| 摘要 |
PURPOSE:To obtain a silver halide photographic emulsion low in fog even if it is developed under highly alkaline conditions by growing silver halide grains in states specified in pH and pAg by the ammoniacal process. CONSTITUTION:Silver halide grains are prepared by mixing an aq. soln. of an ammoniacal silver nitrate and an aq. soln. of halide into a mixture of aq. solns. of halide and a hydrophilic colloid by the simultaneously mixing method. Ammonium ions of the mixture are fed, preferably, in the form of an aq. ammonia. A preferable pH during the growth of the silver halide grains is <=9, especially, in 7-9. The value of pAg is controlled to <=9.3, preferably, 6-9.3, till the average diameter of the growing silver halide grains becomes to 75-95, preferably, 80-90% of that after the growth, an to >=9.8, preferably, 9.8-11. |
