초록 ▼

An aqueous acidic composition for providing improved corrosion resistance and improved paint adhesive to metals; e.g., ferrous, aluminum, or magnesium alloys; upon contact. The composition comprises a Group IV-A metal such as zirconium in an acidic solution with one or more oxyanions to stabilize an

An aqueous acidic composition for providing improved corrosion resistance and improved paint adhesive to metals; e.g., ferrous, aluminum, or magnesium alloys; upon contact. The composition comprises a Group IV-A metal such as zirconium in an acidic solution with one or more oxyanions to stabilize and solubilize the metal while fluorides and organic solvents are specifically excluded from the composition. The coating is at a pH below about 5.0 and is preferably in a range between about 1.0 and about 4.0. The coating may contain surfactants, sequestering agents, or organic additives for improved corrosion protection and paint adhesion. The substrate may be treated by immersion, spray, fogging or rollcoat.

대표청구항 ▼

[ I claim:] [1.] A chromium-free aqueous composition for coating metal surfaces with a Group IV oxide matrix to improve corrosion protection comprising:a. between about 2.0.times.10.sup.-4 moles per liter and about 2.0 moles per liter, based on the aqueous composition, of dissolved Group IV-A metal

[ I claim:] [1.] A chromium-free aqueous composition for coating metal surfaces with a Group IV oxide matrix to improve corrosion protection comprising:a. between about 2.0.times.10.sup.-4 moles per liter and about 2.0 moles per liter, based on the aqueous composition, of dissolved Group IV-A metal ions selected from the group consisting of titanium, zirconium and hafnium alone or in combination;b. at least one or more mono- or polyvalent oxyanions (excluding silicate anions) in a mole ratio of about 0.5 or more moles of anion per mole of dissolved Group IV-A metal;c. sufficient hydrogen ion to maintain the solution pH below about 5.0;d. fluoride atoms which are optionally present in a ratio of no more than zero to 2 fluoride atoms per Group IV-A metal ion, ande. water, the composition forming a Group IV oxide matrix on a surface of a metal to which the composition is applied.