Expired Canadian patentCanada
Process of catalytically reacting so2 to form so3 and of producing sulfuric acid
CA 920774 A · Owner: Metallgesellschaft Aktiengesellschaft · Inventors: Karl-Heinz Dorr; Herbert Drechsel; Hugo Grimm
Overview
Drawings and full text
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordRead 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
- Granted February 13, 1973. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended February 13, 1990.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Filed—
GrantedFebruary 13, 1973
Term endedFebruary 13, 1990
Patent numberCA 920774 A
Classification (IPC)C01B17/76
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.