PRODUCTION OF ALUMINATE SALT FLUORESCENT SUBSTANCE HAVING AFTERGLOW CHARACTERISTIC

摘要

PROBLEM TO BE SOLVED: To obtain the subject fluorescent substance having an afterglow characteristic hardly deteriorating a particle diameter originated from alumina powder of raw material by employing specificα-alumina powder preliminarily determined as the alumina of raw material. SOLUTION: This method for producing the aluminate salt fluorescent substance comprises mixing (A) alumina of raw material with (B) one or more metal elements forming a mother crystal together with the component A, (C) an activator and (D) a coactivator and subsequently calcining the mixture at a prescribed temperature. Therein,α-alumina powder having a preliminarily determined average particle diameter and a preliminarily determined particle size distribution is used as the component A, and when the mixture of the raw materials is calcined, theα-alumina powder of the raw material is calcined without being melted by the use of a flux. The calcination is preferably carried out at a prescribed temperature without the addition of a flux.