US4746559A
Expired / Lapsed
US
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Magnetic recording medium
Assignee: Fujifilm Holdings Corp
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Filing: 1986-11-18
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Granted: 1988-05-24
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Expires: 2006-11-18
Abstract
Abstract Disclosed is a magnetic recording medium comprising a non-magnetic support having provided thereon a ferromagnetic metal thin film provided with a layer containing a compound having a mercapto group. This layer may also contain an ester bond. The magnetic recording medium shows improved running properties and wear resistance over wide ranges of temperature and humidity.
Inventors
- 👤 Yasuo Nishikawa
- 👤 Tadashi Ishikuro
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 23:57
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/72; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/24; Y10T428/24273; Y10T428/24281; Y10T428/24355; Y10T428/24364; Y10T428/24372; Y10T428/24413; Y10T428/24942; Y10T428/2495; Y10T428/24967; Y10T428/24975; Y10T428/26; Y10T428/263; Y10T428/264; Y10T428/265; Y10T428/31504; Y10T428/31678
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
131 words
A magnetic recording medium comprising a non-magnetic support having provided thereon a ferromagnetic metal thin film provided with a layer containing a compound having a mercapto group which has a molecular weight of from about 78 to about 10,000, wherein: said compound having a mercapto group also has an ester bond; the layer containing the compound having a mercapto group has a thickness of 0.5 mg/m 2 to 100 mg/m 2 and wherein said compound having a mercapto group and an ester bond is represented by general formula A--COO--B wherein one of A and B represents a hydrocarbon group substituted with one or more mercapto groups, and the other represents a hydrocarbon group, or both of A and B independently represent a hydrocarbon group substituted with one or more mercapto group.
Claim 2
Dependent Claim
131 words
A magnetic recording medium comprising a non-magnetic support having provided thereon a ferromagnetic metal thin film provided with a layer containing a compound having a mercapto group which has a molecular weight of from about 78 to about 10,000, wherein: said compound having a mercapto group also has an ester bond; the layer containing the compound having a mercapto group has a thickness of 0.5 mg/m 2 to 100 mg/m 2 and wherein said compound having a mercapto group and an ester bond is represented by general formula A--COO--B wherein one of A and B represents a hydrocarbon group substituted with one or more mercapto groups, and the other represents a hydrocarbon group, or both of A and B independently represent a hydrocarbon group substituted with one or more mercapto group.
Claim 3
Dependent Claim
18 words
A magnetic recording medium as claimed in claim 1, wherein said support has provided thereon an under layer.
Claim 4
Dependent Claim
18 words
A magnetic recording medium as claimed in claim 1, wherein said support has provided thereon an under layer.
Claim 5
Dependent Claim
26 words
A magnetic recording medium as claimed in claim 1, wherein said metal thin film is one treated with a surface active agent or a coupling agent.
Claim 6
Dependent Claim
26 words
A magnetic recording medium as claimed in claim 1, wherein said metal thin film is one treated with a surface active agent or a coupling agent.
Claim 7
Dependent Claim
26 words
A magnetic recording medium as claimed in claim 1, wherein said hydrocarbon group substituted with one or more mercapto groups contains at least 3 carbon atoms.
Claim 8
Dependent Claim
54 words
A magnetic recording medium as claimed in claim 1, wherein said compound having a mercapto group and an ester bond is represented by general formula HS--R--COO--R', or R'--COO--R--SH wherein R represents a divalent hydrocarbon group having 1 to 20 carbon atoms, and R' represents a monovalent hydrocarbon group having 1 to 20 carbon atoms.
Claim 9
Dependent Claim
40 words
A magnetic recording medium as claimed in claim 7, wherein said compound having a mercapto group and an ester bond is selected from the group consisting of monoester or diester compounds and oligoester or polyester compounds having a mercapto group.
Claim 10
Dependent Claim
67 words
A magnetic recording medium as claimed in claim 7, wherein said compound having a mercapto group and ester bond is selected from the group consisting of behenyl β-mercaptopropionate, octadecyl β-mercaptopropionate, dodecyl β-mercaptopropionate, octyl β-mercaptopropionate, oleyl β-mercaptopropionate, behenyl thioglycolate, octadecyl thioglycolate, dodecyl thioglycolate, octyl thioglycolate, oleyl thioglycolate, behenyl thiosalycilate, octadecyl thiosalycilate, dodecyl thiosalycilate, octyl thiosalycilate, methyl thiosalycilate, oleyl thiosalcilate, 2-mercaptoethyl stearate, 2-mercaptoethyl oleate, 2-mercaptoethyl myristate, and 2-mercaptoethyl laurate.
Claim 11
Dependent Claim
49 words
A magnetic recording medium as claimed in claim 7, wherein said compound having a mercapto group and an ester bond is selected from the group consisting of behenyl β-mercaptopriopionate, octadecyl β-mercaptopropionate, dodecyl β-mercaptopropionate, oleyl-mercaptopropionate, behenyl thioglycolate, octadecyl thioglycolate, dodecyl thioglycolate, oleyl thioglycolate, 2-mercaptoethyl stearate, 2-mercaptoethyl oleate and 2-mercaptoethyl myristate.
Claim 12
Dependent Claim
52 words
A magnetic recording medium as claimed in claim 1, wherein said compound having a mercapto group and an ester bond is a product derived from one or more of a polyfunctional acid, a polyfunctional alcohol, an acid having a hydroxy group and a self-condensation product of an acid having a hydroxy group.
Claim 13
Dependent Claim
28 words
A magnetic recording medium as claimed in claim 1, wherein said layer containing a compound having a mercapto group has a surface unevenness of 10 to 1,000 Angstroms.
Claim 14
Dependent Claim
28 words
A magnetic recording medium as claimed in claim 1, wherein said layer containing a compound having a mercapto group has a surface unevenness of 10 to 1,000 Angstrom.
Claim 15
Dependent Claim
23 words
A magnetic recording medium as claimed in claim 1, wherein the thickness of the support is from about 4 to about 50 μm.
Claim 16
Dependent Claim
23 words
A magnetic recording medium as claimed in claim 1, wherein the thickness of the support is from about 4 to about 50 μm.
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) | 1991-05-24 | 1991-11-23 | 1992-05-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-05-24 | 1995-11-23 | 1996-05-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-05-24 | 1999-11-23 | 2000-05-24 | $7700.00 | Window Closed / Lapsed |