| 摘要 |
PURPOSE:To improve the sensitivity of a silver halide photographic sensitive material and the graininess thereof by incorporating a specified spectral sensitizer into at least one layer of silver halide emulsion layers and providing specified conditions to the silver halide particles in the emulsion layer. CONSTITUTION:At least one silver halide emulsion layer of a silver halide photographic emulsion layer contains a spectral sensitizer expressed by formula I, wherein said silver halide particles corresponding to >=70% of total projected area of the whole particles are plate-shaped particles having >=0.15mum diameter. A mean aspect ratio of the particles is <=8.0, wherein particles having >=5 ratio of the largest distance between two parallel twin faces to the thickness of the particles occupy >=50% of the whole plate-shaped particles. In formula I, each Z1 and Z2 is an atomic group necessary for forming a heterocyclic ring; R1 is H, alkyl group, etc.; each R2 and R3 is alkyl group or substituted alkyl group; Y1 a cationic residue; W1 is an anionic residue; each n1 and n2 is zero or 1. By this constitution, a photographic sensitive material having high sensitivity and improved graininess is obtd. |
