| 摘要 |
PURPOSE:To form a high-performance separator with a simple method by impregnating a sulfuric acid solution in a woven fabric or a nonwoven fabric made of fibers coated with polyvinyl alcohol on the surface of polypropylene fibers and heat-treating it. CONSTITUTION:Fibers coated with polyvinyl alcohol on polypropylene are used as a base, a dilute sulfuric acid solution is impregnated in a woven fabric or a nonwoven fabric made of the fibers, moisture in dilute sulfuric acid is evaporated in the air or the inert gas phase, a small quantity of concentrated sulfuric acid is left and held in the high-temperature atmosphere, and sulfonic group is combined with polyvinyl alcohol. The degree of sulfonation is determined by the quantity of impregnated sulfuric acid and the heat treatment temperature. Polyvinyl alcohol is shrunk in concentrated alkali when used alone, but it is not shrunk when coated on polypropylene, and a higher hydrophilic property is obtained by the sulfonation processing. A separator with a good liquid holding property and a good hydrophilic property and stable in an alkaline electrolyte can be formed with simple processing. |
