Water Whitening Reduction in Waterborne Pressure‐Sensitive Adhesives Produced with Polymerizable Surfactants

Abstract

Water whitening resistance of pressure‐sensitive adhesives obtained from high solids content acrylic dispersions is studied. The effect of the pH and surfactant system on the water whitening of the final films is investigated. The pH used throughout the polymerization process and the pH at which the final latex is adjusted just before the application have a substantial influence on the water whitening resistance. The performance of films obtained from latexes stabilized using conventional surfactant is compared to that of latexes stabilized using polymerizable surfactant or polymerizable stabilizer. In the films containing the conventional anionic surfactant, the water whitening phenomenon is affected by two counteracting mechanisms: latex stability and excess of surfactant in the aqueous phase. However, when polymerizable surfactants or stabilizer are used, due to their incorporation into the polymer backbone, no effect of the surfactant excess is observed leading to films with superior performance increasing their concentration.