Process for the halogenation of butyl rubber with chlorine and bromine, and product obtained thereby

Claim 1

A PROCESS WHICH COMPRISES HALOGEENATING A BUTYL RUBBER COPOLYMER OF AN ISOOLEFIN WITH A MULTIOLEFIN AT A TEMPERATURE BETWEEN O AND 100*C. BY A FIRST REACTION WITH AN ELEMENTAL HALOGEN SELECTED FROM THE GROUP CONSISTING OF CHLORINE AND BROMINE AND A SECOND REACTION WITH THE OTHER ELEMENTAL HALOGEN WHICH IS NOT SELECTED IN THE FIRST REACTION TO INCORPORATE BY SUBSTITUTION AT LEAST 0.5 WEIGHT PERCENT EACH OF CHLORINE AND BROMINE THEREIN BUT THE RATIO OF COMBINED HALOGENS BEING NOT MORE THAN ABOUT ONE ATOM OF COMBINED CHLORINE AND ABOUT TWO ATOMS OF COMBINED BROMINE PER DOUBLE BOND IN THE COPOLYMER TO PROVIDE A HALOGENATED COPOLYMER THEREFROM WHICH IS CAPABLE OF BEING PLACED ADJACENT TO A PREVIOUSLY VULCANIZED HIGH UNSATURATION RUBBER LAYER SELECTED FROM THE GROUP CONSISTILNG OF NATURAL RUBBER, DIENE-STYRENE RUBBER, AND DIENE-ACRYLONITRILE RUBBER, AND SUBSEQUENTLY BEING CURED TO PROVIDE A PRODUCT HAVING IMPORVED ADHESION BETWEEN SAID HALOGENATED COPOLYMER AND SAID LAYER.