Patent ID: 8993053
Filing Date: 2015-03-31
Classification: B01D,B05D

Abstract:
1. A method of manufacturing a reverse osmosis membrane, the method comprising: forming a polysulfone layer by applying a solution including a polymer having a sulfonic acid group and a mixed solvent containing two or more solvents having different solubility parameter values to a surface of a porous support, wherein the mixed solvent includes N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) mixed in a ratio of 90:10 to 60:40, or N,N-dimethylformamide (DMF) and γ-butyrolactone (GBL) mixed in a ratio of 90:10 to 60:40; and forming an active polyamide layer on the polysulfone layer; wherein for the same percentage of polysulfone the number of pores that are 0.40 nm or greater is in the range of 0.20% to 0.45%.