Azo dye images prodn. by alkali-induced coupling - using (silver) image catalysing liberation of base from transition metal complex

摘要

In the prodn. of azo dye images by alkali-induced coupling between a diazonium cpd. (I) and a coupler (II) yielding an azo dye, a cpd. or element (III), which catalyses decompsn. of a transition metal complex (IV), with liberation of a base, and is distributed in the form of an image, opt. on a substrate, is contacted with a (pref. hydrophobic) layer contg. (I) on a substrate in the presence of (IIe and an aq. soln. of (IV). Pref. (III) is Ag, Au, Pd, Ag2S, NiS, CuS, CoS or C and (IV) is a complex of Co, Ti, Ni, V, Cr, Mn, Rh, Pd, Ir or Pt, esp. a Co complex which liberates NH3. After contact with (III), the layer contg. (I) is exposed to activating radiation to destroy uncoupled (I). The speed of the material is comparable with that of photographic Ag halide systems, whilst the costs and stability of the image correspond to those of the usual diazo systems.