Basf Aktiengesellschaft

Basf Magnetics Gmbh

Emtec Magnetics Gmbh

Basi Magnetics Gmbh

Emtech Magnetics Gmbh

August Lehner

Werner Lenz

Albert Kohl

Werner Balz

Norbert Schneider

Hermann Roller

Heinrich Hartmann

Michael Bobrich

Helmut Kopke

Werner Grau

Rudolf Bachmann

Werner Loch

Gregor Brodt

Guenter Heil

Ria Kress

Rudolf Suettinger

Friedrich Sommermann

Reinhold Baur

Ludwig Kreitner

Milan Velic

Joachim Hack

Herbert Spoor

Guenther Schulz

Uwe Keppeler

Milena Melzer

Peter Rudolf

Eberhard Koester

Roland Falk

Thomas Wunsch

Gunnar Schornick

Jenoe Kovacs

Hans-Uwe Schenck

Herbert Motz

Guenter Vaeth

Peter Richter

Ingolf Buethe

Albrecht Eckell

Hans-Joerg Hartmann

Mong-Jon Jun

Hermann Dikow

Ernst Ricker

Axel Sanner

Rainer Blum

Gerhard Hoffmann

Manfred Ohlinger

Helmut Jakusch

Alexander Kud

Helmut Barzynski

Horst Reimann

Karl Uhl

Peter Heilmann

Herbert Stutz

Dieter Naegele

Guenter Eckert

Heinz-Ulrich Werther

Franz Weingart

Ronald J Veitch

Hermann Graf

Volker Koch

Harald Jachow

Uwe Burkhardt

Peter Nagel

Juergen Gimpel

Michael Hitzfeld

Peter Engelhardt

Rudi Lehnert

Attila Vass

Karl Mahler

Ursula Klein

Uwe Woweries

Erich Hoffmann

Josef Schelble

Hans Reichert

Guenter Bettinger

Harald Frischmann

Heinz U Werther

Karl Krucker

Karl H Roemer

Eerhard Koester

Werner H&uuml;bner

Roller Hermann

Gerd Erhardt

Alfred Lindner

Winfried Gutermann

Described are tape-type magnetic recording media (I) including a non-magnetic substrate (III), at least one film applied to the substrate and, in at least one of these films, an inorganic acicular pigment (II) suitable for use as a supporting pigment, the ratio of the mean length to the mean diameter of the pigment (II) being at least 3 and the mean modulus of elasticity of the films being not less than 15 GPa in the longitudinal direction of the tape-type recording medium (I).

Magnetic recording media

Hydroxyl-containing polyurethanes I are composed essentially of

Polyurethanes

Magnetic recording media contain a nonmagnetic substrate and a magnetizable layer, the magnetizable layer containing ferromagnetic pigments and a system of polymeric materials, wherein the system of polymeric materials contains

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

Materials suitable as crosslinkable binder components

A polymeric material I is obtainable by reacting

Polymeric materials suitable as dispersing resins

Polymeric materials (I) are obtainable by reacting

In magnetic recording media consisting of a nonmagnetic substrate and at least one magnetizable layer firmly applied thereon and based on magnetic material dispersed in a binder mixture which contains at least one hydroxyl-containing, preferably low molecular weight polyureaurethane and one polyurethaneurea (meth)acrylate, the polyurethaneurea (meth)acrylate is obtained by reacting a poly(meth)acrylate having up to 2 terminal OH groups per mol and a molecular weight of from 200 to 50,000 with a mixture of aliphatic polyisocyanates having an average functionality of from 3.0 to 6.0 NCO groups per mol, consisting of from 0.1 to 10% by weight of a diisocyanate, from 30 to 80% by weight of a triisocyanate and from 20 to 60% by weight of an isocyanate having a functionality of from 4 to 10, with the proviso that from 1.2 to 3.0 NCO groups react per OH group and the remaining NCO groups are converted into substituted terminal urea groups with a polyfunctional amine or with a mixture of different polyfunctional amines.

Magnetic recording medium containing magnetic material dispersed in a

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 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.

A material suitable as crosslinking binder component for pigment-containing coatings and having an average molecular weight of from 25,000 to 150,000, obtainable by reacting a polyurethane comprising a diol having a molecular weight between 400 and 4,000, an aliphatic or cycloaliphatic diol of 2-18 carbon atoms, an aromatic diol of 8-36 carbon atoms, a trihydric or polyhydric alcohol of 3-18 carbon atoms, a polyhydric alcohol of 3-40 carbon atoms containing a tertiary amino group, and a diisocyanate of 3-34 carbon atoms with a compound containing one or more hydroxyl groups and one or more amino groups reactive toward isocyanate groups. The materials may be used as crosslinkable binder components for pigment-containing coatings, in particular for the production of magnetic recording materials.

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.

Magnetic recording media consisting of a nonmagnetic substrate and at least one magnetizable layer which is firmly applied thereon and is based on a magnetic material which essentially consists of ferromagnetic chromium dioxide and is finely dispersed in a polymer binder and further conventional additives are distinguished by a particular stability to the chemical decomposition due to moisture and oxidizable compounds and hence particular stability to the deterioration in the magnetic properties, as a result of the addition of from 0.1 to 8% by weight, based on the amount of chromium dioxide, of a monomeric, polyunsaturated, organic compound to the magnetic layer.

Magnetic recording medium having a magnetic layer containing chromium

Magnetic recording media consist of a nonmagnetic substrate and at least one magnetizable layer which is firmly applied thereon and is based on a polyurethane binder, not less than 50% by weight of the binder consisting of a high molecular weight branched polyurethane elastomer having OH-containing urea groups at the chain ends, and the frictional properties of the binder being improved and its coefficient of friction reduced by incorporation of perfluoro groups.

Magnetic recording media comprising a polyurethane binder resin

Magnetic recording media consist of a nonmagnetic substrate and at least one magnetizable layer which is applied firmly thereon and is based on a polyurethane binder, not less than 50% by weight of binder consisting of a branched polyurethane elastomer having urea groups at the chain ends.

Magnetic recording medium containing an isocyanate-free branched

Magnetic recording media consist of a nonmagnetic substrate and at least one magnetizable layer which is firmly applied thereon and is based on a polyurethane binder which may be crosslinked with a polyisocyanate, not less than 50% by weight of the binder consisting of a low molecular weight branched polyurethane having OH-containing urea groups at the chain ends, and the frictional properties of the binder being improved and its friction reduced by the incorporation of perfluoro groups.

Growing community of inventors

Roedersheim-Gronau, Germany

August Lehner