Orthogonal non-Newtonian inkjet inks

Patent metadata

Field	Value
Publication number	US-9631104-B2
Application number	US-201415119026-A
Country	US
Kind code	B2
Filing date	Mar 6, 2014
Priority date	Mar 6, 2014
Publication date	Apr 25, 2017
Grant date	Apr 25, 2017

Abstract

The present disclosure provides orthogonal non-Newtonian inkjet inks and related methods. In one example, an orthogonal non-Newtonian inkjet ink can comprise a low molecular weight organic gelator in an amount ranging from 0.1% to 10% by weight; a metal oxide in an amount ranging from 0.1% to 10% by weight; a first salt in an amount of 0.05% to 20% by weight; a second salt in an amount of 0.05% to 20% by weight; and an organic solvent. The metal oxide and the first salt form a first structured network and the low molecular weight organic gelator and the second salt form a second structured network.

First claim

What is claimed is:

1. An orthogonal non-Newtonian inkjet ink, comprising:
a metal oxide in an amount ranging from 0.1% to 10% by weight based on the total weight of the orthogonal non-Newtonian inkjet ink;
a low molecular weight organic gelator in an amount ranging from 0.1% to 10% by weight based on the total weight of the orthogonal non-Newtonian inkjet ink;
a first salt in an amount of 0.05% to 20% by weight based on the total weight of the orthogonal non-Newtonian inkjet ink;
a second salt in an amount of 0.05% to 20% by weight based on the total weight of the orthogonal non-Newtonian inkjet ink; and
an organic solvent,
wherein the metal oxide and the first salt form a first structured network and the low molecular weight organic gelator and the second salt form a second structured network.

2. The orthogonal non-Newtonian inkjet ink of claim 1 , wherein
the orthogonal non-Newtonian inkjet ink has a dynamic viscosity ranging from 25 cps to 10,000 cps at a shear rate of 5 s −1 and a dynamic viscosity ranging from 1 cps to 50 cps at a shear rate of 10,000 s −1 , measured at a temperature of 25° C.; or
the orthogonal non-Newtonian inkjet ink has a viscosity ranging from 25 cps to 10,000 cps at a temperature of 25° C. and a viscosity ranging from 1 cps to 50 cps at a temperature of 50° C.

3. The orthogonal non-Newtonian inkjet ink of claim 1 , wherein
the metal oxide is selected from the group consisting of aluminum oxide, silicon dioxide, zinc oxide, iron oxide, titanium dioxide, indium oxide, zirconium oxide, and mixtures thereof;
the low molecular weight organic gelator is selected from the group consisting of amino acids, peptides, cyclic peptides, amino acids having a protecting group, peptides having a protecting group, cyclic peptides having a protecting group, and mixtures thereof; and
the first salt and the second salt is independently includes i) a carboxylic acid or a cation selected from the group consisting of sodium, lithium, potassium, magnesium, and calcium; and ii) an anion selected from the group consisting of nitrate, chloride, sulfate, and acetate.

4. The orthogonal non-Newtonian inkjet ink of claim 1 , wherein the first and second structured networks are free of polymer.

5. The orthogonal non-Newtonian inkjet ink of claim 1 , wherein the organic solvent is network participating solvent selected from the group consisting of ethylhydroxypropanediol (EHPD), glycerol, 1,5 pentanediol, ethylene glycol, triethylene glycol, and mixtures thereof; or the organic solvent is a network non-participating solvent selected from the group consisting of 2-pyrrolidinone, 1,2 pentanediol, 2-methyl-1,3-propanediol (MPDIOL), 1,2 hexanediol, and mixtures thereof.

6. The orthogonal non-Newtonian inkjet ink of claim 1 , wherein the organic solvent comprises only network participating solvent, or comprises a mixture of network participating solvent and network non-participating solvent.

7. The orthogonal non-Newtonian inkjet ink of claim 1 , wherein the first salt and the second salt are the same.

8. The orthogonal non-Newtonian inkjet ink of claim 1 , wherein the metal oxide is present in an amount ranging from 1% to 5% by weight based on the total weight of the orthogonal non-Newtonian inkjet ink, the low molecular weight organic gelator is present in an amount ranging from 1% to 5% by weight based on the total weight of the orthogonal non-Newtonian inkjet ink, the first salt is present in an amount ranging from 0.05% to 4% by weight based on the total weight of the orthogonal non-Newtonian inkjet ink, and the second salt is present in an amount ranging from 0.5% to 10% by weight based on the total weight of the orthogonal non-Newtonian inkjet ink.

9. The orthogonal non-Newtonian inkjet ink of claim 1 , wherein the metal oxide and the first salt are present at a metal oxide to salt ratio ranging from 0.5:1 to 5:1 by weight, the metal oxide having an average particle size ranging from 5 to 50 nm, and the low molecular weight organic gelator and the second salt are present at an organic gelator to salt ratio ranging from 1:1 to 1:5 by weight.

10. The orthogonal non-Newtonian inkjet ink of claim 1 , further comprising a colorant, wherein the optical density of the non-Newtonian inkjet ink is increased by at least 5% over a comparative inkjet ink printed from the same inkjet printer on the same recording media with the same print coverage.

11. The orthogonal non-Newtonian inkjet ink of claim 1 , wherein the dynamic viscosity is 50 cps to 1000 cps at shear rate of 100 s −1 and a temperature of 25° C., and is 1 cps to 25 cps at a shear rate of 10,000 s −1 and a temperature of 25° C.

12. A method of printing a orthogonal non-Newtonian inkjet ink, comprising:
shearing the orthogonal non-Newtonian inkjet ink of claim 1 within a printhead of an inkjet printing apparatus at a shear rate of at least 10,000 s −1 to provide a dynamic viscosity ranging from 1 cps to 50 cps, or heating the orthogonal non-Newtonian inkjet ink to a temperature of at least 50° C. to provide the viscosity ranging from 1 cps to 50 cps; and
ejecting droplets of the orthogonal non-Newtonian inkjet ink.

13. A method of manufacturing an orthogonal non-Newtonian inkjet ink, comprising:
forming a metal oxide dispersion which includes a mixture of metal oxide, water, a first organic solvent, and a first salt;
forming an organic solution which includes a low molecular weight organic gelator, water, a second organic solvent, and a second salt; and
mixing the metal oxide dispersion and the organic solution under a shear rate ranging 5 s −1 to 100 s −1 to form the orthogonal non-Newtonian inkjet ink.

14. The method of claim 13 , further comprising the step of heating the orthogonal non-Newtonian inkjet ink to form a homogenous mass or gel, or heating one or both of the metal oxide dispersion or the organic solution prior to mixing to form a homogenous mass or mass upon mixing.

15. The method of claim 13 , further comprising mixing a colorant therein.

Assignees

• Hewlett Packard Development Co Lp

Inventors

• Adamic Raymond

Classifications

• C09D11/38 Primary

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

• B41J2/01

  Ink jet · CPC title

• C09D11/322

  Pigment inks · CPC title

• C09D11/36

  based on non-aqueous solvents · CPC title