Preparation process of polyamide and/or polyimide
CA 1250689 A · Owner: Mitsui Chemicals, Incorporated · Inventors: Kouno, Masahiro; Osawa, Masanori; Toyoda, Toshihiro
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A polyamide and/or polyimide is prepared by using N,N'-dimethylethyleneurea or N,N'-dimethylpropyleneurea as a solvent upon polycondensation of a polycarboxylic acid and a diisocyanate at a temperature above 100°C in the presence of an alkali metal carbonate, alkali metal hydrogencarbonate alkali metal, hydroxide or an alkali metal salt of a polycarboxylic acid.
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 February 28, 1989. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended February 28, 2006.
- 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.