산성 염료의 모발 염색성 연구(1)

Dyeability of Hair with Semi Permanent Hair Dyeing(1)

Although permanent hair dyeing gives an advantage to wash fastness, it may introduce damages on hair skin from the oxidant used. On the contrary, when acid dyes are used for semi permanent hair dyeing, they show poor wash fastness in the absence of damages on the hair. In the present study, the milling acid dyes, such as C.I. Acid Blue 90 were chosen to approach the appropriate conditions for semi permanent hair dyeing. The chemical structures of dyestuffs were characterized by UV and FT-IR analysis. The maximum absorption wavelength determined by the UV-visible spectrum were 520㎚ for the respective dyestuff of C.I. Acid Blue 90. The milling type acid dyes showed good affinity to hair. As the concentration of acid dyes increased from 0.1% up to 1.0%, the dye adsorption to hair was sharply increased at relatively lower concentration and reached saturation at above 0.3 - 0.4% showing almost Langmuir type isotherm. Therefore, the dyeing process can be explained as ionic bonding of the dye molecules on the positive site in the hair. The dyeing mechanism can be confirmed by the effects of pH on dye exhaustion shown as dye uptake increase at lower pH and higher K/S value obtained at higher temperature and longer dyeing time.