KR20150020853A - Thermosetting resin composition - Google Patents

Abstract

The present invention relates to a thermosetting resin composition and a protective film made of the composition, and more particularly, to a thermosetting composition suitable for forming a protective film used in a color filter for an optical device and a protective film made of the composition, (A) a curing compound [B] in a thermosetting resin composition comprising a carboxylic acid or an anhydride thereof, (a2) an epoxy group-containing unsaturated compound, and (a3) an olefinically unsaturated compound A protective film having excellent surface hardness, planarization property, mechanical property, UV resistance and heat resistance, sufficient adhesion with a substrate, acid resistance and alkali resistance can be produced, and a yellowing phenomenon , It is very suitable as a material for forming a protective film for an optical device It is possible to provide a curable resin composition.

Description

TECHNICAL FIELD The present invention relates to a thermosetting resin composition,

The present invention relates to a thermosetting resin composition and a protective film made of the composition, and relates to a thermosetting composition preferable as a material for forming a protective film used in a color filter for an optical device and a protective film made of the composition.

An optical device such as a liquid crystal display device (LCD) is immersed in an organic solvent, an acid, an alkali solution or the like during the manufacturing process, or the wiring electrode layer is subjected to severe treatment such as being subjected to high temperature locally heated by sputtering . Therefore, a protective film may be provided on the surface of these devices in order to prevent deterioration at the time of manufacturing.

The protective film serves to protect the colored layer and to flatten the color filter.

Therefore, the protective film must be able to withstand such a severe treatment as described above, and must have good adhesion to the substrate or the underlayer, and it is required to have excellent smoothness, surface hardness, transparency and excellent heat resistance and light resistance without deterioration such as coloration, do. It is also required to have excellent chemical resistance such as solvent resistance, acid resistance and alkali resistance, and excellent water resistance. Also, when such a protective film is applied to a color filter of a color liquid crystal display device, it is preferable that a step of a general color filter can be flattened as a substrate.

The protective film composition is prepared in the form of a curable resin composition and satisfactorily classified into thermosetting and photocurable (photosensitive). When a pattern of a protective film is required, a photosensitive resin composition is required. Otherwise, a thermosetting resin composition is used. This is because it is convenient in the process and can increase the crosslinking density and is excellent in mechanical properties and heat resistance.

Japanese Patent Application Laid-Open Nos. 2000-103937, 2000-119472, and 2000-143772 disclose a thermosetting resin composition as a composition constituting a protective film. That is, a composition composed of an acrylic resin containing a carboxyl group or an epoxy group, a polyfunctional monomer containing an ethylenic unsaturated group serving as a crosslinking agent, and a heat polymerization initiator is used.

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

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and it is an object of the present invention to provide a thermosetting resin composition excellent in mechanical properties and heat resistance by effectively improving crosslinking density by using an alicyclic epoxy compound as a crosslinking agent and a protective film made of the composition have.

It is another object of the present invention to provide a thermosetting resin composition which does not exhibit yellowing even at a high temperature and a protective film made of the composition.

In order to achieve the above object, the present invention provides a thermosetting resin composition comprising (a1) an unsaturated carboxylic acid or an anhydride thereof, (a2) an epoxy group-containing unsaturated compound, and (a3) an olefinically unsaturated compound [A] And a thermosetting resin composition characterized by containing an alicyclic epoxy compound as the curable compound [B].

The curable compound [B] is contained in an amount of 1 to 10 parts by weight based on 100 parts by weight of the copolymer [A].

The thermosetting resin composition further comprises a polymerizable compound [C] having an ethylenic 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 further comprises a thermal radical polymerization initiator 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 from the thermosetting resin composition.

As described above, the thermosetting resin of the present invention has excellent planarization property, mechanical properties, and has a UV resistance and heat resistance, so that yellowing does not occur even at a high temperature, and a protective film having sufficient adhesion with the substrate, acid resistance and alkali resistance It is possible to provide a thermosetting resin composition which is very suitable as a protective film forming material for optical devices.

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

The curable compound [B] used in the present invention acts as a curing agent with respect to the copolymer [A]. The copolymer [A] will be described later.

The curable compound [B] is selected from an alicyclic epoxy compound. The reactivity of the alicyclic epoxy compound makes it possible to ensure a higher curing density of the cured film, thereby preventing deterioration of the heat resistance, UV resistance, and chemical resistance of the cured film.

