Surface modified magnetic carriers using hydrophobized titania

Patent metadata

Field	Value
Publication number	US-9835967-B2
Application number	US-201615367654-A
Country	US
Kind code	B2
Filing date	Dec 2, 2016
Priority date	Dec 23, 2014
Publication date	Dec 5, 2017
Grant date	Dec 5, 2017

Abstract

A developer mix used in a dual component development (DCD) system is a mixture of toner particles and magnetic carrier particles, wherein the magnetic carrier particle is surface treated with a hydrophobized titania particle. The surface treatment with a hydrophobized titania particle may be selected from either a spherical, disk, or spindle shaped. Tribocharge of the toner and the toner charge stability across cartridge life or environments may be suitably modified by selecting a preferred size and shape of the hydrophobized titania.

First claim

What is claimed is:

1. A developer mix formulation to be used in an electrophotographic imaging device comprising:
toner particles; and
magnetic carrier particles having a polymer coating on their outer surface, wherein the outer surface of the polymer coated magnetic carrier particles is surface treated with a hydrophobized titania extra particular additives.

2. The developer mix formulation of claim 1 , wherein the polymer coating on the outer surface of the magnetic carrier particles is acrylic.

3. The developer mix formulation of claim 1 , wherein the polymer coated magnetic carrier particles have a ferrite core.

4. The developer mix formulation of claim 1 , wherein the hydrophobized titania extra particular additives have a spherical shape.

5. The developer mix formulation of claim 4 , wherein the spherical hydrophobized titania extra particular additives have a primary particle size of 40 nm and an anatase crystal form.

6. The developer mix formulation of claim 4 , wherein the spherical shaped hydrophobized titania extra particular additives have a primary particle size of 15 nm and an anatase crystal form.

7. The developer mix formulation of claim 1 , wherein the hydrophobized titania extra particular additives have a disk shape.

8. The developer mix formulation of claim 7 , wherein the disk shaped hydrophobized titania extra particular additives have a primary particle size of 40 nm and an anatase crystal form.

9. The developer mix formulation of claim 7 , wherein the disk shaped hydrophobized titania extra particular additives have a primary particle size of 40 nm and an anatase-rutile crystal form.

10. The developer mix formulation of claim 1 , wherein the hydrophobized titania extra particular additives have a spindle shape.

11. The developer mix formulation of claim 10 , wherein the spindle shaped hydrophobized titania extra particular additives have a primary particle size of 5 nm×60 nm and a rutile crystal form.

12. The developer mix formulation of claim 1 , wherein the hydrophobized titania extra particular additives have an acicular shape.

13. The developer mix formulation of claim 12 , wherein the acicular shaped hydrophobized titania extra particular additives have a primary particle size of 130 nm×1.68 μm and a rutile crystal form.

14. The developer mix formulation of claim 1 , wherein the hydrophobizing agent is a silane.

Assignees

• Lexmark Int Inc

Inventors

• Srinivasan Kasturi Rangan
• Blassingame Michael Anthony

Classifications

• G03G9/0827

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

• G03G9/1131 Primary

  Coating methods; Structure of coatings · CPC title

• G03G9/0815

  Post-treatment · CPC title

• G03G9/0819

  characterised by the dimensions of the particles · CPC title

• G03G9/1135

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