¬indole naphthopyrans, preparation, compositions and (co)polymer matrices containing them, synthesis intermediates
CA 2305753 A1 · Owner: Corning S.A. · Inventors: Bourchteine, Konstantine; Breyne, Olivier
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The object of the present invention is novel indolenaphthopyrans compounds as well as the compositions and (co)polymer matrices containing them. Said compounds have interesting photochromic properties. Another object of the present invention is a method of preparing said novel compounds as well as , intermediates useful in said preparation.
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 October 20, 1998. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended October 20, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 20, 2020.
- 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.