Pigment dispersants, their production process, and their use

摘要

A pigment dispersant contains (a) 5 to 30 wt% of aromatic and/or heterocyclic vinyl monomer units, (b) 10 to 30 wt% of monomer units having acid groups, (c) 40 to 80 wt% of (meth) acrylate ester monomer units, and (d) 5 to 30 wt% of monomer units having poly(C 2-6 -alkylene glycol) chains or mono(C 1-22 -alkyl) ether chains of said glycol, said poly(C 2-6 -alkylene glycol) chains or mono (C 1-22 -alkyl) ether chains having a number average molecular weight of from 150 to 1,500. A sum of the monomer units (a) to (d) amounts to 100 wt%. The pigment dispersant has an acid value of from 30 to 300 mgKOH/g, a number average molecular weight of from 5,000 to 30,000, and a content of organic compounds, boiling points of which are not higher than 250°C, of not higher than 0.2 wt%. Also disclosed are its production process, its aqueous solution and its dispersion.