To provide a humidity conditioning material for an electric power or a communication equipment storage box exhibiting a sufficient moisture absorption/releasing performance for a long period of time even if it is placed under an environment with a large temperature variation and it is placed under an environment that a high relative humidity is continued.
In the humidity conditioning material comprising an inorganic porous material arranged in the electric power or communication equipment storage box, the inorganic porous material contains amorphous silica and/or a silicate compound as a main component, a difference of balanced moisture content of a relative humidity of 75% and a relative humidity of 40% under a temperature environment of 5-50C is in a range of 9.5-55.0 mg/g. Further, a difference of balanced moisture content of a relative humidity of 95% and a relative humidity of 75% under the same temperature condition is in a range of 15.0-80.0 mg/g, and a moisture permeability coefficient is in a range of 450-2,700 ng/(m2sPa).
YOKOYAMA YUZO
TSUTAO TOMOSHIGE
Table of contents Makoto