| abstract |
The invention relates to the inhibition of tripolyphosphate and pyrophosphate scales in aqueous systems involving adding to said aqueous system at least one copolymer comprising the following monomers in polymerized form: (I) 50-80% by weight of one or more weak acids; (II) 2-50% by weight of one or more strong acids; (III) 0-30% by weight of one or more monoethylenically unsaturated C4-C8 dicarboxylic acids; and (IV) 0-30% by weight of one or more monomethylenically unsaturated monomers polymerisable with (I), (II) and (III); wherein the total of monomers (I), (II), (III), and (IV) equals 100% by weight of copolymer. The invention is particularly suited to the inhibition of tripolyphosphate and pyrophosphate scales which occur as a result of using low phosphate (STPP) containing detergent formulations. |