| 摘要 |
<p>PURPOSE:To erase printing by chemical treatment without damaging a card substrate so as to be capable of reutilizing or regenerating the substrate by treating a part or all of a surface to be printed with an org. solvent such as halogenated alkane or a ketone type solvent. CONSTITUTION:An org. solvent to be used is selected from halogenated alkane, halogenated alkene and a ketone type solvent. As halogenated alkane, dichloromethane, chloroform or dichloroethane can be designated and, as halogenated alkene, trichloroethylene can be designated and, as the ketone type solvent, acetone or methyl ethyl ketone can be designated. Especially, halogenated alkane is pref. from an aspect of printing erasing capacity. In a prepaid card, plastic based on polyethylene or polyester is used as a substrate and a part or all of the surface to be printed thereof is treated with the aforementioned org. solvent. By this constitution, printing can be uniformly erased.</p> |
