| abstract |
A composite semipermeable membrane which comprises a finely porous support membrane composed of a base material and a porous support and a layer having a separation function, comprising a polyamide and formed on the finely porous support membrane, and which is characterized in that the polyamide has an irreversible endothermic heat amount of 275 J/g or more in a temperature range from -20˚C to 150˚C in the initial temperature-rising stage which is measured by a temperature-modulated DSC method.nProvided is a high-performance composite semipermeable membrane having high chemical resistance, a high water permeation amount and a high removal ratio. |