Aluminum Company of America

Alfred M Dennis

Joseph D Guthrie

George T Gregory

An aluminum alloy substrate is pretreated with an aqueous solution containing an organophosphorus compound, preferably a vinyiphosphonic acid-acrylic acid copolymer, before coating the substrate with a polymer. Passing the substrate through the solution contaminates it with aluminum and other elements. The pretreatment solution is rejuvenated by removing aluminum with a cation exchange resin that preferably contains a styrene-divinyl benzene copolymer functionalized with sulfonate groups. Rinsing the substrate contaminates the rinse water with the copolymer. The rinse water is concentrated by reverse osmosis or membrane ultrafiltration and returned to the pretreatment solution.

Coating an aluminum alloy substrate

A method for cleaning and modifying the surface of aluminum container sheet to make improved food can bodies and/or beverage can ends therefrom. The lowering of magnesium levels on an aluminum oxide surface and through the oxide-metal interface of this sheet, and deposition of at least some phosphorus-containing complex thereon produces container sheet that exhibits improved corrosion performance. The method comprises contacting said container sheet for less than about 20 seconds with a cleaner which preferably includes: about 1.0-10.0 wt. % (10.0-100.0 g/L) of sodium carbonate; about 0.1-2.5 wt. % (1.0-25.0 g/L) of sodium hydroxide, said cleaner including a total carbonate and hydroxide concentration in excess of about 3.0 wt. % (30.0 g/L); about 0.1-2.5 wt. % (1.0-25.0 g/L) of sodium gluconate; about 0.1-2.0 wt. % (1.0-20.0 g/L) of a compound containing 1-hydroxyethylidene-1,1-diphosphonic acid (or 'HEDP'); and about 0.05-1.0 wt. % (0.5-10.0 g/L) of an alkylphenoxypolyethoxyethanol-based surfactant, the balance water and incidental impurities.

Growing community of inventors

Newburgh, IN, United States of America

Alfred M Dennis