GB717866A - Improvements in or relating to the degreasing and pickling of metallic surfaces - Google Patents

Abstract

Metallic surfaces are pickled and degreased with a fat solvent emulsified in an acid aqueous medium by means of an organic compound containing nitrogen-bound polyether groups in the molecule. The emulsifying agent may be of the general formula <FORM:0717866/III/1> where R is a radical containing at least 8 carbon atoms, R1, R2 are organic radicals or hydrogen atoms and n is at least 4. The emulsion may also contain a pickling inhibitor, e.g. a thioureaformaldehyde condensation product, or a foaming inhibitor, e.g. polyvinyl alcohol, or both; the acid may be phosphoric, hydrochloric or sulphuric; the fat solvent may be petroleum and the organic compound may be a reaction product of ethylene oxide with an amino compound, e.g. oleyl amine, dodecyl propylene amine, amino-anthraquinone, lauric acid amide or oleyl anilide, or the condensation product of a mixture of an ether and hydroxylamine and a high molecular weight carboxylic acid, sulphonic acid or sulphonated carboxylic acid, e.g. the reaction product of lauric acid with triethanolamine dihydroxy ethyl ether. The emulsion may be applied by spraying at 30-80 DEG C.ALSO:Metallic surfaces are pickled and degreased by treatment with a fat solvent emulsified in an acid aqueous medium by means of an organic compound containing nitrogen-bound polyether groups in the molecule. The emulsifying agent may be of the general formula <FORM:0717866/II/1> where R is a radical containing at least 8 carbon atoms, R1, R2 are organic radicals or hydrogen atoms and n is at least 4. The emulsion may also contain a pickling inhibitor, e.g. a thiourea formaldehyde condensation product, or a foaming inhibitor, e.g. polyvinyl alcohol, or both; the acid may be phosphoric, hydrochloric or sulphuric; the fat solvent petroleum and the organic compound the reaction product of ethylene oxide containing materials with amino compounds, e.g. oleyl amine, dodecyl propylene amine, amino-anthraquinone, lauryl acid amide or oleyl anilide, or the condensation product of a mixture of an ether and hydroxylamine and a high molecular weight carboxylic acid, sulphonic acid or sulphonated carboxylic acid, e.g. the reaction product of lauric acid with triethanolamine dihydroxy ethyl ether. The emulsion may be applied by spraying at 30 DEG -80 DEG C.