It is the purpose of this paper to present the data of gas evolution from the surfaces coated with a black-epoxy paint which is widely used in space simulation chambers. The data have been taken by measuring the pressures in the test dome pumped through a pipe of known conductance. In the first evacuation, the remarkably high rate of gas evolution has been observed for the epoxy painted surfaces ; their rate decreases with time by degassing in vacuum even at a room temperature. It is supposed that organic solvent or unreacted substances in addition to water vapor could increase the amount of evolution gas at the initial stage. For all samples exposed to gases or air after degassing in vacuum, the rate of gas evolution is inversely proportional to the pumping time. The evolution rate at a room temperature for the epoxy painted surfaces after exposure to atmospheric, humid air is higher by a factor of 6 to 10 than that after exposure to nitrogen, oxygen, and argon for the same time. This is probably due to sorption of water vapor in air. The results are compared with available data obtained by different workers for similar materials.
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