| 摘要 |
PROBLEM TO BE SOLVED: To obtain a solid fine particle dispersion of an alkali-soluble photographically useful material having low haze and a silver halide photographic sensitive material containing the dispersion and having enhanced sharpness by carrying out desalting in parallel with solid dispersion. SOLUTION: When particles obtained by dissolution under alkali conditions are re-deposition by the acidification of the resultant solution are dispersed, a double salt included in the particles is released and the pH in the system rises even through the particles are sufficiently desalted before dispersion. When an acid enough to avoid the pH rise is added before dispersion, the concentration of ions in the resultant dispersion increases and unfavorable flocculation is promoted. It is preferable that the pH in the initial stage of dispersion is adjusted to 3-6.5 and dispersion is carried out in parallel with desalting within the pH range. This desalting method is not limited but an ultrafiltration desalting apparatus 4 is preferably used. An ultrafiltration membrane requires the addition of water. This water to be added may be pure water or may contain an auxiliary dispersant such as an activator and a pH adjusting agent.
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