HEAT-STABLE DIKETOPYRROLOPYRROLE PIGMENT MIXTURES

摘要

The present invention relates to a process for the preparation of a mixture comprising at least two structurally different diketopyrrolopyrrole pigments of formula (1) wherein A1 and A2 are each independently of the other an aromatic or heteroaromatic radical, by reacting a succinic acid ester with at least one unsubstituted or substituted aromatic or heteroaromatic nitrile, which process comprises carrying out the reaction in the presence of at least one compound of formula (2) wherein A is an aromatic or heteroaromatic radical, R3 is hydrogen, halogen, methyl, methoxy, -CF3 or -CN, R4 is a linear or, from C3 upwards, optionally branched C1-C30alkyl, C6-C10aryl or C6-C24aralkyl radical, X is -S-, -0-, -CR5R5'-, -COO-, -CONR5-, -SO-, SO2-, -SO2NR5- or -NR5 -and R5 and R5'are each independently of the other hydrogen or a linear or, from C3 upwards, optionally branched C1-C30alkyl, C6-C10aryl or C6-C24aralkyl radical, to the use of such a mixture in the colouring of organic material and in cosmetics, and also to novel diketopyrrolopyrrole pigment mixtures.