Thermosetting resin composition and color filter

Abstract

To provide a thermosetting resin composition which enables formation of a cured film with excellent NMP resistance and residual metal ionic property, and has good storage stability, and a color filter using a protective film composed of the cured product.SOLUTION: A thermosetting resin composition contains component (A): a polyfunctional epoxy resin having two or more epoxy groups in one molecule, component (B): polyvalent carboxylic acid hemiacetal ester represented by formula (1) or formula (2), and component (C): a heat acid generator, wherein the component (C) is 0.05 to 10 pts.mass with respect to 100 pts.mass of the total of the component (A) and the component (B), and the functional group equivalent ratio of the carboxyl groups of the component (B) to the epoxy groups of the component (A) is within a range of 0.25 to 0.95.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a thermosetting resin composition and a color filter having a protective film obtained by curing the same. [Background technology]

[0002] Recently, the demands on the display performance of liquid crystal displays have become stricter. In addition to display performance such as brightness, color purity, and contrast, there is an increasing demand for reliability in color filters, such as preventing image burn-in (where the image on the display element becomes fixed) and preventing display unevenness. According to Patent Document 1, the occurrence of burn-in is influenced by the fact that Na ions and K ions contained in the developing solution, such as potassium hydroxide or sodium carbonate, remain on the surface of the protective film during the photospacer formation process. For this reason, the protective film needs to have the ability to suppress the residue of Na ions and K ions even when in contact with developing solutions such as potassium hydroxide or sodium carbonate (hereinafter referred to as residual metal ion property). Patent Document 1 proposes a resin composition for color filter protective films that has excellent residual metal ion properties, which is a combination of an epoxy group or oxetanyl group-containing polymer, a polyvalent carboxylic acid hemiacetal ester, a specific epoxy compound, and a bifunctional bisphenol A type epoxy resin.

[0003] Furthermore, if the coating liquid used to form the protective film undergoes a change in viscosity (especially an increase in viscosity), it becomes difficult to apply the film with a uniform thickness. Therefore, sufficient storage stability is required for the protective film coating liquid. Typically, protective film coating liquids are stored under refrigeration (around 5°C), and considering in-house inventory storage and production adjustments by customers, it is preferable that the coating liquid has excellent storage stability for 180 days or more under refrigeration (around 5°C). Patent Document 2 proposes a resin composition for color filter protective films that has excellent storage stability, which combines an epoxy-containing polymer and a polyvalent carboxylic acid hemiacetal ester. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2022-112451 [Patent Document 2] Japanese Patent Publication No. 2001-350010 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] In recent years, in order to expand the color gamut that can be displayed in liquid crystal displays, there has been progress in miniaturizing the pigments contained in the colored layer and increasing the pigment concentration. However, this has led to the problem that the pigments penetrate the protective film and dissolve into the liquid crystal layer, causing display defects. It is thought that this dissolution of pigment components occurs in the alignment film formation process, which is a post-processing step for the protective film, via the solvent (N-methyl-2-pyrrolidone, hereinafter referred to as NMP) of the alignment film that has permeated the protective film. In this process, the protective film and NMP may be exposed to high temperatures of around 180°C while in contact, so the protective film is required to have the ability to suppress NMP penetration even at high temperatures (hereinafter referred to as NMP resistance). Previously, it was considered sufficient for color filter protective films to suppress solvent penetration at around 25-40°C, but in order to suppress the dissolution of the pigment components mentioned above, it is necessary to suppress solvent penetration at significantly higher temperatures than before. According to the inventors' studies, the compositions described in Patent Documents 1 and 2 did not sufficiently achieve both NMP resistance and residual metal ion properties.

[0006] The present invention has been made in view of the above-mentioned prior art, and aims to provide a thermosetting resin composition that can form a cured film with excellent NMP resistance and residual metal ion properties, and has good storage stability, and a color filter using a protective film made of the cured product thereof. [Means for solving the problem]

[0007] As a result of various studies conducted by the present inventors to solve the above problems, the present inventors have found that the above problems can be solved by combining a specific polyfunctional epoxy resin, a specific polyvalent carboxylic acid hemiacetal ester, and a thermal acid generator in a specific ratio range, and have completed the present invention. That is, the present invention relates to the following [1] and [2].

