Patent ID: 6419755
Filing Date: 2002-07-16
Classification: C09D,C22B,Y02P

Abstract:
A process for removal of coatings from a coated metal substrate prior to the recycling of the coated metal substrate, comprising the steps of:providing a coated aluminum or steel metal substrate selected from the group consisting of aluminum food containers, aluminum food container parts, aluminum beverage containers, steel food containers, steel beverage containers, aluminum finstock, aluminum lithographic sheet scrap, and automotive scrap, said coated aluminum or steel metal substrate having one or more coating compositions thereon wherein said coating composition is selected from the group consisting of alkylamides, polyesters, polyethylenes, polypropylenes, polyolefins, epoxies, polyvinylchloride polymers, natural varnishes, synthetic varnishes, polyuretanes, polyacrylic polymers, polybutylenes, and polycarbonates; providing an aqueous solution consisting essentially of at least one organic acid in an amount between about 0.05-8% by weight, and water; immersing said coated aluminum or steel metal substrate in said aqueous solution; heating said aqueous solution; and removing said coatings from said coated metal substrate by contacting the coated aluminum or steel metal substrate with said at least one organic acid.