SYMMETRICAL SULPHUR-CONTAINING SCHIFFS BASES AND PHOTOGRAPHIC EMULSIONS CONTAINING THEM

摘要

1353527 Symmetrical sulphur containing Schiff's bases ILFORD Ltd 1 Nov 1972 [3 Nov 1971] 51158/71 Heading C2C [Also in Division G2] The invention comprises compounds of the formula wherein D represents the atoms necessary to complete a phenyl or naphthyl ring system which may carry one or two further substituent groups selected from alkyl and C 1 to C 6 hydroxyalkyl groups. They may be obtained by reacting one molecular proportion of a dialdehyde of the formula with two molecular proportions of an amine of the formula Examples are given for the preparation of the compounds. They are useful as additives to photographic materials.