| abstract |
A process for preparing homo- and copolymers of alpha-mono-olefins by polymerizing the monomer with a Ziegler catalyst system comprising: 1 degree a titanium-containing component, and 2 degrees a metal compound Me Am-n X n , where Me - Al, Mg or Zn, A = hydrocarbon residue and X = H or Hal. Component 1 is prepared by bringing a substance of the inorganic oxide type SiO 2 .aAl2 O3 into contact with a solution obtained by mixing a saturated alcohol, a titanium-III halide and a magnesium compound soluble in alcohol, evaporating at dryness the dispersion obtained, and by contacting the solid product obtained with a metallic compound Mt Gs-t where M = Al or Si, G = hydrocarbon residue, E = H, Hal or -OD, D being a hydrocarbon residue, s is the valence of the metal Mt and t = sl if Mt = Al and between 0 and 4 if Mt - Si. |