Temporary corrosion inhibiting coatings are applied to metal articles for protection during manufacture, transportation or storage. Various sulfonates or carboxylic acids are often used in such corrosion inhibiting coatings. Combinations of sulfonates and carboxylic acids are generally more effective than the same level of either alone. 1 This effect is demonstrated for calcium and sodium dinonylnaphthalene sulfonate with a succinic acid derivative and an oxidized petrolatum. Calcium, magnesium, sodium and ammonia salts of dinonylnaphthalene sulfonic acid are combined with a succinic acid derivative, a dimer acid and an oxidized petrolatum. Oil/solvent solutions of these combinations are applied to brass, aluminum, galvanized steel, zinc alloy and steel and subjected to salt fog and humidity testing. The effect of these sulfonate/carboxylic acid combinations in anticorrosive coatings is evaluated for each metal. The effectiveness of these various corrosion inhibiting formulations, varied widely for each metal tested. This suggests that formulations should be optimized based on the metal of concem. With respect to the chemistries under discussion here, if more than one metal is to be protected, the choice of corrosion inhibitor will almost always be a compromise.
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