Method for in situ isomerization of polybutadiene

Abstract

Methods for in situ isomerization if polybutadiene may include adding mixture components of the cross-linkable rubber composition into a mixer, the mixture components comprising at least 10 phr of a polybutadiene rubber having at least 80 wt % cis-bonds and up to 90 phr of a second rubber component having at least some dienic unsaturation and mixing the mixture components during a nonproductive phase. Such methods may include processing the mixture components on a mill during a productive phase, adding at least 3 phr of a disulfide isomerization agent and mixing the disulfide isomerization agent with the mixture components. The mixing may take place in an internal mixer with the isomerization agent added to the mixer or alternatively, it may be added to the mill after the mixture components have been dropped from the mixer for cooling on the mill.

Dependencies are inferred from the claim text.