Patent US4388376A successfully refreshed from Google Patents.
US4388376A
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US
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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 10:49
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.
References Cited (Backward Citations)
GB974627A
Cited
US3149995A
Cited
GB1102968A
Cited
US3404997A
Cited
US3728262A
Cited
US3929659A
Cited
US4018967A
Cited
SU627528A1
Cited
US4234438A
Cited
US4340644A
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 |