JP2022112451A - Thermosetting resin composition and color filter having cured film thereof - Google Patents

Abstract

To provide a thermosetting resin composition that has the great ability to prevent a liquid crystal panel from being burnt in as there are few residual metal ions even if the cured film of it comes into contact, following UV ozone cleaning, with an alkali development liquid at photospacer formation, while maintaining the general performances needed for a color filter protective film such as a coating appearance, smoothness, and chemical resistance; and a color filter having a protective film composed of the cured product.SOLUTION: A thermosetting resin composition contains following components (A)-(D). Component (A): an epoxy group-containing polymer, (B): polycarboxylic acid hemiacetal ester, (C): novolac epoxy resin, (D): bifunctional bisphenol A type epoxy resin.SELECTED DRAWING: None

Description

TECHNICAL FIELD The present invention relates to a thermosetting resin composition and a color filter having a protective film obtained by curing the same.

In recent years, with the spread of liquid crystal display devices, the demand for color filters used in liquid crystal display devices is increasing. The color filter consists of a transparent substrate, a black matrix layer formed in a predetermined pattern, a colored layer in which red (R), green (G), and blue (B) are arranged in a predetermined order, a protective film, and a photospacer. structure is common. This protective film serves to physically and chemically protect the color filter during manufacturing and use of the liquid crystal display device. Therefore, the protective film is required to have excellent properties such as smoothness and chemical resistance. In addition, if the viscosity change (especially viscosity increase) occurs in the protective film coating solution, it will be difficult to apply the coating film with a uniform thickness. storage stability is required. Therefore, in this type of protective film, conventional efforts have been made to improve these performances (Patent Document 1).

In recent years, the demand for display performance in liquid crystal display devices has become stricter, and in addition to display performance such as brightness, color purity and contrast for color filters, image sticking (afterimage) that the image of the display element becomes fixed is called. Demands for reliability against phenomena and display unevenness are increasing more and more. Among the above characteristics, many studies have been made on suppression of image sticking in particular.

According to Patent Document 2, it is disclosed that image sticking occurs when ionic impurities derived from the black matrix layer of a color filter or red (R), green (G), and blue (B) pigments and dyes are eluted into the liquid crystal. It is Since the ionic impurities pass through the protective film and are eluted into the liquid crystal, a protective film with excellent ion barrier properties is desired.

In addition, Patent Document 3 also discloses a protective film-forming resin composition containing an ion scavenger for the purpose of preventing the elution of ionic impurities derived from dyes, and has excellent liquid crystal resistance characteristics (voltage holding ratio). have been reported to have

Furthermore, in Patent Document 4, a material with a low dielectric constant, which is a reaction product of an acrylic copolymer and an epoxy compound, reduces the charging of electric charges in the protective film and prevents the alignment disorder of the liquid crystal in the vicinity of the protective film. is disclosed.
As described above, various studies have been conducted on image sticking, but according to the inventors' studies, image sticking of liquid crystal panels does not occur even if the protective film has sufficient ion barrier properties, voltage holding ratio and dielectric constant. There was a problem that could not be improved.
Accordingly, an object of the present invention is to provide a thermosetting resin composition capable of forming a color filter protective film having an ability to suppress image sticking in a liquid crystal panel, and a color filter using a protective film comprising a cured product thereof. is.

Japanese Patent Application Laid-Open No. 2001-350010 JP 2015-106032 A JP 2017-120387 A JP-A-10-332921

As a result of intensive studies against this background, the authors discovered that image sticking in liquid crystal panels was caused by metal ions remaining in the protective film during the photospacer formation process during the production of color filters, leading to the development of the present invention. rice field.

A photospacer is formed on the protective film of the color filter by a photolithographic process. The photospacer is applied on the protective film in the form of a coating liquid, and at that time, the surface of the protective film is washed before application in order to improve the coating property (recoating property). UV ozone cleaning is widely used for this pre-coating cleaning, and the protective film is mainly exposed to UV light of 185 nm and 254 nm emitted from a low-pressure mercury lamp as a light source during pre-coating cleaning of the photospacer. As described above, when the protective film is exposed to high-energy UV light, ester bonds and the like in the film are decomposed, and polar functional groups such as carboxyl groups and hydroxyl groups are generated on the surface of the protective film. When this generated carboxyl group comes into contact with an alkaline developer such as potassium hydroxide and sodium carbonate used in the photospacer formation process, alkali metal ions such as Na ions and K ions in the developer are transferred to the surface of the protective film. It forms an ionic bond with a carboxyl group. It was clarified that these bonded metal ions affect image sticking of liquid crystal panels, and it was found that reduction of these metal ions leads to suppression of image sticking.

