Patent ID: 7713919
Filing Date: 2010-05-11
Classification: C11D,C23F,C23G

Abstract:
1. A method of removing metallic copper from a steel surface, the method comprising contacting the steel surface with a composition consisting of a polyphosphonic acid; a hydroxyl-substituted primary amine; water; optionally an ethoxylated propylated fatty alcohol; optionally one or more additional nonionic surfactants; optionally one or more additional amine components selected from the group consisting of dialkanolamines and trialkanolamines; optionally one or more degreasers selected from the group consisting of propylene glycol, polyglycols, and glycol dialkyl ethers derived from a polyglycol, ethylene glycol, diethylene glycol, propylene glycol, or dipropylene glycol; and optionally a rust inhibitor, for a period of time sufficient to remove the metallic copper, wherein the steel surface defines a bore or cylinder of a gun.