Photochromic polymer membrane
CA 2080899 A1 · Owner: Reid, Jerome L. · Inventors: Wasserman, Nelson; Do, Pauline; Reid, Jerome L.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A photochromic material adapted for coating light transmissive materials. The photochromic material contains photosensitive silver halide crystals having dimensions in the range of approximately 50 Angstroms to 800 Angstroms. The silver halide crystals are surface doped with copper ions and another sensitizer selected from mild reducing agents, thioethers, or sulfur-bearing ions and are treated with an agent to accelerate the forward reaction and control the reverse reaction. The accelerants are ions selected from the group consisting of cobalt, chromium manganese, magnesium, and rare earth metals such as cerium samarium and europium. The, agent for controlling the reverse reaction is …
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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 April 17, 1991. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended April 17, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 17, 2013.
- 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.