Patent US4396659A successfully refreshed from Google Patents.
US4396659A
Expired / Lapsed
US
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Magnetic recording medium
Assignee: TDK Corp
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Filing: 1980-01-02
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Granted: 1983-08-02
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Expires: 2000-01-02
Abstract
Abstract A magnetic recording tape or disc which has excellent physical characteristics of adhesive strength, a repeated running durability, and a gloss degree of the surface as well as excellent electromagnetic characteristics. A binder of a magnetic paint coating comprises 30 to 70 wt. % of an urethane resin, 10 to 50 wt. % of an epoxy resin and 10 to 50 wt. % of nitrocellulose, and if necessary a curing agent.
Inventors
- 👤 Fujio Shibata
- 👤 Kiyotaka Okuyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 12:48
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; Y10T428/31511; Y10T428/31551; Y10T428/31609
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
66 words
In a magnetic recording medium comprising a substrate and a magnetic paint coating which comprises a binder and a magnetic powder, the improvement characterized in that the binder in the magnetic paint comprises 30 to 70 wt.% of a urethane resin, 10 to 50 wt. % of a thermosetting epoxy resin characterized by its content of epoxide groups, and 10 to 50 wt.% of a nitrocellulose.
Claim 2
Dependent Claim
66 words
In a magnetic recording medium comprising a substrate and a magnetic paint coating which comprises a binder and a magnetic powder, the improvement characterized in that the binder in the magnetic paint comprises 30 to 70 wt.% of a urethane resin, 10 to 50 wt. % of a thermosetting epoxy resin characterized by its content of epoxide groups, and 10 to 50 wt.% of a nitrocellulose.
Claim 3
Dependent Claim
14 words
A magnetic recording medium according to claim 1 which is a magnetic recording tape.
Claim 4
Dependent Claim
14 words
A magnetic recording medium according to claim 1 which is a magnetic recording disc.
Claim 5
Dependent Claim
31 words
A magnetic recording medium according to claim 1 wherein a curing agent is incorporated at a ratio of 8 to 20 wt. parts based on 100 wt. parts of the binder.
Claim 6
Dependent Claim
15 words
A magnetic recording medium according to claim 4 wherein the curing agent is a polyisocyanate.
References Cited (Backward Citations)
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Cited
US3740266A
Cited
US3840400A
Cited
US4115290A
Cited
JPS5497403A
Cited
US4323628A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-08-01 | 1987-01-31 | 1987-08-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-08-01 | 1991-01-31 | 1991-08-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-08-01 | 1995-01-31 | 1995-08-02 | $7700.00 | Window Closed / Lapsed |