Silver complex diffusion transfer process employing an image-receiving element containing an S-thiuronium alkyl sulfonate

A silver complex diffusion transfer process, which process comprises the steps of exposing a photosensitive element containing a silver halide emulsion layer, developing the exposed photosensitive silver halide emulsion layer and forming a soluble silver complex of unexposed silver halide by treating the said photosensitive silver halide emulsion layer with an alkaline processing fluid in the presence of a developing agent and a silver halide complexing agent, transferring said soluble silver complex by diffusion to the silver receptive layer of an image-receiving element in superposed relationship with said silver halide emulsion, forming at said silver receptive layer an image incorporating silver from said silver complex under the action of development nuclei, and separating said image-receiving element from said photosensitive element, wherein said image-receiving element includes, in at least one layer thereof, an S-thiuronium alkyl sulfonate in an amount, within the range of 20 to 150 mg/m.sup.2, effective to accelerate the physical development of silver, said S-thiuronium alkyl sulfonate having the general formula:

• ##STR3## wherein R is a C.sub.1 -C.sub.6 linear or branched, substituted or unsubstituted, alkylene group.