Electrostatic ink compositions

Patent metadata

Field	Value
Publication number	US-9899124-B2
Application number	US-201214416453-A
Country	US
Kind code	B2
Filing date	Jul 23, 2012
Priority date	Jul 23, 2012
Publication date	Feb 20, 2018
Grant date	Feb 20, 2018

Abstract

The present disclosure is drawn to an electrostatic ink composition comprising a resin and an elongate conductive species. Also disclosed herein is a substrate on which is electrostatically printed a conductive trace, wherein the trace comprises a resin and an elongate conductive species. Further disclosed herein is a method of electrophotographic printing an electrostatic ink composition comprising a resin and an elongate conductive species.

First claim

The invention claimed is:

1. An electrostatic ink composition comprising:
chargeable particles comprising a resin and an elongate conductive species, wherein the resin comprises:
a combination of a first co-polymer, a second co-polymer, and a third co-polymer, each of the first co-polymer, the second co-polymer, and the third co-polymer being independently selected from the group consisting of a co-polymer of an alkylene monomer and a methacrylic acid monomer and a co-polymer of an alkylene monomer and an acrylic acid monomer, and the first co-polymer having a first melt viscosity of more than 60,000 poise, the second co-polymer having a second melt viscosity ranging from 15,000 poise to 40,000 poise, and the third co-polymer having a melt viscosity of 15,000 poise or less; and
a fourth co-polymer of an alkylene monomer and a maleic anhydride;
wherein a weight ratio of the combination of the first co-polymer, the second co-polymer, and the third co-polymer to the fourth co-polymer of the alkylene monomer and the maleic anhydride ranges from 10:1 to 1:10.

2. The electrostatic ink composition of claim 1 , wherein the elongate conductive species comprises a species selected from carbon black, graphene and metals.

3. The electrostatic ink composition of claim 1 , wherein the elongate conductive species comprises or is carbon nanotubes.

4. The electrostatic ink composition of claim 1 , wherein the chargeable particles are dispersed in a carrier liquid.

5. The electrostatic ink composition of claim 1 , wherein the electrostatic ink composition comprises a charge director.

6. The electrostatic ink composition of claim 1 , wherein each of the first co-polymer, the second co-polymer and the third co-polymer has a hardness, as measured at 25° C. using ASTM D2240, that is more than a hardness of the fourth co-polymer of the alkylene monomer and maleic anhydride.

7. The electrostatic ink composition of claim 1 , wherein the resin partially or completely encapsulates the elongate conductive species.

8. The electrostatic ink composition of claim 5 , wherein the charge director is selected from the group consisting of metal salts of sulfo-succinates, metal salts of oxyphosphates, metal salts of alkyl-benzenesulfonic acid, metal salts of aromatic carboxylic acids, metal salts of sulfonic acids, lecithin, polyvinylpyrrolidone, oil-soluble petroleum sulfonates, polybutylene succinimides, glyceride salts, and sulfonic acid salts.

9. The electrostatic ink composition of claim 1 , wherein:
the first co-polymer is a polyethylene-methacrylic acid co-polymer;
the second co-polymer is a polyethylene-methacrylic acid co-polymer; and
the third co-polymer is a polyethylene-acrylic acid co-polymer.

10. The electrostatic ink composition of claim 9 , wherein the fourth co-polymer of the alkylene monomer and the maleic anhydride is an ethylene maleic anhydride co-polymer.

11. The electrostatic ink composition of claim 10 , wherein the weight ratio of the combination of the first co-polymer, the second co-polymer, and the third co-polymer to the fourth co-polymer of the alkylene monomer and the maleic anhydride is 2:1.

12. The electrostatic ink composition of claim 1 , wherein a weight ratio of the first co-polymer to the second co-polymer to the third co-polymer is 65:14:14.

13. A substrate on which is electrostatically printed a conductive trace, wherein the trace comprises chargeable particles comprising a resin and an elongate conductive species, wherein the resin comprises:
a combination of a first co-polymer, a second co-polymer, and a third co-polymer, each of the first co-polymer, the second co-polymer, and the third co-polymer being independently selected from the group consisting of a co-polymer of an alkylene monomer and a methacrylic acid monomer and a co-polymer of an alkylene monomer and an acrylic acid monomer, and the first co-polymer having a first melt viscosity of more than 60,000 poise, the second co-polymer having a second melt viscosity ranging from 15,000 poise to 40,000 poise, and the third co-polymer having a melt viscosity of 15,000 poise or less; and
a fourth co-polymer of an alkylene monomer and a maleic anhydride;
wherein a weight ratio of the combination of the first co-polymer, the second co-polymer, and the third co-polymer to the fourth co-polymer of the alkylene monomer and the maleic anhydride ranges from 10:1 to 1:10.

14. The substrate of claim 13 , wherein the elongate conductive species comprises carbon nanotubes.

15. A method of electrophotographic printing an electrostatic ink composition, wherein the electrostatic ink composition comprises chargeable particles comprising a resin and an elongate conductive species, the resin comprising:
a combination of a first co-polymer, a second co-polymer, and a third co-polymer, each of the first co-polymer, the second co-polymer, and the third co-polymer being independently selected from the group consisting of a co-polymer of an alkylene monomer and a methacrylic acid monomer and a co-polymer of an alkylene monomer and an acrylic acid monomer, and the first co-polymer having a first melt viscosity of more than 60,000 poise, the second co-polymer having a second melt viscosity ranging from 15,000 poise to 40,000 poise, and the third co-polymer having a melt viscosity of 15,000 poise or less; and
a fourth co-polymer of an alkylene monomer and a maleic anhydride;
wherein a weight ratio of the combination of the first co-polymer, the second co-polymer, and the third co-polymer to the fourth co-polymer of the alkylene monomer and the maleic anhydride ranges from 10:1 to 1:10; and
the method comprises:
forming a latent electrostatic image on a surface; and
contacting the surface with the electrostatic ink composition, such that at least some of the chargeable particles adhere to the surface to form a developed toner image on the surface, and transferring the toner image to a substrate.

Assignees

• Grinwald Yaron
• Amir Gideon
• Reznikov Rita
• Avigdor Reut
• Gefen Haim
• Bar Haim Gil
• Sandler Mark
• Kella Dror
• Hewlett Packard Indigo Bv

Inventors

• Grinwald Yaron
• Amir Gideon
• Reznikov Rita
• Avigdor Reut
• Gefen Haim
• Bar Haim Gil
• Sandler Mark
• Kella Dror

Classifications

• G03G9/0827

  characterised by their shape, e.g. degree of sphericity · CPC title

• B05D5/12

  to obtain a coating with specific electrical properties · CPC title

• H05K2201/0323

  Carbon · CPC title

• C09D11/037 Primary

  characterised by the pigment · CPC title

• G03G9/08704

  Polyalkenes · CPC title