JP6737027B2 - Photocurable resin composition and color filter having cured film thereof - Google Patents

Description

The present invention relates to a photocurable resin composition suitable for a color filter protective film used in a liquid crystal display device and the like, and a color filter having a protective film having excellent UV absorption obtained by curing the composition.

With the rapid spread of liquid crystal display devices (liquid crystal panels) in recent years, demand for high-quality color filters used in liquid crystal display devices is also increasing. The color filter comprises a transparent substrate, a black matrix layer formed in a predetermined pattern, a colored layer in which a plurality of colors (RGB pixels) such as red, green, and blue are arranged in a predetermined order, and a protective film. This is a structure, and has a role of creating an image color including an intermediate color and white by adding three colors of the basic light of red, green and blue to the light passing through the colored layer and additively mixing the lights. The protective film plays a role of physically and chemically protecting the color filter at the time of manufacturing or using the liquid crystal display device, and is required to have excellent moisture permeability and chemical resistance. Further, the protective film is required to have properties such as transparency and flatness so as not to adversely affect the color and display of the liquid crystal display device. Further, when it is desired to form a pattern on the protective film for the purpose of improving the adhesion to the liquid crystal panel, a protective film material having photosensitivity is required. In this case, high pattern resolution is required in addition to the above performance. Therefore, a negative resist having an alkali developability is widely applied to this type of protective film. The basic composition of this negative resist is based on (A) a copolymer having a carbon-carbon unsaturated bond, (B) a polyfunctional acrylic ester, (C) a polyfunctional epoxy resin, and (D) a photopolymerization initiator. The composition is added.

By the way, the color filter has a structure in which a plurality of materials are stacked in layers, and on the protective film,
Further, a photo spacer and an alignment film are formed. The photo spacers and the alignment film are applied onto the protective film in the state of the coating liquid, and at this time, the surface of the protective film is washed before application in order to improve the application 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 that is a light source during pre-coating cleaning of photo spacers and alignment films. .. At this time, the light of 254 nm has a higher intensity and is hard to be absorbed as compared with the light of 185 nm. Therefore, if the UV absorption of the protective film is insufficient, the light of 254 nm reaches the lower layer (RGB pixel) of the protective film. As a result, the RGB pixels may be deteriorated.

Further, in recent years, the thickness of RGB pixels has been reduced, and in order to maintain the conventional color development, the mixing ratio of pigments and dyes in the RGB pixels has increased, and the ratio of binder such as acrylic resin has decreased. Pigments and dyes tend to absorb UV and deteriorate more easily than binder components. Therefore, the RGB pixel itself has a composition that is more likely to deteriorate than in the past. Further, in recent years, as the alignment treatment method for the alignment film, photo-alignment by UV irradiation has begun to be adopted instead of the conventional rubbing method, and the load of UV irradiation is increasing in the manufacturing process. It is required to impart absorbency.

Therefore, it is possible to prevent deterioration of the RGB pixels by providing the protective film with high UV absorbency, and thus the protective film is required to have higher UV absorbency than ever. On the other hand, the transmittance in the visible light region is desired to be high as in the past in order to secure high image visibility. That is, a protective film having a high UV absorptivity at a short wavelength (254 nm) and a high transmittance in the visible light region is desired.

Against this background, the protective film has UV absorbability while maintaining various physical properties such as pattern resolution, flatness, transparency, chemical resistance, adhesion, and moisture permeability, which are conventionally required. Is required to do.

For example, in Patent Document 1, dicyclohexyl fumarate as the above-mentioned (A), 2-hydroxyethyl acrylate, a copolymer obtained by adding 2-acryloyl isocyanate to a polymer consisting of styrene, (B) dipentaerythritol hexaacrylate, ( A pattern using a composition using EP-1001 which is a bisphenol epoxy resin as C) and 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone-1 (Irgacure369) as (D). , A protective film having excellent properties such as transparency and chemical resistance has been reported. However, the applied epoxy resin (EP-1001) has a low film density and thus has insufficient moisture permeability. Further, styrene or EP-1001 contained in the copolymer cannot exhibit sufficient UV absorption.

In Patent Document 2, (A) a carboxylic acid-containing copolymer obtained by adding glycidyl methacrylate to a polymer composed of methacrylic acid, benzyl methacrylate, and tricyclo[5.2.1.0 ^2.6 ]decane-8-yl methacrylate. Polymer, (B) dipentaerythritol hexaacrylate, (C) 9,9-bis(6-glycidyloxynaphthalen-2-yl)fluorene (7.5), (D) 1,2-octanedione Report on a protective film having excellent physical properties such as pattern resolution, transparency, and moisture permeability with a composition using 1,1-[4-(phenylthio)phenyl-,2-(O-benzoyloxime)] (IrgacureOXE01) Has been done. However, the above-mentioned resin to which glycidyl methacrylate is added has a high Tg and a low fluidity, and thus has insufficient flatness.

JP 2007-137947 A JP, 2013-76821, A

As described above, it is not easy to develop a protective film having excellent UV absorption and flatness while maintaining various physical properties required for the protective film, and a protective film satisfying these properties has not been developed so far. ..

The object of the present invention is to have excellent UV absorption and flatness while maintaining the basic physical properties such as pattern resolution, transparency, chemical resistance, and adhesion that have been conventionally required. Another object of the present invention is to provide a photocurable resin composition capable of forming a color filter protective film, and a color filter comprising the protective film obtained by curing the same.

（Ｘは炭素数が２〜３のアルキレン基であり、ｎは０または１の整数である。） The present invention provides a photocurable resin composition for a color filter protective film containing the following component (A), component (B) polyfunctional acrylic ester, component (C) polyfunctional epoxy compound and component (D) photopolymerization initiator. And
Component (A) is 15 to 60 parts by weight, component (B) is 30 to 60 parts by weight, component (C) is 2 to 40 parts by weight, and component (D) is components (A) to (C) in total of 100. 0.1 to 5 parts by weight with respect to parts by weight,
Component (C) is a photocurable resin composition for a color filter protective film, wherein at least 2 parts by weight of its content is a naphthene group-containing fluorene type epoxy compound having a structure of the following formula (1).
Ingredient (A):
(A1) a monomer having a carbon-carbon unsaturated bond and a carboxyl group,
(A2) a monomer having a carbon-carbon unsaturated bond and a hydroxyl group, and (a3) a copolymer comprising a monomer having a carbon-carbon unsaturated bond other than (a1) and (a2),
(A4) an isocyanate compound having a carbon-carbon unsaturated bond,
Is a reaction product of
5 to 25% by weight of (a1), 10 to 40% by weight of (a2), 10 to 70% by weight of (a3) and 10 to 40% by weight of (a4), and a total of (a1) to (a4) Carboxyl group-containing copolymer whose amount is 100% by weight

(X is an alkylene group having 2 to 3 carbon atoms, and n is an integer of 0 or 1.)

