Abstract: The first group of the present invention is a wood reinforcing carbon fiber prepreg, which is produced through impregnation with a mixture resin at a viscosity of 3 to 150 poises at 20° C., wherein the mixture resin contains one or more resins selected from resorcinol based resins and resol type phenol based resins, formaldehydes as curing agents and inorganic acids or organic acids as curing catalysts. The first group of the present invention is a wood reinforcing carbon fiber prepreg having a longer usable time and being capable of imparting the rigidity and elastic modulus of carbon a fiber to the wood to be reinforced at a high ratio. The second group of the present invention is a wood reinforcing carbon fiber prepreg attached wood based sheet, wherein a wood based sheet of a thickness of 0.01 mm to 0.06 mm is arranged on at least one face of a carbon fiber prepreg sheet produced through impregnation with a mixture resin containing a thermosetting resin and a curing agent or a curing catalyst.

Abstract: To provide a steering wheel which is lightweight, and which has adequate strength and shock resistance, a carbon fiber prepreg 13 is wound on a mandrel 11 or a lightweight foam core 40 so as to obtain a preformer 14. By heating this preformer 14 in a mold 18, a steering wheel is obtained wherein the rim is formed from a fiber-reinforced synthetic resin joined to a metal skeleton 23.

Abstract: Depositing a thermoplastic resin powder in between the individual fibers of a reinforcing continuous fiber bundle and subsequently applying a solution of a binder resin dissolved in a solvent to the resulting reinforcing continuous fiber bundle, the thermoplastic resin powder is fixed in between the individual fibers via the binder resin which concurrently works to bind the individual fibers together. Then, the solvent of the binder resin is substantially removed from the resulting reinforcing continues fiber bundle within a temperature zone not above the melting point or flow point of the thermoplastic resin powder. In the molding material produced by the method, the individual fibers of the reinforcing continuous fiber bundle, the individual fibers and the thermoplastic resin powder, and the individual thermoplastic resin powders are independently fixed together, all in a pin-point fashion via the binder resin, so the molding material substantially does not contain the solvent of the binder resin.

Abstract: By depositing a thermoplastic resin powder inbetween the individual fibers of a reinforcing continuous fiber bundle and subsequently applying a solution of a binder resin dissolved in a solvent to the resulting reinforcing continuous fiber bundle, the thermoplastic resin powder is fixed inbetween the individual fibers via the binder resin which concurrently works to bind the individual fibers together. Then, the solvent of the binder resin is substantially removed from the resulting reinforcing continuous fiber bundle within a temperature zone not above the melting point or flow point of the thermoplastic resin powder. In the molding material produced by the method, the individual fibers of the reinforcing continuous fiber bundle, the individual fibers and the thermoplastic resin powder, and the individual thermoplastic resin powders are independently fixed together, all in a pin-point fashion via the binder resin, so the molding material contains substantially no solvent of the binder resin.

Abstract: To provide a steering wheel which is lightweight, and which has adequate strength and shock resistance, a carbon fiber prepreg 13 is wound on a mandrel 11 or a lightweight foam core 40 so as to obtain a preformer 14. By heating this preformer 14 in a mold 18, a steering wheel is obtained wherein the rim is formed from a fiber-reinforced synthetic resin joined to a metal skeleton 23.

Abstract: An apparatus for producing a cylindrical product of a fiber reinforcement-thermoplastic resin composite, which involves disposing a mandrel on a flexible guide sheet which can be formed in the shape of the letter U around the mandrel, heating a fiber reinforcement-thermoplastic resin composite sheet to a temperature not lower than the distortion temperature of the resin and lower than the thermal degradation temperature of the resin of the composite, disposing an end of the heated composite sheet at a line of contact of the mandrel with the flexible guide sheet, then rolling the mandrel on the guide sheet while moving the guide sheet, the guide sheet forming a shape of the letter U around the mandrel being drawn into the concave portion of the letter U, and the composite sheet disposed between the mandrel and the guide sheet being in intimate contact with the mandrel and the guide sheet, to thereby wind the composite sheet on the mandrel, and then recovering a cylindrical product made from the wound composite

Abstract: In a carbon fiber reinforced resin coil spring the carbon fibers A,B are oriented at an angle of .+-.30.about..+-.60.degree. relative to the axis of the cord of the spring. Further, the ratio A/B of the amount of the fibers A oriented in the compression direction and the fibers B oriented in the tension direction lies within the range of;1.1<A/B<4.

