of the monomer (ma), 5 to 45 mol% of the monomer (mb), 5 to 50 mol% of the monomer (mc), and 5 to 75 of the monomer (md). More preferably, it is mol%, monomer (ma) 15 to 35 mol%, monomer (mb) 10 to 35 mol%, monomer (mc) 10 to 40 mol%, monomer (md). ) It is more preferably 10 to 50 mol%.

(Chain transfer agent solution)
The chain transfer agent solution is a solution of the chain transfer agent in a solvent (B-2).
By dropping the chain transfer agent solution in the dropping polymerization step (II), the degree of polymerization of the copolymer (A) synthesized in the post-polymerization step (III) can be controlled. Therefore, the copolymer (A) having a desired molecular weight range can be easily produced.
The chain transfer agent is not particularly limited, but for example, a polyfunctional thiol can be preferably used. A polyfunctional thiol is a compound having two or more mercapto groups in the molecule.

The polyfunctional thiol is not particularly limited, and is, for example, thioglycolic acid, 1,2-ethanedithiol, 1,4-bis (3-mercaptobutyryloxy) butane, tetraethylene glycolbis (3-mercaptopropionate). ), Trimethylolethane (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) -trion , Tris-[(3-mercaptopropionyloxy) -ethyl] -isocyanurate, dipentaethritol hexakis (3-mercaptopropionate) and the like.

Among the above, the chain transfer agents include pentaerythritol tetrakis (3-mercaptobutyrate) and / or thioglycolic acid and pentaerythritol tetrakis (3-mercaptopropio) from the viewpoint of availability, cost and quality. Nate) is preferably used.
The concentration of the chain transfer agent in the polymerization initiator solution is preferably a concentration at which a mixed solution having a uniform concentration can be easily obtained, and is, for example, 0.1 to 10% by mass, and is not particularly limited.

The amount of the chain transfer agent used is 100 mass of the total amount of the monomer charged in the chain transfer agent contained in the mixed solution (that is, the mass of the monomer (ma) to the monomer (md) in the monomer solution). For example, the amount is preferably 0.5 to 20 parts by mass, and more preferably 1.0 to 10 parts by mass. By setting 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 as the solvent (B-1) used in the solvent heating step (I) can be used. Like the solvent (B-1), the solvent (B-2) may be only a hydroxy group-containing solvent, may be only a hydroxy group-free solvent, or may be a hydroxy group-containing solvent and hydroxy. It may contain both groups-free solvents. The solvent (B-2) preferably contains a hydroxy group-containing solvent containing a hydroxy group, and more preferably only a hydroxy group-containing solvent.

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

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. It is preferably by mass, more preferably 20 to 90% by mass, and even more preferably 40 to 80% by mass. When the content ratio of the hydroxy group-containing solvent is 10% by mass or more, the isocyanato group and the monomer (mb) derived from the monomer (ma) in the dropping polymerization step (II) and / or the post-polymerization step (III). ) Sufficiently obtains the effect of inhibiting the reaction with the hydroxy group derived from. When one or both of the solvent (B-1) and the solvent (B-2) contain a solvent containing no hydroxy group, if the content ratio of the hydroxy group-containing solvent is 90% by mass or less, for example, polymerization initiation is started. When 2,2'-azobis (2,4-dimethylvaleronitrile) is used as the agent, 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) contains a hydroxy group-containing solvent. , The following effects can be obtained.
That is, in the dropping polymerization step (II) and / or the post-polymerization step (III), the hydroxy group of the hydroxy group-containing solvent reacts with a part of the isocyanato group generated from the blocked isocyanato group of the monomer (ma). do.

Thereby, in the present embodiment, in the dropping polymerization step (II) and / or the post-polymerization step (III), the isocyanato group derived from the monomer (ma) and the hydroxy group derived from the monomer (mb) are used. Reaction is moderately inhibited. Therefore, in the post-polymerization step (III), it is possible to prevent the copolymer (A) during production from gelling. Further, the storage stability of the resin composition containing the copolymer (A) is improved.

Further, in the present embodiment, the reaction in the dropping polymerization step (II) and / or the post-polymerization step (III) is appropriately inhibited to thermally cure the resin composition containing the copolymer (A). Previously, it is possible to prevent the isocyanato group derived from the monomer (ma) and the hydroxy group derived from the monomer (mb) from decreasing. Therefore, the copolymer (A) in which the isocyanato group derived from the monomer (ma) and the hydroxy group derived from the monomer (mb) are appropriately left can be obtained. Therefore, by thermally curing the resin composition containing the copolymer (A), a crosslinked structure is sufficiently generated, and a cured product having good solvent resistance can be obtained.

The 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 not particularly limited, but the total amount of the monomer charged (that is, the monomer solution). For example, the total amount of the solvent (B-1) and the solvent (B-2) is 30 to 1,000 with respect to 100 parts by mass of the monomer (ma) to the monomer (md) in the mixture. It is preferably parts by mass, more preferably 50 to 800 parts by mass. 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 the monomer charged, the copolymer weight obtained in the post-polymerization step (III) is obtained. The viscosity of the reaction solution containing the coalescence (A) becomes appropriate. Further, by setting the total amount of the solvent (B-1) and the solvent (B-2) to 1,000 parts by mass or less, the chain transfer action is performed when the chain transfer agent solution is dropped in the dropping polymerization step (II). It is possible to suppress a decrease in the molecular weight of the copolymer (A) due to the above. Further, 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 the monomer charged, abnormal polymerization in the post-polymerization step (III) is performed. The reaction can be prevented and the polymerization reaction can be stably carried out. As a result, it is possible to prevent the copolymer (A) during production from gelling, and the copolymer (A) without coloring can be obtained.

