Patent ID: 8841392

Claim:
A process for the production of ultra high molecular weight polyethylene comprising polymerizing ethylene in the presence of a catalyst system to produce the ultra high molecular weight polyethylene having an average molecular weight higher than 280,000 g/mol and lower than 10,000,000 g/mol, wherein the catalyst system comprises: I. a solid reaction product obtained by reaction of (a) a hydrocarbon solution comprising (1) an organic oxygen containing magnesium compound; (2) an organic oxygen containing titanium compound; and (3) a compound containing zirconium and/or hafnium; and (b) a mixture comprising a metal compound having the formula MeR n X 3-n wherein X is a halogenide, Me is a metal of Group III of Mendeleev's Periodic System of Chemical Elements, R is a hydrocarbon radical containing 1-10 carbon atoms and 0≦n<3 and a silicon compound of formula R m SiCl 4-m wherein 0≦m≦2 and R is a hydrocarbon radical containing 1-10 carbon atoms wherein the molar ratio of metal from (b): titanium from (a) is lower than 1:1; and II. an organo aluminum compound having the formula AlR 3 in which R is a hydrocarbon radical containing 1-10 carbon atoms.