Process for the metathetic degradation of nitrile rubbers

1. A process comprising the metathetic degradation of nitrite rubber in the presence of a catalyst and a phosphane or a diphosphane, wherein from 0.01 to 1 equivalent of the phosphane or diphosphane is used per 1 equivalent of catalyst.

2. The process according to claim 1 , wherein the phosphane or diphosphane is used in an amount in the range from 0.05 to 0.5 equivalent, based on 1 equivalent of catalyst.

3. The process according to claim 1 or 2 , wherein a compound of the general formula (IA),

wherein

all the radicals R″ are identical or different and are each alkyl, alkenyl, alkadienyl, alkoxy, aryl, heteroaryl, cycloalkyl, cycloalkenyl, cycloalkadienyl, halogen or trimethylsilyl,

is used as phosphane.

4. The process according to claim 1 or 2 , wherein a compound of the general formula (IB),

wherein

all the radicals R″ are identical or different and are each alkyl, alkenyl, alkadienyl, alkoxy, aryl, heteroaryl, cycloalkyl, cycloalkenyl, cycloalkadienyl, halogen or trimethylsilyl,

k is 0 or 1 and

S is a straight-chain or branched alkanediyl, alkenediyl or alkynediyl group,

is used as diphosphane.

5. The process according to claim 3 , wherein trialkylphosphanes, tricycloalkylphosphanes, triarylphosphanes, trialkarylphosphanes, triaralkylphosphanes, diarylmonoalkyl-phosphanes, diarylmonocycloalkylphosphanes, dialkylmonoarylphosphanes, dialkylmono-cycloalkylphosphanes or dicycloalkylmonoarylphosphanes are used as phosphanes of the general formula (IA).

6. The process according to claim 3 , wherein phosphanes of the general formula (IA) in which all the radicals R″ are identical or different and are each phenyl, cyclohexyl, cyclohexenyl, cyclopentyl, cyclopentadienyl, phenylsulphonate or cyclohexylsulphonate are used.

7. The process according to claim 3 , wherein PPh 3 , P(p-Tol) 3 , P(o-Tol) 3 , PPh(CH 3 ) 2 , P(CF 3 ) 3 , P(p-FC 6 H 4 ) 3 , P(p-CF 3 C 6 H 4 ) 3 , P(C 6 H 4 —SO 3 Na) 3 , P(CH 2 C 6 H 4 —SO 3 Na) 3 , P(iso-Pr) 3 , P(CHCH 3 (CH 2 CH 3 )) 3 , P(cyclopentyl) 3 , P(cyclohexyl) 3 , P(neopentyl) 3 , P(C 6 H 5 CH 2 )(C 6 H 5 ) 2 , P(NCCH 2 CH 2 ) 2 (C 6 H 5 ), P[(CH 3 ) 3 C] 2 Cl, P[(CH 3 ) 3 C] 2 (CH 3 ), P(tert-Bu) 2 (biph), P(C 6 H 11 ) 2 Cl, P(CH 3 )(OCH 2 CH 3 ) 2 , P(CH 2 ═CHCH 2 ) 3 , P(C 4 H 3 O) 3 , P(CH 2 OH) 3 , P(m-CH 3 OC 6 H 4 ) 3 , P(C 6 F 5 ) 3 , P[(CH 3 ) 3 Si] 3 or P[(CH 3 O) 3 C 6 H 2 ] 3 , wherein Tol is tolyl, biph is biphenyl, Bu is butyl and Pr is propyl, are used as phosphanes of the general formula (IA).

8. The process according to claim 4 , wherein Cl 2 PCH 2 CH 2 PCl 2 , (C 6 H 11 ) 2 PCH 2 P(C 6 H 11 ), (CH 3 ) 2 PCH 2 CH 2 P(CH 3 ) 2 , (C 6 H 5 ) 2 PCCP(C 6 H 5 ) 2 , (C 6 H 5 ) 2 PCH═CHP(C 6 H 5 ) 2 , (C 6 F 5 ) 2 PCH 2 CH 2 P(C 6 F 5 ) 2 , (C 6 H 5 ) 2 P(CH 2 ) 4 P(C 6 H 5 ) 2 , (C 6 H 5 ) 2 PCH(CH 3 )CH(CH 3 )P(C 6 H 5 ) 2 or (C 6 H 5 ) 2 PCH(CH 3 )CH 2 P(C 6 H 5 ) 2 are used as diphosphanes of the general formula (IB).

