Patent US3634252A successfully refreshed from Google Patents.
US3634252A
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US
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Chromium dioxide recording compositions stabilized with long-chain ammonium salts
Assignee: EIDP Inc
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Filing: 1970-06-22
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Granted: 1972-01-11
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Expires: 1990-06-22
Abstract
Abstract FERROMAGNETIC CHROMIUM DIOXIDE PARTICLES ARE ADMIXED WITH STABLIZING AMOUNTS OF AMMONIUM SALTS HAVING AT LEAST ONE SATURATED ALIPHATIC CHAIN OF LEAST EIGHT CARBON ATOMS AND INCORPORATED WITH A POLYMERIC BINDER. THE SALTS RETARD LOSS OF RESIDUAL INTRINSIC FLUX DENSITY. MAGNETIC RECORDING MEMBERS, E.G., TAPES, DISC, AND CYLINDERS, HAVE A LAYER OF THE COMPOSITIONS.
Inventors
- 👤 Boynton Graham
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 09:23
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/706; G11B5/70626; G11B5/70636; C; C09; C09C; C09C1/00; C09C1/34; C09C1/346; C01; C01P; C01P2006/00; C01P2006/42
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) | 1975-01-10 | 1975-07-12 | 1976-01-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-10 | 1979-07-12 | 1980-01-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-10 | 1983-07-12 | 1984-01-11 | $7700.00 | Window Closed / Lapsed |