| abstract |
Provided is an aromatic polysulfone resin which has high toughness and is suitable for use as the material of membranes such as porous membranes. The aromatic polysulfone resin has a reduced viscosity of 0.55 to 0.65dL/g, preferably 0.58 to 0.62dL/g, a number-average molecular weight (Mn) of 22000 or more, preferably 23500 or more, and a ratio of weight-average molecular weight (Mw)/number-average molecular weight (Mn) of 2.54 or less, preferably 2.50 or less. |