Abstract: An immersion type membrane filter apparatus 200 is intended for obtaining filtrate by filtrating a fluid to be processed stored within a storage bath 150 and primarily includes a filtration membrane module 300 and an air bubbles supply device 500 disposed therebelow. The filtration membrane module 300 has numerous tubular membranes 310 having on the inner surfaces thereof the function of filtrating a fluid to be processed packed within a cylindrical housing vessel 301 having a discharge port 303 for filtrate. The tubular membranes 310 are held in an opened state at both the ends of the housing vessel 301. The filtration membrane module 300 is soaked in a fluid to be processed in such a way that the tubular membranes 310 are opened in the vertical direction. When air bubbles are supplied to the filtration membrane module 300 from an air bubbles supply device 500, the fluid to be processed flows through the tubular membranes 310 from the down side upwards to naturally circulate within the storage bath 150.

Abstract: An immersion type membrane filter apparatus 200 is intended for obtaining filtrate by filtrating a fluid to be processed stored within a storage bath 150 and primarily includes a filtration membrane module 300 and an air bubbles supply device 500 disposed therebelow. The filtration membrane module 300 has numerous tubular membranes 310 having on the inner surfaces thereof the function of filtrating a fluid to be processed packed within a cylindrical housing vessel 301 having a discharge port 303 for filtrate. The tubular membranes 310 are held in an opened state at both the ends of the housing vessel 301. The filtration membrane module 300 is soaked in a fluid to be processed in such a way that the tubular membranes 310 are opened in the vertical direction. When air bubbles are supplied to the filtration membrane module 300 from an air bubbles supply device 500, the fluid to be processed flows through the tubular membranes 310 from the down side upwards to naturally circulate within the storage bath 150.

Abstract: This invention provides a hydrophilic membrane wherein a hydrophilic cellulose derivative of a number average molecular weight of 2000˜8000 is adsorbed irreversibly to a hydrophobic membrane of an aromatic polymer. Since an amount of leaching substances is extremely small, the membrane can be used suitably in such fields as medical applications, electronics, etc. where even a quite small quantity of leaching substances from the membranes is limited especially small.

Abstract: A porous hollow fiber of polysulfone suitable for use in filtration such as microfiltration and having a prolonged life, the hollow fiber having an inner surface with a network structure such that approximately circular openings having a minor axial length of 0.1 to 10 .mu.m are present in proximity to each other at intervals of not more than the average minor axial length of the openings, thus providing a surface fraction of openings of 50 to 90% and/or an outer surface of a structure such that the outer surface region has undergone fibrillation to a high degree to form fibrils oriented in the fiber axial direction at intervals of 0.2 to 3 .mu.m, thus providing a surface fraction of openings of at least 50%. The hollow fiber is prepared by a process characterized in that a polymer substance having an extremely high molecular weight such as polyethylene glycol and polyvinyl pyrrolidone is added to the spinning solution of polysulfone, thereby improving the spinnability.

Abstract: A hollow fiber type filter having a simple structure and also having an excellent heat resistance which can withstand a rapid temperature change due to high temperature generated in, for example, a steam sterilization is disclosed. The hollow fiber type filter comprises a case and a plurality of hollow fiber type filter membranes which are bundled and fixed with a potting material in the case, wherein a stop ring designed such that a thickness thereof increases inwardly is provided on an inner surface of the case into which the potting material is poured, and air release portions which penetrate the stop ring in the direction of the thickness of the stop ring is formed at an appropriate portion of the stop ring.

Abstract: A porous hollow fiber of polysulfone suitable for use in filtration such as microfiltration and having a prolonged life, the hollow fiber having an inner surface of a network structure such that approximately circular openings having a minor axial length of 0.1 to 10 .mu.m are present in proximity to each other at intervals of not more than the average minor axial length of the openings, thus providing a surface fraction of openings of 50 to 90%, and/or an outer surface of a structure such that the outer surface region has undergone fibrillation to a high degree to form fibrils oriented in the fiber axial direction at intervals of 0.2 to 3 .mu.m, thus providing a surface fraction of openings of at least 50%. The hollow fiber is prepared by a process characterized in that a polymer substance having an extremely high molecular weight such as polyethylene glycol and polyvinyl pyrrolidone is added to the spinning solution of polysulfone, thereby improving the spinnability.

Abstract: Uniform discoid particles made of at least one member selected from the group consisting of a natural high molecular substance, a synthetic high molecular substance and an inorganic compound, wherein each particle has a diameter of 20 to 2,000 .mu.m and a thickness/diameter ratio of 1/2 to 1/50, and not less than 80% of the whole particles have a diameter within the range of 0.5 to 2 times the number average diameter, and a process for preparing the particles. The discoid particle of the present invention has a larger surface area and therefore has a high efficiency when employed in various uses such as a parent material for an ion exchange resin, a packing material for a chromatograph, a catalyst and an culture medium for cell culture in comparison with conventional spherical particle.

