Abstract: An aromatic polysulfone type resin hollow fiber membrane having a thickness of 100 to 600 .mu.m and a five-layer structure of an outer surface layer, an outer void layer, an intermediate layer, an inner void layer and an inner surface layer and wherein the inner and outer void layers are present in a thickness ratio of the inner void layer to the outer void layer of 1.5 to 0.6, the intermediate layer has a thickness of 5 to 70 .mu.m, and each of the outer and inner surface layers has an extremely small thickness. The hollow fiber membrane of the kind is excellent in heat resistance, acid resistance, alkali resistance, chemicals resistance and has an improved mechanical strength as well as a high water permeability.

Abstract: An inline intravenous final filter unit especially of the bacteria-retentive type and adapted to be incorporated in administering sets for administering infusion solutions to patients. The filter unit comprises a casing having an inlet cap at its one end and an outlet cap at the other end thereof, at least one porous hollow fiber arranged within the casing in parallel to the longitudinal direction thereof and having a porosity rating of 0.1 to 5.mu., the hollow fiber being closed at its one end opposed to the inlet cap and open at the other end thereof opposed to the outlet cap, the hollow fiber further being tightly fixed at the outer peripheral portion of its open end to the inner wall of the casing by a securing member, and the ratio of the total effective filtration area of the hollow fiber to the capacity of the casing being at least about 4:1.

Abstract: A semipermeable membrane of a polyaryl ether sulfone having repeating units of the formula, ##STR1## wherein Ar.sup.1 and Ar.sup.2 independently represent ##STR2## wherein X, Y and Z independently represents an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a chlorine atom or a bromine atom; and l, m and n independently represent zero or an integer of 1 to 4, andhaving a contact angle of its surface to water of at most 65.degree..

Abstract: Hollow fibers of acrylonitrile polymers having water-permeability greater than 0.2 ml/cm.sup.2.min.atm and useful as an inexpensive superior ultrafilter, comprising(1) a porous layer or layers existing on the outer or/and inner sides of said hollow fibers, the average sizes of pores contained in said porous layer or layers and existing on each of assumptive cylindrical surfaces concentric with the central axis of said hollow fibers, having such a gradient that the average sizes of pores contained in the porous layer existing on the outer side become smaller toward the outer surface of said hollow fibers while the average sizes of pores contained in the porous layer existing on the inner side become smaller toward the inner surface of said hollow fibers, and(2) a reticulate porous layer adjacent to said porous layer or layers (1) and containing therein at least one succession of voids having diameters of at least 10-50 .mu.

Abstract: A semipermeable composite membrane which shows only a small reduction of water permeability even when it is subjected to one time hot water treatment or drying treatment is provided according to the method of the present invention. Said semipermeable composite membrane consists of a porous substance and a reinforcing material embedded therein. Said porous substance has a porous region of network structure at least in one part thereof and numbers of voids in said porous region. Said reinforcing material is a fabric in case of flat type membrane or a braid having a central hollow portion in case of hollow fiber type membrane which is embedded in the wall of the membrane. Said method comprises impregnating said reinforcing material with a polymer solution and treating the impregnated reinforcing material with a coagulating liquid.

Abstract: An ultrafiltration apparatus comprising a module in which a number of hollow fibers having semipermeable walls, disposed in approximately parallel and collected orderly to form a bundle and fixed with a cast-molding material at at least one end portion thereof, are used as semipermeable membrane, a back washing means and a control means for controlling said module and said back washing means, is presented. Said apparatus can be used for a long time without accompanying reduction of filtration capacity.

Abstract: Membranes of acrylonitrile polymers having water-permeability greater than 0.2 ml/cm.sup.2.min.atm and useful as an inexpensive superior ultrafilter, comprising (1) a porous layer or layers existing near and on the surfaces of said membranes, the average sizes of pores contained in said porous layer or layers and existing on each of assumptive parallel planes to the surfaces of said membranes, having such a gradient that said average sizes become smaller toward the surfaces of said membranes, and (2) a reticulate porous layer adjacent to said porous layer or layers (1) and containing therein a succession of voids of cylindrical shape or revolving ellipsoid shape having diameters of 5 - 50.mu. and lengths of at least 10.mu.

Abstract: A method of obtaining urokinase directly from human urine comprising contacting human urine with an acrylonitrile polymer of a unique porous structure formed at the time of polymerization for formation of the polymer and having a porosity of not less than 10% and a specific surface area of .Iadd.not less than .Iaddend.5 m.sup.2 /g. and subsequently eluting the urokinase adsorbed on the polymer. The acrylonitrile polymer employed in the method of the present invention has an excellent adsorption activity to urokinase and therefore, with use of an extremely small amount of the adsorbent, the satisfactory results can be obtained. Moreover, the porous polymer of the present method can also be utilized for purification of low purity crude urokinase obtained by the prior art methods.