Polyetherimides and precursors therefor
CA 1319461 C · Owner: General Electric Company · Inventors: Berdahl, Donald Richard
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Abstract, Polyetherimide precursor compositions are prepared by reacting a mixture of at least two diamines selected from the group consisting of o-phenylenediamine m-phenylenedia-, mine and 4-aminophenyl ether with the esterification product of a low molecular weight alkanol such as methanol and an ether tetracarboxylic acid dianhydride preferably 3,4-di-, carboxyphenyl ether dianhydride. Said polyimide precursor compositions may be converted to polyimides useful in composite formation, by gently heating to remove excess alkanol and subsequently baking at temperatures in the range of about 275-375°C.
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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 June 22, 1993. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended June 22, 2010.
- 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.