Branched ether surfactants and their use in an enhanced oil recovery process
CA 2078110 A1 · Owner: Holmberg, Krister · Inventors: Hellberg, Per-Erik; Sonesson, Clas; Svennberg, Stig
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention relates to a surfactant having general formula (I) in which R3 is C8-12 alkyl R4 is C2-6 alkyl, A, is an alkyleneoxy group derived from an alkylene oxide having 2-3 carbon atoms, p has an average number of from 2 to 6 Y is an, alkylene group having 1-3 carbon atoms and optionally containing a hydroxyl group, m1 and m2 is 0 or 1, both m1 and m2 not being 0 at the same time, and r is 0 or 1 or a salt thereof.
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 April 2, 1991. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended April 2, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 2, 2013.
- 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.