US4556604A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording media
Assignee: Kanto Denka Kogyo Co Ltd
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Filing: 1984-09-06
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Granted: 1985-12-03
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Expires: 2004-09-06
Abstract
Abstract By inclusion of a fluorinated graphite material in conjunction with a silicone oil in the magnetic layer of a magnetic recording medium, the medium is improved significantly in its smooth-running properties and electromagnetic performance properties.
Inventors
- 👤 Nobuo Ohbayashi
- 👤 Akiho Kawata
- 👤 Shuichi Miya
- 👤 Teruhisa Niinuma
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 05:10
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/71; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/25; Y10T428/30; Y10T428/31504; Y10T428/31652; Y10T428/31663
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
60 words
A magnetic recording medium consisting of a magnetic layer comprising particles of a magnetic powder material embedded in a matrix of a binder and a substrate carrying said magnetic layer, said magnetic layer further comprising a lubricant comprising a mixture of silicone oil and an amount of fluorinated graphite material effective to significantly enhance the lubricating effect of said lubricant.
Claim 2
Dependent Claim
60 words
A magnetic recording medium consisting of a magnetic layer comprising particles of a magnetic powder material embedded in a matrix of a binder and a substrate carrying said magnetic layer, said magnetic layer further comprising a lubricant comprising a mixture of silicone oil and an amount of fluorinated graphite material effective to significantly enhance the lubricating effect of said lubricant.
Claim 3
Dependent Claim
32 words
A magnetic recording medium as claimed in claim 1 wherein said fluorinated graphite material is represented by the formula: (CF.sub.x).sub.n wherein x is a value greater than 0.1 but less than unity.
Claim 4
Dependent Claim
28 words
A magnetic recording medium as claimed in claim 1 wherein said fluorinated graphite material has an average primary particle size ranging from about 0.01 to about 0.1 microns.
Claim 5
Dependent Claim
35 words
A magnetic recording medium as claimed in claim 1 wherein said fluorinated graphite material is present in a proportion of about 2-15 parts by weight per 100 parts by weight of said magnetic powder material.
Claim 6
Dependent Claim
34 words
A magnetic recording medium as claimed in claim 1 wherein said silicone oil is present in a proportion of about 0.1-10 parts by weight per 100 parts by weight of said magnetic powder material.
Claim 7
Dependent Claim
90 words
A process for producing a magnetic recording medium having a magnetic layer as claimed in claim 1 comprising the steps of: providing a magnetic paint composition comprising a magnetic powder material, a lubricant comprising a mixture of a silicone oil and an amount of a fluorinated graphite material effective to significantly enhance the lubricating effect of said lubricant; applying said paint composition to a substrate; drying said coated substrate to form said magnetic layer; and then calendering and aging said dried substrate to condition the thus formed magnetic layer thereon.
Claim 8
Dependent Claim
25 words
A process as claimed in claim 6 comprising a further step of slitting the conditioned product into a strip or ribbon of magnetic recording medium.
Claim 9
Dependent Claim
30 words
A process as claimed in claim 6, wherein said fluorinated graphite material is represented by the formula: (CF.sub.x).sub.n wherein x is a value greater than 0.1 but less than unity.
Claim 10
Dependent Claim
26 words
A process as claimed in claim 6, wherein said fluorinated graphite material has an average primary particle size ranging from about 0.01 to about 0.1 microns.
Claim 11
Dependent Claim
40 words
A process as claimed in claim 6, wherein said fluorinated graphite material and silicone oil are present in proportions of about 2-15 parts and about 0.1-10 parts by weight, respectively, per 100 parts by weight of said magnetic powder material.
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) | 1988-12-02 | 1989-06-03 | 1989-12-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-12-02 | 1993-06-03 | 1993-12-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-12-02 | 1997-06-03 | 1997-12-03 | $7700.00 | Window Closed / Lapsed |