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

摘要

A moisture absorbent composition and a moisture absorbent molding each comprising a thermoplastic resin compounded with a moisture absorbent. The composition and the molding 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 moisture absorbent composition comprises a thermoplastic resin compounded with a moisture absorbent having an equilibrium vapor pressure, the moisture absorbent being magnesium sulfate represented by the formula MgSO 4 · nH 2 O (wherein 0‰¤n‰¤3). The surface of the moisture absorbent is coated with a fatty acid metal salt so that the moisture absorbent comes to have a secondary particle size 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.