Patent ID: 8302781

Claim:
A semipermeable hollow-fibre membrane, particularly for use in hemodialysis, hemodiafiltration and hemofiltration, comprising a hydrophilic, water-wettable membrane being based on a hydrophobic first polymer being selected from the group consisting of an aromatic sulfone polymer, a polycarbonate, polyimide, polyetherimide, polyetherketone, polyphenylene sulfide, or a copolymer or a modification of these polymers, or a mixture of these polymers and a hydrophilic second polymer being selected from the group consisting of polyvinylpyrrolidone, polyethylene glycol, polyvinyl alcohol, polyglycol monoester, polysorbate, carboxymethylcellulose, or a modification or copolymer of these polymers, possessing an open-pored, integrally asymmetric structure across its wall with a porous separating layer of thickness 0.1 to 2 μm on its inner surface facing a lumen and an open-pored supporting layer adjoining the separating layer, characterized in that a polyelectrolyte with negative fixed charges is physically bound in the separating layer, characterized in that the supporting layer being essentially free from polyelectrolyte with negative fixed charges, and having an ultrafiltration rate in albumin solution in the range of 25 to 60 ml/(h·m 2 ·mmHg), wherein after drying, the hollow-fibre membrane has a minimum sieving coefficient for cytochrome c of 0.8 combined with a maximum sieving coefficient for albumin of 0.005, and whereby the hollow-fibre membrane in the dry state is free from pore-stabilising additives in the membrane wall.