US4042518A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stoichiometric ferrite carriers
Assignee: Xerox Corp
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Filing: 1975-07-07
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Granted: 1977-08-16
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Expires: 1995-07-07
Abstract
Abstract Humidity insensitive, uncoated electrostatographic carrier materials comprising substantially stoichiometric ferrite compositions using various divalent metal oxides and/or one monovalent metal oxide, singly and in combination, which are within about ± 3 mol percent deviation from stoichiometry in divalent metal content. The carrier materials may be mixed with toner materials to form developer mixtures and employed to develop electrostatic latent images.
Inventors
- 👤 Lewis O. Jones
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 06:49
CPC Classifications
H; H01; H01F; H01F1/00; H01F1/01; H01F1/03; H01F1/12; H01F1/34; H01F1/36; G; G03; G03G; G03G9/00; G03G9/08; G03G9/10; G03G9/107; G03G9/108; G03G9/1085
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
67 words
Humidity-insensitive magnetically attractable, semi-conductive, uncoated electrostatographic ferrite carrier material useful for development of electrostatic latent images, said carrier material having an average particle diameter of between about 50 microns and about 500 microns and consisting essentially of a sintered mixture of metal oxides of the formulation NiO 0 .176 ZnO 0 .45 MgO 0 .3 MnO 0 .05 CuO 0 .06 (Fe 2 O 3 ).sbsb.1 .sbsb.0.
Claim 2
Dependent Claim
67 words
Humidity-insensitive magnetically attractable, semi-conductive, uncoated electrostatographic ferrite carrier material useful for development of electrostatic latent images, said carrier material having an average particle diameter of between about 50 microns and about 500 microns and consisting essentially of a sintered mixture of metal oxides of the formulation NiO 0 .176 ZnO 0 .45 MgO 0 .3 MnO 0 .05 CuO 0 .06 (Fe 2 O 3 ).sbsb.1 .sbsb.0.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-08-15 | 1981-02-14 | 1981-08-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-08-15 | 1985-02-14 | 1985-08-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-08-15 | 1989-02-14 | 1989-08-16 | $7700.00 | Window Closed / Lapsed |