09.03.14
US Patent No. 8,758,453 B2; Kao Germany GmbH, Darmstadt, has patented a process for treating hair in which hair is dyed with a composition comprising one or more hair dyes and at least one oxidizing agent. The composition is obtained by mixing two compositions prior to application onto hair. Composition A comprises one or more hair dyes and a second composition B comprises at least one oxidizing agent. In a further step, hair is treated with a third composition C comprising at least one surfactant other than amino acid surfactant. At least two of the compositions A, B and C comprise at least one amino acid surfactant and composition C is substantially free of sulphate surfactant.