Reactive aqueous polyurea dispersions prepared by an emulsion polymerization process
CA 2091198 C · Owner: Rosthauser, James W. · Inventors: Rosthauser, James W.; Tirpak, Robin E.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention is directed to a process for the preparation of an aqueous polyurea dispersion containing blocked isocyanate groups and unreacted isocyanate-reactive groups by I) dispersing in water, a) a polyisocyanate b) a monofunctional blocking agent which is more reactive with isocyanate groups than water and, c) an amine component II) reacting the polyisocyanate with components b) and c) to form an aqueous polyurea dispersion. The present invention is also directed to the aqueous polyurea dispersion prepared by this process.
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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 March 8, 1993 and granted June 17, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 8, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 8, 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
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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.