METHOD FOR PRODUCING THE PIGMENT RED 149

摘要

The invention relates to a method for producing N,N'-di(3',5'-dimethylphenyl)perylene bis-dicarboximide by reaction of perylene-3,4,9,10-tetracarboxylic acid dianhydride with 3,5-dimethylaniline in the presence of a secondary or tertiary amine as catalyst, characterised in that the reaction is carried out in an aqueous reaction medium and in the presence of added seed crystals of N,N'-di(3',5'-dimethylphenyl)perylene bis-dicarboximide.