A method for the production of transparent pigment preparations based on perylene - 3,4,9,10 - tetra carboxylic acid diimide

摘要

The present invention relates to a process for the production of transparent perylimide - pigment preparations based on perylene - 3,4,9,10 - tetracarboximides of the formula (xxx) whereinu is a number from 0 to 8, and when u 0 is,E, a chlorine - or bromine atom and, if u 1, and, if applicable, a combination thereof, characterized in that a perylimide - crude pigment of formula (xxx) in a liquid, aqueous medium, in the presence of at least one pigment dispersant from the group consisting of the perylene dispersants and the derived from p.v.23 dispersants, in a stirred ball mill, the with a power density of not more than 1,0 kw per liter is operated, under the action of grinding media from the diameter of less than or equal to 5 mm and at a temperature of at least 50°C. and the resulting pigment preparation in a wet grinding isolated.