Alumoxane-enhanced, supported Ziegler-Natta catalysts, methods of making same, processes of using same and polymers produced therefrom

摘要

The invention relates to an improved olefin catalyst, a method of in situ-activated catalyst preparation and a process for the polymerization of olefinic monomers via, for example, a titanium trichloride/magnesium dichloride/tetrahydrofuran reaction product catalyst precursor. The activated catalyst is prepared in situ in a polymerization reactor using an alumoxane based co-catalyst wherein the cumbersome traditional steps of catalyst activation and isolation, prior to polymerization are eliminated. An unexpected advantage of this invention is a significant increase in catalyst productivity while maintaining a relatively constant value of the bulk density of polymeric materials produced while concomitantly producing a polymeric product having a broad molecular weight distribution compared with typical alumoxane-activated metallocene catalysts.