Catalyst system and process for the polymerization of olefins

1. A catalyst system for polymerizing olefins comprising a product obtained by contacting:

(A) a metallocene complex of formula (I):

(Cp)(ZR 1 m ) n (A) r ML p   (I)

wherein (ZR 1 m ) n is a divalent group bridging Cp and A;

Z is selected from C, Si, Ge, N or P;

R 1 being equal or different from each other, is selected from 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, C 7 –C 20 arylalkyl and combinations thereof;

Cp is a substituted or unsubstituted cyclopentadienyl group, optionally condensed to one or more substituted or unsubstituted, saturated, unsaturated or aromatic rings, containing from 4 to 6 carbon atoms, optionally containing one or more heteroatoms;

A is selected from —O—, —S—, or —N(R 2 )—, wherein R 2 is selected from hydrogen, 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, or A is Cp;

M is selected from a transition metal belonging to group 3, 4, 5, or 6, or a lanthanide or actinide metal of the Periodic Table;

L being equal or different from each other, is a monoanionic sigma ligand selected from the group consisting of hydrogen, halogen, —R 3 , —OR 3 , —OCOR 3 , —SR 3 , —NR 3 2 , —PR 3 2 and combinations thereof, wherein R 3 is selected from 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, C 7 –C 20 arylalkyl and combinations thereof, wherein R 3 optionally contains one or more Si or Ge atoms;

m is 1 or 2;

n is an integer ranging from 0 to 4;

r is 0 or 1, with the proviso that n is 0 when r is 0;

p is an integer equal to an oxidation state of M minus 2 when r=1, and minus 1 when r=0, and ranges from 1 to 4;

(B) an organometallic aluminum compound of formula (II):

Al[CH 2 —C(Ar)R 4 R 5 ] x H y   (II)

wherein Ar is a substituted aryl group corresponding to formula (III):

wherein R 6 , R 8 and R 10 are selected from the group consisting of hydrogen, halogen, —C(O)R 3 , —OR 3 , —SR 3 , —NR 3 2 and —NO 2 ;

R 7 and R 9 are selected from the group consisting of hydrogen, halogen, C 6 –C 20 aryl, C 7 –C 20 alkylaryl and C 7 –C 20 arylalkyl, wherein R 7 and R 9 optionally contain one or more Si or Ge atoms; two adjacent substituents R 6 –R 10 optionally form a ring, having 3 to 8 carbon atoms; with the proviso that Ar is not an unsubstituted phenyl;

R 4 is selected from a linear or branched, saturated or unsaturated, C 1 –C 10 alkyl, C 6 –C 20 aryl, C 7 –C 20 arylalkyl or C 7 –C 20 alkylaryl;

R 5 is selected from hydrogen or a linear or branched, saturated or unsaturated, C 1 –C 10 alkyl, C 6 –C 20 aryl, C 7 –C 20 arylalkyl or C 7 –C 20 alkylaryl; R 4 and R 5 optionally form a ring, having 3 to 8 carbon atoms; a carbon atom in the compound of formula (II) being optionally replaced by a Si or a Ge atom;

x is 2 or 3;

y=3 minus x; and

(C) water;

wherein a molar ratio between the organometallic aluminium compound (B) and the water (C) is between 1:1 and 100:1.

2. The catalyst system according to claim 1 , wherein the molar ratio is about 2:1.

3. The catalyst system according to claim 1 , wherein a molar ratio between the organometallic aluminium compound (B) and the metallocene complex (A) ranges from 50:1 to 50,000:1.

4. The catalyst system according to claim 1 , wherein M is selected from Ti, Zr or Hf.

5. The catalyst system according to claim 1 , wherein the divalent group (ZR 1 m ) n is selected from the group consisting of CR 1 2 , (CR 1 2 ) 2 , (CR 1 2 ) 3 , SiR 1 2 , GeR 1 2 , NR 1 and PR 1 , R 1 has the same meaning as in claim 1 .

6. The catalyst system according to claim 5 , wherein the divalent group (ZR 1 m ) n is selected from the group consisting of Si(CH 3 ) 2 , SiPh 2 , CH 2 , (CH 2 ) 2 , (CH 2 ) 3 and C(CH 3 ) 2 .

7. The catalyst system according to claim 1 , wherein Cp is selected from the group consisting of cyclopentadienyl; mono-, di-, tri- and tetra-methyl cyclopentadienyl; 4- t butyl-cyclopentadienyl; 4-adamantyl-cyclopentadienyl; indenyl; mono-, di-, tri- and tetra-methyl indenyl; 3- t butyl-indenyl; 3-trimethylsilyl-indenyl; 4,5,6,7-tetrahydroindenyl; fluorenyl; 5,10-dihydroindeno[1,2-b]indol-10-yl; N-methyl- or N-phenyl-5,10-dihydroindeno[1,2-b]indol-10-yl; 5,6-dihydroindeno[2,1-b]indol-6-yl; N-methyl- or N-phenyl-5,6-dihydroindeno[2,1-b]indol-6-yl; azapentalene-4-yl; thiapentalene-4-yl; azapentalene-6-yl; thiapentalene-6-yl; and mono-, di- and tri-methyl-azapentalene-4-yl.