Abstract: A process for producing a cylindrical product of a fiber reinforcement-thermoplastic resin composite, which involves disposing a mandrel on a flexible guide sheet which can be formed in the shape of the letter U around the mandrel, heating a fiber reinforcement-thermoplastic resin composite sheet to a temperature not lower than the distortion temperature of the resin and lower than the thermal degradation temperature of the resin of the composite, disposing an end of the heated composite sheet at a line of contact of the mandrel with the flexible guide sheet, then rolling the mandrel on the guide sheet while moving the guide sheet, the guide sheet forming a shape of the letter U around the mandrel being drawn into the concave portion of the letter U, and the composite sheet disposed between the mandrel and the guide sheet being in intimate contact with the mandrel and the guide sheet, to thereby wind the composite sheet on the mandrel, and then recovering a cylindrical product made from the wound composite sh

Abstract: A process for the preparation of an organic solvent soluble ion-doped poly(alkyl-substituted pyrrole) which comprises dissolving an alkyl-substituted pyrrole compound represented by formula (I) in an organic solvent, oxidation-polymerizing the dissolved alkyl-substituted pyrrole in the presence of at least one oxidation polymerization agent selected from the group consisting of a ferric salt and a copper (II) salt to form an ion-doped poly(alkyl-substituted pyrrole), next adding water to the polymerization reaction system thus obtained and then recovering an organic solvent soluble ion-doped poly(alkyl-substituted pyrrole): ##STR1## wherein X represents an alkyl group; and Y represents a hydrogen atom or an alkyl group.

Abstract: (1) A carbon film derived from a polyimide film, which has a tensile strength of at least 15 Kgf/mm.sup.2, a tensile modulus of elasticity of at least 5000 Kgf/mm.sup.2 and an electric conductivity of at least 200 S/cm.(2) A process for preparing a carbon film which comprises the following steps:1) reacting a monomer combination selected from the group consisting of a combination comprising a tetracarboxylic acid dianhydride and an aromatic diamine and a combination comprising a tetracarboxylic acid dianhydride, an aromatic diamine, and a polyamino compound having at least three amino groups to form a polyamic acid;2) forming a film of polyamic acid;3) imidizing the polyamic acid film to form a polyimide film having a tensile strength of at least 10 Kgf/mm.sup.2 and a tensile modulus of elasticity of at least 500 Kgf/mm.sup.2 ; and4) carbonizing the polyimide film in an inert gas or in a vacuum until a carbon film having a tensile strength of at least 15 Kgf/mm.sup.

Abstract: A polyamic acid composite comprising i) a polyamic acid having three dimensional network molecular structure obtained by a ring-opening polyaddition reaction of a tetracarboxylic acid dianhydride with an aromatic diamine and a tri- or tetramino compound and ii) (a) a high polymer component having a different molecular structure from the polyamic acid, which is dispersed in the three dimensional network molecular structure of the polyamic acid and of which molecular chains are interpenetrated with molecular chains of the polyamic acid or (b) a curable resin composition which is dispersed in the three dimensional network molecular structure of the polyamic acid and which is capable of forming a cured resin of which molecular chains are interpenetrated with molecular chains of the polyamic acid, and a polyimide composite obtained from the polyamic acid composite, and process for production thereof.

Abstract: The resin composition comprises, as essential components, (A) an epoxy resin, (B) a thermoplastic resin and (C) particles of a diaminodiphenylsulfone compound whose cross linking reactivity with the epoxy resin is prevented until the resin composition is subjected to molding or curing by a resin coating which is formed (i) by forming or adhering resin particles onto the surface of the diaminodiphenylsulfone particles or (ii) by forming a resin film on the diaminodiphenylsulfone particles, the coating resin used for forming the resin coating is not compatible with components included in the resin composition at the temperature up to the curing temperature of the resin composition.

Abstract: (1) A carbon film derived from a polyimide film, which has a tensile strength of at least 15 Kgf/mm.sup.2, a tensile modulus of elasticity of at least 5000 Kgf/mm.sup.2 and an electric conductivity of at least 200 S/cm.(2) A process for preparing a carbon film which comprises the following steps:1) reacting a monomer combination selected from the group consisting of a combination comprising a tetracarboxylic acid dianhydride and an aromatic diamine and a combination comprising a tetracarboxylic acid dianhydride, an aromatic diamine, and a polyamino compound having at least three amino groups to form a polyamic acid;2) forming a film of polyamic acid;3) imidizing the polyamic acid film to form a polyimide film having a tensile strength of at least 10 Kgf/mm.sup.2 and a tensile modulus of elasticity of at least 500 Kgf/mm.sup.2 ; and4) carbonizing the polyimide film in an inert gas or in a vacuum until a carbon film having a tensile strength of at least 15 Kgf/mm.sup.

