Method for producing ethylene polymers in a high-pressure process

A process for preparing a polyethylene wax, comprising:

• dissolving one or more free-radical initiators in one or more ketones of the formula I,
• thereby obtaining a solution;
• and
• compressing the solution, to obtain a compressed solution;
• metering said compressed solution into a polymerization reactor at one or more points;
• and
• subsequently polymerizing ethylene, thereby obtaining a polyethylene wax having a molecular weight Mw of not more than 40,000 g/mol;
• wherein in formula I, R1 and R2 are identical or different and are C1-C6-alkyl, C3-C12-cycloalkyl or R1 and R2 are covalently linked to one another to form a 4- to 13-membered ring, prior to the polymerization;
• wherein said process proceeds at a temperature of from 140 to 350° C. and a pressure of from 400 to 4500 bar.