（Ｒ_１は水素原子またはメチル基であり、Ｒ_２は炭素数が１〜８の直鎖アルキル基、炭素数３〜８の分岐アルキル基または炭素数６〜１０のシクロアルキル基である。）

（Ｒ_３およびＲ_４は、それぞれ独立して炭素数３〜８の分岐アルキル基または炭素数６〜１０のシクロアルキル基である。）

（Ｒ_５およびＲ_６は、それぞれ独立して水素原子またはメチル基である。）

（Ｒ_７は、炭素数１〜４の直鎖アルキル基、炭素数３〜８の分岐アルキル基または炭素数６〜１０のシクロアルキル基である。） The component (A) of the photocurable resin composition (a3) is preferably any one or more of the monomers represented by the following formulas (2) to (5).

(R ₁ is a hydrogen atom or a methyl group, and R ₂ is a linear alkyl group having 1 to 8 carbon atoms, a branched alkyl group having 3 to 8 carbon atoms or a cycloalkyl group having 6 to 10 carbon atoms.)

(R ₃ and R ₄ are each independently a branched alkyl group having 3 to 8 carbon atoms or a cycloalkyl group having 6 to 10 carbon atoms.)

(R ₅ and R ₆ are each independently a hydrogen atom or a methyl group.)

(R ₇ is a linear alkyl group having 1 to 4 carbon atoms, a branched alkyl group having 3 to 8 carbon atoms, or a cycloalkyl group having 6 to 10 carbon atoms.)

Further, a color filter having a protective film obtained by curing the photocurable resin composition can be provided.

Unless otherwise specified, the description of “○○ to ΔΔ” representing a numerical range in the present specification includes the upper limit and the lower limit thereof. That is, to be precise, it means “more than XX and less than ΔΔ”. In addition, the term “transparency” in the present specification means a property of high visible light transmittance, unless otherwise specified.

The photocurable resin composition for a color filter protective film of the present invention is excellent in UV absorption while maintaining the basic physical properties such as pattern resolution, transparency, moisture permeability, chemical resistance, and adhesion. In addition, a color filter protective film having good flatness can be formed. In particular, by containing a predetermined amount of the naphthyl group-containing fluorene-type epoxy compound represented by the above formula (1) as the component (C), high UV absorption is exhibited.

<< Photocurable resin composition for color filter protective film >>
The cured product of the photocurable resin composition of the present invention can be suitably used as a protective film for a color filter, and comprises a component (A) carboxyl group-containing copolymer and a component (B) polyfunctional acrylic ester. , A component (C) a polyfunctional epoxy compound and a component (D) a photopolymerization initiator.

<Component (A): carboxyl group-containing copolymer>
Component (A) is other than (a1) a monomer having a carbon-carbon unsaturated bond and a carboxyl group, (a2) a monomer having a carbon-carbon unsaturated bond and a hydroxyl group, and (a3) other than (a1) and (a2). It can be obtained by reacting (a4) an isocyanate compound having a carbon-carbon unsaturated bond with a copolymer obtained by polymerizing the monomer having a carbon-carbon unsaturated bond. In that case, the content of (a1) in the component (A) is 5 to 25% by weight, the content of (a2) is 10 to 40% by weight, the content of (a3) is 10 to 70% by weight, and (a4). Is 10 to 40% by weight and the total amount of (a1) to (a4) is 100% by weight, the pattern resolution, transparency, moisture permeability, chemical resistance, adhesiveness, etc. Good flatness can be obtained while maintaining good basic physical properties. In addition, (a1) to (a4) may be used alone or in combination of two or more kinds. The polymerization mode of the component (A) may be linear or branched. The branched polymerization mode means, for example, that methylene hydrogen of a polymer which has finished growing is radically generated on carbon when the radical derived from the polymerization initiator is abstracted, and the radical is a polymer in the growth process. This is the case of recombining with.

The polymerization method of (a1) to (a3) is not particularly limited, and a polymerization method such as radical polymerization or ionic polymerization can be used. More specifically, in the presence of a polymerization initiator, a polymerization method such as a bulk polymerization method, a solution polymerization method, a suspension polymerization method or an emulsion polymerization method can be used. Moreover, you may add additives, such as a catalyst and a solvent, to a polymerization reaction system as needed. (A4) can be added to the obtained copolymers (a1) to (a3) by a known reaction between a hydroxyl group and an isocyanate group. The weight average molecular weight (Mw) of the component (A) is preferably 3,000 to 100,000. When the weight average molecular weight (Mw) of the component (A) is less than 3,000, the film density is low, so that the chemical resistance tends to deteriorate, and when the weight average molecular weight (Mw) is more than 100,000, the developing solution is Since the solubility in water decreases, the pattern resolution tends to deteriorate.

When the component (A) is exposed through a photomask in the exposure step by photolithography due to the carbon-carbon unsaturated bond introduced by (a4), the exposed portion is exposed to UV irradiation from the component (D) photopolymerization initiator. A polymerization reaction proceeds from the generated radical as a starting point, and the radical can be insolubilized in a developing solution in a subsequent developing step. On the other hand, in the unexposed area, the polymerization reaction does not proceed, so the solubility in the developing solution does not change. That is, since the component (A) can exhibit a difference in solubility in a developing solution in a subsequent developing step by being exposed through a photomask, a pattern is formed on the cured film of the curable resin composition. Can be formed.

The component (A) is contained in an amount of 15 to 60 parts by weight based on 100 parts by weight of the total of the components (A) to (C), and preferably 30 to 50 parts by weight in terms of pattern resolution, residual film thickness after development and adhesion. Part included. When the content of the component (A) is less than 15 parts by weight, the polymerization reaction due to UV irradiation becomes insufficient and the pattern resolution decreases. When the content of the component (A) exceeds 60 parts by weight, the curing shrinkage due to the polymerization reaction by UV irradiation becomes large and the adhesion with the base is lowered. For this reason, water vapor easily enters from the interface between the cured film and the underlying layer, and the moisture permeability tends to deteriorate. The component (A) may be used alone or in combination of two or more.

