Use of neutralized or partially neutralized copolymers obtainable from A) from 50 to 99% by weight of monoethylenically unsaturated carboxylic acid and B) from 1 to 50% by weight of at least one comonomer chosen from the groups a) to d) or also mixtures of different monomers from groups a) to d) a) monoethylenically unsaturated carboxylic acid esters with a saturated C8- to C30-alcohol b) N-alkyl- or N,N-dialkyl-substituted carboxamides, the alkyl radicals independently of one another being aliphatic or cycloaliphatic alkyl radicals having at least 8 to 18 carbon atoms, c) vinyl esters of aliphatic C8- to C30-carboxylic acids, d) C8- to C18-alkyl vinyl ethers, for the preparation of hair cleansers.