US4560624A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording media with a dual protective coating of silicon monoxide and chromium
Assignee: Emtec Magnetics GmbH
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Filing: 1984-11-29
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Granted: 1985-12-24
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Expires: 2004-11-29
Abstract
Abstract Magnetic recording media possess, on a dimensionally stable base which may or may not be provided with a non-magnetic lower layer, a thin ferromagnetic metal layer on which a protective layer consisting of a silicon monoxide/chromium dual coating is applied.
Inventors
- 👤 Christine Guttner
- 👤 Peter Heilmann
- 👤 Udo Kullmann
- 👤 Dieter Mayer
- 👤 Werner Grau
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 00:25
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/72; G11B5/726; G11B5/7262; Y; Y10; Y10T; Y10T428/00; Y10T428/12; Y10T428/12493; Y10T428/12535; Y10T428/12611; Y10T428/12771; Y10T428/12806
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
52 words
A magnetic recording medium which possesses, on a dimensionally stable base which may or may not be provided with a non-magnetic lower layer, a thin ferromagnetic metal layer on which a protective layer is applied, wherein the protective layer is in the form of a dual coating of chromium and silicon monoxide.
Claim 2
Dependent Claim
52 words
A magnetic recording medium which possesses, on a dimensionally stable base which may or may not be provided with a non-magnetic lower layer, a thin ferromagnetic metal layer on which a protective layer is applied, wherein the protective layer is in the form of a dual coating of chromium and silicon monoxide.
Claim 3
Dependent Claim
35 words
A magnetic recording medium as claimed in claim 1, wherein on the 300-1500 Å thick ferromagnetic metal layer, the protective layer in the form of a dual coating is from 200 to 5000 Å thick.
Claim 4
Dependent Claim
38 words
A magnetic recording medium as claimed in claim 2, wherein a first, 100-1000 Å thick layer of chromium and a second, 100-4900 Å thick layer of silicon monoxide are applied onto a 300-1500 Å thick ferromagnetic metal layer.
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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) | 1988-12-23 | 1989-06-24 | 1989-12-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-12-23 | 1993-06-24 | 1993-12-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-12-23 | 1997-06-24 | 1997-12-24 | $7700.00 | Window Closed / Lapsed |