US Patent 7321017 Amine containing catalyst system and methods of use thereof

The present invention is directed to an amine containing catalyst system for synthesizing rubbery polymers, such as polybutadiene rubber and styrene-butadiene rubber, having a high trans microstructure. The catalyst system, in one embodiment, includes (a) an organolithium compound, (b) a group IIa metal salt, (c) an organoaluminum compound, and (d) an amine compound which can be selected from (1) a heterocyclic aromatic compound which includes a ring structure with one or more nitrogen atoms as part of the ring; (2) a heterocyclic non-aromatic compound which includes a ring structure with two or more nitrogen atoms as part of the ring; (3) an aromatic compound including a ring structure substituted with at least one amine and at least one polar functionality containing group selected from a carboxyl group or a hydroxyl group; (4) a bicyclic chelating diamine compound; or (5) an aliphatic amine which includes a C5-C20 alkyl group.