Method for obtaining polyols and polyol thus obtained.
CA 2257181 A1 · Owner: Marechal, Jean-Charles · Inventors: Hubert, Franck; Tersac, Gilles; Durand, Gerard
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The invention relates to the field of polymer chemistry. It features a method for obtaining polyols consisting in a first step in reacting glycols i.e. plurialcohols with a functionality at least equal to two (MEG DEG, DPG,...) on polyethyleneterephthalate (PET) in the presence of a transesterefication catalyst (CAT) (MEG DEG, DPG;...), on polyethyleneterephthalate (PET) in the presence of a glycolysis catalyst (CAT) then in a last step, in distilling the free glycols. The method is characterised in that a step subsequent to the first and prior to or simultaneous with, the last step, comprises the glycolysis catalyst deactivation by a deactivating agent (DES). As an example the glycolysis …
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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 4, 1997. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended June 4, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 4, 2019.
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Timeline
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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.