SILVER HALIDE PHOTOGRAPHIC SENSITIVE MATERIAL

摘要

PURPOSE:To increase the sensitivity while maintaining the satisfactory stress characteristics of silver halide particles by successively forming silver halide layers around each silver halide nucleus by a specified three-step particle growing means. CONSTITUTION:The 1st coating layer 2 of silver iodide, silver iodobromide or silver chloroiodobromide is formed around each internal nucleus 1 of silver bromide, silver iodobromide or silver chloroiodobromide by an iodine substituting means or with a halide soln. contg. iodine ions by >=10mol% of the total amount of halogen ions reacting with silver ions. The 2nd coating layer 3 of silver bromide, silver iodobromide or silver chloroiodobromide different from the layer 2 in halogen composition is formed around the layer 2. The 3rd coating layer 4 is then formed around the layer 3 with a halide soln. having an iodine ion content higher than the iodine ion content in a soln. used to form the layer 3 by >=2mol%. A sensitive material contg. the resulting silver halide particles having <5 ratio of projection area/thickness is produced.