US4323628A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording medium
Assignee: TDK Corp
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Filing: 1980-08-05
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Granted: 1982-04-06
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Expires: 2000-08-05
Abstract
Abstract A magnetic recording medium comprises a substrate coated with a magnetic composition comprising a magnetic powder in a binder comprising a vinyl chloride-vinyl acetate vinyl alcohol copolymer having more than 10 wt. % of vinyl alcohol component and a vinyl chloride polymer-impregnated nitrocellulose which is crosslinked with a polyisocyanate.
Inventors
- 👤 Kiyotaka Okuyama
- 👤 Akihiko Hosaka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 17:43
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/702; G11B5/7021; G11B5/7022; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31551; Y10T428/31609; Y10T428/31855; Y10T428/31935
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
49 words
A magnetic recording medium which comprises a substrate coated with a magnetic composition comprising a magnetic powder in a binder comprising a vinyl chloride-vinyl acetate vinyl alcohol copolymer having more than 10 wt. % of vinyl alcohol component and polyvinyl chloride impregnated nitrocellulose which is crosslinked with a polyisocyanate.
Claim 2
Dependent Claim
49 words
A magnetic recording medium which comprises a substrate coated with a magnetic composition comprising a magnetic powder in a binder comprising a vinyl chloride-vinyl acetate vinyl alcohol copolymer having more than 10 wt. % of vinyl alcohol component and polyvinyl chloride impregnated nitrocellulose which is crosslinked with a polyisocyanate.
Claim 3
Dependent Claim
28 words
The magnetic recording medium according to claim 1 wherein said polyvinyl chloride impregnated nitrocellulose is obtained by replacing isopropyl alcohol in a nitrocellulose composition with polyvinyl chloride polymer.
Claim 4
Dependent Claim
55 words
The magnetic recording medium according to claim 1 wherein said composition comprises about 3 to 10 wt. parts of said vinyl chloride-vinyl acetate-vinyl alcohol copolymer, about 3 to 10 wt. parts of said polyvinyl chloride impregnated nitrocellulose, and about 5 to 20 wt. parts of said polyisocyanate to 100 wt. parts of said magnetic powder.
References Cited (Backward Citations)
US4234438A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-04-05 | 1985-10-05 | 1986-04-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-04-05 | 1989-10-05 | 1990-04-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-04-05 | 1993-10-05 | 1994-04-06 | $7700.00 | Window Closed / Lapsed |