Process for the preparation of chloro-fluoro-butenes
CA 2093608 C · Owner: Marhold, Albrecht · Inventors: Lui, Norbert; Bielefeldt, Dietmar; Marhold, Albrecht
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Avoiding hexachlorobutadiene as the starting material 2-chloro- and 2,3-dichloro-1,1,1,4,4,4-hexafluoro-2-butene are prepared by reacting a chlorobutene derivative of the formula (I), Cl2C=CH-X (I), in which, X represents CCl=CCl2 or CCl2-CCl2H with hydrogen fluoride and chlorine in the presence of a catalyst at temperatures in the range of 50 to 550°C.
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 April 7, 1993 and granted August 3, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 7, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 7, 2015.
- 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.