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. 02, 1976
Filed:
Dec. 23, 1974
GTE Sylvania Incorporated, Stamford, CT (US);
Abstract
A process suitable for reclaiming europium-activated yttrium oxysulfide contaminated with europium-activated yttrium oxide and other non-rare earth cathodoluminescent phosphors comprises forming a relatively uniform admixture of specific fluxing agents, the contaminated yttrium oxysulfide phosphor, a sufficient amount of reactive rare earth source selected from reactive yttrium and europium sources to achieve a predetermined yttrium to europium ratio in the admixture and an excess of the theoretical amount of sulfur required to convert the yttrium oxide and the yttrium source to yttrium oxysulfide, heating the admixture at a temperature of at least 850.degree.C in non-oxidizing atmosphere for a time sufficient to convert the yttrium oxide and the yttrium source to a europium-activated yttrium oxysulfide whereby the rare earth materials form a cathodoluminescent material and whereby the non-rare earth materials form water soluble reaction products, washing the resulting material with sufficient water to remove water soluble materials leaving a cathodoluminescent europium-activated yttrium oxysulfide phosphor.