In the production method of the present embodiment, in the post-polymerization 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, and more preferably 2 to 3 hours. When the reaction time is 1 to 5 hours, the copolymer (A) having an appropriate molecular weight can be produced in good yield.

The copolymer (A) of the present embodiment has a structural unit (a) having a blocked isocyanato group blocked by a pyrazole compound, a structural unit (b) having a hydroxy group, and a structural unit (c) having an acid group. ), And the glass transition temperature is 30 ° C. or lower. Therefore, the resin composition containing the copolymer (A) of the present embodiment has good alkali developability when used as a photosensitive material, has excellent storage stability, and is cured at a low temperature. However, a cured product having excellent solvent resistance can be 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) is used. It is a solvent containing a hydroxy group-containing solvent. In the solvent heating step (I), the temperature of the solvent (B-1) is raised to 60 to 90 ° C., and in the post-polymerization step (III), the mixed solution is reacted at 60 to 90 ° C. .. Therefore, in the dropping polymerization step (II) and / or the post-polymerization step (III), the reaction between the isocyanato group derived from the monomer (ma) and the hydroxy group derived from the monomer (mb) is moderately performed. Be hindered. As a result, the copolymer (A) of the present embodiment sufficiently containing the structural unit (a) having a block isocyanate group and the structural unit (b) having a hydroxy group can be obtained.

On the other hand, conventionally, when a solvent is used when polymerizing a copolymer, a solvent that does not react with the monomer is selected and used. Therefore, in the conventional technique, when the copolymer is polymerized using a solvent, the monomer and the solvent do not react with each other. Therefore, in the conventional technique, it is not assumed that the reaction between the monomer and the solvent is used, and there is no method for controlling the characteristics of the copolymer by using the reaction between the monomer and the solvent.

<Resin composition>
Next, the resin composition of this embodiment will be described.
The resin composition of the present embodiment contains the copolymer (A) of the present embodiment and the solvent (B).
The resin composition of the present embodiment further contains not only the copolymer (A) and the solvent (B), but also the reactive diluent (C) and the photopolymerization initiator (D). May be good. Such a resin composition can be preferably used as a photosensitive resin composition.
The resin composition of the present embodiment may further contain a colorant (E) in addition to the above-mentioned copolymer (A) to the photopolymerization initiator (D). Such a resin composition can be preferably used as a material for forming a coloring pattern such as a color filter, a black matrix, and a black column spacer.

(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 the present embodiment, since the solvent (B) contains a hydroxy group-containing solvent, the storage stability is improved.

The hydroxy group-containing solvent used as the solvent (B) is not particularly limited as long as it is a hydroxy group-containing solvent, and the solvent (B-1) and the solvent (B-) are used in the step of producing the copolymer (A). The same as the one that can be used as 2) can be used. As the hydroxy group-free solvent that can be used as the solvent (B), the same ones that can be used as the solvent (B-1) and the solvent (B-2) in the step of producing the copolymer (A) are used. Can be mentioned.

The content ratio of the hydroxy group-containing solvent in the solvent (B) can be set in the same manner as the content ratio of the hydroxy 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 is, for example, a copolymer (A) isolated from a reaction solution containing the copolymer (A) obtained in the post-polymerization step (III) for producing the copolymer (A). ) And the solvent (B) can be produced by a method of appropriately mixing.
As the resin composition of the present embodiment, the reaction solution containing the copolymer (A) obtained when the copolymer (A) is produced may be used as it is. In this case, it is not necessary to isolate the copolymer (A) from the reaction solution. When the solvent (B-1) and / or the solvent (B-2) used for producing the copolymer (A) is contained in the reaction solution, the solvent (B-1) in the reaction solution is contained. ) And / or the solvent (B-2) can be used as it is as the solvent (B). If necessary, the solvent (B) may be added to the reaction solution.

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 the present embodiment, for example, it is preferable to contain 30 to 1,000 parts by mass of the solvent (B) with respect to 100 parts by mass of the copolymer (A), and more preferably 50 to 800 parts by mass. preferable. 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 in an appropriate range, and the film thickness can be appropriately adjusted.

(Reactive Diluent (C))
The reactive diluent (C) is contained together with the photopolymerization initiator (D), if necessary. 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 preparing the resin composition containing the reactive diluent (C), the viscosity can be easily adjusted. Further, by preparing the resin composition containing the reactive diluent (C), the adhesion of the cured resin composition to the substrate can be improved, and the strength of the cured resin composition can be adjusted. ..

