Studies for improving a stability of light sensitive material has led to find the new system which has much higher stability during storage.
In the new system, a light sensitive diazo compound and a coupling component are finely powdered and dispersed in a binder. Besides these chemicals the finely powdered substance which melts easily upon heating is also dispersed in the binder.
In some cases, the compound which can generate an alkali on heating is incoporated in a form of fine particle to promote a coupling reaction.
The new material can be used entirely in the same manner as the conventional diazo type materials in light exposure and in heat development. Furthermore reversal and thermographic processes can be well applied to the new material for obtaining a reproduction.