Treating processes for improving physical properties of phosphors

Claim 1

THE PROCESS COMPRISING EFFECTING CONTACT BETWEEN A LUMINESCENT PHOSPHOR, SAID PHOSPHOR HAVING A SURFACE DISCOLORATION OF A WATER-INSOLUBLE COMPOUND THE CATION OF WHICH IS FROM THE GROUP CONSISTING OF SILVER, COPPER, GOLD, LEAD AND MANGANESE AND THE ANION OF WHICH IS FROM THE CLASS CONSISTING OF SULFIDE, SELENIDE, TELLURIDE, SULFOSELENIDE AND SULFOTELLURIDE, AND AN AQUEOUS SOLUTION AT A PH FROM 1 TO 4 AND A TEMPERATURE BETWEEN 15*C. AND 95*C. CONTAINING (1) AND ACID HAVING A PK, OF LESS THAN 5, (2) FROM 5% TO 50% BY WEIGHT OF A WATER SOLUBLE COMPOUND FROM THE GROUP CONSISTING OF (A) THIOUREA, AND (B) A SALT THE CATION OF WHICH IS SELECTED FROM THE GROUP CONSISTING OF LITHIUM, SODIUM, POTASSIUM, RUBIDIUM, CESIUM, MAGNESIUM, CALCIUM, STRONTITUM, BARIUM AND AMMONIUM, AND THE ANION OF WHICH IS SELECTED FROM THE GROUP CONSISTING OF IODIDE, THIOSULFATE, AND THIOCYANATE, AND (3) LESS THAN 15% BY WEIGHT OF AN OXIDIZING AGENT SELECTED FROM THE GROUP CONSISTING OF POTASSIUM FERRICYANIDE AND SULFUROUS ACID, SAI CONTACT BEING EFFECTED FOR A TIME SUFFICIENT TO REMOVE SAID WATER-INSOLUBLE COMPOUND FROM SAID SURFACE, AND SAID ACID BEING SELECTED FROM THE GROUP CONSISTING OF ACETIC ACID, SULFURIC ACID, HYDROCHLORIC ACID, SODIUM BISULFATE, AND PHOSPHORIC ACID.