| 摘要 |
<p>PURPOSE:To obtain a highly hygroscopic laminate by covering a water absorbable polymer and carboxylate or a mixture of carboxylate and at least one component selected from amino acids, inorg. salts and org. acids with an air permeable film to form a hygroscopic layer and arranging a non-hydrating porous sheet to one surface of said layer and arranging a water impermeable sheet to the other surface thereof to hold the hygroscopic layer between both sheets. CONSTITUTION:A highly hygroscopic laminate is prepared by forming a water absorbable layer 5 wherein a water absorbable polymer 2, a humectant 3 and, if necessary, an insect control agent or a fungicide 4 are held between air permeable films 1 and arranging a non- hydrating porous sheet 6 to one surface of the water absorbable layer 5 and arranging a water impermeable sheet 7 to the other surface thereof to hold the layer 5 between both sheets and heat-sealing the peripheral edge of the formed laminate. By this constitution, when an object is packed within the closed space of the laminate or received along with the laminate, the object is adjusted to atmospheric temp. of RH=20-40%. As the water absorbable polymer, a material prepared by three-dimensionaly polymerizing polysaccharides such as starch or cellulose and a water soluble polymerizable monomer or a polymerizable monomer becoming water-soluble by hydrolysis by a crosslinking agent is designated and, as the humectant, carboxylate or a mixture of carboxylate and amino acids, inorg. salts or org. acids is pref.</p> |
