US4388369A
Expired / Lapsed
US
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Magnetic recording medium
Assignee: TDK Corp
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Filing: 1982-01-20
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Granted: 1983-06-14
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Expires: 2002-01-20
Abstract
Abstract A magnetic recording medium comprises a magnetic layer formed by coating a magnetic powder composition obtained by mixing an abrasive powder having an average diameter of 0.8 μm or more and an abrasive powder having an average diameter of 0.4 μm or less and a magnetic powder in a binder, on a base film.
Inventors
- 👤 Kiminori Tamai
- 👤 Masashi Hayama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 08:53
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/708; G11B5/7085; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/26; Y10T428/269
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
106 words
A magnetic recording medium comprising a magnetic layer on a base film said magnetic layer comprising a magnetic powder composition in a binder, said magnetic powder composition consisting essentially of a magnetic powder and from 0.1 to 3.0 wt. percent based on said magnetic powder of a mixture of (a) an abrasive powder having an average particle diameter of 0.4 μm or less and (b) an abrasive powder having an average particle diameter of 0.8 μm or more, said abrasive particles having a moh's hardness or greater than 6, wherein the ratio of (a) and (b) is in a range of 1.0:0.08 to 1.0 to 0.33.
Claim 2
Dependent Claim
106 words
A magnetic recording medium comprising a magnetic layer on a base film said magnetic layer comprising a magnetic powder composition in a binder, said magnetic powder composition consisting essentially of a magnetic powder and from 0.1 to 3.0 wt. percent based on said magnetic powder of a mixture of (a) an abrasive powder having an average particle diameter of 0.4 μm or less and (b) an abrasive powder having an average particle diameter of 0.8 μm or more, said abrasive particles having a moh's hardness or greater than 6, wherein the ratio of (a) and (b) is in a range of 1.0:0.08 to 1.0 to 0.33.
References Cited (Backward Citations)
US3687725A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-06-13 | 1986-12-13 | 1987-06-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-06-13 | 1990-12-13 | 1991-06-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-06-13 | 1994-12-13 | 1995-06-14 | $7700.00 | Window Closed / Lapsed |