Ethylene Polymerization Behavior of Polymethylene-Bridged Bis (Phenoxy-Imine) Zr Complexes

摘要

New zirconium complexes containing polymethylene-bridged bis(phenoxy-imine) ligands [-(CH_2)_n-; n=2-6] were investigated as ethylene polymerization catalysts. Activities displayed by the complexes combined with methylalumoxane (MAO) increased as the number of methylene units increased. Complexes having hexa-methylene bridges exhibited higher activities at higher polymerization temperatures (25-75℃). One of the complexes with a hexa-methylene bridge had a very high activity of 142, 900 kg/mol-cat/h at 150℃ under 3.0 MPa ethylene pressure conditions.