Ink composition, recording method and recording images using the same, as well as ink set and ink head

• US 20040059020A1
• Filed: 09/22/2003
• Published: 03/25/2004
• Est. Priority Date: 09/18/2002
• Status: Active Grant

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Kamoto, Takanori, Morimoto, Kiyobumi, Nakatsu, Hiromi, Kinomoto, Masanori
• Granted Patent: US 7,432,315 B2
• Time in Patent Office: Days
• US Class Current: 523/160
• CPC Class Codes: C09D 11/30 Inkjet printing inks
• CPC Class Codes: C09D 11/40 Ink-sets specially adapted for multi-colour inkjet printing

Abstract

An ink composition is prepared by incorporating water, a colorant and a polyester resin in which a polybasic carboxylic acid ingredient contains an aromatic dicarboxylic acid having a metal sulfonate group. The ink composition is stored in an ink tank of an ink head, the ink composition is supplied from the ink tank into an ink chamber having a discharge port, a voltage is applied to partition wall portions formed of a piezoelectric material, a pressure is applied to the ink composition contained in the ink chamber by the partition wall portions and liquid droplets of the ink composition are discharged from the discharge port and deposited on a recording material thereby recording images.

Claims

1. An ink composition comprising:

water;

a colorant; and

a polyester resin containing a polybasic carboxylic acid ingredient and a polyhydric alcohol ingredient,

the polybasic carboxylic acid ingredient containing an aromatic dicarboxylic acid having a metal sulfonate group.

2. The ink composition of claim 1, wherein the polyester resin has a number average molecular weight within a range of from 5,000 to 50,000.

3. The ink composition of claim 1, wherein the polyester resin has a glass transition point Tg within a range of from −

20°

C. to 70°

C.

4. The ink composition of claim 1, wherein the polyhydric alcohol ingredient contains at least one glycol selected from the group consisting of aliphatic glycols and cycloaliphatic glycols.

5. The ink composition of claim 1, wherein electroconductivity of the water is 250 μ

S/cm or less.

6. The ink composition of claim 1, wherein the colorant contains a pigment.

7. The ink composition of claim 6, wherein the pigment has a hydrophilic group.

8. The ink composition of claim 7, wherein the hydrophilic group is at least one of carboxyl group and sulfonic group.

9. The ink composition of claim 1, wherein the ink composition further comprises a water-soluble organic solvent having a vapor pressure lower than that of the water.

10. The ink composition of claim 9, wherein the water-soluble organic solvent contains glycol ethers and/or polyhydric alcohols.

11. The ink composition of claim 1, the ink composition further comprising:

a nonionic surfactant,

content of the nonionic surfactant being at a critical micelle concentration or more.

12. The ink composition of claim 6, wherein the pigment contains at least one of C.I. pigment blue 15:

3 and C.I. pigment blue 15;

4.

13. The ink composition of claim 6, wherein the pigment contains at least one selected from the group consisting of C.I. pigment red 122, C.I. pigment red 209 and C.I. pigment violent 19.

14. The ink composition of claim 6, wherein the pigment contains at least one selected from the group consisting of C.I. pigment yellow 74, C.I. pigment yellow 138, C.I. pigment yellow 150 and C.I. pigment yellow 180.

15. The ink composition of claim 6, wherein the pigment contains a carbon black.

16. A recording method of recording images comprising:

depositing an ink composition on a recording material,

wherein for the ink composition is used the ink composition of claim 1.

17. A recording method of recording images comprising:

discharging liquid droplets of an ink composition by applying a pressure to the ink composition; and

depositing the liquid droplets on a recording material,

wherein for the ink composition is used the ink composition of claim 1.

18. The recording method of claim 16, wherein for the ink composition are used at least the ink composition of claim 12, the ink composition of claim 13, and the ink composition of claim 14.

19. The recording method of claim 17, wherein for the ink composition are used at least the ink composition of claim 12, the ink composition of claim 13, and the ink composition of claim 14.

20. The recording method of claim 16, wherein for the ink composition are used at least the ink composition of claim 12, the ink composition of claim 13, the ink composition of claim 14 and the ink composition of claim 15.

21. The recording method of claim 17, wherein for the ink composition are used at least the ink composition of claim 12, the ink composition of claim 13, the ink composition of claim 14 and the ink composition of claim 15.

22. A recorded image recorded by the recording method of claim 16.

23. A recorded image recorded by the recording method of claim 17.

24. An ink set comprising:

the ink composition of claim 12;

the ink composition of claim 13;

and

the ink composition of 14.

25. An ink set comprising:

the ink composition of claim 12;

the ink composition of claim 13;

the ink composition of 14; and

the ink composition of claim 15.

26. An ink head comprising:

an ink tank for storing the ink composition of claim 1;

an ink chamber having a discharge port for discharging liquid droplets of the ink composition, the ink chamber being supplied with the ink composition from the ink tank;

a piezoelectric element disposed to at least a portion of the ink chamber, for applying a pressure to the ink composition contained in the ink chamber, the piezoelectric element generating distortion in response to a voltage applied thereto, and

an electrode for applying the voltage to the piezoelectric element.

27. An ink head comprising:

an ink tank for storing the ink composition of claim 1;

an ink chamber having a discharge port for discharging liquid droplets of the ink composition, the ink chamber being supplied with the ink composition from the ink tank;

a heat generation body disposed to at least a portion of the ink chamber, for heating the ink composition contained in the ink chamber to generate air bubbles and thereby applying a pressure to the ink composition, and

an electrode for applying a voltage to the heat generation body.

28. A recorded image recorded by depositing liquid droplets of the ink composition which are discharged by the ink head of claim 26, on a recording material.

29. A recorded image recorded by depositing liquid droplets of the ink composition which are discharged by the ink head of claim 27, on a recording material.