Method for producing copolymer, method for producing photosensitive resin composition, and method for producing image display element

Abstract

To provide a method for producing a copolymer capable of forming a resin cured film having sufficient solvent resistance and hardness.SOLUTION: The method for producing a copolymer of the present invention comprises a step (I) of mixing a polymerization initiator (I) and a solvent (I) to obtain a solution (I), a step (II) of mixing a monomer (m-a), a monomer (m-b) and a monomer (m-c), the method includes a step (II) of obtaining a solution (ii), a step (III) of placing a solvent (iii) in a reaction tank and raising the temperature to a set temperature in the range of 40 to 70 °C, and a step (IV) of stirring and copolymerizing a reaction solution in the reaction tank while adding the solution (I) and the solution (ii) to the reaction tank. The monomer (m-a) is an ethylenically unsaturated group-containing compound having one or more selected from an active methylene group to which a methoxycarbonyl group is connected and an active methine group to which a methoxycarbonyl group is connected. The 10-hour half-life temperature of the polymerization initiator (I) is 50 °C or lower.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to a method for producing a copolymer, a method for producing a photosensitive resin composition, and a method for producing an image display element. [Background technology]

[0002] Conventionally, some image display devices such as displays are equipped with color filters, which are typically formed by baking a resin composition on a substrate at a temperature above 200°C to harden it. In recent years, with the trend toward more flexible and wearable displays, substrate materials are being switched from glass to organic materials such as resins. Furthermore, in order to realize image display elements with even higher brightness and contrast, colorants used in color filters are being switched from pigments to dyes and / or fluorescent compounds, quantum dots, and other materials.

[0003] Organic materials used as substrate materials have poorer heat resistance than glass. Furthermore, dyes used as colorants in color filters have poorer heat resistance than pigments. For these reasons, it is desirable to lower the heating temperature required for curing resin compositions used as color filter materials. Specifically, depending on the heat resistance of the substrate material and colorant materials, the heating temperature required for curing resin compositions used as color filter materials may be required to be 80 to 150°C, and in recent years, 80 to 100°C in particular. Furthermore, with growing awareness of environmental protection, a trend toward lowering heating temperatures is gaining attention, with the aim of reducing energy consumption during manufacturing.

[0004] If the heating temperature for curing the resin composition is low, it becomes difficult to obtain sufficient solvent resistance. In color filters provided in image display devices, the content of colorant in the resin composition used as the material for the color filter tends to be increased in order to improve color reproducibility. Furthermore, dyes have higher solubility in solvents than pigments. Therefore, if the solvent resistance of the color filter is insufficient, the dye contained in the color filter may dissolve in the solvent, causing a change in the chromaticity of the color filter.

[0005] Resin compositions that can exhibit these two contradictory properties are described, for example, in Patent Documents 1 and 2. Patent Documents 1 and 2 describe examples in which a copolymer having a thermal crosslinking mechanism derived from an inherent structure is given a characteristic feature as a condition necessary to provide a desired resin composition. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 7189875 [Patent Document 2] Patent No. 7306267 Summary of the Invention [Problem to be solved by the invention]

[0007] However, resin compositions using the copolymers described in Patent Documents 1 and 2 are unable to exhibit sufficient curability due to the characteristics of the thermal crosslinking mechanism of the copolymer, and are unable to accommodate the low heating temperature range of 80 to 100°C that has become particularly required in recent years.

[0008] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method for producing a copolymer capable of forming a cured resin film having sufficient solvent resistance and hardness, a method for producing a photosensitive resin composition using the copolymer, and a method for producing an image display element. [Means for solving the problem]

[0009] The present invention includes the following aspects. [1] A step (I) of mixing a polymerization initiator (i) and a solvent (i) to obtain a solution (i); a step (II) of mixing the monomer (ma), the monomer (mb), and the monomer (mc) to obtain a solution (ii); A step (III) of adding the solvent (iii) to a reaction vessel and heating the reaction vessel to a set temperature in the range of 40 to 70°C; a step (IV) of adding the solution (i) and the solution (ii) to the reaction vessel while stirring the reaction solution in the reaction vessel to copolymerize; and the monomer (ma) is an ethylenically unsaturated group-containing compound having one or more selected from an active methylene group having a methoxycarbonyl group bonded thereto and an active methine group having a methoxycarbonyl group bonded thereto, the monomer (mb) is an ethylenically unsaturated group-containing compound having a hydroxy group, the monomer (mc) is an ethylenically unsaturated group-containing compound having an acid group, A method for producing a copolymer, wherein the 10-hour half-life temperature of the polymerization initiator (i) is 50°C or lower. [2] The method for producing a copolymer according to [1], wherein the polymerization initiator (i) is a peroxide-based thermal polymerization initiator. [3] The method for producing a copolymer according to [2], wherein a reducing agent (i-2) is further added in the step (IV). [4] The method for producing a copolymer according to [2], wherein the polymerization initiator (i) is one or more selected from the group consisting of 1-methyl-1-phenylethyl 7,7-dimethylperoxyoctanoate, benzoyl peroxide, di(2-phenoxyethyl) peroxydicarbonate, cumyl peroxyneodecanoate, and di(4-t-butylcyclohexyl) peroxydicarbonate (10-hour half-life temperature: 41°C). [5] The method for producing a copolymer according to [3], wherein the reducing agent (i-2) is one or more selected from 1,1'-[(4-methylphenyl)imino]bis(2-propanol), N,N-dimethyl-aniline, and N,N-dimethyl-p-toluidine. [6] The method for producing a copolymer according to any one of [1] to [5], further comprising a step (V) of continuing the copolymerization reaction with stirring for 1 to 10 hours after completion of the step (IV). [7] The method for producing a copolymer according to any one of [1] to [6], wherein in the step (IV), the solution (i) and the solution (ii) are each added dropwise to a reaction vessel. [8] The method for producing a copolymer according to any one of [1] to [7], wherein the copolymer has an acid value of 10 to 300 KOHmg / g. [9] The method for producing a copolymer according to any one of [1] to [8], wherein the copolymer has a weight average molecular weight of 3,000 to 50,000.

[10] The method for producing a copolymer according to any one of [1] to [9], wherein the monomer (ma) has one or more selected from the group consisting of a group represented by the following formula (1) and a group represented by the following formula (2): [ka] (In formula (1), n1 and n2 each independently represent an integer of 0 to 2. * represents a linking site with the residue obtained by removing the blocked isocyanato group from the monomer (ma).) [ka] (In formula (2), n3 and n4 each independently represent an integer of 0 to 2. * represents a linking site with the residue obtained by removing the blocked isocyanato group from the monomer (ma).)

[11] The amount of the polymerization initiator (i) used is 0.5 to 30 parts by mass relative to 100 parts by mass of the total of all the monomers used in the step (II), The method for producing a copolymer according to any one of [1] to

[10] , wherein the amount of the solvent (i) used is 100 to 3000 parts by mass per 100 parts by mass of the polymerization initiator (i).

[12] In the step (II), the monomer (ma), the monomer (mb), the monomer (mc), and a solvent (ii) are further mixed together, The method for producing a copolymer according to any one of [1] to

[11] , wherein the amount of the solvent (ii) used is 10 to 500 parts by mass when the total amount of the monomers (ma), (mb), and (mc) is 100 parts by mass.

[13] A method for producing a copolymer, comprising the steps of preparing a copolymer (A), a reactive diluent (B), a photopolymerization initiator (C), and a solvent (D), A method for producing a photosensitive resin composition, wherein the copolymer (A) is a copolymer obtained by the production method according to any one of [1] to

[12] .

[14] The method for producing a photosensitive resin composition according to

[13] , further comprising adding a colorant (E).

[15] A method for producing a cured resin film, which comprises applying a photosensitive resin composition obtained by the method according to

[13] or

[14] , exposing the composition to light, and thermally curing the composition.

[16] A method for producing a patterned cured resin film, comprising coating, exposing, developing, and thermally curing a photosensitive resin composition obtained by the method according to

[13] or

[14] .

[17] The method for producing a cured resin film according to

[16] , wherein the curing is carried out at 50 to 150°C.

[18] A method for producing an image display element, comprising repeatedly applying, exposing, and developing the photosensitive resin composition obtained by the production method according to

[13] or

[14] for each color, to form a color filter having a colored pattern made of a cured product of the photosensitive resin composition. [Effects of the Invention]

[0010] According to the present disclosure, it is possible to provide a method for producing a copolymer capable of forming a cured resin film having sufficient solvent resistance and hardness, a method for producing a photosensitive resin composition using the copolymer, and a method for producing an image display element. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present invention will be described in detail. However, the present invention is not limited to the embodiments shown below. In this specification, the term "(meth)acryloyloxy group" refers to one or more groups selected from methacryloyloxy groups and acryloyloxy groups. The same applies to "(meth)acrylic acid" and "(meth)acrylate." Furthermore, in this specification, when "~" is used to describe a numerical range, the numerical values ​​at both ends are the upper and lower limits, respectively, and are included in the numerical range. When multiple upper or lower limits are listed, numerical ranges can be created from all combinations of the upper and lower limits. Similarly, when multiple numerical ranges are listed, separate numerical ranges can be created by individually selecting and combining upper and lower limits from those numerical ranges.

[0012] In this specification, a "structural unit having an XYZ group" refers to a structural unit having the same structure as a monomer unit corresponding to the monomer in a polymer produced by addition polymerization of a compound having an XYZ group and an ethylenically unsaturated group as a monomer. For example, when the original monomer (a compound having a hydroxy group and an ethylenically unsaturated group) of a "structural unit having a hydroxy group" is 2-hydroxyethyl methacrylate, the "structural unit having a hydroxy group" has the chemical structure "-C(CH3)(COOC2H4OH)CH2-". Note that a unit produced by first addition polymerizing a compound having an ethylenically unsaturated group but not an XYZ group as a monomer and then introducing an XYZ group into the monomer unit also falls under the category of a "structural unit having an XYZ group".

[0013] In this specification, a "structural unit derived from an ethylenically unsaturated compound having an XYZ group" refers to a structural unit having the same structure as a monomer unit corresponding to the monomer in a polymer produced by addition polymerization of the ethylenically unsaturated compound as a monomer. For example, acrylic acid is a type of ethylenically unsaturated compound having a carboxy group. A structural unit derived from acrylic acid would be "-CH(COOH)-CH-". Note that a unit produced by first addition polymerization of a compound having an ethylenically unsaturated group but not an XYZ group as a monomer, and then introducing an XYZ group into the monomer unit, also falls under the category of a "structural unit derived from an ethylenically unsaturated compound having an XYZ group."

[0014] [Method of producing copolymer] The method for producing a copolymer according to one embodiment of the present invention (sometimes referred to as the "production method of the present embodiment") comprises the following steps (I) to (IV). Step (I): A step of mixing a polymerization initiator (i) with a solvent (i) to obtain a solution (i). Step (II): A step of mixing an ethylenically unsaturated group-containing compound (ma) (hereinafter also referred to simply as "monomer (ma)") having one or more selected from an active methylene group connected to a methoxycarbonyl group and an active methine group connected to a methoxycarbonyl group, an ethylenically unsaturated group-containing compound (mb) (hereinafter also referred to simply as "monomer (mb)") having a hydroxy group, and an ethylenically unsaturated group-containing compound (mc) (hereinafter also referred to simply as "monomer (mc)") having an acid group, to obtain a solution (ii). Step (III): A step of adding the solvent (iii) to a reaction vessel and heating it to a set temperature in the range of 40 to 70°C. Step (IV): A step of adding the solution (i) and the solution (ii) to the reaction vessel while stirring the reaction solution in the reaction vessel to copolymerize them. In the step (I), the 10-hour half-life temperature of the polymerization initiator (i) is 50° C. or lower.

[0015] The steps (I) to (III) may be carried out in this order or in another order. The step (IV) is carried out after the steps (I) to (III). If necessary, step (I-2) described below may be carried out. Step (I) and step (I-2) may be combined, but it is preferable to separate them. If necessary, the following step (V) may be carried out after step (IV). Step (V): A step of continuing the copolymerization reaction with stirring for 1 to 10 hours.

[0016] <Process (I)> The step (I) is a step of mixing a polymerization initiator (i) with a solvent (i) to obtain a solution (i). As a mixing method, a known method can be appropriately adopted.

[0017] "Polymerization initiator (i)" The polymerization initiator (i) is a polymerization initiator having a 10-hour half-life temperature of 50°C or less. By using the polymerization initiator (i), the polymerization reaction temperature can be set low. As a result, the copolymerization reaction using the monomer (ma) can proceed without gelation. By using the polymerization initiator (i), one or more groups selected from an active methylene group having a methoxycarbonyl group attached thereto and an active methine group having a methoxycarbonyl group attached thereto can be introduced into the copolymer. As a result, the photosensitive resin composition can be cured at a low temperature, and a cured resin film having excellent solvent resistance and hardness can be obtained. Examples of the polymerization initiator (i) that can be used in this copolymerization reaction include azo-based thermal polymerization initiators such as azobisisobutyronitrile and azobisisovaleronitrile; and peroxide-based thermal polymerization initiators such as benzoyl peroxide and t-butylperoxy-2-ethylhexanoate. These polymerization initiators may be used alone or in combination of two or more. Among them, it is more preferable to use a peroxide-based thermal polymerization initiator from the viewpoint of suppressing gel formation during the copolymerization reaction.