The present invention has been made in view of the above-mentioned circumstances, and maintains the performance such as coating appearance, smoothness, and chemical resistance that are generally required for color filter protective films. In the film, a thermosetting resin composition that has little residual metal ions even when it comes into contact with an alkaline developer during photospacer formation and has a good ability to prevent image sticking in a liquid crystal panel, and a protective film made of a cured product thereof. To provide a color filter that is

The inventors of the present invention conducted various studies to solve the above problems, and found that a specific polymer, a specific carboxylic acid derivative compound, a specific epoxy compound, and a bifunctional bisphenol A type epoxy resin were mixed in a specific ratio range. The inventors have found that the above problems can be solved by combining the above, and have completed the present invention.
That is, the present invention is the following [1] and [2].

（式中のＲ^１は炭素数１～６のアルキル基を表す。）
（Ｃ）成分：下記式（２）で表されるエポキシ樹脂

（式中のｎは１～１５を表す。）
（Ｄ）成分：２官能ビスフェノールＡ型エポキシ樹脂
〔２〕
〔１〕に記載の熱硬化性樹脂組成物を硬化させてなる保護膜を有するカラーフィルター。 [1]
A thermosetting resin composition containing the following components (A) to (D),
In a total of 100 parts by mass of the components (A) to (D), 20 to 80 parts by mass of the component (A), 10 to 50 parts by mass of the component (B), and 1 to 50 parts by mass of the component (C) Parts by mass and component (D) are 1 to 15 parts by mass, and the mass ratio (C)/(D) of component (C) and component (D) is 3.0 to 9.0. A thermosetting resin composition.
Component (A): (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). Epoxy group-containing polymer containing 10 to 90 parts by weight of component (a1) and 90 to 10 parts by weight of component (a2) in 100 parts by weight of the total amount of component (a2): component (B) of the following formula (1): ) Polyvalent carboxylic acid hemiacetal ester represented by

(R ¹ in the formula represents an alkyl group having 1 to 6 carbon atoms.)
(C) component: an epoxy resin represented by the following formula (2)

(n in the formula represents 1 to 15.)
(D) component: bifunctional bisphenol A type epoxy resin [2]
A color filter having a protective film obtained by curing the thermosetting resin composition according to [1].

According to the thermosetting resin composition of the present invention, while maintaining performance such as coating appearance, smoothness, and chemical resistance, the cured film after UV ozone cleaning comes into contact with an alkaline developer during photospacer formation. It is possible to form a color filter protective film with less residual metal ions. In addition, the color filter formed from the thermosetting resin composition of the present invention is excellent in the ability to prevent image sticking in liquid crystal panels.

<<Thermosetting resin composition>>
The thermosetting resin composition of the present invention comprises (A) an epoxy group-containing polymer, (B) a polyvalent carboxylic acid hemiacetal ester, (C) a polyfunctional epoxy resin, and (D) a bifunctional bisphenol A type epoxy resin. including.

<(A) Epoxy Group-Containing Polymer>
(A) 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 that constitutes the main chain of the polymer.
The epoxy group-containing polymer has 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). It is preferably a copolymer consisting of

(a1) The monomer having a carbon-carbon unsaturated bond and an epoxy group may be any known monomer as long as it has a carbon-carbon unsaturated bond and an epoxy group.

（式中、Ｒ^２は水素原子又はメチル基、ｋは１～３の整数を示す。） More preferable examples of the (a1) monomer having a carbon-carbon unsaturated bond and an epoxy group include monomers represented by the following formulas (3) to (5).

(In the formula, R ² is a hydrogen atom or a methyl group, and k is an integer of 1 to 3.)

