High contrast photographic materials
CA 1328761 C · Owner: Hall, Kevin Peter · Inventors: Hall, Kevin Peter
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Pepper fog may be reduced in high contrast photographic materials comprising silver halide emulsion in association with a hydrazine by the presence of at least 0.001 mole per mole of silver halide of a water-soluble bromide and/or water-soluble chloride. Suitable water-soluble bromides and chlorides are alkali metal bromides and chlorides which are advantageously added to the silver halide emulsion after physical ripening and washing.
Read the whole patent
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 26, 1994. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended April 26, 2011.
- 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.