US4454195A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording medium
Assignee: TDK Corp
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Filing: 1982-07-12
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Granted: 1984-06-12
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Expires: 2002-07-12
Abstract
Abstract A magnetic recording medium has a magnetic recording layer comprising from 75 to 90% by weight of Co and up to 5% by weight of Cr, the rest being V. The magnetic recording layer has an easy magnetization axis in the perpendicular direction to the layer surface. The magnetic recording medium is prepared by sputtering a composition of Co-V-Cr onto a substrate at an industrially feasible deposition speed of at least 3000 Å/min to form the above mentioned recording layer on the substrate.
Inventors
- 👤 Kazumasa Fukuda
- 👤 Yoshimi Kitahara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 13:33
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/84; G11B5/851; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/26; Y10T428/263; Y10T428/264; Y10T428/265; Y10T428/31504; Y10T428/31678; Y10T428/31681
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
67 words
A magnetic recording medium having a magnetic recording layer comprising from 75 to 90% by weight of Co and up to 5% by weight of Cr, the rest being V, said magnetic recording layer having an easy magnetization axis in the perpendicular direction to the layer surface, being of a thickness of from 2000 Å to 2μ, and having a coercive force of at most 600 Oe.
Claim 2
Dependent Claim
67 words
A magnetic recording medium having a magnetic recording layer comprising from 75 to 90% by weight of Co and up to 5% by weight of Cr, the rest being V, said magnetic recording layer having an easy magnetization axis in the perpendicular direction to the layer surface, being of a thickness of from 2000 Å to 2μ, and having a coercive force of at most 600 Oe.
Claim 3
Dependent Claim
34 words
The magnetic recording medium according to claim 1 wherein the magnetic recording layer comprises 80 to 85% by weight of Co and from 1 to 4% by weight of Cr, the rest being V.
Claim 4
Dependent Claim
73 words
A process for producing a magnetic recording medium which comprises sputtering a composition comprising from 75 to 90% by weight of Co and up to 5% by weight of Cr, the rest being V, onto a substrate to a thickness of from 2000 Å to 2μ at a deposition speed of at least 3000 Å/min. to form on the substrate a magnetic recording layer of a coercive force of at most 600 Oe.
Claim 5
Dependent Claim
73 words
A process for producing a magnetic recording medium which comprises sputtering a composition comprising from 75 to 90% by weight of Co and up to 5% by weight of Cr, the rest being V, onto a substrate to a thickness of from 2000 Å to 2μ at a deposition speed of at least 3000 Å/min. to form on the substrate a magnetic recording layer of a coercive force of at most 600 Oe.
Claim 6
Dependent Claim
67 words
A magnetic recording medium having a magnetic recording layer comprising from 75 to 90% by weight of Co and 1 to 5% by weight of Cr, the rest being V, said magnetic recording layer having an easy magnetization axis in the perpendicular direction to the layer surface, being of a thickness of from 2000 Å to 2μ, and having a coercive force of at most 600 Oe.
Claim 7
Dependent Claim
67 words
A magnetic recording medium having a magnetic recording layer comprising from 75 to 90% by weight of Co and 1 to 5% by weight of Cr, the rest being V, said magnetic recording layer having an easy magnetization axis in the perpendicular direction to the layer surface, being of a thickness of from 2000 Å to 2μ, and having a coercive force of at most 600 Oe.
Claim 8
Dependent Claim
34 words
The magnetic recording medium according to claim 4 wherein the magnetic recording layer comprises 80 to 85% by weight of Co and from 1 to 4% by weight of Cr, the rest being V.
Claim 9
Dependent Claim
32 words
The process according to claim 3 wherein the magnetic recording layer comprises 80 to 85% by weight of Co and from 1 to 4% by weight of Cr, the rest being V.
Claim 10
Dependent Claim
73 words
A process for producing a magnetic recording medium which comprises sputtering a composition comprising from 75 to 90% by weight of Co and 1 to 5% by weight of Cr, the rest being V, onto a substrate to a thickness of from 2000 Å to 2μ at a deposition speed of at least 3000 Å/min. to form on the substrate a magnetic recording layer of a coercive force of at most 600 Oe.
Claim 11
Dependent Claim
73 words
A process for producing a magnetic recording medium which comprises sputtering a composition comprising from 75 to 90% by weight of Co and 1 to 5% by weight of Cr, the rest being V, onto a substrate to a thickness of from 2000 Å to 2μ at a deposition speed of at least 3000 Å/min. to form on the substrate a magnetic recording layer of a coercive force of at most 600 Oe.
Claim 12
Dependent Claim
32 words
The process according to claim 7 wherein the magnetic recording layer comprises 80 to 85% by weight of Co and from 1 to 4% by weight of Cr, the rest being V.
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) | 1987-06-12 | 1987-12-12 | 1988-06-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-06-12 | 1991-12-12 | 1992-06-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-06-12 | 1995-12-12 | 1996-06-12 | $7700.00 | Window Closed / Lapsed |