[0008] [1] Component (A): a polyfunctional epoxy resin having two or more epoxy groups in one molecule, Component (B): a polyvalent carboxylic acid hemiacetal ester represented by the following formula (1) or the following formula (2), Component (C): a thermal acid generator, wherein the content of the component (C) is 0.05 to 10 parts by mass based on 100 parts by mass in total of the component (A) and the component (B), and the functional group equivalent ratio of the carboxyl group of the component (B) to the epoxy group of the component (A) is in the range of 0.25 to 0.95, the thermosetting resin composition being characterized. [Chemical Formula] (wherein R 1 each independently represents an alkyl group having 1 to 6 carbon atoms.) [Chemical Formula] (wherein R 2 each independently represents an alkyl group having 1 to 6 carbon atoms.)

[0009] [2] A color filter having a protective film formed by curing the thermosetting resin composition according to the above [1]. [Effects of the Invention]

[0010] According to the thermosetting resin composition of the present invention, a color filter protective film excellent in NMP resistance and residual metal ion property can be formed. In addition, the thermosetting resin composition of the present invention is excellent in storage stability. [Modes for Carrying Out the Invention]

[0011] The thermosetting resin composition of the present invention comprises the following components (A), (B), and (C).

[0012] <(A) component> Component (A) is a polyfunctional epoxy resin having two or more epoxy groups in one molecule, and is not particularly limited as long as it is a compound having two or more epoxy groups in one molecule; known materials can be used. Examples of such compounds include epoxy group-containing polymers, bisphenol A type epoxy resins, bisphenol A novolac type epoxy resins, bisphenol F type epoxy resins, brominated bisphenol A type epoxy resins, bisphenol S type epoxy resins, diphenyl ether type epoxy resins, hydroquinone type epoxy resins, naphthalene type epoxy resins, biphenyl type epoxy resins, fluorene type epoxy resins, phenol novolac type epoxy resins, orthocresol novolac type epoxy resins, trishydroxyphenylmethane type epoxy resins, tetraphenyloleethane type epoxy resins, dicyclopentadienephenol type epoxy resins, hydrogenated bisphenol A type epoxy resins, polypropylene glycol type epoxy resins, glycidyl ester type epoxy resins, alicyclic epoxy resins, and heterocyclic epoxy resins. These polyfunctional epoxy resins may be used individually or in combination of two or more. Among these, it is preferable to use an epoxy group-containing polymer. When an epoxy group-containing polymer is used as a polyfunctional epoxy resin, a sufficient crosslinked structure is obtained, improving NMP resistance. Furthermore, from the viewpoint of storage stability when used in combination with component (C), it is preferable to use an epoxy resin with a glycidyl ether structure.

[0013] (Epoxy group-containing polymer) The epoxy group-containing polymer is a polymer having a structure in which an epoxy group is bonded directly or indirectly via another group to a hydrocarbon chain constituting the main chain of the polymer. The epoxy group-containing polymer is preferably a copolymer having a structure derived from both components of (a1) a monomer having a carbon-carbon unsaturated bond and an epoxy group, and (a2) a monomer having a carbon-carbon unsaturated bond other than (a1).

[0014] The monomer (a1) having a carbon-carbon unsaturated bond and an epoxy group is not particularly limited as long as it has a carbon-carbon unsaturated bond and an epoxy group, and any known monomer can be used.

[0015] As the monomer (a1) having a carbon-carbon unsaturated bond and an epoxy group, for example, monomers represented by the following formulas (3) to (5) may be mentioned as more preferred examples.

Chemical Formula

[0016]

Chemical Formula

[0017]

Chemical Formula

[0018] Among the above formulas (3) to (5), particularly preferably, formula (3) is a monomer in which R 3 is a methyl group and k is 1, and formula (4) is a monomer in which R 4 is a hydrogen atom, R 5is a -CH2O- group, R 6 The monomer is a hydrogen atom and m is 1, and in formula (5) R 7 It is a monomer with a methyl group and n = 1.

[0019] (a2) Monomers having carbon-carbon unsaturated bonds other than (a1) can be any known monomers that have carbon-carbon unsaturated bonds and do not fall under (a1). Preferably, monomers represented by the following formulas (6) to (9) are used as monomers for component (a2).

[0020] [ka] (In the formula, R 8 R is a hydrogen atom or a methyl group. 9 (This represents an alkyl group, aryl group, or alicyclic hydrocarbon group with 3 to 12 carbon atoms in the main ring.)

