| abstract |
A composite semipermeable membrane in which a polyamide separation functional layer is formed on a microporous support membrane composed of a base material and a porous support, and is −20 in the initial temperature rising process measured using a temperature modulation DSC method. A composite semipermeable membrane, wherein the polyamide has an irreversible endothermic amount of 275 J / g or more in a range of ˜150 ° C. A high-performance composite semipermeable membrane having high chemical resistance, high water permeability, and high removal rate is provided. |