KR20080067427A - Thermosetting resin composition - Google Patents

Abstract

A thermosetting resin composition is provided to realize excellent surface hardness, smoothness, mechanical properties, UV resistance, and heat resistance, and to produce a protective film for a color filter of an optical device having excellent adhesion to a substrate and causing no yellowing phenomenon at high temperature. A thermosetting resin composition comprises a copolymer[A] of (a1) an unsaturated carboxylic acid or anhydride thereof; (a2) an epoxy group-containing unsaturated compound; (a3) a trialkoxysilane-based unsaturated compound; and (a4) an olefinic unsaturated compound. The copolymer[A] comprises repeating units derived from (a3) trialkoxysilane-based unsaturated compound in an amount of 5-60 wt%. The thermosetting resin composition optionally further comprises [B] a polymerizable compound having ethylenically unsaturated bonds in an amount of 150 parts by weight or less based on 100 parts by weight of the copolymer [A].

Description

Thermosetting resin composition

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermosetting resin composition and a protective film made of the composition, and more particularly to a thermosetting composition and a protective film made of the composition as a material for forming a protective film used for a color filter for an optical device.

Optical devices such as liquid crystal display devices (LCDs) are subjected to harsh processing such as immersion treatment with organic solvents, acids, alkaline solutions, etc. during the manufacturing process, or localized high temperature heating of the surface by sputtering when forming wiring electrode layers. Will receive. Therefore, in order to prevent the deterioration at the time of manufacture, these elements may provide a protective film in the surface.

The protective film protects the colored layer and serves to planarize the color filter. Therefore, the protective film must withstand such harsh treatments and at the same time have excellent adhesion to the substrate or lower layer, and have high smoothness, surface hardness, transparency, and excellent heat resistance and light resistance without deterioration such as coloring, yellowing and whitening over a long period of time. do. Moreover, what is excellent in chemical-resistance, such as solvent resistance, acid resistance, and alkali resistance, and water resistance is calculated | required. In addition, when applying such a protective film to the color filter of a color liquid crystal display element, it is preferable that the level | step difference of a general color filter can be planarized with a board | substrate.

The protective film composition is manufactured in the form of a curable resin composition so as to satisfy the above conditions, and largely classified into thermosetting and photocurable (photosensitive). When the patterning of the protective film is required, a photosensitive resin composition is required, but otherwise, a thermosetting resin composition is used, because it is convenient in the process and can increase the crosslinking density, thereby providing excellent mechanical properties and heat resistance.

Japanese Patent Laid-Open Nos. 2000-103937, 2000-119472, and 2000-143772 describe thermosetting resin compositions as compositions constituting a protective film. That is, the composition which consists of an acrylic resin containing a carboxyl group or an epoxy group, the polyfunctional monomer containing the ethylenically unsaturated group which functions as a crosslinking agent, and a thermal polymerization initiator is used.

However, when the protective film is prepared using these compositions, mechanical properties are not excellent, and in particular, yellowing phenomenon is often exhibited due to poor heat resistance at high temperatures. In consideration of the mechanical properties, the polyfunctional monomer containing an ethylenically unsaturated group can be used excessively. In this case, there is a problem that the yellowing phenomenon at a high temperature becomes more severe.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and an object of the present invention is to provide a thermosetting resin composition excellent in mechanical properties and heat resistance by effectively improving the crosslinking density using a trialkoxysilane-based unsaturated compound and a protective film made of the composition. have.

In addition, an object of the present invention is to provide a thermosetting resin composition and a protective film made of the composition which does not appear yellowing even at high temperatures.

The present invention for achieving the above object is a copolymer of (a1) unsaturated carboxylic acid or anhydride thereof, (a2) epoxy group-containing unsaturated compound, (a3) trialkoxysilane-based unsaturated compound and (a4) olefinically unsaturated compound [A It provides a thermosetting resin composition comprising a.

The copolymer [A] is characterized by comprising 5 to 60% by weight of a structural unit derived from the (a3) trialkoxysilane-based unsaturated compound.

The thermosetting resin composition is characterized by further comprising a polymerizable compound [B] having an ethylenically unsaturated bond in an amount of 150 parts by weight or less based on 100 parts by weight of the copolymer [A].

