Process of polymerization of conjugated diolefins using iron catalysts and sulfur ligands

Claim 1

A catalyst composition consisting essentially of (1) an iron compound selected from the group consisting of ferric oxalate, ferric hexanoate, ferric octanoate, ferric decanoate, ferric stearate, ferric naphthenate, ferrous acetylacetonate, ferric acetylacetonate, ferric-1-ethoxy-1,3-butanedionate, ferrous dimethyl glyoxime, ferric chloride, ferrous chloride, ferric bromide, ferric phosphate, iron tetracarbonyl, iron pentacarbonyl and iron nonacarbonyl, (2) an organometallic compound selected from the group consisting of trialkylaluminums, dialkylaluminum halides, dialkylaluminum hydrides and dialkylaluminum alkoxides, and (3) a sulfur containing ligand selected from the group consisting of N,N'-dimethyldithiooxamide, dithiooxamide, N,N'-dicyclohexyldithiooxamide, N,N'-didodecyldithiooxamide, 2-mercaptobenzimidazole, 5-methyl-2-mercaptobenzimidazole, 5-chloro-2-mercaptobenzimidazole, thiourea and N,N'-diphenylthiourea, in which the molar ratio of the sulfur ligand to the iron compounds (S/Fe) ranges from about 0.1/1 to about 100/1 and when the organometallic compound is an aluminum trialkyl, the molar ratio of the aluminum trialkyl to the iron compound (Al/Fe) ranges from about 1/1 to about 400/1 and when the organometallic compound is a dialkylaluminum halide or a dialkylaluminum hydride, or a dialkylaluminum alkoxide, then the organometallic component to the iron component (AlX/Fe) can be varied from about 6/1 to about 25/1.