摘要:
A process for the production of magnetic recording media by applying a magnetic layer, which consists essentially of magnetic material finely dispersed in organic polymers, to one side of a flexible base, and applying a non-magnetizable backing coating which is free of inorganic solids to that side of the base which is opposite the magnetic layer, wherein the backing coating consists of two or more polymers which are incompatible with one another and have precipitated from a solvent mixture, and magnetic recording media produced by this process.
摘要:
Magnetic recording media are produced by a method wherein a fluid dispersion of finely divided magnetically anisotropic material in a film-forming binder mixture containing a polyurethane (obtained from a polyester which possesses free hydroxyl groups, and a di- or polyisocyanate) is applied to a non-magnetic base and the magnetic layer is then hardened.
摘要:
Magnetic recording media are produced by preparing a dispersion consisting of finely divided magnetic material, a dispersant, the conventional additives and a solution or a dispersion of a polymeric binder, applying the dispersion in the form of a layer onto a non-magnetizable base, orienting the anisotropic magnetic material by means of a magnetic field and drying the applied layer, by a process in which the dispersant employed is obtained by reactingA. from 70 to 95 parts by weight of a reaction product ofI. from 0.5 to 1.5 moles of an oxoalcohol of 6 to 20 carbon atoms,II. from 6 to 18 moles of ethylene oxide andIII. from 2 to 10 moles of propylene oxide, withB. from 5 to 30 parts by weight of a polyphosphoric acid having a P.sub.2 O.sub.5 content of from 80 to 88%.
摘要:
In magnetic recording media consisting of a non-magnetic base and, bonded on top of this, one or more magnetizable layers based on magnetic material finely dispersed in a polymer binder, a lubricant and further conventional additives, the lubricant used is a triethanolamine esterified with oleic acid.
摘要:
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.
摘要:
Magnetic recording media are produced by dispersing finely divided anisotropic magnetic material and conventional additives in a solution of a polymeric binder in an organic solvent, or in an aqueous dispersion of a polymeric binder, adding a polymer based on hydrophilic ethylenically unsaturated compounds to the magnetic dispersion, applying a layer of the dispersion to a non-magnetizable base, orienting the anisotropic magnetic material in a magentic field and drying the applied layer.
摘要:
A magnetic dispersion which can be applied to a non-magnetic base to produce a recording medium is prepared by dispersing a magnetically anisotropic material in a polymer binder and in an organic solvent by a method wherein the magnetically anisotropic material is worked in a jet mill before and/or during dispersing.
摘要:
Magnetic recording media comprising a non-magnetic base which is provided with a magnetic layer which consists essentially of a dispersion of an anisotropic magnetic material in a mixture of an OH-containing polyurea-urethane binder, which is crosslinked with a polyisocyanate, with a physically drying binder.
摘要:
A process for the preparation of acicular ferrimagnetic iron oxides by reducing gamma-iron(III) oxide hydroxide to magnetite, at from 280.degree. to 620.degree. C., by means of an organic compound which is decomposable at this temperature in the presence of iron oxide, and, optionally, a stream of reducing gas, and, if desired, then oxidizing the magnetite with oxygen-containing gases, at from 150.degree. to 450.degree. C., to acicular ferrimagnetic iron oxide of the formula FeO.sub.x, where x is from above 1.33 to 1.50, wherein the organic compound used for the reduction is a non-polar glycerol ester of a fatty acid which is introduced into the aqueous reaction suspension during the preparation of the gamma-iron(III) oxide hydroxide.