Process for the preparation of polyurethanes containing uretdione rings
CA 1290889 C · Owner: Hess, Heinrich · Inventors: Hess, Heinrich; Kopp, Richard; Grogler, Gerhard
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Polyurethanes containing uretdione rings are produced by reacting a polyisocyanate containing a uretdione ring with a relatively high molecular weight dihydroxyl compound in the presence of a bismuth salt of an organic carboxylic acid and a low molecular weight aromatic diamine. The low molecular weight aromatic diamine is used in a quantity which is 5 to 10 times the quantity of bismuth salt used. These solid polyuethanes are formed in relatively short reaction times and possess outstanding mechanical properties.
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
- Granted October 15, 1991. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended October 15, 2008.
- 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.