Specific examples of such alicyclic epoxy compounds include CELLOXIDE 3000, CELLOXIDE 2021P, CELLOXIDE 2081, EPOLEAD GT301 and EPOLEAD GT401 commercially available from Daicel Chemical.

The curable compound [B] is preferably contained in an amount of 1 to 10 parts by weight, more preferably 3 to 10 parts by weight, per 100 parts by weight of the copolymer [A]. When the content of the curable compound [B] is within the above range, it is preferable in obtaining a protective film having a sufficiently high crosslinking density in order to improve various resistance of the protective film. In addition, The content can be reduced, and as a result, the properties of the protective film can be stabilized or the adhesion can be improved.

The copolymer [A] is obtained by a conventionally known polymerization method, that is, the compounds (a1), (a2) and (a3) can be synthesized by performing radical polymerization in a solvent in the presence of a polymerization initiator.

The copolymer [A] preferably contains 5 to 40% by weight, more preferably 10 to 30% by weight, of the constituent unit derived from the compound [a1]. When the content of the constituent unit is less than 5% by weight, heat resistance, chemical resistance and surface hardness of the protective film to be produced later tend to decrease. When the content exceeds 40% by weight, the storage stability is deteriorated. 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. One of these dicarboxylic acids may be used alone, or two or more dicarboxylic acids may be used in combination. Of these, acrylic acid, methacrylic acid, maleic anhydride and the like are mainly used because they are excellent in copolymerization reactivity and heat resistance and are easily available.

The copolymer [A] preferably contains 10 to 70% by weight, more preferably 20 to 60% by weight, of the constituent unit derived from the compound [a2]. When the content of the constituent unit is within the above range, it is preferable from the viewpoint of maintaining safety and preservation in improving the heat resistance and surface hardness of a protective film to be produced later. Examples of the compound (a2) include glycidyl acrylate, glycidyl methacrylate, glycidyl? -Ethyl acrylate, glycidyl? -N-propyl acrylate, glycidyl? -N-butyl acrylate, Epoxybutyl, methacrylic acid-3,4-epoxybutyl, acrylic acid-6,7-epoxyheptyl, methacrylic acid-6,7-epoxyheptyl,? -Ethylacrylic acid-6,7-epoxyheptyl, o Vinylbenzyl glycidyl ether, p-vinylbenzyl glycidyl ether, or a combination of two or more thereof, and the copolymerization reactivity and the heat resistance and hardness of the obtained protective film are increased Is preferably used.

The copolymer [A] preferably contains 10 to 70% by weight, more preferably 20 to 50% by weight, of the constituent unit derived from the compound [a3]. It is preferable that the content of the constituent unit is within the above range in order to improve the heat resistance and surface hardness of the protective film to be produced after the stabilization of the storage stability. 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; Alkyl acrylate esters such as methyl acrylate and isopropyl acrylate; Methacrylic acid cycloalkyl esters such as cyclohexyl methacrylate, 2-methylcyclohexyl methacrylate, dicyclopentenyl methacrylate, dicyclopentenyloxyethyl methacrylate and isobornyl methacrylate; Acrylic acid cycloalkyl esters such as cyclohexyl acrylate, 2-methylcyclohexyl acrylate, dicyclopentenyl acrylate, dicyclopentenyloxyethyl acrylate, and isobornyl 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 itaconate; Hydroxyalkyl esters such as 2-hydroxyethyl methacrylate and 2-hydroxypropyl methacrylate; And styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, vinyltoluene, p-methoxystyrene, 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. Of these, styrene, t-butyl methacrylate, dicyclopentenyl methacrylate, p-methoxystyrene, 2-methylcyclohexyl acrylate and 1,3-butadiene 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 acid anhydride and an epoxy group and can be easily cured by heating even without using a special curing agent. However, it is difficult to obtain a sufficient cross- When a curable compound [B] is used, the crosslinking density can be sufficiently increased.

The molecular weight of the copolymer [A] is not particularly limited, but is appropriately selected depending on the thickness of the film to be formed, the solution application conditions of the curable composition, the purpose, and the like. The number average molecular weight of the copolymer [A] is preferably in the range of 3,000 to 100,000, more preferably 3,000 to 50,000 in view of the surface smoothness of the protective film to be produced later.

Examples of the solvent used for the synthesis of the copolymer [A] include alcohols such as methanol and ethanol; Ethers such as tetrahydrofuran, diethylene glycol dimethyl ether and diethylene glycol diethyl ether; And propylene glycol alkyl ether acetates such as propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, propylene glycol propyl ether acetate, propylene glycol butyl ether acetate and the like, or a combination of two or more thereof.