Examples of the monofunctional monomer used as the reactive diluent (C) include (meth) acrylamide, methylol (meth) acrylamide, methoxymethyl (meth) acrylamide, ethoxymethyl (meth) acrylamide, propoxymethyl (meth) acrylamide, and butoxymethoxy. Methyl (meth) acrylamide, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) Acrylate, 4-hydroxybutyl (meth) acrylate, 2-phenoxy-2-hydroxypropyl (meth) acrylate, 2- (meth) acryloyloxy-2-hydroxypropylphthalate, glycerin mono (meth) acrylate, tetrahydrofurfuryl (meth) ) Acrylate, glycidyl (meth) acrylate, 2,2,2-trifluoroethyl (meth) acrylate, 2,2,3,3-tetrafluoropropyl (meth) acrylate, phthalic acid derivative half (meth) acrylate, etc. (Meta) acrylates; aromatic vinyl compounds such as styrene, α-methylstyrene, α-chloromethylstyrene, vinyltoluene; and carboxylic acid esters such as vinyl acetate and vinyl propionate can be mentioned. 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, propylene glycol di (meth) acrylate, and polypropylene glycol. Di (meth) acrylate, butylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1,6-hexane glycol di (meth) acrylate, trimethyl propanthry (meth) acrylate, glycerinji (meth) Acrylate, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 2,2-bis (4- (meth) acryloxidi Ethoxyphenyl) 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 (ie, tolylene diisocyanate), Reactants of trimethylhexamethylene diisocyanate, hexamethylene diisocyanate, etc. and 2-vidroxyethyl (meth) acrylate, (meth) acrylates such as tri (meth) acrylate of tris (hydroxyethyl) isocyanurate; divinylbenzene, diallylphthalate, diallyl. Aromatic vinyl compounds such as benzenephosphonate; dicarboxylic acid esters such as divinyl adipate; triallyl cyanurate, methylenebis (meth) acrylamide, (meth) acrylamide methylene ether, polyhydric alcohols and N-methylol (meth) acrylamide. Examples thereof include the condensate of. These polyfunctional monomers may be used alone or in combination of two or more.

Among these monomers, from the viewpoint of improving the development form and curability of the resin composition, it is preferable to use a polyfunctional (meth) acrylate as the reactive diluent (C), and trimethylolpropane tri (meth) acrylate, It is more preferable to use one or more selected from dipentaerythritol penta (meth) acrylate and dipentaerythritol hexa (meth) acrylate.

When the resin composition contains the reactive diluent (C), the blending amount of each component is the same weight with respect to 100 parts by mass of the total amount of the copolymer (A) and the reactive diluent (C). The coalescence (A) is preferably 10 to 90 parts by mass, the solvent (B) is preferably 30 to 1,000 parts by mass, the reactive diluent (C) is preferably 10 to 90 parts by mass, and the copolymer (A) is. It is more preferable that the amount is 20 to 80 parts by mass, the solvent (B) is 50 to 800 parts by mass, the reactive diluent (C) is 20 to 80 parts by mass, and the copolymer (A) is 30 to 75 parts by mass. It is more preferable that the solvent (B) is 100 to 700 parts by mass and the reactive diluent (C) is 25 to 70 parts by mass. When the blending amount of each component is within the above range, the resin composition has an appropriate viscosity and can be suitably used for various coatings, adhesives, binders for printing inks and the like.

(Photopolymerization Initiator (D))
The photopolymerization initiator (D) is not particularly limited, and is, for example, benzophenones 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- [4- (methylthio) phenyl] -2-morpholino-propane-1-one, 2-benzyl-2 -Acetophenones such as dimethylamino-1- (4-morpholinophenyl) butanone-1; anthracinones such as 2-methylanthraquinone, 2-amylanthraquinone, 2-t-butylanthraquinone, 1-chloroanthraquinone; xanthone, thioxanthone, Thioxanthons such as 2,4-dimethylthioxanthone, 2,4-diisopropylthioxanthone, 2-chlorothioxanthone; acetophenone dimethyl ketal, ketals such as benzyl dimethyl ketal; benzophenone, 4- (1-t-butyldioxy-1-methylethyl) ) Benzophenones, 3,3', 4,4'-Benzophenones such as tetrakis (t-butyldioxycarbonyl) benzophenone; acylphosphine oxides; etanone 1- [9-ethyl-6- (2-methylbenzoyl)- 9H-carbazole-3-yl] -1- (O-acetyloxime) and the like can be mentioned. These photopolymerization initiators (D) may be used alone or in combination of two or more.

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

(Colorant (E))
The colorant (E) is contained as needed. The colorant (E) is not particularly limited as long as it dissolves or disperses in the solvent (B), and examples thereof include dyes and pigments. The colorant (E) may be used alone or in combination of two or more, depending on the color of the cured product of the target resin composition. As the colorant (E), only the dye may be used, only the pigment may be used, or the dye and the pigment may be used in combination.

As the dye, an acidic dye having an acidic group such as a carboxylic acid or a sulfonic acid from the viewpoints of solubility in the solvent (B) and an alkaline developing solution, interaction with other components in the resin composition, heat resistance, and the like. It is preferable to use a salt of an acidic dye with a nitrogen compound, a sulfonamide of an acidic dye, or the like.

Examples of such dyes include acid alizarin violet N; acid black1, 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 orange 6, 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, 257, 260, 266, 274; acid violet 6B, 7, 9, 17, 19; acid chrome 1, 3, 9, 11, 17, 23, 25, 29, 34, 36, 42, 54, 72, 73, 76, 79, 98, 99, 111, 112, 114, 116; food hello3 and derivatives thereof and the like can be mentioned. Among these dyes, it is preferable to use azo-based, xanthene-based, anthraquinone-based or phthalocyanine-based acid dyes. These dyes may be used alone or in combination of two or more, depending on the color of the cured product of the target resin composition.

