Hair-treatment composition and hair-treatment method using same
Provided is a hair-treatment composition containing an amphoteric surfactant having a structure represented by general formula (1) below, and a sugar nonionic surfactant. In general formula (1), R 1 represents an alkyl group the carbon number of which is 6 to 20; R 2 represents a methyl group, an ethyl group, or a hydroxyethyl group; R 3 represents a methyl group, an ethyl group, or a —CH 2 COOH group; and n is an integer from 1 to 3.
1. A hair-treatment composition applied to hair in a wet state immediately after the hair is dyed with an oxidative hair dye, comprising:
(A) an amphoteric surfactant having a structure represented by the following general formula (1)
(wherein R 1 represents an alkyl group the carbon number of which is 6 to 20; R 2 represents a methyl group, an ethyl group, or a hydroxyethyl group; R 3 represents a methyl group, an ethyl group, or a —CH 2 COOH group; and n is an integer from 1 to 3); and
(B) a sugar nonionic surfactant.
2. The hair-treatment composition according to claim 1 , wherein the sugar nonionic surfactant is of at least one type selected from the group consisting of sugar ester surfactants and alkyl glucosides.
3. A hair-treatment method comprising applying a hair-treatment composition to hair in a wet state immediately after the hair is dyed with an oxidative hair dye, wherein the hair-treatment composition comprises:
(A) an amphoteric surfactant having a structure represented by the following general formula (1)
(wherein R 1 represents an alkyl group the carbon number of which is 6 to 20; R 2 represents a methyl group, an ethyl group, or a hydroxyethyl group; R 3 represents a methyl group, an ethyl group, or a —CH 2 COOH group; and n is an integer from 1 to 3); and
(B) a sugar nonionic surfactant.
4. The hair-treatment method according to claim 3 , further comprising, following application of the hair-treatment composition to hair:
washing and drying the hair; and
applying the same hair-treatment composition again to the washed and dried hair.