Ag2s membrane for detecting halide ions during the preparation of photographic emulsions
CA 2075897 A1 · Owner: Robert, Philippe G. · Inventors: Robert, Philippe G.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Silver sulphide crystalline membrane for the determination of halide ions and method of production. According to the invention the membrane comprises silver sulphide doped with an ion capable of forming either with Ag+ or X- a salt which presents a much higher degree of insolubility than chemical species in solution. Preferably the membrane also contains a hydrophobic compound which is resistant to reagents. The membrane is prepared by co-precipitating silver sulphide and the doping agent homogenizing with, the hydrophobic compound and then pressing. The membrane may be used in an electrode for the detection of halides during the preparation of photographic emulsions.
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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 February 4, 1991. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended February 4, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 4, 2013.
- 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.