Sulfonation of fatty acid esters
CA 2130027 C · Owner: Chemithon Corporation (The) · Inventors: Hovda, Keith D.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A sulfonation process includes the process steps of air sulfonating a fatty acid alkyl ester feedstock, bleaching the crude product with coaddition of up to about 40 wt.% of an alcohol based upon the weight of the crude product. The bleaching/alcohol addition step of the process is performed in a non-metallic or low-iron alloy system at temperatures above 90°C. The resulting product is then neutralized with a liquid base or metal carbonate.
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 August 12, 1994 and granted July 2, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended August 12, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 12, 2016.
- 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.