Mixed ester retreated propylene polymerization catalyst

摘要

A comminuted, supported polymerization catalyst for alpha-olefins comprises (A) an organoaluminum compound and (B) a solid titanium-containing component formed by at least one halogen-containing compound of titanium(IV); (b) at least one electron donor; and (c) at least one hydrocarbon-insoluble magnesium-containing compound; and (2) retreating such comminuted product with (a) at least one halogen-containing compound of titanium(IV); and (b) a mixture containing ethylbenzoate and a substituted alkyl aromatic acid ester in which the substituent group has a negative Hammett constant; and optionally, at least one chlorocarbon and/or at least one haloalkylchlorosilane.