Preparation of isocyanurate-and/or uretdione-containing polyisocyanates having a reduced color index and improved shelf life, and products prepared by this method
CA 2126285 C · Owner: Basf Aktiengesellschaft · Inventors: Stiefenhoefer, Konrad; Wolff, Stefan; Bruchmann, Bernd
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Isocyanurate- and/or uretdione-containing polyisocyanates having a reduced color index and improved shelf life are prepared by conventional catalytic oligomerization of aliphatic and/or cycloaliphatic diisocyanates and treatment of the oligomerization products with peroxycarboxylic acids.
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 June 20, 1994 and granted December 22, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 20, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 20, 2016.
- 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.