| 摘要 |
<p>By utilizing the techniques of this invention, trans-1,4-polybutadiene can be synthesized continuously to a high level of conversion utilizing a low level of a highly active cobalt-based catalyst system. The trans-1,4-polybutadiene made with the cobalt-based catalyst system of this invention also typically has a molecular weight which is acceptable for use in tire applications without the need for employing a molecular weight regulator. It is also not typically necessary to utilize a gel inhibitor, such as carbon disulfide, in the polymerizations of this invention. Since a low level of residual cobalt is present in the trans-1,4-polybutadiene which is made utilizing the catalyst system of this invention, it is much more stable than trans-1,4-polybutadiene made with standard cobalt-based catalyst systems. This invention specifically relates to a process for synthesizing trans-1,4-polybutadiene by polymerizing 1,3-butadiene monomer in the presence of a catalyst system which is comprised of cobalt (III) acetylacetonate, an organoaluminum compound and a para-alkyl-substituted phenol, wherein the cobalt (III) acetylacetonate is mixed with the para-substituted phenol prior to the polymerization. Such polymerizations can be conducted on a batch or a continuous basis.</p> |
