Trialkysiloxy-ethers as New External Donors in the Ziegler-Natta Catalyst

A catalyst for the polymerization of propene comprises a product of the following components: (A) TiCl 4 -MgCl 2 -phthalate-based catalyst; (B) Al(C 2 H 5 ) 3 , and (C) an external electron donor. The polymerization of propene using a trialkylsiloxy-ether as a new external donor keeps high activity and exhibits well response to hydrogen, and gives polymers having higher melt index in high H 2 pressure than using cyclohexylmethyldimethyloxysilane, which commonly used as an external electron donor in industry.