Back to results
US 6,638,703 B2Granted
Method for preparing silver halide photographic tabular grains emulsions
AssigneeEastman Kodak Company
InventorsPierre-Henri Jezequel, Bruno C. Barillon, Christian S. Schmuckle
Life of this patent
Estimating the term…
Abstract
The invention relates to a method for preparing photographic silver halide tabular grains emulsions. The method of the invention comprises a first single nucleation step wherein stable tabular seeds of silver halide are formed, and a second step wherein different batches of seeds obtained in the first step are grown to yield identical or different emulsions. This combination of steps represent a robust process for preparing tabular grain emulsions at different scales.
Claims17
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 Mf×(Vs:Vf), and
- Nb is substantially equal to Mb:Ms.
7 more elements
Dependencies are inferred from the claim text.