Process for preparing a photographic emulsion containing tabular grains having narrow size distribution
CA 1316036 C · Owner: E.I. Du Pont De Nemours And Company · Inventors: Nottorf, Robert William
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Process for preparing a photographic emulsion containing tabular silver halide grains which have narrow size distribution comprising: A. adding silver nitrate to a vessel, containing dispersing medium/bromide mixture, initial bromide ion, concentration is 0.08 to 0.25 N to form tabular seed grains;, B. adding a basic silver halide solvent e.g. ammonia, ammoniacal solution, etc. to achieve 0.02 N to 0.2 N of the solvent (e.g. after at least 2% by, weight of total silver nitrate hag been added);, C. stopping silver nitrate addition for 0.5 to 60 minutes, e.g. bromide ion, concentration is in the range of 0.005 to 0.05 N;, D. neutralizing at least some of the basic silver halide solvent …
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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
- Granted April 13, 1993. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended April 13, 2010.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
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Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.