| abstract |
This invention relates to a process for preparing perylene pigment compositions by reaction of (a) a perylene tetracarboxylic compound; (b) about 0.01 to about 20% by weight, relative to the perylene tetracarboxylic compound, of a non-pigmentary cyclic anhydride or imide of formula (I) wherein W is O or NR1 (where R1 is hydrogen, a metal, or optionally substituted alkyl, cycloalkyl, aralkyl, or aryl), R2, R3, and R4 are various combinations of substituents and/or fused-on rings, and the dotted line is an optional double bond representing R2-C=C-R3; (c) ammonia or a primary alkyl, aralkyl, or aryl amine; optionally in the presence of (d) a solvent and/or (e) one or more dispersants. |