| abstract |
The present invention provides a porous membrane having constituent components of an aromatic polyamide having good affinity with an electrolyte and having high heat resistance, a thin film, and high air permeability. It contains an aromatic polyamide and a hydrophilic polymer, the content of the hydrophilic polymer is 12 to 50 parts by mass with respect to 100 parts by mass of the aromatic polyamide, the film thickness is 2 to 30 µm, and the Gurley air permeability is 0.5 to 300 seconds / 100 ml It is set as the aromatic polyamide porous membrane whose thermal contraction rate in 200 degreeC is -0.5 to 1.0%. |