IP Library › Granted Patent US 9,835,967
Granted Patent B2
US 9,835,967 · App. 15/367,654 · Granted Dec 5, 2017

Surface modified magnetic carriers using hydrophobized titania

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Quick Facts
Patent No.
US 9,835,967
App. No.
15/367,654
Granted
Dec 5, 2017
Kind
B2
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.

Claims (16)

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.

Assignments (8)
SECURITY INTEREST Recorded Jan 5, 2026
From: LEXMARK INTERNATIONAL, INC.
To: BANK TRUST COMPANY, NATIONAL ASSOCIATION
Reel/Frame 074202/0293 →
SECURITY INTEREST Recorded Jan 5, 2026
From: LEXMARK INTERNATIONAL, INC.
To: BANK TRUST COMPANY, NATIONAL ASSOCIATION
Reel/Frame 074202/0192 →
SECURITY INTEREST Recorded Sep 23, 2025
From: LEXMARK INTERNATIONAL, INC.
To: CITIBANK, N.A.
Reel/Frame 073007/0118 →
SECURITY INTEREST Recorded Sep 23, 2025
From: LEXMARK INTERNATIONAL, INC.
To: JEFFERIES FINANCE LLC
Reel/Frame 073007/0346 →
RELEASE OF SECURITY INTEREST Recorded Jan 18, 2024
From: CHINA CITIC BANK CORPORATION LIMITED, GUANGZHOU BRANCH, AS COLLATERAL AGENT
To: LEXMARK INTERNATIONAL, INC.
Reel/Frame 066345/0026 →
CORRECTIVE ASSIGNMENT TO CORRECT THE INCORRECT U.S. PATENT NUMBER PREVIOUSLY RECORDED AT REEL: 046989 FRAME: 0396. ASSIGNOR(S) HEREBY CONFIRMS THE PATENT SECURITY AGREEMENT. Recorded Oct 24, 2018
From: LEXMARK INTERNATIONAL, INC.
To: CHINA CITIC BANK CORPORATION LIMITED, GUANGZHOU BRANCH, AS COLLATERAL AGENT
Reel/Frame 047760/0795 →
PATENT SECURITY AGREEMENT Recorded Aug 30, 2018
From: LEXMARK INTERNATIONAL, INC.
To: CHINA CITIC BANK CORPORATION LIMITED, GUANGZHOU BRANCH, AS COLLATERAL AGENT
Reel/Frame 046989/0396 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jan 13, 2017
From: SRINIVASAN, KASTURI RANGAN; BLASSINGAME, MICHAEL ANTHONY
To: LEXMARK INTERNATIONAL, INC.
Reel/Frame 040964/0192 →