Abstract: The novel process for preparing ethylene copolymers by polymerizing ethylene with, as comonomer, up to 10% by weight, based on the total amount of the monomers, of a 1-olefin of the formula R—CH═CH2, where R is a straight-chain or branched alkyl radical having from 1 to 4 carbon atoms, is carried out in a polymerization reactor and in suspension with a dispersion medium at a temperature of from 20 to 100° C. and a pressure of from 2 to 20 bar, in the presence of a catalyst. The dispersion medium is then separated from the polymer. After carrying out the polymerization, but before removing the dispersion medium from the polymer, the suspension stream is partly evaporated, with the result that some of the wax formed in the polymerization is adsorbed onto the polymer and the resultant vapor stream is fed directly into the reactors after condensation or back into the process after distillative removal of the comonomer.

Abstract: Process for preparing a poly-1-olefinBy means of a highly active spherical Ziegler catalyst based on a dialkylmagnesium, spherical polymers can be obtained in the polymerization of alpha-olefins. A further advantage of the catalyst of the invention lies in the high catalyst activity, so that only very small amounts of the catalyst are required for the polymerization. The residual titanium and/or zirconium content in the polymers prepared according to the invention is less than 10 ppm. Owing to its good responsiveness to hydrogen, the catalyst is particularly suited to two-stage processes for preparing polymers having a broad bimodal molecular weight distribution. The replacement of sulfur-containing electron donors such as diethyl sulfite by alcohols such as ethanol leads to less odor problems and broadened opportunities for use of the polymer.