Dainichiseika Color And
Patent No. U.S. 7,393,404 B2
Dainichiseika Color and Chemicals Manufacturing Company has been granted a patent for a pigment dispersant comprised of the following component (a) alone or the following components (a) and (b) in combination. Component (a): a composite pigment formed of a diketopyrrolopyrrole pigment having a sulfonic group and another diketopyrrolopyrrole pigment having no sulfonic group, wherein the number of sulfonic group per molecule of the diketopyrrolopyrrole pigments in the composite pigment is from 0.05 to 0.5; and component (b): a pigment other than the component (a), wherein the pigment has a sulfonic group or a metal salt, ammonium salt or amine salt thereof.