Abstract: A process for preparing a polyethylene wax by polymerization of ethylene in the presence of a Ziegler-Natta catalyst system composed of titanium tetrachloride and dialkylaluminium halide, wherein the polymerization temperature is in the range from 170 to 200° C., the polymerization is carried out essentially in the absence of solvents and the Al/Ti molar ratio is less than 1.6, gives a wax having the following property profile: dropping point of from 115 to 125° C.; penetration number of not more than 1 mm·10?1; viscosity at 150° C. of less than 60 mPas; density of from 0.945 to 0.960 g/cm3 at 23° C.; molar mass of less than 1500 g/mol and crystallinity of more than 70%.

Abstract: A process for preparing a polyethylene wax by polymerization of ethylene in the presence of a Ziegler-Natta catalyst system composed of titanium tetrachloride and dialkylaluminium halide, wherein the polymerization temperature is in the range from 170 to 200° C, the polymerization is carried out essentially in the absence of solvents and the Al/Ti molar ratio is less than 1.6, gives a wax having the following property profile: dropping point of from 115 to 125° C.; penetration number of not more than 1 mm·10?1; viscosity at 150° C. of less than 60 mPas; density of from 0.945 to 0.960 g/cm3 at 23° C.; molar mass of less than 1500 g/mol and crystallinity of more than 70%.

Abstract: The use of a synthetic wax oxidate having a number-average molecular weight in the range from 300 to 1000 g/mol and an acid number in the range from 15 to 60 mg KOH/g as a processing aid for a moulding compound which contains a polar polymer which in at least 60% of the repeating units contains at least one group selected from ester groups, amide group, sulphone groups and imide groups produces a good release effect and also mouldings whose transparency is undiminished by the processing aid.

Abstract: The preparation of pigment concentrates for the coloring of resin molding compositions in which the pigment is very finely dispersed is carried out successfully using, for the preparation of the pigment concentrates, a dispersant which contains the following components:from 0 to 90% by weight of a substantially amorphous poly-.alpha.-olefin,from 0 to 90% by weight of polyolefin wax,from 0 to 30% by weight of crystalline polyolefin, andfrom 1 to 50% by weight of a specific polyacrylic acid ester.