TREATING COMPOSITION FOR HAIR

PROBLEM TO BE SOLVED: To prepare a composition for perming of hair capable of significantly reducing the damage to the hair and a perming smell by including a thiolactate anion and monoethanolamine at a specific ratio and further combining a specified polymeric substance therewith. SOLUTION: This composition for treating hair is obtained by regulating the amounts of a thiolactate anion as a reducing agent and monoethanolamine as an alkaline agent to 1.0 ratio expressed in terms of molar concentration of the thiolactate anion to the monoethanolamine for forming a counterion to the anion and in an excessive amount and further blending at least one polymeric substance selected from the group of an amino-modified silicone, a glycol-modified silicone, a microemulsion of a silicone oil, a cationic polymer and an amphoteric polymer in the system. The resultant composition is prepared by regulating the amount of the thiolactate anion to 1.0-20wt.%, that of the polymeric substance to 0.01-10wt.% and pH to 7.5-10.0. The composition can be used as the first agent for perming the hair or a curly hair straightening agent for the hair.