KR101004380B1 - Thermosetting resin composition for overcoating material of photo-device - Google Patents

Abstract

The present invention further comprises one or two or more curable compounds selected from salt compounds represented by the following general formula (1) or (2) to a copolymer of unsaturated carboxylic acid and / or unsaturated carboxylic anhydride, an epoxy group-containing unsaturated compound and an olefinically unsaturated compound other than the above. It provides a thermosetting resin composition comprising a, which satisfies the characteristics required in the past as a protective film, while effectively improving the crosslinking density, excellent mechanical properties and heat resistance, color of the optical device without yellowing at high temperature A filter protective film can be provided.

Wherein R ₁ , R ₂ and R ₃ are the same as or different from each other, and are a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and X is SbF ₆ or PF ₆ .

Wherein R ₄ and R ₅ are the same as or different from each other, and are a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and Y is SbF ₆ or PF ₆ .

Description

Thermosetting resin composition for overcoating material of photo-device} useful as a protective film forming material for optical devices

The present invention relates to a thermosetting resin composition suitable as a protective film forming material for an optical device.

An optical device such as a liquid crystal display device is subjected to harsh processing such as being immersed by an organic solvent, an acid, an alkali solution, or the like during the manufacturing process, or subjected to localized high temperature heating of the surface by sputtering when forming a wiring electrode layer. Therefore, in order to prevent the deterioration at the time of manufacture, these elements may provide a protective film in the surface.

This protective film withstands the above treatments, and has excellent adhesion to the substrate or lower layer, high smoothness and surface hardness, excellent transparency, and excellent heat resistance and light resistance without deterioration such as coloring, yellowing and whitening over a long period of time. What is excellent in chemical-resistance, such as chemical resistance, acid resistance, and alkali resistance, water resistance, etc. 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 base substrate.                         

Such a material is manufactured in the form of curable resin composition, and is 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.

Patents related to a protective film made of such a thermosetting resin composition have been proposed in Japanese Patent Laid-Open Nos. 2000-103937, 2000-119472, and 2000-143772.

As a material applied to such a protective film, a composition composed of an acrylic resin containing a carboxyl group or an epoxy group, a polyfunctional monomer containing an ethylenically unsaturated group serving as a crosslinking agent, and a thermal polymerization initiator are used. In the case of such a conventional thermosetting resin composition, mechanical properties are not excellent, and in particular, yellowing phenomenon is often exhibited due to poor heat resistance at high temperatures. Therefore, in order to prevent such a phenomenon, the polyfunctional monomer containing an ethylenically unsaturated group is excessively used, and such excessive use has a disadvantage of intensifying a yellowing phenomenon at a high temperature.

Accordingly, the present inventors further include a salt-type curable compound as a crosslinking agent, while trying to solve the problems of the prior art as described above. As a result, the present invention satisfies the characteristics conventionally required as a protective film, and effectively improves the crosslinking density. The present invention has been completed to find out that a thermosetting resin composition excellent in mechanical properties and heat resistance and highly suitable as a protective film forming material for an optical device can be provided.

Accordingly, it is an object of the present invention to provide a thermosetting resin composition which satisfies the required properties as an optical device protective film forming material, and also effectively improves the crosslinking density, thereby providing excellent mechanical properties and heat resistance.

The thermosetting resin composition of the present invention for achieving the above object is (a-1) unsaturated carboxylic acid and / or unsaturated carboxylic anhydride, (a-2) epoxy group-containing unsaturated compound and (a-3) said (a-1) And a copolymer of an olefinically unsaturated compound other than (a-2), characterized in that it further comprises one or two or more curable compounds selected from salt compounds represented by the following general formula (1) or (2).

Formula 1

Wherein R ₁ , R ₂ and R ₃ are the same as or different from each other, and are a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and X is SbF ₆ or PF ₆ .

Formula 2

Wherein R ₄ and R ₅ are the same as or different from each other, and are a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and Y is SbF ₆ or PF ₆ .

The present invention will be described in more detail as follows.

The thermosetting resin composition according to the present invention includes a copolymer and a curing catalyst represented by Chemical Formula 1 or 2.

(A) Copolymer

The copolymer in the composition of the present invention is obtained by a conventionally known polymerization method, that is, (a-1) unsaturated carboxylic acid and / or unsaturated carboxylic anhydride, (a-2) epoxy group-containing unsaturated compound and (a-3) Olefinically unsaturated compounds other than (a-1) and (a-2) can be synthesized by radical polymerization in the presence of a polymerization initiator in a solvent.

The copolymer in the composition of the present invention thus synthesized preferably contains 5 to 40% by weight, particularly preferably 10 to 30% by weight, of structural units derived from compound (a-1). Copolymers having a structural unit of less than 5% by weight tend to lower heat resistance, chemical resistance and surface hardness, whereas copolymers of more than 40% by weight lower storage safety.

