JP2010120977A - Curable resin composition for forming protection film, protection film and method for forming protection film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a curable resin composition which can form cured films high in flatness even on substrates having unevenness formed with color filters, gives cured films having high transparency and surface hardness and excellent in various resistances such as heat resistance, pressure resistance, acid resistance, and alkali resistance, gives resin composition solutions excellent in storage stability, and can form protection films for liquid crystal display elements. <P>SOLUTION: This curable resin composition for forming the protection films includes (A) a copolymer, (B) a multi-functional S compound, and (C) a curing agent. Therein, (A) the copolymer includes a copolymer produced through a process for polymerizing a polymerizable unsaturated compound including an epoxy group-containing unsaturated compound in the presence of a compound represented by formula (1): Z<SP>1</SP>S-CS-S-S-CS-SZ<SP>2</SP>(wherein, Z<SP>1</SP>and Z<SP>2</SP>are each mutually independently a 4-18C alkyl or a benzyl group which may be substituted). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a curable resin composition for forming a protective film, a method for forming a protective film from the composition, and a protective film. More specifically, a composition suitable as a material for forming a protective film used in a color filter for a liquid crystal display element (LCD) and a color filter for a charge coupled device (CCD), and formation of a protective film using the composition The present invention relates to a method and a protective film formed from the composition.

  Devices such as LCDs and CCDs are immersed in a solvent, acid or alkali solution during the manufacturing process, and when the wiring electrode layer is formed by sputtering, the surface of the device is locally heated. Be exposed. Therefore, in order to prevent the element from being deteriorated or damaged by such treatment, a protective film made of a thin film having resistance to these treatments is provided on the surface of the element.

  Such a protective film has high adhesion to the substrate or lower layer on which the protective film is to be formed, and further to the layer formed on the protective film, the film itself is smooth and tough, transparent Have good heat resistance, high heat resistance, no deterioration such as coloring, yellowing, and whitening over a long period of time, excellent water resistance, solvent resistance, and alkali resistance The performance such as being is required. As a material for forming a protective film satisfying these various properties, for example, a resin composition containing a polymer having a glycidyl group is known (see Patent Document 1 and Patent Document 2).

  In addition, when such a protective film is used as a protective film for a color liquid crystal display device or a color filter of a charge coupled device, it is generally required that the step formed by the color filter formed on the base substrate can be flattened. The

  Further, in a color liquid crystal display device, for example, a STN (Super Twisted Nematic) type or TFT (Thin Film Transistor) type color liquid crystal display element, a bead-like spacer is provided on the protective film in order to uniformly maintain the cell gap of the liquid crystal layer. The panels are pasted together after spraying. After that, the liquid crystal cell is sealed by thermocompression bonding with a sealing material, but the heat and pressure applied at that time show a phenomenon that the protective film in the part where the beads exist is recessed, and the cell gap may be distorted. It is a problem.

In particular, in recent years, in order to improve the brightness of the panel, an opening other than red (R), green (G), and boule (B) is provided in the pixel of the color filter, and this opening is formed as a resin composition for forming a protective film. Flattening with an object is performed. In this case, since the width of the opening is wide, the protective film is required to have a very high level flattening performance.
For the formation of such a protective film, it is convenient to use a resin composition capable of forming a protective film having excellent hardness by a simple method. However, there is a problem that the shelf life of the composition itself is very short because it has a reactive crosslinking group or catalyst in order to form strong crosslinking. When the shelf life of the composition is short, not only the application performance of the composition deteriorates with time, but also frequent maintenance and cleaning of the coating machine are required.

  A material that satisfies general performance requirements for a protective film such as transparency and that can easily form a protective film that satisfies the above-mentioned various performances and that has excellent storage stability as a composition is still known. Absent.

  Patent Document 3 discloses a resin composition containing a latent carboxyl compound that is used in paints, inks, adhesives, and molded articles, but does not disclose any color filter protective film.

  On the other hand, Patent Documents 4 and 5 disclose polymers polymerized using a disulfide compound such as tetraethylthiuram disulfide or bis (pyrazol-1-yl-thiocarbonyl) disulfide as a molecular weight control agent. However, these disulfide compounds have a problem that they are very difficult to handle because they tend to change with time due to decomposition during storage after synthesis.

JP-A-5-78453 JP 2001-91732 A JP-A-4-218561 International Publication No. 07/029871 Pamphlet JP 2007-126647 A

The present invention has been made based on the circumstances as described above, and the object thereof is to form a cured film having high flatness on the substrate even if the substrate has irregularities formed by color filters. In addition, it is suitably used for forming a protective film for liquid crystal display elements having high transparency and surface hardness, excellent heat resistance and pressure resistance, and alkali resistance, and at the time of forming the protective film. An object of the present invention is to provide a composition having a small amount of generated sublimates and excellent storage stability as a composition, a method for forming a protective film using the composition, and a protective film formed from the composition.
Still other objects and advantages of the present invention will become apparent from the following description.

  The above objects and advantages of the present invention are, firstly, a curable resin composition containing (A) a copolymer, (B) a polyfunctional compound and (C) a curing agent, wherein (A) The coalescence contains a copolymer produced through a step of polymerizing a polymerizable unsaturated compound containing an epoxy group-containing unsaturated compound in the presence of a compound represented by the following formula (1). This is achieved by a protective film-forming curable resin composition (hereinafter referred to as “resin composition”).

In [Equation ^(1), Z 1 and Z ² is an alkyl group or an optionally substituted benzyl group having 4 to 18 carbon atoms independently of one another. ]
Secondly, the above objects and advantages of the present invention are achieved by a resin composition characterized in that the component (A) is a copolymer produced through a step of living radical polymerization.

  Thirdly, the above objects and advantages of the present invention are that the component (A) has a polystyrene-reduced weight average molecular weight (Mw) measured by gel permeation chromatography (GPC) of 1,000 to 50,000, and Mw And a ratio (Mw / Mn) of polystyrene equivalent number average molecular weight (Mn) measured by gel permeation chromatography (GPC) is 1.8 or less. .

  Fourth, the above objects and advantages of the present invention are achieved by a resin composition further containing (D) a heat-sensitive radiation acid generator.

  Fifth, the above objects and advantages of the present invention are solved by a method for forming a protective film in which a film is formed using the resin composition, and then a radiation treatment and / or a heat treatment is performed.

  According to the present invention, a cured film having high flatness can be formed on a substrate having irregularities formed on the color filter, and the transparency and surface hardness are high, and the heat resistance is high. It is suitably used for forming a protective film for liquid crystal display elements excellent in various resistances such as pressure resistance, acid resistance, and alkali resistance, and the amount of sublimates generated during the formation of the protective film is small, and as a composition A resin composition having excellent storage stability, a method for forming a protective film using the resin composition, and a protective film formed from the composition are provided.

Hereinafter, each component of the resin composition of this invention is demonstrated.
(A) Copolymer The copolymer of the present invention comprises a polymerizable unsaturated compound containing an epoxy group-containing unsaturated compound (hereinafter referred to as “compound (a1)”) represented by the formula (1) (hereinafter referred to as “molecular weight”). A copolymer (hereinafter referred to as “copolymer (A)”) produced through a step of polymerizing in the presence of a compound represented by the formula:
Examples of the compound (a1) include glycidyl (meth) acrylate, glycidyl α-ethyl acrylate, glycidyl α-n-propyl acrylate, glycidyl α-n-butyl acrylate, (meth) acrylic acid 3,4- Epoxy butyl, 3,4-epoxy butyl α-ethyl acrylate, 6,7-epoxy heptyl (meth) acrylate, 6,7-epoxy heptyl α-ethyl acrylate, p-vinylbenzyl glycidyl ether, 3-methyl- 3- (meth) acryloylmethyloxetane, 3-ethyl-3- (meth) acryloylmethyloxetane, etc. can be mentioned.
Among these compounds (a1), glycidyl methacrylate, methacrylic acid-6,7-epoxyheptyl, p-vinylbenzyl glycidyl ether, 3-methyl-3- (meth) acryloxymethyloxetane, 3-ethyl-3- (Meth) acryloylmethyloxetane is preferably used from the viewpoint of increasing the copolymerization reactivity, the heat resistance of the resulting protective film, and the surface hardness.

