Inkjet inks containing crosslinked polyurethanes

Patent metadata

Field	Value
Publication number	US-9255207-B2
Application number	US-15763308-A
Country	US
Kind code	B2
Filing date	Jun 12, 2008
Priority date	Jan 21, 2004
Publication date	Feb 9, 2016
Grant date	Feb 9, 2016

Abstract

Inkjet inks are described that have, as a principal component, a crosslinked polyurethane dispersoid binder additive. These inks can be used for printing on different media, and are particularly suitable for printing on paper.

First claim

The invention claimed is:

1. An aqueous inkjet ink composition comprising an aqueous vehicle having stably dispersed therein a pigment and a crosslinked polyurethane dispersoid binder, wherein the ink comprises the crosslinked polyurethane dispersoid binder in an amount of more than about 0.5% to about 30% by weight based on the total weight of the ink, wherein the crosslinking in the crosslinked polyurethane is greater than about 1% and less than about 50% as measured by a THF insolubles test and the crosslinking of the binder is substantially completed before the binder is added to the ink.

2. The inkjet ink composition of claim 1 , wherein the crosslinking in the crosslinked polyurethane dispersoid binder is greater than about 4 weight % and less than about 50 weight % as measured by a THF insoluble test.

3. The inkjet ink composition of claim 1 , having a surface tension in the range of about 20 dyne/cm to about 70 dyne/cm, and a viscosity is in the range of about 1 cP to about 30 cP at 25° C.

4. The inkjet ink composition of claim 1 , wherein the crosslinked polyurethane dispersoid binder has incorporated therein hydrophilic functionality to the extent required to maintain a stable dispersion of the polymer in the aqueous vehicle.

5. The inkjet ink composition of claim 4 , wherein the hydrophilic functionality of the crosslinked polyurethane dispersoid binder is derived from anionic substituents.

6. An aqueous inkjet ink set comprising at least three differently colored inkjet inks, wherein at least one of the inks is an inkjet ink composition comprising an aqueous vehicle having stably dispersed therein a pigment colorant and a crosslinked polyurethane dispersoid binder, wherein the ink comprises the crosslinked polyurethane dispersoid in an amount of more than about 0.5% to about 30% by weight, based on the total weight of the ink, wherein the amount of crosslinking in the crosslinked polyurethane dispersoid binder is greater than about 1% and less than about 50% as measured by a THF insolubles test and the crosslinking of the binder is substantially completed before the binder is added to the ink.

7. The inkjet ink set of claim 6 , wherein the ink set comprises:
(a) a first colored ink comprising a first aqueous vehicle having stably dispersed therein a first pigment colorant and a first crosslinked polyurethane dispersoid binder, wherein the first crosslinked polyurethane dispersoid binder is more than about 0.5% to about 30% by weight based on the total weight of the first ink, and wherein crosslinking in the first crosslinked polyurethane dispersoid hinder is greater than about 1 weight % and less than about 50 weight % as measured by a THF insoluble test and the crosslinking of the binder is substantially completed before the binder is added to the ink;
(b) a second colored ink comprising a second aqueous vehicle having stably dispersed therein a second pigment colorant and a second crosslinked polyurethane dispersoid binder, wherein the second crosslinked polyurethane dispersoid binder is more than about 0.5% to about 30% by weight, based on the total weight of the second ink, and wherein the amount of crosslinking in the second crosslinked polyurethane dispersoid binder is greater than about 1 weight % and less than about 50 weight % as measured by a THF insoluble test and the crosslinking of the hinder is substantially completed before the binder is added to the ink; and
(c) a third colored ink comprising a third aqueous vehicle having stably dispersed therein a third pigment colorant and a third crosslinked polyurethane dispersoid binder, wherein the third crosslinked polyurethane dispersoid binder is more than about 0.5% to about 30% by weight, based on the total weight of the third ink, and wherein the amount of crosslinking in the third crosslinked polyurethane dispersoid binder is greater than about 1 weight % and less than about 50 weight % as measured by a THF insoluble test and the crosslinking of the binder is substantially completed before the binder is added to the ink.