Examples of pigments include C.I. 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, Yellow pigments such as 147, 148, 150, 153, 154, 166, 173, 194, 214; C.I. I. Pigment Orange 13, 31, 36, 38, 40, 42, 43, 51, 55, 59, 61, 64, 65, 71, 73 and other orange pigments; I. Pigment Red 9, 97, 105, 122, 123, 144, 149, 166, 168, 176, 177, 180, 192, 209, 215, 216, 224, 242, 254, 255, 264, 265 and other red pigments; C. I. Pigment Blue 15, 15: 3, 15: 4, 15: 6, 60 and other blue pigments; C.I. I. Pigment Violet 1, 19, 23, 29, 32, 36, 38 and other violet color pigments; C.I. I. Pigment Green 7, 36, 58, 59 and other green pigments; C.I. I. Pigment Brown 23, 25 and other brown pigments; C.I. I. Pigment Blacks 1 and 7, carbon black, titanium black, black pigments such as iron oxide and the like can be mentioned. These pigments may be used alone or in combination of two or more, depending on the color of the cured product of the target resin composition.

When a pigment is used as the colorant (E), a known dispersant may be contained in the resin composition from the viewpoint of improving the dispersibility of the pigment. As the dispersant, it is preferable to use a polymer dispersant having excellent dispersion stability over time.
Examples of polymer dispersants include urethane dispersants, polyethyleneimine dispersants, polyoxyethylene alkyl ether dispersants, polyoxyethylene glycol diester dispersants, sorbitan aliphatic ester dispersants, and aliphatic modified esters. Examples include system dispersants.

As polymer dispersants, commercially available under trade names such as EFKA (manufactured by EFKA), Disperbyk-161 (manufactured by Big Chemie), Disparon (manufactured by Kusumoto Kasei Co., Ltd.), and SOLPERSE (manufactured by Zeneca). You may use what has been done.
The type and blending amount of the dispersant may be appropriately set according to the type of pigment to be used and the like.

When the resin composition contains the colorant (E), the content thereof is 3 to 80 parts by mass with respect to 100 parts by mass of the total amount of the copolymer (A) and the reactive diluent (C). Is preferable, 5 to 70 parts by mass is more preferable, and 10 to 60 parts by mass is further preferable. The resin composition containing the copolymer (A) of the present embodiment has excellent storage stability, and a cured product having excellent solvent resistance can be obtained even when cured at a low temperature. Therefore, for example, the content of the colorant (E) can be 20 parts by mass or more with respect to 100 parts by mass of the total amount of the copolymer (A) and the reactive diluent (C). By using the resin composition containing 20 parts by mass or more of the colorant (E) as a material of the color filter, the color reproducibility in the image display element provided with the color filter can be enhanced.

In addition to the above components, 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 properties. The blending amount of these additives is not particularly limited as long as it does not impair the effects of the present invention.

Since the resin composition of the present embodiment contains the copolymer (A) of the present embodiment, the crosslinking reaction proceeds sufficiently even at a low temperature. Therefore, the resin composition of the present embodiment can be cured at a 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. Is. 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 small. Further, when the resin composition contains a colorant (E) having inferior heat resistance, deterioration of the colorant (E) due to heat curing can be suppressed, and a cured product exhibiting the original characteristics of the colorant (E) can be obtained. Easy to get rid of. Therefore, as the colorant (E), those made of various materials can be used. Further, when a cured product is formed by a method of applying a resin composition on a substrate and thermally curing the substrate, the cured product can be formed even if the substrate is made of a material having inferior heat resistance. Therefore, as the substrate, for example, a substrate made of various materials such as a resin for a flexible display 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, and even more preferably 70 ° C. or higher. When the temperature at which the resin composition is cured is 50 ° C. or higher, a sufficiently 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 according to the size, thickness, curing temperature, etc. of the cured product, and is, for example, 10 minutes to 4 hours. It can be done, preferably 20 minutes to 2 hours.

The resin composition of the present embodiment can be produced by a method of mixing the above components using a known mixing device. The solvent contained in each component used as a raw material in producing the resin composition of the present embodiment can be used as the solvent (B).
When the resin composition of the present embodiment contains components other than the copolymer (A) and the solvent (B), for example, in the resin composition containing the copolymer (A) and the solvent (B) prepared in advance. , The reactive diluent (C), the photopolymerization initiator (D), and the colorant (E) may be added and mixed.

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 can be 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 protrusion for liquid crystal alignment, a microlens, an insulating film for a touch panel, and an adhesive for electronic materials around a flexible printed wiring board. It can be preferably used as a material for agents, adhesive sheets and the like.

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 alkaline. It can be preferably used as a photosensitive material having good developability. In particular, for organic electroluminescence (EL) displays (for black Pixel Defining Layer (PDL)), liquid crystal displays, charge-coupled devices (CCD), and solid-state imaging devices using complementary metal oxide semiconductor (CMOS) elements. It is suitable as a resist used for a built-in color filter.

Further, 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 ( When E) is contained, a colored pattern made of a cured product having excellent solvent resistance can be formed at a low temperature. Therefore, deterioration of the colorant (E) due to heat curing is suppressed, and a coloring pattern in which the original characteristics of the colorant (E) are exhibited can be formed. Therefore, the above resin composition can be preferably used as a photosensitive material for a color filter.

