Abstract: A stabilized p-phenylenediamine color developer solution having about 10 to 40 weight percent of a p-phenylenediamine free base color developer, about 40 to 70 weight percent of a hydroxy-containing organic solvent for the p-phenylenediamine free base color developer, and about 1 to 40 weight percent of a preservative for the p-phenylenediamine free base color developer, wherein the weight percentages are based on the total weight of the stabilized solution. Another aspect are processes for making stabilized p-phenylenediamine color developer solutions. Another embodiment is a p-phenylenediamine color developer solid having from 50 to about 99 weight percent of a p-phenylenediamine free base color developer, and from about 1 to 50 weight percent of a preservative for the p-phenylenediamine free base color developer, wherein the weight percentages are based on the total weight of the composition. Another aspect is a process for making the stabilized solid p-phenylenediamine color developer.

Abstract: A process for purifying p-phenylenediamine color developers in their free-base form. The process includes subjecting a solution containing p-phenylenediamine-type free base color developer to short path distillation which includes at least one of falling film evaporator, thin film evaporator, wiped film evaporator, or short-path evaporator.