A method of making a flexible pipe layer, which method comprises: commingling polymer filaments and carbon fibre filaments to form an intimate mixture, forming yarns of the commingled filaments, forming the yarns into a tape, and applying the tape to a pipe body to form a flexible pipe layer.

Polypropylene composition comprising a polypropylene base material, a carbon fibre and an adhesion promoter with an excellent impact/stiffness balance, its preparation, articles comprising the composition and the use of the composition.

The present invention aims to provide an epoxy resin composition for a fiber-reinforced composite material that maintains low viscosity during injection into reinforcing fibers to realize good impregnating and also has high toughness and high heat resistance and also aims to provide a fiber-reinforced composite material produced therefrom. Also provided is a molding method for a fiber-reinforced composite material including at least a reinforcing fiber [A] and a cured product of an epoxy resin composition [B], wherein the epoxy resin composition [B] includes the components [a], [b], and [c] specified below, and the epoxy resin composition [B] is cured in such a manner that the absorbance ratio Da/(Da+Db) is in the range of 0.4 to 1 in producing the fiber-reinforced composite material: [a] an epoxy resin having at least two oxirane groups in the molecule, [b] an epoxy resin curing agent having at least two isocyanate groups in the molecule, and [c] a catalyst.

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.

The objective of the present invention is to provide a polyarylketone resin composition, a fiber-reinforced resin base material, and formed products therefrom having excellent thermal stability and mechanical properties. In order to achieve the above objective, the present invention has the following constitution. That is, the polyaryletherketone resin composition comprises (A) a polyaryletherketone and (B) a transition metal compound, wherein the transition metal content is between 0.001 parts by mass and 4 parts by mass inclusive with respect to 100 parts by mass of (A) the polyaryletherketone.

Composite materials are described herein. The composite materials include a polymer matrix comprising at least one fluorinated homo- or copolymer and continuous fibers dispersed within the polymer matrix. The continuous fibers are present within the composite material in an amount between about 10 wt % and about 90 wt % of a weight of the composite material. The composite materials also include a filler dispersed within the polymer matrix. The filler is present within the composite material in an amount between about 5 wt % and about 25 wt % of an amount of the polymer matrix.

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 tape material is favorable in followability to molds and impregnation with matrix resins, and capable of enhancing the productivity in producing a reinforcing fiber laminate by a method of fiber placement and capable of providing a molded body with high mechanical strength when the material is impregnated with a resin and molded. The carbon fiber tape material has a carbon fiber bundle group including a plurality of carbon fiber bundles arranged in parallel with the fiber orientation direction and a fabric are integrated, and satisfies (a) to (c): (a) the fabric includes one or more thermoplastic resins; (b) the carbon fiber tape material excluding the fabric is between 120 g/m.sup.2 and 400 g/m.sup.2 in basis weight; and (c) the fabric elongation rate with a load of 80 mN/50 mm applied to the fabric is 5% to 100% in at least one direction of the fabric.

An object of the present invention is to provide an epoxy resin composition that can be preferably used for prepreg and fiber reinforced composite material applications, has high Tg, and is excellent in elastic modulus and strength. The present invention is the epoxy resin composition including the following components [A] to [C] and satisfying the following conditions (1) to (2): [A]: epoxy resin [B]: polyamine curing agent, and [C]: a compound having a boiling point of 130° C. or more and a molecular weight m of 50 or more and 250 or less, the compound having no epoxy group in the molecule and having substantially no curing ability of an epoxy resin, (1): at least a part of the component [C] satisfies that the sum of the polar component and the hydrogen bond component in the Hansen solubility parameters is 10.0 or less, (2): the ratio C/E of the amount by mole, E, for epoxy groups of the component [A] to the amount by mole, C, of the component [C] satisfying the condition (1) is 0.01 or more and 0.20 or less.

Carbon fiber composites containing lignin carbon fibers are described. The lignin carbon fibers can be derived from organosolv lignin obtained from single source lignocellulosic feedstocks or combinations of such feedstocks or lignin obtained via other pulping or extraction methods. Also described are methods of preparing the carbon fiber composites.