Abstract: According to the present invention there is provided a method for opening a fabric, in which warp and weft yarns can be uniformly opened using a simple method without having to alter the fabric weaving procedure. The method is a method for opening a fabric (4) produced by weaving a warp yarn (2) and a weft yarn (3), each of which having a bundled plurality of fiber filaments (1). A contact body (6) is provided to a surface of the fabric (4) with a protective film (5) interposed therebetween, and the contact body (6) is caused to move over the fabric (4) obliquely, and in a relative manner, with respect to the longitudinal direction of the warp yarn (2) or the weft yarn (3), whereby the warp yarn (2) or the weft yarn (3) is spread.

Abstract: A carbon fiber strand obtained by bundling 20,000-30,000 carbon fibers each having, in the surface thereof, creases which are parallel to the fiber-axis direction. In an examination with a scanning probe microscope, the creases in the carbon fiber surface are apart from each other at a distance of 120-160 nm and have a depth of 12-23 nm, excluding 23 nm. The carbon fibers have an average fiber diameter of 4.5-6.5 nm, specific surface area of 0.9-2.3 m2/g, and density of 1.76 g/cm3 or higher. The carbon strand has a tensile strength of 5,900 MPa or higher and a tensile modulus of 300 GPa or higher. When would on a bobbin at a tension of 9.8 N, the strand on the bobbin has a width of 5.5 mm or larger. When the carbon fiber strand is examined by a strand splitting evaluation method in which the strand is caused to run through three stainless-steel rods while applying a tension of 9.8 N thereto, no strand splitting is observed.

Abstract: A carbon fiber strand which is produced by obtaining a solidified-yarn strand by spinning with a spinneret having 20,000-30,000 spinning holes, passing the strand through an interlacing nozzle having an air blowing pressure of 20-60 kPa to obtain precursor fibers, oxidizing them in heated air having a temperature of 200-280° C. to obtain oxidized fibers, subjecting these oxidized fibers to a first carbonization treatment in an inert-gas atmosphere at a temperature of 300-900° C. in which the fibers are firstly stretched in a stretch ratio of 1.03-1.06 and then secondarily stretched in a stretch ratio of 0.9-1.01, subsequently conducting a second carbonization treatment in an inert-gas atmosphere at 1,360-2,100° C., and then conducting a surface oxidization treatment in an aqueous solution of an inorganic acid salt in a quantity of electricity of 20-100 C per g of the carbon fibers.

Abstract: The present invention provides a prepreg made by impregnating a resin composition into a fiber reinforcing material, the resin composition comprising 50 to 60 parts by weight of an aromatic bismaleimide (A), 30 to 40 parts by weight of an alkenylphenol ether compound (B) expressed by a specific general formula, 5 to 15 parts by weight of an alkenyl aromatic comonomer (C), and 1 to 10% by weight of a thermoplastic resin (D) soluble in (B) or (C) based on the total amount of (A), (B) and (C), the aromatic bismaleimide (A) including 90% by weight or more of bismaleimide diphenylmethane, and a composite material having a glass transition temperature of 260 to 350° C. obtained by heat-curing the prepreg.

Abstract: Provided are a thermosetting resin composition suitable for forming a composite material that has excellent mechanical characteristics, such as wet heat resistance and toughness, and also a prepreg using the same. The thermosetting resin composition includes at least a component [A] including thermoplastic resin particles and a thermosetting resin [B]. The component [A] includes a melt blend of at least the components [A-1] and [A-2] given below. In the particles, the component [A-1] and the component [A-2] may be in a non-compatibilized state or a compatibilized state.

Abstract: There are provided a prepreg obtained by impregnating into a fiber reinforcement a resin composition including 40 to 70 parts by weight of an aromatic bismaleimide (A) expressed by a specific general formula, 60 to 30 parts by weight of an alkenylphenol (B) expressed by a specific general formula, 1 to 10% by weight of a polyetherimide (C) of a thermoplastic resin base on the total amount of components (A) and (B), and 15 to 50% by weight of an amorphous polyimide (D) having a glass transition temperature of 200° C. or higher, and a composite material obtained by heating and curing the prepreg. Also provided are the fiber-reinforced prepreg and the composite material without spoiling thermal resistance characteristic of the aromatic bismaleimide resin used as a main component of a resin and having excellent toughness imparted thereto.

Abstract: Disclosed is an epoxy resin composition comprising at least component [A]: a glycidyl-amino-group-containing polyfunctional epoxy resin, component [B]: an epoxy resin other than the component [A], component [C]: a polyisocyanate compound, component [D]: an aromatic-amine-based curing agent, and component [E]: a thermoplastic resin, characterized in that the epoxy resin composition has an epoxy group concentration of 0.67 to 1.51 Eq/kg of the total amount of the components [A] to [D], and preferably that the component [E] is in a proportion of 10 to 50% by weight of the total epoxy resin composition. Use of a prepreg having the resin composition as a matrix resin makes it possible to obtain a composite material with excellent heat resistance and wet heat resistance together with high mechanical properties.

