Aqueous acid, phosphatising solution containing an organic N-oxide accelerator

摘要

An aqueous acid, phosphatising solution (I) contains 0.2-3 g/l zinc ions, 3-50 g/l phosphate ions, calculated as PO4<3>- and 0.05-4 g/l of an organic N-oxide accelerator. (I) is prepared by a 10-100 fold dilution of a concentrate and adjustment of pH to 2.5-3.6. AN Independent claim is included for a method of phosphatising steel, zinc coated and/or zinc alloy steel and/or aluminium surfaces by spraying and/or dipping the metal surface for 3 seconds to 8 minutes with the solution (I).