US4268369A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process of making silicon dioxide films for use as wear resistant coatings in video and digital magnetic recording
Assignee: QUANTEGY MEDIA Corp
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Filing: 1979-08-30
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Granted: 1981-05-19
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Expires: 1999-08-30
Abstract
Abstract A magnetic recording medium of improved durability is obtained by depositing a coating of silicon dioxide over a magnetic metallic film.
Inventors
- 👤 Malcolm Barlow
- 👤 Jerry R. Lundquist
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 14:22
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/72
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
94 words
The process of making a wear resistant magnetic recording medium comprising the following steps: a. providing a metallic, non-magnetic substrate, b. forming a metal magnetic film selected from cobalt-nickel, cobalt and cobalt-nickel-phosphorus over said substrate, c. oxidizing said magnetic film to provide a graded surface thereon by heating said metallic magnetic film in air at a temperature of from 100°-200° C. to form an oxidized interface layer over said metallic magnetic layer and, c. sputtering a film having a thickness of 1-20 microinches of silicon dioxide over the oxydized surface of said magnetic film.
Claim 2
Dependent Claim
94 words
The process of making a wear resistant magnetic recording medium comprising the following steps: a. providing a metallic, non-magnetic substrate, b. forming a metal magnetic film selected from cobalt-nickel, cobalt and cobalt-nickel-phosphorus over said substrate, c. oxidizing said magnetic film to provide a graded surface thereon by heating said metallic magnetic film in air at a temperature of from 100°-200° C. to form an oxidized interface layer over said metallic magnetic layer and, c. sputtering a film having a thickness of 1-20 microinches of silicon dioxide over the oxydized surface of said magnetic film.
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) | 1984-05-18 | 1984-11-17 | 1985-05-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-05-18 | 1988-11-17 | 1989-05-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-05-18 | 1992-11-17 | 1993-05-19 | $7700.00 | Window Closed / Lapsed |