US4564549A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording media and process for fabricating the same
Assignee: Panasonic Holdings Corp
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Filing: 1984-10-03
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Granted: 1986-01-14
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Expires: 2004-10-03
Abstract
Abstract A thin film of a ferromagnetic metal or alloy and containing oxygen is formed over the surface of an elongated polyester film, said surface being formed with worm-like or particle-like projections consisting of cured high-molecular weight compounds.
Inventors
- 👤 Takashi Suzuki
- 👤 Koichi Shinohara
- 👤 Masaru Odagiri
- 👤 Takashi Fujita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 20:01
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/73; G11B5/7368; G11B5/739; G11B5/73923; G11B5/73927; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/24; Y10T428/24355; Y10T428/24372; Y10T428/24405; Y10T428/24446; Y10T428/24942
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
87 words
A magnetic recording medium characterized in that a thin film of ferromagnetic metal containing oxygen is formed over the surface of an elongated polyester film which is coated with worm-like or particle-like projections comprising a cured high-molecular weight compound having a surface roughness, R max , of 0.003 to 0.1 micrometers and wherein the back surface of said film also has worm-like or particle-like projections comprising a cured high-molecular weight compound and is further formed with a thin film of a high-molecular weight compound containing a lubricant.
Claim 2
Dependent Claim
87 words
A magnetic recording medium characterized in that a thin film of ferromagnetic metal containing oxygen is formed over the surface of an elongated polyester film which is coated with worm-like or particle-like projections comprising a cured high-molecular weight compound having a surface roughness, R max , of 0.003 to 0.1 micrometers and wherein the back surface of said film also has worm-like or particle-like projections comprising a cured high-molecular weight compound and is further formed with a thin film of a high-molecular weight compound containing a lubricant.
Claim 3
Dependent Claim
44 words
A magnetic recording medium as set forth in claim 1 further characterized in that said thin film of ferromagnetic metal is formed over a nonmagnetic thin film which in turn is formed over the surface of said elongated polyester film and which contains oxygen.
Claim 4
Dependent Claim
95 words
A process for fabricating magnetic recording media characterized by the steps of forming, in vacuum containing oxygen, a thin film of a ferromagnetic metal or alloy over the front surface of an elongated polyester film, the front surface thereof being coated with worm-like or particle-like projections comprising a cured high-molecular weight compound having a surface roughness, R max , of 0.003 to 0.1 micrometers while the back surface thereof being coated with worm-like or particle-like projections comprising a cured high-molecular compound or with a thin film of a resin dispersed with finely divided solid particles.
Claim 5
Dependent Claim
95 words
A process for fabricating magnetic recording media characterized by the steps of forming, in vacuum containing oxygen, a thin film of a ferromagnetic metal or alloy over the front surface of an elongated polyester film, the front surface thereof being coated with worm-like or particle-like projections comprising a cured high-molecular weight compound having a surface roughness, R max , of 0.003 to 0.1 micrometers while the back surface thereof being coated with worm-like or particle-like projections comprising a cured high-molecular compound or with a thin film of a resin dispersed with finely divided solid particles.
Claim 6
Dependent Claim
52 words
A process for fabricating magnetic recording media as set forth in claim 3 further characterized by a step of, after said thin film or a ferromagnetic metal or alloy having been formed, forming a thin film of a high-molecular compound containing a lubricant over the back surface of said elongated polyester film.
Claim 7
Dependent Claim
94 words
A magnetic recording medium characterized in that a thin ferromagnetic metal film containing more than 3% oxygen, in terms of atomic ratio, is directly or through a thin non-magnetic film containing more than 3% oxygen, formed over the front surface of an elongated polyester film whose surface roughness is from 0.003 to 0.1 micrometers in terms of R max and whose front and back surfaces have worm-like or particle-like projections comprised of a cured high-molecular weight compound and wherein said back surface has a thin film of a high-molecular weight compound containing a lubricant.
Claim 8
Dependent Claim
94 words
A magnetic recording medium characterized in that a thin ferromagnetic metal film containing more than 3% oxygen, in terms of atomic ratio, is directly or through a thin non-magnetic film containing more than 3% oxygen, formed over the front surface of an elongated polyester film whose surface roughness is from 0.003 to 0.1 micrometers in terms of R max and whose front and back surfaces have worm-like or particle-like projections comprised of a cured high-molecular weight compound and wherein said back surface has a thin film of a high-molecular weight compound containing a lubricant.
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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) | 1989-01-13 | 1989-07-15 | 1990-01-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-01-13 | 1993-07-15 | 1994-01-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-01-13 | 1997-07-15 | 1998-01-14 | $7700.00 | Window Closed / Lapsed |