Basf Aktiengesellschaft

Karl Mahler

Werner Balz

Roland Falk

Heinrich Hartmann

August Lehner

Werner Steck

Albert Kohl

Gerd Wunsch

Herbert Spoor

Paul Deigner

Werner Loeser

Job-Werner Hartmann

Rudolf Bachmann

Friedrich Domas

Peter Felleisen

Aribert Krug

Georg Huber

A process for the manufacture of magnetic recording media, comprising a non-magnetic base and, applied thereto, one or more magnetizable layers, consisting of an anisotropic magnetic material finely dispersed in an organic binder, wherein the binder contains at least 40% of an aqueous ionomeric polyurethane dispersion which at 50.degree. C. forms films having a modulus of elasticity of from 50 to 700 N/mm.sup.2 and a DIN No. 53,157 pendulum hardness of from 20 to 110 s, the corresponding values of the modulus and hardness at room temperature being more than 3.5 times higher.

Process of making a magnetic recording media

A process for the manufacture of rigid magnetic recording media by depositing a cobalt-containing ferromagnetic metal layer on a non-magnetic metallic base disc provided with a cured layer of binder which does not dissolve or swell in organic solvents and contains non-magnetic pigments, and which has been activated, before deposition of the ferromagnetic layer, by treatment with a solution of a palladium (O) complex in an organic solvent, followed by decomposition of this complex, to prepare it to receive the ferromagnetic metal layer which is produced by electroless deposition.

Process of making a magnetic recording medium

A process and apparatus for producing magnetic discs in which the preferred direction of orientation of the anisotropic magnetic particles, contained in an organic binder system, is tangential to the circumference of the disc. Orientation is effected, prior to solidification of the magnetic layer, by the action of a magnetic field which is formed in the plane of symmetry between at least two pairs of magnetic poles, the poles of each pair being of the same polarity and opposite each other. One pair of poles flares out in cross section toward the plane of symmetry between the pairs of poles, whereas the other pair or pairs of poles of opposite polarity, when viewed in cross section, taper toward the said plane of symmetry to a point, the distance between the poles of such pair(s) being greater than that between the flared poles, and the plane of symmetry of the pairs of poles being in the plane of the disc. Using this process and apparatus, magnetic discs with a non-magnetic metallic base are obtained, in which the anisotropic magnetic particles in the layer of fluid binder applied to the base are oriented tangentially to the circumference of the disc during spin-coating.

Device for the magnetic orientation of magnetic recording media

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Kehl, Germany

Karl Mahler