Patent ID: 6949611

Claim:
A process for preparing polyethylene, comprising: dissolving one or more free-radical initiators in one or more ketones of the formula I, thereby obtaining a monomer free solution; and compressing the monomer free solution, to obtain a compressed solution; metering said compressed solution into a tube reactor at one or more points; and subsequently polymerizing ethylene, thereby obtaining a polyethylene having a molecular weight M w of greater than 40,000 g/mol; wherein in formula I, R 1 and R 2 are identical or different and are C 1 -C 6 -alkyl, C 3 -C 12 -cycloalkyl or R 1 and R 2 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.