A Novel (SiO2/MgO/MgCl2)•TiClx Ziegler-Natta Catalyst for Ethylene and Ethylene/1-Hexene Polymerization

A novel (SiO2/MgO/MgCl2)TiClx Ziegler-Natta catalyst for ethylene and ethylene/1-hexene polymerization is successfully developed through impregnation of aqueous solution of water-soluble Mg-compounds such as magnesium acetate on silica gel, and forming a supported thin layer of magnesium oxide on the surface of SiO2 after high temperature calcination in dry air or oxygen, followed by further reacting with titanium tetrachloride to synthesize the magnesium dichloride carrier in situ and to support the titanium species simultaneously. The method is relatively simple and the resulting catalysts exhibit high activity, good hydrogen response, and copolymerization ability with high 1-hexene incorporation. Unlike the traditional industrial Ti/Mg Ziegler-Natta catalysts using the relatively expensive, anhydrous and moisture-sensitive MgCl2, Mg(OEt)(2), MgR2 or RMgCl as Mg-sources, the most unique feature of this novel catalyst is its capability of utilization of any soluble Mg-compounds and thus shows great potential for application in commercial gas-phase polyolefin processes.