US4329398A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording medium
Assignee: TDK Corp
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Filing: 1979-11-19
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Granted: 1982-05-11
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Expires: 1999-11-19
Abstract
Abstract A magnetic recording medium consisting of a base coated with a magnetic coating material, characterized in that the binder composition in said magnetic coating material is ternary, consisting of from 30 to 70% of a polyurethane resin having an --OH group in the terminal position, from 10 to 50% of an epoxy resin, and from 10 to 50% of a vinyl chloride-vinylidene chloride copolymer, all by weight on the basis of the total weight of the binder together with a curing agent. The magnetic recording medium exhibits superior electromagnetic properties and physical properties such as stability on repeated runs and bonding strength of the coating.
Inventors
- 👤 Akihiko Hosaka
- 👤 Kazushi Tanaka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 22:43
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/702; G11B5/7021; G11B5/7022; C; C08; C08K; C08K3/00; C08K3/18; C08K3/20; C08K3/22; C08L; C08L27/00; C08L27/02; C08L27/04; C08L27/08; C08L63/00; C08L75/00; C08L75/04; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31511; Y10T428/31551; Y10T428/31609; Y10T428/31786; Y10T428/31797; Y10T428/31855; Y10T428/31935
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
92 words
A magnetic recording medium consisting of a base coated with a magnetic coating material containing a magnetic powder and a binder composition therefor, characterized in that the binder composition in said magnetic coating material is ternary, consisting of from 30 to 70% of a polyurethane resin having an --OH group in the terminal position, from 10 to 50% of an epoxy resin, and from 10 to 50% of a vinyl chloride-vinylidene chloride copolymer, all by weight on the basis of the total weight of the binder together with a polyisocyanate curing agent.
Claim 2
Dependent Claim
92 words
A magnetic recording medium consisting of a base coated with a magnetic coating material containing a magnetic powder and a binder composition therefor, characterized in that the binder composition in said magnetic coating material is ternary, consisting of from 30 to 70% of a polyurethane resin having an --OH group in the terminal position, from 10 to 50% of an epoxy resin, and from 10 to 50% of a vinyl chloride-vinylidene chloride copolymer, all by weight on the basis of the total weight of the binder together with a polyisocyanate curing agent.
Claim 3
Dependent Claim
25 words
A magnetic recording medium according to claim 1, wherein said curing agent is from 8 to 20 parts polyisocyanate based on the weight of binder.
Claim 4
Dependent Claim
17 words
A magnetic recording medium according to claim 1, or 2, wherein said base is a polyester film.
Claim 5
Dependent Claim
19 words
A magnetic recording medium according to claim 3, wherein said polyester film is in the form of a tape.
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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) | 1985-05-10 | 1985-11-09 | 1986-05-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-05-10 | 1989-11-09 | 1990-05-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-05-10 | 1993-11-09 | 1994-05-11 | $7700.00 | Window Closed / Lapsed |