Process for producing Ce-Mn coactivated fluoroapatite phosphors as the yellow emitting component for high efficacy lamp blends

Claim 1

A process for producing cerium and manganese activated calcium-strontium fluoroapatite luminescent material composition containing sodium, comprising: mixing a calcium source, a strontium source, a cerium source, a sodium source, a manganese source, a phosphate source, and a fluoride source together in amounts in accordance with the formula (Ca.sub.1-s Sr.sub.s).sub.t Ce.sub.v Na.sub.w Mn.sub.x (PO.sub.4).sub.y F.sub.z wherein s is from 0 to 1 t is from about 3.43 to about 4.01 v is about 0.3 x is from about 0.3 to about 0.4 y is about 3.00 z is from 1.0 to about 4.0 to form a reagent mixture wherein said calcium source is selected from the group consisting of calcium hydrogen phosphate, calcium carbonate, calcium fluoride, and mixtures thereof; said strontium source is selected from the group consisting of strontium hydrogen phosphate, strontium carbonate, strontium fluoride, and mixtures thereof; said cerium source is selected from the group consisting of cerium (IV) oxide, cerium (III) fluoride, and mixtures thereof; said sodium source consists of sodium carbonate; said manganese source consists of manganese (II) carbonate; said phosphate source is selected from the group consisting of diammonium hydrogen phosphate, calcium hydrogen phosphate, strontium hydrogen phosphate, and mixtures thereof; and said fluoride source is selected from the group consisting of calcium fluoride, strontium fluoride, cerium (III) fluoride, and mixtures thereof; comminuting said reagent mixture to form a thoroughly mixed powder blend, firing said blend for about 1 to about 1.5 hours at about 900° C. to about 1050° C. in about 1.0 l/minute flow of N 2 containing 5% H 2 and a small amount of water vapor; cooling the fired blend to about 700° C. in about 2 hours; further cooling the fired blend to about 25° C.; and milling the cooled blend.