Abstract: The present invention relates to an improvement for gas-phase olefin polymerization process having relatively high bed bulk density. The improvement involves the use of mixed external electron donors when polymerizing propylene in a gas-phase reactor having a polymer bed with a bulk density greater than 128 kg/m3, optionally with one or more comonomers, wherein the mixed electron donor system comprises at least a first external electron donor and a second external electron donor, and wherein the first external electron donor is a carboxylate compound.

Abstract: A gas-phase process for making a propylene-based polymer in a fluidized-bed reactor, the reactor containing a fluidized bed including polymer product particles and a catalyst, the process having a set of quantitative criteria for maximum monomer partial pressure, maximum reactor temperature, and comonomer content(s) in the propylene-based polymer. The propylene-based polymer may be EBPT or BPRCP. The catalyst may include a catalyst/donor system comprising (1) a supported Ziegler-Natta pro-catalyst, (2) a co-catalyst, and (3) a mixed external electron donor system including (a) an activity limiting agent including at least one carboxylate ester functional group, and (b) a selectivity control agent.

Abstract: A gas-phase process for making a propylene-based polymer in a fluidized-bed reactor, the reactor containing a fluidized bed including polymer product particles and a catalyst, the process having a set of quantitative criteria for maximum monomer partial pressure, maximum reactor temperature, and comonomer content(s) in the propylene-based polymer. The propylene-based polymer may be EBPT or BPRCP. The catalyst may include a catalyst/donor system comprising (1) a supported Ziegler-Natta pro-catalyst, (2) a co-catalyst, and (3) a mixed external electron donor system including (a) an activity limiting agent including at least one carboxylate ester functional group, and (b) a selectivity control agent.

Abstract: Propylene impact copolymers (ICPs) are provided which comprise: (a) a matrix phase which comprises from 60 to 95 weight % of a polypropylene polymer containing from 0 to 6 mole % of units derived from one or more alpha-olefins other than propylene, and (b) a dispersed phase which comprises from 5 to 40 weight % of a copolymer derived from a first comonomer which can be either propylene or ethylene together with a second alpha-olefin comonomer. The ICP is further characterized by having a beta/alpha ratio less than or equal to 1.1. The ICPs of the present invention are particularly well suited for applications requiring clear, tough polymers such as thin walled injection molded articles for frozen food packaging applications.

Abstract: The present invention relates to an improvement for gas-phase olefin polymerization process having relatively high bed bulk density. The improvement involves the use of mixed external electron donors when polymerizing propylene in a gas-phase reactor having a polymer bed with a bulk density greater than 128 kg/m3, optionally with one or more comonomers, wherein the mixed electron donor system comprises at least a first external electron donor and a second external electron donor, and wherein the first external electron donor is a carboxylate compound.

Abstract: Propylene impact copolymers (ICPs) are provided which comprise: (a) a matrix phase which comprises from 60 to 95 weight % of a polypropylene polymer containing from 0 to 6 mole % of units derived from one or more alpha-olefins other than propylene, and (b) a dispersed phase which comprises from 5 to 40 weight % of a copolymer derived from a first comonomer which can be either propylene or ethylene together with a second alpha-olefin comonomer. The ICP is further characterized by having a beta/alpha ratio less than or equal to 1.1. The ICPs of the present invention are particularly well suited for applications requiring clear, tough polymers such as thin walled injection molded articles for frozen food packaging applications.

Abstract: A process for producing polymer particles in a gas phase polymerization reaction using a group 4 metal complex containing delocalized &pgr;-electrons and optionally a flow aid.