| 摘要 |
PURPOSE:To increase the fractional mol.wt. of the title membrane without decreasing the strength of the membrane by bringing ozone into contact with a permselective membrane having specified strength and fractional mol.wt. CONSTITUTION:The permselective membrane to be used consists of a polymer, the limiting viscosity of which is decreased by oxidation, and is previously provided with a specified fractional mol.wt. For example, a permselective membrane consisting of a polymer contg. an ether coupling, a sulfone coupling, and an aromatic ring on its principal chain is used. The fractional mol.wt. of such a permselective membrane is increased by bringing ozone at 0.1-10g/m<2> into contact with the membrane in accordance with the degree to which the fractional mol.wt. is increased. The membrane is brought into contact with ozone by dipping the membrane in an aq. ozone-contg. soln. or pressing the aq. ozone-contg. soln. on the permselective membrane. |
