Expired Canadian patentCanada
Process for preparation of cellulose esters
CA 480357 A · Owner: Camille Dreyfus · Inventors: Arnold J. Rosenthal; Clifford I. Haney; Mervin E. Martin
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 January 15, 1952. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended January 15, 1969.
- 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—
GrantedJanuary 15, 1952
Term endedJanuary 15, 1969
Patent numberCA 480357 A
Classification (IPC)C08B3/24
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.