Water-based ink for ink-jet recording and ink cartridge

Patent metadata

Field	Value
Publication number	US-9732243-B2
Application number	US-201615240647-A
Country	US
Kind code	B2
Filing date	Aug 18, 2016
Priority date	Sep 30, 2015
Publication date	Aug 15, 2017
Grant date	Aug 15, 2017

Abstract

A water-based ink for ink-jet recording includes: a pigment; water; oligoethylene glycol monoalkyl ether; and a water-soluble resin. The water-soluble resin is an ABA-type triblock copolymer which has a polymer block A composed only of methyl methacrylate and methacrylic acid and a polymer block B composed only of benzyl methacrylate and methacrylic acid; which has a weight average molecular weight of 3,000 to 30,000; which has an acid value of 90 mgKOH/g to 200 mgKOH/g; and which is partially or completely neutralized.

First claim

What is claimed is:

1. A water-based ink for ink-jet recording, comprising:
a pigment;
water;
oligoethylene glycol monoalkyl ether; and
a water-soluble resin,
wherein the water-soluble resin is an ABA-type triblock copolymer which has a polymer block A composed only of methyl methacrylate and methacrylic acid and a polymer block B composed only of benzyl methacrylate and methacrylic acid; which has a weight average molecular weight of 3,000 to 30,000; which has an acid value of 90 mgKOH/g to 200 mgKOH/g; and which is partially or completely neutralized.

2. The water-based ink for ink-jet recording according to claim 1 , wherein the oligoethylene glycol monoalkyl ether includes an alkyl group having 1 to 6 carbon atoms.

3. The water-based ink for ink-jet recording according to claim 1 , wherein the oligoethylene glycol monoalkyl ether includes an alkyl group having 4 carbon atoms.

4. The water-based ink for ink-jet recording according to claim 1 , wherein a polymerization degree of ethylene glycol of the oligoethylene glycol monoalkyl ether is in a range of 2 to 4.

5. The water-based ink for ink-jet recording according to claim 1 , wherein the oligoethylene glycol monoalkyl ether is diethylene glycol-n-butyl ether or triethylene glycol-n-butyl ether.

6. The water-based ink for ink-jet recording according to claim 1 , wherein a ratio of a weight average molecular weight of the polymer block A to a weight average molecular weight of the polymer block B is in a range of 0.2 to 8.

7. The water-based ink for ink-jet recording according to claim 1 , wherein a weight ratio of the methyl methacrylate to the methacrylic acid in the polymer block A is in a range of 1.7 to 3.8; and
a weight ratio of the benzyl methacrylate to the methacrylic acid in the polymer block B is in a range of 3.8 to 32.0.

8. The water-based ink for ink-jet recording according to claim 1 , wherein the ABA-type triblock copolymer is neutralized by potassium hydroxide.

9. The water-based ink for ink-jet recording according to claim 1 , wherein the pigment is a resin-dispersible pigment.

10. The water-based ink for ink-jet recording according to claim 1 , wherein the pigment is a self-dispersible pigment.

11. The water-based ink for ink-jet recording according to claim 1 , wherein a weight ratio of a blending amount of the oligoethylene glycol monoalkyl ether in the water-based ink to a blending amount of the water-soluble resin in the water-based ink is in a range of 1 to 25.

12. The water-based ink for ink-jet recording according to claim 1 , wherein a weight ratio of a blending amount of the water-soluble resin in the water-based ink to a blending amount of the pigment in the water-based ink is in a range of 0.04 to 0.5.

13. The water-based ink for ink-jet recording according to claim 1 , further containing oligopropylene glycol.

14. The water-based ink for ink-jet recording according to claim 13 , wherein a polymerization degree of propylene glycol of the oligopropylene glycol is in a range of 2 to 4.

15. The water-based ink for ink-jet recording according to claim 13 , wherein the oligopropylene glycol is tripropylene glycol.

16. The water-based ink for inkjet recording according to claim 13 , wherein a weight ratio of a blending amount of the oligoethylene glycol monoalkyl ether in the water-based ink to a blending amount of the oligopropylene glycol in the water-based ink is in a range of 0.25 to 4.

17. The water-based ink for inkjet recording according to claim 13 , wherein a weight ratio of a total blending amount of the oligoethylene glycol monoalkyl ether and the oligopropylene glycol in the water-based ink to a blending amount of the water-soluble resin in the water-based ink is in a range of 4 to 50.

18. An ink cartridge comprising the water-based ink for ink-jet recording as defined in claim 1 .

Assignees

• Brother Ind Ltd

Inventors

• Tanaka Hiroyuki
• Maeda Mitsunori
• Okumura Yuki

Classifications

• C08F265/02

  on to polymers of acids, salts or anhydrides · CPC title

• C08F212/06

  Hydrocarbons · CPC title

• C09D11/38

  characterised by non-macromolecular additives other than solvents, pigments or dyes · CPC title

• C08F287/00

  Macromolecular compounds obtained by polymerising monomers on to block polymers · CPC title

• C09D11/107

  from unsaturated acids or derivatives thereof · CPC title