FLUORESCENT SUBSTANCE FOR SELECTING POSITION OF PRINT INFORMATION

摘要

PURPOSE:To obtain the title fluorescent substance made it possible to select the position of print information printed on a stump and automatically carry out postmarking by blending Zn2SiO4 with Mn at a specific amount. CONSTITUTION:The aimed fluorescent substance obtained by blending Zn2SiO4 with Mn of 0.1-2.0wt.% based on the weight of Zn2SiO4. The above-mentioned fluorescent substance is produced as follows: SiO2 is blended with ZnO at a ratio of about 1mol to 1.5-1.8mol and then MnCO3 is blended therewith at a ratio of 0.1-2.0wt.% (expressed in terms of Mn). Then the blend is mixed using a ball mill for about 1hr and then calcined at about 1000-1300 deg.C for about 1-3hr. The calcined product is pulverized for about 1-3hr using a wet ball mill and then sieved through washing by water and dehydration to provide the the blend (Zn2SiO4:Mn) having about 1-3mu particle size.