| 摘要 |
PURPOSE:To obtain an AgX emulsion composed of fine particles and having a monodispersing property by carrying out a pAg (EAG) control of a growing rate of a silver halide (AgX) particle in an aqueous solution of a hydrophilic colloid under a specific condition. CONSTITUTION:In a process for producing the AgX emulsion by adding an aqueous solutions of the water soluble silver salt and the water soluble halide into an aqueous solution of the hydrophilic colloid by means of a double jet method, the silver salt solution and the halide solution are added to the aqueous solution of the hydrophilic colloid so as not to exceed the growing rate of the AgX particles to a critical growing rate thereof, and so as to maintain the EAG value of the aqueous solution of the hydrophilic colloid to a constant value within 140-200mV ranges for 1/30-1/5th the whole addition time from a start of addition, and also so as to maintain the EAG value to a constant value within 80-140mV ranges fro at least a half of the whole additional time. By controlling the additional rate as mentioned above, the fine particles of AgX having 0.1-0.4mum particle size are obtd. in the monodispersing state, and a quantum efficiency of the titled emulsion is improved, thereby obtaining the titled emulsion having a high sensitivity and a high contrast, and depressing a fog of the obtd. image. |
