Zinc phosphate conversion coating compositions and process
CA 2234819 C · Owner: Ppg Industries, Inc. · Inventors: Rossio, Charles E.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for forming a zinc phosphate coating on an aluminum substrate is provided to obtain good coverage by the coating. The coating preferably has a columnar or nodular crystal morphology and a coating weight of at least about 1612 mg/m2. The aluminum substrate is contacted with a zinc phosphate conversion coating bath which contains: from about 0.4 to 2.5 g/l zinc ion; from about 5 to 26 g/l phosphate ion; from about 0.4 to 1.5 g/l fluoride ion; from about 4 to 400 mg/l ferrous ion; and from about 0.01 to 2 g/l ammonium ion. The zinc phosphate conversion coating is formable on an aluminum substrate in the presence or absence of an accelerator. Also provided is an aqueous zinc …
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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 25, 1996 and granted April 17, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended November 25, 2016.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 25, 2018.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
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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.