Sulfonation process for viscous sulfonic acid
CA 2102176 C · Owner: Chemithon Corporation (The) · Inventors: Sheats, William Bradford; Loughney, Thomas Joseph; Farmer, David Eugene
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process is provided for sulfonating an organic reactant which upon sulfonation, produces a viscous sulfonation reaction product having a viscosity substantially greater than 1,500 centipoises at a reaction temperature wherein the sulfonation reaction product is more than 85 % by weight completely reacted. The process utilizes an elongated enclosed reactor surface greater than, about 15 feet in length having upstream and downstream ends and equipped with a heat exchanging surface. The process comprises cocurrently flowing a film of organic reactant and a gaseous sulfonating agent downwardly in the reactor while pressurizing the sulfonating agent cocurrently along said reactor surface while …
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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 March 3, 1992 and granted September 15, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 3, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 3, 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
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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.