Patent US4187345A successfully refreshed from Google Patents.
US4187345A
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Magnetic recording medium
Assignee: Fujifilm Holdings Corp
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Filing: 1978-08-21
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Granted: 1980-02-05
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Expires: 1998-08-21
Abstract
Abstract This invention relates to a magnetic recording medium which comprises a support having a surface roughness of at most 0.35 micron, a magnetic recording layer on one side of the support and a lubricant layer containing a lubricant represented by the following general formula, ##STR1## in which R=C n H 2n+1 , n=12-18, x=0-8 and y=1-50 and being coated onto the opposite side to the magnetic recording layer with a mean coating quantity of 1 to 500 mg/m 2 .
Inventors
- 👤 Nobutaka Yamaguchi
- 👤 Masaaki Fujiyama
- 👤 Satoru Takayama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 15:40
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/72; G11B5/725; G11B5/73; G11B5/735; G11B5/739; G11B5/73923; G11B5/73927; G11B5/73929; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/26; Y10T428/266; Y10T428/27; Y10T428/273; Y10T428/277; Y10T428/31504; Y10T428/3154; Y10T428/31544; Y10T428/31721; Y10T428/31725; Y10T428/31765; Y10T428/31786; Y10T428/31855
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
96 words
A magnetic recording medium which comprises a support having a surface roughness of at most 0.35 micron, a magnetic recording layer on one side of the support and a lubricant layer on the other side of the support, the lubricant layer being a lubricant represented by the following general formula: ##STR6## in which R=C n H 2n+1 , n=12-18, x=0-8 and y=1-50, which is coated on the support in a mean coating quantity of 1 to 200 mg/m 2 and which is applied to the support in the form of a solution in an organic solvent.
Claim 2
Dependent Claim
96 words
A magnetic recording medium which comprises a support having a surface roughness of at most 0.35 micron, a magnetic recording layer on one side of the support and a lubricant layer on the other side of the support, the lubricant layer being a lubricant represented by the following general formula: ##STR6## in which R=C n H 2n+1 , n=12-18, x=0-8 and y=1-50, which is coated on the support in a mean coating quantity of 1 to 200 mg/m 2 and which is applied to the support in the form of a solution in an organic solvent.
Claim 3
Dependent Claim
59 words
The magnetic recording medium as claimed in claim 1, wherein the support is of a material selected from the group consisting of polyesters such as polyethylene terephthalate and polyethylene-2,6-naphthalate, polyolefins such as polyethylene and polypropylene, cellulose derivatives such as cellulose triacetate and cellulose diacetate and other plastics such as polycarbonates, polyamides, polyimides, polytetrafluoroethylene, polytrifluoroethylene, polyvinyl chloride and polyvinylidene chloride.
Claim 4
Dependent Claim
20 words
The magnetic recording medium as claimed in claim 1, wherein the support has a thickness of 2 to 38 microns.
Claim 5
Dependent Claim
23 words
The magnetic recording medium as claimed in claim 1, wherein the magnetic recording layer comprises a ferromagnetic fine powder, binder and coating solvent.
Claim 6
Dependent Claim
23 words
The magnetic recording medium as claimed in claim 1, wherein the magnetic recording layer has a surface roughness of at most 0.25 micron.
Claim 7
Dependent Claim
88 words
The magnetic recording medium as claimed in claim 4, wherein the ferromagnetic fine powder is selected from the group consisting of γ-Fe 2 O 3 , Co-doped γ-fe 2 O 3 , Fe 3 O 4 , Co-doped Fe 3 O 4 , Berthollide compounds of γ-Fe 2 O 3 and Fe 3 O 4 , Co-doped Berthollide compounds of γ-Fe 2 O 3 and Fe 3 O 4 , CrO 2 , Co-Ni-P alloys, Co-Ni-Fe alloys, Co-Ni-Fe-B alloys, Fe-Ni-Zn alloys, Fe-Mn-Zn alloys, Fe-Co-Ni-P alloys and Ni-Co alloys.
Claim 8
Dependent Claim
26 words
The magnetic recording medium as claimed in claim 4, wherein the binder is selected from the group consisting of thermoplastic resins, thermosetting resins and mixtures thereof.
Claim 9
Dependent Claim
34 words
The magnetic recording medium as claimed in claim 4, wherein said coating solvent is selected from the group consisting of ketones, alcohols, esters, ethers, glycol ethers, aromatic hydrocarbons, chlorinated hydrocarbons, tetrahydrofuran and dimethyl sulfoxide.
Claim 10
Dependent Claim
14 words
The magnetic recording medium of claim 1 wherein the lubricant has the formula: ##STR7##
References Cited (Backward Citations)
US2804401A
Cited
US3293066A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-02-04 | 1983-08-06 | 1984-02-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-02-04 | 1987-08-06 | 1988-02-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-02-04 | 1991-08-06 | 1992-02-05 | $7700.00 | Window Closed / Lapsed |