Anti-reflective coatings for CRTs by sol-gel process

Two types of anti-reflective coatings composed of nano-particles were developed for cathode ray tubes (CRTs). The anti-reflective and anti-static coating is composed of two layers. An outer SiO2 layer is formed over a porous inner layer composed of titanium oxynitride (TiOxNy), antimony-doped tin oxide (ATO) and SiO2. To control the reflection of the film, a porous structure is formed using a mixed sol composed of TiOxNy-ATO particles and hydrolyzed-polymerized tetraethoxy-silane (TEOS). The resulting double layered coating is shown to consist in a nanocomposite pseudo three-layer structure. The antireflective electromagnetic-wave-shielding coating is also composed of two layers. An outer SiO2 layer is formed over an electric-conductive inner layer composed of silver colloids, TiOxNy nano particles. Silver colloids are used to obtain a film having low surface resistivity and TiOxNy nano-particles contained in the inner layer enhance the durability of the film. To reduce the plasma-resonance absorption caused by silver colloids, silver ions are added to the outer layer solution. The silver ions diffuse into the inner layer from the outer layer when the film is cured, touch to the surface of silver colloids, suppress the silver colloid growth and reduce the specific absorption of the film. These coatings are successfully applied to the panel glass for CRTs on an industrial scale.