Abstract: 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.

Abstract: Magnetic recording media are produced by preparing a dispersion of anisotropic magnetic materials in solution in an organic binder using dispersants and further conventional additives, applying the dispersion in the form of a layer onto a nonmagnetic substrate and solidifying the applied magnetic layer, by a process in which a cylindrical grinding chamber is used which is provided with an anchor stirrer or helical stirrer and contains grinding media whose specific gravity is lower than that of the magnetic material.

Abstract: 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.

Abstract: Magnetic recording media consist of a nonmagnetic base and at least one matnetizable layer which is firmly applied thereon and is based on a magnetic material finely dispersed in a binder, consisting of not less than 50% by weight of a polyurethane, and further conventional additives, wherein the magnetizable layer also contains a saturated, branched hydrocarbon.

Abstract: 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.

Abstract: In a tape cassette possessing symmetrically arranged support liners, a compressive force dependent on the tape roll diameter is exerted by the liner and utilized for centering the roll and the tape. Force/diameter relationships, and embodiments of folded liners for achieving individual forces are described. A novel dynamic liner arrangement can be used in any tape cassette possessing high winding speeds and sensitive tapes, with frequently alternating rewind/playback operation.

Abstract: A wet comminuting machine is provided with a sieve which is located at the mill base outlet and has orifices of such dimensions that they block the passage of grinding medium. Opposite the exit surface of the sieve a plate, which can be moved toward the sieve, is provided, on the side facing the sieve, with elements for pushing through the orifices of the sieve, and can be moved manually, pneumatically, hydraulically or electrically by means of a connecting rod. The elements of the movable plate are arranged in alignment with the orifices of the sieve, and are in the form of strips or spikes, depending on the particular design of sieve.

Abstract: Storage-stable, pourable and pumpable silicate suspensions are prepared by wet milling of aluminosilicates, after the preparation of the latter, without intermediate drying.