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

Patent metadata

Field	Value
Publication number	US-9738802-B2
Application number	US-201615240539-A
Country	US
Kind code	B2
Filing date	Aug 18, 2016
Priority date	Sep 30, 2015
Publication date	Aug 22, 2017
Grant date	Aug 22, 2017

Abstract

A water-based ink for ink-jet recording includes: a pigment; water; a first resin containing at least one of methacrylic acid and acrylic acid as a monomer; and a second resin, wherein the second 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;
a first resin containing at least one of methacrylic acid and acrylic acid as a monomer; and
a second resin, wherein the second 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 a weight ratio of a blending amount of the second resin in the water-based ink to a blending amount of the first resin in the water-based ink is in a range of 0.2 to 1.

3. The water-based ink for ink-jet recording according to claim 1 , wherein a total blending amount of the first resin and the second resin in the water-based ink is not more than 4% by weight.

4. The water-based ink for ink-jet recording according to claim 1 , wherein the second resin has a weight average molecular weight of 8,000 to 15,000.

5. The water-based ink for ink-jet recording according to claim 1 , wherein the second resin has an acid value of 100 mgKOH/g to 150 mgKOH/g.

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 0.5 to 2.

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 a weight ratio of a total blending amount of the first resin and the second resin in the water-based ink to a blending amount of the pigment in the water-based ink is in a range of 0.26 to 1.4.

10. The water-based ink for ink-jet recording according to claim 1 , wherein the first resin is a dispersant and adsorbs to the pigment to disperse the pigment in the water.

11. The water-based ink for ink-jet recording according to claim 1 , wherein the first resin is one selected from the group consisting of a styrene-acrylic acid copolymer, a styrene-methacrylic acid copolymer, and salts thereof.

12. The water-based ink for ink-jet recording according to claim 1 , wherein the pigment is a color pigment.

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

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

15. An ink-jet recording method comprising discharging the water-based ink for ink-jet recording as defined in claim 1 on glossy paper in accordance with an ink-jet system to perform recording.

Assignees

• Brother Ind Ltd

Inventors

• Tanaka Hiroyuki
• Maeda Mitsunori
• Okumura Yuki

Classifications

• C08F220/14

  Methyl esters {, e.g. methyl (meth)acrylate} · CPC title

• C09D133/12

  Homopolymers or copolymers of methyl methacrylate · CPC title

• B41J2/01

  Ink jet · CPC title

• C08F265/02

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

• B41J2/17503

  Ink cartridges · CPC title