Лако-красочные материалы — производство

This group of pigments has improved fastness to heat, solvents and light compared to monoazo pigments due to molecular enlargement. They are produced by the coupling of substituted aromatic diami­nes as diazonium salts with acetoacetic arylides or pyrazolones as coupling components to give diarylide yellows and pyrazolone oran­ges, respectively. In another approach, diazotized aromatic amines are coupled with bisacetoacetic arylides. A range of light fastness properties are obtained, from poor to good, depending upon sub­stitution on the aromatic diamine and coupling compounds. Some important diarylide yellow pigments include Pigment Yellow 12, 13, 14, 15, 55, 63, 83, 106, 126 and 174 while important pyrazolone oranges and reds are Pigment Orange 13 and 34 and Pigment Red 38. Examples are shown in Figure 3.10.