 Solid state electrochemical pollution control device |
| OF PREFERRED EMBODIMENTS Referring to FIG. 1, overall pollution control device or scrubber ... |
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| Electrochemical device |
| It is therefore an object of the present invention to provide an electrochemical device, for ... |
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| Sensor for determining the oxygen content in a gas |
| What is claimed is: 1. A sensor for determining oxygen content in a gas to be analyzed comprising ... |
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| Novel ceramic binder comprising poly(ethyloxazoline) |
| OF THE INVENTION In general, any ceramic which comprises an inorganic, nonmetallic material as its ... |
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| Separation of polymetallic sulphides by froth flotation |
| We claim: 1. A reagent for enhanced mineral separation of metal sulphides present in sulphidic ores,... |
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| Method for producing electricity from a fuel cell having solid-oxide ionic electrolyte |
| What is claimed is: 1. A method of producing electicity with a fuel cell having first and second ... |
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| Fuel cell system including porous, panel type support and process for producing the same |
| OF THE INVENTION Referring now to the figures of the drawing in detail and first, particularly, to ... |
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| Fluid catalytic cracking catalyst |
| We claim: 1. A composition of matter as a component in catalytic cracking compositions which ... |
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| Integral manifolding structure for fuel cell core having parallel gas flow |
| This invention provides a solid oxide fuel cell having improved manifolding for fuel and oxidant ... |
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| Semi-permeable membranes with an internal discriminating region |
| OF THE INVENTION The membranes of this invention have two porous surfaces. More particularly, the ... |
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Magnetic recording discs
| Details |
Inventors: Hartmann, Hans-Joerg; Falk, Roland; Gawlik, Peter; Balz, Werner; Uhl, Karl; Schaefer, Dieter; Motz, Herbert;
Assignee: BASF Aktiengesellschaft (Ludwigshafen (Rhine), DT)
Primary Examiner: Pianalto; Bernard D.
Assistant Examiner:
Attorney, Agent or Firm: Keil, Thompson & Shurtleff
The invention relates to a process for the manufacture of improved magnetic discs by applying a thin layer of a liquid dispersion of magnetic pigments and optionally further, non-magnetic, pigments in a binder mixture to a non-magnetic rigid base, and curing the magnetic coating which has been applied. The binder used is a mixture of polycondensates comprising 60 to 70% by weight of a solid curable polycondensate of 2,2-bis(4-hydroxyphenyl)-propane and epichlorohydrin having an epoxy equivalent weight from about 400 to 2,500 and a melting point from about 50.degree. to 150.degree. C, 10 to 30% by weight of a curable allyloxybenzene-formaldehyde condensate of the resol type with free methylol groups or with methylol groups etherified with a lower alcohol, and having a molecular weight of less than 1,000, and 10 to 30% by weight of a curable melamine-formaldehyde condensate with more than two methylol groups etherified with n-butanol or iso-butanol, and having a molecular weight of less than 2,500. A magnetic dispersion using such a binder allows the application of a firmly adhering magnetic coating, even in thicknesses of less than 4 .mu., to aluminum discs or pre-coated aluminum discs, and the magnetic coating produced has high resistance to mechanical wear. |
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DETAILED DESCRIPTION We claim: 1.
A magnetic recording disc which comprises a base and an adhesive magnetic coating composition thereon, said coating comprising a binder and finely divided magnetic pigment dispersed in said binder, said binder comprising a mixture of polycondensates consisting essentially of A.
60 to 70% by weight of a solid curable polycondensate of 2,2-bis-(4-hydroxyphenyl)-propane and epichlorohydrin, with and epoxy equivalent weight from about 400 to 2,500 and having a melting point from about 50.
degree.
to 150.
degree.
C.
, B.
10 to 30% by weight of a curable allyloxybenzene-formaldehyde condensate of the resol type with free methylol groups or methylol groups etherified with a lower alcohol, and having a molecular weight of less than 1,000, and C.
10 to 30% by weight of a curable melamine-formuladehyde condensate with more than two methylol groups etherified with n-butanol or isobutanol and having a molecular weight of less than 2,500.
2.
A magnetic recording disc as set forth in claim 1 wherein said base is a non-magnetic, metallic disc selected from the group consisting of aluminum and aluminum alloy.
3.
A magnetic recording disc as set forth in claim 2 wherein said disc has a polished, hard intermediate layer of a coating resin containing pigment.
4.
A magnetic recording disc as set forth in claim 1 wherein said binder contains from 5 to 20% by weight, based on the sum of the amounts of the resins in A, B, and C of polyvinyl methyl ether.
5.
A magnetic recording disc as set forth in claim 1 wherein said magnetic pigment is magnetite (Fe.
sub.
3 O.
sub.
4).
6.
A magnetic recording disc as set forth in claim 1 wherein said magnetic pigment is acicular gamma-iron-(III) oxide with average particle size from about 0.
1 to 2.
mu.
.
Description:
This application discloses and claims subject matter described in German patent application No.
P 23 19 363.
7 filed Apr.
17, 1973, which is incorporated herein by reference.
The invention relates to a process for the manufacture of improve magnetic recording discs by applying a thin layer of a liquid dispersion of magnetic pigments and optionally further, non-magnetic, pigments in a binder mixture to a non-magnetic rigid base, and curing the magnetic coating which has been applied
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Fuel Cells 
