Process for preparation of a porous membrane from at least one thermoplastic polymer and at least one water soluble polymer

Abstract

A process for preparing a porous membrane containing a thermoplastic polymer, the process containing: (i) forming a film shaped compound containing the thermoplastic polymer and a water soluble polymer; and (ii) extracting the film shaped compound with a solvent mixture, thereby obtaining the porous membrane; wherein the thermoplastic polymer has pores with an average pore diameter <2000 nm, determined using Hg porosimetry according to DIN 66133, the thermoplastic polymer contains a polyurethane, wherein the polyurethane contains: −11 to 79% by weight of a mixture of a diol and a diisocyanate; and 21 to 89% by weight of the compound with two functional groups which are reactive towards isocyanate groups.

Dependencies are inferred from the claim text.