9. The process according to claim 1 , wherein a compound of the general formula (A),

where

M is osmium or ruthenium,

the radicals R are identical or different and are each alkyl, cycloalkyl, alkenyl, alkynyl, aryl, carboxylate, alkoxy, alkenyloxy, alkynyloxy, aryloxy, alkoxycarbonyl, alkylamino, alkylthio, arylthio, alkylsulphonyl, or alkylsulphinyl, each of which may optionally be substituted by one or more alkyl, halogen, alkoxy, aryl or heteroaryl radicals,

X 1 and X 2 are identical or different and are two ligands, and

L are identical or different ligands,

is used as catalyst.

10. The process according to claim 9 , wherein X 1 and X 2 are anionic ligands and L are uncharged electron donors.

11. The process according to claim 9 , wherein X 1 and X 2 are identical or different and are each hydrogen, halogen, pseudohalogen, straight-chain or branched C 1 -C 30 -alkyl, C 5 -C 24 -aryl, C 1 -C 20 -alkoxy, C 5 -C 24 -aryloxy, C 3 -C 20 -alkyldiketonate, C 5 -C 24 -aryldiketonate, C 1 -C 20 -carboxylate, C 1 -C 20 -alkylsulphonate, C 5 -C 24 -arylsulphonate, C 1 -C 20 -alkylthiol, C 5 -C 24 -arylthiol, C 1 -C 20 -alkylsulphonyl or C 1 -C 20 -alkylsulphinyl radicals.

12. The process according to claim 9 , wherein X 1 and X 2 are identical or different and are each halogen, benzoate, C 1 -C 5 -carboxylate, C 1 -C 5 -alkyl, phenoxy, C 1 -C 5 -alkoxy, C 1 -C 5 -alkylthiol, C 5 -C 24 -arylthiol, C 5 -C 24 -aryl or C 1 -C 5 -alkylsulphonate.

13. The process according to claim 9 , wherein X 1 and X 2 are identical and are each halogen CF 3 COO, CH 3 COO, CFH 2 COO, (CH 3 ) 3 CO, (CF 3 ) 2 (CH 3 )CO, (CF 3 )(CH 3 ) 2 CO, PhO (phenoxy), MeO (methoxy), EtO (ethoxy), tosylate (p-CH 3 —C 6 H 4 —SO 3 ), mesylate (2,4,6-trimethylphenyl) or CF 3 SO 3 (trifluoromethanesulphonate).

14. The process according to claim 9 , wherein the two ligands L are each, independently of one another, a phosphine, sulphonated phosphine, phosphate, phosphinite, phosphonite, arsine, stibine, ether, amine, amide, sulphoxide, carboxyl, nitrosyl, pyridine, thioether or imidazolidine (“Im”) ligand.

15. The process according to claim 14 , wherein the imidazolidine radical (Im) has a structure of the general formula (IIa) or (IIb),

where

R 8 , R 9 , R 10 , R 11 are identical or different and are each hydrogen, straight-chain or branched C 1 -C 30 -alkyl, C 3 -C 20 -cycloalkyl, C 2 -C 20 -alkenyl, C 2 -C 20 -alkynyl, C 5 -C 24 -aryl, C 1 -C 20 -carboxylate, C 1 -C 20 -alkoxy, C 2 -C 20 -alkenyloxy, C 2 -C 20 -alkynyloxy, C 5 -C 20 -aryloxy, C 2 -C 20 -alkoxycarbonyl, C 1 -C 20 -alkylthio, C 5 -C 20 -arylthio, C 1 -C 20 -alkylsulphonyl, C 1 -C 20 -alkylsulphonate, C 5 -C 20 -arylsulphonate or C 1 -C 20 -alkylsulphinyl.

16. The process according to claim 1 , wherein the catalyst has the structure (III) or (IV), where Cy is in each case cyclohexyl and Mes is in each case 2,4,6-trimethylphenyl

17. The process according to claim 1 , wherein a catalyst of the general formula (B),

where

M is ruthenium or osmium,

Y is oxygen (O), sulphur (S), a radical N—N 1 or a radical P—R 1 ,

X 1 and X 2 are identical or different ligands,

R 1 is an alkyl, cycloalkyl, alkenyl, alkynyl, aryl, alkoxy, alkenyloxy, alkynyloxy, aryloxy, alkoxycarbonyl, alkylamino, alkylthio, arylthio, alkylsulphonyl or alkylsulphinyl radical, each of which may optionally be substituted by one or more alkyl, halogen, alkoxy, aryl or heteroaryl radicals,

R 2 , R 3 , R 4 and R 5 are identical or different and are each hydrogen or an organic or inorganic radical,

R 6 is hydrogen or an alkyl, alkenyl, alkynyl or aryl radical and

L is a ligand,

is used.