As a compound (a-1), For example, 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. Among these, acrylic acid, methacrylic acid, maleic anhydride and the like are preferably used in view of copolymerization reactivity, heat resistance and easy availability. It can be used as a compound (a-1) among these compounds individually or in combination.

In addition, the copolymer of the present invention preferably contains 10 to 70% by weight, particularly preferably 20 to 60% by weight, of structural units derived from compound (a-2). The copolymer having less than 10% by weight of the structural unit tends to lower the heat resistance and surface hardness of the protective film to be obtained, whereas when it exceeds 70% by weight, the storage stability of the copolymer tends to be lowered.

As the compound (a-2), for example, glycidyl acrylate, glycidyl methacrylate, α-ethyl acrylate glycidyl, α-n-propyl acrylate glycidyl, α-n-butyl acrylate glycidyl , 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-vinyl benzyl glycidyl ether, m-vinyl benzyl glycidyl ether, p-vinyl benzyl glycidyl ether, and the like are preferably used in view of copolymerization reactivity and heat resistance and hardness of the resulting protective film. . It can be used as a compound (a-2) by selecting among these compounds individually or in combination.

The copolymer of the present composition contains 10 to 70% by weight of the structural unit derived from compound (a-3), and particularly preferably 20 to 50% by weight. When this structural unit is less than 10 weight%, there exists a tendency for the storage safety of a copolymer to fall, and when it exceeds 70 weight%, there exists a tendency for the heat resistance and surface hardness of a copolymer to fall.

Examples of the compound (a-3) 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-methyl cyclohexyl 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; Hydroxyalkyl 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 And vinyl acetate, 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, and the like. 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. It can be used alone or in combination as a compound (a-3) by selecting from these compounds.

The copolymer thus obtained has a carboxyl group and / or a carboxylic anhydride group and an epoxy group, and can be easily cured by heating even without using a special curing agent.

As a solvent which can be used for the synthesis | combination of a copolymer, Alcohol, such as methanol and ethanol; Ethers such as tetrahydrofuran, diethylene glycol dimethyl ether and diethylene glycol diethyl ether; 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, etc. are preferable.

As a polymerization initiator which can be used for the synthesis | combination of a copolymer, 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, Azo compounds such as 4-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, you may use it as a redox initiator, using a peroxide together with a reducing agent.

(B) Curable Compound

The curable compound included in the composition of the present invention is a curing catalyst in salt form, which acts as a curing agent for the copolymer. The curing catalyst in salt form is selected from the compounds represented by Formula 1 or 2 above.

Such a curable compound is contained in an amount of 0.0001 to 10 parts by weight, preferably 0.001 to 1 part by weight, based on 100 parts by weight of the copolymer. If the content of the curable compound is less than 0.0001 parts by weight with respect to 100 parts by weight of the copolymer, it is difficult to obtain a protective film having a sufficiently high crosslinking density, and the resistance of the protective film may be lowered in some cases. On the other hand, when the content of the curable compound exceeds 10 parts by weight with respect to 100 parts by weight of the copolymer, a large amount of unreacted curable compound is likely to remain inside the film of the resulting protective film, and as a result, the property of the protective film becomes unstable or adhesive. It is easy to fall.

(C) other

In the thermosetting resin composition of the present invention, a polymerizable compound having an ethylenically unsaturated bond (hereinafter referred to as a "polymerizable compound") or a thermal radical polymerization initiator may be included in addition to the copolymer and the curable compound.

At this time, as a polymeric compound, monofunctional, bifunctional, or trifunctional or more than (meth) acrylate is preferable from a viewpoint that a polymerizability is favorable and the heat resistance and surface hardness of the protective film obtained are improved.

Here, as monofunctional (meth) acrylate, 2-hydroxy ethyl (meth) acrylate, carbitol (meth) acrylate, isobornyl (meth) acrylate, 3-methoxy butyl (meth), for example Acrylate, 2- (meth) acryloyl oxy ethyl 2-hydroxy propyl phthalate, etc. are mentioned.

As a bifunctional (meth) acrylate, for example, ethylene glycol (meth) acrylate, 1,6-hexanediol (meth) acrylate, 1,9-nonanediol (meth) acrylate, propylene glycol (meth) ) Acrylate, tetraethylene glycol (meth) acrylate, bisphenoxy ethyl alcohol fluorene diacrylate, etc. are mentioned.

As (meth) acrylate more than trifunctional, for example, tris hydroxyethyl isocyanurate tri (meth) acrylate, trimethyl propane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (Meth) acrylate, dipentaerythritol hexa (meth) acrylate, etc. are mentioned.

Such mono-, bi-, or tri- or more (meth) acrylates are used alone or in combination.

