Basf Aktiengesellschaft

Basf Magnetics Gmbh

Basi Magnetics Gmbh

Werner Balz

August Lehner

Albert Kohl

Werner Lenz

Norbert Schneider

Werner Grau

Milena Melzer

Jenoe Kovacs

Hermann Roller

Guenter Heil

Helmut Kopke

Reinhold Baur

Wulf Muenzner

Eberhard Koester

Roland Falk

Heinz Berger

Friedrich Sommermann

Roland Roos

Milan Velic

Heinrich Hartmann

Helmut Jakusch

Rudolf Bachmann

Peter Rudolf

Gregor Brodt

Joachim Hack

Herbert Spoor

Klaus D Schomann

Dieter Schaefer

Ria Kress

Horst Fitterer

Karl Mahler

Klaus Schoettle

Gunnar Schornick

Werner Steck

Werner Loch

Gregor Ley

Karl Uhl

Herbert Motz

Michael Bobrich

Thomas Wunsch

Guenter Eckert

Wilhelm Sarnecki

Ingolf Buethe

Rudolf Suettinger

Job-Werner Hartmann

Hans-Joerg Hartmann

Volker Richter

Peter Engelhardt

Josef Woellhaf

Aribert Krug

Ursula Klein

Guenter Bettinger

Georg Huber

Paul Willmann

Dieter Scheffel

Ernst Ricker

Hilmar Lechner

Peter Gawlik

Karl Krucker

Karl H Roemer

Eerhard Koester

Wulf Muenzer

Preparation of materials (I) having an average molecular weight from 4000 to 30,000, obtainable by reacting

Materials suitable as crosslinkable binder components

Magnetic recording media consist of a nonmagnetic substrate and at least one magnetizable layer bonded thereon and based on a magnetic material dispersed in at least one polyurethane and one polyurethaneurea (meth)acrylate, the polyurethaneurea (meth)acrylate being obtained by reacting a hydroxyl-containing poly(meth)acrylate with a mixture of di- and polyisocyanates and converting the remaining NCO groups with ammonia or primary or secondary amines into urea groups.

Magnetic recording media

Magnetic recording media are obtained by preparing a dispersion of anisotropic magnetic material and additives in a solution of a polymeric binder in an organic solvent, applying the dispersion as a layer to a nonmagnetizable substrate, then orienting the anisotropic magnetic material in a magnetic field and solidifying the applied magnetic layer, and the magnetic layer contains water-repellent polysilica and, if required, a highly viscous polysiloxane.

Magnetic recording media are obtained by preparing a dispersion of anisotropic magnetic material and conventional additives in a solution of a polymeric binder in an organic solvent, applying the dispersion as a layer to a nonmagnetizable substrate, then orienting the anisotropic magnetic material in a magnetic field and solidifying the applied magnetic layer, the magnetic layer containing finely divided organic, hydrophobic supporting pigments and a highly viscous polysiloxane.

In magnetic recording media which have at least one magnetizable layer firmly applied to a nonmagnetic base, the magnetizable layer essentially consists of a magnetic material finely dispersed in an organic polymer binder, a dispersant, a lubricant and other conventional additives.

Magnetic recording media, consisting of a non-magnetic base and a magnetic layer firmly bonded thereto, exhibit improved properties in sustained operation if, in the course of their production, a dispersion of inorganic particles in a solvent is applied to the magnetic layer, and the solvent is then removed.

Production of magnetic recording media

In a tape cassette, particularly a video tape cassette, equalization of electrostatic charges between the two faces of the tape is effected by a connector element or connector elements electrically connecting at least one of two electrically conducting guide elements contacting the front of the tape and provided on the two sides, respectively, of the cassette with at least the associated one of two electrically conducting tape deflecting elements provided in the two respective front corners of the tape cassette. In this manner sticking of the tape to the deflecting elements due to electrostatic attraction therebetween and also the build-up of electrostatic charges along the tape path parallel to the front of the cassette housing due to the transporting of such charges from the deflecting elements as a result of the tape travel, are counteracted.

Magnetic tape cassette with equalization of electrostatic charges

Layer-type magnetic recording media are produced by dispersing a finely divided magnetically anisotropic material in a binder which consists of not less than 30% of a radiation-curable aqueous binder dispersion, applying the dispersion onto a non-magnetic base, orienting the magnetically anisotropic material and drying and crosslinking the applied layer by means of UV or high-energy electron radiation.

Production of layer-type magnetic recording media

Layer-type magnetic recording media are produced by dispersing a finely divided magnetically anisotropic material in a binder which consists of not less than 40% of a radiation-curable aqueous binder dispersion, applying the dispersion onto a non-magnetic base, orienting the magnetically anisotropic material and drying and crosslinking the applied layer by means of UV or high-energy electron radiation.

In magnetic recording media consisting of a non-magnetic base and, bonded on top of this, one or more magnetizable layers based on magnetic material finely dispersed in a polymer binder, a lubricant and further conventional additives, the lubricant used is a triethanolamine esterified with oleic acid.

Magnetic recording media comprising a non-magnetic substrate and a magnetic layer comprising a finely divided magnetic material dispersed in an organic solvent soluble, crosslinkable, essentially linear, thermoplastic polyurethane which possesses acrylate side and terminal groups wherein said polyurethane is prepared by reacting poly- and/or diisocyanates with a mixture of (a) methacrylate - or acrylate - diols having molecular weights of from 146 to 3,000, (b) monoesters of methacrylic or acrylic acid and a diol having a molecular weight of from 116 to 300, and (c) other organic polydiol compounds which have molecular weights of from 400 to 5,000.

Magnetic recording media consisting of a non-magnetic base and, applied thereto, one or more firmly adhering magnetizable layers based on magnetic material finely dispersed in a polymeric binder, at least one lubricant and other conventional additives, wherein the lubricant used is a mixture of zinc stearate which has been rendered hydrophilic and stearylamide.

Magnetic recording media consisting of a non-magnetic base and, applied thereto, one or more firmly adhering magnetizable layers based on magnetic material finely dispersed in a polymeric binder, at least one lubricant and further conventional additives, wherein the lubricant used is zinc stearate which has been rendered hydrophilic.

Layer-type magnetic recording media are produced by applying a dispersion of a magnetically anisotropic material in a binder solution onto a flexible plastic base provided with an adhesion-promoting layer and then solidifying the magnetic layer, by a method in which the adhesion-promoting layer consists of a radiation-curable aqueous dispersion of a polymer.

A tape guide system, especially a tape guide system for a magnetic tape cassette, comprising conductive connecting means between the tape guide elements and/or the front and back of the tape, prevents the tape from blocking, slipping from the tape reels, or folding over. In practical embodiments, pieces of flexible conductive plastics film are arranged in the vicinity of the guide elements. The novel tape guide system can be used in any type of magnetic tape transport mechanism in which increased friction occurs when the tape is transported, especially in video cassettes for all systems.

Guide system and magnetic tape cassette comprising such a system

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Limburgerhof, Germany

Werner Balz