Uv Curable Materials with Non-Polar Binders - Properties and Limitations

Non-polar polyols with either hydrocarbon or fluorinated hydrocarbon backbones were used in UV curable systems. This was camed out either by direct addition of non-polar polyols (in dual curing systems with additional isocyanate crosslinking) or by the synthesis of urethane acrylates with hydrophobic units. The dual curing formulations showed many incompatibilities and, thus, required an intense binder screening. The conversion to urethane acrylates gave improved compatibility and, therefore, wider options for formulation. Further attempts were made by the addition of hydrophobic particles and by fluorinated surfactants with acrylate groups. The resulting coatings showed good mechanical and chemical resistance. Partially, corrosion protection could be improved. The contact angles against water reached 80-93°, i.e., 10-20° higher than comparative non-modified systems.