The content of the repeating unit derived from the compound (a1) is preferably 10 to 90% by weight, particularly preferably 20 to 80% by weight.
When the content of the repeating unit derived from the compound (a1) is 10 to 90% by weight, the heat resistance, surface hardness and chemical resistance of the protective film are excellent.
As the copolymer (A), other than the compound (a1), an unsaturated compound having other radical polymerizability (hereinafter referred to as compound (a2)) can be used.
Examples of the compound (a2) include unsaturated carboxylic acid, unsaturated polyvalent carboxylic acid anhydride, (meth) acrylic acid linear alkyl ester, (meth) acrylic acid branched alkyl ester, (meth) acrylic acid Alicyclic alkyl ester, (meth) acrylic acid ester having hydroxyl group, (meth) acrylic acid aryl ester, unsaturated dicarboxylic acid diester, bicyclounsaturated compound, maleimide compound, vinyl aromatic compound, conjugated diene, acetal of carboxylic acid And (meth) acrylic acid ester compounds having a 1-alkylcycloalkyl ester structure of a carboxylic acid.
Specific examples of the unsaturated carboxylic acid include (meth) acrylic acid, crotonic acid, α-ethylacrylic acid, α-n-propylacrylic acid, α-n-butylacrylic acid, maleic acid, fumaric acid, citraconic acid and the like. Can be mentioned.
Examples of the unsaturated polycarboxylic acid anhydride include maleic anhydride, itaconic anhydride, citraconic anhydride, cis-1,2,3,4-tetrahydrophthalic anhydride and the like.
As these unsaturated carboxylic acid or unsaturated polyvalent carboxylic acid anhydride, acrylic acid, methacrylic acid, and maleic anhydride are particularly preferable.

Furthermore, specific examples of the compound (a2) include (meth) acrylic acid hydroxyalkyl esters such as (meth) acrylic acid 2-hydroxyethyl and (meth) acrylic acid 2-hydroxypropyl;
Methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, sec-butyl (meth) acrylate, t-butyl (meth) acrylate Such (meth) acrylic acid alkyl esters;
(Meth) acrylic acid cyclopentyl, (meth) acrylic acid cyclohexyl, (meth) acrylic acid 2-methylcyclohexyl, (meth) acrylic acid tricyclo [5.2.1.0 ^2,6 ] decan-8-yl (hereinafter, Tricyclo [5.2.1.0 ^2,6 ] decan-8-yl is referred to as “dicyclopentanyl”), 2-dicyclopentanyloxyethyl (meth) acrylate, and isobornyl (meth) acrylate. Such (meth) acrylic acid alicyclic ester;
(Meth) acrylic acid aryl esters such as (meth) acrylic acid benzyl;
Unsaturated dicarboxylic acid diesters such as diethyl maleate and diethyl fumarate;
Unsaturated dicarbonylimide derivatives such as N-phenylmaleimide, N-benzylmaleimide, N-cyclohexylmaleimide, N-succinimidyl-3-maleimidobenzoate, N-succinimidyl-4-maleimidobutyrate;
Aromatic vinyl compounds such as styrene, α-methylstyrene, p-methylstyrene, vinyltoluene, p-methoxystyrene;
Examples thereof include conjugated diene compounds such as 1,3-butadiene.
Further, specific examples of the (meth) acrylic acid ester compound having an acetal, ketal or 1-alkylcycloalkyl ester structure of carboxylic acid include, for example, 1-ethoxyethyl (meth) acrylate, tetrahydro-2H-pyran-2- Yl (meth) acrylate, 1- (cyclohexyloxy) ethyl (meth) acrylate, 1- (2-methylpropoxy) ethyl (meth) acrylate, 1- (1,1-dimethyl-ethoxy) ethyl (meth) acrylate, 1 -(Cyclohexyloxy) ethyl (meth) acrylate, 1-methylcyclopropyl (meth) acrylate, 1-methylcyclobutyl (meth) acrylate, 1-methylcyclopentyl (meth) acrylate, 1-methylcyclohexyl (meth) acrylate, 1 -Mechi Cycloheptyl (meth) acrylate, 1-ethylcyclopropyl (meth) acrylate, 1-ethylcyclobutyl (meth) acrylate, 1-ethylcyclopentyl (meth) acrylate, 1-ethylcyclohexyl (meth) acrylate, 1-ethylcyclooctyl A (meth) acrylate etc. can be mentioned.

  Among these, as the compound (a2), (meth) acrylic acid hydroxyalkyl ester, methyl methacrylate, t-butyl methacrylate, cyclohexyl acrylate, dicyclopentanyl methacrylate, 2-methylcyclohexyl acrylate, N- Phenylmaleimide, N-cyclohexylmaleimide, styrene, p-methoxystyrene, 1-ethoxyethyl methacrylate, tetrahydro-2H-pyran-2-yl methacrylate, 1- (cyclohexyloxy) ethyl methacrylate, 1- (2-methylpropoxy) ethyl Methacrylate, 1- (1,1-dimethyl-ethoxy) ethyl methacrylate, 1- (cyclohexyloxy) ethyl methacrylate, 1-ethylcyclopentyl (meth) acrylate, 1-ethylcyclohexyl Le (meth) preferably used acrylate.

  These preferred compounds (a2) have high copolymerization reactivity and are effective in increasing the heat resistance and surface hardness of the protective film obtained.

The said compound (a2) can be used individually or in mixture of 2 or more types.
The copolymer (A) may contain a structural unit derived from the compound (a2), preferably 5 to 90% by weight, particularly preferably 10 to 80% by weight. The amount of the structural unit is 5 to 90% by weight, and the heat resistance and surface hardness of the protective film and the storage stability of the composition are excellent.

Next, the polymerization method for producing the copolymer (A) will be described.
The polymerization can be carried out, for example, by polymerizing the polymerizable unsaturated compound constituting the copolymer (A) in a solvent in the presence of a molecular weight controller using a radical polymerization initiator. Thus, a copolymer (A) having a controlled molecular weight and molecular weight distribution can be obtained.

  The molecular weight controlling agent used in the present invention has a bis (alkyl mercapto-thiocarbonyl) disulfide or bis (benzyl mercapto-thiocarbonyl) disulfide structure, and the copolymer produced using this molecular weight controlling agent is It is effective to develop good flatness. In addition, the molecular weight control agent used in the present invention is stable over time, can synthesize the copolymer (A) stably, and as a result, can improve the quality of the resin composition.

In the formula (1) showing a molecular weight control agent, examples of the alkyl group having 4 to 18 carbon atoms of Z ¹ and Z ² include an n-butyl group, a t-butyl group, an n-heptyl group, an n-hexyl group, Examples include n-pentyl group, n-octyl group, n-nonyl group, n-decyl group, n-dodecyl group, t-dodecyl group, n-tetradecyl group, n-hexadecyl group, n-octadecyl group and the like. . Among these alkyl groups, n-hexyl group, n-pentyl group, n-octyl group, n-decyl group, n-dodecyl group and the like are preferable, and in particular, n-octyl group, n-decyl group and n-dodecyl group. Etc. are preferred.
In Z ¹ and Z ² , examples of the benzyl group and the optionally substituted benzyl group include o-chlorobenzyl group, p-chlorobenzyl group, o-cyanobenzyl group, p-cyanobenzyl group, o- A methoxybenzyl group, p-methoxybenzyl group, etc. can be mentioned. Of these substitutions, a benzyl group is particularly preferred.
In the polymerization, the molecular weight control agents can be used alone or in admixture of two or more.

