| 摘要 |
PURPOSE:To obtain an impregnated membrane suitable for an osmotic evaporation membrane or a steam permeable membrane and having org. acid permselectivity, by using a liquid mixture, which consists of a polar group- containing compound of which the org. acid solubility is a specific value or more and an chemically inert compound and of which the solubility to water and steam pressure are specific values or less, as a liquid impregnant. CONSTITUTION:A liquid mixture consisting of a polar group-containing compound having the strong interaction with an org. acid to be selectively permeated and the solubility of the org. acid of 10 (g/100g) or more, the example, trioctylamine and a compound low in chemical reactivity, for example, petrolatum is used as a liquid impregnant. In this case, one, of which the solubility of water to the liquid impregnant is 0.001 (g/100g liquid impregnant) or less and the vapor pressure of the liquid impregnant is 30 mmHg or less, is used. A polymer porous membrane comprising polypropylene is impregnated with the liquid impregnant. By using this impregnated membrane, the osmotic evaporative separation of a low concn. org. acid aqueous solution such an aqueous acetic acid solution or vapor permeating separation of org. acid-water vapor mixture is performed.
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