Use of a copolymer containing pendant ammonium or phosphonium ions as a development inhibitor scavenger
CA 1082974 A · Owner: Eastman Kodak Company · Inventors: Holmes, Edmund T.; Campbell, Gerald A.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A photographic element comprises a support a, silver halide emulsion layer and a layer containing a polymeric scavenger for development inhibitors. The movement of development inhibitor anions from layer to layer in a film, out of the film, or into the film from processing solutions, can be controlled by the presence of the polymeric scavenger layer. -1-
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 August 5, 1980. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended August 5, 1997.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
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.