Naphthol as colorants and their use

1. A Naphthol AS colorant according to Formula (A):

or a salt thereof;

wherein R 1 , R 2 , R 3 , R 4 , and R 5 are each independently selected from the group consisting of hydrogen, methyl, ethyl, halogen, methoxy, ethoxy, —CONH-phenyl, and —NO 2 .

2. The Naphthol AS colorant according to claim 1 , wherein R 1 , R 2 , R 3 , R 4 , and R 5 all represent hydrogen.

3. The Naphthol AS colorant according to claim 1 , wherein the Naphthol AS colorant is an ammonium salt.

4. The Naphthol AS colorant according to claim 3 , wherein the ammonium salt is a salt of a substituted ammonium group selected from the group consisting of + N(CH 3 ) 2 (C 18 H 37 ) 2 , + NH(CH 3 ) 2 (C 18 H 37 ), + N(CH 3 ) 2 (C 12 H 25 ) 2 , + NH(CH 3 ) 2 (C 12 H 25 ), + N(CH 3 ) 2 (C 10 H 21 ) 2 , + NH(CH 3 ) 2 (C 10 H 21 ), + N(CH 3 ) 2 (C 8 H 17 ) 2 , + NH(CH 3 ) 2 (C 8 H 17 ), + NH(C 8 H 17 ) 3 , + NH(C 10 H 21 ) 3 , + NH(C 12 H 25 ) 3 , and + NH(C 18 H 35 ) 3 .

5. A non-aqueous pigment dispersion comprising:

a non-aqueous liquid dispersion medium;

a polymeric dispersant;

a Naphthol AS pigment or a mixed crystal thereof; and

a Naphthol AS colorant according to Formula (I):

wherein R 1 , R 2 , R 3 , R 4 , and R 5 are each independently selected from the group consisting of hydrogen, methyl, ethyl, halogen, methoxy, ethoxy, —CONH-phenyl, and —NO 2 ; and

the group Q is a group including two carboxyl groups or salts thereof.

6. The non-aqueous pigment dispersion according to claim 5 , wherein the Naphthol AS colorant is represented by Formula (II):

or a salt thereof;

wherein R 1 , R 2 , R 3 , R 4 , and R 5 have the same meaning as in Formula (I).

7. The non-aqueous pigment dispersion according to claim 5 , wherein the Naphthol AS pigment or mixed crystal thereof includes sulfonamide groups and/or carbonamide groups.

8. The non-aqueous pigment dispersion according to claim 7 , wherein the Naphthol AS pigment or mixed crystal thereof is selected from the group consisting of C. I. Pigment Red 146, C. I. Pigment Red 170, C. I. Pigment Red 184, and C. I. Pigment Red 210.

9. The non-aqueous pigment dispersion according claim 5 , wherein R 1 , R 2 , R 3 , R 4 , and R 5 is hydrogen.

10. The non-aqueous pigment dispersion according claim 5 , wherein the non-aqueous pigment dispersion is radiation curable.

11. The non-aqueous pigment dispersion according claim 5 , wherein the non-aqueous pigment dispersion is an inkjet ink.

12. The non-aqueous pigment dispersion according claim 6 , wherein R 1 , R 2 , R 3 , R 4 , and R 5 is hydrogen.

13. The non-aqueous pigment dispersion according claim 6 , wherein the non-aqueous pigment dispersion is radiation curable.

14. The non-aqueous pigment dispersion according claim 6 , wherein the non-aqueous pigment dispersion is an inkjet ink.