Function of surfactants in hair dyeing by oxidation dyes 2. Effect on formation of oxidation dyes by p-aminophenol and 5-amino-o-cresol in dye bath(1).
The effect of surfactants on an oxidation-hair-dye-formation reaction in a dye bath was studied in order to learn the mechanism of the effect of surfactants on the dyeability of hair by the oxidation dye. The dye-formation behaviours for the p-aminophenol and 5-amino-o-cresol system with the surfactants, of which the hydrophilic parts have different charges, were compared changing the concentration of surfactants. It was found that the same dyes are produced, regardless of the charge of surfactants added, and the rate of dye produced in the dyebath is increased in the presence of surfactants. The order of the production rate is, with an anionic surfactant > with non-ionic surfactant > with cationic surfactant > without surfactant. The relation between the dyeability of hair and the rate of dye produced in the dyebath in the presence of surfactants is not found. The major factor governing the dyeability of hair is different from the mechanism of the increased dye in the solution. It was also found that the dye-formation rate is increased by immersing hair into the reaction solution, and hair works as an accelerator for the dye-formation reaction.
Yasunaga
H
H
Department of Chemistry and Materials Technology, Kyoto Institute of Technology, Kyoto Sakyo-ku, Matugasaki, Japan. yasunaga@kit.ac.jp
Ishii
Y
Y
Komoda
T
T
Shinkawa
T
T
Kajiwara
K
K
Urakawa
H
H