Dihydrazides

A photographic silver halide material which comprises at least one silver halide emulsion layer, wherein at least one layer of said material comprises at least one hydrazide having the general formula:

• B--(A.sup.+)--C (G.sup.-)
• where B and C are the same or different and have formula I:
• ##STR69## where R.sub.1 is hydrogen, alkyl, alkoxy or a blocking group selected from the group consisting of ##STR70## wherein R.sub.5 and R.sub.6 each are independently selected from the group consisting of hydrogen, alkyl, aminoalkyl, alkylaminoalkyl, acylaminoalkyl, alkylsulphonylaminoalkyl, arylsulphonylaminoalkyl, trialkylammoniumalkyl, hydroxyalkyl, haloalkyl, cycloalkyl, alkoxyalkyl, polyethyleneoxy, aryl, aralkyl, heterocyclic, and wherein R.sub.5 and R.sub.6 taken together can form a ring which optionally contains at least one unsaturated bond;
• R.sub.7 and R.sub.8 are independently selected from the group consisting of hydrogen, alkyl, aralkyl, hydroxy, alkoxy, haloalkoxy, aryloxy, aralkoxy, hydroxyalkyl, acylamino, phenoxy, alkoxyalkoxy, sulphonylamino and halogen;
• wherein R.sub.2 and R.sub.3 are independently hydrogen, alkyl, alkoxy, hydroxyalkyl, aralkyl, aralkoxy and halogen;
• and
• R.sub.2 and R.sub.3 taken together can form a saturated or unsaturated carbocyclic ring;
• R.sub.4 is hydrogen, alkyl or substituted alkyl;
• and
• m is 1 or 2;
• i, j and k are independently 0 or 1;
• and
• A.sup.+ is an activity regulating group having the formula:
• ##STR71## where Z denotes the elements necessary to form a 5-membered heterocyclic ring, optionally having one or two double bonds:
• n is i or 2;
• and G.sup.- is a negatively charged ion.