| 摘要 |
PURPOSE:To deliver the transmission letter of a facsimile to the specific person of a destination in such a state that secret information is concealed by providing a color erasing layer receiving high energy printing heat to erase developed color information to the upper surface of a thermal color forming layer and laminating a photosensitive color forming layer recording information latently even by any one of high and low energy printing heats and developing said information by the irradiation with light. CONSTITUTION:At the time of the application of low energy heat, a lower thermal color forming layer 2 develops a color by the same reaction device as conventional thermal recording paper. At the time of the application of high energy heat, an color erasing agent is melted in an intermediate color erasing layer 3 to flow in the lower thermal color forming layer 2 and erases the developed color due to applied heat in the thermal color forming layer 2. Therefore, no printing mark remains from the aspect of appearance at this time and information is latently recorded on a photosensitive color forming layer 4 to secure the concealability of the information. When this concealed information is read, the photosensitive color formable composition formed at the time of the application of printing heat may be exposed to a light source such as solar rays or a mercury lamp and the color developed at this time is fixed permanently. |
