| abstract |
Corrosion inhibiting compositions for inhibiting corrosion and the deposition of mineral scale on metal in aqueous systems contain sequestrants such as carboxylic acids, phosphates, or optionally sulfur containing lignosulfonates, as well as carboxylated phosphonic acids of the formula <IMAGE> FORMULA I <IMAGE> FORMULA II wherein m is from 1 to about 6, wherein n is from 0 to about 6, wherein R is -H, -alkyl, -alkenyl, -alkynyl, -aryl, -alkyl substituted aryl, -cycloalkyl, -methylene phosphonic acid, or -methylene carboxylic acid, and wherein R1, R2, R3 and R4 independently is -H, -alkyl, -aryl, -alkyl substituted aryl, -OH, -SH, -NH2, -PO3H2, -CH2PO3H2, -CO2H, -CH2CO2H, halogen, or -SO3H. The composition can also contain other corrosion inhibiting compounds such as azoles, molybdates, and the like. |