Corrosion inhibitors
CA 2074460 C · Owner: Jovancicevic, Vladimir · Inventors: Kreh, Robert P.; Carter, Charles G.; Jovancicevic, Vladimir
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A composition and method for inhibiting corrosion of ferrous metals in contact with an aqueous solution comprising adding to the system from 0.1 to 500 ppm of an aminohydroxysuccinic acid compound selected from group consisting of compounds of the generalized formulas: A), wherein R is H or C1 to C6 alkyl, optionally substituted with -OH, -CO2H, -SO3H or phenyl, C4 to C7 cycloalkyl or, phenyl which is optionally substituted with -OH or -CO2H, and R' is H, C1 to C6 alkyl, optionally substituted with - OH or CO2H; and, B), wherein R' is as above and Z is selected from the group, consisting of i) -(CH2)n- wherein n is an integer from 2 to 10, ii) -(CH2)2-X-(CH2)2- wherein X is -0- -S-, -NR"-;, …
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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 July 24, 1992 and granted May 6, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended July 24, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 24, 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
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.