| 摘要 |
PURPOSE:To dye gray hair, by permeating and depositing iron ions on the hair with repeated use of a ferrous salt alone in a hair cosmetic, and by treating the hair with a composition comprising a coupler and no iron salt at a suitable time. CONSTITUTION:The gray hair is treated with a hairdressing of pH 2.5-7.0 comprising a ferrous salt, e.g. FeSO4 or FeCl2, and no coupler, and periodically or unperiodically treated with a composition of pH 1.0-9.0 comprising 0.1-5% of a coupler, and then dyed black gradually. The coupler, e.g. tannic, gallic acid, pyrogallol or dopa, reacts with ferrous ions, and turns black. EFFECT:The dye is very convenient since the ordinary hairdressing shampoo or rinse is usable. No problem of staining hands or clothing. Stable incorporation of the ferrous salt in the hairdressing produces improved hair dyeing effects. |
