Patent US4370384A successfully refreshed from Google Patents.
US4370384A
Expired / Lapsed
US
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Magnetic recording medium
Assignee: TDK Corp
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Filing: 1981-09-29
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Granted: 1983-01-25
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Expires: 2001-09-29
Abstract
Abstract A magnetic recording medium having a substrate coated with a magnetic layer comprising a magnetic powder and a binder essentially consisting of 20 to 70 wt. % of a polyester resin, 80 to 30 wt. % of a vinyl chloride-vinylidene chloride copolymer and a polyisocyanate.
Inventors
- 👤 Akihiko Hosaka
- 👤 Yukihiro Isobe
- 👤 Kiyotaka Okuyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 09:47
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; Y10T428/31551; Y10T428/31609; Y10T428/31786; Y10T428/31794
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
55 words
In a magnetic recording medium having a substrate coated with a magnetic layer comprising a magnetic powder and a binder, the improvement characterized in that said binder in said magnetic layer consists essentially of 20 to 70 wt.% of a polyester resin, 80 to 30 wt.% of a vinyl chloride-vinylidene chloride copolymer and a polyisocyanate.
Claim 2
Dependent Claim
55 words
In a magnetic recording medium having a substrate coated with a magnetic layer comprising a magnetic powder and a binder, the improvement characterized in that said binder in said magnetic layer consists essentially of 20 to 70 wt.% of a polyester resin, 80 to 30 wt.% of a vinyl chloride-vinylidene chloride copolymer and a polyisocyanate.
Claim 3
Dependent Claim
28 words
The magnetic recording medium according to claim 1 wherein said polyisocyanate is incorporated in a range of 5 to 30wt.% based on the total amounts of said resins.
Claim 4
Dependent Claim
20 words
The magnetic recording medium according to claim 1 wherein said magnetic recording medium is a magnetic recording tape or sheet.
References Cited (Backward Citations)
US3840400A
Cited
FR2143315A1
Cited
US4241139A
Cited
JPS54151417A
Cited
JPS54151412A
Cited
JPS555171A
Cited
US4307154A
Cited
US4329398A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-01-24 | 1986-07-26 | 1987-01-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-01-24 | 1990-07-26 | 1991-01-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-01-24 | 1994-07-26 | 1995-01-25 | $7700.00 | Window Closed / Lapsed |