Beta-naphthol ether sulfonates, processes for preparing them and use thereof as brightness improvers

摘要

The present invention relates to beta-naphthol ether sulfonic acids or salts thereof having the general formula (I) R—O-(AO)_n—CH₂—CH₂—S(O)₃M (I), where R, AO, n and M have the definitions stated in the claims and in the description, to mixtures thereof, to aqueous solutions and to electrolytes comprising them, to processes for preparing them and to the use of these.