Pigment Dispersion in a Water Based Paint Using Amphoteric Acrylic Resins

Abstract

Pigment dispersion in acid-neutralized water soluble acrylic resins which have both acidic and basic functional groups was studied. The dispersibility was evaluated by the gloss and the yield value of the pastes.As for the dispersion of a positively charged pigment, an excellent dispersibility of the pigment was obtained by the resin adsorption through electrostatic interaction between positive charge of the pigment and negative charge of the resins when the acid strength of the resin was higher than that of the neutralizing acid.On the other hand, when the acid strength of the neutralizing acid was higher or a negatively charged pigment was used, no effect on the introduction of the acidic functional group to the resins was observed.