Patent ID: 6846336

Claim:
An aqueous solution of a mixture containing (A) 5 to 50% by weight of at least one aromatic formaldehyde condensation product containing sulfonate and/or carboxylate groups, (B) 2 to 30% by weight of at least one aliphatic carboxylate acid, (C) 1 to 20% by weight of at least one aromatic sulfonic acid, and (D) 1 to 15% by weight of at least one solvent of the formula (I) R 1 O(CH 2 CHR 3 O) n —R 2 , (I) where R 1 and R 2 are independently H, straight-chain or branched C 1 -C 6 -alkyl, phenyl, or C 1 -C 4 -acyl, R 3 is H or CH 3 and n is an integer from 1 to 10, and where the weight percentages indicated for components (A) to (D) are each based on the entire aqueous solution.