Silver halide photographic material showing improved latent image stability
OwnerKris Viaeneinventor
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Abstract
A silver halide photosensitive material has been provided which has, in at least one light-sensitive emulsion layer thereof, a silver halide emulsion comprising grains or crystals rich in silver chloride, which grains have been chemically sensitized in a specific way in the presence of a substituted phenyl-mercaptotetrazole compound according to the formula represented in the detailed description and in the claims, said compound having been added at the end of chemical sensitization, and, moreover the method of preparing said material has been claimed.
Claims25
A method of preparing an emulsion in an aqueous medium containing a protective colloid, said method comprising as consecutive steps
- precipitating cubic emulsion crystals rich in silver chloride;
- flocculating, washing and redispersing by addition of a binder material;
- adjusting pH and pAg;
- adding, prior to chemical sensitization, a compound releasing iodide ions,
- adding as chemical sensitizing agents consecutively, a gold compound, an oxidizing compound and a compound releasing sulphur;
- chemically sensitizing said cubic emulsion crystals;
- characterized in that, after ending said chemically sensitizing step, addition of a compound according to the general formula (I) is performed,
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- wherein R represents a substituted aryl and wherein M represents a hydrogen atom, an alkali metal atom or an ammonium group.
Dependencies are inferred from the claim text.