Ink composition, ink cartridge, ink recording device, and recorded matter

Patent metadata

Field	Value
Publication number	US-9617439-B2
Application number	US-201514625051-A
Country	US
Kind code	B2
Filing date	Feb 18, 2015
Priority date	Mar 6, 2014
Publication date	Apr 11, 2017
Grant date	Apr 11, 2017

Abstract

An ink composition contains (a) a pigment represented by chemical formula 1a or chemical formula 1b, (b) a polymer having a structure unit having a diphosphonic acid group and represented by Chemical formula 2, (c) a hydrosoluble solvent, and (d) water.

First claim

What is claimed is:

1. An ink composition comprising:
a pigment represented by Chemical formula 1a or Chemical formula 1b;
a polymer comprising a structure unit having a diphosphonic acid group;
a hydrosoluble solvent; and
water,
wherein when the pigment is represented by Chemical formula 1a, the pigment satisfies the relation 1: Y/X≦0.800, where X represents a peak intensity at a Bragg (2θ±0.2°) angle in a range of 2θ of from 5.5° to 6.0° and Y represents a peak intensity at a Bragg (2θ±0.2°) angle in a range of 2θ of from 26.5° to 27.5°, in a CuKα X-ray diffraction spectrum having a wavelength of 1.541 Å,

where R each, independently represents hydrogen atoms, methyl groups, or chlorine atoms,
wherein when the pigment is represented by Chemical formula 1b, the pigment satisfies the relation 2: Y′/X′≦0.200, where X′ represents a peak intensity at a Bragg (2θ±0.2°) angle in a range of 2θ of from 26.5° to 27.5° and Y′ represents a peak intensity at a Bragg (2θ±0.2°) angle in a range of 2θ of from 11.0° to 11.5°, in a CuKα X-ray diffraction spectrum having a wavelength of 1.541 Å,

wherein the structure unit having a diphosphonic acid group is represented by Chemical formula 2

where R 1 represents a hydrogen atom or a methyl group and M 1 + , M 2 + , M 3 + , and M 4 + each, independently represent alkali metal ions, organic ammonium ions, or hydrogen ions.

2. The ink composition according to claim 1 , wherein the polymer comprising a structure unit having a diphosphonic acid group is a copolymer comprising the structure unit having a diphosphonic acid group.

3. The ink composition according to claim 1 , wherein when the pigment is represented by Chemical formula 1a, the pigment has no peak at a Bragg (2θ±0.2°) angle in a range of 2θ of from 28.0° to 29.0° in a CuKα X-ray diffraction spectrum having a wavelength of 1.541 Å.

4. The ink composition according to claim 1 , wherein the structure unit represented by Chemical formula 2 accounts for 10% by weight to 60% by weight in the polymer comprising a structure unit having a diphosphonic acid group.

5. The ink composition according to claim 1 , wherein R 1 in Chemical formula 2 is a methyl group.

6. The ink composition according to claim 1 , wherein the polymer comprising a structure unit having a diphosphonic acid group comprises a structure unit represented by Chemical formula 3 or Chemical formula 4,

where R 2 represents a hydrogen atom or a methyl group,

where R 3 represents a hydrogen atom or a methyl group.

7. The ink composition according to claim 1 , wherein the polymer comprising a structure unit having a diphosphonic acid group has a weight average molecular weight of from 4,000 to 50,000.

8. An ink cartridge comprising:
a container to accommodate the ink composition of claim 1 .

9. An inkjet recording device comprising:
a container to accommodate the ink composition of claim 1 ; and
a recording head to discharge the ink composition of claim 1 supplied from the container.

10. Recorded matter comprising:
a recording medium; and
an image or information recorded on the recording medium using the ink composition of claim 1 .

Assignees

• Matsuyama Akihiko
• Harada Shigeyuki
• Katoh Keita
• Fukuoka Masayuki
• Naruse Mitsuru
• Nagai Kazukiyo
• Koizuka Yuusuke
• Nonogaki Masayasu
• Ricoh Co Ltd

Inventors

• Matsuyama Akihiko
• Harada Shigeyuki
• Katoh Keita
• Fukuoka Masayuki
• Naruse Mitsuru
• Nagai Kazukiyo
• Koizuka Yuusuke
• Nonogaki Masayasu

Classifications

• C09D11/326

  characterised by the pigment dispersant · CPC title

• Y10T428/24901

  including coloring matter · CPC title

• C09D11/106

  containing macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds · CPC title

• C08K5/3437

  condensed with carbocyclic rings · CPC title

• C08K5/29

  Compounds containing {one or more} carbon-to-nitrogen double bonds · CPC title