Synthetic polyvinyl alcohol fiber and process for its production
CA 2015406 C · Owner: Kubotsu, Akira · Inventors: Nakahara, Fumio; Miyazaki, Hirotoshi; Kubotsu, Akira
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention is directed to a high-performance PVA fiber and its production. Each filament of the PVA fiber of the present invention has a structure comprising an aggregate of substantially innumerable fibrils the fiber, has high strength, elastic modulus and resistance to, fatigue, hot water and chemicals and can be pulpified while maintaining its excellent features, e.g. high strength. The PVA fiber of the present invention cannot even drawn to a, high ratio, be readily whitened by virtue of its fibril-aggregate structure, and can hence be made still higher in performances. The PVA fiber can be obtained by adding to a PVA solution a relatively large amount of surface active …
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 April 25, 1990 and granted May 23, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 25, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 25, 2012.
- 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.