Liquid electrophotographic ink composition

Patent metadata

Field	Value
Publication number	US-11960241-B2
Application number	US-201917413943-A
Country	US
Kind code	B2
Filing date	Apr 30, 2019
Priority date	Apr 30, 2019
Publication date	Apr 16, 2024
Grant date	Apr 16, 2024

Abstract

A liquid electrophotographic ink composition is disclosed herein. One example of the liquid electrophotographic ink composition includes a resin, a liquid carrier, a pigment chosen from titanium oxide, and a spacer chosen from barium sulfate, calcium carbonate, clay, magnesium silicate and mixtures thereof, in an amount from 5 to 15 wt. % of the total solids of the composition. A method for making a liquid electrophotographic ink composition is also disclosed herein.

First claim

What is claimed is:

1. A liquid electrophotographic ink composition, consisting of:
a resin;
a liquid carrier;
a pigment chosen from titanium oxide;
a spacer selected from the group consisting of barium sulfate, clay, magnesium silicate, and mixtures thereof, the spacer being present in an amount from 5 to 15 wt. % of the total solids of the composition;
optionally, a charge adjuvant selected from the group consisting of aluminum distearate, aluminum tristearate, aluminum dipalmitate, aluminum tripalmitate, and combinations thereof; and
optionally, an additive selected from the group consisting of waxes, surfactants, biocides, organic solvents, viscosity modifiers, pH adjusters, sequestering agents, preservatives, compatibility additives, emulsifiers, and combinations thereof.

2. The liquid electrophotographic ink composition of claim 1 , wherein the resin comprises a polymer selected from the group consisting of alkylene acrylic acid copolymers; alkylene methacrylic acid copolymers; ethylene vinyl acetate copolymers; copolymers of ethylene or propylene, and alkyl ester of methacrylic or acrylic acid; copolymers of ethylene, acrylic or methacrylic acid and alkyl ester of methacrylic or acrylic acid; copolymers of ethylene or propylene and maleic anhydride; polyethylene; polystyrene; isotactic polypropylene; polyesters; polyvinyl toluene; polyamides; styrene/butadiene copolymers; ethylene-acrylic esters-maleic anhydride or glycidyl methacrylate terpolymers; ethylene-acrylic acid ionomers and combinations thereof.

3. The liquid electrophotographic ink composition of claim 1 , wherein the resin comprises a polymer having acidic side groups.

4. The liquid electrophotographic ink composition of claim 1 , wherein the resin comprises a polymer selected from the group consisting of copolymers of alkylene acrylic acid copolymers; alkylene methacrylic acid copolymers and combination thereof.

5. The liquid electrophotographic ink composition of claim 1 , wherein the spacer is barium sulfate.

6. The liquid electrophotographic ink composition of claim 5 , wherein barium sulfate is in the form of particle having a median particle size (d50) ranging from 500 nm to 900 nm.

7. The liquid electrophotographic ink composition of claim 5 , wherein barium sulfate is in the form of particle having a median particle size (d50) ranging from 650 nm to 750 nm.

8. The liquid electrophotographic ink composition of claim 5 , wherein barium sulfate is in the form of particle having a median particle size (d50) ranging from 10 nm to 70 nm.

9. The liquid electrophotographic ink composition of claim 1 , wherein the spacer is present in an amount from 5 to 10 wt. % of the total solids of the composition.

10. The liquid electrophotographic ink composition of claim 1 , wherein the pigment chosen from titanium oxide is present in an amount of 50 to 65 wt. % of the total solids of the composition.

11. A method of making the liquid electrophotographic ink composition of claim 1 , the method comprising:
heating the resin in the liquid carrier to dissolve the resin;
mixing the pigment and the spacer;
adding the pigment and the spacer in the liquid carrier;
controlling cooling of the liquid carrier to effect precipitation of the resin;
grinding the liquid carrier, the resin, the pigment and the spacer to form the liquid electrophotographic ink composition.

12. The method of claim 11 , wherein the liquid carrier is heated to at least 100° C. to dissolve the resin.

13. The method of claim 11 , wherein the liquid carrier is or comprises an isoparaffinic liquid carrier.

14. The method of claim 11 , wherein the spacer is chosen from barium sulfate.

15. A method of printing on a plastic substrate, the method comprising:
providing the liquid electrophotographic ink composition of claim 1 ;
forming a latent electrostatic image on a surface;
contacting the surface with the liquid electrophotographic ink composition such that at least some of the resin, the pigment and the spacer are transferred to the surface to form a developed toner image on the surface; and
transferring the toner image to the plastic substrate.

Assignees

• Hewlett Packard Development Co

Inventors

• Marom Tchaicheeyan Hanit
• Teishev Albert
• Mann Adi
• Mizrahi Orel Yosef
• Gurovich Doron
• Kaploun Vladislav
• Masoud Emad

Classifications

• G03G9/0823 Primary

  Electric parameters · CPC title

• G03G9/122

  characterised by the colouring agents · CPC title

• G03G9/125

  characterised by the liquid · CPC title

• G03G9/131

  obtained by reactions only involving carbon-to-carbon unsaturated bonds · CPC title

• G03G9/132

  obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds · CPC title