(C) Peter Meiers - http://www.fluoride-history.de


Patents on Cleaning Compositions



Frank A. GOOCH, New Haven, Connecticut: "Art of soldering aluminium", US Patent 597,111; filed March 26, 1895; granted Jan. 11, 1898

("I have found, however, that mixtures of metallic fluorids with many other suitable substances may be made, which, while fusing at temperatures below the fusing point of aluminium, possess the property in a state of fusion of cleaning the surface of the aluminium and of protecting it from atmospheric oxidation")


Stephan JAHN, of Charlottenburg, Germany, assignor to Aktiengesellschaft Mix & Genest, Telephon- und Telegraphenwerke, of Berlin, Germany: "Process for pickling aluminium and its alloys prior to galvanizing or coating the same with other metals", US Patent 1,011,203; filed June 16, 1910; granted Dec. 12, 1911

(cleaning aluminium in a bath containing e.g. dilute hydrofluoric acid mixed with ethanol) 


Harry V. CHURCHILL, assignor to Aluminum Company of America, Pittsburgh, Pa.: "Cleaning composition", US Patent 1,890,214; filed May 18, 1929; granted Dec. 6, 1932

("I have discovered that an aqueous solution of an organic fruit acid in which is also contained a small amount of an alkali fluoride will, when brought to a temperature somewhat near the boiling point of water, completely remove the stain and discoloration on aluminum articles if the articles are but dipped into the solution for a few moments and then rinsed with hot or warm water. I have further discovered that it is the presence of the fluoride in the solution which completely eliminates the objection to the former use of inorganic fruit acids of this nature, namely, the fluoride appears to remove the resultant scum or general discoloration which is produced by the action of the fruit acid on the metal.")


Pierre PRIER, Paris, France: "Process of protecting light metals against corrosion", US Patent 1,957,354; filed April 27, 1931 (France), April 26, 1932 (U.S.), granted May 1, 1934

(uses fluovanadates, fluosilicates, fluorides)


Wayne E. WHITE, assignor to Aluminum Company of America, Pittsburgh, Pa.: "Method for cleaning aluminum", US Patent 2,431,595; filed Aug. 6, 1942, granted Nov. 25, 1947

("It is my discovery that molten ammonium fluoride (NH4F) will remove the various surface coatings and films, including the heaviest of oxide coatings, from aluminum surfaces")


Mike A. MILLER, Wayne E. WHITE, assignors to Aluminum Company of America, Pittsburgh, Pa.: "Method of removing oxide coating from aluminum surfaces", US Patent 2,399,134; filed Feb. 24, 1943; granted April 23, 1946

("... a satisfactory solution may be prepared by mixing a strong aqueous solution of hydrogen fluoride with the alcoholic compound")