Heat-developable photographic materials
AssigneeFuji Photo Film Co., Ltd.
InventorsMinoru Sakai, Shigeo Hirano, Katsuyuki Watanabe
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Abstract
A heat developable photographic material comprising a reducible silver salt, a reducing agent, a contrast enhancer, and a binder further contains a thiosulfonic acid ester compound and/or a thiosulfonic acid compound. The material exhibits ultrahigh contrast and low fog and is minimized in the variation of photographic characteristics with heat development conditions.
Claims13
A heat developable photographic material comprising a reducible silver salt, a reducing agent, a contrast enhancer, a binder, and at least one compound selected from thiosulfonic acid ester compounds of the following formula (1) and thiosulfonic acid compounds of the following formula (2):
- R.sup.1 --S--SO.sub.2 --R.sup.2 ( 1)
- wherein each of R.sup.1 and R.sup.2 is an aliphatic hydrocarbon group, aryl group, alkoxycarbonyl group, aryloxycarbonyl group or heterocyclic group,
- Z.sup.1 --SO.sub.2 SM.sup.1 ( 2)
- wherein Z.sup.1 is an aliphatic hydrocarbon group, aryl group or heterocyclic group, and M.sup.1 is a cation,
- with the proviso that the thiosulfonic acid compound of formula (2) is contained in an amount of 0.2 mmol to 200 mmol per mol of silver.
Dependencies are inferred from the claim text.