Process for preparing a photographic emulsion containing tabular grains exhibiting high speed
CA 1316035 C · Owner: E.I. Du Pont De Nemours And Company · Inventors: Ellis, Charles Daniel
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, exhibit high speed upon sensitization having a thickness of about 0.05 to 0.5 µm, average grain volume of about 0.05 to 1.0 µm3 and mean aspect ratio of greater than 2:1 comprising, A. adding silver nitrate to a vessel containing dispersing medium/bromide, mixture initial bromide ion, concentration 0.08 to 0.25 N to form, tabular seed grains;, B. adding an ammoniacal base solution to, achieve 0.002 to 0.2 normal of the base (e.g. after at least 2% of total silver nitrate has been added); and, C. adding additional silver nitrate and halide, i.e. Br- or BrI- by, balanced double jet procedure. The …
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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.
Timeline
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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.