13.2 Maximizing the Performance of Low-VOC Acrylic Metal Coatings
(Room 243-245)
11 Apr 18
10:00 AM
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10:30 AM
Tracks:
Session 13: Direct-to-Metal-Coatings, Session 13: Protective Coatings
As 1K direct to metal (DTM) coatings have transitioned into waterborne acrylic formulations to lower volatile organic content (VOC), certain sacrifices in performance, particularly corrosion resistance, had to be made. The features that make acrylics colloidally stable in water, e.g. acidic functional groups and/or surfactants, can work against their ability to deliver suitable corrosion resistance. Additionally, formulation additives designed for waterborne systems such as dispersants and wetting agents often further increase the overall hydrophilicity of the coating. Every polymer responds differently to selected additive packages so any resin designed for metal protection must be combined with an optimized formulation to maximize performance. To address the performance gaps of legacy waterborne acrylics, a novel polymer capable of <50g/L VOC formulations has been developed with exceptional corrosion resistance at film builds as low as 1mil dry film thickness (DFT). Formulation variables such as dispersants, wetting agents, and pigments were also systematically evaluated. The performance of low VOC DTM systems and the impact of formulation choices will be discussed with both empirical and structure/property descriptions.