Patent US4847156A successfully refreshed from Google Patents.
US4847156A
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Magnetic recording medium
Assignee: Fujifilm Holdings Corp
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Filing: 1987-10-20
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Granted: 1989-07-11
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Expires: 2007-10-20
Abstract
Abstract A magnetic recording medium comprising a non-magnetic support having thereon a magnetic layer containing (a) ferromagnetic particles, (b) a binder containing at least one resin substituted with at least one polar group selected from an --SO 3 M group, a --COOM group, an --OSO 3 M group, an ##STR1## group and a ##STR2## group, wherein M represents H, Li, Na or K and M' represents H, Li, Na, K or an alkyl group, and (c) at least one fatty acid lubricating agent comprising at least one fatty acid derivative represented by formula (I): ##STR3## in which R represents a hydrocarbon group having from 11 to 21 carbon atoms, X represents hydrogen or a methyl group, R' represents a hydrocarbon group having from 1 to 8 carbon atoms and n is an integer of from 2 to 20.
Inventors
- 👤 Yasuo Nishikawa
- 👤 Akihiro Matsufuji
- 👤 Kenichi Masuyama
- 👤 Yutaka Kakuishi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 16:08
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/702; G11B5/7028; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31551; Y10T428/31609
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
199 words
A magnetic recording medium comprising a non-magnetic support having thereon a magnetic layer containing (a) ferromagnetic particles; (b) a binder containing at least one resin substituted with at least one polar group selected from an --SO 3 M group, a --COOM group, an --OSO 3 M group, an ##STR15## group and a ##STR16## group, wherein M represents H, Li, Na or K and M' represents H, Li, Na, K or an alkyl group; and (c) at least one fatty acid lubricating agent comprising at least one fatty acid derivative represented by formula (I): ##STR17## wherein R represents a hydrocarbon group having from 11 to 21 carbon atoms; X represents hydrogen or a methyl group; R' represents a hydrocarbon group having from 1 to 8 carbon atoms; and n is the integer of from 2 to 20, wherein said magnetic layer further contains a long chain fatty acid and wherein the total amount of said fatty acid derivative and said long chain fatty acid is from about 0.1 wt % to 10.0 wt % based on said ferromagnetic particles, and the weight ratio of said fatty acid derivative to said long chain fatty acid is from about 70/30 to 10/90.
Claim 2
Dependent Claim
199 words
A magnetic recording medium comprising a non-magnetic support having thereon a magnetic layer containing (a) ferromagnetic particles; (b) a binder containing at least one resin substituted with at least one polar group selected from an --SO 3 M group, a --COOM group, an --OSO 3 M group, an ##STR15## group and a ##STR16## group, wherein M represents H, Li, Na or K and M' represents H, Li, Na, K or an alkyl group; and (c) at least one fatty acid lubricating agent comprising at least one fatty acid derivative represented by formula (I): ##STR17## wherein R represents a hydrocarbon group having from 11 to 21 carbon atoms; X represents hydrogen or a methyl group; R' represents a hydrocarbon group having from 1 to 8 carbon atoms; and n is the integer of from 2 to 20, wherein said magnetic layer further contains a long chain fatty acid and wherein the total amount of said fatty acid derivative and said long chain fatty acid is from about 0.1 wt % to 10.0 wt % based on said ferromagnetic particles, and the weight ratio of said fatty acid derivative to said long chain fatty acid is from about 70/30 to 10/90.
Claim 3
Dependent Claim
31 words
The magnetic recording medium as claimed in claim 1, wherein said ferromagnetic particles are ferromagnetic metal particles having a specific surface area S BET of 45 m 2 /g or more.
Claim 4
Dependent Claim
31 words
The magnetic recording medium as claimed in claim 1, wherein R represents a saturated straight chain hydrogen group; X represents hydrogen; and n is an integer of from 2 to 4.
Claim 5
Dependent Claim
29 words
The magnetic recording medium as claimed in claim 1, wherein said fatty acid lubricating agent is selected from the group consisting of the following compounds 1 to 13: ##STR18##
Claim 6
Dependent Claim
22 words
The magnetic recording medium as claimed in claim 1, wherein said long chain fatty acid contains from 11 to 32 carbon atoms.
Claim 7
Dependent Claim
22 words
The magnetic recording medium as claimed in claim 2, wherein said long chain fatty acid contains from 12 to 22 carbon atoms.
Claim 8
Dependent Claim
20 words
The magnetic recording medium as claimed in claim 1, wherein said long chain fatty acid is a saturated fatty acid.
Claim 9
Dependent Claim
60 words
The magnetic recording medium as claimed in claim 1, wherein the total amount of said fatty acid derivative and said long chain fatty acid is from about 0.05 wt % to 6 wt % based on said ferromagnetic particles, and the weight ratio of said fatty acid derivative to said long chain fatty acid is from about 70/30 to 30/70.
Claim 10
Dependent Claim
24 words
The magnetic recording medium as claimed in claim 1, wherein said resin is a polyurethane resin, a vinyl chloride copolymer, or a polyester resin.
Claim 11
Dependent Claim
39 words
The magnetic recording medium as claimed in claim 9, wherein said vinyl chloride copolymer is a copolymer of a repeating unit of vinyl chloride, a repeating unit having an epoxy group and a repeating unit having said polar group.
Claim 12
Dependent Claim
74 words
The magnetic recording medium as claimed in claim 10, wherein said vinyl chloride copolymer comprises from about 0.01 to 5.0 mol % of said repeating unit having said polar group, and from about 1.0 to 30 mol % of said repeating unit having said epoxy group, said repeating unit having said epoxy group being present in an amount of from about 0.01 to 0.5 mol per mol of the repeating unit of vinyl chloride.
Claim 13
Dependent Claim
74 words
The magnetic recording medium as claimed in claim 10, wherein said vinyl chloride copolymer comprises from about 0.5 to 3.0 mol % of said repeating unit having said polar group, and from about 1 to 20 mol % of said repeating unit having said epoxy group, said repeating unit having said epoxy group being present in an amount of from about 0.01 to 0.3 mol per mol of the repeating unit of vinyl chloride.
Claim 14
Dependent Claim
17 words
The magnetic recording medium as claimed in claim 10, wherein said polar group is --SO 3 Na.
Claim 15
Dependent Claim
31 words
The magnetic recording medium as claimed in claim 9, wherein said resin is a polyurethane resin containing from about 0.01 to 5 mol % of repeating units having said polar group.
Claim 16
Dependent Claim
31 words
The magnetic recording medium as claimed in claim 14, wherein said resin is a polyurethane resin containing from about 0.1 to 2.0 mol % of repeating units having said polar group.
Claim 17
Dependent Claim
30 words
The magnetic recording medium as claimed in claim 1, wherein said polar group is present in an amount of from about 1×10 -5 to 100×10 -5 mol/g of said binder.
Claim 18
Dependent Claim
35 words
The magnetic recording medium as claimed in claim 1, wherein said binder is present in an amount of from about 10 to 100 parts by weight per 100 parts by weight of said ferromagnetic particles.
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) | 1992-07-10 | 1993-01-09 | 1993-07-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-07-10 | 1997-01-09 | 1997-07-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-07-10 | 2001-01-09 | 2001-07-11 | $7700.00 | Window Closed / Lapsed |