Patent ID: 7964679

Claim:
A process for preparing 1-butene polymers, comprising polymerizing 1-butene or copolymerizing 1-butene with ethylene, propylene or an alpha-olefin of formula CH 2 ═CHT wherein T is a C 3 -C 10 alkyl group, in the presence of a catalyst system obtained by contacting: A) a metallocene compound belonging to formula (I): wherein M is zirconium, titanium or hafnium; X, equal to or different from each other, is a hydrogen atom, a halogen atom, an R, OR, OR′O, OSO 2 CF 3 , OCOR, SR, NR 2 or PR 2 group wherein R is a linear or branched, saturated or unsaturated 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 heteroatoms belonging to groups 13-17 of the Periodic Table of the Elements, and R′ is a C 1 -C 20 -alkylidene, C 6 -C 20 -arylidene, C 7 -C 20 -alkylarylidene, or C 7 -C 20 -arylalkylidene radical; R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , and R 11 , 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; at least two R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , and R 11 can also optionally join to form at least one C 4 -C 10 condensed saturated or unsaturated ring; R 12 and R 13 , equal to or different from each other, are hydrogen atoms or C 1 -C 40 hydrocarbon radical optionally containing heteroatoms belonging to groups 13-17 of the Periodic Table of the Elements; and R 1 is a linear or branched, C 1 -C 20 -alkyl radicals, optionally containing heteroatoms belonging to groups 13-17 of the Periodic Table of the Elements; R 2 and R 3 , equal to or different from each other, are linear C 1 -C 20 -alkyl radicals, optionally containing heteroatoms belonging to groups 13-17 of the Periodiv Table of the Elements; B) an alumoxane or a compound that forms an alkyl metallocene cation; and optionally C) an organo aluminum compound.