| abstract |
The present invention relates to a method for the layer-forming phosphating of metallic surfaces using a colloidal, aqueous solution as the activation stage containing a dispersed particulate component, the particulate component containing, in addition to dispersed inorganic compounds of phosphates of polyvalent metal cations, polymeric organic compounds as dispersing aids, at least in part are composed of styrene and / or an α-olefin with not more than 5 carbon atoms and maleic acid, its anhydride and / or its imide and which additionally have polyoxyalkylene units. The cleaning and rinsing stages preceding the activation stage as well as the activation stage itself can be operated in a resource-saving manner without loss of activation performance using process water, the colloidal, aqueous solution containing at least 0.5 mmol / L of alkaline earth metal ions dissolved in water. |