Abstract: The present invention relates to a polysufone porous membrane having a high water flux, an excellent resistance to moist heat and an excellent repercolation characteristic, and which comprises a mixed polymer having polyarylsulfone and polyethersulfone at a ratio of from 9/1-1/9 (by weight), the membrane being a graded porous membrane forming a cross-linked polymer network wherein a number of micropores being interconnected from one surface to the other surface, and the membrane comprising two layers wherein one layer being a dense layer having a number of pores with pore sizes in the range of 0.01-1 &mgr;m and thereby having a separation function, and the other layer being a graded type supporting layer supporting said dense layer and having a pore size distribution wherein the pores existing therein and having sizes of 1-100 &mgr;m increase continuously from the dense layer side toward the other surface side, wherein the separation particle size is not larger than 0.

Abstract: This invention relates to a plastic optical fiber having a three-layer structure comprising a core, a cladding and a protective layer wherein the core material is polymethyl methacrylate and the cladding material is a copolymer composed of 20 to 45% by weight of long-chain fluoroalkyl methacrylate units represented by the following formula (1), 54 to 79% by weight of methyl methacrylate units, and 0.05 to 2% by weight of methacrylic acid units. This invention also relates to a plastic optical fiber cable having a four-layer structure wherein the optical fiber cable is produced by covering the aforesaid optical fiber with a jacket layer.CH.sub.2 .dbd.C(CH.sub.3)--COO--(CH.sub.2).sub.2 (CF.sub.2).sub.7 CF.sub.

Abstract: A microporous membrane made of a non-crystalline polymer having, within its wall, microfibrils and slit-like micropores which are oriented in the lengthwise direction of the membrane, said slit-like micropores communicating from one surface to the other surface of the membrane, and forming a stacked construction. This membrane has a high flux value of AFR and WFR, excellent heat-, solvent-, and pressure-resistance, and a high mechanical strength, and does not contain any undesirable materials which eluate during use. This membrane is thus useful as a multi-purpose separation membrane, such as for medical uses, food industries, purification of water or air, and the separation of hot liquids.

Abstract: Disclosed is a porous polypropylene hollow fiber membrane of large pore diameter which have (a) rectangular pores formed by microfibrils that are oriented in the lengthwise direction of the fibers and joint portions that are composed of stacked lamellae, the pores being contiguous with each other from the inner wall surface to the outer wall surface of the hollow fiber membrane to form a stacked, multicellular structure, (b) an average pore diameter ranging from 1.7 .mu.m up to 10 .mu.m as measured with a mercury porosimeter, (c) a porosity of 80 to 95%, and (d) an air permeability of not less than 4.times.10.sup.5 l/m.sup.2.hr.0.5 atm. This hollow fiber membrane can be produced by melt-spinning polypropylene, annealing the resulting unstretched hollow fiber under specific conditions, and then cold-stretching and hot-stretching the annealed hollow fiber under specific conditions.

Abstract: Disclosed is a hydrophobic porous membrane with a polymer having fluorinated alkyl side chains held in physical contact with the surface of a polyolefin porous membrane in which the fluorinated alkyl side chains of the polymer are crystallized, as well as its manufacturing process. Also disclosed is a hydrophobic porous membrane with a fluorinated crosslinked polymer from a fluorinated monomer with a fluorinated alkyl side chain and a crosslinking monomer held in physical contact with the surface of a polyolefin porous membrane, in which the fluorinated alkyl side chains of the fluorinated crosslinked polymer are crystallized, as well as its manufacturing process. These porous membranes use polyolefin porous membranes having a higher mechanical strength and lower costs than the fluorinated polymer porous membranes and still provide superior hydrophobicity over polytetrafluoroethylene type membranes.

Abstract: An apparatus for exchanging substances, such as artificial lung, in which, for raising exchange efficiency by feeding liquid to the outer wall of hollow fiber membranes efficiently without channeling and for reducing the size of the apparatus, an exchanging part comprising a multitude of hollow fiber membrane (3) disposed cylindrically or annularly to permit liquid to flow through the hollow parts is provided, and a pump (P) is disposed on the inner periphery of said exchanging part so that liquid may continuously be fed to the hollow membrane vertically with respect to the axial direction of said hollow fiber membrane (3).

Abstract: A heat-resisting porous membrane comprises a porous polyolefin membrane having a crosslinked copolymer held on at least a part of the pore surfaces thereof, the crosslinked copolymer being composed of a monomer (A) comprising at least one multifunctional (meth)acrylate and a monomer (B) comprising at least one monofunctional (meth)acrylate having a hydrocarbon radical of 5 to 20 carbon atoms; and the heat-resisting porous membrane can be hydrophilized by additionally having a crosslinked polymer thereon. These heat-resisting porous membranes can be used in hot water for a long period of time without deteriorating the mechanical properties inherently possessed by the matrix of the porous membrane.

Abstract: Disclosed is a porous polyethylene hollow fiber membrane of large pore diameter which have (a) rectangular pores formed by microfibrils that are oriented in the lengthwise direction of the fibers and joint portions that are composed of stacked lamellae, the pores being contiguous with each other from the inner wall surface to the outer wall surface of the hollow fiber membrane to form a stacked, multicellular structure, (b) an average pore diameter ranging from greater than 2 .mu.m up to 10 .mu.m as measured with a mercury porosimeter, (c) a porosity of 75 to 95%, and (d) an air permeability of not less than 8.times.10.sup.5 l/m.sup.2 .multidot.hr.multidot.0.5 atm. This hollow fiber membrane can be produced by melt-spinning polyethylene, annealing the resulting unstretched hollow fiber under specific conditions, and then cold-stretching and hot-stretching the annealed hollow fiber under specific conditions.

