PROCESS FOR PREPARING CRYSTALLINE HIGH 1,4 TRANS POLYBUTADIENE

摘要

Diene polymers having a high content of trans-1,4 addition and two distinct melting points in the ranges of 30.degree.C to 50.degree.C and 70.degree.C to 130.degree.C are prepared by polymerizing a 1,3diene monomer in a hydrocarbon solvent in the presence of a catalyst composition comprising (a) a carboxylated nickel oxy borate compound; (b) an organoaluminum compound; (c) a triaryloxy phosphorus compound and (d) a carboxylic acid preferably a fluorinated carboxylic acid. The resultant polymers are useful as additives to tire rubbers to improve processability by reducing compound Mooney viscosity and reducing the shrinkage of various compound stocks.