Preparation of homopolymers and copolymers of α-monoolefins using a ziegler catalyst system

Claim 1

A process for the preparation of homopolymers and copolymers of C 2 -C 8 -α-monoolefins, by polymerization of the monomer or monomers at from 30° to 200° C., and under a pressure of from 0.1 to 200 bar, using a Ziegler catalyst system comprising (1) a transition metal catalyst component and (2) an organoaluminum catalyst component of the formula AlR.sub.m X.sub.3-m where X is a radical OR, chlorine, bromine or hydrogen, R is a C 1 -C 18 -hydrocarbon radical and m is a number from 1 to 3, with the provisos (i) that the atomic ratio of the transition metal from the catalyst component (1) to aluminum from catalyst component (2) is from 1:0.1 to 1:500, and (ii) that the transition metal catalyst component (1) used is a solid-phase product (VI), obtained by a method in which (1.1) first (1.1.1) a finely divided, porous, inorganic oxidic substance (I), which has a particle diameter of from 1 to 1,000 μm, a pore volume of from 0.3 to 3 cm 3 /g and a specific surface area of from 100 to 1,000 m 2 /g and is of the formula SiO 2 .aAl 2 O 3 -where a is a number from 0 to 2, and (1.1.2) a solution (II), as obtained on combining (IIa) 100 parts by weight of an alcohol of the formula Z--OH where Z is saturated C 1 -C 8 -hydrocarbon radical, and (IIb) from 0.01 to 40 parts by weight of a transition metal composition, are brought into contact with one another to form a suspension (III), with the proviso that the weight ratio of inorganic oxidic substance (I) to transition metal composition (IIb) is from 1:0.01 to 1:1.2, the suspension (III) is evaporated to dryness at below 200° C., and above the melting point of the alcohol (IIa) used, a solid-phase intermediate (IV) being formed, and (1.2) thereafter (1.2.1) the solid-phase intermediate (IV) obtained from stage (1.1) and (1.2.2) a solution, in an organic solvent, of an aluminum compound (V) of the formula AlR.sub.m X.sub.3-m where X is a radical OR, chlorine, bromine or hydrogen, R is a C 1 -C 18 -hydrocarbon radical, and m is a number from 1 to 3, are brought into contact with one another to form a suspension, with the proviso that the weight ratio of the solid-phase intermediate (IV) to the aluminum compound (V) is from 1:0.05 to 1:2, and the resulting suspended solid-phase product (VI) is the transition metal catalyst component (1), wherein the transition metal catalyst component (1) employed is a solid-phase product (VI) obtained using a transition metal composition (IIb) comprising (IIb1) 100 molar parts of a vanadium trihalide in which the halogen can be chlorine and/or bromine, and (IIb2) from 5 to 400 molar parts of a zirconium tetrahalide in which the halogen can be chlorine and/or bromine with the further proviso that the metal compound components of solid phase product (VI) are derived solely from substance (I), compound (V) and the transition metal compounds in composition (IIb).