Patent ID: 6413425
Filing Date: 2002-07-02
Classification: B01D,C02F,Y02A

Abstract:
A reverse osmosis composite membrane comprising:a sponge layer; and a separation layer formed on a surface of the sponge layer, wherein said separation layer is formed of an aromatic polyamide, wherein a surface of the separation layer is coated with at least one electrically neutral organic substance having a nonionic hydrophilic group, wherein the at least one electrically neutral organic substance comprises polyvinyl alcohol that is water-insoluble at 25Â° C., is water-soluble at 80Â° C., and has a degree of saponification in a range of 99% to 100%, wherein a specific surface area of the separation layer before the surface coating is in the range of 2 to 1,000; and wherein the reverse osmosis composite membrane has a flux of 0.6 m3/m2/day or more in a reverse osmosis test conducted by feeding a 1500 ppm NaCl solution at a pressure of 15 kgf/cm2 and a temperature of 25Â° C.