US4172176A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording medium
Assignee: Sony Corp
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Filing: 1978-05-22
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Granted: 1979-10-23
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Expires: 1998-05-22
Abstract
Abstract A magnetic recording medium is formed of a non-magnetic base and a magnetic layer coated thereon and which contains magnetizable particles dispersed in resinous binder and, as a lubricating agent, a 2-ethylhexanoic acid ester of a saturated alcohol having 12 to 20 carbon atoms.
Inventors
- 👤 Toshiro Tanaka
- 👤 Toshihiko Yamada
- 👤 Yoshiaki Hisagen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 16:08
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; Y10T428/31504
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
56 words
A magnetic recording medium comprising: a non-magnetic base; and a magnetic layer on said base formed of a resinous binder containing magnetizable particles and a lubricant consisting of at least one 2-ethylhexanoic acid ester of a saturated alcohol having 12 to 20 carbon atoms, said lubricant having a melting point of less than about 0° C.
Claim 2
Dependent Claim
56 words
A magnetic recording medium comprising: a non-magnetic base; and a magnetic layer on said base formed of a resinous binder containing magnetizable particles and a lubricant consisting of at least one 2-ethylhexanoic acid ester of a saturated alcohol having 12 to 20 carbon atoms, said lubricant having a melting point of less than about 0° C.
Claim 3
Dependent Claim
31 words
A magnetic recording medium according to claim 1; wherein said lubricant is present in an amount of 1 to 10 parts by weight for 100 parts by weight of the binder.
Claim 4
Dependent Claim
17 words
A magnetic recording medium according to claim 1; wherein said saturated alcohol is a straight chain alcohol.
Claim 5
Dependent Claim
38 words
A magnetic recording medium according to claim 1; wherein said saturated alcohol is selected from the group consisting of lauryl alcohol, tridecyl alcohol, myristyl alcohol, pentadecyl alcohol, cetyl alcohol, heptadecyl alcohol, stearyl alcohol, nonadecyl alcohol and arachidic alcohol.
Claim 6
Dependent Claim
15 words
A magnetic recording medium according to claim 1; wherein said saturated alcohol is cetyl alcohol.
Claim 7
Dependent Claim
81 words
A magnetic recording medium according to claim 1; wherein the magnetizable particles are selected from the group consisting of γ-Fe 2 O 3 , Fe 3 O 4 , spinel-structure intermediate phase between γ-Fe 2 O 3 and Fe 3 O 4 , Cobalt-doped γ-Fe 2 O 3 , Cobalt-doped Fe 3 O 4 , said intermediate phase which is Cobalt-doped, chromium dioxide, barium ferrite, alloy powders of Fe-Co, Co-Ni, Fe-Co-Ni, Fe-Co-B, Fe-Co-Cr-B, Mn-Bi, Mn-Al, Fe-Co-V, iron nitride and mixtures thereof.
Claim 8
Dependent Claim
43 words
A magnetic recording medium according to claim 1; wherein said lubricant is a mixture of at least two 2-ethylhexanoic acid esters of saturated alcohols having 12 to 20 carbon atoms and said mixture has a melting point of less than about 0° C.
Claim 9
Dependent Claim
49 words
A magnetic recording medium according to claim 7; in which one of said 2-ethylhexanoic acid esters has a melting point higher than 0° C. and is present in said mixture in a minor proportion, and another of said 2-ethylhexanoic acid esters has a melting point lower than 0° C.
Claim 10
Dependent Claim
27 words
A magnetic recording medium according to claim 8; in which said one 2-ethylhexanoic acid ester is the ester of stearyl alcohol and constitutes 40% of said mixture.
Claim 11
Dependent Claim
27 words
A magnetic recording medium according to claim 5; in which said one 2-ethylhexanoic acid ester is the ester of arachidic alcohol and constitues 20% of said mixture.
Claim 12
Dependent Claim
46 words
A magnetic coating for a recording medium comprising a resinous binder containing magnetizable particles and a lubricant consisting of at least one 2-ethylhexanoic acid ester of a saturaed alcohol having 12 to 20 carbon atoms, said lubricant having a melting point less than about 0° C.
Claim 13
Dependent Claim
46 words
A magnetic coating for a recording medium comprising a resinous binder containing magnetizable particles and a lubricant consisting of at least one 2-ethylhexanoic acid ester of a saturaed alcohol having 12 to 20 carbon atoms, said lubricant having a melting point less than about 0° C.
