Patent ID: 8651284

Claim:
A hydrophilic, water-wettable, semi-permeable hollow-fibre membrane for blood purification comprising a synthetic first polymer being a hydrophobic first polymer, characterized in that the hydrophobic first polymer is an aromatic sulfone polymer such as polysulfone, polyethersulfone, polyphenylenesulfone or polyarylethersulfone, a polycarbonate, polyimide, polyetherimide, polyetherketone, polyphenylene sulfide or a copolymer or mixture of these polymers, a hydrophilic second polymer characterized in that the hydrophilic second polymer is polyvinylpyrrolidone, polyethylene glycol, polyvinyl alcohol, polyglycol monoester, polysorbate, carboxymethylcellulose, or a copolymer of these polymers, the hollow-fibre membrane possessing an open-pored integrally asymmetric structure across its wall, a porous separating layer of thickness between 0.1 and 2 μm on its inner surface facing the lumen characterised in that a polyelectrolyte with negative fixed charges is physically bound in the separating layer, and an open-pored supporting layer adjoining the separating layer, and having an ultrafiltration rate in albumin solution in the range of 5 to 23.5 ml/(h·m 2 ·mmHg), characterized in that the hollow-fibre membrane a) contains no pore stabilizing additives in the membrane wall either before or after drying; and b) has a maximum sieving coefficient for albumin of 0.005 combined with a sieving coefficient for cytochrome c that satisfies the relation SCcc≧5·10 −5 ·UFR Alb 3 −0.004·UFR Alb 2 +0.1081·UFR Alb −0.12.