ブラウン管用内装塗布材料のガス放出・吸着特性-黒鉛-酸化鉄-水ガラス系を中心として- Gas Desorption and Adsorption Properties of Inner Coating Materials Used for Cathode Ray Tube-For Graphite, Iron Oxide and Water Glass Mixed Material-

The gas desorption properties of coating materials on the inner wall of a cathode ray tube, mixture materials from graphite, iron oxide and water glass, were examined by using a technique of thermal desorption spectroscopy (TDS). The major outgassing species during the heating up to 500°C were CO<SUB>2</SUB> and H<SUB>2</SUB>O. TDS spectra of water and carbon dioxide desorption showed sharp peakes at temperatures around 100-200°C. The desorbed gas amount was very small for the mixture samples of Fe<SUB>2</SUB>O<SUB>3</SUB> powder and water glass, and large for the mixture samples of graphite powder. In order to reduce the occuluded gas amount in samples as low as possible, it is essential to elevate at least the temperature of heat treatment for samples up to 400-500°C.<BR>For samples after degassing in TDS experiments, readsorption test were made and TDS spectra were taken again. The adsorption amount of H<SUB>2</SUB>O or CO<SUB>2</SUB> increased as the composition ratio of graphite powder. In particular, the adsorption capacity of gas largely increased by the addition of Fe<SUB>2</SUB>O<SUB>3</SUB> powder. The enhancement of adsorption capacity is due to that the surface structure became porous and also the effective surface area large by the addition of small content of Fe<SUB>2</SUB>O<SUB>3</SUB> powder.