| 摘要 |
PURPOSE:To obtain a separator which has improved permeability for an alkaline electrolyte or a nonaqueous electrolyte and can absorb an increased amount of the electrolyte at an increased rate by forming the separator by a porous membrane made of a fluorinated polymer. CONSTITUTION:PE, PP, PVA or a polyester is suitable as a polymer to be fluorinated. A nonwoven porous fibrous fabric is preferable as a porous structure. The nonwoven polymer fabric is fluorinated, for example, by replacing the internal atmosphere of a case in which the nonwoven fabric is enclosed with nitrogen gas and then feeding a fluorine gas properly diluted with nitrogen gas into the case for an appropriate time so that the polymer fiber constituting the nonwoven fabric is fluorinated. The fluorinated polymer has a decreased contact angle and improved affinity for a liquid such as water. When thus fluorinated nonwoven polymer fabric is used as a separator for a battery, the separator has improved permeability for an alkaline electrolyte or similar electrolyte and can absorb an increased amount of the electrolyte at an increased rate. |
