US4499138A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording medium
Assignee: Fujifilm Holdings Corp
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Filing: 1984-02-01
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Granted: 1985-02-12
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Expires: 2004-02-01
Abstract
Abstract A magnetic recording medium having a thin magnetic metal layer on a base is disclosed. A thin metal film of Group IA, IB, IIA, IIB, IIIB, IVA, IVB, VA, VB, VIA, VIB or VIIB of the Periodic Table is formed on the thin magnetic metal layer or the base on the reverse side of which the thin magnetic metal layer is formed. A layer of aliphatic acid is further formed on said thin metal film.
Inventors
- 👤 Nobuyuki Yamamoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:45
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/84; G11B5/851; G11B5/62; G11B5/64; G11B5/72; G11B5/725; G11B5/8416; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10S428/922; Y10S428/9265; Y10S428/928; Y10T; Y10T428/00; Y10T428/12; Y10T428/12431; Y10T428/12438; Y10T428/12493; Y10T428/12535; Y10T428/12583; Y10T428/1259; Y10T428/24; Y10T428/24942; Y10T428/2495; Y10T428/24967; Y10T428/24975; Y10T428/26; Y10T428/263; Y10T428/264; Y10T428/265
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
83 words
A magnetic recording tape comprising: a base; a thin magnetic metal layer formed on a first side of said base; a thin metal film formed on a second side of said base wherein, said thin metal film is comprised of a metal selected from the group consisting of Mg, Ca, Sr, Ba, Cu, Zn, Cd, Sn and Pb; and a layer of aliphatic acid formed on said thin metal film wherein said thin magnetic metal film chemically reacts with said aliphatic acid layer.
Claim 2
Dependent Claim
83 words
A magnetic recording tape comprising: a base; a thin magnetic metal layer formed on a first side of said base; a thin metal film formed on a second side of said base wherein, said thin metal film is comprised of a metal selected from the group consisting of Mg, Ca, Sr, Ba, Cu, Zn, Cd, Sn and Pb; and a layer of aliphatic acid formed on said thin metal film wherein said thin magnetic metal film chemically reacts with said aliphatic acid layer.
Claim 3
Dependent Claim
24 words
A magnetic recording tape as claimed in claim 1, wherein said thin metal film has a thickness of about 5 to about 2,000 Å.
Claim 4
Dependent Claim
22 words
A magnetic recording tape as claimed in claim 2, wherein said thin metal film has a thickness of 10 to 500 Å.
Claim 5
Dependent Claim
26 words
A magnetic recording tape as claimed in claim 1, wherein said aliphatic acid is a saturated or unsaturated aliphatic acid having 8 to 26 carbon atoms.
Claim 6
Dependent Claim
28 words
A magnetic recording tape as claimed in claim 1, wherein said thin metal film is formed by co-vapor deposition of two or more different types of said metals.
Claim 7
Dependent Claim
27 words
A magnetic recording tape as claimed in claim 1, wherein said thin magnetic metal layer has a thickness in the range of from 0.05 to 2 μm.
Claim 8
Dependent Claim
24 words
A magnetic recording tape as claimed in claim 1, wherein said thin magnetic metal layer has a thickness of from 0.1 to 0.4 μm.
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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) | 1988-02-12 | 1988-08-13 | 1989-02-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-02-12 | 1992-08-13 | 1993-02-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-02-12 | 1996-08-13 | 1997-02-12 | $7700.00 | Window Closed / Lapsed |