Basf Magnetics Gmbh

Josef Schelble

Reinhard Kraetschmer

Albert Pertzsch

Wolf-Dieter Schroeer

Gerhard Huebler

A wet-on-wet application process by means of a sheet extruder having at least two slot dies is described, the upper layer containing metal powders and/or metal powder alloys while the lower layer contains the same magnetic pigments and conductivity-increasing and/or transparency-reducing additives, preferably carbon black, and both layers having virtually the same rheological properties. The magnetic recording medium has improved conductivity and very good running behavior, in particular when used as a mirror mastertape.

A magnetic recording medium

A wet-on-wet application process by means of an extrusion coater having at least two slot dies is described, the upper lip of the common outlet orifice of the slot dies being recessed relative to the lower lip and a right parallelepiped magnet whose upper edge is opposite the extruder orifice at a distance of, preferably, from 1 to 1.5 mm away being arranged on the other side of the nonmagnetic substrate and parallel to the latter, in which the uppermost layer contains magnetic pigments and has a layer thickness of more than 2.0 .mu.m while the lower layer is nonmagnetic, may contain a conductivity-increasing additive or nonmagnetic fillers and has a thickness of less than 0.5 .mu.m when dry. The magnetic recording medium has very good mechanical and electroacoustic properties, improved conductivity, very good adhesion, improved surface quality and a smaller number of dropouts.

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Munich, Germany

Josef Schelble