Pigment dispersion and offset printing ink composition using the same

摘要

A pigment dispersion is disclosed which comprises a pigment, a pigment dispersant, and optionally a binder resin, wherein the pigment dispersion comprises as the pigment dispersion at least 0.2 parts by weight of a modified novolak resin (A) and/or a graft copolymer (B) relative to 100 parts by weight of the pigment, the modified novolak resin (A) and the graft copolymer (B) each having an aromatic ring and a ring structure given by ring opening of an epoxy group by a carboxyl group of a hydroxycarboxylic acid or a derivative thereof. An ink composition for offset printing containing the pigment dispersion is also disclosed.