US4405481A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording medium
Assignee: Fujifilm Holdings Corp
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Filing: 1980-12-24
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Granted: 1983-09-20
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Expires: 2000-12-24
Abstract
Abstract A magnetic recording medium containing a ferromagnetic powder, a binder and a lubricant is disclosed. The lubricant comprises (1) abrasive particles having a Mohs' hardness of about 6 or more and a particle size of about 5 microns or less and (2) an ester of an aliphatic acid having 20 to 26 carbon atoms and a monovalent alcohol having 1 to 26 carbon atoms.
Inventors
- 👤 Yasuyuki Yamada
- 👤 Nobuo Tsuji
- 👤 Tsutomu Okita
- 👤 Yasuo Mukunoki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 18:39
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/708; G11B5/7085; G11B5/71; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/25; Y10T428/256; Y10T428/257
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
70 words
A magnetic recording medium containing one or more ferromagnetic powders, one or more binders and a lubricant, said lubricant comprising (1) non-magnetic abrasive particles having a Mohs' hardness of about 6 or more and a particle size of about 5 microns or less and (2) one or more esters selected from the group consisting of ethyl erucate, butyl erucate, butoxyethyl erucate, butyl behenate, butoxyethyl behenate, octyl behenate and 2-ethylhexyl behenate.
Claim 2
Dependent Claim
70 words
A magnetic recording medium containing one or more ferromagnetic powders, one or more binders and a lubricant, said lubricant comprising (1) non-magnetic abrasive particles having a Mohs' hardness of about 6 or more and a particle size of about 5 microns or less and (2) one or more esters selected from the group consisting of ethyl erucate, butyl erucate, butoxyethyl erucate, butyl behenate, butoxyethyl behenate, octyl behenate and 2-ethylhexyl behenate.
Claim 3
Dependent Claim
36 words
A magnetic recording medium according to claim 1 wherein the abrasive particles are selected from the group consisting of diamond, emery, spinel, garnet, flint, iron oxides, chromium oxides, alumina, silicon carbide, boron carbide and mixtures thereof.
Claim 4
Dependent Claim
43 words
A magnetic recording medium according to claim 1 wherein the one or more fine ferromagnetic powders are selected from the group consisting of γ-Fe 2 O 3 , alloys, CrO 2 , Fe 3 O 4 and Co-containing γ-Fe 2 O 3 .
Claim 5
Dependent Claim
25 words
A magnetic recording medium according to claim 1 wherein the one or more fine ferromagnetic powders have a particle size between 0.1 and 2.0 microns.
Claim 6
Dependent Claim
17 words
A magnetic recording medium according to claim 1 wherein the fine ferromagnetic powder is a Fe-Co alloy.
Claim 7
Dependent Claim
28 words
A magnetic recording medium according to claim 1 wherein the binder is selected from the group consisting of nitrocellulose, a vinyl chloride-vinyl acetate resin or a polyurethane resin.
Claim 8
Dependent Claim
41 words
A magnetic recording medium according to claim 1 wherein the abrasive particles are Cr 2 O 3 , Al 2 O 3 and SiC, and the ester is selected from the group consisting of butyl erucate, butoxyethyl erucate and butyl behenate.
Claim 9
Dependent Claim
13 words
A magnetic recording medium according to claim 1 which further comprises carbon black.
Claim 10
Dependent Claim
30 words
A magnetic recording medium according to claim 1 wherein 20 to 35 parts by weight of the binder is present per 100 parts by weight of the fine ferromagnetic powder.
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) | 1986-09-19 | 1987-03-21 | 1987-09-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-09-19 | 1991-03-21 | 1991-09-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-09-19 | 1995-03-21 | 1995-09-20 | $7700.00 | Window Closed / Lapsed |