Catalytic system for the (co)polymerization of alpha-olefins

Claim 2

The catalyst according to claim 1, wherein said metallocene derivative comprises or can be obtained starting from a metallocene having the following formula (II): wherein: M represents a metal selected from metals of groups 3 to 5, or from the group of lanthanides in the periodic table of elements; C p is an anion containing a 5 -cyclopentadienyl ring co-ordinated to the metal M; each of the n R' independently represent a substituent group selected from hydride, halide, a C 1 -C 8 alkyl group, a C 3 -C 12 alkylsilyl group, a C 5 -C 8 cycloalkyl group, a C 6 -C 10 aryl group, a C 1 -C 8 alkoxyl group, a C 1 -C 8 carboxyl group, a C 2 -C 10 dialkylamide group and a C 4 -C 20 alkylsilylamide group; R'' represents a substituent group of the same nature as the previous R' groups, independently selected from these, or a second anion containing an 5 -cyclopentadienyl ring co-ordinated to the metal M; R''' represents a divalent group having from 1 to 10 carbon atoms, optionally containing one or more heteroatoms, preferably O, N, P or Si, which is bridge-linked between C p and R'' with a covalent bond. R''' is preferably selected from alkylene, dialkylsilylene, diarylsilylene, alkyl- or aryl amino or phosphino radicals, arylene, arylene-bis-alkylene etc. "n" is an integer and is equal to the valence of M less 2; "x" can be 0 or 1.

Claim 3

The catalyst according to claim 2, wherein, in formula (II), "x" is 1, R''' is selected from alkylene, dialkylsilylene, diarylsilylene, arylene and arylene-bis-alkylene and R'' is a second anion containing a 5 -cyclopentadienyl ring co-ordinated to the metal M.

Claim 4

The catalyst according to claim 2, wherein, in formula (II), "x" is 0, and R'' is a second anion containing a 5 -cyclopentadienyl ring co-ordinated to the metal M.

Claim 5

The catalyst according to any of the previous claims, wherein the metal of said metallocene derivative is selected in the group consisting of titanium, zirconium and hafnium.

Claim 6

The catalyst according to any of the previous claims, wherein said metallocene derivative is of an ionic nature and the metal M is inclued in the cation.

Claim 7

The catalyst according to any of the previous claims, wherein said metallocene derivative in component (A) is in solution or in suspension in an inert liquid medium, preferably apolar.

Claim 8

The catalyst according to any of the previous claims, wherein said metallocene derivative in component (A) is supported on an inert solid medium, preferably selected from inert inorganic oxides, more preferably selected from alumina, silica and silicoaluminates.

Claim 9

The catalyst according to any of the previous claims, wherein said component (B) consists of a compound having a dielectric constant greater than or equal to 3 and a co-ordinating capacity DN less than or equal to 10 kcal/mole.

Claim 10

The catalyst according to any of the previous claims, wherein said component (B) consists of a compound having a co-ordinating capacity DN less than or equal to 5.0 kcal/mole.

Claim 11

The catalyst according to any of the previous claims from 1 to 10, wherein said component (B) consists of an organic compound containing at least one heteroatom selected from O, N, P or S, which has a co-ordinating capacity DN less than 5 kcal/mole.

Claim 12

The catalyst according to previous claim 11, wherein said component (B) consists organic compound containing O, N, P or S atom(s) bonded to at least one fluorinated carbon atom or to a fluorinated aromatic ring.

Claim 13

The catalyst according to previous claim 11, wherein said component (B) is a fluorinated heteroaromatic compounds.

Claim 14

The catalyst according to claim 12, wherein said component (B) consists of pentafluoroanisol.

Claim 15

The catalyst according to any of the previous claims, wherein the ratio between the moles of said substance of component (B) and the gram-atom weight of the transition metal or lanthanide in component (A) is between 2 and 10,000, preferably between 20 and 500.

Claim 16

A process for the (co)polymerization of alpha-olefins, comprising feeding said alpha-olefin and the possible co-monomers to a continuous or batch reactor, and (co)polymerizing the mixture in suspension or solution in a suitable liquid medium in the presence of a polymerization catalyst, characterized in that said catalyst is the catalyst according to any of the previous claims from 1 to 15.

Claim 17

The process according to claim 16, wherein the polymerization reaction is carried out at a temperature from 50 to 140 °C.

Claim 18

The process according to any of the previous claims 16 or 17, wherein said alpha-olefin is ethylene.

Claim 19

The process according to any of the previous claims from 16 to 18, wherein said catalyst is formed in situ in the polymerization reactor by contact of said components (A) and (B) according to claim 1.

Claim 20

The process according to claim 19, wherein said component (B) is fed to the reactor mixed with the alpha-olefin.