Amide-imide copolymer resin of lowered water absorption and composites made therefrom
CA 2021929 A1 · Owner: Bockrath, Ronald E. · Inventors: Hanson, Robert B.; Bockrath, Ronald E.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Polyamide-imide matrix resins derived from trimellitic acid compounds and an aromatic diamine are improved in moisture resistance when from 10 to about 90 mole % of the trimellitic acid compounds are replaced by biphenyl tetracarboxylic acid compounds. The matrix resins are particularly useful for fiber-filled composites having improved retention of properties when exposed to moisture. 28,168 EP
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 July 25, 1990. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended July 25, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 25, 2012.
- 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.