Patent US4547419A successfully refreshed from Google Patents.
US4547419A
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Magnetic recording medium
Assignee: TDK Corp
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Filing: 1984-07-18
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Granted: 1985-10-15
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Expires: 2004-07-18
Abstract
Abstract A magnetic recording medium which comprises a plastic base film and a magnetic layer formed on one side of the base film and composed of a ferromagnetic alloy powder dispersed in a resin binder, characterized in that said ferromagnetic alloy powder has a surface area of at least 48 m2/g measured by BET method, said magnetic layer has a coercive force of at least 1,000 Oe and a surface roughness of at most 0.08 mu m, and a radiation-cured backing layer made of a radiation sensitive resin and having a surface roughness of from 0.05 to 0.6 mu m is formed on the other side of the base film.
Inventors
- 👤 Masaharu Nishimatsu
- 👤 Toshiaki Ide
- 👤 Hiroyuki Arioka
- 👤 Yuichi Kubota
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 22:44
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/714; G11B5/73; G11B5/735; G11B5/739; G11B5/73923; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/24; Y10T428/24942; Y10T428/25; Y10T428/256
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
110 words
A magnetic recording medium which comprises a plastic base film and a magnetic layer formed on one side of the base film and composed of a ferromagnetic alloy powder dispersed in a resin binder, characterized in that said ferromagnetic alloy powder has a surface area of at least 48 m 2 /g as measured by BET method, said magnetic layer has a coercive force of at least 1,000 Oe and a surface roughness of at most 0.08 μm, and a radiation-cured backing layer made of a radiation sensitive resin and having a surface roughness of from 0.05 to 0.6 μm is formed on the other side of the base film.
Claim 2
Dependent Claim
110 words
A magnetic recording medium which comprises a plastic base film and a magnetic layer formed on one side of the base film and composed of a ferromagnetic alloy powder dispersed in a resin binder, characterized in that said ferromagnetic alloy powder has a surface area of at least 48 m 2 /g as measured by BET method, said magnetic layer has a coercive force of at least 1,000 Oe and a surface roughness of at most 0.08 μm, and a radiation-cured backing layer made of a radiation sensitive resin and having a surface roughness of from 0.05 to 0.6 μm is formed on the other side of the base film.
Claim 3
Dependent Claim
41 words
The magnetic recording medium according to claim 1, wherein the radiation sensitive resin is a resin having a radiation curable double bond selected from the group consisting of an acrylic double bond, a maleic double bond and an allyl-type double bond.
References Cited (Backward Citations)
US4109046A
Cited
US4439486A
Cited
US4419406A
Cited
US4451531A
Cited
US4455345A
Cited
US4465737A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-10-14 | 1989-04-15 | 1989-10-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-10-14 | 1993-04-15 | 1993-10-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-10-14 | 1997-04-15 | 1997-10-15 | $7700.00 | Window Closed / Lapsed |