Fabrication of UV-curable fluorosilicone coatings with impressive hydrophobicity and solvent resistance

Novel UV-curable methacrylate functionalized fluorosilicone resin (MAFSR) and sulfhydryl functionalized fluorosilicone resin (SFSR) were synthesized respectively. The molecular structure, UV curing process, thermal properties and surface properties were studied. Further application as protective coatings in the field of printed circuit board (PCB) was explored. Results show that the MAFSR with more than 30 wt % SFSR possess a high carbon-carbon double bonds conversion above 95 % after 15 s UV exposure. Besides, the surface energy of the coatings is as low as 11.5 mN/m, showing excellent hydrophobicity. The XPS results further reveal that the migration and orientation of the fluorine groups to the surface is an intrinsic reason for low surface energy. In addition, the coatings also demonstrate excellent heat resistance and solvent resistance. This study shows that UV-curable fluorosilicone resins are presumably promising special protective coatings for PCB.