US3630771A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording medium
Assignee: Fujifilm Holdings Corp
•
Filing: 1968-09-06
•
Granted: 1971-12-28
•
Expires: 1988-09-06
Abstract
Abstract A magnetic recording medium wherein a magnetic recording layer is formed from a ferromagnetic powder dispersed in a binder applied onto a support, said binder being a polyether prepolymer having terminal -NCO radicals prepared from a polyisocyanate and a polyether glycol with a cellulose derivative having 7.5-40 percent of residual hydroxyl radicals in a weight ratio of from 1:2 to 20:1.
Inventors
- 👤 Goro Akashi
- 👤 Yasuyuki Yamada
- 👤 Masaaki Fujiyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 23:19
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/702; G11B5/7021; G11B5/7022; C; C08; C08G; C08G18/00; C08G18/06; C08G18/08; C08G18/10; C08G18/28; C08G18/40; C08G18/48; C08G18/4825; C08G18/52; C08G18/64; C08G18/6484; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31551; Y10T428/31609
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
12 words
The recording medium of claim 1 wherein said cellulose derivative is nitrocellulose.
Claim 2
Dependent Claim
14 words
The recording medium of claim 1 wherein said cellulose derivative is acetyl butyryl cellulose.
Claim 3
Dependent Claim
34 words
The recording medium of claim 1 wherein said polyether in said prepolymer is selected from the group consisting of polyalkylene ether glycol, polyalkylene ether thio glycol, polyarylene ether thio glycol, polyalkylene arylene ether glycol.
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) | 1974-12-27 | 1975-06-28 | 1975-12-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-12-27 | 1979-06-28 | 1979-12-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-12-27 | 1983-06-28 | 1983-12-28 | $7700.00 | Window Closed / Lapsed |