Pigment dispersion and ink composition for ink jet printing

1. A pigment dispersion for ink jet, comprising:

a pigment dispersed with a cross-linked water-soluble resin and a resin having a urethane bond, which is obtained by

blending the water-soluble resin with the pigment,

pulverizing the pigment in a kneading step and a dispersing step,

adding a crosslinking agent; and

adding the resin having a urethane bond,

wherein the pigment dispersion provides a gloss value at a 20° mirror surface of from 54.3 to 78.5.

2. The pigment dispersion according to claim 1 , wherein the resin having a urethane bond also has an amide bond.

3. The pigment dispersion according to claim 1 , wherein the water-soluble resin has a crosslinking rate of from 20 to 100%.

4. The pigment dispersion according to claim 1 , which is a dispersion for ink jet.

5. An ink composition for ink jet, which is obtained by adding an organic solvent to the pigment dispersion as defined in claim 1 .

6. The ink composition for ink jet according to claim 5 , wherein the water-soluble resin has a crosslinking rate of from 20 to 100%.

7. An ink jet recording method, which comprises printing by discharging the ink composition for ink jet as defined in claim 5 from a nozzle of an ink jet printer.

8. An ink jet recording method, which comprises printing by discharging the ink composition for ink jet as defined in claim 6 from a nozzle of an ink jet printer.

9. An ink set having the ink composition for ink jet as defined in claim 5 charged into a cartridge.

10. An ink set having the ink composition for ink jet as defined in claim 6 charged into a cartridge.

11. An ink jet recording method, which comprises printing by discharging the ink composition for ink jet as defined in claim 5 from a nozzle of an ink jet printer.

12. An ink jet recording method, which comprises printing by discharging the ink composition for ink jet as defined in claim 6 from a nozzle of an ink jet printer.

13. The pigment dispersion according to claim 1 , comprising the water-soluble resin and a resin having a urethane bond that is different from the cross-linked water-soluble resin.

14. The pigment dispersion according to claim 1 , wherein the pigment has a particle size of from 5 to 100 nm.

15. The ink composition according to claim 5 , wherein the pigment has a particle size of from 5 to 100 nm.

16. The ink composition according to claim 6 , wherein the pigment has a particle size of from 5 to 100 nm.

17. A pigment dispersion for ink jet, comprising:

a pigment dispersed with a cross-linked water-soluble resin and a resin having an amide bond that is different from the cross-linked water-soluble resin;

wherein the pigment dispersion is obtained by

blending the water-soluble resin with the pigment,

pulverizing the pigment in a kneading step and a dispersing step,

adding a crosslinking agent; and

adding the resin having an amide bond,

wherein the pigment dispersion provides a gloss value at a 20° mirror surface of from 54.3 to 78.5.

18. The pigment dispersion according to claim 17 , wherein the water-soluble resin has a crosslinking rate of from 20 to 100%.

19. An ink composition for ink jet, which is obtained by adding an organic solvent to the pigment dispersion as defined in claim 17 .

20. The ink composition for ink jet according to claim 19 , wherein the water-soluble resin has a crosslinking rate of from 20 to 100%.

21. An ink jet recording method, which comprises printing by discharging the ink composition for ink jet as defined in claim 19 from a nozzle of an ink jet printer.

22. An ink set having the ink composition for ink jet as defined in claim 19 charged into a cartridge.

23. An ink jet recording method, which comprises printing by discharging the ink composition for ink jet as defined in claim 19 from a nozzle of an ink jet printer.

24. An ink jet recording method, which comprises printing by discharging the ink composition for ink jet as defined in claim 20 from a nozzle of an ink jet printer.

25. An ink set having the ink composition for ink jet as defined in claim 20 charged into a cartridge.

26. The pigment dispersion according to claim 17 , wherein the pigment has a particle size of from 5 to 100 nm.

27. The ink composition according to claim 19 , wherein the pigment has a particle size of from 5 to 100 nm.