US4522885A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording medium
Assignee: Maxell Ltd
•
Filing: 1984-02-10
•
Granted: 1985-06-11
•
Expires: 2004-02-10
Abstract
Abstract A magnetic recording medium which comprises a substrate and a magnetic layer comprising magnetic powder and a resinous binder formed on the substrate, characterized in that the magnetic layer further comprises a lubricant and an unsaturated fatty acid ester, which is improved in durability.
Inventors
- 👤 Masaya Funahashi
- 👤 Kenichi Inoue
- 👤 Kunio Mizushima
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 16:12
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/71; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/31504; Y10T428/3154; Y10T428/31544; Y10T428/31652; Y10T428/31663; Y10T428/31844; Y10T428/31855
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
85 words
A magnetic recording disc which comprises a disc substrate and a magnetic layer comprising magnetic powder and a resinous binder formed on the substrate, characterized in that the magnetic layer further comprises at least one lubricant chosen from hydrocarbons, fluorinated compounds and silicone compounds and at least one unsaturated fatty acid ester chosen from oleyl oleate and n-butyl oleate, the combined amount of the lubricant and the unsaturated fatty acid ester being from 0.1 to 40% by weight to the amount of the magnetic powder.
Claim 2
Dependent Claim
85 words
A magnetic recording disc which comprises a disc substrate and a magnetic layer comprising magnetic powder and a resinous binder formed on the substrate, characterized in that the magnetic layer further comprises at least one lubricant chosen from hydrocarbons, fluorinated compounds and silicone compounds and at least one unsaturated fatty acid ester chosen from oleyl oleate and n-butyl oleate, the combined amount of the lubricant and the unsaturated fatty acid ester being from 0.1 to 40% by weight to the amount of the magnetic powder.
Claim 3
Dependent Claim
26 words
The magnetic recording medium according to claim 1, wherein the weight ratio of the lubricant and the unsaturated fatty acid ester is from 99:1 to 1:99.
Claim 4
Dependent Claim
14 words
The magnetic recording medium according to claim 1, wherein the lubricant is a hydrocarbon.
Claim 5
Dependent Claim
30 words
The magnetic recording medium according to claim 3, wherein the lubricant is a hydrocarbon chosen from liquid paraffin, natural squalane, natural squalene, synthetic squalane, synthetic squalene and olefin polymerized oil.
Claim 6
Dependent Claim
15 words
The magnetic recording medium according to claim 1, wherein the lubricant is a fluorinated compound.
Claim 7
Dependent Claim
26 words
The magnetic recording medium according to claim 5, wherein the fluorinated compound is the one chosen from tetrafluoroethylene, hexafluoropropylene, trichlorofluoroethylene, perfluoroalkyl polyether and fluorinated alkyl ester.
Claim 8
Dependent Claim
15 words
The magnetic recording medium according to claim 1, wherein the lubricant is a silicone compound.
Claim 9
Dependent Claim
28 words
The magnetic recording medium according to claim 7, wherein the silicone compound is the one chosen from dimethyl silicone oil, methyl phenyl silicone oil and fluorinated silicone oil.
Claim 10
Dependent Claim
20 words
The magnetic recording disc according to claim 1, wherein the magnetic layer is provided on each side of the substrate.
Claim 11
Dependent Claim
46 words
The magnetic recording disc according to claim 1, wherein the magnetic layer is prepared by a process which includes the steps of mixing the magnetic powder, the resinous binder and the unsaturated fatty acid ester, applying the mixture to said substrate and drying the magnetic layer.
Claim 12
Dependent Claim
57 words
The magnetic recording disc according to claim 1, wherein the magnetic layer is prepared by a process which includes the steps of mixing the magnetic powder, the resinous binder, the unsaturated fatty acid ester and a solvent, applying the mixture to said substrate to form a layer, applying the lubricant to the layer and drying the layer.
Claim 13
Dependent Claim
91 words
A magnetic recording disc which comprises a disc substrate and a magnetic layer formed on said substrate, said magnetic layer consisting essentially of a mixture of magnetic powder, a resinous binder and 0.1 to 40% by weight based on the amount of the magnetic powder of at least one unsaturated fatty acid ester chosen from oleyl oleate and n-butyl oleate and at least one lubricant chosen from hydrocarbons, fluorinated compounds and silicone compounds wherein the weight ratio of the lubricant and the unsaturated fatty acid ester is from 99:1 to 1:99.
Claim 14
Dependent Claim
91 words
A magnetic recording disc which comprises a disc substrate and a magnetic layer formed on said substrate, said magnetic layer consisting essentially of a mixture of magnetic powder, a resinous binder and 0.1 to 40% by weight based on the amount of the magnetic powder of at least one unsaturated fatty acid ester chosen from oleyl oleate and n-butyl oleate and at least one lubricant chosen from hydrocarbons, fluorinated compounds and silicone compounds wherein the weight ratio of the lubricant and the unsaturated fatty acid ester is from 99:1 to 1:99.
References Cited (Backward Citations)
US3492235A
Cited
US3490946A
Cited
US3993824A
Cited
US4096079A
Cited
US4232072A
Cited
JPS54124708A
Cited
US4390601A
Cited
US4409300A
Cited
US4431702A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-06-10 | 1988-12-10 | 1989-06-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-06-10 | 1992-12-10 | 1993-06-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-06-10 | 1996-12-10 | 1997-06-11 | $7700.00 | Window Closed / Lapsed |