PROBLEM TO BE SOLVED: To provide an electrostatic filter in which collection efficiency does not decrease significantly in a short period and the high collection efficiency can last for a longer term.SOLUTION: An electrostatic filter includes charged nonwoven fabric. The nonwoven fabric includes a first component composed of thermoplastic resin, and a second component composed of thermoplastic resin having a melting point after spinning higher than a melting point of the first component after spinning, and also includes odd-form cross-sectional composite fiber formed by the first component covering at least a part of a surface of the second component.SELECTED DRAWING: Figure 1COPYRIGHT: (C)2017,JPO&INPIT【課題】捕集効率が短期間で著しく低下することなく、より長期間にわたって持続する静電フィルターの提供。【解決手段】帯電した不織布を含む静電フィルターであって、該不織布は、熱可塑性樹脂からなる第1成分と、該第1成分の紡糸後の融点よりも高い紡糸後の融点を有する熱可塑性樹脂からなる第2成分とを含み、かつ該第1成分が該第2成分の表面の少なくとも一部を被覆してなる異形断面複合繊維を含む、静電フィルター。【選択図】図1
