| 摘要 |
Continuous processes for the polymerization of olefinically unsaturated compounds in liquid media comprising "Zeigler" catalysts comprise continuously or intermittently adding to the polymerization zones during polymerization catalyst-containing liquid media formed in separate catalyst-forming zones by mixing catalyst-forming components in the presence of polymer-containing reaction media from the polymerization zones under such conditions that catalyst concentrations in the resulting admixture are at least six times larger than the concentrations in the polymerization zones. Specified monomers are ethylene, propylene, n-butylene and styrene; and mixtures, e.g. of ethylene and propylene. Inert diluents may be present, e.g. ethylene/ethane mixtures may be used. The catalyst may be formed by mixing a compound of a Group 4a, 5a, 6a, 7a or 8 metal with a metal or alloy thereof of Groups 1, 2 and 3, organometallic compounds or hydrides of metals of Group 1, 2 and 3, tin and lead, or organic boron compounds. The solvent may be heptane, isooctane or a light petroleum fraction. Polymerization may be effected in a plurality of polymerization zones which may be served by one catalyst-forming zone. The catalyst is preferably aged before passing into the polymerization zone, e.g. by passing through an elongated catalyst-ageing zone at a rate sufficient to prevent back mixing. Examples describe the polymerization of ethylene in the presence of catalysts formed by mixing titanium tetrachloride and aluminium diethyl chloride. Specifications 799,392, 799,823, 801,031, 810,023, 816,234, 819,867, 820,263, 837,053, 837,064 and 840,859 are referred to.
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