| 摘要 |
PURPOSE:To stabilize photographic characteristics by using silver halide particles having a core/shell structure comprising convertible core and including polyvalent metal ions in a photographic element contg. an internal latent image type silver halide emulsion layer. CONSTITUTION:Convertible type silver halide particles are prepd. by a method wherein aq. soln. of a bromide is added to silver halide emulsion obtd. by mixing aq. AgNO3 soln. with aq. chloride soln. in the presence of gelatin to convert silver chloride to silver bromide, etc. Then, silver halide is precipitated on the surface of convertible silver halide particles to form a shell obtd. core/shell type particles, including simultaneously polyvalent metal ions (e.g. Ir ions) in the inside of the particles in the stage of formation of the particles. Thus, an emulsion layer contg. internal latent image type silver halide particles contg. no surface development nuclei, obtd. by the above described process, is formed, which is utilized as the aimed silver halide photographic element for giving a posi-type picture image by a reverse development or illumination development. |
