Method for reducing the chlorine content of organobisphosphites

1. Process for reducing the chlorine content in an organobisphosphite of one of the general formulae I, II, III, IV, V and VI:

where

R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 are each independently selected from: —H, —(C 1 -C 12 )-alkyl, —O—(C 1 -C 12 )-alkyl, —O—(C 6 -C 20 )-aryl, —(C 6 -C 20 )-aryl, halogen, —COO—(C 1 -C 12 )-alkyl, —CONH—(C 1 -C 12 )-alkyl, —(C 6 -C 20 )-aryl-CON[(C 1 -C 12 )-alkyl] 2 , —CO—(C 1 -C 12 )-alkyl, —CO—(C 6 -C 20 )-aryl, —COOH, —OH,—SO 3 H, —SO 3 Na, —NO 2 , —CN, —NH 2 , —N[(C 1 -C 12 )-alkyl] 2 ;

and the four following pairs of radicals are not both the same radical in all four pairs:

R 1 and R 5 , R 2 and R 6 , R 3 and R 7 , R 4 and R 8 ;

comprising the process steps of:

a) partly or fully dissolving the organobisphosphite in a first solution,

b) introducing the first solution into a second solution, which results in precipitation of the purified organobisphosphite,

wherein

the first solution comprises a first solvent and a first base,

the second solution comprises a second solvent and a second base,

and

the first solvent is selected from:

aromatics, alcohols, acetone, ethyl acetate, acetonitrile, ethers,

the second solvent is selected from:

aromatics, C5-C10-alkanes, alcohols, acetone, ethyl acetate, acetonitrile, ethers,

the first base is selected from:

amine bases, alkoxides, pyridine, pyridine derivatives, N-methyl-2-pyrrolidone, triethanolamine,

the second base is selected from:

amine bases, alkoxides, pyridine, pyridine derivatives, N-methyl-2-pyrrolidone, triethanolamine, and the organobisphosphite has better solubility in the first solvent than in the second solvent.

2. Process according to claim 1 ,

wherein the first solvent is selected from: ethyl acetate, anisole, ortho-xylene, toluene, acetone, methanol, ethanol, propanol, isopropanol, acetonitrile.

3. Process according to claim 1 ,

wherein the second solvent is selected from: ethyl acetate, anisole, ortho-xylene, toluene, acetone, methanol, ethanol, propanol, isopropanol, acetonitrile, tetrahydrofuran, diethyl ether, glycol, C5-C10-alkanes.

4. Process according to claim 1 ,

wherein the first base is selected from: triethylamine, dimethylaminobutane, pentylamine, hexylamine, dibutylamine, N-methyl-2-pyrrolidone, triethanolamine, sodium methoxide, sodium ethoxide, pyridine, dimethylaminopyridine.

5. Process according to claim 1 ,

wherein the second base is selected from: triethylamine, dimethylaminobutane, pentylamine, hexylamine, dibutylamine, N-methyl-2-pyrrolidone, triethanolamine, sodium methoxide, sodium ethoxide, pyridine, dimethylaminopyridine.

6. Process according to claim 1 ,

wherein the second solution comprises a third solvent non-identical to the second solvent.

7. Process according to claim 6 ,

wherein the third solvent is selected from: aromatics, alcohols, acetone, ethyl acetate, acetonitrile, ethers.

8. Process according to claim 1 ,

wherein the organobisphosphite is dissolved fully in the first solution in process step a).

9. Process according to claim 1 ,

wherein the first base and the second base are not the same base.

10. Process according to claim 1 ,

wherein the organobisphosphite has a chlorine content of 1500 ppm to 100 000 ppm on introduction in process step b).

11. Process according to claim 1 ,

wherein the second solution is heated to a temperature in the range from −20° C. to 120° C. before the first solution is introduced into the second solution in process step b).

12. Process according to claim 1 ,

wherein the organobisphosphite has one of the general formulae I, II, IV and VI:

13. Process according to claim 1 ,

wherein the organobisphosphite has one of the general formulae I, II and VI:

14. Process according to claim 1 ,

wherein the organobisphosphite has one of the general formulae I, II and VI:

and where

R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 are each independently selected from: —H, —(C 1 -C 12 )-alkyl,—O—(C 1 -C 12 )-alkyl, —O—(C 6 -C 20 )-aryl, —(C 6 -C 20 )-aryl.