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US RE34,239 EGranted
Semi-permeable membranes
AssigneeHospal AG
InventorXavier Marze
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AssigneeHospal AG
InventorXavier Marze
Estimating the term…
A semi-permeable membrane [which comprises] having high permeability characteristics is disclosed. This may comprise either (i) a copolymer of acrylonitrile and at least one ionic or ionizable monomer, or (ii) a copolymer of acrylonitrile, at least one ionic or ionizable monomer, and at least one non-ionic and non-ionizable monomer, or (iii) a mixture of at least two copolymers as defined under (i) and/or (ii), or (iv) a mixture of at least one copolymer as defined under (i) and/or (ii), and at least one copolymer of acrylonitrile and at least one non-ionic and non-ionizable monomer, the ionic or ionizable monomer units representing from 1 to 80 mole % of the monomer units in one of said copolymers, and representing from 1 to 50 mole % of the monomer units in the membrane, said membrane having a degree of salt rejection of less than 1% and a permeability to water of more than 100 liters/day.m.sup.2 at a relative pressure of 2 bars is provided having excellent properties for use in ultrafiltration and dialysis. A process for preparing a semi-permeable membrane is also provided which comprises treating a film containing at least one copolymer of acrylonitrile and an ionic or ionizable monomer, with water or an aqueous non-solvent mixture at a temperature between 60.degree. and 250.degree. C.
A semi-permeable membrane material for use in an apparatus adapted for dialysis and ultrafiltration of blood, having the following characteristics:
In an apparatus adapted for dialysis and ultrafiltration of blood which comprises two compartments separated by a membrane, the improvement wherein the membrane is one of claim [45] 1 which has been obtained by treating a film containing at least one copolymer of acrylonitrile and an ionic or ionisable olefinically unsaturated monomer by immersion in water or an aqueous non-solvent mixture at a temperature between 60.degree. and 250.degree. C.
Apparatus according to claim [1] 2 , wherein during the treatment the film is monoaxially or biaxially stretched between 20 and 1,000% measured linearly during said treatment.
Process according to claim [1] 26 in which the ionic or ionisable monomer is selected from the group consisting of vinyl sulphonic acid, vinyloxybenzene sulphonic acid and methallylsulphonic acid and salts thereof and N-methylvinylpyridinium salts.
A semi-permeable membrane material for use in an apparatus adapted for dialysis and ultrafiltration of blood, having the following characteristics:
Dependencies are inferred from the claim text.