Improved process for the preparation of stabilized polyalkenyl sulfonic acids
CA 2762014 C · Owner: Chevron Oronite Company Llc · Inventors: Campbell, Curtis B.; King, William F.; Nelson, Richard J.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An improved process for making stabilized polyalkenyl sulfonic acids whereby the product resulting from the reaction between a polyalkene and sulfur trioxide is stabilized by neutralizing with a neutralizing agent prior to storage or further processing. Neutralization at this point in the process results in polyalkenyl sulfonic acid that is stable and has a decreased amount of sultones.
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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 August 12, 2004 and granted October 22, 2013. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended August 12, 2024.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 12, 2026.
- 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.