<(a1): Monomer having carbon-carbon unsaturated bond and carboxyl group>
(A1) has only to have a carbon-carbon unsaturated bond and a carboxyl group, and any monomer known for such use can be used. (A1) is a component involved in the solubility in a developing solution in the developing step of the photocurable resin composition. Of these, acrylic acid and methacrylic acid are preferable from the viewpoint of pattern resolution.

(A1) is contained in an amount of 5 to 25% by weight in the total amount of 100% by weight of (a1) to (a4), and is preferably contained in an amount of 10 to 20% by weight from the viewpoint of pattern resolution and residual film development rate. When the content of (a1) is less than 5% by weight, the solubility in the developing solution becomes poor and the pattern resolution decreases. When the content of (a1) exceeds 25% by weight, the solubility in the developing solution becomes too high, and the residual film development rate decreases.

<(a2): Monomer having carbon-carbon unsaturated bond and hydroxyl group>
(A2) only needs to have a carbon-carbon unsaturated bond and a hydroxyl group, and any monomer known for such use can be used. (A2) is a component for introducing the carbon-carbon unsaturated bond of (a4) into the component (A) by reacting the hydroxyl group of itself with the isocyanate group of (a4). From the aspect of pattern resolution, (a2) is preferably hydroxyethyl acrylate, hydroxyethyl methacrylate and hydroxypropyl methacrylate.

(A2) is contained in an amount of 10 to 40% by weight based on 100% by weight of the total amount of (a1) to (a4), and preferably 20 to 40% by weight in terms of pattern resolution, residual film thickness after development and adhesion. included. If the content of (a2) is less than 10% by weight, the amount of (a4) introduced is insufficient, and the polymerization reaction due to UV irradiation becomes insufficient, resulting in poor pattern resolution. When the content of (a2) exceeds 40% by weight, the amount of (a4) introduced becomes excessive, and the curing shrinkage accompanied by the polymerization reaction by UV irradiation becomes large, so that the adhesion to the base is lowered.

（Ｒ_１は水素原子またはメチル基であり、Ｒ_２は炭素数が１〜８の直鎖アルキル基、炭素数３〜８の分岐アルキル基または炭素数６〜１０のシクロアルキル基である。）

（Ｒ_３およびＲ_４は、それぞれ独立して炭素数３〜８の分岐アルキル基または炭素数６〜１０のシクロアルキル基である。）

（Ｒ_５およびＲ_６は、それぞれ独立して水素原子またはメチル基である。）

（Ｒ_７は、炭素数１〜４の直鎖アルキル基、炭素数３〜８の分岐アルキル基又は炭素数６〜１０のシクロアルキル基である。）
（ａ３）は、（ａ１）〜（ａ４）の合計量１００重量％中に１０〜７０重量％含まれる。（ａ３）の含有量が１０重量％を下回ると、成分（Ａ）の親水性が高くなり過ぎるため現像残膜率が低下する。（ａ３）の含有量が７０重量％を上回ると、成分（Ａ）の疎水性が高くなり過ぎるためパターン解像性が悪化する傾向がある。 <(a3): Monomer having carbon-carbon unsaturated bond other than (a1) and (a2)>
(A3) may be a compound having a carbon-carbon unsaturated bond and not corresponding to (a1) and (a2), and any monomer known for such use can be used. As (a3), a monomer that can improve physical properties such as transparency, heat resistance, and hardness of a cured film of a photocurable resin composition is well known, and therefore may be appropriately selected according to the purpose. Monomers represented by the following formulas (2) to (5) are preferable.

(R ₁ is a hydrogen atom or a methyl group, and R ₂ is a linear alkyl group having 1 to 8 carbon atoms, a branched alkyl group having 3 to 8 carbon atoms or a cycloalkyl group having 6 to 10 carbon atoms.)

(R ₃ and R ₄ are each independently a branched alkyl group having 3 to 8 carbon atoms or a cycloalkyl group having 6 to 10 carbon atoms.)

(R ₅ and R ₆ are each independently a hydrogen atom or a methyl group.)

(R ₇ is a linear alkyl group having 1 to 4 carbon atoms, a branched alkyl group having 3 to 8 carbon atoms, or a cycloalkyl group having 6 to 10 carbon atoms.)
(A3) is contained in 10 to 70% by weight in the total amount of 100% by weight of (a1) to (a4). When the content of (a3) is less than 10% by weight, the hydrophilicity of the component (A) becomes too high and the residual film development rate decreases. When the content of (a3) exceeds 70% by weight, the hydrophobicity of the component (A) becomes too high, and thus the pattern resolution tends to deteriorate.

<(a4): Isocyanate compound having a carbon-carbon unsaturated bond>
(A4) only needs to have a carbon-carbon unsaturated bond and an isocyanate group, and any monomer known for such applications can be used. (A4) is a component for introducing a carbon-carbon unsaturated bond into the component (A) by reacting the isocyanate group which it has with the hydroxyl group of (a2), and 2-acryloyloxyethyl isocyanate (Karenzu AOI : Showa Denko KK) and 2-methacryloyloxyethyl isocyanate (Karenzu MOI: Showa Denko KK) are preferable from the viewpoint of pattern resolution.

Further, since (a4) lowers the Tg of the component (A), it has the action of increasing the fluidity of the component (A). At the same time, since the polarity of the component (A) is also increased, the affinity with the color filter hydrophilized by ozone treatment or the like is improved. By these, good flatness can be exhibited.

(A4) is contained in an amount of 10 to 40% by weight in the total amount of 100% by weight of (a1) to (a4), and preferably 20 to 40% by weight in terms of pattern resolution, residual film thickness after development and adhesion. Be done. When the content of (a4) is less than 10% by weight, the polymerization reaction due to UV irradiation becomes insufficient and the pattern resolution is deteriorated. When the content of (a4) exceeds 40% by weight, the curing shrinkage becomes too large in the curing reaction by UV irradiation, so that the adhesion to the base is lowered.