Abstract: A process for the production of hollow carbon fibres by the treatment of a stabilised carbon fibre precursor in an application device using high-frequency electromagnetic waves. The application device includes structure supplying the electromagnetic waves to a outcoupling region and a hollow outer conductor terminating in the outcoupling region. For the treatment, a field of the high-frequency electromagnetic waves is generated and a field strength in the range from 15 to 40 kV/m is set in the outcoupling region of the application device. The stabilised carbon fibre precursor is conveyed continuously as an inner conductor through the hollow outer conductor, thereby forming a coaxial conductor having an outer and an inner conductor, and through the subsequent outcoupling region. An inert gas atmosphere is created in the coaxial conductor and in the outcoupling region by passing through an inert gas.

Abstract: The present invention relates to a carbon fiber having enhanced surface properties, tensile strength and tensile modulus to be able to obtain a composite material having high composite properties such as excellent impact resistance, preferably a carbon fiber of which tensile modulus is greater than or equal to 340 GPa and tensile strength is greater than or equal to 5970 MPa. The carbon fiber has the properties that the compression strength in the transverse direction of monofilament of the carbon fiber is greater than or equal to 130 kgf/mm2, the surface oxygen concentration (O/C) of the carbon fiber is in the range of 20 to 30%, and the value of the specific surface area of the carbon fiber based on a BET method by krypton absorption is in the range of 0.65 to 2.5 m2/g. The present invention also relates to a composite material including the carbon fiber and a matrix resin wherein the compression strength after impact is preferably greater than or equal to 220 MPa.

Abstract: There is disclosed a method of producing a pre-oxidation fiber in the production of the pre-oxidation fiber by subjecting a polyacrylic precursor fiber to pre-oxidation processing in an oxidizing atmosphere, including shrinking the precursor fiber as a pretreatment of pre-oxidation at a load of 0.58 g/tex or less in the temperature range of 220 to 260° C. under conditions in which the degree of cyclization (I1620/I2240) of the precursor fiber measured by a Fourier transform infrared spectrophotometer (FT-IR) does not exceed 7%, initially-drawing the precursor fiber at a load of 2.7 to 3.5 g/tex in an oxidizing atmosphere at 230 to 260° C. in the ranges of the degree of cyclization of not exceeding 27% and of the density of not exceeding 1.2 g/cm3, and then subjecting the pre-oxidation fiber to pre-oxidation treatment.

Abstract: The present invention discloses: a resin composition comprising, as essential components, 100 parts by mass of a component (A) which is an epoxy resin, 41 to 80 parts by mass of a component (B) which is thermoplastic resin particles, and 20 to 50 parts by mass (in terms of diaminodiphenylsulfone) of a component (C) which is diaminodiphenylsulfone microencapsulated with a coating agent, in which resin composition the thermoplastic resin particles (B) comprise at least thermoplastic resin particles (B1) having an average particle diameter of 1 to 50 ?m and thermoplastic resin particles (B2) having an average particle diameter of 2 to 100 ?m at a mass ratio of 3:1 to 1:3 and the average particle diameter ratio D2/D1 of the average particle diameter D2 of the thermoplastic resin particles (B2) to the average particle diameter D1 of the thermoplastic resin particles (B1) is 2 or more, and a prepreg produced using the resin composition.

Abstract: To provide a rubber-reinforcing cord having good adhesion to rubber and exhibiting excellent fatigue resistance to stress deformation such as bending deformation, and a method for producing the same. Disclosed a rubber-reinforcing carbon fiber cord in which a resin composition containing a styrenic thermoplastic elastomer resin modified with maleic acid or the like adheres to a carbon fiber bundle that the number of filaments is from 500 to 50,000. The styrenic thermoplastic elastomer resin is preferably a styrene-terminated ethylene-butylene copolymer resin, and the resin composition preferably contains at least one sticky resin of a hydrogenated terpene resin, a ?-pinene resin and a terpene resin.

Abstract: The present invention provides a prepreg made by impregnating a resin composition into a fiber reinforcing material, the resin composition comprising 50 to 60 parts by weight of an aromatic bismaleimide (A), 30 to 40 parts by weight of an alkenylphenol ether compound (B) expressed by a specific general formula, 5 to 15 parts by weight of an alkenyl aromatic comonomer (C), and 1 to 10% by weight of a thermoplastic resin (D) soluble in (B) or (C) based on the total amount of (A), (B) and (C), the aromatic bismaleimide (A) including 90% by weight or more of bismaleimide diphenylmethane, and a composite material having a glass transition temperature of 260 to 350° C. obtained by heat-curing the prepreg.

