procedures for the development of photographic material at elevated temperature.

摘要

1399449 Photographic silver halide development AGFA-GEVAERT 15 Sept 1972 [17 Sept 1971] 43517/71 Heading G2C [Also in Division C2] An exposed photographic material comprising a support and at least one silver halide emulsion is developed above 30‹C in the presence of at least one non-quarternary, non-heterocyclic nitrobenzene compound of the Formula:- where (R) n is one or more substituents selected from H, halogen, OH, NO 2 , CN, sulpho or carboxy in acid or salt from, alkoxycarbonyl, acyl derived from a carboxylic or sulphonic acid or optionally substituted alkyl, alkenyl, alkynyl, alkoxy, alkylmercapto, amino or aryl. Preferred compounds are nitrobenzene, m- or pdinitrobenzene, 2,4-dinitrobenzene sulphonic acid or its sodium salt, 2-benzoylvinyl-4-nitrophenol, 1,2,3-trinitro-4,5-dimethoxy-benzene, N-methyl- 2,4-dinitroaniline, p-nitrobenzonitrile, 2-nitroacetophenone, 4-nitrophthalic acid, 2-carboxymethylthio-nitrobenzene, 4-carboxyethynyl-nitrobenzene, 4-pentadecyl- 1,3-dinitrobenzene, 4-n-hexadecylthio-1,3- dinitrobenzene, 4-n-hexadecyloxy-1,3- dinitrobenzene or 4,4'-dinitro-biphenyl. The compound is preferably present in the silver halide emulsion. These compounds reduce fog produced by processing at elevated temperatures without significantly reducing emulsion speed and in some cases increase emulsion speed. The emulsion may contain mercury cyanide (Ex 1-3) and 5-methyl-7-hydroxy -s-triazolo [1,5-a] pyrimidine (Ex 1-4). The ratio of hydrophilic colloid to silver halide (as AgNO 3 ) may be 0À2 to 0À6.