Abstract: A fiber reinforced plastic pipe is provided to prevent it from being damaged and make full use of its practical performance when the fiber reinforced plastic pipe, reduced in thickness and increased in diameter by pultrusion process, is reduced in the circumferential direction and inserted into a metal pipe. The fiber reinforced plastic pipe, reduced in thickness and increased in diameter by pultrusion process, includes a fiber bundle spun and aligned in the longitudinal direction, and circumferential reinforced fiber sheet provided at least on one of the outer and inner surface layers. The circumferential reinforced fiber sheet is inserted into the metal pipe to form a power transmission shaft such as an intermediate shaft for use with a propeller shaft or a drive shaft.

Abstract: A fiber reinforced plastic pipe is provided to prevent it from being damaged and make full use of its practical performance when the fiber reinforced plastic pipe, reduced in thickness and increased in diameter by pultrusion process, is reduced in the circumferential direction and inserted into a metal pipe. The fiber reinforced plastic pipe, reduced in thickness and increased in diameter by pultrusion process, includes a fiber bundle spun and aligned in the longitudinal direction, and circumferential reinforced fiber sheet provided at least on one of the outer and inner surface layers. The circumferential reinforced fiber sheet is inserted into the metal pipe to form a power transmission shaft such as an intermediate shaft for use with a propeller shaft or a drive shaft.

Abstract: Extract of tea leaves or (-)-epigallocatechin gallate as the principal ingredient of the extract forms a complex with active aluminum hydroxide. The animal test using rats has established that these complexes have therapeutic effect for gastric ulcers, e.g. pylorus-ligated ulcer and indomethacin-induced ulcer, when orally administered. Tests were also undertaken for the effect on the secretion of gastric juice and acute toxicity of these complexes using rats and mice as the test animals.

Abstract: Disclosed are polyacrylonitrile carbon fibers excellent in substrate strength and adhesion to matrix resin wherein average nitrogen content in the whole carbon fibers which is measured by elementary analysis is 0.5-4.5% by weight and average nitrogen concentration (N/C atom number ratio) in the whole carbon fibers which is measured by elementary analysis and surface silicon concentration (Si.sub.2p /C.sub.1s atom number ratio), surface nitrogen concentration (N.sub.1s /C.sub.1s atom number ratio) and surface oxygen concentration (O.sub.1s /C.sub.1s atom number ratio) which are measured by X-ray photoelectron spectroscopy satisfy the following formulas:0.ltoreq.Si.sub.2p /C.sub.1s .ltoreq.0.020.67 N/C+0.08.ltoreq.O.sub.1s /C.sub.1s -2 Si.sub.2p /C.sub.1s .ltoreq.0.40.ltoreq.N.sub.1s /C.sub.1s -N/C.ltoreq.0.04and method for producing the carbon fibers.

Abstract: A method for detecting the surface characteristic of a carbon fiber, which comprises making the carbon fiber travel through an electrolyte solution, applying an electric potential in said solution between the carbon fiber serving as a working electrode and a counter electrode provided in the solution, said potential being varied continuously within a range of potential not higher than the standard electrode potential, and detecting continuously the resulting charnge of intensity of electric current, and a process for producing a carbon fiber giving a high interfacial bond strength between the fiber and matrix resin, which comprises making the carbon fiber have a constant surface characteristic by application of the above-mentioned detection method.

Abstract: A sizing agent for use with carbon fibers is described, comprising a compound of formula (I) ##STR1## wherein R is --OH or ##STR2## n is 8 to 100, preferably 10 to 50.

Abstract: An intermediate for composite materials which comprises a carbon fiber or a graphite fiber having a tensile strength of 300 to 600 kg/mm.sup.2 and a tensile modulus of 30 to 50 t/mm.sup.2 and giving an intensity of electric current per unit surface area as determined by a potential sweep method in the range of 0.1 to 0.4 .mu.A/cm.sup.2 and a matrix resin.

Abstract: A polymer composition in which an organic polymer and carbon fiber are strongly combined and a process for producing the polymer composition by the electrolytic polymerization of a reactive monomer using the carbon fiber as an electrode, which process is characterized in that the polymerization is carried out by adding an aliphatic epoxy compound, alicyclic epoxy compound, organic titanate compound, or vinylsilane compound, as part or all of the reactive monomer.

Abstract: A non-solvent type thermosetting resin film exhibiting excellent uniformity in thickness is prepared by a process wherein a molten thermosetting resin composition having a curing agent incorporated therein is extruded through a linear slit of a flat die, maintained at a constant temperature, onto a release sheet continuously moving at a constant rate in close proximity to the exit end of the linear slit. As the flat die a flat sheeting die having a substantially circular manifold is used and the molten thermosetting resin is extruded onto the release sheet, which is supported by a back-up roll and confronts the exit end of the linear slit of the flat sheeting die.