Preparation of unsaturated polyesters
CA 2479130 A1 · Owner: Yang, Lau S. · Inventors: Armstead, Diandre; Puckett, Paul Malcolm; Albano, Paul A.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for making unsaturated polyesters from 2-methyl-1,3-propanediol (MPD) is disclosed. The process comprises reacting one equivalent of an aromatic diacid with about two equivalents of MPD to produce an ester diol and then reacting one equivalent of the ester diol with from about 1.1 to about 1.9 equivalents of maleic anhydride to produce the polyester. The polyester has a fumarate/maleate ratio of 90/10 or greater.
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 March 5, 2003. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended March 5, 2023.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 5, 2025.
- 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.