COMPOSITE SEMIPERMEABLE MEMBRANE AND ITS PRODUCTION

摘要

PURPOSE:To obtain the title separation membrane wherein the removal ratio is increased by drying and remoistening and having excellent resistance to pH and heat by using sulfonated polyallyl ether ketone having <=2.5 milliequivalent/g ion exchange capacity. CONSTITUTION:The sulfonated polyallyl ether ketone having <=2.5 milli- equivalent ion exchange capacity per gram of the dry resin and having >=0.2 logarithmic viscosity at 40 deg.C with respect to a soln. of 0.5g resin in 100ml N-methyl-2-pyrolidone is used as the semi-permeable membrane. The polymer is dissolved by 0.05-10wt% in methylene glycol alkyl ether or the solvent mixed with a small amt. of an aprotic polar org. solvent. The membrane is formed by using the soln. At this time, when an additive is used, the removal rate of a solute and the amt. of water permeated through the membrane can be controlled over a wide range.