Paper dye
CA 2277533 A1 · Owner: Catlin, Joseph C. · Inventors: Kokel, Richard H.; Catlin, Joseph C.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
This invention relates to a dye having the formula (I) (see formula I), wherein each M is a hydrogen ion an alkali metal ion, or R a R b R c R d N+ (where R a, R b, R c, and R d are independently hydrogen C1-C6 alkyl, or, C1-C6 hydroxyalkyl). This invention further relates to the use of the dye.
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 July 16, 1999. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended July 16, 2019.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 16, 2021.
- 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.