| abstract |
ABSTRACT OF THE DISCLOSURE A process for the homopolymerization or copolymerization of olefins is disclosed, which is carried out in the presence of a catalyst system comprising the combination of at least one organometallic compound with a component resulting from the reaction of (a) a magnesium halide, (b) a compound represented by the formula, A?(OR)nX3-n, where R is a hydrocarbon residual group having 1 to 20 carbon atoms, X is a hydrogen atom, and n is 0?n?3, (c) a compound represented by the formula, Si(OR')mX4-m, where R' is a hydrocarbon residual group having 1 to 20 carbon atoms, X is a halogen atom, and m is 0?m?4, and (d) a titanium compound and/or a vanadium compound. The resulting polymers have a large bulk density and a narrow range of molecular weight distribution. |