[0018] Peroxide-based thermal polymerization initiators with a 10-hour half-life temperature of 50°C or less include: 1-methyl-1-phenylethyl 7,7-dimethylperoxyoctanoate and benzoyl peroxide, di(2-phenoxyethyl) peroxydicarbonate, Cumyl peroxyneodecanoate (10-hour half-life temperature 36.5°C), Di(4-t-butylcyclohexyl) peroxydicarbonate (TCP (purity 90%) manufactured by NOF Corporation, 1-minute half-life temperature: 92.1°C, 1-hour half-life temperature: 57.5°C, 10-hour half-life temperature: 40.8°C), Diisopropyl peroxydicarbonate (Peroyl IPP (purity 50%) manufactured by NOF Corporation, 1-minute half-life temperature: 88.3°C, 1-hour half-life temperature: 56.2°C, 10-hour half-life temperature: 40.5°C), Di(2-ethylhexyl) peroxydicarbonate (Peroyl OPP (70% purity) manufactured by NOF Corporation, 1-minute half-life temperature: 90.6°C, 1-hour half-life temperature: 59.1°C, 10-hour half-life temperature: 43.6°C), Di-sec-butyl peroxydicarbonate (Peroyl SBP (purity 50%) manufactured by NOF Corporation, 1-minute half-life temperature: 92.4°C, 1-hour half-life temperature: 57.4°C, 10-hour half-life temperature: 40.5°C), 3-hydroxy-1,1 dimethylbutyl peroxyneodecanoate (10-hour half-life temperature T10: 37°C), Diisobutyryl peroxide (NOF Corporation, trade name: Peroyl IB, 10-hour half-life temperature 32.7°C), Examples include di-n-propyl peroxydicarbonate (manufactured by NOF Corporation, trade name: Peroyl NPP, 10-hour half-life temperature 40.3°C).

[0019] The amount of the polymerization initiator (i) used is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, and even more preferably 5 parts by mass or more, based on 100 parts by mass of the total amount of monomers charged. The amount of the polymerization initiator (i) used is preferably 30 parts by mass or less, more preferably 25 parts by mass or less, and even more preferably 20 parts by mass or less, based on 100 parts by mass of the total amount of monomers charged. When the amount of the polymerization initiator (i) used is 0.5 parts by mass or more, the copolymer can be polymerized efficiently. When the amount of the polymerization initiator (i) used is 30 parts by mass or less, the weight-average molecular weight of the copolymer can be controlled within a desired range.

[0020] "Solvent (i)" The solvent (i) is not particularly limited as long as it is a solvent that can dissolve or disperse the polymerization initiator (i). Examples of the solvent (i) include hydroxyl group-containing solvents and hydroxyl group-free solvents.

[0021] Examples of the hydroxy group-containing solvent include hydroxy group-containing ethers such as (poly)alkylene glycol monoalkyl ethers, 1,3-butanediol monoalkyl ethers, 1,4-butanediol monoalkyl ethers, glycerin monoalkyl ethers, and glycerin dialkyl ethers; methanol, ethanol, propanol, C5-6 cycloalkanediols, C 5-6Examples of the (poly)alkylene glycol monoalkyl ether include alcohols such as cycloalkane dimethanol; hydroxy group-containing carboxylic acid esters such as methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, methyl 2-hydroxy-2-methylpropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl hydroxyacetate, and methyl 2-hydroxy-3-methylbutyrate; diethylene glycol, ethyl lactate, diacetone alcohol, etc. Examples of the (poly)alkylene glycol monoalkyl ether 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 monomethyl ether, propylene glycol monoethyl ether, dipropylene glycol monomethyl ether, tripropylene glycol monoethyl ether, and 3-methoxy-1-butanol.

[0022] Examples of the hydroxy group-free solvent include hydroxy group-free ethers such as (poly)alkylene glycol monoalkyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol diethyl ether, and tetrahydrofuran; ketones such as methyl ethyl ketone, cyclohexanone, 2-heptanone, and 3-heptanone; methyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl ethoxyacetate, 3-methyl-3-methoxybutyl acetate, and 3-methyl-3-methoxybutyl acetate. Examples of the (poly)alkylene glycol monoalkyl ether acetate include esters such as 1-methyl-3-methoxybutylpropionate, ethyl acetate, n-butyl acetate, i-propyl acetate, i-butyl acetate, n-amyl acetate, i-amyl acetate, n-butyl propionate, ethyl butyrate, n-propyl butyrate, i-propyl butyrate, ethyl pyruvate, n-propyl pyruvate, methyl acetoacetate, ethyl acetoacetate, and ethyl 2-oxobutyrate; aromatic hydrocarbons such as toluene and xylene; and carboxylic acid amides such as N-methylpyrrolidone, N,N-dimethylformamide, and N,N-dimethylacetamide. Examples of the (poly)alkylene glycol monoalkyl ether acetate include ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, and propylene glycol monoethyl ether acetate.

[0023] The solvent (i) may be used alone or in combination of two or more kinds. Among these, from the viewpoints of availability, cost, and stability during resist preparation, it is preferable to use the hydroxy group-containing ethers or the hydroxy group-free ethers. Specifically, it is preferable to use one or more selected from propylene glycol monomethyl ether acetate, diethylene glycol methyl ethyl ether, propylene glycol monomethyl ether, ethylene glycol monomethyl ether, and 3-methoxy-1-butanol. Hydroxy group-containing ethers are more preferable. Even more preferable are the (poly)alkylene glycol monoalkyl ethers. Specifically, it is most preferable to use one or more selected from propylene glycol monomethyl ether and ethylene glycol monomethyl ether.

[0024] The amount of the solvent (i) used is preferably 100 to 3,000 parts by mass, more preferably 150 to 2,500 parts by mass, relative to 100 parts by mass of the polymerization initiator (i). When the amount of the solvent (i) used is 100 parts by mass or more, the polymerization initiator (i) can be sufficiently dissolved and homogenized, and in step (IV) for the copolymerization reaction, the polymerization initiator (i) can be added to the reaction vessel at a constant rate. When the amount of the solvent (i) used is 3,000 parts by mass or less, the concentration of the polymerization initiator (i) can be sufficiently ensured, and the copolymerization reaction can be carried out efficiently.

[0025] <Process (I-2)> The production method of this embodiment may further include the following step (I-2). Step (I-2): A step of mixing a reducing agent (i-2) with a solvent (i-2) to obtain a solution (i-2). In the production method of this embodiment, when a peroxide-based thermal polymerization initiator is used, the reducing agent (i-2) may be used in combination. By using the reducing agent (i-2) in combination, the following effects I to III can be expected. Effect I: Polymerization is possible at lower temperatures. Effect II: The effect of using a polymerization initiator with a higher half-life temperature when the reaction temperature is fixed. Effect III: Effect of reducing the molecular weight of the copolymer. When the reducing agent (i-2) is used, the step (I-2) is employed. In the step (I-2), a known mixing method can be appropriately adopted. The step (I) and the step (I-2) may be integrated and the materials to be used in each step may be mixed in the same container, but from the viewpoint of storage stability and ensuring working time, it is preferable to mix and adjust the materials in separate containers.

[0026] "Reducing agent (i-2)" The reducing agent (i-2) is a compound that exhibits a reducing effect on the peroxide-based thermal polymerization initiator. Examples of the reducing agent (i-2) include aliphatic amines, aromatic amines, sulfinic acid derivatives, sulfur-containing reductive inorganic compounds, nitrogen-containing reductive inorganic compounds, borate compounds, barbituric acid derivatives, triazine compounds, and halogen compounds, as described in JP 2021-054814 A. Among these, aromatic amines are preferred from the viewpoint of ease of progression of the oxidation-reduction reaction with the peroxide-based polymerization initiator. Examples of aromatic amine compounds include 2,2-[3-(methylphenyl)imino]bisethanol acetate, 1,1'-[(4-methylphenyl)imino]bis(2-propanol), p-tolyldiethanolamine, N,N-bis(2,2,2-trifluoroethyl)-p-toluidine, N,N-di(1-hydroxyethyl)-p-toluidine, N,N-di(2-hydroxypropyl)-p-toluidine, N-(1-cyanoethyl)-N-(1-acetoxyethyl)-m-toluidine, N,N-di(1-chloroethyl)-p-toluidine, N,N-dimethyl-p-toluidine, N-ethyl-N-methylaniline, N,N-dimethyl-aniline, N,N-dipropyl-o-toluidine, N,N-dipropyl-m-toluidine, N,N-dipropyl-p-toluidine, and ethyl 4-dimethylaminobenzoate. Among these, 1,1'-[(4-methylphenyl)imino]bis(2-propanol), N,N-dimethyl-aniline, N,N-dimethyl-p-toluidine, and the like are preferred from the viewpoint of reducing the copolymerization reaction temperature. In the step (I-2), the amount of the reducing agent (i-2) used is preferably 0.001 to 10 parts by mass, and more preferably 0.01 to 5 parts by mass, relative to 100 parts by mass of the total amount of the monomers charged.

[0027] "Solvent (i-2)" The solvent (i-2) may be the same as the solvent (i). In step (I-2), the amount of solvent (i-2) used is preferably 400 to 10,000 parts by mass, more preferably 500 to 8,000 parts by mass, per 100 parts by mass of reducing agent (i-2). When the amount of solvent (i-2) used is 400 parts by mass or more, the reducing agent (i-2) can be sufficiently dissolved and homogenized, and in step (IV) for the copolymerization reaction, the reducing agent (i-2) can be added to the reaction vessel at a constant rate. When the amount of solvent (i-2) used is 10,000 parts by mass or less, the concentration of the reducing agent (i-2) can be sufficiently ensured, and the copolymerization reaction can be carried out efficiently.

[0028] <Process (II)> Step (II) is a step of mixing the monomers to be used in the copolymerization reaction. Any known mixing method can be used. If necessary, a solvent (ii) may be further mixed. Examples of the monomer used in the copolymerization reaction include the monomer (ma), the monomer (mb), and the monomer (mc).

[0029] As the monomer used in the copolymerization reaction, an ethylenically unsaturated group-containing compound (md) having a linear or branched alkyl group having 1 to 20 carbon atoms (hereinafter also simply referred to as "monomer (md)") may further be used, if necessary. As the monomer used in the copolymerization reaction, an ethylenically unsaturated group-containing compound (me) having a bridged cyclic hydrocarbon group having 10 to 20 carbon atoms (hereinafter simply referred to as "monomer (me)") may further be used, if necessary. As the monomers used in the copolymerization reaction, if necessary, other copolymerizable monomers (mf) (hereinafter also simply referred to as "monomer (mf)") other than the monomers (ma) to (me) may further be used.

[0030] The proportions of the monomers used in the copolymerization reaction of copolymer (A) are not particularly limited, and are preferably 1 to 40 mol% of monomer (ma), 1 to 40 mol% of monomer (mb), and 1 to 40 mol% of monomer (mc), more preferably 5 to 30 mol% of monomer (ma), 5 to 30 mol% of monomer (mb), and 3 to 30 mol% of monomer (mc), and even more preferably 10 to 25 mol% of monomer (ma), 10 to 25 mol% of monomer (mb), and 5 to 25 mol% of monomer (mc). When monomer (md) is further used, preferably, monomer (ma) is 1 to 40 mol%, monomer (mb) is 1 to 40 mol%, monomer (mc) is 1 to 40 mol%, and monomer (md) is 10 to 95 mol%, more preferably, monomer (ma) is 5 to 30 mol%, monomer (mb) is 5 to 30 mol%, monomer (mc) is 3 to 30 mol%, and monomer (md) is 30 to 90 mol%, and even more preferably, monomer (ma) is 10 to 25 mol%, monomer (mb) is 10 to 25 mol%, monomer (mc) is 5 to 25 mol%, and monomer (md) is 50 to 80 mol%. When monomer (me) is further used, preferably, monomer (ma) is 1 to 40 mol%, monomer (mb) is 1 to 40 mol%, monomer (mc) is 1 to 40 mol%, monomer (md) is 10 to 95 mol%, and monomer (me) is 1 to 30 mol%, more preferably, monomer (ma) is 5 to 30 mol%, monomer (mb) is 5 to 30 mol%, monomer (mc) is 3 to 30 mol%, monomer (md) is 30 to 80 mol%, and monomer (me) is 3 to 20 mol%, and even more preferably, monomer (ma) is 10 to 25 mol%, monomer (mb) is 10 to 25 mol%, monomer (mc) is 5 to 25 mol%, monomer (md) is 30 to 70 mol%, and monomer (me) is 5 to 10 mol%.

[0031] "Monomer (MA)" The monomer (ma) according to this embodiment is an ethylenically unsaturated group-containing compound having at least one selected from an active methylene group having a methoxycarbonyl group attached thereto and an active methine group having a methoxycarbonyl group attached thereto.

[0032] The monomer (ma) is not particularly limited as long as it is a compound copolymerizable with the monomer (mb) and the monomer (mc) described below. The monomer (ma) preferably has at least one selected from the group consisting of a group represented by the following formula (1) and a group represented by the following formula (2).

[0033] [ka]

[0034] (In formula (1), n1 and n2 each independently represent an integer of 0 to 2. * represents a linking site with the residue obtained by removing the blocked isocyanato group from the monomer (ma).) In formula (1), n1 and n2 each independently represent preferably 0 or 1, and more preferably 0.

[0035] [ka]

[0036] (In formula (2), n3 and n4 each independently represent an integer of 0 to 2. * represents a linking site with the residue obtained by removing the blocked isocyanato group from the monomer (ma).) In formula (2), n3 and n4 each independently represent preferably 0 or 1, and more preferably 0.

[0037] As the monomer (ma), for example, from the viewpoint of reactivity when synthesizing the copolymer (A), a monomer having the above-mentioned methoxycarbonyl group and an ethylenically unsaturated bond can be used. Specific examples of the group having an ethylenically unsaturated bond include a vinyl group and a (meth)acryloyloxy group. From the viewpoint of the degree of freedom in the monomer blending ratio, a (meth)acryloyloxy group is preferred, and from the viewpoint of the solvent resistance of the cured product of the photosensitive resin composition and the reduction of dye elution when a dye is used as the colorant (E), an acryloyloxy group is preferred.