[0021] [ka] (In the formula, R 10 R is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. 11 (This represents an alkyl group, alkoxy group, siloxyalkyl group, or aromatic hydrocarbon group having 1 to 12 carbon atoms.)

[0022] [ka] (In the formula, R 12 (This represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 12 carbon atoms, or an aromatic hydrocarbon group.)

[0023] [ka] (In the formula, R 13 R is a hydrogen atom or a methyl group. 14 (Independently, is either a methyl group or an ethyl group, and p is an integer from 1 to 5.)

[0024] Among the above formulas (6) to (9), formula (6) is particularly preferred as R 8 is a hydrogen atom or a methyl group, R 9 The monomer is an alkyl group having 4 carbon atoms or an alicyclic hydrocarbon group with 6 carbon atoms in the main ring, and formula (7) is R 10 is a hydrogen atom, R 11 It is a monomer of a 6-membered ring aromatic hydrocarbon group, and as formula (8), R 12 It is a monomer of a 6-membered ring alicyclic hydrocarbon group, and as formula (9), R 13 and R 14 It is a monomer with a methyl group and p = 3.

[0025] The epoxy group-containing polymer can be obtained by copolymerizing component (a1) and component (a2). The polymerization can be linear or branched, and may be a random copolymer, block copolymer, graft copolymer, etc. Furthermore, each component of (a1) or (a2) may consist of only one monomer, or two or more monomers may be used in combination.

[0026] The polymerization method between component (a1) and component (a2) is not particularly limited, and various polymerization methods such as radical polymerization and ionic polymerization such as anionic polymerization can be used. In addition, polymerization methods such as bulk polymerization, solution polymerization, suspension polymerization, and emulsion polymerization can be used. Furthermore, additives such as catalysts and solvents may be added to the polymerization reaction system as needed.

[0027] The epoxy equivalent of component (A) is preferably 100 to 1000 g / mol, more preferably 100 to 600 g / mol, and even more preferably 100 to 300 g / mol. By keeping the epoxy equivalent within the above range, a sufficient crosslinking structure is obtained, and NMP resistance is improved.

[0028] The weight-average molecular weight (Mw) of component (A) is not particularly limited, but is, for example, 3,000 to 100,000, preferably 4,000 to 80,000, more preferably 5,000 to 50,000, and even more preferably 10,000 to 30,000.

[0029] <(B) component> Component (B) is a vinyl ether-blocked polycarboxylic acid in which the carboxyl group of a polycarboxylic acid represented by the following formula (1) or (2) is latently converted as a hemiacetal ester by a vinyl ether compound, i.e., blocked, and can be obtained by the reaction represented by the following general formula (10). [ka] (In the formula, R 1 (This independently represents an alkyl group having 1 to 6 carbon atoms.) [ka] (In the formula, R 2 (This independently represents an alkyl group having 1 to 6 carbon atoms.) [ka] (In the formula, R 15 R is a 6-membered ring aromatic hydrocarbon group, 1 , R 2 (where n is an alkyl group with 1 to 6 carbon atoms, and n is an integer between 3 and 4.)

[0030] Preferably, the polycarboxylic acid is trimellitic acid or pyromellitic acid. Of these, trimellitic acid is particularly preferred from the viewpoint of storage stability. The polycarboxylic acid can be used alone or in combination of two or more.

[0031] The number of carbon atoms in vinyl ether compounds excluding the carbon in vinyl (R in general formula (10)) 1 , R 2The number of carbon atoms in the compound is 1 to 6, preferably 2 to 6. Specific examples of vinyl ether compounds include aliphatic vinyl ether compounds such as methyl vinyl ether, ethyl vinyl ether, i-propyl vinyl ether, n-propyl vinyl ether, n-butyl vinyl ether, i-butyl vinyl ether, t-butyl vinyl ether, and cyclohexyl vinyl ether. Among these, n-propyl vinyl ether and i-propyl vinyl ether are preferred because they are readily available and their curing temperatures are suitable for the protective film process. The vinyl ether compounds can be used individually or in combination of two or more.

[0032] Component (B) can be obtained by reacting a carboxylic acid with a vinyl ether compound at a temperature ranging from room temperature to 150°C. Since the blocking reaction is an equilibrium reaction, adding a certain excess amount of the vinyl ether compound to the carboxylic acid can accelerate the reaction and improve the yield. Furthermore, catalysts and solvents can be added to the reaction between the carboxylic acid and the vinyl ether compound, depending on the purpose. When the acid value of the reaction solution decreases to 2.0 mg KOH / g or less due to the progress of the blocking reaction, it is judged that the reaction has proceeded sufficiently, and the reaction is terminated.

