Abstract: Photographic emulsions are quickly chilled to a homogeneous, particulate gel by injection of carbon dioxide coolant, while the emulsion is agitated. This process is carried out in a housing having a pair of parallel auger screws to transport emulsion circuitously within the housing. Carbon dioxide coolant is injected through a plurality of nozzles in the housing and is then removed from the housing through a vent line.

Abstract: The present invention is a process for continuous preparation of solutions of water-immiscible or water-insoluble organic compounds in substantially non-aqueous organic solvents. Particularly, a process for the continuous preparation of colour forming coupler solutions for use in the photographic industry is described. The process uses a twin screw extruder wherein the compound to be dissolved is introduced into a first section of the extruder. The compound passes along the extruder interior to a section where organic solvent is introduced to form the required solution.