[0038] Examples of the monomer (ma) having a methoxycarbonyl group and an ethylenically unsaturated bond include a reaction product of an isocyanate compound containing an ethylenically unsaturated group with dimethyl malonate or methyl acetoacetate. These monomers (ma) may be used alone or in combination of two or more.

[0039] The ethylenically unsaturated group-containing isocyanate compound that produces the monomer (ma) is preferably a compound represented by the following formula (3).

[0040] [ka] (In formula (3), R 4 represents a hydrogen atom or a methyl group. 5 -CO-, -COOR 6 -(where R 6 is an alkylene group having 1 to 6 carbon atoms.) or -COO-R7 O-CONH-R 8 -(where R 7 is an alkylene group having 2 to 6 carbon atoms. 8 represents an alkylene group having 2 to 12 carbon atoms or an arylene group having 6 to 12 carbon atoms, which may have a substituent.

[0041] R in equation (3) 4 represents a hydrogen atom or a methyl group. From the viewpoint of the solvent resistance of the cured product of the photosensitive resin composition and the reduction of dye elution when a dye is used as the colorant (E), R 4 is preferably a hydrogen atom. R in equation (3) 5 -CO-, -COOR 6 -or-COO-R 7 O-CONH-R 8 - where R 6 is an alkylene group having 1 to 6 carbon atoms. 7 is an alkylene group having 2 to 6 carbon atoms. 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. 5 -COOR 6 - is preferred. 5 Ga-COOR 6 -If R 6 is preferably an alkylene group having 1 to 4 carbon atoms.

[0042] Specific examples of the ethylenically unsaturated group-containing isocyanate compound represented by the above formula (3) include 2-isocyanatoethyl (meth)acrylate, 2-isocyanatopropyl (meth)acrylate, 3-isocyanatopropyl (meth)acrylate, 2-isocyanato-1-methylethyl (meth)acrylate, 2-isocyanato-1,1-dimethylethyl (meth)acrylate, 4-isocyanatocyclohexyl (meth)acrylate, and (meth)acryloyl isocyanate.

[0043] The ethylenically unsaturated group-containing isocyanate compound represented by the formula (3) can also be an equimolar (1 mol:1 mol) reaction product of a 2-hydroxyalkyl (meth)acrylate and a diisocyanate compound. The alkyl group contained in the 2-hydroxyalkyl (meth)acrylate is preferably an ethyl group or an n-propyl group, more preferably an ethyl group. Examples of the diisocyanate compound include hexamethylene diisocyanate, 2,4- (or 2,6-) tolylene diisocyanate (TDI), 4,4'-diphenylmethane diisocyanate (MDI), 3,5,5-trimethyl-3-isocyanatomethylcyclohexyl isocyanate (IPDI), m- (or p-) xylene diisocyanate, 1,3- (or 1,4-) bis(isocyanatomethyl)cyclohexane, and lysine diisocyanate.

[0044] Among these ethylenically unsaturated group-containing isocyanate compounds, 2-isocyanatoethyl (meth)acrylate, 2-isocyanatopropyl (meth)acrylate, 3-isocyanatopropyl (meth)acrylate, 2-isocyanato-1-methylethyl (meth)acrylate, 2-isocyanato-1,1-dimethylethyl (meth)acrylate, 4-isocyanatocyclohexyl (meth)acrylate, and (meth)acryloyl isocyanate are preferred, and 2-isocyanatoethyl (meth)acrylate and 2-isocyanatopropyl (meth)acrylate are more preferred. These ethylenically unsaturated group-containing isocyanate compounds may be used alone or in combination of two or more.

[0045] The reaction of an ethylenically unsaturated group-containing isocyanate compound with dimethyl malonate or methyl acetoacetate can be carried out in the presence or absence of a solvent. When the reaction is carried out using a solvent, a solvent inert to the isocyanato group is used. In the reaction, a catalyst such as an organic metal salt of tin, zinc, lead, or the like, or a tertiary amine may be used. The above reaction can generally be carried out at a temperature of -20 to 150°C, preferably 25 to 130°C. When the reaction temperature is -20°C or higher, a sufficient reaction rate can be obtained. Furthermore, when the reaction temperature is 150°C or lower, it is possible to prevent the raw material having a C=C (double bond) from polymerizing, thereby preventing gelation of the monomer (ma) that gives the structural unit (a) produced after the reaction.

[0046] Specific examples of the monomer (ma) include the following AOI-DMM and MOI-DMM. AOI-DMM: Karenz™ AOI-DMM, a reaction product of isocyanatoethyl acrylate and dimethyl malonate (malonic acid-2-[[[[2-[1-oxo-2-propenyl]oxy]ethyl]amino]carbonyl]-1,3-dimethyl ester, manufactured by Resonac Corporation. MOI-DMM: Karenz™ MOI-DMM, a reaction product of isocyanatoethyl methacrylate and dimethyl malonate (malonic acid-2-[[[2-methyl-1-oxo-2-propenyl]oxy]ethyl]amino]carbonyl]-1,3-dimethyl ester, manufactured by Resonac Corporation.

[0047] "Monomer (mb)" The monomer (mb) is an ethylenically unsaturated group-containing compound having a hydroxy group. The monomer (mb) is not particularly limited as long as it does not have the methoxycarbonyl group and has an ethylenically unsaturated group and a hydroxy group. Examples of the ethylenically unsaturated group contained in the monomer (mb) include a vinyl group and a (meth)acryloyloxy group. Examples of the monomer (mb) include a (meth)acrylic acid ester derivative having a hydroxy group. Specific examples of such a monomer (mb) include 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2,3-dihydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, polyethylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate, etc. These monomers (mb) may be used alone or in combination of two or more.

[0048] . Among the above-mentioned monomers, hydroxyalkyl(meth)acrylates and polyalkylene glycol mono(meth)acrylates are preferred as the monomer (mb) from the viewpoints of reactivity during synthesis of the copolymer (A), low-temperature curing properties of the resin composition containing the copolymer (A), and ease of availability. As the hydroxyalkyl(meth)acrylate, 2-hydroxyethyl(meth)acrylate, 3-hydroxypropyl(meth)acrylate, and 4-hydroxybutyl(meth)acrylate are preferred, and from the viewpoint of obtaining solvent resistance as a cured product, 2-hydroxyethyl(meth)acrylate is more preferred. As the polyalkylene glycol mono(meth)acrylate, polyethylene glycol mono(meth)acrylate is preferred from the viewpoint of solvent resistance, and -(OC x H 2x ) m Polyethylene glycol mono(meth)acrylates in which x in —OH is 2 and m is 2 to 6 are more preferred.

[0049] "Monomer (MC)" The monomer (mc) according to this embodiment is an ethylenically unsaturated group-containing compound having an acid group. Examples of the monomer (mc) according to this embodiment include unsaturated carboxylic acids or their anhydrides, unsaturated sulfonic acids, and unsaturated phosphonic acids. Specific examples include unsaturated carboxylic acids or anhydrides thereof such as (meth)acrylic acid, α-bromo(meth)acrylic acid, β-furyl(meth)acrylic acid, crotonic acid, propiolic acid, cinnamic acid, α-cyanocinnamic acid, maleic acid, maleic anhydride, monomethyl maleate, monoethyl maleate, monoisopropyl maleate, fumaric acid, itaconic acid, itaconic anhydride, citraconic acid, and citraconic anhydride; unsaturated sulfonic acids such as 2-acrylamido-2-methylpropanesulfonic acid, tert-butylacrylamidosulfonic acid, and p-styrenesulfonic acid; and unsaturated phosphonic acids such as vinylphosphonic acid. These monomers (mc) may be used alone or in combination of two or more. Among these, (meth)acrylic acid is preferred from the viewpoint of developability as a photosensitive resin composition, and acrylic acid is more preferred from the viewpoint of solvent resistance.

[0050] "Monomer (MD)" The monomer (md) according to this embodiment is a (meth)acrylate having a linear or branched alkyl group having 1 to 20 carbon atoms. Specific examples of the monomer (md) include methyl (meth)acrylate, ethyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, pentyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, and dodecyl (meth)acrylate. Among these, alkyl (meth)acrylates having a linear alkyl group having 1 to 6 carbon atoms are preferred, and methyl (meth)acrylate and ethyl (meth)acrylate are preferred, from the viewpoint of having little influence on the thermosetting reaction of the copolymer (A) in terms of the stereostructure. Additionally, from the viewpoint of being able to appropriately adjust the substrate adhesion, alkyl(meth)acrylates having a branched alkyl group having 4 to 10 carbon atoms are preferred, and iso-butyl(meth)acrylate, tert-butyl(meth)acrylate, and 2-ethylhexyl(meth)acrylate are more preferred. These may be used alone or in combination of two or more.

[0051] "Monomer (me)" The monomer (me) according to this embodiment is a (meth)acrylate having a bridged cyclic hydrocarbon group having 10 to 20 carbon atoms. Specifically, the monomer (me) is more preferably adamantyl (meth)acrylate or a (meth)acrylate having a structure represented by the following formula (5):

[0052] [ka]

[0053] In formula (5), R 7 ~R 9 R each independently represents a hydrogen atom or a methyl group. 10 and R 11represents a hydrogen atom or a methyl group, or may be bonded to form a saturated or unsaturated ring. The ring is preferably a 5- or 6-membered ring. * represents a bond connected to the (meth)acryloyloxy group.

[0054] Specific examples of the (meth)acrylate having the structure represented by the above formula (5) include dicyclopentenyl (meth)acrylate, dicyclopentanyl (meth)acrylate, isobornyl (meth)acrylate, etc. Among these, dicyclopentanyl (meth)acrylate is particularly preferred from the viewpoints of being able to control the glass transition temperature of the copolymer (A) to a high level and having excellent heat resistance. These may be used alone or in combination of two or more.

[0055] "Monomer (mf)" The monomer (mf) according to this embodiment is a copolymerizable monomer (mf) other than the monomers (ma) to (me) (hereinafter, also simply referred to as "monomer (mf)"). Specific examples of the monomer (mf) according to this embodiment include aromatic vinyl compounds, cyclic olefins having a norbornene structure, dienes, (meth)acrylic acid amides, vinyl compounds, unsaturated dicarboxylic acid diesters, monomaleimides, (meth)acrylic acid anilides, (meth)acrylonitriles, and acrolein. Examples of aromatic vinyl compounds include styrene, α-methylstyrene, o-vinyltoluene, p-vinyltoluene, o-chlorostyrene, m-chlorostyrene, methoxystyrene, p-nitrostyrene, p-cyanostyrene, and p-acetylaminostyrene. Cyclic olefins having a norbornene structure include norbornene (bicyclo[2.2.1]hept-2-ene), 5-methylbicyclo[2.2.1]hept-2-ene, and tetracyclo[4.4.0.1 2,5 .1 7,10 ]dodec-3-ene, 8-ethyltetracyclo[4.4.0.1 2,5 .1 7,10]dodec-3-ene, dicyclopentadiene, tricyclo[5.2.1.0 2,6 ]dec-8-ene, tricyclo[4.4.0.1 2,5 ]undec-3-ene, tricyclo[6.2.1.0 1,8 ]undec-9-ene, tetracyclo[4.4.0.1 2,5 .1 7,10 .0 1,6 ]dodec-3-ene, 8-ethylidenetetracyclo[4.4.0.1 2,5 .1 7,12 ]dodec-3-ene, pentacyclo[6.5.1.1 3,6 .0 2,7 .0 9,13 ]pentadec-4-ene, etc. Examples of dienes include butadiene, isoprene, and chloroprene. Examples of (meth)acrylic acid esters include benzyl (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, and ethoxylated phenyl (meth)acrylate. Examples of the (meth)acrylic acid amide include (meth)acrylic acid amide, (meth)acrylic acid N,N-dimethylamide, (meth)acrylic acid N,N-diisopropylamide, and (meth)acrylic acid anthracenylamide. Examples of the vinyl compound include vinyl chloride, vinylidene chloride, vinyl fluoride, vinylidene fluoride, N-vinylpyrrolidone, vinylpyridine, vinyl acetate, and vinyltoluene. Examples of the unsaturated dicarboxylic acid diester include diethyl citraconate, diethyl maleate, diethyl fumarate, and diethyl itaconate. Examples of monomaleimides include N-phenylmaleimide, N-cyclohexylmaleimide, N-laurylmaleimide, and N-(4-hydroxyphenyl)maleimide.

[0056] "Solvent (ii)" The solvent (ii) may be the same as the solvent (i). The amount of the solvent (ii) used is preferably 10 to 500 parts by mass, more preferably 20 to 300 parts by mass, per 100 parts by mass of the total amount of the monomers.

[0057] <Process (III)> In the step (III), the solvent (iii) is placed in a reaction vessel and heated to a set temperature in the range of 40 to 70°C. The set temperature is preferably 50 to 70°C. By setting the temperature at 40° C. or higher, the polymerization reaction is promoted. By setting the temperature at 70° C. or less, it is possible to prevent gel formation during the polymerization reaction.

[0058] "Solvent (iii)" The solvent (iii) can be the same as the solvent (i). The amount of the solvent (iii) used can be appropriately determined depending on the amount of the solvent (i) used in the step (I) and the amount of the solvent (ii) used as needed in the step (II). The amount of the solvent (iii) used is preferably 50 to 500 parts by mass, more preferably 100 to 400 parts by mass, per 100 parts by mass of the total of the monomers.

