| 摘要 |
PROBLEM TO BE SOLVED: To obtain a seal which prevents the illicit reuse of the seal and allows easy authenticity decision even if the once used seal is peeled, is stuck to another medium and is reused by forming a printing ink layer by using thermosensitive decoloring ink which is decolored at a prescribed temperature higher than ordinary temperature. SOLUTION: A polymer alloy, etc., consisting of plastic materials are used as a base material 2 used for the seal 1. A release layer 3 is formed on the rear surface side of the base material 2 by a known coating method, such as gravure coating or roll coating. The printing ink layer 4 formed by using the thermosensitive decoloring ink which is decolored at the prescribed temperature higher than ordinary temperature is formed on the surface of the release layer 3 by known printing methods, such as gravure, offset, silk, flexographic and typographic printing. A tacky adhesive layer 5 is formed on the rear surfaces of the release layer 3 and the printing ink layer 4. Release paper 6 is constituted on the rear surface of this tacky adhesive layer 5 in a peelably stuck state. |
