Ready-to-use aqueous composition for bleaching keratin fibers, comprising a combination of a water-soluble solvent and a nonionic and/or anionic amphiphilic polymer comprising at least one fatty chain

A process for bleaching keratin fibers, comprising

• preparing, immediately before application, an aqueous bleaching composition, wherein said composition comprises at least one alkaline agent, from 2 to 20% by weight of at least one peroxygenated salt, hydrogen peroxide, at least one water-soluble solvent, and at least one amphiphilic polymer chosen from nonionic and anionic amphiphilic polymers and comprising at least one fatty chain;
• applying said composition to the keratin fibers to be bleached;
• leaving the mixture to stand on the fibers for a period sufficient to obtain the desired bleaching effect;
• and
• removing the bleaching mixture by rinsing with water, followed by washing with a shampoo, and then drying.

A multi-compartment device for bleaching keratin fibers, comprising at least three compartments, wherein

• a first compartment comprises a peroxygenated salt chosen from ammonium and alkali metal persulphates, percarbonates and perborates;
• a second compartment comprises:
• a water-soluble solvent chosen from linear or branched C1-6 aliphatic monoalcohols, linear or branched C3-20 aliphatic polyols, and polyol ethers, and
• an alkaline agent chosen from aqueous ammonia and organic amines;
• and
• a third compartment comprises an aqueous hydrogen peroxide composition, and wherein at least one amphiphilic polymer chosen from nonionic and anionic amphiphilic polymers and comprising at least one fatty chain is present in any of said at least three compartments.