Process for the preparation of amines, the amines thus obtained and the use thereof as hardeners for the epoxide resins
CA 2041909 C · Owner: Hentschel, Karl-Heinz · Inventors: Nachtkamp, Klaus; Hentschel, Karl-Heinz; Pedain, Josef
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 amines containing urethane and urea groups. The amines are produced by reacting A) isocyanate prepolymers containing urethane groups and in which the isocyanate groups are reversibly blocked with secondary monoamines with B) amines having molecular weights of from 60 to 500 which are at least, difunctional and which have a total of at least two primary or secondary amino groups, with splitting off of the secondary monoamine. The invention is also directed to the amines so produced and to the use as a hardener for an epoxide resin.
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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 May 7, 1991 and granted September 17, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 7, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 7, 2013.
- 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.