Polyvinyl alcohol based block copolymer and pigment dispersion aqueous liquid using the same and recording liquid

摘要

A recording liquid capable of giving a printed matter which is high in printing density, is suppressed in blur, has high printing quality, and has good fastness of a recorded matter including light fastness, water fastness and the like and having a low viscosity, good discharge properties and excellent storage stability. The invention is concerned with a polyvinyl alcohol based block copolymer represented by the following general formula (1), a pigment dispersion aqueous liquid containing this polyvinyl alcohol based block copolymer and a pigment in an aqueous medium, and a recording liquid containing this pigment dispersion aqueous liquid. wherein A, B, X¹, X², X³, X⁴, m1, and m2 have the same meanings as defined in the specification.