US4824724A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording medium
Assignee: TDK Corp
•
Filing: 1986-05-30
•
Granted: 1989-04-25
•
Expires: 2006-05-30
Abstract
Abstract A magnetic recording medium is provided comprising a non-magnetic substrate, a magnetic metal layer of continuous thin film type deposited on the substrate, and a topcoat film on the magnetic layer. The topcoat film is formed by sputtering or ion plating a fluorocarbon resin so that it consists essentially of carbon and fluorine, and fluorine atoms of the topcoat film are chemically combined with metal atoms of the magnetic layer in proximity to the interface.
Inventors
- 👤 Kunihiro Ueda
- 👤 Yasufumi Takasugi
- 👤 Masatoshi Nakayama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 17:28
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/84; G11B5/8408; G11B5/62; G11B5/72; G11B5/722; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/26; Y10T428/263; Y10T428/264; Y10T428/265; Y10T428/31504; Y10T428/3154; Y10T428/31544
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
127 words
In a magnetic recording medium having improved corrosion resistance and minimum head clogging comprising a non-magnetic substrate, a magnetic metal layer of continuous thin film type deposited on the substrate, and a topcoat film on the magnetic layer, the improvement wherein the topcoat film has a thickness of about 5 Å to about 100 Å and has a contact angle with water between 70° and 120° and consists essentially of flourine and carbon in an atomic ratio of flourine to carbon in the range of 0.5:1 to 3:1 formed by sputtering or ion plating a flourocarbon resin, and flourine atoms of the topcoat film are chemically combined with metal atoms of the magnetic layer in proximity to the interface between the topcoat film and the magnetic layer.
Claim 2
Dependent Claim
127 words
In a magnetic recording medium having improved corrosion resistance and minimum head clogging comprising a non-magnetic substrate, a magnetic metal layer of continuous thin film type deposited on the substrate, and a topcoat film on the magnetic layer, the improvement wherein the topcoat film has a thickness of about 5 Å to about 100 Å and has a contact angle with water between 70° and 120° and consists essentially of flourine and carbon in an atomic ratio of flourine to carbon in the range of 0.5:1 to 3:1 formed by sputtering or ion plating a flourocarbon resin, and flourine atoms of the topcoat film are chemically combined with metal atoms of the magnetic layer in proximity to the interface between the topcoat film and the magnetic layer.
References Cited (Backward Citations)
US4260466A
Cited
US4390601A
Cited
US4419404A
Cited
US4495242A
Cited
US4521482A
Cited
US4429024A
Cited
US4529651A
Cited
JPS59160828A
Cited
US4582746A
Cited
US4565734A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-04-24 | 1992-10-24 | 1993-04-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-04-24 | 1996-10-24 | 1997-04-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-04-24 | 2000-10-24 | 2001-04-25 | $7700.00 | Window Closed / Lapsed |