Regeneratable dehumidifying bag having doubly-protected humidity indicator

Abstract

A dehumidifying bag includes a water-vapor permeable pouch 1 , a desiccant material 2 filled in the pouch 1 for absorbing moisture through the pouch for dehumidifying a surrounding wherein the pouch 1 is placed, and a doubly-protected humidity indicator 3 printed on an outer surface of the pouch 1 for reminding an user for replacing or regenerating the desiccant material 2 when saturated by moisture.

I claim: 
     
         1 . A regeneratable dehumidifying bag comprising:
 a water-vapor permeable pouch;   a desiccant material selected from water-vapor absorbing materials and filled in the pouch, and   a doubly-protected humidity indicator printed or coated on an outer surface of said pouch, and capillarily communicated with the desiccant material in the pouch;   the improvement which comprises:   said doubly-protected humidity indicator comprising: a color-changeable pattern printed or coated on the outer surface of the pouch; and an air or vapor permeable transparent protective layer coated or covered on an outer surface of the color-changeable pattern, whereby upon saturation of water vapor as absorbed by the desiccant material in the pouch, the color-changeable pattern of the humidity indicator changes the color for reminding an user for replacing or regenerating the desiccant material in the pouch.   
     
     
         2 . A bag according to  claim 1 , wherein said color-changeable pattern is presented by printing or coating a printing ink on the pouch, said printing ink including: a plurality of silica gel granules, each said granule having cobalt chloride or copper sulfate inwardly bound in a plurality of capillaries formed in each said granule, and having said cobalt chloride or copper sulfate outwardly locked by an air or vapor permeable resin binder; with the silica gel granules dispersed in the resin binder to form the printing ink to be adhered on the outer surface of the pouch. 
     
     
         3 . A bag according to  claim 2 , wherein said printing ink of the color-changeable pattern is prepared by the following process steps:
 A. Binding cobalt chloride or copper sulfate into a plurality of capillaries formed in each said silica gel granule by mixing an aqueous solution of cobalt chloride or copper sulfate with the silica gel granules to be a paste; and   B. Adding an air or vapor permeable water-based acrylic resin binder, together with a surfactant into the paste by well agitation to form the printing ink of the color-changeable pattern.   
     
     
         4 . A bag according to  claim 1 , wherein said air or vapor permeable transparent protective layer is made of air or vapor permeable transparent acrylic resin.