| abstract |
Ethylene propylene copolymers with a density p of between 0.905 and 0.935 g cm3 and a melt index of between 0.4 and 2 dg / min, the rate of which of methyl groups is between 22 and 62 per 1000 carbon atoms in the molecule and such as: 0.9530 ≤ p + 0.83 m ≤ 0.9568. Their production process consists in copolymerizing ethylene and propylene at a temperature between 180 ° and 320 ° C under a pressure between 300 and 2,500 bar by means of a catalytic system comprising at least one halogenated metal compound of transition, the gas flow supplying the reactor being made up of 65 to 85% by weight of ethylene and 15 to 35% by weight of propylene under steady state conditions, and the halogenated transition metal compound comprising a complex compound of formula (MCl e ) (MgX 2 ) y (AlCl 3 ) z (RMgX) b in which M is a metal chosen from titanium and vanadium, X is a halogen, R is a hydrocarbon radical, 2 ≤ a ≤ 3.2 ≤ y ≤ 20.0 ≤ z ≤ and 0n n n Application to the manufacture of films of thickness less than 12 microns. |