摘要 |
<p>A process for making ethylene copolymers is disclosed. Ethylene copolymerizes with an alpha-olefin in the presence of a catalyst system comprising an activator and a silica-supported, bridged indenoindolyl metal complex having "open architecture." The supported complex incorporates comonomers with exceptional efficiency, and the process gives ethylene copolymers having high molecular weights (Mw > 100K) and very low densities (< 0.910 g/cm3). Open architecture catalysts that include bridging through the indolyl nitrogen of the indenoindolyl framework are also described. Additionally, supported and unsupported indeno[1,2-b]indolyl catalysts provide exceptional activities in the preparation of elastomeric polypropylene and ethylene copolymers.</p> |