SEMIPERMEABLE MEMBRANES OF COPOLYAMIDES

摘要

Semipermeable membranes of copolyamides The invention relates to semipermeable membranes with a water absorption capacity of from 4.5 to 11. % by weight, preferably from 4.5 to 8 % by weight, as measured on approximately 40 .mu. thick symmetrical films at room temperature and at 65 % relative air humidity, a throughflow of 130 to 200 l/m2d for a desalination level of 94.6 to 99.5 % and consisting of an aromatic heterocycle-containing copolyamide with a relative viscosity of ?1.4, as measured on a 0.5 % N-methyl pyrrolidone solution at a temperature of 20.degree.C.