Water-Based Ink for Ink-Jet Recording and Method for Evaluating Water-Based Ink for Ink-Jet Recording

Patent metadata

Field	Value
Publication number	US-2016289474-A1
Application number	US-201514867651-A
Country	US
Kind code	A1
Filing date	Sep 28, 2015
Priority date	Mar 31, 2015
Publication date	Oct 6, 2016
Grant date	—

Abstract

There is provided a water-based ink for ink jetrecording containing a pigment; a surfactant; and water, wherein a slope value of the water-based ink at an evaporation rate of 0% is not more than 15%/hour; and a slope value of the water-based ink at an evaporation rate of 30% is not less than 9%/hour, the slope value of the water-based ink being measured by a centrifugal transmission sedimentation method.

First claim

What is claimed is:

1 . A water-based ink for ink-jet recording comprising:
a pigment; a surfactant; and water, wherein a slope value of the water-based ink at an evaporation rate of 0% is not more than 15%/hour; and a slope value of the water-based ink at an evaporation rate of 30% is not less than 9%/hour, the slope value of the water-based ink being measured by a centrifugal transmission sedimentation method.

2 . The water-based ink for ink-jet recording according to claim 1 , wherein the pigment is a carbon black.

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

4 . The water-based ink for ink-jet recording according to claim 1 , wherein the pigment is a self-dispersible carbon black modified by a carboxyl group.

5 . The water-based ink for ink-jet recording according to claim 1 , wherein a content of the pigment in the water-based ink is not less than 8% by weight.

6 . The water-based ink for ink-jet recording according to claim 1 , wherein a content of the pigment in the water-based ink is in a range of 8% by weight to 10% by weight.

7 . The water-based ink for ink-jet recording according to claim 1 , wherein an average particle size of the pigment is in a range of 140 nm to 160 nm.

8 . The water-based ink for ink-jet recording according to claim 1 , wherein the pigment is a carbon black of which an average particle size is in a range of 140 nm to 160 nm and a content of the carbon black in the water-based ink is in a range of 8% by weight to 10% by weight.

9 . The water-based ink for ink-jet recording according to claim 1 , wherein the surfactant is a nonionic surfactant, and a content of the nonionic surfactant in the water-based ink is in a range of 0.1% by weight to 0.5% by weight.

10 . The water-based ink for ink-jet recording according to claim 1 , wherein the surfactant is a nonionic surfactant, and a content of the nonionic surfactant in the water-based ink is in a range of 0.2% by weight to 0.5% by weight.

11 . The water-based ink for ink-jet recording according to claim 1 , wherein the surfactant is an acetylenic glycol-based nonionic surfactant represented by the following formula (1):

in the formula (1), “m” and “n” are identical to each other or different from each other, and are numbers satisfying: m+n=1 to 15; and
R 1 , R 2 , R 3 and R 4 are identical to one another or different from one another, and each of R 1 , R 2 , R 3 and R 4 is a straight-chain or branched-chain alkyl group of which carbon atom number is 1 to 5.

12 . The water-based ink for ink-jet recording according to claim 11 , wherein in the formula (1), the “m” and “n” are numbers satisfying: m+n=1 to 6.

13 . The water-based ink for ink-jet recording according to claim 11 , wherein the surfactant contains the acetylenic glycol-based nonionic surfactant represented by the formula (1) and an anionic surfactant; and
a weight ratio (A/N) of a blending amount (A) of the anionic surfactant to a blending amount (N) of the acetylenic glycol-based nonionic surfactant represented by the formula (1) in the water-based ink is in a range of 0.2 to 0.8.

14 . The water-based ink for ink-jet recording according to claim 11 , wherein a weight ratio (N/P) of a blending amount (N) of the acetylenic glycol-based nonionic surfactant represented by the formula (1) to a blending amount (P) of the pigment in the water-based ink is in a range of 1.2/100 to 8.4/100.

15 . The water-based ink for ink-jet recording according to claim 11 , wherein HLB of the acetylenic glycol-based nonionic surfactant represented by the formula (1) is in a range of 8 to 12.

16 . The water-based ink for ink-jet recording according to claim 1 , further comprising glycerol, and a content of the glycerol in the water-based ink is in a range of 15% by weight to 25% by weight.

17 . The water-based ink for ink-jet recording according to claim 1 , further comprising glycerol;
wherein a weight ratio (G/P) of a blending amount (G) of the glycerol to a blending amount (P) of the pigment in the water-based ink is in a range of 1.0 to 4.0.

18 . The water-based ink for ink-jet recording according to claim 1 , wherein the slope value of the water-based ink at the evaporation rate of 0% is in a range of 5%/hour to 15%/hour; and
the slope value of the water-based ink at the evaporation rate of 30% is in a range of 9%/hour to 18%/hour.

19 . A method for evaluating a water-based ink for ink jetrecording containing a pigment, a surfactant and water, the method comprising:
performing a first evaluation of aggregation for measuring a slope value of the water-based ink at an evaporation rate of 0%, by a centrifugal transmittance sedimentation method; and performing a second evaluation of aggregation for measuring a slope value of the water-based ink at an evaporation rate of 30%, by the centrifugal transmittance sedimentation method.

20 . The method for evaluating the water-based ink for ink-jet recording according to claim 19 , wherein dispersion stability of the pigment before recording is evaluated by the first evaluation of the aggregation; and
aggregating property of the pigment during the recording is evaluated by the second evaluation of the aggregation.

Assignees

• Brother Ind Ltd

Inventors

• Tsuzaka Yuka
• Maeda Mitsunori

Classifications

• C09D11/324 Primary

  containing carbon black · CPC title

• G01N21/59

  Transmissivity (G01N21/25 takes precedence) · CPC title

• G01N1/4022

  by thermal techniques; Phase changes · CPC title

• C09D11/38

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

• G01N2001/4027

  evaporation leaving a concentrated sample · CPC title