| 摘要 |
A manufacturing method of porous layer comprises: drying a mixed solution containing conductive carbon powder and water-repellent resin powder by a spray-drying method, so as to produce a powdery substance including the conductive carbon powder coated with the water-repellent resin powder; and producing the porous layer from the powdery substance. Water-vapor permeability of the porous layer measured in conformity with the Japanese Industrial Standard JIS-Z-0208 is 10000 to 25000 g/m 2 ·24h under conditions of temperature of 40°C and relative humidity of 90% RH. |
