Abstract:
The invention is directed essentially to photographic material containing, on a carrier, a layer with azo dyestuffs of the formula ##STR1## wherein A, B, X and Y are certain substituents, in a second main aspect azo dyestuffs of the formula ##STR2## wherein B' represents certain substituents and in a third main aspect azo deystuffs of the formulaA.sub.1 --N.dbd.N--B.sub.1 --NH--CO--X.sub.1 --Y--Z.sub.1 --OC--HN--B.sub.1 --N.dbd.N--A.sub.1wherein A.sub.1, B.sub.1, X.sub.1, Z.sub.1 and Y are certain substituents.The photographic materials provide advantages stemming from the use of the dyestuffs of the invention which are distinguished by particularly high fastness to light coupled with excellent bleachability, good resistance to diffusion and advantageous color strength.
Abstract:
The present invention relates to a novel process for the preparation of aminodiarylazo compounds by reducing nitrodiarylazo compounds using 1,2-alkanediols or 1,2-aminoalkanols.
Abstract:
Para-coupled products of the 1-naphthol series can be destroyed in the presence of the ortho-coupled product by reduction with salts of dithionous acid or of hydroxymethanesulphinic acid or with hydrazine optionally in the presence of redox-catalysts.