Bio-based free-radical photo-initiators for UV-curing resins

 
The coating industry is making great efforts to replace fossil with renewable carbon sources. So far only petro-chemical aromatic photo-initiators are utilized throughout industry for starting the photo-polymerization even of partially bio-based coatings. We have formulated UV-curing resins based on mono- and oligomers partially made from renewable raw materials like soy-bean or castor oil. The free-radical photo-initiation is done at l = 365 nm by simple bio-based aliphatic a-ketoacids like pyruvic or ketoglutaric acid as well as corresponding esters.