  In the polymerization, one or more other molecular weight control agents such as α-methylstyrene dimer and t-dodecyl mercaptan can be used in combination with the molecular weight control agent.

  Further, the polymerization of the polymerizable unsaturated compound in the presence of the molecular weight control agent may take the form of living radical polymerization in which an active radical is formed at the growth terminal of the polymer chain.

  When the polymerization takes the form of living radical polymerization, when the polymerizable unsaturated compound contains a compound having a functional group that may deactivate an active radical such as a carboxyl group, the growth terminal should not be deactivated. Therefore, the copolymer (A) can also be obtained by protecting the functional group, for example, by esterification, and then deprotecting it if necessary.

The radical polymerization initiator is appropriately selected according to the type of the polymerizable unsaturated compound used. For example, 2,2′-azobisisobutyronitrile, 2,2′-azobis- (2 , 4-dimethylvaleronitrile), 2,2′-azobis- (4-methoxy-2,4-dimethylvaleronitrile), 4,4′-azobis (4-cyanovaleric acid), dimethyl-2,2′-azobis Azo compounds such as (2-methylpropionate) and 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile);
Of these radical polymerization initiators, 2,2′-azobisisobutyronitrile, 2,2′-azobis (2,4-dimethylvaleronitrile) and the like are preferable.
The radical polymerization initiators can be used alone or in admixture of two or more.

  In the said polymerization, the usage-amount of a radical polymerization initiator is 0.1-50 weight part normally with respect to 100 weight part of polymerizable unsaturated compounds, Preferably it is 0.1-20 weight part.

  Moreover, the usage-amount of a molecular weight control agent is 0.1-50 weight part normally with respect to 100 weight part of polymerizable unsaturated compounds, Preferably it is 0.2-16 weight part, Most preferably, it is 0.4-8. Parts by weight. In this case, if the amount of the molecular weight control agent used is less than 0.1 parts by weight, the control effect of the molecular weight and molecular weight distribution tends to be reduced, whereas if it exceeds 50 parts by weight, low molecular weight components are preferentially generated. There is a risk that.

  Moreover, the usage-amount of another molecular weight control agent is 200 weight% or less normally with respect to all the molecular weight control agents, Preferably it is 40 weight% or less. In this case, if the use ratio of the other molecular weight control agent exceeds 200% by weight, the intended effect of the present invention may be impaired. Moreover, the usage-amount of a solvent is 50-1,000 weight part normally with respect to 100 weight part of polymerizable unsaturated compounds, Preferably it is 100-500 weight part. The polymerization temperature is usually 0 to 150 ° C., preferably 50 to 120 ° C., and the polymerization time is usually 10 minutes to 20 hours, preferably 30 minutes to 6 hours.

  The polystyrene-converted weight average molecular weight (Mw) measured by gel permeation chromatography (GPC) of the copolymer (A) is preferably 1,000 to 50,000, particularly preferably 2,000 to 30,000, And ratio (Mw / Mn) of Mw and polystyrene conversion number average molecular weight (Mn) measured by gel permeation chromatography (GPC) is preferably 1.8 or less, particularly preferably 1.6 or less.

By using such a copolymer (A) having Mw and Mw / Mn, a cured film with high flatness can be formed, and the transparency and surface hardness are high. It is possible to obtain a composition that is suitably used for forming a protective film excellent in various resistances such as alkalinity, and that has a small amount of sublimation generated during the formation of the protective film and is excellent in storage stability as a composition.
(B) Polyfunctional compound As the (B) polyfunctional compound used in the present invention, a cationic polymerizable compound and / or a polyfunctional (meth) acrylate compound is used. The cationically polymerizable compound is a compound having two or more epoxy groups in the molecule (excluding the above-mentioned copolymer (A)). Examples of the compound having two or more epoxy groups in the molecule include a compound having two or more epoxy groups in the molecule or a compound having a 3,4-epoxycyclohexyl group.

Examples of the compound having two or more epoxy groups in the molecule include bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, bisphenol S diglycidyl ether, hydrogenated bisphenol A diglycidyl ether, and hydrogenated bisphenol F diglycidyl. Ether, hydrogenated bisphenol AD diglycidyl ether;
Polyhydric alcohols such as 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin triglycidyl ether, trimethylolpropane triglycidyl ether, polyethylene glycol diglycidyl ether, and polypropylene glycol diglycidyl ether Glycidyl ethers;
Polyglycidyl ethers of polyether polyols obtained by adding one or more alkylene oxides to aliphatic polyhydric alcohols such as ethylene glycol, propylene glycol and glycerin;
Phenol novolac type epoxy resin;
Cresol novolac type epoxy resin;
Polyphenol type epoxy resin;
Diglycidyl esters of aliphatic long-chain dibasic acids;
Glycidyl esters of higher fatty acids;
Examples include epoxidized soybean oil and epoxidized linseed oil.

Commercially available compounds having two or more epoxy groups in the molecule include, for example, Epicoat 1001, 1002, 1003, 1004, 1007, 1009, 1010, and the like as bisphenol A type epoxy resins. 828 (above, manufactured by Japan Epoxy Resin Co., Ltd.) and the like;
As bisphenol F type epoxy resin, Epicoat 807 (manufactured by Japan Epoxy Resin Co., Ltd.) and the like;
As a phenol novolac type epoxy resin, Epicoat 152, 154, 157S65 (above, manufactured by Japan Epoxy Resin Co., Ltd.), EPPN 201, 202 (above, manufactured by Nippon Kayaku Co., Ltd.), etc .;
As cresol novolac type epoxy resin, EOCN102, 103S, 104S, 1020, 1025, 1027 (above, manufactured by Nippon Kayaku Co., Ltd.), Epicoat 180S75 (manufactured by Japan Epoxy Resin Co., Ltd.) and the like;
As a polyphenol type epoxy resin, Epicoat 1032H60, XY-4000 (above, manufactured by Japan Epoxy Resin Co., Ltd.) and the like;
As cycloaliphatic epoxy resins, CY-175, 177, 179, Araldite CY-182, 192, 184 (above, manufactured by Ciba Specialty Chemicals Co., Ltd.), ERL-4234, 4299, 4221, 4206 ( As described above, manufactured by U.C.C. Co., Ltd., Shodyne 509 (manufactured by Showa Denko KK), Epicron 200, 400 (above, manufactured by Dainippon Ink Co., Ltd.), Epicoat 871, 872 (above, Japan Epoxy) Resin Co., Ltd.), ED-5661, 5562 (above, made by Celanese Coating), etc .;
Examples of the aliphatic polyglycidyl ether include Epolite 100MF (manufactured by Kyoeisha Chemical Co., Ltd.) and Epiol TMP (manufactured by Nippon Oil & Fats Co., Ltd.).

  Examples of the compound having two or more 3,4-epoxycyclohexyl groups in the molecule include 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate, 2- (3,4-epoxy Cyclohexyl-5,5-spiro-3,4-epoxy) cyclohexane-meta-dioxane, bis (3,4-epoxycyclohexylmethyl) adipate, bis (3,4-epoxy-6-methylcyclohexylmethyl) adipate, 3, 4-epoxy-6-methylcyclohexyl-3 ′, 4′-epoxy-6′-methylcyclohexanecarboxylate, methylenebis (3,4-epoxycyclohexane), dicyclopentadiene diepoxide, di (3,4-ethylene glycol) Epoxycyclohexylmethyl) A Le, ethylenebis (3,4-epoxycyclohexane carboxylate), lactone-modified 3,4-epoxycyclohexylmethyl-3 ', may be mentioned 4'-epoxycyclohexane carboxylate. Of such cationically polymerizable compounds, phenol novolac type epoxy resins and polyphenol type epoxy resins are preferred.

