US4833044A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Film type magnetic recording medium
Assignee: Tohoku Steel Co Ltd
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Filing: 1984-05-29
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Granted: 1989-05-23
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Expires: 2004-05-29
Abstract
Abstract A film type magnetic recording medium comprising as a magnetic recording layer an iron-cobalt-nickel-chromium magnetic alloy containing 10-51 wt. % cobalt, 1-30 wt. % nickel, 1-10 wt. % of chromium and 6 wt. % or less of at least one of the elements molybdenum, tungsten, vanadium, niobium, tantalum, copper, titanium and zirconium, high in durability and magnetic property, and moreover, capable of easily forming a magnetic alloy film thereon by vacuum deposition.
Inventors
- 👤 Minoru Takahashi
- 👤 Terunobu Miyazaki
- 👤 Susumu Shinagawa
- 👤 Yuudou Abe
- 👤 Yoshinobu Saitou
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 08:01
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/64; G11B5/65; G11B5/656; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/12; Y10T428/12465; Y10T428/31504; Y10T428/31507; Y10T428/31786
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
76 words
A film type magnetic recording medium comprising a base and a magnetic recording layer formed on said base, wherein said recording layer comprises an iron-cobalt-nickel-chromium magnetic alloy comprising from 10 to 51 wt% cobalt, from 1 to 30 wt% nickel, 10 wt% chromium or less, 6 wt% or less of at least one element selected from the group consisting of molybdenum, tungsten, vanadium, niobium, tantalum, copper, titanium and zirconium, the balance being iron and inevitable impurities.
Claim 2
Dependent Claim
76 words
A film type magnetic recording medium comprising a base and a magnetic recording layer formed on said base, wherein said recording layer comprises an iron-cobalt-nickel-chromium magnetic alloy comprising from 10 to 51 wt% cobalt, from 1 to 30 wt% nickel, 10 wt% chromium or less, 6 wt% or less of at least one element selected from the group consisting of molybdenum, tungsten, vanadium, niobium, tantalum, copper, titanium and zirconium, the balance being iron and inevitable impurities.
Claim 3
Dependent Claim
39 words
The film type magnetic recording medium as in claim 1 wherein the alloy comprises 51 wt% cobalt or less and 20 wt% nickel or less within the hatched area in FIG. 1, and from 3 to 9 wt% chromium.
Claim 4
Dependent Claim
33 words
The film type magnetic recording medium as in claim 2 further comprising 3 wt% or less of at least one element selected from the group consisting of calcium, magnesium, aluminum, silicon and manganese.
Claim 5
Dependent Claim
44 words
The film type magnetic recording medium as in claim 3 further comprising 0.1 wt% or less of at least one element selected from the group consisting of gold, silver, one of platinum group elements, lanthanum and cerium, the balance being iron and inevitable impurities.
Claim 6
Dependent Claim
38 words
The film type magnetic recording medium as in claim 1, wherein said base comprises a film made of a plastic selected from the group consisting of polyethylene terephthalate, polycarbonate, and polypropylene and a primary-coating layer on said film.
Claim 7
Dependent Claim
38 words
A film type magnetic recording medium as in claim 2, wherein said base comprises a film made of a plastic selected from the group consisting of polyethylene terephthalate, polycarbonate, and polypropylene and a primary-coating layer on said film.
Claim 8
Dependent Claim
38 words
A film type magnetic recording medium as in claim 3, wherein said base comprises a film made of a plastic selected from the group consisting of polyethylene terephthalate, polycarbonate, and polypropylene and a primary-coating layer on said film.
Claim 9
Dependent Claim
38 words
A film type magnetic recording medium as in claim 4, wherein said base comprises a film made of a plastic selected from the group consisting of polyethylene terephthalate, polycarbonate, and polypropylene and a primary-coating layer on said film.
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) | 1992-05-22 | 1992-11-21 | 1993-05-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-05-22 | 1996-11-21 | 1997-05-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-05-22 | 2000-11-21 | 2001-05-23 | $7700.00 | Window Closed / Lapsed |