Patent ID: 7491670

Claim:
A catalyst composition for the polymerization of propylene or mixtures of propylene and one or more copolymerizable comonomers, said catalyst composition comprising: one or more Ziegler-Natta procatalyst compositions comprising one or more transition metal compounds and one or more esters of aromatic dicarboxylic acid internal electron donors; one or more aluminum containing cocatalysts; a selectivity control agent (SCA) comprising at least one silicon containing compound containing at least one C 1-10 alkoxy group bonded to a silicon atom; one or more activity limiting agent (ALA) compounds of C 1-20 alkyl esters of aliphatic C 8-20 monocarboxylic acids and inertly substituted derivatives of the foregoing, said ALA compounds and amounts being selected such that the normalized polymerization activity of the catalyst composition at a temperature from 85 to 130° C., is less than the normalized polymerization activity of the catalyst composition in the presence of only the SCA compound at the same total molar quantity of SCA at said temperature; and the catalyst composition does not impart an undesirable odor to the polymer formed therefrom.