| 摘要 |
PURPOSE:To prepare a porous membrane of ethylene-tetrafluoroethylene copolymerizate having superb chemical resistance, heat resistance, filtering characteristics and mechanical solid-state properties by setting specific average bore diameter and void content and arranging the number of fibers constituting network structure to comply with the specified formula. CONSTITUTION:10-60vol% of ethylene-tetrafluoroethylene copolymerizates, 7-42vol% of inorganic finely divided component such as finely divided silicic acid and 30-75vol% of chlorotrifluoroethylene oligomer are mixed, and, after being fused and kneaded by the extruder and the like, melt molded intol the form of plane membrane, hollow membrane, etc. The molded membrane part is dipped in the solvent such as trichloroethane to extract chlorotrifluoroethylene oligomer. Then, inorganic finely divided component is extracted with such solvents as caustic soda. Thus, a micro porous membrane of a three-dimensional network having average bore diameter D 0.01-5mu, void content P 40-90% and the number of fibers N, constituting the network, N>=2P/D per 1mm to the direction of thickness of the membrane, is prepared.
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