A mild permanent wave reducing agent-containing composition and method of permanently waving or straightening human hair that provides a strong, long lasting curl, or long lasting straight hair formation, while minimizing hair damage. The composition includes two ionic compounds, one cationic and the other anionic, that complex in solution over a molar ratio of cationic compound to anionic compound in the range of about 1:1.2 to about 1.2:1, preferably in the range of about 1:1.1 to about 1.1:1, to provide synergy in waving efficiency, thereby providing a strongly reconfigured hair configuration (curled or straightened). At least one of the ionic compounds functions as a reducing agent for hair, capable of breaking the disulfide bonds in the hair so that the bonds later can be reformed via oxidation, when the hair is in the desired configuration. Examples of cationic compounds include thiocholine, choline, cysteineamide, cysteamine, and combinations thereof. Examples of anionic compounds include cysteine, N-acetylcysteine, thioglycolic acid or its salts, and combinations thereof. The preferred ionic compounds are thiocholine and N-acetylcysteine. The composition is effective over a wide pH range of about 4 to about 12.
CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of U.S. application Ser. No. 08/194,076 filed Feb. 9, 1994 now abandoned.
The hair shaping composition for permanent shaping of hair contains a cysteine ester of the formula (I): as a keratin-reducing material, wherein R is a hydroxy group, alkoxy groups, a poly(alkoxy) group or a hydroxypoly(alkoxy) group, or one of its acid additional salts. Cysteine ester compounds and their methods of preparation are also described. Preferred embodiments of the hair shaping composition have a pH of from 4.5 to 9.0 and contain from 4 to 30% by weight of the cysteine ester or its acid addition salt and provide a safe and uniform shaping of hair without allergic or sensitizing reactions.
