| PATENT NUMBER | This data is not available for free |
| PATENT GRANT DATE | 15.08.2000 |
| PATENT TITLE |
Functionalized styrene polymers and copolymers |
| PATENT ABSTRACT |
The present invention provides a functionalized styrenic polymer or copolymer which contains functionalized stryene moiety having the formula: ##STR1## wherein R.sub.1 is hydrogen, alkyl, primary and secondary halo alkyl groups, and R.sub.2 is: ##STR2## where n is an integer of from 2 to about 10, R.sub.3 is independently hydrogen or an alkyl group and X is NH, O or S. The novel copolymers of the present invention have particular utility in forming polymer blends. For example, the amine and alcohol functionalized polymers can be used as compatabilizers by reacting them with a carboxylic acid containing polymer or the like. |
| PATENT INVENTORS | This data is not available for free |
| PATENT ASSIGNEE | This data is not available for free |
| PATENT FILE DATE | February 10, 1998 |
| PATENT PARENT CASE TEXT | This data is not available for free |
| PATENT CLAIMS |
What is claimed: 1. A method for functionalizing a copolymer of styrene and an isoolefin comprising: contacting the copolymer with a compound having the formula: ##STR7## wherein y is an integer of from 2 to about 10, R.sub.3 is hydrogen or an alkyl group of from 1 to about 10 carbon atoms and A is NH, CO.sub.3, O or S, the contacting being conducted in the presence of a Lewis acid catalyst at temperatures of from about -50.degree. C. to about 100.degree. C. for a time sufficient to functionalize the copolymer. 2. The method of claim 1 wherein the contacting is conducted in the presence of a solvent and the mole ratio of compound to styrene moiety in the polymer or copolymer ranges from about 0.01:1 to about 10:1. 3. The method of claim 2 wherein A is NH. 4. The method of claim 2 wherein A is O. -------------------------------------------------------------------------------- |
| PATENT DESCRIPTION |
FIELD OF THE INVENTION This invention relates to functionalized copolymers of styrene and an isoolefin. BACKGROUND OF THE INVENTION Styrene containing polymers, especially copolymers of para-alkylstyrene and an isoolefin having from about 4 to 7 carbon atoms, are well-known in the art. Indeed, copolymers of para-alkylstyrene and isobutylene are low Tg elastomers which possesses low air permeability, unique damping properties, excellent environmental aging resistance and low surface energy which makes them particularly desirable in many applications. Unfortunately, these polymers also have low reactivity and poor compatibility with most other polymers. Thus there is a need for functionalizing styrenic containing polymers and copolymers, especially copolymers of isoolefins and para-alkylstyrene, with more compatible units for blending. It is an object of the present invention therefore to functionalize styrene containing polymers with reactive groups which will permit the functionalized polymer to be co-reacted or compatabilized with other polymers by grafting techniques. SUMMARY OF THE INVENTION Accordingly, the present invention provides a functionalized styrenic polymer or copolymer which contains functionalized stryene moiety having the formula: ##STR3## wherein R.sub.1 is hydrogen, alkyl, primary or secondary halo alkyl groups, and R.sub.2 is ##STR4## where n is an integer of from 2 to 10, R.sub.3 is independently hydrogen or an alkyl group of from 1 to 10 carbon atoms and X is NH, O or S. The novel copolymers of the present invention have particular utility in forming polymer blends. For example, the amine and alcohol functionalized polymers can be used as compatabilizers by reacting them with a carboxylic acid containing polymer or the like. DETAILED DESCRIPTION OF THE INVENTION Polymers containing styrene units may be functionalized in accordance with the process of the present invention. Particularly suitable styrene containing polymers for functionalization are copolymers of an isoolefin having from about 4 to 7 carbon atoms and a styrene or para-alkylstyrene moiety represented by the formula ##STR5## wherein R.sub.1, is a hydrogen, alkyl, primary or secondary haloalkyl which alkyl and haloalkyl groups have from about 1 to about 6 carbon atoms. In the practice of the present invention, however, it is particularly preferred to use a copolymer of isobutylene and para-methyl styrene. The foregoing polymers are functionalized by reacting the styrene containing polymer or copolymer with a compound having the formula ##STR6## in the presence of a Lewis acid. In the foregoing formula, R.sub.3 is independently hydrogen or an alkyl group of from 1 to about 10 carbon atoms, A is NH, O, S and CO.sub.3 and y is an integer of from 2 to 10. In the case when A is NH, R.sub.3 preferably is an alkyl group. A specific example of such a compound is methylaziridine. In the case when A is CO.sub.3, propylene carbonate is particularly suitable. When A is O, an epoxy, such as epoxybutane is suitable. Finally, ethylene sulfide is useful when A is S. Any Lewis acid catalyst can be used in preparing the functionalized styrene containing polymers; however, the preferred Lewis acid catalysts are based on metals such as boron, aluminum, gallium, indium, titanium, zirconium, tin, arsenic, antimony and bismuth. Especially preferred are the halide containing compounds of the foregoing metals such as boron trifluoride, aluminum trichloride, aluminum dichloride and the like. Typically, the functionaliztion will be carried out in the presence of a hydrocarbon diluent such as aliphatic hydrocarbons or in the presence of a polar solvent such as nitrobenzene, methylene chloride, 1,2 dichloroethane and the like. It is particularly preferred in the practice of the present invention to carry out the process in the presence of a solvent. The functionalization of the polymers typically is carried out at temperatures of from about -50.degree. C. to about 100.degree. C., for times sufficient to add the functional group, i.e., the alkyl amine or alkyl alcohol, to the aromatic ring of the styrene containing polymer. The ratio of aziridine, alkylene oxide, or alkylene carbonate to the styrenic units in the styrene containing polymer can vary widely. In general, however, from about 0.01 to 10 mols of aziridine, alkylene oxide or alkylene carbonate per 1 mols of styrenic moieties in the styrene containing polymer will be employed. The following examples illustrate the invention: |
| PATENT EXAMPLES | This data is not available for free |
| PATENT PHOTOCOPY | Available on request |
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