Patent US4652500A successfully refreshed from Google Patents.
US4652500A
Expired / Lapsed
US
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Magnetic recording medium
Assignee: Fujifilm Holdings Corp
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Filing: 1986-04-04
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Granted: 1987-03-24
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Expires: 2006-04-04
Abstract
Abstract A magnetic recording medium such as a magnetic recording disk or a magnetic recording tape comprising a nonmagnetic support and a magnetic recording layer provided on said support, said magnetic recording layer comprising a nonmagnetic inorganic powder and a ferromagnetic metal powder of a specific surface area in the range of 35-65 m 2 /g dispersed in a binder, which is characterized in that said magnetic recording layer contains an alkyl ester of a fatty acid and an alkoxyalkyl ester of a fatty acid in amounts in the ranges of 5-15 wt. % and 0.5-10 wt. %, respectively, based on the amount of the ferromagnetic metal powder.
Inventors
- 👤 Kiyomi Ejiri
- 👤 Shigeo Komine
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 18:35
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/714; G11B5/708; G11B5/71; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/25; Y10T428/256; Y10T428/257
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
94 words
A magnetic recording medium comprising a non-magnetic support and a magnetic recording layer provided on said support, said magnetic recording layer comprising a nonmagnetic inorganic powder and a ferromagnetic metal powder of a specific surface area in the range of 35-65 m 2 /g dispersed in a binder, which is characterized in that said magnetic recording layer contains an alkyl ester of a fatty acid and an alkoxyalkyl ester of a fatty acid in amounts in the ranges of 5-15 wt.% and 0.5-10 wt.%, respectively, based on the amount of the ferromagnetic metal powder.
Claim 2
Dependent Claim
94 words
A magnetic recording medium comprising a non-magnetic support and a magnetic recording layer provided on said support, said magnetic recording layer comprising a nonmagnetic inorganic powder and a ferromagnetic metal powder of a specific surface area in the range of 35-65 m 2 /g dispersed in a binder, which is characterized in that said magnetic recording layer contains an alkyl ester of a fatty acid and an alkoxyalkyl ester of a fatty acid in amounts in the ranges of 5-15 wt.% and 0.5-10 wt.%, respectively, based on the amount of the ferromagnetic metal powder.
Claim 3
Dependent Claim
53 words
The magnetic recording medium as claimed in claim 1, wherein said alkyl ester of a fatty acid and said alkoxyalkyl ester of a fatty acid are contained in the magnetic recording layer in amounts in the ranges of 7-13 wt.% and 0.5-5 wt.%, respectively, based on the amount of the ferromagnetic metal powder.
Claim 4
Dependent Claim
33 words
The magnetic recording medium as claimed in claim 1, wherein the amount of said alkyl ester of a fatty acid is larger than the amount of said alkoxyalkyl ester of a fatty acid.
Claim 5
Dependent Claim
39 words
The magnetic recording medium as claimed in claim 3, wherein the amount of said alkyl ester of a fatty acid is as much as twice or more larger than the amount of said alkoxyalkyl ester of a fatty acid.
Claim 6
Dependent Claim
55 words
The magnetic recording medium as claimed in any one claim of claims 1 to 3, wherein said alkylester of a fatty acid has the following formula: ##STR3## wherein R 1 is a saturated or unsaturated alkyl group having 12-24 carbon atoms and R 2 is a saturated or unsaturated alkyl group having 2-8 carbon atoms.
Claim 7
Dependent Claim
68 words
The magnetic recording medium as claimed in any one claim of claims 1 to 3, wherein said alkoxyalkylester of a fatty acid has the following formula: ##STR4## wherein R 3 is a saturated or unsaturated alkyl group having 12-24 carbon atoms, R 4 is a saturated or unsaturated alkyl group having 2-6 carbon atoms and R 5 is a saturated or unsaturated alkyl group having 2-8 carbon atoms.
Claim 8
Dependent Claim
38 words
The magnetic recording medium as claimed in any one claim of claims 1 to 3, wherein said nonmagnetic inorganic powder is a powder of a material selected from the group consisting of α-alumina, chromic oxide and α-iron oxide.
Claim 9
Dependent Claim
25 words
The magnetic recording medium as claimed in any one claim of claims 1 to 3, wherein the medium is in the form of a disk.
Claim 10
Dependent Claim
26 words
The magnetic recording medium as claimed in any one claim of claims 1 to 3, wherein the medium is in the form of a continuous tape.
Claim 11
Dependent Claim
105 words
A process for the preparation of a magnetic recording disk which comprises coating a magnetic paint comprising a ferromagnetic metal powder of a specific surface area in the range of 35-65 m 2 /g, a binder, a solvent, an alkyl ester of a fatty acid in an amount of in the range of 5-15 wt.% and an alkoxyalkyl ester of a fatty acid in an amount in the ranges of 0.5-10 wt.%, the amount being based on the amount of the ferromagnetic metal powder, on a nonmagnetic support to form a coated layer, and drying the coated layer without subjecting it to magnetic orienting treatment.
Claim 12
Dependent Claim
105 words
A process for the preparation of a magnetic recording disk which comprises coating a magnetic paint comprising a ferromagnetic metal powder of a specific surface area in the range of 35-65 m 2 /g, a binder, a solvent, an alkyl ester of a fatty acid in an amount of in the range of 5-15 wt.% and an alkoxyalkyl ester of a fatty acid in an amount in the ranges of 0.5-10 wt.%, the amount being based on the amount of the ferromagnetic metal powder, on a nonmagnetic support to form a coated layer, and drying the coated layer without subjecting it to magnetic orienting treatment.
Claim 13
Dependent Claim
36 words
The magnetic recording disk as claimed in claim 10, wherein the ratio of the amounts of said alkyl ester of a fatty acid and said alkoxyalkyl ester of a fatty acid ranges from 10:1 to 10:10.
Claim 14
Dependent Claim
51 words
The magnetic recording disk as claimed in claim 10 or 11, wherein said alkylester of a fatty acid has the following formula: ##STR5## wherein R 1 is a saturated or unsaturated alkyl group having 12-24 carbon atoms and R 2 is a saturated or unsaturated alkyl group having 2-8 carbon atoms.
Claim 15
Dependent Claim
64 words
The magnetic recording disk as claimed in claim 10 or 11, wherein said alkoxyalkylester of a fatty acid has the following formula: ##STR6## wherein R 3 is a saturated or unsaturated alkyl group having 12-24 carbon atoms, R 4 is a saturated or unsaturated alkyl group having 2-6 carbon atoms and R 5 is a saturated or unsaturated alkyl group having 2-8 carbon atoms.
References Cited (Backward Citations)
US4455345A
Cited
US4465737A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-03-23 | 1990-09-22 | 1991-03-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-03-23 | 1994-09-22 | 1995-03-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-03-23 | 1998-09-22 | 1999-03-24 | $7700.00 | Window Closed / Lapsed |