Process for the preparation of high-purity 5,5'-2,2,2,- trifluoro-1- (trifluoromethyl)-ethylidenebis-1,3-isobenzofurandione
CA 1339574 C · Owner: Hoechst Aktiengesellschaft · Inventors: Rohrscheid, Freimund
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Process for the preparation of high-purity 5,5'-2,2,2trifluoro-1-(trifluoromethyl)ethylidenebis-1,3-isobenzofurandione A process for the preparation of high-purity perfluorinated compounds, specifically of an aromatic tetracarboxylic acid and its anhydride 5,5'-2,2,2-trifluoro-, 1-(trifluoromethyl)ethylidene bis-1,3-isobenzofurandione by a multi-step treatment of the crude compounds. The metal ion content of the compounds treated is reduced considerably. After polymerization with an aromatic diamine, the anhydride is used in microelectronics.
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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
- Granted December 9, 1997. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended December 9, 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
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.