Polyisocyanates containing isocyanurate groups and a process for their production
CA 2008064 C · Owner: Scholl, Hans-Joachim · Inventors: Scholl, Hans-Joachim
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 an isocyanurate group-containing polyisocyanate by, a) partially reacting the isocyanate groups of an organic diisocyanate containing aliphatically and/or cycloaliphatically bound isocyanate groups in the presence of an ammonium or phosphonium fluoride trimerization catalyst, b) introducing carbon dioxide into the reaction mixture at least periodically during the reaction and c) terminating the reaction at the desired degree of conversion. The present invention also relates to the isocyanurate group-containing polyisocyanates obtained in accordance with this process.
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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 January 18, 1990 and granted August 18, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended January 18, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 18, 2012.
- 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.