8. The inkjet ink set of claim 7 , wherein the first colored ink is a cyan ink, the second colored ink is a magenta ink and the third colored ink is a yellow ink.

9. The inkjet ink set of claim 7 , further comprising (d) a fourth colored ink comprising a fourth aqueous vehicle having stably dispersed therein a fourth pigment colorant and a fourth crosslinked polyurethane dispersoid binder, wherein the fourth crosslinked polyurethane dispersoid binder is more than about 0.5% to about 30% by weight, based on the total weight of the fourth ink, and wherein the amount of crosslinking in the fourth crosslinked polyurethane dispersoid binder is greater than about 1 weight % and less than about 50 weight % as measured by a THF insoluble test.

10. The inkjet ink set of claim 9 , wherein the first colored ink is a cyan ink, the second colored ink is a magenta ink, the third colored ink is a yellow ink and the fourth colored ink is a black ink.

11. A method for inkjet printing onto a substrate, comprising the steps of:
(a) providing an inkjet printer that is responsive to digital data signals;
(b) loading the printer a substrate to be printed;
(c) loading the printer with an aqueous inkjet ink composition inkjet ink composition comprising an aqueous vehicle having stably dispersed therein a pigment and a crosslinked polyurethane dispersoid binder, wherein the ink comprises the crosslinked polyurethane dispersoid binder in an amount of more than about 0.5% to about 30% by weight, based on the total weight of the ink, wherein the amount of crosslinking in the crosslinked polyurethane dispersoid binder is greater than about 1 weight % and less than about 50 weight % as measured by a THF insolubles test and the crosslinking of the binder is substantially completed before the binder is added to the ink; and
(d) printing onto the substrate using the ink in response to the digital data signals.

12. The method of claim 11 , wherein the printer is loaded with an inkjet ink set comprising at least three differently colored inkjet inks, wherein at least one of the inks is an inkjet ink composition comprising an aqueous vehicle having stably dispersed therein a pigment colorant and a crosslinked polyurethane dispersoid binder, wherein the ink comprises the crosslinked polyurethane dispersoid in an amount of more than about 0.5% to about 30% by weight, based on the total weight of the ink, and wherein the amount of crosslinking in the crosslinked polyurethane dispersoid binder is greater than about 1 weight % and less than about 50 weight % as measured by a THF insolubles test and the crosslinking of the binder is substantially completed before the binder is added to the ink.

13. The method of claim 12 , wherein ink set comprises:
(a) a first colored ink comprising a first aqueous vehicle having stably dispersed therein a first pigment colorant and a first crosslinked polyurethane dispersoid binder, wherein the first crosslinked polyurethane dispersoid binder is more than about 0.5% to about 30% by weight, based on the total weight of the first ink, and wherein the amount of crosslinking in the first crosslinked polyurethane dispersoid binder is greater than about 1 weight % and less than about 50 weight % as measured by a THF insoluble test and the crosslinking of the binder is substantially completed before the binder is added to the ink;
(b) a second colored ink comprising a second aqueous vehicle having stably dispersed therein a second pigment colorant and a second crosslinked polyurethane dispersoid hinder, wherein the second crosslinked polyurethane dispersoid binder is more than about 0.5% to a

Assignees

• Berge Charles T
• Li Xiaoqing
• Du Pont

Inventors

• Berge Charles T
• Li Xiaoqing

Classifications

• B41M5/0088

  by ink-jet printing · CPC title

• B41M5/0023

  Digital printing methods characterised by the inks used (inks per se C09D11/00) · CPC title

• B41M5/0047

  by ink-jet printing · CPC title

• C09D11/322

  Pigment inks · CPC title

• C09D11/40

  Ink-sets specially adapted for multi-colour inkjet printing · CPC title