GB823163A - Corrosion inhibition - Google Patents

Abstract

A corrosion-inhibiting composition for addition to aqueous solutions normally corrosive to metal surfaces comprises a non-surface-active quaternized - N - heterocyclic base devoid of alkyl radicals of more than 5 carbon atoms and a water-soluble non-ionic surface-active agent containing a polyoxyethylene group. The composition may also contain an alcohol, and may be employed (a) in acid solutions used for pickling metals, (b) in the acids used in acidizing treatments of oil-wells to prevent damage of metal equipment and to prevent or inhibit the formation of water-in-oil emulsions or resolve such emulsions, (c) in the transportation and storage of acid solutions, and (d) to inhibit the action on metals of such liquids as distilled water, boiler water, automobile radiator cooling solutions, and brine solutions used for refrigeration purposes. The quaternized base is prepared by the reaction of such heterocyclic nitrogen bases as pyridine, quinoline, isoquinoline, quinaldine, acridine, collidine, lutidine, lepidine, picoline, morpholine and diethyl piperazine (which may be in the pure form or in such materials as denaturing or flotation pyridines, bone-oils and coal-tar distillates), with an organic halide, sulphate or sulphonate. The surface-active agent preferably contains 4-60 oxyethylene groups and is obtained by the reaction of ethylene oxide with C10-20 compounds containing an active group such as hydroxy, carboxy, amino amido, sulphonamide and mercapto. The alcohol preferably contains no more than 6 carbon atoms and may be aliphatic or carbocyclic. The examples disclose compositions containing (a) a quaternized quinoline base obtained by reacting benzyl chloride with "Barrett's Quinoline Residue", (b) surface-active agents obtained by condensing nonyl, dinonyl, or iso-octyl-phenol with ethylene oxide, and (c) the following alcohols:- isopropanol, a a - dimethyl benzyl alcohol, nonyl - and dinonyl-phenol, propargyl alcohol, "Oxo" tridecyl alcohol, nonyl phenoxy ethanol, cyclohexanol, terpene carbinol, ethanol, tert-butyl alcohol and terpineol. Reference is made to the treatment of an alloy steel containing Ni 2.0%, Cu 1.0% and C 0.08%. Specifications 380,431 and 380,851 [both in Group III] are referred to.