Process for the production of isocyanurate polyisocyanates, the compounds obtained by this process and their use
CA 2042004 C · Owner: Bayer Aktiengesellschaft · Inventors: Pedain, Josef
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention relates to a process for the production of isocyanurate group-containing polyisocyanates by partially trimerizing the isocyanate groups of (cyclo)aliphatic diisocyanates in the presence of catalysts which accelerate the trimerization of isocyanate groups and optionally in the presence of an inert solvent, terminating the trimerization reaction at the desired degree of trimerization and removing unreacted starting diisocyanate and any other volatile constituents, characterized in that at least one monohydric alcohol containing ester groups corresponding to the formula is added to the reaction mixture prior to removing the excess starting diisocyanate in a quantity of 1 …
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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 May 7, 1991 and granted February 12, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 7, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 7, 2013.
- 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.