Abstract: Described is a process for making acrylic resins suitable as polymeric surfactants used in emulsion polymerization, as pigment grinding resins and for preparing dispersions used as overprint varnishes. The feedstock is styrene, .alpha.-methyl styrene, acrylic acid and a polymerization initiator and is preferably free of solvent. This mix is passed through a continuous tube reactor run at a controlled range of pressure and relatively low residence time and temperature. Optimally, when the polymer/unreacted monomers blend exits the reactor and is devolatilized, the recovered monomers are used to make up part of the feedstock.

Abstract: A method of preparing a pigment dispersion useful in the preparation of printing inks is provided. Said method comprises dispersing a pigment in an aqueous medium further comprised of a dispersing binder resin composition, said aqueous medium being essentially free of volatile organic solvents and said dispersing binder resin consisting essentially of the reaction product of a mixture of X equivalent percent of an acid component and Z equivalent percent of an amine component wherein the acid component is comprised of an aromatic dicarboxylic acid alone or in a mixture with an aliphatic dicarboxylic acid having from 2-25 carbon atoms, and said amine component is comprised of a mixture of a diamine and monoalkanol amine and the ratio of Z:X is less than 1 to provide a polyamide having an acid value greater than about 35. This invention also relates to printing inks comprising the pigment dispersion composition of this invention and a method of preparation thereof.