Modified polyureas and a process for their production
CA 2079980 C · Owner: Muenzmay, Thomas · Inventors: Muenzmay, Thomas; Hassel, Tillmann
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention relates to polyureas which contain anionic Ncyanaminocarbonyl urea groups corresponding to formula (I) (see formula I), incorporated in the polymer chain and optionally, terminal anionic, cyanourea groups corresponding to formula (II) (see formula), wherein the ratio of incorporated groups (I) to terminal groups (II) is more than 1:1, preferably more than 2:1. The present invention also relates to a process for the preparation of these polyureas.
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 October 6, 1992 and granted February 11, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended October 6, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 6, 2014.
- 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.