Patent ID: 8602221

Claim:
A membrane for treating liquid made from an aromatic ether polymer shown by the following formula (1), wherein R 1 , R 2 , R 3 , R 4 , R 5 , and R 6 represent hydrogen, an organic functional group having 1 to 6 carbon atoms, or a non-protonic organic functional group having 6 or less carbon atoms containing oxygen, nitrogen, or silicon, and these groups may be same or differ from each other, and m is the number of repeating units, and the polymer may be a copolymer containing two or more different repeating units, wherein the aromatic ether polymer is hydrophilized with a hydrophilizing agent; wherein the hydrophilizing agent is a block copolymer consisting of polystyrene and polyethylene glycol of the following formula: wherein R 8 , R 9 , R 10 , R 11 , R 12 , R 13 , R 14 , and R 15 represent hydrogen, a halogen atom excluding fluorine, an organic functional group having 1 to 6 carbon atoms, or a functional group having 6 or less carbon atoms and containing oxygen, nitrogen, or silicon, and these groups may be the same or differ from each other; 1 is 2 or more; and n is 1 or more; wherein said polyethylene glycol has a molecular weight of 2,000 to 50,000.