SILVER HALIDE PHOTOGRAPHIC SENSITIVE MATERIAL AND FORMATION OF EXTREMELY CONTRASTY NEGATIVE IMAGE USING IT

摘要

PURPOSE:To form an extremely contrasty negative image having such photographic characteristics as >10 gamma, extremely high sensitivity and few black spots by imagewise exposure and development with a stable developer by incorporating a hydrazine deriv. into an emulsion layer or other hydrophilic colloidal layer. CONSTITUTION:A silver halide photographic sensitive material is obtd. by forming a silver halide emulsion layer contg. singly dispersed silver halide particles having a practically octahedral crystal form prepd. in the presence of an iridium salt added by 10<-8>-1X10<-5>mol per 1mol Ag. A hydrazine deriv. having an aliphatic or aromatic group is incorporated into the sensitive material by 10<-6>-1X10<-1>mol per 1mol silver halide. At this time, the hydrazine deriv. is incorporated into the silver halide emulsion layer. It may be incorporated into other nonphotosensitive hydrophilic colloidal layer. The sensitive material contains >=0.15mol/l sulfite ions as a preservative and gives an extremely contrasty negative image with a developer of 9.5-12.3pH.