Patent US4722859A successfully refreshed from Google Patents.
US4722859A
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US
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Magnetic recording medium
Assignee: HGST Japan Ltd
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Filing: 1986-09-08
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Granted: 1988-02-02
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Expires: 2006-09-08
Abstract
Abstract This invention relates to a magnetic recording medium comprising a magnetic recording film formed on a substrate directly or with a protective layer therebetween, characterized in that a surface treatment layer made of a reaction product of an azide compound is provided on the magnetic recording film, and preferably a lubricative material layer is further provided on the surface treatment layer. The surface treatment agent is covalently bonded to the surface of the magnetic recording film with an aid of nitrene to improve the durability of the magnetic recording film.
Inventors
- 👤 Takanori Kudo
- 👤 Heigo Ishihara
- 👤 Motoo Akagi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 19:02
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/72; G11B5/725; G11B5/7253; G11B5/7257; G11B5/64; G11B5/66; G11B5/726; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/24; Y10T428/24942; Y10T428/2495; Y10T428/24967; Y10T428/24975; Y10T428/26; Y10T428/263; Y10T428/264; Y10T428/265; Y10T428/31; Y10T428/31504; Y10T428/3154; Y10T428/31544
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
124 words
A magnetic recording medium comprising a magnetic recording film formed on a substrate directly or with a protective layer therebetween, characterized in that a surface treatment layer having a thickness in the range of 5 to 500 Å and being made of a reaction product of an azide compound having as a fundamental skeleton partially or entirely fluorinated alkyl chain and at least one azido group is provided on said magnetic recording film directly or on a protective layer formed on said magnetic recording film, and a layer of a lubricative material having a thickness in the range of 20 to 500 Å and being made of a perfluoroalkyl polyether or a partially or entirely fluorinated alkane is provided on said surface treatment layer.
Claim 2
Dependent Claim
124 words
A magnetic recording medium comprising a magnetic recording film formed on a substrate directly or with a protective layer therebetween, characterized in that a surface treatment layer having a thickness in the range of 5 to 500 Å and being made of a reaction product of an azide compound having as a fundamental skeleton partially or entirely fluorinated alkyl chain and at least one azido group is provided on said magnetic recording film directly or on a protective layer formed on said magnetic recording film, and a layer of a lubricative material having a thickness in the range of 20 to 500 Å and being made of a perfluoroalkyl polyether or a partially or entirely fluorinated alkane is provided on said surface treatment layer.
Claim 3
Dependent Claim
121 words
A magnetic recording medium comprising a magnetic recording film formed on a substrate directly or with a protective layer therebetween, characterized in that a surface treatment layer having a thickness in the range of 5 to 500 Å and being made of a reaction product of a fluorinecontaining azide compound having perfluoroalkyl polyether chains and also having at least one azido group is provided on said magnetic recording film directly or on a protective layer formed on said magnetic recording film, and a layer of a lubricative material having a thickness in the range of 20 to 500 Å and being made of a fluorine-containing compound having as a fundamental skeleton a perfluoroalkyl polyether is provided on said surface treatment layer.
Claim 4
Dependent Claim
121 words
A magnetic recording medium comprising a magnetic recording film formed on a substrate directly or with a protective layer therebetween, characterized in that a surface treatment layer having a thickness in the range of 5 to 500 Å and being made of a reaction product of a fluorinecontaining azide compound having perfluoroalkyl polyether chains and also having at least one azido group is provided on said magnetic recording film directly or on a protective layer formed on said magnetic recording film, and a layer of a lubricative material having a thickness in the range of 20 to 500 Å and being made of a fluorine-containing compound having as a fundamental skeleton a perfluoroalkyl polyether is provided on said surface treatment layer.
Claim 5
Dependent Claim
85 words
A magnetic recording medium comprising a magnetic recording film formed on a substrate directly or with a protective layer therebetween, characterized in that a surface treatment layer having a thickness in the range of 5 to 500 Å and being made of a reaction product of an azide compound having as a fundamental skeleton partially or entirely fluorinated alkyl chain and at least one azido group is provided on said magnetic recording film directly or on a protective layer formed on said magnetic recording film.
Claim 6
Dependent Claim
85 words
A magnetic recording medium comprising a magnetic recording film formed on a substrate directly or with a protective layer therebetween, characterized in that a surface treatment layer having a thickness in the range of 5 to 500 Å and being made of a reaction product of an azide compound having as a fundamental skeleton partially or entirely fluorinated alkyl chain and at least one azido group is provided on said magnetic recording film directly or on a protective layer formed on said magnetic recording film.
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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) | 1991-02-01 | 1991-08-03 | 1992-02-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-02-01 | 1995-08-03 | 1996-02-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-02-01 | 1999-08-03 | 2000-02-02 | $7700.00 | Window Closed / Lapsed |