Process for the preparation of high chloride tabular grain emulsions (iii)
CA 2076991 A1 · Owner: Chang, Yun C. · Inventors: Maskasky, Joe E.; Chang, Yun C.; Maskasky, Joe E.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Abstract of the Disclosure, A process of preparing a radiation sensitive high chloride high aspect ratio tabular grain emulsion is disclosed wherein silver ion is introduced into a gelatino-peptizer dispersing medium containing a stoichiometric excess of chloride ions of less than 0.5 molar and a grain growth modifier of the formula: where, Z8 is -C(R8)= or -N=;, R8 is H, NH2 or CH3; and R1 is hydrogen or a hydrocarbon of from 1 to 7 carbon atoms.
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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 August 27, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended August 27, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 27, 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
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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.