US4816341A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording medium
Assignee: TDK Corp
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Filing: 1985-12-23
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Granted: 1989-03-28
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Expires: 2005-12-23
Abstract
Abstract In a magnetic recording medium comprising a base film and a magnetic layer formed on the base film, the base film has been plasma treated in an atmosphere consisting essentially of an inorganic gas containing N, H, and optionally O at frequencies in the range of 10 to 200 kHz. A perpendicular magnetizable metal thin film layer can be deposited on the plasma-treated surface of a resin substrate having a heat distortion temperature of at least 150° C. without disturbance on the crystal structure of the layer.
Inventors
- 👤 Masatoshi Nakayama
- 👤 Haruyuki Morita
- 👤 Yuichi Kubota
- 👤 Keiko Tsuchiya
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 14:40
CPC Classifications
C; C23; C23C; C23C14/00; C23C14/02; C23C14/021; C23C14/022; G; G11; G11B; G11B5/00; G11B5/62; G11B5/73; G11B5/7368; G11B5/739; G11B5/73923; G11B5/73927; G11B5/73933; G11B5/73937; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31678; Y10T428/31681; Y10T428/31786
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
44 words
A magnetic recording medium comprising: a base film which has been plasma treated at a frequency of 10 kHz to 200 kHz in an atmosphere consisting essentially of an inorganic gas containing N and H, and; a magnetic layer formed on said base film.
Claim 2
Dependent Claim
44 words
A magnetic recording medium comprising: a base film which has been plasma treated at a frequency of 10 kHz to 200 kHz in an atmosphere consisting essentially of an inorganic gas containing N and H, and; a magnetic layer formed on said base film.
Claim 3
Dependent Claim
23 words
A magnetic recording medium according to claim 1 which further comprises an undercoat layer interposed between the base film and the magnetic layer.
Claim 4
Dependent Claim
45 words
A magnetic recording medium comprising: a base film which has been plasma treated at a frequency of 10 kHz to 200 kHz in an atmosphere consisting essentially of an inorganic gas containing N, H and O, and; a magnetic layer formed on said base film.
Claim 5
Dependent Claim
45 words
A magnetic recording medium comprising: a base film which has been plasma treated at a frequency of 10 kHz to 200 kHz in an atmosphere consisting essentially of an inorganic gas containing N, H and O, and; a magnetic layer formed on said base film.
Claim 6
Dependent Claim
23 words
A magnetic recording medium according to claim 3 which further comprises an undercoat layer interposed between the base film and the magnetic layer.
Claim 7
Dependent Claim
60 words
A magnetic recording medium comprising: a substrate formed of a resin having a heat distortion temperature of at least 150° C. which has been plasma treated at a frequency of 10 kHz to 200 kHz in an atmosphere consisting essentially of an inorganic gas containing N, H or O, or mixtures thereof, and; a magnetic layer formed on said substrate.
Claim 8
Dependent Claim
60 words
A magnetic recording medium comprising: a substrate formed of a resin having a heat distortion temperature of at least 150° C. which has been plasma treated at a frequency of 10 kHz to 200 kHz in an atmosphere consisting essentially of an inorganic gas containing N, H or O, or mixtures thereof, and; a magnetic layer formed on said substrate.
Claim 9
Dependent Claim
23 words
A magnetic recording medium according to claim 5 which further comprises an undercoat layer interposed between the base film and the magnetic layer.
Claim 10
Dependent Claim
45 words
A magnetic recording medium according to claim 5 wherein the rsin of which the substrate is formed is one member selected from the group consisting of a polyamide, polyimide, polyphenylene sulfide, polysulfone, all aromatic polyester, polyether ether ketone, polyether sulfone and polyetherimide, and mixtures thereof.
Claim 11
Dependent Claim
17 words
A magnetic recording medium according to claim 5 wherein the magnetic layer is a metallic thin film.
Claim 12
Dependent Claim
14 words
A magnetic recording medium according to claim 5 wherein the inorganic gas contains oxygen.
Claim 13
Dependent Claim
16 words
A magnetic recording medium according to claim 5 wherein the inorganic gas contains N and H.
Claim 14
Dependent Claim
17 words
A magnetic recording medium according to claim 5 wherein the inorganic gas contains N, H and O.
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) | 1992-03-27 | 1992-09-26 | 1993-03-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-03-27 | 1996-09-26 | 1997-03-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-03-27 | 2000-09-26 | 2001-03-28 | $7700.00 | Window Closed / Lapsed |