Effect of Urea-Formaldehyde (UF) with Waterborne Emulsion Microcapsules on Properties of Waterborne Acrylic Coatings Based on Coating Process for American Lime

Abstract

The purpose of this paper is to explore the effect of urea-formaldehyde (UF) with waterborne emulsion microcapsules on the optical, mechanical and aging resistance properties of waterborne coatings from the perspective of coating process. In this paper, the microcapsules were prepared with UF resin as the wall materials and waterborne emulsion as the core materials. Based on the coating process, the optical, mechanical and aging resistance properties of the waterborne acrylic coatings with microcapsules for American lime were tested. The good coating process is three layers of primer, two layers of topcoat, and adding microcapsules into primer. The results showed that the coating process had little effect on the color difference of the paint film with microcapsules, the gloss of the paint film prepared by the good coating process was basically not changed, and the mechanical properties of the paint film were good. At this time, the hardness grade of the paint film was 3H, the adhesion was grade 0, the impact resistance was 110.0 N·cm−2, and the elongation at break was 29.7%. The microcapsules added to the primer had better liquid resistance than those added to the topcoat. The paint film had good stability and aging resistance, and could inhibit the generation of microcracks to a certain extent. The paint film prepared by the good coating process had better comprehensive performance. This work provides a technical reference for self-healing of the waterborne coatings on American lime.