US3687851A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Manufacture of highly coercive chromium dioxide
Assignee: Individual
•
Filing: 1971-05-06
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Granted: 1972-08-29
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Expires: 1991-05-06
Abstract
Abstract A PROCESS FOR THE MANUFACTURE OF HIGHLY COERCIVE CHROMIUM DIOXIDE MODIFIED WITH AT LEAST TWO DIFFERENT FOREIGN ELEMENTS, ONE OF WHICH IS SELECTED FROM THE GROUP CONSISTING OF ANTIMONY, SELENIUM AND T ELLURIUM, IS DISCLOSED. THE ADDITION OF ACICULAR IRON OR ACICULAR IRON OXIDE PRODUCES A HIGHLY COERCIVE CHROMIUM DIOXIDE.
Inventors
- 👤 Hans Joerg Hartmann
- 👤 Karl Wilhelm Leonhard
- 👤 Manfred Ohlinger
- 👤 Matthias Schwarzmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 07:21
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/706; G11B5/70626; G11B5/70636; C; C01; C01G; C01G37/00; C01G37/02; C01P; C01P2006/00; C01P2006/42; C01P2006/60
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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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) | 1975-08-29 | 1976-02-28 | 1976-08-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-29 | 1980-02-28 | 1980-08-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-29 | 1984-02-28 | 1984-08-29 | $7700.00 | Window Closed / Lapsed |