Covestro’s bio-based automotive refinish coating to be tested on World Solar Challenge car

Covestro, which is among the world’s largest polymer companies supplying to the automotive industry, is putting one of its products to the test at the upcoming Bridgestone World Solar Challenge 2017 in Australia.

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 are participating in what is probably the toughest race in the world for solar cars.

The World Solar Challenge is considered to be the toughest race on earth for solar cars and this year celebrates its 30th anniversary. From October 8 to 15, 2017, approximately 40 teams from all over the world will be competing in their ‘homemade’ vehicles to win the 3,000 kilometre race from Darwin to Adelaide – without using one drop of fuel.

Covestro is supporting the Sonnenwagen 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. Temperatures in the Australian desert can soar to as much as 45 degrees Celsius in October, with intense UV radiation. This time of year also typically sees a high particle concentration in the air.

Automotive coating with sustainable raw material
The most important product application is a three-layer polyurethane coating from PPG, world leaders in paints, coatings and specialty materials, and experts in automotive coatings. The coating system is particularly suited to coating body parts made of carbon fiber 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,” explains Ulf Wentzien, global head of Industrial Marketing in the Coatings, Adhesives, Specialties Business Unit at Covestro. “This reduces the environmental footprint by around 30 percent.”

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

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.

Covestro has a long-standing partnership with the RWTH Aachen University. “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,” says Covestro’s Ulf Wentzien. “At the same time, we have the opportunity to inspire and support young people at universities.”