DESICCANT COMPOSITION, MOLDED DESICCANT, METHOD OF CONTROLLING EQUILIBRIUM HUMIDITY FOR THE SAME, AND METHOD OF CONTROLLING EQUILIBRIUM HUMIDITY RETENTION TIME

摘要

A desiccant composition and a molded desiccant each comprising a thermoplastic resin compounded with a desiccant. The composition and the molded desiccant can be formulated so as to attain a different equilibrium humidity by replacement with a resin which is of the same kind but has a different specific gravity. Environments suitable for the preservation of a variety of products can be easily formed. The desiccant composition comprises a thermoplastic resin compounded with a desiccant having an equilibrium vapor pressure, the desiccant being magnesium sulfate represented by the formula MgSO₄ nH₂O (wherein 0=n=3). The surface of the desiccant is coated with a fatty acid metal salt before the desiccant is kneaded together with the thermoplastic resin so that the desiccant comes to have a secondary-particle diameter of 1-40 µm when dispersed in the thermoplastic resin. It has become possible to increase/reduce the equilibrium humidity by a given value with an increase/decrease in specific gravity by a certain value without changing the kind of the thermoplastic resin.