Abstract A fluorescent lamp having a phosphor coating on the inside surface of the tubular glass envelope, the phosphor coating comprising finely divided phosphor particles coated with a glassy phosphate material. The lamp is prepared by providing an aqueous slurry of the phosphor particles in a solution containing a material yielding a phosphate glass upon firing, coating the interior envelope walls with the aqueous suspension, and firing the phosphor coating at a temperature which promotes the formation of the phosphate glass coating about the particulate phosphor material. A suitable phosphate glass-yielding material is ammonium dihydrogen phosphate, and phosphor coatings produced therewith have been found to have improved adherence to the envelope walls.
A FLUORESCENT LAMP COMPRISING A TUBULAR ENVELOPE; A COATING OF THE INTERIOR SURFACE THEREOF, SAID COATED CONSISTING ESSENTIALLY OF A MAJOR AMOUNT OF FINELY-DIVIDED PHOSPHOR PARTICLES WITHIN A MINOR AMOUNT OF A GLASSY PHOSPHATE MATRIX SELECTED FROM THE GROUP CONSISTING OA AMMONIUM DIHYDROGEN PHOSPHATE AND A MIXTURE OF ZINC NITRATE AND ORTHOPHOSPHERIC ACID, SAID COATING EXHIBITING IMPROVED ADHERENCE TO SAID INTRIOR SURFACE WITHOUT SIGNIFICANTLY DECREASING THE LUMINOSITY OF SAID COATING UPON EXCITATION, MERCURY VAPOR WITHOUT SAID ENVELOPE; AND A PAIR OF ELECTRODES SPACED WITHIN SAID TUBULAR ENVELOPE AND BEING ADAPTED FOR CONNECTION, AT THOSE PORTIONS THEREOF EXTENDING OUTSIDE OF SAID ENVELOPE, TO MEANS FOR PRODICING AN ELECTRIC DISCHARGE WITHIN SID TUBULAR ENVELOPE.
Claim 2
Dependent Claim
112 words
A FLUORESCENT LAMP COMPRISING A TUBULAR ENVELOPE; A COATING OF THE INTERIOR SURFACE THEREOF, SAID COATED CONSISTING ESSENTIALLY OF A MAJOR AMOUNT OF FINELY-DIVIDED PHOSPHOR PARTICLES WITHIN A MINOR AMOUNT OF A GLASSY PHOSPHATE MATRIX SELECTED FROM THE GROUP CONSISTING OA AMMONIUM DIHYDROGEN PHOSPHATE AND A MIXTURE OF ZINC NITRATE AND ORTHOPHOSPHERIC ACID, SAID COATING EXHIBITING IMPROVED ADHERENCE TO SAID INTRIOR SURFACE WITHOUT SIGNIFICANTLY DECREASING THE LUMINOSITY OF SAID COATING UPON EXCITATION, MERCURY VAPOR WITHOUT SAID ENVELOPE; AND A PAIR OF ELECTRODES SPACED WITHIN SAID TUBULAR ENVELOPE AND BEING ADAPTED FOR CONNECTION, AT THOSE PORTIONS THEREOF EXTENDING OUTSIDE OF SAID ENVELOPE, TO MEANS FOR PRODICING AN ELECTRIC DISCHARGE WITHIN SID TUBULAR ENVELOPE.
Claim 3
Dependent Claim
29 words
The lamp of claim 1 wherein said glassy phosphate matrix is a mixture of zinc nitrate and orthophosphoric acid, said coating exhibiting substantially improved adherence to said interior surface.