US4391864A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording medium
Assignee: TDK Corp
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Filing: 1980-12-09
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Granted: 1983-07-05
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Expires: 2000-12-09
Abstract
Abstract A magnetic recording tape or disc which has excellent total characteristics of an adhesive strength, a repeat running durability, an electromagnetic characteristic, a gloss degree of the surface and a curling is provided. A binder of a magnetic layer comprises 40 to 70 wt. % of a urethane resin, 15 to 40 wt. % of an epoxy resin and 10 to 40 wt. % of a phenoxy resin.
Inventors
- 👤 Akihiko Hosaka
- 👤 Kiyotaka Okuyama
- 👤 Yukihiro Isobe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 12:57
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
71 words
A magnetic recording medium having a substrate coated with a magnetic layer which comprises a binder and a magnetic powder, said binder in the magnetic layer comprising 40 to 70 wt. % of a urethane resin, 15 to 40 wt. % of a thermosetting epoxy resin characterized by its content of epoxide groups, and 10 to 40 wt. % of a thermoplastic phenoxy resin characterized by its content of polyhydroxyether groups.
Claim 2
Dependent Claim
71 words
A magnetic recording medium having a substrate coated with a magnetic layer which comprises a binder and a magnetic powder, said binder in the magnetic layer comprising 40 to 70 wt. % of a urethane resin, 15 to 40 wt. % of a thermosetting epoxy resin characterized by its content of epoxide groups, and 10 to 40 wt. % of a thermoplastic phenoxy resin characterized by its content of polyhydroxyether groups.
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)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-07-04 | 1987-01-03 | 1987-07-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-07-04 | 1991-01-03 | 1991-07-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-07-04 | 1995-01-03 | 1995-07-05 | $7700.00 | Window Closed / Lapsed |