| 摘要 |
PROCESS FOR THE PRODUCTION OF POLYETHLENE WITH A BROAD AND/OR BIMODAL MOLECULAR WEIGHT DISTRIBUTION of the Invention A process for the production of an ethylene homopolymer or copolymer comprising passing ethylene with or without at least one alpha-olefin comonomer having 3 or more carbon atoms into contact with a mixed catalyst system, under polymerization conditions, said mixed catalyst system comprising: (a) the reaction product of (i) a vanadium halide having the formula VX3 wherein X is chlorine, bromine, or iodine and each X is alike or different; (ii) a modifier having the formula BX3or AlR(3-a)Xa wherein X is as defined above; R is an alkyl radical having 1 to 14 carbon atoms; each R is alike or different; and a is 0, 1, or 2 and (iii) an electron donor, which is a liquid Lewis base in which the vanadium halide and modifier are soluble; (b) one of the following: (i) a complex having the formula ZrMgbXc(ED)d wherein X as defined above; ED is an electron donor, which is a liquid Lewis base in which the precursors of the complex are soluble; b is a number from 1 to 3; c is a positive number equal to or less than 4+2b; and d is a number from 4 to 10; or (ii) a vanadium oxy compound having the formula VOX3, VOX2, VOX, or VO2X wherein X is as defined above, or VO(OR)3 wherein R is a monovalent hydrocarbon radical having 2 to 10 carbon atoms and each R can be alike or different, wherein the vanadium halide and the vanadium oxy compound are supported; (c) a hydrocarbyl aluminum cocatalyst; and (d) a halocarbon promoter having the formula ReCX(4-e) wherein R is hydrogen or an unsubstituted or halo substituted alkyl radical having 1 to 6 carbon atoms; each R is alike or different; X is chlorine, bromine, iodine, or fluorine; each X is alike or different; and e is 0, 1, or 2 provided that, if no fluorine is present, e is 2.
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