N- phenyl-p-phenylenediamines

N- phenyl-p-phenylenediamines as well as its salts N- phenyl-p-phenylenediamines HCL and N- phenyl-p-phenylenediamine sulphates are substances used as permanent hair dyes in cosmetic formulations. They cause a coloration of the hair matrix (the hair keratin). N- Phenyl-p-phenylenediamines and its salts belong to the colourless oxidation bases for permanent hair dyeing. These are easily oxidizable, initially colorless dye bases. Principle: The dye bases migrate into the hair shaft which is swollen by the alkaline medium. There they are oxidized to complex dyes, whereby they chemically bind with the hair keratin. Only through the oxidation of the (colourless) dye bases by the hydrogen peroxide the actual dye is formed.