The thermosetting resin composition is characterized in that it further comprises a thermal radical polymerization initiator [C] in an amount of 20 parts by weight or less based on 100 parts by weight of the copolymer [A].

The present invention also provides a protective film formed of the thermosetting resin composition.

Hereinafter, the present invention will be described in more detail.

The copolymer [A] used in the present invention is obtained by a conventionally known polymerization method, that is, radical polymerization of compounds (a1), (a2), (a3) and (a4) in the presence of a polymerization initiator in a solvent. It can synthesize | combine by performing.

The copolymer [A] preferably contains 5 to 40% by weight, more preferably 10 to 30% by weight of the structural unit derived from the compound [a1]. It is preferable that the content of this structural unit is within the above range because it is possible to prevent a decrease in storage stability or to improve the heat resistance, chemical resistance and surface hardness of the protective film to be produced later. Examples of the compound (a1) include monocarboxylic acids such as acrylic acid, methacrylic acid and crotonic acid; Dicarboxylic acids such as maleic acid, fumaric acid, citraconic acid, mesaconic acid and itaconic acid; And anhydrides of these dicarboxylic acids, and one or more selected from these can be used in combination. Among them, acrylic acid, methacrylic acid, maleic anhydride and the like are mainly used because of their excellent copolymerization reactivity and heat resistance and easy availability.

The copolymer [A] preferably contains 10 to 70% by weight, more preferably 20 to 60% by weight of the structural unit derived from the compound [a2]. It is preferable that the content of this structural unit is within the above range in the improvement of heat resistance and surface hardness of the protective film to be produced later and in the maintenance of storage stability. Examples of the compound (a2) include glycidyl acrylate, glycidyl methacrylate, α-ethyl acrylate glycidyl, α-n-propyl acrylate glycidyl, α-n-butyl acrylate glycidyl, and acrylic acid-3. , 4-epoxy butyl, methacrylic acid-3,4-epoxy butyl, acrylic acid-6,7-epoxy heptyl, methacrylic acid-6,7-epoxy heptyl, α-ethyl acrylic acid-6,7-epoxy heptyl, o It is used alone or in combination of two or more selected from -vinyl benzyl glycidyl ether, m-vinyl benzyl glycidyl ether, and p-vinyl benzyl glycidyl ether to improve the copolymerization reactivity and the heat resistance and hardness of the resulting protective film. It is preferably used in that point.

On the other hand, copolymer [A] contains the structural unit derived from compound [a3], Preferably it is 5 to 60 weight%, More preferably, it contains 10 to 50 weight%. It is preferably 5 to 60% by weight, more preferably 10 to 50% by weight. It is preferable that the content of this structural unit is within the above range in improving heat resistance and surface hardness and maintaining storage safety. As the compound (a3), for example, 3-amino propyl trimethoxy silane, 3-amino fluoro triethoxy silane, 3-chloro propyl trimethoxy silane, 3-chloro propyl triethoxy silane, 2-amino ethyl 3- Amino propyl trimethoxy silane, 3-glycidoxy propyl trimethoxy silane, 3-glycidoxy propyl triethoxy silane, 3-methacryl oxy propyl trimethoxy silane, 3-methacryl oxy propyl triethoxy silane Is used alone or in combination of two or more selected from vinyl trimethoxy silane, vinyl triethoxy silane, vinyl benzyl amino ethyl amino propyl trimethoxy silane, isobutyl trialkoxy silane and octyl triethoxy silane. It is preferable from the viewpoint of reactivity and heat resistance.

The present invention provides a thermosetting resin composition having excellent mechanical properties, particularly wear resistance and ITO processability, by improving the crosslinking density by preparing a copolymer including the trialkoxysilane-based unsaturated compound.

