Patent US4411957A successfully refreshed from Google Patents.
US4411957A
Expired / Lapsed
US
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Magnetic recording medium
Assignee: TDK Corp
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Filing: 1982-08-27
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Granted: 1983-10-25
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Expires: 2002-08-27
Abstract
Abstract A magnetic recording medium, consisting of a base coated with a magnetic coating material, uses as a binder a synthetic resin having a metal sulfonate group and a vinyl chloride-vinyl acetate copolymer containing not less than 8% vinyl alcohol, in which magnetic particles are dispersed. The binder may contain an isocyanate compound as a crosslinking agent for added particle durability.
Inventors
- 👤 Fukunori Tokuda
- 👤 Yutaka Nakashima
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 22:12
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; Y10T428/31786; Y10T428/31794; Y10T428/31855; Y10T428/31935
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
61 words
A magnetic recording medium comprising a base and a magnetic coating material applied thereon, said coating being made of a binder which consists of a synthetic resin having a metal sulfonate group and a vinyl chloride-vinyl acetate copolymer containing not less than 8% vinyl alcohol on the basis of the weight of the copolymer, and magnetic particles dispersed in said binder.
Claim 2
Dependent Claim
61 words
A magnetic recording medium comprising a base and a magnetic coating material applied thereon, said coating being made of a binder which consists of a synthetic resin having a metal sulfonate group and a vinyl chloride-vinyl acetate copolymer containing not less than 8% vinyl alcohol on the basis of the weight of the copolymer, and magnetic particles dispersed in said binder.
Claim 3
Dependent Claim
17 words
A magnetic recording medium according to claim 1 wherein said metal sulfonate group is --SO 3 Na.
Claim 4
Dependent Claim
30 words
A magnetic recording medium according to claim 1 or 2 wherein said synthetic resin having said metal sulfonate group is selected from the class consisting of polyurethane and polyester resins.
Claim 5
Dependent Claim
69 words
A magnetic recording medium comprising a base and a magnetic coating material applied thereon, said coating being made of a binder which consists of a synthetic resin having a metal sulfonate group and a vinyl chloride-vinyl acetate copolymer containing not less than 8% vinyl alcohol on the basis of the copolymer weight, said binder containing an isocyanate compound as a crosslinking agent, and magnetic particles dispersed in said binder.
Claim 6
Dependent Claim
69 words
A magnetic recording medium comprising a base and a magnetic coating material applied thereon, said coating being made of a binder which consists of a synthetic resin having a metal sulfonate group and a vinyl chloride-vinyl acetate copolymer containing not less than 8% vinyl alcohol on the basis of the copolymer weight, said binder containing an isocyanate compound as a crosslinking agent, and magnetic particles dispersed in said binder.
Claim 7
Dependent Claim
17 words
A magnetic recording medium according to claim 4 wherein said metal sulfonate group is --SO 3 Na.
Claim 8
Dependent Claim
30 words
A magnetic recording medium according to claim 4 or 5 wherein said synthetic resin having said metal sulfonate group is selected from the class consisting of polyurethane and polyester resins.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-10-24 | 1987-04-25 | 1987-10-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-10-24 | 1991-04-25 | 1991-10-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-10-24 | 1995-04-25 | 1995-10-25 | $7700.00 | Window Closed / Lapsed |