Procedure for the manufacture of a mixture of starch and polyvinyl alcohol and thus manufactured mixture
CA 2004308 A1 · Owner: Nachtergaele, Willy A.M. · Inventors: Van Nuffel, Jan H.; Nachtergaele, Willy A.M.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
1 -, EXCERPT, "Procedure for the manufacture of a mixture of starch and polyvinyl alcohol and thus manufactured mixture". to 95 parts by weight starch and 5 to 50 parts by weight polyvinyl alcohol with a degree of saponification between 87 and 100% are thoroughly mixed and furthermore the moisture content of the mixture is regulated between and 25 weight %. Subsequently the mixture obtained is subjected to a thermo-mechanical treatment at a temperature situated between 110 and 180°C. During the extrusion the mixture is subjected to shearing forces so that the product obtained when it is dispersed in cold water and subsequently is centrifuged, divides into a watery phase and a coacervate …
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 November 30, 1989. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended November 30, 2009.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 30, 2011.
- 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.