Waterborne two-component polyurethane (PU) coatings are increasingly replacing solventborne systems. And for good reason: They are environment-friendly and satisfy statutory VOC guidelines intended to limit the emission of volatile organic compounds. Thanks to a new polyacrylate dispersion from Bayer MaterialScience, waterborne coatings can now begin replacing their established solvent-borne counterparts in one of the few domains in which they still dominate: Bayhydrol® A XP 2695 enables coatings that are resistant to graffiti and are perfectly suited for the high-end coating of industrial goods, trains, commercial vehicles and even aircraft thanks to their extraordinary chemical resistance.
Furthermore, the coatings formulated with the new waterborne binder are extremely resistant to weathering and very scratch-resistant.
"Coatings formulated with Bayhydrol® A XP 2695 are miles ahead of other waterborne systems with respect to chemical resistance," says Robert Reyer of Bayer MaterialScience. Adds the expert from the Coatings, Adhesives and Sealants Business Unit: "They even outperform solventborne reference coatings in some tests." For example, marker pen stains could be more easily and completely removed from panels coated with clearcoats formulated with Bayhydrol® A XP 2695 than from coatings based on established solventborne products. The new polyacrylate dispersion also imparts coatings with excellent resistance to aggressive liquids such as Skydrol® hydraulic fluid.
Extraordinary resistance to chemicals and high scratch resistance are advantageous not only for commercial vehicles and industrial applications, but also for kitchen furniture, whose surfaces are subject to attack from coffee and wine stains, spilled bottles of bleach or disinfectant and sharp objects.
The new binder is ideally suited not only for clearcoats but also for primers and surfacers for the coating of metals, and can also be used to easily formulate coatings that meet the requirements of European VOC legislation.