[0033] Examples of catalysts include tertiary amines, imidazoles, organophosphorus compounds, quaternary phosphonium salts, diazabicycloalkenes, organometallic compounds, quaternary ammonium salts, boron compounds, and metal halides. Catalysts can be used individually or in combination of two or more.

[0034] Examples of solvents include aromatic hydrocarbons, ethers, esters, ether esters, ketones, phosphate esters, nitriles, aprotic polar solvents, and propylene glycol alkyl ether acetates. The solvent can be used individually or in combination of two or more.

[0035] The functional group equivalent ratio of the carboxyl groups of component (B) to the epoxy groups of component (A) is 0.25 to 0.95, preferably 0.30 to 0.80, and more preferably 0.40 to 0.65. By setting the blending ratio of components (A) and (B) within the above range, it is possible to achieve both NMP resistance and residual metal ion properties when combined with component (C). If the functional group equivalent ratio of the carboxyl groups of component (B) to the epoxy groups in component (A) is less than 0.25, sufficient NMP resistance cannot be obtained, and if it exceeds 0.95, residual metal ion properties become insufficient.

[0036] <(C) component> Component (C) is a thermal acid generator and is not particularly limited as long as it is a compound that generates acid when heated; known materials such as sulfonium salts, ammonium salts, and iodonium salts can be used. As for the anionic component, known materials such as phosphorus-based, borate-based, and antimony-based materials can be used, but from the viewpoint of hazards, non-antimony materials such as phosphorus-based or borate-based materials are preferred. Examples of commercially available products of component (C) include San-Aid SI-80 (Sanshin Chemical Industry Co., Ltd.), SI-100 (same), SI-110 (same), SI-150 (same), SI-B3 (same), SI-B4 (same), SI-B5 (same), TA-100 (Sun Apro Co., Ltd.), TA-100FG (same), IK-1 (same), and IK-1FG (same).

[0037] Component (C) is 0.05 to 10 parts by mass, preferably 0.1 to 7.0 parts by mass, and more preferably 0.15 to 5.0 parts by mass, relative to 100 parts by mass of the total of components (A) and (B). If component (C) is less than 0.05 parts by mass, sufficient NMP resistance cannot be obtained, and if it exceeds 10 parts by mass, storage stability decreases.

[0038] (C) From the viewpoint of storage stability, it is preferable that the exothermic peak of a mixture of a thermoacid generator and bisphenol A type epoxy resin (manufactured by Mitsubishi Chemical Corporation, trade name "jER-828") is 150°C or higher when measured by differential scanning calorimetry (heating rate: 10°C / min).

[0039] <Other additives> The thermosetting resin composition of the present invention may contain additives such as silane coupling agents, leveling agents, antioxidants, stabilizers, and organic solvents, to the extent that they do not impair the effects of the invention.

[0040] <Silane coupling agent> Silane coupling agents are compounds having an alkoxysilyl group (Si-OR) and a reactive group in one molecule. The reactive group is preferably an epoxy group. Examples of silane coupling agents having an epoxy group include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane. These silane coupling agents can be used individually or in combination of two or more.

[0041] <Leveling agent> Leveling agents are added to improve the appearance of the resulting coating film, and can be used without particular limitation by any means, including silicone-based, fluorine-based, and acrylic-based agents that have been commonly used in protective films for this type of color filter. Examples of commercially available leveling agents include Megafac F-410 (DIC Corporation), F-477 (DIC Corporation), F-552 (DIC Corporation), F-553 (DIC Corporation), F-554 (DIC Corporation), F-555 (DIC Corporation), F-556 (DIC Corporation), F-558 (DIC Corporation), F-559 (DIC Corporation), F-561 (DIC Corporation), Novec FC-4430 (Sumitomo 3M Co., Ltd.), FC-4432 (Sumitomo 3M Co., Ltd.), and Surflon S-611 (AGC Seimi Chemical Co., Ltd.). ), S-651 (same), S-386 (same), Futergent 208G (Neos Co., Ltd.), 602A (same), 650A (same), 610FM (same), 710FM (same), FTX-218 (same), BYK-302 (Big Chemie Japan Co., Ltd.), BYK-307 (same), BYK-337 (same), Polyflow KL-400HF (Kyoeisha Chemical Co., Ltd.), KL-700 (same), LE-604 (same), etc. can be used.

