ブラウン管用内装黒鉛のガス脱離特性 - 大気中ベーキング後の放置環境の影響 - Gas Desorption Property of Inner Coating Graphite Used for Cathode Ray Tube - Effect of exposure to the atmosphere after baking in the atmosphere -

For inner coating graphite baked in the atmosphere, gas desorption properties after exposure to the atmosphere were investigiated by using a thermal desorption spectroscopy. The temperature and the water vapor pressure during the exposure were varied from 25 to 50°C, and from 950 Pa to 6150 Pa, respectively. In the heating up to 410°C, the major gas species desorbed were CO<SUB>2</SUB> and H<SUB>2</SUB>O. In the thermal desorption spectra of CO<SUB>2</SUB>and H<SUB>2</SUB>O, a desorption peak was observed at around 130°C. The peak intensities decreased with increases of both the exposure temperature and the water vapor pressure. When the water vapor pressure increased, the desorption amount of H<SUB>2</SUB>O increased, although that of CO<SUB>2</SUB> decreased. The total desorption amount was almost the same even when the water vapor pressure was changed. In order to lengthen a life time of a cathode ray tube, it is necessary to reduce the water vapor pressure in the atmosphere environment, since the cathode is damaged by mainly the water.