Process for preparing ethylene polymer wax.

摘要

Ethylene polymer wax has been prepared by polymerizing ethylene, optionally with up to 10 mole% of an alphaolefin having 3 to 20 carbon atoms, in the presence of a catalyst composed of (A) a highly active titanium catalyst component activated by a magnesium compound and (B) an organoaluminum catalyst component. With known catalysts ethane is formed to an undesirable extent by the hydrogenation of ethylene and it can be difficult to obtain a wax of the desired low viscosity average molecular weight.
These problems are overcome or mitigated by a process in which the organoaluminum catalyst component (B) is composed of (B-1) an organoaluminum compound free from halogen bonded directly to the aluminum atom and (B-2) a halogen compound of an element of Group III or IV of Mendelejeff's periodic table, the atomic ratio of halogen to aluminum in the organoaluminum catalyst component (B) being from 1:6 to 9:10, provided that when said halogen compound is a halogen compound of carbon, this atomic ratio is from 1:6 to 10:1, and the polymerization is carried out under such conditions that the concentration of ethylene polymer wax in the polymerization system is 200 to 600 g/liter of solvent, a wax being formed having a viscosity average molecular weight of up to 6000.