Method and composition for inhibiting corrosion in aqueous systems
CA 2369954 A1 · Owner: Ehrhardt, William C. · Inventors: Ehrhardt, William C.; Cheng, Longchun; Whitaker, Kim A.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method for controlling corrosion of metals such as stainless steel, in , contact with an aqueous system which comprises introducing into said system at least one tetrazolium compound of formula (I) wherein R1 R2 and R3 are , selected from the group consisting of lower alkyl branched lower alkyl, aryl, substituted aryl alkylaryl, substituted alkylaryl and heterocyclic substituted aryl, with the proviso that neither R1 R2, or R3 contain more , than 14 carbon atoms; and n is 1 or 2 such tetrazolium compound optionally , having associated water soluble ionic species if needed to obtain a neutral charge.
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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 May 2, 2000. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended May 2, 2020.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 2, 2022.
- 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.