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Expired Canadian patentCanada

Photothermographic stabilizers for syringaldazine leuco dyes

CA 1264977 C · Owner: Minnesota Mining And Manufacturing Company · Inventors: Weigel, David C.; Ishida, Takuzo

CIPO record

Overview

Drawings and full text

Its claims, description and drawings are in the Canadian Patents Database.

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Abstract From the Canadian patent

Certain effective leuco dyes for silver halide/silver salt/reducing agent photothermographic color imaging materials tend to bleach in the final image. The presently disclosed system of a syringaldazine and a stabilizing binder resin is more stable.

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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 January 30, 1990. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended January 30, 2007.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledDecember 31, 1985
GrantedJanuary 30, 1990
Term endedJanuary 30, 2007
Patent numberCA 1264977 C
Classification (IPC)G03C5/39 +1 more

Timeline

Timeline From CIPO dates

19861989199219951998200120042007Application filedDec 31, 1985Patent grantedJan 30, 1990Term endedJan 30, 2007

Sources & verification

Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.