US4394420A
Expired / Lapsed
US
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Magnetic recording medium
Assignee: TDK Corp
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Filing: 1981-10-29
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Granted: 1983-07-19
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Expires: 2001-10-29
Abstract
Abstract A magnetic recording medium having a magnetic layer comprises a magnetic powder, a binder, a nonionic or anionic surfactant and a silicone oil having a viscosity of 500 c.s. or lower.
Inventors
- 👤 Kiminori Tamai
- 👤 Masashi Hayama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 22:02
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/71; G11B5/702; G11B5/7028; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31652; Y10T428/31663
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
97 words
In a magnetic recording medium having a magnetic layer which comprises a magnetic powder, a binder and a nonionic or anionic surfactant in an amount of 1.0 to 5.0 wt. % based on said magnetic powder, the improvement comprising within said magnetic layer of 0.5 to 5.0 wt. % based on said binder of a silicone oil of the formula ##STR2## where n is a value such that the viscosity of the silicone oil is 500 c.s. or lower at 25° C., whereby the blooming of the surfactant and the plasticization of the magnetic layer are diminished.
Claim 2
Dependent Claim
97 words
In a magnetic recording medium having a magnetic layer which comprises a magnetic powder, a binder and a nonionic or anionic surfactant in an amount of 1.0 to 5.0 wt. % based on said magnetic powder, the improvement comprising within said magnetic layer of 0.5 to 5.0 wt. % based on said binder of a silicone oil of the formula ##STR2## where n is a value such that the viscosity of the silicone oil is 500 c.s. or lower at 25° C., whereby the blooming of the surfactant and the plasticization of the magnetic layer are diminished.
References Cited (Backward Citations)
US4171406A
Cited
US4267206A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-07-18 | 1987-01-17 | 1987-07-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-07-18 | 1991-01-17 | 1991-07-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-07-18 | 1995-01-17 | 1995-07-19 | $7700.00 | Window Closed / Lapsed |