Coating metal surfaces

A phosphate coating is formed on a metal surface by contacting the surface with a composition in which 1-15% by weight of water and 2,5-25% by weight of phosphoric or phosphorus acid is dissolved in a hydrophilic organic compound having 12-30 carbon atoms in a connected group, the composition being a stable single phase liquid at a temperature at least as low as 80 DEG C. The hydrophilic compound may be a non-volatile metal lubricant: alternatively, a non-hydrophilic metal lubricant may be included in the composition. Suitable hydrophilic compounds are amides and amines. The composition may also contain supplementary lubricants such as mineral and fatty oils; drying or semi-drying oils; and a coupling agent such as an alkylene glycol, an alkylene glycol ether and/or a fatty acid. Metals which may be coated are iron, steel, aluminium and zinc. The composition may be applied by immersion, flooding, applicator rolls, brushing or spraying, and the phosphate coating is stated to facilitate the ...

Mittel und Verfahren zur Behandlung von Metallen fuer die Kaltverformung