Method of producing fluorescent material

Abstract

Abstract PURPOSE: On the production of fluorescent substances of rare earth metal silicate activated with rare earth metal, ammonium fluoride or acid ammonium fluoride is added as a flux and they are calcined to increase the emission efficiency and brightness of rare earth metal-activated rare earth silicate under excitation with ultraviolet rays, which is used as a fluorescent film for cathod ray tubes or discharge lamps. CONSTITUTION: On the production of fluorescent substance of rare earth activated rare earth silicate of the formula (L n is yttrium, lanthanum, gadolinium, lutetium; Ln' is cerium, europium or terbium; x, y satisfy following relations; 1×10 -4 ≤x≤ 3×10 -1 , 0.8≤y≤2.2), at least one of ammonium fluoride and acid ammonium fluoride and, when necessary, additional barium compound are added to the starting materials for fluorescent substance as a flux by 1W7.5wt% and 0.5W3wt% respectively; they are calcined to give the objective fluorescent substance. The starting materials are provided by weighing, for example, Ln 2 O 3 , SiO 2 and Ln' 2 O 3 stoichiometrically and mixing them. The flux is mixed by a dry or wet method. COPYRIGHT: (C)1981,JPO&Japio

Inventors

• 👤 Shigeo Fujino
• 👤 Toshio Jinnai
• 👤 Takashi Hase

Bibliographic Details