Expired Canadian patentCanada
Stable photographic developer and replenisher therefor containing 1-phenyl-3-pyrazolidone and hydroquinone
CA 1181624 A · Owner: E. I. Du Pont De Nemours And Company · Inventors: Wuelfing, Peter, Jr.
Overview
Drawings and full text
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An aqueous photographic silver halide developer/replenisher solution particularly useful in low throughput machine processing of X-ray silver halide elements.
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
- Granted January 29, 1985. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended January 29, 2002.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledJuly 22, 1982
GrantedJanuary 29, 1985
Term endedJanuary 29, 2002
Patent numberCA 1181624 A
Classification (IPC)G03C5/30 +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.