Easily dispersible pigment preparation based on C.I. pigment yellow 155

1. A solid pigment preparation comprising

A) 5% to 99% by weight of an azo pigment of formula (1)

(B) 1% to 95% by weight of a copolymer containing the following structural units:

(i) 1 to 70 mol % of structural unit B1

(ii) 1 to 70 mol % of structural unit B2

(iii) 1 to 70 mol % of structural unit B3

wherein

R 1 , R 3 and R 5 are each independently hydrogen or C 1 -C 4 -alkyl,

R 2 is C 1 -C 60 -alkyl, C 6 -C 18 -aryl, C 1 -C 4 -alkylene-C 6 -C 12 -aryl or C 3 -C 18 -hetaryl,

R 4 is linear or branched C 1 -C 40 -alkyl, C 6 -C 30 -cycloalkyl, C 1 -C 4 -alkylene-C 6 -C 12 -aryl or C 6 -C 30 -aryl,

R 6 is —COO—(CH 2 ) p —,

p is between 1 and 8,

R 7 , R 8 and R 9 are each independently hydrogen, linear or branched C 1 -C 40 -alkyl, C 5 -C 30 -cycloalkyl, C 6 -C 30 -aryl or benzyl, and

n is between zero and 1.

2. The pigment preparation as claimed in claim 1 , containing

(A) 40% to 95% by weight of an azo pigment of formula (1), and

(B) 5% to 60% by weight of the copolymer.

3. The pigment preparation as claimed in claim 1 , wherein the copolymer (B) contains

(i) 5 to 60 mol % of structural unit B1,

(ii) 5 to 60 mol % of structural unit B2, and

(iii) 5 to 60 mol % of structural unit B3.

4. The pigment preparation as claimed in claim 1 , wherein the copolymer (B) consists of

(i) structural unit B1 to an extent from 1 to 70 mol %,

(ii) structural unit B2 to an extent from 1 to 70 mol %, and

(iii) structural unit B3 to an extent from 1 to 70 mol %.

5. The pigment preparation as claimed in claim 1 , wherein the copolymer (B) consists of

(i) structural unit B1 to an extent from 5 to 60 mol %,

(ii) structural unit B2 to an extent from 5 to 60 mol %, and

(iii) structural unit B3 to an extent from 5 to 60 mol %.

6. The pigment preparation as claimed in claim 1 , R 1 , R 3 and R 5 are the same or different and are each hydrogen or methyl.

7. The pigment preparation as claimed in claim 1 , wherein R 2 is C 6 -C 30 -alkyl, C 8 -C 10 -aryl, benzyl or five- or six-membered aromatic nitrogen-containing C 3 -C 9 -heterocycles.

8. The pigment preparation as claimed in claim 1 , wherein R 4 is C 1 -C 20 -alkyl, C 5 -C 6 -cycloalkyl, benzyl, phenyl or naphthyl.

9. The pigment preparation as claimed in claim 1 , wherein R 7 , R 8 and R 9 are the same or different and are each hydrogen, C 1 -C 8 -alkyl, C 5 -C 6 -cycloalkyl, phenyl or benzyl.

10. The pigment preparation as claimed in claim 1 , wherein the pigment of formula (1) has a particle size (d 50 ) of 30 to 500 nm.

11. The pigment preparation as claimed in claim 1 containing at least one auxiliary selected from the group of fillers, flame retardants, preservatives, photoprotectants, pigmentary and nonpigmentary dispersants, surfactants, antioxidants, resins, waxes, defoamers, antistats and charge control agents.

12. A process for producing a pigment preparation as claimed in claim 1 , comprising the steps of mixing the pigment of formula (1) as a powder, granulate, presscake or suspension with at least one copolymer (B) in the presence of water or of an organic solvent or of a mixture of water and organic solvent and isolating the resultant solid form.

13. A pigmented natural or synthetic material pigmented with a pigment formulation as claimed in claim 1 .

14. A pigmented article pigmented with a pigment preparation as claimed in claim 1 , wherein the pigmented article is selected from the group consisting of wallpaper colors, printing inks, emulsion and gloss colors, electrophotographic toners, electrophotographic developers, ink-jet inks, and color filters.

15. An electrophotographic toner containing 30% to 99.99% by weight of a binder, 0.001% to 50% by weight of the pigment preparation as claimed in claim 1 , optionally 0.001% to 50% by weight of a further colorant, optionally 0.01% to 50% by weight of a wax and optionally 0.01% to 50% by weight of a charge control agent, all based on the total weight of the electrophotographic toner.