On the other hand, as a polyfunctional (meth) acrylate compound, for example,
Ethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol (meth) acrylate, tetraethylene glycol di (meth) acrylate, bisphenoxyethanol full orange acrylate, trimethylolpropane tri (Meth) acrylate, pentaerythritol tri (meth) acrylate, tri ((meth) acryloyloxyethyl) phosphate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) Acrylate, triacryloyloxypentaerythritol succinic acid {also known as: 3-acryloyloxy-2,2-bisacryloyloxymethyl-propyl) ester} Diacryloyloxypentaerythritol succinic acid {alias: 3-acryloyloxy-2-acryloyloxymethyl-propyl) ester}, pentaacryoyloxydipentaerythritol succinic acid {alias: [3- (3-acryloyloxy-2,2 -Bis-acryloyloxymethyl-propyl) -2,2-bis-acryloyloxymethyl-propyl] ester}, tetraacryloyloxydipentaerythritol succinic acid {alias: [3- (3-acryloyloxy-2,2 -Bis-acryloyloxymethyl-propyl) -2-acryloyloxymethyl-propyl] ester} and the like. As the commercial product, for example, Aronix M-210, M-240, M-6200, M-309, M-400, M-402, M-405, M-450, M -7100, M-8030, M-8060 (manufactured by Toagosei Co., Ltd.), KAYARAD HDDA, HX-220, R-604, TMPTA, DPHA, DPCA-20, DPCA-30 , DPCA-60, DPCA-120 (manufactured by Nippon Kayaku Co., Ltd.), Viscoat 260, 312, 335HP, 295, 300, 360, GPT, 3PA, 400 (Osaka Organic Industries) Etc.).

These may be used alone or in combination.
As such a polyfunctional (meth) acrylate compound, pentaerythritol triacrylate, pentaerythritol tetraacrylate, and dipentaerythritol hexaacrylate are preferable.
(B) The usage-amount of a polyfunctional compound becomes like this. Preferably it is 80 weight part or less with respect to 100 weight part of copolymers (A), More preferably, it is 60 weight part or less. (B) A protective film excellent in heat resistance and solvent resistance can be formed when the proportion of the polyfunctional compound used is 80 parts by weight or less.

(C) Curing Agent The (C) curing agent can be added to improve the heat resistance and hardness of the protective film to be formed. (C) As the curing agent, a polymer of a polymerizable unsaturated compound having an acid anhydride group and an olefinically unsaturated compound (excluding the copolymer (A)), or a polyvalent carboxylic acid anhydride may be used. Can be mentioned.

  Examples of the polymerizable unsaturated compound having an acid anhydride group include itaconic anhydride, citraconic anhydride, maleic anhydride, and cis 1,2,3,4-tetrahydrophthalic anhydride.

Examples of the olefinically unsaturated compound include styrene, p-methylstyrene, p-methoxystyrene, methyl methacrylate, t-butyl methacrylate, and tricyclomethacrylic acid [5.2.1.0 ^2,6 ] decane. Examples include 8-yl, 2-methylcyclohexyl acrylate, phenylmaleimide, and cyclohexyl.

  The copolymerization ratio of the polymerizable unsaturated compound having an acid anhydride group in 100 parts by weight of the copolymer of the polymerizable unsaturated compound having an acid anhydride group and the olefinically unsaturated compound is preferably 1 to 80 wt. Parts, more preferably 10 to 60 parts by weight. By using such a copolymer, a protective film excellent in flatness can be obtained.

Preferable examples of the copolymer of the polymerizable unsaturated compound having an acid anhydride group and the olefinically unsaturated compound include maleic anhydride copolymer / styrene, citraconic anhydride / tricyclomethacrylate [5.2.1]. .0 ^2,6] decan-8-yl copolymer.

  The polystyrene-converted weight average molecular weight of the copolymer of the polymerizable unsaturated compound having an acid anhydride group and the olefinically unsaturated compound is preferably 500 to 50,000, more preferably 500 to 10,000. is there. By using a copolymer having such a molecular weight range, a protective film having excellent flatness can be obtained.

Examples of the polyvalent carboxylic acid anhydride include itaconic anhydride, succinic anhydride, citraconic anhydride, dodecenyl succinic anhydride, tricarbanilic anhydride, maleic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, and hymic anhydride. Aliphatic dicarboxylic anhydrides such as acids; alicyclic polycarboxylic dianhydrides such as 1,2,3,4-butanetetracarboxylic dianhydride and cyclopentanetetracarboxylic dianhydride; phthalic anhydride And aromatic polyvalent carboxylic anhydrides such as pyromellitic anhydride, trimellitic anhydride, and benzophenone tetracarboxylic anhydride; and ester group-containing acid anhydrides such as ethylene glycol bistrimellitic anhydride and glycerin tris anhydrous trimellitate. . Of these, aromatic polycarboxylic anhydrides, particularly trimellitic anhydride and hexahydrophthalic anhydride are preferred in that a cured film having high heat resistance can be obtained.
(C) The usage-amount of a hardening | curing agent becomes like this. Preferably it is 40 weight part or less with respect to 100 weight part of copolymers (A), More preferably, it is 30 weight part or less. (C) When the proportion of the curing agent used is 30 parts by weight or less, the storage stability of the resin composition is good, and a protective film having excellent heat resistance and solvent resistance can be formed.

(D) Thermal radiation-sensitive acid generator A (D) thermal radiation-acid generator can be added to the resin composition of the present invention. Examples of the heat-sensitive radiation acid generator include sulfonium salts, benzothiazonium salts, ammonium salts, phosphonium salts, etc. Among them, sulfonium salts and benzothiazonium salts are preferably used.

Specific examples of these heat-sensitive radiation acid generators include benzylsulfonium salts such as benzyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate, benzyl-4-hydroxyphenylmethylsulfonium hexafluorophosphate, 4-acetoxyphenylbenzylmethyl. Sulfonium hexafluoroantimonate, benzyl-4-methoxyphenylmethylsulfonium hexafluoroantimonate, benzyl-2-methyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate, etc .;
Specific examples of the benzothiazonium salt include 3-benzylbenzothiazonium hexafluoroantimonate, 3-benzylbenzothiazonium hexafluorophosphate, 3-benzylbenzothiazonium tetrafluoroborate, 3- (p- Methoxybenzyl) benzothiazonium hexafluoroantimonate, 3-benzyl-2-methylthiobenzothiazonium hexafluoroantimonate.

  Among these (D) heat-sensitive radiation acid generators, in particular, benzyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate, 4-acetoxyphenylbenzylmethylsulfonium hexafluoroantimonate, 4-acetoxyphenylbenzylsulfonium hexafluoro Antimonate and 3-benzylbenzothiazolium hexafluoroantimonate are preferably used. Examples of these commercially available products include Sun-Aid SI-L85, SI-L110, SI-L145, SI-L150, SI-L160 (manufactured by Sanshin Chemical Industry Co., Ltd.).

  (D) The usage-amount of a heat sensitive radiation-acid generator becomes like this. Preferably it is 10 weight part or less with respect to 100 weight part of copolymers (A), More preferably, it is 5 weight part or less. (D) When the use ratio of the heat-sensitive acid generator is 10 parts by weight or less, no deposit is deposited in the coating film forming step, and a protective film excellent in heat resistance and chemical resistance can be formed.

Arbitrary additional components In the resin composition of the present invention, optional additional components other than the above (A) to (D), for example, surfactants, adhesives, etc. An auxiliary agent, a hardening accelerator, etc. can be mix | blended.

    The surfactant is added to improve the coating property of the composition.

  Preferred examples of such surfactants include fluorine-based surfactants and silicone-based surfactants.

  Of the above-mentioned commercially available fluorosurfactants and silicone surfactants, examples of the fluorosurfactant include BM-1000 and BM-1100 (above, manufactured by BM CHIMID); MegaFuck F142D, MegaFuck F172, Megafuck F173, Megafuck F183, Megafuck R08-MH (above, manufactured by Dainippon Ink & Chemicals, Inc.); Florard FC-135, Florado FC-170C, Florado FC-430, Florado FC-431 , Sumitomo 3M Co., Ltd.); Footgent 250, 251, 222F, FTX-218 (above, Neos Co., Ltd.), and the like.

