Patent ID: 7615597

Claim:
A process for producing a polymer of ethylene containing from 0.1 to 99% by mol of at least one derived unit of alpha-olefins of formula CH 2 ═CHZ, wherein Z is a C 2 -C 20 alkyl radical, and optionally from 0 to 5% by mol polyene, comprising contacting, under polymerization conditions, ethylene, said at least one alpha-olefin and optionally said polyene, in the presence of a catalyst system obtained by contacting: a) a metallocene compound of formula (IV) or (V): wherein M is zirconium, hafnium or titanium; X, equal to or different from each other, is a hydrogen atom, a halogen atom, an R, OR, OSO 2 CF 3 , OCOR, SR, NR 2 or PR 2 group, wherein R is a linear or branched, C 1 -C 20 -alkyl, C 3 -C 20 -cycloalkyl, C 6 -C 20 -aryl, C 7 -C 20 -alkylaryl, or C 7 -C 20 -arylalkyl radical, optionally containing at least one heteroatom belonging to groups 13-17 of the Periodic Table of the Elements; two X can join to form a C 4 -C 40 dienyl ligand; R 1 and R 6 are each independently a linear or branched, C 1 -C 20 -alkyl, C 3 -C 20 -cycloalkyl, C 6 -C 20 -aryl, C 7 -C 20 -alkylaryl, or C 7 -C 20 -arylalkyl radical, optionally containing at least one heteroatom belonging to groups 13-17 of the Periodic Table of the Elements; R 2 , and R 5 , equal to or different from each other, are hydrogen atoms, halogen atoms, linear or branched, C 1 -C 20 -alkyl, C 3 -C 20 -cycloalkyl, C 6 -C 20 -aryl, C 7 -C 20 -alkylaryl, or C 7 -C 20 -arylalkyl radicals, optionally containing at least one heteroatom belonging to groups 13-17 of the Periodic Table of the Elements; R 3 and R 4 are each independently a hydrogen atom or a linear or branched, C 1 -C 10 -alkyl radical, optionally containing at least one halogen atom, wherein when R 3 is a hydrogen atom, R 4 is a linear or branched, C 1 -C 10 -alkyl radical, optionally containing at least one halogen atom, and when R 3 is a linear or branched, C 1 -C 10 -alkyl radical optionally containing at least one halogen atom, R 4 is a hydrogen atom; L is a divalent bridging group selected from C 1 -C 20 alkylidene, C 3 -C 20 cycloalkylidene, C 6 -C 20 arylidene, C 7 -C 20 alkylarylidene, or C 7 -C 20 arylalkylidene radicals, optionally containing heteroatoms belonging to groups 13-17 of the Periodic Table of the Elements, or a silylidene radical containing up to 5 silicon atoms; b) an alumoxane or a compound that forms an alkyl metallocene cation.