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:
May. 16, 1995
Filed:
Feb. 22, 1994
Applicant:
Inventors:
Assignee:
Shin-Etsu Chemical Co., Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C09K / ; C01F / ;
U.S. Cl.
CPC ...
423263 ; 2523 / ;
Abstract
A precipitation method is proposed for the preparation of a rare earth phosphate powder by the reaction of a water-soluble salt of the rare earth element in an aqueous solution with an ammonium phosphate, which gives a rare earth phosphate powder consisting of non-agglomerate discrete particles having a spherical particle configuration suitable as a base material of rare earth-based phosphors. The method is characterized by the addition of the ammonium phosphate in the form of a powder to an acidic aqueous solution of the rare earth salt under specified conditions in contrast to the conventional method in which the ammonium phosphate is admixed in the form of an aqueous solution.