PIGMENT DISPERSANT, PRODUCTION METHOD FOR PIGMENT DISPERSANT, AND PIGMENT DISPERSION LIQUID

摘要

The present invention provides : a pigment dispersant that exhibits an effect in a small amount of addition and imparts a high degree of fine dispersibility, stability, and fluidity; a pigment dispersion liquid using the pigment dispersant; and a technology that makes it possible to obtain the pigment dispersant through living radical polymerization: which is environmentally friendly; the process of which is easy; and which is advantageous in terms of cost. The pigment dispersant containing a polymer as a main component, wherein the polymer is a graft copolymer formed through living radical polymerization using two or more monomers containing: a methacrylate A having an acidic group or a basic group; and a methacrylate-based macromonomer B having a methacrylate residue at one terminal of a particular polymer chain having a molecular weight of from 500 to 5000, in a ratio so that the total number of moles of the methacrylate-based monomers in the raw material monomers is from 20 to 50 mol based on 1 mol of a polymerization-initiating compound, the graft copolymer: having a main chain with the A component-derived acidic group or basic group bonded thereto; and the B component-derived polymer chain in a proportion of the polymer chain in the polymer of from 50 to 90 mass% expressed as a mass ratio.