Process for the manufacture of halogenated elastomers

Continuous halogenation of olefinically unsaturated rubber is achieved in an extruder - reactor employing reactants, conditions and design features directed to maximizing mixing and contact of the rubber with the halogenating agent and neutralizing agent while simultaneously minimizing side reactions and polymer degradation. The rubber passes through five extruder-reactor zones under controlled conditions to achieve halogenation: feed, reaction, neutralization, wash and exit. The halogenated rubber, for example, halogenated butyl rubber can be vulcanized in the absence of sulfur, e.g., with zinc oxide and stearic acid, and is useful in all applications where commercially available chlorinated and brominated rubbers are presently employed.