Bio-based UV-curable clear coats

 
Radiation-curable clear varnish systems, such as for furniture, decorative or graphic applications, have the advantage of extremely fast curing and resistance to environmental influences. Conventionally, photoinitiators with usually high toxicity potential as well as petroleum-based binders and resins are used. Until now, commercially available UV-curable clear coat systems contain a maximum bio-based content of approx. 25 %, but at the same time customers from the industry are requesting systems with over 80 % bio-based content. This demand has increased significantly again, especially as a result of the Green Deal decision. In order to implement these requirements, sustainable alternatives for the paint components (monomers and oligomers, initiators, additives) must be found from renewable ressources. As part of the research project BioInit from the network Go2green, UV-curable clear coats with the highest possible proportion of bio-based raw materials are to be developed. The focus of the project is the need for less toxic photoinitiators, which pose a significant problem for humans and the environment due to their migration. Although the project is still in the funding phase, successful interim results have already been achieved. A naturally occurring photoinitiator has been successfully formulated into a coating system with a total bio-based content of more than 60 %.