Expired Canadian patentCanada
Cellulosic material bleaching method
CA 388237 A · Owner: The Mathieson Alkali Works · Inventors: George P. Vincent
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 April 23, 1940. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended April 23, 1957.
- 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—
GrantedApril 23, 1940
Term endedApril 23, 1957
Patent numberCA 388237 A
Classification (IPC)D06L4/24
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.