As the polymerization initiator used in the synthesis of the copolymer [A], those generally known as radical polymerization initiators can be used. Azo compounds such as 2,2'-azobisisobutyronitrile, 2,2'-azobis- (2,4-dimethylvaleronitrile), 2,2'-azobis- (4-methoxy- Dimethylvaleronitrile); and the like; Organic peroxides such as benzoyl peroxide, t-butyl peroxypivalate, and 1,1'-bis- (t-butylperoxy) cyclohexane; And hydrogen peroxide. When a peroxide is used as a radical polymerization initiator, the peroxide can be used as a redox type initiator together with a reducing agent.

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

The above polymerizable compound [C] is preferable from the viewpoint that the monofunctional, bifunctional or trifunctional or higher functional (meth) acrylate is excellent in the polymerizability and the heat resistance and surface hardness of the protective film obtained later are improved.

Examples of the monofunctional (meth) acrylate include 2-hydroxyethyl (meth) acrylate, carbitol (meth) acrylate, isobonyl (meth) acrylate, 3-methoxybutyl And 2- (meth) acryloyloxyethyl 2-hydroxypropyl phthalate.

Examples of the bifunctional (meth) acrylate include ethylene glycol (meth) acrylate, 1,6-hexanediol (meth) acrylate, 1,9-nonanediol (meth) acrylate, propylene glycol Tetraethylene glycol (meth) acrylate, bisphenoxy ethyl alcohol fluorene diacrylate, and the like.

Examples of the above (meth) acrylate having three or more functional groups include (meth) acrylic acid esters such as trishydroxyethylisocyanurate tri (meth) acrylate, trimethylpropanetri (meth) acrylate, pentaerythritol tri (Meth) acrylate, dipentaerythritol hexa (meth) acrylate, and the like.

These polymerizable compounds [C] may be used alone or in combination of two or more selected from monofunctional, bifunctional or trifunctional (meth) acrylates.

The polymerizable compound [C] is preferably contained in an amount of 150 parts by weight or less, more preferably 120 parts by weight or less, based on 100 parts by weight of the copolymer [A]. The content of the polymerizable compound [C] is preferably 150 parts by weight or less based on 100 parts by weight of the copolymer [A], which is preferable in improving the adhesion of the obtained protective film.

The thermosetting resin composition of the present invention may further contain a thermal radical polymerization initiator, and it is contained in an amount 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]. It is preferable that the heat radical polymerization initiator is used in an amount of 20 parts by weight or less in view of heat resistance and planarization property of the protective film to be obtained later.

As the thermal radical polymerization initiator, those generally known as radical polymerization initiators can be used, and a polymerization initiator used for the polymerization of the copolymer [A] described above can be used.

The thermosetting resin composition of the present invention can be produced by optionally dissolving the polymerizable compound [C] and thermal radical polymerization initiator in a solvent together with the copolymer [A] and the curable compound [B]. The solvent used at this time is one which does not react with any one component. For example, a solvent used for the polymerization of the copolymer [A] can be used. Of these solvents, diethylene glycol dimethyl ether, diethylene glycol diethyl ether and propylene glycol methyl ether are preferable from the viewpoints of solubility, reactivity, Acetate is preferred. It is also possible to use a high boiling point solvent together with the above solvent.

Examples of the high boiling point solvent include N, N-dimethylformamide, N-methylacetamide, N, N-dimethylacetamide, N-methylpyrrolidone, dimethylsulfoxide, And the like. When such a high boiling point solvent is used in combination, the mixing ratio with the solvent is preferably "(the above solvent): (high boiling point solvent) = 50 to 100: 50 to 0".

In addition, the thermosetting resin composition of the present invention may contain other components as needed within the technical scope of the present invention. Other components herein include surfactants for improving the coating properties, for example. Examples of the surfactant include fluorine or silicone surfactants, and examples thereof include FC-129, FC-170C and FC-430 of 3M Company. It may 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]. When a surfactant is used in an amount exceeding 5 parts by weight based on 100 parts by weight of the copolymer [A], there is a problem that bubbles easily occur during application.

The thermosetting resin composition thus mixed can be used after filtration using a filter having a diameter of about 0.1 to 5 탆.

In the thermosetting resin composition of the present invention, for example, a protective film can be formed by the following method.

