| 摘要 |
<p>A process for polymerizing ethylene comprising contacting under polymerization condition ethylene and optionally one or more olefins with a catalyst system obtainable by contacting: a bis amido compound of formula (I) wherein Y is Si, Ge and Sn; X is hydrogen, halogen or an hydrocarbon radical; R1, R2, R3, R4, R5 and R6, are hydrocarbon radical; Q is a neutral Lewis base; and m is 0-2; one or more boron activating cocatalysts and one or more aluminum alkyls or alumoxanes.</p> |
