Method of preparation of direct dispersions of photographically useful chemicals

Abstract

A process for making a direct dispersion of a photographically useful material comprising: mixing (i) an aqueous phase and (ii) a liquid organic phase under conditions of shear or turbulence to form a dispersion of the organic phase dispersed in the aqueous phase; wherein the liquid organic phase comprises one or more photographically useful materials and one or more organic solvents having a boiling point of at least 150° C., a molecular weight less than or equal to 300, and a solvatochromic parameter β value greater than or equal to 0.50, wherein the weight ratio of the sum of the solvents having a boiling point of at least 150° C., a molecular weight less than or equal to 300, and a solvatochromic parameter β value greater than or equal to 0.50 to the photographically useful materials does not exceed 0.25. The use of relatively low levels of specified high-boiling organic solvents enables the direct dispersion of hydrophobic photographically useful materials with low solubility in conventional primary photographic useful solvents without crystallization problems or excessive decomposition.

Dependencies are inferred from the claim text.