| 摘要 |
A process for polymerizing one or more alpha -olefins of up to 10 carbon atoms which comprises contacting the one or more alpha -olefin under polymerization conditions with a catalyst system comprising: (a) a titanium halide-containing magnesium, containing procatalyst component wherein the component is obtained by contacting a magnesium compound of the formula MgR'R'', wherein R' and R'' are, independently, alkoxide group, aryloxide group or halogen, with a halogenated tetravalent titanium compound in the presence of a halohydrocarbon and an alkyl ester of a polycarboxylic acid electron donor, (b) an organoaluminum cocatalyst component, and (c) an organosilane selectivity control agent represented by general formula (I) wherein R<1>, R<2> and R<3>, are, independently, alkyl group of 1 to 12 carbon atoms; aryl group of 1 to 12 carbon atoms, alkaryl group of 1 to 12 carbon atoms, aralkyl of 1 to 12 carbon atoms or halogen; and R<4> is hydrocarbyloxy of 1 to 2 carbon atoms. The process affords high catalyst productivity and produces polymer products that have broad molecular weight distribution while retaining low oligomer content properties. |
