Improvement of surface scratch resistance of siloxane hard coating by hydrophobic surface treatment

Abstract

Recently, a flexible display has been used to substitute a flat panel display for commercialization of foldable smartphones and tablets. To realize the foldable device, all devices in the display should be flexible, especially

flexible hard coating has aroused considerable interest in the utilization of flexible cover window as a replacement of glass which exhibits high hardness but brittle to bending. However, critical challenges, for example, scratch and abrasion resistance, despite the high hardness, hinder the long-term use of the commercialized foldable device. The hydrophobic treatment is generally introduced to the conventional cover window to provide the silky touch to the screen and further improve the scratch resistance. However, the hydrophobicity is worn out after several months of usage. The durable hydrophobic surface can be done through the introduction of fluoro-containing polymer to the hard coating. On the other hand, the combination leads to the lower hardness and could result in the lower scratch and abrasion resistance of the surface. In this thesis, I incorporated fluorosilane treatment on the transparent flexible hard coating to obtain hydrophobic surface with scratch and abrasion resistance. The hydrophobic surface treatment was simply obtained by utilizing plasma treatment and chemisorption of fluorosilane on the surface of the hard coating. The abrasion tests suggested that fluorosilane treated hard coating is suitable material as a transparent flexible cover window for long-term use.