Process for preparing bisimides and bisimides prepared thereby
CA 1079286 A · Owner: Columbian Chemicals Company · Inventors: Wolford, Lionel T.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
White N, N' -alkylene-bis-tetrabromophthalimides are prepared by reacting about two molar proportions of tetrabromophthalic anhydride with about one molar proportion of a diaminoalkane containing 2-6 carbon atoms in a solvent mixture having a boiling point of at least about 125°C. and comprising about 50-97. 5% by weight of a liquid aromatic hydrocarbon or halohydrocarbon having a boiling point of at least about 80°C. and about 50-2.5% by weight of an alkanoic or aralkanoic acid having a dissociation constant not higher than about 6 x 10-5 at 25°C. A preferred solvent is a mixture of about 70% by weight of xylenes and about 30% by weight of propionic acid having a boiling point of about …
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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 June 10, 1980. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended June 10, 1997.
- 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.