| 摘要 |
PURPOSE:To obtain an image which can be preserved for a long period of time, by a method wherein a color forming sheet comprising a laminate of a color forming layer and a synthetic resin covering layer is heated to expose the color forming layer, and a developing sheet comprising an adhesive containing a component not contained in the color forming layer is laminated on the back side of a base sheet. CONSTITUTION:The color forming layer 2 comprising a binding resin containing either one of a leuco substance and an acidic developer (e.g., boric acid) is provided on the surface of the base sheet (e.g., paper) 1, and the synthetic resin covering layer 3 is laminated on the color forming layer 2 to obtain the color forming sheet A. The adhesive layer 4 containing one of the leuco substance and the acidic developer which is not contained in the color forming layer 2 of the color forming sheet A is provided on the back side of a transparent base sheet (similar to the base sheet 1) 5 to obtain the developing sheet B. Both of the sheets are laminated on each other so that the developing layer side comes into contact with the color forming layer 2, and the leuco substance and the acidic color developer of the sheets A, B are brought into reaction at an exposed part of the color forming layer 2 to develop a color, thereby forming an image. |
