Defoamer composition based on organofunctionally modified polysiloxanes

1. A defoamer composition based on organofunctionally modified polysiloxanes, comprising:

one or more laterally polyether-modified polysiloxanes as component A which conforms to general formula (I)

wherein

R=identical and/or different alkyl radicals having 1 to 8 carbon atoms,

R 1 ═C p H 2p O[(C 2 H 4 O) x (C 3 H 6 O) y ]R 2 , wherein p=2, 3 or 4, and R 2 =hydrogen and/or an alkyl radical having 1 to 3 carbon atoms,

m=10-400,

n=1 to 15, and

wherein x and y are selected such that a molar weight of the polyoxyalkylene block —C p H 2p O[(C 2 H 4 O) x (C 3 H 6 O) y ]— is in the range of 500-10000 g/mol, and

at least one terminally polyether-modified polysiloxane as component B.

2. The composition according to claim 1 , wherein the organofunctionally modified polysiloxanes are linear organofunctionally modified polysiloxanes.

3. The composition according to claim 1 , wherein component B conforms to general formula (II)

wherein

R 3 =identical and/or different alkyl radicals having 1 to 8 carbon atoms,

R 4 =R 3 and/or —C p H 2p O[(C 2 H 4 O) x (C 3 H 6 O) y ]R 2 and/or —C p H 2 O(C 3 H 6 O) y ]R 2 , wherein p=2, 3 or 4, with the proviso that at least one R 4 =—C p H 2p O[(C 2 H 4 O) x (C 3 H 6 O) y ]— or —C p H 2p O(C 3 H 6 O) y ]— is terminal,

R 2 =alkyl radical having 1 to 3 carbon atoms and/or hydrogen,

f=20-500,

g=1 to 15, and

wherein x and y are selected such that the molar weight of the polyoxyalkylene block —C p H 2p O[(C 2 H 4 O) x (C 3 H 6 O) y ]— and/or —C p H 2p O(C 3 H 6 O) y ]— is in the range of 200-4000 g/mol.

4. The composition according to claim 1 , wherein y>x in the polyoxyalkylene block —C p H 2p O[(C 2 H 4 O) x (C 3 H 6 O) y ]—, and wherein x and y are natural numbers.

5. The composition according to claim 1 , wherein the polyoxyalkylene block —C p H 2p O[(C 2 H 4 O) x (C 3 H 6 O) y ]— in component A has a blockwise construction.

6. The composition according to claim 3 , wherein R 4 =—C p H 2p O[(C 2 H 4 O) x (C 3 H 6 O) y ]R 2 and/or —C p H 2p ((C 3 H 6 O) y ]R 2 , wherein p=2, 3 or 4, with the proviso that at least one R 4 =—C p H 2p O[(C 2 H 4 O) x (C 3 H 6 O) y ]— or —C p H 2p O(C 3 H 6 O) y ]— is terminal.

7. The composition according to claim 1 , wherein a molar ratio of siloxane fraction to polyoxyalkylene fraction of component A is smaller than a molar ratio of siloxane fraction to polyoxyalkylene fraction of component B.

8. The composition according to claim 1 , wherein component A has a molar ratio of siloxane fraction to polyoxyalkylene fraction of 0.15 to 0.35.

9. The composition according to claim 1 , wherein component A has a viscosity in the range of 2500-60 000 mPas, measured according to DIN 53015.

10. The composition according to claim 1 , wherein component B has a molar ratio of siloxane fraction to polyoxyalkylene fraction of 0.4 to 2.

11. The composition according to claim 1 , wherein component B has a viscosity in the range of 250-1200 mPas, measured according to DIN 53015.

12. The composition according to claim 1 , wherein component A has a higher compatibility than component B.

13. The composition according to claim 1 , wherein component B has a higher defoamer activity than component A.

14. The composition according to claim 1 obtainable by stirring components A and B.

15. The composition according to claim 1 , consisting of:

(a) 20% to 80% by weight of component A,

(b) 20% to 80% by weight of component B, and

(c) 0% to 70% by weight of a component B′;

and

wherein component B and component B′ conform to general formula (II)

wherein

R 3 =identical and/or different alkyl radicals having 1 to 8 carbon atoms,

R 4 =R 3 and/or —C p H 2p O[(C 2 H 4 O) x (C 3 H 6 O) y ]R 2 and/or —C p H 2p (C 3 H 6 O) y ]R 2 ,

wherein p=2, 3 or 4, with the proviso that at least one R 4 =—C p H 2p O[(C 2 H 4 O) x (C 3 H 6 O) y ]— or —C p H 2p O(C 3 H 6 O) y ]— is terminal,

R 2 =alkyl radical having 1 to 3 carbon atoms and/or hydrogen,

f=20-500,

g=1 to 15, and

wherein x and y are selected such that the molar weight of the polyoxyalkylene block —C p H 2p O[(C 2 H 4 O) x (C 3 H 6 O) y ]— and/or

—C p H 2p O(C 3 H 6 O) y ]— is in the range of 200-4000 g/mol;

wherein in Component B, at least one polyoxyalkylene block —C p H 2 >O[(C 2 H 4 O) x (C 3 H 6 O) y ]— is terminal,

wherein in Component B′, at least one polyoxyalkylene block —C p H 2p O(C 3 H 6 O) y ]— is terminal, and

wherein the amounts of components A, B and B′ sum to 100% by weight and are based on the composition.

16. The composition according to claim 15 , obtainable by stirring component A into a mixture of components B and B′.

17. The composition according to claim 1 , wherein the composition has a viscosity of 250 to 5000 mPas, measured according to DIN 53015.

18. The composition according to claim 1 , wherein the composition has a static surface tension of 20 to 65 mN/m, measured with a Krüss K100 measuring instrument for static surface tension on the basis of DIN EN 14370:2004; and a dynamic surface tension of 20 to 65 mN/m, measured with a Krüss BP 50 bubble pressure tensiometer on the basis of DIN EN 14370:2004.

19. An article comprising the composition according to claim 1 ,

wherein the article is a defoamer additive, a flow control additive, and/or a substrate wetting additive.

20. A method, comprising:

producing an article comprising the composition according to claim 1 ,

wherein the article is selected from the group consisting of dispersions, millbases, paints, coatings, printing inks, inkjet, grind resins, pigment concentrates, colour preparations, pigment preparations, filler preparations, and coating compositions.

21. A method of producing the defoamer composition according to claim 1 , the method comprising:

mixing component A with component B,

and

wherein component B conforms to general formula (II)

wherein

R 3 =identical and/or different alkyl radicals having 1 to 8 carbon atoms,

R 4 =R 3 and/or —C p H 2p O[(C 2 H 4 O) x (C 3 H 6 O) y ]R 2 and/or —C p H 2p (C 3 H 6 O) y ]R 2 ,

wherein p=2, 3 or 4, with the proviso that at least one R 4 =—C p H 2p O[(C 2 H 4 O) x (C 3 H 6 O) y ]— or —C p H 2p O(C 3 H 6 O) y ]— is terminal,

R 2 =alkyl radical having 1 to 3 carbon atoms and/or hydrogen,

f=20-500,

g=1 to 15, and

wherein x and y are selected such that the molar weight of the polyoxyalkylene block —C p H 2p O[(C 2 H 4 O) x (C 3 H 6 O) y ]— and/or

—C p H 2p O(C 3 H 6 O) y ]— is in the range of 200-4000 g/mol.