Abstract: A porous polypropylene hollow fiber membrane constructed and arranged for artificial lung use and an artificial lung. The membrane includes a solid phase in an inner surface region thereof formed with particles of polypropylene closely fused and joined to give rise to a continuous phase while partially exposed through the surface thereof, a solid phase in an interior and an outer surface region thereof formed with particles of polypropylene interconnected in the direction of axis of the fiber to give rise to a multiplicity of lumps of polyproplylene and an interstice between the phases having continuous pores interconnected in the form of a three-dimensional network.

Abstract: A permeable membrane excellent in biocompatibility, produced by forming coagulation by melting method in the form of a membrane a terminal-modified polyamide, i.e. a polyether amide comprising component units represented by the following structural formula (I), (II), (III), or (IV), possessing hydrocarbon groups of one to 22 carbon atoms at the terminals thereof, and having a molecular weight in the range of from 10,000 to 100,000, said terminal-modified polyamide being such that the number of said hydrocarbon groups is in the range of from 5 to 100% based on the number of all of the terminal groups of said polyether amide, placing said membrane in contact with a medium capable of swelling or partially dissolving said membrane, and further placing the resultant altered membrane in contact with a solution consisting mainly of a nonsolvent for said polyether amide. ##STR1## wherein R.sup.1, R.sup.2, and R.sup.3 are independently a linear or branched alkylene group of two to four carbon atoms, R.sup.4,R.sup.

Abstract: A porous hydrophilic polypropylene membrane possessing a fine reticular structure, which is characterized by the fact that at least either of the opposite surfaces of membrane forms a surface layer of a reticular structure substantially equal to that in the interior of membrane, the membrane surfaces and the surfaces of pores in the membrane have a hydrophilic polymer chemically bonded thereto, and the membrane is composed substantially of a polypropylene possessing an average pore diameter in the range 0.1 to 2.0 .mu.m, a bubble point of not more than 2.0 kg/cm.sup.2, a porosity in the range of 60 to 85%, and a water permeability of not less than 2 ml/min.mmHgm.sup.2, a method for the production thereof, and a blood plasma separation apparatus incorporating such membranes in a housing are disclosed.

Abstract: A porous polypropylene hollow fiber membrane is disclosed which is characterized by the fact that the solid phase in the inner surface region thereof is formed with particles of polypropylene closely fused and joined to give rise to a continuous phase while partially exposed through the surface thereof, the solid phase in the interior and the outer surface region thereof is formed with particles of polypropylene interconnected in the direction of axis of fiber to give rise to a multiplicity of lumps of polypropylene, and the interstices between these solid phases has continuous pores interconnected in the form of a three-dimensional network. When this porous polypropylene hollow fiber membrane is used in an artificial lung, without reference to the choice between the type adapted to pass blood inside the hollow fiber membrane, it exhibits a high gas-exchange capacity without infliction of injury upon blood cells, aggravation of pressure loss, or leakage of blood plasma.

Abstract: A permeable membrane excellent in biocompatibility, produced by forming coagulation by melting method in the form of a membrane a terminal-modified polyamide, i.e. a polyether amide comprising component units represented by the following structural formula (I), (II), (III), or (IV), possessing hydrocarbon groups of one to 22 carbon atoms at the terminals thereof, and having a molecular weight in the range of from 10,000 to 100,000, said terminal-modified polyamide being such that the number of said hydrocarbon groups is in the range of from 5 to 100% based on the number of all of the terminal groups of said polyester amide, placing said membrane in contact with a medium capable of swelling or partially dissolving said membrane, and further placing the resultant altered membrane in contact with a solution consisting mainly of a nonsolvent for said polyether amide. ##STR1## wherein R.sup.1, R.sup.2, and R.sup.3 are independently a linear or branched alkylene group of two to four carbon atoms, R.sup.4, R.sup.

Abstract: A sheetlike permeable membrane is characterized by being provided on at least one surface thereof with a plurality of minute protuberances. When a plurality of such sheetlike permeable membranes are incorporated as superposed in a modular structure, the minute projections on the surfaces of these permeable membranes form a stable and proper body fluid flow path between the adjacent permeable membranes and permit dimensional reduction of the modular structure and impart improved performance thereto. Thus, the permeable membranes are suitable for use in such body fluid filtration apparatus as blood plasma separation apparatus.

Abstract: A flat permeable membrane of polyolefin 10 to 500 .mu.m in thickness, which membrane has compact layers of intimately bound fine particles of polyolefin formed one each in the opposite surface regions of the membrane and a layer of an aggregate of fine discrete particles of an average diameter of 0.01 to 5 .mu.m formed between the compact layers and, consequently, has fine through pores labyrinthically extended in the direction of thickness of the membrane to establish communication between the opposite surfaces of the membrane and a method for the manufacture of the permeable membrane.

Abstract: A method for the production of a hydrophilic porous membrane of polyvinylidene fluoride excelling in perviousness to water and other various properties and enjoying high commercial value, having uniform hydrohilicity imparted to the surface of pores therein, which porous membrane is characterized by the fact that the reflection spectrum thereof in the visible zone is substantially unchanged from that which existed before the treatment for impartation of hydrophilcity. The method for the production of the hydrophilic porous membrane is characterized by chemically treating the porous membrane is a strong alkali solution containing an oxidizing agent.

