| abstract |
PURPOSE:To obtain a polysulfone-based membrane improved in permeability to water, by a method wherein a solution exhibiting microscopic phase separation obtained by adding polyethylene glycol to a polysulfone in such amount as to attain a turbidity concentration is cooled to form a clear solution, and a membrane is produced from the clear solution. CONSTITUTION:Polyethylene glycol (PEG) having a molecular weight of 200- 100,000 is added to 5-40wt% of an aromatic polysulfone or an aromatic polyether sulfone (PS) in an amount of 130-190%/PS, and the mixture is sufficiently mixed by heating it at a temperature of 80 deg.C or above to obtain a turbid composition. By cooling the composition to a temperature of 40 deg.C or below, a uniform clear solution is obtained, from which the membrane is produced by a conventional process. |