<Component (B): polyfunctional acrylic ester>
The component (B) may be a bifunctional or higher functional acrylic acid ester, and any compound known for such purposes can be used, and two or more kinds may be used in combination. Since the component (B) has a carbon-carbon unsaturated bond, it is necessary to form a pattern on the cured film of the photocurable resin composition by performing exposure and development through a photomask in the same manner as the component (A). You can When it is desired to enhance the pattern resolution when forming a pattern, pentaerythritol triacrylate (light acrylate PE-3A: manufactured by Kyoeisha Chemical Co., Ltd.), pentaerythritol tetraacrylate (light acrylate PE-4A: Kyoeisha chemical (stock) )) and dipentaerythritol hexaacrylate (light acrylate DPE-6A: manufactured by Kyoeisha Chemical Co., Ltd.) are preferable.

The component (B) is contained in an amount of 30 to 60 parts by weight in the total 100 parts by weight of the components (A) to (C), and preferably 35 to 50 parts by weight in terms of pattern resolution, residual film thickness after development and adhesion. Part included. When the content of the component (B) is less than 30 parts by weight, the polymerization reaction by UV irradiation becomes insufficient and the pattern resolution decreases. When the content of the component (B) exceeds 60 parts by weight, the curing shrinkage due to the polymerization reaction due to UV irradiation becomes large and the adhesion with the base is lowered.

（Ｘは炭素数が２〜３のアルキレン基であり、ｎは０または１の整数である。） <Component (C): polyfunctional epoxy compound>
As the component (C), (C1) a naphthyl group-containing fluorene type epoxy compound having a structure of the following formula (1) is essential, and (C2) other polyfunctional epoxy compounds may be optionally mixed. That is, (C) may be composed of (C1) alone or may be a mixture of (C1) and (C2).

(X is an alkylene group having 2 to 3 carbon atoms, and n is an integer of 0 or 1.)

The component (C) plays a role of improving the film strength by reacting with the carboxyl group contained in the component (A) during post-baking. (C1) is a component that exhibits UV absorption in addition to the role of improving the film strength of (C). On the other hand, (C2) may be a bifunctional or higher functional epoxy compound, and any known epoxy compound for such applications can be used. Among them, Tecmore VG3101L (Printech Co., Ltd.), jER157S70 (Mitsubishi Chemical Co., Ltd.), Celoxide 2021P (Daicel Corp.) and EHPE-3150 (Daicel Corp.) are preferable from the viewpoint of developability. Each of (C1) and (C2) may be used alone or in combination of two or more.

The content of the component (C) in the total 100 parts by weight of the components (A) to (C) is 2 to 40 parts by weight. When the content of the component (C) exceeds 40 parts by weight, the compatibility is deteriorated and the coating film is whitened, so that the transparency is lowered. Of the content of the component (C), the essential (C1) is at least 2 parts by weight. That is, (C1) is contained in an amount of 2 to 40 parts by weight in 100 parts by weight of the components (A) to (C) in total, and preferably 2 to 20 parts by weight in terms of transparency. If the content of (C1) is less than 2 parts by weight, sufficient UV absorption cannot be exhibited. On the other hand, the optional component (C2) can be added in an amount of 0 to 38 parts by weight in the total 100 parts by weight of the components (A) to (C).

<Component (D): Photopolymerization initiator>
The component (D) is a component that generates radicals by UV irradiation and serves as a starting point of a polymerization reaction of the components (A) and (B), and any photopolymerization initiator well known for such use should be used. You can When it is desired to use with a small exposure amount, 1,2-octanedione, 1-[4-(phenylthio)phenyl-,2-(O-benzoyloxime)] (OXE-01: manufactured by BASF), ethanone, 1- [9-Ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-,1-(0-acetyloxime) (OXE-02: (same)), 2-methyl-1-[4 -(Methylthio)phenyl]-2-morpholinopropan-1-one (Irgacure 907:(same)) and 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure 184:(same)) are preferred.

The component (D) is contained in an amount of 0.1 to 5 parts by weight based on 100 parts by weight of the components (A) to (C) in total. When the content of the component (D) is less than 0.1 part by weight, the polymerization reaction due to UV irradiation does not proceed and it becomes impossible to form a pattern well. When the content of the component (D) exceeds 5 parts by weight, the number of starting points of the polymerization reaction due to UV irradiation becomes too large, so that the polymerization reaction easily proceeds even in the unexposed area and the pattern resolution is deteriorated. In addition, the transparency deteriorates because the decomposition products due to UV irradiation increase.

<Additive>
If necessary, a leveling agent, a silane coupling agent, an antioxidant, a solvent and the like can be added to the photocurable resin composition of the present invention. Further, in a range that does not impair the curing of the present invention, a quenching agent, a carbon dioxide gas generation inhibitor, a flexibility imparting agent, an antioxidant, a plasticizer, a lubricant, a surface treatment agent, a flame retardant, an antistatic agent, an ion trap. Agents, slidability improvers, impact modifiers, thixotropic agents, surfactants, surface tension reducing agents, defoamers, anti-settling agents, light diffusing agents, ultraviolet absorbers, antioxidants, mold release agents Agents and fluorescent agents can also be added.

<Leveling agent>
The leveling agent is added for the purpose of improving the appearance of the resulting protective film, and a silicon-based agent, a fluorine-based agent, an acryl-based agent or the like can be used without particular limitation. The leveling agent may be used alone or in combination of two or more kinds.

<Silane coupling agent>
The silane coupling agent is a coupling agent that uses silane to bond an organic material and an inorganic material. Generally, a vinyl group, an epoxy group, an amino group, or the like is included as a functional group that reacts with an organic material. These silane coupling agents may be used alone or in combination of two or more.

<Antioxidant>
The antioxidants are IRGANOX1010 (BASF Japan Ltd.), IRGANOX1035 (same), IRGANOX1076 (same), IRGANOX1098 (same), IRGANOX1135 (same), IRGANOX1330 (same), IRGANOX1726 (same), IRGANOX1425WL (same), LGANOX15. Examples thereof include hindered phenolic antioxidants such as (same), IRGANOX245 (same), IRGANOX259 (same), IRGANOX3114 (same), IRGANOX5057 (same), IRGANOX565 (same), IRGANOX295 (same).

<Solvent>
The solvent is added for the purpose of adjusting the viscosity and the like when using the photocurable resin composition. Specific examples thereof include aromatic hydrocarbons, ethers, esters and ether esters, ketones, phosphoric acid esters, aprotic polar solvents, glycol derivatives and the like. These solvents may be used alone or in combination of two or more.

