US3905779A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording body
Assignee: Fujifilm Holdings Corp
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Filing: 1973-11-16
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Granted: 1975-09-16
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Expires: 1993-11-16
Abstract
Abstract A magnetic recording body, having excellent impact and wear resistance, which comprises a nonmagnetic support, a magnetic recording medium layer applied thereon and composed mainly of Co or a Co-Ni alloy, a first protecting layer of Cu having a thickness of less than 0.2 Mu and applied on the magnetic recording medium layer, and a second protecting layer of Rh having a thickness of more than 0.01 Mu and applied on the first protecting layer. In order to improve the magnetic properties of the magnetic recording body, Cu, Ag, Hg, or P can be added to the Co-Ni alloy of the magnetic recording medium layer.
Inventors
- 👤 Eiichi Tadokoro
- 👤 Masashi Aonuma
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 12:37
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/72; G11B5/726; G11B5/7262; Y; Y10; Y10S; Y10S428/00; Y10S428/922; Y10S428/923; Y10S428/924; Y10S428/926; Y10S428/9265; Y10S428/928; Y10T; Y10T428/00; Y10T428/12; Y10T428/12493; Y10T428/12771; Y10T428/12861; Y10T428/12875; Y10T428/12903; Y10T428/12986
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
64 words
A MAGNETIC RECORDING ELEMENT COMPRISING A NONMAGNETIC BASE SUPPORT HAVING THEREON A MAGNETIC RECORDING MEDIUM LAYER COMPOSED PREDOMINANTLY OF COBALT OR A COBALT-NICKEL ALLOY, A FIRST PROTECTING LAYER OF COPPER HAVING A THICKNESS OF LESS THAN 0.2 MICRON ON SAID MAGNETIC RECORDING MEDIUM LAYER, AND A SECOND PROTECTING LAYER OF RHODIUM HAVING A THICKNESS OF MORE THAN 0.01 MICRON ON SAID FIRST PROTECTING LAYER.
Claim 2
Dependent Claim
64 words
A MAGNETIC RECORDING ELEMENT COMPRISING A NONMAGNETIC BASE SUPPORT HAVING THEREON A MAGNETIC RECORDING MEDIUM LAYER COMPOSED PREDOMINANTLY OF COBALT OR A COBALT-NICKEL ALLOY, A FIRST PROTECTING LAYER OF COPPER HAVING A THICKNESS OF LESS THAN 0.2 MICRON ON SAID MAGNETIC RECORDING MEDIUM LAYER, AND A SECOND PROTECTING LAYER OF RHODIUM HAVING A THICKNESS OF MORE THAN 0.01 MICRON ON SAID FIRST PROTECTING LAYER.
Claim 3
Dependent Claim
22 words
The magnetic recording element of claim 1, wherein said magnetic recording medium contains a small amount of copper, silver mercury, or phosphorus.
Claim 4
Dependent Claim
23 words
The magnetic recording element of claim 2, wherein said magnetic recording medium layer contains 0.02 to 10 wt.% of copper, silver or mercury.
Claim 5
Dependent Claim
20 words
The magnetic recording element of claim 2, wherein said magnetic recording medium layer contains 0.1 to 10 wt.% of phosphorus.
Claim 6
Dependent Claim
21 words
The magnetic recording element of claim 1, wherein said magnetic recording medium layer has a thickness of 0.01 to 5 microns.
Claim 7
Dependent Claim
22 words
The magnetic recording element of claim 1, wherein said first protecting layer of copper has a thickness of 0.01 to 0.2 micron.
Claim 8
Dependent Claim
22 words
The magnetic recording element of claim 1, wherein said second protecting layer of rhodium has a thickness of 0.01 to 2 microns.
Claim 9
Dependent Claim
50 words
The magnetic recording medium of claim 1, wherein said magnetic recording medium layer has a thickness of 0.1 to 5 microns, said first protecting layer of copper has a thickness of 0.01 to 0.2 microns and said second protecting layer of rhodium has a thickness of 0.01 to 2 microns.
References Cited (Backward Citations)
US3717504A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-09-15 | 1979-03-17 | 1979-09-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-15 | 1983-03-17 | 1983-09-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-15 | 1987-03-17 | 1987-09-16 | $7700.00 | Window Closed / Lapsed |