| abstract |
Monoazomethine pigments of formula (in which R is an opt. substd. aliphatic, aromatic or heterocyclic gp.f M is a divalent metal atom; Z is a gp. capable of forming a metal complex; each X is a COOH gp., or together form a gp. of formula -CO-O-CO-, -CO-N-CO- or R1 is hydrogen, an opt. substd. amino gp., an opt. etherified hydroxy gp. or an opt. substd. (cyclo)alipathic, aromatic or heterocyclic gp.; A is an ortho- or periarylene or heterocyclic gp.) are used for colouring aq. or oil paints, plastics, rubber, printing inks, paper, etc. They give excellent fastness to migration, light, weather and solvents (esp. the metal complexes). Excellent heat resistance, high colour strength, good transparency, and often surprisingly pure shades. |