（式中、Ｒ^３は水素原子又はメチル基、Ｒ^４は－ＣＨ_２Ｏ－基又は－ＣＨ_２－基、Ｒ^５は水素原子又は炭素数１～２のアルキル基、ｍは１～３の整数を示す。）

(wherein R ³ is a hydrogen atom or a methyl group, R ⁴ is a -CH ₂ O- group or a -CH ₂ - group, R ⁵ is a hydrogen atom or an alkyl group having 1 to 2 carbon atoms, m is a indicates an integer.)

（式中、Ｒ^６は水素原子又はメチル基、ｎは１～３の整数を示す。）

(In the formula, R ⁶ is a hydrogen atom or a methyl group, and n is an integer of 1 to 3.)

Among the above formulas (3) to (5), particularly preferred formula (3) is a monomer in which R ² is a methyl group and k is 1, and formula (4) is a monomer in which R ³ is a hydrogen atom and R ⁴ is A monomer in which R ₅ is a hydrogen atom and m is 1, and R ⁶ is a methyl group and n is ¹ in formula (5).

(a2) A monomer having a carbon-carbon unsaturated bond other than (a1) may be a compound having a carbon-carbon unsaturated bond and not falling under (a1), and any known monomer can be used. can. Monomers of the component (a2) are preferably monomers represented by the following formulas (6) to (9).

（式中、Ｒ^７は水素原子又はメチル基、Ｒ^８は炭素数１～８のアルキル基、アリール基又は主環構成炭素数３～１２の脂環式炭化水素基を示す。）

(In the formula, R ⁷ represents a hydrogen atom or a methyl group, and R ⁸ represents an alkyl group having 1 to 8 carbon atoms, an aryl group, or an alicyclic hydrocarbon group having 3 to 12 main ring-constituting carbon atoms.)

（式中、Ｒ^９は水素原子又は炭素数１～５のアルキル基、Ｒ^１０は炭素数１～１２のアルキル基、アルコキシ基、シロキシアルキル基又は芳香族炭化水素基を示す。）

(In the formula, R ⁹ represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and R ¹⁰ represents an alkyl group having 1 to 12 carbon atoms, an alkoxy group, a siloxyalkyl group or an aromatic hydrocarbon group.)

（式中、Ｒ^１１は水素原子又は炭素数１～８のアルキル基、炭素数３～１２の脂環式炭化水素基又は芳香族炭化水素基を示す。）

(In the formula, R ¹¹ 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.)

（式中、Ｒ^１２は水素原子又はメチル基、Ｒ^１３はメチル基又はエチル基、ｐは１～５の整数を示す。）

(In the formula, R ¹² is a hydrogen atom or a methyl group, R ¹³ is a methyl group or an ethyl group, and p is an integer of 1 to 5.)

Among the above formulas (6) to (9), in formula (6), R ⁷ is a hydrogen atom or a methyl group, and R ⁸ is an alkyl group having 4 carbon atoms or an alicyclic group having 6 main ring carbon atoms It is a hydrocarbon group monomer, and in formula (7), R ⁹ is a hydrogen atom, R ¹⁰ is a 6-membered aromatic hydrocarbon group monomer, and in formula (8), R ¹¹ is a 6-membered ring It is a monomer of an alicyclic hydrocarbon group, and is a monomer in which R ¹² and R ¹³ are methyl groups and p is 3 as the formula (9).

(A) Epoxy group-containing polymer can be obtained by copolymerizing components (a1) and (a2). The polymerization mode may be linear or branched, and may be any of random copolymers, block copolymers, graft copolymers, and the like. In addition, as each component of (a1) component or (a2) component, only 1 type may be used for a monomer, and 2 or more types may be used together.

The method of polymerizing the components (a1) and (a2) is not particularly limited, and various polymerization methods such as ionic polymerization such as radical polymerization and anionic polymerization can be used. Further, polymerization methods such as bulk polymerization method, solution polymerization method, suspension polymerization method and emulsion polymerization method can be used. Furthermore, additives such as catalysts and solvents may be added to the polymerization reaction system as necessary.

(A) The weight average molecular weight (Mw) of the epoxy group-containing polymer is 3,000 to 100,000, preferably 4,000 to 80,000, more preferably 5,000 to 50,000. , more preferably 8,000 to 30,000. If the weight average molecular weight is less than 3,000, chemical resistance may deteriorate, and if it exceeds 100,000, smoothness may deteriorate. Moreover, an epoxy-group-containing polymer may be used individually by 1 type, and may be used in combination of 2 or more types.

