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:
Apr. 26, 1977
Filed:
Mar. 31, 1976
Robert A Hedler, Seneca Falls, NY (US);
W Wentworth Slobbe, Seneca Falls, NY (US);
GTE Sylvania Incorporated, Stamford, CT (US);
Abstract
A composite article comprises a core of a phosphor particle having a light modifying layer thereon. The light modifying layer is comprised of a co-precipitated mixture of a free-flowing agent such as silica or pyrophosphate and a pigment which modifies the light output of the energized phosphor. Also disclosed is a method of making the composite article which comprises the steps of preparing an aqueous mixture of particles of phosphor, particles of a pigment and a positively charged colloidal silica or pyrophosphate and mixing thoroughly. After mixing, a base, in the case of silica, or a salt which will form an insoluble pyrophosphate in the case of the pyrophosphate, is added thereto in sufficient amount to gel the mixture causing the silica or pyrophosphate and the pigment to co-precipitate upon and coat the phosphor particles. After the coating operation the supernatant liquid is removed and the coated phosphor is dried.