Patent ID: 8512686

Claim:
A method of treating hair, comprising applying to the hair a hair cosmetic composition A and a hair cosmetic composition B in any order, wherein composition A is a first hair cosmetic composition comprising: (a) at least one polycarboxylic acid or a salt thereof wherein said polycarboxylic acid is selected from the group consisting of malonic acid, maleic acid and malic acid, and (c) at least one organic solvent selected from the group consisting of an aromatic alcohol, an alkylene carbonate and a polyol, at a weight ratio of (a)/(c)=0.6 or greater, and composition B is a second hair cosmetic composition comprising: (b) at least one hydroxymonocarboxylic acid or a salt thereof wherein said hydroxymonocarboxylic acid is selected from the group consisting of glycolic acid and lactic acid, and (c) at least one organic solvent selected from the group consisting of an aromatic alcohol, an alkylene carbonate and a polyol, at a weight ratio of (b)/(c)=0.25 or greater, and the pH at 25° C. of each of composition A and composition B is from 2 to 5.5 when diluted to 20 times by weight with water.