Process for halogenating para-alkyl styrene/isoolefin copolymers

Abstract

A process for halogenating copolymers of an isoolefin having from 4 to 7 carbon atoms and a para-alkylstyrene in the melt phase is provided in which the halogenation reaction is performed in a continuous flow device, such as an extruder-reactor. Halogenated copolymers produced by the process are also provided.

What is claimed is: 
     
       1. A process for halogenating a polymer in the melt phase, which comprises: contacting a copolymer of an isoolefin having from 4 to 7 carbon atoms and a para-alkylstyrene with a halogenating agent, in a continuous flow device, at reaction conditions, in a reaction zone, to produce a halogenated copolymer of said isoolefin and said para-alkylstyrene, said halogenated copolymer comprising a para-haloalkyl group. 
     
     
       2. The process of claim 1 wherein said reaction is conducted in the presence of an initiator selected from the group consisting of light, chemical initiators and mixtures thereof. 
     
     
       3. The halogenated copolymer produced according to the process of claim 2. 
     
     
       4. The cured halogenated copolymer of claim 3. 
     
     
       5. A composition comprising the cured halogenated copolymer of claim 4. 
     
     
       6. The cured halogenated copolymer of claim 4. 
     
     
       7. The process of claim 1, wherein said reaction conditions, in said reaction zone, include a temperature ranging from about 80° to about 200° C. 
     
     
       8. The halogenated copolymer produced according to the process of claim 7. 
     
     
       9. A composition comprising the cured halogenated copolymer of claim 8. 
     
     
       10. The process of claim 1 wherein said halogenating agent is selected from the group consisting of chlorine gas, chloride liquid; sulfuryl chloride; N-chlorosuccinimide; 1,3-dibromo-5,5-dimethylhydantoin; bromine gas; bromine liquid; bromine chloride; sodium hypochlorite; sulfur bromide; N-bromosuccinimide, and mixtures thereof. 
     
     
       11. The halogenated copolymer produced according to the process of claim 10. 
     
     
       12. The cured halogenated copolymer of claim 11. 
     
     
       13. A composition comprising the cured halogenated copolymer of claim 12. 
     
     
       14. The process of claim 1 wherein said halogenating agent is selected from the group consisting of bromine gas, chlorine gas, compounds which decompose to yield bromine gas and mixtures thereof. 
     
     
       15. The halogenated copolymer produced according to the process of claim 14. 
     
     
       16. The cured halogenated copolymer of claim 15. 
     
     
       17. A composition comprising the cured halogenated copolymer of claim 16. 
     
     
       18. The process of claim 1, wherein said halogenated copolymer comprises from above zero to about 7.5 weight percent chemically bound halogen, based on the total halogenated copolymer. 
     
     
       19. The halogenated copolymer produced according to the process of claim 18. 
     
     
       20. The cured halogenated copolymer of claim 19. 
     
     
       21. A composition comprising the cured halogenated composition of claim 20. 
     
     
       22. The process of claim 1, wherein said halogenated copolymer comprises from about 0.25 to about 5 weight percent chemically bound halogen, based on the total halogenated copolymer. 
     
     
       23. The halogenated copolymer produced according to the process of claim 22. 
     
     
       24. The cured halogenated copolymer of claim 23. 
     
     
       25. A composition comprising the cured halogenated composition of claim 24. 
     
     
       26. The process of claim 1 wherein said isoolefin is isobutylene, said para-alkylstyrene is para-methylstyrene, and said halogenated copolymer is isobutylene-para-halomethylstyrene. 
     
     
       27. The process of claim 26, wherein said halogenating agent is bromine and wherein said halogenated copolymer is isobutylene-para-bromomethylstyrene. 
     
     
       28. The halogenated copolymer produced according to the process of claim 27. 
     
     
       29. The cured halogenated copolymer of claim 28. 
     
     
       30. A composition comprising the cured halogenated copolymer of claim 29. 
     
     
       31. The halogenated copolymer produced according to the process of claim 26. 
     
     
       32. The cured halogenated copolymer of claim 31. 
     
     
       33. A composition comprising the cured halogenated copolymer of claim 32. 
     
     
       34. The process of claim 1 wherein said copolymer has a number average molecular weight of at least 25,000. 
     
     
       35. The halogenated copolymer produced according to the process of claim 34. 
     
     
       36. The cured halogenated copolymer of claim 35. 
     
     
       37. A composition comprising the cured halogenated copolymer of claim 36. 
     
     
       38. The process of claim 1 wherein said copolymer comprises from about 0.5 to about 90 weight percent of said para-alkylstyrene. 
     
     
       39. The halogenated copolymer produced according to the process of claim 38. 
     
     
       40. The cured halogenated copolymer of claim 39. 
     
     
       41. A composition comprising the cured halogenated copolymer of claim 40. 
     
     
       42. The process of claim 1, wherein said copolymer comprises from about 0.5 to about 20 weight percent of said para-alkylstyrene. 
     
     
       43. The halogenated copolymer produced according to the process of claim 42. 
     
     
       44. The cured halogenated copolymer of claim 43. 
     
     
       45. A composition comprising the cured halogenated copolymer of claim 44. 
     
     
       46. The process of claim 1, wherein said continuous flow device comprises means for conveying said copolymer through said device wherein said copolymer and said halogenating agent are subjected to deformation, and means for disengaging by-product of the reaction and unreacted halogenating agent from said halogenated copolymer, said means comprising means for injecting an inert gas into said continuous flow device downstream of said contacting step to strip said by-product and said unreacted halogenating agent from said halogenated copolymer. 
     
     
       47. The halogenated copolymer produced according to the process of claim 46. 
     
     
       48. The cured halogenated copolymer of claim 47. 
     
     
       49. A composition comprising the cured halogenated copolymer of claim 48. 
     
     
       50. The process of claim 1, wherein said copolymer and said halogenating agent are present during said contacting step as either co-continuous phases or wherein said halogenating agent is present as a continuous phase and said polymer is present as a discontinuous phase or wherein the zone in which said polymer and said halogenating agent are contacted is filled with said copolymer. 
     
     
       51. The halogenated copolymer produced according to the process of claim 50. 
     
     
       52. The cured halogenated copolymer of claim 51. 
     
     
       53. A composition comprising the cured halogenated copolymer of claim 52. 
     
     
       54. The halogenated copolymer produced according to the process of claim 1. 
     
     
       55. The cured halogenated copolymer of claim 54. 
     
     
       56. A composition comprising the cured halogenated copolymer of claim 55.