A protective film can be obtained by applying a thermosetting resin composition to a substrate and removing the solvent to form a coating film of the thermosetting resin composition, followed by heat treatment.

As the substrate, glass, quartz, silicon, resin, or the like can be used, and examples of the resin include polyethylene terephthalate, polybutylene terephthalate, polyether sulfone, polycarbonate, polyimide, and ring- And hydrogenated products thereof.

The method of applying the thermosetting resin composition solution is not particularly limited, and for example, a spray method, a roll coating method, a spin coating method, or the like can be used.

The removal of the solvent is preferably performed by a heat treatment (preliminary firing). The conditions of this preliminary firing are preferably baked at 60 to 120 DEG C for about 0.5 to 20 minutes, though they vary depending on the kind, ratio, and the like of each component of the composition solution.

The protective film for optical devices can be manufactured by treating the substrate at a temperature of 150 to 300 DEG C for 10 to 100 minutes.

The thickness of the protective film formed as described above is preferably 0.1 to 6.0 占 퐉. In the case where the protective film has unevenness on the substrate, the value should be understood as a value at the uppermost surface 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'-azobisisobutyronitrile and 200 parts by weight of diethylene glycol dimethyl ether were placed in a reaction vessel equipped with a cooling tube and a stirrer. Then, 20 parts by weight of styrene, 30 parts by weight of methacrylic acid, 40 parts by weight of glycidyl methacrylate and 10 parts by weight of dicyclopentenyloxyethyl methacrylate were charged, and the mixture was gradually replaced with nitrogen. The temperature of the solution was raised to 80 캜 and maintained at this temperature for 4 hours to obtain a polymer solution containing the copolymer [A1]. The solid content concentration of the obtained copolymer solution was 33% by weight.

5 parts by weight of CELLOXIDE 2021P (alicyclic epoxy compound) manufactured by Daicel Chemical Co., Ltd. as a curing compound [B] and 100 parts by weight of FC-430 (a fluorine surfactant ) Were mixed and dissolved in diethylene glycol dimethyl ether so that the solid content concentration was 25%. Thereafter, the solution was filtered with a filter having a pore diameter of 0.45 mu m to prepare a thermosetting resin composition solution.

The thermosetting resin composition solution was coated on the glass substrate using a spin coater so that the thickness of the solution became 2 占 퐉 and fired in a clean oven at 220 占 폚 for 30 minutes to form a protective film on the glass substrate.

≪ Example 2 >

Except that 5 parts by weight of CELLOXIDE 2081 (alicyclic epoxy compound) manufactured by Daicel Chemical Co., Ltd. as the curable compound [B] in Example 1 and 0.1 part by weight of KP341 (silicone surfactant) of Shin-Etsu Silicone Co., Ltd. as a surfactant were mixed A thermosetting resin composition solution was prepared and a protective film was formed on a glass substrate in the same manner.

≪ Example 3 >

In Example 1, EPOLEAD GT301 (alicyclic epoxy compound) manufactured by Daicel Chemical Corporation as a curable compound [B], 100 parts by weight of trimethylpropane trimethacrylate as a polymerizable compound [C], 100 parts by weight of benzoyl peroxide And 0.1 part by weight of FC430 (a fluorine surfactant) manufactured by 3M Co., Ltd. as a surfactant were mixed in the same manner as above, and a protective film was formed on a glass substrate in the same manner.

<Example 4>

In Example 1, EPOLEAD GT401 (alicyclic epoxy compound) manufactured by Daicel Chemical Co., Ltd., 100 parts by weight of pentaerythritol tetramethacrylate as the polymerizable compound [C] as the curable compound [B] 5 parts by weight of 1'-azobis-1-cyclohexylnitrile and 0.1 parts by weight of KP341 (silicone surfactant) of Shin-Etsu Silicone Co., Ltd. as a surface active agent were mixed to prepare a thermosetting resin composition solution. A protective film was formed in the same manner.

&Lt; Example 5 >

In Example 1, 100 parts by weight of CELLOXIDE 3000 (an alicyclic epoxy compound) manufactured by Daicel Chemical Corporation as a curable compound [B], 100 parts by weight of dipentaerythritol penta methacrylate as a polymerizable compound [C], 1 part by weight of a thermal radical polymerization initiator 5 parts by weight of 1'-azobis-1-cyclohexylnitrile, and 0.1 parts by weight of KP341 (silicone surfactant) of Shin-Etsu Silicone Co., Ltd. as a surfactant were mixed, A protective film was formed in the same manner as above.

