Effective Functional Additives for Low- to Zero-VOC Coating Formulations

摘要

Over the past several decades, the mar- ket share for waterborne coatings has increased at the expense of solvent- borne formulations. There were several drivers for this shift, but one of the pri- mary motivations was a conversion to a more environmentally friendly medium in formulations. These waterborne formulations were still typically supplemented with other co-solvents to address some of the issues associated with utilizing water-based dispersions. For example, glycols were included to depress the freezing point of the water to protect the formulation in the event of exposure to freezing conditions, and to slow the evaporation of water during film formation in an effort to provide more robustness in the final application. Volatile coalescents were also used to temporarily depress the glass transition temperature of the higher-molecular-weight polymers in the latex to allow for adequate film formation at lower temperatures while still ultimately yielding a hard, resistant final film.