Process for making polyetherester resins with high aromatic ester content
CA 2316929 A1 · Owner: Armstead, Diandre · Inventors: Armstead, Diandre; Cai, Gangfeng; Yang, Lau S.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for making polyetherester resins is disclosed wherein a glycol , ester of an aromatic diacid such as terephthalic acid is reacted with a polyether and a source of a dicarboxylic acid such as maleic anhydride to produce a polyetherester resin, wherein the aromatic diester content may be conveniently adjusted as desired. The process permits the preparation of unsaturated polyetherester resins with relatively high levels of terephthalate repeating units while avoiding the difficulties associated with the direct use of terephthalic acid in previously known procedures. Such unsaturated polyetheresters are useful for making thermoset resins with excellent mechanical and physical …
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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
- Filed February 9, 1999. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended February 9, 2019.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 9, 2021.
- 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.