Applications to Prevent Special Kinds of Fog

  • Gunther Fischer
Part of the Topics In Applied Chemistry book series (TAPP)

Abstract

Yellow fog (dichroic fog) is caused by special conditions of emulsion making and processing [R-1, p. 126ff.] that favor physical development; it was a special problem of earlier black-and-white photography [R-27b]. Patents [cf. R-35; R-36] center on heterocyclic compounds (Chart 14.1):
  • BT [P-1460], also combined with thiosulfonates (e.g., 202c )[P-1461],

  • heterocyclic thiols (e.g., MBT) [P-1462], in a special case PMT derivatives (e.g., 32c) in the final bath after low-replenishment development [P-1463],

  • bis-triazolium salts (e.g., 629) [P-1464] or mesoionic nitron (57) [P-1465],

  • masked NBI (e.g., 294) on paper support with baryta coating [P-1466], and

  • DIR hydroquinones (e.g., 415) with Lippmann emulsions [P-872].

Keywords

Phenol Iodide Disulfide Thiol Porphyrin 

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Copyright information

© Springer Science+Business Media New York 2004

Authors and Affiliations

  • Gunther Fischer
    • 1
  1. 1.LeipzigGermany

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