Patent ID: 7390862

Claim:
A process for preparing 1-butene polymers, said process comprising polymerizing 1-butene or copolymerizing 1butene 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 obtainable by contacting: (A) a metallocene compound having the following formula (I) wherein: M is an atom of a transition metal selected from those belonging to group 3, 4, or to the lanthanide or actinide groups in the Periodic Table of the Elements; X, are equal to or different from each other, and are hydrogen, a halogen, R, OR, 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 1 , R 2 , R 5 , R 6 , R 7 , R 8 and R 9 , are equal to or different from each other, and are hydrogen, or 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; wherein R 5 and R 6 can optionally form a saturated or unsaturated, optionally substituted 5 or 6 membered ring, the ring can be optionally substituted with at least one C 1 -C 20 alkyl radical; R 8 and R 9 can optionally form a saturated or unsaturated, optionally substituted 5 or 6 membered ring, the ring can be optionally substituted with at least one C 1 -C 20 alkyl radical; with the proviso that at least one of R 6 or R 7 is a linear or branched, saturated or unsaturated C 1 -C 20 -alkyl radical, optionally containing heteroatoms belonging to groups 13-17 of the Periodic Table of the Elements; R 3 and R 4 , are equal to or different from each other, and are linear or branched, saturated or unsaturated C 1 -C 20 -alkyl, optionally containing heteroatoms belonging to groups 13-17 of the Periodic Table of the Elements; and (B) an alumoxane or a compound capable of forming an alkyl metallocene cation, wherein the process prepares at least one 1-butene polymer, the 1-butene polymer comprising an intrinsic viscosity greater than 1.9 dL/g measured in tetrahydronaphtalene at 135° C.