[0042] <Antioxidant> As antioxidants, hindered phenol-based antioxidants such as IRGANOX1010 (BASF), IRGANOX1035 (ibid.), IRGANOX1076 (ibid.), IRGANOX1135 (ibid.), and IRGANOX1726 (ibid.) can be used.

[0043] <Stabilizer> The stabilizer refers to the excess vinyl ether mentioned above, which is added to improve the yield of the carboxylic acid hemiacetal ester. Specifically, this includes the vinyl ether described in "<Component (B)>" above.

[0044] <Organic solvents> Organic solvents are added to thermosetting resin compositions to adjust their viscosity and other properties. Specifically, examples include esters such as amyl acetate, ether esters such as ethyl ethoxypropionate and 3-methoxy-3-methyl-1-butyl acetate; ketones such as methyl ethyl ketone and cyclohexanone; and glycol derivatives such as propylene glycol monomethyl ether acetate, propylene glycol diacetate, and diethylene glycol ethyl methyl ether.

[0045] (Formation of a protective film on the color filter) The color filter of the present invention comprises a layer of cured material obtained by curing the above-mentioned thermosetting resin composition as a protective film. The thermosetting resin composition is applied to cover the colored layer and black matrix arranged on the substrate. The application method is not particularly limited, and known coating methods such as inkjet, spin coating, and die coating can be employed.

[0046] The obtained coating is dried, and if necessary, preheating (hereinafter referred to as "pre-bake") is performed, followed by main curing heating (hereinafter referred to as "post-bake") to form a layer of cured resin. In this case, preferred conditions for pre-bake are 40 to 140°C for 0 to 1 hour, and preferred conditions for post-bake are 150 to 280°C for 0.2 to 2 hours. Furthermore, the heating method at this time is not particularly limited, and curing equipment such as a closed curing furnace or a tunnel furnace capable of continuous curing can be used. The heating source is not particularly restricted and can be carried out by methods such as hot air circulation, infrared heating, and high-frequency heating. [Examples]

[0047] The present invention will be specifically described below with reference to examples and comparative examples. <Polymerization Example 1: Synthesis of epoxy group-containing polymer (A-1)> In a four-necked flask equipped with a thermometer, reflux condenser, stirrer, and dropping funnel, 76.0 parts by mass of propylene glycol monomethyl ether acetate (PGMEA) was charged as a solvent and heated while stirring to raise the temperature to 88°C. Then, at 88°C, a pre-mixed mixture of 56.9 parts by mass of glycidyl methacrylate (GMA) as component (a1), 43.1 parts by mass of cyclohexyl methacrylate (CHMA) as component (a2), 8.0 parts by mass of the peroxide-based polymerization initiator "Perhexyl O (PHO)" manufactured by NOF Corporation as a polymerization initiator, and 16.0 parts by mass of PGMEA (dropping component) was added dropwise at a constant rate from the dropping funnel over 2 hours. Subsequently, the temperature was maintained at 88°C for 5 hours to obtain a 50% PGMEA solution of epoxy group-containing polymer (A-1) with a weight-average molecular weight (Mw) of 12,700 and an epoxy equivalent of 250 g / mol (calculated as active ingredient).

[0048] <Weight average molecular weight (Mw)> The weight-average molecular weight (Mw) was determined using a Tosoh Corporation HLC-8320GPC gel permeation chromatography system, with a Tosoh Corporation TSKgel HZM-M column, THF as the eluent, and measured with an RI detector, then converted to polystyrene equivalent.

[0049] <Polymerization Examples 2-5: Synthesis of epoxy group-containing polymers (A-2-A-5)> The raw materials shown in Table 1 were mixed under the conditions shown in Table 1, and polymers A-2 to A-5 were obtained in the same manner as in Polymerization Example 1. The amount of each raw material, the weight-average molecular weight, and the epoxy equivalent are shown in Table 1.

