INK COMPOSITION CONTAINING CATIONIC WATER-SOLUBLE POLYMER

• US 20020177633A1
• Filed: 02/23/1999
• Published: 11/28/2002
• Est. Priority Date: 02/23/1998
• Status: Active Grant

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: OHTA, HITOSHI, KITAMURA, KAZUHIKO, KOMATSU, HIDEHIKO
• Granted Patent: US 7,265,164 B2
• Time in Patent Office: Days
• US Class Current: 523/160
• CPC Class Codes: C09D 11/30 Inkjet printing inks

Abstract

An ink composition for ink jet recording is provided which can realize both good waterfastness of prints and high-quality recorded images on specialty recording media. The ink composition comprises a water-soluble colorant, such as an acid dye, a cationic water-soluble polymer, such as polyallylamine, and an inorganic salt, such as potassium chloride, in combination.

Claims

1. An ink composition comprising water, a colorant, a cationic water-soluble polymer, and an inorganic salt.

2. The ink composition according to claim 1, wherein the inorganic salt is contained in an ionized state in the ink composition.

3. The ink composition according to claim 1 or 2, wherein an alkali metal ion or an alkaline earth metal ion is a cation which forms the inorganic salt.

4. The ink composition according to any one of claims 1 to 3, wherein the inorganic salt-forming cation is added as a hydroxide of an alkali metal to the ink composition.

5. The ink composition according to any one of claims 1 to 4, wherein an anion, which forms the inorganic salt, is a chloride ion derived from the cationic water-soluble polymer that has been added as a hydrochloride.

6. The ink composition according to any one of claims 1 to 5, wherein the inorganic salt is contained in an amount in the range of 0.5 to 5% by weight.

7. The ink composition according to any one of claims 1 to 6, wherein the colorant is an organic dye or pigment that is soluble in an alkali.

8. The ink composition according to any one of claims 1 to 7, wherein the colorant is contained in an amount in the range of 0.5 to 20% by weight.

9. The ink composition according to any one of claims 1 to 8, wherein the cationic water-soluble polymer has in its molecule at least one structure selected from the group consisting of ethyleneimine, allylamine, diallylamine, and dimethylallylamine.

10. The ink composition according to any one of claims 1 to 9, wherein the cationic water-soluble polymer is contained in an amount in the range of 0.1 to 20% by weight.

11. The ink composition according to any one of claims 1 to 10, which further comprises a water-soluble organic solvent and/or a saccharide having a lower vapor pressure than pure water as a humectant.

12. The ink composition according to any one of claims 1 to 11, which further comprises at least one penetrant selected from the group consisting of lower alcohols, cellosolves, carbitols, and nonionic surfactants.

13. The ink composition according to any one of claims 1 to 12, which is used for ink jet recording.

14. A recording method comprising the step of depositing an ink composition onto a recording medium to perform printing, wherein the ink composition is one according to any one of claims 1 to 13.

15. An ink jet recording method comprising the steps of:

ejecting a droplet of an ink composition; and

depositing the droplet onto a recording medium to perform printing, wherein the ink composition is one according to any one of claims 1 to 13.

16. A record printed by the method according to claim 14 or 15.