Preparation and gas barrier characteristics of polysilazane-derived silica thin films using ultraviolet irradiation

The gas barrier film formation technique using simultaneous photo-irradiation and heat-treatment has been researched on alicyclic polyimide film coated with a polysilazane solution. A fine SiO2 thin film on polyimide film was formed at low temperatures, which greatly improved the substrate’s gas barrier characteristics by this technique. The values of gas barrier characteristics depended on the substrate temperature at the time of photo-irradiation. For photo-irradiated thin film heat-treated to 150°C, the water vapor transmission rate and oxygen transmission rate fell below the equipment measurement limit of 0.02 g/m2/day and 0.02 cm3/m2/day, respectively. This polyimide film with a gas-barrier film coating has good transmittance in the region of visible light, heat resistance, and flexibility.