| abstract |
Catalysts for the polymerization of olefins, particularly alpha olefin CH2=CHR in which R is an alkyl radical with 1-6 carbon atoms or an aryl radical, obtained by the reaction of: a) an Al-alkyl compound; b) an ether containing at least two ether groups which can form complexes with anhydrous magnesium dichloride, under standard conditions of reaction, in amount less than 60 mmol per 100 g Mg dichloride; and c) a solid catalyst component comprising an anhydrous magnesium dihalide in active form and having supported thereon a titanium compound containing at least a Ti-halogen bond and an electron-donor compound which is extractable with Al-triethyl, under standard conditions of extraction, for at least 70% in mol, wherein the solid, after extraction, has a surface area of more than 20 m2/gr. |