(A) the epoxy group-containing polymer contains 10 to 90 parts by mass, preferably 20 to 80 parts by mass, of component (a1) in a total of 100 parts by mass of components (a1) and (a2); 10 to 90 parts by mass, preferably 20 to 80 parts by mass of components.

(A) The content of the epoxy group-containing polymer is 20 to 80 parts by mass, preferably 20 to 75 parts by mass, more preferably 25 to 70 parts by mass, based on 100 parts by mass of components (A) to (D) in total. contains part. When component (A) is less than 20 parts by mass, the smoothness is deteriorated, and when it exceeds 80 parts by mass, the number of carboxyl groups in the cured film increases, resulting in the effect of reducing the amount of metal ions remaining when contacted with an alkaline developer. It may not work.

（式中のＲ^１は炭素数１～６のアルキル基を表す。） <(B) Polyvalent carboxylic acid hemiacetal ester>
(B) Polyvalent carboxylic acid hemiacetal ester is a vinyl ether block polyvalent carboxylic acid in which the carboxyl group of trimellitic acid represented by the following formula (1) is latent, i.e. blocked, as a hemiacetal ester by a vinyl ether compound. and can be obtained by the reaction represented by the following general formula (10).

(R ¹ in the formula represents an alkyl group having 1 to 6 carbon atoms.)

（式中のＲ^１は、炭素数１～６のアルキル基を表す。）

(R ¹ in the formula represents an alkyl group having 1 to 6 carbon atoms.)

(B) The polyvalent carboxylic acid of the polyvalent carboxylic acid hemiacetal ester is trimellitic acid from the viewpoint of availability. The number of carbon atoms in R ¹ in formulas (1) and (10) is 1-6, preferably 2-6. Specific examples of the vinyl ether compound in formula (10) include 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, cyclohexyl vinyl ether, and the like. of aliphatic vinyl ether compounds. Among them, n-propyl vinyl ether and i-propyl vinyl ether are preferred because they are readily available and the curing temperature is suitable for the protective film process. In addition, a vinyl ether compound can be used individually by 1 type or in combination of 2 or more types.

(B) Polyvalent carboxylic acid hemiacetal ester can be obtained by reacting trimellitic acid with a vinyl ether compound at a temperature in the range of 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 trimellitic acid promotes the reaction and can improve the yield. Moreover, a catalyst and a solvent can be added to the reaction between the trimellitic acid and the vinyl ether compound depending on the purpose. When the blocking reaction progresses and the acid value of the reaction solution decreases to 2.0 mgKOH/g or less, it is determined that the reaction has progressed sufficiently, and the reaction is terminated.

Examples of catalysts include tertiary amines, imidazoles, organophosphorus compounds, quaternary phosphonium salts, diazabicycloalkenes, organometallic compounds, quaternary ammonium salts, boron compounds and metal halides. A catalyst can be used individually by 1 type or in combination of 2 or more types.

Examples of solvents include aromatic hydrocarbons, ethers, esters, ether esters, ketones, phosphoric acid esters, nitriles, aprotic polar solvents and propylene glycol alkyl ether acetates. A solvent can be used individually by 1 type or in combination of 2 or more types.

(B) Polyvalent carboxylic acid hemiacetal ester is 10 to 50 parts by mass, preferably 15 to 45 parts by mass, more preferably 20 to 40 parts by mass in 100 parts by mass of components (A) to (D). contains. If the component (B) is less than 10 parts by mass, the chemical resistance may deteriorate.

（式中のｎは１～１５を表す。） <(C) Polyfunctional epoxy resin>
(C) Polyfunctional epoxy resin has a structure represented by the following formula (2). (C) The polyfunctional epoxy resin has a large number of aromatic rings as repeating units, so it shows resistance to UV light and has the performance of reducing the amount of residual metal ions when it comes into contact with an alkaline developer. Express. Moreover, since it has a polyfunctional epoxy group, a cured film having excellent chemical resistance can be obtained by a thermosetting reaction with (B) the polyvalent carboxylic acid hemiacetal ester.