The copolymer [A] preferably contains 10 to 70% by weight, more preferably 20 to 50% by weight of the structural unit derived from the compound [a4]. It is preferable that the content of this structural unit is within the above range in the maintenance of storage stability or improvement of the heat resistance and surface hardness of the protective film produced later. Examples of the compound (a3) include methacrylic acid alkyl esters such as methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, sec-butyl methacrylate and t-butyl methacrylate; Acrylic acid alkyl esters such as methyl acrylate and isopropyl acrylate; Methacrylic acid cycloalkyl esters such as cyclohexyl methacrylate, 2-methylcyclohexyl methacrylate, dicyclopentenyl methacrylate, dicyclopentenyloxyethyl methacrylate and isoboroyl methacrylate; Acrylic acid cycloalkyl esters such as cyclohexyl acrylate, 2-methyl cyclohexyl acrylate, dicyclopentenyl acrylate, dicyclopentenyloxyethyl acrylate and isoboroyl acrylate; Methacrylic acid aryl esters such as phenyl methacrylate and benzyl methacrylate; Acrylic acid aryl esters such as phenyl acrylate and benzyl acrylate; Dicarboxylic acid diesters such as diethyl maleate, diethyl fumarate and diethyl itaconic acid; Hydroxy alkyl esters such as 2-hydroxy ethyl methacrylate and 2-hydroxy propyl methacrylate; And styrene, o-methyl styrene, m-methyl styrene, p-methyl styrene, vinyl toluene, p-methoxy styrene, acrylonitrile, methacrylonitrile, vinyl chloride, vinylidene chloride, acrylamide, methacrylamide, Vinyl acetate, 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, or a combination of two or more thereof. Among them, styrene, t-butyl methacrylate, dicyclopentenyl methacrylate, p-methoxy styrene, 2-methyl cyclohexyl acrylate, 1,3-butadiene and the like are preferred from the viewpoint of copolymerization reactivity and heat resistance.

The copolymer [A] used in the present invention has a carboxyl group and / or a carboxylic anhydride and an epoxy group, and can be easily cured by heating even without using a special curing agent.

Although the molecular weight of copolymer [A] is not specifically limited, It is suitably selected according to the thickness of the film | membrane formed, the solution coating conditions of a curable composition, the objective, etc .. It is preferable that the number average molecular weight of copolymer [A] exists in the range of 3,000-100,000 in consideration of the surface smoothness of the protective film manufactured later, More preferably, it is 3,000-50,000.

As a solvent used for the synthesis | combination of copolymer [A], Alcohol, such as methanol and ethanol; Ethers such as tetrahydrofuran, diethylene glycol dimethyl ether and diethylene glycol diethyl ether; One or a combination of two or more selected from propylene glycol alkyl ether acetates such as propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, propylene glycol propyl ether acetate, and propylene glycol butyl ether acetate is preferred.

As a polymerization initiator used for the synthesis | combination of a copolymer [A], what is generally known as a radical polymerization initiator can be used. For example 2,2'-azobis isobutyronitrile, 2,2'-azobis- (2,4-dimethylvaleronitrile), 2,2'-azobis- (4-methoxy-2,4- Azo compounds such as dimethylvaleronitrile); Organic peroxides such as benzoyl peroxide, t-butyl peroxy pibarate, 1,1'-bis- (t-butyl peroxy) cyclohexane; And hydrogen peroxide. When a peroxide is used as a radical polymerization initiator, a peroxide can be used together with a reducing agent as a redox type initiator.

On the other hand, the thermosetting resin composition of the present invention may further include a polymerizable compound [B] having an ethylenically unsaturated bond in addition to the copolymer [A].

The said polymeric compound [B] is preferable from a viewpoint that monofunctional, bifunctional, or trifunctional or more (meth) acrylate has favorable polymerizability, and the heat resistance and surface hardness of the protective film obtained later improve.

As said monofunctional (meth) acrylate, 2-hydroxy ethyl (meth) acrylate, carbitol (meth) acrylate, isobornyl (meth) acrylate, 3-methoxybutyl (meth) acrylate, for example , 2- (meth) acryloyloxy ethyl 2-hydroxy propyl phthalate, and the like.

As said bifunctional (meth) acrylate, ethylene glycol (meth) acrylate, 1, 6- hexanediol (meth) acrylate, 1, 9- nonanediol (meth) acrylate, propylene glycol (meth) acryl The rate, tetraethylene glycol (meth) acrylate, bisphenoxy ethyl alcohol fluorene diacrylate, etc. are mentioned.

As said trifunctional or more than (meth) acrylate, a tris hydroxyethyl isocyanurate tri (meth) acrylate, a trimethyl propane tri (meth) acrylate, a pentaerythritol tri (meth) acrylate, pentaerythritol tetra ( Meta) acrylate, dipentaerythritol hexa (meth) acrylate, and the like.

