US4820565A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording medium
Assignee: Maxell Ltd
•
Filing: 1987-12-14
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Granted: 1989-04-11
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Expires: 2007-12-14
Abstract
Abstract A magnetic recording medium improved in durability over a wide range of temperature 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 monovalent alcohol ester of a fatty acid and a straight chain saturated fatty acid ester of not less than 28 carbon atoms in a weight proportion of 99:1 to 1:99 in a combined amount of 0.1 to 20 percent by weight based on the weight of the magnetic powder.
Inventors
- 👤 Masaya Funahashi
- 👤 Teruhisa Miyata
- 👤 Kenichi Inoue
- 👤 Akira Miyake
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 14:46
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/71; Y; Y10; Y10S; Y10S428/00; Y10S428/90
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
124 words
A magnetic recording disc improved in wear-resistance and durability, which comprises a substrate and a magnetic layer comprising magnetic powder and a resinous binder formed on at least one surface of the substrate, characterized in that the magnetic layer further comprises (A) a monovalent alcohol ester of oleic acid, and (B) a straight chain saturated fatty acid ester of not less than 28 carbon atoms derived from a saturated fatty acid of 16 to 30 carbon atoms and a saturated alcohol of 12 to 30 carbon atoms, wherein the combined amount of (A) and (B) is from 0.1 to 20% by weight based on the weight of the magnetic powder and the weight proportion of (A) and (B) is from about 99:1 to 1:99.
Claim 2
Dependent Claim
124 words
A magnetic recording disc improved in wear-resistance and durability, which comprises a substrate and a magnetic layer comprising magnetic powder and a resinous binder formed on at least one surface of the substrate, characterized in that the magnetic layer further comprises (A) a monovalent alcohol ester of oleic acid, and (B) a straight chain saturated fatty acid ester of not less than 28 carbon atoms derived from a saturated fatty acid of 16 to 30 carbon atoms and a saturated alcohol of 12 to 30 carbon atoms, wherein the combined amount of (A) and (B) is from 0.1 to 20% by weight based on the weight of the magnetic powder and the weight proportion of (A) and (B) is from about 99:1 to 1:99.
Claim 3
Dependent Claim
31 words
The magnetic recording disc according to claim 1, wherein the monovalent alcohol ester of oleic acid (A) is a member selected from the group consisting of oleyl oleate and octyl oleate.
Claim 4
Dependent Claim
50 words
The magnetic recording disc according to claim 1, wherein the straight chain saturated fatty acid ester of not less than 28 carbon atoms (B) is a member selected from the group consisting of lauryl palmitate, myristyl palmitate, palmityl palmitate, stearyl palmitate, lauryl stearate, myristyl stearate, palmityl stearate and stearyl stearate.
References Cited (Backward Citations)
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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) | 1992-04-10 | 1992-10-10 | 1993-04-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-04-10 | 1996-10-10 | 1997-04-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-04-10 | 2000-10-10 | 2001-04-11 | $7700.00 | Window Closed / Lapsed |