Composition and process for chromating metal surfaces
CA 2096642 A1 · Owner: Oyama, Kazuyuki · Inventors: Hatano, Norifumi; Oyama, Kazuyuki; Hasebe, Akihiko
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A chromating treatment composition particularly suitable for preparing aluminum and stainless steel for clear coating comprises water, anions containing hexavalent chromium trivalent chromium, cations, phosphate ions dry process finely divided silica, and acrylic and/or methacrylic acid polymer or copolymer in such amounts that: (A) the concentration of the total of hexavalent and trivalent chromium atoms is in the range from 1 to 60 g/L; (B) the (trivalent chromium atom)/(hexavalent chromium atom) weight ratio is in the range from 0.6 to 2.5; (C) the (phosphate ion)/(total chromium atoms in hexavalent chromium ions and trivalent chromium ions) weight ratio is in the range from 0.5 to 4.5; …
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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 November 26, 1991. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended November 26, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 26, 2013.
- 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.