Patent US4588654A successfully refreshed from Google Patents.
US4588654A
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US
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Magnetic recording medium
Assignee: TDK Corp
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Filing: 1982-05-27
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Granted: 1986-05-13
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Expires: 2002-05-27
Abstract
Abstract A magnetic recording medium having a subbing metal layer formed by sputtering under a thin magnetic layer formed by vapor deposition possesses excellent magnetic properties and high surface hardness. The presence of the subbing layer improves the adhesion of the thin magnetic layer to the support.
Inventors
- 👤 Takayoshi Kobuke
- 👤 Toshiaki Izumi
- 👤 Seitoku Saito
- 👤 Kazumasa Fukuda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 13:53
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/84; G11B5/851; G11B5/85; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10S428/922; Y10S428/9265; Y10S428/928; Y10T; Y10T428/00; Y10T428/12; Y10T428/12493; Y10T428/12535; Y10T428/12556; Y10T428/12569; Y10T428/31504; Y10T428/31678; Y10T428/31681; Y10T428/31786
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
75 words
A magnetic recording medium comprising a high molecular-weight polyester resin substrate having thereon, in succession, a sub-layer of aluminum or Co/Ni metal formed by a sputtering method, and a thin magnetic layer formed by a vapor deposition method, thereby imparting a surface hardness to said magnetic recording medium which is substantially greater than that of a magnetic recording medium in which the sub-layer and thin magnetic layer are both formed by a vapor deposition method.
Claim 2
Dependent Claim
75 words
A magnetic recording medium comprising a high molecular-weight polyester resin substrate having thereon, in succession, a sub-layer of aluminum or Co/Ni metal formed by a sputtering method, and a thin magnetic layer formed by a vapor deposition method, thereby imparting a surface hardness to said magnetic recording medium which is substantially greater than that of a magnetic recording medium in which the sub-layer and thin magnetic layer are both formed by a vapor deposition method.
Claim 3
Dependent Claim
16 words
The magnetic recording medium of claim 1, wherein the thin magnetic layer is a Co/Ni layer.
References Cited (Backward Citations)
DE2402481A1
Cited
US4003813A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-05-12 | 1989-11-11 | 1990-05-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-05-12 | 1993-11-11 | 1994-05-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-05-12 | 1997-11-11 | 1998-05-13 | $7700.00 | Window Closed / Lapsed |