The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 25, 1986
Filed:
Feb. 27, 1984
Joachim Greiner, Ebenhausen, DE;
Burkhard Nippe, Munich, DE;
Agfa-Gevaert Aktiengesellschaft, Leverkusen, DE;
Abstract
This invention relates to a process for the production of a magnetic recording material having at least one layer of magnetic oxidic and/or metallic needle shaped pigments with dimensional anisotropy and/or some other type of magnetic anisotropy, e.g. crystalline, dielectric or magnetic field induced anisotropy, which process may be used to produce a layer having perpendicular anisotropy or a layer which passes from an initial perpendicular anisotropy to an isotropic distribution of the preferential magnetic axes of the pigments. According to the present process, the magnetic dispersion, after having been applied to the layer support, is subjected to an external magnetic field while still in the state of a liquid suspension, with the result that the pigments move with the preferential axis thereof into the perpendicular axis of the layer, and the pigments are subsequently fixed by drying.