  Examples of the silicone surfactant include SH-28PA, SH-190, SH-193, SZ-6032, SF-8428, DC-57, DC-190 (above, Toray Dow Corning Silicone Co., Ltd. KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.); F-top DF301, F-top DF303, F-top DF352 (above, manufactured by Shin-Akita Kasei Co., Ltd.) and the like.

  Further, other commercially available surfactants include polyflow No. 1 which is a (meth) acrylic acid copolymer. 57 and polyflow no. 90 (manufactured by Kyoeisha Chemical Co., Ltd.).

  The compounding amount of the surfactant is preferably 5 parts by weight or less, more preferably 2 parts by weight or less with respect to 100 parts by weight of the copolymer (A). When the compounding amount of the surfactant exceeds 5 parts by weight, the coating film tends to be rough.

  The adhesion assistant is added to improve the adhesion between the protective film to be formed and the substrate.

  As such an adhesion assistant, for example, a silane coupling agent having a reactive group such as a carboxyl group, a methacryloyl group, a vinyl group, an isocyanate group, or an epoxy group is preferable.

  Specific examples of the adhesion assistant include trimethoxysilylbenzoic acid, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, vinyltrimethoxysilane, γ-isocyanatopropyltriethoxysilane, γ-glycidoxypropyltrimethoxy. Examples include silane and β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane.

  The blending amount of the adhesion assistant is preferably 30 parts by weight or less, more preferably 25 parts by weight or less with respect to 100 parts by weight of the copolymer (A). When the compounding amount of the adhesion aid exceeds 30 parts by weight, the heat resistance of the protective film obtained may be insufficient.

  As the curing accelerator, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-phenylimidazole, 2,4-diamino-6- [2′-methylimidazolyl- (1 ′)] — Ethyl-S-triazine, 2,4-diamino-6- [2'-undecylimidazolyl- (1 ')]-ethyl-S-triazine, 2,4-diamino-6- [2'-ethyl-4' -Methylimidazolylundecylimidazolyl- (1 ')]-ethyl-S-triazine, 2-phenyl-4,5-dihydroxymethylimidazole and the like can be mentioned.

  The addition amount of the curing accelerator is preferably 0.0001 to 10 parts by weight with respect to 100 parts by weight of the copolymer (A). It is more preferable to add 0.001 to 1 part by weight from the viewpoint of heat resistance and storage stability.

Solvent The resin composition of the present invention is prepared by uniformly dissolving or dispersing each of the above components in an appropriate solvent. As the solvent to be used, a solvent in which each component of the composition is dissolved or dispersed and does not react with each component is preferably used.

  Examples of such a solvent include diethylene glycol dialkyl ether, propylene glycol alkyl ether acetate, propylene glycol alkyl ether propionate, and ketone.

Specific examples thereof include diethylene glycol dialkyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol ethyl methyl ether and the like;
As propylene glycol alkyl ether acetate, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, propylene glycol propyl ether acetate, propylene glycol butyl ether acetate, etc .;
As propylene glycol alkyl ether propionate, propylene glycol methyl ether propionate, propylene glycol ethyl ether propionate, propylene glycol propyl ether propionate, propylene glycol butyl ether propionate, etc .;
Examples of ketones include methyl ethyl ketone, cyclohexanone, 4-hydroxy-4-methyl-2-pentanone, methyl isoamyl ketone and the like;
Of these, propylene glycol alkyl acetate and diethylene glycol dialkyl ether are preferred, and in particular, diethylene glycol ethyl methyl ether, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, diethylene glycol dimethyl ether, ethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol diethyl Ether and the like are preferable.

  The amount of the solvent used is preferably 1 to 50% by weight, more preferably 5% by weight, based on the total solid content in the composition of the present invention (the amount obtained by removing the amount of the solvent from the total amount of the composition including the solvent). It is the range which becomes -40 weight%.

  A high boiling point solvent can be used in combination with the above solvent. Examples of the high boiling point solvent that can be used in combination here include N-methylformamide, N, N-dimethylformamide, N-methylformanilide, N-methylacetamide, N, N-dimethylacetamide, N-methylpyrrolidone, dimethylsulfoxide, and benzyl. Examples include ethyl ether, dihexyl ether, acetonyl acetone, isophorone, caproic acid, caprylic acid, and γ-butyrolactone.

  The amount of the high-boiling solvent used in combination is preferably 90% by weight or less, more preferably 80% by weight or less based on the total amount of the solvent.

  The composition prepared as described above is preferably filtered after using a Millipore filter having a pore size of 0.2 to 3.0 μm, more preferably a pore size of about 0.2 to 0.5 μm, and then used. You can also.

Formation of Protective Film Next, a method for forming a protective film for a color filter, for example, using the composition of the present invention will be described.

  After applying the resin composition solution of the present invention to the substrate surface, pre-baking to remove the solvent to form a coating film, a heat treatment can be performed to form a protective film for the target color filter. .

  Examples of the substrate that can be used include substrates such as glass, quartz, silicon, and resin. Examples of the resin include resins such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, polyimide, and cyclic olefin ring-opening polymers and hydrogenated products thereof.

  As a coating method, for example, an appropriate method such as a spray method, a roll coating method, a spin coating method, a bar coating method, an ink jet method or the like can be adopted, and in particular, coating using a spin coater, a spinless coater, or a slit die coater. Can be suitably used.

  The pre-baking conditions vary depending on the types and blending ratios of the components, but conditions of 70 to 90 ° C. and 1 to 15 minutes can be preferably used. The thickness of the coating film is preferably 0.15 to 8.5 μm, more preferably 0.15 to 6.5 μm, and still more preferably 0.15 to 4.5 μm. In addition, the thickness of a coating film here should be understood as thickness after solvent removal.

  The heat treatment after the coating film is formed can be carried out by an appropriate heating device such as a hot plate or a clean oven. The processing temperature is preferably about 150 to 250 ° C., and the heating time can be 5 to 30 minutes when using a hot plate, and 30 to 90 minutes when using an oven.

  When the resin composition contains a radiation-sensitive acid generator, the resin composition is applied to the substrate surface, the solvent is removed by pre-baking to form a coating film, and then a radiation irradiation process (exposure process) is performed. Thus, a desired protective film can be formed. If necessary, a heat treatment may be further performed after the exposure processing.

  Examples of the radiation that can be used in the radiation irradiation treatment include visible light, ultraviolet light, far ultraviolet light, electron beams, X-rays, and the like, and ultraviolet light including light having a wavelength of 190 to 450 nm is preferable.

Exposure of radiation to the coating film is preferably 100~20,000J / ^{m 2,} more preferably 150~10,000J / ^{m 2.}

  A heat treatment may be optionally further performed after the coating is irradiated with radiation. As heating temperature at this time, about 150-250 degreeC is preferable, and appropriate apparatuses, such as a hotplate and a clean oven, can be used as a heating apparatus, for example. As the heating time, a processing time of 5 to 30 minutes can be employed when using a hot plate, and 30 to 90 minutes when using an oven.

Protective film The protective film thus formed has a thickness of preferably 0.1 to 8 μm, more preferably 0.1 to 6 μm, and still more preferably 0.1 to 4 μm. In addition, when the protective film of this invention is formed on the board | substrate which has the level | step difference of a color filter, said film thickness should be understood as the thickness from the uppermost part of a color filter.

  As is clear from the examples described below, the protective film of the present invention satisfies adhesiveness, surface hardness, transparency, heat resistance, light resistance, solvent resistance, and the like, and also with a load in a heated state. It is suitable as a protective film for a liquid crystal display element that is excellent in performance of flattening the steps of the color filter formed on the base substrate without being recessed.

  In particular, since the protective film of the present invention may be exposed to heating exceeding 250 ° C. in the panel manufacturing process, sufficient dimensional stability at 270 ° C. has sufficient heat resistance even in that case. Guaranteed by having.

