Surface treatment method for aluminum
CA 2111850 A1 · Owner: Nakada, Kazuya · Inventors: Nakada, Kazuya; Yoshida, Masayuki
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The cleaned surface of an aluminum or aluminum alloy product for, example, aluminum coil, is treated with a 0.5 to 3 second spray of a chromating bath heated to 40 to 60 ·C said bath having a pH, of 1.0 to 3.0 and containing 0.1 to 3.0 g/L of tungstate ions and/or molybdate ions, 0.5 to 4.0 g/L of hexavalent chromium ions 5.0 to 30.0 g/L of phosphate ions, and 0.05 to 2.0 g/L of free fluoride ions. A highly corrosion-resistant highly paint-adherent , chromate coating can thereby be formed on the surface of aluminum in less time than that required by prior phosphoric acid-based chromating treatments.
Read the whole patent
Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed June 11, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended June 11, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 11, 2014.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.