Patent ID: 8178636

Claim:
A process for obtaining an atactic, amorphous 1-butene homopolymer comprising polymerizing 1-butene in the presence of a catalyst system obtained by contacting: a) at least one meso or meso-like 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 Elements; p is an integer from 0 to 3, wherein p is equal to a formal oxidation state of M minus 2; X, same or different, is hydrogen, halogen, R, OR, OSO 2 CF 3 , OCOR, SR, NR 2 or PR 2 , wherein R is a 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 radical, optionally comprising at least one heteroatom belonging to groups 13-17 of the Periodic Table of 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 a C 1 -C 40 alkylidene, C 6 -C 40 arylidene, C 7 -C 40 alkylarylidene or C 7 -C 40 arylalkylidene radical; L is a divalent C 1 -C 40 hydrocarbon radical optionally comprising at least one heteroatom belonging to groups 13-17 of the Periodic Table of Elements, or a divalent silylidene radical comprising up to 5 silicon atoms; R 1 and R 2 , same or different, are C 1 -C 40 hydrocarbon radicals optionally comprising at least one heteroatom belonging to groups 13-17 of the Periodic Table of Elements; T, same or different, are a moiety of formula (IIa) or (IIb): wherein the atom marked with the symbol * bonds the atom marked with the same symbol in the compound of formula (I); R 3 is a C 1 -C 40 hydrocarbon radical optionally comprising at least one heteroatom belonging to groups 13-17 of the Periodic Table of Elements; R 4 and R 6 , same or different, are hydrogen or C 1 -C 40 hydrocarbon radicals optionally comprising at least one heteroatom belonging to groups 13-17 of the Periodic Table of Elements; R 5 is a C 1 -C 40 hydrocarbon radical optionally comprising at least one heteroatom belonging to groups 13-17 of the Periodic Table of Elements; R 7 and R 8 , same or different, are hydrogen or C 1 -C 40 hydrocarbon radicals optionally comprising at least one heteroatom belonging to groups 13-17 of the Periodic Table of Elements; and b) an alumoxane or a compound capable of forming an alkyl metallocene cation; wherein the atactic, amorphous 1-butene homopolymer comprises an isotactic pentad content (mmmm) lower than 15% and an intrinsic viscosity of at least 1.3 dL/g.