| abstract |
A compound of formula (1) and its use as fluidising agents for dispersions of particulate solids in a polar liquid, such as water, wherein R?1, R2 and R3¿ are each, independently, aryl, heteroaryl or alkyl, all of which may be optionally substituted, or polyoxyalkylene chain; X?1, X2 and X3¿ are each, independently, a direct link, -O-, -S- or a group -NR4- wherein R4 is hydrogen or C¿1-6?-alkyl, provided that at least one of R?1, R2 and R3¿ carries an anionic group, including salts thereof. Preferably R1-X1- is the residue of either 5-aminosalicylic acid and R2-X2 is the residue of either 5-aminosalicylic acid or sulphanilic acid. |