Covestro, PPG’s First Automotive Refinish Coating with Bio-Based Hardener

Electric mobility and photovoltaics play a vital role in protecting the climate and conserving fossil resources. Combining them leads to even more innovative and sustainable mobility concepts. To show that these kinds of solutions are already feasible using state-of-the-art materials and technologies, a team of around 45 young researchers has developed a solar-powered electric car. Calling themselves “Team Sonnenwagen,” the students from RWTH Aachen University and Aachen University of Applied Sciences.

Covestro AG is supporting this project with materials and technical service and as a gold sponsor. The company wants to use the project to test coatings under the harsh climate conditions prevailing along the race’s route.

Road test: automotive coating with sustainable raw material

The most important product application is a three-layer polyurethane coating from PPG Industries Inc. The coating system is particularly suited to coating body parts made of carbon fibre composites. Climate conditions have a significant impact on the top clearcoat.

The Sonnenwagen uses an innovative automotive refinish coating that contains Covestro’s bio-based hardener Desmodur eco N 7300.

“Some 70 percent of its carbon content comes from biomass. This reduces the environmental footprint by around 30 percent,” said Ulf Wentzien, global head of industrial marketing in the coatings, adhesives, specialities business unit, Covestro.

“The bio-based hardener achieved the highest sustainability standards and meets both our customers’ and our own requirements. The coating is to the same outstanding quality as a polyurethane clearcoat with a conventionally produced hardener,” said Ignasi Roig, EMEA product platform manager at PPG Refinish.

Easy processing

The two-component coating is also impressive on the practical side. In PPG’s training centre in Hilden, it was applied to the Sonnenwagen's bodywork parts under similar conditions to an automotive paint shop. The coating is particularly suitable for the temperature-sensitive surface of the solar-powered car as it hardens at low temperatures.

Covestro and PPG have been working together in the field of coatings development for many years now. Both partners are using the Sonnenwagen project to demonstrate the role coatings can play in sustainable mobility.

“Through our developments and this project partnership, we are committed to future mobility and aim to show that these kinds of concepts are already feasible,” added  Ulf Wentzien.