Water-based radiation curable oligomers open new horizons for hardcoats

Water-based radiation curable polymers largely respond to the current environmental concerns and to the quest for high-end coating performances. New advances in the technology are placed in the perspective of the different stabilization mechanisms of waterborne colloids ranging from dispersions to emulsions. The main physico-chemical differences between the two systems are provided with an emphasis on the major parameters that govern the emulsification process and the colloidal stability of the final product. The market requirements for hard coats are provided and tentatively transposed into a molecular design considering both functionality and equivalent weight of model urethane acrylates. Finally, it is shown that stable waterborne high-solid oligomers with a low viscosity for spray application are delivering outstanding performances as hard coats on many substrates, like plastics.