| abstract |
An organic pigment dispersion in a non-aqueous medium is prepared directly from an aqueous slurry containing 0.1-20% by weight of the pigment by mixing the aqueous slurry with the non-aqueous medium under vigorous agitation and subsequently isolating the organic pigment dispersion from the residual aqueous phase.A substantial part of water in the resulting pigment dispersion can be removed by passing the organic pigment dispersion in the non-aqueous medium over a series of surfaces, the surface material thereof having different affinity for water and the non-aqueous medium, respectively, and then removing water and pigment dispersion in the non-aqueous medium, respectively, from respective surfaces. |