18. The process according to claim 17 , wherein L is a P(R 7 ) 3 radical, where the radicals R 7 are each, independently of one another, C 1 -C 6 -alkyl, C 3 -C 8 -cycloalkyl or aryl or else a substituted or unsubstituted imidazolidine radical (“Im”) which has the structure of the general formulae

where

R 8 , R 9 , R 10 , R 11 are identical or different and are each hydrogen, straight-chain or branched C 1 -C 30 -alkyl, C 3 -C 20 -cycloalkyl, C 2 -C 20 -alkenyl, C 2 -C 20 -alkynyl, C 5 -C 24 -aryl, C 1 -C 20 -carboxylate, C 1 -C 20 -alkoxy, C 2 -C 20 -alkenyloxy C 1 -C 20 -alkynyloxy, C 5 -C 20 -aryloxy, C 2 -C 20 -alkoxycarbonyl, C 1 -C 20 -alkylthio, C 5 -C 20 -arylthio, C 1 -C 20 -alkylsulphonyl, C 1 -C 20 -alkylsulphonate, C 5 -C 20 -arylsulphonate or C 1 -C 20 -alkylsulphinyl.

19. The process according to claim 17 , wherein X 1 and X 2 in the general formula (B) are anionic ligands.

20. The process according to claim 17 , wherein a catalyst of the general formula (B1),

where

M, L, X 1 , X 2 , R 1 , R 2 , R 3 , R 4 and R 5 are as defined for the general formula (B) in claim 17 ,

is used.

21. The process according to claim 20 , wherein a catalyst of the general formula (B1) in which

M is ruthenium,

X 1 and X 2 are both halogen,

R 1 is a straight-chain or branched C 1 -C 12 -alkyl radical,

is used.

22. The process according to claim 20 , wherein a catalyst of the general formula (B1) in which

M is ruthenium,

X 1 and X 2 are both chlorine,

R 1 is an isopropyl radical,

R 2 , R 3 , R 4 , R 5 are each hydrogen and

L is a substituted or unsubstituted imidazolidine radical of the formula (IIa) or (IIb),

where

R 8 , R 9 , R 10 , R 11 are identical or different and are each hydrogen, straight-chain or branched C 1 -C 30 -alkyl, C 3 -C 20 -cycloalkyl, C 2 -C 20 -alkenyl, C 2 -C 20 -alkynyl, C 5 -C 24 -aryl, C 1 -C 20 -carboxylate, C 1 -C 20 -alkoxy, C 2 -C 20 -alkenyloxy, C 2 -C 20 -alkynyloxy, C 5 -C 24 -aryloxy, C 2 -C 20 -alkoxycarbonyl, C 1 -C 20 -alkylthio, C 5 -C 24 -arylthio, C 1 -C 20 -alkylsulphonyl, C 1 -C 20 -alkylsulphonate, C 5 -C 24 -arylsulphonate or C 1 -C 20 -alkylsulphinyl,

is used.

23. The process according to claim 20 , wherein a catalyst of one of the following structures (VI), (VII), (VIII), (IX), (X), (XI), (XII) or (XIII),

where Mes is in each case a 2,4,6-trimethylphenyl radical,

is used as catalyst of the general structural formula (B1).

24. The process according to claim 17 , wherein a catalyst of the general formula (B2),

where

M, L, X 1 , X 2 , R 1 and R 6 are as defined for the general formula (B) in claim 17 ,

the radicals R 12 are identical or different and have the meanings given for the radicals R 2 , R 3 , R 4 and R 5 in the general formula (B) in claim 17 with the exception of hydrogen and

n is 0, 1, 2 or 3,

is used.

25. The process according to claim 24 , wherein a catalyst of the following structures (XIV) or (XV),

where Mes is in each case a 2,4,6-trimethylphenyl radical,

is used.

26. The process according to claim 17 , wherein a catalyst of the general formula (B3),

where D 1 , D 2 , D 3 and D 4 each have a structure of the general formula (XVI) which is bound via the methylene group to the silicon of the formula (B3)

where

M, L, X 1 , X 2 , R 1 , R 2 , R 3 , R 5 and R 6 are as defined for the general formula (B) in claim 17 ,

is used.

27. The process according to claim 1 , wherein a catalyst of the general formula (B4),

where the symbol

●

is a support,

is used.

28. The process according to claim 1 , wherein a catalyst of the general formula (C),

where

M is ruthenium or osmium,

X 1 and X 2 are identical or different and are anionic ligands,

the radicals R′ are identical or different and are organic radicals,

Im is a substituted or unsubstituted imidazoline radical and

An is an anion,

is used.

