SILVER HALIDE PHOTOGRAPHIC SENSITIVE MATERIAL

摘要

PURPOSE:To obtain silver halide particles having pressure resistance by specifying the ratio between bromine ions and iodine ions during the formation of the 1st and 2nd coating layers and the 2nd and the 3rd coating layers. CONSTITUTION:The 1st coating layer 2 is formed around each internal nucleus 1 of silver chloroiodobromide, silver iodobromide or silver bromide by an iodine substitution method or by the reaction of halogen ions contg. >=25mol% iodine ions with silver ions. The 2nd coating layer 3 is formed around the 1st coating layer 2 by the reaction of halogen ions contg. bromine ions and iodine ions with silver ions. The amount of the bromine ions is larger than the amount of the bromine ions used to form the 1st coating layer by >=10mol%. The 3rd coating layer 4 is formed around the 2nd coating layer 3 by the reaction of halogen ions contg. iodine ions and bromine ions with silver ions. The amount of the iodine ions is smaller than the amount of the iodine ions used to form the 2nd coating layer by >=12mol%. The average aspect ratio of the resulting silver halide particles is <8/1.