Charge adjuvants in electrostatic inks

• US 7,736,829 B2
• Filed: 01/09/2007
• Issued: 06/15/2010
• Est. Priority Date: 01/09/2007
• Status: Active Grant

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Katz, Gregory, Teishev, Albert, Israeli, Yaffa, Silcoff, Elliad
• Primary Examiner(s): Huff; Mark F
• Assistant Examiner(s): Vajda; Peter L
• Application Number:
  US11/651,281
• Publication Number:
  US 20080163789A1
• Time in Patent Office: 1,253 Days
• Field of Search: 106/31.6, 106/31.66, 106/31.67, 106/31.9, 430/115
• US Class Current: 430/115
• CPC Class Codes: G03G 9/135 characterised by stabiliser or charge-controlling agents
• CPC Class Codes: G03G 9/1355 Ionic, organic compounds

Abstract

Ink toners, electroink compositions, methods of making ink toners, methods of making electroink compositions, and the like, are described.

Claims

1. An ink toner, comprising:

a charge adjuvant selected from aluminum monostearate monobenzoate hydroxide;

a carrier liquid;

a resin;

a pigment; and

a charge director, wherein the ink toner does not include aluminum stearate.

2. The ink toner of claim 1, wherein ink toner has a viscosity of about 20 cPs to 600 cPs.

3. The ink toner of claim 1, wherein the aluminum monostearate monobenzoate hydroxide is about 0.05 to 4% by total weight of ink solids in the ink toner.

4. The ink toner of claim 1, wherein the aluminum monostearate monobenzoate hydroxide is about 0.125 to 4% by total weight of ink solids in the ink toner.

5. The ink toner of claim 1, wherein the electrostatic ink toner has a low field conductivity of about 4 pS to 300 pS.

6. A method of making an ink toner, comprising:

grinding a carrier liquid, a resin, and a pigment, to form a slurry; and

mixing a charge adjuvant and a charge director with the slurry after grinding, wherein the charge adjuvant is aluminum monostearate monobenzoate hydroxide, and wherein the ink toner does not include aluminum stearate.

7. The method of claim 6, wherein mixing includes:

mixing the charge adjuvant with the slurry homogeneously prior to mixing the charge director with the ink slurry.

8. The method of claim 6, wherein mixing includes:

mixing the charge director and the charge adjuvant simultaneously to the ink slurry.

9. The method of claim 6, wherein mixing includes:

mixing the charge director prior to adding the charge adjuvant to the ink slurry.

10. The method of claim 6, wherein the charge adjuvant added to the to the ink slurry at multiple times during the preparation of the ink toner.

11. The method of claim 6, further comprising:

adding the charge adjuvant to change a characteristic selected from;

viscosity of the ink toner, conductivity of the ink toner, and combinations thereof, wherein the addition of the charge adjuvant does not change a particle shape or a morphology of the ink toner.

12. A method of making an electrostatic ink, comprising:

grinding a charge adjuvant, a carrier liquid, a resin, a pigment, and a charge director together to form an ink toner, wherein the charge adjuvant is aluminum monostearate monobenzoate hydroxide, and wherein the ink toner does not include aluminum stearate; and

forming the electrostatic ink.