The present invention addresses the problem of providing a prepreg that has excellent short-time and low-pressure handling properties, during pasting and layering work. In order to solve the problem, this invention has the following configuration. The prepreg includes reinforcing fibers and an epoxy resin composition, has a fiber content of 90 mass % or less, and satisfies conditions (a) and (b) below. (a) When the average thickness of the prepreg is set as D (D being 3 μm or greater), the viscosity at 25° C. of the epoxy resin composition at a site (I) located at a depth of D/4 to 3D/4 from the surface on one side of the prepreg is 50,000 to 300,000 Pa.Math.s inclusive. (b) From among sites (II) located at a depth of up to 0.5 μm from each surface on both sides of the prepreg, the viscosity at 25° C. of the epoxy resin composition at least at a site (II) on the one side is 10,000 to 40,000 Pa.Math.s inclusive.

A composite laminate structure includes one or more layers of prepreg and a thermoplastic polyurethane film layer on the surface of the one or more prepregs. A method of making a composite laminate structure including a thermoplastic polyurethane film is also provided.

A thermosetting resin composition contains at least: [A] a thermosetting resin; [B] a curing agent; and [C] polyamide particles satisfying following (c1) to (c6): (c1) a melting point of polyamide resin constituting the polyamide particles is 200 to 300° C.; (c2) a crystallization temperature of the polyamide resin constituting the polyamide particles is 150° C. to 250° C.; (c3) a number average particle size of the polyamide particles is 1 to 100 μm; (c4) a sphericity of the polyamide particles is 80 to 100; and (c5) the linseed oil absorption of the polyamide particles is 10 to 100 mL/100 g. A thermosetting resin composition of the present invention enables suitable production of a fiber-reinforced composite material having sufficient compressive strength after impact and wet heat compression performance.

A thermally conductive sheet has a thermally conductive resin composition layer, wherein the thermally conductive resin composition layer is made of a thermally conductive resin composition (1) including an inorganic filler and a binder resin (3). The inorganic filler includes a boron nitride particle (2), the content of the inorganic filler in the thermally conductive resin composition layer is 65% by volume or more, and the boron nitride particle (2) has an average aspect ratio of 7 or less, which is calculated from a major axis and a minor axis of a primary particle measured by a specific method. The thermally conductive resin composition layer has a thickness of 200 μm or less.

A method for recycling matrix residues includes steps of degrading a target epoxy to form matrix residues, collecting the matrix residues, and adding the matrix residues into a polymer-forming formulation. Characteristically, the polymer-forming formulation includes multifunctional anhydride monomers and polyfunctional co-reactant monomers.

A sheet molding compound which is a thickened material of an epoxy resin composition, including a component (A), a component (B), and a component (C), in which the component (A) is an epoxy resin staying at a liquid state at 25° C., the component (B) is an acid anhydride, the component (C) is an epoxy resin curing agent, and in the thickened material, at least some of epoxy groups of the component (A) and at least some of carboxy groups derived from the component (B) form ester.

A resin producing method is a method of producing a resin with which an insulating structure formed on an outer peripheral portion of a conductor is impregnated, the method including: a filler mixing step of mixing a nanofiller at a ratio of 15 wt % or more with an epoxy resin to form a mixture; a shear mixing step of causing the mixture to be subjected to shear mixing; a diluent mixing step of mixing a reactive diluent that reduces a viscosity of the epoxy resin, with the mixture after the shear mixing step; and a curing agent mixing step of mixing an acid anhydride curing agent with the mixture after the diluent mixing step.

A resin composition is provided, which includes a first polymer and a second polymer. The first polymer is formed by a reaction of an epoxy resin modified with a first elastic molecular segment and an epoxy resin curing agent. The second polymer is formed by a polymerization of an acrylate modified with a second elastic molecular segment.

A method for producing a composite material, includes: immersing a carbon fiber bundle, including continuous carbon fibers, in a dispersion in which carbon nanotubes are dispersed in water, alcohol, or organic solvent; applying a tensile force to the carbon fibers, which are linearly arranged, using flat rollers; moving the carbon fibers linearly, under the tensile force by the flat rollers, at a constant depth inside the dispersion at a traveling speed of 1 to 20 m/min, such that the carbon nanotubes in the dispersion are adhered to respective surfaces of the carbon fibers; and applying a sizing agent to cover at least a part of the respective surfaces.

The present disclosure provides compositions including a carbon fiber material comprising one or more of dibromocyclopropyl or polysilazane disposed thereon; and a thermosetting polymer or a thermoplastic polymer. The present disclosure further provides metal substrates including a composition of the present disclosure disposed thereon. The present disclosure further provides vehicle components including a metal substrate of the present disclosure. The present disclosure further provides methods for manufacturing a vehicle component, including contacting a carbon fiber material with a polysilazane or a dibromocarbene to form a coated carbon fiber material; and mixing the coated carbon fiber material with a thermosetting polymer or a thermoplastic polymer to form a composition. Methods can further include depositing a composition of the present disclosure onto a metal substrate.