| 摘要 |
PURPOSE:To prepare a compsn. which discolors reversibly in a desired humidity range by disposing >=2 kinds of compsn. for displaying humidity which contain cobalt salts and surface active agents and have differenct discoloring humidity ranges on the surface of a holding body. CONSTITUTION:The phenomenon that the intrinsic discoloring humidity range of a cobalt salt changes when a surface active agent is added to the cobalt salt is utilized. The discoloring humidity range migrates to a higher range with cationic and nonionic surface active agents and migrates to a lower range with an anionic surface active agent. The cobalt salt and surface active agent are dissolved in 18g water and the aq. soln. is impregnated to filter paper which is then dried. The paper is rested in the atmosphere of 40, 50, 60, 70, 80 and 90% relative humidity at 25 deg.C then the results shown in the table are obtd. Such filter paper is cut 1cm square and the cut sheets are disposed sequentially on a cardbord. Such cardboard is usable as a hygrometer by observing the discoloring region. |
