| 摘要 |
PURPOSE:To obtain such a seal that unathorized opening of a document bag or the like and forgery of a seal can easily be verified by allowing a color developing ink layer to develop color with an org. solvent or with heat. CONSTITUTION:This seal has a color developing ink layer 20 containing a leuco pigment and developer and a protective film layer 30 which does not transmit a solvent successively formed on a base sheet 10 which transmits a solvent. A releasing sheet 50 is formed with an adhesive layer in-between on the back surface of the base sheet 10. The base sheet 10 is such a sheet 10 that has brittleness and transmits a solvent. |
