Highly effective polarizers
CA 2010598 C · Owner: Bayer Aktiengesellschaft · Inventors: Starzewski, Karl-Heinz Aleksander Ostoja
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Highly effective polarizers are described having a degree of polarization P of at least 95% and a dichroic ratio Q E = quotient of the extinction in the blocked position to the extinction in the transmission position over almost the entire wavelength range of visible light between 400 and 800 nm, of 10 or greater the said, polarizers comprising polyacetylene-containing polymer products with a matrix of pure polyvinyl alcohol (PVA). They are used in the form of films with a stretch ratio (see formula I), (l = length after stretching l o = length prior to, stretching) of more than 300%. They can be prepared by polymerizing acetylene in a solution of pure PVA in the presence of a nickel …
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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 February 21, 1990 and granted January 11, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 21, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 21, 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.
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.