Claim 14
Dependent Claim
32 words
A magnetic coating according to claim 11; in which said lubricant is present in an amount of 1 to 10 parts by weight for each 100 parts by weight of the binder.
Claim 15
Dependent Claim
17 words
A magnetic coating according to claim 11; in which the saturated alcohol is a straight chain alcohol.
Claim 16
Dependent Claim
44 words
A magnetic coating according to claim 11; in which said lubricant is a mixture of at least two 2-ethylhexanoic acid esters of said saturated alcohols having 12 to 20 carbon atoms and said mixture has a melting point of less than about 0° C.
Claim 17
Dependent Claim
48 words
A magnetic coating according to claim 14; in which one of said 2-ethylhexanoic acid esters has a melting point higher than 0° C. and is present in said mixture in a minor proportion, and another of said 2-ethylhexanoic acid esters has a melting point lower than 0° C.
Claim 18
Dependent Claim
37 words
A magnetic coating according to claim 11; wherein the saturated alcohol is selected from the group consisting of lauryl alcohol, tridecyl alcohol, myristyl alcohol, pentadecyl alcohol, cetyl alcohol, heptadecyl alcohol, stearyl alcohol, nonadecyl alcohol and arachidic alcohol.
Claim 19
Dependent Claim
80 words
A magnetic coating according to claim 11; wherein the magnetizable particles are selected from the group consisting of γ-Fe 2 O 3 , Fe 3 O 4 , spinel-structure intermediate phase between γ-Fe 2 O 4 and Fe 3 O 4 , Cobalt-doped γ-Fe 2 O 3 , Cobalt-doped Fe 3 O 4 , said intermediate phase which is Cobalt-doped, chromium dioxide, barium ferrite, alloy powders of Fe-Co, Co-Ni, Fe-Co-Ni, Fe-Co-B, Fe-Co-Cr-B, Mn-Bi, Mn-Al, Fe-Co-V, iron nitride or mixtures thereof.
Claim 20
Dependent Claim
95 words
A magnetic recording medium comprising: a non-magnetic base; and a magnetic layer on said base formed of a resinous binder containing magnetizable particles and a lubricant having a melting point of less than 0° C. and being present in an amount of 1 to 10 parts by weight of said lubricant for 100 parts by weight of said binder, said lubricant consisting of at least one 2-ethylhexanoic acid ester of a saturated alcohol having 12 to 20 carbon atoms, with at least 50 weight percent of said lubricant being 2-ethylhexanoic acid ester of cetyl alcohol.
Claim 21
Dependent Claim
95 words
A magnetic recording medium comprising: a non-magnetic base; and a magnetic layer on said base formed of a resinous binder containing magnetizable particles and a lubricant having a melting point of less than 0° C. and being present in an amount of 1 to 10 parts by weight of said lubricant for 100 parts by weight of said binder, said lubricant consisting of at least one 2-ethylhexanoic acid ester of a saturated alcohol having 12 to 20 carbon atoms, with at least 50 weight percent of said lubricant being 2-ethylhexanoic acid ester of cetyl alcohol.
Claim 22
Dependent Claim
86 words
A magnetic coating for a recording medium comprising a resinous binder containing magnetizable particles and a lubricant having a melting point of less than 0° C. and being present in an amount of 1 to 10 parts by weight of said lubricant for 100 parts by weight of said binder, said lubricant consisting of at least one 2-ethylhexanoic acid ester of a saturated alcohol having 12 to 20 carbon atoms, with at least 50 weight percent of said lubricant being 2-ethylhexanoic acid ester of cetyl alcohol.
Claim 23
Dependent Claim
86 words
A magnetic coating for a recording medium comprising a resinous binder containing magnetizable particles and a lubricant having a melting point of less than 0° C. and being present in an amount of 1 to 10 parts by weight of said lubricant for 100 parts by weight of said binder, said lubricant consisting of at least one 2-ethylhexanoic acid ester of a saturated alcohol having 12 to 20 carbon atoms, with at least 50 weight percent of said lubricant being 2-ethylhexanoic acid ester of cetyl 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) | 1982-10-22 | 1983-04-23 | 1983-10-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-10-22 | 1987-04-23 | 1987-10-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-10-22 | 1991-04-23 | 1991-10-23 | $7700.00 | Window Closed / Lapsed |