Synthesis of elastomeric high trans-1,4-polybutadiene

This invention is based upon the unexpected discovery that elastomeric trans-1,4-polybutadiene can be made by utilizing a catalyst system that is comprised of an organocobalt compound, an organoaluminum compound, a para-alkyl substituted phenol, and ortho-phenyl phenol wherein the molar ratio of the para-substituted phenol to the organoaluminum compound is within the range of about 1.2:1 to about 1.8:1, and wherein the molar ratio of the ortho-phenyl phenol to the organoaluminum compound is within the range of about 0.7:1 to about 1.3:1. Accordingly, the elastomeric trans-1,4-polybutadiene made by the process of this invention does not need to be heated, such as in a hot-house, before being used in making rubber stocks. This invention more specifically discloses a process for synthesizing elastomeric trans-1-4-polybutadiene by polymerizing 1,3-butadiene monomer in the presence of a catalyst system that is comprised of an organocobalt compound, an organoaluminum compound, a para-alkyl substituted phenol, and ortho-phenyl phenol, wherein the molar ratio of the para-alkyl substituted phenol to the organoaluminum compound is within the range of about 1.2:1 to about 1.8:1, wherein the molar ratio of the ortho-phenyl phenol to the organoaluminum compound is within the range of about 0.7:1 to about 1.3:1, and wherein the organaluminum compound is reacted with the ortho-phenyl phenol prior to coming in contact with the organocobalt compound.