Process for crystallising polyethylene naphthalate copolymers in the absence of a devolatilization step
CA 2336293 A1 · Owner: Callander, Douglas David · Inventors: Callander, Douglas David; Sisson, Edwin Andrew; Duh, Ben
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention provides a process for crystallising polyethylene naphthalate copolymer in the absence of a devolatilization step comprising: a) copolymerising carboxylic acids made up of at least 60 mole % of 2,6naphthalene dicarboxylic acid; with polyols comprising at least 80 mole % ethylene glycol and from 2 to 20 mole % of a polyol having three or more carbon atoms, based on the total moles of polyols to form PEN copolymer , solids; and b) subsequently crystallising said solids comprising heating said solids to at least their sticking temperature at an average rate of at least 10 ~C/min, to form agglomerate-free crystallised solids. In another embodiment of the invention, …
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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 June 29, 1999. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended June 29, 2019.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 29, 2021.
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Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.