Phosphate conversion coating composition and process
CA 2269455 A1 · Owner: Henkel Corporation · Inventors: Boulos, Mervet S.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An aqueous liquid combination of simple and complex fluorides citric acid , and/or its salts, phosphate ions a hydroxylamine source, and an oxidizing agent selected from among water soluble nitroaromatic organic compounds molybdates, and tungstates, provides good quality protective phosphate conversion coatings on ferrous, zinciferous aluminous, and magnesium and , magnesium alloy metal surfaces without needing any divalent or higher valent metal cations such as are generally used to produce high quality phosphate conversion coatings. These combinations that contain citric acid produce less sludge than otherwise similar combinations in which gluconic acid is used instead of citric …
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 November 4, 1997. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended November 4, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 4, 2019.
- 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.