Alkaline black-and-white developer for silver halide photographic material
CA 2064934 A1 · Owner: Marchesano, Carlo · Inventors: Marchesano, Carlo; Faranda, Filippo; Buriano, Franco
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Alkaline Black and White Developer for Silver Halide Photographic Material, ABSTRACT OF THE DISCLOSURE The present invention relates to an alkaline aqueous black-and-white photographic developer composition comprising:, (1) at least one black-and-white developing agent (2) at least one black-and-white auxiliary developing agent, (3) at least one antifoggant, (4) at least one sequestering agent (5) a sulfite antioxidant, (6) at least one buffering agent (7) a tone agent, and, (8) at least one tone promoting agent wherein said tone agent is a primary organic amine compound and said tone promoting agent is a silver halide solvent.
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
- Filed April 2, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended April 2, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 2, 2014.
- 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.