Direct urea-based dyes derived from diamines with increased solubilities

Sulphonic acid derivatives of diaminediphenylureas were used to synthesise disazo urea dyes. The properties of the dyes were compared with those of their analogues containing no sulphonic groups in the diazo component. It was found that the properties of the dyes were affected by both the position of the urea group as well as the number and position of sulphonic acid groups.