Ballast conversion hydrophobic isochio urea content high contrast photograph element

摘要

Silver halide photographic elements which are capable of high contrast development, when processed in the presence of a hydrazine compound that functions as a nucleating agent, contain both an amino compound which functions as an incorporated booster and a ballasted hydrophobic isothiourea compound comprising a ballasting group, that is attached to the sulfur atom, which serves to restrict the mobility of the compound and thereby aid in retaining it in the photographic element during development. The ballasted hydrophobic isothiourea compound is highly effective in reducing pepper fog and also serves to restrain image spread.