US4477488A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of manufacturing magnetic recording medium
Assignee: Panasonic Holdings Corp
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Filing: 1983-03-10
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Granted: 1984-10-16
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Expires: 2003-03-10
Abstract
Abstract In making magnetic recording media by vapor-depositing magnetic metal film containing Co-Cr with 70-90 weight % Co as host material on a high polymer substrate, with or without intermediate layer(s) inbetween, making the high polymer substrate run around a cylindrical can, condition is selected such that linear expansion coefficient of the substrate is 1.0x10-5-2.9x10-5/ DEG C. and temperature of the can surface is 150 DEG -300 DEG C.; thereby normal or inverse curling of the resultant recording medium is substantially eliminated.
Inventors
- 👤 Ryuji Sugita
- 👤 Kenji Kanai
- 👤 Seishi Sasaki
- 👤 Ken Takahashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 06:39
CPC Classifications
H; H01; H01F; H01F41/00; H01F41/14; H01F41/20; G; G11; G11B; G11B5/00; G11B5/84; G11B5/851
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
107 words
A method of manufacturing a magnetic recording medium including a high polymer substrate with a magnetic film deposited thereon, with or without intermediate layer(s) therebetween, the magnetic film containing Co-Cr as a host material, the constituent of Co being in a range of 70-90 weight %, comprising the steps of: selecting the polymer substrate to have a linear expansion coefficient in the range of 1.0×10 -5 to 2.9×10 -5 /°C.; temperature controlling the outer surface of a cylindrical can to be within the range of 150°-300° C.; and running the polymer substrate around the temperature controlled can and vapor depositing the magnetic film thereon during the running.
Claim 2
Independent Claim
107 words
A method of manufacturing a magnetic recording medium including a high polymer substrate with a magnetic film deposited thereon, with or without intermediate layer(s) therebetween, the magnetic film containing Co-Cr as a host material, the constituent of Co being in a range of 70-90 weight %, comprising the steps of: selecting the polymer substrate to have a linear expansion coefficient in the range of 1.0×10 -5 to 2.9×10 -5 /°C.; temperature controlling the outer surface of a cylindrical can to be within the range of 150°-300° C.; and running the polymer substrate around the temperature controlled can and vapor depositing the magnetic film thereon during the running.
Claim 3
Independent Claim
154 words
A method manufacturing a magnetic recording medium including a high polymer substrate with a vertical magnetization magnetic film deposited thereon, and having an intermediate layer therebetween of vapor deposited Ti film, the magnetic film containing Co-Cr as a host material, the constituent of Co being in a range of 70-90 weight %, comprising the steps of: (a) selecting the polymer substrate to have a linear expansion coefficient in the range of 1.0×10 -5 to 2.9×10 -5 /°C.; (b) temperature controlling the outer surface of a cylindrical can to be within the range of 10°-120° C.; (c) running the polymer substrate around the can and vapor depositing the Ti film intermediate layer thereon; (d) temperature controlling the outer surface of a cylindrical can to be within the range of 150°-300° C.; and (e) running the polymer substrate around the temperature controlled can and vapor depositing the magnetic film over the intermediate layer during the running.
Claim 4
Independent Claim
154 words
A method manufacturing a magnetic recording medium including a high polymer substrate with a vertical magnetization magnetic film deposited thereon, and having an intermediate layer therebetween of vapor deposited Ti film, the magnetic film containing Co-Cr as a host material, the constituent of Co being in a range of 70-90 weight %, comprising the steps of: (a) selecting the polymer substrate to have a linear expansion coefficient in the range of 1.0×10 -5 to 2.9×10 -5 /°C.; (b) temperature controlling the outer surface of a cylindrical can to be within the range of 10°-120° C.; (c) running the polymer substrate around the can and vapor depositing the Ti film intermediate layer thereon; (d) temperature controlling the outer surface of a cylindrical can to be within the range of 150°-300° C.; and (e) running the polymer substrate around the temperature controlled can and vapor depositing the magnetic film over the intermediate layer during the running.
Claim 5
Dependent Claim
42 words
A method in accordance with claim 2, further comprising the steps of: prior to step (b), vapor depositing onto the substrate a permalloy film while running the substrate around said cylindrical can which is temperature controlled in a range of 120°-260° C.
Claim 6
Dependent Claim
42 words
A method in accordance with claim 2, further comprising a step of after step (c), vapor depositing a permalloy film onto said high polymer substrate while running it around said cylindrical can which is temperature controlled in a range of 120°-260° C.
References Cited (Backward Citations)
US3342633A
Cited
US4226681A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-10-16 | 1988-04-16 | 1988-10-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-10-16 | 1992-04-16 | 1992-10-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-10-16 | 1996-04-16 | 1996-10-16 | $7700.00 | Window Closed / Lapsed |