WL-T8000 is mainly suitable for dispersing of organic pigment, especially carbon black in UV inks. Especial designed anchor group and expansion chain make pigments surface wetted immediately and WL-T8000 adsorbed in pigment surface strongly. It can surprisingly decrease viscosity of dispersions. Milling time will be significantly shorted. Dispersions thus obtained have higher pigment content, improved color strength, better gloss, more excellent anti-flocculation ability and dispersing stability than conventional manner. Because of color strength of dispersions has been increased more than 20% (carbon black dispersion can be increased more than 70%), energy consumption needed for milling has been reduced more than 30%, and production efficiency has been doubly increased, manufacturing cost of inks and paints will be reduced. The forming-film of inks or paints will be more lubricous, glossy and clear.