Patent US1855304A successfully refreshed from Google Patents.
Patent US3649541A successfully refreshed from Google Patents.
US3649541A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording elements containing stabilized chromium dioxide a polyurethane binder and an isocyanate hardening agent
Assignee: EIDP Inc
•
Filing: 1969-07-10
•
Granted: 1972-03-14
•
Expires: 1989-07-10
Abstract
Abstract MAGNETIC RECORDING COMPOSITIONS CONTAIN AT LEAST 75% BY WEIGHT OF PARTICULATE FERROMAGNETIC CHROMIUM OXIDE, STABILIZED AGAINST REDUCTIVE DEGRADATION, IN A BINDER COMPRISING A NON-REACTIVE, PREFORMED POLYURETHANE RESIN (OPTIONALLY WITH OTHER RESINS) AND A POLYFUNCTIONAL ISOCYANATE HARDENING AGENT. THE COMPOSITIONS ARE USEFUL FOR MAKING MAGNETIC RECORDING MEMBERS, E.G., TAPES, DISCS, CYLINDERS AND THE LIKE.
Inventors
- 👤 Henry Gilbert Ingersoll
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 16:32
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/706; G11B5/70626; G11B5/70636; G11B5/702; G11B5/7021; G11B5/7022; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31551; Y10T428/31609
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-03-14 | 1975-09-13 | 1976-03-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-03-14 | 1979-09-13 | 1980-03-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-03-14 | 1983-09-13 | 1984-03-14 | $7700.00 | Window Closed / Lapsed |