Method for stabilizing organic materials, including dye images, to light

摘要

The stability to light, especially to sunlight, of organic substrates having an absorption maximum between 300 and 800 nm is improved by the use of a metal chelate of one of four general formulae each of which contains the central structure IMAGE wherein M represents an atom of Cu, Co, Ni, Pd or Pt, and the substituents on the N atoms are each hydrogen, alkyl, aryl or hydroxy or together are the non-metallic atoms necessary to complete a 5 or 6-membered ring together with the metal atom; the other substituents can be various organic groups or halogen atoms or can together complete a benzene ring which can be substituted. Examples of synthesis of the complexes are given. The metal chelate compound is mixed with the substrate material, which usually contains a dye, or is put into an adjacent layer thereto in a multilayered colour photographic material or into a mordanting layer of a diffusion-transfer image-receiving element. The dye may be the dye of a color photograph. Details of suitable color couplers are given. 102 specific compounds are shown.