Thermal ink jet ink compostion
View Patent ↗A solvent-based ink composition for a thermal inkjet printhead includes (a) 55-90 wt. % of an organic solvent including a ketone and a C 1 to C 4 alcohol; and (b) 0.01-10 wt. % of a colorant.
1. A solvent-based ink composition for a thermal inkjet printhead, the ink composition comprising:
(a) 55-90 wt. % of an organic solvent comprising a ketone and a C 1 to C 4 alcohol;
(b) 0.01-10 wt. % of a colorant; and
(c) one or more humectants, wherein the thermal ink jet ink composition is free or substantially free of binder resin, and wherein the ink composition has a decap time of at least 30 seconds when used in the thermal inkjet printhead.
2. The ink composition of claim 1 , wherein the ketone is methyl ethyl ketone.
3. The ink composition of claim 1 , wherein the ketone is cyclohexanone.
4. The ink composition of claim 1 , wherein the C 1 to C 4 alcohol is ethanol.
5. The ink composition of claim 1 , wherein the colorant is a dye or a pigment.
6. The ink composition of claim 1 , further comprising: 0.01-2 wt. % of a surfactant.
7. The ink composition of claim 6 , wherein the surfactant is a nonionic surfactant.
8. The ink composition of claim 6 , wherein the surfactant is non-polymeric.
9. The ink composition of claim 1 , wherein the composition does not comprise any polymers.
10. The ink composition of claim 1 , consisting essentially of the ketone, the C 1 to C 4 alcohol and the colorant.
11. An ink cartridge for a thermal inkjet printhead, the ink cartridge containing the solvent-based ink composition according to claim 1 .
12. The ink cartridge of claim 11 , wherein the ink cartridge comprises the thermal inkjet printhead integrated therewith.
13. A substrate having an ink composition according to claim 1 disposed thereon.
14. The substrate of claim 13 , which is a semi-porous or non-porous substrate.
15. A method of ejecting ink from a thermal inkjet printhead, the method comprising the steps of:
(i) supplying an ink to at least one nozzle chamber of the printhead; and
(ii) actuating a heater element in the nozzle chamber and heating the ink to a temperature sufficient to form a bubble therein, thereby causing the ink to be ejected from a nozzle opening associated with the nozzle chamber,
wherein the ink is a solvent-based ink composition comprising:
(a) 55-90 wt. % of an organic solvent comprising a ketone and a C 1 to C 4 alcohol;
(b) 0.01-10 wt. % of a colorant; and
(c) one or more humectants, wherein the thermal ink let ink composition is free or substantially free of binder resin, and wherein the ink composition has a decap time of at least 30 seconds when used in the thermal inkjet printhead.
16. The method of claim 15 , wherein the ink is ejected onto a non-porous or a semi-porous substrate.
17. The method of claim 16 , wherein the ink adheres to the substrate.
18. The method of claim 16 , wherein the substrate is a plastics substrate.
19. The method of claim 15 , wherein the ketone is methylethylketone.
20. The method of claim 15 , wherein the ketone is cyclohexanone.
21. The method of claim 15 , wherein the C 1 to C 4 alcohol is ethanol.
22. The method of claim 15 , further comprising: 0.001-2 wt. % of a surfactant.
23. The method of claim 15 , wherein the ink composition does not comprise any polymers.
24. The method of claim 15 , wherein the ink composition consists only of the ketone, the C 1 to C 4 alcohol and the colorant.
25. The method of claim 15 , wherein the ink composition consists only of the ketone, the C 1 to C 4 alcohol, the colorant and 0.01-2 wt. % of a surfactant.
26. An inkjet printer comprising:
an ink reservoir containing a respective ink; and
a thermal inkjet printhead in fluid communication with the ink reservoir,
wherein the ink is a solvent-based ink composition comprising:
(a) 55-90 wt. % of an organic solvent comprising a ketone and a C 1 to C 4 alcohol;
(b) 0.01-10 wt. % of a colorant; and
(c) one or more humectants, wherein the thermal ink jet ink composition is free or substantially free of binder resin, and wherein the ink composition has a decap time of at least 30 seconds when used in a thermal inkjet print head.
27. The inkjet printer of claim 26 , wherein the thermal inkjet printhead comprises a plurality of nozzles, each of the plurality of nozzles comprising:
a nozzle chamber containing the ink, the nozzle chamber having a nozzle opening for ejection of the ink; and
a heater element in contact with the ink, the heater element being configured for heating the ink to a temperature sufficient to form a bubble therein and thereby cause ejection of the ink from the nozzle opening.