Patent ID: 8703887

Claim:
A process for the production of high density polyethylene comprising: polymerizing ethylene in the presence of a supported chromium oxide based catalyst and an activator, wherein the activator comprises the reaction mixture of a boron compound and/or an alkyl aluminium compound; and a nitrogen containing compound wherein the boron compound is a (C 1 -C 10 ) alkyl boron compound or a (C 5 -C 20 ) aromatic boron compound, wherein the alkyl aluminum compound is an organo aluminium compound having the formula AlR 3 in which R is a hydrocarbon radical containing 1-10 carbon atom and wherein the nitrogen containing compound comprises —NH 2 , —NHR, and/or —NR 2 , wherein R may be an alkyl or a substituted alkyl having from 1 to 40 carbon atoms; wherein the nitrogen containing compound is decylamine, undecylamine, octylamine, octadecylamine, dodecylamine, N-methyloctadecylamine, N-ethyl-dodecylamine, hexadecylamine and/or N—N″ dimethyl-n-octadecylamine.