Abstract: A flat permeable membrane of polyolefin 10 to 500 .mu.m in thickness, which membrane has compact layers of intimately bound fine particles of polyolefin formed one each in the opposite surface regions of the membrane and a layer of an aggregate of fine discrete particles of an average diameter of 0.01 to 5 .mu.m formed between the compact layers and, consequently, has fine through pores labyrinthically extended in the direction of thickness of the membrane to establish communication between the opposite surfaces of the membrane and a method for the manufacture of the permeable membrane.

Abstract: A method of manufacturing a porous membrane by dissolving vinylidene fluoride polymer in a good solvent such as acetone and then causing solidification of the resultant solution in a non-solvent. The dissolution of the vinylidene fluoride polymer in the solvent is done in a predetermined pressure condition, namely 0.1 kg/cm.sup.2, preferably in a range of 0.5 to 5.0 kg/cm.sup.2.

Abstract: A hydrophilic porous membrane of polyvinylidene fluoride excelling in perviousness to water and other various properties and enjoying high commercial value, having uniform hydropilicity imparted to the surface of pores therein, which porous membrane is characterized by the fact that the reflection spectrum thereof in the visible zone is substantially unchanged from that which existed before the treatment for impartation of hydrophilicity. A method for the production of the hydrophilic porous membrane, characterized by chemically treating the porous membrane in a strong alkali solution containing an oxidizing agent.

Abstract: A method of manufacture of flat permeable membrane comprises the steps of mixing a polyolefin, an organic filler uniformly dispersible in the polyolefin in the molten state, and crystal seed forming agent for the polyolefin; discharging the resultant mixture in the molten state through a die; bringing one surface of the discharged molten membrane into contact with a cooling roll; placine the cooled and solidified flat membrane into contact with an extractant capable of dissolving and extracting the organic filler and capable of dissolving the polyolefin; and subjecting the cooled and solidified flat membrane in a fixed state in longitudinal and lateral directions to a heat treatment at a temperature 20.degree. to 50.degree. C. lower than the melting point of the polyolefin.

Abstract: A porous membrane for use in the separation of blood components, made of a polyolefin, having a wall thickness in the range of 10 to 500 .mu.m, and possessing through holes having an average diameter of 0.01 to 5 .mu.m at a porosity in the range of 10 to 85%, which porous membrane is characterized by exhibiting a shrinkage of not more than 6.0% in a heat treatment carried out at 121.degree. C. for 120 minutes. A method for the manufacture of the porous membrane is also disclosed.

Abstract: A hydrophilic porous membrane has graft chains of a hydrophilic monomer formed on the surface of a hydrophobic porous membrane so as to impart to the surface perfect hydrophilicity such that the produced membrane, when wetted, exhibits a swelling ratio of not more than 1% and a bubble point in the range of 0.5 to 8 kg/cm.sup.2. The hydrophilic porous membrane is produced by irradiating the hydrophobic porous membrane with plasma, feeding the hydrophilic monomer in a gaseous state, and allowing the hydrophilic monomer to be graft polymerized on the surface of the porous membrane. A plasma separator is obtained by using the aforementioned hydrophilic porous membrane as a plasma separation membrane.

Abstract: A flat permeable polyolefin membrane 10 to 500 .mu.m in thickness, which has in one surface thereof a compact layer formed of intimately bound fine polyolefin particles and possessed of fine pores and in the interior and the other surface thereof a layer formed of an aggregate of fine discrete polyolefin particles of an average diameter in the range of 0.01 to 5 .mu.m so adjoined as to form fine labyrinthically continuing through pores and which, therefore, establishes communication between the opposite surfaces of said membrane.

Abstract: A porous hollow fiber membrane, comprising a polyolefin hollow fiber membrane of an annular cross section of substantial circle 150 to 300 .mu.m in inside diameter and 10 to 150 .mu.m in wall thickness, said hollow fiber membrane forming on the inner wall side thereof a tight layer of intimately bound fine polyolefin particles and on the outer wall side thereof a porous texture of fine polyolefin particles bound in chains and containing fine pores extended continuously form said inner wall side to said outer wall side.

Abstract: A dialytic hollow fiber having an improved dialytic effect is disclosed which is characterized by having a wall thickness of 5 to 35 .mu.m and a truly circular cross section 50 to 500 .mu.m in outside diameter throughout the entire length and the entire circumference thereof, having a skin layer of not more than 300 .ANG. in thickness in the outer surface thereof, and containing substantially no voids in the inner surface thereof. This dialytic hollow fiber shows a permeation ratio of 20 to 40% to cytochrome C having an average molecular weight of 12,400 and a maximum fractional molecular weight of about 40,000 at an inhibition ratio of 95%, and an artificial kidney using said dialytic hollow fiber.

Abstract: A method for the manufacture of a hollow fiber which comprises extruding a cellulosic spinning dope through an annular spinning nozzle directly into a non-coagulative liquid layer in a bath filled in the upper layer with a coagulative liquid relative to said spinning dope and in the lower layer with a non-coagulative liquid of a halogenated hydrocarbon and, at the same time, introducing a non-coagulative liquid relative to said spinning dope into the inner center of the tubularly extruded thread of spinning dope, and subsequently passing the resultant tubular fiber of spinning dope through said coagulative liquid thereby coagulating and regenerating the fiber.