Pigment composition based on C.I. pigment yellow 191

1. A pigment composition based on P.Y. 191 of formula (1)

comprising 0.05 to 5 mol %, based on the sum total of the P.Y. 191 and a further yellow colorant, wherein the further yellow colorant is of formula (2), of C.I. Pigment Yellow 100, or both

wherein R1, R2, R3 and R4 are each independently hydrogen, halogen, —CH 3 , —NO 2 or NH—R6, wherein R6 is C 1 -C 4 -alkyl;

R5 is methyl or carboxyl,

and the compound of formula (2) is not C.I. Pigment Yellow 191.

2. The pigment composition as claimed in claim 1 , comprising 0.1 to 5 mol % of the further yellow colorant.

3. The pigment composition as claimed in claim 1 , comprising 1 to 5 mol % of the further yellow colorant.

4. The pigment composition as claimed in claim 1 , wherein in the compound of formula (2) R1=R2=Cl, R3=R4=H or Cl and R5=CH 3 .

5. The pigment composition as claimed in claim 1 , wherein the compound of formula (2) is C.I. Pigment Yellow 183.

6. The pigment composition as claimed in claim 1 , obtained by at least one of the following production steps for P.Y. 191 and the further yellow colorant being carried out conjointly:

(a) azo coupling; (b) laking.

7. A process for producing a pigment composition as claimed in claim 1 , comprising the steps of diazotization, azo coupling, laking and optionally finishing, wherein at least one of the following production steps for P.Y. 191 and the further yellow colorant is carried out conjointly: (a) azo coupling; (b) laking.

8. The process as claimed in claim 7 , wherein two different amines of formula (4)

wherein R1 and R2 are each independently hydrogen, halogen, —CH 3 , —NO 2 or

NH—R6 wherein R6 is C 1 -C 4 -alkyl,

are separately diazotized and conjointly coupled onto 1-(3′-sulfophenyl)-3-methyl-5-pyrazolone.

9. The process as claimed in claim 7 , wherein 2-amino-4-chloro-5-methylbenzenesulfonic acid is diazotized and coupled onto a mixture of 1-(3′-sulfophenyl)-3-methyl-5-pyrazolone and a compound of general formula (5)

wherein

R3 and R4 are each independently hydrogen, halogen, —CH 3 , —NO 2 or NH—R6 wherein R6 is C 1 -C 4 -alkyl; and

R5 is methyl or carboxyl.

10. A natural or synthetic material pigmented by a pigment composition as claimed in claim 1 .

11. A composition pigmented by a pigment composition as claimed in claim 1 , wherein the composition is in the form of electrophotographic toners, inkjet inks, metallic varnishes and color filters.

12. The natural or synthetic materials as claimed in claim 10 , wherein the natural or synthetic material is selected from the group consisting of paints, coating systems, wallpaper colors, printing inks, emulsion and varnish colors which are water- and/or solvent-containing, and plastics.