When it contains such a polymeric compound, the content is 150 weight part or less with respect to 100 weight part of copolymers, Preferably it is 120 weight part or less. When content of a polymeric compound exceeds 150 weight part with respect to 100 weight part of said copolymers, the adhesiveness of the protective film obtained will fall easily.

On the other hand, as a thermal radical polymerization initiator, 2,2'- azobis isobutyronitrile, 2,2'- azobis- (2,4-dimethylvaleronitrile), 2,2'- azobis- (4- Azo compounds such as methoxy-2,4-dimethylvaleronitrile) and 1,1'-azobis-1-cyclohexylnitrile; Organic peroxides such as benzoyl peroxide, t-butyl peroxide, 1,1'-bis- (t-butyl peroxy) cyclohexane, and the like.

When the thermal radical polymerization initiator is included, the content thereof is 20 parts by weight or less, preferably 15 parts by weight or less based on 100 parts by weight of the copolymer. If the content of the thermal radical polymerization initiator exceeds 20 parts by weight with respect to 100 parts by weight of the copolymer, the heat resistance, the flattening property, and the like of the protective film tend to be lowered.

Such a thermosetting resin composition of the present invention is prepared by uniformly mixing each component of the copolymer, curable compound or polymerizable compound, and thermal radical polymerization initiator. Usually, the thermosetting resin composition of this invention is melt | dissolved in a suitable solvent, and is used in a solution state. That is, a copolymer, a curable compound or a polymerizable compound, a thermal radical polymerization initiator, and other additives are mixed at a predetermined ratio to prepare a thermosetting resin composition in a solution state. The composition of the present invention must include a copolymer and a curable compound.

As a solvent used for preparation of the thermosetting resin composition of this invention, as long as it can melt | dissolve each component of a copolymer, a curable compound, a polymeric compound, and a thermal radical polymerization initiator uniformly, it is possible to react with neither component. Specifically, For example, Alcohol, 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, and propylene glycol butyl ether acetate. Among these solvents, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, propylene glycol methyl ether acetate are preferably used in view of solubility, reactivity with each component, and convenience of coating film formation.

Moreover, it is also possible to use a high boiling point solvent together with the said solvent. As a high boiling point solvent which can be used together, it is N-methyl formamide, N, N-dimethyl formamide, N-methyl acetamide, N, N-dimethyl acetamide, N-methyl pyrrolidone, dimethyl sulfoxide, for example. And benzyl ethyl ether.

The thermosetting resin composition of this invention may contain other components of that excepting the above as needed in the range which does not impair the objective of this invention.

As an example of another component, surfactant for improving applicability | paintability is mentioned. Examples of the surfactant include fluorine and silicone-based surfactants, and examples thereof include FC-129, FC-170C, FC-430, KP322, KP323, KP340, and KP341 manufactured by Shin-Etsu Silicone. The content of such surfactant may be 5 parts by weight or less, preferably 2 parts by weight or less, based on 100 parts by weight of the copolymer. When the amount of the surfactant exceeds 5 parts by weight with respect to 100 parts by weight of the copolymer, bubbles are liable to occur during application.

The composition solution prepared as described above is used after filtration using a filter having a pore diameter of about 0.1 to 5 μm.

The target protective film can be obtained by apply | coating the thermosetting resin composition of this invention obtained in this way to a base substrate, and processing at 150-300 degreeC for 10 to 100 minutes in oven.

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

≪ Example 1 >

5 parts by weight of 2,2'-azobis isobutyronitrile was dissolved in 200 parts by weight of diethylene glycol dimethyl ether in a reaction vessel equipped with a cooling tube and a stirrer. Subsequently, 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 added thereto, followed by nitrogen substitution, followed by gentle stirring. The temperature of the solution was raised to 80 ° C. and maintained at this temperature for 4 hours to obtain a polymer solution containing the copolymer (A-1). Solid content concentration of the obtained polymer solution was 33 weight%.

) 0.01중량부 및 계면활성제로서 FC-430 (3M) 0.1중량부를 혼합하여 디에틸렌글리콜디메틸에테르와 N-메틸 피롤리돈에 용해시킨 후 고형분 농도가 25중량%가 되도록 하였다. 100 parts by weight (solid content) of the obtained copolymer (A-1) and the curable compound were manufactured by Adeka Opton CP-66 (

) 0.01 part by weight and 0.1 part by weight of FC-430 (3M) as a surfactant were mixed and dissolved in diethylene glycol dimethyl ether and N-methyl pyrrolidone so that the solid content concentration was 25% by weight.

Then, it filtered by the filter of 0.45 micrometers of pore diameters, and prepared the thermosetting resin composition solution (S-1).                     