The method for mixing the photocurable resin composition is not particularly limited, and all components may be mixed at the same time, or each component may be sequentially dissolved. In addition, the order of introduction and the working conditions for mixing are not particularly limited.

<Formation of color filter protective film>
The color filter includes a layer obtained by curing the photocurable resin composition as a protective film, and the cured film preferably has a transmittance of 254 nm light of 0.05% or less. The photocurable resin composition is applied so as to cover the colored layer and the black matrix layer arranged on the substrate. The coating method is not particularly limited, and conventionally known coating methods such as a gravure coating method, a spin coating method, and a die coating method can be adopted. The obtained coating film is dried, and if necessary, preheating (prebaking) is performed, and then the coating film is subjected to pattern exposure through a predetermined photomask. Usually, the pre-bake temperature is 70 to 140° C., the time is about 1 to 5 minutes, and the exposure amount is usually about 10 to 300 mJ/cm ² . After the exposure, it is developed with an alkali developing solution to dissolve the coating film in the unexposed area. The light source used for the exposure is usually ultraviolet rays such as g-line, h-line and i-line, and the alkali developer is sodium hydroxide, potassium hydroxide, sodium carbonate, tetramethylammonium hydroxide or the like. As the developing method, a paddle developing method, an immersion developing method, a shower developing method, or the like is adopted. After the development, a main cured heating (post-baking) is performed to form a layer of the cured resin. Usually, the post-baking temperature is 180 to 280° C., and the time is 15 minutes to 2 hours. The heating method is not particularly limited, and for example, a hardening apparatus such as a closed hardening furnace or a tunnel furnace capable of continuous hardening can be adopted. The heating source is not particularly limited, and hot air circulation, infrared heating, high frequency heating or the like can be used.

Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited thereto.
<Synthesis of carboxyl group-containing copolymer (A-1)>
To a four-necked flask having a capacity of 300 mL equipped with a thermometer, a reflux condenser, a stirrer, and a dropping funnel, 75.2 parts by weight of diethylene glycol ethyl methyl ether (EDM) as a solvent was charged, and heated to 96° C. with stirring. Warmed. Then, at a temperature of 96° C., 5.0 parts by weight of acrylic acid (AA) as (a1), 19.5 parts by weight of hydroxyethyl methacrylate (HEMA) as (a2), and butyl acrylate (BA) as (a3). 25.7 parts by weight of 55.7 parts by weight, 6.0 parts by weight of a peroxide-based polymerization initiator (“Perhexyl O” manufactured by NOF CORPORATION), and 18.8 parts by weight of EDM (dripping component) were mixed in advance. It dripped at a constant speed from the dropping funnel over time. Then, the temperature of 96° C. was maintained for 3 hours, then the temperature was raised to 120° C., and the temperature of 120° C. was maintained for 2 hours. Then, the mixture was cooled to 80° C., 19.8 parts by weight of 2-acryloyloxyethyl isocyanate (AOI) and 0.04 parts by weight of methquinone (MQ) were added dropwise as (a4), and the temperature was maintained at 80° C. for 3 hours after the addition. did. As a result, a 50% EDM solution of the carboxyl group-containing copolymer (A-1) having a weight average molecular weight (Mw) of 16,000 was obtained.

表１中の略号は次の通りである。
ＡＡ：アクリル酸
ＭＡＡ：メタクリル酸
ＨＥＭＡ：ヒドロキシエチルメタクリレート
ＨＰＭＡ：ヒドロキシプロピルメタクリレート
ＨＢＡ：ヒドロキシブチルアクリレート
ＢＡ：ブチルアクリレート
ＭＭＡ：メチルメタクリレート
ＢＭＡ：ブチルメタクリレート
ＣＨＭＡ：シクロヘキシルメタクリレート
ＤｉＰＦ：ジイソプロピルフマレート
Ｓｔ：スチレン
ＣＨＭＩ：シクロヘキシルマレイミド
ＡＯＩ：２-アクリロイルオキシエチルイソシアネート
ＭＯＩ：２-メタクリロイルオキシエチルイソシアネート
パーヘキシルＯ：日油（株）製の過酸化物系重合開始剤
ＭＱ：メトキノン（重合禁止剤）
ＥＤＭ：ジエチレングリコールエチルメチルエーテル
ＰＧＭＥＡ：プロピレングリコールモノメチルエーテルアセテート <Synthesis of carboxyl group-containing copolymers (A-2 to A-10)>
Using the materials and conditions shown in Table 1 below, a solution of the carboxyl group-containing copolymer of A-2 to A-10 was obtained in the same manner as in the synthesis of A-1. In Table 1, the numerical values showing the composition (content of each component) are parts by weight.

The abbreviations in Table 1 are as follows.
AA: acrylic acid MAA: methacrylic acid HEMA: hydroxyethyl methacrylate HPMA: hydroxypropyl methacrylate HBA: hydroxybutyl acrylate BA: butyl acrylate MMA: methyl methacrylate BMA: butyl methacrylate CHMA: cyclohexyl methacrylate DiPF: diisopropyl fumarate St: styrene CHMI: cyclohexyl Maleimide AOI: 2-acryloyloxyethyl isocyanate MOI: 2-methacryloyloxyethyl isocyanate Perhexyl O: Peroxide type polymerization initiator manufactured by NOF CORPORATION MQ: Metoquinone (polymerization inhibitor)
EDM: diethylene glycol ethyl methyl ether PGMEA: propylene glycol monomethyl ether acetate

The weight average molecular weight (Mw) was measured using Tosoh Corp. gel permeation chromatography apparatus HLC-8220GPC, using Tosoh Corp. “TSKgel HZM-M” as a column, and THF as an eluent. It was measured by an RI detector and calculated in terms of polystyrene.