Abstract: This invention relates to acrylic fiber strands suitable for use in production of carbon fibers and to a process for the production of the acrylic fiber used, in which an aminopolysiloxane and a dialkyl sulfosuccinate are coated on acrylic polymer filaments which permits the avoidance of problems such as the generation of static electricity and the deposition of an oil scum on rollers and guides. Because of such effects, excellent bundlability of fiber strands and stable operation of the carbonization process can be attained. The acrylic fiber strands thus obtained can be used for the production of high quality carbon fiber strands.

Abstract: A low fuming phenolic resin prepreg comprising a fibrous base impregnated with 20 to 60% by weight of a resin composition comprising (a) 100 parts by weight of a resol phenolic resin, (b) from 1.5 to 15 parts by weight of polyacrylamide, (c) from 1.5 to 25 parts by weight of an epoxy resin, and (d) from 1.5 to 15 parts by weight of an inorganic filler, and the method for preparing the prepreg by impregnating a solution of (a), (b) and (c) having dispersed therein the filler into a fibrous base. The method for the prepreg comprising impregnating the fibrous base with the resin composition. The phenolic resin prepreg has low fuming properties as well as excellent self-adhesion.

Abstract: A polyamic acid having a three-dimensional network molecular structure produced by a gel forming ring-opening polyaddition reaction in an organic solvent of the reaction components comprising:(A) an acid component consisting of at least one tetracarboxylic acid dianhydride selected from the group consisting of a tetracarboxy benzene dianhydride, a tetracarboxy dianhydride of a compound having 2 to 5 condensed benzene rings, and compounds represented by formula (III), and substituted compounds thereof: ##STR1## wherein R.sub.1 represents --O--, --CO--, --SO.sub.2 --, --SO--, an alkylene group, an alkylene bicarbonyloxy group, an alkylene bioxycarbonyl group, a phenylene group, a phenylene alkylene group, or a phenylene dialkylene group, n.sub.4 is 0 or 1, n.sub.5 is 0 or 1; and n.sub.6 is 1 or 2, provided that the sum of n.sub.5 and n.sub.

Abstract: A carbon fiber chopped strands suitable for use in production of a composite with a matrix material, which have a circular or elliptical cross-section, wherein carbon fiber filaments are bundled by a sizing agent in an amount of from 1 to 10% by weight based on the chopped strand, and which have denseness of from 0.4 to 0.9 according to the formula below: ##EQU1## where D denotes the average diameter of the chopped strands, d denotes the average diameter of filaments constituting the chopped strand and N denotes the number of the filaments, and a method for production thereof by impregnating a carbon fiber strand with a sizing agent in an amount of from 1 to 10% by weight based on the total weight of the chopped strand to form a sized strand, and then cutting the sized strand, thereby giving the denseness of from 0.4 to 0.9 according to the formula (1).

Abstract: A method for producing graphite fiber comprising graphitizing carbon fiber having a strength of 500 kgf/mm.sup.2 or more and a modulus of elasticity of from 27,000 to 33,000 kgf/mm.sup.2, and having at least on the surface of the fibers, from 0.2 to 2% by weight of an epoxy resin as a sizing agent, from 0.005 to 0.10% by weight of silicon and 0.005 to 0.02% by weight of phosphorus based on the weight of carbon fiber having said epoxy resin, silicon and phosphorus.

Abstract: A process for producing an electrically conductive polymer film which comprises electrically polymerizing a monomer, capable upon polymerization of providing conjugated double bonds, in an electrolytic polymerization solution containing a fluorocarbon surfactant and a dopant electrolyte using a working electrode and a counter-electrode immersed in the electrolytic polymerization solution, with the proviso that for an anodic oxidation electrolytic polymerization a fluorocarbon surfactant except an anionic fluorocarbon surfactant is used, and for a cathodic reduction electrolytc polymerization a fluorocarbon surfactant except a cationic fluorocarbon surfactant is used.

Abstract: A process for electrolytically treating the surface of a carbon fiber without using a surface treatment bath, comprising forming a flow of an electrolyte solution in the form of a liquid film or column at at least one anode and at at least one cathode which alternate along the direction of the length of the carbon fiber, and passing carbon fiber strands through the flows of the electrolyte solution to apply electric current to the carbon fiber strands.