Low hysteresis processing of butyl rubber

Claim 1

A PROCESS WHICH COMPRISES MIXING CARBON BLACK WITH A LOW UNSATURATION SOLID OLEFIN-MULTIOLEFIN SYNTHETIC RUBBERY COPOLYMER, SAID OLEFIN AND MULTIOLEFIN HAVING FROM 4 TO 14 CARBON ATOMS, AND A SMALL BUT NON-VULCANIZING AMOUNT UP TO 1% OF A REACTANT SELECTED FROM THE GROUP CONSISTING OF THE ELEMENTS SULFUR, SELENIUM, TELLURIUM AND REACTIVE COMPOUNDS CONTAINING SAID ELEMENTS AND CAPABLE OF YIELDING THEM AT TEMPERATURES ABOVE 250*F., AND SUBJECTING SAID MIXTURE TO AN ELEVATED TEMPERATURE ABOVE ABOUT 250*F. UP TO ABOUT 450*F., INVERSELY FOR AN EXTENDED PERIOD OF TIME OF ABOUT 7 HOURS TO 10 MINUTES, IN THE ABSENCE OF ACCELERATORS CAPABLE OF EFFECTING SUBSTANTIAL VULCANIZATION OF THE COPOLYMER, THE COMBINATION OF SAID HEATING TEMPERATURE AND TIME BEING INSUFFICIENT TO CAUSE ANY SUBSTANTIAL VULCANIZATION OF SAID COPOLYMER, BUT BEING SUFFICIENT TO PRODUCE A HEAT-INTERACTION INVOLVING SAID COPOLYMER, SAID CARBON BLACK AND SAID SULFUR MATERIAL, WHEREBY BOTH THE STRESS PROPERTIES AND THE ELASTICPROPERTIES OF THE SUBSEQUENTLY CURED COPOLYMER ARE IMPROVED.