Process for producing polyolefins

摘要

An improved catalyst system is disclosed for use in the polymerization or copolymerization of olefins. The catalyst comprises a transition metal compound, an organometal compound and a composite carrier. This carrier is constituted by a SO3 treated alumina and a magnesium and/or a calcium compound. The polymerization or copolymerization of olefins such as ethylene, propylene and 1-butene is effected under conditions similar to those for reactions by means of Ziegler catalysts, but the resulting polyolefins have a wider molecular weight distribution, viz, a larger flow parameter as required for extrusion or blow molding.