At this year’s European Technical Coatings Congress (ETCC) in Amsterdam, Covestro received the Alain Clause Award of the Belgian Association of Technicians from the Paint and Allied Industries ATIPIC for the best lecture on ecological and environmentally compatible developments. The award is endowed with 1,000 euros.
Dr. Eva Tejada was honored for her particularly sustainable coating technology based on the UV-curing, aqueous polyurethane dispersion Bayhydrol® UV 2877. Formulations containing this binder have a low content of volatile organic compounds (VOCs) and cure quickly. Moreover, around 38 percent of the product is based on biomass. The author has now succeeded in reducing the drying time by another 50 percent and also made it possible to cure shaded areas.
Optimum balance of speed and surface quality
UV curing has proven itself as a technology for the rapid curing of coats. However, shaded areas, such as complex shaped parts, or the use of pigmented paints are a challenge.
In addition to UV curing, the award-winning development introduces self-crosslinking of the polyurethane dispersion, which opens up various possibilities: Either the previously UV-cured coating film is self-crosslinking, resulting in subsequent curing of shaded areas, or curing takes place only in the form of self-crosslinking, without the influence of UV radiation. In both cases, coatings of high quality result. If the crosslinked coating layer is post-cured under UV radiation, its quality can be further improved.
In the case of aqueous dispersions as binders, the drying speed of the coating also depends primarily on the evaporation of the water. The author was able to achieve a faster release of the water and, as a result, a 50 percent reduction of the drying time. Potential applications include pigmented and clear coats, curing with LED lamps and on-site coating of parquet floors.
This new multicuring product thus increases robustness and efficiency in waterborne UV curable systems, overcoming the main pain points of this technology in a more sustainable way. At the same time, it is a perfect example for achieving more with less: As a result, a reduced consumption of energy and fossil resources leads to better surface properties.