<Color filter>
Next, the color filter of this embodiment will be described.
The color filter of the present embodiment includes a substrate, a plurality of pixels composed of three coloring patterns of a red (R) pattern, a green (G) pattern, and a blue (B) pattern formed on the substrate, and each coloring pattern. It has a black matrix formed at the boundary and a protective film formed on the pixels and the black matrix.

As the substrate, a known substrate can be adopted, and for example, a glass substrate, a silicon substrate, a polycarbonate substrate, a polyester substrate, a polyamide substrate, a polyamide-imide substrate, a polyimide substrate, an aluminum substrate, a printed wiring board, an array substrate, or the like is used. be able to. In the color filter of the present embodiment, an organic substrate such as a polycarbonate substrate, a polyester substrate, a polyamide substrate, a polyamide-imide substrate, or a polyimide substrate having a relatively low heat resistant temperature can be used, which is suitable as a flexible substrate. ..

In the color filter of the present embodiment, the black matrix and the three coloring patterns forming each pixel are the copolymer (A) of the present embodiment, the solvent (B), and the reactive diluent (C). , A coloring pattern comprising a cured product of the resin composition of the present embodiment containing a photopolymerization initiator (D) and a coloring agent (E).
The protective film is not particularly limited, and a known one can be used.

Next, an example of the method for manufacturing the color filter of the present embodiment will be described.
In order to manufacture the color filter of the present embodiment, first, a coloring pattern to be a black matrix and three coloring patterns forming each pixel are formed on a substrate. First, a coloring pattern that becomes a black matrix is formed on the substrate, and then a red pattern, a green pattern, and a blue pattern that form each pixel are formed within the range partitioned by the black matrix. The order in which the red pattern, the green pattern, and the blue pattern are formed is not particularly limited.

Each coloring 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 the substrate to form a coating film. Next, the coating film is exposed through a photomask having a predetermined pattern shape, and the exposed portion is photocured. Then, the unexposed portion of the coating film is alkaline-developed with an alkaline aqueous solution and removed. Then, by baking, the exposed portion of the coating film is heated and cured. By the above steps, a colored pattern having a predetermined shape and made of a cured product of the resin composition of the present embodiment can be obtained.

The method of applying the resin composition for forming the coloring pattern is not particularly limited, and for example, a screen printing method, a roll coating method, a curtain coating method, a spray coating method, a spin coating method, or the like is used. Can be done.
After applying the resin composition, the solvent (B) contained in the coating film is volatilized by heating the coating film using a heating means such as a circulating oven, an infrared heater, or a hot plate, if necessary. May be removed.
The heating for removing the solvent (B) in the coating film can be performed at a temperature of, for example, 50 ° C to 120 ° C. Further, 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 according to the composition of the resin composition, the thickness of the coating film, and the like.

When exposing the coating film, for example, a known negative type mask can be used as the photomask.
When exposing the coating film, it is preferable to use, for example, active energy rays such as ultraviolet rays and excimer laser light. The light source used for the 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 energy dose to be 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 alkaline aqueous solution used for alkaline development is not particularly limited, and is, for example, an aqueous solution of sodium carbonate, potassium carbonate, calcium carbonate, sodium hydroxide, potassium hydroxide and the like; amine-based compounds such as ethylamine, diethylamine and dimethylethanolamine. Aqueous solution of: 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 their sulfates, hydrochlorides or p-toluenesulfonates, etc. An aqueous solution of a p-phenylenediamine-based compound or the like can be used, and can be appropriately selected depending on the composition of the resin composition and the like.
Antifoaming agents and surfactants may be added to these alkaline aqueous solutions, if necessary.
Further, in the present embodiment, it is preferable to wash the substrate with water after alkaline development with an alkaline aqueous solution and before baking to remove the alkaline aqueous solution and dry the substrate.

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

The temperature for heating the exposed portion of the coating film can be, for example, 210 ° C or lower, 150 ° C or lower, 120 ° C or lower, 100 ° C or lower, or even 80 ° C or lower, if necessary. .. When the temperature for heating the exposed portion of the coating film is 210 ° C. or lower, a material having low heat resistance such as a substrate having low heat resistance can be used as the material for the color filter. When the temperature for heating the exposed portion of the coating film is 150 ° C. or lower, the amount of energy required to cure the coating film is small, which is preferable. Further, when the temperature at which the exposed portion of the coating film is heated is set to 150 ° C. or lower, the coloring pattern containing the coloring agent (E) having inferior heat resistance, which has been difficult to use as a material for the coloring pattern in the past, is deteriorated by the coloring agent (E). Can be formed while suppressing. Further, when the temperature for heating the exposed portion of the coating film is set to 150 ° C. or lower, a coloring pattern can be formed on a substrate having poor heat resistance, which has been difficult to use as a substrate for a conventional color filter.

The temperature for heating the exposed portion of the coating film is preferably 50 ° C. or higher, more preferably 60 ° C. or higher, and even 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 solvent resistance of the coloring pattern becomes good, which is good. A pattern shape is obtained. Further, when the temperature for heating the exposed portion of the coating film 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 for heating the exposed portion of the coating film, the thickness of the coating film, the composition of the resin composition, and the like, for example, 10 minutes to 4 hours. It can be done, preferably 20 minutes to 2 hours.

Next, a protective film is formed by a known method on a coloring pattern that becomes a black matrix and three coloring patterns that form each pixel.
By the above steps, the color filter of the present embodiment can be obtained.

