Canadian application, no grantCanada
Use of phosphonium compounds in the production of leather
CA 2096844 A1 · Owner: Matthews, Nigel S. · Inventors: Lloyd, Graham R.; Matthews, Nigel S.
Overview
Drawings and full text
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Hydroxyalkyl phosphine compounds such as tetrakis, (hydroxymethyl)phosphonium salts are applied to raw or pre-cured skins or hides, or leather, in pretanning and finishing operations respectively.
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 September 25, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended September 25, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 25, 2014.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledSeptember 25, 1992
GrantedNo grant recorded
Term endedSeptember 25, 2012
Patent numberCA 2096844 A1
Classification (IPC)C14C1/08 +1 more
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.