Patent ID: 6410663
Filing Date: 2002-06-25
Classification: C08F

Abstract:
A process for the copolymerization of olefins, comprising:(a) making a catalyst by the steps comprising: (2) selecting a conventional Ziegler-Natta catalyst component supported on a magnesium compound wherein the conventional supported Ziegler-Natta catalyst component is obtained by: (iii) suspending a dialkoxy magnesium is an aromatic hydrocarbon that is liquid at normal temperatures; (iv) contacting the dialkoxy magnesium with a titanium halide and further (v) contacting the resulting composition a second time with the titanium halide, and contacting the dialkoxy magnesium with a diester of an aromatic dicarboxlic acid at some point during the treatment with the titanium halide in steo (ii); and (2) contacting the catalyst component with an organoaluminum compound; (3) contacting said catalyst component with an electron donor either simultaneously with or after step (2), said electron donor being described by the formula: wherein R1 is a linear alkyl group attached to the silicon atom; R2 and R3 are alkyl or aryl groups and R4 is a linear alkyl attached to the silicon atom, R1 and R4 are the same or different; (b) introducing said catalyst into a polymerization reaction zone containing ethylene and propylene under polymerization conditions; and (c) withdrawing a copolymer product having a high melt flow index in the range of from about 15 to about 60.