Photothermographic material and method for preparing photosensitive silver halide emulsion

摘要

The invention provides a photothermographic material containing a tabular photosensitive silver halide having an average silver iodide content of 40 mol % or higher, 50% or more of a total projected area of the photosensitive silver halide being occupied by tabular grains having an aspect ratio of 2 or more, the photosensitive silver halide grains having a mean equivalent spherical diameter of from 0.2 mum to 5 mum and a variation coefficient of an equivalent spherical diameter distribution of 30% or less. Further, a method for preparing the photosensitive silver halide used in the photothermographic material is characterized in that grains are formed in the presence of at least one selected from a silver halide solvent and an amino group-modified gelatin. A high-sensitivity photothermographic material exhibiting a low fog and a high optical density is provided.