Patent ID: 6156691
Filing Date: 2000-12-05
Classification: C08F

Abstract:
A catalyst system of the Ziegler-Natta type consisting essentially of as active constituentsa) a titanium-containing solid component which is obtained by reacting a compound of titanium with a compound of magnesium, an inorganic oxide as support, a C.sub.1 -C.sub.8 -alkanol and a carboxylic ester as electron donor compound,and also as cocatalystb) an aluminum compound andc) optionally a further electron donor compound, wherein the titanium-containing solid component a) is prepared by first, in a first stage, admixing an inorganic oxide as support with a solution of a chlorine-free compound of magnesium in an inert solvent, stirring this mixture for from 0.5 to 5 hours at from 10 to 120.degree. C. and subsequently reacting it at from -20 to +80.degree. C. while stirring continually in an inert solvent with a C.sub.1 -C.sub.8 -alkanol in a 1.3 to 1.8-fold molar amount excess, based on the compound of magnesium, to give a chlorine-free intermediate, then, without purification or extraction of the intermediate, adding a compound of trivalent or tetravalent titanium and a carboxylic ester as electron donor compound to this intermediate, stirring the resulting mixture for at least 30 minutes at from 20 to 130.degree. C., subsequently filtering off and washing the solid thus obtained and subsequently, in a second stage, extracting the solid obtained from the first stage in an inert solvent comprising at least 5% by weight of titanium tetrachloride and washing it with a liquid alkane.