Patent US4180597A successfully refreshed from Google Patents.
US4180597A
Expired / Lapsed
US
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Manufacture of magnetic recording media
Assignee: BASF SE
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Filing: 1978-09-08
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Granted: 1979-12-25
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Expires: 1998-09-08
Abstract
Abstract A process for the manufacture of a magnetic recording medium by producing a dispersion of a finely divided anisotropic magnetic material and conventional additives in a solution of a polymeric binder in an organic solvent, applying a layer of the dispersion to a nonmagnetizable base material, then orienting the anisotropic magnetic material by means of a magnetic field, and drying the layer, wherein a compound of the formula (I) ##STR1## where R 1 is straight-chain or branched akyl of 2 to 10 carbon atoms, cycloalkyl of 6 to 10 carbon atoms or aralkyl of 7 to 14 carbon atoms and R 2 is hydrogen or one of the radicals given in the definition of R 1 , is added to the dispersion.
Inventors
- 👤 Herbert Motz
- 👤 Norbert Schneider
- 👤 Hans-Joerg Hartmann
- 👤 Reinhold Baur
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 00:57
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/7013; Y; Y10; Y10S; Y10S428/00; Y10S428/90
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
171 words
A process for the manufacture of a magnetic recording medium which comprises forming a dispersion of finely divided particulate anisotropic magnetic material in a solution of polymeric binder in an organic solvent, the dispersion containing from 0.05% to 5% by weight, based on the amount of the magnetic material, of a compound of the formula (I) ##STR3## wherein R 1 is methyl, straight-chain or branched alkyl of 2 to 10 carbon atoms, cycloalkyl of 6 to 10 carbon atoms or aralkyl of 7 to 14 carbon atoms and R 2 is hydrogen, methyl, straight-chain or branched alkyl of 2 to 10 carbon atoms, cycloalkyl of 6 to 10 carbon atoms or aralkyl of 7 to 14 carbon atoms; applying a layer of the dispersion to a non-magnetizable base; and thereafter drying the layer of dispersion and magnetically orienting the particles of anisotropic magnetic material of said dispersion, said drying and orienting steps being effected in any order provided that the magnetic layer has not solidified prior to orientation of the particles.
Claim 2
Dependent Claim
171 words
A process for the manufacture of a magnetic recording medium which comprises forming a dispersion of finely divided particulate anisotropic magnetic material in a solution of polymeric binder in an organic solvent, the dispersion containing from 0.05% to 5% by weight, based on the amount of the magnetic material, of a compound of the formula (I) ##STR3## wherein R 1 is methyl, straight-chain or branched alkyl of 2 to 10 carbon atoms, cycloalkyl of 6 to 10 carbon atoms or aralkyl of 7 to 14 carbon atoms and R 2 is hydrogen, methyl, straight-chain or branched alkyl of 2 to 10 carbon atoms, cycloalkyl of 6 to 10 carbon atoms or aralkyl of 7 to 14 carbon atoms; applying a layer of the dispersion to a non-magnetizable base; and thereafter drying the layer of dispersion and magnetically orienting the particles of anisotropic magnetic material of said dispersion, said drying and orienting steps being effected in any order provided that the magnetic layer has not solidified prior to orientation of the particles.
Claim 3
Dependent Claim
31 words
A process for the manufacture of a magnetic recording medium as set forth in claim 1, wherein the compound of the formula (I) is selected from the group comprising aliphatic ketoximes.
Claim 4
Dependent Claim
29 words
A process for the manufacture of a magnetic recording medium as set forth in claim 2, wherein the aliphatic ketoxime is one having from 3 to 8 carbon atoms.
Claim 5
Dependent Claim
25 words
The process of claim 1 wherein the compound of the formula (I) is added after the magnetic material has been dispersed in the polymeric binder.
Claim 6
Dependent Claim
21 words
The process of claim 1 in which the dispersion contains from 0.2 to 2% of a compound of the formula (I).
Claim 7
Dependent Claim
21 words
The process of claim 1 in which the dispersion contains from 0.5 to 1% of a compound of the formula (I).
Claim 8
Dependent Claim
17 words
The process of claim 1 wherein the non-magnetizable base is from 4 to 200 μm in thickness.
Claim 9
Dependent Claim
24 words
The process of claim 7 wherein the layer of the dispersion applied to the non-magnetizable base is from 3 to 20 μm in thickness.
Claim 10
Dependent Claim
17 words
The process of claim 1 wherein the non-magnetizable base is from 6 to 36 μm in thickness.
Claim 11
Dependent Claim
22 words
The process of claim 9 wherein the layer of the dispersion applied to the non-magnetizable base is from 6 to 15 μm.
References Cited (Backward Citations)
US3625760A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-12-24 | 1983-06-25 | 1983-12-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-12-24 | 1987-06-25 | 1987-12-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-12-24 | 1991-06-25 | 1991-12-25 | $7700.00 | Window Closed / Lapsed |