In the color filter of the present embodiment, the three coloring patterns and the black matrix forming each pixel are composed of the copolymer (A), the solvent (B), and the reactive diluent (C) of the present embodiment. , A coloring pattern comprising a cured product of the resin composition of the present embodiment containing a photopolymerization initiator (D) and a coloring agent (E). The resin composition of the present embodiment has good alkali developability, and a cured product having excellent solvent resistance can be obtained even when cured at a low temperature. Therefore, in the color filter of the present embodiment, the pixels and the black matrix can be formed by using the method of curing the resin composition at a low temperature, and the selection of materials that can be used for the color filter can be increased.

Therefore, the color filter of the present embodiment may have, for example, a pixel and / or a black matrix containing a colorant (E) having a poor heat resistance and having a good pattern shape. Further, by forming the pixels and the black matrix by using a method of curing the resin composition at a low temperature, a color filter having a substrate made of a material having inferior heat resistance can be obtained.

On the other hand, when a coloring pattern is formed by using a conventional resin composition instead of the resin composition of the present embodiment, 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, which is a cured product, is insufficient. Therefore, when the coloring pattern is formed using the conventional resin composition, the temperature for heating the exposed portion of the coating film cannot be set to 210 ° C. or lower. Therefore, in the conventional technique, it is difficult to use the colorant (E) having inferior heat resistance as the material of the coloration pattern. Further, it is difficult to use a substrate having inferior heat resistance as the substrate of the color filter.

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

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

<Image display element>
Next, the image display element of this 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 and a second substrate having a second electrode formed on the surface thereof can be used. Examples thereof include a device in which a first electrode and a second electrode are arranged so as to face each other via a spacer, and a liquid crystal composition is sandwiched between the first substrate and the second substrate.
The liquid crystal display element of the present embodiment includes the color filter of the present embodiment as the color filter. In the liquid crystal display element of the present embodiment, known members other than the color filter can be used.

The liquid crystal display element of the present embodiment can be manufactured, for example, by using the manufacturing method shown below.
First, a color filter and a first electrode are formed on the first substrate in this order. The color filter can be formed by using the manufacturing method described above. The first electrode can be formed by using a known method.
Next, the second electrode and the spacer are formed on the second substrate by a known method.
After that, the first substrate and the second substrate are arranged and bonded with the first electrode and the second electrode facing each other, and the liquid crystal composition is injected and sealed between the first substrate and the second substrate.
By the above steps, the liquid crystal display element of the present embodiment can be obtained.

Since the liquid crystal display element of the present embodiment includes the color filter of the present embodiment, the pixels of the color filter and the black matrix can be formed by using a method of curing the resin composition at a low temperature. Therefore, as a material that can be used for the liquid crystal display element, it is possible to use a material having inferior heat resistance, and it is possible to increase the choices of usable materials.

In the above-described embodiment, a liquid crystal display element has been described as an example of the image display element of the present embodiment, but the image display element of the present embodiment may include the color filter of the present embodiment. It is not limited to the liquid crystal display element. The image display element of the present embodiment may be, for example, an organic EL display element, a solid-state image pickup device using a CCD element / CMOS element.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. The present invention is not limited to the following examples.

[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, a dropping funnel, a condenser, a thermometer and a gas introduction tube, and replaced with nitrogen gas. While stirring, the temperature was raised to 78 ° C. (solvent heating step (I)).

Next, 20.6 g of 2,2'-azobis (2,4-dimethylvaleronitrile) (polymerization initiator) was dissolved in 79.1 g of propylene glycol monomethyl ether as a solvent (B-2). A polymerization initiator solution was used.
Also, 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). 2-Ethylhexyl acrylate (2EHA) (mol%) was dissolved in 61.8 g of propylene glycol monomethyl ether as a solvent (B-2) and then mixed to obtain a monomer solution.
Then, while stirring the solvent (B-1) in the flask, the polymerization initiator solution and the monomer solution were simultaneously added dropwise using a dropping funnel into the flask containing the solvent heated to 78 ° C. The drop polymerization was carried out to prepare a mixed solution (drop polymerization step (II)). The dropping rate was 1.7 ml / min for both the polymerization initiator solution and the monomer solution.

After completion of the dropping, the mixed solution was reacted at 78 ° C. for 3 hours while stirring to form the copolymer (A) (post-polymerization step (III)).
Propylene glycol monomethyl ether as the solvent (B) was added to the reaction solution containing the copolymer (A) thus obtained so that the content other than the solvent was 35% by mass, and the weight of Synthesis Example 1 was increased. A coalesced composition was obtained.

[Synthesis Examples 2 to 6, Comparative Synthesis Examples 1 to 3]
Polymers of Synthesis Examples 2 to 6 and Comparative Synthesis Examples 1 to 3 in the same manner as in Synthesis Example 1 except that the materials shown in Tables 1 and 2 were used in the proportions shown in Tables 1 and 2. The composition was obtained.

In Tables 1 and 2, (ma) represents a monomer having a blocked isocyanate group. (Mb) represents a hydroxy group-containing monomer. (Mc) indicates an acid group-containing monomer. (D) indicates other monomers that do not correspond to (ma), (mb), and (mc).
Further, in Tables 1 and 2, (equivalent number of block isocyanate groups) indicates the number of equivalents of block isocyanate groups contained in the molecule of the copolymer (A).

