Dialysis method and semi-permeable membrane thereof

Claim 1

THE DIALYSIS METHOD WHICH COMPRISES INTERPOSING A SEMI-PERMEABLE MEMBRANE BETWEEN TWO SOLUTION AT LEAST ONE OF WHICH CONTAINS A PLURALITY OF SOLUTES, AT LEAST ONE SAID SOLUTE BEING DIFFUSIBLE THROUGH SAID MEMBRANE, AND MAINTAINING A DECREASING POTENTIAL WITH RESPECT TO SAID LAST-NAMED SOLUTE FROM SAID SOLUTION CONTAINING A PLURALITY OF SOLUTES TO THE SECOND SAID SOLUTION, THEREBY CAUSING SAID LAST-NAMED SOLUTE TO DIFFUSE THROUGH SAID MEMBRANE FROM THE SOLUTION OF HIGHER TO THE SOLUTION OF LOWER POTENTIAL, SAID MEMBRANE COMPRISING A SOLID LAYER OF A HOMOGENEOUS MOLECULAR DISPERSION OF A WATER-INSOLUBLE, ACID AND ALKALI-RESITANT THERMOPLASTIC FILM-FORMING POLYMER, AND A POLYMER OF N-VINYL PYRROLIDONE IN SAID MEMPORTION OF POLYMERIZED N-VINYL JPYRROLIDONE IN SAID MEMBRANE BEING ABOUT 10% TO 50% BY WEIGHT OF THE SOLIDS CONTENT AND THE REMAINDER OF THE SOLIDS IN SAID MEMBRANE CONSISTING ESSENTIALLY OF SAID THERMOPLASTIC FILM-FORMING POLYMER, SAID N-VINYL PYRROLIDONE POLYMER HAVING A MOLECULAR WEIGHT GREATER THAN ABOUT 20,000, AND SAID MEMBRANE HAVING A MAXIMUM RESISTANCE OF 10 OHMS PER SQUARE CENTIMETER MEASURED IN 0.15 N KCI.