FIELD: chemistry.
SUBSTANCE: invention relates to Ziegler-Natta catalysts. Described is a catalyst composition containing: Ziegler-Natta procatalyst composition containing titanium, magnesium and an internal electron donor, containing at least two oxygen-containing functional groups, the oxygen-containing functional groups being separated by at least one saturated C2-C10 hydrocarbon chain which can optionally contain a heteroatom; organoaluminium compounds as a cocatalyst; and a mixed external electron donor (M-EED) comprising an activity limiting agent (ALA), a first selectivity control agent (SCA1) containing an alkoxysilane, a second selectivity control agent (SCA2) selected from a group consisting of an alkoxysilane, a diether, and a dialkoxybenzene, wherein the molar ratio SCA1:SCA2 ranges from 0.1:1 to 1.0:1, the molar ratio of total-SCA to ALA is less than 1.0, and wherein the ALA is selected from a group consisting of an aromatic ester or a derivative thereof, an aliphatic ester or a derivative thereof, a diether, poly(alkylene glycol) of an ester and combinations thereof.
EFFECT: novel catalyst composition is described.
10 cl, 2 dwg, 8 tbl, 2 ex