29. The process according to claim 1 , where a catalyst of the general formula (D),

where

M is ruthenium or osmium,

R 13 and R 14 are each, independently of one another, hydrogen, C 1 -C 20 -alkyl, C 2 -C 20 -alkenyl, C 2 -C 20 -alkynyl, C 5 -C 24 -aryl, C 1 -C 20 -carboxylate, C 1 -C 20 -alkoxy, C 2 -C 20 -alkenyloxy, C 2 -C 20 -alkynyloxy, C 5 -C 24 -aryloxy, C 2 -C 20 -alkoxycarbonyl, C 1 -C 20 -alkylthio, C 1 -C 20 -alkylsulphonyl or C 1 -C 20 -alkylsulphinyl,

X 3 is an anionic ligand,

L 2 is an uncharged π-bonded ligand which can be either monocyclic or polycyclic,

L 3 is a ligand from the group consisting of phosphines, sulphonated phosphines, fluorinated phosphines, functionalized phosphines having up to three aminoalkyl, ammonioalkyl, alkoxyalkyl, alkoxycarbonylalkyl, hydrocarbonylalkyl, hydroxyalkyl or ketoalkyl groups, phosphites, phosphinites, phosphonites, phosphinamines, arsines, stibines, ethers, amines, amides, imines, sulphoxides, thioethers and pyridines,

Y − is a noncoordinating anion and

n is 0, 1, 2, 3, 4 or 5,

is used.

30. The process according to claim 1 , wherein a catalyst of the general formula (E),

where

M 2 is molybdenum or tungsten,

R 15 and R 16 are identical or different and are each hydrogen, C 1 -C 20 -alkyl, C 2 -C 20 -alkenyl, C 2 -C 20 -alkynyl, C 5 -C 24 -aryl, C 1 -C 20 -carboxylate, C 1 -C 26 -alkoxy, C 2 -C 20 -alkenyloxy, C 2 -C 20 -alkynyloxy, C 5 -C 24 -aryloxy, C 2 -C 20 -alkoxycarbonyl, C 1 -C 20 -alkylthio, C 1 -C 20 -alkylsulphonyl or C 1 -C 20 -alkylsulphinyl,

R 17 and R 18 are identical or different and are each a substituted or halogen-substituted C 1 -C 20 -alkyl, C 5 -C 24 -aryl, C 6 -C 30 -aralkyl radical or silicon-containing analogues,

is used.

31. The process according to claim 1 , wherein a catalyst of the general formula (F),

where

M is ruthenium or osmium,

X 1 and X 2 are identical or different and are anionic ligands,

L are identical or different ligands,

R 19 and R 20 are identical or different and are each hydrogen or substituted or unsubstituted alkyl,

is used.

32. The process for producing hydrogenated nitrile rubber, wherein the metathetic degradation of nitrile rubber according to claim 1 is followed by a hydrogenation of the nitrile rubber degraded by metathesis.

33. The process according to claim 13 , wherein X 1 and X 2 are identical and are chlorine.

34. The process according to claim 19 , wherein X 1 and X 2 in the general formula (B) are identical or different and are each hydrogen, halogen, pseudohalogen, straight-chain or branched C 1 -C 30 -alkyl, C 5 -C 24 -aryl, C 1 -C 20 -alkoxy, C 5 -C 24 -aryloxy, C 3 -C 20 -alkyldiketonate, C 5 -C 24 -aryldiketonate, C 1 -C 20 -carboxylate, C 1 -C 20 -alkylsulphonate, C 5 -C 24 -arylsulphonate, C 1 -C 20 -alkylthiol, C 5 -C 24 -arylthiol, C 1 -C 20 -alkylsulphonyl or C 1 -C 20 -alkylsulphinyl radicals.

35. The process according to claim 19 , wherein X 1 and X 2 in the general formula (B) are identical or different and are each halogen, benzoate, C 1 -C 5 -carboxylate, C 1 -C 5 -alkyl, phenoxy, C 1 -C 5 -alkoxy, C 1 -C 5 -alkylthiol, C 5 -C 24 -arylthiol, C 5 -C 24 -aryl or C 1 -C 5 -alkylsulphonate.

36. The process according to claim 19 , wherein X 1 and X 2 in the general formula (B) are identical and are each halogen, CF 3 COO, CH 3 COO, CFH 2 COO, (CH 3 ) 3 CO, (CF 3 ) 2 (CH 3 )Co, (CF 3 )(CH 3 ) 2 CO, PhO (phenoxy), MeO (methoxy), EtO (ethoxy), tosylate (p-CH 3 —C 6 H 4 —SO 3 ), mesylate (2,4,6-trimethylphenyl) or CF 3 SO 3 (trifluoromethanesulphonate).

37. The process according to claim 31 wherein X 1 and X 2 are anionic ligands and L are uncharged electron donors.