[0059] <Process (IV)> The step (IV) is a step of stirring and copolymerizing the reaction solution in the reaction tank while adding the solution (i) and the solution (ii) to the reaction tank, and, if necessary, stirring and copolymerizing the reaction solution in the reaction tank while further adding the solution (i-2). The solutions (i), (ii), and (i-2), which are used as needed, are preferably added dropwise to the reaction vessel at a constant rate from the start to the end of the process from their respective raw material tanks, thereby supplying the raw materials to the reaction vessel at a constant rate, thereby controlling the progress of the polymerization reaction and preventing unintended runaway or gelation. During step (IV), the set temperature of the reaction vessel is maintained at the set temperature of step (III). If necessary, the set temperature may be changed within a range of 40 to 70°C. However, from the viewpoint of suppressing variations in the physical properties of the copolymer and producing the desired copolymer with good reproducibility, it is preferable not to change the set temperature.

[0060] The time required for step (IV) varies depending on the size of the reaction vessel and the amount of raw materials used, but is preferably 10 minutes to 5 hours, more preferably 30 minutes to 3 hours, and even more preferably 40 minutes to 2 hours. By setting the time for adding solution (i), solution (ii), and optionally solution (i-2) to the raw material vessel to 10 minutes or more, runaway of the reaction solution and generation of gel can be prevented. By setting the time for adding solution (i), solution (ii), and optionally solution (i-2) to the raw material vessel to 5 hours or less, the efficiency of copolymer production can be improved. From the viewpoint of controlling the polymerization reaction, step (IV) is preferably carried out in an inert gas atmosphere, more preferably in a nitrogen gas atmosphere. Step (IV) is preferably carried out under normal pressure in order to control the polymerization reaction.

[0061] <Process (V)> In the production method of this embodiment, after the completion of the step (IV), a step (V) may be added as necessary. The step (V) is a step of continuing the copolymerization reaction while stirring the reaction solution. This allows the copolymerization reaction to proceed until the copolymer reaches the desired weight-average molecular weight. During the step (V), the set temperature of the reaction vessel is maintained at the set temperature of the step (III) in the same manner as in the step (IV). The time required for step (V) depends on the time required for step (IV), the size of the reaction vessel, and the amount of raw materials used, but is preferably 10 minutes to 20 hours, more preferably 30 minutes to 10 hours, even more preferably 1 to 10 hours, and particularly preferably 1 to 5 hours. The step (V) is preferably carried out in an inert gas atmosphere, more preferably in a nitrogen gas atmosphere, from the viewpoint of controlling the polymerization reaction. The step (V) is preferably carried out under normal pressure in order to control the polymerization reaction.

[0062] <Copolymer (A)> The copolymer obtained by the production method of the present embodiment (hereinafter sometimes simply referred to as "copolymer (A)") contains a structural unit (a) (hereinafter sometimes simply referred to as "structural unit (a)") having one or more types selected from an active methylene group connected to a methoxycarbonyl group and an active methine group connected to a methoxycarbonyl group, a structural unit (b) (hereinafter sometimes simply referred to as "structural unit (b)") having a hydroxy group, and a structural unit (c) (hereinafter sometimes simply referred to as "structural unit (c)") having an acid group.

[0063] The copolymer (A) may further contain, as necessary, a structural unit (d) derived from a (meth)acrylate having a linear or branched alkyl group having 1 to 20 carbon atoms (hereinafter also simply referred to as "structural unit (d)"). The copolymer (A) may further contain, as necessary, a structural unit (e) derived from a (meth)acrylate having a bridged cyclic hydrocarbon group having 10 to 20 carbon atoms (hereinafter simply referred to as "structural unit (e)"). The copolymer (A) may further contain a structural unit (f) (hereinafter simply referred to as "structural unit (f)") other than the structural units (a) to (e) above, as necessary.

[0064] "Constituent unit (a)" The structural unit (a) constituting the copolymer (A) is a structural unit derived from the monomer (ma) having one or more selected from an active methylene group having a methoxycarbonyl group attached thereto and an active methine group having a methoxycarbonyl group attached thereto. When a resin composition containing the copolymer (A) is thermally cured, the methoxycarbonyl group of the structural unit (a) in the copolymer (A) undergoes transesterification with the hydroxy group in the structural unit (b) to form a crosslinked structure. Therefore, a resin composition containing the copolymer (A) can produce a cured film with excellent solvent resistance even when cured at a low temperature of 50°C to 150°C. Furthermore, when the methoxycarbonyl group in the structural unit (a) in the copolymer (A) undergoes transesterification with the hydroxy group in the structural unit (b), methanol is produced. The methanol produced during thermal curing of the resin composition is easily evaporated and removed by the heating required for thermal curing the resin composition, which is preferred. When the alcohol produced by transesterification is methanol, evaporation and removal from the resin composition and curing of the resin composition proceed quickly, resulting in a cured resin film with sufficiently high hardness.

[0065] The active methylene group refers to a group in which an electron-withdrawing group is bonded to at least one side (preferably both sides) of a methylene group, and examples of the electron-withdrawing group include a carbonyl group, an ester group, a cyano group, a nitro group, a sulfonyl group, a sulfinyl group, a phosphono group, etc. As the active methylene group, a structure in which a carbonyl group or an ester group is bonded to both sides of a methylene group is preferred, and a group in which an ester group is bonded to both sides of a methylene group, i.e., a -COO-CH-COO- structure, is particularly preferred.

[0066] The structural unit (a) is preferably a structural unit having at least one type selected from the group consisting of groups represented by the following formula (1) and groups represented by the following formula (2).

[0067] [ka]

[0068] (In formula (1), n1 and n2 each independently represent an integer of 0 to 2. * represents a linking moiety.)

[0069] [ka]

[0070] (In formula (2), n3 and n4 each independently represent an integer of 0 to 2. * represents a linking moiety.)

[0071] In the formulas (1) and (2), n1 to n4 are each independently preferably 0 or 1, more preferably 0, from the viewpoint of further promoting transesterification and improving low-temperature curing properties.

[0072] "Constituent unit (b)" The hydroxyl-containing structural unit (b) constituting the copolymer (A) does not have an active methylene group connected to a methoxycarbonyl group or an active methine group connected to a methoxycarbonyl group, but has a hydroxyl group. The structural unit (b) is a structural unit derived from the hydroxyl-containing monomer (mb). When a resin composition containing the copolymer (A) is thermally cured, the hydroxyl group of the structural unit (b) in the copolymer (A) undergoes transesterification with the group represented by formula (1) or formula (2) in the structural unit (a), thereby forming a crosslinked structure.

[0073] From the viewpoint of low-temperature curing, the structural unit (b) is -(CH2) n A structural unit having a group represented by —OH (n is an integer of 2 to 6) and —(OC x H 2x ) m It is more preferable that the structural unit is at least one selected from the group consisting of structural units having a group represented by —OH (where x is an integer of 2 to 4, and m is an integer of 2 to 10). n The value of n in the group represented by —OH is preferably 2 to 4, more preferably 2 and 4. —(OC x H 2x ) mIn the group represented by —OH, x is preferably 2 to 3, more preferably 2. —(OC x H 2x ) m The value m in the group represented by —OH is preferably 2-6, and more preferably 4-6.

[0074] "Constituent unit (c)" The structural unit (c) is a structural unit that does not have an active methylene group connected to a methoxycarbonyl group, an active methine group connected to a methoxycarbonyl group, or a hydroxy group, but has an acid group. Examples of the acid group include a carboxy group, a sulfo group, and a phospho group. Among these acid groups, a carboxy group is preferred in terms of availability. The structural unit (c) is a structural unit derived from the above-mentioned monomer (mc) having an acid group.

[0075] "Constituent unit (d)" The copolymer (A) may further contain, as necessary, a structural unit (d) derived from a (meth)acrylate having a linear or branched alkyl group having 1 to 20 carbon atoms. The structural unit (d) derived from a (meth)acrylate having a linear or branched alkyl group having 1 to 20 carbon atoms is a structural unit derived from the monomer (md) having a linear or branched alkyl group having 1 to 20 carbon atoms and ethylenic unsaturation, and does not have an active methylene group having a methoxycarbonyl group attached, an active methine group having a methoxycarbonyl group attached, a hydroxy group, an acid group, or a bridged cyclic hydrocarbon group having 10 to 20 carbon atoms. By including the structural unit (d), the flexibility of the copolymer (A) as a photosensitive resin composition can be adjusted, and appropriate substrate adhesion can be imparted.

[0076] "Constituent unit (e)" The copolymer (A) may further contain, as necessary, a structural unit (e) derived from a (meth)acrylate having a bridged cyclic hydrocarbon group having 10 to 20 carbon atoms. The structural unit (e) derived from a (meth)acrylate having a bridged cyclic hydrocarbon group having 10 to 20 carbon atoms is a structural unit derived from the monomer (me) having a bridged cyclic hydrocarbon group having 10 to 20 carbon atoms and ethylenic unsaturation, and does not have a methoxycarbonyl group or a hydroxy group. By including the structural unit (e) in the copolymer (A), the glass transition temperature of the copolymer (A) can be controlled to a high level, and solvent resistance and surface uniformity can be achieved as a cured product. Furthermore, when a dye is used as the colorant (E) in the photosensitive resin composition, appropriate voids can be created to confine the dye within the resin, thereby reducing dye elution from the cured product.

[0077] "Other structural units (f)" The copolymer (A) may contain a structural unit (f) other than the structural units (a) to (e) as needed. The structural unit (f) is a structural unit derived from another monomer (mf) (hereinafter simply referred to as "monomer (mf)") that is copolymerizable with the monomers (ma) to (me).

[0078] "Proportion of each constituent unit" The content of the structural unit (a) is preferably 1 mol% or more, more preferably 5 mol% or more, and even more preferably 10 mol% or more, when the total of the structural units constituting the copolymer (A) is taken as 100 mol%. The content of the structural unit (a) is preferably 40 mol% or less, more preferably 30 mol% or less, and even more preferably 25 mol% or less, when the total of the structural units constituting the copolymer (A) is taken as 100 mol%. The combination of these lower and upper limits may be any combination. When the content of the structural unit (a) is 1 mol% or more, a sufficient amount of crosslinking due to transesterification with the hydroxy group of the structural unit (b) can be ensured, and the cured product has good solvent resistance even when the photosensitive resin composition is cured at low temperatures. When the content of the structural unit (a) is 40 mol% or less, the content of the crosslinking partner structural unit (b) can be ensured sufficiently. Furthermore, the content of the structural unit (c) can be ensured sufficiently, and the developability of the photosensitive resin composition is good.

[0079] The content of the structural unit (b) is preferably 1 mol% or more, more preferably 5 mol% or more, and even more preferably 10 mol% or more, when the total of the structural units constituting the copolymer (A) is taken as 100 mol%. The content of the structural unit (b) is preferably 40 mol% or less, more preferably 30 mol% or less, and even more preferably 25 mol% or less, when the total of the structural units constituting the copolymer (A) is taken as 100 mol%. The combination of these lower and upper limits may be any combination. When the content of the structural unit (b) is 1 mol % or more, a sufficient amount of crosslinking due to transesterification with the structural unit (a) can be ensured, and the cured product has good solvent resistance even when the photosensitive resin composition is cured at low temperatures. Furthermore, the developability of the photosensitive resin composition can be adjusted to a desired range. When the content of the structural unit (b) is 40 mol % or less, the content of the crosslinking partner structural unit (a) can be ensured sufficiently. Furthermore, the content of the structural unit (c) can be ensured sufficiently, and the developability of the photosensitive resin composition is good.

[0080] The content of the structural unit (c) is preferably 1 mol% or more, more preferably 3 mol% or more, and even more preferably 5 mol% or more, when the total of the structural units constituting the copolymer (A) is taken as 100 mol%. The content of the structural unit (c) is preferably 40 mol% or less, more preferably 30 mol% or less, and even more preferably 25 mol% or less, when the total of the structural units constituting the copolymer (A) is taken as 100 mol%. The combination of these lower and upper limits may be any combination. When the content of the structural unit (c) is 1 mol % or more, the developability of the photosensitive resin composition can be adjusted to a desired range. When the content of the structural unit (c) is 40 mol % or less, the content of the structural unit (a) and the structural unit (b) can be sufficiently ensured, and the amount of crosslinking by transesterification can be sufficiently ensured.

[0081] When the copolymer (A) contains the structural unit (d), the content of the structural unit (d) is preferably 10 mol% or more, more preferably 30 mol% or more, and even more preferably 50 mol% or more, when the total of the structural units constituting the copolymer (A) is taken as 100 mol%. The content of the structural unit (d) is preferably 95 mol% or less, more preferably 80 mol% or less, and even more preferably 70 mol% or less, when the total of the structural units constituting the copolymer (A) is taken as 100 mol%. The combination of these lower and upper limits may be any combination. When the content of the structural unit (d) is 10 mol % or more, the photosensitive resin composition can be provided with desired properties such as flexibility and substrate adhesion. When the content of the structural unit (d) is 95 mol % or less, the content of the structural units (a) to (c) can be sufficiently ensured, the low-temperature curing property and developability of the photosensitive resin composition can be ensured, and the cured product will have good solvent resistance and hardness.

[0082] When the copolymer (A) contains the structural unit (e), the content of the structural unit (e) is preferably 1 mol% or more, more preferably 3 mol% or more, and even more preferably 5 mol% or more, when the total of the structural units constituting the copolymer (A) is taken as 100 mol%. The content of the structural unit (e) is preferably 30 mol% or less, more preferably 20 mol% or less, and even more preferably 10 mol% or less, when the total of the structural units constituting the copolymer (A) is taken as 100 mol%. The combination of these lower and upper limits may be any combination. When the content of the structural unit (e) is 1 mol % or more, the properties derived from the structural unit (e) are well expressed. When the content of the structural unit (e) is 30 mol % or less, the contents of the structural units (a) to (c) can be sufficiently ensured, the low-temperature curing properties of the photosensitive resin composition are good, and the solvent resistance and hardness of the cured product are good.

