Abstract: There is provided an aqueous pigment dispersion that makes it possible to prepare an environmentally conscious aqueous inkjet ink in which a pigment is finely dispersed in a stable manner and at a high level and which is capable of recording an image having excellent durability, glossiness, color developability, and adhesiveness to various printing substrates. The aqueous pigment dispersion is an aqueous pigment dispersion containing a pigment, water, a water-soluble organic solvent, and a polymeric dispersant that disperses the pigment, wherein the polymeric dispersant is a polymer including a constitutional unit (i) derived from at least one of (meth)acrylic acid and itaconic acid, and a constituent unit (ii) derived from a (meth)acrylate derived from biological material, such as ethyl (meth)acrylate, having an acid value of 30 to 250 mgKOH/g, having a number average molecular weight of 1,000 to 30,000, and having a polydispersity index (weight average molecular weight/number average molecular weight) of 2.

Abstract: The present invention provides an A-B block copolymer that enables preparation of a polymer emulsion useful as a binder component for an aqueous inkjet ink that is excellent in inkjet printability and is capable of forming a printed film excellent in durability, such as adhesiveness and rub resistance, on a substrate to be printed, such as a polyolefin-based plastic film. The block copolymer is an A-B block copolymer satisfying the following requirements (1-1) to (1-3). (1-1) Containing 90% by mass or more of a constituent unit derived from a methacrylate-based monomer or the like. (1-2) The chain A has a constituent unit (A-i) derived from methyl methacrylate or the like and a constituent unit (A-ii) derived from 2-ethylhexyl methacrylate or the like. (1-3) The chain B has a constituent unit (B) derived from methacrylic acid, a constituent unit (B-i) derived from methyl methacrylate or the like, and a constituent unit (B-ii) derived from 2-ethylhexyl methacrylate or the like.