Abstract: A process for the preparation of a supported catalyst for the polymerization of .alpha.-olefins, in which(1) a silicon dioxide-containing support gel is prepared by(1.1) introducing a sodium water glass or potassium water glass solution into a swirling stream of an aqueous mineral acid longitudinally and tangentially to the stream, spraying the resultant silica hydrosol in drop form into a gaseous medium and allowing it to solidify to form a hydrogel, and freeing the resultant hydrogel from salts by washing without prior ageing,(1.2) drying the hydrogel resulting from (1.1) to form the support gel,(2) the support gel (1) is charged with chromium trioxide or a chromium compound which can be converted into chromium trioxide under the conditions of process step (3), giving a chromium-containing support gel, and(3) the chromium-containing support gel (2) is heated at from 400.degree. to 1100.degree. C.

Abstract: A process for the preparation of a supported catalyst for the polymerization of .alpha.-olefins, in which(1) a silicon dioxide-containing support gel is prepared by(1.1) introducing a sodium water glass or potassium water glass solution into a swirling stream of an aqueous mineral acid longitudinally and tangentially to the stream, spraying the resultant silica hydrosol in drop form into a gaseous medium and allowing it to solidify to form a hydrogel, and freeing the resultant hydrogel from salts by washing without prior ageing,(1.2) drying the hydrogel resulting from (1.1) to form the support gel,(2) the support gel (1) is charged with chromium trioxide or a chromium compound which can be converted into chromium trioxide under the conditions of process step (3), giving a chromium-containing support gel, and(3) the chromium-containing support gel (2) is heated at from 400.degree. to 1100.degree. C.

Abstract: In a novel process for the preparation of a supported catalyst for the polymerization of .alpha.-olefins, a carrier gel (1) is first prepared by a method in which a sodium or potassium waterglass solution is introduced into a stream of an aqueous mineral acid which is subjected to angular momentum and may contain aluminum ions, longitudinally and tangentially to the stream, the resulting silica hydrosol sprayed in the form of drops into a gaseous medium and allowed to solidify into a hydrogel, and the resulting hydrogel is freed from salts by washing without prior aging and, if necessary, freed from some of the water by extraction with alcohols and/or ketones and is then dried. This gives the carrier gel (1), which is milled and is fractionated according to particle size. In a second process step, the carrier gel (1) is laden with chromium trioxide or with a chromium compound which can be converted into chromium trioxide, after which the resulting chromium-containing carrier gel (2) is heated at from 400.

Abstract: A transition-metal catalyst component for a Ziegler catalyst system, obtainable by1) mixing, in a solvent, an inorganic, oxidic carrier with1.1) a vanadium trihalide alcohol complex of the formula VY.sub.3.nZ--OH, whereY is chlorine or bromine,n is from 1 to 6, andZ is a monovalent, saturated, aliphatic, aromatic or araliphatic hydrocarbon radical having not more than 10 carbon atoms, and1.2) a titanium halide or a titanium trihalide/aluminum trihalide complex, where the halogen can be chlorine and/or bromine, or a titanium trihalide complex of the formula TiY.sub.3.nZ--OH or mixtures thereof, whereY is chlorine or bromine,n is from 1 to 6, andZ is a monovalent, saturated, aliphatic, aromatic or araliphatic hydrocarbon radical having not more than 10 carbon atoms, and1.3) a compound of the formula BX.sub.n Y.sub.m R.sub.p or SiX.sub.n Y.sub.m R.sub.q or mixtures thereof, whereX is OR,Y is chlorine, bromine or hydrogen, andR is a C.sub.1 - to C.sub.