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US 8,784,664 B2Granted
Hollow fibre membrane
AssigneeFresenius Medical Care Deutschland GmbH
InventorsRainer Fislage, Igor Raiko
Life of this patent
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Abstract
The present invention relates to a composite hollow fiber capillary membrane in particular for exploiting the value of dialysate and a method for the production thereof as well as its use in particular in haemo and peritoneal dialysis.
Claims26
A supported hollow fiber membrane comprising a coextrudate comprising a porous support layer and a dense selection layer,
- wherein the dense selection layer is impermeable to bivalent cations within the framework of customary measurement accuracy, consists of an esterified cellulose with an acylation degree in the range of from 0.5 to 3, and has a urea permeability in the range of from 10-80 g per day per m2.
A method for producing a supported hollow fiber membrane comprising a coextrudate having a support layer and a selection layer impermeable to bivalent cations, said method comprising:
- providing two spinning mass solutions A and B, wherein the spinning mass solution A is a solution of an esterified cellulose and the spinning mass solution B a solution containing a polymer selected from the group consisting of polyvinylpyrrolidone (PVP), polyethersulfone (PES), polyetherimide (PEI), polyamide (PA), polycarbonate (PC), polystyrene (PS), polymethyl methacrylate (PMMA), polyvinylidene fluoride (PVDF), polyacrylonitrile (PAN), polyimide (PI), polysulfone (PSU), polyurethane (PU), and mixtures thereof;
- setting the precipitation bath temperature at 40 to 95° C.;
- bringing the spinning mass solutions A and B into contact with water as an internal precipitant via a hollow fiber spinneret with a spinning speed of 200 to 400 mm/sec;
- and
- coagulating and precipitating the extrudate consisting of the substances dissolved in the spinning mass solutions A and B.
2 more elements
Dependencies are inferred from the claim text.