A coated fiber for polymer reinforcement is disclosed. The coated fiber comprises a fiber and a coating disposed about said fiber. The fiber has a denier of from about 250 to about 3,000. The coating comprises a branched polyethylene imine. The fiber is present in the coated fiber in an amount of from about 80 to about 99.8 percent by weight and the coating is present in the coated fiber in an amount of from about 0.2 to about 20 percent by weight, with percent by weight based on the total weight of the coated fiber. A method of producing the coated fiber is also disclosed.

The invention relates to fluoropolymer composites having a fluoropolymer matrix containing a functionalized fluoropolymer composition, and reinforced with fibers. The fibers can be chopped fibers, long fibers, or a mixture thereof, and the fluoropolymer matrix preferably is based on polyvinylidene fluoride. Any type of fibers, sized or unsized may be used with the functionalized fluoropolymer matrix composition to form the fluoropolymer composite.

A composition for fiber-reinforced resin that provides a fiber-reinforced resin with sufficient mechanical strength. The composition for fiber-reinforced resin contains at least one resin (A) selected from the group consisting of rosin resins, petroleum resins, terpene resins, and hydrides of cyclic ketone-aldehyde resins, and the resin (A) has a softening point of 80° C. to 180° C.

Provided is a polyamide resin molded article having high mechanical properties and dimensional accuracy as well as low friction coefficient, low wear, and/or low abrasion property. The present invention provides a polyamide resin molded article composed of a polyamide resin composition including (A) a polyamide resin, (B) chemically modified cellulose microfibers having a weight average molecular weight (Mw) of 100,000 or more, a ratio (Mw/Mn) of the weight average molecular weight (Mw) and the number average molecular weight (Mn) of 6 or less, an alkali-soluble polysaccharides average content of 12 mass percent or less, and a degree of crystallization of 60% or more, and (C) a dispersant having a melting point of 80° C. or less and a number average molecular weight of 1000-50,000, wherein the melting point (Tm) and the crystallization temperature (Tc) of the polyamide resin molded article satisfy formula (1): Tm−Tc≥30° C. . . . (1).

A fiber-reinforced resin molding material includes at least components (A) to (D), wherein the fiber-reinforced resin molding material has a weight loss on heating, when heated at 300° C. for 10 minutes either in a nitrogen atmosphere or in an air atmosphere, of 1.5% or less, and components (A) to (D) are:

(A) an amorphous thermoplastic resin: 100 parts by weight
(B) a reinforcement fiber: 4 to 60 parts by weight
(C) a phosphorus-based flame retardant: 20 to 60 parts by weight
(D) an antioxidant (D): 1.0% by weight or more.

[Problem] To provide a sizing-agent-coated carbon fiber bundle in which, even when the sizing-agent-coated carbon fiber bundle has superior handling properties, the sizing agent on the sizing-agent-coated carbon fiber bundle exhibits excellent solubility in water and the adhesion amount of remaining sizing agent is reduced. [Solution] A sizing-agent-coated carbon fiber bundle obtained by applying polyethylene glycol and/or a surfactant to a carbon fiber bundle as a sizing agent, wherein all of the following conditions (i)-(iii) are satisfied. (i) The adhesion amount of the sizing agent is 0.15-0.80 parts by mass (inclusive) per 100 mass parts of the sizing-agent-coated carbon fiber bundle 100. (ii) The dry F-F friction coefficient is 0.39 or less. (iii) The adhesion amount of the sizing agent after washing for 50 seconds under the conditions disclosed in the specification is 0.12 parts by mass or less per 100 parts by mass of the sizing-agent-coated carbon fiber bundle 100.

The present application relates to a sizing agent composition, a carbon fiber material and a composite material. The sizing agent composition includes a first composition solution and a second composition solution, and those solutions respectively has specific compound. The sizing agent comprising the composition has an excellent bonding property with a carbon fiber, and further the sizing agent can efficiently enhance heat resistance, wear resistance and processability of the carbon fiber material. The carbon fiber material sized with the sizing agent has a high adhesion property with specific resin material, therefore producing the composite material with high processability.

A sizing agent for matrix-resin-reinforcement fibers that simultaneously attains excellent cohesion and abrasion resistance of sized fibers, uniform size application on fiber surface and good bonding between sized fiber and a matrix resin; a synthetic fiber strand sized therewith; and a fiber-reinforced composite material reinforced by the sized fiber strand. The sizing agent contains a polyamide (A), a carbodiimide group-containing compound (B) and water (C), wherein the polyamide (A) has a melt viscosity ranging from 100 to 15,000 mPa.Math.s at 150° C. and the compound (B) has at least two carbodiimide groups per molecule. The polyamide (A) is preferably a water-soluble polyamide.

A sizing agent for matrix-resin-reinforcement fibers that simultaneously attains excellent cohesion and abrasion resistance of sized fibers, uniform size application on fiber surface and good bonding between sized fiber and a matrix resin; a synthetic fiber strand sized therewith; and a fiber-reinforced composite material reinforced by the sized fiber strand. The sizing agent contains a polyamide (A), a carbodiimide group-containing compound (B) and water (C), wherein the polyamide (A) has a melt viscosity ranging from 100 to 15,000 mPa.Math.s at 150° C. and the compound (B) has at least two carbodiimide groups per molecule. The polyamide (A) is preferably a water-soluble polyamide.

A carbon fiber is obtained by sequentially performing: a step (I) of dissolving a fullerene mixture including fullerenes C.sub.60 and C.sub.70 in an organic solvent to prepare a fullerene solution; a step (II) of immersing a material carbon fiber in the fullerene solution; and a step (III) of extracting the carbon fiber from the fullerene solution and drying the extracted carbon fiber.