Patent ID: 7977444

Claim:
A process for preparing a polymer containing derived units of 1-hexene or 1-octene and from 19 to 59% by mol. of derived units of 1-butene, the process comprising contacting under polymerization conditions 1-hexene or 1-octene and 1-butene in the presence of a catalyst system obtained by contacting: a) a metallocene compound of formula (I): wherein M is an atom of a transition metal selected from those belonging to group 3, 4, 5, 6 or to the lanthanide or actinide groups in the Periodic Table of the Elements; p is an integer from 0 to 3, being equal to the formal oxidation state of the metal M minus 2; X, same or different, is a hydrogen atom, a halogen atom, or a R, OR, OSO 2 CF 3 , OCOR, SR, NR 2 or PR 2 group, wherein R is a are linear or branched, cyclic or acyclic, C 1 -C 40 -alkyl, C 2 -C 40 alkenyl, C 2 -C 40 alkynyl, C 6 -C 40 -aryl, C 7 -C 40 -alkylaryl or C 7 -C 40 -arylalkyl radicals; optionally containing heteroatoms belonging to groups 13-17 of the Periodic Table of the Elements; or two X can optionally form a substituted or unsubstituted butadienyl radical or a OR′O group wherein R′ is a divalent radical selected from C 1 -C 40 alkylidene, C 6 -C 40 arylidene, C 7 -C 40 alkylarylidene and C 7 -C 40 arylalkylidene radicals; L is a divalent C 1 -C 40 hydrocarbon radical optionally containing heteroatoms belonging to groups 13-17 of the Periodic Table of the Elements or a divalent silylene radical containing up to 5 silicon atoms; R 1 and R 2 , equal to or different from each other, are linear C 1 -C 20 alkyl radicals; T, equal to or different from each other, is a moiety of formula (IIb): wherein the atom marked with the symbol * bonds the atom marked with the same symbol in the compound of formula (I); R 7 is a group of formula (III): wherein R 9 , R 10 , R 11 , R 12 and R 13 , equal to or different from each other, are hydrogen atoms or linear or branched, cyclic or acyclic, C 1 -C 20 -alkyl, C 2 -C 20 alkenyl, C 2 -C 20 alkynyl, C 6 -C 20 -aryl, C 7 -C 20 -alkylaryl or C 7 -C 20 -arylalkyl radicals; optionally containing heteroatoms belonging to groups 13-17 of the Periodic Table of the Elements; R 8 , equal to or different from each other, are hydrogen atoms or C 1 -C 40 hydrocarbon radicals optionally containing heteroatoms belonging to groups 13-17 of the Periodic Table of the Elements; R 7 and R 8 can optionally form a saturated or unsaturated, 5 or 6 membered rings, said ring can bear C 1 -C 20 alkyl radicals as substituents; and (b) an alumoxane or a compound that forms an alkyl metallocene cation.