| 摘要 |
PURPOSE: To form an image of low gradation by a direct thermography by forming a plurality of imaging layers each containing uniformly distributed, in a film-forming resin binder, a non-photosensitive metal salt in thermal working relationship with an organic reducing agent and forming at least one heat- attenuating space layer for separating the imaging layers from each other. CONSTITUTION: At least two imaging layers each containing uniformly distributed in a film-forming resin binder a metal salt in thermal working relationship with an organic reducing agent, that is, a non-photosensitive metal salt capable of forming a metal itself by a reaction with heat of a substantially organic reducing agent. The imaging layers are separated from each other by at least one heat-attenuating spacer layer. The heat-sensitive layers to be separated by the heat-attenuating spacer layer does not always necessarily contain the same composition, but preferably formed of a film forming transparent aqueous resin or polymer. |
