Composition containing 4-(3-ethoxy-4-hydroxyphenyl)butan-2-one, a preservative and/or antioxidant, a surfactant and a polymer, and the method for processing keratin materials from the composition

A mixture comprising:

• i) one or more 4-(3-ethoxy-4-hydroxyphenyl) butan-2-one compounds or one or more organic or mineral base salts thereof, solvates thereof or mixtures thereof;
• ii) one or more preserving agents other than i) chosen from organic preserving agents bearing aromatic groups, and optionally one or more antioxidants;
• iii) one or more nonionic surfactants and one or more anionic surfactants;
• iv) one or more organic non-associative thickening polymers;
• and optionally
• v) one or more fatty substances;
• wherein when the mixture comprises one or more cationic surfactants, they are in an amount of less than 0.5% by weight relative to the total weight of i) to v);
• wherein i) is present in the mixture in an amount of 0.06% to 10% by weight relative to the total weight of i) to v);
• i) and ii) are present in amounts such that the weight ratio i)/ii) ranges from 0.05 to 5;
• the one or more nonionic surfactants are present in the mixture in an amount of 0.5% to 20% by weight relative to the total weight of i) to v), one or more anionic surfactants are present in the mixture in an amount of 0.5% to 20% by weight relative to the total weight of i) to v);
• the total weight of one or more nonionic surfactants and one or more anionic surfactants is 1% to 30% by weight relative to the total weight of i) to v);
• one or more organic non-associative thickening polymers are present in the mixture in an amount of 0.01% to 10% by weight relative to the total weight of i) to v);
• i), ii), iii) and iv) and optionally v) comprise 80% to 90% by weight relative to the total weight of the mixture, and the mixture has a viscosity of less than 90 poises.