12.18.06
Patent No. U.S. 7,074,267 B2 Ciba Specialty Chemicals has received a patent for a pigment composition comprised of an organic pigment selected from the group consisting of monoazo, disazo, naphthol, dioxazone, azomethin, azocondensation, metal complex, nitro, perinone, quinoline, anthraquinone, benzimidozolone, isoindoline, isoindolinone, quinacridone, hydroxyanthraquinone, aminoanthraquinone, anthrapyrimidine, indanthrone, flavanthrone, pyranthrone, anthantrone, isoviolanthrone, diketopyrrolopyrrole, carbazole, indigo and thioindigo pigments; and a combination of at least one anionic and at least one cationic colored compound wherein the combination is comprised at least one anionic and at least one cationic dye, each of a chemical structure differing from that of the organic pigment, at least one anionic and at least one cationic pigment derivative, the chemical structure of at least one of which is not derived from the organic pigment, or mixtures of the three.