PROCESS FOR PREPARING POLYOLEFINS

摘要

An improvement is provided in a process for preparing polyolefins wherein olefins are polymerized or copolymerized in the presence of a catalyst. The improvement resides in using, as the catalyst, a solid component and an organometallic compound. The solid component is either (A) a substance obtained by the copulverization of (1) a reaction product resulting from a heat reaction of magnesium oxide and aluminum trichloride, at an A1/Mg atomic ratio of from 0.3 to 5 at a temperature of from 150.degree. to 600.degree.C., and (2) a titanium compound and/or a vanadium compound, or (B)a substance obtained by copulverization of (1) a reaction product resulting from a heat reaction of magnesium oxide and aluminum trichloride at an Al/Mg atomic ratio of from 0.3 to 5 at a temperature of from 150.degree. to 600.degree.C., (2) at least one of a titanium compound and a vanadium compound, and (3) an organic halide. The polyolefins obtained by this process have a wide molecular weight distribution. In other words, they have a large flow parameter. When such polyolefin is extruded, the molding obtained has superior surface conditions.