US4352859A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording medium
Assignee: TDK Corp
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Filing: 1981-07-20
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Granted: 1982-10-05
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Expires: 2001-07-20
Abstract
Abstract A magnetic recording medium comprises a substrate coated with a magnetic layer comprising a magnetic powder and a binder comprising an urethane resin or a polyester and a vinyl chloride type copolymer of vinyl chloride-vinyl acetate-vinyl alcohol copolymer, vinyl chloride-vinyl acetate-maleic acid copolymer or vinyl chloride-vinylidene chloride copolymer having a polymerization degree of up to 300.
Inventors
- 👤 Kuniichi Yoda
- 👤 Takehisa Ohkawa
- 👤 Hitoshi Azegami
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 18:41
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; Y10T428/31855; Y10T428/31935
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
57 words
A magnetic recording medium which comprises a substrate coated with a magnetic layer comprising a magnetic powder and a binder comprising an urethane resin or a polyester and a vinyl chloride type copolymer of vinyl chloride-vinyl acetate-vinyl alcohol copolymer, vinyl chloride-vinyl acetate-maleic acid copolymer or vinyl chloride-vinylidene chloride copolymer having a polymerization degree of less than 300.
Claim 2
Dependent Claim
57 words
A magnetic recording medium which comprises a substrate coated with a magnetic layer comprising a magnetic powder and a binder comprising an urethane resin or a polyester and a vinyl chloride type copolymer of vinyl chloride-vinyl acetate-vinyl alcohol copolymer, vinyl chloride-vinyl acetate-maleic acid copolymer or vinyl chloride-vinylidene chloride copolymer having a polymerization degree of less than 300.
Claim 3
Dependent Claim
16 words
The magnetic recording medium according to claim 1 wherein said urethane resin is an urethane elastomer.
Claim 4
Dependent Claim
16 words
The magnetic recording medium according to claim 1 wherein said urethane resin is an urethane prepolymer.
Claim 5
Dependent Claim
18 words
The magnetic recording medium according to claim 1, 2 or 3 wherein said binder further comprises a polyisocyanate.
Claim 6
Dependent Claim
51 words
The magnetic recording medium according to claim 1 wherein said vinyl chloride type copolymer is vinyl chloride-vinyl acetate-maleic acid copolymer comprising 20 to 95% of vinyl chloride component, 80 to 5% of vinyl acetate component and 1.5 to 5.0% of maleic acid component and a polymerization degree of less than 300.
Claim 7
Dependent Claim
27 words
The magnetic recording medium according to claim 1 wherein said vinyl chloride type copolymer is incorporated at a ratio of 20 to 90% based on said binder.
References Cited (Backward Citations)
US4152485A
Cited
US4256852A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-10-04 | 1986-04-05 | 1986-10-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-10-04 | 1990-04-05 | 1990-10-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-10-04 | 1994-04-05 | 1994-10-05 | $7700.00 | Window Closed / Lapsed |