Photographic coat - contg. rhodium-doped silver halide and hydrazine cpd. as stabiliser, avoiding loss of lith characteristics in lith developer

摘要

Photographic coats contg. Rh-doped Ag halide (AgX) grains are stabilised with N-acyl-N'-phenylhydrazine on semicarbazide cpds. of formula (I). In (I) R1 is H or an alkyl, aryl, acyl, (substd.) amino or (substd.) hydrazine gp.; R2 is H or a substit. (I) are readily available and can be prepd. by well-known methods. Specifically R1 is Ph, NH2, dialkylamino, H or Me; R2 is H. Pref. (I) is used in a concn. of 10 power(-2) to 10 power(-5) mole/mole AgX. USE/ADVANTAGE - (I) are very effective stabilisers and are free from the disadvantages associated with phenidone, such as loss of lith characteristics in a lith developer.