US5055359A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording medium with an intermediate protective layer of silicon dioxide and a perfluoroalkylpolyether lubricant layer
Assignee: Nippon Sheet Glass Co Ltd
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Filing: 1991-02-20
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Granted: 1991-10-08
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Expires: 2011-02-20
Abstract
Abstract In a magnetic recording medium having a layer of a perfluoroalkylpolyether-based liquid lubricant as an uppermost layer, the liquid lubricant has an atomic group including an aromatic ring at a terminal end of a perfluoropolyether main chain, and is coated on an inorganic oxide. Therefore, adhesion force of the lubricant is greatly improved, and interaction within the lubricant can be decreased, thus realizing a magnetic recording medium having excellent lubricity and wear resistance.
Inventors
- 👤 Toshio Tsuno
- 👤 Shinya Katayama
- 👤 Shinya Kawakita
- 👤 Tomoyasu Shimizu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 11:36
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/72; G11B5/725; G11B5/7253; G11B5/7257; G11B5/726; G11B5/7262; Y; Y10; Y10S; Y10S428/00; Y10S428/90
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
116 words
A magnetic recording medium comprising: (a) a magnetic recording layer; (b) a protective layer of silicon dioxide provided on the magnetic recording layer directly or with another protective layer interposed therebetween; and (c) an uppermost layer of a perfluoroalkylpolyether-based liquid lubricant having an atomic group which contains an aromatic ring at a terminal end of a perfluoropolyether main chain, wherein said layer of lubricant is provided directly on the layer of silicon dioxide, and wherein adhesion between said layer of silicon dioxide and said layer of lubricant is strengthened by thermal treatment of the layer of lubricant coated on the layer of silicon dioxide at a temperature in the range of 60° C. to 250° C.
Claim 2
Dependent Claim
116 words
A magnetic recording medium comprising: (a) a magnetic recording layer; (b) a protective layer of silicon dioxide provided on the magnetic recording layer directly or with another protective layer interposed therebetween; and (c) an uppermost layer of a perfluoroalkylpolyether-based liquid lubricant having an atomic group which contains an aromatic ring at a terminal end of a perfluoropolyether main chain, wherein said layer of lubricant is provided directly on the layer of silicon dioxide, and wherein adhesion between said layer of silicon dioxide and said layer of lubricant is strengthened by thermal treatment of the layer of lubricant coated on the layer of silicon dioxide at a temperature in the range of 60° C. to 250° C.
References Cited (Backward Citations)
US4721795A
Cited
US4757145A
Cited
US4808472A
Cited
US4889939A
Cited
US4729924A
Cited
JPS63285723A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-10-07 | 1995-04-08 | 1995-10-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-10-07 | 1999-04-08 | 1999-10-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-10-07 | 2003-04-08 | 2003-10-08 | $7700.00 | Window Closed / Lapsed |