A fiber-reinforced composite material includes a matrix resin, and reinforcing fibers, in which the matrix resin includes a polyaryl ketone resin and a resin having a nitrogen atom in a repeating structural unit. A surface of the fiber-reinforced composite material includes a portion in which a contact angle with water is 60° or less.

The present invention provides an amide acid oligomer which has specific composition and which is capable of providing a cured product having excellent physical properties, in particular, an excellent glass transition temperature, etc.

A gear is provided that has excellent continuous moldability for practical use, and both high slidability and high durability. The provided gear is a molded resin constructed of a resin composition comprising a thermoplastic resin (A) and cellulose nanofibers (B) with an average fiber diameter of 1000 nm or smaller, and having a number average molecular weight of the thermoplastic resin (A) in the range of 10,000 to 150,000, wherein a sliding surface of the gear with another gear teeth has an arithmetic mean surface roughness Sa of 3.0 μm or lower.

Embodiments of the present invention include composite compositions extrusion compounded together comprising a polymer, an amount of nanotubes, and an amount of finely milled carbon fiber having an aspect ratio greater than 1 and less than about 5. The resulting composite materials allow for high carbon loading levels with improved tribological properties including coefficient of friction and wear rates, provides uniform surface resistance with minimal processing sensitivity, retains rheological properties similar to the base resin, and provides isotropic shrink and a reduced coefficient of thermal expansion leading to minimal warp. In general, various articles can be formed that take advantage of the properties of the composite materials incorporating a polymer, carbon nanotubes and finely milled carbon fiber.

The present invention is directed to plant fiber-reinforced thermoplastic compositions and a method for reinforcing thermoplastic resins. The present invention provides a use for the cellulose portion of a plant material, which is the portion left over after processing the selected plant materials to separate the hemi-cellulose and lignin from the cellulose.

The present invention relates to a process for impregnating a fibrous substrate consisting of long fibers by a liquid (meth)acrylic mixture mainly containing methacrylic and/or acrylic components. The invention also relates to such a (meth)acrylic mixture and its composition, said (meth)acrylic mixture comprising a (meth)acrylic syrup and an aqueous dispersion of radical initiator. The invention also relates to a process for manufacturing mechanical parts or structured elements or articles made of composite material by impregnating the fibrous substrate with the (meth)acrylic mixture then polymerizing said (meth)acrylic mixture, and also such parts obtained according to said manufacturing process and used in varied fields such as the automotive industry, aeronautics, or else construction.

Provided is a prepreg including: a fiber layer containing unidirectionally arranged carbon fibers impregnated with a first thermosetting resin; and a resin layer disposed on at least one side of the fiber layer and containing a second thermosetting resin and a thermoplastic resin that is insoluble in the second thermosetting resin. The prepreg is configured such that the areal weight of fibers and the weight fraction of resin in the prepreg are 120 to 300 g/m.sup.2 and 25 to 50 mass %, respectively, and in the case where a plurality of prepregs are laid up, and the coefficient of interlayer friction is measured every 10° C. in a temperature range of 40 to 100° C. at a pull-out speed of 0.2 mm/min under a perpendicular stress of 0.8 bar, the temperature at which the coefficient of interlayer friction is 0.02 or less is present within a temperature range of 40 to 100° C. The prepreg exhibits high impact strength when formed into a fiber-reinforced plastic suitable for an aircraft structural member, and the prepreg also has excellent drapeability when a prepreg laminate is made to conform to a three dimensional shape.

Disclosed are a reinforcing fiber bundle composed of a carbon fiber bundle treated with an emulsion; a carbon fiber reinforced thermoplastic resin molded body using the same; and a method for producing a reinforcing fiber bundle; wherein the emulsion contains a modified polyolefin (A1) comprising at least a metal carboxylate bonded to the polymer chain, and 0.1 to 5,000 moles of an amine compound (B) represented by the following general formula (1), per one mole of the carboxylate group in the modified polyolefin (A1);

R—NH.sub.2  (1) wherein the formula (1), R is a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms.

A composite reinforcing bar is formed by providing a reinforcing material supply of fiber strands ravings; a resin supply bath, and a puller for pulling the resin-impregnated reinforcing material through the resin bath. The material is wound on a holder, while the resin remains unset, rotated about its axis on a drive system so that the material is wrapped around a plurality of guides at spaced positions around the axis such that the fed length of the body is wrapped from one bar to the next to form bent portions of the body wrapped partly around each guide and straight portions between the guides. The guide surfaces are shaped by a machining, blasting or similar process to form projections and recesses which retain a roughness on the outside surface of the reinforcing bar during the curing action while supported on the surface. This arrangement can be used with an optional sand coating to prevent the sand particles from being compressed into the resin or body.

A carbon-fiber-reinforced resin composite material includes: carbon fibers including carbon fiber bundles and a thermoplastic resin, in which (1) a coefficient of variation (CV1) of a total areal weight of the carbon-fiber-reinforced resin composite material is 10% or lower, (2) a coefficient of variation (CV2) of a carbon fiber volume fraction (Vf) in the carbon-fiber-reinforced resin composite material which is defined by Expression (a) is 15% or lower, and (3) a weight average fiber length of the carbon fibers is 1 to 100 mm. Carbon Fiber Volume Fraction (Vf)=100×Volume of Carbon Fibers/(Volume of Carbon Fibers+Volume of Thermoplastic Resin) . . . Expression (a).