Abstract
The mechanisms of beautifulness of Japanese black and brown hairs, the structure factors influencing on appearance, and technologies to develop hair shine and vividness of color are reviewed. Various types of pores in each part of the fiber generated by hair damage cause light scattering, which leads to loosing hair shine. Pore fixation technology using aqueous malic acid solution was found effective to reduce light scattering due to swelling ability of the organic acid. Furthermore, the novel chroma enhancement technology with using only shampoo and conditioner is reviewed. Fibers with surface structures having fine concaves and convexes show developing vividness in color. The mechanism of the color enhancement was explained by approximation theory of effective media, by which the refractive index of the treated fiber surfaces was estimated to be less than 1.3.