Abstract: A porous polypropylene hollow fiber membrane of large pore diameter which have (a) rectangular pores formed by microfibrils that are oriented in the lengthwise direction of the fibers and joint portions that are composed of stacked lamellae, the pores being contiguous with each other from the inner wall surface to the outer wall surface of the hollow fiber membrane to form a stacked, multicellular structure, (b) an average pore diameter ranging from greater than 1 .mu.m up to 10 .mu.m as measured with a mercury porosimeter, (c) a porosity of 70 to 95%, and (d) an air permeability of not less than 4.times.10.sup.5 l/m.sup.2 .multidot.hr.multidot.0.5 atm can be produced by melt-spinning polypropylene, annealing the resulting unstretched hollow fiber under specific conditions, and then cold-stretching and hot-stretching the annealed hollow fiber under specific conditions.

Abstract: Disclosed is a membranous gas separator comprising (a) a porous substrate having an average pore diameter of not greater than 100 .ANG. and (b) a .pi.-electron conjugated conducting polymer retained within at least a part of the pores of the porous substrate in such a way that the pores are not blocked characterized in that retaining the .pi. -electron conjugated conducting polymer within the pore is carried out by a chemical oxidative polymerization.

Abstract: Disclosed is a process for preparing a membranous gas separator comprising (a) a porous substrate having an average pore diameter of not greater than 100 .ANG. and (b) a .pi.-electron conjugated conducting polymer retained within at least a part of the pores of the porous substrate in such a way that the pores are not blocked, characterized in that retaining the .pi.-electron conjugated conducting polymer within the pore is carried out by a chemical oxidative polymerization.

Abstract: Disclosed are a multilayer composite hollow fiber comprising at least one nonporous separating membrane layer (A) performing a separating function and two or more porous layers (B) performing a reinforcing function, the layer (A) and the layers (B) being alternately laminated so as to give a structure having internal and external surfaces formed by the porous layers (B), as well as a method of making such a hollow fiber.In this multilayer composite hollow fiber, the separating membrane can be formed as an ultrathin, homogeneous membrane. Moreover, the separating membrane is not liable to get damaged owing to the unique structure of the hollow fiber. Furthermore, such hollow fibers can be readily and stably produced on an industrial scale.

Abstract: The present invention provides a heat exchanger using hollow fibers formed of an organic polymer as the heat transfer tubes; a blood oxygenating device comprising a blood oxygenator combined with the aforesaid heat exchanger; and a small-sized and lightweight blood oxygenator which comprises a blood oxygenator of the hollow-fiber membrane type having the aforesaid heat exchanger incorporated thereinto to form an integral unit, and hence has excellent gas exchange and heat exchange performance.

Abstract: Disclosed are a multilayer composite hollow fiber comprising at least one nonporous separating membrane layer (A) performing a separating function and two or more porous layers (B) performing a reinforcing function, the layer (A) and the layers (B) being alternately laminated so as to give a structure having internal and external surfaces formed by the porous layers (B), as well as a method of making such a hollow fiber.In this multilayer composite hollow fiber, the separating membrane can be formed as an ultrathin, homogeneous membrane. Moreover, the separating membrane is not liable to get damaged owing to the unique structure of the hollow fiber. Furthermore, such hollow fibers can be readily and stably produced on an industrial scale.

Abstract: A blood oxygenator comprising a housing generally in the form of a box and bundles of hollow fibers of semipermeable membrane set therein for effecting gas exchange therethrough. In this blood oxygenator, each end of each bundle of hollow fibers of semipermeable membrane is secured together by potting material in such a way as to allow their open ends to communicate separately with a gas inlet and a gas outlet; the space around the bundles of hollow fibers of semipermeable membrane communicates with a blood inlet and a blood outlet; the blood-gas contact chamber within the housing is divided into a plurality of compartments with the interposition of blood flow channels narrowed by baffles; and the bundle of hollow fibers of semipermeable membrane is disposed in the contact chamber so as to be substantially parallel to the baffles.

Abstract: A blood oxygenator of the outside perfusion type using hollow fibers as the gas exchange membrane. In this blood oxygenator, a plurality of contact chambers each containing a bundle or bundles of hollow fibers for gas exchange use and communicating with a blood inlet and a blood outlet are disposed to make blood flow in multiple paths within a housing, and each bundle of hollow fibers is arranged so as to be substantially perpendicular to the direction of blood flow. In spite of its compact construction, this blood oxygenator has high oxygen and carbon dioxide exchange rates per unit of membrane even when used in the gas exchange of blood having high flow rate, exhibits only a small pressure loss, and causes little channeling of the blood and gas. Moreover, it is easy to manufacture because of its relatively simple structure.

Abstract: A regenerated cellulose hollow fiber exhibiting a good cellulose II crystalline structure and an exchanged wet strength/wet elongation ratio is prepared by a process wherein: a dope comprised of cellulose ester in a non-volatile organic solvent is extruded through a circular slit defined between inner and outer tubes of a spinning nozzle having a double tube structure, while a core liquid is forced through the inner tube of said nozzle; the hollow fibrous extrudate is coagulated in a coagulating bath; the coagulated hollow fibrous extrudate is drawn 1.05 to 2.00 times its original length; and then, the drawn hollow fiber still containing a core liquid in the hollow is treated with an aqueous caustic alkali solution containing at least 0.5% by weight of a water soluble metal salt, thereby hydrolyzing the cellulose ester into cellulose.