Patent ID: 6204338
Filing Date: 2001-03-20
Classification: C08C,C08F

Abstract:
A C.sub.4 -C.sub.6 isoolefin-C.sub.4 -C.sub.6 conjugated diolefin, wherein said isoolefin-conjugated diolefin polymer is an isobutylene-isoprene polymer comprising from about 97 to 99.5 mole percent of isobutylene and from about 0.5 to about 3 mole percent of isoprene, wherein a solution of said polymer is prepared in a solvent, bromine is added to said solution and said bromine is reacted with said polymer at a temperature of from about 20.degree. C. to about 50.degree. C. and the brominated isoolefin-conjugated diolefin polymer is separated, wherein the brominated isobutylene-isoprene polymer contains from about 1 to about 4 weight percent of bromine based on the brominated polymer and not less that about 80 percent of the bound bromine atoms are present in a form suitable to participate in the vulcanization of said polymer and not less than about 70 percent of the 1,4-isoprene units in the original isobutylene-isoprene polymer are converted in the brominated polymer into a form suitable to participate in the vulcanization of said polymer, the improvement being that said solvent is a mixture comprising an inert saturated paraffinic hydrocarbon and an inert halogen-containing hydrocarbon in a volume ratio of from about 90/10 to about 10/90 of said paraffinic hydrocarbon to said halogen-containing hydrocarbon, wherein said halogen-containing hydrocarbon is selected from the group consisting of methyl chloride, methylene chloride, ethyl chloride, ethyl bromide, dichloroethane, n-butyl chloride and monochlorobenzene and said paraffinic hydrocarbon is selected from the group consisting of pentane, hexane and heptane, the reaction time is from about 1 to about 5 minutes.