process for the production of jodobromid emulsions, the monodisperse tabulare grains

摘要

PURPOSE: To provide the new and simple method for producing an emulsion improved in developing property and containing a plate-like silver (iodo)bromide particles. CONSTITUTION: In the production method of the silver bromide or silver iodobromide in which the content of monodisperse platelike particles is at least 50% of whole projected area of whole particles and the coefficient of variation of the particle size distribution of the platlike particles is 15%, and aminoazaindene is added at the optional stage of the emulsion production before 50% of the whole silver halide is precipitated. A preferable aminoazaindene is an adenine deriv. or a 4-amino pyrazolopyrimidine deriv.. Most preferable substance is adenine or 4-aminopyrazolo[3,4d]pyrimidine.