Effect of pre-exposure heating on thermally developed dry silver type imaging materials

The sensitometric effects of pre-exposure heating in TDPM of the Dry Silver type were investigated. Loss of developable density with increasing time o f pre-exposure heating was shown to involve the toners which are essential to selective, image-wise TDPM: development. Pre-exposure heating was found not to affect the latent image forming system (silver halide-silver carboxy late interface) in TDPM. Our observations support previously proposed inter pretations of the mechanism of TDPM development. Preexposure heating may th us lead to either (a) loss oftener, e.g., by volatilization or air oxidatio n, and/or (b) side reactions between toner and silver carboxylate leading t o formation of less reactive species. From a practical point of view these results provide mechanisms for both the storage instability of the TDPM sen sitometric responses, as well as for inefficiency in latent image amplifica tion.