Patent US3767464A successfully refreshed from Google Patents.
US3767464A
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Magnetic recording member and method of producing same
Assignee: Fujifilm Holdings Corp
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Filing: 1972-02-17
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Granted: 1973-10-23
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Expires: 1992-02-17
Abstract
Abstract Magnetic recording member having a high Br/Bm ratio, an excellent squareness ratio of the magnetization curve, low noise level and excellent surface smoothness, especially suitable for high density recording, produced by pressing a magnetic recording member having a magnetic recording layer which is composed of an acicular ferromagnetic alloy powder having an average length of larger than 1 micron, dispersed in a binder and being magnetically orientated in order to crush the powder having a larger particle size.
Inventors
- 👤 G Akashi
- 👤 T Kitamoto
- 👤 T Katada
- 👤 Y Yamada
- 👤 M Kazuhiko
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 23:33
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/84; G11B5/842; G11B5/845; Y; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24355; Y10T428/24372; Y10T428/24413; Y10T428/25; Y10T428/256; Y10T428/257; Y10T428/31504; Y10T428/31786; Y10T428/31971; Y10T428/31993
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
15 words
The method of claim 1 wherein said ferromagnetic metal compound is a ferromagnetic metal oxalate.
Claim 2
Dependent Claim
22 words
The method of claim 1 wherein said ferromagnetic-metal compound is selected from the group consisting of ferrous-cobalt oxalate, ferrous-cobalt acetate and geothite.
Claim 3
Dependent Claim
10 words
A magnetic recording member produced by the process of claim
Claim 4
Dependent Claim
21 words
The method of claim 1 wherein said pressing step comprises subjecting said magnetic layer to a pressure of about 150 kg/cm2.
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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) | 1976-10-22 | 1977-04-23 | 1977-10-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-22 | 1981-04-23 | 1981-10-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-22 | 1985-04-23 | 1985-10-23 | $7700.00 | Window Closed / Lapsed |