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:
Sep. 16, 1997
Filed:
Sep. 20, 1996
Cheryl M Forster, Granville, OH (US);
Scott A Meilicke, Seattle, WA (US);
Osram Sylvania Inc., Danvers, MA (US);
Abstract
A pure gamma calcium pyrophosphate for use in e.g., the production of calcium haloapatite fluorescent phosphor host materials, and a process for the synthesis thereof. Dicalcium orthophosphate is dissolved in a dilute solution of nitric acid in water, and spray-dried to form a calcium phosphate powder including a major phase of spherically shaped particles of dicalcium orthophosphate. The calcium phosphate powder is fired in air to convert the calcium phosphate powder to pure gamma calcium pyrophosphate. Gamma pyrophosphate will not undergo dehydration during firing of the fluorescent phosphor; thus larger quantities of phosphor can be processed in a firing vessel.