Antonelli, Terry, Stout & Kraus, LLP
Long afterglow phosphor and a process for the preparing thereof
 The invention relates to a long afterglow phosphor and a process for preparing the phosphor, characterized in that the phosphor comprises the sinter expressed by a general formula MO.multidot.(n-x)a Al.sub.2 O.sub.3.sup..alpha. .div.(1-a)Al.sub.2 O.sub.3.sup..gamma. !.multidot.B.sub.2 O.sub.3 : R, where, M represents and alkaline earth metal, R represents a rare earth element, 0.5<a.ltoreq.0.99, 0.001.ltoreq.x.ltoreq.0.35, and 1.ltoreq.n.ltoreq.8, and a part of M may be replaced with at least one alkaline earth metal selected from Mg, Ca and Ba. R may also use other rare earth elements in addition to Eu as additional activators. The process for preparing the long afterglow phosphor of the present invention comprises several steps, wherein the sintering temperature needs to be 800.degree.-1200.degree. C. 
C
C09K
inventional
Jun Pengcheng Qinglong Jingfeng Qian Baoshan
Li Li Hao Gao Xu Lu