| 摘要 |
PURPOSE:To improve selective gas permeability of titled shield and improve operability and workability by making the shield three layered structure of a weakly hydrophobic porous member, a thin, dense hygroscopic film formed on one side of the above,and another porous member laminated on a thin film. CONSTITUTION:A thin, dense hygroscopic film 3 is formed on one side of a weakly hydrophobic porous member 1 by coating aqueous solution of a hydrophilic high molecular compound containing a moisture absorbent. Another porous member 2 is laminated on the thin film 3 to form a permeable gas shield of three-layered structure. In this case, a porous high molecular film properly treated to make it hydrophilic, or paper treated to make it weakly hydrophobic by sizing agent is used as a weakly hydrophobic porous member 1. Selective permeability of gas, that is, moisture permeability and gas permeability, is realized to a high degree by controlling hygroscopicity and thickness of the film. |