(n in the formula represents 1 to 15.)

n in the formula (2) represents the average number of repetitions, and preferably has a structure in which n is 1 to 10 repetitions.

(C) The polyfunctional epoxy resin is contained in an amount of 1 to 50 parts by mass, preferably 5 to 45 parts by mass, more preferably 7 to 40 parts by mass, based on 100 parts by mass of components (A) to (D). If the amount of component (C) is less than 1 part by mass, the effect of reducing the amount of metal ions remaining when contacted with an alkaline developer and chemical resistance may be impaired. and smoothness may deteriorate.

（式中のｎは０～８を表す。） <(D) Bifunctional bisphenol A type epoxy resin>
(D) The bifunctional bisphenol A type epoxy resin has a structure represented by the following formula (11). (D) The bifunctional bisphenol A type epoxy resin can improve the compatibility during curing, can prevent appearance such as white turbidity of the cured film, and can obtain good smoothness.

(n in the formula represents 0 to 8.)

n in the above formula (11) represents an average number of repetitions, and preferably has a structure in which n has a number of repetitions of 0 to 6. (D) Commercial products of bifunctional bisphenol A type epoxy resins include liquid or semi-solid epoxy resins such as jER825 (Mitsubishi Chemical Co., Ltd.), jER827 (same), jER828 (same), jER834 (same). can be used.

(D) Difunctional bisphenol A type epoxy resin is 1 to 15 parts by mass, preferably 1.5 to 8.0 parts by mass, more preferably 2 parts by mass in total 100 parts by mass of components (A) to (D) .0 to 5.0 parts by mass. If component (C) is less than 1 part by mass, smoothness may be impaired, and if it exceeds 15 parts by mass, chemical resistance may be degraded.

The mass ratio (C)/(D) of (C) polyfunctional epoxy resin and (D) difunctional bisphenol A type epoxy resin contributes to the appearance and smoothness of the cured film, and both properties are satisfied at a specific ratio. can do. The mass ratio (C)/(D) is 3.0 to 9.0, preferably 4.0 to 6.0. If the mass ratio (C)/(D) is less than 3.0, the chemical resistance may be impaired, and if it exceeds 9.0, the cured film may become cloudy and the smoothness may deteriorate.

<Other additives>
Additives such as silane coupling agents, leveling agents, antioxidants, stabilizers and organic solvents can be added to the thermosetting resin composition of the present invention as long as they do not impair the effects of the present invention.

<Epoxy resins other than (C) and (D) components>
Epoxy resins other than components (C) and (D) may be contained as necessary for the purpose of improving compatibility and chemical resistance. For example, bisphenol F type epoxy resin, bisphenol S type epoxy resin, diphenyl ether type epoxy resin, naphthalene type epoxy resin, biphenyl type epoxy resin, fluorene type epoxy resin, trishydroxyphenylmethane type epoxy resin, trifunctional epoxy resin, tetraphenyl Roll ethane type epoxy resin, dicyclopentadiene phenol type epoxy resin, hydrogenated bisphenol A type epoxy resin, bisphenol A nucleated polyol type epoxy resin, polypropylene glycol type epoxy resin, glycidyl ester type epoxy resin, glycidylamine type epoxy resin, glyoxal type epoxy resins, alicyclic type epoxy resins, heterocyclic type epoxy resins, and the like. Among them, alicyclic epoxy resins are particularly preferred.

<Silane coupling agent>
A silane coupling agent is a compound having an alkoxysilyl group (Si--O--R) and a reactive group such as a vinyl group, an epoxy group, an amino group and a mercapto group in one molecule. As the reactive group, one having an epoxy group is preferred. Specifically, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, and 2-(3 ,4-epoxycyclohexyl)ethyltrimethoxysilane and the like. These silane coupling agents may be used alone or in combination of two or more.

<Leveling agent>
The leveling agent is added for the purpose of improving the appearance of the resulting coating film, and is commonly used in this type of protective film for color filters. etc. can be used without any particular restrictions. Examples of commercially available leveling agents include Megafac F-410 (DIC Corporation), F-477 (same), F-552 (same), F-553 (same), F-554 (same). ), F-555 (same), F-556 (same), F-558 (same), F-559 (same), F-561 (same), Novec FC-4430 (Sumitomo 3M Co., Ltd.), FC-4432 (same), 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 (BYK-Chemie Japan Co., Ltd.), BYK-307 (same), BYK-337 (same), Polyflow KL-400HF (Kyoeisha Chemical Co., Ltd.), KL-700 (same), LE-604 (same) and the like can be used.

