Ink, ink cartridge and ink jet recording method

Patent metadata

Field	Value
Publication number	US-8998397-B2
Application number	US-201213530504-A
Country	US
Kind code	B2
Filing date	Jun 22, 2012
Priority date	Jul 27, 2011
Publication date	Apr 7, 2015
Grant date	Apr 7, 2015

Abstract

The invention provides an ink that inhibits lowering of ejection stability caused by a precipitate derived from a self-dispersible type monoazo pigment and also inhibits deterioration of a liquid contact surface of a heater portion of a recording head. The ink is an ink for ink jet recording system employing an thermal energy, containing a monoazo pigment, a resin and a surfactant represented by the following formula (1). A proportion of a molecular weight of an ethylene oxide group moiety occupying the surfactant is 10% or more and 85% or less, the monoazo pigment is a self-dispersible pigment to the particle surface of which at least one hydrophilic group selected from the group consisting of —COOM, —SO 3 M, —PO 3 HM and —PO 3 M 2 is bonded directly or through another atomic group, and the acid value of the resin is 240 mg KOH/g or less.

First claim

What is claimed is:

1. An ink for use in an ink jet recording system in which ink is ejected from a recording head by an action of thermal energy, the ink comprising a monoazo pigment, a resin, and a surfactant represented by the following formula (1):

wherein n is 1.0 or more, and m is 1.0 or more,
a proportion of a molecular weight of an ethylene oxide group moiety occupying the surfactant is 10% or more and 85% or less,
the monoazo pigment is a self-dispersible pigment to a particle surface of which at least one hydrophilic group selected from the group consisting of —COOM, —SO 3 M, —PO 3 HM, and —PO 3 M 2 (M in the formula is a hydrogen atom, alkali metal, ammonium or organic ammonium) is bonded directly or through another atomic group, and a kind of the monoazo pigment is C.I. Pigment Yellow 74, and
an acid value of the resin is 240 mg KOH/g or less.

2. The ink according to claim 1 , wherein the monoazo pigment is a self-dispersible pigment to the particle surface of which at least one hydrophilic group selected from the group consisting of —COOM, —SO 3 M, —PO 3 HM, and —PO 3 M 2 (M in the formula is a hydrogen atom, alkali metal, ammonium or organic ammonium) is bonded through at least one other atomic group selected from the group consisting of an alkylene group, an arylene group, an amide group, a sulfonyl group, an amino group, a carbonyl group, an ester group, and an ether group.

3. The ink according to claim 1 , wherein a content (% by mass) of the resin in the ink is 0.25 times or more and 1.0 times or less in terms of mass ratio as much as the content (% by mass) of the monoazo pigment.

4. The ink according to claim 1 , wherein the acid value of the resin is 170 mg KOH/g or less.

5. The ink according to claim 1 , wherein m in the formula (1) is 10.0 or more and 60.0 or less.

6. The ink according to claim 1 , wherein a content (% by mass) of the surfactant in the ink is 0.05 times or more and 0.5 times or less in terms of mass ratio as much as the content (% by mass) of the monoazo pigment.

7. The ink according to claim 1 , wherein the proportion of the molecular weight of the ethylene oxide group moiety occupying the surfactant is 41% or more and 85% or less.

8. The ink according to claim 1 , wherein the proportion of a molecular weight of an ethylene oxide group moiety occupying the surfactant is 57% or more and 85% or less.

9. An ink cartridge comprising an ink and an ink storage portion storing the ink, wherein the ink is the ink according to claim 1 .

10. An ink jet recording method comprising ejecting an ink from a recording head of an ink jet system by an action of thermal energy to record an image on a recording medium, wherein the ink is the ink according to claim 1 .

11. The ink according to claim 1 , wherein the acid value of the resin is 100 mg KOH/g or more.

12. The ink according to claim 1 , wherein the content (% by mass) of the resin in the ink is 1.0% by mass or more and 5.0% by mass or less.

13. The ink according to claim 1 , wherein the content (% by mass) of the monoazo pigment in the ink is 2.5% by mass or more and 10.0% by mass or less.

14. The ink according to claim 1 , wherein the content (% by mass) of the surfactant represented by the formula (1) is 0.05% by mass or more and 5.0% by mass or less.

15. The ink according to claim 1 , wherein the surfactant represented by the formula (1) has a block of the ethylene oxide group moiety bonded to both ends of the propylene oxide group.

16. The ink according to claim 1 , wherein the n in the surfactant represented by the formula (1) is 7.9 or more and 450.0 or less.

17. The ink according to claim 1 , wherein the m in the surfactant represented by the formula (1) is 10.0 or more and 60.0 or less.

Assignees

• Mori Yasuhito
• Yamashita Tomohiro
• Canon Kk

Inventors

• Mori Yasuhito
• Yamashita Tomohiro

Classifications

• C09D11/38 Primary

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

• C09D11/322

  Pigment inks · CPC title

• B41J2/2107

  characterised by the ink properties (supplying ink in a solid state B41J2/17593) · CPC title