CORROSION INHIBITOR OF METALS IN SULFURIC AND HYDROCHLORIC ACIDS Russian patent published in 2000 - IPC

FIELD: protection of metals against acid corrosion by means of inhibitors. SUBSTANCE: inhibitor is introduced in acids in amount of 2.4 to 5.6 g/l at the following concentrations of individual components: product of condensation of amine with aldehyde; used as this product is 3-nitrobenzal-4-aminophenol, 0.4 to 0.9 g/l; urotropin, 0.9 to 3.1 g/l; pyridinethiol-2-oxide 1-zinc salt, 0.6 to 1.2 g/l and allyl trimethyl ammonia iodide, 0.5 to 1.3 g/l. Inhibitor retards corrosion of steel, cobalt, nickel and titanium considerably reducing tendency of steel to absorb hydrogen. Proposed inhibitor is recommended for use in pickling solutions and for acid cleaning of equipment. EFFECT: enhanced efficiency. 1 tbl