Polyimide resins prepared by addition reactions
CA 2033308 C · Owner: Serafini, Tito Thomas · Inventors: Wright, Ward Francis; Ueda, Kenneth Kaoru; Cheng, Paul Gung
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Polyimides having a high thermal and oxidative stability are prepared by reacting a mixture of monomers comprising (a) a dialkyl, trialkyl, or tetraalkylester of an aromatic tetracarboxylic acid, (b) an aromatic diamine and, (c) an end cap compound. The ratio of (a) (b), and (c) is, chosen so that upon heating the mixtures low molecular, weight prepolymers are formed the prepolymers having only, one end cap radical and being suitable for chain extension and crosslinking to form high molecular weight thermally, stable polyimides. Upon heating the prepolymers form, polyimide resins which can have Tg in excess of 600°F and superior physical properties.
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 December 27, 1990 and granted January 14, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 27, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 27, 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.