INKJET RECORDING INK AND INKJET RECORDING DEVICE USING THE SAME

• US 20130038660A1
• Filed: 04/08/2011
• Published: 02/14/2013
• Est. Priority Date: 04/30/2010
• Status: Active Grant

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: Fushimi, Hiroyuki, Hasegawa, Shin
• Granted Patent: US 9,045,659 B2
• Time in Patent Office: Days
• US Class Current: 347/20
• CPC Class Codes: B41J 2/17503 Ink cartridges
• CPC Class Codes: C09D 11/322 Pigment inks
• CPC Class Codes: C09D 11/324 containing carbon black
• CPC Class Codes: C09D 11/326 characterised by the pigment dispersant

Abstract

An inkjet recording ink, which contains: carbon black; a surfactant; water; a water-soluble organic solvent; and particles formed of an anionic self-emulsifying poly(ether urethane) resin, wherein the carbon black contains first carbon black whose surface has been treated with an anionic surfactant and second carbon black which has been coated with a resinous polymer, where a mass ratio of the first carbon black to the second carbon black is 10/90 to 90/10, and wherein the anionic surfactant is a naphthalenesulfonic acid-formaldehyde condensate.

Claims

1. An inkjet recording ink, comprising:

carbon black;

a surfactant;

water;

a water-soluble organic solvent; and

particles comprising an anionic self-emulsifying poly(ether urethane) resin,

wherein the carbon black comprises a first carbon black and a second carbon black,

a surface of the first carbon black is obtained by a process comprising treating with a naphthalenesulfonic acid-formaldehyde condensate as an anionic surfactant,

the second carbon black is obtained by a process comprising coating with a resinous polymer, and

a mass ratio of the first carbon black to the second carbon black is from 10/90 to 90/10.

2. The ink of claim 1,

wherein the first carbon black has an average particle diameter (D₅₀) of from 50 nm to 100 nm, and

the second carbon black has an average particle diameter (D₅₀) of from 100 nm to 150 nm.

3. The ink claim 1,

wherein the water-soluble organic solvent comprises 2-ethyl-1,3-hexanediol, and

an amount of the 2-ethyl-1,3-hexanediol in the ink is from 0.1% by mass to 10% by mass.

4. The ink of claim 1, wherein the anionic self-emulsifying poly(ether urethane) resin has an acid value of from 40 mgKOH/g to 120 mgKOH/g.

8. The ink of claim 1, wherein the mass ratio of the first carbon black to the second carbon black is from 30/70 to 70/30.

9. The ink of claim 1, wherein a content of the anionic surfactant is from 0.1 to 2 parts by mass relative to 1 part of the first carbon black.

10. The ink of claim 9, wherein the content of the anionic surfactant is from 0.25 to 1 part by mass.

11. The ink of claim 1, wherein a concentration of the carbon black in the ink is from 1% to 20% by mass.

12. The ink of claim 1, wherein the water-soluble organic solvent comprises 1,3-butylglycol, diethylene glycol, triethylene glycol, glycerin, or any combination thereof.

13. The ink of claim 1, wherein a content of the water-soluble organic solvent is from 5% to 40% by mass of a total amount of the ink.

14. The ink of claim 3, wherein the amount of the 2-ethyl-1,3-hexanediol in the ink is from 1.5% by mass to 5.0% by mass.

5. An ink cartridge, comprising:

a container; and

an inkjet recording ink housed in the container,

wherein the ink comprises carbon black, a surfactant, water, a water-soluble organic solvent, and particles comprising an anionic self-emulsifying poly(ether urethane) resin,

the carbon black comprises a first carbon black and a second carbon black,

a surface of the first carbon black is obtained by a process comprising treating with a naphthalenesulfonic acid-formaldehyde condensate as an anionic surfactant,

the second carbon black is obtained by a process comprising coating with a resinous polymer, and

a mass ratio of the first carbon black to the second carbon black is from 10/90 to 90/10.

15. The ink cartridge of claim 5, wherein the container is an ink bag comprising an aluminum laminated film or a resin film.

16. The ink cartridge of claim 5, wherein the container is a plastic case.

6. (canceled)

7. An inkjet recording method, comprising:

applying a stimulus to an inkjet recording ink, thereby ejecting the ink as a jet and recording an image,

wherein the ink comprises carbon black, a surfactant, water, a water-soluble organic solvent, and particles comprising an anionic self-emulsifying poly(ether urethane) resin,

the carbon black comprises a first carbon black and a second carbon black,

a surface of the first carbon black is obtained by a process comprising treating with a naphthalenesulfonic acid-formaldehyde condensate as an anionic surfactant,

the second carbon black is obtained by a process comprising coating with a resinous polymer, and

a mass ratio of the first carbon black to the second carbon black is from 10/90 to 90/10.