Ink composition and ink-jet recording method

• US 20040138335A1
• Filed: 07/21/2003
• Published: 07/15/2004
• Est. Priority Date: 12/21/2000
• Status: Abandoned Application

• Current Assignee: Kenji Ikeda, Takahiro Ishizuka
• Original Assignee: Kenji Ikeda, Takahiro Ishizuka
• Inventors: Ikeda, Kenji, Ishizuka, Takahiro
• Application Number:
  US10/622,746
• Publication Number:
  US 20040138335A1
• Time in Patent Office: Days
• US Class Current: 523/160
• CPC Class Codes: C09D 11/32 characterised by colouring agents

Abstract

The present invention provides an aqueous ink composition including a hydrophilic organic solvent, a surfactant, and a colored fine particle dispersion which contains an oil-soluble dye, and exhibiting a dynamic surface tension of 25 to 35 mN/m, as well as an ink-jet recording method including a step of carrying out recording using the aqueous ink composition.

Claims

1. An aqueous ink composition comprising a hydrophilic organic solvent, a surfactant, and a colored fine particle dispersion which contains an oil-soluble dye, and exhibiting a dynamic surface tension of 25 to 35 mN/m.

2. The aqueous ink composition according to claim 1, wherein the colored fine particles contain the oil-soluble dye and an oil-soluble polymer.

3. The aqueous ink composition according to claim 1, wherein the oil-soluble dye has a melting point of 200°

C. or less.

4. The aqueous ink composition according to claim 1, wherein the oil-soluble dye is selected from the group consisting of an anthraquinone-type dye, a naphthoquinone-type dye, a styryl-type dye, an indoaniline-type dye, an azo-type dye, a nitro-type dye, a coumarin-type dye, a methine-type dye, a porphyrin-type dye, an azaporphyrin-type dye and a phthalocyanine-type dye.

5. The aqueous ink composition according to claim 4, wherein the dye is contained in an amount of 0.05 to 50% by mass relative to the ink composition.

6. The aqueous ink composition according to claim 2, wherein the oil-soluble polymer has a carboxyl group as a dissociative group.

7. The aqueous ink composition according to claim 2, wherein the oil-soluble polymer has a molecular weight (Mw) of 1,000 to 200,000.

8. The aqueous ink composition according to claim 2, wherein the oil-soluble polymer is selected from the group consisting of a vinyl polymer, polyurethane and polyester.

9. The aqueous ink composition according to claim 2, wherein the oil-soluble polymer is used in an amount of 10 to 1,000 parts by mass relative to 100 parts by mass of the oil-soluble dye.

10. The aqueous ink composition according to claim 1, wherein the colored fine particles are contained in an amount of 1 to 45% by mass relative to the colored fine particle dispersion.

11. The aqueous ink composition according to claim 1, wherein an average particle diameter of the colored fine particles is 1 to 500 nm.

12. The aqueous ink composition according to claim 1, wherein the hydrophilic organic solvent is selected from the group consisting of a polyvalent alcohol, an aliphatic monovalent alcohol, a heterocyclic compound and a sulfur-containing compound.

13. The aqueous ink composition according to claim 1, wherein the hydrophilic organic solvent is contained in an amount of 5 to 60% by mass relative to the ink composition.

14. The aqueous ink composition according to claim 1, wherein a molecular weight of the surfactant is 200 to 1,000.

15. The aqueous ink composition according to claim 1, wherein the surfactant is contained in an amount of 0.5 to 5.0% by mass relative to the ink composition.

16. The aqueous ink composition according to claim 1, further comprising an additive selected from the group consisting of a neutralizing agent, a hydrophobic high-boiling point organic solvent, a dispersant and a dispersion stabilizer.

17. The aqueous ink composition according to claim 1, wherein a viscosity of the ink is 30 mPa·

s or less.

18. An ink-jet recording method comprising a step of carrying out recording using an aqueous ink composition which comprises a hydrophilic organic solvent, a surfactant, and a colored fine particle dispersion containing an oil-soluble dye, and exhibits a dynamic surface tension of 25 to 35 mN/m.

19. The ink-jet recording method according to claim 18, using a system selected from the group consisting of a charge regulating system, a drop-on-demand system, an acoustic inkjet system and a thermal ink-jet system.

20. The ink-jet recording method according to claim 18, wherein a material to undergo recording is selected from the group consisting of a plain paper, a coated paper and a plastic film.