Process for polymerizing 1-butene

A process for preparing 1-butene polymers, said process comprising polymerizing 1-butene or copolymerizing 1-butene with ethylene, propylene or an alpha-olefin of formula CH2═CHT wherein T is a C3-C10 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, OR′O, OSO2CF3, OCOR, SR, NR2 or PR2 group, wherein R is a linear or branched, saturated or unsaturated C1-C20-alkyl, C3-C20-cycloalkyl, C6-C20-aryl, C7-C20-alkylaryl or C7-C20-arylalkyl radical, optionally containing heteroatoms belonging to groups 13-17 of the Periodic Table of the Elements;
• and R′ is a C1-C20-alkylidene, C6-C20-arylidene, C7-C20-alkylarylidene, or C7-C20-arylalkylidene radical;
• R1, R2, R5, R6, R7, R8 and R9, are equal to or different from each other, and are hydrogen, or a linear or branched, saturated or unsaturated C1-C20-alkyl, C3-C20-cycloalkyl, C6-C20-aryl, C7-C20-alkylaryl or C7-C20-arylalkyl radical, optionally containing heteroatoms belonging to groups 13-17 of the Periodic Table of the Elements;
• wherein R5 and R6 can optionally form a saturated or unsaturated, optionally substituted 5 or 6 membered ring, the ring can be optionally substituted with at least one C1-C20 alkyl radical;
• R and R9 can optionally form a saturated or unsaturated, optionally substituted 5 or 6 membered ring, the ring can be optionally substituted with at least one C1-C20 alkyl radical;
• with the proviso that at least one of R6 or R7 is a linear or branched, saturated or unsaturated C1-C20-alkyl radical, optionally containing heteroatoms belonging to groups 13-17 of the Periodic Table of the Elements;
• R3 and R4, are equal to or different from each other, and are linear or branched, saturated or unsaturated C1-C20-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.

A 1-butene homopolymer comprising:

• isotactic pentads (mmmm)>90;
• intrinsic viscosity (I.V.) measured in tetrahydronaphtalene (THN) at 135° C.>1.2;
• melting point (D.S.C.) higher than 100° C.;
• and
• molecular weight distribution Mw/Mn 21 4;

A 1-butene homopolymer comprising:

• isotactic pentads (mmrm)>95;
• intrinsic viscosity (I.V.) measured in tetrahydronaphtalene (THN) at 135° C.>1.5;
• melting point (D.S.C.) higher than 100° C.;
• and
• molecular weight distribution Mw/Mn<4.

A metallocene compound of formula (II):

• wherein:
• M is an atom of a transition metal selected from groups 3 and 4, or to a lanthanide or actinide group in the Periodic Table of the Elements;
• X, are equal to or different from each other, and are hydrogen, a halogen, R, OR, OR′O, OSO2CF3, OCOR, SR, NR2 or PR2 group wherein R is a linear or branched, saturated or unsaturated C1-C20-alkyl, C3-C20-cycloalkyl, C6-C20-aryl, C7-C20-alkylaryl or C7-C20-arylalkyl radical, optionally containing heteroatoms belonging to groups 13-17 of the Periodic Table of the Elements;
• and R′ is a C1-C20-alkylidene, C6-C20-arylidene, C7-C20-alllylarylidene, or C7-C20-arylalkylidene radical;
• R1, R2, R5, R6, R7, R8 and R9, are equal to or different from each other, and are hydrogen, or a linear or branched, saturated or unsaturated C1-C20-alkyl, C3-C20-cycloalkyl, C6-C20-aryl, C7-C2o-alkylaryl or C7-C2o-arylalkyl radical, optionally containing heteroatoms belonging to groups 13-17 of the Periodic Table of the Elements;
• wherein R8 and R9 can optionally form a saturated or unsaturated, optionally substituted 5 or 6 membered ring;
• R3 and R4, are equal to or different from each other, and are linear or branched, saturated or unsaturated C1-C20-alkyl radicals, optionally containing heteroatoms belonging to groups 13-17 of the Periodic Table of the Elements;
• R6 is a linear or branched, saturated or unsaturated C1-C20-alkyl radical, optionally containing heteroatoms belonging to groups 13-17 of the Periodic Table of the Elements;
• wherein R5 and R6 can optionally form a saturated or unsaturated, optionally substituted 5 or 6 membered ring, the ring can be optionally substituted with at least one C1-C20 alkyl radical.