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US5049448A
Expired / Lapsed
US
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Magnetic recording medium containing an ester lubricant branched from the number 2 carbon position of the acid residue
Assignee: Fujifilm Holdings Corp
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Filing: 1989-07-24
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Granted: 1991-09-17
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Expires: 2009-07-24
Abstract
Abstract A magnetic recording medium is disclosed, comprising a nonmagnetic support having thereon a magnetic layer, wherein at least one of ester compounds represented by formula (I) is present in or on the magnetic layer, ##STR1## wherein R 1 represents a straight chain, saturated alkyl group having 6 to 12 carbon atoms, R 2 represents a straight chain, saturated alkyl group having 4 to 10 carbon atoms, and R represents a branched or straight chain alkyl group having 4 to 22 carbon atoms.
Inventors
- 👤 Takao Ohya
- 👤 Yasuo Nishikawa
- 👤 Jun Nakagawa
- 👤 Fusao Yamanaka
- 👤 Toshio Kawamata
- 👤 Tsutomu Okita
- 👤 Hiroshi Hashimoto
- 👤 Mikihiko Kato
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 11:03
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/71; G11B5/72; G11B5/725; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/31; Y10T428/31504; Y10T428/31551; Y10T428/31605; Y10T428/31609
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
80 words
A magnetic recording medium comprising a nonmagnetic support having thereon a magnetic layer, wherein at least one of ester compounds represented by formula (I) is present in or on the magnetic layer, ##STR32## wherein R 1 represents a straight chain, saturated alkyl group having 6 to 12 carbon atoms, R 2 represents a straight chain, saturated alkyl group having 4 to 10 carbon atoms, and R represents a branched or straight chain alkyl group having 4 to 22 carbon atoms.
Claim 2
Dependent Claim
80 words
A magnetic recording medium comprising a nonmagnetic support having thereon a magnetic layer, wherein at least one of ester compounds represented by formula (I) is present in or on the magnetic layer, ##STR32## wherein R 1 represents a straight chain, saturated alkyl group having 6 to 12 carbon atoms, R 2 represents a straight chain, saturated alkyl group having 4 to 10 carbon atoms, and R represents a branched or straight chain alkyl group having 4 to 22 carbon atoms.
Claim 3
Dependent Claim
18 words
The magnetic recording medium as claimed in claim 1, wherein said magnetic layer comprises ferromagnetic particles and binders.
Claim 4
Dependent Claim
77 words
The magnetic recording medium as claimed in claim 2, wherein said binders are polymers having at least one polar group selected from the group consisting of ##STR33## wherein M is H, Li, Na or NR 0 in which R 0 is H, an alkyl group, an alkenyl group or an alkanol group, and M' is H, Li, Na, an alkyl group, or NR' 0 in which R' 0 is H, an alkenyl group or an alkanol group.
Claim 5
Dependent Claim
23 words
The magnetic recording medium as claimed in claim 3, wherein said binders are a polymer having a polar group of --SO 3 M.
Claim 6
Dependent Claim
56 words
The magnetic recording medium as claimed in claim 2, wherein said binders are a polymer having at least one polar group selected from the group consisting of ##STR34## wherein M and M' are hydrogen, an alkali metal or ammonium and having at least one carbon-carbon unsaturated bond, and further said magnetic layer is exposed to radiation.
Claim 7
Dependent Claim
41 words
The magnetic recording medium as claimed in claim 5, wherein said binders are a vinyl chloride copolymer or a urethane resin, and the amount of the polar group is 1×10 -7 to 1×10 -3 equivalent per 1 g of the binders.
Claim 8
Dependent Claim
38 words
The magnetic recording medium as claimed in claim 1, wherein said ester compound represented by formula (I) is present in an amount of from 1 to 25 wt % based on the ferromagnetic particles in the magnetic layer.
Claim 9
Dependent Claim
30 words
The magnetic recording medium as claimed in claim 1, wherein a center line surface roughness of the magnetic layer is not more than 0.1 μm (cutoff value of 0.25 μm).
Claim 10
Dependent Claim
19 words
The magnetic recording medium as claimed in claim 1, wherein said magnetic layer is a ferromagnetic metal thin film.
Claim 11
Dependent Claim
16 words
The magnetic recording medium as claimed in claim 1, wherein said medium is a floppy disk.
Claim 12
Dependent Claim
16 words
The magnetic recording medium as claimed in claim 5, wherein said medium is a floppy disk.
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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) | 1994-09-16 | 1995-03-18 | 1995-09-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-09-16 | 1999-03-18 | 1999-09-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-09-16 | 2003-03-18 | 2003-09-17 | $7700.00 | Window Closed / Lapsed |