Aqueous, colloidal gas black suspension

1. An aqueous, colloidal gas black suspension, comprising:

a gas black,

an azo compound of the formula 1

wherein R 1 to R 12 may be the same or different and consist of hydrogen, hydrophilic or hydrophobic groups, acceptor or donor substituents or parts of aliphatic, aromatic or heteroaromatic, acyclic, cyclic or polycyclic systems having acceptor, donor, hydrophilic or hydrophobic groups, and water.

2. The aqueous, colloidal gas black suspension according to claim 1 , wherein the gas black has a content of volatile constituents (950° C.) of <21 wt. %, a BET surface area of from 80 to 350 m 2 /g, a primary particle size of from 8 to 40 nm and a DBP number of from 40 to 200 ml/100 g.

3. The aqueous, colloidal gas black suspension according to claim 1 , wherein the gas black is present in the amount of <30 wt. %.

4. The aqueous, colloidal gas black suspension according to claim 1 , wherein the azo compound of the formula 1 is present in an amount of <5 wt. %.

5. The aqueous, colloidal gas black suspension according to claim 1 , wherein the azo compound of the formula 1 contains less than 30 wt. % impurity.

6. The aqueous, colloidal gas black suspension according to claim 1 , wherein the azo compound of the formula 1 contains less than 10 wt. % salt.

7. The aqueous, colloidal gas black suspension according to claim 1 , wherein the azo compound is Acid Black 1, Mordant Green 17 or Mordant Blue 13.

8. The aqueous, colloidal gas black suspension according to claim 7 , wherein the azo compound Acid Black 1, Mordant Green 17 or Mordant Blue 13 contains less than 30 wt. % impurity and less than 10 wt. % salt.

9. The aqueous, colloidal gas black suspension according to claim 1 , further comprising a biocide, wetting agent and/or additive.

10. The aqueous, colloidal gas black suspension according to claim 9 , wherein the wetting agent is a fatty alcohol ethoxylate, polyacrylic acid or/and derivatives thereof, copolymer containing acrylic acid, acrylic acid derivatives, styrenes, styrene derivatives and/or polyethers, lignosulfonate, alkylbenzenesulfonate, naphthalenesulfonic acid derivative, copolymer containing maleic anhydride and/or maleic acid derivatives, or combinations of the mentioned wetting agents.

11. The aqueous, colloidal gas black suspension according to claim 9 , wherein the wetting agent is present from 0 to 1 wt. %.

12. The aqueous, colloidal gas black suspension according to claim 9 , wherein the additive is an alcohol, glycol, heterocyclic compound or glycerol.

13. The aqueous, colloidal gas black suspension according to claim 9 , wherein the additive is present in an amount of <25 wt. %.

14. A process for the production of the aqueous, colloidal gas black suspension according to claim 1 , comprising dispersing the gas black and the azo compound of the formula 1 in water.

15. The aqueous, colloidal gas black suspension according to claim 14 , further comprising dispersing by using bead mills, ultrasonic devices, homogenisers, microfluidizers or mixers.

16. A composition of matter selected from the group consisting of an ink, ink-jet ink, surface coating and colored printing ink containing the aqueous, colloidal gas black suspension according to claim 1 .

17. An ink composition containing the aqueous, colloidal gas black suspension according to claim 1 .

18. The aqueous, colloidal gas black suspension according to claim 1 , wherein the substituents R 1 R 12 can be phenyl, naphthyl, pyrrolyl, pyridinyl, furyl, puryl, —COOR 13 , —CO—R 13 , —CN, —SO 2 R 13 or —SO 2 OR 13 , wherein R 13 ═H, alkali metal cation, ammonium, alkyl, aryl, ω-carboxyalkyl, HSO 3 —C x H y —, H 2 N—C x H y , H 2 N—SO 2 —C x H y —(x =1–20; y =1–45), donor substituents, that are alkyl, aryl groups, OR 14 , N(R 14 ) 2 , SR 14 or P(R 14 ) 2 , wherein R 14 ═H, alkyl, aryl or functionalised alkyl or aryl, oligomers or polymers of the form—(O—R 14 ) y —OR 15 , wherein R 15 ═H, alkyl or aryl.

19. The aqueous, colloidal gas black suspension according to claim 1 , wherein the azo compound is Acid Black 1 (C.I. 20470)

or

Mordant Green 17 (C.I. 17225)

or

Mordant Blue 13 (C.I. 16680)