Patent ID: 8901060

Claim:
A process for pickling a metallic surface, the process comprising: treating the metallic surface with an acidic, aqueous composition, wherein the composition comprises: an acid; water; and a compound of formula (I) HO—(A) n (B) m —C p H p+2 —S—C p′ H p′+2 —(B) m′ (A) n′ —OH (I), where A is ethylenoxy, B is C 3-5 -alkylenoxy or at least one mixture of C 3-5 -alkylenoxy groups, A and B are present in random distribution, alternately, or in the form of two or more blocks in any sequence, n and n′ each independently correspond to a number of from 1 to 50, m and m′ each independently correspond to a number of from 0 to 50, and p and p′ each independently correspond to an integer of from 2 to 4.