Abstract: An anionic coloring agent according to the following formula: CA—RSA. CA comprises at least a chromophore and RSA is a spacer-arm with the chemical structure: —X—R-Z. X is a chemical bond, —S(O)n, or —NR1, wherein R1 is hydrogen or a C1-C10 alkyl group; R is a C1-C10 alkylene group; Z is —NR2R3, wherein R2 and R3 are, independently hydrogen or a C1-C10 alkyl group. Alternatively, Z is —NR4—(CH2)m—W, wherein R4 is hydrogen, a hydroxy C1-C10 alkyl group, or C1-C10 alkyl group; m is an integer from 1 to 10; and W is —COOR5, wherein R5 is hydrogen, a C1-C10 alkyl group; or —CONR6R7. R6 and R7 are, independently, a hydrogen atom, a C1-C10 alkyl group, —SO3H; —S—SO3H; —CN: or SO3R8 wherein, R8 is hydrogen, a C1-C10 alkyl group, or —S—SO3R9 group, wherein, R9 is hydrogen atom, or a C1-C10 alkyl group; provided that when X is —NR1, and Z is —NR2R3, then R1, R2 and R3 cannot be simultaneously a hydrogen atom.

Abstract: Anionic coloring agents comprising at least one spacer-arm bounded to their chemical structure, wherein said anionic coloring agents have the following formula: CA—RSA, wherein, CA is an anionic coloring agent comprising at least a chromophore group selected from the group consisting of azo, anthraquinone, formazane, dioxazine, phthalocyanine and/or sulphur; and RSA is said spacer-arm, which has the following chemical structure: —X—R-Z, wherein, X is a chemical bond or a group having the formula —S(O)n, wherein n is 1 or 2; or a —NR1— group, wherein R1 is a hydrogen atom or a linear or branched C1-C10 alkyl group; R is a linear or branched C1-C10 alkylene group; Z is a —NR2R3, —S—SO3R4, or —SO3R5 group, wherein, R2, R3, R4 and R5 are, independently, a hydrogen atom or a linear or branched C1-C10 alkyl group; or, Z is a —NR6—(CH2)m—W group, wherein, R6 a hydrogen atom, a linear or branched hydroxy C1-C10 alkyl group, or a linear or branched C1-C10 alkyl group; m is an integer from 1 to 10; and W is a —COOR7, —

Abstract: Anionic coloring agents comprising at least one spacer arm bounded to their chemical structure. These anionic coloring agents have the following general formula: CA-BE, wherein, CA is an anionic coloring agent comprising at least a cromophore group; and BE is the spacer arm, which has the following chemical structure: —(X—R—Z)r, wherein X is a direct link or a group having the formula —S(O)s, wherein s is 0, 1 or 2; or —NR1—, wherein, R1 is hydrogen or a C1-C10 alkyl group; R is a C1-C10 straight or branched alkylene group: Z is a polar group; and r is an integer equal or higher than 1.