<Antioxidant>
As the antioxidant, hindered phenolic antioxidants such as IRGANOX1010 (BASF), IRGANOX1035 (same), IRGANOX1076 (same), IRGANOX1135 (same), IRGANOX1726 (same) and the like can be used.

<Stabilizer>
The stabilizer refers to the excess vinyl ether described in "<(B) Polyvalent carboxylic acid hemiacetal ester>", and is added for the purpose of improving the yield of the polyvalent carboxylic acid hemiacetal ester. Specific examples thereof include the vinyl ethers described in the above "<(B) Polyvalent carboxylic acid hemiacetal ester>".

<Organic solvent>
The organic solvent is added for the purpose of adjusting the viscosity and the like of the thermosetting resin composition. Specifically, 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; propylene glycol monomethyl ether acetate and Glycol derivatives such as propylene glycol diacetate and diethylene glycol ethyl methyl ether can be mentioned.

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

The resulting coating film is dried, and if necessary, preheated (hereinafter referred to as "prebake"), and then subjected to main curing heating (hereinafter referred to as "postbake") to form a cured resin layer. to form In this case, preferable pre-baking conditions are 40 to 140° C. and 0 to 1 hour, and post-baking conditions are 150 to 280° C. and 0.2 to 2 hours. Moreover, the heating method at this time is not particularly limited, and for example, a curing apparatus such as a closed curing furnace or a tunnel furnace capable of continuous curing can be employed. The heating source is not particularly limited, and methods such as hot air circulation, infrared heating, and high-frequency heating can be used.

EXAMPLES 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)>
A four-necked flask equipped with a thermometer, a reflux condenser, a stirrer, and a dropping funnel was charged with 76.0 parts by mass of propylene glycol monomethyl ether acetate (PGMEA) as a solvent, and heated to 88°C while stirring. . Then, at a temperature of 88 ° C., 64.0 parts by mass of glycidyl methacrylate (GMA) as component (a1), 36.0 parts by mass of cyclohexyl acrylate (CHMA) as component (a2), and a polymerization initiator manufactured by NOF Corporation 8.0 parts by mass of the peroxide-based polymerization initiator "Perhexyl O (PHO)" and 16.0 parts by mass of PGMEA (dropping component) were uniformly mixed in advance and dropped from the dropping funnel at a constant speed over 2 hours. . Thereafter, the temperature of 88° C. was maintained for 5 hours to obtain a 50% PGMEA solution of epoxy group-containing polymer (A-1) having a weight average molecular weight (Mw) of 14,000.

<Weight average molecular weight (Mw)>
The weight average molecular weight (Mw) is measured using a gel permeation chromatography device HLC-8320GPC manufactured by Tosoh Corporation, using TSKgel HZM-M manufactured by Tosoh Corporation as a column, using THF as an eluent, and using an RI detector. It was obtained by measuring and converting to polystyrene.

<Polymerization Examples 2 to 9: Synthesis of epoxy group-containing polymers (A-2 to A-9)>
The raw materials shown in Table 1 were mixed under the conditions shown in Table 1, and in the same manner as in Polymerization Example 1, polymers A-2 to A-9 were obtained. Table 1 shows the charged amount, reaction temperature and weight average molecular weight of each raw material.

Abbreviations in Table 1 are as follows.
(a1) component GMA: glycidyl methacrylate (a2) component CHMA: cyclohexyl methacrylate CHA: cyclohexyl acrylate MPS: methacryloxypropyltrimethoxysilane St: styrene CHMI: cyclohexylmaleimide (polymerization initiator)
PHO: t-hexylperoxy-2-ethylhexanoate (a peroxide polymerization initiator manufactured by NOF Corporation "Product name: Perhexyl O")
(solvent)
PGMEA: propylene glycol monomethyl ether acetate

