Tetra-aza indene compounds
AssigneeCiba-Geigy Corporation
InventorsDavid Rowland, Michael E. Dale, Geoffrey E. Ficken, William E. Long, Andrew W. Yates
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Abstract
Tetra-aza indene compounds of the formula ##STR1## wherein R.sub.1 is alkyl or a ring system and R.sub.2 and R.sub.3 are hydrogen or alkyl. These compounds are of use as image toners in photographic materials.
Claims3
A photographic silver halide material which comprises at least one silver halide emulsion layer, said material comprising at least one tetra-aza indene compound of the formula ##STR10## wherein R.sub.1 is unsubstituted alkyl containing 6 to 11 carbon atoms, cyclohexyl, cycloheptyl or cyclooctyl and the groups R.sub.2 and R.sub.3 are each individually hydrogen or alkyl containing 1 to 4 carbon atoms.
Dependencies are inferred from the claim text.