Basf Aktiengesellschaft

Basf Magnetics Gmbh

Basf Magnetic Gmbh

Michael Bobrich

Werner Lenz

August Lehner

Hermann Roller

Rudolf Suettinger

Albert Kohl

Gregor Brodt

Uwe Keppeler

Norbert Schneider

Werner Loch

Guenther Schulz

Hermann Dikow

Helmut Auweter

Ria Kress

Ludwig Kreitner

Peter Rudolf

Helmut Kopke

Peter Engelhardt

Ekkehard Schwab

Manfred Ohlinger

Helmut Jakusch

Werner Balz

Guenter Heil

Peter Richter

Milena Melzer

Reinhold Baur

Norbert Mueller

Ronald J Veitch

Hermann Graf

Harald Jachow

Rudi Lehnert

Reinhard Koerner

Werner Latzel

Alfred Lindner

Roller Hermann

Jochen Rudolph

Polymeric materials (I) are obtainable by reacting

Polymeric materials suitable as dispersing resins

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 consist of a nonmagnetic substrate and at least one magnetizable layer which is firmly applied thereon is based on a magnetic material dispersed in at least one polyureaurethane and a polyurethaneurea (meth)acrylate, the polyurethaneurea (meth)acrylate being obtained by reacting a polyacrylate with a mixture of di- and polyisocyanates and converting the remaining NCO groups into substituted urea groups with aminoalkyltrialkoxysilanes.

A magnetic recording medium comprising a nonmagnetic substrate and at least one magnetic layer applied thereon and containing an acicular chromium dioxide uniformly distributed in a polymeric binder and additives and having a coercive force of at least 60 kA/m, a mean particle length of the chromium dioxide of less than 300 nm, whose factor HD according to the formula ##EQU1## where KT is the coercive force of the magnetic layer in [kA/m], measured in an external field of 380 kA/m, L is the mean particle length and .DELTA.L is the range of the particle size distribution, determined from the numerical distribution of the particle length, both measured in [nm], is greater than 1.85, and a process for the preparation of this chromium dioxide.

Process for preparing modified chromium dioxide

In flexible magnetic recording media consisting essentially of a web-like nonmagnetic substrate, the magnetic layer is applied to one main side of the web-like substrate and a backing coating formed on the opposite main side of the substrate from a polymeric binder and nonmagnetic fillers as well as supporting pigments, the backing coating contains a precipitated silica treated on the surface with a phosphate-containing polyurethane.

Flexible magnetic recording media having a backing coating containing a

Flexible magnetic recording media essentially consist of a web-like nonmagnetic substrate, a magnetic layer applied to one main side of the web-like substrate and a backing coating formed on the opposite main side of the substrate from a polymeric binder and nonmagnetizable fillers and supporting pigments.

Process of producing a flexible magnetic recording media having a

In magnetic recording media consisting of a nonmagnetic substrate and one or more magnetizable layers bonded thereon and based on a polyurethane binder, the binder consists of not less than 50% by weight of an isocyanate-free, branched polyurethane which is soluble in tetrahydrofuran and has sulfonate groups along the polyurethane branches and OH-containing urea groups at the chain ends and a molecular weight of from 4,000 to 30,000.

Magnetic recording media consist of a nonmagnetic substrate and one or more magnetizable layers bonded thereon and based on a polyurethane binder, the binder consisting of not less than 50% by weight of a branched polyurethane elastomer having sulfonate groups and possessing urea groups at the chain ends.

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.

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 polyisocyanate, not less than 50% by weight of the binder consisting of a low molecular weight branched polyureaurethane having OH-containing urea groups at the chain ends, and the sliding properties of the said binder being improved and its coefficient of friction reduced by incorporation of siloxane groups.

Magnetic recording media having a branched thermoplastic polyurethane

Magnetic recording media consist of a nonmagnetic substrate and one or more magnetizable layers which are firmly applied thereon and are based on a magnetic material which is finely dispersed in a polymer binder and further conventional additives and essentially consists of ferromagnetic chromium dioxide, and the said recording media are particularly stable to the chemical decomposition due to moisture and oxidizable compounds and hence to deterioration in the magnetic properties, owing to the addition of from 0.1 to 8% by weight of an organic compound from the group consisting of the antioxidants, based on the amount of chromium dioxide, to the magnetic layer.

In magnetic recording media consisting of a nonmagnetic base and, firmly applied to this, one or more magnetic layers based on a magnetic material finely dispersed in organic binders, the binder consists of not less than 50% by weight of a high molecular weight branched polyurethane elastomer possessing OH-containing urea groups at the chain ends.

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Boehl-Iggelheim, Germany

Michael Bobrich