Photothermographic process with erasure of unwanted image - by heating exposed emulsion contg. halohydrocarbon andN-vinyl cpd.

摘要

The photographic process employs a matl. coated with a photosensitive mixt. of discrete particles of a halohydrocarbon and an N-vinyl cpd. dispersed in a hydrophilic binder for erasing a first latent image, if it is not wished to develop this, and then for producing a second latent image on the same photographic matl. The matl. is (a) exposed selectivity with actinic light to produce a first latent image, (b) heated to 60-120 degrees C to erase this image, and (c) exposed selectivity with actinic light to produce a second latent image, exposure with actinic light being moderate, so that the latent image is not developed to a visible image by stage (b) alone. The cycle of stages (b) and nc) can be repeated at least once if the second latent image is also unwanted. In addn. to the possibility of erasing unwanted images, numerous images can be produced on different areas of the same matl.