表１には記載されていない表２中の略号は次の通りである。
ＨＥＡ：ヒドロキシエチルアクリレート
ＢｅＭＡ：ベンジルメタクリレート
ＴＣＤＭＡ：トリシクロ[５.２.１.０^２．６]デカン−８−イルメタクリレート
ＤｃＨＦ：ジシクロヘキシルフマレート
ＧＭＡ：グリシジルメタクリレート
ＤＭＢＡ：ジメチルベンジルアミン <Synthesis of carboxyl group-containing copolymers (A'-1 to A'-6)>
Using the materials and conditions shown in Table 2 below, the carboxyl group-containing copolymers of the comparative polymers A'-1, A'-2 and A'-6 were prepared in the same manner as in the synthesis of A-1. A solution was obtained. A′-3 and A′-4 were the same as in the synthesis of A-1, except that dimethylbenzylamine was mixed and dropped when (a4)′ was charged using the materials and conditions shown in Table 2 below. A solution of the carboxyl group-containing copolymer was obtained. Similarly, A′-5 was a carboxyl group-containing copolymer by the same method as in the synthesis of A-1, except that pyridine was mixed and dropped when (a4)′ was charged using the materials and conditions shown in Table 2 below. A combined solution was obtained. In Table 2, the numerical value indicating the composition (content of each component) is parts by weight.

Abbreviations in Table 2 which are not described in Table 1 are as follows.
HEA: hydroxyethyl acrylate BeMA: benzyl methacrylate TCDMA: tricyclo[5.2.1.0 ^2.6 ] decan-8-yl methacrylate DcHF: dicyclohexyl fumarate GMA: glycidyl methacrylate DMBA: dimethylbenzylamine

<Examples 1 to 11, Comparative Examples 1 to 16>
The components were dissolved and mixed in the amounts shown in Tables 3 and 4 below to prepare coating solutions of the photocurable resin composition for a color filter protective film for Examples 1-11 and Comparative Examples 1-16. In Tables 3 and 4, the numerical value indicating the content of each component is parts by weight.

（Ｃ１−２）：

（Ｃ１−３）：

（Ｃ１−４）：大阪ガスケミカル(株)製ナフチル基含有フルオレン型エポキシ化合物、商品名「ＯＧＳＯＬ ＣＧ-５００」
［（Ｃ２）その他の多官能エポキシ化合物］
ＶＧ３１０１Ｌ：（株）プリンテック製エポキシ樹脂、商品名「テクモアＶＧ３１０１Ｌ」
Ｅｐ−１５７：三菱化学（株）製エポキシ樹脂、商品名「ｊＥＲ １５７Ｓ７０」
Ｃｅｌ２０２１Ｐ：ダイセル化学工業（株）製エポキシ樹脂、商品名「セロキサイド２０２１Ｐ」
ＥＨＰＥ-３１５０：ダイセル化学工業（株）製エポキシ樹脂、商品名「ＥＨＰＥ−３１５０」
Ｅｐ−８２８：三菱化学（株）製エポキシ樹脂、商品名「ｊＥＲ ８２８」
（Ｃ２−１）：

（Ｃ２−２）：

（Ｃ２−３）：

［（Ｄ）光重合開始剤］
ＯＸＥ−０１：１、２−オクタンジオン,１−［４−（フェニルチオ）フェニル−,２−（Ｏ−ベンゾイルオキシム）］（ＢＳＦジャパン（株）製）、商品名「ＩｒｇａｃｕｒｅＯＸＥ０１」
ＯＸＥ−０２：エタノン,１−[９−エチル−６−（２−メチルベンゾイル）−９Ｈ−カルバゾール−３イル]−,１−（０−アセチルオキシム）（同）、商品名「ＩｒｇａｃｕｒｅＯＸＥ０２」
［レベリング剤］
Ｆ−５５４：フッ素系レベリング剤（ＤＩＣ（株）製、商品名：「メガファック Ｆ−５５４」）
ＦＴＸ−２１８：フッ素系レベリング剤（（株）ネオス製、商品名：「ＦＴＸ−２１８」）
Ｆ−５５９：フッ素系レベリング剤（ＤＩＣ（株）製、商品名：「メガファック Ｆ−５５９」）
６０２Ａ：フッ素系レベリング剤（（株）ネオス製、商品名：「フタージェント ６０２Ａ」）
Ｆ−４７７：フッ素系レベリング剤（ＤＩＣ（株）製、商品名：「メガファック Ｆ−４７７」）
ＢＹＫ−３０７：シリコーン系レベリング剤（ビックケミー・ジャパン（株）製、商品名：「ＢＹＫ−３０７」）
［シランカップリング剤］
ＯＦＳ−６０４０：３−グリシドキシプロピルトリメトキシシラン（東レ・ダウコーニング（株）製、商品名：「ＯＦＳ−６０４０」）
Ｘ−４１−１０５９Ａ：シラン化合物（信越化学（株）製、商品名：「Ｘ−４１−１０５９Ａ」）
Ｘ−４１−１０５３：シラン化合物（信越化学（株）製、商品名：「Ｘ−４１−１０５３」）
［その他添加剤］
ＴＩＮＵＶＩＮ：ヒドロキシフェニルトリアジン系紫外線吸収剤（ＢＡＳＦ製、商品名：「ＴＩＮＵＶＩＮ４００」）
［溶剤］
ＰＧＭＥＡ：プロピレングリコールモノメチルエーテルアセテート
ＭＭＢＡ：３−メトキシ−３−メチル−１−ブチルアセテート
ＥＤＭ：ジエチレングリコールエチルメチルエーテル
ＥＥＰ：エチルエトキシプロピオネート The abbreviations in Tables 3 and 4 and the structures of the compounds are as follows.
[(B) Polyfunctional acrylic ester]
PE-4A: Pentaerythritol tetraacrylate DPE-6A: Dipentaerythritol hexaacrylate [(C1) Naphthyl group-containing fluorene type epoxy compound]
(C1-1):

(C1-2):

(C1-3):

(C1-4): naphthene group-containing fluorene type epoxy compound manufactured by Osaka Gas Chemicals Co., Ltd., trade name "OGSOL CG-500"
[(C2) Other polyfunctional epoxy compound]
VG3101L: Epoxy resin manufactured by Printec Co., Ltd., trade name "Techmore VG3101L"
Ep-157: Epoxy resin manufactured by Mitsubishi Chemical Corporation, trade name "jER 157S70"
Cel2021P: Epoxy resin manufactured by Daicel Chemical Industries, Ltd., trade name "Celoxide 2021P"
EHPE-3150: Epoxy resin manufactured by Daicel Chemical Industries, Ltd., trade name "EHPE-3150"
Ep-828: Epoxy resin manufactured by Mitsubishi Chemical Corporation, trade name "jER 828"
(C2-1):

(C2-2):

(C2-3):

