US3929657A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stoichiometric ferrite carriers
Assignee: Xerox Corp
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Filing: 1973-09-05
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Granted: 1975-12-30
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Expires: 1993-09-05
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 + OR - 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
2026-10-28 16:08
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; G03G9/1075; G03G9/108; G03G9/1085
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
47 words
AN ELECTROSTATOGRAPHIC DRY DEVELOPER MIXTURE FOR DEVELOPING ELECTROSTATIC LATENT IMAGES COMPRISING FINELY-DIVIDED TONER PARTICLES ELECTROSTATICALLY CLINGING TO THE SURFACE OF HUMIDITY-INSENSITIVE, UNCOATED ELECTROSTATOGRAPHIC CARRIER MATERIALS, SAID CARRIER MATERIALS COMPRISING SUBSTANTIALLY STOICHIOMETRIC FERRITE COMPOSITIONS WHICH ARE WITHIN $ 3 MOLE PERCENT DEVIATION FROM STOICHIOMETRY IN DIVALENT METAL CONTENT.
Claim 2
Dependent Claim
47 words
AN ELECTROSTATOGRAPHIC DRY DEVELOPER MIXTURE FOR DEVELOPING ELECTROSTATIC LATENT IMAGES COMPRISING FINELY-DIVIDED TONER PARTICLES ELECTROSTATICALLY CLINGING TO THE SURFACE OF HUMIDITY-INSENSITIVE, UNCOATED ELECTROSTATOGRAPHIC CARRIER MATERIALS, SAID CARRIER MATERIALS COMPRISING SUBSTANTIALLY STOICHIOMETRIC FERRITE COMPOSITIONS WHICH ARE WITHIN $ 3 MOLE PERCENT DEVIATION FROM STOICHIOMETRY IN DIVALENT METAL CONTENT.
Claim 3
Dependent Claim
15 words
An electrostatographic developer mixture according to claim 1 wherein said carrier materials are magnetically attractable.
Claim 4
Dependent Claim
14 words
An electrostatographic developer mixture according to claim 1 wherein said carrier materials are semi-conductive.
Claim 5
Dependent Claim
24 words
An electrostatographic developer mixture according to claim 1 wherein said ferrite compositions comprise from about +1 to about +3 mol percent deviation from stoichiometry.
Claim 6
Dependent Claim
24 words
An electrostatographic developer mixture according to claim 1 wherein said ferrite compositions comprise from about 0 to about +1 mol percent deviation from stoichiometry.
Claim 7
Dependent Claim
25 words
An electrostatographic developer mixture according to claim 1 wherein said ferrite compositions are obtained from a molar mixture of metal oxides comprising NiO0.3ZnO0.7 . (Fe2O3)0.99.
Claim 8
Dependent Claim
25 words
An electrostatographic developer mixture according to claim 1 wherein said ferrite compositions are obtained from a molar mixture of metal oxides comprising NiO0.39ZnO0.68MnO0.03 . (Fe2O3)1.0.
Claim 9
Dependent Claim
25 words
An electrostatographic developer mixture according to claim 1 wherein said ferrite compositions are obtained from a molar mixture of metal oxides comprising NiO0.38ZnO0.57MnO0.03CuO0.07 . (Fe2O3)1.0.
Claim 10
Dependent Claim
25 words
An electrostatographic developer mixture according to claim 1 wherein said ferrite compositions are obtained from a molar mixture of metal oxides comprising NiO0.176ZnO0.45MgO0.3MnO0.05CuO0.06 . (Fe2O3)1.0.
Claim 11
Dependent Claim
39 words
An electrostatographic developer mixture according to claim 1 wherein said ferrite compositions are represented by MOaM''O1-a (Fe2O3)x, where M and M'' always total 1.0 mole of metal oxide and x comprises about 0.88 to about 1.13 moles of iron.
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) | 1978-12-29 | 1979-06-30 | 1979-12-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-29 | 1983-06-30 | 1983-12-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-29 | 1987-06-30 | 1987-12-30 | $7700.00 | Window Closed / Lapsed |