PRODUCING HIGH COMONOMER CONTENT PROPYLENE-BASED POLYMERS

摘要

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.