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:
Jan. 13, 1981
Filed:
Jul. 16, 1979
Giampiero Basile, Alessandria, IT;
Giancarlo Boero, Asti, IT;
Montedison S.p.A., Milan, IT;
Abstract
A ferromagnetic chromium dioxide stabilized by coating the particles thereof with a stabilizing substance is disclosed, wherein the stabilizing substance consists essentially of an equimolecular mixture of Fe.sub.2 O.sub.3 and MnO or of a mixture of ferrite MeFe.sub.2 O.sub.4 with oxides Fe.sub.2 O.sub.3 and MeO, wherein Me represents Cu, Co, Zn or Mg and wherein the molar ratio Fe.sub.2 O.sub.3 /MeO is equal to 1, the quantity of the ferrite in the mixture being such as results from calcining, at temperature between 250.degree. and 350.degree. C., equimolecular quantities of Fe.sub.2 O.sub.3 and MeO. A process for obtaining the stabilized CrO.sub.2 is also disclosed wherein the CrO.sub.2 is dispersed in water and on it are co-precipitated Fe(OH).sub.3 and Mn(OH).sub.2 or Me(OH).sub.2 in stoichiometric quantities with respect to each other; after which the CrO.sub.2, in admixture with the hydroxides, is separated from the water, dried at a temperature not exceeding 100.degree. C. and then calcined at temperatures between 250.degree. and 350.degree. C.