US3873356A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of manufacturing electrophotographic carriers
Assignee: International Business Machines Corp
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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
2026-10-28 20:05
CPC Classifications
G; G03; G03G; G03G9/00; G03G9/08; G03G9/10; G03G9/113; G03G9/1132; G03G9/1135; G03G9/1133; G03G9/1134; G03G9/1136; G03G9/1137; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2991; Y10T428/2998; Y10T428/31504; Y10T428/3154
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
108 words
A METHOD OF MAKING AN ELECTROPHOTOGRAPHIC DEVELOPMENT CARRIER FOR USE WITH TONER PARTICLES COMPRISING THE STEPS OF: COATING CORE PARTICLES WITH A SUBSTANTIALLY CONTINOUS FILM OF A MIXTURE OF AN INHERENTLY TRIBOELECTRICALLY NEGATIVE FLUOROPOLYMER AND A MODIFYING RESIN IN WHICH THE FLUOROPOLYMER IS ESSENTIALLY INSOLUBLE; AND HEATING THE COATED CORE PARTICLES TO A TEMPERATURE LESS THAN ABOUT 700*F. AT WHICH THE MIXTURE FIRMLY ADHERES TO THE CORE PARTICLES FORMING A CURED FILM THEREON HAVING A POSITIVE TRIBOELECTRIC CHARGE CHARACTERISTIC WITH RESPECT TO THE TONER PARTICLES WITH WHICH THE COATED CORE PARTICLES ARE USED AS THE CARRIER AND WITH RESPECT TO TONER PARTICLES FORMED OF IBM PART NUMBER 1132057.
Claim 2
Independent Claim
108 words
A METHOD OF MAKING AN ELECTROPHOTOGRAPHIC DEVELOPMENT CARRIER FOR USE WITH TONER PARTICLES COMPRISING THE STEPS OF: COATING CORE PARTICLES WITH A SUBSTANTIALLY CONTINOUS FILM OF A MIXTURE OF AN INHERENTLY TRIBOELECTRICALLY NEGATIVE FLUOROPOLYMER AND A MODIFYING RESIN IN WHICH THE FLUOROPOLYMER IS ESSENTIALLY INSOLUBLE; AND HEATING THE COATED CORE PARTICLES TO A TEMPERATURE LESS THAN ABOUT 700*F. AT WHICH THE MIXTURE FIRMLY ADHERES TO THE CORE PARTICLES FORMING A CURED FILM THEREON HAVING A POSITIVE TRIBOELECTRIC CHARGE CHARACTERISTIC WITH RESPECT TO THE TONER PARTICLES WITH WHICH THE COATED CORE PARTICLES ARE USED AS THE CARRIER AND WITH RESPECT TO TONER PARTICLES FORMED OF IBM PART NUMBER 1132057.
Claim 3
Dependent Claim
13 words
The method according to claim 1 in which the fluoropolymer is a fluorocarbon.
Claim 4
Dependent Claim
26 words
The method according to claim 2 in which the fluorocarbon is a copolymer of tetrafluoroethylene and hexafluoropropylene having thermal properties very close to the 1:1 copolymer.
Claim 5
Dependent Claim
14 words
The method according to claim 3 in which the modifying material is epoxy resin.
Claim 6
Dependent Claim
14 words
The method according to claim 3 in which the modifying material is urethane resin.
Claim 7
Dependent Claim
16 words
The method according to claim 3 in which the modifying material is methyl phenyl silicone resin.
References Cited (Backward Citations)
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US3533835A
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US3507686A
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US3558492A
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US3798167A
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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 |