Basf Aktiengesellschaft

Basf Magnetics Gmbh

Manfred Steuerwald

Manfred Ohlinger

Eberhard Koester

Jenoe Kovacs

Joachim Hack

Werner Steck

Gerd Wunsch

Paul Deigner

Werner Loeser

Dieter Schaefer

Job-Werner Hartmann

Heinz Stritzinger

Ursula Klein

Egon Von Gross

Dieter Schwarz

A transfer film having a magnetic layer consists essentially of a substrate film, a parting layer and a transfer layer which is detachable from the said parting layer and is formed by one or more magnetic layers, and, on that side of the magnetic layer which faces the substrate film, after detachment of the substrate film, the surface-forming layer consists of a top layer which contains inorganic pigments in a cross-linked polymer matrix and has a thickness of from 0.2 to 5.0 .mu.m and a surface resistance of from 10.sup.-1 to 10.sup.-8 ohm/cm.

Transfer film with magnetic layer

Transfer films consist essentially of a support film, a release layer and a transfer layer detachable from this release layer and composed of two magnetic layers and said transfer films may have, on the second magnetic layer, an adhesive layer which serves for fixing the transfer layer to a substrate, the two magnetic layers each containing a magnetizable material having a different coercive force.

Transfer film having magnetic layers

A process for authenticating recording media which are to be safeguarded against falsification and which possess a layer of exchange-anisotropic magnetic material, by determining the residual recording which is left over, because of the exchange anisotropy of the magnetic material, from a recording of a sequence of signals after exposure of the material to a specific temperature cycle and, subsequently, to a magnetic AC field which decreases to zero, and an apparatus for carrying out the said process.

Document identification employing exchange-anisotropic magnetic material

A process for authenticating recording media which are to be safeguarded against falsification and which possess discrete regions of an exchange-anisotropic magnetic material, by comparison of the polarity of a residual magnetization which is left over, because of the exchange anisotropy of the magnetic material, from a predetermined initial magnetization after exposure of the material to a specific temperature cycle and, subsequently, to a magnetic AC field which decreases to zero, with the polarity of a residual magnetization formed in the same way from an opposite initial magnetization, and an apparatus for carrying out the said process.

Document authentication by means of exchange-anisotropic magnetic

A process for the manufacture of wear-resistant magnetic recording media comprising a dimensionally stable base, a thin ferromagnetic metal layer, containing cobalt and/or nickel, firmly bonded thereto and a thin protective layer applied thereon. The protective layer is produced by treating the recording medium in a liquid basic medium, containing gaseous oxygen, for from 1 to 60 minutes at from 5.degree. to 70.degree. C., washing and drying the treated recording medium and then heating it in air at from 170.degree. to 300.degree. C. This method offers a particularly simple way of providing the ferromagnetic layer of the recording medium with a thin but uniform, mechanically stable and wear-resistant protective layer.

Manufacture of magnetic recording media having a wear-resistant surface

Magnetic recording media comprising a non-magnetizable flexible base and a firmly adhering magnetic coating based on a dispersion, containing a silane, of a magnetic pigment in a polymeric binder, and a process for their manufacture. The silane is an aminoalkylsilane R.sub.n Si(OR').sub.4-n, wherein n is 1, 2 or 3, R' is alkyl of 1 to 8 carbon atoms and R is aminoalkyl of the formula with one or more primary and/or secondary amino groups and from 3 to 11 carbon atoms. Magnetic recording media comprising a magnetic coating containing such a silane exhibit better abrasion resistance and better electromagnetic properties than comparable coatings.

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Frankenthal, Germany

Manfred Steuerwald