US3873355A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Coated carrier particles
Assignee: International Business Machines Corp
•
Filing: 1973-10-04
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Granted: 1975-03-25
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Expires: 1993-10-04
Abstract
Abstract An electrophotographic development carrier comprises core particles coated with a mixture of a fluoropolymer and a modifying material. When utilized with appropriate electroscopic toner materials, the carrier is effective in producing a relatively negative triboelectric charging of the toner particles while it obtains a relatively positive charge. The relatively positive triboelectric characteristic is obtained by curing the coated particles through heating at a temperature less than about 700*F.
Inventors
- 👤 Carl A Queener
- 👤 William G Ralston
- 👤 Thomas C Smith
- 👤 Joseph P Welsh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 02:26
CPC Classifications
G; G03; G03G; G03G9/00; G03G9/08; G03G9/10; G03G9/113; G03G9/1132; G03G9/1137; G03G9/1133; G03G9/1134; G03G9/1135; G03G9/1136; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2991; Y10T428/2998; Y10T428/31504; Y10T428/3154; Y10T428/31652; Y10T428/31663
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
97 words
ELECTROPHOTOGRAPHIC DEVELOPMENT CARRIER PARTICLES FOR USE WITH TONER PARTICLES INCLUDING: A PLURALITY OF CORE PARTICLES; A SUBSTANTIALLY CONTINOUS FILM COATING SURROUNDING EACH OF SAID CORE PARTICLES AND FIRMLY ADHERED THERETO; SAID COATING BEING FORMED OF AN INHERENTLY TRIBOELECTRICALLY NEGATIVE FLUOROPOLYMER AND A MODIFYING RESIN IN WHICH SAID FLUOROPOLYMER IS ESSENTIALLY INSOLUBLE, SAID FLUOROPOLYMER AND SAID MODIFYING RESIN BEING PHYSICALLY MIXED WITH EACH OTHER; SAID CARRIER PARTICLES HAVING A POSITIVE TRIBOELECTRIC CHARGE CHARACTERISTIC WITH RESPECT TO TONER PARTICLES FORMED OF IBM PART NUMBER 1162057 AND WITH RESPECT TO THE TONER PARTICLES WITH WHICH SAID CARRIER PARTICLES ARE USED.
Claim 2
Dependent Claim
97 words
ELECTROPHOTOGRAPHIC DEVELOPMENT CARRIER PARTICLES FOR USE WITH TONER PARTICLES INCLUDING: A PLURALITY OF CORE PARTICLES; A SUBSTANTIALLY CONTINOUS FILM COATING SURROUNDING EACH OF SAID CORE PARTICLES AND FIRMLY ADHERED THERETO; SAID COATING BEING FORMED OF AN INHERENTLY TRIBOELECTRICALLY NEGATIVE FLUOROPOLYMER AND A MODIFYING RESIN IN WHICH SAID FLUOROPOLYMER IS ESSENTIALLY INSOLUBLE, SAID FLUOROPOLYMER AND SAID MODIFYING RESIN BEING PHYSICALLY MIXED WITH EACH OTHER; SAID CARRIER PARTICLES HAVING A POSITIVE TRIBOELECTRIC CHARGE CHARACTERISTIC WITH RESPECT TO TONER PARTICLES FORMED OF IBM PART NUMBER 1162057 AND WITH RESPECT TO THE TONER PARTICLES WITH WHICH SAID CARRIER PARTICLES ARE USED.
Claim 3
Dependent Claim
14 words
The carrier particles according to claim 1 in which said fluoropolymer is a fluorocarbon.
Claim 4
Dependent Claim
26 words
The carrier particles to claim 2 in which said fluorocarbon is a copolymer of tetrafluoroethylene and hexafluoropropylene having thermal properties very close to the 1:1 copolymer.
Claim 5
Dependent Claim
15 words
The carrier particles according to claim 3 in which said modifying material is epoxy resin.
Claim 6
Dependent Claim
15 words
The carrier particles according to claim 3 in which said modifying material is urethane resin.
Claim 7
Dependent Claim
17 words
The carrier particles according to claim 3 in which said modifying material is methyl phenyl silicone resin.
References Cited (Backward Citations)
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Cited
US3533835A
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US3507686A
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US3558492A
Cited
US3798167A
Cited
US3725118A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-24 | 1978-09-23 | 1979-03-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-24 | 1982-09-23 | 1983-03-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-24 | 1986-09-23 | 1987-03-25 | $7700.00 | Window Closed / Lapsed |