To obtain a modified copolymer useful as a pigment dispersant excellent in pigment dispersing ability and capable of providing e.g. coating materials, inks and plastic coloring agents which are excellent in water resistance, antifriction, etc., to provide a method for producing the modified copolymer, and to obtain a pigment composition using the copolymer.
This modified copolymer is such a copolymer that a copolymer of an aromatic hydrophobic monomer having polymerizable unsaturated double bond and a monomer having a functional group capable of reacting with hydroxyl group and a polymerizable unsaturated double bond, and an oxycarboxylic acid or an intermolecular condensate thereof are bound to each other through the reaction between at least part of the above-mentioned functional groups in the copolymer and the hydroxyl groups in the oxycarboxylic acid or the intermolecular condensate thereof. The second objective method for producing the modifed copolymer comprises reacting a copolymer of an aromatic hydrophobic monomer and a monomer having a functional group capable of reacting with hydroxyl group, with an oxycarboxylic acid or an intermolecular condensate.
SATAKE JUN
URAKI HISATSUGU
IKEGAMI TOMONORI
CHIYOUSOKABE HIROSHI
YOSHIDA MITSUO
