PROCESS FOR PRODUCING AN ALPHA-OLEFIN POLYMER

摘要

The gas-phase polymerization of alpha-olefins is difficult to carry out efficiently in a stable, smooth and reproducible manner and it is usually necessary to deash the resulting polymer to remove catalyst residues. These problems are overcome by carrying out the gas-phase polymerization of at least one alpha -olefin under the following set of parameters (A) to (E):- (A) the polymerization is carried out in the presence of a catalyst composed of a solid halogen-containing titanium catalyst component supported on a magnesium compound and an organoaluminum compound and pretreated by polymerising in its presence at least one olefin; (B) the polymerization is carried out while maintaining the polymerization system in the fluidized state by mechanically stirring it and blowing into it said olefin in the gaseous state and/or a gaseous, easily volatile non-polymerizable hydrocarbon; (C) said olefin in the liquid state and/or a liquid, easily volatile non-polymerizable hydrocarbon is introduced into the polymerization system and the gas-phase polymerization is carried out while gasifying said olefin and/or said hydrocarbon in said system; (D) unreacted olefin gas and/or hydrocarbon gas discharged from the polymerization system is partly or wholly liquefied and recycled as liquid olefin and/or hydrocarbon in (C), and (E) said olefin is blown or introduced into the polymerization system in at least one of (B) and (C).