US4514451A
Expired / Lapsed
US
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Polyester substrate for magnetic recording medium having oligomer protrusions thereon
Assignee: Panasonic Holdings Corp
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Filing: 1983-07-18
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Granted: 1985-04-30
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Expires: 2003-07-18
Abstract
Abstract A magnetic recording media comprises a polyester substrate having 1000/mm2 or more protrusions of polyester oligomer, and a ferromagnetic thin film of 400 ANGSTROM or larger thickness both formed on the surface of the polyester substrate; the recording media has substantially no squealing even at 30 DEG C. at over 80% relative humidity.
Inventors
- 👤 Takashi Suzuki
- 👤 Koichi Shinohara
- 👤 Masaru Odagiri
- 👤 Takashi Fujita
- 👤 Shigeki Kawase
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 22:25
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/64; G11B5/65; G11B5/658; G11B5/73; G11B5/739; G11B5/73923; G11B5/73927; G11B5/84; H; H01; H01F; H01F41/00; H01F41/14; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/24; Y10T428/24355; Y10T428/24372; Y10T428/24405; Y10T428/24446; Y10T428/24942; Y10T428/2495; Y10T428/24967; Y10T428/24975; Y10T428/24992; Y10T428/31; Y10T428/31504; Y10T428/31678; Y10T428/31681
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
70 words
A magnetic recording medium comprising: a polyester substrate having oligomer protrusions at least on its principal face, said protrusions present at a density of 1000/mm 2 or higher, and a ferromagnetic thin film having a thickness of 400 Å or larger formed on said principal face, wherein the heights of said oligomer protrusions are 100Å-14 2000 Å and the lateral spread of said oligomer protrusions is 1 μm or smaller.
Claim 2
Dependent Claim
70 words
A magnetic recording medium comprising: a polyester substrate having oligomer protrusions at least on its principal face, said protrusions present at a density of 1000/mm 2 or higher, and a ferromagnetic thin film having a thickness of 400 Å or larger formed on said principal face, wherein the heights of said oligomer protrusions are 100Å-14 2000 Å and the lateral spread of said oligomer protrusions is 1 μm or smaller.
Claim 3
Dependent Claim
32 words
A magnetic recording medium in accordance with claim 1, wherein the heights of said oligomer protrusions are 150Å-1000 Å and the lateral spread of said oligomer protrusions is 0.5 μm or smaller.
Claim 4
Dependent Claim
21 words
A magnetic recording medium in accordance with claim 1, wherein said ferromagnetic thin film comprises predominantly a ferromagnetic metal containing oxygen.
Claim 5
Dependent Claim
23 words
A magnetic recording medium in accordance with claim 1 which further comprises a lubrication layer on the surface of said ferromagnetic thin film.
Claim 6
Dependent Claim
24 words
A magnetic recording medium in accordance with claim 1 which further comprises an interface thin film between said polyester substrate and ferromagnetic thin film.
Claim 7
Dependent Claim
35 words
A magnetic recording medium in accordance with claim 5, wherein said interface thin film is of a substance selected from the group consisting of Ti, Cr, Ni, Al 2 O 3 and SiO 2 .
Claim 8
Dependent Claim
25 words
A magnetic recording medium in accordance with claim 5, wherein said interface thin layer is in the form of a wave or granular shaped pattern.
Claim 9
Dependent Claim
19 words
A magnetic recording medium in accordance with claim 5, wherein said interface thin film layer has a wrinkled surface.
Claim 10
Dependent Claim
70 words
A magnetic recording medium comprising: a polyester substrate having oligomer protrusions at least on its principal face, said protrusions present at a density of 2500/mm 2 or higher, and a ferromagnetic thin film having a thickness of 400 Å or larger formed on said principal face, wherein the heights of said oligomer protrusions are 150 Å-1000 Å and the lateral spread of said oligomer protrusions is 1 μm or smaller.
Claim 11
Dependent Claim
70 words
A magnetic recording medium comprising: a polyester substrate having oligomer protrusions at least on its principal face, said protrusions present at a density of 2500/mm 2 or higher, and a ferromagnetic thin film having a thickness of 400 Å or larger formed on said principal face, wherein the heights of said oligomer protrusions are 150 Å-1000 Å and the lateral spread of said oligomer protrusions is 1 μm or smaller.
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) | 1988-04-29 | 1988-10-29 | 1989-04-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-04-29 | 1992-10-29 | 1993-04-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-04-29 | 1996-10-29 | 1997-04-30 | $7700.00 | Window Closed / Lapsed |