Aqueous ink-jet inks containing amphoteric polyurethane as binder

1. An ink-jet ink comprising an aqueous vehicle, a colorant, and a self-stabilized amphoteric polyurethane as a binder, wherein said amphoteric polyurethane contains a plurality of tertiary amine groups derived from an amine-containing monomer, and a plurality of anionic acid groups, said colorant is selected from the group consisting of a self-dispersing pigment, a pigment dispersed by a polymeric dispersant, a dispersed dye, and a dye, and wherein said amphoteric polyurethane is not a dispersant.

2. The ink of claim 1 , wherein said colorant is a pigment dispersed by a polymeric dispersant.

3. The ink of claim 2 , wherein said ink is neutralized by alkaline to having a pH of greater than about 7.

4. The ink of claim 3 , wherein said ink has a viscosity drift of less than 20% after oven aging at 70° C. for 14 days.

5. The ink of claim 4 , wherein said anionic acid groups are carboxylic groups with an acid number in the range of 10 through 90.

6. The ink of claim 5 , wherein said binder is crosslinked.

7. The ink of claim 6 , wherein the % THF insoluble of said crosslinked binder is equal or greater than 30%.

8. The ink of claim 1 , wherein said colorant is a self-dispersing pigment.

9. The ink of claim 8 , wherein said ink is neutralized by alkaline to having a pH of greater than about 7.

10. The ink of claim 9 , wherein said ink has a viscosity drift of less than 20% after oven aging at 70° C. for 14 days.

11. The ink of claim 10 , wherein said anionic acid groups are carboxylic groups with an acid number in the range of 10 through 90.

12. The ink of claim 11 , wherein said binder is crosslinked.

13. The ink of claim 12 , wherein the % THF insoluble of said crosslinked binder is equal or greater than 30%.