<Synthesis Example 1: (B) Synthesis of polyvalent carboxylic acid hemiacetal ester (B-1)>
In a four-necked flask equipped with a thermometer, a reflux condenser and a stirrer, 26.8 parts by mass of propylene glycol monomethyl ether acetate (PGMEA) as a solvent, 26.9 parts by mass of trimellitic acid (TMA) as a polyvalent carboxylic acid, 46.3 parts by mass of n-propyl vinyl ether (NPVE) was charged as vinyl ether and heated to 80° C. while stirring. Next, continue to stir while maintaining the temperature, and after confirming that the acid value of the mixture has reached 2.0 mgKOH/g or less, terminate the reaction, and give the polyhydric carboxylic acid hemiacetal having an acid value of 0.6 mgKOH/g of the solution. A 60% PGMEA solution of ester (B-1) was obtained.

<Acid value>
The acid value was measured according to JIS K0070-1992 "Methods for testing acid value, saponification value, ester value, iodine value, hydroxyl value and unsaponifiable matter of chemical products".

<Synthesis Example 2: Synthesis of polyvalent carboxylic acid hemiacetal ester (B-2)>
The raw materials shown in Table 2 were mixed under the conditions shown in Table 2, and the reaction product B-2 was obtained in the same manner as in Synthesis Example 1. Table 2 shows the charged amount, reaction temperature and acid value of each raw material.

Abbreviations in Table 2 are as follows.
(polycarboxylic acid)
TMA: trimellitic acid (vinyl ether)
NPVE: n-propyl vinyl ether IPVE: i-propyl vinyl ether (solvent)
PGMEA: propylene glycol monomethyl ether acetate

<Examples 1 to 9, Comparative Examples 1 to 6>
The components shown in Tables 3 and 4 were dissolved and mixed in the amounts shown in Tables 3 and 4, and the thermosetting resin compositions for color filter protective films of Examples 1 to 9 and Comparative Examples 1 to 6 were applied. A working solution was prepared. In Tables 3 and 4, the numerical value indicating the content of each component is parts by mass. Abbreviations in Tables 3 and 4 are as follows.

<(C) Polyfunctional epoxy resin>
C-1: Polyfunctional epoxy resin of formula (2) (average number of repetitions n: 5.5)
C-2: Polyfunctional epoxy resin of formula (2) (average number of repetitions n: 3.2)
C-3: Polyfunctional epoxy resin of formula (2) (average number of repetitions n: 1.5)
<(D) Bifunctional bisphenol A type epoxy resin>
D-1: Bisphenol A type epoxy resin (manufactured by Mitsubishi Chemical Corporation, trade name "jER-828")
<Silane coupling agent>
OFS-6040: 3-glycidoxypropyltrimethoxysilane (manufactured by Dow Corning Toray Co., Ltd., trade name: “OFS-6040”)
<Leveling agent>
F-477: Fluorine-based leveling agent (manufactured by DIC Corporation, trade name: “Megafac F-477”)
FTX-218: fluorine-based leveling agent (manufactured by Neos Co., Ltd., trade name: "FTX-218")
<Other additives>
CEL2021: 3′,4′-epoxycyclohexylmethyl 3,4-epoxycyclohexane carboxylate (manufactured by Daicel Corporation, trade name: “Celoxide 2021P”)
<Stabilizer>
NPVE: n-propyl vinyl ether IPVE: i-propyl vinyl ether <solvent>
PGMEA: Propylene glycol monomethyl ether acetate EEP: Ethyl ethoxy propionate

The coating liquids of the thermosetting resin compositions for color filter protective films of Examples 1 to 9 and Comparative Examples 1 to 6 were each filtered through a membrane filter (material: PE, pore size: 0.2 μm), and then further filtered. It was filtered through a hollow filter (material: PP, pore size: 0.02 μm). The obtained coating liquid of the thermosetting resin composition for a color filter protective film was spin-coated on an alkali-free glass substrate using a spin coater (model 1H-DX-2, manufactured by Mikasa Co., Ltd.). After coating, the substrate was pre-baked 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 thickness. The thermosetting resin composition for color filter protective film or the resulting cured film was evaluated for the following "coating appearance", "smoothness", "residual metal ionicity", and "chemical resistance". rice field. Tables 3 and 4 show the evaluation results.