It can be used as a polymeric compound [B] by 1 type, or in combination of 2 or more types selected from such monofunctional, bifunctional, or trifunctional or more than (meth) acrylate.

The polymerizable compound [B] is preferably contained in an amount of 150 parts by weight or less based on 100 parts by weight of the copolymer [A], and more preferably 120 parts by weight or less. It is preferable in the adhesiveness improvement of the protective film obtained that content of polymeric compound [B] is 150 weight part or less with respect to 100 weight part of copolymers [A].

In addition, the thermosetting resin composition of the present invention may further comprise a thermal radical polymerization initiator [C], which is contained in a proportion of 20 parts by weight or less, more preferably 15 parts by weight or less, based on 100 parts by weight of the copolymer [A]. . The use of thermal radical polymerization initiator [C] at 20 parts by weight or less is preferable in terms of heat resistance and planarization property of the protective film obtained later. As said thermal radical polymerization initiator [C], what is generally known as a radical polymerization initiator can be used, The polymerization initiator used for superposition | polymerization of the above-mentioned copolymer [A] can be used.

The thermosetting resin composition of this invention can be manufactured by melt | dissolving a polymeric compound [B] and a thermal radical polymerization initiator [C] selectively with a copolymer [A] mentioned above in a solvent. The solvent used at this time does not react with any component. For example, a solvent used for the polymerization of the copolymer [A] can be used, and among them, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, and propylene glycol methyl ether in view of solubility, reactivity, and convenience of coating film formation. Acetate is preferred. It is also possible to use a high boiling point solvent together with the solvent. As the high boiling point solvent, for example, N-methyl formamide, N, N-dimethyl formamide, N-methyl acetamide, N, N-dimethyl acetamide, N-methylpyrrolidone, dimethyl sulfoxide, benzylethyl ether Etc. can be mentioned. When using such a high boiling point solvent together, it is preferable that the mixing ratio with the said solvent is "(the said solvent): (high boiling point solvent) = 50-100: 50-0".

In addition, the thermosetting resin composition of this invention may contain another component as needed within the scope of the technical idea of this invention. Other components herein include, for example, a surfactant for improving applicability. As surfactant, a fluorine or silicone type surfactant is mentioned, for example, 3M's FC-129, FC-170C, FC-430, etc. are mentioned. This can be used in an amount of 5 parts by weight or less, more preferably 2 parts by weight or less, based on 100 parts by weight of the copolymer [A]. It is preferable that surfactant is 5 weight part or less with respect to 100 weight part of copolymers [A] from the point which can prevent foaming etc. at the time of application | coating.

The thermosetting resin composition mixed as described above may be used after filtering using a filter having a diameter of about 0.1 ~ 5㎛.

The thermosetting resin composition of this invention can form a protective film by the following method, for example.

After applying a thermosetting resin composition to a board | substrate, removing a solvent and forming the coating film of a thermosetting resin composition, it can heat-process and can obtain a protective film.

As the substrate, for example, glass, quartz, silicone, resin, etc. may be used, and the resin may be a ring-opening polymer of polyethylene terephthalate, polybutylene terephthalate, polyether sulfone, polycarbonate, polyimide, and cyclic olefin. And its hydrogenated substance.

It does not specifically limit as a coating method of the said thermosetting resin composition solution, For example, a spray method, a roll coating method, a rotary coating method, etc. can be used.

The removal of the solvent is preferably carried out by heat treatment (pre-firing). Although the conditions of such preliminary baking differ with kinds, ratios, etc. of each component of a composition solution, it is preferable to bake about 0.5 to 20 minutes at 60-120 degreeC.

Subsequent heat treatment, the treatment temperature at this time can be treated for 10 to 100 minutes at 150 ~ 300 ℃ to produce a protective film for an optical device.