[0083] When the copolymer (A) contains the structural unit (f), the content of the structural unit (f) is preferably 0.5 to 25 mol % or more, more preferably 1 to 20 mol % or more, and even more preferably 5 to 15 mol % or more, when the total of the structural units constituting the copolymer (A) is taken as 100 mol %. When the content of the structural unit (f) is within the above range, the function of the structural unit (f) can be imparted to the photosensitive resin composition without impairing the functions of the structural units (a) to (c).

[0084] "Acid value" The acid value of the copolymer (A) is preferably 10 KOHmg / g or more, more preferably 15 KOHmg / g or more, and even more preferably 20 KOHmg / g or more. The acid value of the copolymer (A) may be 300 KOHmg / g or less, preferably 250 KOHmg / g or less, more preferably 200 KOHmg / g or less, even more preferably 150 KOHmg / g or less, and even more preferably 100 KOHmg / g or less. When the acid value of the copolymer (A) is 10 KOHmg / g or more, the developability of the photosensitive resin composition is good. When the acid value of the copolymer (A) is 250 KOHmg / g or less, the storage stability of the photosensitive resin composition is good. The acid value of the copolymer (A) is the acid value of the curable polymer measured in accordance with JIS K6901 5.3, i.e., the acid value means the number of milligrams of potassium hydroxide required to neutralize the acidic components contained in 1 g of the copolymer.

[0085] "Hydroxyl group equivalent" The hydroxyl equivalent of the copolymer (A) is preferably 200 g / mol or more, more preferably 600 g / mol or more, and even more preferably 1000 g / mol or more. The hydroxyl equivalent of the copolymer (A) is preferably 3000 g / mol or less, more preferably 2000 g / mol or less, and even more preferably 1600 g / mol or less. When the hydroxyl group equivalent of the copolymer (A) is 200 g / mol or more, the amounts of the structural units (a) and (c) can be sufficiently secured, and a photosensitive resin composition with good developability and low-temperature curability can be obtained. When the hydroxyl group equivalent of the copolymer (A) is 3000 g / mol or less, a sufficient amount of crosslinking with the structural unit (a) can be ensured, and a cured resin film with good solvent resistance and hardness can be obtained. The hydroxyl group equivalent is the mass of copolymer (A) per mole of hydroxy groups in copolymer (A). The hydroxyl group equivalent can be determined by dividing the mass of copolymer (A) by the number of hydroxy groups in the resin (g / mol). In this specification, the hydroxyl group equivalent of copolymer (A) is a theoretical value calculated from the amounts of raw materials used to introduce hydroxy groups into the resin.

[0086] "Alkoxycarbonyl group equivalent" The alkoxycarbonyl group equivalent of the copolymer (A) is preferably 100 g / mol or more, more preferably 200 g / mol or more, and even more preferably 500 g / mol or more. The alkoxycarbonyl group equivalent of the copolymer (A) is preferably 5000 g / mol or less, more preferably 4000 g / mol or less, and even more preferably 3000 g / mol or less. When the alkoxycarbonyl group equivalent of the copolymer (A) is 100 g / mol or more, the storage stability of the photosensitive resin composition is good. When the alkoxycarbonyl group equivalent of the copolymer (A) is 5000 g / mol or less, a sufficient amount of crosslinking with the structural unit (b) can be ensured, and a cured resin film with good solvent resistance and hardness can be obtained. The alkoxycarbonyl group equivalent is the mass of copolymer (A) per mole of alkoxycarbonyl groups in copolymer (A). The alkoxycarbonyl group equivalent can be determined by dividing the mass of copolymer (A) by the number of alkoxycarbonyl groups in the resin (g / mol). In this specification, the alkoxycarbonyl group equivalent of copolymer (A) is a theoretical value calculated from the amount of raw material used to introduce alkoxycarbonyl groups into the resin.

[0087] "Measurement of weight average molecular weight, number average molecular weight, and molecular weight distribution" The weight average molecular weight of the copolymer (A) is preferably 3000 or more, more preferably 5000 or more, and even more preferably 6000 or more. The weight average molecular weight of the copolymer (A) is preferably 50000 or less, more preferably 40000 or less, and even more preferably 30000 or less. When the weight-average molecular weight of the copolymer (A) is 3,000 or more, the copolymerization reaction of the copolymer (A) can be carried out stably, and the copolymer (A) can be provided with high reproducibility of physical properties. When the weight-average molecular weight of the copolymer (A) is 50,000 or less, the copolymerization reaction of the copolymer (A) can be carried out stably, and the copolymer (A) can be provided with high reproducibility of physical properties, and the developability when formed into a photosensitive resin composition is good. Insoluble matters in the photosensitive resin composition described below can be easily removed by filtration.

[0088] The number average molecular weight of the copolymer (A) is preferably 1000 or more, more preferably 2000 or more, and even more preferably 3000 or more. The number average molecular weight of the copolymer (A) is preferably 25000 or less, more preferably 15000 or less, and even more preferably 10000 or less. When the number average molecular weight of the copolymer (A) is 1,000 or more, the copolymerization reaction of the copolymer (A) can be stably carried out, and the copolymer (A) can be provided with high reproducibility of physical properties. When the number average molecular weight of the copolymer (A) is 25,000 or less, the copolymerization reaction of the copolymer (A) can be stably carried out, and the copolymer (A) can be provided with high reproducibility of physical properties, and the developability when formed into a photosensitive resin composition is good. Insoluble matters in the photosensitive resin composition described below can be easily removed by filtration.

[0089] The molecular weight distribution of the copolymer (A) is preferably 1.5 or more, more preferably 1.8 or more, and even more preferably 2.1 or more. The molecular weight distribution of the copolymer (A) is preferably 6.0 or less, more preferably 5.0 or less, and even more preferably 4.0 or less. Any combination of these lower and upper limits may be used. When the molecular weight distribution of the copolymer (A) is 1.5 or more, the copolymerization reaction of the copolymer (A) can be stably carried out, and the production can be easily controlled.When the molecular weight distribution of the copolymer (A) is 6.0 or less, the copolymer (A) can have high reproducibility of physical properties, and the photosensitive resin composition can have good developability.

[0090] In this specification, the weight average molecular weight and number average molecular weight refer to the weight average molecular weight and number average molecular weight measured using gel permeation chromatography (GPC) under the following conditions, converted into standard polystyrene. The molecular weight distribution is calculated from the measured weight average molecular weight and number average molecular weight. Column: Showdex (trademark) LF-804 + LF-804 (manufactured by Resonac Co., Ltd.) Column temperature: 40℃ Sample: 0.2% by mass solution of the object to be measured in tetrahydrofuran Developing solvent: tetrahydrofuran Detector: Differential refractometer (Shodex (trademark) RI-71S) (manufactured by Resonac Co., Ltd.) Flow rate: 1mL / min

[0091] [Method for producing photosensitive resin composition] A method for producing a photosensitive resin composition according to one embodiment of the present invention includes a step of preparing the copolymer (A) obtained by the method for producing a copolymer according to the present embodiment, a reactive diluent (B), a photopolymerization initiator (C), and a solvent (D). The photosensitive resin composition according to the present embodiment can be produced by mixing the copolymer (A), the reactive diluent (B), the photopolymerization initiator (C), the solvent (D), and the colorant (E), which is optionally contained, using a known mixing device.

[0092] When producing a photosensitive resin composition, the reaction solution used in producing the copolymer (A) can be used as is as a raw material. In this case, the solvent (D) contained in the reaction solution can be used as part or all of the solvent (D) contained in the photosensitive resin composition or the photosensitive coloring composition.

[0093] The photosensitive resin composition has good low-temperature curability because it contains the copolymer (A) containing the structural unit (a) having a methoxycarbonyl group and the structural unit (b) having a hydroxy group.

[0094] For this reason, when a cured product is formed using the photosensitive resin composition, it can be cured at a lower temperature than when a conventional resin composition is used. Therefore, when a baking treatment is performed after exposing a coating film formed on a substrate, the photosensitive resin composition allows the crosslinking reaction to proceed sufficiently even if the baking temperature is low, so that a cured product having excellent solvent resistance and hardness can be formed.

[0095] Therefore, when a cured product is formed using a photosensitive resin composition, less energy is required for heating to cure. In addition, by using a photosensitive resin composition, a cured product can be formed on a substrate with low heat resistance, such as a resin substrate, without causing any damage to the substrate. Furthermore, even when a colorant (E) with low heat resistance is used, a cured product can be formed that exhibits the inherent properties of the colorant (E).

[0096] The photosensitive resin composition can provide a cured product with excellent solvent resistance and hardness even when the baking temperature is low, so the colorant (E) is less likely to leach out of the cured product. Therefore, it is possible to increase the content of the colorant (E) in the photosensitive resin composition. A photosensitive resin composition with a high content of the colorant (E) can be used, for example, as a material for the color pattern of a color filter to form a color filter with excellent color reproducibility.

[0097] The copolymer (A) contained in the photosensitive resin composition has a structural unit (c) having an acid group, and therefore the photosensitive resin composition has good alkaline developability. Because such a photosensitive resin composition has excellent alkaline developability, it is possible to form a cured product having a predetermined pattern shape and excellent solvent resistance by, for example, applying the composition to a substrate to form a coating film, exposing the film through a photomask corresponding to a predetermined pattern shape, developing the unexposed portions with an alkaline aqueous solution, and then baking the resulting film at a sufficiently low temperature.

[0098] The photosensitive resin composition can be suitably used as a material for a color filter.

[0099] For these reasons, the photosensitive resin composition is extremely useful as a material for forming components of image display elements, such as pixels of color filters, black matrices, protective films for color filters, photospacers, protrusions for liquid crystal alignment, microlenses, and insulating films for touch panels.

[0100] <Photosensitive resin composition> The photosensitive resin composition obtained by the method for producing a photosensitive resin composition of this embodiment contains the copolymer (A), the reactive diluent (B), the photopolymerization initiator (C), and the solvent (D). The photosensitive resin composition of this embodiment contains the colorant (E) as needed. The photosensitive resin composition of this embodiment is polymerized and cured by light irradiation to form a cured resin film.

[0101] <Copolymer (A)> The copolymer (A) used in the photosensitive resin composition is the copolymer (A) obtained by the copolymer production method of this embodiment.

[0102] the content of the copolymer (A) in the photosensitive resin composition is preferably 10% by mass or more relative to 100% by mass of the total of the copolymer (A) and the reactive diluent (B); It is more preferably 25% by mass or more, and even more preferably 40% by mass or more. The content of the reactive diluent (B) is preferably less than 100% by mass, more preferably 80% by mass or less, and even more preferably 60% by mass or less, based on 100% by mass of the total of the copolymer (A) and the reactive diluent (B). When the content of the copolymer (A) is within the above range, the viscosity and photocurability of the photosensitive resin composition become more appropriate.

[0103] <Reactive diluent (B)> The reactive diluent (B) contained in the photosensitive resin composition of this embodiment is not particularly limited as long as it is a low-molecular-weight compound having an ethylenically unsaturated group such as a vinyl group, an allyl group, or a (meth)acryloyloxy group. To improve the curability (reactivity) of the photosensitive composition, the reactive diluent (B) is preferably a reactive compound having multiple ethylenically unsaturated groups (a polyfunctional reactive diluent). Specific examples of the reactive diluent (B) include aromatic vinyl monomers; polycarboxylic acid monomers such as vinyl acetate and vinyl adipate; monofunctional (meth)acrylates; polyfunctional (meth)acrylates; triallyl cyanurate, etc.

[0104] Specific examples of aromatic vinyl monomers include styrene, α-methylstyrene, α-chloromethylstyrene, vinyltoluene, divinylbenzene, diallyl phthalate, and diallyl benzene phosphonate.

[0105] Specific examples of monofunctional (meth)acrylates include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, β-hydroxyethyl (meth)acrylate, and hydroxypropyl (meth)acrylate.

[0106] Specific examples of polyfunctional (meth)acrylates include ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, ethylene glycol di(meth)acrylate, trimethylolpropane di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and tris(hydroxyethyl)isocyanurate tri(meth)acrylate.

[0107] Among these, polyfunctional (meth)acrylates are preferred as the reactive diluent (B) in order to improve curability (reactivity), and dipentaerythritol penta(meth)acrylate and / or dipentaerythritol hexa(meth)acrylate are particularly preferred. These reactive diluents (B) may be used singly or in combination of two or more.

[0108] The content of the reactive diluent (B) in the photosensitive resin composition of the present embodiment is, relative to 100% by mass of the total of the copolymer (A) and the reactive diluent (B), Preferably, it is greater than 0% by mass, More preferably, it is 20% by mass or more. More preferably, it is 40% by mass or more. The content of the reactive diluent (B) is, relative to 100% by mass of the total of the copolymer (A) and the reactive diluent (B), Preferably, it is 90% by mass or less, More preferably, it is 75% by mass or less. More preferably, it is 60% by mass or less. Any combination of these lower and upper limits may be used. When the content of the reactive diluent (B) is within the above range, the viscosity and photocurability of the photosensitive resin composition become more appropriate.

