Suppression of the evolution of hydrogen sulfide gases from petroleum residua
CA 2007965 C · Owner: Petrolite Corporation · Inventors: Weers, Jerry J.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Hydrogen sulfide gas evolution during storage or transport of petroleum residua are suppressed by the incorporation of an effective amount of a diamine of the formula, wherein R1, R2, R3, and R4 are independently an alkyl radical containing 1 to 14 carbon atoms (CH2)n-OR6 or, cycloalkyl containing 5 or 6 carbon atoms and R5 is hydrogen or methyl. R1 and R2 and R3 and R4 can be alkylene groups joined together with their respective adjacent N to form a heterocyclic ring. R6 is hydrogen or an alkyl radical having 1 to 5 carbon atoms and n is an integer of 1 to 5.
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 January 17, 1990 and granted February 27, 1996. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended January 17, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 17, 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.