Spectrally sensitised silver halide emulsion super-sensitised without excessive fogging

摘要

Spectrally-sensitised photographic silver halide (AgX) emulsion is super-sensitised with a cyclic diorganotellurium compound, which is a dibenzotellurophene, telluroxanthene, dibenzoa,dtellurepin or analogue of formula (I) or a thieno3,2-b1benzotellurophene or 1benzotelluropheno3,2-bpyrrole of formula (II). In the formulae, Q = a group completing a 5-7-membered ring; X = sulphur (S) or imino (N-R1); R1-4 = hydrogen (H), alkyl, aryl, O-alkyl or O-aryl; R1R2 and R3R4 may = groups completing another 5-7-membered ring. Also claimed is colour photographic AgX material containing this emulsion.