Biodegradable polyester and natural polymer compositions and films therefrom
CA 2254908 A1 · Owner: Xu, Wayne · Inventors: Xu, Wayne; Doane, William M.; Lawton, John W. Jr.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A blend of gelatinized starch and a biodegradable hydroxy-functional polyester is disclosed. The polyester is preferably formed from diglycidylesters of dicarboxyl acids like cyclohexane dicarboxylic acid adipic acid or decane , decarboxylic acid and a dihydroxy compound like bisphenol A or hydroguinone. The composition may also contain polyvinylalcohol. Water-resistant biodegradable films are made from this composition.
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 May 13, 1997. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended May 13, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 13, 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.