Halogenation of rubbery copolymers

Claim 1

A COMPOSITION FORMED BY REACTING AT A TEMPERATURE OF -50*C. TO +200*C. A COPOLYMER OF 85 TO 99.5 WT. PERCENT OF A C4 TO C8 ISOOLEFIN AND 0.5 TO 15 WT. PERCENT OF A C4 TO C14 MULTIOLEFIN; WITH A HALOGENATING AGENT CAPABLE BY ITSELF OF INCORPORATING HALOGEN ONLY, WITHIN SAID COPOLYMER, SAID HALOGENATING AGENT BEING PRESENT IN AN AMOUNT SUFFICIENT TO COMBINE ABOUT 0.1 TO 30 WT. PERCENT (BASED ON COPOLYMER) OF HALOGEN IN SAID COPOLYMER; IN THE PRESENCE OF A C4 TO C20 ETHYLENICALLY UNSATURATED ORGANIC DICARBOXYLIC ACID ANHYDRIDE IN THE AMOUNT OF ABOUT 0.1 TO 20 MOLES OF HALOGEN PER MOLE OF SAID ACID ANHYDRIDE; AND ABOUT 0.05 TO 20,000 MOLES PER MOLE OF ADDED HALOGEN OF A HALOGEN-SUBSTITUTED-HYDROCARBON SOLVENT FOR SAID COPOLYMER WHICH IS INCAPABLE BY ITSELF OF INCORPORATING HALOGEN ONLY, WITHIN SAID COPOLYMER, SAID SOLVENT CONTAINING A HALOGEN SELECTED FROM THE GROUP CONSISTING OF CHLORINE AND BROMINE.