PROCESS FOR PREPARING POLYOLEFINS

摘要

Olefin is polymerized using a catalyst which comprises the combination of: ¢I! a solid substance obtained by the reaction of at least the following two components: (i) a magnesium halide and (ii) a titanium compound and/or a vanadium compound; ¢II! a compound represented by the general formula R1mSi(OR2)4-m wherein R1 and R2 are hydrocarbon radicals having 1 to 24 carbon atoms and 0 ? m ? 3; ¢III! a compound represented by the general formula R3nAl(OR4)3-n wherein R3 and R4 are hydrocarbon radicals having 1 to 24 carbon atoms and 1 ? n ? 2; and ¢IV! an organometallic compound, the molar ratio of silicon in said component ¢II! to titanium and/or vanadium in said component ¢I! being in the range of 0.1 to 100, the molar ratio of aluminum in said component III to silicon in said component being in the range of 0.01 to 10 and the molar ratio of the metal in said component ¢IV! to titanium and/or vanadium in said component ¢I! being in the range of 0.1 to 1,000.