| 摘要 |
A process for polymerizing a -olefins comprises (a) preparing a catalytic system comprising a carrier containing silicon compounds and having a chromium oxide deposited on the carrier by a chemical reaction between chromyl fluoride and the carrier; and (b) polymerizing the a -olefin in the presence of the catalytic system and an organic liquid solvent or diluent. Specified olefins are ethylene, propylene, butene-1, isobutene, pentene-1, butadiene and isoprene. Specified solvents and diluents are propane, butane, isobutane, n-pentane, n-heptane, isooctane and cyclohexane. The catalysts are preferably prepared by reacting silica or silica-alumina with chromyl fluoride, and activated by heating in a stream of oxygen-containing gas or inert gas. In examples ethylene is polymerized in (1-6) cyclohexane using catalysts formed from chromyl fluoride and silica/alumina, (7, 9 and 12-14) n-heptane using catalysts formed from chromyl fluoride and silica/alumina, and (8) n-heptane using a catalyst formed from chromyl fluoride and silica; and propylene is polymerized in (10) n-heptane and hexene-1 is polymerized in (11) isooctane using catalysts formed from chromyl fluoride and silica/alumina. |