The present invention will be described more specifically with reference to synthesis examples and examples. However, the present invention is not limited to the following examples.
Mw and Mn of the resin obtained in each of the following synthesis examples were measured by gel permeation chromatography (GPC) according to the following specifications. Apparatus: GPC-101 (manufactured by Showa Denko KK). Column: GPC-KF-801, GPC-KF-802, GPC-KF-803 and GPC-KF-804 were used in combination. Mobile phase: Tetrahydrofuran containing 0.5% by weight of phosphoric acid.

Production synthesis example 1 of copolymer (A)
In a flask equipped with a condenser and a stirrer, 1 part by weight of 2,2′-azobis-isobutyronitrile, 4 parts by weight of bis (n-octylmercapto-thiocarbonyl) disulfide immediately after synthesis, and 200 parts by weight of propylene glycol monomethyl ether acetate Prepared the department. Subsequently, 70 parts by weight of glycidyl methacrylate and 30 parts by weight of styrene were charged, and after the atmosphere was replaced with nitrogen, stirring was started gently. The solution temperature was raised to 95 ° C., and this temperature was maintained for 5 hours to obtain a polymer solution containing the copolymer (A-1). The solid content concentration of the obtained polymer solution was 32.8% by weight. This copolymer had Mw = 11,000 and Mw / Mn = 1.4.

Synthesis example 2
In a flask equipped with a condenser and a stirrer, 1 part by weight of 2,2′-azobis-isobutyronitrile, 4 parts by weight of bis (n-octylmercapto-thiocarbonyl) disulfide and propylene glycol left at room temperature after synthesis for 2 months 200 parts by weight of monomethyl ether acetate was charged. Subsequently, 70 parts by weight of glycidyl methacrylate and 30 parts by weight of styrene were charged, and after the atmosphere was replaced with nitrogen, stirring was started gently. The solution temperature was raised to 95 ° C., and this temperature was maintained for 5 hours to obtain a polymer solution containing the copolymer (A-1 ′). The solid content concentration of the obtained polymer solution was 32.9% by weight. This copolymer had Mw = 11,500 and Mw / Mn = 1.4.

Synthesis example 3
In a flask equipped with a condenser and a stirrer, 1 part by weight of 2,2′-azobis-isobutyronitrile, 4 parts by weight of bis (n-octylmercapto-thiocarbonyl) disulfide immediately after synthesis, and 200 parts by weight of propylene glycol monomethyl ether acetate Prepared the department. Subsequently, 80 parts by weight of 3-ethyl-3-metaacryloxymethyloxetane and 20 parts by weight of styrene were charged, and after the atmosphere was replaced with nitrogen, stirring was started gently. The solution temperature was raised to 95 ° C., and this temperature was maintained for 5 hours to obtain a polymer solution containing the copolymer (A-2). The solid content concentration of the obtained polymer solution was 33.0% by weight.
This copolymer had Mw = 9,500 and Mw / Mn = 1.2.

Synthesis example 4
In a flask equipped with a condenser and a stirrer, 1 part by weight of 2,2′-azobis-isobutyronitrile, 4 parts by weight of bis (n-octylmercapto-thiocarbonyl) disulfide immediately after synthesis, and 200 parts by weight of propylene glycol monomethyl ether acetate Prepared the department. Subsequently, 70 parts by weight of glycidyl methacrylate, 15 parts by weight of styrene and 15 parts by weight of N-cyclohexylmaleimide were charged, and after the atmosphere was replaced with nitrogen, stirring was started gently. The solution temperature was raised to 95 ° C., and this temperature was maintained for 5 hours to obtain a polymer solution containing the copolymer (A-3). The resulting polymer solution had a solid content concentration of 33.1% by weight.
This copolymer had Mw = 12,000 and Mw / Mn = 1.5.

Synthesis example 5
In a flask equipped with a condenser and a stirrer, 1 part by weight of 2,2′-azobis-isobutyronitrile, 4 parts by weight of bis (n-octylmercapto-thiocarbonyl) disulfide immediately after synthesis, and 200 parts by weight of propylene glycol monomethyl ether acetate Prepared the department. Subsequently, 60 parts by weight of glycidyl methacrylate, 10 parts by weight of styrene, and 30 parts by weight of tricyclo [5.2.1.0 ^2,6 ] decan-8-yl methacrylate were charged, and after substituting with nitrogen, stirring was started gently. The solution temperature was raised to 95 ° C., and this temperature was maintained for 5 hours to obtain a polymer solution containing the copolymer (A-4). The solid content concentration of the obtained polymer solution was 32.9% by weight.
This copolymer had Mw = 11,000 and Mw / Mn = 1.2.

Synthesis Example 6
In a flask equipped with a condenser and a stirrer, 1 part by weight of 2,2′-azobis (2,4-dimethylvaleronitrile), 4 parts by weight of bis (n-octylmercapto-thiocarbonyl) disulfide immediately after synthesis, and propylene glycol monomethyl 200 parts by weight of ether acetate was charged. Subsequently, 50 parts by weight of glycidyl methacrylate, 15 parts by weight of styrene, 15 parts by weight of N-cyclohexylmaleimide and 20 parts by weight of methacrylic acid were charged, and after the atmosphere was replaced with nitrogen, stirring was started gently. The solution temperature was raised to 70 ° C., and this temperature was maintained for 5 hours to obtain a polymer solution containing the copolymer (A-5). The solid content concentration of the obtained polymer solution was 33.0% by weight.
This copolymer had Mw = 12,500 and Mw / Mn = 1.3.

Synthesis example 7
In a flask equipped with a condenser and a stirrer, 5 parts by weight of 2,2′-azobis-isobutyronitrile, 4 parts by weight of bis (n-octylmercapto-thiocarbonyl) disulfide immediately after synthesis, and 200 parts by weight of propylene glycol monomethyl ether acetate Prepared the department. Subsequently, 45 parts by weight of glycidyl methacrylate, 40 parts by weight of 3-ethyl-3-methacryloyloxymethyloxetane and 15 parts by weight of styrene were charged, and the mixture was purged with nitrogen. The solution temperature was raised to 70 ° C., and this temperature was maintained for 5 hours to obtain a polymer solution containing the copolymer (A-6). The resulting polymer solution had a solid content concentration of 33.3% by weight.
This copolymer had Mw = 11,000 and Mw / Mn = 1.3.

Synthesis example 8
In a flask equipped with a condenser and a stirrer, 1 part by weight of 2,2′-azobis (2,4-dimethylvaleronitrile), 4 parts by weight of bis (n-octylmercapto-thiocarbonyl) disulfide immediately after synthesis, and propylene glycol monomethyl 200 parts by weight of ether acetate was charged. Subsequently, 20 parts by weight of styrene, 20 parts by weight of N-cyclohexylmaleimide, 20 parts by weight of methacrylic acid, 20 parts by weight of glycidyl methacrylate, and 20 parts by weight of 1-ethylcyclohexyl methacrylate were charged, and after gently substituting with nitrogen, stirring was started gently. The solution temperature was raised to 70 ° C., and this temperature was maintained for 5 hours to obtain a polymer solution containing the copolymer (A-7). The solid content concentration of the obtained polymer solution was 32.6% by weight.
This copolymer had Mw = 12,000 and Mw / Mn = 1.5.

Synthesis Example 9
In a flask equipped with a condenser and a stirrer, 1 part by weight of 2,2′-azobis (2,4-dimethylvaleronitrile), 4 parts by weight of bis (n-octylmercapto-thiocarbonyl) disulfide immediately after synthesis, and propylene glycol monomethyl 200 parts by weight of ether acetate was charged. Subsequently, 20 parts by weight of styrene, 20 parts by weight of N-cyclohexylmaleimide, 20 parts by weight of methacrylic acid, 20 parts by weight of glycidyl methacrylate, and 20 parts by weight of 1-ethylcyclopentyl methacrylate were charged, and after the atmosphere was replaced with nitrogen, stirring was started gently. The solution temperature was raised to 70 ° C., and this temperature was maintained for 5 hours to obtain a polymer solution containing the copolymer (A-8). The resulting polymer solution had a solid content concentration of 32.7% by weight.
This copolymer had Mw = 10,000 and Mw / Mn = 1.4.

