| 摘要 |
PURPOSE:To display the effective period of a product at a glance without any influence of temperature and humidity and other conditions by making a change of color with time by utilizing the property that an easy migrating dye migrates in synthetic resin. CONSTITUTION:Coloring and discoloring with time are caused by utilizing the property that the easy migrating dye migrates in synthetic resin, and an elapsed time is displayed by its graphic variation. A dye which has relatively low molecular weight and no polarity group migrates in polyurethane resin which includes noncrystal areas at a high ratio in a long period. The dye is bound with the resin by dyeing or printing the surface of the resin, or press-contacting another printed material. When the dyed part 2 of a sheet 1 reaches a ring 3, a time display is made. Therefore, the effective period of a product is displayed at a without any influence of temperature and humidity and other conditions. |
