Organopolysiloxanes for defoaming aqueous systems

1. A method for defoaming aqueous media which comprises adding to the aqueous media an organopolysiloxane derivative of the general average formula (I)

where the radicals

R 1 are alky radicals or aryl radicals, but at least 80% of the radicals R 1 are methyl radicals,

R 2 in the molecule are identical or different and have the following definitions:

 in which

R 3 is a hydrogen or alkyl radical,

R 4 is a hydrogen, alkyl or carboxyl radical,

c is a number from 1 to 20,

d is a number from 0 to 50,

e is a number from 0 to 50 or

(b)

—(CH 2 —) f OR 5 ,

 in which

R 5 is a hydrogen, alkyl or carboxyl radical or a dimethylol propane radical containing ether groups if desired, and

f is a number from 2 to 20 or

c)

—(CH 2 —) g (OC 2 H 4 —) h (OC 3 H 6 —) i (OC 4 H 8 ) j (OCH 2 CH(C 6 H 5 )) k OK 6

 in which

R 6 is a hydrogen, alkyl or carboxyl radical,

g is a number from 2 to 6,

h is a number from 0 to 20,

i is a number from 1 to 50,

j is a number form 0 to 10,

k is a number from 0 to 10 or

(d)

correspond to the radical R 1 ,

with the proviso that in the average molecule at least one radical R 2 has the definition (a),

a is a number from 1 to 500,

b is a number from 0 to 10.

and wherein the water solubility of the organopolysiloxane is such that it forms a clear solution in water in an amount not more than 20 g/l at 25° C.

2. The method according to claim 1 , where b=0 in the organopolysiloxane derivative.

3. The method according to claim 1 , where in the organopolysiloxane derivative the radicals R 1 are methyl radicals, a=1 to 50 and b=0.

4. The method according to claim 1 , where R 3 is hydrogen in the organopolysiloxane derivative.

5. The method according to claim 1 , where R 4 is hydrogen or an acyl radical in the organopolysiloxane derivative.

6. The method according to claim 1 , where the index c=1 or 2 and d and e independently of one another arm from 0 to 10 in the organopolysiloxane derivative.

7. The method according to claim 1 , where R 6 is hydrogen or a methyl radical, g=3, h=0 to 12, i=8 to 30 and j and k independently of one another are <5, in the organopolysiloxane derivative.

8. The method according to claim 7 , where j and k are zero in the organopolysiloxane derivative.

9. The method according to claim 1 , wherein the organopolysiloxane forms a clear solution in water in an amount not more than 5 g/l.

10. The method according to claim 1 , wherein the aqueous media is an aqueous surfactant system.

11. The method according to claim 1 , wherein the aqueous media is a printing ink or an ink.

12. The method according to claim 1 , wherein the aqueous media is an aqueous coating material.

13. The method according to claim 1 , wherein the aqueous media is a polymer dispersion.

14. The method according to claim 1 , wherein the organopolysiloxane has an average structure selected from the group consisting of

where

R 2 is a radical of the formula

15. A method for defoaming aqueous media which comprise adding to the aqueous media an organopolysiloxane derivative of the general average formula (I)

where the radicals

R 1 are alkyl radicals having 1 to 4 carbon atoms or aryl radicals, but at least 80% of the radicals R 1 are methyl radicals,

R 2 in the molecule are identical or different and have the following definitions:

in which

R 3 is a hydrogen, alkyl radical

R 4 is a hydrogen, alkyl or carbonyl radical,

c is a number from 1 to 20,

d is a number from 0 to 50,

e is a number from 0 to 50,

(b)

—(CH 2 —) f OR 5 ,

in which

R 5 is a hydrogen, alkyl or carboxyl radical, or a dimethylol propane radical containing ether groups if desired, and

f is a number from 2 to 20 or

c)

—(CH 2 —) g (OC 2 H 4 —) h (OC 3 H 6 —) i (OC 4 H 8 ) j (OCH 2 CH(C 6 H 5 )) k OR 6

in which

R 6 is a hydrogen, alkyl or carboxyl radical,

g is a number from 2 to 6,

h is a number from 0 to 20,

i is a number from 1 to 50,

j is a number from 0 to 10,

k is a number from 0 to 10, or

(d)

correspond to the radical R 1 ,

with the proviso that in the average molecule at least one radical R 2 has the definition (a),

a is a number from 1 to 500, and

b is a number from 0 to 10

and wherein the water solubility of the organopolysiloxane is such that forms a clear solution in water in an amount not more than 20 g/l at 25° C.

16. A defoamer emulsion, which comprises from about 5 to about 50% of at least one water-insolule organopolysiloxane derivative of the general average formula (I)

where the radicals

R 1 are alkyl radicals or aryl radicals, but at least 80% of the radicals R 1 are methyl radicals,

R 2 in the molecule are identical or different and have the following definitions:

in which

R 3 is a hydrogen, alkyl radical

R 4 is a hydrogen, alkyl or carbonyl radical

c is a number from 1 to 20,

d is a number from 0 to 50,

e is a number from 0 to 50,

(b)

—(CH 2 —) f OR 5 ,

in which

R 5 is a hydrogen, alkyl or carboxyl radical, or a dimethylol propane radical containing ether groups if desired, and

f is a number from 2 to 20 or

c)

—(CH 2 —) g (OC 2 H 4 —) h (OC 3 H 6 —) j (OCH 2 CH(C 6 H 5 )) k OR 6

in which

R 6 is a hydrogen, alky or carboxyl radical,

g is a number from 2 to 6,

h is a number from 0 to 20,

i is a number from 1 to 50,

j is a number from 0 to 10,

k is a number from 0 to 10, or

(d)

correspond to the radical R 1 ,

with the priviso that in the average molecule at least one radical R 2 has the definition (a),

a is a number from 1 to 500,

b is a number from 0 to 10, and

wherein the organopolysiloxane forms a clear solution in water in an amount not more that 20 g/l at 25° C.

water, and optionally an auxiliary or additive.

17. An ink or a paint which comprise a pigment and a defoam emulsion according to claim 16 .

18. A polymer dispersion which comprises a polymer and a defoam emulsion according to claim 16 .

19. An aqueous coating material which comprises an emulsion according to claim 16 .