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:
Aug. 22, 1989
Filed:
Jan. 17, 1989
Kenneth T Reilly, Towanda, PA (US);
Richard G Gingerich, Towanda, PA (US);
GTE Products Corporation, Stamford, CT (US);
Abstract
A process is disclosed for producing an electroluminescent phosphor which comprises blending a chloride flux, a copper source, and zinc sulfide to form a relatively uniform admixture, heating the admixture at a temperature of from about 1000.degree. C. to about 1300.degree. C. for about 2 to about 8 hours to convert at least a portion of the admixture to a crystalline material containing zinc sulfide, at least some chloride ions, and copper ions, washing the material with sufficient water to remove at least a major portion of the water soluble material from the crystalline material, drying the material to produce a relatively moisture-free material which is low intensity milled for a sufficient time to change the crystallographic structure of at least a portion of the moisture-free material, blending the milled material with zinc sulfate and copper sulfate, with or without manganese carbonate depending on whether manganese is desired as an activator, to form a second admixture, which is heated at a temperature of from about 750.degree. C. to about 850.degree. C. for about 1.5 to about 3 hours to form an activated material which is cooled for a period of time of from about 10 minutes to about 20 minutes followed by immediately quenching in water, removing the water from the cooled and quenched activated material, washing the material with reactive aqueous solutions to remove residual fluxes and excess activator materials, and drying the material to form an electroluminescent phosphor.