Low toxicity ink formulations with improved printhead lifetime

Patent metadata

Field	Value
Publication number	US-10696855-B2
Application number	US-201815933284-A
Country	US
Kind code	B2
Filing date	Mar 22, 2018
Priority date	Apr 13, 2017
Publication date	Jun 30, 2020
Grant date	Jun 30, 2020

Abstract

An inkjet ink includes: (i) a disazo dye of formula (I):

(ii) 1,3-propanediol; (iii) a glycol compound selected from the group consisting of: triethylene glycol and tetraethylene glycol; and (iv) water. The ink has low toxicity and is preferably absent ethylene glycol and sulfolane.

First claim

The invention claimed is:

1. An inkjet ink comprising:
(i) a disazo dye of formula (I):

wherein:
A is a C6-14 aryl group having 0, 1, 2, 3, 4 or 5 substituents selected from the group consisting of: —SO3M, nitro, carboxyl, halogen, hydroxyl, amino, C1-4 alkylamino, C1-4 alkoxy, C1-4 alkyl, C1-4 haloalkyl, cyano, sulfonamide, carbamoyl, C1-4 alkylamido and C1-4 alkoxycarbonyl;
B is a C6-14 aryl group having 0, 1, 2, 3, 4 or 5 substituents selected from the group consisting of: —SO3M, nitro, carboxyl, halogen, hydroxyl, amino, C1-4 alkylamino, C1-4 alkoxy, C1-4 alkyl, C1-4 haloalkyl, cyano, sulfonamide, carbamoyl, C1-4 alkylamido and C1-4 alkoxycarbonyl;
each M is independently selected from the group consisting of: hydrogen, lithium, sodium, potassium, ammonium and quaternary ammonium; and the dye of formula (I) comprises at least 3 groups of formula —SO3M;
(ii) 1,3-propanediol;
(iii) a glycol compound selected from the group consisting of: triethylene glycol and tetraethylene glycol; and
(iv) water,
wherein an amount of 1,3-propanediol or the glycol compound is greater than an amount of any other co-solvent in the ink.

2. The inkjet ink of claim 1 , wherein the ink is absent any co-solvents selected from the group consisting of: ethylene glycol and sulfolane.

3. The inkjet ink of claim 1 , which is absent any co-solvents having a GHS classification of GHS08.

4. The inkjet ink of claim 1 , wherein an amount of glycol compound exceeds an amount of 1,3-propanediol.

5. The inkjet ink of claim 1 , wherein a ratio of the glycol compound to 1,3-propanediol is in the range of 1:1 to 2:1.

6. The inkjet ink of claim 1 , wherein 1,3-propanediol is present in an amount ranging from 3 to 25 wt. %.

7. The inkjet ink of claim 1 , wherein the glycol compound is present in an amount ranging from 1 to 20 wt. %.

8. The inkjet ink of claim 1 , further comprising glycerol.

9. The inkjet ink of claim 1 , further comprising a non-ionic surfactant.

10. The inkjet ink of claim 1 , wherein M is sodium.

11. The inkjet ink of claim 1 , wherein A is a phenyl or naphthyl group having 1, 2 or 3 substituents selected from the group consisting of: —SO3M, nitro, carboxyl, halogen, hydroxyl, amino, C1-4 alkoxy and C1-4 alkyl; and B is a phenyl or naphthyl group having 1, 2 or 3 substituents selected from the group consisting of: —SO3M, nitro, carboxyl, halogen, hydroxyl, amino, C1-4 alkoxy and C1-4 alkyl.

12. A method of improving a lifetime of an inkjet printhead, the method comprising the steps of:
supplying an ink according to claim 1 to nozzle chambers of the printhead, each nozzle chamber having an associated actuator in contact with the ink; and
actuating one or more of the actuators to eject ink from the printhead.

13. The method of claim 12 , wherein each actuator comprises a resistive heater element.

14. The method of claim 13 , wherein the heater element is uncoated.

15. The method of claim 14 , wherein the heater element is comprised of a material selected from the group consisting of:
a titanium alloy;

titanium nitride; and
a nitride of a titanium alloy.

16. The method of claim 15 , wherein the printhead has a lifetime of at least 100 million ejections.

Assignees

• Memjet Technology Ltd

Inventors

• Prashar Jognandan
• Blake Iain
• Shepard Michele

Classifications

• B41J2/14112

  Resistive element · CPC title

• C09D11/38

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

• B41J2/1404

  Geometrical characteristics · CPC title

• B41J2002/14475

  characterised by nozzle shapes or number of orifices per chamber · CPC title

• C09B31/025

  containing acid groups, e.g. -COOH, -SO3H, -PO3H2, -OSO3H, -OPO2H2; Salts thereof · CPC title