[(D) Photopolymerization Initiator]
OXE-01:1,2-octanedione, 1-[4-(phenylthio)phenyl-,2-(O-benzoyloxime)] (manufactured by BSF Japan Ltd.), trade name "Irgacure OXE01".
OXE-02: Ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3yl]-,1-(0-acetyloxime) (the same), trade name "Irgacure OXE02"
[Leveling agent]
F-554: Fluorine-based leveling agent (manufactured by DIC Corporation, trade name: "Megafuck F-554")
FTX-218: Fluorine-based leveling agent (manufactured by Neos, trade name: "FTX-218")
F-559: Fluorine-based leveling agent (manufactured by DIC Corporation, trade name: "Megafuck F-559")
602A: Fluorine-based leveling agent (manufactured by Neos Co., Ltd., trade name: “Futagent 602A”)
F-477: Fluorine-based leveling agent (manufactured by DIC Corporation, trade name: "Megafuck F-477")
BYK-307: Silicone-based leveling agent (manufactured by Big Chemie Japan KK, trade name: "BYK-307")
[Silane coupling agent]
OFS-6040: 3-glycidoxypropyltrimethoxysilane (manufactured by Toray Dow Corning Co., Ltd., trade name: "OFS-6040")
X-41-1059A: Silane compound (Shin-Etsu Chemical Co., Ltd., trade name: "X-41-1059A")
X-41-1053: Silane compound (Shin-Etsu Chemical Co., Ltd., trade name: "X-41-1053")
[Other additives]
TINUVIN: Hydroxyphenyltriazine-based UV absorber (manufactured by BASF, trade name: "TINUVIN400")
[solvent]
PGMEA: Propylene glycol monomethyl ether acetate MMBA: 3-Methoxy-3-methyl-1-butyl acetate EDM: Diethylene glycol ethyl methyl ether EEP: Ethyl ethoxy propionate

The obtained coating liquid of the photocurable resin composition for a color filter protective film for Examples 1 to 11 and Comparative Examples 1 to 16 was filtered with a membrane filter (material: PE, pore size: 0.2 μm). After that, it was further filtered through a hollow filter (material: PP, pore size: 0.02 μm). The filtered coating liquid was spin-coated on a 10 cm square quartz glass or non-alkali glass substrate by a spin coater (model 1H-DX-2, manufactured by Mikasa Co., Ltd.). After coating, the substrate was dried in a clean oven at 90° C. for 2 minutes to obtain a thin film (A). This thin film (A) was tested by Canon Inc. g+h+i line mask aligner (PLA-501F) with various line widths and contact hole test patterns with line and space widths of 1:1 to 40 mJ in i-line illuminance conversion. /Cm ² exposure and development with 0.4 wt% tetrahydroxyammonium hydroxide at 23° C. for 60 seconds to form a thin film (B) having line and space patterns and contact hole patterns with a line and space width of 1:1 (B ) Got. The thin film (B) was heated in a clean oven at 230° C. for 30 minutes to obtain a cured film having a film thickness of 1.5 μm. Using the thin film (A), thin film (B) and cured film, pattern resolution, residual film ratio after development, flatness, UV absorption, transparency, chemical resistance, moisture permeability, and adhesion are evaluated below. I went with the method. The results are also shown in Tables 3 and 4.

<Pattern resolution>
A 10 μm hole pattern was observed with a SEM (scanning electron microscope) in the cured film formed by the above procedure. The case where no residue was observed inside and inside the contact hole was evaluated as ◎, the case where residue was observed only at the end of the contact hole was evaluated as ○, and the case where residue was observed both inside and inside the contact hole was evaluated as ×. ..

<Development residual film rate>
From the film thicknesses of the thin film (A) and the thin film (B) obtained by the above procedure, the residual film development ratio was calculated by the following formula.
Development residual film rate (%)=thin film (B) film thickness/thin film (A) film thickness×100
The residual film development rate was evaluated by the value calculated by the above formula. Tables 3 and 4 show the residual film development rate (%). A film with a residual film development rate of 95% or more is evaluated as ⊚, a film with a residual film rate of 90% or more and less than 95% is evaluated as ◯, and a film having a residual film ratio of less than 90% is evaluated as x.

<Flatness>
In the dummy color filter for flatness evaluation, the difference in height between the central portions of red and green pixels, the difference in height between the central portions of red and blue pixels, and the difference in height between the central portions of green and blue pixels ( The step difference between pixels) was obtained. Subsequently, according to the above-described cured film forming method except that the test pattern is not used, a pattern-less cured film (protective film) having a film thickness of 1.5±0.05 μm is formed on the dummy color filter, and then the same portion is formed. The difference in height between the central portions of the red pixels and the green pixels, the difference in height between the central portions of the red pixels and the blue pixels, and the difference in height between the central portions of the green pixels and the blue pixels were obtained. These steps were measured with a stylus type surface roughness meter (model EK4000AK, manufactured by Kosaka Laboratory Ltd.). Among the steps between pixels before applying the protective film, the maximum value is the maximum step between pixels (d1) before applying, and the maximum value among the steps between pixels after applying the protective film is the maximum step between pixels (d2) after applying, From these d1 and d2, the flattening rate X due to the protective film was obtained by the following calculation formula.
Flattening rate X(%)=((d1)−(d2))/(d1)×100
The flatness was evaluated by the value of the flattening rate calculated by the above formula, and Tables 3 and 4 show the values of the flattening rate X (%). The flattening rate X (%) of 90% or more is evaluated as ◯, and the flattening rate of less than 90% is evaluated as x.

<UV absorption>
A cured film having no pattern was obtained on a quartz glass substrate according to the above-described cured film forming method except that the test pattern was not used. This cured film-coated substrate was scanned with a UV-visible spectrophotometer (model UV-3700, manufactured by Shimadzu Corporation) to a wavelength of 200 nm to 800 nm, and the light transmittance was measured. The UV absorptivity was evaluated by the transmittance value at 254 nm, and the transmittance (%) is shown in Tables 3 and 4. For the purpose of the present invention, a transmittance of 254 nm of 0.05% or less is required.

