Preparation of polyurethanes having improved curing
CA 2210970 A1 · Owner: Knorr, Gottfried · Inventors: Guettes, Bernd; Seifert, Holger; Knorr, Gottfried
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Polyurethanes having improved curing are prepared by reacting a) organic and/or modified organic diisocyanates and/or polyisocyanates with, b) polyether polyols based on aromatic amines able to be, prepared by reacting specific amine combinations and if, desired, further coinitiators in a stage wise molecular addition of alkylene oxide, and also, if desired further, relatively high molecular weight compounds containing at least two reactive hydrogen atoms and, if desired c) low molecular weight chain extenders and/or crosslinkers in the presence of, d) blowing agents, e) catalysts and if desired, f) further auxiliaries and/or additives wherein the specific amine combination used is a …
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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 July 30, 1997. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended July 30, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 30, 2019.
- 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.