Low lead release plumbing components made of copper based alloys containing lead, and a method for obtaining the same
November 19, 2017. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 3556883 Etching liquid for etching aluminum Process for stripping tin or tin-lead alloy from copper Continuous casting method Continuous casting mold Process for removing tin and tin-lead alloy from copper substrates Synergistic combination of sodium silicate and orthophosphate for controlling carbon steel corrosion Continuous casting mold Post-etch, printed circuit board cleaning process Process for the continuous casting of metal, in particular of steel into bloom and billet cross-sections InventorAssigneeApplicationNo. 875881 filed on 11/19/1997US Classes:148/282, Metal substrate contains elemental copper or alloy thereof134/3, Including acidic agent148/901, SURFACE DEPLETED IN AN ALLOY COMPONENT (E.G., DECARBURIZED)216/105, Metal is elemental copper, an alloy, or compound thereof216/106, Etchant contains acid216/107Etchant contains fluoride ionExaminersPrimary: Ip, SikyinAttorney, Agent or FirmForeign Patent References
International ClassesC23C 008/06E03B 007/09 AbstractA method for treating a component made of a copper-based alloy containing lead. The component has Pb and Pb salts on a surface thereof. The method includes the step of etching the surface of the component selectively to remove almost entirely the Pb and Pb salts from the surface. The etching includes treating the surface with an acidic aqueous solution that is a) a non-oxidizing acidic aqueous solution of an acid capable of forming soluble Pb salts or b) an oxidizing acidic aqueous solution of an organic acid mixed with peroxide. The method also includes the step of passivating the etched surface whereby to inhibit release of any Pb or Pb salts remaining in the component when the passivated surface is in contact with water.Other References
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