US4411958A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording medium
Assignee: Fujifilm Holdings Corp
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Filing: 1981-10-23
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Granted: 1983-10-25
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Expires: 2001-10-23
Abstract
Abstract A magnetic recording medium comprising a base and a magnetic layer formed thereon is disclosed. The coefficient of friction (μ B ) of the surface opposite to the magnetic layer in transversal direction against the axial direction of loading post is under the straight line represented by the formula: μ B =0.1S TD -0.05 (wherein S TD is the stiffness of the medium in transversal direction and 0.5<S TD ≦6.0), and the total thickness of the medium is 15.5μ or less.
Inventors
- 👤 Masami Sato
- 👤 Yasutoshi Okuzawa
- 👤 Noburo Hibino
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 11:04
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31678
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
104 words
A magnetic recording medium comprising a base, a magnetic layer formed thereon and a back coating layer on the surface of the base opposite and magnetic layer, the coefficient of friction (μ B ) of the surface opposite to the magnetic layer in transversal direction against the axial direction of loading post being under the straight line represented by the following formula, with the proviso that μ B is less than or equal to 0.30, and the total thickness of the medium being 15.5 μm or less: μ.sub.B =0.1S.sub.TD -0.05 (wherein S.sub.TD is the stiffness of the medium in transversal direction and 0.5<S.sub.TD ≦6.0).
Claim 2
Dependent Claim
104 words
A magnetic recording medium comprising a base, a magnetic layer formed thereon and a back coating layer on the surface of the base opposite and magnetic layer, the coefficient of friction (μ B ) of the surface opposite to the magnetic layer in transversal direction against the axial direction of loading post being under the straight line represented by the following formula, with the proviso that μ B is less than or equal to 0.30, and the total thickness of the medium being 15.5 μm or less: μ.sub.B =0.1S.sub.TD -0.05 (wherein S.sub.TD is the stiffness of the medium in transversal direction and 0.5<S.sub.TD ≦6.0).
Claim 3
Dependent Claim
32 words
A magnetic recording medium, as claimed in claim 1, wherein said magnetic layer comprises ferromagnetic powders selected from the group consisting of ferromagnetic iron oxide, ferromagnetic chromium oxide and ferromagnetic alloy powders.
References Cited (Backward Citations)
US4322474A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-10-24 | 1987-04-25 | 1987-10-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-10-24 | 1991-04-25 | 1991-10-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-10-24 | 1995-04-25 | 1995-10-25 | $7700.00 | Window Closed / Lapsed |