Process for producing silver halide photographic materials
CA 2039759 A1 · Owner: Arai, Takeo · Inventors: Arai, Takeo; Kato, Mariko; Nagashima, Toshiharu
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An improved process for producing a silver halide photographic material that has at least one light-sensitive silver halide emulsion layer on a support as well as at least one hydrophilic colloidal layer coated on both sides of the support. The process is characterized in that the hydrophilic colloidal layers on the two sides of the support are dried simultaneously and that a matting agent having a particle size of at least 4 um is incorporated in the outermost layer on both sides of the support in an amount of at least 4 mg/m2.
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
- Filed April 4, 1991. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended April 4, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 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.