Synthesis Example 10
In a flask equipped with a condenser and a stirrer, 1 part by weight of 2,2′-azobis (2,4-dimethylvaleronitrile), 4 parts by weight of bis (n-octylmercapto-thiocarbonyl) disulfide immediately after synthesis, and propylene glycol monomethyl 200 parts by weight of ether acetate was charged. Subsequently, 20 parts by weight of styrene, 20 parts by weight of N-cyclohexylmaleimide, 20 parts by weight of methacrylic acid, 20 parts by weight of glycidyl methacrylate and 20 parts by weight of tetrahydro-2H-pyran-2-yl ester were charged, and after gently substituting with nitrogen, gently stirred. Started. The solution temperature was raised to 70 ° C., and this temperature was maintained for 5 hours to obtain a polymer solution containing the copolymer (A-9). The solid content concentration of the obtained polymer solution was 32.4% by weight.
This copolymer had Mw = 11,000 and Mw / Mn = 1.3.

Synthesis Example 11
In a flask equipped with a condenser and a stirrer, 1 part by weight of 2,2′-azobis (2,4-dimethylvaleronitrile), 4 parts by weight of bis (n-dodecylmercapto-thiocarbonyl) disulfide immediately after synthesis, and propylene glycol monomethyl 200 parts by weight of ether acetate was charged. Subsequently, 50 parts by weight of glycidyl methacrylate, 15 parts by weight of styrene, 15 parts by weight of N-cyclohexylmaleimide and 20 parts by weight of methacrylic acid were charged, and after the atmosphere was replaced with nitrogen, stirring was started gently. The solution temperature was raised to 70 ° C., and this temperature was maintained for 5 hours to obtain a polymer solution containing the copolymer (A-10). The solid content concentration of the obtained polymer solution was 32.8% by weight.
This copolymer had Mw = 12,000 and Mw / Mn = 1.5.

Synthesis Example 12
In a flask equipped with a condenser and a stirrer, 1 part by weight of 2,2′-azobis (2,4-dimethylvaleronitrile), 4 parts by weight of bis (benzylmercapto-thiocarbonyl) disulfide immediately after synthesis, and propylene glycol monomethyl ether acetate 200 parts by weight were charged. Subsequently, 50 parts by weight of glycidyl methacrylate, 15 parts by weight of styrene, 15 parts by weight of N-cyclohexylmaleimide and 20 parts by weight of methacrylic acid were charged, and after the atmosphere was replaced with nitrogen, stirring was started gently. The solution temperature was raised to 70 ° C., and this temperature was maintained for 5 hours to obtain a polymer solution containing the copolymer (A-11). The solid content concentration of the obtained polymer solution was 32.9% by weight.
This copolymer had Mw = 11,500 and Mw / Mn = 1.3.

Synthesis Example 13
In a flask equipped with a condenser and a stirrer, 1 part by weight of 2,2′-azobis (2,4-dimethylvaleronitrile), 4 parts by weight of bis (pyrazol-1-yl-thiocarbonyl) disulfide immediately after synthesis and propylene glycol 200 parts by weight of monomethyl ether acetate was charged. Subsequently, 50 parts by weight of glycidyl methacrylate, 15 parts by weight of styrene, 15 parts by weight of N-cyclohexylmaleimide and 20 parts by weight of methacrylic acid were charged, and after the atmosphere was replaced with nitrogen, stirring was started gently. The solution temperature was raised to 70 ° C., and this temperature was maintained for 5 hours to obtain a polymer solution containing the copolymer (A-12). The resulting polymer solution had a solid content concentration of 33.2% by weight.
This copolymer had Mw = 10,500 and Mw / Mn = 1.3.

Synthesis Example 14
1 part by weight of 2,2′-azobis (2,4-dimethylvaleronitrile), bis (pyrazol-1-yl-thiocarbonyl) disulfide 4 left at room temperature after synthesis in a flask equipped with a condenser and a stirrer 4 Part by weight and 200 parts by weight of propylene glycol monomethyl ether acetate were charged. Subsequently, 50 parts by weight of glycidyl methacrylate, 15 parts by weight of styrene, 15 parts by weight of N-cyclohexylmaleimide and 20 parts by weight of methacrylic acid were charged, and after the atmosphere was replaced with nitrogen, stirring was started gently. The solution temperature was raised to 70 ° C., and this temperature was maintained for 5 hours to obtain a polymer solution containing a copolymer (A-12 ′). The solid content concentration of the obtained polymer solution was 33.0% by weight. This copolymer had Mw = 21,500 and Mw / Mn = 2.1.

Synthesis Example 15
A flask equipped with a condenser and a stirrer was charged with 5 parts by weight of 2,2′-azobis (2,4-dimethylvaleronitrile) and 200 parts by weight of propylene glycol monomethyl ether acetate. Subsequently, 50 parts by weight of glycidyl methacrylate, 15 parts by weight of styrene, 15 parts by weight of N-cyclohexylmaleimide and 20 parts by weight of methacrylic acid were charged, and after the atmosphere was replaced with nitrogen, stirring was started gently. The solution temperature was raised to 70 ° C., and this temperature was maintained for 5 hours to obtain a polymer solution containing the copolymer (A-13). The resulting polymer solution had a solid content concentration of 33.1% by weight. This copolymer had Mw = 24,500 and Mw / Mn = 2.3.

Synthesis Example 16
A flask equipped with a condenser and a stirrer was charged with 5 parts by weight of 2,2′-azobis-isobutyronitrile and 200 parts by weight of propylene glycol monomethyl ether acetate. Subsequently, 70 parts by weight of glycidyl methacrylate and 30 parts by weight of styrene were charged, and after the atmosphere was replaced with nitrogen, stirring was started gently. The solution temperature was raised to 95 ° C., and this temperature was maintained for 5 hours to obtain a polymer solution containing the copolymer (A-14). The solid content concentration of the obtained polymer solution was 32.8% by weight. This copolymer had Mw = 25,000 and Mw / Mn = 2.4.

Preparation and Evaluation of Resin Composition Example 1
In the solution containing copolymer (A-1) obtained in Synthesis Example 1 above (amount corresponding to 100 parts by weight (solid content) of copolymer (A-1)),
(B-1) 20 parts by weight of a bisphenol A novolac type epoxy resin (trade name: Epicoat 828, manufactured by Japan Epoxy Resin Co., Ltd.)
30 parts by weight of hexahydrophthalic anhydride (C-1) as a curing agent,
Add 1 part by weight of benzyl-2-methyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate (D-1) as a heat-sensitive acid generator, and add propylene glycol monomethyl ether acetate so that the solid content concentration is 20% by weight. Then, the mixture was filtered through a Millipore filter having a pore diameter of 0.5 μm to prepare a resin composition.