[0050] [Table 1]

[0051] The abbreviations in Table 1 are as follows: (a1) component GMA: Glycidyl methacrylate (a2) Component CHMA: Cyclohexyl methacrylate MPS: Methacryloxypropyltrimethoxysilane CHMI: Cyclohexylmaleimide BMA: Butyl methacrylate (Polymerization initiator) PHO:t-Hexylperoxy-2-ethylhexanoate (Peroxide-based polymerization initiator manufactured by NOF Corporation, "Product Name: Perhexyl O") (solvent) PGMEA: Propylene glycol monomethyl ether acetate

[0052] <Synthesis Example 1: Synthesis of Component (B) (B-1)> In a four-necked flask equipped with a thermometer, reflux condenser, and stirrer, 26.8 parts by mass of propylene glycol monomethyl ether acetate (PGMEA) as the solvent, 26.9 parts by mass of trimellitic acid (TMA) as the polycarboxylic acid, and 46.3 parts by mass of n-propyl vinyl ether (NPVE) as the vinyl ether were charged and heated with stirring until the temperature rose to 80°C. Then, stirring was continued while maintaining the temperature, and after confirming that the acid value of the mixture reached 2.0 mg KOH / g or less, the reaction was terminated to obtain a 60% PGMEA solution of polycarboxylic acid hemiacetal ester (B-1) with an acid value of 0.6 mg KOH / g and a carboxyl group equivalent of 156 g / mol (calculated as active ingredient).

[0053] <Acid value> The acid value was measured using a method in accordance with JIS K0070-1992, "Test methods for acid value, saponification value, ester value, iodine value, hydroxyl value, and unsaponifiable matter of chemical products."

[0054] <Synthesis Examples 2-3: Synthesis of Polycarboxylic Acid Hemiacetal Esters (B-2-B-3)> The raw materials shown in Table 2 were mixed under the conditions shown in Table 2, and reaction products B-2 to B-3 were obtained in the same manner as in Synthesis Example 1. The amount of each raw material, acid value, and carboxyl group equivalent are shown in Table 2.

[0055] [Table 2]

[0056] The abbreviations in Table 2 are as follows: (Polyhydric carboxylic acid) TMA: Trimellit Acid PMA: Pyromelit acid (vinyl ether) NPVE: n-propyl vinyl ether IPVE: i-propyl vinyl ether (solvent) PGMEA: Propylene glycol monomethyl ether acetate

[0057] <Comparative Synthesis Example 1: Synthesis of Thermally Latent Catalyst (CAT-1)> 100.0 parts by mass of zinc 2-ethylhexylate were charged into a four-necked flask equipped with a thermometer, reflux condenser, stirrer, and dropping funnel, and stirred at room temperature. Then, 41.1 parts by mass of triethanolamine were added dropwise at a constant rate from the dropping funnel over 30 minutes. The reaction was allowed to proceed for 1 hour after addition to obtain a thermally latent catalyst (CAT-1).

[0058] <Examples 1-23, Comparative Examples 1-7> Each component shown in Tables 3 to 5 was dissolved and mixed in the amounts shown in Tables 3 to 5 to prepare the coating solutions for the thermosetting resin compositions for color filter protective films of Examples 1 to 23 and Comparative Examples 1 to 7. In Tables 3 to 5, the numerical values ​​indicating the content of each component are in parts by mass. The abbreviations used in Tables 3 to 5 are as follows:

[0059] <(A) component> EP157: Bisphenol A novolac type epoxy compound (manufactured by Mitsubishi Chemical Corporation, product name: "jER157S70", epoxy equivalent 210 g / eq, glycidyl ether type) VG3101L: Glycidyl ether type epoxy compound (manufactured by Printec Co., Ltd., product name: "Tecmore VG3101L", epoxy equivalent 210 g / eq), glycidyl ether type CEL2021P: 3',4'-Epoxycyclohexylmethyl 3,4-Epoxycyclohexanecarboxylate (manufactured by Daicel Corporation, product name: "Celoxide 2021P", epoxy equivalent 130 g / eq), alicyclic epoxy type EP828: Bisphenol A type epoxy resin (manufactured by Mitsubishi Chemical Corporation, product name "jER-828", epoxy equivalent 190 g / eq, glycidyl ether type) <(C) component> C-1: San-Aid SI-110 (manufactured by Sanshin Chemical Industry Co., Ltd., peak exothermic temperature 160°C) C-2: San-Aid SI-B5 (manufactured by Sanshin Chemical Industry Co., Ltd., peak exothermic temperature 210°C) C-3: San-Aid SI-B3 (manufactured by Sanshin Chemical Industry Co., Ltd., peak exothermic temperature 140°C) <Leveling agent> F-477: Fluorine-based leveling agent (manufactured by DIC Corporation, trade name: "Megafac F-477") <Stabilizer> NPVE: n-propyl vinyl ether IPVE: i-propyl vinyl ether <Catalyst> ZrOct: Zirconium octylate <Solvent> PGMEA: Propylene glycol monomethyl ether acetate

