US4713293A
Expired / Lapsed
US
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Magnetic recording media
Assignee: Konica Minolta Inc
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Filing: 1985-07-30
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Granted: 1987-12-15
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Expires: 2005-07-30
Abstract
Abstract A magnetic recording medium comprising a magnetic layer containing a magnetic metal powder, a fatty acid and an ester thereof, and wherein the surface of said magnetic metal powder is pre-treated with a surfactant.
Inventors
- 👤 Masao Asano
- 👤 Ryosuke Isobe
- 👤 Yasuhisa Yamauchi
- 👤 Hiroaki Yamagishi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 09:51
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/71; G11B5/712; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/25; Y10T428/256; Y10T428/257; Y10T428/29; Y10T428/2982; Y10T428/2991; Y10T428/2998; Y10T428/31504; Y10T428/31551; Y10T428/31609; Y10T428/31855; Y10T428/31935; Y10T428/31942; Y10T428/31949
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
83 words
A magnetic recording medium comprising a magnetic recording layer and a support wherein said magnetic recording layer contains a magnetic metal powder, a fatty acid and an ester thereof, and wherein the surface of said magnetic powder is pre-treated with a surfactant, the total amount of said fatty acid and said ester being in the range of 1.5% to 7.5% by weight of said magnetic metal powder, and the weight ratio of said fatty acid to said ester being from 85/15 to 99/1.
Claim 2
Dependent Claim
83 words
A magnetic recording medium comprising a magnetic recording layer and a support wherein said magnetic recording layer contains a magnetic metal powder, a fatty acid and an ester thereof, and wherein the surface of said magnetic powder is pre-treated with a surfactant, the total amount of said fatty acid and said ester being in the range of 1.5% to 7.5% by weight of said magnetic metal powder, and the weight ratio of said fatty acid to said ester being from 85/15 to 99/1.
Claim 3
Dependent Claim
45 words
The magnetic recording medium of claim 1, wherein said surfactant is selected from the group consisting of lechithin, phosphoric ester, amine compound, alkyl sulfate, fatty acid amide, higher alcohol, polyethylene oxide, succinic acid, sulfosuccinate, polymers having an anionic group or salts thereof and silicone compound.
Claim 4
Dependent Claim
30 words
The magnetic recording medium of claim 2, wherein said surfactant is a copolymer containing a monomer unit having an anionic organic group or salt thereof and the other monomer unit.
Claim 5
Dependent Claim
28 words
The magnetic recording medium of claim 2, wherein the amount of said surfactant is in the range of 0.5% to 5% by weight of said magnetic metal powder.
Claim 6
Dependent Claim
37 words
The magnetic recording medium of claim 2, wherein said fatty acid is selected from the group consisting of stearic acid, lauric acid, caprylic acid, oleic acid, linolic acid, linolenic acid, myristic acid, palmitic acid and behenic acid.
Claim 7
Dependent Claim
34 words
The magnetic recording medium of claim 5, wherein said ester is selected from the group consisting of methyl esters ethyl esters, propyl esters, butyl esters, amyl esters and butoxyethyl esters of said fatty acids.
Claim 8
Dependent Claim
37 words
The magnetic recording medium of claim 1, wherein said magnetic metal powder is selected from the group consisting of Fe, Ni, Co, Fe-Ni-Co alloy, Fe-Mn-Zn alloy, Fe-Ni-Zn alloy, Fe-Al alloy, Fe-Co-Ni-Cr alloy, Fe-Co-Ni-P alloy and Co-Ni alloy.
Claim 9
Dependent Claim
40 words
The magnetic recording medium of claim 1, wherein said magnetic metal powder is pre-treated by the process which includes adding said magnetic metal powder into a solution consisting essentially of a solvent and said surfactant dissolved therein, stirring and dispersing.
Claim 10
Dependent Claim
19 words
The magnetic recording medium of claim 1, wherein said magnetic recording layer contains a polyurethane resin and a isocyanate.
Claim 11
Dependent Claim
22 words
The magnetic recording medium of claim 9, wherein said magnetic recording layer further contains a cellulose resin and/or a vinyl chloride copolymer.
Claim 12
Dependent Claim
14 words
The magnetic recording medium of claim 1, wherein said medium has a backing-coat layer.
Claim 13
Dependent Claim
16 words
The magnetic recording medium of claim 1, wherein said magnetic recording layer contains a phenoxy resin.
Claim 14
Dependent Claim
23 words
The magnetic recording medium of claim 1 wherein the weight ratio of said fatty acid to said ester is from 85/15 to 95/5.
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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) | 1990-12-14 | 1991-06-15 | 1991-12-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-12-14 | 1995-06-15 | 1995-12-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-12-14 | 1999-06-15 | 1999-12-15 | $7700.00 | Window Closed / Lapsed |