The materials used in Tables 1 and 2 are as follows.
MOI-BP: Karenz (registered trademark) MOI-BP (2-[(3,5-dimethylpyrazolyl) carbonylamino] ethyl methacrylate, manufactured by Showa Denko KK)
MOI-BM: Karenz (registered trademark) MOI-BM (2-"0- (1'-methylpropanolamino) carboxyamino] ethylmethacrylate, manufactured by Showa Denko KK)
・ 4-Hydroxybutyl acrylate (manufactured by Mitsubishi Chemical Corporation)
・ 2-Hydroxyethyl methacrylate (manufactured by Kyoeisha 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 NOF CORPORATION)

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

<Weight average molecular weight (Mw)>
The weight average molecular weight (Mw) of each of the copolymers (A) contained 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 standard polystyrene-equivalent weight average molecular weight measured under the following conditions using gel permeation chromatography (GPC).
Column: Showdex (registered trademark) LF-804 + LF-804 (manufactured by Showa Denko KK)
Column temperature: 40 ° C
Sample: 0.2 mass% tetrahydrofuran solution of copolymer Developing solvent: Tetrahydrofuran Detector: Differential refractometer (SHODEX (registered trademark) RI-71S) (manufactured by Showa Denko KK)
Flow velocity: 1 mL / min

<Glass transition temperature (Tg)>
The polymer compositions of Synthesis Examples 1 to 6 and Comparative Synthesis Examples 1 to 3 were applied to a glass substrate and dried at 50 ° C. under reduced pressure for 24 hours. Then, it was redissolved in acetone and dried again at 50 ° C. under reduced pressure for 24 hours. Regarding the solid content of the copolymer solution from which the volatile components have been removed in this manner, using DSC (differential scanning calorimetry, measuring instrument: Seiko DSC6200), JIS- at a temperature rise rate of 10 ° C./min under a nitrogen stream. Measured according to K7121 (midpoint glass transition point). The obtained result was taken as the glass transition temperature (Tg) of the copolymer (A).

<Storage stability>
After the adjustment, weigh the polymer compositions of Synthesis Examples 1 to 6 and Comparative Synthesis Examples 1 to 3 in which the components other than the solvent are 35% by mass in equal amounts in a glass container, and cover them with a lid to prevent dust from entering. , As a sample. After measuring the viscosity of each sample, it was allowed to stand in an incubator kept at 12 ° C. for 3 months. Then, the viscosity of each sample left to stand for 3 months was measured. The viscosity was measured using an E-type viscometer (RE-80L, manufactured by Toki Sangyo, Cone No. 3) at 25 ° C. and a rotation speed of 10 rpm.

For each sample, the viscosity increase rate of the viscosity after standing for 3 months with respect to the viscosity before standing in the incubator {(1- (Viscosity after standing for 3 months / Viscosity before standing) Viscosity)) × 100 (%)} was calculated and evaluated according to the criteria shown below.
◎ (excellent): thickening rate 10% or less 〇 (good): thickening rate 10.1% to 20%
△ (inferior): thickening rate of 20.1% or more

As shown in Tables 1 and 2, the polymer compositions of Synthesis Examples 1 to 6 and Comparative Synthesis Example 3 were all evaluated for storage stability as ⊚ (excellent) or ○ (good), and were excellent in storage. It was confirmed that it had stability.
On the other hand, as shown in Table 2, the polymer compositions of Comparative Synthesis Examples 1 and 2 had an evaluation of storage stability of Δ (inferior) and were not cured by storage, but the results of Examples were obtained. The viscosity was higher than that of the above, and the storage 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 measured and used as the acid value of the copolymer (A).
The acid value of the curable polymer measured according to JIS K6901 5.3. That is, the acid value means the number of mg 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]
The 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) dipenta as a reactive diluent. A mixture of erythritol pentaacrylate and dipentaerythritol hexaacrylate (Kayarad DPHA, manufactured by Nippon Kayaku Co., Ltd.) and (D) etanone as a photopolymerization initiator, 1- [9-ethyl-6- (2-methylbenzoyl)). The ratios of -9H-carbazole-3-yl]-, 1- (o-acetyloxime) (manufactured by BASF Japan Co., Ltd.) and (E) dye as a colorant (VALIFAST BLUE 2620) are shown in Table 3, respectively. The resin compositions of Examples 1 to 6 and Comparative Examples 1 to 3 were prepared.

The copolymer (A) shown in Table 3 does not include the amount of the solvent contained in the reaction solution used for producing the copolymer (A).
The amount of the solvent (B) shown in Table 3 is the sum of the solvent contained in the polymer composition (propylene glycol monomethyl ether) and the solvent added during the production of the resin composition (propylene glycol monomethyl ether acetate). Is. The content ratio of the hydroxy group-containing solvent in the solvent (B) shown in Table 3 is 79.1% by mass.

The resin compositions of Examples 1 to 6 and Comparative Examples 1 to 3 were evaluated for alkali developability and solvent resistance by the methods shown below.
(1) Alkaline Developability The resin compositions of Examples and Comparative Examples are placed on a square glass substrate (non-alkali glass substrate) having a length of 5 cm and a width of 5 cm, respectively, and have a thickness of 2.5 μm after exposure. The coating film was formed by spin coating as described above. Then, the solvent in the coating film was volatilized and removed by heating at 100 ° C. for 3 minutes.

