Patent US4599266A successfully refreshed from Google Patents.
US4599266A
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Magnetic recording medium
Assignee: TDK Corp
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Filing: 1985-03-18
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Granted: 1986-07-08
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Expires: 2005-03-18
Abstract
Abstract A magnetic recording medium is coated, over its magnetic layer, with a thin film of a siloxane-linkage-containing polymer. The magnetic layer consists of a thin film formed by vacuum evaporation or sputtering or by dispersion of a ferromagnetic metal powder in a binder. The polymer having the siloxane linkage is prepared by polymerizing an organo-silicon compound which either inherently possesses the linkage or is capable of producing it. The polymerization is preferably effected by the plasma polymerization technique.
Inventors
- 👤 Masatoshi Nakayama
- 👤 Haruyuki Morita
- 👤 Yasumichi Tokuoka
- 👤 Toshiaki Izumi
- 👤 Kazumasa Fukuda
- 👤 Yuichi Kubota
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 09:17
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/72; G11B5/725; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/26; Y10T428/263; Y10T428/264; Y10T428/265; Y10T428/31504; Y10T428/31652; Y10T428/31663
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
50 words
A magnetic recording medium comprising a base, a magnetic layer formed thereon consisting essentially of a metal or a metal with a binder, and a thin film of a polymer having a siloxane linkage, said thin film formed by a plasma polymerization means so as to cover said magnetic layer.
Claim 2
Dependent Claim
50 words
A magnetic recording medium comprising a base, a magnetic layer formed thereon consisting essentially of a metal or a metal with a binder, and a thin film of a polymer having a siloxane linkage, said thin film formed by a plasma polymerization means so as to cover said magnetic layer.
Claim 3
Dependent Claim
38 words
The medium according to claim 1 wherein said magnetic layer consists of a thin film formed by a means selected from the group consisting of vacuum evaporation, sputtering and dispersion of a ferromagnetic metal powder in a binder.
Claim 4
Dependent Claim
33 words
The medium according to claim 1 wherein said polymer having a siloxane linkage is prepared by polymerizing an organosilicon compound which either inherently possesses the linkage or is capable of producing the same.
Claim 5
Dependent Claim
14 words
The medium according to claim 1 having a frictional coefficient of less than 0.30.
Claim 6
Dependent Claim
33 words
The medium according to claim 2 wherein said polymer having a siloxane linkage is prepared by polymerizing an organosilicon compound which either inherently possesses the linkage or is capable of producing the same.
Claim 7
Dependent Claim
21 words
The medium according to claim 1 wherein the thickness of the polymer film is from about 5 Å to about 1000Å.
Claim 8
Dependent Claim
14 words
The medium according to claim 1 wherein the plasma polymerization means includes high-frequency-waive discharge.
Claim 9
Dependent Claim
14 words
The medium according to claim 1 wherein the plasma polymerization means includes microwaive discharge.
Claim 10
Dependent Claim
64 words
A process for forming a low-friction siloxane polymer on a magnetic recording medium comprising contacting a medium having a base and a magnetic layer formed thereon consisting essentially of a metal or a metal with a binder with a plasma of a monomer polymerizable to a siloxane polymer, and polymerizing said monomer to form a thin polymer film on the surface of said medium.
Claim 11
Dependent Claim
64 words
A process for forming a low-friction siloxane polymer on a magnetic recording medium comprising contacting a medium having a base and a magnetic layer formed thereon consisting essentially of a metal or a metal with a binder with a plasma of a monomer polymerizable to a siloxane polymer, and polymerizing said monomer to form a thin polymer film on the surface of said medium.
Claim 12
Dependent Claim
12 words
A process according to claim 9 wherein polymerization is by high-frequency discharge.
Claim 13
Dependent Claim
11 words
A process according to claim 9 wherein polymerization is by microwave-discharge.
Claim 14
Dependent Claim
62 words
A process according to claim 10 comprising the steps of injecting said monomer and a carrier gas into an evacuated reaction vessel maintained at a pressure of between about 0.01 and about 10 Torr, and contacting said monomer with a medium continuously conveyed between a pair of parallel energized electrodes to cause said monomer to polymerize on the surface of the medium.
Claim 15
Dependent Claim
47 words
A process according to claim 12 wherein the monomer is fed into the reaction vessel at a flow rate between about 1 and about 100 ml/mn and the carrier gas is fed into the reaction vessel at a flow rate between about 50 to about 500 ml/mn.
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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) | 1989-07-07 | 1990-01-06 | 1990-07-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-07-07 | 1994-01-06 | 1994-07-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-07-07 | 1998-01-06 | 1998-07-08 | $7700.00 | Window Closed / Lapsed |