| abstract |
A method of forming a polyolefin catalyst component which includes chlorinating magnesium ethoxide, and then treating the product first with an electron donor, particularly diethyl phthalate or di-isobutyl phthalate, at a relatively low donor level, and then second with a titanating agent, such as titanium tetrachloride, to produce a catalyst component. The catalyst component is activated with an aluminum alkyl cocatalyst. An external electron donor, such as an organosilane compound, is added for stereoselectivity control. The activated catalyst is used in the polymerization of olefins, particularly propylene, to obtain a polymer product with a broad molecular weight distribution. |