Patent ID: 8765107

Claim:
A process for relaxing keratin fibres, comprising: (i) applying to the keratin fibres a hair-relaxing composition containing at least two denaturing agents chosen from: (a) ureas of formula (I): in which R1, R2, R3 and R4 are independently chosen from: a hydrogen atom, and linear or branched C1-C4 lower alkyl or alkenyl radicals, optionally substituted with a radical chosen from hydroxyl, amino, and dimethylamino radicals, and (b) α-hydroxy acid derivatives of formula (IV): in which: R is chosen from OH and NR3R4, wherein R3 and R4 are independently chosen from hydrogen and linear or branched C1-C4 alkyl radicals optionally substituted with at least one OH radical; R1 is chosen from H, OH, NH2, CH2-COOH, and linear or branched C1-C4 alkyl radicals, R2 is chosen from: H, COOH, CHOH—COOH, CF3, CH═CH2, NHCONH2, linear, branched or cyclic C1-C8 alkyl radicals optionally substituted with a radical chosen from OH, Cl, NH2, COOH, CF3, and SCH3; phenyl and benzyl radicals optionally substituted with an OH or OCH3 radical; and the radical R1 and R2 may optionally form together an oxo radical (═O) or a cyclopropyl, cyclobutyl, hydroxycyclobutyl, cyclopentyl or cyclohexyl ring with the carbon atom that bears them, and when R1 is H, then R2 may also be chosen from (CHOH)2CH2OH and (CHOH)3CH2OH, or alternatively the α-hydroxy acid derivative corresponds to the radical and the stereoisomers, organic or mineral salts, and solvates thereof, and (ii) raising the temperature of the keratin fibres, using a heating means, to a temperature of between 110 and 250° C.; wherein the hair-relaxing composition comprises ureas of formula (I) at a concentration greater than or equal to 2 M; wherein the hair-relaxing composition comprises α-hydroxy acid derivatives of formula (IV) at a concentration greater than or equal to 2 M; and wherein the overall concentration of denaturing agents is less than or equal to 8 M.