Process of treating metallic surfaces

This invention relates to a process of treating metallic surfaces which consist of zinc, magnesium or aluminium, or of the alloys of zinc, magnesium or aluminium, and to which lacquers, plastic coatings, paints, sealing compounds or adhesives are applied after the treatment. The invention relates to a method for treating metallic surfaces consisting of zinc, magnesium or aluminium or of the alloys of zinc, magnesium or aluminium, to which lacquer, coatings of plastic material, paint, sealants or adhesives are applied after treatment. The treatment of the metallic surfaces takes place at between 10° C. and 100° C. by immersion, spraying or rolling with an aqueous solution. The solution has a pH of between 2 and 13 and contains one or more compounds of the type XYZ at a concentration of between 10and 1 mol/l. Y is an organic group containing between 2 and 50 C atoms and has a straight-chain structure. X is a COOH, HSO, HSO, (OH)PO, (OH)PO, (OH)(OR′)PO or (OH)(OR′)POgroup. Z is a OH, SH, NH, NHR′, CN, CH CH, OCN, epoxy, CH CR″-COO, acrylamide, COOH, (OH)PO, (OH)PO, (OH)(OR′)PO or (OH)(OR′)POgroup. R′ is an alkyl group with between 1 and 4 C atoms. R″ is an H atom or an alkyl group with between 1 and 4 C atoms. Groups X. and Z are each bonded to group Y in their final positions.