Process for producing blocked, urea group-containing polyisocyanates and products manufactured according to said process
CA 1331758 C · Owner: Huls Aktiengesellschaft · Inventors: Gras, Rainer
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for the production of a blocked urea group-containing polyisocyanate from a partially blocked polyisocyanate and a polyamine comprising the, steps of:, (i) reacting a partially blocked polyisocyanate said polyisocyanate being substantially free of monomeric polyisocyanate, with a primary polyamine secondary polyamine, or mixtures thereof in relative, proportions such that the ratio of isocyanate groups to amino groups is in the range from about 1:1 to 1.3:1 and, (ii) isolating said urea group-containing polyisocyanate by vacuum thin-layer evaporation wherein the vacuum boiling point of said polyisocyanate is lower than the deblocking temperature of said urea group-containing …
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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
- Granted August 30, 1994. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended August 30, 2011.
- 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.