ALTERNATIVE COMPOSITION AND ALTERNATIVE METHOD FOR EFFECTIVELY PHOSPHATING METAL SURFACES

摘要

The present invention relates to an alternative acidic, aqueous composition for effectively phosphating metal surfaces, said composition comprising, in addition to zinc ions, manganese ions, phosphate ions and preferably nickel ions, at least one accelerator of the formula R₁R₂R₃C-NO₂, wherein each of the substituents R₁, R₂ and R₃ on the C atom is selected, independently of the others, from the group consisting of hydroxymethyl, 1-hydroxyethyl, 2-hydroxyethyl, 1-hydroxypropyl, 2-hydroxypropyl, 3-hydroxypropyl, 1-hydroxy-1-methylethyl, and 2-hydroxy-1-methylethyl. The invention also relates to a method for preparing such a composition, to an alternative method for phosphating metal surfaces, and to the use of phosphate coatings produced therewith.