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:
Feb. 15, 1983
Filed:
Nov. 05, 1981
Giampiero Basile, Alessandria, IT;
Giancarlo Boero, Asti, IT;
Emiliano M Ceresa, Vigliano Biellese, IT;
Franco Montino, Casale Monferrato, IT;
Montedison S.p.A., Milan, IT;
Abstract
This invention relates to a process for stabilizing ferromagnetic chromium dioxide in respect of water and oxidizable organic compounds which it may contact in magnetic tapes. The process is applicable to a starting CrO.sub.2 having good magnetic properties, i.e. a coercive force not lower than about 400 Oersted, a maximum magnetic induction B.sub.m not lower than about 2500 gauss, and a magnetic induction B.sub.r not lower than about 1600 gauss. The CrO.sub.2 is subjected to a heat treatment at a temperature ranging from 300.degree. to 390.degree. C. in the presence of a gas stream not exerting any oxidizing or reducing action on the compounds of trivalent, tetravalent and hexavalent chromium. Suitable gases are, for example, nitrogen, helium and argon.