| abstract |
This invention relates to a process for preparing perylene pigment compositions by(a) reacting, at a temperature of less than about 25° C., a mixture of(1) a perylene tetracarboxylic compound,(2) at least about 0.1% by weight, relative to the perylene tetracarboxylic compound, of a surfactant of formula (I) wherein R1, R2, R3, X, Y, Z, and Z' are defined herein,(3) an equivalent excess, relative to the amount of the perylene tetracarboxylic compound, of ammonia or a primary amine RA-NH2, wherein RA is defined herein, and(4) optionally, a solvent, to form a perylene intermediate;(b) heating the perylene intermediate at a temperature of about 50° C. to about 250° C., optionally in the presence of certain non-pigmentary cyclic anhydrides or imides and/or solvents; and(c) collecting the perylene pigment composition. |