After applying the above composition on a SiO ₂ dip glass substrate using a spinner, pre-baking is performed on a hot plate at 80 ° C. for 5 minutes to form a coating film, and further, heat treatment is performed in an oven at 230 ° C. for 60 minutes. Thus, a protective film having a thickness of 2.0 μm was formed.
Evaluation of Protective Film (1) Evaluation of Transparency About the substrate having the protective film formed as described above, using a spectrophotometer (150-20 type double beam (manufactured by Hitachi, Ltd.)), 400 to 800 nm. The Noto rate was measured. Table 1 shows the minimum transmittance of 400 to 800 nm. When this value is 95% or more, it can be said that the transparency of the protective film is good.
(2) Evaluation of heat-resistant film thickness stability About the board | substrate which has a protective film formed as mentioned above, it heated on conditions on 250 degreeC in oven for 1 hour, and measured the film thickness before and behind a heating. The heat resistant film thickness stability calculated according to the following formula is shown in Table 1. When this value is 95% or more, it can be said that the heat-resistant film thickness stability is good.
Heat resistant film thickness stability = (film thickness after heating) / (film thickness before heating) × 100 (%)
(3) Evaluation of heat-resistant color change About the board | substrate which has a protective film formed as mentioned above, it heated at 250 degreeC in oven for 1 hour, and the transparency before and behind a heating was measured similarly to said (1). The heat discoloration calculated according to the following formula is shown in Table 1. When this value is 5% or less, the heat discoloration is good.
Heat discoloration property = transmittance before heating−transmittance after heating (%)
(4) Measurement of pencil hardness About the board | substrate which has a protective film formed as mentioned above, the surface hardness of the protective film was measured by the 8.4.1 pencil scratch test of JISK-5400-1990. This value is shown in Table 1. When this value is 4H or higher, the surface hardness is good.
(5) Evaluation of adhesion The substrate having the protective film formed as described above was subjected to a pressure cooker test (120 ° C., humidity 100%, 4 hours), and then 8.5 according to JIS K-5400-1990. .3 Adhesiveness Adhesiveness of the protective film (adhesiveness to SiO ₂ ) was evaluated by a cross-cut tape method. Table 2 shows the number of remaining grids out of 100 grids.
In addition, as an evaluation of adhesion to Cr, a protective film having a film thickness of 2.0 μm was formed in the same manner as above except that a Cr substrate was used instead of the SiO ₂ dip glass substrate, and the same was performed by the cross-cut tape method. Evaluated. The results are shown in Table 1.
(6) Evaluation of flattening ability A pigment-based color resist (trade names “JSR RED 689”, “JSR GREEN 706”, “CR 8200B”, above, manufactured by JSR Corporation) is applied to a spinner on an SiO ₂ dip glass substrate. And prebaked at 90 ° C. for 150 seconds on a hot plate to form a coating film. Thereafter, ghi rays (intensity ratio of wavelengths 436 nm, 405 nm, and 265 nm = 2.7: 2.5: 4.8) using an exposure machine Canon PLA501F (manufactured by Canon Inc.) through a predetermined pattern mask. Irradiated with an exposure dose of 2,000 J / m ^{2 in} terms of i-line, developed with 0.05% aqueous potassium hydroxide solution, rinsed with ultrapure water for 60 seconds, and further in an oven at 230 ° C. Heat treatment was performed for 30 minutes to form a striped color filter (stripe width 100 μm) of three colors of red, green, and blue.
The unevenness on the surface of the substrate on which the color filter was formed was measured with a surface roughness meter “α-step” (trade name: manufactured by Tencor), and found to be 1.0 μm. However, the measurement was performed with a measurement length of 2,000 μm, a measurement range of 2,000 μm square, and a measurement point n = 5. That is, the measurement direction is two directions of the stripe line minor axis direction of red, green and blue directions and the stripe axis major axis direction of red, red, green, green, blue and blue, and n = 5 for each direction. Measured (total n number is 10).
On the obtained stripe color filter, the composition for forming a protective film was applied to a spinner, and then pre-baked on a hot plate at 90 ° C. for 5 minutes to form a coating film, and further in an oven at 230 ° C. And a protective film having a thickness of 2.0 μm from the upper surface of the color filter was formed. However, the film thickness mentioned here means the thickness from the uppermost surface of the color filter formed on the substrate.
About the board | substrate which has a protective film on the color filter formed as mentioned above, the unevenness | corrugation on the surface of a protective film was measured with the contact-type film thickness measuring apparatus alpha-step (made by Tencor Japan Co., Ltd.). However, the measurement was performed with a measurement length of 2,000 μm, a measurement range of 2,000 μm square, and a measurement point n = 5. That is, the measurement direction is two directions of the stripe line minor axis direction of red, green and blue directions and the stripe axis major axis direction of red, red, green, green, blue and blue, and n = 5 for each direction. Measured (total n number is 10). Table 1 shows the average value of 10 times of the height difference (nm) between the highest and lowest parts for each measurement. When this value is 300 nm or less, it can be said that the flatness is good.
(7) Evaluation of storage stability The viscosity in the resin composition for forming a protective film prepared in Example 1 was measured using an ELD viscometer manufactured by Tokyo Keiki Co., Ltd. Thereafter, the solution viscosity at 25 ° C. was measured every day while the composition was allowed to stand at 25 ° C. The number of days required to increase the viscosity by 5% based on the viscosity immediately after the preparation was determined, and the number of days is shown in Table 1. When this number of days is 15 days or more, it can be said that the storage stability is good.
(8) Evaluation of alkali resistance About the board | substrate which has a protective film formed as mentioned above, it is 30 minutes in 30 degreeC 5% NaOH. After the immersion, the film thickness after removing moisture with a hot plate was measured. The alkali resistance calculated according to the following formula is shown in Table 1. When this value is 95% or more, it can be said that the alkali resistance is good.
Alkali resistance = (film thickness after moisture removal) / (film thickness before immersion) × 100 (%)
Examples 2 to 16 and Comparative Examples 1 to 4
Resin composition in the same manner as in Example 1 except that the types and amounts of the respective components of the composition are as shown in Table 1, and the solvents shown in Table 1 were used to match the solid content concentrations shown in Table 1. A product was prepared.
Using the protective film-forming resin composition prepared as described above, a protective film was formed and evaluated in the same manner as in Example 1. The results are shown in Table 1.
In Table 1, the polyfunctional compound (B), the curing agent (C), the curing accelerator (D), and the abbreviation represent the following, respectively.
B-1: Bisphenol A novolac type epoxy resin (trade name: Epicoat 828, manufactured by Japan Epoxy Resin Co., Ltd.)
B-2: Phenol novolac type epoxy resin (trade name: Epicoat 154 manufactured by Japan Epoxy Resin Co., Ltd.)
B-3: Dipentaerythritol hexaacrylate (trade name: KAYARAD DPHA, manufactured by Nippon Kayaku Co., Ltd.)
B-4: Pentaacylyloxydipentaerythritol succinic acid {also known as: [3- (3-acryloyloxy-2,2-bis-acryloyloxymethyl-propyl) -2,2-bis-acryloyloxymethyl-propyl ] Ester, abbreviation: PADPS}
C-1: hexahydrophthalic anhydride C-2: trimellitic anhydride D-1: benzyl-2-methyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate

Claims (6)

(A) A curable resin composition containing a copolymer, (B) a polyfunctional compound, and (C) a curing agent, wherein (A) the copolymer contains an epoxy group-containing unsaturated compound. A curable resin composition for forming a protective film, comprising a copolymer produced through a step of polymerizing an unsaturated compound in the presence of a compound represented by the following formula (1).

In [Equation ^(1), Z 1 and Z ² is an alkyl group or an optionally substituted benzyl group having 4 to 18 carbon atoms independently of one another. ]   The curable resin composition for forming a protective film according to claim 1, wherein the copolymer (A) according to claim 1 is a copolymer produced through a step of living radical polymerization. .   The (A) copolymer according to claim 1 has a polystyrene-reduced weight average molecular weight (Mw) measured by gel permeation chromatography (GPC) of 1,000 to 10,000, and Mw and gel permeation chromatography. The protection according to claim 1 or 2, wherein the ratio (Mw / Mn) to polystyrene-reduced number average molecular weight (Mn) measured by (GPC) is a copolymer of 1.8 or less. Curable resin composition for film formation.   (D) The curable resin composition for forming a protective film according to any one of claims 1 to 3, further comprising a thermal radiation-sensitive acid generator.   The protective film formed using the curable resin composition for protective film formation in any one of Claims 1-4.   A method for forming a protective film, comprising: forming a film using the curable resin composition for forming a protective film according to any one of claims 1 to 4; and then performing radiation treatment and / or heat treatment.