INFLUENCE OF SODIUM-SULFITE ON THE PROTECTIVE PROPERTIES OF A ZINC PHOSPHONATE INHIBITOR

During the past decade many researchers and the leading firms have been searching for various synergistic additives capable of improving the properties of the known complexonate inhibitors of steel corrosion Of neutral aqueous media [1, 3]. One of the best studied inhibitors of this type is the zinc salt of nitrilotrimethylphosphonic acid (NTPZn). Our investigations of various inhibitors based on NTP [4] have made it possible to refine the mechanism of the protection of steel by phosphonates. On the basis of them it can be assumed that the introduction of a reducing agent into the phosphonate inhibitor can increase its effectiveness. This would make it possible to lower the concentrations of the complexonates necessary for reliable protection of industrial systems, i. e., to make these inhibitors ecologically cleaner. In this work the results of the first experiments conducted along this line are discussed.