neodymium - carboxylatederivate and its use for the polymerization of conjugated serve

摘要

The invention is related to a novel compound represented by NdHA4 wherein A is a carboxylate, and to a diene polymerization catalyst using the novel compound. NdHA4 has monomeric structure and does not contain water, bases and salts. NdHA4 is mixed with a halogen compound and an organic metal compound to prepare a catalyst system. The catalyst system in the polymerization of 1,3-butadiene (BD) or isoprene produces high cis polydiene with a high activity (100 g BD/4.0 x 10-5 mole Nd) and without gel formation. The polydiene thus obtained is useful for tires and golf balls and as a polystyrene modifier.