Ethylene polymers with alpha-olefins

Ethylene-octene copolymers and terpolymers of ethylene, octene with at least an alpha-olefin from 3 to 12 carbon atoms, optionally in the presence of other comonomers containing more than one ethylenic unsaturation, obtainable by polymerization of the monomers in the presence of catalysts comprising the reaction product among:

• 1) a bis-cyclopentadienyl derivative having the general formula:
• (Cp1Cp2)—M—(L2L3)
• containing groups with oxygen bound to the transition metal, wherein
• M is a metal from the IIIb group to the Vb group or of the lanthanide series of the Element Periodic Table;
• Cp1 and CP2, equal to or different from each other, represent the following groups bound to M with delocalized π bonds, in particular with an eta bond 5 when the groups are selected from cyclopentadiene, indene, fluorene, or derivatives thereof substituted in the case of indene and fluorene also with the hydrogenated phenyl ring (rings) and with substituents both in the phenilic and cyclopentadienylic rings, also with heteroatoms;
• or with π bonds in the case of cyclooctatriene;
• or said Cp1 Cp2 groups constrained with M by a bivalent linking bridge, —R— type, wherein R is an alkylene, preferably from 1 to 4 carbon atoms, —Si(R′)2— wherein R′ is an alkyl from 1 to 10 C atoms, preferably from 1 to 6 carbon atoms;
• or an aryl optionally containing heteroatoms, such as O, N, or alkylaryl or arylalkyl- from 7 to 20 carbon atoms;
• L2 and L3, equal to or different from each other represent an ORa group wherein Ra is an aryl group, optionally the ring carbon atoms being substituted by heteroatoms, and optionally containing substituents of alkyl type from 1 to 10 carbon atoms with
• 2) a co-catalyst selected from the compounds represented by the following formulas:
• 2a) alumoxane, having the general formula:
• (Rb—Al—O)m,
• in the form of cyclic compound or in the form of linear polymeric compound having the formula
• Rb(Rb—Al—O)mAl (Rb)2;
• alumoxane is generally a mixture of the two mentioned forms;
• Rb is an alkyl group from 1 to 5 C atoms, preferably methyl,
• m is an integer from 1 to 30, preferably from 4 to 20;
• m′ is an integer from 3 to 20, preferably from 4 to 20;
• 2b) (L1—H)+(A)−
• wherein (A)− is a compatible non coordinating anion, preferably
• (B Qq)−
• wherein L1is a neutral Lewis basis,
• (Li—H)+ is a Bronsted acid,
• B is an element of the group from IIIa up to VIa of the Element Periodic Table with metalloidic characteristics, preferably boron, phosphorus or arsenic with valence 3 or 5, silicon, more preferably boron with valence 3;
• Q, equal to or different from each other, are selected from the following groups:
• hydrides, halides, alkyls, aryls optionally substituted, with halogens, preferably F, alkoxides, aryloxides, dialkylamido, or RcCOO− wherein R0 has from 1 to 20 carbon atoms, with the proviso that Q can be equal to halide only once, q is an integer equal to the valence of B plus 1.