US4388376A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording medium
Assignee: TDK Corp
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Filing: 1980-06-11
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Granted: 1983-06-14
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Expires: 2000-06-11
Abstract
Abstract A magnetic recording medium comprises a substrate coated with a magnetic powder composition comprising a magnetic powder and an organic binder having a main component of vinyl chloride-vinyl alcohol copolymer.
Inventors
- 👤 Yuichi Kubota
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 00:29
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/702; G11B5/7021; G11B5/7022; G11B5/7023; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31551; Y10T428/31609; Y10T428/31855; Y10T428/31935
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
144 words
A magnetic recording medium which comprises a substrate coated with a magnetic powder composition comprising a magnetic powder and an organic binder consisting essentially of as a main component (A) a copolymer consisting essentially of a vinyl chloride-vinyl alcohol copolymer, wherein said copolymer comprises less than 2 mole % of vinyl acetate component and 8 to 22 wt. % of vinyl alcohol component and wherein said vinyl chloride-vinyl alcohol copolymer is obtained by a hydrolysis of a vinyl chloride-vinyl acetate copolymer having a molar ratio of vinyl chloride component to vinyl acetate component of 85:15 to 70:30, with or without a stabilizer for the vinyl chloride-vinyl alcohol copolymer and (B) as a minor component at least one polymer which is an elastomer or soft thermoplastic resin or mixture thereof at a ratio of 50 to 10 wt. % based on the total organic binder.
Claim 2
Dependent Claim
144 words
A magnetic recording medium which comprises a substrate coated with a magnetic powder composition comprising a magnetic powder and an organic binder consisting essentially of as a main component (A) a copolymer consisting essentially of a vinyl chloride-vinyl alcohol copolymer, wherein said copolymer comprises less than 2 mole % of vinyl acetate component and 8 to 22 wt. % of vinyl alcohol component and wherein said vinyl chloride-vinyl alcohol copolymer is obtained by a hydrolysis of a vinyl chloride-vinyl acetate copolymer having a molar ratio of vinyl chloride component to vinyl acetate component of 85:15 to 70:30, with or without a stabilizer for the vinyl chloride-vinyl alcohol copolymer and (B) as a minor component at least one polymer which is an elastomer or soft thermoplastic resin or mixture thereof at a ratio of 50 to 10 wt. % based on the total organic binder.
Claim 3
Dependent Claim
30 words
The magnetic recording medium according to claim 1 wherein component B is an elastomer incorporated at a ratio of 50 to 10 wt. % based on the total organic binder.
Claim 4
Dependent Claim
23 words
The magnetic recording medium according to claim 2 wherein said organic binder is crosslinked with a compound which is reactive with hydroxyl group.
Claim 5
Dependent Claim
32 words
The magnetic recording medium according to claim 1 wherein component B is a soft thermoplastic resin incorporated at a ratio of 50 to 10 wt. % based on the total organic binder.
Claim 6
Dependent Claim
23 words
The magnetic recording medium according to claim 4 wherein said organic binder is crosslinked with a compound which is reactive with hydroxyl group.
Claim 7
Dependent Claim
31 words
The magnetic recording medium according to claim 1 wherein component B is a polyurethane elastomer incorporated at a ratio of 50 to 10 wt. % based on the total organic binder.
Claim 8
Dependent Claim
27 words
The magnetic recording medium according to claim 1 where said binder is crosslinked by a cross-linking agent which is a polyfunctional isocyanate or an isocyanate containing compound.
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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 |