[0109] <Photopolymerization initiator (C)> The photopolymerization initiator (C) is not particularly limited, and examples thereof include 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-,-1-(O-acetyloxime); benzoin and its alkyl ethers such as benzoin, benzoin methyl ether, benzoin ethyl ether, and benzoin butyl ether; acetophenone compounds such as acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, and 4'-(1-t-butyldioxy-1-methylethyl)acetophenone; 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-propan-1-one; 2-benzyl-2-dimethylamino-1-(4-morpholino) Examples of the photopolymerization initiator (C) include anthraquinone compounds such as 2-methylanthraquinone, 2-amylanthraquinone, 2-t-butylanthraquinone, and 1-chloroanthraquinone; xanthone; thioxanthone compounds such as thioxanthone, 2,4-dimethylthioxanthone, 2,4-diisopropylthioxanthone, and 2-chlorothioxanthone; ketal compounds such as acetophenone dimethyl ketal and benzyl dimethyl ketal; benzophenone compounds such as 4-(1-t-butyldioxy-1-methylethyl)benzophenone and 3,3',4,4'-tetrakis(t-butyldioxycarbonyl)benzophenone; and acylphosphine oxide photopolymerization initiators. The photopolymerization initiator (C) may be used alone or in combination of two or more.

[0110] The content of the photopolymerization initiator (C) in the photosensitive resin composition is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, and even more preferably 1.0 parts by mass or more, relative to 100 parts by mass of the total of the copolymer (A) and the reactive diluent (B). The content of the photopolymerization initiator (C) in the photosensitive resin composition is preferably 30 parts by mass or less, more preferably 15 parts by mass or less, and even more preferably 10 parts by mass or less, relative to 100 parts by mass of the total of the copolymer (A) and the reactive diluent (B). Any combination of these lower and upper limits may be used. When the content of the photopolymerization initiator (C) is 0.1 parts by mass or more, a photosensitive resin composition with good photocurability can be obtained. When the content of the photopolymerization initiator (C) is 30 parts by mass or less, it is possible to prevent adverse effects on the physical properties of the cured product of the photosensitive resin composition caused by an excessive amount of the photopolymerization initiator (C).

[0111] <Solvent (D)> The solvent (D) is not particularly limited as long as it can dissolve the copolymer (A), the reactive diluent (B), and the photopolymerization initiator (C). The solvent (D) may be the same as the solvent (i), solvent (ii), or solvent (iii) described above.

[0112] The content of solvent (D) in the photosensitive resin composition is preferably 30 parts by mass or more, more preferably 50 parts by mass or more, based on 100 parts by mass of the total of all components excluding solvent (D). The content of solvent (D) in the photosensitive resin composition is preferably 1,000 parts by mass or less, more preferably 800 parts by mass or less, based on 100 parts by mass of the total of all components excluding solvent (D). Any combination of these lower and upper limits may be used. When the content of solvent (D) is 30 parts by mass or more, the viscosity of the photosensitive resin composition can be set within an appropriate range. When the content of solvent (D) is 1,000 parts by mass or less, the solvent (D) can be easily removed from a coating film formed by applying the photosensitive resin composition to a substrate.

[0113] <Colorant (E)> The photosensitive resin composition may contain a colorant (E) as needed. The photosensitive resin composition containing the colorant (E) can be used as a material for a color filter.

[0114] The colorant (E) is not particularly limited as long as it is soluble or dispersible in the solvent (D), and examples thereof include dyes and pigments.

[0115] As the dye, it is preferable to use an acid dye having an acid group such as a carboxy group or a sulfo group, a salt of an acid dye with a nitrogen compound, or a sulfonamide adduct of an acid dye, from the viewpoints of solubility in the solvent (D) and an alkaline developer, interaction with other components in the photosensitive resin composition, heat resistance, etc.

[0116] Examples of such dyes include acid alizarin violet N; acid black 1, 2, 24, 48; acid blue 1, 7, 9, 25, 29, 40, 45, 62, 70, 74, 80, 83, 90, 92, 112, 113, 120, 129, 147; solvent blue 38, 44, 70; 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; and acid red. 1, 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 yellow 1, 3, 9, 11, 17, 23, 25, 29, 34, 36, 42, 54, 72, 73, 76, 79, 98, 99, 111, 112, 114, 116; Food Yellow 3 and derivatives thereof. Among these, azo-based, xanthene-based, anthraquinone-based, or phthalocyanine-based acid dyes are preferred. The dyes can be used alone or in combination of two or more.

[0117] Examples of pigments include yellow pigments such as CI Pigment Yellow 1, 3, 12, 13, 14, 15, 16, 17, 20, 24, 31, 53, 83, 86, 93, 94, 109, 110, 117, 125, 128, 137, 138, 139, 147, 148, 150, 153, 154, 166, 173, 194, and 214; orange pigments such as CI Pigment Orange 13, 31, 36, 38, 40, 42, 43, 51, 55, 59, 61, 64, 65, 71, and 73; and CI Pigment Red 9, 97, 105, 122, 123, 144, 149, 166, and 173. Examples of suitable pigments include red pigments such as CI Pigment Blue 15, 15:3, 15:4, 15:6, and 60; violet pigments such as CI Pigment Violet 1, 19, 23, 29, 32, 36, and 38; green pigments such as CI Pigment Green 7, 36, 58, and 59; brown pigments such as CI Pigment Brown 23 and 25; and black pigments such as CI Pigment Black 1, 7, carbon black, titanium black, and iron oxide. These pigments can be used alone or in combination of two or more.

[0118] The colorant (E) can be appropriately determined depending on, for example, the color of the desired color pattern (black matrix and pixels). The colorant (E) may be used alone or in combination of two or more. When two or more types of colorants (E) are used, a dye and a pigment may be used in combination.

[0119] When a pigment is used as the colorant (E), a known dispersant may be blended into the photosensitive resin composition to improve the dispersibility of the pigment. It is preferable to use a polymeric dispersant that exhibits excellent dispersion stability over time. Examples of polymeric dispersants include urethane-based dispersants, polyethyleneimine-based dispersants, polyoxyethylene alkyl ether-based dispersants, polyoxyethylene glycol diester-based dispersants, sorbitan aliphatic ester-based dispersants, and aliphatic modified ester-based dispersants. Commercially available polymeric dispersants, such as EFKA (manufactured by EFKA CHEMICALS BV), Disperbyk (manufactured by BYK), Disparlon (manufactured by Kusumoto Chemicals Co., Ltd.), and SOLSPERSE (manufactured by Lubrizol Corporation), may also be used. The content of the dispersant may be appropriately determined depending on the type and amount of the pigment used as the colorant (E).

[0120] The content of the colorant (E) in the photosensitive resin composition is preferably 3 parts by mass or more, more preferably 5 parts by mass or more, and even more preferably 10 parts by mass or more, based on 100 parts by mass of the total of the copolymer (A) and the reactive diluent (B). The content of the colorant (E) in the photosensitive resin composition is preferably 80 parts by mass or less, more preferably 70 parts by mass or less, and even more preferably 60 parts by mass or less, based on 100 parts by mass of the total of the copolymer (A) and the reactive diluent (B). Any combination of these lower and upper limits may be used. When the content of the colorant (E) is 3 parts by mass or more, the effect of including the colorant (E) is significant, and a photosensitive resin composition suitable as a material for colored patterns in color filters can be obtained. When the content of the colorant (E) is 80 parts by mass or less, the colorant (E) does not interfere with the curing properties of the photosensitive resin composition, and a photosensitive resin composition with good low-temperature curing properties can be obtained.

[0121] <Other ingredients> In one embodiment, the photosensitive resin composition may contain, in addition to the copolymer (A), the reactive diluent (B), the photopolymerization initiator (C), the solvent (D), and the colorant (E) that is optionally contained, known additives such as dispersants, coupling agents, leveling agents, and thermal polymerization inhibitors, as necessary. The amount of the additives to be added is not particularly limited as long as it does not impair the effects of the present invention.

[0122] [Method of manufacturing cured resin film] A method for producing a cured resin film according to one embodiment of the present invention includes the steps of applying, exposing, and thermally curing a photosensitive resin composition obtained by the method for producing a photosensitive resin composition, preferably at a temperature of 50 to 150°C. The cured resin film of the present embodiment can be produced, for example, by applying the photosensitive resin composition to a substrate, volatilizing and removing the solvent (D) to form a coating film, exposing the coating film to light to photocure it, and then performing a baking treatment.

[0123] When forming a cured resin film having a predetermined pattern, for example, the following method can be used. That is, a photosensitive resin composition is applied to a substrate, and the solvent (D) is removed by volatilization to form a coating film. Next, the coating film is exposed to light through a photomask having a predetermined pattern, and the exposed portions are photocured. Next, the unexposed portions of the coating film are developed with an alkaline aqueous solution. Thereafter, the developed coating film is baked to form a cured resin film having a predetermined pattern.

[0124] When producing a cured resin film, known methods can be used for applying the photosensitive resin composition, exposing the applied film, and developing the same.

[0125] The conditions for the baking treatment performed when producing a cured resin film can be appropriately determined depending on the composition of the photosensitive resin composition, the thickness of the coating film, the material of the substrate, and other factors. Baking can be performed, for example, at a temperature of 70°C to 250°C. Baking at a temperature of 70°C or higher results in crosslinking through transesterification between the methoxycarbonyl group of the structural unit (a) contained in the copolymer (A) in the photosensitive resin composition and the hydroxy group of the structural unit (b). As a result, a good degree of curing is achieved, resulting in a cured product with excellent solvent resistance and hardness. The structural unit (a) can undergo both a deblocking reaction, in which it dissociates to produce an isocyanato group, and a transesterification reaction. By adjusting the baking temperature, either reaction can be prioritized. The baking temperature is preferably 75°C or higher, more preferably 80°C or higher. A baking temperature of 250°C or lower is preferable because it is a temperature that can be tolerated by materials with low heat resistance and can suppress discoloration of the photosensitive resin composition. The photosensitive resin composition has good low-temperature curing properties. Therefore, the baking temperature can be set to 160°C or less depending on the heat resistance of the substrate on which the cured resin film is formed. For example, when a resin substrate is used as the substrate, the baking temperature may be set to 150°C or less, 120°C or less, or 100°C or less.

[0126] The baking treatment carried out when producing a cured resin film can be carried out for, for example, 10 minutes to 4 hours, preferably 20 minutes to 2 hours, and can be appropriately determined depending on the composition of the photosensitive resin composition, the temperature of the baking treatment, the film thickness of the coating film, etc.

[0127] <Cured resin film> The cured resin film obtained by the method for producing a cured resin film of the present embodiment is made of a cured product of the photosensitive resin composition. The cured resin film is made of a cured product of a photosensitive resin composition, and therefore can be produced by a baking treatment at a low temperature, and has excellent solvent resistance.

[0128] [Method of manufacturing image display element] A method for producing an image display element according to one embodiment of the present invention is a method for forming a color filter having a colored pattern made of a cured product of the photosensitive resin composition by repeatedly applying, exposing, and developing the photosensitive resin composition obtained by the method for producing a photosensitive resin composition for each color. The image display element includes a color filter. The components of the image display element other than the color filter may be any known components. Specific examples of the image display element include a liquid crystal display element, an organic EL display element, and a solid-state imaging element such as a CCD element or a CMOS element.

[0129] Components other than the color filter in the image display element can be manufactured by known methods. For example, when manufacturing a liquid crystal display element as the image display element, it can be manufactured using the method shown below. First, a color filter is formed on a substrate using the method described above. Then, electrodes, spacers, etc. are formed sequentially on the substrate having the color filter. Next, electrodes, etc. are formed on another substrate, and the substrate having the color filter is placed opposite and bonded to it. Then, a predetermined amount of liquid crystal is injected between the opposing substrates and sealed.

[0130] The image display device has a color filter having excellent solvent resistance and hardness, and therefore exhibits little color change. <Color filter> The color filter has a colored pattern made of a cured product of the photosensitive resin composition. The color filter preferably has a colored pattern made of a cured product of a photosensitive resin composition containing 10 to 100% by mass of copolymer (A), more than 0 to 90% by mass of reactive diluent (B) relative to 100% by mass of the total of copolymer (A) and reactive diluent (B), 0.1 to 30 parts by mass of photopolymerization initiator (C), 3 to 80 parts by mass of colorant (E), and 30 to 1,000 parts by mass of solvent (D) relative to 100 parts by mass of the total of components excluding solvent (D).

[0131] The color filter may include, for example, a substrate, RGB pixels formed thereon, a black matrix formed at the boundaries of each pixel, and a protective film formed on the pixels and the black matrix.

[0132] In the color filter, the pixels and black matrix are colored patterns formed from the cured product of the photosensitive resin composition. In the color filter, known materials can be used for the components other than the materials for the pixels and black matrix.

[0133] The substrate used for the color filter is not particularly limited, and a glass substrate, a silicon substrate, a polycarbonate substrate, a polyester substrate, a polyamide substrate, a polyamideimide substrate, a polyimide substrate, an aluminum substrate, a printed wiring board, an array substrate, or the like can be used as appropriate depending on the application.

[0134] Next, an exemplary method for manufacturing a color filter will be described. First, a colored pattern is formed on a substrate. Specifically, a colored pattern that will become a black matrix formed at the boundaries of each pixel, and a colored pattern that will become each of the RGB pixels are sequentially formed on the substrate by the method described below.

[0135] The colored pattern can be formed by photolithography. Specifically, a photosensitive resin composition is applied to a substrate to form a coating film. The coating film is then exposed to light through a photomask having a predetermined pattern shape, causing the exposed portions to photocure. The unexposed portions of the coating film are then developed with an alkaline aqueous solution. The developed coating film is then subjected to a baking treatment, thereby forming a colored pattern having a predetermined pattern shape.

[0136] The method for applying the photosensitive resin composition is not particularly limited, but known methods such as screen printing, roll coating, curtain coating, spray coating, and spin coating can be used.

[0137] After the photosensitive resin composition is applied to the substrate, the substrate may be heated using a heating means such as a circulation oven, an infrared heater, or a hot plate, as necessary, to volatilize and remove the solvent (D) contained in the coating film. The conditions for heating the substrate to remove the solvent (D) are not particularly limited and may be appropriately set depending on the material of the substrate, the composition of the photosensitive resin composition, the thickness of the coating film, and the like. The substrate may be heated, for example, at a temperature of 50°C to 120°C for 30 seconds to 30 minutes.

