Alternative Compositions and Alternative Methods for Effectively Phosphating Metal Surfaces

摘要

The present invention comprises, in addition to zinc ions, manganese ions, phosphate ions, and preferably nickel ions, one or more promoters of the formula R 1 R 2 R 3 C-NO 2, wherein substituents R 1 , R on carbon atoms 2 and R 3 each independently represent hydroxymethyl, 1-hydroxyethyl, 2-hydroxyethyl, 1-hydroxypropyl, 2-hydroxypropyl, 3-hydroxypropyl, 1-hydroxy-1- An alternative acidic, aqueous composition for effectively phosphating metal surfaces is selected from the group consisting of methylethyl and 2-hydroxy-1-methylethyl. The present invention also relates to a process for preparing such a composition, to an alternative process for phosphating metal surfaces, and to the use of a phosphate coating made therefrom.