COMPONENTS AND CATALYSTS FOR THE POLYMERIZATION OF ALPHA-OLEFINS TO STEREOREGULAR POLYMERS HAVING NARROW MOLECULAR WEIGHT DISTRIBUTION

摘要

Components of catalysts suitable for the (co)polymerization of alpha-olefins to stereoregular polymers having narrow molecular weight distribution, obtained by reaction of a solid catalyst - forming component comprising a Ti compound having at least a Ti-halogen bond and optionally an electron donor compound supported on a Mg halide in active form, with a compound (AH) containing at least an active hydrogen atom, used in controlled amounts and made to react in a liquid medium not reactive towards the solid component and having a dielectric constant higher than 2, measured at 20.degree.C. Catalysts comprising the product of reaction of a solid catalyst component as above described, with an Al-alkyl compound and an electron donor compound.