Inkjet inks containing crosslinked polyurethanes
View Patent ↗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 textiles.
1. An inkjet ink composition comprising an aqueous vehicle, a colorant and a crosslinked polyurethane dispersoid binder, wherein the weight ratio of crosslinked polyurethane dispersoid binder to colorant is at least about 1.0, and wherein the colorant is a pigment and wherein the crosslinking in the crosslinked polyurethane binder is greater than about 1 weight % and less than about 50 weight % as measured by the THF insoluble test,
wherein the crosslinking of the crosslinked polyurethane dispersoid binder is substantially completed before said binder is combined with other inkjet ink components to prepare the aqueous inkjet composition.
2. The inkjet ink composition of claim 1 , wherein the ink comprises from about 0.1 to about 30% by weight of the colorant, based on the total weight of the ink.
3. The inkjet ink composition of claim 1 , wherein the ink comprises more than about 1% to about 30% by weight of the crosslinked polyurethane dispersoid binder, based on the total weight of the ink.
4. The inkjet ink composition of claim 1 , wherein the ink comprises from about 0.1 to about 30% by weight of the colorant, and more than about 1% to about 30% by weight of the crosslinked polyurethane dispersoid binder, based on the total weight of the ink; and the crosslinking in the crosslinked polyurethane is greater than about 1% and less than about 50% as measured by a THF insolubles test.
5. 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.
6. The inkjet ink composition of claim 1 , wherein the crosslinked polyurethane binder has incorporated therein hydrophilic functionality to the extent required to maintain a stable dispersion of the polymer in the aqueous vehicle.
7. 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, a colorant and a crosslinked polyurethane dispersoid binder, wherein the weight ratio of crosslinked polyurethane to colorant is at least about 1.0 and the crosslinking in the crosslinked polyurethane dispersoid binder is greater than about 1 weight % and less than about 50 weight % as measured by a THF insoluble test, and wherein the colorant is a pigment and wherein the crosslinking of the crosslinked polyurethane dispersoid binder is substantially completed before said binder is combined with other inkjet ink components to prepare the aqueous inkjet composition.
8. The inkjet ink set of claim 7 , wherein the inkjet ink composition comprises from about 0.1 to about 30% by weight of the colorant, and more than about 1% to about 30% by weight of the crosslinked polyurethane dispersoid binder, based on the total weight of the ink; and the crosslinking in the crosslinked polyurethane dispersoid binder is greater than about 1% and less than about 50 weight % as measured by a THF insoluble test.
9. The inkjet ink set of claim 8 , wherein the inkjet ink composition has 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.
10. The inkjet ink set of claim 7 , 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.
11. The inkjet ink set of claim 7 , wherein ink set comprises:
(a) a first colored ink comprising a first aqueous vehicle, a first colorant and a first crosslinked polyurethane dispersoid binder, wherein the weight ratio of the second polyurethane dispersoid binder to second colorant is at least about 1.0, and wherein the colorant is a pigment;
(b) a second colored ink comprising a second aqueous vehicle, a second colorant and a second crosslinked polyurethane dispersoid binder, wherein the second colorant is soluble or dispersible in the second aqueous vehicle, and wherein the weight ratio of the second polyurethane dispersoid to second colorant is at least about 1.0; and
(c) a third colored ink comprising a third aqueous vehicle, a third colorant and a third crosslinked polyurethane dispersoid binder, wherein the weight ratio of the third polyurethane dispersoid binder to third colorant is at least about 1.0, and wherein the colorant is a pigment.
12. The inkjet ink set of claim 11 , 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.
13. The inkjet ink set of claim 11 , further comprising (d) a fourth colored ink comprising a fourth aqueous vehicle, a fourth colorant and a fourth crosslinked polyurethane dispersoid binder, wherein the weight ratio of the fourth polyurethane dispersoid binder to fourth colorant is at least about 1.0, and wherein the colorant is a pigment.
14. The inkjet ink set of claim 13 , wherein the fourth colored ink is a black ink.
15. 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 with a substrate to be printed;
(c) loading the printer with an inkjet ink composition comprising an aqueous vehicle, a colorant and a crosslinked polyurethane dispersoid binder, wherein the colorant is a pigment, and wherein the weight ratio of crosslinked polyurethane binder to pigment is at least about 1.0; the crosslinking in the crosslinked polyurethane dispersoid binder is greater than about 1 weight % and less than about 50 weight % as measured by the THF insoluble test and said crosslinking is substantially completed before said binder is combined with other inkjet ink components; and
(d) printing onto the substrate using the ink in response to the digital data signals.
16. The method of claim 15 , 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, a colorant and a crosslinked polyurethane dispersoid binder, wherein the weight ratio of crosslinked polyurethane dispersoid binder to colorant is at least about 1.0; wherein the crosslinking of the crosslinked polyurethane dispersoid binder is substantially completed before said binder is combined with other inkjet ink components; wherein the colorant is a pigment and wherein the printing onto the substrate uses the inkjet ink set.
17. The method of claim 15 , wherein the substrate is a textile.
18. The method of claim 17 , wherein the printed substrate is post treated with a combination of heat and pressure.
19. The method of claim 17 , wherein the printed textile has a wash fastness of at least 2.0 and a stain rating of at least 3.3 (as measured in accordance with AATCC Test Method 61-1996 as the 2A test).
20. An inkjet printed textile inkjet printed with a pigmented inkjet ink composition, said composition comprising an aqueous vehicle, a colorant and a crosslinked polyurethane dispersoid binder, wherein the weight ratio of crosslinked polyurethane dispersoid binder to colorant is at least about 1.0, and wherein the colorant is a pigment and wherein the crosslinking in the crosslinked polyurethane binder is greater than about 1 weight % and less than about 50 weight % as measured by the THF insoluble test and said crosslinking is substantially completed before said binder is combined with other inkjet ink components, and said printed textile having a wash fastness of at least 2.0 and a stain rating of at least 3.0 (as measured in accordance with AATCC Test Method 61-1996 as the 2A test).
21. The inkjet ink composition of claim 1 wherein the pigment is a disperse dye.
22. The inkjet ink set of claim 7 wherein the pigment is a disperse dye.