Patent ID: 8679341
Filing Date: 2014-03-25
Classification: B01D,C09B

Abstract:
1. A method of concentrating nanoparticles, comprising the steps of: preparing a nanoparticle-dispersion liquid comprising pigment nanoparticles having an average diameter of 5 nm to 200 nm dispersed in an aqueous solvent, the organic pigment nanoparticles being made of quinacridone-compound pigment an azo-series pigment, a diketopyrrolopyrrole-series pigment, and mixtures thereof; adding and mixing an ester compound solvent with the nanoparticle-dispersion liquid so as to form a liquid of concentrated extract by concentrating and drawing the organic pigment nanoparticles from a phase of the aqueous solvent into a phase of the ester compound solvent, and removing the ester compound solvent by filter-filtrating the liquid of concentrated extract; wherein the ester compound solvent is substantially incompatible with the aqueous solvent, and wherein the ester compound solvent can form an interface after the ester compound solvent is mixed with the aqueous solvent and the mixture is left still.