The thickness of the protective film formed as described above is preferably 0.1 to 6.0 µm, and when the unevenness is formed on the substrate forming the protective film, the value should be understood as the value at the top of the unevenness.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

<Example 1>

5 parts by weight of 2,2'-azobis isobutyronitrile and 200 parts by weight of diethylene glycol dimethyl ether were added to a reaction vessel equipped with a cooling tube and a stirrer. Then, 30 parts by weight of methacrylic acid with unsaturated carboxylic acid (a1), 40 parts by weight of glycidyl methacrylate with (a2), and a trialkoxysilane-based unsaturated compound (a3) with Dow Corning Co., Ltd. Z-6040 SILANE 10 20 parts by weight of styrene was added to the parts by weight and olefinically unsaturated compounds (a4) other than (a1), (a2) and (a3), nitrogen was substituted, and stirring was gradually started. The temperature of the solution was raised to 80 ° C. and maintained at this temperature for 4 hours to obtain a polymer solution containing copolymer [A1]. Solid content concentration of the obtained copolymer solution was 33 weight%.

100 parts by weight (solid content) of the obtained copolymer [A1], 5 parts by weight of CELLOXIDE 2021P (cycloaliphatic epoxy compound) manufactured by Daicel Chemical Co., Ltd. as the curable compound [B], and FC-430 (fluorine-based surfactant) manufactured by 3M as a surfactant. ) 0.1 parts by weight was mixed and dissolved in diethylene glycol dimethyl ether to obtain a solid content concentration of 25%. Then, it filtered by the filter of 0.45 micrometers of pore diameters, and manufactured the thermosetting resin composition solution.

The thermosetting resin composition solution was coated on the glass substrate using a spin coater to have a thickness of 2 μm, and then fired at 220 ° C. for 30 minutes in a clean oven to form a protective film on the glass substrate.

<Example 2>

In Example 1, except that 10 parts by weight of Dow Corning Co., Ltd. Z-6032 SILANE and 0.1 parts by weight of Shin-Etsu Silicone KP341 (silicone surfactant) were mixed as the trialkoxysilane-based unsaturated compound (a3). A thermosetting resin composition solution was prepared in the same manner, and a protective film was formed on the glass substrate in the same manner.

<Example 3>

Dow Corning Co., Z-6020 SILANE 10 parts by weight as a trialkoxysilane-based unsaturated compound (a3) in Example 1, 100 parts by weight of trimethylpropane trimethacrylate as a polymerizable compound [B], thermal radical polymerization initiator A thermosetting resin composition solution was prepared in the same manner except that 5 parts by weight of benzoyl peroxide as [C] and 0.1 part by weight of FC430 (fluorine-based surfactant) manufactured by 3M Corporation were mixed as a surfactant, and a protective film was formed on the glass substrate by the same method. Formed.

<Example 4>

10 parts by weight of Dow Corning Co., Ltd. Z-6020 SILANE as a trialkoxysilane-based unsaturated compound (a3) in Example 1, 100 parts by weight of pentaerythritol tetramethacrylate as the polymerizable compound [B], thermal radical polymerization A thermosetting resin composition solution in the same manner except that 5 parts by weight of 1,1′-azobis-1-cyclohexylnitrile as an initiator [C] and 0.1 parts by weight of KP341 (silicone surfactant) manufactured by Shin-Etsu Silicone Co., Ltd. were mixed as a surfactant. Was prepared, and a protective film was formed on the glass substrate in the same manner.

<Example 5>

10 parts by weight of Dow Corning Co., Ltd. X1-6124 SILANE as a trialkoxysilane-based unsaturated compound (a3) in Example 1, 100 parts by weight of dipentaerythritol pentamethacrylate as a polymerizable compound [B], thermal radicals Thermosetting resin composition in the same manner except for mixing 5 parts by weight of 1,1′-azobis-1-cyclohexylnitrile as a polymerization initiator [C] and 0.1 parts by weight of KP341 (silicone-based surfactant) manufactured by Shin-Etsu Silicone Co., Ltd. as a surfactant. The solution was prepared, and a protective film was formed on the glass substrate in the same manner.

Comparative Example 1

A thermosetting resin composition solution was prepared in the same manner as in Example 1 except that the trialkoxysilane-based unsaturated compound (a3) was not used, and a protective film was formed on the glass substrate by the same method.

Comparative Example 2

A thermosetting resin composition solution was prepared in the same manner as in Example 3, except that the trialkoxysilane-based unsaturated compound (a3) was not used, and a protective film was formed on the glass substrate by the same method.

Evaluation method for the protective film used in the present invention is as follows, the evaluation results for the protective film prepared in Examples and Comparative Examples are shown in Table 1.

