| 摘要 |
<p>1. A manufacturing process for ethylene polymers with a melt index between 0.1 and 2 and a polydispersity index exceeding 10, by polymerizing ethylene in the presence of a catalytic system comprising at least one halogenated compound of a transition metal and at least one activator selected from the hydrides and the organo-metallic compounds of the metals of groups I through III of the periodic table, in a set of two reactors operating under different temperature and pressure conditions, characterized in that the first reactor operates at a pressure between 800 and 2,000 bars and at a temperature between 160 degrees C and 260 degrees C and the second reactor operates at a pressure between 300 and 600 bars and at a temperature between 240 degrees C and 340 degrees C, the ethylene polymerization taking place in each of said reactors in the total absence of hydrogen and the flow of ethylene feeding the second reactor representing from 17 to 69% of the total ethylene flow.</p> |
