1. Field of the Invention
This invention relates to a process for the preparation in high yield of a polybutadiene having at least 70% cis-1,4 and in many cases more than 95% cis-1,4 microstructure. More specifically this process involves the polymerization of 1,3-butadiene in the presence of a novel catalyst composition.
2. Related Prior Art
U.S. Pat. No. 3,778,424 discloses the preparation of 1,2-polybutadiene which is syndiotactic in character and uses for the polymerization of 1,3-butadiene a catalyst composition comprising (a) a soluble cobalt compound, (b) an AlR.sub.3 compound in which R is a hydrocarbon radical of 1-6 carbon atoms, and (c) CS.sub.2. The soluble cobalt compound is defined as including, among various other compounds, (1) a cobalt salt of an organic carboxylic acid of at least 6 carbon atoms, such as cobalt octoate and cobalt naphthenate and (2) a complex of a cobalt halide, such as CoCl.sub.2, with "a tertiary amine, e.g. pyridine, triethylamine, tributylamine and dimethylaniline, . . . ; and an N,N-dialkylamide, e.g., N,N-dimethyl formamide, N,N-dimethyl acetamide and N,N-diethyl formamide." The products described are highly syndiotactic-1,2.