Nonabrasive, corrosion resistant, hydrophilic coatings for aluminum surfaces, methods of application, and articles coated therewith
AssigneeAlcan International Limited
InventorSadashiv K. Nadkarni
Life of this patent
Estimating the term…
Abstract
A nonabrasive, corrosion-resistant, hydrophilic coating on aluminum sheet such as fin stock, produced by applying to the sheet surface a coating material containing, in an aqueous vehicle, effective amounts of nitrilotrismethylenetriphosphonic acid, phosphoric acid, and borate material of the group consisting of zinc borate and sodium borate, and essentially free of silica, alumina and precursors thereof, and heating the surface to establish the coating thereon. The coating formulation may also contains up to about 1 wt. % of polyacrylic acid and a surfactant to aid in application.
Claims13
An aluminum article having a surface bearing a nonabrasive, corrosion-resistant, nonporous, hydrophilic coating, produced by the steps of applying to said surface a coating formulation comprising, in an aqueous vehicle, effective minor amounts of nitrilotrismethylenetriphosphonic acid, phosphoric acid, and borate material selected from the group consisting of zinc borate and sodium borate, subject to the proviso that said material includes an effective amount of at least one borate, said coating formulation also containing an effective minor amount of polyacrylic acid, said coating formulation being essentially free of silica, alumina and precursors thereof, and said amounts, in combination, being effective to provide a coating on said surface producing a stable contact angle with water of not more than about 15.degree.;
- and heating the surface to dry the coating thereon.
Dependencies are inferred from the claim text.