US4696859A
Expired / Lapsed
US
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Magnetic recording medium
Assignee: Fujifilm Holdings Corp
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Filing: 1986-02-28
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Granted: 1987-09-29
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Expires: 2006-02-28
Abstract
Abstract A magnetic recording medium comprising a non-magnetic support having coated thereon a magnetic layer, the magnetic layer containing (i) ferromagnetic alloy particles having an average length in the long axis of 0.25 μm or less and (ii) fatty acid components comprising behenic acid in an amount of 20 to 75 wt%, stearic acid in an amount of 10 to 45 wt% and oleic acid in an amount of 10 to 45 wt% based on the total weight of the three fatty acids.
Inventors
- 👤 Takahito Miyoshi
- 👤 Nobuo Aoki
- 👤 Takashi Yoneyama
- 👤 Akira Kasuga
- 👤 Toshimitu Okutu
- 👤 Masaaki Fujiyama
- 👤 Yasutoshi Okuzawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 01:31
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/714; G11B5/71; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/25
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
102 words
A magnetic recording medium comprising a non-magnetic support having coated thereon a magnetic layer, the magnetic layer containing (i) ferromagnetic alloy particles having an average length in the long axis of 0.25 μm or less and (ii) fatty acid components comprising behenic acid in an amount of 20 to 75 wt %, stearic acid in an amount of 10 to 45 wt % and oleic acid in an amount of 10 to 45 wt % based on the total weight of the three fatty acids, wherein the ferromagnetic alloy particles having a specific surface area of 45 m 2 /g or more.
Claim 2
Dependent Claim
102 words
A magnetic recording medium comprising a non-magnetic support having coated thereon a magnetic layer, the magnetic layer containing (i) ferromagnetic alloy particles having an average length in the long axis of 0.25 μm or less and (ii) fatty acid components comprising behenic acid in an amount of 20 to 75 wt %, stearic acid in an amount of 10 to 45 wt % and oleic acid in an amount of 10 to 45 wt % based on the total weight of the three fatty acids, wherein the ferromagnetic alloy particles having a specific surface area of 45 m 2 /g or more.
Claim 3
Dependent Claim
22 words
The magnetic recording medium as claimed in claim 1, wherein the ferromagnetic alloy particles have an axis ratio of 7/1 or more.
Claim 4
Dependent Claim
33 words
The magnetic recording medium as claimed in claim 1, wherein the ferromagnetic alloy particles have 75 wt % or more of metal content based on the total weight of the ferromagnetic alloy particles.
Claim 5
Dependent Claim
44 words
The magnetic recording medium as claimed in claim 1, wherein the magnetic layer contains an additional lubricant, and the total amount of stearic acid, oleic acid and behenic acid is 20 wt % or more based on the total weight of the additional lubricant.
Claim 6
Dependent Claim
18 words
The magnetic recording medium as claimed in claim 1, wherein the magnetic layer further contains an abrasive agent.
Claim 7
Dependent Claim
24 words
The magnetic recording medium as claimed in claim 5, wherein the the average particle size of the abrasive agent is 0.2 to 0.8 μm.
Claim 8
Dependent Claim
34 words
) The magnetic recording medium as claimed in claim 5, wherein the amount of the abrasive agent is 15 wt % or less based on on the total weight of the ferromagnetic alloy particles.
Claim 9
Dependent Claim
28 words
) The magnetic recording medium as claimed in claim 1, wherein the ferromagnetic alloy particles have an average length in the long axis of 0.20 μm or less.
Claim 10
Dependent Claim
62 words
The magnetic recording medium as claimed in claim 1, wherein the magnetic layer contains fatty acid components comprising behenic acid in an amount of 25 to 65 wt %, stearic acid in an amount of 10 to 40 wt %, and oleic acid in an amount of 10 to 40 wt %, based on the total weight of the three fatty acids.
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) | 1990-09-28 | 1991-03-30 | 1991-09-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-09-28 | 1995-03-30 | 1995-09-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-09-28 | 1999-03-30 | 1999-09-29 | $7700.00 | Window Closed / Lapsed |