US4680218A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording medium
Assignee: Victor Company of Japan Ltd
•
Filing: 1985-09-23
•
Granted: 1987-07-14
•
Expires: 2005-09-23
Abstract
Abstract A magnetic recording medium comprises a base, a magnetic layer made of a magnetic material and formed on the base, a lubricant layer made of a lubricant material having lubricity and formed on the magnetic layer, and a corrosion resisting layer made of a corrosion resisting material having corrosion resistance and formed on the lubricant layer. An additional corrosion resisting layer made of a corrosion resisting material having corrosion resistance may be provided between the magnetic layer and the lubricant layer.
Inventors
- 👤 Akihiro Kimura
- 👤 Toshio Ando
- 👤 Toshikazu Nishihara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 03:52
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/64; G11B5/66; G11B5/72; G11B5/722; G11B5/725; G11B5/726; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/24; Y10T428/24802
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
117 words
A magnetic recording medium comprising: a base; a magnetic layer formed on the base, said magnetic layer being made of a magnetic material; a lubricant layer formed on the magnetic layer, said lubricant layer being made of a lubricant material having lubricity; and having a thickness in a range of approximately 5 nm to 200 nm; and a corrosion resisting layer formed on the lubricant layer, said corrosion resisting layer being made of a corrosion resisting material having corrosion resistance and being distributed locally on said lubricant layer so that at least a part of said lubricant layer is exposed, said corrosion resisting layer having a thickness in a range of approximately 1 nm to 7 nm.
Claim 2
Dependent Claim
117 words
A magnetic recording medium comprising: a base; a magnetic layer formed on the base, said magnetic layer being made of a magnetic material; a lubricant layer formed on the magnetic layer, said lubricant layer being made of a lubricant material having lubricity; and having a thickness in a range of approximately 5 nm to 200 nm; and a corrosion resisting layer formed on the lubricant layer, said corrosion resisting layer being made of a corrosion resisting material having corrosion resistance and being distributed locally on said lubricant layer so that at least a part of said lubricant layer is exposed, said corrosion resisting layer having a thickness in a range of approximately 1 nm to 7 nm.
Claim 3
Dependent Claim
40 words
A magnetic recording medium as claimed in claim 1 in which said corrosion resisting material is selectd out of a group of chromium, titanium, Ni--Cr alloy, Fe--Cr alloy, Co--Cr alloy, molybdenum, TiC, TiN, zinc, aluminum, Fe--Ni alloy, and Fe--Ni--Cr alloy.
Claim 4
Dependent Claim
29 words
A magnetic recording medium as claimed in claim 1 in which said lubricant material is selected out of a group of carbon, molybdenum disulfide, carbon nitride, and boron nitride.
Claim 5
Dependent Claim
26 words
A magnetic recording medium as claimed in claim 1 in which said corrosion resisting layer is distributed locally on said lubricant layer in an insular manner.
Claim 6
Dependent Claim
163 words
A magnetic recording medium comprising: a base; a magnetic layer formed on the base, said magnetic layer being made of a magnetic material; a first corrosion resisting layer formed on said magnetic layer, said first corrosion resisting layer being made of a first corrosion resisting material having corrosion resistance and having a thickness in a range of a approximately 2 nm to 100 nm; a lubricant layer formed on the first corrosion resisting layer, said lubricant layer being made of a lubricant material having lubricity and having a thickness in a range of approximately 5 nm to 100 nm; and a second corrosion resisting layer formed on the lubricant layer, said second corrosion resisting layer having made of a second corrosion resisting material being corrosion resistance and being distributed locally on said lubricant layer so that at least a part of said lubricant layer is exposed said second corrosion layer having a thickness in a range of approximately 1 nm to 7 nm.
Claim 7
Dependent Claim
163 words
A magnetic recording medium comprising: a base; a magnetic layer formed on the base, said magnetic layer being made of a magnetic material; a first corrosion resisting layer formed on said magnetic layer, said first corrosion resisting layer being made of a first corrosion resisting material having corrosion resistance and having a thickness in a range of a approximately 2 nm to 100 nm; a lubricant layer formed on the first corrosion resisting layer, said lubricant layer being made of a lubricant material having lubricity and having a thickness in a range of approximately 5 nm to 100 nm; and a second corrosion resisting layer formed on the lubricant layer, said second corrosion resisting layer having made of a second corrosion resisting material being corrosion resistance and being distributed locally on said lubricant layer so that at least a part of said lubricant layer is exposed said second corrosion layer having a thickness in a range of approximately 1 nm to 7 nm.
Claim 8
Dependent Claim
43 words
A magnetic recording medium as claimed in claim 5 in which said first and second corrosion resisting materials are selected out of a group of chromium, titanium, Ni--Cr alloy, Fe--Cr alloy, Co--Cr alloy, molybdenum, TiC, TiN, zinc, aluminum, Fe--Ni alloy, and Fe--Ni--Cr alloy.
Claim 9
Dependent Claim
29 words
A magnetic recording medium as claimed in claim 5 in which said lubricant material is selected out of a group of carbon, molybdenum disulfide, carbon nitride, and boron nitride.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-07-13 | 1991-01-12 | 1991-07-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-07-13 | 1995-01-12 | 1995-07-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-07-13 | 1999-01-12 | 1999-07-14 | $7700.00 | Window Closed / Lapsed |