Hydroxamic acid containing polymers used as corrosion inhibitors
CA 2074535 C · Owner: Khambatta, Binaifer S. · Inventors: Khambatta, Binaifer S.; Fong, Dodd W.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Hydroxamic acid containing low molecular weight polymers have been found to be excellent corrosion inhibitors for iron and steel alloys in contact with industrial waters. When the waters contain hardness ions, such as calcium, magnesium and mixtures thereof, the waters are preferably treated with combinations of the hydroxamic acid containing polymers and scale inhibiting/dispersing polymers, which polymers do not contain hydroxamic acid functional groups. The hydroxamic acid containing polymers as well as the, combination of hydroxamic acid and scale inhibiting/dispersing polymers may also both be formulated with other corrosion inhibitors.
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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 23, 1992 and granted September 24, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended July 23, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 23, 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.