Processing of cis polybutadiene rubber by compounding with liquid polybutadienes

Claim 1

A VULCANIZABLE RUBBER COMPOSITION COMPRISING A RUBBER SELECTED FROM THE GROUP CONSISTING OF CIS-POLYBUTADIENE RUBBER AND BLENDS OF A MAJOR AMOUNT OF CISPOLYBUTADIENE RUBBER AND A LESSER AMOUNT OF RUBBER SELECTED FROM THE GROUP CONSISTING OF NATURAL RUBBER AND STYRENE-BUTADIENE RUBBER; SAID CIS-POLYBUTADIENE RUBBER HAVING A CIS- 1-4-CONTENT GREATER THAN ABOUT 85% BY WEIGHT AND A MOONEY VISCOSITY (ML-4@212*F.) OF FROM ABOUT 35 TO ABOUT 55, A LIQUID POLYBUTADIENE HAVING AN INTRINSIC VISCOSITY OF FROM ABOUT 0.1 TO ABOUT 1.2 AND A MICROSTRUCTURE OF FROM ABOUT 35 TO ABOUT 55 PERCENT CIS-1,4CONFIGURATION, FROM ABOUT 35 TO ABOUT 60 PERCENT TRANS1,4-CONFIGURATION AND LESS THAN ABOUT 15 PERCENT, 1,2CONFIGURATION, AND PREPARED BY POLYMERIZING BUTADIENE IN THE ADSENCE OF OXYGEN IN AN INERT HYDROCARBON SOLVENT IN THE PRESENCE OF A HYDROCARBYLLITHUM CATALYST, THE AMOUNT OF SAID LIQUID POLUBUTADIENE BEING FROM ABOUT 10 TO ABOUT 60 PERCENT BY WEIGHT OF SAID RUBBER; AND CARBON BLACK IN AN AMOUNT OF FROM ABOUT 40 TO ABOUT 85 PERCENT BY WEIGHT OF THE COMBINED WEIGHT OF SAID RUBBER AND SAID LIQUID POLYBUTADIENE.