LIGHT-STORING PHOSPHOR AND LIGHT-STORING PIGMENT

摘要

An object of the present invention is to provide a phosphorescent phosphor having an excellent afterglow luminance after 10 to 12 hours after sunset under the outdoor excitation conditions. The phosphorescent phosphor is represented by the formula (Sr 1-a-b-x-y Mg a Ba b Eu x Dy y )Al 2 O 4 , wherein a satisfies a relation 0.02‰¤a‰¤0.1, b satisfies a relation 0.03‰¤b‰¤0.15, x satisfies a relation 0.001‰¤x‰¤0.04, y satisfies a relation 0.004‰¤y‰¤0.05, and (a + b) satisfies a relation 0.08‰¤(a + b)‰¤0.2. The phosphorescent phosphor has an excellent afterglow luminance after a long period of period of time in a manner most suitable for outdoor applications.