Author(s)

Tomoji Ohishi^*, Yoshimi Yamazaki

Department of Applied Chemistry, Faculty of Engineering, Shibaura Institute of Technology, Koto-ku, Tokyo, Japan.

The effects of excimer light irradiation on polysilazane coatings formed on PET films with vacuum-evaporated SiO₂ coatings and the effects of these coatings on gas barrier characteristics have been investigated. The temperature during light irradiation has a large effect on the coating’s molecular structure and gas barrier characteristics. When irradiation was performed at 100℃, the polysilazane coating transformed into a silica coating, and a compact silica coating at a much lower temperature than with heat treatment alone was produced. Surface irregularities in the vapor-deposited silica coating were smoothed out by the formation of a polysilazane coating, which was transformed into a compact silica coating when irradiated with light, resulting in a significant improvement in the gas barrier characteristics. The water vapor permeability of the thin coating irradiated with excimer light at 100℃ showed only 0.04 g/m²•day (40℃, 90% RH). According to the results of investigation of temperature variation of water-vapor permeability, it is inferred that the developed film has an excellent gas barrier value, namely, 4.90 × 10^–4 g/m²•day at 25℃. This gas barrier coated PET film is transparent and flexible, and can be used in the fabrication of flexible electronics. Also, the proposed fabrication method effectively provides a simple low-cost and low-temperature fabrication technique without the need for high vacuum facility.

Polysilazane, Photo-Irradiation, Excimer Light, Gas Barrier Characteristics, PET Film, Flexible Electronics

Ohishi, T. and Yamazaki, Y. (2017) Formation and Gas Barrier Characteristics of Polysilazane-Derived Silica Coatings Formed by Excimer Light Irradiation on PET Films with Vacuum Evaporated Silica Coatings. Materials Sciences and Applications, 8, 1-14. doi: 10.4236/msa.2017.81001.