[0138] Next, the coating film thus formed is partially exposed to active energy rays such as ultraviolet rays or excimer laser light through a negative photomask, and the exposed portions are photocured. The amount of active energy rays irradiated onto the coating film may be appropriately selected depending on the composition of the photosensitive resin composition, and may be, for example, 30 to 2000 mJ / cm. 2 The light source used for exposure is not particularly limited, but may be 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.

[0139] The alkaline aqueous solution used for developing the coating film is not particularly limited, but may include aqueous solutions of inorganic alkaline compounds such as sodium carbonate, potassium carbonate, calcium carbonate, sodium hydroxide, and potassium hydroxide; aqueous solutions of amine compounds such as ethylamine, diethylamine, and dimethylethanolamine; aqueous solutions of quaternary ammonium salts such as tetramethylammonium sulfate, hydrochloride, or p-toluenesulfonate; aqueous solutions of aniline compounds and salts thereof such as 3-methyl-4-amino-N,N-diethylaniline, 3-methyl-4-amino-N-ethyl-N-β-hydroxyethylaniline, 3-methyl-4-amino-N-ethyl-N-β-methanesulfonamidoethylaniline, and 3-methyl-4-amino-N-ethyl-N-β-methoxyethylaniline, and their sulfates, hydrochlorides, or p-toluenesulfonates; and aqueous solutions of p-phenylenediamine compounds and salts. Additives such as antifoaming agents and surfactants may be added to the alkaline aqueous solution as needed.

[0140] After the coating film is developed using the above-mentioned aqueous alkaline solution, it is preferable to wash the coating film with water and dry it.

[0141] The conditions for the baking treatment carried out when producing a color filter can be appropriately determined depending on the composition of the photosensitive resin composition, the thickness of the coating film, the material of the substrate, etc. The baking temperature can be, for example, 70°C to 210°C. A baking temperature of 70°C or higher provides good curing properties, and a cured product with excellent solvent resistance and hardness can be obtained. The baking temperature is preferably 75°C or higher, and more preferably 80°C or higher. A baking temperature of 210°C or lower is preferred because it allows the use of low-heat-resistant materials, such as low-heat-resistant substrates, as materials for the color filter.

[0142] When a colored pattern of a color filter is formed using a conventional photosensitive resin composition, if the baking temperature is set to 200°C or less, the solvent resistance of the colored pattern is insufficient. In contrast, the photosensitive resin composition of one embodiment has good low-temperature curing properties, and therefore the baking temperature can be lowered compared to when using conventional photosensitive resin compositions while ensuring the solvent resistance of the colored pattern. Specifically, the baking temperature can be set to 160°C or less depending on the heat resistance of the substrate on which the cured resin film is formed. For example, when a colored pattern is formed using a resin substrate as the substrate, the baking temperature may be set to 150°C or less, 120°C or less, or 100°C or less.

[0143] The baking treatment carried out when producing a color filter can be carried out for, for example, 10 minutes to 4 hours, preferably 20 minutes to 2 hours, and can be appropriately determined depending on the composition of the photosensitive resin composition, the temperature of the baking treatment, the thickness of the coating film, etc.

[0144] The photosensitive resin composition has good photocurability and low-temperature curability. Therefore, when a colored pattern is formed using the photosensitive resin composition of one embodiment, the baking time can be shortened and a color filter can be efficiently formed, provided that the baking temperature is the same as when a colored pattern is formed using a conventional photosensitive resin composition.

[0145] Using the above-described method for manufacturing a colored pattern, a colored pattern that will become each of the RGB pixels and a colored pattern that will become a black matrix formed at the boundaries of each pixel are formed, and then a protective film is formed on the colored pattern (each of the RGB pixels and the black matrix).

[0146] The method for producing the protective film is not particularly limited, and the protective film may be formed using the photosensitive resin composition of one embodiment, or may be formed using known materials and known methods.

[0147] Through the above steps, a color filter is obtained.

[0148] The color filter has a colored pattern made of the cured product of the photosensitive resin composition described above. Therefore, the colored pattern in the color filter can be formed by a method of performing a baking treatment at a low temperature. Therefore, the energy required for the baking treatment can be reduced.

[0149] In addition, the colorant (E) contained in the photosensitive resin composition used as a material for the color filter can be one with low heat resistance. This allows for a wider range of options for the colorant (E). Therefore, for example, it is possible to form a color filter containing a colorant (E) with low heat resistance and having a color pattern that exhibits the inherent properties of the colorant (E).

[0150] Furthermore, the colored pattern in the color filter can be formed on a substrate with low heat resistance, such as a resin substrate, without damaging the substrate. This increases the options for usable substrates. Specifically, for example, since a color filter can be formed on a substrate with low heat resistance, such as a resin substrate, the display can be made flexible. In addition, the colored pattern in the color filter has excellent solvent resistance and hardness, so there is little color change.

[0151] Here, an example has been described in which a colored pattern is produced by using a photosensitive resin composition containing a photopolymerization initiator (C) and photocuring the photosensitive resin composition. However, for example, a colored pattern made of a cured product of a photosensitive resin composition containing a copolymer (A) may be formed by using a photosensitive resin composition containing a curing accelerator and a known epoxy resin instead of the photopolymerization initiator (C) contained in the photosensitive resin composition, applying the composition to a substrate by an inkjet method, and then heating the composition. [Example]

[0152] The present invention will be explained in more detail below with reference to examples and comparative examples, but the present invention is not limited to the following examples. The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. In these examples, parts and percentages are all by mass unless otherwise specified.

[0153] <Method for measuring weight average molecular weight, number average molecular weight, and calculating molecular weight distribution> The weight average molecular weight and number average molecular weight described below refer to standard polystyrene equivalent weight average molecular weight and number average molecular weight measured using gel permeation chromatography (GPC) under the following conditions. The molecular weight distribution described below is calculated from the measured weight average molecular weight and number average molecular weight. Column: Showdex (registered trademark) LF-804 + LF-804 (manufactured by Resonac Co., Ltd.) Column temperature: 40℃ Sample: 0.2% by mass solution of copolymer (A) in tetrahydrofuran Developing solvent: tetrahydrofuran Detector: Differential refractometer (Shodex RI-71S) (Showa Denko K.K.) Flow rate: 1mL / min

[0154] <Acid value measurement method> The amount of potassium hydroxide (mg) required to neutralize the acidic components contained in 1 g of the solid content of the copolymer (A) was measured according to JIS K6901 5.3.2. Measuring instrument: 776 Dosimat (Metrohm) Mixed indicator: Bromothymol blue and phenol red mixed indicator

[0155] Examples of the copolymer (A) or copolymer (A') of this embodiment are shown below.

[0156] <Alkoxycarbonyl group equivalent> A theoretical value calculated from the amounts of the monomers (ma) to (me) and the polymerization initiator used in producing the copolymer is used.

[0157] <Hydroxyl group equivalent> A theoretical value calculated from the amounts of the monomers (ma) to (me) and the polymerization initiator used in producing the copolymer is used.

[0158] [Example 1] (Synthesis of Copolymer (A)) Into a flask equipped with a stirrer, a dropping funnel, a condenser, a thermometer and a gas inlet tube, 243.0 g of propylene glycol monomethyl ether was placed as solvent (D), and the mixture was stirred while being purged with nitrogen and heated to 65°C.

[0159] Next, 88.5 g (18 mol%) of AOI-DMM as the monomer (ma), 32.8 g (14 mol%) of 2-hydroxyethyl methacrylate as the monomer (mb), 17.0 g (11 mol%) of methacrylic acid as the monomer (mc), 155.7 g (47 mol%) of 2-ethylhexyl acrylate and 18.0 g (10 mol%) of methyl methacrylate as the monomer (md), and 118.5 g of propylene glycol monomethyl ether as the solvent (ii) were mixed to prepare raw material monomer solution (ii). Next, 38.1 g of Percumyl ND as the polymerization initiator (i) and 140.4 g of propylene glycol monomethyl ether acetate as the solvent (i) were mixed to prepare a solution (i) of the polymerization initiator (i).

[0160] The entire amount of the prepared raw material monomer solution (ii) and polymerization initiator (i) solution (i) was added dropwise over 1 hour using a dropping funnel to the solvent (D) in a flask under normal pressure and a nitrogen gas atmosphere. After the dropwise addition was completed, the solution in the flask was stirred and subjected to a polymerization reaction at 65°C for 2 hours to obtain a liquid containing the copolymer (A) and the solvent (D). To the reaction liquid containing the copolymer (A) and the solvent (D) thus obtained, propylene glycol monomethyl ether acetate was added as the solvent (D) so that the components other than the solvent were 35% by mass, thereby obtaining a liquid (resin composition) containing the copolymer (A) of Example 1.

[0161] [Examples 2 to 13] A raw material monomer solution (ii) was prepared in the same manner as in Example 1, except that the blending ratio of the monomers was as shown in Table 1. Furthermore, a solution (i) was prepared in the same manner as in Example 1, except that the blending amount of the polymerization initiator (i) was as shown in Table 1. For Examples 4, 12, and 13, a solution (i-2) was prepared by mixing a chain transfer agent or a reducing agent with propylene glycol monomethyl ether acetate as a solvent (i-2). Each solution was added dropwise to a flask in the same manner as in Example 1 to obtain a mixture containing each copolymer (A) of the example (respective sample numbers P1 to P13) and a solvent (D). The amount of polymerization initiator (i) added was adjusted according to the desired weight-average molecular weight. The blending ratio of each monomer, as well as the weight-average molecular weight, number-average molecular weight, molecular weight distribution, acid value, alkoxycarbonyl equivalent, and hydroxyl equivalent of each copolymer (A) are shown in Table 1.

[0162] [Comparative Example 1] Into a flask equipped with a stirrer, a dropping funnel, a condenser, a thermometer and a gas inlet tube, 237.6 g of propylene glycol monomethyl ether was placed as solvent (D), and the mixture was stirred while being purged with nitrogen and heated to 78°C.

[0163] Next, 90.6 g (18 mol%) of AOI-DEM as monomer (m-a'), 30.4 g (14 mol%) of 2-hydroxyethyl methacrylate as monomer (mb), 15.8 g (11 mol%) of methacrylic acid as monomer (mc), 175.4 g (57 mol%) of 2-ethylhexyl acrylate as monomer (md), and 112.4 g of propylene glycol monomethyl ether as solvent (ii) were mixed to prepare a raw material monomer solution. Next, 37.8 g of 2,2'-azobis(2,4-dimethylvaleronitrile) as a polymerization initiator and 143.6 g of propylene glycol monomethyl ether acetate as a solvent (i) were mixed to prepare a polymerization initiator solution.

[0164] The entire amount of the prepared raw material monomer solution and polymerization initiator solution was added dropwise over 1 hour using a dropping funnel to solvent (D) in a flask under normal pressure and a nitrogen gas atmosphere. After the dropwise addition was completed, the solution in the flask was stirred while undergoing a polymerization reaction at 78°C for 3 hours to obtain a liquid containing copolymer (A) and solvent (D). To the reaction liquid containing copolymer (A) and solvent (D) thus obtained, propylene glycol monomethyl ether acetate was added as solvent (D) so that the components other than the solvent were 35% by mass, thereby obtaining a liquid (resin composition) containing copolymer (A) of Comparative Example 1.

[0165] Comparative Example 2 Copolymer cP2 of Comparative Example 2 was obtained in the same manner as in Comparative Example 1, except that the raw materials shown in Table 2 were used in the proportions shown in Table 2.

[0166] Comparative Example 3 Into a flask equipped with a stirrer, a dropping funnel, a condenser, a thermometer and a gas inlet tube, 242.9 g of propylene glycol monomethyl ether was placed as solvent (D), and the mixture was stirred while being purged with nitrogen and heated to 78°C.

[0167] Next, 88.5 g (18 mol%) of AOI-DMM as the monomer (ma), 32.8 g (14 mol%) of 2-hydroxyethyl methacrylate as the monomer (mb), 17.1 g (11 mol%) of methacrylic acid as the monomer (mc), 155.8 g (47 mol%) of 2-ethylhexyl acrylate as the monomer (md), and 118.6 g of propylene glycol monomethyl ether as the solvent (ii) were mixed to prepare raw material monomer solution (ii). Next, 37.8 g of 2,2'-azobis(2,4-dimethylvaleronitrile) as a polymerization initiator and 140.5 g of propylene glycol monomethyl ether acetate as a solvent (i) were mixed to prepare a polymerization initiator solution.

[0168] The entire amount of the prepared raw material monomer solution (ii) and polymerization initiator solution was added dropwise to the solvent (D) in a flask under nitrogen gas atmosphere at normal pressure using a dropping funnel over 1 hour, but gelation occurred.

[0169] The weight-average molecular weight (Mw), number-average molecular weight (Mn), molecular weight distribution (Mw / Mn), acid value, methoxycarbonyl equivalent, and hydroxyl equivalent were determined for each of the copolymers cP1 to cP3 thus obtained in Comparative Examples 1 to 3. The results are shown in Table 2.

