Rinsable metal pretreatment methods and compositions

摘要

Disclosed is a method of coating a metal or metal alloy surface comprising contacting said surface with an effective amount of a chromate free aqueous treatment solution or dispersion comprising (a) a material or materials comprising one or more elements selected from Group IV B elements; (b) fluoride; (c) phosphonic acid or phosphonate selected from the group consisting of the formulas II, III or IV wherein the substituents are as defined in the specification and (d) silane provided that the solution does not comprise tannins.