摘要:
A process for dyeing hair by preparing and thereafter applying to the hair an aqueous reaction medium comprising dopa and an oxidant, said aqueous reaction medium further containing at least one hair dyeing agent selected from the group consisting of primary intermediates and couplers and also containing a buffer to maintain the pH in the range from 6 to 10 during the reaction, and removing said aqueous reaction medium from the hair within about one hour following its preparation.
摘要:
The present invention relates to a method of imparting a controlled tanning of skin by treating the skin with an aqueous medium containing melanin or a precursor of melanin.
摘要:
The present invention is directed to the preparation of an aqueous hair dyeing composition containing an effective hair dyeing amount--at least 2 mg/ml--5,6-dihydroxyindole (DHI). An aqueous hair dyeing composition is produced by reacting under essentially anaerobic conditions dopa or a salt thereof with an alkali metal ferricyanide oxidant in an aqueous reaction medium to obtain dopachrome, and permitting the dopachrome to undergo rearrangement in the aqueous medium to form 5,6-dihydroxyindole, said rearrangement being conducted in the substantial absence of oxidant, the aqueous medium being buffered by sufficient buffering agent to maintain a pH of from about 4.5 to about 9 for the reaction medium throughout the series of reactions that take place thereafter, removing the ferrocyanide species present in the aqueous system, and lastly, charging the composition into a suitable container.
摘要:
A process for altering the color of hair that has been dyed with dihydroxyindole comprising the steps of treating the dyed hair with an acidic solution for an effective amount of time and rinsing the treated hair.
摘要:
A process for dyeing hair by preparing and thereafter applying to the hair an aqueous reaction medium comprising a substituted dopa species and an oxidant which is a ferricyanide salt, said aqueous reaction medium further containing a buffer to maintain the pH in the range from 6 to 10 during the reaction, and removing said aqueous reaction medium from the hair within about one hour following its preparation.