Ink, ink container, image forming method, image forming apparatus, and image formed matter

Patent metadata

Field	Value
Publication number	US-2016333208-A1
Application number	US-201615149440-A
Country	US
Kind code	A1
Filing date	May 9, 2016
Priority date	May 14, 2015
Publication date	Nov 17, 2016
Grant date	—

Abstract

Provided is an ink containing a colorant, an organic solvent, and water, wherein the ink contains as the organic solvent, at least one kind of an organic solvent having a solubility parameter of greater than or equal to 9 but less than 11.8, wherein a content of the organic solvent having a solubility parameter of greater than or equal to 9 but less than 11.8 is greater than or equal to 20% by mass of a total amount of the ink, wherein a dynamic surface tension A of the ink at 25° C. at a surface lifetime, measured by a maximum foaming pressure method, of 15 msec is less than or equal to 34.0 mN/m, and wherein the dynamic surface tension A and a static surface tension B of the ink at 25° C. satisfy a formula of 10.0%≦[(A−B)/(A+B)]×100≦19.0%.

First claim

What is claimed is:

1 . An ink comprising:
a colorant; an organic solvent; and water, wherein the ink comprises as the organic solvent, at least one kind of an organic solvent having a solubility parameter of greater than or equal to 9 but less than 11.8, wherein a content of the organic solvent having a solubility parameter of greater than or equal to 9 but less than 11.8 is greater than or equal to 20% by mass of a total amount of the ink, wherein a dynamic surface tension A of the ink at 25° C. at a surface lifetime, measured by a maximum foaming pressure method, of 15 msec is less than or equal to 34.0 mN/m, and wherein the dynamic surface tension A and a static surface tension B of the ink at 25° C. satisfy a formula of 10.0%≦[(A−B)/(A+B)]×100≦19.0%.

2 . The ink according to claim 1 ,
wherein the dynamic surface tension A of the ink at 25° C. at a surface lifetime, measured by a maximum foaming pressure method, of 15 msec is less than or equal to 30.0 mN/m, and wherein the dynamic surface tension A and the static surface tension B of the ink at 25° C. satisfy a formula of 12.0%≦[(A−B)/(A+B)]×100≦17.0%.

3 . The ink according to claim 1 ,
wherein the static surface tension B of the ink at 25° C. is greater than or equal to 20.0 mN/m but less than or equal to 30.0 mN/m.

4 . The ink according to claim 1 ,
wherein the organic solvent having a solubility parameter of greater than or equal to 9 but less than 11.8 comprises at least one kind selected from the group consisting of compounds represented by general formulae (I) and (II) below,

where in the general formula (I), R′ represents an alkyl group that comprises 4 through 6 carbon atoms,

where in the general formula (II), R″ represents an alkyl group that comprises 1 or 2 carbon atoms.

5 . The ink according to claim 1 ,
wherein the organic solvent is free of a polyvalent alcohol having an equilibrium water content of greater than or equal to 30% at a temperature of 23° C. and a relative humidity of 80%.

6 . The ink according to claim 1 , further comprising a surfactant.

7 . The ink according to claim 6 ,
wherein the surfactant comprises a polyether-modified siloxane compound.

8 . The ink according to claim 7 ,
wherein the polyether-modified siloxane compound comprises at least one kind selected from the group consisting of compounds represented by general formulae (III) to (VI) below,

where in the general formula (III), m represents an integer in a range of from 0 through 23, n represents an integer in a range of from 1 through 10, a represents an integer in a range of from 1 through 23, b represents an integer in a range of from 0 through 23, and R represents a hydrogen atom or an alkyl group that comprises 1 through 4 carbon atoms,

where in the general formula (IV), m represents an integer in a range of from 1 through 8, c and d represent an integer in a range of from 1 through 10, and R 2 and R 3 represent a hydrogen atom or an alkyl group that comprises 1 through 4 carbon atoms,

where in the general formula (V), e represents an integer in a range of from 1 through 8 and R 4 represents a hydrogen atom or an alkyl group that comprises 1 through 4 carbon atoms,

where in the general formula (VI), f represents an integer in a range of from 1 through 8 and R 5 represents a polyether group represented by general formula (A) below,

where in the general formula (A), g represents an integer in a range of from 0 through 23, h represents an integer in a range of from 0 through 23, where g and h do not take 0 at a same time, and R 6 represents a hydrogen atom or an alkyl group that comprises 1 through 4 carbon atoms.

9 . The ink according to claim 7 ,
wherein a content of the polyether-modified siloxane compound in the ink is greater than or equal to 0.001% by mass but less than or equal to 5% by mass.

10 . The ink according to claim 1 ,
wherein the colorant comprises a water-dispersible pigment.

11 . The ink according to claim 10 ,
wherein the water-dispersible pigment comprises a hydrophilic functional group on a surface, and the hydrophilic functional group comprises a quaternary ammonium salt.

12 . The ink according to claim 10 ,
wherein the water-dispersible pigment comprises a reformed pigment reformed with at least one of a geminal bisphosphonic acid group and a geminal bisphosphonic acid salt group.

13 . The ink according to claim 10 ,
wherein the water-dispersible pigment comprises at least one kind selected from the group consisting of black pigments, cyan pigments, magenta pigments, and yellow pigments.

14 . The ink according to claim 1 ,
wherein the colorant comprises one selected from the group consisting of carbon black pigments, phthalocyanine pigments, quinacridone pigments, monoazo pigments, and disazo pigments, and wherein a gamut cover rate reproduced by the ink is greater than or equal to 90% of a gamut cover rate defined in Japan Color 2011 coat paper.

15 . The ink according to claim 1 , further comprising
a water-dispersible resin.

16 . The ink according to claim 1 ,
wherein the ink is intended for either inkjet recording or spray painting.

17 . An ink container comprising:
an ink; and a container storing the ink, wherein the ink comprises: a colorant; an organic solvent; and water, wherein the ink comprises as the organic solvent, at least one kind of an organic solvent having a solubility parameter of greater than or equal to 9 but less than 11.8, wherein a content of the organic solvent having a solubility parameter of greater than or equal to 9 but less than 11.8 is greater than or equal to 20% by mass of a total amount of the ink, wherein a dynamic surface tension A of the ink at 25° C. at a surface lifetime, measured by a maximum foaming pressure method, of 15 msec is less than or equal to 34.0 mN/m, and wherein the dynamic surface tension A and a static surface tension B of the ink at 25° C. satisfy a formula of 10.0%≦[(A−B)/(A+B)]×100≦19.0%.

18 . An image forming method comprising
applying at least one stimulus selected from the group consisting of heat, pressure, vibration, and light to an ink to fly the ink and record an image, wherein the ink comprises: a colorant; an organic solvent; and water, wherein the ink comprises as the organic solvent, at least one kind of an organic solvent having a solubility parameter of greater than or equal to 9 but less than 11.8, wherein a content of the organic solvent having a solubility parameter of greater than or equal to 9 but less than 11.8 is greater than or equal to 20% by mass of a total amount of the ink, wherein a dynamic surface tension A of the ink at 25° C. at a surface lifetime, measured by a maximum foaming pressure method, of 15 msec is less than

Assignees

• Goto Hiroshi
• Ishikawa Masahiko

Inventors

• Gotou Hiroshi
• Ishikawa Masahiko

Classifications

• C09D11/38

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

• C09D11/322 Primary

  Pigment inks · CPC title

• C09D11/033

  characterised by the solvent · CPC title

• B41J2/01

  Ink jet · CPC title

• C09D11/037

  characterised by the pigment · CPC title