Patent US2061047A successfully refreshed from Google Patents.
US4595640A
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US
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Lubricant system for magnetic recording media containing isomeric acids or alcohols
Assignee: 3M Co
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Filing: 1983-12-27
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Granted: 1986-06-17
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Expires: 2003-12-27
Abstract
Abstract An improved lubricant system for magnetic recording media such as helical scan video tapes is disclosed. The resulting improved magnetic recording media comprise the usual flexible or rigid backing and a magnetizable layer on the backing, but the lubricant is comprised of an organic compound selected from the group consisting of isomeric carboxylic acids and isomeric alcohols (e.g. iso-stearic acid and iso-stearyl alcohol). A fatty acid ester may be included in the lubricant. A typical composition utilizes 0.5 parts by weight iso-stearic acid per 100 parts of magnetizable material (e.g., cobalt doped ferric oxide particles) and 1 part by weight of isopropyl palmitate per 100 parts of the magnetizable material. Video tapes lubricated with this new system, have shown improved electromagnetic output (e.g., higher signal-to-noise ratios). In addition, they are able to withstand the stop motion of a helical scan video head better than prior known lubricant systems.
Inventors
- 👤 John G. Chernega
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 22:32
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/71; Y; Y10; Y10S; Y10S428/00; Y10S428/90
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
59 words
A magnetic recording medium comprising: a backing; a magnetizable layer containing a magnetizable material on said backing; and a lubricant comprising both an organic compound selected from the group consisting of isomers of carboxylic acids having about 12 to 30 carbon atoms per molecule and a fatty acid ester having about 12 to 40 carbon atoms in its molecules.
Claim 2
Dependent Claim
59 words
A magnetic recording medium comprising: a backing; a magnetizable layer containing a magnetizable material on said backing; and a lubricant comprising both an organic compound selected from the group consisting of isomers of carboxylic acids having about 12 to 30 carbon atoms per molecule and a fatty acid ester having about 12 to 40 carbon atoms in its molecules.
Claim 3
Dependent Claim
52 words
The magnetic recording medium of claim 1 wherein the magnetizable material is selected from the group consisting of: chromium oxide, ferric oxide, magnetite, cobalt doped ferric oxide, cobalt absorbed ferric oxide, cobalt doped magnetite, cobalt adsorbed magnetic, fine metal particles and the metal or metal alloy of a thin metal film medium.
Claim 4
Dependent Claim
29 words
The magnetic recording medium of claim 1 wherein the organic compound is present in an amount of less than or equal to five weight percent of the magnetizable material.
Claim 5
Dependent Claim
30 words
The magnetic recording medium of claim 1 in which the major carbon chain of the fatty acid ester has about the same number of carbon atoms as the organic compound.
Claim 6
Dependent Claim
28 words
The magnetic recording medium of claim 1 wherein the fatty acid ester is present in an amount of about five or less weight percent of the magnetizable material.
Claim 7
Dependent Claim
60 words
A magnetic recording medium comprising: a backing; a magnetizable layer containing a magnetizable material on said backing; and a lubricant which comprises both an organic compound selected from the group consisting of iso-stearic acid and iso-stearyl alcohol and a fatty acid ester selected from the group consisting of isopropyl palmitate, butoxy ethyl stearate, butyl stearate, iso-stearyl iso-stearate and isopropyl stearate.
Claim 8
Dependent Claim
60 words
A magnetic recording medium comprising: a backing; a magnetizable layer containing a magnetizable material on said backing; and a lubricant which comprises both an organic compound selected from the group consisting of iso-stearic acid and iso-stearyl alcohol and a fatty acid ester selected from the group consisting of isopropyl palmitate, butoxy ethyl stearate, butyl stearate, iso-stearyl iso-stearate and isopropyl stearate.
Claim 9
Dependent Claim
42 words
A magnetic recording medium comprising: a backing, a magnetizable layer containing a magnetizable material on said backing; and a lubricant comprising an organic compound selected from the group consisting of isomers of alcohols having about 12 to 30 carbon atoms per molecule.
Claim 10
Dependent Claim
42 words
A magnetic recording medium comprising: a backing, a magnetizable layer containing a magnetizable material on said backing; and a lubricant comprising an organic compound selected from the group consisting of isomers of alcohols having about 12 to 30 carbon atoms per molecule.
Claim 11
Dependent Claim
52 words
The magnetic recording medium of claim 2 wherein the magnetizable material is selected from the group consisting of: chromium oxide, ferric oxide, magnetite, cobalt doped ferric oxide, cobalt absorbed ferric oxide, cobalt doped magnetite, cobalt adsorbed magnetic, fine metal particles and the metal or metal alloy of a thin metal film medium.
Claim 12
Dependent Claim
29 words
The magnetic recording medium of claim 7 wherein the organic compound is present in an amount of less than or equal to five weight percent of the magnetizable material.
Claim 13
Dependent Claim
27 words
The magnetic recording medium of claim 7 in which the lubricant further comprises a fatty acid ester having about 12 to 40 carbon atoms in its molecules.
Claim 14
Dependent Claim
30 words
The magnetic recording medium of claim 10 in which the major carbon chain of the fatty acid ester has about the same number of carbon atoms as the organic compound.
Claim 15
Dependent Claim
28 words
The magnetic recording medium of claim 10 wherein the fatty acid ester is present in an amount of about five or less weight percent of the magnetizable material.
Claim 16
Dependent Claim
14 words
The magnetic recording medium of claim 7 wherein the organic compound is iso-stearyl alcohol.
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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) | 1989-06-16 | 1989-12-16 | 1990-06-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-06-16 | 1993-12-16 | 1994-06-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-06-16 | 1997-12-16 | 1998-06-17 | $7700.00 | Window Closed / Lapsed |