Abstract: An object of the present invention is to provide a humidifying apparatus capable of improving the humidification efficiency while lowering the pressure loss of gas even when a low-pressure gas is used, and is suitably usable for fuel cells. The present invention relates to a humidifying apparatus for fuel cells, fabricated by loading a hollow fiber membrane element into a container such that the space communicating with the hollow side of the hollow fiber membranes is isolated from the space communicating with the outer side of the hollow fiber membranes, wherein (a) the inner diameter of the hollow fiber membrane is larger than 400 ?m, (b) the water vapor permeation rate (P?H2O) of the hollow fiber membranes is 0.5×10?3 cm3 (STP)/cm2·sec·cm Hg or more, (c) the ratio (P?H2O/P?O2) of the water vapor permeation rate to the oxygen gas permeation rate of the hollow fiber membranes is 10 or more, and (d) the elongation at tensile break of the hollow fiber membranes after hot water treatment in hot water at 100° C.

Abstract: An asymmetric membrane is formed using a mixture of two or more different polymers including at least one type of polyimide. It is thereby possible to produce a gas separation membrane with low permeation resistance (a high permeation rate) for permeate gases passing through the porous layer of the membrane, which also maintains a practical level of mechanical strength of the membrane and has excellent water resistance and hot water resistance.

Abstract: An asymmetric membrane is formed using a mixture of two or more different polymers including at least one type of polyimide. It is thereby possible to produce a gas separation membrane with low permeation resistance (a high permeation rate) for permeate gases passing through the porous layer of the membrane, which also maintains a practical level of mechanical strength of the membrane and has excellent water resistance and hot water resistance.

Abstract: A gas separating asymmetric membrane such as a gas separating asymmetric hollow fiber comprises an aromatic polyimide comprising recurring units of the formulae (I) and (II): ##STR1## wherein A.sup.1 is a tetravalent unit having a diphenylhexafluoropropane structure, A.sup.2 is a tetravalent unit having a benzene structure, and A.sup.3 is a divalent aromatic unit which is a unit derived from a sulfur atom-containing diamine such as diaminodibenzothiophene, diaminodiphenylenesulfone, diaminothioxanthene-5,5-dioxide or diaminothioxanthone-5,5-dioxide. The aromatic polyimide contains the recurring unit of the formula (I) in an amount of 40 to 90 molar % and the recurring unit of the formula (II) in an amount of 10 to 40 molar %. Further, a process for the preparation of the gas separating asymmetric hollow fiber membrane is also disclosed.

Abstract: An aromatic polyimide double layered hollow filamentary membrane having an excellent heat resistance, chemical resistance, pressure-resistance, and gas-permeating and separating properties comprises (A) an aromatic imide polymer hollow filamentary microporous inner layer and (B) an aromatic imide polymer tubular filamentary asymmetric outer layer composed of (a) tubular filamentary microporous intermediate layer covering and united with the outside surface of the inner layer (A) and (b) a thin dense outside surface layer covering and united with the intermediate layer (a).

Abstract: A photosetting composition useful as a coating varnish comprising a modified, epoxidized butadiene polymer, at least one photopolymerizable monomer and a photosensitizer, the modified, epoxidized butadiene polymer comprising (1) an epoxidized butadiene polymer backbone group, (2) 5 to 50 aromatic or cyclocyclic polybasic carboxylic ester side chain groups per 100 butadiene units, each having at least one acryloyl or methacryloyl terminal group and a linking group formed by a reaction between a carboxylic acid radical in the polybasic carboxylic ester and an epoxy radical in the epoxidized butadiene polymer and, optionally, (3) 0 to 50 phosphoric ester additional side chain groups per 100 butadiene units, each having a linking group formed by a reaction between a hydroxyl radical attached to a P atom in the phosphoric ester and an epoxy radical in the epoxidized butadiene polymer.

Abstract: Carbon fibers having excellent modulus of elasticity and tensile strength are produced in a high yield by a process wherein polybutadiene fibers are prepared by melt-spinning polybutadiene having at least 85% of vinyl structure, a melting point of at least 100.degree. C and a reduced viscosity of 0.3 to 1.2 dl/g; the fibers are then treated in a solution or suspension of a Lewis acid in an inert organic liquid, whereby the pollybutadiene is cyclized and cross-linked; the polybutadiene fibers treated as mentioned above are further treated in a melted sulphur or a sulphur-containing solution at a temperature of 170 to 300.degree. C, whereby the cyclized and cross-linked polybutadiene is dehydrogenated and aromatized; and the fibers treated as mentioned above are carbonized by raising the temperature thereof to 750.degree. C to 3000.degree. C to form carbon fibers or graphite fibers. If so desired, the ordinary carbon fibers which have been produced at 750 to 1500.degree.