Improved process for the production of polyester resins
CA 2209752 C · Owner: Al Ghatta, Hussain · Inventors: Al Ghatta, Hussain
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Process for the production of aromatic polyester resins starting from resins with IV from 0.1 to 0.4 dl/g comprising the steps of blending the resin with a dianhydride of a tetracarboxylic acid, extruding the resin under form of strand, cooling the strand or the chips obtainable by cutting the strand, at a temperature between 150°C and 210°C and maintaining the same temperature for sufficient time to obtain a crystalline product wherein the DSC curves of the same do not show presence of premelt peaks or only in negligible amount.
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 July 7, 1997 and granted April 2, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended July 7, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 7, 2019.
- 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.