[0060] The coating solutions of the thermosetting resin compositions of Examples 1 to 23 and Comparative Examples 1 to 7 were each filtered through a membrane filter (material: PE, pore size: 0.2 μm), and then further filtered through a hollow fiber filter (material: PP, pore size: 0.02 μm). The obtained coating solution of the thermosetting resin composition for color filter protective films was spin-coated onto a substrate using a spin coater (Model 1H-DX-2, manufactured by Mikasa Co., Ltd.). After coating, the substrate was prebaked in a clean oven at 90°C for 2 minutes, and then post-baked in a clean oven at 230°C for 30 minutes to obtain a cured film with a predetermined film thickness. The thermosetting resin composition or the obtained cured film was evaluated for the following "NMP resistance", "residual metal ion property", and "storage stability". The evaluation results are shown in Tables 3 to 5.

[0061] <NMP resistance> 100 μL of NMP was dropped onto a 10 cm square alkali-free glass substrate (EAGLE XG, manufactured by Corning Incorporated) on which a 1.5 μm thick cured film was formed, covered with an 8 cm square cover glass, and then heated at 180°C for 15 minutes. After the heating was completed, the cover glass was removed, and NMP on the surface of the cured film was removed by air blow. The film thickness of the cured film before and after the test was measured, and the film thickness change rate was calculated. A film thickness change rate of 30% or less before and after the test was regarded as acceptable.

[0062] <Residual metal ion property> An alkali-free glass substrate (EAGLEXG, Corning) with a 1.5 μm thick cured film was subjected to UV cleaning using a UV cleaning device (model i UV-Ozone Cleaning Device, Iwasaki Electric Co., Ltd.) at an irradiation dose of 3,000 mJ / cm². 2 After UV-ozone irradiation, the substrate was immersed in a 0.05 wt% potassium hydroxide developer for 60 seconds. The substrate was then washed with pure water for 10 seconds and thoroughly dried with compressed air. The substrate was then subjected to X-ray fluorescence (model ZSX100e, Rigaku Corporation) to measure the residual potassium content on the cured film surface. A residual potassium content of 0.6% or less was considered acceptable.

[0063] <Storage stability> The coating solution of the thermosetting resin composition was left in a sealed container at 5°C, and the time (in days) until the viscosity at a measurement temperature of 25°C doubled from the viscosity immediately after preparation was measured. A result of ◎ was given if the time until the viscosity of the coating solution doubled was 180 days or more, ○ if it was 90 days or more but less than 180 days, and × if it was less than 90 days.

[0064] [Table 3]

[0065] [Table 4]

[0066] [Table 5]

[0067] From the results in Tables 3 and 4, Examples 1 to 23 showed good NMP resistance and residual metal ion properties of the cured films, and the thermosetting resin compositions also exhibited good storage stability under refrigeration (5°C). On the other hand, from the results in Table 5, Comparative Examples 1 to 5 either did not use component (C) or contained too little of component (C), resulting in insufficient NMP resistance. Furthermore, in Comparative Examples 6 and 7, the functional group equivalent ratio of carboxyl groups in component (B) to epoxy groups in component (A) was either too high or too low, resulting in insufficient residual metal ion properties or NMP resistance.

Claims

1. (A) Components: A polyfunctional epoxy resin having two or more epoxy groups in one molecule, (B) Component: A polyvalent carboxylic acid hemiacetal ester represented by the following formula (1) or formula (2), (C) Ingredients: Contains a heat acid generator, With respect to a total of 100 parts by mass of component (A) and component (B), component (C) is 0.05 to 10 parts by mass. A thermosetting resin composition characterized in that the functional group equivalent ratio of the carboxyl groups of component (B) to the epoxy groups of component (A) is in the range of 0.25 to 0.

95. 【Chemistry 1】 (In the formula, R １ (This independently represents an alkyl group having 1 to 6 carbon atoms.) 【Chemistry 2】 (In the formula, R ２ (This independently represents an alkyl group having 1 to 6 carbon atoms.)

2. A color filter characterized by having a protective film formed by curing the thermosetting resin composition described in claim 1.

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