Abstract: Uniform polymer particles in a spherical form, having a three dimensional network structure, wherein not less than 80% by volume of the whole particles have a particle size within the range of .+-.20% of the volume average particle size of said uniform polymer particles, and said uniform polymer particles do not include particles having a particle size of not more than 5% of the volume average particle size, a process for preparing the uniform polymer particles, an apparatus suitable for use in the process, and a method of direct extracorporeal hemo-perfusion treatment using the uniform polymer particles. The uniform polymer particles of the present invention can be also used in various uses such as a parent material for an ion exchange resin, an adsorbent, and a packing material for a chromatography.

Abstract: A solution containing at least two metals comprising (a) at least one member selected from the group consisting of a metal alkoxide and an oligomer thereof, and (b) at least one member selected from the group consisting of a metal chelate and a chelating agent. By decomposing the solution, there is provided an inorganic composite material and a maltilayer film which are useful as novel functional ceramic materials such as various sensors, electric conductive materials, magnetic recording materials, piezoelectric materials, dielectric materials and materials for optical devices.

Abstract: A polysulfone hollow fiber filter medium having substantially no skin layer in the outer and inner surface areas, the maximum diameter of the pores being from 0.1 to 5 .mu.m., the maximum diameter of the openings of the pores formed in the inner surface being from 0.01 to 10 .mu.m. and the maximum diameter of the openings of the pores formed in the outer surface being from 0.01 to 5 .mu.m., which is prepared by extruding a solvent solution of a polysulfone from a ring nozzle together with an inside coagulating liquid extruded from the inside of the ring nozzle, said solution having a transition temperature at which the viscosity rise changes to the viscosity drop when the temperature of the solution is dropped, and being maintained at a temperature of not less than the transition temperature, and immediately or after passing through a dry space of not more than 50 cm.

Abstract: A process for preparing a porous ceramic thin film which comprises applying an anhydrous solution containing an organometallic compound and a multifunctional organic compound to a substrate, and thermally decomposing the compounds. The porous ceramic thin film prepared by the process has pores of not more than 10 .mu.m in pore size, and is useable as for materials of various sensors.

Abstract: A solution containing at least two metals comprising (a) at least one member selected from the group consisting of a metal alkoxide and an oligomer thereof, and (b) at least one member selected from the group consisting of a metal chelate and a chelating agent. By decomposing the solution, there is provided an inorganic composite material and a multilayer film which are useful as novel functional ceramic materials such as various sensors, electric conductive materials, magnetic recording materials, piezoelectric materials, dielectric materials and materials for optical devices.

Abstract: The invention provides a tubular membrane separation apparatus useful for ultrafiltration and reverse osmosis. A tubular separation element (1) is fitted in a porous pressure-resistant tube (2) which is inserted in a liquid collector tube (3) of larger diameter. The collector tube (3) is detachably connected to connector tubes (6) by joints (4). Each end of the separation element (1) is held between the inner surface of the joint (4) and the end of the connector tube (6) and thereby sealed. The separation element (1) is replaceable, and the apparatus can be disassembled for cleaning.

Abstract: A process for preparing a composite amphoteric ion exchange membrane, which comprises forming a thin membrane not exceeding 5 microns thick by applying to a surface of a microporous polymer substrate having a physical, selective permeability of its own, a coating consisting of a polymer having either a cation or anion exchange group and a functional group capable of receiving another ion exchange group having an opposite sign from the cation or anion exchange group or a mixture of two polymers one of which has either a cation or an anion exchange group and the other of which has a functional group capable of receiving an ion exchange group having an opposite sign from the cation or anion exchange group, and introducing the ion exchange group having an opposite sign to said functional group to provide a ratio of anion to cation exchange capacity in the range of from 0.5 to 2.0.

Abstract: A membrane separation apparatus adapted for use in ultrafiltration is provided comprising a casing and a membrane unit enclosed therein, said membrane unit comprising a composite membrane folded flatly in zigzag relation to form a plurality of stacked layers defining a plurality of first flow channels in alternately interleaving relation thereto, said composite membrane being made of a flexible porous support and having a pair of selectively permeable membranes on opposite outer surfaces thereof and a second flow channel therebetween.

Abstract: Composite membranes bearing ion-exchange groups suitable for use in membrane separation processes are produced by providing a porous substrate which is physically semipermeable by itself, applying a coating composition consisting essentially of a filmforming polymeric material to which ion-exchange groups are introduceable and a liquid medium onto the surface of said substrate, removing said liquid medium to provide an ultrathin membrane of said material having a thickness less than 10 microns, and treating said ultrathin membrane to provide said ion-exchange groups throughout said ultrathin membrane.