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. 29, 1991
Filed:
Sep. 19, 1989
E Douglas Dickens, Jr, Richfield, OH (US);
Anthony M Mazany, Akron, OH (US);
The B. F. Goodrich Company, Akron, OH (US);
Abstract
Oxidation of particles of rare earth magnetic materials is greatly reduced when a passivating agent such as an oxidation resistant composition or corrosion inhibitor or combinations thereof, is coated thereon. The oxidation resistant composition is a binary or a ternary composition made from (a) at least one amino containing silane compound such as an aminosilane or a polyaminosilane, or (b) at least one epoxy resin, or (c) an epoxy silane compound, or all three such compounds. The oxidation resistant composition, the corrosion inhibitor, or combinations thereof, passivate the surface of the magnetic particles and generally form a highly concentrated coating on the surface thereof. Antidegradants are optionally utilized to improve the performance of the rare earth magnet composition with regard to improved oxidation resistant properties and generally include organic phosphorous compounds and/or alcohols. Various binders such as an elastomer, a thermoplastic, a thermoset, or a polymer generally formed by reaction based injection molding (RIM), act to adhere the various particles together and form an oxidation resistant rare earth magnet composition. Products can be made by various polymer processing techniques such as extrusion, calendering, injection molding, compression molding, and the like. The passivated rare earth magnetic materials of the present invention have excellent high temperature (e.g. 150.degree. C.) oxidation resistance, and excellent corrosion resistance.