<Coating Appearance>
The appearance of the alkali-free glass substrate on which the 2.0 μm-thick cured film was formed was visually confirmed. The case where the coating appearance of the coating film surface was good was evaluated as ◯, and the case where surface roughness or whitening of the coating film was observed was evaluated as ×. If the coating appearance is ◯, the coating appearance is good.

<Smoothness>
A non-alkali glass substrate on which a 2.0 μm-thick cured film was formed was measured with a scanning probe microscope (AFM5100N, manufactured by Hitachi High-Tech Science Co., Ltd.) to measure the arithmetic mean roughness of the surface of the cured film. The arithmetic average roughness (Ra) was evaluated as ⊚ when 0.5 nm or less, ∘ when 0.5 to 1.5 nm, and x when over 1.5 nm. Arithmetic mean roughness (Ra) of 1.5 nm or less was accepted.

<Residual metal ionicity>
A non-alkali glass substrate having a cured film of 2.0 μm thick was irradiated with a UV cleaning device (model eye UV-ozone cleaning device, manufactured by Iwasaki Electric Co., Ltd.) so that the irradiation amount was 3,000 mJ/cm ² . , UV-ozone irradiation, and then immersed in a 0.05 wt % potassium hydroxide developer for 90 seconds. After that, the substrate was washed with pure water for 10 seconds and dried, and the residual potassium content of the dried substrate was measured with a fluorescent X-ray device (model ZSX100e, manufactured by Rigaku Corporation). Note that samples with a residual potassium content of 0.6% or less were considered acceptable.

<Chemical resistance>
A non-alkali glass substrate having a cured film of 2.0 μm thick was immersed in NMP at 25° C. for 30 minutes, and the thickness of the cured film was measured before and after the test to calculate the film thickness change rate. A film thickness change rate of 1.5% or less before and after the test was considered acceptable.

From the results in Tables 3 and 4, in Examples 1 to 9, the residual metal ionicity was excellent, and the smoothness and chemical resistance of the cured film were also good.
On the other hand, in Comparative Example 1, since the component (C) was not contained, the effects of improving residual metal ionicity and chemical resistance could not be obtained.
In Comparative Example 2, since component (D) was not contained, poor coating appearance and smoothness were obtained.
In Comparative Example 3, the content of component (A) was less than 20 parts by mass and the content of component (C) was greater than 50 parts by mass in the total of 100 parts by mass of components (A) to (D). , The mass ratio (C)/(D) of the component (C) and the component (D) was more than 9.0, resulting in poor coating appearance and smoothness.
In Comparative Example 4, the content of component (D) is more than 15 parts by mass in a total of 100 parts by mass of components (A) to (D), and the mass ratio of component (C) to component (D) (C )/(D) was less than 3.0, resulting in poor chemical resistance.
In Comparative Example 5, the content of component (A) is more than 80 parts by mass and the content of component (B) is less than 10 parts by mass in a total of 100 parts by mass of components (A) to (D). Therefore, the effect of improving residual metal ionicity and chemical resistance was not observed, and the smoothness was also poor.
In Comparative Example 6, since the content of component (B) is more than 50 parts by mass in the total of 100 parts by mass of components (A) to (D), the effect of improving residual metal ionicity and chemical resistance was not accepted.

Claims (2)

A thermosetting resin composition containing the following components (A) to (D),
In a total of 100 parts by mass of the components (A) to (D), 20 to 80 parts by mass of the component (A), 10 to 50 parts by mass of the component (B), and 1 to 50 parts by mass of the component (C) Parts by mass and component (D) are 1 to 15 parts by mass, and the mass ratio (C)/(D) of component (C) and component (D) is 3.0 to 9.0. A thermosetting resin composition.
Component (A): (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). Epoxy group-containing polymer containing 10 to 90 parts by weight of component (a1) and 90 to 10 parts by weight of component (a2) in 100 parts by weight of the total amount of component (a2): component (B) of the following formula (1): ) Polyvalent carboxylic acid hemiacetal ester represented by

(R ¹ in the formula represents an alkyl group having 1 to 6 carbon atoms.)
(C) component: an epoxy resin represented by the following formula (2)

(n in the formula represents 1 to 15.)
(D) Component: Bifunctional bisphenol A type epoxy resin A color filter having a protective film obtained by curing the thermosetting resin composition according to claim 1 .