Hydraulic drag reducing agents for low temperature
CA 2009210 C · Owner: Murray, Christopher B. · Inventors: Young, John C.O'C.; Murray, Christopher B.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Heat exchange fluids have improved flow characteristics at low temperatures by incorporation of specific surfactant drag reducing compositions. The drag reducing composition comprises (1) a quaternary ammonium surfactant and (2) a preferably stoichiometric or greater amount of an organic counterion. The counterion is preferably a benzoate naphthalate, carboxylate or sulfonate and preferably contains a negatively charged head group substituent and an electron withdrawing a delocalizing group preferably a, hydroxyl group, in both adjacent positions.
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 February 2, 1990 and granted June 15, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 2, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 2, 2012.
- 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.