A laminar pre-preg of fibre-reinforced curable composite material. The pre-preg includes at least one layer of reinforcing fibres impregnated with a curable resin containing one or more curable thermosetting resin(s) and at least one liquid curative, wherein the curable resin exhibits a cure conversion of at least 95% when cured at a cure temperature in the range of from about 100° C. to about 160° C. and the cure cycle has a duration of no more than 10 minutes, and the glass transition temperature (Tg) of the curable resin when cured is in the range of from about 130° C. to about 165° C.

Provided is a resin composition that has satisfactory impregnability into reinforcing fibers due to low viscosity and small viscosity increase even in an impregnation process performed for a long time. The resin composition being suitable as a matrix resin for a fiber-reinforced composite material for producing a cured molded article that has toughness and fatigue resistance. The resin composition for a fiber-reinforced composite material includes an epoxy resin, an acid anhydride-based curing agent, an imidazole-based curing accelerator, a radically polymerizable monomer, and a radical polymerization initiator as essential components, has a viscosity at 25° C. that falls within a range of 50 mPa.Math.s to 800 mPa.Math.s as measured by an E-type viscometer, and exhibits a viscosity increase ratio of 200% or less after 8 h at 25° C., wherein 50% by mass or more of the acid anhydride-based curing agent is an alicyclic acid anhydride having no olefinic unsaturated bond.

A multiaxial fabric resin base material includes a multiaxial fabric base material laminate impregnated with a thermosetting resin (B), the multiaxial fabric base material laminate including fiber bundle sheets layered at different angles, the fiber bundle sheets including unidirectionally aligned fiber bundles stitched with stitching yarns composed of a thermoplastic resin (A), the multiaxial fabric base material laminate being penetrated in the thickness direction by other bodies of the stitching yarns, and being stitched with the other bodies of the stitching yarns such that the yarns reciprocate at predetermined intervals along the longitudinal direction, the thermoplastic resin (A) constituting the stitching yarns having a softening point, the softening point being higher than the resin impregnation temperature of the thermosetting resin (B).

A composite includes a filler comprising boron nitride nanosheets (BNN) and a resin. The resin includes a multifunctional oxirane epoxy phenol novolac resin (EP8370), a multifunctional acrylate dipenta erythritol hexaacrylate (DPHA), 2-(perfluorooctyl)ethyl acrylate (PFOEA), urethane dimethacrylate (UDMA), and tetryhydrofuran (THF). Additional resins for use with the composite include bisphenol A glycidyl dimethacrylate (BisGMA), urethane dimethacrylate (UDMA), and/or triethylene glycol dimethacrylate (TEGDMA) in any combination thereof.

A curative resin containing at least 50 wt % of an epoxy phenolic resin comprising a mixture of a carboxylic hydrazide and a hydroxy substituted urone.

An object is to provide an epoxy resin composition which exhibits excellent tracking resistance and additionally has excellent heat resistance with a Tg of 200° C. or higher and flame retardancy. Provided is an epoxy resin composition which contains a phosphorus-containing epoxy resin and a curing agent and has a phosphorus content of within a range of 1.0 to 1.8%, wherein the phosphorus-containing epoxy resin has a ratio (L/H) of 0.6 to 4.0 of the content of trinuclear bodies (L) to the content of hepta or higher nuclear bodies (H) measured by GPC, and is a product obtained from a novolac epoxy resin having an average number of functional groups (Mn/E) of 3.8 to 4.8 and a phosphorus compound represented by the following general formula (1) and/or general formula (2).

Provided are an epoxy resin composition including hexagonal boron nitride particles having an aspect ratio of 2 or more, a liquid crystalline epoxy monomer, and a curing agent, and the epoxy resin composition being capable of forming a resin matrix having a smectic domain by reacting the liquid crystalline epoxy monomer with the curing agent, and a thermally-conductive material precursor, a B-stage sheet, a prepreg, a heat dissipation material, a laminate, a metal substrate, and a printed circuit board, which use the epoxy resin composition.

A prepreg having at least one layer of fibres and a curable thermosetting resin system at least partly impregnating the at least one layer of fibres, wherein the curable thermosetting resin system includes a curable thermosetting resin including at least two epoxide groups, a curing agent that includes at least one amine group, and an accelerator that includes an azole group; wherein the curable thermosetting resin, the curing agent and the accelerator are provided in respective concentrations in the prepreg to provide that, after curing the thermosetting resin at a cure temperature of at least 140° C. for a period of from 1 to 6 minutes, (i) the cured thermosetting resin has a glass transition temperature Tg which is greater than the cure temperature and is within the range of from 150° C. to 180° C. and (ii) the cured thermosetting resin is at least 90% cured.

The prepreg includes a first resin layer and a second resin layer disposed on both surfaces of the first resin layer. The first resin layer is a half-cured product of a first resin composition that includes a glass cloth impregnated with the first resin composition and contains no hexagonal boron nitride. The second resin layer is a half-cured product of a second resin composition containing hexagonal boron nitride. The glass cloth has a warp and weft weave density of 54 pieces/25 mm or more. The hexagonal boron nitride has an average particle size ranging from 10 μm to 30 μm. The hexagonal boron nitride is contained in an amount ranging from 20 parts by mass to 40 parts by mass relative to 100 parts by mass of a residual component other than the hexagonal boron nitride in the second resin composition.

A resin composition is comprised of an epoxy resin comprised of a solid epoxy resin and a liquid polyurethane toughener that is dissolved in the epoxy resin and, upon curing of the liquid epoxy resin, the liquid polyurethane toughener phase separates into particles having a particle size of 50 nm to 2 micrometers, an epoxy hardener; and an epoxy soluble latent catalyst. The resin composition provides a more homogeneous infusion of the resin into a fibrous material for forming a prepreg and ultimately an epoxy fiber reinforced composition with improved toughness without sacrificing speed of impregnation or uniformity of the epoxy matrix within the composite.