| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a phosphor, which is a plate-like crystal body having a particle size of nanometer size in the thickness direction but sufficiently broad in the surface direction, emitting blue light when irradiated with ultraviolet, and to provide a coating material suitable for security printing for preventing forgery of records by using the phosphor. <P>SOLUTION: A fired compact, in which the crystal structure of zeolite is broken down into an amorphous state while the contour of the plate-like crystal is maintained, is obtained by performing ion exchange of K<SP>+</SP>ion with Ce<SP>3+</SP>ion in "Linde Q" type zeolite having a hexagonal plate-like crystal form and composition of K<SB>2</SB>O-Al<SB>2</SB>O<SB>3</SB>-2SiO<SB>2</SB>-xH<SB>2</SB>O and by subsequently performing filtration, washing and drying, and then firing at a temperature of about 900°C under nonoxidative atmosphere. The fired compact is a plate-like phosphor and emits blue fluorescence having a peak at about 410 nm when excited by 295 nm UV light. A fluorescent coating material is obtained by dispersing the plate-like phosphor in a vehicle and can be used for security printing. <P>COPYRIGHT: (C)2011,JPO&INPIT |
