HALOGENATED BUTYL RUBBER PRODUCTION PROCESS Russian patent published in 2001 - IPC

FIELD: rubber industry. SUBSTANCE: halogenated butyl rubber is prepared by isobutylene/isoprene copolymerization in presence of catalyst in hydrocarbon diluent or solvent, after which reaction mixture is deactivated, stabilized, and polymer is isolated from solution or dispersion involving water degassing technique. Rubber crumb is the dried and dissolved in inert C5-C8-hydrocarbon solvent, after which solution is treated with gaseous or liquid halogen or halogenation agent, washed, neutralized, subjected to water degassing followed by drying thus prepared halogenated butyl rubber. Process is distinguished by that treatment of butyl rubber solution is performed in two temperature steps: first at 0-25 C and then at 26-50 C, gaseous or liquid halogen or halogenation agent being supplied in the first or in both steps. EFFECT: reduced consumption of halogen or halogenation agent, reduced Mooney viscosity drop during halogenation process, and increased productivity of drying units. 2 cl, 1 dwg, 12 ex