Preparation And Application Of New Hair Dye

For the shortcomings of the hair dye nowadays , this paper selects safety Acid yellow 73 and Acid red 87 as materials, reaction with epichlorohydrin and NaSH through 2 steps to prepare thio-modified reactive dye. The structures of the compounds were confirmed by HPLC, IR, UV, MS, NMR. Added the product into hair dye and studied the results of hair dying, tested the wash fastness and light fastness of the dyed hair by L, a, b parameters.The 2 steps reaction used DMSO and water as mixed solvent, the intermediate and final product was got after acidification, centrifugation and water washing. After single-factor experiment, optimized the process of modifying Acid yellow 73, the best condition of the first step as follow: n(ECH): n(Acid yellow 73)= 20:1, reaction 4h under 80℃, the productivity can reach 65%. the best condition of the second step as follow: n(NaSH):n(intermediate)= 6.5:1, reaction 2h under 50℃, the productivity can reach 80%. The intermediate and final product prepared by Acid yellow 73 was purified by silica gel use methyl alcohol and chloroform as mixed solvent.Applied the two thio-modified reactive dyes into hair dye, tested the effects of pH, temperature, time on the hair coloring, and the best condition as follow: under alkaline condition, maintain 50℃for 40min, the color of the dyed hair is natural and shiny and didn't change after 12 times washing and basked in the sun for 3 months. Instrument test result showed the color difference is very small, the thio-modified acid yellow 73 and acid red 87 can be used in hair dye and the effects can be equal to perpetual hair dye.