Next, a photomask having a predetermined pattern is placed at a distance of 100 μm from the coating film, and the coating film is exposed to ultraviolet rays having a wavelength of 365 nm at an energy dose of 40 mJ / cm ² through the photomask to expose the exposed portion. It was photocured.
Next, 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 to dissolve and develop the unexposed portion. Then, it was baked at 100 ° C. for 20 minutes to form a predetermined pattern.

Then, by observing the pattern after alkaline development using an electron microscope S-3400 manufactured by Hitachi High-Technologies Corporation, the residue after alkaline 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 × (No): Residue in the unexposed part

(2) Solvent resistance The resin compositions of Examples and Comparative Examples are placed on a square glass substrate (non-alkali glass substrate) having a length of 5 cm and a width of 5 cm, respectively, and have a thickness of 2.5 μm after exposure. The coating film was formed by spin coating as described above. Then, the solvent in the coating film was volatilized and removed by heating at 100 ° C. for 3 minutes.

Next, the coating film was exposed to ultraviolet rays having a wavelength of 365 nm at an energy dose of 40 mJ / cm ² , and the exposed portion was photocured. Then, the coating film was cured by baking at 80 ° C. for 30 minutes or at 100 ° C. for 20 minutes to obtain a cured film.
The prepared cured membrane 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 the solvent resistance was evaluated based on the results. The results are shown in Table 4. The smaller the value, the better the color change before and after immersion.

As shown in Table 4, the cured films obtained by curing the resin compositions of Examples 1 to 6 had a good evaluation of alkali developability.
Further, in the cured film obtained by curing the resin compositions of Examples 1 to 6, 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. In all of these cases, ΔEab was less than 2, and the solvent resistance was good.

The cured film obtained by curing the resin compositions of Comparative Examples 1 to 3 had a good evaluation of alkali developability. However, the cured film obtained by curing the resin compositions of Comparative Examples 1 and 2 has a ΔEab of 2 or more when the temperature at which the coating film is cured is 80 ° C. and the time is 30 minutes, and the solvent resistance is high. It was inadequate. Further, in the cured film obtained by curing the resin composition of Comparative Example 3, even when the temperature for curing the coating film is 80 ° C. and the time is 30 minutes, the temperature is 100 ° C. and the time is 20 minutes. However, ΔEab was 2 or more, and the solvent resistance was insufficient.

According to the present invention, a resin composition capable of obtaining a cured product having good alkali developability when used as a photosensitive material, excellent storage stability, and excellent solvent resistance even when cured at a low temperature. A product, a copolymer useful for preparing the resin composition, and a method for producing the copolymer are provided. Further, according to the present invention, a coloring pattern made of a cured product of a resin composition, which has good alkaline developability and a cured product having excellent solvent resistance even when cured at a low temperature, and a color filter having the same. And an image display element including the color filter thereof.
The resin composition of the present invention can be preferably used in a wide range of applications as a material such as a transparent film, a protective film, an insulating film, an overcoat, a photo spacer, a black matrix, a black column spacer, and a resist for a color filter.

Claims

A structural unit (a) having a blocked isocyanato group blocked with a pyrazole compound, and
The structural unit (b) having a hydroxy group and
Containing a structural unit (c) having an acid group,
A copolymer characterized by having a glass transition temperature of 30 ° C. or lower.
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 isocyanate group and the (meth) acryloyloxy group. Combined.
Any of claims 1 to 4, wherein the structural unit (a) is contained in an amount of 1 to 45 mol%, the structural unit (b) is contained in an amount of 1 to 50 mol%, and the structural unit (c) is contained in an amount of 1 to 60 mol%. The copolymer according to claim 1.
The copolymer according to any one of claims 1 to 5, wherein the weight average molecular weight is 1000 to 50,000.
The copolymer (A) according to any one of claims 1 to 6 and the solvent (B) are contained.
A resin composition, wherein 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 containing the colorant (E).
With respect to 100 parts by mass of the total amount of the copolymer (A) and the reactive diluent (C).
The copolymer (A) is 10 to 90 parts by mass,
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 claim 9, wherein the colorant (E) is contained in an amount of 3 to 80 parts by mass.
A color filter having a coloring pattern made of 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.
The solvent heating step (I) for raising the temperature of the solvent (B-1) to 60 to 90 ° C.
The solvent (B) in which the temperature of the monomer (ma) having a blocked isocyanato group blocked by the pyrazole compound, the hydroxy group-containing monomer (mb), and the acid group-containing monomer (mc) was heated. In addition to dropping in -1)
A dropping polymerization step (II) in which a polymerization initiator solution in which a polymerization initiator is dissolved in a solvent (B-2) is added dropwise to the solvent (B-1) to form a mixed solution.
It has a post-polymerization step (III) in which the mixed solution is reacted at 60 to 90 ° C. for 1 to 5 hours while stirring.
A method for producing a copolymer, wherein one or both of the solvent (B-1) and the solvent (B-2) contains a hydroxy group-containing solvent.
The method for producing a copolymer according to claim 13, wherein in the solvent heating step (I), a chain transfer agent is added to the solvent (B-1) and then the temperature is raised.
By the post-polymerization step (III)
It contains a structural unit (a) having a blocked isocyanato group blocked by a pyrazole compound, a structural unit (b) having a hydroxy group, and a structural unit (c) having an acid group, and has a glass transition temperature of 30 ° C. The method for producing a copolymer according to claim 13, wherein the following copolymer can be obtained.