<Transparency>
A cured film having no pattern was obtained on the alkali-free glass substrate according to the above-described cured film forming method except that the test pattern was not used. The obtained substrate was further overbaked at 230° C. for 60 minutes, and the substrate with the cured film was scanned using an ultraviolet-visible light spectrophotometer (model UV-3700, manufactured by Shimadzu Corporation) to a wavelength of 200 nm to 800 nm. Then, the light transmittance was measured. The transparency was evaluated by the value of the average transmittance of 380 nm to 580 nm, and Table 3 and Table 4 show the values of the average transmittance (%). The average transmittance of 380 nm to 580 nm of 98% or more is evaluated as ⊚, 95% or more and less than 98% is evaluated as ◯, and less than 95% is evaluated as x.

<Chemical resistance>
A glass substrate with a cured film obtained by the same procedure as the UV absorption and transparency test was immersed in N-methylpyrrolidone at 25° C. for 30 minutes, and the change in film thickness before and after immersion was 5% or less. Those exceeding 5% were evaluated as x.

<Moisture permeability>
A glass substrate covered with a polyimide film (Kapton 100H: manufactured by Toray DuPont Co., Ltd.) was used, and a cured film having no pattern was obtained on the polyimide film according to the above-mentioned cured film forming method except that the test pattern was not used. After removing the glass substrate, the moisture permeability was measured by using a polyimide film with a cured film by a method based on the cup method described in JIS K8123. The temperature and relative humidity were 40° C. and 90%. The moisture permeability was evaluated by the value of moisture permeability, and Tables 3 and 4 show the values of moisture permeability (g/m ² ·24h). In addition, the water vapor permeability of 65 g/m ² ·24 h or less is evaluated as ◯, and the water vapor permeability of more than 65 g/m ² ·24 h is evaluated as x.

<Adhesion>
The cured film-coated substrate obtained by the same procedure as the UV absorption and transparency test was passed through the pressure cooker test (PCT), and then JIS K 5600-5-6:1999 General paint test method-Part 5: Coating Mechanical Properties of Film-Section 6: Adhesion was evaluated by a method based on the adhesiveness (cross-cut method). The conditions of PCT were 120° C., humidity 100%, pressure 2 atm, and test time 6 hours. If the edges of the cut are completely smooth and do not peel off in any grid, ◎, if small peeling of the coating film is seen at the intersection of the cuts, ○, the coating film is partially or along the edges of the cut. When peeling was observed on the whole, it was evaluated as x.

From the results of Table 3, in Examples 1 to 11, the components (A) to (D) were contained in appropriate amounts, and the component (C) contained a predetermined amount of (C1) having a specific structure. Excellent UV absorption was obtained while maintaining the pattern resolution, residual film ratio after development, flatness, transparency, chemical resistance, moisture permeability and adhesion.

On the other hand, from the results in Table 4, in Comparative Example 1, the pattern resolution and the chemical resistance deteriorated because the contents of (a2) and (a4) in the component (A) were too small. In Comparative Example 2, the content of (a1) in the component (A) was too small, so the pattern resolution was deteriorated. Further, since the contents of (a2) and (a4) in the component (A) were excessive, the adhesiveness was deteriorated. In Comparative Example 3, since the content of the component (A) was too small, the pattern resolution and the residual film development rate were deteriorated. In Comparative Example 4, the moisture permeability and the adhesion were deteriorated because the content of the component (A) was excessive. In Comparative Examples 5 to 7, since the component (A) did not contain (a4), the flatness was deteriorated. Further, the deterioration of transparency seen in Comparative Examples 5 to 7 is due to the influence of DMBA used in synthesizing A'-3 and A'-4 and pyridine used in synthesizing A'-5. is there. In Comparative Examples 8 to 13, since the component (C) did not contain the (C1) naphthyl group-containing fluorene type epoxy, the UV absorption was deteriorated. Further, from the results of Comparative Example 13, even if a general ultraviolet absorber is used in an amount usually used in place of the (C1) naphthyl group-containing fluorene type epoxy, the UV absorptivity targeted by the present invention cannot be exhibited. It was confirmed. In Comparative Example 14, the UV absorption was deteriorated because the content of the (C1) naphthyl group-containing fluorene type epoxy was too small. In Comparative Examples 15 and 16, the content of the component (C), that is, the total amount of (C1) and (C2) was excessive, so that the compatibility was poor and the flatness and transparency were poor.

Claims (3)

A photocurable resin composition for a color filter protective film, comprising the following component (A), component (B) polyfunctional acrylic ester, component (C) polyfunctional epoxy compound and component (D) photopolymerization initiator,
Component (A) is 15 to 60 parts by weight, component (B) is 30 to 60 parts by weight, component (C) is 2 to 40 parts by weight, and component (D) is components (A) to (C) in total of 100. 0.1 to 5 parts by weight with respect to parts by weight,
The component (C) is a photocurable resin composition for a color filter protective film, of which at least 2 parts by weight is a naphthene group-containing fluorene type epoxy compound having a structure of the following formula (1).
Ingredient (A):
(A1) a monomer having a carbon-carbon unsaturated bond and a carboxyl group,
(A2) a monomer having a carbon-carbon unsaturated bond and a hydroxyl group, and (a3) a copolymer comprising a monomer having a carbon-carbon unsaturated bond other than (a1) and (a2),
(A4) an isocyanate compound having a carbon-carbon unsaturated bond,
Is a reaction product of
5 to 25% by weight of (a1), 10 to 40% by weight of (a2), 10 to 70% by weight of (a3) and 10 to 40% by weight of (a4), and a total of (a1) to (a4) Carboxyl group-containing copolymer whose amount is 100% by weight

(X is an alkylene group having 2 to 3 carbon atoms, and n is an integer of 0 or 1.) The photocurable resin composition for a color filter protective film according to claim 1, wherein (a3) is any one or more of the monomers represented by the following formulas (2) to (5).

(R ₁ is a hydrogen atom or a methyl group, and R ₂ is a linear alkyl group having 1 to 8 carbon atoms, a branched alkyl group having 3 to 8 carbon atoms or a cycloalkyl group having 6 to 10 carbon atoms.)

(R ₃ and R ₄ are each independently a branched alkyl group having 3 to 8 carbon atoms or a cycloalkyl group having 6 to 10 carbon atoms.)

(R ₅ and R ₆ are each independently a hydrogen atom or a methyl group.)

(R ₇ is a linear alkyl group having 1 to 4 carbon atoms, a branched alkyl group having 3 to 8 carbon atoms, or a cycloalkyl group having 6 to 10 carbon atoms.) A color filter having a protective film obtained by curing the photocurable resin composition for a protective film for a color filter according to claim 1 or 2.