Patent US4539266A successfully refreshed from Google Patents.
US4539266A
Expired / Lapsed
US
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Magnetic recording medium
Assignee: Sony Corp
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Filing: 1984-11-21
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Granted: 1985-09-03
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Expires: 2004-11-21
Abstract
Abstract A magnetic recording medium such as magnetic tape or magnetic disc is disclosed in which a magnetic layer if formed on the non-magnetic base material and in which the fatty acid ester with diglycerol is contained as the lubricant. The fatty acid ester with diglycerol employed as the lubricant is an ester of diglycerol with a saturated or unsaturated fatty acid with 8 to 22 carbon atoms.
Inventors
- 👤 Takahiro Miyazaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 15:07
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/72; G11B5/725; G11B5/68; G11B5/70; G11B5/71; Y; Y10; Y10S; Y10S428/00; Y10S428/90
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
38 words
A magnetic recording medium comprising a non-magnetic base and a magnetic layer provided on one surface of said non-magnetic base, in which said magnetic recording medium is provided with a layer containing a fatty acid ester with diglycerol.
Claim 2
Dependent Claim
38 words
A magnetic recording medium comprising a non-magnetic base and a magnetic layer provided on one surface of said non-magnetic base, in which said magnetic recording medium is provided with a layer containing a fatty acid ester with diglycerol.
Claim 3
Dependent Claim
21 words
A magnetic recording medium according to claim 1, wherein said fatty acid ester with diglycerol is contained in said magnetic layer.
Claim 4
Dependent Claim
28 words
A magnetic recording medium according to claim 1, wherein said fatty acid ester with diglycerol is contained in a layer provided over a surface of said magnetic layer.
Claim 5
Dependent Claim
39 words
A magnetic recording medium according to claim 1, wherein said fatty acid ester with diglycerol is contained in a layer provided on a surface opposite to said surface of the non-magnetic base on which said magnetic layer is formed.
Claim 6
Dependent Claim
40 words
A magnetic recording medium according to claim 1, wherein said fatty acid ester with diglycerol is contained in a back coat provided on a surface opposite to said surface of said non-magnetic base on which said magnetic layer is formed.
Claim 7
Dependent Claim
28 words
A magnetic recording medium according to claim 1, wherein said fatty acid ester with diglycerol is contained in a layer provided on a surface of said back coat.
Claim 8
Dependent Claim
23 words
A magnetic recording medium according to claim 1, wherein the fatty acid is a saturated fatty acid having 8 to 22 carbon atoms.
Claim 9
Dependent Claim
23 words
A magnetic recording medium according to claim 1, wherein the fatty acid is an unsaturated fatty acid having 8 to 22 carbon atoms.
Claim 10
Dependent Claim
19 words
A magnetic recording medium according to claim 1, wherein said magnetic layer is composed of binder and magnetic powder.
Claim 11
Dependent Claim
19 words
A magnetic recording medium according to claim 1, wherein said magnetic layer is composed of ferromagnetic metal thin film.
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) | 1988-09-02 | 1989-03-04 | 1989-09-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-09-02 | 1993-03-04 | 1993-09-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-09-02 | 1997-03-04 | 1997-09-03 | $7700.00 | Window Closed / Lapsed |