Patent ID: 7825202

Claim:
A method comprising: polymerizing one or more different types of conjugated diene monomers and optionally vinyl aromatic monomers in the presence of a catalyst system for synthesizing rubbery polymers, the catalyst system comprising: a complex defined by the following formula: (R) 3 A − (H)K + wherein A is boron or aluminum, and R, which is the same or different, is either H, a C 1 -C 10 alkyl, a C 3 -C 10 cycloalkyl, phenyl, or phenyl substituted C 1 -C 10 alkyl, or a C 3 -C 10 cycloalkyl, with the proviso that at least one R group is a C 1 -C 10 alkyl, and further wherein any two R groups may optionally be part of a carbocyclic ring; and an organolithium compound.