Back to results
US 4,758,505 AGranted
Process and an apparatus for the production of photographic silver halide emulsions
AssigneeAgfa-Gevaert
InventorKlaus Hoffmann
Life of this patent
Estimating the term…
Abstract
Silver halide emulsions are prepared by precipitation, transfer of the silver halide emulsion from the precipitation chamber into a separate circuit comprising a cleaning stage for the removal of dispersion medium and compounds soluble therein and exit into a collecting vessel.
Claims8
A process for the production of photosensitive silver halide emulsions by
- (a) reaction of at least one silver salt with at least one halide in an aqueous dispersion medium, salt silver salt and said halide being soluble in said aqueous dispersion medium and/or
- (b) combination of silver halide emulsions in an aqueous dispersion medium containing a silver halide solvent said silver halide emulsions having different solubility in said aqueous dispersion medium containing said silver halide solvent,
- in a reaction chamber,
- at least partial removal of the aqueous dispersion medium and any compound dissolved therein in a cleaning stage and
- entry of the silver halide emulsion into a collection vessel
- the improvement delivering the aqueous halide emulsion continously to the cleaning stage during reaction (a) and/or combination (b) and dividing the mass flow leaving the cleaning stage into two parts one part being delivered to the collecting vessel and one part being again delivered to the cleaning stage, the mass flow re-entering the cleaning stage being greater by a factor of at least 1.2 than the mass flow entering the collecting vessel.
3 more elements
Dependencies are inferred from the claim text.