Abstract: According to the present invention, there is disclosed a carbon fiber having a strand tensile strength of 6,100 MPa or more, a strand tensile modulus of 340 GPa or more and a density of 1.76 g/cm3 or more and possessing, on the surface, striations oriented in a direction parallel to the fiber axis, wherein the distance between striations in a 2×2 ?m area of the carbon fiber surface when observed by a scanning probe microscope is 0.1 to 0.3 ?m, the root mean square surface roughness Rms (5 ?m) in a 5×5 ?m area of the carbon fiber surface when observed by a scanning probe microscope is 20 to 40 nm, and the root mean square surface roughness Rms (0.5 ?m) when measured in a 0.5×0.5 ?m area is 2 to 12 nm.

Abstract: According to the present invention, there is disclosed a carbon fiber having a strand tensile strength of 6,100 MPa or more, a strand tensile modulus of 340 GPa or more and a density of 1.76 g/cm3 or more and possessing, on the surface, striations oriented in a direction parallel to the fiber axis, wherein the distance between striations in a 2×2 ?m area of the carbon fiber surface when observed by a scanning probe microscope is 0.1 to 0.3 ?m, the root mean square surface roughness Rms (5 ?m) in a 5×5 ?m area of the carbon fiber surface when observed by a scanning probe microscope is 20 to 40 nm, and the root mean square surface roughness Rms (0.5 ?m) when measured in a 0.5×0.5 ?m area is 2 to 12 nm.

Abstract: A process for continuous production of carbon fibres whereby stabilised precursor fibres are carbonised and graphitised with the help of high-frequency electromagnetic waves, characterised in that the stabilised precursor fibres are continuously conveyed, as the inner conductor of a coaxial conductor consisting of an outer and an inner conductor, through the coaxial conductor and a treatment zone; that the stabilised precursor fibres are irradiated in the treatment zone with high-frequency electromagnetic waves that are absorbed by the precursor fibres, which are thereby heated and converted into carbon fibres; and that the stabilised precursor fibres or carbon fibres are conveyed under an inert gas atmosphere through the coaxial conductor and the treatment zone.

Abstract: A radiation-curing resin composition that includes a resin component that includes an epoxy resin and/or oxetane resin having a naphthalene structure or a biphenyl structure, a boron-based diaryliodonium salt polymerization initiator represented by a specific formula at 0.005 to 0.5 mol per kg of the resin component, and a viscosity adjusting agent, the resin composition having a viscosity at 50° C. of at least 50 Pa·s, and a prepreg obtained by impregnating a fiber reinforcement with such a resin composition. This resin composition has excellent reactivity, and a prepreg formed from this resin composition and a fiber reinforcement is used for producing a composite material/member suitable for the aerospace field in particular.

Abstract: The present invention discloses: a composition comprising (A) an epoxy group-containing vinyl ester resin having, in the molecule, 0.8 to 0.3 equivalent of epoxy group and 0.2 to 0.7 equivalent of an ethylenically unsaturated group, (B) a radical-polymerizable monomer, (C) a curing agent, and (D) a carbon fiber impregnated with 0.5 to 5% by mass of (d) a vinyl ester resin as a sizing agent, obtained by an addition reaction of an epoxy resin and an ethylenically unsaturated carboxylic acid, and a carbon fiber-reinforced resin composite material produced by curing the above composition.

Abstract: A heat treatment apparatus for oxidation having an oven for oxidation having a heat treatment chamber having a plurality of slits through which fiber strands running horizontally leave or returned strands enter and capable of sending hot air vertically from above the fiber strands to allow the fiber strands to have oxidation, and a device for feeding hot air into the heat treatment chamber, and a plurality of returning rollers which are provided at the two outsides of the oven for oxidation and which return the fiber strands entering and leaving through said slits, into the oven for oxidation, wherein each gap formed between fiber strands and each side wall of heat treatment chamber parallel to the running direction of fiber strands running in the heat treatment chamber, or each gap formed between fiber strands and each channeling-preventing plate interposed between the side wall and the fiber strands in parallel to the running direction of fiber strands is set at 150 mm or less.

Abstract: The present invention discloses a method of resin transfer molding which comprises superposing a bagging film on a layer of reinforcing fibers laid on a mold, airtightly bonding the periphery of the bagging film to the mold, evacuating the space between the bagging film and the mold, injecting a resin into the space between the bagging film and the mold to thereby impregnate the resin into the reinforcing fibers, and curing the resin, characterized in that resin injection passages and resin discharge passages are alternately formed outside the reinforcing fiber layer along a surface of the reinforcing fiber layer and the resin is injected into the resin injection passages to allow the resin injected to move to the resin discharge passages via the reinforcing fiber layer and thereby impregnate the resin into the reinforcing fiber layer.