US Patent 7824488 Pigment composition based on C.I. pigment yellow 191

The invention relates to a pigment composition based on P.Y. 191 of the formula (1) containing 0.05 to 30 mol %, based on the sum of P.Y. 191 and a further yellow colorant, of at least one further yellow colorant of the formula (2) and/or of C.I. Pigment Yellow 100 in which R1, R2, R3 and R4 are each independently hydrogen, halogen, —CH3, —NO2, or NH—R6 where R6 is C1-C4-alkyl; R5 is methyl or carboxyl, and where the compound of the formula (2) is not C.I. Pigment Yellow 191.