| 摘要 |
PURPOSE:To enable confidential information to be preserved, by providing an electrically conductive layer on the surface of a paper comprising or coated with a color developing agent which is invisible on discharge breakdown recording but is thereafter visualized under the action of a color developing assistant. CONSTITUTION:The discharge breakdown recording paper comprises the conductive layer on the surface of a paper comprising or coated with a color developing agent, and information is recorded by breaks the conductive layer by passing an electric current. In this case, the recorded image is invisible as it is, since the color developing agent layer and the conductive layer have the same hue. The recorded image is visualized under the action of a color developing assistant, and the visualized recorded image can be made invisible by the action of an erasing color developing assistant. Accordingly, confidential information is sufficiently preserved. The color developing agent is a pH indicator or a discolorable dye, and the color developing assistant is a pH adjustor. |
