US4420540A
Expired / Lapsed
US
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Magnetic recording medium
Assignee: Fujifilm Holdings Corp
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Filing: 1982-09-30
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Granted: 1983-12-13
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Expires: 2002-09-30
Abstract
Abstract A magnetic recording medium is disclosed. The medium is comprised of non-magnetic flexible support base having coated thereon a magnetic layer comprised of a ferromagnetic powder dispersed in a binder and a branched saturated fatty acid. The fatty acid has a melting point of 20° C. or less and contains from 12 to 30 carbon atoms. By including the particular fatty acid, it is possible to obtain a magnetic recording medium having excellent electromagnetic properties, excellent running properties and durability.
Inventors
- 👤 Hiroshi Ogawa
- 👤 Yasuo Tamai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 04:52
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/71; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31678
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
47 words
A magnetic recording medium, comprising; a non-magnetic flexible support base, having coated thereon; a magnetic layer comprised of a ferromagnetic powder dispersed in a binder and a branched saturated fatty acid having a melting point of 20° C. or less and having 12 or more carbon atoms.
Claim 2
Dependent Claim
47 words
A magnetic recording medium, comprising; a non-magnetic flexible support base, having coated thereon; a magnetic layer comprised of a ferromagnetic powder dispersed in a binder and a branched saturated fatty acid having a melting point of 20° C. or less and having 12 or more carbon atoms.
Claim 3
Dependent Claim
24 words
A magnetic recording medium, as claimed in claim 1, wherein the branched saturated fatty acid has a melting point of 10° C. or less.
Claim 4
Dependent Claim
24 words
A magnetic recording medium, as claimed in claim 1 or 2, wherein the branched saturated fatty acid contains from 12 to 30 carbon atoms.
Claim 5
Dependent Claim
34 words
A magnetic recording medium, as claimed in claim 3, wherein the branched saturated fatty acid is present in an amount of about 0.1 to 10 wt% based on the amount of the ferromagnetic powder.
Claim 6
Dependent Claim
33 words
A magnetic recording medium, as claimed in claim 4, wherein the branched saturated fatty acid is present in an amount of 0.5 to 5 wt% based on the amount of the ferromagnetic powder.
Claim 7
Dependent Claim
30 words
A magnetic recording medium, as claimed in claim 5, wherein the ferromagnetic powder is comprised of γ-Fe 2 O 3 , Co-modified iron oxide and an alloy powder containing iron.
Claim 8
Dependent Claim
56 words
A magnetic recording medium, as claimed in claim 3, wherein the branched saturated fatty acid is selected from the group consisting of lauric acid having a melting point of 10° C. or less, myristic acid having a melting point of 0° C. or less and stearic acid having a melting point of 0° C. or less.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-12-12 | 1987-06-13 | 1987-12-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-12-12 | 1991-06-13 | 1991-12-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-12-12 | 1995-06-13 | 1995-12-13 | $7700.00 | Window Closed / Lapsed |