| 摘要 |
PURPOSE: A process for preparing transparent perylimide pigments of formula(I) having advantageous coloristic and rheological properties are provided to prepare in a simple and environmentally friendly way from crude perylimide pigments by means of a special beadmilling operation with high energy density. CONSTITUTION: The process for preparing transparent perylimide pigments of the formula(I), in which u is a number from 0 to 8 and, if u>0, E is a chlorine or bromine atom and, where u>1, may be a combination thereof, comprises wet-grinding a crude perylimide pigment in a liquid medium in a stirred ball-mill operated at a power density of from 1.0 kW per liter of milling space and at a stirrer tip speed of more than 12 m/s under the action of grinding media having a diameter of less than or equal to 0.9 mm, and isolating the resulting pigment.
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