| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent forgery and alteration by providing a copy discoloring body having a color different from the visually recognizable color of a copy by a copier by forming the wavelength selecting layer laminated on a reflecting layer from at least a binder resin containing fine particles. SOLUTION: As fine particles used when the wavelength selecting layer constituting a copy discoloring body 1 is formed of at least a binder resin containing fine particles, one kind of org. fine particles such as micro-silica, mica, talc, calcium carbonate or the like or a combination of two or more kinds of org. fine particles can be used. Since the wavelength region and intensity of synthetic light of reflected light L1 toward a light receiving part S on the surface of the wavelength selecting layer and light L2 transmitted through the wavelength selecting layer 3 to be reflected by a reflecting layer 2 to be again transmitted through the wavelength reflecting layer 3 to go toward the light receiving part S in the irradiation light L from the light source of a copier to the wavelength selecting layer 3 of the copy discoloring material are different from those of light directly entering a human's eye from the wavelength selecting layer 3, the color of the copy of the copy discoloring material 1 can be made different from a visually recognizable color.</p> |
