Corrosion-inhibiting method using latex paints and article

Claim 1

In a method of maintenance painting clean or rusty ferrous metal, the steps of applying one or more coats, to a coated or uncoated ferrous surface, of a corrosion-inhibiting aqueous latex paint containing a synthetic or natural polymer dispersed therein, said polymer consisting essentially of one being insoluble in an aqueous system at a pH of between about 3 and 11, any unsaturated acid monomer contained in said polymer being present in an amount of less than 5% of the monomers, and, dissolved in said paint, a water-soluble complex of a polyvalent metal, a volatile complexing agent, and a corrosion-inhibiting anion, said complex having the formula M(Z) x An, wherein M is a polyvalent metal cation, An is a corrosion-inhibiting anion, Z is a complexing volatile component, and x is the number of moles of volatile complexing agent per mole of M and being from 2 to 6, M and An being such that upon evaporation of the volatile complexing agent, M and An form an insoluble corrosion-inhibiting material, in which the quantity of said complex is from about 0.2 to about 20 millimoles per mole of water in the latex paint, the polymer on a solids basis being present in an amount of 10 to 30%, in which a pigment is present in an amount of 15to 55%, said pigment including at least one metal oxide, at least one dispersant or surfactant being present in an amount of 0.1-2.5%, in which a bodying agent is present in an amount of 0.1-5%, and in which water and any optional ingredients are present in an amount to make the total of the ingredients 100%, all parts being by weight unless otherwise stated, and air-drying the coating, whereby the ferrous metal is protected from flash rusting and, upon evaporation of the volatile complexing agent, is provided with long-term rust resistance and blistering resistance by the insoluble complex of M and An, the latex pH being alkaline.