PRODUCTION OF OXIDE-BASED RED LUMINOUS FLUORESCENT SUBSTANCE

摘要

PURPOSE: A process for preparing novel oxide-based red luminous fluorescent substance by blending calcium, titanium and silicon as a major component with praseodymium as an activator and then with boric acid as a flux is provided which produces long decay luminescent materials having improved long decay time. CONSTITUTION: The process for preparing the oxide-based red luminous fluorescent substance comprises the sequential steps of mixing a calcium compound, a titanium compound and a silicon compound with praseodymium as an activator; adding boric acid as a flux to the mixture; calcining under reducing atmosphere two times and then under oxidative atmosphere one time; and producing long decay phosphors of the formula; Ca1-xTi1-ySiyO3:Prx, (0.00001≤x≤0.1, 0≤y≤0.8). The amount of praseodymium to be added is 0.001 to 10% by mole based on the calcium, the amount of substitution of Si 0 to 80% by mole based on the titanium and the amount of boric acid 0.01 to 20% by weight based on the total weight of the raw material.