Photographic material and process for retouching dye images
CA 2029578 A1 · Owner: Harder, John W. · Inventors: Harder, John W.; Burns, Paul A.; Harder, John W.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Abstract, A method of retouching a dye image comprises selective removal with an aqueous acidic organic solvent solution of a portion of a dye image from an exposed and processed photographic silver halide element comprising a support bearing a dye image from a dye-forming coupler and a primary amine photographic color developing agent, wherein the dye-forming coupler: (a) contains no ionizable group that is retained as part of a dye formed upon oxidative coupling, (b) has a structure such that the Log P of the coupler is greater than 4 and is derived from a four-equivalent coupler that has a Log P less than 8, and (c) hag a coupling reactivity that enables formation of maximum image …
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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 November 8, 1990. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended November 8, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 8, 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.