US3833412A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording medium
Assignee: Fujifilm Holdings Corp
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Filing: 1971-06-25
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Granted: 1974-09-03
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Expires: 1991-06-25
Abstract
Abstract A magnetic recording medium which comprises a support; a magnetic layer carried on said support, said magnetic layer comprising: a thermo-plastic resin binder which contains: ferromagnetic material dispersed th erein, an abrasive material having a size of less than 5 Mu and a hardness greater than 6 on the Mohs hardness scale and a monobasic fatty acid having at least four carbon atoms and a melting point lower than 50*C. said monobasic fatty acid being present in an amount greater than about 0.1 percent by weight, based on the whole magnetic layer.
Inventors
- 👤 G Akashi
- 👤 M Fujiyama
- 👤 Y Yamada
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 23:33
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/708; G11B5/7085; G11B5/71; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31551; Y10T428/31616
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
29 words
The magnetic recording medium claimed in claim 1, wherein said ferromagnetic material is selected from the group consisting of gamma -Fe2O3, Fe3O4, Fe-Co alloy, Fe-Co-Ni alloy and Fe-Co-Cu alloy.
Claim 2
Dependent Claim
40 words
The magnetic recording medium claimed in claim 1, wherein said abrasive material is selected from the group consisting of orthoclase, quartz, rock crystal, topaz, corundum, garnet, zirconia, alumina, silicon carbide, boron carbide, titanium carbide, tungsten carbide, chrome oxide and molybdenum.
Claim 3
Dependent Claim
145 words
A magnetic recording medium having excellent durability and useful in still reproduction consisting essentially of a suport and a magnetic layer coated thereon, said magnetic layer consisting essentially of, dispersed in a binder, ferromagnetic material, an abrasive material having a size less than 5 microns and a hardness greater than 6 on the Mohs hardness scale and a monobasic fatty acid having at least four carbon atoms and a melting point lower than 50*C. selected from the group consisting of caprylic acid, capric acid, lauric acid, linolenic acid, linolic acid and oleic acid, said monobasic fatty acid being present in said magnetic layer in an amount of greater than about 0.1 percent by weight, based upon the weight of said magnetic layer, and said abrasive material being present in said magnetic layer in an amount sufficient to provide excellent durability for said magnetic recording medium.
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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) | 1977-09-02 | 1978-03-04 | 1978-09-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-02 | 1982-03-04 | 1982-09-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-02 | 1986-03-04 | 1986-09-03 | $7700.00 | Window Closed / Lapsed |