(1) adhesion

According to the checkered tape method (ASTM D3359), 100 checker marks were formed in a protective film by a cutter knife, and the adhesive test was done. The number of the checkerboard scales which peeled was measured, and the adhesiveness of a protective film was evaluated by the following reference | standard.

(Circle): The number of the peeled checkerboard patterns 5 or less

(Triangle | delta): The number of the peeled checkerboard patterns 6-49

×: 50 or more pieces of checkered patterns

(2) surface hardness

According to the pencil hardness method (ASTM D3363), the pencil hardness test method was performed on the protective film to evaluate the surface hardness of the protective film.

(3) transparency

The transmittance of the protective film was measured at 400-700 nm using a spectrophotometer (UV-VIS spectrophotometer UV-3101PC of SHIMADZU), and the transparency of the protective film was evaluated according to the following criteria.

○: 95% minimum transmittance

△: minimum transmittance of 90 to 95%

X: less than 90% of the lowest transmittance

(4) flatness

The surface irregularities of the protective film were irradiated using the α step, and the step difference of the substrate was measured.

(5) UV resistance

The protective film was irradiated with UV (2000mJ / cm 2). The transmission spectrum of the protective film before and after UV irradiation was measured, and UV resistance of the protective film was evaluated by the following criteria.

(Circle): The change of a transmission spectrum is within 1%.

X: 1% or more of change in transmission spectrum

(6) heat resistance (degree of yellowing)

The protective film was heated in a clean oven at 240 ° C. for 60 minutes, the transmission spectrum before and after heating was measured, and the heat resistance and the degree of yellowing of the protective film were evaluated by the following criteria.

○: Change in transmission spectrum is less than 1% (no yellowing)

X: 1% or more of change in transmission spectrum (with yellowing)

(7) acid resistance

After the glass substrate on which the protective film was formed was immersed in a 25 wt% aqueous hydrochloric acid solution for 30 minutes at 30 ° C., the appearance change of the protective film was observed to evaluate the acid resistance of the protective film.

(8) alkali resistance

After the glass substrate on which the protective film was formed was immersed in a 10 wt% sodium hydroxide aqueous solution for 30 ° C. for 60 minutes, the appearance change of the protective film was observed to evaluate the alkali resistance of the protective film.

division Adhesion Surface hardness Transparency Leveling property UV resistance Heat resistance Acid resistance Alkali resistance Example 1 ○ 5H ○ 0.1 μm ○ ○ No change No change Example 2 ○ 5H ○ 0.1 μm ○ ○ No change No change Example 3 ○ 5H ○ 0.1 μm ○ ○ No change No change Example 4 ○ 5H ○ 0.1 μm ○ ○ No change No change Example 5 ○ 5H ○ 0.1 μm ○ ○ No change No change Comparative Example 1 ○ 3H ○ 0.3 μm × × No change No change Comparative Example 2 ○ 3H ○ 0.3 μm × × No change No change

As a result of the physical property measurement, when the thermosetting resin of the present invention is used to form the color filter protective film on the substrate, it can be seen that the planarization, mechanical properties, UV resistance and heat resistance are particularly superior to the comparative example.

As described above, the thermosetting resin of the present invention has excellent planarization and mechanical properties, has UV resistance and heat resistance, and does not exhibit yellowing at high temperatures. It can manufacture and can provide the thermosetting resin composition which is very suitable as a protective film formation material for optical devices.

Claims (5)

The thermosetting resin composition containing the copolymer [A] of (a1) unsaturated carboxylic acid or its anhydride, (a2) epoxy group containing unsaturated compound, (a3) trialkoxysilane-type unsaturated compound, and (a4) olefinic unsaturated compound. The method of claim 1, The copolymer [A] contains 5 to 60 weight% of structural units derived from the (a3) trialkoxysilane-type unsaturated compound. The thermosetting resin composition characterized by the above-mentioned. The method of claim 1, The thermosetting resin composition further comprises a polymerizable compound [B] having an ethylenically unsaturated bond in an amount of 150 parts by weight or less based on 100 parts by weight of the copolymer [A]. The method of claim 1, The thermosetting resin composition further comprises a thermal radical polymerization initiator [C] in an amount of 20 parts by weight or less based on 100 parts by weight of the copolymer [A]. The protective film for optical devices formed from the composition of any one of Claims 1-4.