High temperature mixed polyimides and composites formed therefrom
CA 2046795 A1 · Owner: General Electric Company · Inventors: Gray, Robert A.; Griffin, Richard N.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Polyimide intercondensation products are prepared from mixed dianhydrides and aromatic diamines. One of the mixed dianhydrides must be 2,2 -bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride (6FDA) and the other dianhydride may be oxydiphthalic anhydride (ODPA) or biphenyl dianhydride (BPDA) or mixtures thereof. Preferred aromatic diamines are p-phenylenediamine (PPD) and/or m-phenylenediamine (MPD). The polyimide products have increased glass transition temperatures (Tg), frequently higher than 400°C. Composites made from the polyimides have high thermal and oxidative stability and may be used in aircraft engine hardware.
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 11, 1991. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended July 11, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 11, 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.