Patent ID: 11964037

Abstract:
A hair dyeing method that involves first step of applying on the hair a hair dye composition containing a compound represented by the following general formula (1A) or a salt thereof and an organic alkaline agent and having a pH of 9.0 or more and 11.0 or less: wherein a broken line represents the presence or absence of a π bond; R1 represents a hydroxy group or an acetoxy group; and R2 represents a hydrogen atom, an acetyl group, a methyl group, or an ethyl group; and a second step of applying on the hair a hair treatment agent containing an organic acid or a salt thereof and having a pH of 5.5 or less. After performing the first step, the hair is subjected to the second step while maintaining in a wet state in which an amount of water per gram of the hair is 0.008 g or more.