2014 Volume 27 Issue 3 Pages 409-414
Polyethylene terephthalate (PET) has excellent transparency, heat resistance, electrical insulation, chemical resistance, and wear resistance. With a miniaturization and multifunctionalization of an industrial product, control of material surface and interface has become important. Active oxygen species were generated via 185/254 nm UV lights irradiation under conditions of high and low humidity, and PET films were exposed to the active oxygen species with these UV lights. Changes in their surface characteristics were evaluated. Contact angle of water droplet on the PET film surface and surface roughness after the treatment in the high humidity condition were higher than those in the low humidity condition, and transmittance of the PET film within a region of the visible light after the treatment in the high humidity condition decreased compared to that in the low humidity condition. The PET film surface can be modified more gently in the low humidity condition than in the high humidity condition.