Patent US4452864A successfully refreshed from Google Patents.
US4452864A
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Magnetic recording medium
Assignee: TDK Corp
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Filing: 1982-09-16
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Granted: 1984-06-05
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Expires: 2002-09-16
Abstract
Abstract A magnetic recording medium comprises a substrate and a magnetic recording layer formed on the substrate and having an easy magnetization axis in the perpendicular direction to the surface of the medium, characterized in that said magnetic recording layer is composed of from 75 to 90% by weight of Co, at most 15% by weight of Mo and the rest being V and unavoidable impurities.
Inventors
- 👤 Yoshimi Kitahara
- 👤 Kazumasa Fukuda
- 👤 Fumio Maruta
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:51
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/64; G11B5/65; G11B5/656; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10S428/922; Y10S428/9265; Y10S428/928; Y10T; Y10T428/00; Y10T428/12; Y10T428/12465; Y10T428/12493; Y10T428/12771; Y10T428/12778; Y10T428/26; Y10T428/263; Y10T428/264; Y10T428/265; Y10T428/31504; Y10T428/31678
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
81 words
A magnetic recording medium comprising a substrate and a magnetic recording layer formed on the substrate and having an easy magnetization axis in the perpendicular direction to the surface of the medium, characterized in that said magnetic recording layer is composed of from 75 to 90% by weight of Co, the remainder being comprised of both Mo and V but wherein Mo is limited to a maximum of 15 weight percent on the bases of the magnetic layer and unavoidable impurities.
Claim 2
Dependent Claim
81 words
A magnetic recording medium comprising a substrate and a magnetic recording layer formed on the substrate and having an easy magnetization axis in the perpendicular direction to the surface of the medium, characterized in that said magnetic recording layer is composed of from 75 to 90% by weight of Co, the remainder being comprised of both Mo and V but wherein Mo is limited to a maximum of 15 weight percent on the bases of the magnetic layer and unavoidable impurities.
Claim 3
Dependent Claim
77 words
A magnetic recording medium comprising a substrate, a high magnetic permeability layer formed on the substrate and a magnetic recording layer formed on the high magnetic permeability layer and having an easy magnetization axis in the perpendicular direction to the surface of the medium, characterized in that said magnetic recording layer is composed of from 75 to 90% by weight of Co, at most 15% by weight of Mo and the rest being V and unavoidable impurities.
Claim 4
Dependent Claim
77 words
A magnetic recording medium comprising a substrate, a high magnetic permeability layer formed on the substrate and a magnetic recording layer formed on the high magnetic permeability layer and having an easy magnetization axis in the perpendicular direction to the surface of the medium, characterized in that said magnetic recording layer is composed of from 75 to 90% by weight of Co, at most 15% by weight of Mo and the rest being V and unavoidable impurities.
Claim 5
Dependent Claim
34 words
The magnetic recording medium according to claim 1 or 2 wherein the amount of Mo is from 3 to 15% by weight and the amount of V is from 6 to 16% by weight.
Claim 6
Dependent Claim
24 words
The magnetic recording medium according to claim 1 or 2 wherein the magnetic recording layer has a coercive force of at most 600 Oe.
Claim 7
Dependent Claim
25 words
The magnetic recording medium according to claim 1 or 2 wherein the magnetic recording layer has a coercive force of from 300 to 600 Oe.
Claim 8
Dependent Claim
39 words
The magnetic recording medium according to claim 1 or 2 wherein the half value width Δθ50 of a X-ray reflection rocking curve from (002) plane of the magnetic recording layer is within a range of from 2.8° to 3.4°.
Claim 9
Dependent Claim
24 words
The magnetic recording medium according to claim 1 to 2 wherein the magnetic recording layer has a thickness of from 0.05 to 3 microns.
Claim 10
Dependent Claim
20 words
The magnetic recording medium according to claim 2 wherein the high magnetic permeability layer is made of a Mo-Fe-Ni alloy.
References Cited (Backward Citations)
US4277809A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-06-05 | 1987-12-05 | 1988-06-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-06-05 | 1991-12-05 | 1992-06-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-06-05 | 1995-12-05 | 1996-06-05 | $7700.00 | Window Closed / Lapsed |