US4238548A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording medium
Assignee: TDK Corp
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Filing: 1979-03-06
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Granted: 1980-12-09
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Expires: 1999-03-06
Abstract
Abstract A magnetic recording medium comprises a substrate coated with a magnetic layer wherein a magnetic powder is orientated in a cured binder comprising a vinyl chloride, vinyl acetate copolymer having more than 10 wt. % of vinyl alcohol component and a polyester and a nitrocellulose.
Inventors
- 👤 Kiyotaka Okuyama
- 👤 Akihiko Hosaka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 17:30
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/702; G11B5/7023; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31786; Y10T428/31855; Y10T428/31935
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
75 words
A magnetic recording medium which comprises a substrate coated with a magnetic layer wherein a magnetic powder is oriented in a cured binder comprising 3 to 10 wt. parts of a vinyl chloride-vinyl acetate copolymer having 10 to 20 wt.% of vinyl alcohol component, 5 to 20 wt. parts of a polyester and 3 to 10 wt. parts of a nitrocellulose; and wherein said magnetic powder is present in an amount of 100 wt. parts.
Claim 2
Dependent Claim
75 words
A magnetic recording medium which comprises a substrate coated with a magnetic layer wherein a magnetic powder is oriented in a cured binder comprising 3 to 10 wt. parts of a vinyl chloride-vinyl acetate copolymer having 10 to 20 wt.% of vinyl alcohol component, 5 to 20 wt. parts of a polyester and 3 to 10 wt. parts of a nitrocellulose; and wherein said magnetic powder is present in an amount of 100 wt. parts.
Claim 3
Dependent Claim
16 words
A magnetic recording medium according to claim 1 wherein the magnetic layer further comprises a lubricant.
Claim 4
Dependent Claim
61 words
A magnetic recording medium according to claim 1 which is prepared by dispersing said magnetic powder in a coating composition comprising said binder and an organic solvent; admixing a curing agent with said dispersion of magnetic powder in said coating composition; coating said admixture on said substrate; and drying and solidifying the coating composition after an orientation of the magnetic powder.
Claim 5
Dependent Claim
31 words
A magnetic recording medium according to claim 1 wherein said vinyl chloride-vinyl acetate copolymer comprises 40 to 90 wt.% of vinyl chloride component 1 to 40 wt.% of vinyl acetate component.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-12-09 | 1984-06-09 | 1984-12-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-12-09 | 1988-06-09 | 1988-12-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-12-09 | 1992-06-09 | 1992-12-09 | $7700.00 | Window Closed / Lapsed |