Terephthalic acid production
CA 2133365 C · Owner: Washington University · Inventors: Litz, Lawrence M.; Kingsley, Jeffrey P.; Roby, Anne K.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An improved process for the production of terephthalic acid comprising introducing a feed directly into a recirculating liquid stream so as to facilitate formation and maintenance of gas bubbles in a dispersed form in a recirculating gas bubble-liquid mixture. By maintaining a gas-liquid interface and overhead gas phase in conjunction with a quiescent zone of liquid apart from the major portion of liquid in which said mixture is maintained in a recirculating flow condition the loss of, appreciable amounts of gas to the overhead gas phase is avoided.
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 September 30, 1994 and granted July 14, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended September 30, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 30, 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.