Multistep, continuous preparation of organic polyisocyanates
CA 2094484 C · Owner: Magnussen, Peter · Inventors: Mattner, Otto; Brandt, Eckhardt; Otterbach, Andreas
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A multistep process for the, continuous preparation of organic polyisocyanates preferably aliphatic or cycloaliphatic diisocyanates by, reacting the corresponding organic polyamines with carbonic acid derivatives and alcohols to give monomeric polyurethanes and pyrolyzing the latter involves separating the resultant polyisocyanates and worthless residues in certain reaction steps and recycling the reusable by-products into earlier steps.
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 April 20, 1993 and granted October 7, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 20, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 20, 2015.
- 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.