Patent ID: 6638703
Filing Date: 2003-10-28
Classification: G03C

Abstract:
A method for preparing a silver halide tabular grain emulsion which comprises the steps of:(a) preparing a batch of a nuclei emulsion in a nucleation reactor in the presence of a colloidal hydrophilic peptizing agent and then physically ripening said nuclei; (b) growing the nuclei obtained in step (a) to obtain Mb moles of tabular seeds with an average grain volume Vs while keeping the ratio of initial volume of nucleation medium to final volume of growth medium of these nuclei in the nucleation reactor between 0.4 and 0.95; (c) calculating the average grain volume Vs: (d) setting and storing the Mb moles of seeds obtained in step (b) (e) taking Ms moles of the batch obtained in step (b); (f) growing the portion of Ms moles taken in a growth reactor to obtain Mf moles of tabular grain emulsion with an average grain volume after growth of Vf; and (g) repeating steps (e) and (f) Nb times to grow a total quantity of Mb moles of seeds, where Ms is substantially equal to MfÃ—(Vs:Vf), and Nb is substantially equal to Mb:Ms.