<Example 2>

) 0.01중량부, 계면활성제로서 KP341(신에츠실리콘) 0.1중량부를 혼합하여 디에틸렌글리콜디메틸에테르와 N-메틸 피롤리돈에 용해시킨 후 고형분농도가 25 중량%가 되도록 하였다. 100 parts by weight of the copolymer (A-1) obtained in Example 1 (solid content) and the curable compound, Adeca Opton CP-77 (

) 0.01 parts by weight and 0.1 parts by weight of KP341 (Shin-Etsu Silicone) as a surfactant were mixed and dissolved in diethylene glycol dimethyl ether and N-methyl pyrrolidone so as to have a solid concentration of 25% by weight.

Then, it filtered by the filter of 0.45 micrometers of pore diameters, and prepared the thermosetting resin composition solution (S-2).

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Comparative Example 1

A thermosetting resin composition solution was prepared in the same manner as in Example 1, except that no curable compound was used.

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<Formation of protective film>

Using a spin coater, the respective thermosetting resin compositions obtained from the above examples and the comparative examples were applied onto the glass substrate so as 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. It was.

The obtained protective film was evaluated for adhesion, transparency, planarization, UV resistance, heat resistance, acid resistance and alkali resistance, and the results are shown in Table 1 below.

Specific evaluation method is as follows.

(1) adhesion

According to the checkered tape method, 100 checkered patterns were formed on the protective film by a cutter knife and the adhesion test was carried out. The number of peeled checkered patterns was measured, and the adhesion of the protective film was evaluated according to the following criteria.

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

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

×: 50 or more pieces of checkered patterns

(2) surface hardness

The surface hardness of the protective film was evaluated by performing a pencil hardness test on the protective film according to the hot pen hardness method.

(3) transparency

The transmittance of the protective film was measured at 400 to 700 nm using a spectrophotometer, and the transparency of the protective film was evaluated according to the following criteria.

○: 95% minimum transmittance

(Triangle | delta): More than 90 to 95% of minimum transmittance | permeability

×: 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. The transmission spectrum of the protective film was measured before and after UV irradiation, and the UV resistance of the protective film was evaluated according to the following criteria.

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

×: change in transmission spectrum is more than 1%

(6) Heat resistance (degree of yellowing)

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

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

×: change in transmission spectrum is more than 1%

(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.                     

From the results of Table 1, it can be seen that the mechanical properties and heat resistance are particularly improved when the curable compound is further included in the resin composition according to the present invention.

As described in detail above, the thermosetting resin composition comprising a curing catalyst in the form of a salt acting as a crosslinking agent to an acrylic resin containing a carboxyl group or an epoxy group according to the present invention satisfies the characteristics conventionally required as a protective film, By effectively improving the crosslinking density, it is possible to provide a color filter protective film of an optical device excellent in mechanical properties and heat resistance and free from yellowing at high temperatures.

Claims (5)

(a-1) Copolymer of unsaturated carboxylic acid and / or unsaturated carboxylic anhydride, (a-2) epoxy group containing unsaturated compound, and (a-3) olefinically unsaturated compound other than said (a-1) and (a-2) In the thermosetting resin composition useful as a protective film forming material for an optical device comprising a, Further comprising a curable compound represented by the formula (2), The curable compound is useful as a protective film forming material for an optical device, characterized in that it comprises 0.0001 to 0.01 parts by weight based on 100 parts by weight of the copolymer. Formula 2

Wherein R ₄ and R ₅ are the same as or different from each other, and are a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and Y is SbF ₆ or PF ₆ . delete The method according to claim 1, further comprising a polymerizable compound having a ethylenically unsaturated bond or a thermal radical polymerization initiator, The polymerizable compound having an ethylenically unsaturated bond is a monofunctional, bifunctional, or trifunctional or higher (meth) acrylate. The thermosetting resin composition useful as a protective film forming material for an optical device. The polymerizable compound having an ethylenically unsaturated bond is included in an amount of 150 parts by weight or less based on 100 parts by weight of the copolymer, and a thermal radical polymerization initiator is included in an amount of 20 parts by weight or less based on 100 parts by weight of the copolymer. A thermosetting resin composition useful as a protective film forming material for an optical device, characterized in that. The method of claim 1, wherein the copolymer of the olefinically unsaturated compound is methacrylic acid, such as methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, sec-butyl methacrylate, t-butyl methacrylate Alkyl esters; Acrylic acid alkyl esters such as methyl acrylate and isopropyl acrylate; Methacrylic acid cycloalkyl esters such as cyclohexyl methacrylate, 2-methyl cyclohexyl 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; Hydroxyalkyl 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, Thermosetting resin useful as a protective film forming material for optical devices, characterized in that at least one compound selected from the group consisting of vinyl acetate, 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, and combinations thereof. Composition.