[0170] [Table 1]

[0171] [Table 2]

[0172] The compounds used in Tables 1 and 2 were as follows: AOI-DMM: Karenz™ AOI-DMM, reaction product of isocyanatoethyl acrylate and dimethyl malonate, (malonic acid-2-[[[1-oxo-2-propenyl]oxy]ethyl]amino]carbonyl]-1,3 dimethyl ester, manufactured by Resonac Corporation) MOI-DMM: Karenz™ MOI-DMM, reaction product of isocyanatoethyl methacrylate and dimethyl malonate (malonic acid-2-[[[2-methyl-1-oxo-2-propenyl]oxy]ethyl]amino]carbonyl]-1,3 dimethyl ester, manufactured by Resonac Corporation) AOI-DEM: Karenz™ AOI-DEM, a reaction product of isocyanatoethyl acrylate and diethyl malonate (malonic acid-2-[[[1-oxo-2-propenyl]oxy]ethyl]amino]carbonyl]-1,3-diethyl ester, manufactured by Resonac Corporation) 2-Hydroxyethyl methacrylate: Tokyo Chemical Industry Co., Ltd. 4-Hydroxybutyl acrylate: Tokyo Chemical Industry Co., Ltd. Methacrylic acid: manufactured by Tokyo Chemical Industry Co., Ltd. Acrylic acid: manufactured by Tokyo Chemical Industry Co., Ltd. 2-Ethylhexyl acrylate: manufactured by Tokyo Chemical Industry Co., Ltd. Methyl methacrylate: manufactured by Tokyo Chemical Industry Co., Ltd. Dicyclopentanyl methacrylate: manufactured by Tokyo Chemical Industry Co., Ltd. Propylene glycol monomethyl ether acetate: manufactured by Tokyo Chemical Industry Co., Ltd. Propylene glycol monomethyl ether: manufactured by Tokyo Chemical Industry Co., Ltd. 3-Methoxy-1-butanol: Tokyo Chemical Industry Co., Ltd. Thioglycolic acid: manufactured by Tokyo Chemical Industry Co., Ltd. Cobalt octylate: manufactured by Nippon Chemical Industry Co., Ltd. Accelerator A: 1,1'-[(4-methylphenyl)imino]bis(2-propanol) (Wako Pure Chemical Industries, Ltd.) Percumyl ND: Cumyl peroxyneodecanoate (manufactured by NOF Corporation) V65: 2,2'-azobis(2,4-dimethylvaleronitrile) (Fujifilm Wako Pure Chemical Industries, Ltd.)

[0173] An example of the production of a photosensitive resin composition is shown below. <Preparation of Photosensitive Coloring Composition> [Production Examples 1 to 13, Comparative Production Examples 1 to 2] As copolymer (A), copolymers P1 to P13, cP1 to cP2 of Production Examples 1 to 13 and Comparative Production Examples 1 to 2 and the (B), (C), and (E) components shown in Table 3 were mixed in the proportions shown in Table 3 to prepare photosensitive coloring compositions R1 to R13 and cR1 to cR2 of Production Examples 1 to 13 and Comparative Production Examples 1 to 2, respectively.

[0174] The blending amount of copolymer (A) in the resin composition in Table 3 does not include the polymerization solvent used when synthesizing copolymer (A). In addition, the blending amount of solvent (D) in Table 3 is the total amount of the polymerization solvent used when synthesizing copolymer (A) in the photosensitive colored resin composition and the solvent added when preparing the photosensitive colored resin composition.

[0175] [Table 3]

[0176] <Evaluation of Photosensitive Coloring Composition> The photosensitive coloring compositions R1 to R13 and cR1 to cR2 of Production Examples 1 to 13 and Comparative Production Examples 1 and 2 were evaluated by the methods shown below.

[0177] (1) Developability The photosensitive coloring compositions R1 to R13 and cR1 to cR2 prepared in Production Examples 1 to 13 and Comparative Production Examples 1 to 2 were each applied to a 5 cm square glass substrate (alkali-free glass substrate) by spin coating so that the thickness after exposure was 2.5 μm (coating step). The glass substrate coated with the photosensitive coloring composition was heated at 70 ° C for 3 minutes to volatilize the solvent and dry the coating film (pre-baking step).

[0178] Next, an ultra-high pressure mercury lamp was used to irradiate 200 mJ / cm 2 The surface of the dried coating film was irradiated with light through a photomask (exposure step). The exposure step was performed by placing a photomask 100 μm away from the coating film. The photomask used had a line and space pattern with a width of 3 to 100 μm. Next, Semiclean DL-A10 developer (manufactured by Yokohama Yushi Kogyo Co., Ltd.) (diluted 5 times) was sprayed onto the surface of the coating film for 60 seconds at a temperature of 23°C and a pressure of 0.1 MPa to remove the unexposed areas (development step). The glass substrate with the coating film after the development step was left standing in a dryer at 85°C for 30 minutes to thermally cure the coating film (post-bake step), thereby obtaining a colored pattern.

[0179] The colored patterns thus obtained were observed using an S-3400 electron microscope manufactured by Hitachi High-Technologies Corporation, and the minimum line width (minimum development dimension) that could be developed and the presence or absence of residue in unexposed areas between the developed patterns were evaluated. The presence or absence of residue was evaluated according to the following criteria. The results are shown in Table 4 or Table 5. "Residue evaluation criteria" ○: No residue in the unexposed areas between the developed patterns ×: Residues found in unexposed areas between developed patterns

[0180] (2) Pencil hardness The photosensitive coloring compositions R1 to R13 and cR1 to cR2 prepared in Production Examples 1 to 13 and Comparative Production Examples 1 and 2 were applied by spin coating onto a square glass substrate (alkali-free glass substrate) measuring 5 cm in length and 5 cm in width, and heated at 70°C for 3 minutes to volatilize the solvent, forming a coating film. Next, the coating film was irradiated with light of 365 nm wavelength at an exposure dose of 200 mJ / cm. 2 The glass substrate with the photocured coating film was then placed in a dryer at 85°C for 30 minutes to thermally cure the coating film (post-baking step), thereby obtaining a cured resin film with a thickness of 2.5 µm.

[0181] The pencil hardness of the cured resin film thus produced was measured using a pencil hardness tester (No. 553-M, manufactured by Yasuda Seiki Seisakusho) in accordance with JIS K5600-5-4 and evaluated according to the following criteria. The results are shown in Table 4 or Table 5. "Evaluation standard for pencil hardness" ○:Pencil hardness 3H or higher ×: Pencil hardness less than 3H

[0182] (3) Solvent resistance A glass substrate having a cured resin film was prepared in the same manner as in the evaluation of pencil hardness (2) above, and the absorption spectrum of the cured resin film was measured using a spectrophotometer (UV-1650PC, manufactured by Shimadzu Corporation). 200 mL of propylene glycol monomethyl ether acetate was placed in a 500 mL glass bottle with a lid and allowed to stand at a temperature of 23°C. The glass substrate having the cured resin film was placed in the glass bottle, immersed in propylene glycol monomethyl ether acetate, and allowed to stand at 23°C for 15 minutes. The glass substrate having the cured resin film was then removed, and the absorption spectrum of the cured resin film was measured using a spectrophotometer (UV-1650PC, manufactured by Shimadzu Corporation) in the same manner as before immersion in propylene glycol monomethyl ether acetate.

[0183] From the above measurement results, the color change (ΔE * The solvent resistance of the cured resin film was evaluated according to the following criteria. The results are shown in Table 4 or Table 5.

[0184] "Solvent resistance evaluation criteria" ○:ΔE * ab is less than 3.0 ×:ΔE * ab is 3.0 or more

[0185] (4) Overall Judgment The cured resin films formed from the cured products of the photosensitive coloring compositions R1 to R13 and cR1 to cR2 prepared in Production Examples 1 to 13 and Comparative Production Examples 1 and 2 were evaluated according to the following criteria. The results are shown in Table 4 or Table 5.

[0186] "Evaluation Criteria" ○: Meets all of the following criteria. (1) The minimum development dimension is 15 μm or less, and there is no residue in the unexposed areas between the developed patterns. (2) The pencil hardness of the resin cured film is 3H or more. (3) Color change ΔE in evaluation of solvent resistance of cured resin film * ab is less than 3.0 ×: One or more of the items marked ○ above are not met.

[0187] [Table 4]

[0188] [Table 5]

[0189] (Consideration) As shown in Table 4, the coating films formed using the photosensitive coloring compositions R1 to R13 of Production Examples 1 to 13 were photocured, and then heat-cured at a low temperature of 85°C to form cured resin films, which had excellent hardness with a pencil hardness of 3H or more. Moreover, the solvent resistance of the cured resin films was evaluated as ○, confirming that they had excellent solvent resistance.

[0190] In contrast, as shown in Table 5, the photosensitive coloring compositions cR1 and cR2 of Comparative Production Examples 1 and 2 were insufficient in pencil hardness or solvent resistance.

[0191] More specifically, the copolymers cP1 and cP2 of Comparative Examples 1 and 2 contained in the photosensitive coloring compositions cR1 and cR2 of Comparative Production Examples 1 and 2 undergo transesterification with hydroxy groups to produce ethanol. However, the reaction proceeds slowly at a curing temperature of 85°C. This resulted in poor hardness and solvent resistance. [Industrial Applicability]

[0192] According to the present invention, there is provided a method for producing a copolymer capable of forming a cured resin film having excellent solvent resistance and hardness. Also provided are a method for producing a photosensitive resin composition using the copolymer, and a method for producing an image display element. The photosensitive resin composition using the copolymer obtained by the copolymer production method can be preferably used as a transparent film, a protective film, an insulating film, an overcoat, a photospacer, a black matrix, a black column spacer, or a resist for a color filter.

Claims

1. A step (I) of mixing a polymerization initiator (i) and a solvent (i) to obtain a solution (i); a step (II) of mixing the monomer (ma), the monomer (mb), and the monomer (mc) to obtain a solution (ii); Step (III) of adding the solvent (iii) to a reaction vessel and heating the reaction vessel to a set temperature in the range of 40 to 70°C; a step (IV) of adding the solution (i) and the solution (ii) to the reaction vessel while stirring the reaction solution in the reaction vessel to copolymerize; and the monomer (m-a) is an ethylenically unsaturated group-containing compound having one or more selected from an active methylene group having a methoxycarbonyl group bonded thereto and an active methine group having a methoxycarbonyl group bonded thereto, the monomer (mb) is an ethylenically unsaturated group-containing compound having a hydroxy group, the monomer (m-c) is an ethylenically unsaturated group-containing compound having an acid group, A method for producing a copolymer, wherein the 10-hour half-life temperature of the polymerization initiator (i) is 50°C or lower.

2. The method for producing a copolymer according to claim 1 , wherein the polymerization initiator (i) is a peroxide-based thermal polymerization initiator.

3. The method for producing a copolymer according to claim 2, wherein a reducing agent (i-2) is further added in the step (IV).

4. 3. The method for producing a copolymer according to claim 2, wherein the polymerization initiator (i) is one or more selected from the group consisting of 1-methyl-1-phenylethyl 7,7-dimethylperoxyoctanoate and benzoyl peroxide, di(2-phenoxyethyl)peroxydicarbonate, cumyl peroxyneodecanoate, and di(4-t-butylcyclohexyl)peroxydicarbonate (10-hour half-life temperature: 41°C).

5. The method for producing a copolymer according to claim 3, wherein the reducing agent (i-2) is one or more selected from the group consisting of 1,1'-[(4-methylphenyl)imino]bis(2-propanol), N,N-dimethyl-aniline, and N,N-dimethyl-p-toluidine.

6. The method for producing a copolymer according to claim 1, further comprising a step (V) of continuing the copolymerization reaction with stirring for 1 to 10 hours after completion of the step (IV).

7. 2. The method for producing a copolymer according to claim 1, wherein in the step (IV), the solution (i) and the solution (ii) are each added dropwise to a reaction vessel.

8. The method for producing a copolymer according to claim 1, wherein the copolymer has an acid value of 10 to 300 KOHmg / g.

9. The method for producing a copolymer according to claim 1, wherein the weight average molecular weight of the copolymer is 3,000 to 50,000.

10. The method for producing a copolymer according to claim 1, wherein the monomer (m-a) has one or more selected from the group consisting of a group represented by the following formula (1) and a group represented by the following formula (2): 【Chemistry 1】 (In formula (1), n1 and n2 each independently represent an integer of 0 to 2. * represents a linking site with the residue obtained by removing the blocked isocyanato group from the monomer (ma).) 【Chemistry 2】 (In formula (2), n3 and n4 each independently represent an integer of 0 to 2. * represents a linking site with the residue obtained by removing the blocked isocyanato group from the monomer (ma).)

11. the amount of the polymerization initiator (i) used is 0.5 to 30 parts by mass relative to 100 parts by mass of the total of all the monomers used in the step (II), 2. The method for producing a copolymer according to claim 1, wherein the amount of the solvent (i) used is 100 to 3,000 parts by mass per 100 parts by mass of the polymerization initiator (i).

12. In the step (II), the monomer (ma), the monomer (mb), and the monomer (mc) are further mixed with a solvent (ii), The method for producing a copolymer according to claim 1, wherein the amount of the solvent (ii) used is 10 to 500 parts by mass when the total amount of the monomer (ma), the monomer (mb), and the monomer (m-c) is 100 parts by mass.

13. The method includes a step of preparing a copolymer (A), a reactive diluent (B), a photopolymerization initiator (C), and a solvent (D), The method for producing a photosensitive resin composition, wherein the copolymer (A) is a copolymer obtained by the production method according to any one of claims 1 to 12.

14. The method for producing a photosensitive resin composition according to claim 13, further comprising adding a colorant (E).

15. A method for producing a cured resin film, comprising coating a photosensitive resin composition obtained by the method according to claim 13, exposing the composition to light, and thermally curing the composition.

16. A method for producing a patterned cured resin film, comprising coating, exposing, developing and thermally curing the photosensitive resin composition obtained by the method according to claim 13.

17. The method for producing a cured resin film according to claim 16, wherein the curing is carried out at a temperature of 50 to 150°C.

18. A method for producing an image display element, comprising repeating coating, exposure, and development of the photosensitive resin composition obtained by the production method according to claim 13 for each color to form a color filter having a colored pattern made of a cured product of the photosensitive resin composition.

Images