Solid particle dispersions for imaging elements

Abstract

Solid particle dispersions of compounds useful in imaging elements can be made with substantially improved stability to particle growth by dispersing the compound of interest in the presence of a relatively small amount of a second compound that is structurally similar to the compound of interest. This second compound is combined with the compound of interest prior to dispersing the compound of interest, i.e., prior to milling in the case of milled dispersions, and prior to precipitation in the case of pH or solvent precipitated dispersions. While being distinct, the second compound has a similar chemical structure to the main compound. More specifically, the second compound and first compound each comprise an identical structural section thereof which makes up at least 75% of the total molecular weight of the first compound, and the second compound has at least one substituent bonded to the identical structural section which has a molecular weight higher than the corresponding substituent of the first compound. In preferred embodiments of the invention, the compound useful in imaging elements is a compound useful in photographic or thermal transfer printing elements, and the resulting stabilized dispersion is used in preparing a photographic or thermal transfer printing element.