Process for the production of polyisocyanates
CA 2574024 C · Owner: Smith, Richard Colin · Inventors: Smith, Richard Colin; Carr, Robert Henry
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for the production of a polyisocyanate comprising (a) phosgenating a polyamine to form a polyisocyanate by reacting (1) a polyamine on which the polyamine on which the polyisocynate is based in solution in an inert solvent with (2) phosgene optionally in solution in an inert solvent (b) separating , the solvent from the polyisocyanate (c) treating the separated solvent to be reused in polyamine solution (1) with an isocyanate trimerisation catalyst.
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 July 28, 2004 and granted June 26, 2012. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended July 28, 2024.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 28, 2026.
- 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.