Biodegradable super-spreading, organomodified trisiloxane

1. A composition comprising polyether-modified siloxanes of formula (I)

M a D b D′ c   Formula (I)

with M is R 1 3 SiO 1/2 , D is R 1 2 SiO 2/2 , D′ is R 1 R 2 SiO 2/2 ,

where

a is 2

b is between 0 and 0.1,

c is between 1.0 and 1.15,

R 1 are independently hydrocarbyl having 1 to 8 carbon atoms,

R 2 are independently a polyether radical of the formula (II)

—R 3 O[CH 2 CH 2 O] m [CH 2 CH(CH 3 )O] n R 5   Formula (II)

where

m is from 3.4 to 11.0,

n is from 2.5 to 8.0,

and wherein m/n is from 1.9 to 2.8,

R 3 are independently divalent hydrocarbyl radicals having 2 to 8 carbon atoms,

R 5 is hydrogen

the polyether-modified siloxanes of formula (I) having a biodegradability of from 60% to 100% and wherein the molar mass of the polyether radical M(PE) is between 520 g/mol and 660 g/mol.

2. The composition according to claim 1 , wherein the sum total of m+n is from 9 up to 19.

3. The composition according to claim 2 , wherein a 0.1 percent by weight solution of the polyether-modified siloxanes of formula (I) in water has a spreading area of from 10 to 60 cm 2 .

4. The composition according to claim 2 , wherein the polyether-modified siloxanes of the formula (I) have an index c between 1 and 1.05, where the m/n ratio is 0.8 to 2.8 and a 0.1% by weight solution of these siloxanes in water has a spreading area of 15 to 60 cm 2 .

5. The composition according to claim 1 , wherein a 0.1 percent by weight solution of the polyether-modified siloxanes of formula (I) in water has a spreading area of from 10 to 60 cm 2 .

6. The composition according to claim 1 , wherein the polyether-modified siloxanes of the formula (I) have an index c between 1 and 1.05, where the m/n ratio is 0.8 to 2.8 and a 0.1% by weight solution of these siloxanes in water has a spreading area of 15 to 60 cm 2 .

7. The composition according to claim 1 , wherein the polyether-modified siloxanes of the formula (I) have a biodegradability of greater than 60%, and the index c is additionally between 1 and 1.05, where the R 5 radical is hydrogen and a 0.1% by weight solution in water has a spreading area of 15 to 60 cm 2 .

8. An adjuvant in crop protection wherein the adjuvant comprises the composition according to claim 1 .

9. A tank mix additive for spray liquors wherein the tank mix additive comprises the composition according to claim 1 .

10. The composition according to claim 1 , wherein the sum total of m+n is from 9.5 to 15.

11. The composition according to claim 1 , wherein the sum total of m+n is from 10 to 12.

12. The composition according to claim 1 , wherein b is 0, c is between 1.00 and 1.10, m is from 3.6 to 9.9, n is from 2.7 to 7.5, R 3 is selected from the group consisting of ethylene, propylene, 1-methylpropylene, 1,1-dimethylpropylene radical, and the polyether-modified siloxanes of formula (I) has a biodegradability of from 63% to 100%.

13. The composition according to claim 1 , wherein b is 0, c is between 1.00 and 1.05, m is from 4.5 to 8.5, n is from 3.0 to 6.0, R 3 is —CH 2 CH 2 CH 2 —, and the polyether-modified siloxanes of formula (I) having a biodegradability of from 65% to 100%.

14. The composition according to claim 1 , wherein a 0.1 percent by weight solution of the polyether-modified siloxanes of formula (I) in water has a spreading area of from 15 to 50 cm 2 .

15. The composition according to claim 1 , wherein a 0.1 percent by weight solution of the polyether-modified siloxanes of formula (I) in water has a spreading area of from 20 to 40 cm 2 .

16. A process for preparing polyether-modified siloxanes, comprising the steps of

a) purifying an H-siloxane of the formula (V)

M a D b D′ d   (V)

with M=R 1 3 SiO 1/2 , D=R 1 2 SiO 2/2 , D′=R 1 R 2 SiO 2/2 ,

where

a is 2,

b is between 0 and 0.1,

d is between 1.16 and 3,

R 1 are independently hydrocarbyl having 1 to 8 carbon atoms,

R 2 is hydrogen

b) reacting the purified product of step a) in the manner of a hydrosilylation with a terminally unsaturated polyether of the formula (VI)

R 4 O[CH 2 CH 2 O] m [CH 2 CH(CH 3 )O] n R 5   (VI)

where

m is from 3.4 to 11.0, n is from 2.5 to 8.0,

wherein m/n is from 1.9 to 2.8,

R 5 are each independently hydrocarbyl radicals having 1 to 16 carbon atoms or hydrogen, preferably hydrogen or methyl, especially hydrogen,

R 4 are independently monovalent terminally unsaturated hydrocarbyl having 2 to 8 carbon atoms and

wherein the molar mass of the polyether radical M(PE) is between 520 g/mol and 660 g/mol.

17. The process according to claim 16 , wherein the H-siloxane of the formula (V) is purified by employing a thermal separation process.

18. The process according to claim 16 , wherein R 1 is selected from the group consisting of methyl, ethyl, propyl or phenyl radicals, m is from 4.5 to 8.5, n is from 2.7 to 7.5, wherein m/n is from 0.55 to 3.00,

R 5 is selected from the group consisting of hydrogen or methyl, and

R 4 is selected from the group consisting of CH 2 ═CH 2 —, CH 2 ═CHCH 2 —, CH 2 ═CHCH(CH 3 )—, CH 2 ═CHC(CH 3 ) 2 , especially preferably CH 2 ═CHCH 2 —.

19. The process according to claim 16 , wherein R 1 is a methyl radical, n is from 3.0 to 6.0, wherein m/n is from 0.8 to 2.8,

R 5 is hydrogen, and

R 4 is CH 2 ═CHCH 2 —.

20. The process according to claim 16 , wherein in m/n is from 1.9 to 2.8.