Fluorescent whitening agents
CA 2284723 A1 · Owner: Metzger, Georges · Inventors: Rohringer, Peter; Reinehr, Dieter; Metzger, Georges
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention provides new compounds having formula (1) in which X is , O or, preferably, NH; M is hydrogen an alkali metal atom, ammonium or a , cation formed from an amine; each R1 independently, is an aminoacid residue from which a hydrogen atom on the amino group has been removed; n is 1 or 2; and each R2, independently, is hydrogen C1-C3alkyl, halogen, cyano, COOR in , which R is hydrogen or C1-C3alkyl CONH-R in which R has its previous , significance SO2NH-R in which R has its previous significance NH-COR in , which R has its previous significance SO3M in which M has its previous , significance or when n is 1, R2 can also be CO-R3 in which R3 is C1-C3alkyl or phenyl; …
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 March 14, 1998. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended March 14, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 14, 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.