Minnesota Mining and Manufacturing Company

David B Oliff

James B Philip, Jr

Mark P Kirk

Ronald W Burrows

A photothermographic material having a photosensitive medium comprising: photosensitive silver halide, a reducible silver source, a reducing agent for silver ion, a hydrobromic acid salt of a nitrogen-containing heterocyclic ring or fused ring nucleus associated with a pair of bromine atoms CHARACTERIZED IN THAT the photosensitive medium additionally comprises as an antifoggant, substantially in the absence of an antifoggant effective amount of mercury and other heavy metal salts, a tribromomethyl ketone compound of general formula (I): ##STR1## in which; R represents an alkyl group, an aryl group, a carbocyclic ring or fused ring nucleus or a heterocyclic ring or fused ring nucleus.

Photothermographic imaging materials and antifoggants therefor

A heptamethine cyanine dye in which both nitrogen atoms of the cyanine chromophore bear a carboxyalkyl substituent comprising an alkyl chain of at least five carbon atoms. The dyes are useful as sensitisers in photothermographic imaging materials.

Growing community of inventors

Bishops Stortford, United Kingdom

David B Oliff