Abstract: A photographic dye diffusion transfer process is provided which operates by imagwise release of a dye.The dye diffuses to a receiving layer and is mordanted there to give a dye image. The dyes are released from a compound of the formula D--E--F--BAL by reductive cleavage.D is a group which contains the residue of diffusible dye, BAL is a ballasting group which renders the compound containing it substantive to the layer in which it is present, D and E being joined by any type of chemical bond and E and F represent a single or double bond system which links D and BAL and which has a reduction potential above -200 mV measured against a standard hydrogen electrode at a pH of less than 3 and which bond can be reductively cleaved at a pH of less than 3 by a reducing agent which is able to act as a pH below 3.

Abstract: A new method to produce photographic images is provided which comprises(a) imagewise exposing a photographic assembly which contains at least during the silver halide developing step, in order optionally a supercoat layer, at least one silver halide emulsion layer, a layer containing a modifiable image substance and a photobase, there being optionally one or more interlayers between each of said components(b) treating the exposed photographic assembly with an aqueous processing bath so as to provide in the silver halide emulsion layer or layers a solution or dispersion of an image substance modifying/silver halide developing compound (dymodev compound), thereby to develop the latent silver image in the silver halide emulsion(s), and(c) in the non-latent image areas allowing the dymodev compound to diffuse in a counter-imagewise manner from the silver halide emulsion layer(s) to the layer containing the modifiable image substance and there to modify reductively the image substance.

Abstract: A photographic dye diffusion transfer process is provided which operates by imagwise release of a dye.The dye diffuses to a receiving layer and is mordanted there to give a dye image. The dyes are released from a compound of the formula D--E--F--BAL by reductive cleavage.D is a group which contains the residue of diffusible dye, BAL is a ballasting group which renders the compound containing it substantive to the layer in which it is present, D and E being joined by any type of chemical bond and E and F represent a single or double bond system which links D and BAL and which has a reduction potential above -200 mV measured against a standard hydrogen electrode at a pH of less than 3 and which bond can be reductively cleaved at a pH of less than 3 by a reducing agent which is able to act at a pH below 3.