&Lt; Comparative Example 1 &

A thermosetting resin composition solution was prepared in the same manner as in Example 1 except that the curable compound [B] was not used, and a protective film was formed on a glass substrate in the same manner.

&Lt; Comparative Example 2 &

A thermosetting resin composition solution was prepared in the same manner as in Example 3 except that the curable compound [B] was not used, and a protective film was formed on a glass substrate in the same manner.

&Lt; Comparative Example 3 &

A thermosetting resin composition solution was prepared in the same manner as in Example 1 except that CN112C60 (novolak epoxy acrylate resin) manufactured by Sartomer was used as the curable compound [B], and a protective film was formed on a glass substrate in the same manner .

&Lt; Comparative Example 4 &

A thermosetting resin composition solution was prepared in the same manner as in Example 1 except that CN2200 (polyester acrylate resin) manufactured by Sartomer was used as the curable compound [B], and a protective film was formed on a glass substrate in the same manner.

The evaluation method of the protective film used in the present invention is as follows, and the evaluation results of the protective film prepared in the above Examples and Comparative Examples are shown in Table 1 below.

(1) Adhesiveness

A checkerboard scale of 100 pieces was formed as a cutter knife on the protective film according to the checkerboard tape method (ASTM D3359), and the adhesion test was conducted. The number of peeled checker scales was measured, and the adhesion of the protective film was evaluated according to the following criteria.

○: Number of peeled checkered patterns No more than 5

B: Number of peeled checkered patterns 6 to 49

X: Number of peeled checkered patterns 50 or more

(2) Surface hardness

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

(3) Transparency

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

○: Minimum transmittance exceeded 95%

?: Minimum transmittance: 90 to 95%

×: Minimum transmittance less than 90%

(4) Flatness

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

(5) UV resistance

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

?: Transmission spectrum change within 1%

X: Change in transmission spectrum is 1% or more

(6) Heat resistance (yellowing degree)

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

○: Transmission spectrum change within 1% (no yellowing phenomenon)

X: Change in transmission spectrum is 1% or more (yellowing phenomenon)

(7) Acid resistance

The glass substrate on which the protective film was formed was immersed in a 25 wt% hydrochloric acid aqueous solution at 30 DEG C for 20 minutes, and then the appearance change of the protective film was observed to evaluate the acid resistance of the protective film.

(8) Alkalinity

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

division Adhesiveness Surface hardness Transparency Planarization property
(Uneven level) UV resistance Heat resistance Acid resistance My alkalinity Example 1 ○ 5H ○ 0.1 탆 ○ ○ No change No change Example 2 ○ 5H ○ 0.1 탆 ○ ○ No change No change Example 3 ○ 5H ○ 0.1 탆 ○ ○ No change No change Example 4 ○ 5H ○ 0.1 탆 ○ ○ No change No change Example 5 ○ 5H ○ 0.1 탆 ○ ○ No change No change Comparative Example 1 ○ 5H ○ 0.3 탆 × × No change No change Comparative Example 2 ○ 5H ○ 0.3 탆 × × No change No change Comparative Example 3 ○ 5H ○ 0.3 탆 × × No change No change Comparative Example 4 ○ 5H ○ 0.3 탆 × × No change No change

As a result of the physical property measurement, it can be seen that when the thermosetting resin of the present invention is used for forming the color filter protective film on the substrate, the flatness, the mechanical properties, the UV resistance and the heat resistance are particularly excellent as compared with the comparative example.

Claims (5)

A thermosetting resin composition comprising (a1) an unsaturated carboxylic acid or an anhydride thereof, (a2) an epoxy group-containing unsaturated compound and (a3) an olefinically unsaturated compound copolymer [A]
A thermosetting resin composition comprising an alicyclic epoxy compound as the curable compound [B].
The thermosetting resin composition according to claim 1, wherein the curable compound [B] contains 1 to 10 parts by weight per 100 parts by weight of the copolymer [A].
The thermosetting resin composition according to claim 1, wherein the thermosetting resin composition further comprises a polymerizable compound [C] 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] Composition.
The thermosetting resin composition according to claim 1, wherein the thermosetting resin composition further comprises a thermal radical polymerization initiator in an amount of 20 parts by weight or less based on 100 parts by weight of the copolymer [A].
A protective film for an optical device formed from the composition of any one of claims 1 to 4.