Patent Yard Sign in
Expired Canadian patentCanada

Hydrophilic colloid layer of a photographic element containing an activator precursor and polymer particles loaded with a hydrophobic developer

CA 1098754 A · Owner: Eastman Kodak Company · Inventors: Chen, Tsang J.; Mclaen, Donald F.

CIPO record

Overview

Drawings and full text

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

Open the CIPO record

Abstract From the Canadian patent

A photographic element is disclosed having coated on a support a hydrophilic colloid layer containing an activator precursor and loaded polymer particles of from 0.02 to 0.2 micron in average diameter. The polymer particles consist essentially of a hydrophobic polymer of which at least 2 percent by weight is comprised of ionizable repeating units, at least half being cationically ionizable and a hydrophobic developing agent present in a weight ratio to the polymer of from about 1:4 to 3:1. Silver halide is present in the hydrophilic colloid layer or in an adjacent layer, and the activator precursor is present in a concentration of from 1 to 4 equivalent for each mole of silver halide. The …

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 7, 1981. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended April 7, 1998.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledNovember 2, 1977
GrantedApril 7, 1981
Term endedApril 7, 1998
Patent numberCA 1098754 A
Classification (IPC)G03C1/72 +2 more

Timeline

Timeline From CIPO dates

1978198119841987199019931996Application filedNov 2, 1977Patent grantedApril 7, 1981Term endedApril 7, 1998

Sources & verification

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