Process for preparing a pre-rinse composition for phosphating metal surfaces using a suspension formed by the same composition for pre-rinsing metal surfaces and processes for using the composition or suspension and to form a phosphate coating on a substrate of metal

摘要

Disclosed is a composition for the pre-rinsing of a metal surface prior to phosphating, a method for preparing the composition, and a method for using the composition to pre-condition the metal surface. The composition is an aqueous suspension containing a water-insoluble manganese phosphate having the formula MnxXyH2(PO4)4.nH2O, in which X is a divalent metal ion other than manganese, x+y is 5 and x is a positive number of from 1 to 5, y is 0, 1, 2, 3 or 4, and n is less than 4.