An ethoxy-silano rhodamine B derivative and its application to surface coatings on display devices

A rhodamine B derivative with ethoxy-silano group was prepared by reacting rhodamine B sulfonyl chloride with aminopropyltriethoxysilane in dry pyridine. This new rhodamine B derivative reacts with an SiO₂ sol to connect directly with the silica matrix network. A wavelength-selective absorption film for display devices was prepared by using an SiO₂ sol solution containing the new derivative. This sol solution was spin-coated onto the surface of a display device, such as a cathode ray tube (CRT) or a plasma display panel (PDP) and then heat-treated at 130 °C to form a thin film. The organic dye did not elute in water or alcohol because it is bonded to an inorganic skeleton. This film exhibits good contrast enhancing properties because the organic dye can be incorporated into the film at high concentrations.