8. The catalyst system according to claim 1 , wherein L is selected from the group consisting of —Cl, —Br, —Me, —Et, —n—Bu, —sec—Bu, —Ph, —Bz, —CH 2 SiMe 3 , —OEt, —OPr, —OBu, —OBz and —NMe 2 .

9. The catalyst system according to claim 1 , wherein Ar is selected from the group consisting of 4-fluoro-phenyl, 4-chloro-phenyl, 4-methoxyphenyl, 4-nitrophenyl, 2,4-difluorophenyl, 2,4-dichlorophenyl, 2,6-difluorophenyl, 2,6-dichlorophenyl, 3,5-difluorophenyl, 3,5-dichlorophenyl, 2,4,6-trifluorophenyl, 2,4,6-trichlorophenyl, 3,4,5-trifluorophenyl, 3,4,5-trichlorophenyl, pentafluorophenyl and pentachlorophenyl.

10. The catalyst system according to claim 1 , wherein the organometallic aluminium compound of formula (II) is selected from the group consisting of tris[2-(4-fluoro-phenyl)-propyl]aluminium, tris[2-(4-chloro-phenyl)-propyl]aluminium, and tris[2-(pentafluorophenyl)-propyl]aluminium.

11. A catalyst system for polymerizing olefins comprising a product obtained by contacting:

(A) a metallocene complex of formula (I):

(Cp)(ZR 1 m ) n (A) r ML p   (I)

wherein M, Cp, (ZR 1 m ) n , A, L, r and p have the same meanings as in claim 1 ; and

(B′) a product of a reaction between water and an organometallic aluminium compound of formula (II):

Al[CH 2 —C(Ar)R 4 R 5 ] x H y   (II)

wherein Ar, R 4 , R 5 , x and y have the same meanings as in claim 1 ;

wherein a molar ratio between the organometallic aluminium compound and the water is between 1:1 and 100:1.

12. The catalyst system according to claim 1 , wherein the metallocene complex is pre-alkylated with at least one organometallic aluminium compound of formula (IV):

AlR 11 3-z H z   (IV)

wherein R 11 is selected from a linear or branched, saturated or unsaturated, C 1 –C 10 alkyl, C 6 –C 20 aryl, C 7 –C 20 arylalkyl, C 7 –C 20 alkylaryl and combination thereof; and

z is 0 or 1.

13. An alumoxane obtained by contacting an organometallic aluminium compound of formula (II)

Al[CH 2 —C(Ar)R 4 R 5 ] x H y   (II)

wherein Ar, R 4 , R 5 , x and y have the same meanings as in claim 1 , with water, wherein a molar ratio between the organometallic aluminium compound and the water is between 1:1 and 100:1.

14. The catalyst system for polymerizing olefins according to claim 1 , wherein the olefins comprise at least one α-olefin of formula CH 2 ═CHR, wherein R is hydrogen or a C 1 –C 20 alkyl radical.

15. The catalyst system for polymerizing olefins according to claim 14 , wherein said α-olefin is selected from the group consisting of propylene, 1-butene, 4-methyl-1-pentene, 1-hexene and 1-octene.

16. The catalyst system for polymerizing olefins according to claim 1 , wherein ethylene is copolymerizied with an α-olefin of formula CH 2 ═CHR′, wherein R′ is selected from a linear, branched or cyclic C 1 –C 20 alkyl radical, or with a cyclooloefin, and optionally with a polyene.

17. The catalyst system according to claim 11 , wherein the metallocene complex is pre-alkylated with one or more organometalic aluminum compounds of formula (IV):

AlR 11 3-z H z   (IV)

wherein R 11 is selected from a linear or branched, saturated or unsaturated, C 1 –C 10 alkyl, C 6 –C 20 aryl, C 7 –C 20 arylalkyl, C 7 –C 20 alkylaryl and combinations thereof; and

z is 0 or 1.

18. The catalyst system for polymerizing olefins according to claim 11 , wherein the olefins comprise at least one α-olefin of formula CH 2 ═CHR, wherein R is hydrogen or a C 1 –C 20 alkyl radical.

19. The catalyst system for polymerizing olefins according to claim 18 , wherein said α-olefin is selected from the group consisting of propylene, 1-butene, 4-methyl-1-pentene, 1-hexene and 1-octene.

20. The catalyst system for polymerizing olefins according to claim 11 , wherein ethylene is copolymerized with an α-olefin of formula CH 2 ═CHR′, wherein R′ is selected from a linear, branched or cyclic C 1 –C 20 alkyl radical, or with a cycloolefin, and optionally with a polyene.

21. The catalyst system for polymerizing olefins according to claim 12 , wherein the olefins comprise at least one α-olefin of formula CH 2 ═CHR, wherein R is hydrogen or a C 1 –C 20 alkyl radical.

22. The catalyst system for polymerizing olefins according to claim 21 , wherein said α-olefin is selected from the group consisting of propylene, 1-butene, 4-methyl-1-pentene, 1-hexene and 1-octene.

23. The catalyst system for polymerizing olefins according to claim 12 , wherein ethylene is copolymerizied with an α-olefin of formula CH 2 ═CHR′, wherein R′ is selected from a linear, branched or cyclic C 1 –C 20 alkyl radical, or with a cycloolefin, and optionally with a polyene.