Process for treating metal with aqueous acidic composition that is substantially free from chromium (vi)
CA 2113453 C · Owner: Henkel Kommanditgesellschaft Auf Aktien · Inventors: Dolan, Shawn E.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A chromium free conversion coating at least equivalent in corrosion protective quality to conventional chromate conversion coatings can be formed on metals, particularly galvanized steel by a dry-, in-place aqueous acidic liquid comprising: (a) a component of anions, each of said anions consisting of (1) at least four fluorine atoms and (ii) at least one atom of an element selected from the group consisting of titanium zirconium, hafnium, silicon, and boron and optionally, (iii) one or more oxygen, atoms; (b) a component of rations of elements selected from the group consisting of cobalt, magnesium, manganese zinc, nickel, tin, zirconium, iron, aluminum and copper; the ratio of the total …
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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 August 12, 1992 and granted April 29, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended August 12, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 12, 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
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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.