| 摘要 |
PURPOSE:To obtain a moisute-permeable gas shield of a high gas selective permeability by the procedure in which the surface of a weakly hydrophobic porous material of a specific sizing degree is only treated with a high polymer containing a hygroscopic agent and then fixed. CONSTITUTION:A natural sizing agent, e.g., rosin, etc., is beforehand added to or impregnated into a non-hydrophobic porous material, e.g., paper, etc., to prepare a weakly hydrophobic porous material of a sizing degree of 20 to 200 sec according to JIS P-8122-54. Then, an aqueous high polymer (PVC, etc.) solution containing a hygroscopic agent, e.g., LiCl, etc., is impregnated into or coated over the surface of the weakly hydrophobic porous material in such a way that the high polymer is contained in a proportion of 10 to 50 wt % and then dried before the aqueous solution penerates into the inside of the porous material. The moisture-permeable gas shield is almost impervious to gases, e.g., air, CO2, etc., because of its thin dense layer, but absorbs water vapor on its surface and sends it to the back of the porous material by capillary phenomenon for causing the water vapor to permeate by revaporization. |
