FI Catalysts: super active new ethylene polymerization catalysts

Based on "ligand-oriented catalyst design", group 4 transition metal comple xes having two phenoxy-imine ligands, Fl Catalysts, were synthesized and in vestigated as olefin polymerization catalysts using ethylene at atmospheric pressure. As a result, these complexes were found to exhibit very high act ivity using MAO as a cocatalyst. Among them, zirconium complexes displayed the highest activity with moderate (Mv: 0.8 x 10(4)) to very high (Mv: 71.6 x 10(4)) molecular weight ranges. The maximum activity exceeded 4 t-PE/(mm ol-cat(superscript:)h) at 25 degreesC even at atmospheric pressure, the act ivity being two orders of magnitude larger than that exhibited by Cp2ZrCl2. Alternatively, by using borate/(Bu3Al)-Bu-i as a cocatalyst, a zirconium F l Catalyst produced exceptionally high molecular weight polyethylene (Mv: 5 05 x 10(4)) displaying considerable activity. As far as we know, this is on e of the highest molecular weight values obtained from homogeneous polymeri zation catalysts. These results indicate that Fl Catalysts possess very hig h potential as olefin polymerization catalysts. (C) 2001 Elsevier Science B .V. All rights reserved.