This invention relates to azo pigments of general formula (I) wherein D represents the radical of a diazo component; R 1 and R 2 are the same or different and represent hydrogen, a C 1 -C 4 alkyl radical which is optionally substituted by hydroxy, amino, halogen or methoxy, or a (C 6 -C 10 ) aryl radical which is optionally substituted by one, two or three substituents from the group C 1 -C 4 alkyl, C 1 -C 4 alkoxy, F, Cl, Br, CF 3 , NO 2 , OH, CONH 2 , CONH(C 1 -C 4 alkyl), CON(C 1 -C 4 alkyl) 2 , COO(C 1 -C 4 alkyl), SO 2 NH 2 , SO 2 NH(C 1 -C 4 alkyl) and SO 2 N(C 1 -C 4 alkyl) 2 , provided that R 1 and R 2 do not simultaneously represent hydrogen; R 4 represents hydrogen, C 1 -C 4 alkyl, halogen, trifluoromethyl, C 1 -C 4 alkoxy, NO 2 , or CN; and n represents 1, 2 or 3
1. An azo pigment of the formula (I),
in which D is the radical of a diazo component,
R 1 and R 2 are identical or different and are hydrogen, C 1 -C 4 -alkyl radical, or a (C 6 -C 10 )-aryl radical which is unsubstituted or substituted by 1, 2 or 3 substituents selected from the group consisting of C 1 -C 4 -alkyl, C 1 -C 4 -alkoxy, F, Cl, Br, CF 3 , NO 2 , OH, CONH 2 , CONH(C 1 -C 4 -alkyl), CON(C 1 -C 4 -alkyl) 2 , COO(C 1 -C 4 -alkyl), SO 2 NH 2 , SO 2 NH(C 1 -C 4 -alkyl) and SO 2 N(C 1 -C 4 -alkyl) 2 ,
with the proviso that R 1 and R 2 are not simultaneously hydrogen:
R 3 is hydrogen, C 1 -C 4 -alkyl, halo, trifluoromethyl, C 1 -C 4 -alkoxy, NO 2 , or CN, and
n is 1, 2 or 3.
2. An azo pigment as claimed in claim 1 , wherein R 1 and R 2 are hydrogen, methyl, ethyl or phenyl.
3. An azo pigment as claimed in claim 1 , wherein R 1 is methyl or ethyl and R 2 is hydrogen.
4. An azo pigment as claimed in claim 1 , wherein R 3 is hydrogen, methyl, ethyl, methoxy, ethoxy, F, Cl, CF 3 or nitro.
5. An azo pigment as claimed in claim 1 , wherein D is a (C 6 -C 12 )-aryl radical substituted by 1, 2 or 3 substituents selected from the group consisting of C 1 -C 4 -alkyl, C 1 -C 4 -alkoxy, phenyl, chlorophenyl, dichlorophenyl, F, Cl, Br, CF 3 , NO 2 , NH 2 , COOH, OH, CONH 2 , CONH(C 1 -C 4 -alkyl), CON(C 1 -C 4 -alkyl) 2 , COO(C 1 -C 4 -alkyl), SO 2 NH 2 , SO 2 NH(C 1 -C 4 -alkyl), and SO 2 N(C 1 -C 4 -alkyl) 2 and a (C 6 -C 10 )-aryl radical, to which a five- or six-membered heterocyclic ring having 1, 2 or 3 heteroatoms selected from the group consisting of N, O and S is fused.
6. An azo pigment as claimed in claim 1 , wherein the C 1 -C 4 -alkyl radical is hydroxy, amino, halogen or methoxy substituted.
7. A process for preparing an azo pigment as claimed in claim 1 , comprising the steps of diazotizing an amine of formula D-NH 2 and coupling the product with a compound of the formula (II)
8. A composition comprising an azo pigment as claimed in claim 1 , wherein the composition is selected from the group consisting of varnishes, plastics, printing inks, electrophotographic toners, electrophotographic developers, powder coating materials, graphics inks, ink-jet inks, aqueous and nonaqueous pigment preparations, and color filters.
9. A colored seed comprising an azo pigment as claimed in claim 1 .
10. A compound of the formula (II)
in which
R 1 and R 2 are identical or different and are hydrogen, C 1 -C 4 -alkyl radical, or a (C 6 -C 10 )-aryl radical which is unsubstituted or substituted by 1, 2 or 3 substituents selected from the group consisting of C 1 -C 4 -alkyl, C 1 -C 4 -alkoxy, F, Cl, Br, CF 3 , NO 2 , OH, CONH 2 , CONH(C 1 -C 4 -alkyl), CON(C 1 -C 4 -alkyl) 2 , COO(C 1 -C 4 -alkyl), SO 2 NH 2 , SO 2 NH(C 1 -C 4 -alkyl) and SO 2 N(C 1 -C 4 -alkyl) 2 ,
with the proviso that R 1 and R 2 are not simultaneously hydrogen;
R 3 is hydrogen, C 1 -C 4 -alkyl, halo, trifluoromethyl, C 1 -C 4 -alkoxy, NO 2 , or CN, and
n is 1, 2 or 3.
11. The compound as claim in claim 10 , wherein the C 1 -C 4 -alkyl radical is hydroxy, amino, halogen or methoxy substituted.