The present invention provides a fiber-reinforced resin which has excellent tensile shear joining strength and is able to be integrated with another structural member with high productivity by means of thermal welding, thereby being suitable as a structural material. The present invention is a fiber-reinforced resin which contains constituents (A), (B) and (C), while having a multilayer structure that is composed of a thermosetting resin layer that is formed of (B) a thermosetting resin, a thermoplastic resin layer that is formed of (C) a thermoplastic resin, and a mixed layer that is present between the thermoplastic resin layer and the thermosetting resin layer, while being obtained by mixing the thermoplastic resin (C) and the thermosetting resin (B), in such a manner that the thermoplastic resin layer is present in the surface. With respect to this fiber-reinforced resin, at least some of (A) reinforcing fibers are present in the mixed layer. (A) Reinforcing fibers (B) Thermosetting resin (C) Thermoplastic resin

A method for manufacturing a carbon nanotube-blended aggregate of the present invention includes the steps of: (1) providing an aqueous solution of a water-soluble polymer having a concentration of 0.005 to 3.0% by mass; (2) impregnating carbon nanotubes with the aqueous solution of the water-soluble polymer in a proportion of 400 to 1,000 parts by mass relative to 100 parts by mass of the carbon nanotubes to prepare a wet aggregate; (3) shear-crushing the wet aggregate to obtain an aggregate of crushed products and (4) drying the aggregate of the crushed products to obtain a carbon nanotube-blended aggregate containing the water-soluble polymer.

The present invention generally relates a composite material containing fibers and a resin matrix that comprises a PEEK-PEoEK copolymer having R.sub.PEEK and R.sub.PEoEK repeat units in a molar ratio R.sub.PEEK/R.sub.PEoEK ranging from 95/5 to 5/95 in contact with at least a part of the surface of such fibers. The present invention also relates to methods for making such composite materials, shaped articles made from such composite materials, and methods of making such articles.

The present invention relates to liquid crystal polyester resin pellets containing a thermoplastic resin comprising a liquid crystal polyester, and a fibrous filler, in which the pellets contain the fibrous filler in the amount of equal to or greater than 1 part by mass and smaller than 120 parts by mass with respect to 100 parts by mass of the thermoplastic resin, and a length-weighted average fiber length of the fibrous filler is equal to or greater than 4 mm and smaller than 50 mm.

The present invention has an object of providing a prepreg for producing a laminate suitable as a structural material, and a laminate, which have excellent combustion resistance, compressive strength and interlaminar fractural toughness values, and can be firmly integrated with another structural member by welding. The present invention is a prepreg including structural components: [A] reinforcing fibers, [B] a thermosetting resin, and [C] a thermoplastic resin [C], wherein [B] includes at least one resin selected from a cyanate ester resin having an average cyanate equivalent of 220 or less, a bismaleimide resin having an average maleimide equivalent of 210 or less, and a benzoxazine resin having an average oxazine equivalent of 300 or less, [C] is present on a surface of the prepreg, and the reinforcing fibers [A] are present which are included in a resin area including [B] and a resin area including [C] across an interface between the two resin areas.

An object is to provide an incised prepreg having desired formability stably, wherein the incised prepreg contains unidirectionally oriented reinforcing fibers and matrix resin and has an incised region containing a plurality of incisions made to divide reinforcing fibers, wherein the incised region includes a plurality of incision rows, each containing a plurality of incisions having nearly equal fiber-directionally projected lengths and aligned at substantially constant intervals in the fiber direction and wherein the distance L1, measured at right angles to the fiber direction, between two incision rows located on either side of an arbitrarily selected incision row and the fiber-directionally projected length L2 of the latter incision row satisfy the following relation: −1.0<L1/L2<0.5.

A method for rapidly fabricating or repairing a fiber reinforced composite may include the use of a covalent adaptable network polymer (CAN) powder for encapsulating reinforcing fibers or welding to a CAN matrix. The fiber reinforced composite may be formed or repaired by applying CAN powder to reinforcing fibers or to a damaged area of a fiber reinforcing composite and compressing the CAN powder with the reinforcing fibers or the damaged area of the fiber reinforced composite at a relatively low temperature, temperature and processing time to form a CAN matrix. The method may be configured for fabricating a fiber reinforced composite having specific desired material properties by varying the arrangement and materials used.

Provided is a thermosetting resin composition which achieves both high heat resistance and high bending strength as a fiber-reinforced composite material, and also has rapid curability that enables high cycle press forming, thermal stability, and storage stability. The thermosetting resin composition of the present invention is a thermosetting resin composition comprising an epoxy resin, an epoxy resin curing agent, an imidazole compound, and an epoxy resin curing accelerator, in which the epoxy resin curing agent is dicyandiamide or a derivative thereof, and the epoxy resin curing accelerator comprises a urea derivative having two or more dimethylureido groups in a molecule.

An epoxy resin represented by the following formula (1), in which in a total amount of an epoxy compound represented by n=1 in the epoxy resin of the above formula, a total content of an epoxy compound represented by the following formula (2) and an epoxy compound represented by the following formula (3) is 1 area % or more and less than 70 area % in HPLC area percentage.

##STR00001##

Provided are a prepreg in which reinforcing fibers are impregnated with an epoxy resin composition containing an epoxy resin (A) and an epoxy resin curing agent (B) containing a reaction product (X) of a component (x1) and a component (x2) described below, a fiber-reinforced composite material that is a cured product of the prepreg, a method for producing the prepreg, and a method for producing a high-pressure gas storage tank.

(x1) At least one selected from the group consisting of meta-xylylenediamine and para-xylylenediamine

(x2) At least one selected from the group consisting of unsaturated carboxylic acids represented by General Formula (1) below and derivatives thereof.

##STR00001##

(In Formula (1), R.sup.1 and R.sup.2 each independently represent a hydrogen atom, an alkyl group having from 1 to 8 carbons, an aryl group having from 6 to 12 carbons, or an aralkyl group having from 7 to 13 carbons.)