| 摘要 |
<p>Catalyst system comprising, on the one hand, at least one halogen compound of a transition metal of groups IV to VI of the Periodic Classification and with a valency lower than or equal to 3 and, on the other hand, at least one metal activator, the atomic ratio of the metal of the activator to the transition metal being between 1 and 50, the said system being characterised in that the metal activator has the formula: (AIR2I)x(B)1-x in which R is an alkyl radical containing from 1 to 12 carbon atoms, 0.1 </= x </= 0.8 and B is chosen from alkylsiloxalanes and dialkylzincs. Application to the (co)polymerisation of ethylene at a pressure of between 300 and 2500 bars and at a temperature of between 160 DEG C and 320 DEG C.</p> |
