VERFAHREN ZUR HERSTELLUNG VON PERYLEN-3,4,9,10-TETRA-CARBONSAEURE-N,N'-DIMETHYLIMID IN HOCHDECKENDER PIGMENTFORM.

摘要

Prepn. of perylene-3,4,9,10-tetracarboxylic acid N,N'-dimethylimide (I) in the form of a pigment with high covering power and pure red shades comprises treating conventionally prepd. pre-pigmentary (I) at 0-100 deg.C in a liq. organic solvent in a mill or disperser. The pre-pigment is finely-divided and dry with crystallite size below 40nm, and the solvent is a satd. aliphatic brominated or chlorinated hydrocarbon or an aromatic hydrocarbon (opt. brominated or chlorinated). The solvent is then distilled out and pigment-grade (I) recovered.