Development of photographic silver halide material

A photographic developer comprising a silver halide developing agent and a polyaddition compound which is the reaction product of a diepoxide and a polyol under conditions to provide in said polyaddition compound recurring units of the following general formula, the recurring units containing at least one thioether sulphur atom linked to two carbon atoms:

• ##STR11## wherein:
• Q is --O--, --S--, --S alkylene S-- or --O alkylene O-- wherein the alkylene group may be interrupted by oxygen or sulphur,
• each of X.sub.1 and X.sub.2 represents oxygen or sulphur,
• Alk stands for alkylene which may be interrupted by oxygen or sulphur, and
• R is hydrogen or COR.sub.1, SO.sub.2 R.sub.1 or CONHR.sub.1 wherein R.sub.1 is an alkyl group or an aryl group, and
• wherein at least one of R, Q, X.sub.1, Alk and X.sub.2 is or comprises a thioether sulphur atom.

A photographic element containing a silver halide emulsion layer and a polyaddition compound which is the reaction product of a diepoxide and a polyol under conditions to provide in said polyaddition compound recurring units of the following general formula, the recurring units containing at least one thioether sulphur atom linked to two carbon atoms:

• ##STR12## wherein:
• Q is --O--, --S--, --S alkylene S-- or --O alkylene O-- wherein the alkylene group may be interrupted by oxygen or sulphur,
• each of X.sub.1 and X.sub.2 represents oxygen or sulphur,
• Alk stands for alkylene which may be interrupted by oxygen or sulphur, and
• R is hydrogen or COR.sub.1, SO.sub.2 R.sub.1 or CONHR.sub.1 wherein R.sub.1 is an alkyl group or an aryl group, and
• wherein at least one of R, Q, X.sub.1, Alk and X.sub.2 is or comprises a thioether sulphur atom.