Bleach-fix regeneration kit and use thereof in photographic processing
CA 2044149 A1 · Owner: Eastman Kodak Company · Inventors: Long, John J.; Cribbs, Thomas P. Iii; Krauss, Susan R.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A three-part bleach-fix regeneration kit is utilized to restore the capability of a spent bleach-fix solution to function as a working solution in photographic processing. The first part which, is an aqueous alkaline solution containing a buffering agent and an aminopolycarboxylic acid, is added to the spent bleach-fix solution prior to electrolytic recovery of silver therefrom. The second and third parts, which are aqueous acidic solutions containing, respectively, an iron salt and a thiosulfate fixing agent are , added after electrolytic recovery of silver. The first part functions to increase the pH of the spent bleach-fix solution to a level at which electrolytic silver recovery is …
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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
- Filed January 29, 1990. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended January 29, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 29, 2012.
- 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.