| 摘要 |
The present invention relates to a catalyst and a process for preparing a catalyst suitable for polymerization of olefins. The process is carried out in a hydrocarbon liquid medium and comprises successively contacting a refractory oxide support with (a) a dialkylmagnesium optionally with a trialkylaluminium, (b) a particular monochloro organic compound, (c) a titanium and/or vanadium compound(s), and then (d) with ethylene optionally mixed with a C3-C8 alpha-olefin in the presence of an organo-aluminium or organozinc compound to form a prepolymerised catalyst. The catalyst has a high activity, particularly in a gas phase polymerization of ethylene, and has a great ability of copolymerizing alpha-olefins with ethylene. |
