Electrolytic stripping bath and process
AssigneeOxy Metal Industries Corporation
InventorLillie C. Tomaszewski
Life of this patent
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Abstract
An improved electrolytic bath composition and process for stripping metal deposits from a different basis metal comprising an aqueous solution containing activating halogen compounds, an amine, nitro and/or nitrate stripping component, and an inhibiting agent to inhibit attack of the basis metal comprising glucoheptonic acid, malic acid, and mixtures thereof as well as the Group IA, IIA and ammonium salts thereof. The stripping of the metal deposit is effected by immersion of the object in the bath while anodically charged and passing electric current through the bath to a cathode for a period of time sufficient to achieve the desired magnitude of stripping of the metal deposit.
Claims21
An electrolytic stripping bath for stripping metal deposits from a different basis metal comprising an aqueous solution having a pH of about 1 to about 14 and containing a halogen compound in an amount sufficient to activate the bath, a stripping component selected from the group consisting of (a) a bath soluble primary, secondary and/or tertiary amine having a carbon content of C.sub.1 to C.sub.8, (b) a bath soluble inorganic nitrate and/or organic nitro compound and mixtures of (a) and (b), and an inhibiting agent present in an effective amount to inhibit attack of the basis metal comprising a compound selected from the group consisting of glucoheptonic acid, malic acid, and mixtures thereof as well as the Group IA, IIA and ammonium salts thereof.
A process for electrolytically stripping metal deposits such as copper, bright and semi-bright nickel, sulfamate nickel, nickel-phosphorous, cadmium, brass, tin, chromium and iron-nickel alloys from a different basis metal which comprises the steps of immersing an object to be stripped in a stripping bath comprising an aqueous solution having a pH of about 1 to about 14 and containing a halogen compound in an amount sufficient to activate the bath, a stripping component selected from the group consisting of (a) a bath soluble primary, secondary and/or tertiary amine having a carbon content of C.sub.1 to C.sub.8, (b) a bath soluble inorganic nitrate and/or organic nitro compound and mixtures of (a) and (b);
- and an inhibiting agent present in an effective amount to inhibit attack of the basis metal comprising a compound selected from the group consisting of glucoheptonic acid, malic acid, and mixtures thereof as well as the Group IA, IIA and ammonium salts thereof;
- anodically charging the object and passing electric current through the solution to a cathode for a period of time to achieve the desired magnitude of stripping of the metal deposit from the object.
Dependencies are inferred from the claim text.